Cryopreserved arterial allografts vs autologous vein for arterial reconstruction in infected fields.

OBJECTIVE: Peripheral arterial infections are rare and difficult to treat when an in situ reconstruction is required. Autologous vein (AV) is the conduit of choice in many scenarios. However, cryopreserved arterial allografts (CAAs) are an alternative. We aimed to assess our experience with CAAs and AVs for reconstruction in primary and secondary peripheral arterial infections. METHODS: Data from patients with peripheral arterial infections undergoing reconstruction with CAA or AV from January 2002 through August 2022 were retrospectively analyzed. Patients with aortic- or iliac-based infections were excluded. RESULTS: A total of 42 patients (28 CAA, 14 AV) with a mean age of 65 and 69 years, respectively, were identified. Infections were secondary in 31 patients (74%) and primary in 11 (26%). Secondary infections included 10 femoral-femoral grafts, 10 femoropopliteal or femoral-distal grafts, five femoral patches, four carotid-subclavian grafts, one carotid-carotid graft, and one infected carotid patch. Primary infection locations included six femoral, three popliteal, and two subclavian arteries. In patients with lower extremity infections, associated groin infections were present in 19 (56%). Preoperative blood cultures were positive in 17 patients (41%). AVs included saphenous vein in eight and femoral vein in six. Intraoperative cultures were negative in nine patients (23%), polymicrobial in eight (21%), and monomicrobial in 22 (56%). Thirty-day mortality occurred in four patients (10%), two due to multisystem organ failure, one due to graft rupture causing acute blood loss and myocardial infarction, and one due to an unknown cause post-discharge. Median follow-up was 20 months and 46 months in the CAA and AV group, respectively. Graft-related reintervention was performed in six patients in the CAA group (21%) and one patient in the AV group (7%). Freedom from graft-related reintervention rates at 3 years were 82% and 92% in the CAA and AV group, respectively (P = .12). Survival rates at 1 and 3 years were 85% and 65% in the CAA group and 92% and 84% in the AV group (P = .13). Freedom from loss of primary patency was similar with 3-year rates of 77% and 83% in the CAA and AV group, respectively (P = .25). No patients in either group were diagnosed with reinfection. CONCLUSIONS: CAAs are an alternative conduit for peripheral arterial reconstructions when AV is not available. Although there was a trend towards higher graft-related reintervention rates in the CAA group, patency is similar and reinfection is rare.

Outcomes of lower extremity arterial bypass using the Human Acellular Vessel in patients with chronic limb-threatening ischemia.

OBJECTIVE: Patients with chronic limb-threatening ischemia (CLTI) and no great saphenous vein to use as a conduit for arterial bypass have a high risk for amputation despite advances in medical and endovascular therapies. This report presents findings from a U.S. Food and Drug Administration (FDA) supported study of the Human Acellular Vessel (HAV) (Humacyte Inc.) used as a conduit for arterial bypass in patients with CLTI and inadequate or absent autologous conduit. METHODS: The HAV is a 6-mm, 40-cm vessel created from human vascular smooth muscle cells seeded onto a polyglycolic acid scaffold pulsed in a bioreactor for 8 weeks as cells proliferate and the scaffold dissolves. The resultant vessel is decellularized, creating a nonimmunogenic conduit composed of collagen, elastin, and extracellular matrix. The FDA issued an Investigational New Drug for an intermediate-sized, single-center study of the HAV under the agency's Expanded Access Program in patients with advanced CLTI and inadequate or absent autologous conduit. Technical results and clinical outcomes were analyzed and reported. RESULTS: Between March 2021 and July 2023, 29 patients (20 males; mean age, 71 ± 11 years) underwent limb salvage operation using the HAV as a bypass conduit. Most patients had advanced CLTI (Rutherford class 5/6 in 72%; wound, ischemia, and foot infection stage 3/4 in 83%), and 97% had previously failed revascularization(s) of the extremity. Two HAVs were sewn together to attain the needed bypass length in 24 patients (83%). Bypasses were to tibial arteries in 23 patients (79%) and to the popliteal artery in 6 (21%). Technical success was 100%, and the 30-day mortality rate was 7% (2 patients). With 100% follow-up (median, 9.3 months), the limb salvage rate was 86% (25/29 patients). There were 16 reinterventions to restore secondary patency, of which 15 (94%) were successful. Primary and secondary patency of the HAV at 9 months were 59% and 71%, respectively. CONCLUSIONS: The HAV has demonstrated short- to intermediate-term safety and efficacy as an arterial bypass conduit in a complex cohort of patients with limb-threatening ischemia and no autologous options. This experience using the FDA's Expanded Access Program provides real-world data to inform regulatory deliberations and future trials of the HAV, including the study of the vessel as a first-line bypass conduit in less severe cases of chronic limb ischemia.

Natural history and long-term outcomes of medically managed Type B intramural hematoma.

OBJECTIVE: Type B intramural hematoma (IMH) is often managed medically, yet may progress to dissection, aneurysmal dilation, or rupture. The aim of this study was to report the natural history of medically managed Type B IMH, and factors associated with progression. METHODS: We reviewed patients with medically managed Type B IMH between January 1995 to December 2022 at a single center. Any patients with immediate surgical or endovascular intervention were excluded. Demographic profiles, comorbidities, imaging, and follow-up details were reviewed. Patients were divided into two groups: Group 1 had isolated IMH, and Group 2 had IMH along with aneurysm or dissection at the time of presentation. On follow-up, progression was defined as degeneration to aneurysm/dissection or increase in the thickness of IMH in Group 1. In Group 2, progression was an increase in the size of aneurysm or development of new dissection. RESULTS: Of 104 patients with Type B IMH during the study period, 92 were medically managed. The median age was 77 years, and 45 (48.9%) were females. Comorbidities included hypertension (83.7%), hypercholesterolemia (44.6%), and active smoking (47.8%). Mean Society for Vascular Surger comorbidity score was 6.3. Mean IMH thickness and aortic diameter at presentation were 8.9 mm and 38.3 mm, respectively. Median follow-up was 55 months. Overall survival at 1 year and 5 years was 85.8% and 61.9%, respectively. During follow-up, 19 patients (20.7%) required intervention, more common in Group 2 (Group 1, 8/66; 12.3% vs Group 2, 11/26; 42.3%; P = .001). This resulted in higher freedom from intervention in Group 1 at 1 year (93.5% vs 62.7%) and 5 years (87.5% vs 51.1%; P < .001). Indication for intervention was dissection (n = 4), aneurysm (n = 12), and progression of IMH (n = 3). In Group 1, progression was seen in 25 (37.9%), three (4.5%) remained stable, 29 (43.9%) had complete resolution of IMH, and nine patients were lost to follow-up. In Group 2, 11 patients (42.3%) had progression, seven (26.9%) remained stable, and eight were lost to follow-up. IMH thickness at presentation >7.2 mm is associated with both increased odds of progression (odds ratio, 3.3; 95% confidence interval, 1.2-11.1; P = .03) and intervention (odds ratio, 5.5; 95% confidence interval, 1.3-36.9; P = .03) during the follow-up. CONCLUSIONS: Although many patients with Type B IMH managed medically stabilize or regress, progression or need for intervention can occur in up to 40% of cases. This is associated with the presence of aneurysm, dissection, and IMH thickness. Long-term follow-up is mandatory as late interventions occur, particularly for higher risk patients.

