Assessment of fitness for open repair in patients with infrarenal abdominal aortic aneurysms.

OBJECTIVE: Endovascular aortic repair (EVAR) was originally designed as a treatment modality for patients with abdominal aortic aneurysms (AAAs) deemed unfit for open repair. However, the definition of "unfit for open repair" is largely subjective and heterogenous. The purpose of this study was to compare patients deemed unfit for open repair who underwent EVAR to a matched cohort who underwent open repair for infrarenal AAAs. METHODS: The Vascular Quality Initiative of the Society for Vascular Surgery was queried for patients who underwent EVAR and open infrarenal AAA repair from 2003 to 2022. Patients that underwent EVAR were included if they were deemed unfit for open repair by the operating surgeon. EVAR patients deemed unfit because of a hostile abdomen were excluded. Patients in both the open and EVAR datasets were excluded if their repair was deemed non-elective or if they had prior aortic surgery. EVAR patients were matched to a cohort of open patients. The primary outcome for this study was 1-year mortality. Secondary outcomes included 30-day mortality, major adverse cardiac events, pulmonary complications, non-home discharge, reinterventions, and 5-year survival. RESULTS: A total of 5310 EVAR patients were identified who were deemed unfit for open repair. Of those, 3028 EVAR patients (57.0%) were able to be matched 1:1 to a cohort of open patients. Open patients had higher rates of major adverse cardiac events (20.2% vs 4.4%; P < .001), pulmonary complications (12.8% vs 1.6%; P < .001), non-home discharges (28.5% vs 7.9%; P < .001), and 30-day mortality (4.5% vs 1.4%; P < .001). There were no differences in early survival, but open repair had better middle and late survival compared with EVAR over the course of 5 years. A total of 74 EVAR patients (2.4%) had reinterventions during the study period. EVAR patients that required interventions had higher 1-year (40.5% vs 7.3%; P < .001) and 5-year mortality (43.2% vs 14.1%; P < .001) compared with those that did not require reinterventions. EVAR patients who had reinterventions had higher 1-year (40.5% vs 6.3%; P < .001) and 5-year (43.2% vs 20.3%; P = .006) mortality compared with their matched open cohort. CONCLUSIONS: Patients undergoing EVAR for AAAs who are deemed unfit for open repair have better perioperative morbidity and mortality compared with open repair. However, patients who had an open repair had better middle and late survival over the course of 5 years. The categorization of unfitness for open surgery may be inaccurate and re-evaluation of this terminology/concept should be undertaken.

Incidence and Outcomes of Visceral Ischemia in Acute Aortic Occlusion.

BACKGROUND: Acute aortic occlusion (AAO) is a morbid diagnosis in which mortality correlates with severity of ischemia on presentation. Visceral ischemia (VI) is challenging to diagnose and its presentation as a consequence of AAO is not well-studied. We aim to identify characteristics associated with VI in AAO to facilitate diagnosis. METHODS: Patients diagnosed with AAO who underwent revascularization were identified retrospectively from institutional records (2006-2020). The primary outcome was the development of VI (intra-abdominal ischemia). Univariate analysis was used to compare demographic, exam, imaging, and intraoperative variables between patients with and without VI in the setting of AAO. RESULTS: Ninety-one patients were included. The prevalence of VI was 20.9%. Preoperative comorbidities, time to revascularization, and operative approach did not differ between patients with and without VI. Patients with VI more frequently were transferred from outside institutions (100% vs. 53%, P = 0.02), presented with advanced acute limb ischemia (Rutherford III 36.9% vs. 7.5%, P < 0.01), and had elevated preoperative serum lactate (4.31 vs. 2.41 mmol/L, P < 0.01). VI patients had an increased occurrence of bilateral internal iliac artery (IIA) occlusion (47.4% vs. 18.1%, P = 0.01). Unilateral IIA occlusion, level of aortic occlusion, and patency of inferior mesenteric arteries were not associated with VI. Patients with VI had worse postoperative outcomes. In particular, VI conferred significant risk of mortality (odds ratio 5.45, P < 0.01). CONCLUSIONS: Visceral ischemia is a common consequence of AAO. Elevated lactate, bilateral IIA occlusion, and advanced acute limb ischemia (ALI) should increase clinical suspicion for concomitant VI with AAO and may facilitate earlier diagnosis to improve outcomes.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms.

BACKGROUND: Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAAs), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear. METHODS: A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency. RESULTS: From 1999 to 2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and 2 (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs. 66 years, P = 0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs. 23.2%, P < 0.001). Conduit type did not impact postoperative complication rates (P = NS each). MALE rates were low overall (19.2% at 2 years), and similar when stratified by conduit type (log rank P = 0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, P < 0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, P = 0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, P = 0.97) were not associated with MALE. CONCLUSIONS: Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

Preoperative Anemia Is Associated With Postoperative Renal Failure After Elective Open Aortic Repair.

