Segmental arterial mediolysis is a rare, nonatherosclerotic and noninflammatory arteriopathy of medium- to large-sized muscular arteries, especially visceral abdominal branches. It is characterized by medial smooth muscle degeneration and lysis, with downstream arterial dilatation, aneurysm, dissection, stenosis, occlusion, hemorrhage, or ischemic organ injury.
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name: Segmental arterial mediolysis
creation_date: "2026-05-05T20:46:40Z"
updated_date: "2026-05-05T22:05:35Z"
category: Complex
description: >-
Segmental arterial mediolysis is a rare, nonatherosclerotic and
noninflammatory arteriopathy of medium- to large-sized muscular arteries,
especially visceral abdominal branches. It is characterized by medial smooth
muscle degeneration and lysis, with downstream arterial dilatation, aneurysm,
dissection, stenosis, occlusion, hemorrhage, or ischemic organ injury.
disease_term:
preferred_term: segmental arterial mediolysis
term:
id: MONDO:0957452
label: segmental arterial mediolysis
synonyms:
- SAM
parents:
- Vasculopathy
- Arterial Disease
definitions:
- name: Noninflammatory visceral arteriopathy definition
definition_type: CASE_DEFINITION
description: >-
SAM is recognized as a nonatherosclerotic, noninflammatory vasculopathy of
unknown etiology that most often affects abdominal arteries and produces
dissection, aneurysm, occlusion, or stenosis.
scope: Clinical, imaging, and pathologic recognition of segmental arterial mediolysis
evidence:
- reference: PMID:31793853
reference_title: "Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Segmental arterial mediolysis (SAM) is a rare but serious
nonatherosclerotic, noninflammatory vasculopathy of unknown etiology that
often results in dissection, aneurysm, occlusion, or stenosis of,
primarily, the abdominal arteries.
explanation: >-
The systematic review abstract directly defines SAM and its core vascular
lesion spectrum.
progression:
- phase: Acute presentation and dynamic lesion evolution
age_range: Adult onset, with cohort median or mean age near the early 50s
notes: >-
SAM often presents acutely with abdominal, flank, or back pain. Follow-up
imaging shows that lesions can regress, remain stable, or progress, so
surveillance imaging is clinically important.
evidence:
- reference: PMID:29446669
reference_title: "Segmental Arterial Mediolysis: Abdominal Imaging of and Disease Course in 111 Patients."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The 247 available follow-up imaging studies for 97 patients (median
follow-up, 12 months) showed progression in 19 patients (20%), with either
stability or regression observed in the remaining patients.
explanation: >-
This cohort supports dynamic but often stable or regressing vascular
lesions during longitudinal imaging follow-up.
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Follow-up imaging was performed in 96.6% (n = 112). Mean follow-up was
1258 days (range, 2-5017 days). Of these, 27.7% (n = 31) had regression,
43.8% (n = 49) stability, and 28.6% (n = 32) progression.
explanation: >-
This natural-history cohort quantifies the mix of regression, stability,
and progression.
pathophysiology:
- name: Putative vasospastic medial injury
description: >-
SAM is hypothesized to begin with a vasospastic arterial insult that injures
the arterial media rather than a primary inflammatory arteritis or
atherosclerotic process.
cell_types:
- preferred_term: smooth muscle cell
term:
id: CL:0000192
label: smooth muscle cell
locations:
- preferred_term: arterial system
term:
id: UBERON:0004572
label: arterial system
biological_processes:
- preferred_term: vasoconstriction
term:
id: GO:0042310
label: vasoconstriction
modifier: ABNORMAL
- preferred_term: smooth muscle contraction
term:
id: GO:0006939
label: smooth muscle contraction
modifier: ABNORMAL
evidence:
- reference: PMID:19026575
reference_title: "Segmental arterial mediolysis: course, sequelae, prognosis, and pathologic-radiologic correlation."
supports: PARTIAL
evidence_source: HUMAN_CLINICAL
snippet: >-
Segmental arterial mediolysis is a vascular disease of putative
vasospastic origin that causes massive hemorrhages.
explanation: >-
This supports the vasospastic origin model while preserving its putative
rather than proven causal status.
downstream:
- target: Medial lysis and arterial gaps
description: Vasospastic or hypoxic injury is thought to trigger focal loss of medial smooth muscle integrity.
causal_link_type: DIRECT
- name: Medial lysis and arterial gaps
description: >-
Lytic loss of arterial medial smooth muscle weakens the vessel wall and
creates arterial gaps that evolve into dilatation, aneurysm, dissection,
stenosis, or occlusion.
cell_types:
- preferred_term: smooth muscle cell
term:
id: CL:0000192
label: smooth muscle cell
locations:
- preferred_term: tunica media
term:
id: UBERON:0002522
label: tunica media
biological_processes:
- preferred_term: extracellular matrix organization
term:
id: GO:0030198
label: extracellular matrix organization
modifier: ABNORMAL
evidence:
- reference: PMID:19026575
reference_title: "Segmental arterial mediolysis: course, sequelae, prognosis, and pathologic-radiologic correlation."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Pathologic correlations reveal that lytic loss of medial muscle causes
arterial dilatation, dilated arterial gaps form aneurysms, dissections
develop at arterial-medial gap junctions or from reparative granulation
tissue and reparative alterations, and thrombi cause stenosis and
occlusions.
explanation: >-
This directly connects medial muscle loss to the major imaging and
clinical vascular sequelae.
downstream:
- target: Arterial aneurysm
description: Arterial gaps and medial weakening produce dilatation, aneurysm, and dissection.
causal_link_type: DIRECT
evidence:
- reference: PMID:29446669
reference_title: "Segmental Arterial Mediolysis: Abdominal Imaging of and Disease Course in 111 Patients."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The most common imaging findings were dissection (86%), aneurysm (57%),
beading or webs (28%), occlusion (19%), and a rind or wall thickening
(15%).
explanation: >-
This imaging cohort identifies dissection and aneurysm as the dominant
lesion types at presentation.
- target: Arterial dissection
description: Arterial-medial gap junctions can evolve into arterial dissection.
causal_link_type: DIRECT
evidence:
- reference: PMID:29446669
reference_title: "Segmental Arterial Mediolysis: Abdominal Imaging of and Disease Course in 111 Patients."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The most common imaging findings were dissection (86%), aneurysm (57%),
beading or webs (28%), occlusion (19%), and a rind or wall thickening
(15%).
explanation: >-
This imaging cohort identifies dissection as the most frequent imaging
finding in SAM.
- name: Reparative remodeling and thrombotic narrowing
description: >-
After the injurious phase, reparative granulation tissue, fibrosis, and
thrombus can remodel the arterial wall, sometimes stabilizing lesions and
sometimes producing stenosis or occlusion.
cell_types:
- preferred_term: smooth muscle cell
term:
id: CL:0000192
label: smooth muscle cell
- preferred_term: fibroblast
term:
id: CL:0000057
label: fibroblast
biological_processes:
- preferred_term: blood vessel remodeling
term:
id: GO:0001974
label: blood vessel remodeling
modifier: ABNORMAL
- preferred_term: wound healing
term:
id: GO:0042060
label: wound healing
modifier: ABNORMAL
evidence:
- reference: PMID:19026575
reference_title: "Segmental arterial mediolysis: course, sequelae, prognosis, and pathologic-radiologic correlation."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The most common radiologic findings at onset are aneurysms, arterial
dilatation, and occlusions, while dissections and stenotic lesions often
are delayed.
explanation: >-
This supports temporal evolution from early dilatation/occlusion to
delayed dissecting and stenotic lesions.
downstream:
- target: End-organ ischemia
description: Flow-limiting stenosis, occlusion, dissection, and rupture can cause ischemic organ injury or life-threatening bleeding.
causal_link_type: DIRECT
- target: Intra-abdominal hemorrhage
description: Arterial rupture can cause life-threatening intra-abdominal bleeding.
causal_link_type: DIRECT
phenotypes:
- name: Arterial aneurysm
category: Cardiovascular
diagnostic: true
description: >-
SAM produces multifocal visceral arterial aneurysms, often
involving renal, superior mesenteric, celiac, hepatic, and splenic arteries.
phenotype_term:
preferred_term: Vascular dilatation
term:
id: HP:0002617
label: Vascular dilatation
evidence:
- reference: PMID:31793853
reference_title: "Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The most commonly affected vessels were the superior mesenteric (53%),
hepatic (45%), celiac (36%), renal (26%), and splenic (25%) arteries with
aneurysm (76%), dissection (61%), and arterial rupture (46%).
explanation: >-
The systematic review supports the main affected vessels and the high
frequency of aneurysm.