Comparative outcomes of arterial bypass using the human acellular vessel and great saphenous vein in patients with chronic limb ischemia.

OBJECTIVE: The Human Acellular Vessel (HAV) is a novel, off-the-shelf biologic conduit being evaluated for arterial reconstructions. Regulatory studies in peripheral arterial disease (PAD) to date have consisted of single-arm cohorts with no comparator groups to contrast performance against established standards. This study aimed to compare outcomes of the HAV with autologous great saphenous vein (GSV) in patients with advanced PAD undergoing infrageniculate bypass. METHODS: Patients with advanced PAD and no autologous conduit who underwent bypass with the 6-mm diameter HAV (Group 1; n = 34) (March 2021-February 2024) were compared with a multicenter historical cohort who had bypass with single-segment GSV (group 2; n = 88) (January 2017-December 2022). The HAV was used under an Investigational New Drug protocol issued by the Food and Drug Administration (FDA) under the agency's Expanded Access Program. RESULTS: Demographics were comparable between groups (mean age 69 ± 10 years; 71% male). Group 1 had higher rates of tobacco use (37 pack-years vs 28 pack-years; P = .059), coronary artery disease (71% vs 43%; P = .007), and prior coronary artery bypass grafting (38% vs 14%; P = .003). Group 1 had more patients classified as wound, ischemia, and foot infection clinical stage 4 (56% vs 33%; P = .018) and with previous index leg revascularizations (97% vs 53%; P < .001). Both groups had a similar number of patients with chronic limb-threatening ischemia (Rutherford class 4-6) (88% vs 86%; P = .693) and Global Anatomic Staging System stage III (91% vs 96%; P = .346). Group 1 required a composite conduit (two HAV sewn together) in 85% of bypasses. The tibial vessels were the target in 79% of group 1 and 100% of group 2 (P < .001). Group 1 had a lower mean operative time (364 minutes vs 464 minutes; P < .001). At a median of 12 months, major amputation-free survival (73% vs 81%; P = .55) and overall survival (84% vs 88%; P = .20) were comparable. Group 1 had lower rates of primary patency (36% vs 50%; P = .044), primary-assisted patency (45% vs 72%; P = .002), and secondary patency (64% vs 72%; P = .003) compared with group 2. CONCLUSIONS: Implanted under Food and Drug Administration Expanded Access provisions, the HAV was more likely to be used in redo operations and cases with more advanced limb ischemia than GSV. Despite modest primary patency, the HAV demonstrated resilience in a complex cohort with no autologous conduit options, achieving good secondary patency and providing major amputation-free survival comparable with GSV at 12 months.

Implications and late outcomes of type II endoleaks after endovascular aneurysm repair.

OBJECTIVE: Type II endoleaks (T2ELs) are the most common cause of reintervention after endovascular aneurysm repair (EVAR). Although most resolve spontaneously, the long-term implications of T2ELs remain elusive. We aim to evaluate the impact of persistent and late T2ELs on clinical outcomes after EVAR. METHODS: This was a single-institution retrospective review of patients who underwent EVAR for degenerative infrarenal abdominal aortic aneurysm between January 2010 and June 2022 with no type I (T1EL) or III (T3EL) endoleak seen at EVAR completion. Patients were categorized based on T2EL status. Group 1 included patients with never detected or transient T2ELs (detected at EVAR completion but not after). Group 2 encompassed persistent T2ELs (seen at EVAR completion and again during follow-up) and late T2ELs (detected for the first time at any point during follow-up). Time-to-event analysis was conducted using a time-dependent approach to T2EL status. Primary outcomes included freedom from sac enlargement (SE), aneurysm-related reinterventions, and overall survival. RESULTS: A total of 803 patients met inclusion criteria. Group 1 included 418 patients (52%), of which 85% had no T2ELs and 15% had transient T2ELs. Group 2 had 385 patients; 23% had persistent T2ELs, and 77% developed a new T2EL. Patients in group 1 had a higher prevalence of smoking (88% vs 83%; P < .001), chronic obstructive pulmonary disease (33% vs 25%; P = .008), chronic kidney disease (13% vs 8%; P = .021), and a higher mean Society for Vascular Surgery score (7 vs 6 points; P = .049). No differences were found in aneurysm diameter or morphology. Mean follow-up was 5 years for the entire cohort. In Group 2, 58 patients (15%) underwent T2EL treatment, most commonly transarterial embolization. At 10 years after EVAR, Group 2 was associated with lower freedom from SE (P < .001) and abdominal aortic aneurysm-related reinterventions (P < .001) and comparable overall survival (P = .42). More T1ELs were detected during follow-up in Group 2 (6 [1%] vs 20 [5%]; P = .004), with 15 (75%) of these detected at a median of 3 years after the T2EL. No difference between groups was observed in explant (0.7% vs 2.1%; P = .130) or aneurysm rupture (0.5% vs 1.3%; P = .269) rates. CONCLUSIONS: One-half of patients treated with infrarenal EVAR developed persistent/late T2ELs, which are associated with a higher risk of SE and reinterventions. No difference in overall survival or aneurysm rupture risk was seen at 10 years, based on T2EL status or T2EL intervention. A conservative approach to T2ELs may be appropriate for most patients with absent T1ELs or T3ELs.

