BACKGROUND:Acute limb ischemia (ALI) is a surgical emergency associated with substantial morbidity and mortality. Although management has traditionally emphasized a 6-hr revascularization threshold, emerging evidence suggests that earlier intervention may be critical to limb salvage. The extent to which these data have been incorporated into clinical practice remains unclear. We therefore evaluated contemporary treatment patterns and perioperative outcomes among patients with ALI. METHODS:Patients with ALI who underwent surgical thrombectomy between March 2018 and April 2025 were identified from a large statewide collaborative. Time from symptom onset to surgical incision and hospital arrival to incision were assessed. The primary outcomes were major amputation at 30 days and 1 year. Multivariable logistic regression was performed to assess the association between patient characteristics, time to surgery, and postthrombectomy outcomes. RESULTS:A total of 1,015 patients underwent open thrombectomy for ALI. Major amputation occurred in 7% of patients within 30 days and in 15.2% within 1 year. Mortality was 2.1% at 30 days and increased to 14% at 1 year. The mean time from hospital presentation to incision was 7.8 ± 5.9 hr, with 78% of patients undergoing revascularization >3 hr after arrival. Surgical incision occurring >6 hr after arrival was significantly associated with an increased risk of 30-day and 1-year major amputation. CONCLUSION:ALI requiring surgical thrombectomy continues to result in high morbidity and mortality. Delays from hospital arrival to surgical incision are common and associated with increased amputation risk, identifying door-to-incision time as an important target for system-led interventions to improve ALI outcomes.

Background: Pediatric renovascular hypertension (PRVH), a rare disorder (1 in 1.9 million annually), is marked by renal artery narrowing and abdominal aortic coarctation, leading to renin-mediated hypertension. Its genetic basis is only partially explained by genetic syndromes, including Williams Syndrome (WS), which features supravalvular aortic stenosis (SVAS) and other vascular abnormalities. The ELN gene on chromosome 7q11.23 encodes elastin, an essential vascular connective tissue protein. ELN deletions are known to be linked to aortic stiffness and narrowing. Whether ELN gene variation is specifically associated with PRVH and whether copy number variation (CNV) or partial deletions of ELN underlie PRVH in individuals without a genetic syndrome is unknown. Methods: Genotype intensities were analyzed using Illumina BeadArray v1.1, comprising 607,780 SNP probes with a median inter-SNP spacing of approximately 3 kb. The study compared 111 University of Michigan PRVH cases to 1,853 controls from the Michigan Genomic Initiative (1:19 ratio), matched by age, sex, and ancestry by principal components. CNVs were inferred using log R ratio (LRR) and B allele frequency (BAF) with a hidden Markov model. CNVRs were defined as CNV regions with at least 25 consecutive SNPs, merged within 50 Kb gaps, and analyzed for case-control associations using Fisher’s exact test. Results: 627 unique CNVRs were identified, with the strongest PRVH-associated risk signal being a deletion (CN=1) at chr7q11.23 (72722981-74126034, GRCh37/hg19), in 5 PRVH cases and absent in all controls (P=5.29×10 -7 ). Genotype-phenotype analysis confirmed that all 5 individuals carried a clinical diagnosis of WS, and all individuals carrying a diagnosis of WS had 7q11.23 copy loss. ELN was deleted across all exons in all cases, with no evidence of smaller deletions. As genotype-phenotype correlations have been identified for non-cardiovascular manifestations of WS, we noted that in addition to ELN , the additional genes deleted in all five cases were B AZ1B, BCL7B, TBL2, MLXIPL, LIMK1, EIF4H, LAT2, RFC2, CLIP2 , and GTF2IRD1 . Vascular phenotypes showed abdominal aortic narrowing in 4 cases and isolated renal artery stenosis in one child, the latter a previously unappreciated WS vascular lesion. Conclusions: Despite PRVH’s rarity, this study reports a statistically significant association between aortorenal dysplasia causing PRVH and a strongly deleterious genetic lesion of WS involving ELN deletions.