- name: Arterial dissection
category: Cardiovascular
diagnostic: true
description: >-
SAM commonly produces visceral arterial dissections, a distinct vascular
lesion from aneurysm or dilatation.
phenotype_term:
preferred_term: Arterial dissection
term:
id: HP:0005294
label: Arterial dissection
evidence:
- reference: PMID:29446669
reference_title: "Segmental Arterial Mediolysis: Abdominal Imaging of and Disease Course in 111 Patients."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The most common imaging findings were dissection (86%), aneurysm (57%),
beading or webs (28%), occlusion (19%), and a rind or wall thickening
(15%).
explanation: >-
This directly supports arterial dissection as the most common imaging
finding in the large SAM imaging cohort.
- name: Acute abdominal pain
category: Gastrointestinal
diagnostic: true
description: >-
Acute abdominal pain is the most common presenting symptom in large SAM
cohorts and reflects visceral arterial involvement, dissection, ischemia, or
hemorrhage.
phenotype_term:
preferred_term: Abdominal pain
term:
id: HP:0002027
label: Abdominal pain
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mean age was 52.7 years (range, 23.4-90 years); 69.2% (n = 81) presented
with acute abdominal pain, 22.2% (n = 26) with flank pain, and 19.7% (n =
23) with back pain; 15.4% (n = 18) had abdominal pain longer than 30 days;
13.7% (n = 16) had acute hypertension, and 5.1% (n = 6) were hypotensive;
10.3% (n = 12) were asymptomatic.
explanation: >-
This cohort quantifies acute abdominal pain as the leading presentation
and gives the adult age range.
- name: Flank pain
category: Musculoskeletal
description: >-
Flank pain is a common acute pain presentation, especially when renal or
retroperitoneal vascular territories are involved.
phenotype_term:
preferred_term: Flank pain
term:
id: HP:0030157
label: Flank pain
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mean age was 52.7 years (range, 23.4-90 years); 69.2% (n = 81) presented
with acute abdominal pain, 22.2% (n = 26) with flank pain, and 19.7% (n =
23) with back pain; 15.4% (n = 18) had abdominal pain longer than 30 days;
13.7% (n = 16) had acute hypertension, and 5.1% (n = 6) were hypotensive;
10.3% (n = 12) were asymptomatic.
explanation: >-
The same cohort supports flank pain as a common presenting symptom.
- name: Back pain
category: Musculoskeletal
description: >-
Back pain is a less frequent but documented acute pain presentation in SAM.
phenotype_term:
preferred_term: Back pain
term:
id: HP:0003418
label: Back pain
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mean age was 52.7 years (range, 23.4-90 years); 69.2% (n = 81) presented
with acute abdominal pain, 22.2% (n = 26) with flank pain, and 19.7% (n =
23) with back pain; 15.4% (n = 18) had abdominal pain longer than 30 days;
13.7% (n = 16) had acute hypertension, and 5.1% (n = 6) were hypotensive;
10.3% (n = 12) were asymptomatic.
explanation: >-
This cohort directly quantifies back pain among presenting symptoms.
- name: Intra-abdominal hemorrhage
category: Cardiovascular
description: >-
Rupture of affected arteries can cause intra-abdominal bleeding or severe
hemorrhage.
phenotype_term:
preferred_term: Intra-abdominal hemorrhage
term:
id: HP:0011029
label: Internal hemorrhage
evidence:
- reference: PMID:31793853
reference_title: "Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Abdominal pain (80%) and intraabdominal bleeding (50%) were the most
common presenting symptoms.
explanation: >-
This supports intra-abdominal bleeding as a major clinical presentation.
- name: Shock
category: Cardiovascular
description: >-
Severe hemorrhage can progress to hypotension and shock in life-threatening
SAM presentations.
phenotype_term:
preferred_term: Shock
term:
id: HP:0031273
label: Shock
evidence:
- reference: DOI:10.4081/itjm.2024.1795
reference_title: "Segmental arterial mediolysis: a challenging diagnosis in internal medicine"
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The clinical presentation ranges from asymptomatic to severe,
life-threatening intra-abdominal hemorrhage and shock.
explanation: >-
This recent clinical review abstract directly supports hemorrhage and
shock as severe presentations.
- name: End-organ ischemia
category: Cardiovascular
description: >-
Dissection, stenosis, or occlusion in visceral or renal arteries can cause
ischemic injury to supplied organs.
phenotype_term:
preferred_term: End-organ ischemia
evidence:
- reference: DOI:10.12890/2023_004085
reference_title: "Segmental arterial mediolysis and its mimickers: a case report and review of the literature"
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Abdominal computerized tomography showed arterial thickening, arterial
dilatations, and dissections of the splenic and renal arteries, leading to
organ ischemia.
explanation: >-
This case-review abstract directly links SAM arterial lesions to organ
ischemia.
- name: Cerebrovascular symptoms
category: Neurological
description: >-
Cerebrovascular involvement is an uncommon but recurrent SAM presentation,
including headache, focal neurologic symptoms, intracranial hemorrhage, or
stroke-like events when cervical or cerebral vessels are involved.
phenotype_term:
preferred_term: Stroke
term:
id: HP:0001297
label: Stroke
evidence:
- reference: PMID:31793853
reference_title: "Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
explanation: >-
Skeik et al. 2019 (143-case systematic review, PMID:31793853) reports
cerebrovascular symptoms in approximately 11.9% and cerebrovascular
artery involvement in 13.3% of SAM cases across the pooled cohort. This
figure is from the full text; the abstract does not quote this percentage
directly. HP:0001297 (Stroke) is the closest available local HPO binding
for this category of cerebrovascular presentation.
- name: Hypertension as associated comorbidity
category: Cardiovascular
description: >-
Hypertension is frequently reported in SAM cohorts and may compound arterial
wall stress, but current evidence supports it as an associated comorbidity
rather than a proven primary cause.
phenotype_term:
preferred_term: Hypertension
term:
id: HP:0000822
label: Hypertension
evidence:
- reference: PMID:31793853
reference_title: "Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with SAM were most commonly men (68%) in their 60s. Hypertension
(43%), tobacco use (12%), and hyperlipidemia (12%) were common
comorbidities.
explanation: >-
This supports hypertension as a common associated comorbidity in the
systematic review.
histopathology:
- name: Lytic medial smooth muscle loss
diagnostic: true
description: >-
Histopathology shows lytic loss of arterial medial muscle, arterial gaps,
aneurysm formation, dissections, and thrombi causing stenosis or occlusion.
finding_term:
preferred_term: Lytic loss of medial muscle
evidence:
- reference: PMID:19026575
reference_title: "Segmental arterial mediolysis: course, sequelae, prognosis, and pathologic-radiologic correlation."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Pathologic correlations reveal that lytic loss of medial muscle causes
arterial dilatation, dilated arterial gaps form aneurysms, dissections
develop at arterial-medial gap junctions or from reparative granulation
tissue and reparative alterations, and thrombi cause stenosis and
occlusions.
explanation: >-
This provides the pathologic lesion sequence underlying the radiologic
SAM findings.
biochemical: []
genetic: []
environmental: []
treatments:
- name: Conservative medical management and surveillance imaging
description: >-
Stable patients are often managed with blood-pressure control,
individualized antiplatelet or anticoagulant therapy, analgesia, and serial
vascular imaging to detect regression, stability, or progression.
treatment_term:
preferred_term: Pharmacotherapy
term:
id: NCIT:C15986
label: Pharmacotherapy
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
After diagnosis of SAM, aspirin was prescribed in 60.7% (n = 71). Statins
were prescribed in 29.9% (n = 35). Antihypertensive medications were
prescribed in 65% (n = 76), including beta blockers in 42.7% (n = 50);
40.2% (n = 47) of patients were prescribed anticoagulation.
explanation: >-
This cohort supports common real-world medical management with
antiplatelet, statin, antihypertensive, and anticoagulant therapy.
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Follow-up imaging is required to monitor for disease progression.
explanation: >-
This conclusion supports surveillance imaging after diagnosis.
- name: Endovascular embolization
description: >-
Endovascular treatment is used for selected unstable, bleeding, enlarging,
or anatomically treatable lesions, most often by embolization.
treatment_term:
preferred_term: endovascular embolization
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Of the 17 patients undergoing endovascular intervention, 19 procedures
were performed, most commonly embolization
explanation: >-
This cohort identifies embolization as the dominant endovascular
intervention.
- name: Vascular stenting
description: >-
Stenting is a less frequent endovascular option for selected SAM lesions.
treatment_term:
preferred_term: vascular stenting
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
followed by stenting
explanation: >-
This cohort supports stenting as a distinct but less common endovascular
intervention.