Clinical presentation, operative management, and long-term outcomes of rupture after previous abdominal aortic aneurysm repair.

OBJECTIVE: The aim of the present study was to evaluate the presentation trends, intervention, and survival of patients who had been treated for late abdominal aortic aneurysm rupture (LAR) after open repair (OR) or endovascular aortic aneurysm repair (EVAR). METHODS: We reviewed the clinical data from a single-center, retrospective database for patients treated for LAR from 2000 to 2020. The end points were the 30-day mortality, major postoperative complication, and survival. The outcomes between LAR managed with EVAR (group I) vs OR were compared (group II). RESULTS: Of 390 patients with infrarenal aortic rupture, 40 (10%) had experienced aortic rupture after prior aortic repair and comprised the LAR cohort (34 men; age 78 ± 8 years). LAR had occurred before EVAR in 30 and before OR in 10 patients. LAR was more common in the second half of the study with 32 patients after 2010. LAR after prior OR was secondary to ruptured para-anastomotic pseudoaneurysms. After initial EVAR, LAR had occurred despite reintervention in 17 patients (42%). The time to LAR was shorter after prior EVAR than after OR (6 ± 4 vs 12 ± 4 years, respectively; P = .003). Treatment for LAR was EVAR for 25 patients (63%; group I) and OR for 15 (37%, group II). LAR after initial OR was managed with endovascular salvage for 8 of 10 patients. Endovascular management was more frequent in the latter half of the study period. In group I, fenestrated repair had been used for seven patients (28%). Salvage for the remaining cases was feasible with EVAR, aortic cuffs, or limb extensions. The incidence of free rupture, time to treatment, 30-day mortality (8% vs 13%; P = .3), complications (32% vs 60%; P = .1), and disposition were similar between the two groups. Those in group I had had less blood loss (660 vs 3000 mL; P < .001) and less need for dialysis (0% vs 33%; P < .001) than those in group II. The median follow-up was 21 months (interquartile range, 6-45 months). The overall 1-, 3-, and 5-year survival was 76%, 52%, and 41%, respectively, and was similar between groups (28 vs 22 months; P = .48). Late mortality was not related to the aorta. CONCLUSIONS: LAR after abdominal aortic aneurysm repair has been encountered more frequently in clinical practice, likely driven by the frequency of EVAR. However, most LARs, including those after previous OR, can now be salvaged with endovascular techniques with lower morbidity and mortality.

Cryopreserved arterial allografts vs rifampin-soaked Dacron for the treatment of infected aortic and iliac grafts.

OBJECTIVE: Aortic and iliac graft infections remain complex clinical problems with high mortality and morbidity. Cryopreserved arterial allografts (CAAs) and rifampin-soaked Dacron (RSD) are options for in situ reconstruction. This study aimed to compare the safety and effectiveness of CAA vs RSD in this setting. METHODS: Data from patients with aortic and iliac graft infections undergoing in situ reconstruction with either CAA or RSD from January 2002 through August 2022 were retrospectively analyzed. Our primary outcomes were freedom from graft-related reintervention and freedom from reinfection. Secondary outcomes included comparing trends in the use of CAA and RSD at our institution, overall survival, perioperative mortality, and major morbidity. RESULTS: A total of 149 patients (80 RSD, 69 CAA) with a mean age of 68.9 and 69.1 years, respectively, were included. Endovascular stent grafts were infected in 60 patients (41 CAA group and 19 RSD group; P ≤ .01). Graft-enteric fistulas were more common in the RSD group (48.8% RSD vs 29.0% CAA; P ≤ .01). Management included complete resection of the infected graft (85.5% CAA vs 57.5% RSD; P ≤ .01) and aortic reconstructions were covered in omentum in 57 (87.7%) and 63 (84.0%) patients in the CAA and RSD group, respectively (P = .55). Thirty-day/in-hospital mortality was similar between the groups (7.5% RSD vs 7.2% CAA; P = 1.00). One early graft-related death occurred on postoperative day 4 due to CAA rupture and hemorrhagic shock. Median follow-up was 20.5 and 21.5 months in the CAA and RSD groups, respectively. Overall post-discharge survival at 5 years was similar, at 59.2% in the RSD group and 59.0% in the CAA group (P = .80). Freedom from graft-related reintervention at 1 and 5 years was 81.3% and 66.2% (CAA) vs 95.6% and 92.5% (RSD; P = .02). Indications for reintervention in the CAA group included stenosis (n = 5), pseudoaneurysm (n = 2), reinfection (n = 2), occlusion (n = 2), rupture (n = 1), and graft-limb kinking (n = 1). In the RSD group, indications included reinfection (n = 3), occlusion (n = 1), endoleak (n = 1), omental coverage (n = 1), and rupture (n = 1). Freedom from reinfection at 1 and 5 years was 98.3% and 94.9% (CAA) vs 92.5% and 87.2% (RSD; P = .11). Two (2.9%) and three patients (3.8%) in the CAA and RSD group, respectively, required graft explantation due to reinfection. CONCLUSIONS: Aorto-iliac graft infections can be managed safely with either CAA or RSD in selected patients for in situ reconstruction. However, reintervention was more common with CAA use. Freedom from reinfection rates in the RSD group was lower, but this was not statistically significant. Conduit choice is associated with long-term surveillance needs and reinterventions.

Midterm Clinical Outcomes of Retrograde Open Mesenteric Stenting for Mesenteric Ischemia.

