Identifying risk factors for postoperative ileus following open abdominal aortic aneurysm repair.

INTRODUCTION: Postoperative ileus (POI) is a common complication following major abdominal surgery. The majority of the data available regarding POI following abdominal surgery is from the gastrointestinal and urologic literature. These data have been extrapolated to vascular surgery, especially with regards to enhanced recovery programs for open abdominal aortic aneurysm (AAA) surgery. However, vascular patients are a unique patient population and extrapolation of gastrointestinal and urological data may not necessarily be appropriate. Therefore, the purpose of this study was to delineate the prevalence and risk factors of POI in patients undergoing open AAA surgery. METHODS: This was a retrospective, single-institution study of patients who underwent open AAA surgery from January 2016 to July 2023. Patients were excluded if they had undergone non-elective repairs or had expired within 72 hours of their index operation. The primary outcome was rates of POI, which was defined as the presence of two or more of the following after the third postoperative day: nausea and/or vomiting, inability to tolerate oral food intake, absence of flatus, abdominal distension, or radiological evidence of ileus. RESULTS: A total of 123 patients met study criteria with an overall POI rate of 8.9% (n=11). Patients who developed a POI had significantly lower BMIs (24.3 kg/m2 versus 27.1 kg/m2, P=.003), were more likely to undergo a transperitoneal approach (81.8% versus 42.0%, P=.022), midline laparotomy (81.8% versus 37.5%, P=.008), longer total clamp times (151.6 minutes versus 97.7 minutes, P=.018), larger amounts of intraoperative crystalloid infusion (3495 mL versus 2628 mL, P=.029), and were more likely to return to the operating room (27.3% versus 3.6%, P=.016). Proximal clamp site was not associated with POI (P=.463). POI patients also had higher rates of post-operative vasopressor use (100% versus 61.1%, P=.014) and larger amounts of oral morphine equivalents in the first 3 post-operative days (488.0 mg + 216.0 versus 203.8 mg + 29.6 P=.016). Patients who developed POI had longer lengths of stay (12.5 days versus 7.6 days, P<.001), longer duration of NGT decompression (5.9 days versus 2.2 days, P<.001), and a longer period of time before diet tolerance (9.1 days versus 3.7 days, P<.001). Of those that developed a POI (n=11), 4 (36.4%) required total parental nutrition during the admission. CONCLUSION: POI is a morbid complication amongst patients undergoing elective open AAA surgery that significantly prolongs hospital stay. Patients at risk for developing a POI are those with lower BMIs, had an operative repair via a transperitoneal approach, midline laparotomy, longer clamp times, larger amounts of intraoperative crystalloid infusion, a return to the operating room, post-operative vasopressor use, and higher amounts of oral morphine equivalents. These data highlight important peri-operative opportunities to reduce the prevalence of POI.

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.

Greater Patient Travel Distance is Associated with Perioperative and One-Year Cost Increases After Complex Aortic Surgery.

BACKGROUND: With increasing regionalization of complex aortic surgery within fewer US centers, patients may face increased travel burden when accessing aortic surgery. Longer travel distances have been associated with inferior outcomes after major surgery; however, the impacts of distance on reinterventions and costs have not been described. This study aims to assess the association between patient travel distance and longer-term outcomes including costs and reinterventions after complex aortic surgery. METHODS: A retrospective review was conducted of all patients in the Vascular Implant Surveillance and Interventional Outcomes Network database undergoing complex endovascular aortic repair including internal iliac or visceral vessel involvement, complex thoracic endovascular aortic repair including Zone 0-2 proximal extent or branched devices, and complex open abdominal aortic aneurysm repair including suprarenal or higher clamp sites. Travel distance was stratified by Rural-Urban Commuting Area population-density category. Multinomial logistic regression models, negative-binomial models, and zero-inflated Poisson models were used to assess the association between travel distance and index procedural and comprehensive first-year costs, long-term imaging, and long-term reinterventions, respectively. RESULTS: Between 2011 and 2018, 8,782 patients underwent complex aortic surgery in the Vascular Implant Surveillance and Interventional Outcomes Network database, including 4,822 complex endovascular aortic repairs, 2,672 complex thoracic endovascular aortic repairs, and 1,288 complex open abdominal aortic aneurysm repairs. Median travel distance was 22.8 miles (interquartile range 8.6-54.8 miles, range 0-2,688.9 miles). Median age was 75 years for all distance quintiles. Patients traveling farther were more likely to be female (26.8% in quintile 5 [Q5] vs. 19.9% in Q1, P < 0.001) and to have had a prior aortic surgery (20.8% for Q5 vs. 5.9% for Q1, P < 0.001). Patients traveling farther had higher index procedural costs, with adjusted odds ratio (OR) 2.34 (95% confidence interval [CI] 1.86-2.94, P < 0.0001) of being in the highest cost tertile versus lowest for patients in Q5 vs. Q1. For patients with ≥ 1-year follow-up, those traveling farther had higher imaging costs, with adjusted Q5 OR 1.55 (95% CI 1.22-1.95, P = 0.0002), and comprehensive first-year costs, with adjusted Q5 OR 2.06 (95% CI 1.57-2.70, P < 0.0001). In contrast, patients traveling farther had similar numbers of reinterventions and imaging studies postoperatively. CONCLUSIONS: Patients traveling farther for complex aortic surgery have higher procedural costs, postoperative imaging costs, and comprehensive first-year costs. These patients should be targeted for increased care coordination for improved outcomes and healthcare system burden.