INTRODUCTION: Preoperative anemia has been consistently shown to be a risk factor for acute kidney injury (AKI) after cardiac surgery. However, this association has not been examined in the open abdominal aortic aneurysm repair (OAR) population and is the subject of this analysis. METHODS: Targeted Vascular Module from the American College of Surgeons National Surgical Quality Improvement Program was queried for patients undergoing OAR from 2013 to 2019. Anemia was defined according to World Health Organization Guidelines: Hematocrit<36% for women or <39% for men. Primary endpoint was 30-day AKI. Anemia's effect on AKI was determined using inverse probability weighted logistic regression. RESULTS: There were 2275 OAR; mean age was 70.9 ± 8.2 y; 24.0% were women. Anemia was present in 498 (26.3%) patients; 165 (7.6%) had a hematocrit<33% and 8 (0.35%) had a hematocrit<24%. Differences in patient factor were nonsignificant after weighting. Any degree of postoperative AKI was more common in the anemia group (11.2% vs 5.1%; unweighted P < 0.001), as was AKI requiring hemodialysis (7.7% vs 3.2%; unweighted P < 0.001). In the weighted multivariable analysis, anemia was independently associated with postoperative AKI (odds ratio 1.51; 95% confidence interval: 1.01-2.26; P = 0.042) while controlling for age and operative factors. Patients with postoperative AKI were significantly more likely to die postoperatively than those without (26.1% vs 1.9%; <0.001). CONCLUSIONS: Preoperative anemia was independently associated with post-OAR AKI after propensity weighting and controlling for operative factors. AKI is a major source of morbidity and mortality in these patients, and, if time permits, preoperative correction of anemia or its underlying cause should be considered in high-risk patients.

Mortality differences by race over 20 years in individuals with peripheral artery disease.

INTRODUCTION: Racial disparities exist in patients with peripheral artery disease (PAD), with Black individuals having worse PAD-specific outcomes. However, mortality risk in this population has been mixed. As such, we sought to evaluate all-cause mortality by race among individuals with PAD. METHODS: We analyzed data from the National Health and Nutrition Examination Survey (NHANES). Baseline data were obtained from 1999 to 2004. Patients with PAD were grouped according to self-reported race. Multivariable Cox proportional hazards regression was performed to calculate adjusted hazard ratios (HR) by race. A separate analysis was performed to study the effect of burden of social determinants of health (SDoH) on all-cause mortality. RESULTS: Of 647 individuals identified, 130 were Black and 323 were White. Black individuals had more premature PAD (30% vs 20%, p < 0.001) and a higher burden of SDoH compared to White individuals. Crude mortality rates were higher in Black individuals in the 40-49-year and 50-69-year age groups compared to White individuals (6.7% vs 6.1% and 8.8% vs 7.8%, respectively). Multivariable analysis demonstrated that Black individuals with both PAD and coronary artery disease (CAD) had a 30% higher hazard of death over 20 years compared to White individuals (HR = 1.3, 95% CI: 1.0-2.1). The cumulative burden of SDoH marginally (10-20%) increased the risk of all-cause mortality. CONCLUSIONS: In a nationally representative sample, Black individuals with PAD and CAD had higher rates of mortality compared to their White counterparts. These findings add further proof to the ongoing racial disparities among Black individuals with PAD and highlight the necessity to identify ways to mitigate these differences.

Preoperative Anemia is Associated with Poorer Postoperative Outcomes in Patients Undergoing Infrainguinal Bypass Surgery.

BACKGROUND: Preoperative anemia is an important, modifiable risk factor among surgical patients. However, data are scarce on the impact of preoperative anemia on postoperative outcomes after infrainguinal bypass. METHODS: In this multi-institutional analysis, data were retrospectively collected on all infrainguinal bypass procedures performed between 2010 and 2020. Patients were grouped by preoperative hemoglobin as per the National Cancer Institute anemia scale (mild, 10 g/dL-lower limit of normal; moderate, 8.0-9.9 g/dL; severe, 6.5-7.9 g/dL). Multivariable comparisons were performed using logistic regression analysis. RESULTS: A total of 492 patients underwent bypass for peripheral artery disease over the 10-year study period. Median preoperative hemoglobin was 11.0 g/dL (interquartile range 9.5-12.7) and median follow-up was 1.7 years. Preoperative anemia was prevalent among bypass patients (mild 52.4% [n = 258], moderate 26.4% [n = 130], and severe 5.1% [n = 25]). Women were more likely to have moderate (49.2% [women] vs. 50.8% [men]) or severe anemia (52.0% [women] vs. 48.0% [men]) compared with normal hemoglobin (17.7% [women] vs. 82.3% [men]) (P < 0.001). Patients with preoperative anemia were more likely to present with tissue loss (22.8% [normal] vs. 47.7% [moderate] vs. 52.0% [severe], P = 0.01). Bypass target and conduit types were similar between groups. Anemic patients had longer median hospital length of stay compared with nonanemic patients (4 days [normal] vs. 5 days [mild] vs. 6 days [moderate] vs. 7 days [severe], P < 0.001). Postoperative mortality at 30 days was similar across anemia groups (2.5% [normal] vs. 4.6% [moderate] vs. 8.0% [severe], P = 0.23). On multivariable analysis, however, postoperative mortality was independently associated with severe anemia (odds ratio 7.5 [1.2-48.8], P = 0.04) and male gender (odds ratio 7.5 [1.2-26.4], P = 0.03). CONCLUSIONS: Preoperative anemia is common among patients undergoing infrainguinal bypass surgery and is an independent risk factor for postoperative mortality. Future investigation is needed to determine whether correction of anemia improves postoperative outcomes in these high-risk patients.