BACKGROUND: Retrograde open mesenteric stenting (ROMS) has become a mainstay in treatment of mesenteric ischemia; however, follow-up in contemporary studies is limited. METHODS: A single-center retrospective review of patients undergoing ROMS from 2007 to 2020 was conducted. Demographics, presentation, and procedural details were reviewed. End points were morbidity and mortality, technical success, primary patency, reinterventions, and freedom from clinical recurrence. RESULTS: ROMS was performed in 34 patients, 19 female (56%). Mean age was 71 ± 10 years. Eighteen patients (53%) presented with acute mesenteric ischemia (AMI), 11 (32%) with acute-on-chronic, and 5 (15%) with chronic mesenteric ischemia. Etiology was chronic atherosclerosis with/without in-situ thrombosis in 28 patients (82%), superior mesenteric artery dissection in 3, and 1 each with embolic, vasculitic, and nonocclusive ischemia. Four patients (12%) had prior mesenteric procedures (3 Celiac/1 superior mesenteric artery stent) and 1 had unsuccessful transbrachial stenting attempt. Technical success, defined as successful stenting through a retrograde approach was attained in 31 patients (91%), with the 3 remaining patients treated with transbrachial stenting in 2 and iliomesenteric bypass in 1. Covered stents were used in 21 patients (64%) with or without stent extension with bare-metal stents. Eight patients (23%) required thromboembolectomy and 9 (26%) underwent patch angioplasty. Thirty-day mortality rate was 35%, all in patients with AMI (10) or acute-on-chronic (2). Eighteen patients (53%) underwent bowel resection, all presenting acutely. Early reinterventions within the first 30 days were required in 5 patients (15%), including 2 redo ROMS with thrombectomy and endarterectomy, 2 percutaneous stent extensions, and 1 aortic septum fenestration with coiling of a jejunal branch pseudoaneurysm. With a median follow-up of 3.7 (interquartile range: 0.8-5.0) years, in patients surviving discharge, 5 required reintervention yielding freedom from reintervention rates of 87% at 1 year and 71% at 3 years. All postdischarge reinterventions were endovascular with no conversion to bypass. The overall 1-year and 3-year primary patency rates were 70% and 61% (primary-assisted patency at 1 and 3 years was 87% and secondary patency at 1 and 3 years was 97%). The freedom from symptom recurrence was 95% at 1 and 3 years. CONCLUSIONS: ROMS carries high rates of technical success in patients with mesenteric ischemia, despite a high chronic atherosclerotic burden. Although mid-term patency rates are acceptable, AMI is still associated with high early morbidity and mortality, with high rates of associated bowel resection. ROMS is a valuable tool in the armamentarium of vascular surgeons.

Cryopreserved Arterial Allografts Versus Rifampin-Soaked Dacron for the Treatment of Infected Aortic and Iliac Aneurysms.

BACKGROUND: Infected aortic and iliac artery aneurysms are challenging to treat. Cryopreserved arterial allografts (CAAs) or rifampin-soaked Dacron (RSD) are standard options for in situ reconstruction. Our aim was to compare the safety and effectiveness of CAA versus RSD for these complex pathologies. METHODS: This is a retrospective review of infected iliac, abdominal, and thoracoabdominal aortic aneurysms treated with either CAAs or RSD between 2002 and 2022 at our institution. The diagnosis was confirmed by intraoperative, radiologic, or microbiological evidence of aortic infection. Perioperative events, 30-day and long-term mortality, reinfection, and reintervention were analyzed. RESULTS: Thirty patients (17 CAA, 13 RSD) with a mean age of 61 and 68 years, respectively, were identified. The infected aneurysm was most commonly suprarenal or infrarenal. Culture-negative infections were present in 47% of the CAA group and 54% in the RSD group. Early major morbidity was 57% and 54% for the CAA and RSD, respectively. Thirty-day mortality was similar between groups (18% vs. 23% CAA vs. RSD, P ≥ 0.99). Median follow-up was longer in the RSD group (14.5 months vs. 13 months). Overall survival at 1 and 5 years was 80.8% and 64.8% in the CAA group and 69.2% and 57.7% in the RSD group. Reinterventions only occurred with CAA repairs and indications included graft occlusion (2), multiple pseudoaneurysms and reinfection (1), and hemorrhagic shock caused by graft rupture (1). Freedom from reintervention at 1 and 3 years was 87.5% and 79.5% (CAA group) versus 100% and 100% (RSD, P = 0.06). Freedom from reinfection at 1 year was 100% in both groups, while at 3 years it was 90.9% for the CAA group and 100% for the RSD group (P = 0.39). CONCLUSIONS: Infected aortic and iliac aneurysms have high early morbidity and mortality. CAA and RSD had similar outcomes in our series; CAA trended toward higher reintervention rates. Both remain viable options for complex scenarios but require close surveillance.

Impact of Shunting Practice Patterns During Carotid Endarterectomy for Symptomatic Carotid Stenosis.

BACKGROUND: We aimed to assess the effect of surgeons' shunting practice and shunt use on the early outcomes of carotid endarterectomy (CEA) in recently symptomatic patients. METHODS: We conducted a retrospective observational study based on a multicenter national prospective database. The Vascular Quality Initiative database (2010-2019) was queried for CEAs performed within 14 days after an ipsilateral stroke or transient ischemic attack. Surgeons were gauged as routine shunters if they shunted in >95% of CEAs, otherwise were classified as selective shunters. In-hospital stroke and death rates were compared between routine and selective shunters, stratifying by type of index event (transient ischemic attack versus stroke) and timing of CEA (≤2 versus >2 days). RESULTS: Thirteen thousand four hundred sixty-nine CEAs were performed after a transient ischemic attack (43%) or stroke (57%), 3186 (24%) by routine shunters, and 10 283 (76%) by selective shunters. Comparing routine and selective shunters, in-hospital stroke (1.9% versus 2.4%; P=0.09) and death (0.4% versus 0.5%; P=0.73) rates were similar. A lower stroke rate (1.5% versus 4.2%; P=0.02) was achieved by routine shunters for CEA performed <2 days after an ischemic stroke. Among selective shunters, a higher stroke rate occurred in case of shunt use (2.9% versus 2.3%; P<0.01), mainly due to cases presenting with stroke (3.5% versus 2.4%; P<0.01) but not transient ischemic attack (1.8% versus 1.5%; P=0.57). Awake anesthesia was adopted in 7.8% of cases by selective shunters and in 0.8% by routine shunters, without impact on the perioperative stroke rate (1.8% versus 2.3%; P=0.349). CONCLUSIONS: In this large national cohort, the overall outcomes of CEA were similar between routine and selective shunters. A lower postoperative stroke rate was achieved by routine shunters in CEA performed <2 days after an ischemic stroke. Among selective shunters, intraoperatively indicated shunting determined an increased stroke rate, likely due to intraoperative hypoperfusion. These data may guide the decision regarding timing of CEA and shunting intention in symptomatic patients.

Aneurysms of the superior mesenteric artery and its branches.