BACKGROUND:The Joint Trauma System (JTS)'s resuscitative endovascular balloon occlusion of the aorta (REBOA) positioning guidance is derived from a predominantly male patient population. We aimed to validate these measurements in women. METHODS:Aortic computed tomography scans of 404 women from a trauma patient data set were analyzed. The aorta was divided into anatomic zones based on REBOA literature, with zone 3 subdivided at the inferior mesenteric artery for pelvic surgery. Balloon placement analysis identified the frequency of out-of-zone placement errors for recommended insertion depths (46 cm for zone 1, 28 cm for zone 3) and determined optimal insertion depths to minimize these errors in women. RESULTS:A 46-cm insertion depth reliably positioned the balloon in zone 1 99.3% of the time, while a 28-cm depth placed the balloon entirely in zone 3 65% of the time (64.3% left, 66.6% right). There were notable malpositioning rates, with balloons extending above the lowest renal artery (20.4%) or below the aortic bifurcation (13.6%). Balloon malposition was most frequent at extreme heights and weights. Adjusting balloon insertion depth to 48 cm improved zone 1 positioning (100%), while adjusting zone 3 positioning to account for differences in weight significantly reduced malpositioning errors. Zone 3b was commonly shorter than the 4-cm balloon, resulting in high rates of the balloon extending above or below the target zone. CONCLUSION:Fixed-length REBOA balloon placement can be performed in women with a low rate of malpositioning in zones 1 and 3. Adjusting for weight can further reduce the frequency of malpositioning when targeting zone 3. Restricting the target zone to below the inferior mesenteric artery may benefit from adjusting for weight or using image guidance. LEVEL OF EVIDENCE:Diagnostic Test or Criteria; Level III.

Background Pediatric renovascular hypertension (pRVH) may lead to significant morbidity and mortality. Rare disease prevalence limits existing data and optimal management remains ill-defined. This study seeks to capture patient and family perceptions around the diagnosis and management of pRVH. Methods The pRVH Patient Centered Outcomes Research Collaborative assembled a global virtual research network of multidisciplinary stakeholders, inclusive of patients and families. We examined self or proxy-reported emotional support, informational support, emotional impact, and number of surgeries/procedures, as well as self-reported pain, global health, fatigue, and social functioning. Descriptive statistics were performed. Results 28 stakeholders (93% parent/guardian; 7% patient self-report) completed the survey. Patients with a surgical or procedural history reported significantly fewer nighttime awakenings due to pain (mean 44 v. 51.5) and less fatigue (48.2 v. 58) than those without. Patients diagnosed before 2 years of age reported better informational (60.9 v. 53.0) and emotional support (57.6 v. 51.5), and better social functioning (64.8 v. 53.0). Respondents unsatisfied with the time to receive a diagnosis indicated more pain (53.3 v. 45.1), fatigue (58.5 v. 50.5), worse global health (37.1 v. 46.6), and worse social functioning (50.8 v. 62.6) than satisfied patients. PCP-diagnosis was associated with worse emotional support (43.2 v. 56.4), informational support (46.9 v. 58.4), and emotional impact (46.6 v. 56.6) than those diagnosed by a specialist. Conclusion These results suggest that early diagnosis, access to centers of excellence, and treatment by multidisciplinary and specialty care teams can optimize pRVH treatment.