Infectious Aortitis of Thoracic Aortic Aneurysm From Clostridium Septicum.

A 71-year-old male presented with 1-day history of back pain. Imaging displayed an enlarging thoracic aortic aneurysm with gas in the aortic wall. Blood cultures grew Clostridium septicum. He underwent resection, debridement, and in situ aortic replacement with a rifampin-soaked graft under deep hypothermic circulatory arrest. His recovery was uncomplicated. (Level of Difficulty: Beginner.).

Surgical Management of Renal Cell Carcinoma with Inferior Vena Cava Tumor Thrombus.

Most kidney cancers are primary renal cell carcinomas (RCC) of clear cell histology. RCC is unique in its ability to invade into contiguous veins - a phenomenon terms venous tumor thrombus. Surgical resection is indicated for most patients with RCC and an inferior vena cava (IVC) thrombus in the absence of metastatic disease. Resection also has an important role in selected patients with metastatic disease. In this review, we discuss the comprehensive management of the patient with RCC with IVC tumor thrombus, emphasizing a multidisciplinary approach to the surgical techniques and perioperative management.

Longer patient travel distance is associated with increased non-index readmission after complex aortic surgery.

OBJECTIVE: Recently evolving practice patterns in complex aortic surgery have led to regionalization of care within fewer centers in the United States, and thus patients may have to travel farther for complex aortic care. Travel distance has been associated with inferior outcomes after non-vascular surgery, particularly non-index readmission. This study aims to assess the impact of patient travel distance on perioperative outcomes and readmissions after complex aortic surgery. METHODS: A retrospective review was conducted of all patients in the Vascular Quality Initiative and Vascular Implant Surveillance and Interventional Outcomes Network databases undergoing complex endovascular aortic repair (EVAR) including internal iliac or visceral vessel involvement, complex thoracic endovascular aortic repair (TEVAR) including zone 0 to 2 proximal extent or branched devices, and complex open abdominal aortic aneurysm (AAA) repair including suprarenal or higher clamp sites. Travel distance was stratified by rural/urban commuting area (RUCA) population-density category. Wilcoxon and χ2 tests were used to assess relationships between travel distance quintiles and baseline characteristics, mortality, and readmission. Travel distance and other factors were included in multivariable Cox models for survival and Fine-Gray competing risk models for freedom from readmission. RESULTS: Between 2011 and 2018, 8782 patients underwent complex aortic surgery in the Vascular Quality Initiative and Vascular Implant Surveillance and Interventional Outcomes Network databases, including 4822 complex EVARs, 2672 complex TEVARs, and 1288 complex open AAA repairs. Median travel distance was 22.8 miles (interquartile range [IQR], 8.6-54.8 miles). Median age was 75 years for all distance quintiles, but patients traveling longer distances were more likely female (26.8% in quintile 5 [Q5] vs 19.9% in Q1; P < .001), white (93.8% of Q5 vs 83.8% of Q1; P < .001), to have larger-diameter AAAs (median 59 mm for Q5 vs 55 mm for Q1; P < .001), and to have had prior aortic surgery (20.8% for Q5 vs 5.9% for Q1; P < .001). Overall 30-day readmission was more common at farther distances (18.1% for Q5 vs 14.8% for Q1; P = .003), with higher non-index readmission (11.2% for Q5 vs 2.7% for Q1; P < .001) and conversely lower index readmission (6.9% for Q5 vs 12.0% for Q1; P < .001). Multivariable-adjusted Fine-Gray models confirmed greater hazard of non-index readmission with farther distance, with a Q5 hazard ratio of 3.02 (95% confidence interval, 2.12-4.30; P < .001). Multivariable-adjusted Cox models demonstrated no association between travel distance and long-term survival but found that non-index readmission was associated with increased long-term mortality (hazard ratio, 1.46; 95% confidence interval, 1.20-1.78; P = .0001). CONCLUSIONS: Patients traveling farther for complex aortic surgery demonstrate higher non-index readmission, which, in turn, is associated with increased long-term mortality risk. Aortic centers of excellence should consider targeting these patients for more comprehensive follow-up and care coordination to improve outcomes.