OBJECTIVE: Aneurysms of the superior mesenteric artery (SMA) and its branches are rare and account for only 6% to 15% of all visceral artery aneurysms. In the present report, we have described our 30-year experience with the management of aneurysms of the SMA and its branches at a high-volume referral center. METHODS: A retrospective review of all patients with a diagnosis of an aneurysm of the SMA or one of its branches from 1988 to 2018 was performed. Pseudoaneurysms and mycotic aneurysms were excluded. The clinical presentation, etiology, aneurysm shape and size, treatment modalities, and outcomes were analyzed. The growth rate of the aneurysms was estimated using linear regression. RESULTS: A total of 131 patients with 144 aneurysms were reviewed. The patients were primarily men (64%), with a median age of 60 years. Of the 144 aneurysms, 57 were fusiform, 30 were saccular, and 57 were dissection-associated aneurysms. Of the 131 patients, 41 had had an isolated SMA branch aneurysm. Degenerative aneurysms were the most common etiology (66%). A total of 35 patients (27%) were symptomatic at presentation. Of the 144 aneurysms, 111 had multiple computed tomography angiograms available, with a median follow-up of 43.6 months (interquartile range, 10.6-87.2 months). Only 18 aneurysms (16%) had had an estimated growth rate of ≥1.0 mm/y. The initial aneurysm size was significantly associated with the growth rate for the fusiform aneurysms (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.0-1.3]; P = .02) but not for the saccular (OR, 0.91; 95% CI, 0.76-1.1; P = 1.1) or dissection-associated (OR, 1.2; 95% CI, 0.91-1.5; P = .20) aneurysms. Acute abdominal pain (OR, 5.9; 95% CI, 1.6-22; P = .01) and chronic abdominal pain (OR, 3.7; 95% CI, 1.1-13; P = .04) were associated with aneurysm growth. Only two patients had a ruptured aneurysm, both of whom presented with rupture with no prior imaging studies. These two patients had a diagnosis of fibromuscular dysplasia and systemic lupus erythematosus, respectively. Of the 131 patients, 46 (34%) had undergone operative repair, including 36 open revascularizations and 8 endovascular procedures. The average aneurysm size for these 46 patients was 24.0 ± 8.6 mm. One patient died perioperatively, and nine patients experienced perioperative complications (25%). Of the 144 aneurysms, 91 were <20 mm, with an average size of 13.4 ± 3.1 mm. These 91 aneurysms had been followed up for a median of 120.8 months (interquartile range, 30.5-232.2 months), with no ruptures within this cohort during the follow-up period. CONCLUSIONS: The present study represents one of the largest series on aneurysms of the SMA and its branches. Our results showed that aneurysms of the SMA are relatively stable. Patients with symptomatic and fusiform aneurysms had a greater risk of growth. Aneurysms <20 mm with a degenerative etiology can be safely monitored without treatment.

Thirty-year single-center experience with arterial thoracic outlet syndrome.

OBJECTIVE: Arterial thoracic outlet syndrome (ATOS) is rare. We present our 30-year experience with the management of ATOS at a high-volume referral center. METHODS: A retrospective review of all patients who had undergone primary operative treatment for ATOS from 1988 to 2018 was performed. ATOS was defined as subclavian artery pathology caused by extrinsic compression from a bony abnormality within the thoracic outlet. RESULTS: A total of 41 patients (45 limbs) underwent surgery for ATOS at a median age of 46 years (interquartile range [IQR], 34-58 years). Chronic symptoms (>6 weeks) were present in 31 limbs (69%). Of the 45 limbs, 13 (29%) presented with acute limb ischemia (ALI), requiring urgent brachial artery thromboembolectomy (BAT) in 9 and catheter-directed thrombolysis and thrombectomy (CDT) in 4. All patients underwent thoracic outlet decompression. 31 limbs (69%) required subclavian artery reconstruction. No perioperative deaths and only one major adverse limb event occurred. Patients with ALI underwent staged thoracic outlet decompression after initial BAT or CDT at a median of 23 days (IQR, 11-140 days). Of the 13 limbs with an initial presentation of ALI, 8 (62%) had recurrent thromboembolic events before thoracic outlet decompression subsequently requiring 10 additional BATs and 1 CDT. The cumulative probability of recurrent embolization at 14, 30, and 90 days was 8.33% (95% confidence interval [CI], 1.28%-54.42%), 16.67% (95% CI, 4.70%-59.06%), and 33.33% (95% CI, 14.98-74.20%), respectively. The median follow-up for 32 patients (35 limbs) was 13 months (IQR, 5-36 months). Subclavian artery/graft primary and secondary patency was 87% and 90%, respectively, at 5 years by Kaplan-Meier analysis. Of the 35 limbs, 5 (14%) had chronic upper extremity pain and 5 (14%) had persistent weakness. Preoperative forearm or hand pain and brachial artery occlusion were associated with chronic pain (P = .04 and P = .03) and weakness (P = .03 and P = .02). Of the 13 limbs that presented with ALI, 11 had a median follow-up after thoracic outlet decompression of 6 months (IQR, 5-14 months), including 9 (82%) with oral anticoagulation therapy. Anticoagulation therapy had no effect on subclavian artery patency (P = 1.0) or the presence of chronic symptoms (P = .93). CONCLUSIONS: The presentation of ATOS is diverse, and the diagnosis can be delayed. Preoperative upper extremity pain and brachial artery occlusion in the setting of ALI were associated with chronic pain and weakness after thoracic outlet decompression. Delayed thoracic outlet decompression was associated with an increased risk of recurrent thromboembolic events for patients who presented with ALI. An early and accurate diagnosis of ATOS is necessary to reduce morbidity and optimize outcomes.

Outcomes of balloon-expandable versus self-expandable stent graft for endovascular repair of iliac aneurysms using iliac branch endoprosthesis.