Background:While the risk of abdominal aortic aneurysm (AAA) rupture typically rises with increasing maximum aortic diameter (Dmax), this metric alone does not reflect the full morphological complexity of AAAs and is inadequate for accurately predicting rupture risk. In this study, we aimed to explore differences in growth and shape between asymptomatic AAA (aAAA) and symptomatic AAA (sAAA). Methods:Patients with infra-renal AAA and ≥2 CTA from 2010-2023 were identified. PRAEVAorta (Nurea, Bordeaux, France) was used to obtain segmentations of the aorta and its branches. Each segmentation was manually reviewed for accuracy using 3D Slicer. Patient demographics, Dmax, AAA flow lumen (AFL), and intraluminal thrombus (ILT) volume were obtained and compared between aAAA and sAAA. A subgroup of aAAA were matched with sAAA on sex and baseline Dmax (12 matched pairs) for comparison of shape, curvature, and 3D-growth. Statistical shape modeling (SSM) derived mean shapes for aAAA and sAAA were compared. Shape [quantified using distance to centerline (DC) in cm], curvature, and 3D-growth (defined as the difference in shape over time) were compared over eight aortic segments. Results:Fifty-five patients with AAA (12 sAAA) were included (47.3% female). Patients with sAAA were younger than those with aAAA [66.0 (60.9, 70.1) vs. 71.0 (65.3, 74.9) years, P=0.026], less likely to be Caucasian (75.0% vs. 95.3%, P=0.030), and less likely to have hypertension (50.0% vs. 81.4%, P=0.027). There was no difference in AAA Dmax (4.6 vs. 4.8 cm), volume (103.5 vs. 98.7 mm3), AFL (65.4 vs. 52.8 mm3), or ILT volume (37.9 vs. 36.7 mm3) between aAAA and sAAA. Although there was no difference in change of Dmax over time, sAAA had larger increases in AAA volume [1.6 (1.1, 7.8) vs. 1.1 (0.4, 2.1) cm3/month, P=0.019] and AFL volume [1.1 (0.5, 5.7) vs. 0.4 (0.2, 1.2) cm3/month, P=0.017] than aAAA. Despite possible qualitative shape differences seen on SSM, quantifiable differences in shape or curvature between aAAA and sAAA were not identified across eight aortic segments. At the left lateral aneurysm neck, sAAA had higher 3D-growth than aAAA [0.17 (0.05, 0.55) vs. 0.01 (-0.03, 0.14) mm/month, P=0.027]. Conclusions:sAAA had larger increase in AAA volume and AFL volume over time when compared to aAAA (despite no difference in diameter, volume, or change in diameter). Despite no quantifiable differences in shape or curvature between aAAA and sAAA, sAAA had larger 3D-growth in the left lateral aneurysm neck compared to aAAA. Volumetric changes, shape, and 3D-growth may be better predictors of AAA rupture risk. However, larger scale studies are warranted to confirm these preliminary findings and explore the mechanisms underlying these differences.

Braet, Drew J. MD; Schechtman, David W. MD; Beaulieu, Robert J. MD; Coleman, Dawn M. MD; Corriere, Matthew A. MD; Osborne, Nicholas H. MD; Eliason, Jonathan L. MD Author Information

Since the first endovascular aneurysm repair of abdominal aortic aneurysms in the 1980s, there has not only been exponential growth of procedures performed per year, but also rapid proliferation of stent grafts. With the resultant growth in revision and explant procedures on these grafts, we developed this guide to aid trainees in surgery and radiology in identifying these grafts. Our goal with this spotter's guide is to allow the identification of key features from commonly implanted devices radiographically, such as points of fixation, radiopaque markers, and stent patterns. The operative approach for the treatment of endograft complications, including endoleak embolization, aortic cuff extension, laser fenestration, limb extension, and endograft explant is often dramatically impacted by the type of endograft and its individual device characteristics. The intent of this guide is to aid practitioners in identifying endovascular aneurysm repair endografts of all ages, even those that have not been implanted in years. (JVS-Vascular Insights 2024;2:100145.)

Introduction: Although Abdominal Aortic Aneurysms (AAA) are more common in men, women are at greater risk for AAA growth and rupture. Vascular deformation mapping (VDM) is a novel technique that utilizes deformable image registration to qualify and quantify three-dimensions (3D) AAA growth using routing clinical computed tomography angiogram (CTA) images. Hypothesis: We hypothesize that females will have higher rates of focal AAA growth when compared to males. Aims: In this study we aimed to leverage VDM to investigate sex differences in AAA growth. Methods: We identified patients with infra-renal AAA and ≥2 CTA from 2010-2021. Patients with non-contrast CT scans or poor image quality were excluded. Propensity score matching was used to identify a cohort of males and females matched on age, hypertension, and smoking history. AAA were segmented and VDM was conducted using a multi-step image registration of aortic CTA studies to generate a deformation field which is then used to quantify 3D AAA growth rate (GR). Patient characteristics, maximum diameter (Dmax), AAA volume (Vmax), and GR were obtained. Statistical shape modeling was utilized to compare average 3D growth patterns between males and females. Results: Seventeen male and females with AAA were matched. There was no differences between sexes in race, diabetes, symptomatic status, or repair. Males had a trend toward larger Dmax (4.9 ± 0.6 vs 4.5 ± 0.6 cm, p = 0.055) and had Vmax at baseline (118.7 ± 69.9 vs 76.6 ± 35.0 cm 3 , p = 0.034). There was no difference between sexes when looking at change in Dmax or Vmax. Male and female AAA had no difference in average GR (0.11 ± 0.08 vs 0.17 ± 0.22 cm/year, p = 0.293). Shape models demonstrated more diffuse AAA growth for males and more eccentric AAA growth for females (Figure 1). Conclusions: Despite comparable changes in Dmax, Vmax, and GR, women demonstrated a more eccentric distribution of AAA growth, a finding which may contribute to higher rupture risk in women.