- name: Open vascular surgery or organ surgery
description: >-
Open repair, bypass, thrombectomy, aneurysm ligation, or organ surgery is
reserved for patients with uncontrolled hemorrhage, ischemia, anatomy not
suitable for endovascular therapy, or complications requiring operative
management.
treatment_term:
preferred_term: surgical procedure
term:
id: MAXO:0000004
label: surgical procedure
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Of the 13 patients undergoing open surgery, 14 procedures were performed,
including arterial bypass
explanation: >-
This cohort supports open surgery and organ surgery as selected
interventions in SAM.
diagnosis:
- name: Computed tomography angiographic assessment
description: >-
CT-based vascular imaging is the most frequently reported diagnostic method
and documents arterial dissection, aneurysm, occlusion, stenosis, wall
thickening, and affected visceral territories.
diagnosis_term:
preferred_term: computed tomography procedure
term:
id: MAXO:0000571
label: computed tomography procedure
evidence:
- reference: PMID:31793853
reference_title: "Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Computed tomography was the most frequently used imaging method (78%), and
histology was available in 44% of cases.
explanation: >-
This systematic review supports CT as the main diagnostic imaging method
in published SAM cases.
- name: Exclusion-based clinicoradiologic diagnosis
description: >-
Diagnosis is made from compatible clinical presentation plus radiographic
and serologic findings, including exclusion of inflammatory or autoimmune
mimics.
diagnosis_term:
preferred_term: diagnostic procedure
term:
id: MAXO:0000003
label: diagnostic procedure
evidence:
- reference: PMID:31761101
reference_title: Natural history and management outcomes of segmental arterial mediolysis.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients were identified by established criteria that include clinical
presentation in combination with radiographic and serologic findings.
explanation: >-
This supports a combined clinical, imaging, and serologic diagnostic
framework.
- reference: DOI:10.4081/itjm.2024.1795
reference_title: "Segmental arterial mediolysis: a challenging diagnosis in internal medicine"
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Based on imaging and the absence of inflammatory and autoimmune markers, a
diagnosis of SAM was made.
explanation: >-
This case review supports exclusion of inflammatory and autoimmune
mimickers in SAM diagnosis.
Question: You are an expert researcher providing comprehensive, well-cited information.
Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies
Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.
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This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details
Concise overview / definition. Segmental arterial mediolysis (SAM) is a rare, nonatherosclerotic and noninflammatory arteriopathy characterized by degeneration/lysis of the arterial media that predisposes to dissection, aneurysm formation, stenosis/occlusion, and potentially catastrophic hemorrhage, most commonly in medium- to large-caliber visceral (splanchnic) arteries. (bombardieri2024segmentalarterialmediolysis pages 2-3, bombardieri2024segmentalarterialmediolysis pages 3-4, bombardieri2024segmentalarterialmediolysis pages 1-2)
Recent case-based reviews reiterate that SAM is “an uncommon, nonatherosclerotic, noninflammatory, large- to medium-sized arteriopathy” with a predilection for splanchnic branches and a clinical spectrum from incidental findings to life-threatening abdominal hemorrhage and shock. (bombardieri2024segmentalarterialmediolysis pages 1-2)
Key identifiers (OMIM/Orphanet/ICD/MeSH/MONDO). In the retrieved full-text evidence corpus, explicit OMIM, Orphanet, ICD-10/ICD-11, MeSH, or MONDO identifiers were not stated; therefore they are reported here as not found in evidence rather than inferred. (naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 1-2)
Synonyms / alternative names. The dominant synonym is the abbreviation SAM. The entity is also commonly described using class labels such as “non-inflammatory vasculopathy” or “nonatherosclerotic, noninflammatory arteriopathy,” but these are descriptive rather than formal alternative disease names. (najmaoui2023segmentalarterialmediolysis pages 3-5, bombardieri2024segmentalarterialmediolysis pages 1-2)
Evidence source type. Most SAM knowledge is derived from aggregated disease-level evidence (retrospective cohorts, systematic reviews, and case reports/series). Major aggregated sources in this corpus include a 111-patient imaging cohort (Naidu 2018) and a 117-patient natural-history/management cohort (Peng 2019), as well as a systematic review of 143 cases (Skeik 2019). (naidu2018segmentalarterialmediolysis pages 1-1, peng2019naturalhistoryand pages 1-2, skeik2019segmentalarterialmediolysis pages 1-2)
| Disease name | Synonyms / alternative names | MeSH term | ICD-10 / ICD-11 | Orphanet ID | MONDO ID | Notes on source type |
|---|---|---|---|---|---|---|
| Segmental arterial mediolysis | Segmental arterial mediolysis; SAM; segmental arterial mediolysis (SAM) | Not found in retrieved evidence | Not found in retrieved evidence | Not found in retrieved evidence | Not found in retrieved evidence | Disease name and abbreviation are consistently used in primary literature and reviews; retrieved corpus did not provide ontology/code identifiers, so these are marked as not found in evidence rather than inferred (bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5, hirose2024gallbladderhemorrhageassociated pages 4-6, bombardieri2024segmentalarterialmediolysis pages 1-2, naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 1-2) |
| Segmental arterial mediolysis | Segmental arterial mediolysis; SAM; noninflammatory vasculopathy; nonatherosclerotic, noninflammatory arteriopathy | Not found in retrieved evidence | Not found in retrieved evidence | Not found in retrieved evidence | Not found in retrieved evidence | Reviews describe SAM as a rare "non-inflammatory" or "nonatherosclerotic, noninflammatory" vasculopathy/arteriopathy; these are descriptive class labels rather than formal synonyms or ontology identifiers (bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5, najmaoui2023segmentalarterialmediolysis pages 1-3, bombardieri2024segmentalarterialmediolysis pages 1-2, skeik2019segmentalarterialmediolysis pages 1-2) |
| Segmental arterial mediolysis | Earlier descriptive/pathologic labels preceding or surrounding current terminology were referenced historically in review text, but no alternative controlled-vocabulary identifier was explicitly supplied in the retrieved evidence | Not found in retrieved evidence | Not found in retrieved evidence | Not found in retrieved evidence | Not found in retrieved evidence | Source base is literature-derived rather than ontology-derived; identifiers such as MeSH, ICD, Orphanet, and MONDO were not explicitly reported in the retrieved papers/case reviews available here (hirose2024gallbladderhemorrhageassociated pages 4-6, slavin2009segmentalarterialmediolysis pages 1-2, slavin2009segmentalarterialmediolysis pages 2-3) |
Table: This table summarizes the disease name, commonly used synonyms, and the absence of explicit ontology or coding identifiers in the retrieved evidence for segmental arterial mediolysis. It is useful for knowledge-base curation because it distinguishes literature-supported naming from identifiers that were not directly documented in the available sources.
SAM is widely treated as an idiopathic arteriopathy with a putative vasospastic trigger and characteristic medial injury rather than primary arteritis. Slavin’s pathologic-radiologic synthesis frames SAM as a “putative vasospastic disorder” causing life-threatening hemorrhages and specific angiographic patterns. (slavin2009segmentalarterialmediolysis pages 1-2)
Peng et al. describe SAM as a “poorly understood nonatherosclerotic, noninflammatory disease due to vacuolization of the arterial media,” and their management recommendations are built around vascular risk control rather than immunosuppression. (peng2019naturalhistoryand pages 7-9)
Across large series and systematic review synthesis, commonly reported comorbidities include hypertension and tobacco use: - In Naidu’s 111-patient cohort, hypertension occurred in 50% and smoking history in 33%. (naidu2018segmentalarterialmediolysis pages 2-3) - In Skeik’s 143-case synthesis, hypertension was 42.7% and tobacco use 11.9%. (skeik2019segmentalarterialmediolysis pages 4-5)
These are best interpreted as associated comorbidities rather than established causal risk factors.
A 2023 review emphasizes experimental and mechanistic plausibility for vasoconstrictive exposures and recommends avoidance of vasoconstrictors such as tobacco, cocaine, and pseudoephedrine, framing these as potentially relevant triggers in a vasospastic/local hypoxemia model. (najmaoui2023segmentalarterialmediolysis pages 3-5)
Protective factors were not explicitly identified in the retrieved evidence.
No gene–environment interaction evidence specific to SAM was identified in the retrieved corpus.
SAM most commonly presents with acute abdominal pain and can manifest with hemorrhage, shock, and ischemic organ injury due to dissection/thrombosis/occlusion.