PURPOSE: The purpose of this study was to compare outcomes of internal iliac artery (IIA) stenting using balloon-expandable (BESG) or self-expandable stent grafts (SESG) during endovascular repair of aortoiliac aneurysms with iliac branch endoprosthesis (IBE; W. L. Gore, Flagstaff, Ariz). METHODS: We retrospectively reviewed all consecutive patients treated for aortoiliac aneurysms using IBE between 2014 and 2020. IIA stenting was performed using either the IIA side branch SESG or a Gore VBX BESG (W. L. Gore). Indications for use of BESGs were "up-and-over" IBE technique for type IB endoleak after prior endovascular aortic aneurysm repair (EVAR), short IIA length, and need for IIA extension into divisional branches (outside instructions for use). End points included technical success, freedom from buttock claudication, primary IIA patency, and freedom from IIA branch instability (eg, branch-related death or rupture, occlusion, disconnection, or reintervention for stenosis, kink, or endoleak), freedom from type IC/IIIC endoleak, and freedom from secondary interventions. RESULTS: There were 90 patients (86 males and 4 females) with a mean age of 74 ± 7 years treated by EVAR with 108 IBEs. Choice of stent was BESG in 43 and SESG in 65 targeted IIAs. BESGs were used more frequently in patients with prior EVAR (22% vs 2%; P = .003,), isolated IBEs (31% vs 2%; P < .001), and in patients with IIA aneurysms requiring stenting into divisional branches (36% vs 5%; P < .001). Technical success was similar for BESGs and SESGs (97% vs 100%; P = .40), respectively. The mean follow-up was 25 ± 16 months (range, 11-34 months). At 2 years, freedom from buttock claudication was 100% for BESG and 95 ± 3% for SESG (Log-rank 0.26), with no difference in primary patency (BESG, 100% vs SESG, 94 ± 4%; Log-rank 0.94). There were four (9%) IIA-related endoleaks in the BESG group and one (2%) in the SESG group (P = .08). Freedom from IIA branch instability was 87 ± 6% for BESG and 96 ± 3% for SESG at 2 years (Log-rank 0.043). Freedom from type IC/IIIC endoleak was 87 ± 7% for BESG and 98 ± 2% for SESG at the same interval (Log-rank 0.06). There was no difference in freedom from reinterventions for BESG and SESG (92 ± 6% vs 98 ± 2%; Log-rank 0.34), respectively. CONCLUSIONS: BESGs were used more frequently during IBE procedures indicated for failed EVAR, isolated common iliac aneurysms, and IIA aneurysms requiring extension into divisional branches. Despite these differences and BESG being used outside instructions for use, both stent types had similar primary patency, freedom from buttock claudication, and freedom from reinterventions. However, BESGs were associated with higher rates of IIA-related branch instability.

Surgical treatment patterns and clinical outcomes of patients treated for expanding aneurysm sacs with type II endoleaks after endovascular aneurysm repair.

OBJECTIVE: Persistent type II endoleaks (T2ELs) after endovascular aneurysm repair (EVAR) with sac growth have been associated with adverse events, including rupture. Whereas intervention in the presence of aneurysm growth has become an accepted treatment paradigm for T2ELs, the efficacy and clinical success of such interventions remain unclear. Therefore, we examined the treatment patterns and clinical outcomes of patients undergoing T2EL interventions after EVAR. METHODS: We performed a retrospective review of all patients treated for expanding aneurysm sacs with T2ELs after EVAR at an academic medical center between 2006 and 2017. The primary outcomes assessed were need for repeated intervention; intervention types; and achievement of clinical success, defined as stable aneurysm sac size on computed tomography angiography after treatment. RESULTS: Fifty-six patients underwent 119 interventions, of which 107 (90%) were technically successful. The median time from EVAR to index T2EL procedure was 37 months (interquartile range, 17-56 months), and the median follow-up time from first T2EL procedure was 27 months (interquartile range, 10-51 months). The most common index procedure was transarterial lumbar embolization (64%), followed by transarterial inferior mesenteric artery (20%), transcaval (14%), and translumbar embolization (1.8%). Thirty-three (59%) patients required further procedures for persistent aneurysm sac expansion. For subsequent T2EL interventions, the most common endovascular procedure was transarterial lumbar embolization (21%), followed by transcaval (21%), translumbar (11%), and transarterial inferior mesenteric artery embolization (8.6%). Twelve patients (21%) were found to have loss of proximal or distal seal on subsequent imaging and required graft extensions to stabilize aneurysm sac size. Ten patients (18%) ultimately underwent graft explantation or sacotomy with oversewing of the endoleak source. Freedom from any endoleak-related reintervention was 57% at 1 year and 36% at 3 years. Freedom from open treatment was 93% at 1 year and 82% at 3 years. Of the 44 patients with ≥6-month follow-up, 39 (89%) achieved clinical success. However, only 11 patients (25%) achieved clinical success without any further reintervention, and 29 patients (66%) achieved clinical success without open treatment. CONCLUSIONS: Despite high technical success, endoleak recurrence after T2EL treatment is common, and multiple interventions are often needed to stabilize aneurysm sac size in patients diagnosed with T2EL-associated sac growth. Notably, one in five patients treated for T2ELs was discovered, on further evaluation, to have proximal or distal seal zone loss that necessitated repair to achieve sac stability. Thus, thorough assessment of all endoleak types should be performed in patients with T2ELs associated with sac growth before T2EL treatment to ensure appropriate care and to minimize ineffective interventions.

Long-term fate of aortic branches in patients with aortic dissection.