Hypertensive disorders of pregnancy (HDoP) negatively impact maternal health and pregnancy outcomes. Renal angioplasty for stenosis due to fibromuscular dysplasia (FMD) has been reported to improve hypertension associated with HDoP, but guidelines do not include renal artery duplex ultrasound (RA-DUS) screening. We report initial results from a single-center cohort of patients with HDoP and positive duplex results managed with selective renal artery angioplasty for failure of medical management and RA-DUS screening rates among women with HDoP during a 2-year period. RA-DUS screening was selectively ordered by maternal-fetal medicine specialists among women with HDoP. Women with renal artery stenosis were evaluated by vascular surgery and offered renal angiography/possible angioplasty if they had severe hypertension despite oral pharmacotherapy. Renal artery interventions on pregnant patients were performed during second trimester. Analysis included descriptive statistics and categorical tests. A total of 130 women with HDoP were screened with RA-DUS over a 2-year period; 35 (26.9%) were diagnosed with renal artery stenosis, and eight (6.1%) were referred for vascular consultation. Five patients underwent angiography (3 transradial, 2 transfemoral). Renal artery stenosis was confirmed on four of five angiograms; two studies with equivocal catheter angiography findings had positive pressure gradients. Pregnancy loss occurred in two patients despite improved hypertension control. Renal artery stenosis may be under-diagnosed among women with HDoP, and RA-DUS screening with selective angioplasty has potential to improve maternal and pregnancy outcomes in this population.

OBJECTIVE:Visceral branch artery dissection (VBAD) is uncommon and may occur with or without an associated aortic dissection (AD). We hypothesized that isolated VBAD would have a more benign clinical course than those with concurrent AD and compared survival outcomes stratified based on aortic involvement. METHODS:VBAD over a 5-year period were identified using International Classification of Diseases codes. Data related to patient demographics, comorbid conditions, clinical presentation, management (including procedural interventions), and survival were obtained from medical records. Anatomic imaging studies were reviewed to characterize anatomy, including the presence or absence of concurrent AD. Overall survival and intervention-free survival were evaluated using Kaplan-Meier and Cox proportional hazards models. RESULTS:A total of 299 VBAD were identified, 174 of which were isolated VBAD and 125 were associated with concurrent AD. Seventy-one percent of patients were men, 77% were White, and 85% were non-Hispanic. The mean age was 61.1 ± 14.4 years. The mean follow-up was 53.2 ± 50.0 months. The estimated overall survival was 88.2% and the estimated overall intervention-free survival was 55.6% at 12 months. Isolated VBAD had better overall survival than those with concurrent AD (69.2% vs 32.4%; P < .001). Concurrent AD was also associated with inferior intervention-free survival (57.5% vs 7.3%; P < .001). Acute presentation was associated with decreased intervention-free survival (86.1% vs 13.4%; P < .001). Acute presentation was also associated with decreased overall survival in patients with isolated VBAD (60.8% vs 80.0% at 180 months; P < .001) and inferior intervention-free survival (48.4% vs 69.5% at 180 months; P < .001) in the subgroup of patients with isolated VBAD. Multivariable Cox models identified that age (hazard ratio [HR]: 1.05, standard deviation [SD]: 0.02; P = .001) was associated with inferior survival and renal dissections (HR: 3.08, SD: 0.99; P = .001) or mesenteric and renal dissections (HR: 3.39, SD: 1.44; P = .004) were associated with inferior intervention-free survival. CONCLUSIONS:Isolated VBAD has superior overall and intervention-free survival to those associated with concurrent AD. The absence vs presence of aortic involvement is useful for risk stratification and may support tailored approaches to the frequency of imaging surveillance.