28-Year Experience with Ruptured and Symptomatic Type I-III Thoracoabdominal Aortic Aneurysms at a Large Tertiary Referral Center.

BACKGROUND: Given the relative rarity of ruptured and symptomatic type I-III thoracoabdominal aortic aneurysms (TAAA), data is scarce with regard the outcomes of those who survive to repair. The goal of this study was to determine short and long-term outcomes after open repair of type I-III TAAA surgery for ruptured and symptomatic TAAA and compare the results to elective TAAA repairs. METHODS: All open type I-III TAAA repairs performed from 1987 to 2015 were evaluated using an institutional database. Charts were retrospectively evaluated for perioperative outcomes: major adverse event (MAE), in-hospital death, spinal cord ischemia (SCI) and long-term survival. Ruptured, symptomatic and elective repair cohorts were created for comparison. Univariate analysis was performed using the Fisher's exact test for categorical variables and analysis of variance (ANOVA) for continuous variables. Logistic regression was used for in-hospital endpoints; survival analysis was performed with Cox proportional hazards modelling and Kaplan-Meier techniques. RESULTS: Five hundred-sixteen patients had an open type I-III TAAA repair during the study period. Fifty-nine (11.4%) were performed for rupture and 51 (9.9%) were performed for symptomatic aneurysms (RAs). Ruptured and symptomatic groups were more likely to be older, female, and have larger presenting aortic diameters. Most of the ruptured and symptomatic cases were transferred from an outside facility (59.3% and 54.9%, respectively). Intraoperatively, the elective cohort was more likely to receive left heart bypass as an operative adjunct; ruptures were less likely to receive a renal bypass, and operative time was highest for the elective cohort. Perioperative mortality was 18.6% for ruptured, 2.0% for symptomatic, and 7.4% for elective indications. Ruptures were most likely to require new hemodialysis after repair (20.3% vs. 10.3% for elective, P = 0.02). On adjusted analysis, ruptures were more likely to suffer from perioperative death (adjusted odds ratio [AOR]: 4.5, 95% confidence interval (CI): 1.7-11.4) and MAEs (AOR: 2.8, 95% CI: 1.4-5.4). Ruptured and symptomatic aneurysms were not independently associated with SCI; however, preoperative hemodynamic instability was predictive (AOR: 8.7, 95% CI: 1.7-44.2). Both rupture and symptomatic cases were associated with decreased survival on Kaplan-Meier analysis with 5-year survival for ruptures at 35%, symptomatic at 47.7% and elective at 63.7%, P < 0.001. Adjusted hazards of death were 1.2 (95% CI: 0.9-1.8) in the symptomatic cohort and 2.3 (95% CI: 1.5-3.7) in the ruptured cohort. CONCLUSIONS: Open ruptured and symptomatic type I-III TAAA repairs can be performed with acceptable morbidity and mortality. Most symptomatic and rupture repairs were performed after transfer from another institution. Postoperative SCI is most strongly related to the preoperative hemodynamic status of the patient.

Partial and complete explantation of aortic endografts in the modern era.

OBJECTIVE: Despite the progressive advancement of devices for endovascular aortic repair (EVAR), endografts continue to fail, requiring explant. We present a single-institutional experience of EVAR explants, characterizing modern failure modes, presentation, and outcomes for partial and complete EVAR explantation. METHODS: A retrospective analysis was performed of all EVARs explanted at an urban quaternary center from 2001 to 2020, with one infected endograft excluded. Patient and graft characteristics, indications, and perioperative and long-term outcomes were analyzed. Partial versus complete explants were performed per surgeon discretion without a predefined protocol. This process was informed by patient risk factors; asymptomatic, symptomatic, or ruptured aneurysm presentation; and anatomical or intraoperative factors, including endoleak type. RESULTS: From 2001 to 2020, 52 explants met the inclusion and exclusion criteria. More than one-half (57.7%) were explants of EVAR devices placed at outside institutions, designated nonindex explants. Most patients were male (86.5%), the median age was 74 years (interquartile range, 70-78 years). More than one-half (61.5%) were performed in the second decade of the study period. The most commonly explanted grafts were Gore Excluder (n = 9 grafts), Cook Zenith (n = 8), Endologix AFX (n = 7), Medtronic Endurant (n = 5), and Medtronic Talent (n = 5). Most grafts (78.8%) were explanted for neck degeneration or sac expansion. Five were explanted for initial seal failure, five for symptomatic expansion, and seven for rupture. The median implant duration was 4.2 years, although ranging widely (interquartile range, 2.6-5.1 years), but similar between index and nonindex explants (4.2 years vs 4.1 years). Partial explantation was performed in 61.5%, with implant duration slightly lower, 3.2 years versus 4.4 years for complete explants. Partial explantation was more frequent in index explants (68.2% vs 56.7%). The median length of stay was 8 days. The median intensive care unit length of stay was 3 days, without significant differences in nonindex explants (4 days vs 3 days) and partial explants (4 days vs 3 days). Thirty-day mortality occurred in two nonindex explants (one partial and one complete explant). Thirty-day readmission was similar between partial and complete explants (9.7% vs 5.0%), without accounting for nonindex readmissions. Long-term survival was comparable between partial and complete explants in Cox regression (hazard ratio, 2.45; 95% confidence interval, 0.79-7.56; P = .12). CONCLUSIONS: Explants of EVAR devices have increased over time at our institution. Partial explant was performed in more than one-half of cases, per operating surgeon discretion, demonstrating higher blood loss, more frequent acute kidney injury, and longer intensive care unit stays, however with comparable short-term mortality and long-term survival.