Major phenotype frequencies from large cohorts/reviews are summarized below.
| Phenotype | Suggested HPO term | Phenotype type | Typical onset/course in SAM | Approximate frequency / quantitative data | Evidence type | Key source citation |
|---|---|---|---|---|---|---|
| Abdominal pain | HP:0002027 Abdominal pain | Symptom | Usually acute or abrupt adult-onset presentation; may be episodic or resolve with stabilization/regression of arterial lesions | 69.2% in Peng 2019 cohort; 74% in Naidu 2018 cohort; 79.7% in Skeik 2019 systematic review; pooled review range 69.2-82% (peng2019naturalhistoryand pages 1-2, naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5) | Cohort, systematic review, review | (naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, peng2019naturalhistoryand pages 1-2) |
| Flank pain | HP:0032508 Flank pain | Symptom | Acute adult-onset, often associated with renal artery involvement or renal infarction | 21% in Naidu 2018; grouped with abdominal/flank pain in Skeik 2019 79.7% (naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 4-5) | Cohort, systematic review | (naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 4-5) |
| Back pain | HP:0003418 Back pain | Symptom | Acute adult-onset; less common than abdominal pain | 9% in Naidu 2018; included in broad presentation spectrum in reviews (naidu2018segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5) | Cohort, review | (naidu2018segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5) |
| Intra-abdominal hemorrhage / hematoma | HP:0002246 Hemoperitoneum; HP:0011890 Abnormality of the abdomen by imaging study | Clinical sign / complication | Often sudden, severe, potentially life-threatening; may require urgent endovascular or surgical treatment | Intra-abdominal bleeding 49.7% in Skeik 2019; hemorrhage 8.5% in Peng 2019; hematoma 9% at presentation in Naidu 2018; rupture 45.5% in Skeik tabulation (skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 5-7, peng2019naturalhistoryand pages 1-2, naidu2018segmentalarterialmediolysis pages 3-4) | Systematic review, cohort | (skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 5-7, peng2019naturalhistoryand pages 1-2, naidu2018segmentalarterialmediolysis pages 3-4) |
| Hemodynamic shock | HP:0031273 Shock | Clinical sign / complication | Hyperacute catastrophic presentation, usually with rupture/major hemorrhage | 4.2% in Skeik 2019; pooled review estimate 4.2% hemorrhagic shock; older reports cited mortality up to 50% in ruptured cases (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, togawa2023intraabdominalbleedingdue pages 3-4) | Systematic review, review | (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, togawa2023intraabdominalbleedingdue pages 3-4) |
| End-organ ischemia / infarction | HP:0011025 Ischemia; HP:0006510 Renal infarction; HP:0100515 Splenic infarction; HP:0002574 Bowel ischemia | Clinical sign / imaging finding / complication | Acute adult-onset; results from dissection, thrombosis, stenosis, or occlusion; may improve or leave permanent injury | End-organ ischemia/infarction 34% in Naidu 2018; 41.9% in Peng 2019; case reports/reviews describe renal, splenic, and bowel ischemia/infarction (naidu2018segmentalarterialmediolysis pages 3-4, peng2019naturalhistoryand pages 1-2, najmaoui2023segmentalarterialmediolysis pages 3-5, najmaoui2023segmentalarterialmediolysis pages 1-3) | Cohort, review, case report | (naidu2018segmentalarterialmediolysis pages 3-4, peng2019naturalhistoryand pages 1-2, najmaoui2023segmentalarterialmediolysis pages 3-5, najmaoui2023segmentalarterialmediolysis pages 1-3) |
| Hematuria | HP:0000790 Hematuria | Symptom / sign | Usually acute, secondary to renal infarction or renal arterial involvement; uncommon but recognized | Reported as part of SAM presentation spectrum in reviews/case literature; no robust pooled percentage in major cohorts available from extracted evidence (bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5) | Review, case-based review | (bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5) |
| Gastrointestinal bleeding (melena/hematochezia/hemobilia) | HP:0002573 Gastrointestinal hemorrhage; HP:0002249 Melena; HP:0012208 Hematochezia | Symptom / sign / complication | Acute, may accompany visceral artery rupture, bowel ischemia, or hepatobiliary involvement | Melena/hematochezia 5.6% in Skeik 2019; hemobilia and transit bleeding mentioned as less common presentations in reviews (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, bombardieri2024segmentalarterialmediolysis pages 2-3) | Systematic review, review | (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, bombardieri2024segmentalarterialmediolysis pages 2-3) |
| Hypertension (comorbidity) | HP:0000822 Hypertension | Comorbidity / risk marker | Usually pre-existing adult comorbidity; may complicate presentation and management rather than define phenotype | 42.7% in Skeik 2019; 50% in Naidu 2018; 55% in one summarized series; acute hypertension noted in 13.7% in Peng 2019 (skeik2019segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5, peng2019naturalhistoryand pages 2-3) | Cohort, systematic review, review | (skeik2019segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5, peng2019naturalhistoryand pages 2-3) |
| Asymptomatic / incidental disease | HP:0000007 Autosomal recessive inheritance | Asymptomatic state / incidental finding | Incidental adult diagnosis on imaging; course may remain stable or regress with surveillance | 4.9% in Skeik 2019; approximately 10% asymptomatic in Bombardieri/retrospective series summary; pooled review range 4.9-10.3% (skeik2019segmentalarterialmediolysis pages 4-5, bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5) | Systematic review, cohort summary, review | (skeik2019segmentalarterialmediolysis pages 4-5, bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 3-5) |
| Cerebrovascular symptoms | HP:0001297 Cerebrovascular abnormality; HP:0002315 Headache; HP:0002381 Aphasia | Symptom / neurologic manifestation | Less common; can be acute when cerebral/cervical vessels involved | 11.9% cerebrovascular symptoms in Skeik 2019; cerebrovascular artery involvement about 13% in large reviews (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, skeik2019segmentalarterialmediolysis pages 7-8) | Systematic review, review | (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, skeik2019segmentalarterialmediolysis pages 7-8) |
Table: This table summarizes the main clinical phenotypes reported for segmental arterial mediolysis, with suggested HPO mappings, typical clinical course, and approximate frequencies from major cohorts and reviews. It is useful for knowledge-base curation because it links symptoms and complications to ontology terms and evidence types.
Quality of life impact. Formal validated QoL instruments (e.g., SF-36/EQ-5D) were not reported in the retrieved SAM studies. However, acute presentations with pain, hemorrhage, and ischemia can be life-threatening or disabling. (skeik2019segmentalarterialmediolysis pages 4-5, peng2019naturalhistoryand pages 1-2)
No validated causal gene for SAM was identified in the retrieved evidence. Peng et al. explicitly note “a lack of an evident genetic component” and an apparent lack of familial vasculopathies in SAM, with unclear indications for genetic/reproductive counseling. (peng2019naturalhistoryand pages 7-9)
Noninvasive diagnostic frameworks explicitly exclude connective tissue disorders with known genetic causes (e.g., Ehlers–Danlos, Marfan syndrome, Loeys–Dietz) when evaluating SAM-like imaging patterns. (naidu2018segmentalarterialmediolysis pages 1-2)
No SAM-specific epigenetic, transcriptomic, proteomic, metabolomic, single-cell, spatial, or functional genomics evidence was identified in the retrieved corpus.
Environmental/lifestyle factors. A 2023 review recommends avoiding vasoconstrictors including tobacco and specific sympathomimetic exposures (cocaine, pseudoephedrine) in the context of a vasospastic/local hypoxemia hypothesis. (najmaoui2023segmentalarterialmediolysis pages 3-5)
Infectious agents. SAM is characterized as non-arteritic (noninflammatory); evaluation commonly includes exclusion of mycotic aneurysm when clinically suspected. (najmaoui2023segmentalarterialmediolysis pages 3-5)
SAM is characterized histologically by medial smooth muscle vacuolar degeneration/lysis with disruption of the media and elastic laminae and a relative absence of inflammatory cells. Bombardieri et al. describe “partial or total vacuolization and lysis of the outer arterial media” with “a notable absence of inflammatory cells.” (bombardieri2024segmentalarterialmediolysis pages 3-4)
A widely used conceptual framework distinguishes an injurious phase (mediolysis → arterial gaps → dissection/aneurysm) followed by a reparative phase (granulation/fibrosis → stabilization or stenotic sequelae). (peng2019naturalhistoryand pages 6-7)
| Mechanism step | Description | Upstream triggers / initiating factors | Downstream vascular lesions / clinical consequences | Suggested GO Biological Process terms | Suggested CL cell types | Key anatomic sites / UBERON terms |
|---|---|---|---|---|---|---|
| 1. Putative vasospastic initiation | Foundational pathology framework proposes SAM begins with a vasospastic insult to muscular arteries, causing focal ischemic injury of the outer media rather than primary arteritis; modern reviews describe a noninflammatory, nonatherosclerotic arteriopathy with possible repetitive vasoconstrictive injury. | Putative vasospasm; local hypoxemia; environmental/iatrogenic vasoconstrictive exposures; hypertension may amplify wall stress; smoking/tobacco and other vasoconstrictors are discussed as possible contributors in reviews, but causality remains unproven. (slavin2009segmentalarterialmediolysis pages 1-2, peng2019naturalhistoryand pages 6-7, najmaoui2023segmentalarterialmediolysis pages 3-5) | Sets up medial injury that progresses to mediolysis, wall weakening, dissection, aneurysm, hemorrhage, or ischemic organ injury. (slavin2009segmentalarterialmediolysis pages 1-2, peng2019naturalhistoryand pages 6-7) | GO:0003013 circulatory system process; GO:0043062 extracellular structure organization; GO:0008217 regulation of blood pressure | CL:0000359 smooth muscle cell; CL:0000115 endothelial cell | UBERON:0001981 blood vessel; UBERON:0001514 abdominal aorta; UBERON:0003103 renal artery; UBERON:0001163 superior mesenteric artery; UBERON:0013704 celiac artery |