Median arcuate ligament syndrome (MALS) is known to promote arterial collateral circulation development from mesenteric vessel compression and can lead to the development of visceral aneurysms. These aneurysms are often diagnosed at the time of rupture and pose a significant morality risk without appropriate intervention. A celiacomesenteric trunk is a rare anatomic variant in which the celiac artery and superior mesenteric artery share a common origin and has been postulated as a risk factor for developing MALS. In this report, we present a novel case of MALS in a patient with a celiacomesenteric trunk and a superior mesenteric artery aneurysm.

Visceral arterial dissections, including mesenteric and renal artery dissections, are uncommon with limited evidence to guide their management. We evaluated patient characteristics associated with visceral dissections as well as anatomic and symptomatic factors associated with intervention and survival.

We performed a contemporary assessment of clinical and radiographic factors of stroke after thoracic endovascular aortic repair (TEVAR). Patients undergoing TEVAR from 2006 to 2017 were identified. We assessed clinical and radiographic data, including preoperative head and neck computed tomography, Doppler ultrasonography, and intraoperative angiography. Our primary outcome was stroke after TEVAR. Four hundred seventy-nine patients underwent TEVAR, mean age 68.1 ± 19.5 years, 52.6% male. Indications for TEVAR included aneurysms (n = 238, 49.7%) or dissections (n = 152, 31.7%). Ishimaru landing zones were Zone 2 (n = 225, 47.0%), Zone 3 (n = 151, 31.5%), or Zone 4 (n = 103, 21.5%). Stroke occurred in 3.8% (n = 18) of patients, with 1.9% (8) major events (modified Rankin Scale >3). Pathophysiology was predominantly embolic (n = 14), and occurred in posterior (n = 6), anterior (n = 6), or combined circulation (n = 4), and in the left hemisphere (n = 10) or bilateral (n = 6). Univariate analysis suggested use of lumbar drain (33.3% versus 57.2%, P = 0.04), inability to revascularize the left subclavian artery (16.7% vs 5.2%, P = 0.04) and number of implanted components (2.5 ± 1.2 vs 2.0 ± 0.97, P = 0.03) were associated with stroke. Multivariable analysis identified number of implanted components (OR 1.7, 95%CI 1.17-2.67 P = 0.00) and inability to revascularize the left subclavian artery as independent predictors of stroke. Stroke was associated with a higher perioperative mortality (27.8% vs 3.9%, P < 0.01). Stroke after TEVAR is primarily embolic in nature and related to both anatomic and procedural factors. This may have important implications for device development in the era of endovascular arch repair.

Abdominal aortic aneurysm (AAA) is a common disease with substantial heritability. In this study, we performed a genome-wide association meta-analysis from 14 discovery cohorts and uncovered 141 independent associations, including 97 previously unreported loci. A polygenic risk score derived from meta-analysis explained AAA risk beyond clinical risk factors. Genes at AAA risk loci indicate involvement of lipid metabolism, vascular development and remodeling, extracellular matrix dysregulation and inflammation as key mechanisms in AAA pathogenesis. These genes also indicate overlap between the development of AAA and other monogenic aortopathies, particularly via transforming growth factor β signaling. Motivated by the strong evidence for the role of lipid metabolism in AAA, we used Mendelian randomization to establish the central role of nonhigh-density lipoprotein cholesterol in AAA and identified the opportunity for repurposing of proprotein convertase, subtilisin/kexin-type 9 (PCSK9) inhibitors. This was supported by a study demonstrating that PCSK9 loss of function prevented the development of AAA in a preclinical mouse model.