OBJECTIVE: Late morbidity and mortality related to aortic branches in patients with aortic dissection (AD) have not been well described. We investigated the fate of aortic branches in a population cohort of patients with newly diagnosed AD. METHODS: We used the Rochester Epidemiology Project record linkage system to identify all Olmsted County, Minnesota, residents with a diagnosis of AD from 1995 to 2015. Only patients with >30 days of available follow-up imaging studies were included in the present analysis. The primary outcome was freedom from any branch-related event (any intervention, aneurysm, malperfusion, rupture, or death occurring after the acute phase >14 days). The secondary outcome was the diameter change in the aortic branches. Univariate and multivariable Cox proportional hazards models were used to identify the predictors of branch-related events. Univariate and multivariate linear regression models were used to assess the aortic branch growth rate. RESULTS: Of 77 total incident AD cases, 58 patients who had survived and had imaging follow-up studies available were included, 28 (48%) with type A and 30 (52%) with type B AD. The presentation was acute in 39 patients (67%), 6 (10%) of whom had had branch malperfusion. Of 177 aortic branches involved by the AD, 81 (46%) had arisen from the true lumen, 33 (19%) from the false lumen, and 63 (36%) from both. After the acute phase, freedom from any branch-related event at 15 years was 48% (95% confidence interval [CI], 32%-70%). A total of 31 branch-related events had occurred in 19 patients within 15 years, including 12 interventions (76% freedom; 95% CI, 63%-92%), 10 aneurysms (67% freedom; 95% CI, 50%-90%), 8 cases of malperfusion (76% freedom; 95% CI, 61%-94%), and 1 rupture (94% freedom; 95% CI, 84%-100%). No branch-related deaths had occurred. Type B AD (hazard ratio [HR], 3.5; 95% CI, 1.1-10.8; P = .033), patency of the aortic false lumen (HR, 6.8; 95% CI, 1.1-42.2; P = .038), and malperfusion syndrome at presentation (HR, 6.0; 95% CI, 1.3-28.6; P = .023) were predictors of late aortic branch-related events. The overall growth rate of aortic branches was 1.3 ± 3.0 mm annually. Patency of the aortic false lumen, initial branch diameter, and Marfan syndrome were significantly associated with diameter increase. CONCLUSIONS: In patients with AD, aortic branch involvement was responsible for significant long-term morbidity, without any related mortality. Type B AD, patency of the aortic false lumen, and malperfusion syndrome at presentation resulted in a greater risk of branch events during the long-term follow-up. Dilatation of the aortic branches was observed in one third of cases during follow-up, especially in the case of a patent aortic false lumen or the presence of Marfan syndrome.

Protamine use in transfemoral carotid artery stenting is not associated with an increased risk of thromboembolic events.

BACKGROUND: Protamine use in carotid endarterectomy has been shown to be associated with fewer perioperative bleeding complications without higher rates of thromboembolic events. However, the effect of protamine use on complications after transfemoral carotid artery stenting (CAS) is unclear, and concerns remain about thromboembolic events. METHODS: A retrospective review was performed for patients undergoing transfemoral CAS in the Vascular Quality Initiative from March 2005 to December 2018. We assessed in-hospital outcomes using propensity score-matched cohorts of patients who did and did not receive protamine. The primary outcome was in-hospital stroke or death. Secondary outcomes included bleeding complications, stroke, death, transient ischemic attack, myocardial infarction, and congestive heart failure exacerbation. Bleeding complications were categorized as bleeding resulting in intervention or blood transfusions. RESULTS: Of the 17,429 patients undergoing transfemoral CAS, 2697 (15%) patients received protamine. We created 2300 propensity score-matched pairs of patients who did and did not receive protamine. There were no statistically significant differences in stroke or death between the two cohorts (protamine, 2.5%; no protamine, 2.9%; relative risk [RR], 0.85; 95% confidence interval [CI], 0.60-1.21; P = .37). Protamine use was not associated with statistically significant differences in perioperative bleeding complications resulting in interventional treatment (0.9% vs 0.5%; RR, 2.10; 95% CI, 0.99-4.46; P = .05) or blood transfusion (1.2% vs 1.2%; RR, 0.92; 95% CI, 0.53-1.61; P = .78). There were also no statistically significant differences for the individual outcomes of stroke (1.8% vs 2.3%; RR, 0.78; 95% CI, 0.52-1.16; P = .22), death (0.9% vs 0.8%; RR, 1.17; 95% CI, 0.62-2.19; P = .63), transient ischemic attack (1.4% vs 1.3%; RR, 1.10; 95% CI, 0.67-1.82; P = .70), myocardial infarction (0.5% vs 0.4%; RR, 1.20; 95% CI, 0.52-2.78; P = .67), or heart failure exacerbation (1.0% vs 0.9%; RR, 1.05; 95% CI, 0.58-1.90; P = .88). Protamine use in patients presenting with symptomatic carotid stenosis was associated with lower risk of stroke or death (3.0% vs 4.3%; RR, 0.69; 95% CI, 0.47-0.998; P = .048), whereas there were no statistically significant differences in stroke or death with protamine use in asymptomatic patients (1.6% vs 1.0%; RR, 1.63; 95% CI, 0.67-3.92; P = .28). CONCLUSIONS: Heparin reversal with protamine after transfemoral CAS is not associated with an increased risk of thromboembolic events, and its use in symptomatic carotid disease is associated with a lower risk of stroke or death.

Patient and institutional factors associated with postoperative opioid prescribing after common vascular procedures.

OBJECTIVE: Overprescription of postoperative opioid medication is a major contributor to the opioid abuse epidemic in the United States. Research into prescribing practices has suggested that patients be limited to 7 days or <200 morphine milligram equivalents (MME) after surgical procedures. Our aim was to identify patient or institutional factors associated with increased opioid prescriptions. METHODS: Opioid naive patients from an integrated health system undergoing one of nine surgical and endovascular procedures tracked within the Vascular Quality Initiative from 2015 to 2017 were identified and matched to their discharge and refill opioid prescriptions. Discharge opioid prescriptions were converted to MME. The primary outcome was discharge MME >200, and secondary outcomes were procedure-specific top-quartile opioid prescription and medication refills. Multivariable logistic regression was used to assess patient and perioperative factors associated with each outcome. RESULTS: Among 1546 opioid naive patients, 739 (48%) received a discharge opioid prescription; median MME was 0 (interquartile range, 0-150), and 349 (23%) had >200 MME. Among those with a discharge prescription, median MME was 180 (interquartile range, 150-300). MME varied by procedure (P < .001), with highest MME after suprainguinal bypass (median, 225) and infrainguinal bypass (200) and lowest MME after carotid artery stenting, carotid endarterectomy, and percutaneous peripheral vascular intervention (all medians of 0). On multivariable analysis, factors associated with MME >200 included younger patient age (<65 vs ≥ 80 years; odds ratio [OR], 3.0; 95% confidence interval [CI], 1.9-4.6; P < .001), treating institution B vs A (OR, 3.50; 95% CI, 2.42-5.07; P < .001) and C vs A (OR, 3.90; 95% CI, 2.66-5.74; P < .001), procedure-specific top-quartile length of stay (OR, 1.45; 95% CI, 1.01-2.08; P = .047), and prior tobacco use (OR, 1.60; 95% CI, 1.07-2.37; P = .02). The same variables along with current tobacco use and lack of preoperative aspirin were associated with procedure-specific top-quartile MME at discharge. Chronic beta-blocker use was protective of top-quartile MME. Based on the observed variability, an institutional standard for opioid prescribing has been developed for standardization. CONCLUSIONS: Opioid prescriptions at discharge vary with the invasiveness of vascular surgical procedures. Less than 25% of patients receive >200 MME. Variation by center represents a lack of standardization in prescribing practices and an opportunity for further improvement based on developed guidelines. Patient factors and procedure type can alert clinicians to patients at risk of higher than recommended MME.