Morbidity and mortality associated with open repair of visceral aneurysms.

BACKGROUND: The Society for Vascular Surgery (SVS) recently published clinical practice guidelines on the management of visceral aneurysms. However, studies investigating the perioperative outcomes of open repair of visceral aneurysms have been limited to single-center experiences with variable results that span multiple decades. In the present study, we sought to detail the morbidity and mortality associated with open repair of visceral aneurysms using a national database in the contemporary era. METHODS: National Surgical Quality Improvement Program data from 2013 to 2019 were queried for patients who had undergone open repair of visceral aneurysms, which had been classified as mesenteric, renal, or splenic using Current Procedural Terminology and International Classification of Diseases codes. The primary endpoint was the composite of major complications (cardiovascular, pulmonary, progressive renal failure, deep wound infection, return to operating room, sepsis) and 30-day mortality. Logistic regression was used to identify the predictors of the primary endpoint for nonruptured aneurysm cases. RESULTS: Of the 304 aneurysms, 263 were nonruptured (137 mesenteric, 66 renal, 60 splenic) and 41 were ruptured (24 mesenteric, 1 renal, 16 splenic) and had undergone open repair. For those with nonruptured aneurysms, their mean age was 59.4 ± 14.7 years and 48.3% were women. For those with nonruptured aneurysms, the 30-day mortality was 1.9% and the major complication rate was 12.9%. A return to the operating room (5.3%) and prolonged ventilator support (3.8%) were especially common. As expected, rupture was associated with significantly greater mortality (22.0%; P < .001) and major complications (34.1%; P = .001). The use of postoperative transfusion was common in the elective group but was significantly greater in the ruptured group (24.3% vs 80.5%; P < .001). The predictors of the primary outcome for nonruptured aneurysms included male sex (odds ratio [OR], 2.93; 95% confidence interval [CI], 1.28-6.7; P = .011), anticoagulation (not discontinued before surgery) or bleeding disorder (OR, 4.52; 95% CI, 1.37-14.7; P = .012), and albumin <3.0 g/dL (OR, 4.66; 95% CI, 1.17-18.6; P = .029). Neither age nor aneurysm location were significant risk factors. CONCLUSIONS: Open repair of visceral aneurysms was associated with acceptable morbidity and mortality, although these risks are significantly greater once ruptured. Male sex, bleeding risk, and low albumin were all risk factors for adverse events and should be considered for operative planning and postoperative care.

Risk factors and consequences of graft infection after femoropopliteal bypass: A 25-year experience.

OBJECTIVE: In this multi-institutional series, we aimed to determine the incidence, risk factors, and long-term outcomes of graft infection in patients post-femoropopliteal bypass. METHODS: A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures from 1995 through 2020. Cumulative incidence function estimated the long-term rate of bypass graft infection (BGI), and the Fine-Gray model was used to determine independent risk factors for BGI to account for death as a competing risk. RESULTS: Over the 25-year period, 1315 femoral popliteal bypasses were identified with a median follow-up of 2.89 years (interquartile range, 0.75-6.55 years). BGI was diagnosed in 34 patients (2.6%). BGI occurred between 9 days and 11.2 years postoperatively, with a median of 109 days. Estimated 1- and 5-year incidence of BGI was 2.1% (95% confidence interval [CI], 1.4%-3.1%) and 2.8% (95% CI, 1.9%-3.9%), respectively. Medical comorbidities, indications for bypass, and popliteal bypass targets (above- vs below-knee) were similar between patients with BGI and all patients (P = not significant for each). Patients with BGI were more frequently complicated by postoperative hematoma (14.7% vs 3.7%), superficial wound infection (38.2% vs 19.2%), lymphocele/lymphorrhea (8.8% vs 2.1%), and 30-day readmission rates (47.1% vs 21.3%) (P < .05 for each). Most commonly isolated pathogens were Staphylococcus aureus (n = 19; 55.9%) and polymicrobial cultures (n = 5; 14.7%). Reoperation for BGI involved incision and drainage (n = 7; 20.6%), graft excision without reconstruction (n = 12; 35.3%), graft excision with in-line reconstruction (n = 11; 32.4%), and graft excision with extra-anatomic reconstruction (n = 2; 5.9%). Nine patients with BGI (26.5%) ultimately required major amputation. Prosthetic bypass (subdistribution hazard ratio [SHR], 3.73; 95% CI, 1.64-8.51; P = .002), postoperative hematoma (SHR, 3.44; 95% CI, 1.23-9.61; P = .018), and 30-day readmission (SHR, 2.75; 95% CI, 1.27-5.44; P = .010) were independently associated with BGI. One-year amputation-free survival was 50% (95% CI, 31.9%-65.7%) after BGI. CONCLUSIONS: BGI is a rare complication of femoral-popliteal bypass with significant morbidity. Graft infection is associated with the use of prosthetic grafts, postoperative hematoma, and unplanned hospital readmission. Mitigation of these risk factors may decrease the risk of this dreaded complication.

Impact of anticoagulation/antiplatelet therapy on femoropopliteal bypass graft outcomes.