BACKGROUND Gastroesophageal resuscitative occlusion of the aorta (GROA) has been shown effective in creating zone II aortic occlusion capable of temporarily improving survival in animal models of lethal noncompressible torso hemorrhage. In this study, tandem application of GROA transitioning to resuscitative endovascular balloon occlusion of the aorta (REBOA) is explored to demonstrate feasibility as a potential point-of-injury bridge to more advanced care, using a swine model of lethal abdominal hemorrhage. METHODS Swine (n = 19) were anesthetized, instrumented, and subjected to a combination of controlled and uncontrolled hemorrhage from a grade-V liver laceration. Animals were designated as intervention (n = 9; GROA to REBOA) or control (n = 10), for 60 minutes. Following intervention, devices were deactivated, and animals received blood and crystalloid resuscitation. Animals were monitored for 4 hours. RESULTS Injury resulted in onset of class IV shock in all animals with a mean arterial pressure (SD) of 24.5 (4.11) mm Hg at the start of intervention. Nine of 10 controls died during the intervention period with a median (interquartile) survival time of 8.5 (9.25) minutes. All animals receiving the intervention survived both the 60-minute intervention period demonstrating a significant survival improvement ( p = 0.0007). Transition from GROA to REBOA was successful in all animals with a transition time ranging from 30 to 90 seconds. Mean arterial pressure significantly improved in animals receiving GROA to REBOA for the duration of intervention, regardless of the method of aortic occlusion, with a range of 70.9 (16.04) mm Hg to 101.1 (15.3) mm Hg. Additional hemodynamics, metrics of shock, and oxygenation remained stable during intervention. CONCLUSION Less invasive technologies such as GROA may present an opportunity to control noncompressible torso hemorrhage more rapidly, with a subsequent transition to more advanced care such as REBOA.

Background: The risk of arterial diseases may be elevated among family members of individuals having multifocal fibromuscular dysplasia (FMD). We sought to investigate the risk of arterial diseases in families of individuals with FMD. Methods: Family histories for 73 probands with FMD were obtained, which included an analysis of 463 total first-degree relatives focusing on FMD and related arterial disorders. A polygenic risk score for FMD (PRS FMD ) was constructed from prior genome-wide association findings of 584 FMD cases and 7139 controls and evaluated for association with an abdominal aortic aneurysm (AAA) in a cohort of 9693 AAA cases and 294 049 controls. A previously published PRS AAA was also assessed among the FMD cases and controls. Results: Of all first degree relatives of probands, 9.3% were diagnosed with FMD, aneurysms, and dissections. Aneurysmal disease occurred in 60.5% of affected relatives and 5.6% of all relatives. Among 227 female first-degree relatives of probands, 4.8% (11) had FMD, representing a relative risk (RR) FMD of 1.5 ([95% CI, 0.75–2.8]; P =0.19) compared with the estimated population prevalence of 3.3%, though not of statistical significance. Of all fathers of FMD probands, 11% had AAAs resulting in a RR AAA of 2.3 ([95% CI, 1.12–4.6]; P =0.014) compared with population estimates. The PRS FMD was found to be associated with an AAA (odds ratio, 1.03 [95% CI, 1.01–1.05]; P =2.6×10 −3 ), and the PRS AAA was found to be associated with FMD (odds ratio, 1.53 [95% CI, 1.2–1.9]; P =9.0×10 −5 ) as well. Conclusions: FMD and AAAs seem to be sex-dimorphic manifestations of a heritable arterial disease with a partially shared complex genetic architecture. Excess risk of having an AAA according to a family history of FMD may justify screening in family members of individuals having FMD.