Outcomes of the Gore Excluder Iliac Branch Endoprosthesis Using Division Branches of the Internal Iliac Artery as Distal Landing Zones.

Purpose: To evaluate the outcomes of the Gore Excluder Iliac Branch Endoprosthesis (IBE) using division branches of the internal iliac artery (IIA) as distal landing zones. Materials and Methods: Between January 1, 2014, and December 31, 2018, 74 patients (mean age 74±7 years; 72 men) treated for aortoiliac or common iliac artery aneurysms had an IBE deployed with distal landing of the side branch within the main trunk (n=60) of the internal iliac artery (IIA) vs within a division branch (n=25). Thirteen (17%) patients received bilateral IBE implantations for a total of 85 vessels evaluated. Early endpoints were technical success, 30-day mortality, 30-day major adverse events (MAEs), and 30-day major access complications. Late endpoints were survival, primary and secondary IIA patency, freedom from IIA branch instability, freedom from new-onset buttock claudication, and aneurysm sac diameter changes. Time-dependent outcomes were reported as Kaplan-Meier curves with differences assessed using the log-rank test. Estimates are presented with the 95% confidence interval (CI). Results: The overall technical success rate was 97%, with 1 technical failure per group (p=0.43). Two patients, one from each group, died within 30 days (p=0.43). No significant differences were seen in the rates of 30-day MAEs (7% vs 17%, p=0.35) or major access complications (9% vs 11%, p>0.99) for patients receiving distal landing in the main trunk vs a division branch, respectively. The mean follow-up for the entire cohort was 19±12 months. The overall 1-year survival rate was 94% (95% CI 74% to 99%). The primary and secondary patency rates at 1 year were 98% (95% CI 88% to 99%) vs 95% (95% CI 72% to 99%, p=0.72) and 98% (95% CI 88% to 99%) vs 100% (p=0.41) for the main trunk vs division branch groups, respectively. Freedom from IIA branch instability estimates were also similar at 1-year follow-up [93% (95% CI 82% to 97%) vs 90% (95% CI 66% to 97%), p=0.29], as were the freedom from new-onset buttock claudication estimates [98% (95% CI 86% to 99%) and 94% (95% CI 67% to 99%), respectively; p=0.62]. Mean sac diameter change was 5.4±5.3 mm, not significantly different between the groups (p=0.85). Conclusion: Use of the posterior or anterior division of the IIA as a distal landing zone for the Gore Excluder IBE was safe and efficacious in the midterm. This technique may permit extending indications for endovascular repair of aortoiliac aneurysms to cases with unsuitable anatomy within the IIA main trunk. Long-term assessment is needed to affirm the efficacy of this technique.

Editor's Choice - Short Term and Long Term Outcomes After Endovascular or Open Repair for Ruptured Infrarenal Abdominal Aortic Aneurysms in the Vascular Quality Initiative.

OBJECTIVE: Repair of ruptured infrarenal abdominal aortic aneurysms (rAAA) has shifted from open surgical (OAR) to endovascular (EVAR) over the last decade. However, the long term impact of EVAR vs. OAR for rAAA has not been well described. METHODS: Prospectively collected registry data (Vascular Quality Initiative [VQI]) were analysed retrospectively to identify patients who underwent EVAR or OAR for rAAA (2004-2018). The primary outcome was death (in hospital and overall post-discharge). Inverse probability weighting (IPW) was used to adjust for treatment selection. Poisson regression assessed the number of one year post-discharge re-interventions. RESULTS: In total, 4257 patients receiving EVAR (n = 2389 [56%]) or OAR (n = 1868 [44%]) for rAAA were identified. Patients were predominantly male (n = 3310 [77.8%]) with a mean ± standard deviation age of 72.7 ± 9.6 years; most (n = 2449 [59.4%]) presented with haemodynamic instability. Use of EVAR for rAAA increased from 7.8% in 2004 to 67.2% in 2018. After IPW, OAR was associated with a higher odds of in hospital mortality (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.54-2.01; p < .001), which was confirmed after multivariable logistic regression (OR 2.08, 95% CI 1.76-2.45; p < .001). Multivariable Cox proportional hazards showed that OAR was also associated with increased overall post-discharge mortality among all patients (hazard ratio 1.36, 95% CI 1.23-1.51; p < .001). Within weighted treatment groups, five year survival was significantly different (55% for EVAR vs. 46% for OAR; p < .001). OAR showed a significantly higher risk of one year post-discharge re-interventions (incidence rate ratio 2.10, 95% CI 1.52-2.89; p < .001). CONCLUSION: Within the VQI, EVAR for rAAA repair has been increasingly adopted with favourable short term outcomes in terms of morbidity and mortality, as compared with OAR. Unlike elective AAA repair, survival rates between EVAR and OAR do not converge in long term follow up for patients who survived the index hospitalisation.

A Mycotic Common Iliac Artery Pseudoaneurysm of Indeterminate Etiology.

We present the unusual case of a mycotic right common iliac artery pseudoaneurysm caused by the methicillin-susceptible Staphylococcus aureus (MSSA) of indeterminate etiology in a healthy 57-year-old man with no risk factors for infection, trauma, or malignancy. The patient initially presented with worsening subacute right lower quadrant pain and was found to have a pseudoaneurysm of the right common iliac artery. Given concern for rupture on a computed tomography angiogram (CTA), he underwent exclusion of the pseudoaneurysm with a covered stent. At the time of presentation, he had no signs or symptoms of infection. However, the patient developed fever, chills, and worsening right lower quadrant pain 13 days after the index operation and was found to have a leukocytosis, blood cultures positive for MSSA, and progressive soft-tissue changes involving the right common iliac artery on CTA consistent with infection. He was definitively treated with stent explantation, aggressive debridement and replacement with an in situ cryopreserved bypass, and short-term suppressive antibiotic therapy.