BACKGROUND: Anticoagulant and antiplatelet (AC/AP) medications have been reported to improve bypass graft patency, however, the optimal AC/AP strategy remains unclear in the heterogenous peripheral artery disease population. METHODS: A multi-institutional retrospective review utilizing the Research Patient Data Registry database from 1995 to 2020 was performed for all patients who underwent femoropopliteal bypass procedures. Electronic medical records were used to obtain demographic information, comorbidities, smoking status, operative details (bypass target), postoperative AC/AP medications, postoperative complications, and long-term outcomes and were reviewed for the cohort. Cox proportional hazards model was used to determine independent risk factors for major adverse limb events (MALE) after bypass. MALE was defined as reintervention for patency or major amputation of index limb (above- or below-knee amputation). RESULTS: A total of 1421 patients underwent femoropopliteal bypass between 1995 and 2020 throughout five institutions included in this study. Complete data were available for 1292 of the 1421 patients (90.9%). The indications for bypass included intermittent claudication (21.4%), rest pain (30.3%), tissue loss (33.5%), and nonatherosclerotic disease (14.8%). Distal bypass targets comprised above-knee (38.6%) and below-knee (61.4%) popliteal arteries. Patients were divided into six groups based on postoperative AC/AP use including none (n = 57 [4.4%]), monoantiplatelet therapy (n = 587 [45.4%]), dual AP therapy (n = 214 [16.6%]), AC alone (n = 73 [5.7%]), AC + monoantiplatelet therapy (n = 319 [24.7%]), and AC + dual AP therapy (n = 42 [3.3%]). Postoperative bleeding complications were low for both hematoma (3.7%) and pseudoaneurysm (0.7%). There was no difference in bleeding complications across AC/AP groups (hematoma, P = .61; pseudoaneurysm, P = .31). After adjusting for patient factors, below-knee bypass target (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.04-1.52; P = .019) and bypass for tissue loss (HR, 1.40; 95% CI, 1.04-1.88; P = .028) were independent predictors for MALE. Great saphenous vein conduit trended toward protection for MALE, compared with prosthetic grafts (HR, 0.84; 95% CI, 0.70-1.01; P = .06). No AC/AP regimen was associated with of MALE, even stratifying by above-knee and below-knee bypass cohorts. The median follow-up period was 2 years. CONCLUSIONS: Among patients undergoing femoropopliteal bypass grafting, no combination of AC or AP medications was associated with improved graft patency; however, a below-knee target and tissue loss were associated with adverse limb events. AC and AP regimen may be individualized after bypass with regard to other concomitant medical comorbidities.

Outcomes of Femoropopliteal Bypass for Lifestyle-Limiting Claudication in the Endovascular Era.

INTRODUCTION: Outcomes after femoropopliteal bypass for intermittent claudication (IC) remain unclear in the endovascular era. METHODS: A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures performed between 1995 and 2020. Demographics, operative details, and outcomes were documented. A statistical analysis included Kaplan-Meier curves and Cox proportional hazards ratios (HR). RESULTS: A total of 282 patients underwent femoropopliteal bypass surgery for IC. Median age was 68 y (interquartile range, 61-73 y). Bypass conduits included great saphenous vein (GSV) (48.2%), prosthetic grafts (48.9%), and non-GSV autogenous grafts (2.8%). Distal bypass target was above-knee in 62.1% and below-knee in 37.9% of patients. The most common postoperative complications were wound infections (14.2%) followed by unplanned 30-d hospital readmissions (12.4%). Mortality rates were low at 0.4% (30 d) and 3.2% (1 y). Five-year primary patency rates trended highest for claudicants undergoing above-knee bypass with GSV conduit (log-rank P = 0.065). Five-year amputation-free survival rates were highest using GSV conduit regardless of distal bypass target (log-rank P = 0.017). On a multivariable analysis, age (HR 1.02 [1.00-1.04], P = 0.023) and active smoking (HR 1.48 [1.06-2.06], P = 0.021) were identified as risk factors for diminished primary graft patency. Risk factors for amputation-free survival included age (HR 1.03 [1.01-1.05], P < 0.001) and GSV conduit type (HR 0.65 [0.46-0.90], P = 0.011). CONCLUSIONS: Femoropopliteal bypass among claudicants is associated with high rates of wound infection and hospital readmission. Active smoking portends worse outcomes in this population. These data may inform clinical decision-making regarding surgical intervention for claudication in the endovascular era.

Differences in Aortic Intramural Hematoma Contrast Attenuation on Multi-Phase CTA Predict Long-Term Aortic Morphologic Change.