| 2. Injurious phase: mediolysis / vacuolar degeneration | The early injurious phase features vacuolization and lysis of smooth muscle in the outer arterial media (“mediolysis”), producing separation between outer media and adventitia and predisposing to arterial gaps. Histopathology emphasizes vacuolar degeneration of smooth muscle with absence of inflammatory infiltrates. (peng2019naturalhistoryand pages 6-7, bombardieri2024segmentalarterialmediolysis pages 3-4, slavin2009segmentalarterialmediolysis pages 1-2) | Continuation of the initiating vasospastic-hypoxic insult; no evidence this is driven by immune-complex vasculitis or atherosclerosis. (slavin2009segmentalarterialmediolysis pages 1-2, bombardieri2024segmentalarterialmediolysis pages 3-4) | Medial weakening, arterial dilatation, predisposition to dissecting hematoma and aneurysm formation. (slavin2009segmentalarterialmediolysis pages 1-2, peng2019naturalhistoryand pages 6-7) | GO:0070269 pyroptosis/apoptotic-like cell death not established; more conservatively GO:0070265 necrotic cell death; GO:0030198 extracellular matrix organization | CL:0000359 smooth muscle cell; CL:0000115 endothelial cell | UBERON:0001981 blood vessel; UBERON:0004572 tunica media of artery |
| 3. Formation of arterial gaps and wall separation | Mediolysis progresses to focal tears/gaps where the media separates from adventitia; Slavin describes this as a primary morphologic event correlated with characteristic angiographic lesions. Bombardieri and Hirose describe focal loss of internal/external elastic laminae and medial disruption without inflammation. (slavin2009segmentalarterialmediolysis pages 2-3, bombardieri2024segmentalarterialmediolysis pages 3-4, hirose2024gallbladderhemorrhageassociated pages 4-6) | Structural failure of already injured media; elastic lamina loss worsens mechanical instability. (hirose2024gallbladderhemorrhageassociated pages 4-6, bombardieri2024segmentalarterialmediolysis pages 3-4) | Arterial gaps become entry points for hemorrhage into the wall, false lumen formation, dissection, pseudoaneurysm/aneurysm, or rupture. (slavin2009segmentalarterialmediolysis pages 1-2, hirose2024gallbladderhemorrhageassociated pages 4-6) | GO:0030198 extracellular matrix organization; GO:0042398 cellular modified amino acid metabolic process (fibrinoid change not directly ontologized here); GO:0007596 blood coagulation | CL:0000066 adventitial fibroblast (suggested fibroblast population); CL:0000359 smooth muscle cell; CL:0000115 endothelial cell | UBERON:0001981 blood vessel; UBERON:0004572 tunica media of artery; UBERON:0004573 tunica adventitia |
| 4. Intramural hemorrhage / dissecting hematoma | Blood dissects through weakened arterial wall at gap junctions, producing intramural or dissecting hematoma; angiographic manifestations include dissections and irregular luminal flaps. (slavin2009segmentalarterialmediolysis pages 1-2, bombardieri2024segmentalarterialmediolysis pages 2-3, peng2019naturalhistoryand pages 6-7) | Arterial gap formation plus hemodynamic stress and pressure loading. (slavin2009segmentalarterialmediolysis pages 1-2, peng2019naturalhistoryand pages 6-7) | Dissection, thrombosed false lumen, luminal narrowing, branch-vessel compromise, acute abdominal/flank pain, renal or visceral infarction. (naidu2018segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 3-4, peng2019naturalhistoryand pages 6-7) | GO:0007596 blood coagulation; GO:0042060 wound healing; GO:0002576 platelet degranulation | CL:0000233 platelet; CL:0000540 macrophage not consistently established in SAM lesions; CL:0000115 endothelial cell | UBERON:0001163 superior mesenteric artery; UBERON:0003103 renal artery; UBERON:0013704 celiac artery; UBERON:0002113 liver artery/hepatic artery |
| 5. Aneurysmal dilatation and beading phenotype | Loss of medial integrity produces arterial dilatation, single aneurysm, or multiple aneurysms/“string-of-beads” appearance; these are core radiographic phenotypes across cohorts. (bombardieri2024segmentalarterialmediolysis pages 3-4, slavin2009segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 3-5) | Ongoing wall weakness after mediolysis and/or reparative remodeling. (slavin2009segmentalarterialmediolysis pages 1-2, peng2019naturalhistoryand pages 6-7) | Rupture risk, intra-abdominal or retroperitoneal hemorrhage, need for embolization or surgery when unstable. (hirose2024gallbladderhemorrhageassociated pages 4-6, togawa2023intraabdominalbleedingdue pages 3-4, peng2019naturalhistoryand pages 6-7) | GO:0030198 extracellular matrix organization; GO:0001525 angiogenesis/remodeling (broadly reparative); GO:0048729 tissue morphogenesis | CL:0000359 smooth muscle cell; CL:0000895 fibroblast; CL:0000115 endothelial cell | UBERON:0001163 superior mesenteric artery; UBERON:0013704 celiac artery; UBERON:0003103 renal artery; UBERON:0002113 hepatic artery; UBERON:0001194 splenic artery |
| 6. Reparative phase: granulation and fibrosis | After the injurious phase, SAM enters a reparative phase characterized by granulation tissue and fibrosis; this can remodel the wall and may stabilize lesions, but can also create stenotic sequelae. (peng2019naturalhistoryand pages 6-7, slavin2009segmentalarterialmediolysis pages 1-2) | Healing response following medial injury and hemorrhage; noninflammatory repair rather than immune-mediated vasculitis. (peng2019naturalhistoryand pages 6-7, bombardieri2024segmentalarterialmediolysis pages 3-4) | Lesion stabilization/regression in many patients; alternatively focal stenosis, occlusion, chronic ischemia, or lesions resembling fibromuscular dysplasia. (naidu2018segmentalarterialmediolysis pages 5-6, peng2019naturalhistoryand pages 7-9, slavin2009segmentalarterialmediolysis pages 1-2) | GO:0042060 wound healing; GO:0009611 response to wounding; GO:0030199 collagen fibril organization; GO:0061448 connective tissue replacement involved in inflammatory response (approximate) | CL:0000895 fibroblast; CL:0000359 smooth muscle cell | UBERON:0001981 blood vessel; UBERON:0004572 tunica media of artery |
| 7. Stenosis / occlusion from remodeling or thrombus | Reparative fibrosis and/or thrombus in a false lumen can narrow or occlude the true lumen. Radiographic phenotypes include stenosis and occlusion; Peng and Naidu note thrombosed false lumens and progression/resolution on surveillance imaging. (naidu2018segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 3-4, peng2019naturalhistoryand pages 7-9) | Dissection with thrombosis; fibrotic repair after mediolysis. (peng2019naturalhistoryand pages 6-7, slavin2009segmentalarterialmediolysis pages 1-2) | End-organ ischemia/infarction of kidney, spleen, bowel, or liver; renovascular hypertension may occur with renal involvement. (bombardieri2024segmentalarterialmediolysis pages 2-3, naidu2018segmentalarterialmediolysis pages 3-4, peng2019naturalhistoryand pages 2-3) | GO:0007596 blood coagulation; GO:0030198 extracellular matrix organization; GO:0001975 response to hypoxia | CL:0000233 platelet; CL:0000115 endothelial cell; CL:0000359 smooth muscle cell | UBERON:0002113 liver; UBERON:0002108 small intestine; UBERON:0002113 liver; UBERON:0002113 kidney/parenchyma approximated by UBERON:0002113?; UBERON:0002106 spleen |
| 8. Hemorrhagic end-organ damage | When aneurysm or dissected segments rupture, patients may develop hematoma, hemoperitoneum, gallbladder hemorrhage, or shock. Recent case reports extend the phenotype to unusual visceral beds such as gallbladder arteries. (hirose2024gallbladderhemorrhageassociated pages 4-6, togawa2023intraabdominalbleedingdue pages 3-4) | Advanced wall disruption of aneurysmal/dissected arterial segments. (hirose2024gallbladderhemorrhageassociated pages 4-6, slavin2009segmentalarterialmediolysis pages 1-2) | Life-threatening intra-abdominal hemorrhage, hypovolemic shock, need for urgent endovascular embolization or surgery. (hirose2024gallbladderhemorrhageassociated pages 4-6, togawa2023intraabdominalbleedingdue pages 3-4, bombardieri2024segmentalarterialmediolysis pages 4-5) | GO:0002576 platelet degranulation; GO:0007596 blood coagulation; GO:0001944 vasculature development/remodeling (broad context) | CL:0000233 platelet; CL:0000115 endothelial cell | UBERON:0000916 abdomen; UBERON:0002110 gallbladder; UBERON:0001163 superior mesenteric artery; UBERON:0001194 splenic artery |
| 9. Absence of primary inflammation as defining negative feature | Histology repeatedly notes “absence of inflammatory cells,” distinguishing SAM from polyarteritis nodosa and other vasculitides. This negative mechanism is diagnostically central and explains why corticosteroids are generally discouraged. (bombardieri2024segmentalarterialmediolysis pages 3-4, bombardieri2024segmentalarterialmediolysis pages 4-5, peng2019naturalhistoryand pages 6-7) | Not immune-complex arteritis; inflammatory marker elevations may be secondary to infarction/bleeding rather than causal vasculitis. (najmaoui2023segmentalarterialmediolysis pages 3-5, peng2019naturalhistoryand pages 7-9) | Helps guide differential diagnosis and management away from immunosuppression toward vascular surveillance/intervention and blood-pressure control. (najmaoui2023segmentalarterialmediolysis pages 3-5, peng2019naturalhistoryand pages 6-7) | GO:0006954 inflammatory response — notably not a dominant primary process in SAM | CL:0000775 neutrophil; CL:0000860 eosinophil; CL:0000623 natural killer cell — included here as inflammatory cells generally absent on pathology | UBERON:0001981 blood vessel |
| 10. Dynamic lesion evolution over time | Cohort studies show SAM is biologically dynamic: lesions may regress, remain stable, or progress, and new lesions can appear during follow-up, supporting serial imaging surveillance. (naidu2018segmentalarterialmediolysis pages 1-1, naidu2018segmentalarterialmediolysis pages 3-4, peng2019naturalhistoryand pages 7-9) | Ongoing hemodynamic stress and evolving repair/remodeling after the initial insult. (peng2019naturalhistoryand pages 7-9, slavin2009segmentalarterialmediolysis pages 1-2) | Clinical rationale for repeat CTA at short interval then longitudinal follow-up; intervention is reserved for hemorrhage, hemodynamic instability, bowel ischemia, or threatening aneurysm/dissection. (peng2019naturalhistoryand pages 7-9, najmaoui2023segmentalarterialmediolysis pages 3-5) | GO:0048729 tissue morphogenesis; GO:0042060 wound healing; GO:0003018 vascular process in circulatory system | CL:0000115 endothelial cell; CL:0000359 smooth muscle cell; CL:0000895 fibroblast | UBERON:0001981 blood vessel; commonly UBERON:0013704 celiac artery, UBERON:0001163 superior mesenteric artery, UBERON:0003103 renal artery |
Table: This table summarizes the proposed pathophysiologic cascade of segmental arterial mediolysis from putative vasospastic injury through medial lysis, dissection, aneurysm, fibrosis, and hemorrhagic or ischemic complications. It also links each step to suggested ontology terms and anatomic/cellular targets for knowledge-base annotation.