Background: Hybrid debranching repair of pararenal and thoracoabdominal aortic aneurysms was initially designed as a better alternative to standard open repair, addressing the limitations of endovascular repair involving the visceral aorta. We reviewed the collective outcomes of hybrid debranching repairs using extra-anatomic, open surgical debranching of the renal-mesenteric arteries, followed by endovascular aortic stenting. Methods: Data from patients who underwent hybrid repair in 14 North American institutions during 10 years were retrospectively reviewed. Society of Vascular Surgery scores were used to assess comorbidity risk. Early and late outcomes, including mortality, morbidity, reintervention, and patency were analyzed. Results: A total of 208 patients (118 male; mean age, 71±8 years old) were treated by hybrid repair with extraanatomic reconstruction of 657 renal and mesenteric arteries (mean 3.2 vessels/patient). Mean aneurysm diameter was 6.6±1.3 cm. Thoracoabdominal aortic aneurysms were identified in 163 (78%) patients and pararenal aneurysms in 45 (22%). A single-stage repair was performed in 92 (44%) patients. The iliac arteries were the most common source of inflow (n=132; 63%), and most (n=150; 72%) had 3 or more bypasses. There were 30 (14%) early deaths, ranging widely across sites (0%–21%). A Society of Vascular Surgery comorbidity score >15 was the primary predictor of early mortality ( P <0.01), whereas mortality was 3% in a score ≤9. Early complications occurred in 140 (73%) patients and included respiratory complications in 45 patients (22%) and spinal cord ischemia in 22 (11%), of whom 10 (45%) fully recovered. At 5 years, survival was 61±5%, primary graft patency was 90±2%, and secondary patency was 93±2%. The most significant predictor of late mortality was renal insufficiency ( P <0.0001). Conclusions: Mortality after hybrid repair and visceral debranching is highly variable by center, but strongly affected by preoperative comorbidities and the centers’ experience with the technique. With excellent graft patency at 5 years, the outcomes of hybrid repair done at centers of excellence and in carefully selected patients may be comparable (or better) than traditional open or even totally endovascular approaches. However, in patients already considered as high-risk for surgery, it may not offer better outcomes.

Objectives: Abdominal aortic coarctation and hypoplasia are uncommon diseases, recognized most often in pediatric-aged individuals. Comprehensive studies regarding the pathologic spectrum of these aortopathies are nonexistent. This investigation was undertaken to better define the histologic and morphologic character of abdominal aortic narrowings affecting children and assess its potential relevance to contemporary clinical practice. Methods: Aortic specimens obtained during open operations in children being treated for symptomatic, noninflammatory abdominal aortic narrowings at the University of Michigan were subjected to histologic study after hematoxylin and eosin, Movat, Verhoeff Van Gieson, and Masson's trichrome preparations. Microscopic findings were correlated with the anatomic aortic images. In addition, a detailed review was completed of all prior reports in the English literature that included images depicting the histologic character of noninflammatory abdominal aortic narrowings in children. Results: Among a series of 67 pediatric-aged individuals undergoing open surgical interventions for abdominal aortic narrowings, eight children ranging in age from 9 months to 18 years, had adequate aortic tissue available for study. The loci of the specimens paralleled the anatomic sites of segmental coarctations observed in the entire series, with involvement of the suprarenal abdominal aorta (n = 3), intrarenal aorta (n = 2), and infrarenal aorta (n = 1). Diffusely hypoplastic abdominal aortas (n = 2) included one case of a de facto aortic duplication, represented by a channel that paralleled the narrow native aorta and gave origin to celiac artery branches, as well as the superior mesenteric and renal arteries. Concentric or eccentric intimal fibroplasia was observed in every aorta, often with internal elastic fragmentation and duplication (n = 4). Media abnormalities included elastic tissue disorganization (n = 3) and focal medial fibrosis (n = 1). Organizing luminal thrombus occurred in two infants. Coexistent ostial stenoses of the celiac, superior mesenteric, or renal arteries were observed in all but the only child who had an infrarenal aortic coarctation. Neurofibromatosis type 1 affected one child whose histologic findings were indistinguishable from those of the other children. A review of prior published histologic images of abdominal aortic coarctation and hypoplasia affecting children from other centers revealed a total of 14 separate reports, each limited to single case photomicrographs, of which 11 exhibited intimal fibroplasia. Conclusions: Intimal fibroplasia is a common accompaniment of developmental abdominal aortic coarctation and hypoplasia. It is posited that intimal fibroplasia, which is likely progressive in instances of abnormal shear stresses in these diminutive vessels, may contribute to less salutary outcomes after endovascular and certain open reconstructions of pediatric abdominal aortic narrowings.