BACKGROUND: Evolution of aortic intramural hematoma (IMH) over time may range from resolution to degeneration and is difficult to predict. We sought to measure differences in contrast attenuation between arterial and delayed phase computed tomography angiography (CTA) images within the IMH as a surrogate of hematoma blood flow to predict resolution versus aortic growth and/or adverse outcomes. METHODS: IMH institutional data were gathered from 2005-2020. Hounsfield unit ratio (HUR) was measured as hematoma Hounsfield unit (HU), on delayed phase images divided by HU on arterial phase images on CTA. Aortic growth and effect of HUR was determined using a linear mixed effects model. Freedom from adverse aortic event, defined as the composite of intervention, recurrence of symptoms, radiographic progression, and rupture, was determined using Kaplan-Meier analysis. RESULTS: IMH occurred in 73 patients, of which 27 met the inclusion criteria. HUR ranged from 0.38-1.92 (mean: 0.98). Baseline aortic diameter growth independent of HUR measurement was 0.49 mm/year (95% confidence interval CI: -1.23 to 2.2). With the HUR was introduced into the model, the beta coefficient for time was -5.83 mm/year (95% CI: -10.4 to -1.28 mm/year) and the beta coefficient for the HUR was 5.05 mm/year per one-unit HUR (95% CI: 0.56 to 9.56 mm/year). Thus, an HUR>1.15 would correspond to aortic growth while an HUR<1.15 would correspond to reduction in aortic diameter, consistent with IMH resolution. Aortic adverse events occurred in 13 (48%) patients, 7 (26%) patients had recurrence of symptoms, 8 (30%) required intervention, 5 (18%) progressed to dissection, and 1(4%) had aortic rupture. There was a trend towards an association between higher HUR and composite adverse aortic events (HR 3.2 per 1-unit HUR; 95% CI: 0.6-17.3; P = 0.18). CONCLUSIONS: Increased HUR is associated with increased aortic growth and a trend toward adverse aortic events. Diminished delayed phase enhancement may predict partial or complete IMH resolution. HUR can be used to guide IMH surveillance and treatment.

Derivation and Validation of a Risk Score for Abdominal Compartment Syndrome after Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysms.

BACKGROUND: Abdominal compartment syndrome (ACoS) is a devastating complication after endovascular aneurysm repair for ruptured abdominal aortic aneurysms (rEVAR). This study sought to develop a risk score for ACoS to identify patients who would benefit from early decompressive laparotomy. METHODS: Model derivation was performed with Vascular Quality Initiative data for rEVAR from 2013 to 2020. The primary outcome was evacuation of abdominal hematoma. A multivariable logistic regression was used to create and validate a scoring system to predict ACoS. The model was validated using institutional data for rEVAR from 1998 to 2019. RESULTS: The derivation cohort included 2,310 patients with rEVAR. Abdominal hematoma evacuation occurred in 265 patients (11.5%). Factors associated with abdominal hematoma evacuation on a multivariable analysis included transfer from an outside hospital, preoperative creatinine ≥1.4 mg/dL, preoperative systolic blood pressure ≤85 mmHg, preoperative altered mental status, ≥3.0 liters intraoperative crystalloid, and ≥4 units of red blood cells transfused intraoperatively. The validation cohort consisted of 67 rEVAR; ACoS occurred in 8 patients (11.9%). The c-statistic was 0.84 in the derivation and 0.87 in the validation cohort, whereas Hosmer-Lemeshow was P = 0.15 in the derivation and 0.84 in the validation cohorts, suggesting good model discrimination and calibration. Points were applied based on ß-coefficients to produce a risk score ranging from -1 to 13. A cutoff of risk score ≥8 resulted in a sensitivity and specificity of 87.5% and 83.1% for detecting patients with ACoS, respectively. ACoS conveyed a significantly higher mortality in both the derivation (ACoS: 49.8% vs. No ACoS: 17.8%; P < 0.001) and validation cohorts (ACoS: 75.0% vs. No ACoS: 15.2%; P < 0.001). CONCLUSIONS: In patients with equivocal signs/symptoms of ACoS, this scoring system can be used to guide surgeons on when to perform decompressive laparotomy prior to leaving the operating room for rEVAR. Patients with a risk score ≥8 would benefit from decompressive laparotomy at index rEVAR.

Multi-institutional outcomes after femoropopliteal bypass in octogenarians.

OBJECTIVES: Open lower extremity revascularization is controversial among octogenarians; however, the indications for surgical bypass are higher in the elderly population. The aim of the study was to compare postoperative outcomes between octogenarians and non-octogenarians following femoropopliteal bypass surgery. METHODS: Our regional, multi-institutional database was queried for femoropopliteal bypass procedures performed between 1995 and 2020. Electronic medical records were individually reviewed for operative and postoperative data. Univariable and multivariable logistic regression were utilized to determine predictors of postoperative outcomes. RESULTS: Among 1315 patients who underwent femoropopliteal bypass, 234 (17.8%) were octogenarians. Octogenarians more frequently underwent bypass for lower extremity tissue loss (48.7% vs 30.2%), whereas claudication was more common among non-octogenarians (24.0% vs 9.8%) (p < .001). Below-knee bypass target (72.2% vs 59.3%) and prosthetic conduit utilization (58.5% vs 43.7%) were more frequent in octogenarians (p < .001 each). Overall hospital length of stay was longer among patients > 80 years (median 6 days [interquartile range [IQR] 4-9] vs 5 days [IQR 4-8], p = .017). The overall 30-day (5.6% vs 1.5%) and one-year mortality rates (25.6% vs 7.9%) were higher among octogenarians (p < .001 each). On multivariable analysis, age greater than 80 years was found to be an independent risk factor for postoperative mortality (OR 3.79 [1.75-8.20], p = .0007). CONCLUSIONS: Octogenarians undergoing bypass femoropopliteal bypass surgery have considerably worse postoperative outcomes, compared with non-octogenarians. These data may help inform elderly patients prior to undergoing open lower extremity revascularization.