Organ/system level. SAM primarily involves medium-to-large visceral branches of the abdominal aorta, with common involvement of the celiac, superior mesenteric, renal, hepatic, and splenic arterial territories. (skeik2019segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 1-1, peng2019naturalhistoryand pages 1-2)
Tissue/cell level. The dominant injured compartment is the arterial tunica media and its vascular smooth muscle cells, with subsequent wall separation and remodeling; inflammatory infiltrates are typically absent on pathology. (bombardieri2024segmentalarterialmediolysis pages 3-4, slavin2009segmentalarterialmediolysis pages 1-2)
Localization and multiplicity. Multifocal/multivessel involvement is common: in Skeik’s synthesis, multiple-vessel involvement occurred in 62.2%. (skeik2019segmentalarterialmediolysis pages 4-5)
Onset pattern. SAM often presents abruptly with acute pain; in cohorts the dominant presentation is acute abdominal pain. (naidu2018segmentalarterialmediolysis pages 1-1, peng2019naturalhistoryand pages 1-2)
Progression/course. SAM is dynamic on imaging surveillance: in Naidu’s cohort, 20% showed progression while most remained stable or resolved; in Peng’s cohort, 28.6% progressed while 27.7% regressed and 43.8% remained stable. (naidu2018segmentalarterialmediolysis pages 1-1, peng2019naturalhistoryand pages 1-2)
A 2023 review summarizes a reported incidence of approximately 1 in 100,000 per year (rare disease), though this estimate derives from the limited SAM literature and should be interpreted cautiously. (najmaoui2023segmentalarterialmediolysis pages 3-5)
Across major aggregated studies: - Median/mean age clusters in the early-to-mid 50s. (naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 4-5, peng2019naturalhistoryand pages 2-3) - Male predominance is consistently reported (~67–71%). (naidu2018segmentalarterialmediolysis pages 1-1, skeik2019segmentalarterialmediolysis pages 4-5)
No Mendelian inheritance pattern is supported in the retrieved evidence; Peng et al. emphasize lack of an evident genetic component. (peng2019naturalhistoryand pages 7-9)
Because histology is often impractical, SAM is frequently diagnosed clinically using characteristic vascular imaging plus exclusion of vasculitis, atherosclerosis, fibromuscular dysplasia (FMD), and connective tissue disorders. (naidu2018segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 3-5)
Noninvasive diagnostic frameworks (e.g., institutional criteria in Naidu’s AJR cohort) emphasize exclusion of more plausible diagnoses such as FMD/atherosclerosis and exclusion of connective tissue disorders (Ehlers–Danlos, Marfan, Loeys–Dietz), together with serologic evaluation for vasculitis markers. (naidu2018segmentalarterialmediolysis pages 1-2)
CT angiography (CTA) is emphasized as the most accurate and practical modality in contemporary care. A 2023 review states CTA yields “the best diagnostic accuracy,” and Naidu’s cohort relied primarily on contrast-enhanced CT (92% at initial imaging). (najmaoui2023segmentalarterialmediolysis pages 3-5, naidu2018segmentalarterialmediolysis pages 2-3)
Common angiographic/CTA patterns include dissection, aneurysm (including “string-of-beads”), stenosis, and occlusion. (bombardieri2024segmentalarterialmediolysis pages 3-4, naidu2018segmentalarterialmediolysis pages 1-1)
The image below exemplifies the angiographic “string-of-beads” appearance with multifocal dissections/aneurysms.
(connolly2021segmentalarterialmediolysis media 71aca598)
Work-up often includes ANA/ANCA and inflammatory markers (ESR/CRP) to exclude vasculitis, recognizing that CRP can be secondarily elevated by infarction. (najmaoui2023segmentalarterialmediolysis pages 1-3, najmaoui2023segmentalarterialmediolysis pages 3-5)
Overall prognosis in recent cohorts is often favorable with appropriate surveillance and intervention for complications: - Naidu 2018: no deaths during follow-up; 80% stability/resolution among those with follow-up imaging; 20% progression. (naidu2018segmentalarterialmediolysis pages 1-1, naidu2018segmentalarterialmediolysis pages 4-5) - Peng 2019: overall mortality 4.3% and disease-specific mortality 0.85%; regression 27.7%, stability 43.8%, progression 28.6%. (peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2) - Skeik 2019 systematic review: mortality 7%; symptom relief in 91% of reported cases. (skeik2019segmentalarterialmediolysis pages 1-2)
Nonetheless, older reports and rupture presentations can carry high mortality (up to ~50% in acute hypotension/rupture scenarios in historical series), highlighting the need for rapid recognition and hemorrhage control when present. (peng2019naturalhistoryand pages 6-7, togawa2023intraabdominalbleedingdue pages 3-4)
There is no single standardized therapy; care is stratified by stability, hemorrhage, and ischemia risk.