Improved outcomes of endovascular repair of thoracic aortic injuries at higher volume institutions.

BACKGROUND: The use of thoracic endovascular aortic repair (TEVAR) has significantly improved the ability to treat traumatic aortic injuries (tTEVAR). We sought to determine whether a greater center volume correlated with better outcomes. METHODS: Vascular Quality Initiative data of TEVAR (2011-2017) for trauma were used in the present analysis. Using the distribution of the annual case volume at the participating centers, the sample was stratified into three terciles. In-hospital mortality at high-volume centers (HVCs) and low-volume centers (LVCs) was compared after adjustment for risk factors established in our previous Vascular Quality Initiative-based risk model containing age, gender, renal impairment, left subclavian artery involvement, and select concomitant injuries. RESULTS: A total of 619 tTEVAR cases were studied across 74 centers. HVCs (n = 184 cases) had performed ≥4.9 cases annually and LVCs (n = 220 cases) had performed ≤2.4 cases annually. Both crude mortality (4.4% vs 8.6%; P = .22) and adjusted odds of mortality (odds ratio, 0.44; 95% confidence interval, 0.18-1.09; P = .08) showed a trend toward better outcomes for tTEVAR performed at HVCs than at LVCs. The addition of center volume to our previous multivariate model significantly improved its discriminative ability (C-statistic, 0.90 vs 0.88; P = .02). The overall TEVAR volume (for all indications) was not associated with increased odds of mortality for tTEVAR (odds ratio, 0.46; 95% confidence interval, 0.17-1.20; P = .11), nor did it improve the model's discriminative ability. CONCLUSIONS: Higher volume centers showed improved perioperative mortality after tTEVAR. The thoracic aortic trauma volume was more predictive than the overall TEVAR volume, suggesting that technical expertise is not the driving factor. Stable patients might benefit from transfer to a higher volume center before repair.

Cost-effectiveness analysis of immediate access arteriovenous grafts versus standard grafts for hemodialysis.

OBJECTIVE: Immediate-access arteriovenous grafts (IAAVGs), or early cannulation arteriovenous grafts (AVGs), are more expensive than standard grafts (sAVGs) but can be used immediately after placement, reducing the need for a tunneled dialysis catheter (TDC). We hypothesized that a decrease in TDC-related complications would make IAAVGs a cost-effective alternative to sAVGs. METHODS: We constructed a Markov state-transition model in which patients initially received either an IAAVG or an sAVG and a TDC until graft usability; patients were followed through multiple subsequent access procedures for a 60-month time horizon. The model simulated mortality and typical graft- and TDC-related complications, with parameter estimates including probabilities, costs, and utilities derived from previous literature. A key parameter was median time to TDC removal after graft placement, which was studied under both real-world (7 days for IAAVG and 70 days for sAVG) and ideal (no TDC placed with IAAVG and 1 month for sAVG) conditions. Costs were based on current Medicare reimbursement rates and reflect a payer perspective. Both microsimulation (10,000 trials) and probabilistic sensitivity analysis (10,000 samples) were performed. The willingness-to-pay threshold was set at $100,000 per quality-adjusted life-year (QALY). RESULTS: IAAVG placement is a dominant strategy under both real-world ($1201.16 less expensive and 0.03 QALY more effective) and ideal ($1457.97 less expensive and 0.03 QALY more effective) conditions. Under real-world parameters, the result was most sensitive to the time to TDC removal; IAAVGs are cost-effective if a TDC is maintained for ≥23 days after sAVG placement. The mean catheter time was lower with IAAVG (3.9 vs 8.7 months; P < .0001), as was the mean number of access-related infections (0.55 vs 0.74; P < .0001). Median survival in the model was 29 months. Overall mortality was similar between groups (76.3% vs 76.7% at 5 years; P = .33), but access-related mortality trended toward improvement with IAAVG (6.1% vs 6.8% at 5 years; P = .052). CONCLUSIONS: The Markov decision analysis model supported our hypothesis that IAAVGs come with added initial cost but are ultimately cost-saving and more effective. This apparent benefit is due to our prediction that a decreased number of catheter days per patient would lead to a decreased number of access-related infections.

Utilization and Outcomes of Radial Artery Access for Lower Extremity Endovascular Intervention.

INTRODUCTION: Radial artery access has become popular for cardiac interventions, but its role in lower extremity interventions is not well defined. We aimed to describe current utilization and outcomes of transradial access for lower extremity interventions. METHODS: Peripheral vascular intervention (PVI) from 2016-2020 where transradial access was employed in the Vascular Quality Initiative (VQI) registry were studied. Cases before 2016 were excluded as documentation of transradial access was not possible in earlier years. PVIs involving radial artery access were evaluated with regard to access guidance, access-site complications, target vessels treated and the technical success of these interventions. RESULTS: Of 167,098 PVIs, 1,096 (0.66%) involved radial access. Utilization varied significantly by region (P < 0.01). The left radial artery was used in 66.9% of cases. Ultrasound-guided access was documented in 72.7% of cases. There were no significant differences in age, body mass index, or sex between the transradial group and other PVIs. In 450 procedures, a second access site was utilized, most commonly a retrograde femoral access (60.0%) or retrograde pedal access (16.7%). The largest sheath was 6-Fr in 78.0%. Interventions documenting radial-only access more commonly treated the aortoiliac segment (49.4% vs. 29.5%, P < 0.001) and less commonly treated the tibial segments (7.1% vs. 32.1%, P < 0.001). Technical success was 94.0%, with inability to cross the lesion (3.1%) and residual stenosis after treatment (2.2%) being most common. There were access-site complications in 2.9%, with hematoma (2.4%) being most common. DISCUSSION: Radial access is associated with high technical success rates and low access-site complication rates. Advances in device profile and shaft length may overcome shortcomings of transradial access and lead to further utilization of this access site.