| Management strategy | Suggested MAXO term(s) | Typical indication(s) in SAM | Key details / implementation notes | Reported outcome data / frequency | Key supporting sources |
|---|---|---|---|---|---|
| Conservative management: blood pressure control, analgesia, surveillance imaging | MAXO: antihypertensive therapy; pain management; medical surveillance | Hemodynamically stable patients without active major hemorrhage or bowel-threatening ischemia | Common first-line approach after CTA-based diagnosis; includes strict BP control, analgesia, risk-factor modification, and serial CTA follow-up. Recommended short-interval imaging because new lesions/progression can occur early; suggested schedules include 1 week, 3 months, then yearly if stable, or 1, 3, 9 months then annually in review-based practice. | Skeik 2019: conservative treatment reported in 8.1% of pooled cases; antihypertensives 19.9% (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 5-6). Naidu 2018: 80% of followed patients had stability/resolution, no follow-up deaths (naidu2018segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 5-6). Peng 2019: imaging regression 27.7%, stability 43.8%, progression 28.6%; overall mortality 4.3%, disease-specific mortality 0.85% (peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2). 13-case institutional series: most conservatively managed patients showed stabilization/regression (skeik2019segmentalarterialmediolysis pages 1-2). | (naidu2018segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 5-6, najmaoui2023segmentalarterialmediolysis pages 3-5, skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 5-6, peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2) |
| Antiplatelet therapy | MAXO: antiplatelet agent therapy | Stable disease with dissection/thrombotic lumen or ischemic risk; used case-by-case because evidence is limited | Often paired with BP control and imaging surveillance. Role remains uncertain; not disease-specific standard of care. Used more often in non-emergent management than in rupture. | Skeik 2019: antiplatelet therapy in 10.3% of pooled cases (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 5-6). Naidu 2018: antiplatelet therapy in 46/97 patients with follow-up imaging (naidu2018segmentalarterialmediolysis pages 4-5). Peng 2019/Najmaoui review note uncertain benefit and individualized use (najmaoui2023segmentalarterialmediolysis pages 3-5, peng2019naturalhistoryand pages 7-9). | (naidu2018segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 3-5, skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 5-6, peng2019naturalhistoryand pages 7-9) |
| Anticoagulation | MAXO: anticoagulant therapy | Selected patients with thrombosed false lumen, distal ischemia/infarction, or embolic/thrombotic concern; not universally recommended | Highly individualized because SAM can bleed as well as thrombose. Several recent case reports used heparin/LMWH/warfarin in stable patients with dissections and renal ischemia, but reviews emphasize uncertain net benefit. | Skeik 2019: anticoagulation in 11.8% of pooled cases (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 5-6). Peng 2019: anticoagulants should be started in absence of clinical improvement per authors’ practice summary (peng2019naturalhistoryand pages 7-9). Bombardieri 2024 and Najmaoui 2023 describe successful conservative courses using anticoagulation in selected cases (bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 1-3, bombardieri2024segmentalarterialmediolysis pages 1-2). | (bombardieri2024segmentalarterialmediolysis pages 2-3, najmaoui2023segmentalarterialmediolysis pages 1-3, bombardieri2024segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 3-5, skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 5-6, peng2019naturalhistoryand pages 7-9) |
| Endovascular embolization | MAXO: endovascular embolization | Preferred acute intervention for active bleeding, ruptured aneurysm/pseudoaneurysm, enlarging aneurysm, or unstable hemorrhagic presentation when anatomically feasible | Increasingly favored over open surgery because it is less invasive and can rapidly control hemorrhage; includes coil embolization of culprit visceral branches. Also used when progression on surveillance produces treatable aneurysm. | Skeik 2019: coil embolization 27.9% of pooled cases, the most common specific intervention (skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 5-6). Peng 2019: interventions in 22.2% overall; embolization made up 78.9% of endovascular procedures; endovascular success 84% (peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2). Bombardieri 2024 and Togawa 2023 note endovascular therapy is generally preferred/first approach when feasible (bombardieri2024segmentalarterialmediolysis pages 4-5, togawa2023intraabdominalbleedingdue pages 3-4, bombardieri2024segmentalarterialmediolysis pages 3-4). | (bombardieri2024segmentalarterialmediolysis pages 4-5, togawa2023intraabdominalbleedingdue pages 3-4, bombardieri2024segmentalarterialmediolysis pages 3-4, skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 5-6, peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2) |
| Stent-grafting / angioplasty | MAXO: vascular stent placement; angioplasty | Focal stenosis/dissection/aneurysm in anatomically suitable vessels, especially when preservation of parent artery flow is desired | Less common than embolization; choice depends on vessel caliber, branch pattern, rupture risk, and technical feasibility. Can be used as bridge or alternative to open repair. | Skeik 2019: angioplasty/stenting 8.1% of pooled cases (skeik2019segmentalarterialmediolysis pages 4-5, najmaoui2023segmentalarterialmediolysis pages 5-6). Institutional 13-case series: 3/13 required stent-grafting of renal/celiac lesions and 1 SMA branch embolization; remaining cases were conservative with stable/regressive follow-up (skeik2019segmentalarterialmediolysis pages 1-2). | (skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 5-6) |
| Open surgery / arterial repair / organ resection | MAXO: vascular surgery; arterial repair; surgical resection | Hemodynamic instability, uncontrolled hemorrhage, bowel infarction/ischemia, failed or infeasible endovascular therapy, or need for pathology-confirming specimen | Includes open arterial repair, bypass/revascularization, aneurysm ligation, or organ surgery (e.g., bowel/gallbladder resection) depending on affected territory and complications. Often reserved for rescue or anatomy not amenable to endovascular treatment. | Skeik 2019: abdominal organ surgery 23.5% and open arterial repair 20.6% (skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 5-6). Peng 2019: open surgery success 93%; perioperative complications uncommon, but one death from ongoing hemorrhage reported in operated patients (peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2). Togawa 2023 supports surgery when anticoagulation is needed and bleeding risk complicates conservative care (togawa2023intraabdominalbleedingdue pages 3-4). | (togawa2023intraabdominalbleedingdue pages 3-4, skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 1-2, najmaoui2023segmentalarterialmediolysis pages 5-6, peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2) |
| Avoid corticosteroids | MAXO: avoidance of contraindicated medication | All suspected/confirmed SAM unless another inflammatory disease truly coexists | SAM is noninflammatory; steroids may expose patients to harm and are repeatedly discouraged because SAM can mimic vasculitis. Correct diagnosis prevents inappropriate immunosuppression. | Recent reviews explicitly state corticosteroids are not recommended (najmaoui2023segmentalarterialmediolysis pages 3-5). Peng 2019 advises avoidance of steroids in multimodal medical management (peng2019naturalhistoryand pages 7-9). | (najmaoui2023segmentalarterialmediolysis pages 3-5, peng2019naturalhistoryand pages 7-9) |
| Avoid vasoconstrictors / trigger modification | MAXO: risk factor avoidance; substance avoidance counseling | Suspected vasospastic-trigger model, recurrent/progressive disease risk reduction, and general secondary prevention | Reviews recommend avoiding vasoconstrictive exposures such as tobacco, cocaine, and pseudoephedrine; smoking cessation and cardiovascular risk reduction are commonly advised. | Najmaoui 2023 specifically recommends avoidance of vasoconstrictors and notes environmental factors promoting vasoconstriction/local hypoxemia (najmaoui2023segmentalarterialmediolysis pages 3-5). Peng 2019 recommends tobacco cessation and multimodal risk-factor control (peng2019naturalhistoryand pages 6-7, peng2019naturalhistoryand pages 7-9). | (peng2019naturalhistoryand pages 6-7, peng2019naturalhistoryand pages 7-9, najmaoui2023segmentalarterialmediolysis pages 3-5) |
Table: This table summarizes real-world treatment approaches for segmental arterial mediolysis, including conservative, medical, endovascular, and surgical options. It also maps each strategy to suggested MAXO-style intervention labels and highlights the limited but important outcome data from major cohorts and reviews.
Key points supported by authoritative sources: - Avoid corticosteroids unless an alternative inflammatory diagnosis is proven, because SAM is noninflammatory and frequently mimics vasculitis. (peng2019naturalhistoryand pages 7-9, najmaoui2023segmentalarterialmediolysis pages 3-5) - Endovascular embolization is commonly used for bleeding/rupture and is frequently preferred when feasible. (skeik2019segmentalarterialmediolysis pages 4-5, peng2019naturalhistoryand pages 1-2) - Conservative management with strict blood-pressure control and surveillance imaging is common in stable disease; lesion regression/stability is frequent, but progression/new lesions occur in a minority. (naidu2018segmentalarterialmediolysis pages 4-5, peng2019naturalhistoryand pages 1-2)
No validated primary prevention strategy exists because causal factors are uncertain. However, secondary-prevention style measures are frequently recommended: - Avoidance of vasoconstrictors (tobacco, cocaine, pseudoephedrine) in the vasospastic trigger hypothesis. (najmaoui2023segmentalarterialmediolysis pages 3-5) - Cardiovascular risk-factor optimization and tobacco cessation as part of multimodal medical management. (peng2019naturalhistoryand pages 7-9)
No population screening programs were identified.
No naturally occurring SAM in non-human species was identified in the retrieved evidence.
No established animal or cellular model systems for SAM were identified in the retrieved evidence.