Complete Venous Ulceration Healing after Perforator Ablation Does Not Depend on Treatment Modality.

BACKGROUND: Venous leg ulceration (VLU) represents the most advanced form of chronic venous insufficiency (CVI). Persistent VLU that fails to respond to noninvasive treatment requires a minimally invasive endovascular treatment, which may include chemical (ultrasound-guided foam sclerotherapy [UGFS]) and thermal ablation (endovenous laser therapy [EVLT] or radiofrequency ablation [RFA]) targeting incompetent veins. Current guidelines suggest ablation of incompetent perforating veins (IPVs) juxtaposed to active or healed VLU; however, the ideal treatment modality is unknown. We hypothesize that similar to incompetent superficial vein treatment options therapies, VLU healing will be equivalent across minimally invasive IPV treatment options. METHODS: Using the Vascular Low Frequency Disease Consortium, adults with VLU across 11 medical centers were retrospectively reviewed (2013-2017). We included those who underwent IPV therapies. The primary outcome was complete ulcer healing over time compared with cumulative hazard curves, log-rank testing, and multivariable Cox proportional hazard regression. Secondary outcomes included number of subsequent procedures, which were compared using negative binomial regression. RESULTS: Of the 832 adults with VLU, 158 (19%) were exclusively treated conservatively, and 232 (28%) underwent index treatment for IPV and constitute the full and final cohort. The mean age was 60 ± 14 years, 57% were men, and the mean ulcer area was 3.0 cm2 (interquartile range, 1-6 cm2). Ninety-one (39%) were treated with EVLT, 127 (55%) RFA, and 14 (6%) UGFS. Patients treated with RFA were older (RFA 62 ± 14 years; EVLT 59 ± 14 years; UGFS 52 ± 9 years; P = 0.01), more likely to be men (RFA 68%, n = 86; EVLT 41%, n = 37; UGFS 64%, n = 9; P < 0.001), with a higher frequency of anticoagulation (RFA 36%, n = 46; EVLT 18%, n = 16; UGFS 14%, n = 2; P = 0.005). VLU did not significantly differ in size between groups (RFA 6.2 ± 8; EVLT 4.2 ± 5.4; UGFS 6.1 ± 8; P < 0.001). There were no differences in 1-year ulcer healing rates between groups (P = 0.18). The number of subsequent procedures did not differ by treatment modality (P = 0.47). CONCLUSIONS: This multi-institutional retrospective study does not demonstrate any association of IPV treatment modality with differing rates of VLU healing or number of subsequent procedures.

Risk factors for mortality after endovascular repair for blunt thoracic aortic injury.

OBJECTIVE: Despite high use of endovascular repair, blunt thoracic aortic injury (BTAI) leads to significant mortality. We sought to identify risk factors and create a predictive model for mortality after thoracic endovascular aortic repair (TEVAR) based on available preoperative clinical data. METHODS: We queried the Vascular Quality Initiative TEVAR dataset from April 2011 to November 2017 to identify patients with BTAI as the indication for repair. Patient characteristics, injury grade, timing of repair, and technical aspects including left subclavian artery (LSCA) involvement and coverage were evaluated. Logistic regression was used to identify univariable predictors of the primary outcome of in-hospital mortality. A multivariable model was constructed to predict in-hospital mortality after TEVAR for traumatic aortic injury. The model was tested as a prediction tool, internally validated using 10-fold cross-validation approach, externally validated using early and late split samples, and finally simplified into a scoring system. RESULTS: We identified 633 TEVAR cases performed for blunt trauma. The majority of patients were male (73.9%) with median age of 39 years (interquartile range, 27-56 years). Although 18.6% documented zone 2 or proximal involvement, 28.1% documented involvement or treatment of the LSCA. 8.9% of repairs were performed for a grade 1 injury, with an increase from 6.4% in 2014 to 16.7% in 2017 (P = .04). The overall in-hospital mortality rate was 7.3%. Independent predictors of mortality were age 60 year or greater (odds ratio [OR], 11.33; 95% confidence interval [CI], 5.30-24.23; P < .001), creatinine 1.2 or greater (OR, 5.28; 95% CI, 2.46-11.34; P < .001), male gender (OR, 4.26; 95% CI, 1.53-11.84; P = .005), Injury Severity Score of greater than 30 (OR, 3.86; 95% CI, 1.74-8.57; P = .001), and LSCA involvement (OR, 2.25; 95% CI, 1.11-4.53; P = .02). The model predicted in-hospital mortality with a C-statistic of 0.86 (95% CI, 0.80-0.92), and a simplified model based on a point system had a similar C-statistic of 0.86 (95% CI, 0.80-0.92; P = .44). CONCLUSIONS: TEVAR for BTAI is associated with a 7.3% in-hospital mortality in the Vascular Quality Initiative. Treatment of grade 1 injuries has increased significantly in recent years. Factors most strongly associated with mortality include age, male gender, renal impairment, LSCA involvement, and high ISS score. A simple point score model based on these variables robustly predicts in-hospital mortality and may assist in appropriate patient selection and risk stratification.