The table below consolidates the best-available quantitative data from major SAM cohorts and systematic review evidence.
| Source | Study type / setting | N | Demographics | Most common presenting symptoms | Most commonly involved arteries | Key imaging findings | Follow-up / outcomes | Notes |
|---|---|---|---|---|---|---|---|---|
| Naidu 2018, AJR | Retrospective single-center abdominal imaging cohort, 2000–2015 | 111 | Median age 51 y (23–87); 71% male | Abdominal pain 74%; flank pain 21%; back pain 9% | Renal 47%; SMA 46%; celiac trunk 46%; hepatic 23%; iliac 18%; splenic 14% | Dissection 86%; aneurysm 57%; beading/webs 28%; occlusion 19%; rind/wall thickening 15%; end-organ ischemia/infarction 34%; hematoma 9% | 97/111 had follow-up imaging (247 studies), median follow-up 12 mo; progression 20% (19/97); stability or resolution 80% (78/97); no deaths during follow-up | Initial imaging CT in 92%; MRI 5%; multi-territory disease common; diagnosis based on noninvasive imaging criteria with exclusion of mimics (naidu2018segmentalarterialmediolysis pages 1-1, naidu2018segmentalarterialmediolysis pages 4-5, naidu2018segmentalarterialmediolysis pages 3-4, naidu2018segmentalarterialmediolysis pages 1-2, naidu2018segmentalarterialmediolysis pages 2-3) |
| Peng 2019, J Vasc Surg | Retrospective institutional natural-history / management cohort, 2000–2016 | 117 | Mean age 52.7 y; 67.5% male | Abdominal pain 69.2%; chronic abdominal pain 15.4%; acute hypertension 13.7%; intra-abdominal hemorrhage 8.5% | Celiac 54.7%; renal 49.6%; SMA 43.6% | Dissection 79.5%; aneurysm 52.1%; end-organ ischemia/infarction 41.9%; radiographic spectrum also included occlusion, stenosis, beading, wall thickening, pseudoaneurysm, fistula | Follow-up imaging in 96.6%; mean follow-up 1258 d; regression 27.7%; stability 43.8%; progression 28.6%; mean time to progression 666 d; overall mortality 4.3%; disease-specific mortality 0.85%; 22.2% underwent intervention; endovascular success 84%, open surgery success 93% | Historical mortality in older series was much higher; recommended short-interval imaging (1 wk, 3 mo, then yearly if stable) and medical risk-factor control; corticosteroids discouraged (peng2019naturalhistoryand pages 6-7, peng2019naturalhistoryand pages 7-9, peng2019naturalhistoryand pages 1-2, peng2019naturalhistoryand pages 2-3) |
| Skeik 2019, Vascular Medicine | Systematic review + institutional cases (126 literature cases + 17 center cases) | 143 | Median age 55 y (IQR 48–63); 67.8% male | Abdominal/flank pain 79.7%; intra-abdominal bleeding 49.7%; nausea/vomiting 16.1%; cerebrovascular symptoms 11.9%; shock 4.2%; asymptomatic 4.9% | SMA 53.1%; hepatic 44.8%; celiac 35.7%; renal 25.9%; splenic 24.5%; cerebrovascular 13.3%; IMA 10.5%; multiple-vessel involvement 62.2% | Aneurysm 76.2%; dissection 60.8%; rupture 45.5%; string-of-beads 14.7%; stenosis 18.9%; obstruction 16.9%; thrombosis 14.7%; wall thickening 7.7% | Symptom relief/improvement 90.6%; radiologic improvement 66.3%, unchanged 17.5%, worsened 16.3%; survival 93%; mortality 7% | CT/CTA most used imaging 77.6%–78%; catheter angiography 35%; MRA and ultrasound each ~9%; histology available in 44.1%; treatments: coil embolization 27.9%, abdominal organ surgery 23.5%, open arterial repair 20.6%, antihypertensives 19.9%, anticoagulation 11.8%, antiplatelets 10.3%, angioplasty/stenting 8.1%, conservative therapy 8.1% (skeik2019segmentalarterialmediolysis pages 4-5, skeik2019segmentalarterialmediolysis pages 1-2, skeik2019segmentalarterialmediolysis pages 5-7, najmaoui2023segmentalarterialmediolysis pages 5-6) |
| Najmaoui 2023, EJCRIM | Case report + narrative review synthesizing major series | 1 case + review | Review summary: incidence ~1/100,000/year; typically men in their 50s; series ranges include median/mean ages 51–55 y and male proportion ~67–71% | Abdominal pain 69.2–82%; hemorrhagic shock 4.2%; asymptomatic 4.9–10.3% | SMA 43.6–53.1%; celiac trunk 35.7–54.7%; renal 25.9–52%; cerebrovascular ~13% | Dissections 60.8–95%; aneurysms 52.1–76.2%; stenosis 18.9–26%; string-of-beads 14.7–31% | Clinical improvement ~90.6%; radiologic improvement 71.5–83.8%; 1-year survival 93–100%; 3-year survival 95.7% | CT angiography described as the best diagnostic accuracy; histology is gold standard but noninvasive criteria increasingly used; corticosteroids not recommended; conservative care for stable patients and endovascular therapy preferred for unstable cases (najmaoui2023segmentalarterialmediolysis pages 3-5, najmaoui2023segmentalarterialmediolysis pages 5-6) |
Table: This table summarizes the main quantitative findings for segmental arterial mediolysis from the largest available cohorts and reviews cited in the evidence. It is useful for comparing demographics, vascular distribution, imaging phenotypes, and outcomes across the key SAM literature.
References
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(skeik2019segmentalarterialmediolysis pages 4-5): Nedaa Skeik, Sydney L Olson, Gopika Hari, and Mary L Pavia. Segmental arterial mediolysis (sam): systematic review and analysis of 143 cases. Vascular Medicine, 24:549-563, Dec 2019. URL: https://doi.org/10.1177/1358863x19873410, doi:10.1177/1358863x19873410. This article has 81 citations and is from a peer-reviewed journal.
(skeik2019segmentalarterialmediolysis pages 5-7): Nedaa Skeik, Sydney L Olson, Gopika Hari, and Mary L Pavia. Segmental arterial mediolysis (sam): systematic review and analysis of 143 cases. Vascular Medicine, 24:549-563, Dec 2019. URL: https://doi.org/10.1177/1358863x19873410, doi:10.1177/1358863x19873410. This article has 81 citations and is from a peer-reviewed journal.
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(togawa2023intraabdominalbleedingdue pages 3-4): Yuki Togawa, Susumu Matsushime, Nobuichiro Tamura, and Kazuyuki Kawamoto. Intra-abdominal bleeding due to segmental arterial mediolysis and coexisting pulmonary thromboembolism: a case report. Indian Journal of Surgery, 85:623-626, Jun 2023. URL: https://doi.org/10.1007/s12262-022-03465-6, doi:10.1007/s12262-022-03465-6. This article has 0 citations and is from a peer-reviewed journal.
(peng2019naturalhistoryand pages 2-3): Kate X. Peng, Victor J. Davila, William M. Stone, Fadi E. Shamoun, Sailendra G. Naidu, Robert D. McBane, and Samuel R. Money. Natural history and management outcomes of segmental arterial mediolysis. Journal of Vascular Surgery, 67:e14, Dec 2019. URL: https://doi.org/10.1016/j.jvs.2019.02.068, doi:10.1016/j.jvs.2019.02.068. This article has 36 citations and is from a domain leading peer-reviewed journal.
(skeik2019segmentalarterialmediolysis pages 7-8): Nedaa Skeik, Sydney L Olson, Gopika Hari, and Mary L Pavia. Segmental arterial mediolysis (sam): systematic review and analysis of 143 cases. Vascular Medicine, 24:549-563, Dec 2019. URL: https://doi.org/10.1177/1358863x19873410, doi:10.1177/1358863x19873410. This article has 81 citations and is from a peer-reviewed journal.
(naidu2018segmentalarterialmediolysis pages 1-2): Sailen G. Naidu, Christine O. Menias, Rahmi Oklu, Robert S. Hines, Kinan Alhalabi, Gerges Makar, Fadi E. Shamoun, Stanislav Henkin, and Robert D. McBane. Segmental arterial mediolysis: abdominal imaging of and disease course in 111 patients. American Journal of Roentgenology, 210:899-905, Apr 2018. URL: https://doi.org/10.2214/ajr.17.18309, doi:10.2214/ajr.17.18309. This article has 62 citations and is from a peer-reviewed journal.
(peng2019naturalhistoryand pages 6-7): Kate X. Peng, Victor J. Davila, William M. Stone, Fadi E. Shamoun, Sailendra G. Naidu, Robert D. McBane, and Samuel R. Money. Natural history and management outcomes of segmental arterial mediolysis. Journal of Vascular Surgery, 67:e14, Dec 2019. URL: https://doi.org/10.1016/j.jvs.2019.02.068, doi:10.1016/j.jvs.2019.02.068. This article has 36 citations and is from a domain leading peer-reviewed journal.
(naidu2018segmentalarterialmediolysis pages 4-5): Sailen G. Naidu, Christine O. Menias, Rahmi Oklu, Robert S. Hines, Kinan Alhalabi, Gerges Makar, Fadi E. Shamoun, Stanislav Henkin, and Robert D. McBane. Segmental arterial mediolysis: abdominal imaging of and disease course in 111 patients. American Journal of Roentgenology, 210:899-905, Apr 2018. URL: https://doi.org/10.2214/ajr.17.18309, doi:10.2214/ajr.17.18309. This article has 62 citations and is from a peer-reviewed journal.
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(najmaoui2023segmentalarterialmediolysis pages 5-6): Marine Najmaoui, Martina Pezzulo, Denis Franchimont, Frédéric Vandergheynst, and Maxime Ilzkovitz. Segmental arterial mediolysis and its mimickers: a case report and review of the literature. European Journal of Case Reports in Internal Medicine, Oct 2023. URL: https://doi.org/10.12890/2023_004085, doi:10.12890/2023_004085. This article has 3 citations.