Nationwide trends in drug-coated balloon and drug-eluting stent utilization in the femoropopliteal arteries.

OBJECTIVE: Drug-coated balloons (DCB) and drug-eluting stents (DES) have significantly altered treatment paradigms for femoropopliteal lesions. We aimed to describe changes in practice patterns as a result of the infusion of these technologies into the treatment of peripheral arterial disease. METHODS: We queried the Vascular Quality Initiative registry from 2010 to 2017 for all peripheral vascular interventions involving the superficial femoral artery and/or the popliteal artery. Cases were divided into a PRE and a POST era with a cutoff of September 2016, when specific device identity was first recorded in Vascular Quality Initiative. For each artery, a primary treatment was identified as either plain balloon angioplasty, atherectomy, DCB, bare-metal stent, or DES. The relative distribution of primary treatments between the PRE and POST eras was evaluated, as were lesion characteristics associated with DCB and DES use and regional variability in the adoption of these new technologies. RESULTS: Of 210,666 arteries in the dataset, 91,864 femoropopliteal arteries (across 74,842 procedures in 55,437 patients) were included. Each artery received 1.5 ± 0.6 treatments. Primary treatment use changed from 40% balloon angioplasty, 45% stenting, and 15% atherectomy in the PRE era to 22% plain balloon angioplasty, 26% bare-metal stent, 8% atherectomy, 37% DCB, and 8% DES in the POST era (P < .001). Forty-three percent of arteries received a drug-containing device as a primary or adjunctive therapy and 1.3% received both a DCB and DES in the POST era. DCB use as the primary treatment was highest in lesions with length 10.0 to 19.9 cm (42%), TransAtlantic InterSociety A, B, or C lesions (38%), and lesions with mild to no calcification (38%). DES use was highest in lesions with a length of 20 cm or more (12%), TransAtlantic InterSociety D lesions (13%), and lesions with moderate to severe calcification (9%). The range of use across 18 regions was 125 to 40% for DCB and 1% to 14% for DES. Regional variability was greater for DES (SD 4% vs mean 8%) than for DCB (SD 7% vs mean 29%). CONCLUSIONS: There has been a rapid dissemination of DCB and DES technology in the femoropopliteal vessels, with nearly one-half of arteries receiving a drug-containing therapy in modern practice. DCBs are most used in medium length, minimally calcified lesions and DESs are most used in longer, more heavily calcified lesions. There is significant regional variability in adoption, especially with DES.

Increasing use of open conversion for late complications after endovascular aortic aneurysm repair.

OBJECTIVE: Open procedures are often required for late complications after endovascular aneurysm repair (EVAR). Our aim was to describe the indications for open interventions and their postoperative outcomes and to specifically examine our experience with limited conversions in which problem endoleaks are targeted without endograft explantation. METHODS: We reviewed patients from 2002 to 2017 who underwent any surgical abdominal aortic operation after a previous EVAR. Baseline characteristics, preoperative imaging, procedural details, and postoperative outcomes were reviewed. The primary end point was 30-day mortality. RESULTS: There were 102 patients who underwent open conversion 3.8 ± 3.1 years after EVAR. The numbers increased significantly in recent years, with 18 cases performed in 2016; 48.5% of patients had undergone 1.9 ± 1.0 prior endovascular interventions. The indication for surgical conversion was an endoleak in 85 patients and infection in 15. One patient had a limb occlusion and another a proximal aneurysm. The 30-day mortality was 6.2% in 65 patients treated electively for endoleak but higher in 20 ruptures (40.0%) and 15 infections (40.0%). In a multivariate logistic regression model, independent predictors of 30-day mortality were rupture (odds ratio [OR], 6.70; 95% confidence interval [CI], 1.75-25.60; P = .005), endograft infection (OR, 8.48; 95% CI, 1.99-36.20; P = .004), and use of a supraceliac clamp (OR, 4.80; 95% CI, 1.47-15.66; P = .009). Transient acute kidney injury (12.8%) and prolonged intubation (11.8%) were the most common postoperative complications. In 65 patients treated for endoleak without rupture, 37 underwent endograft explantation, whereas 28 had a graft-preserving intervention (branch vessel ligation for type II endoleak in 26, external banding of the aneurysm neck for type IA endoleak in 8). Mortality was 8.1% when the endograft was explanted and 3.6% when it was not (P = .63). During 3.0 ± 3.5 years of follow-up, there was one reintervention after endograft explantation (for rupture secondary to type IB endoleak) and two reinterventions after graft preservation (for a new type IA endoleak and a new type II endoleak). Survival was 87.4% at 1 year and 70.9% at 5 years. CONCLUSIONS: Open conversion is playing an increasing role in the management of late EVAR complications. Endoleaks treated electively by open conversion are reasonably safe and show good midterm durability, even with graft-preserving interventions that avoid endograft explantation.