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.

Cadaver Simulation is Associated with Increased Comfort in Performing Open Vascular Surgery Among Integrated Vascular Surgery (0+5) Residents and Recent Graduates.

BACKGROUND: With the evolution in vascular surgery toward increased endovascular therapy and decreased open surgical training, comfort with open procedures by current trainees is declining. A proposed method to improve this discomfort is simulator training. We hypothesized that open, cadaver, and endovascular surgery simulation would be associated with increased self-perceived comfort in performing corresponding procedures. METHODS: Integrated (0 + 5) vascular surgery residents and recent graduates in the United States were asked to complete a survey quantifying comfort via a Likert scale with procedures and experience with simulation training. Simulation groups were then matched using coarsened exact matching. Ordinal logistic regression assessed the association between simulation experience and comfort in performing procedures. RESULTS: Surveys were completed by 68 trainees and 20 attending surgeons in their first 5 years of practice. On unmatched analyses, there were no significant differences in comfort in performing any open or endovascular aorto-mesenteric or peripheral vascular procedures between respondents who reported experience with open or endovascular simulation, respectively. However, respondents who reported cadaver simulation experience (58%, 51/88) had a significantly higher reported comfort score performing open juxtarenal aortic repair (2.4 vs. 1.7), superior mesenteric artery thrombectomy or bypass (2.5 vs. 1.9), inferior vena cava or iliac vein repair (2.2 vs. 1.7), axillary-femoral artery bypass (3.4 vs. 2.5), femoral-popliteal artery bypass (3.7 vs. 2.8), and inframalleolar artery bypass (2.8 vs. 2.1; all P < 0.05). After matching on training level, number of abdominal cases completed, and number of open vascular cases completed, ordinal logistic regression demonstrated that previous cadaver simulation was significantly associated with increased comfort in performing open aortic repairs, venous repair, visceral revascularization, and peripheral bypasses. CONCLUSIONS: In this nationally representative sample, cadaver, but not open or endovascular, simulation was associated with increased comfort in performing open vascular surgery. Providing cadaver simulation to trainees may help to improve comfort levels in performing open surgery. Integrated vascular surgery training programs should consider implementing these experiences into their curriculum.

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.

Evaluating proximal clamp site and intraoperative ischemia time among open repair of juxtarenal aneurysms.

BACKGROUND: The proportion of open aneurysm repairs requiring at least a suprarenal clamp has increased in the past few decades, partly owing to preferred endovascular approaches for most patients with infrarenal aneurysms, suggesting that the management of aortic clamp placement has become even more relevant. This study evaluated the association between the proximal clamp site and intraoperative ischemia times with postoperative renal dysfunction and mortality. METHODS: We used the Vascular Quality Initiative to identify all patients undergoing open repairs of elective or symptomatic juxtarenal AAAs from 2004 to 2018 and compared outcomes by clamp site: above one renal artery, above both renal arteries (suprarenal), or above the celiac trunk (supraceliac). Outcomes evaluated included acute kidney injury (AKI), new-onset renal failure requiring renal replacement therapy (RRT), 30-day mortality, and 1-year mortality. We used multilevel logistic regressions and Cox proportional hazards models, clustered at the hospital level, to adjust for confounding. RESULTS: We identified 3976 patients (median age, 71 years; 70% male; 8.2% non-Caucasian), with a median aneurysm diameter of 5.9cm (interquartile range [IQR], 5.4-6.8 cm). Proximal clamp sites were above one renal artery (31%), suprarenal (52%), or supraceliac (17%). The rates of unadjusted outcomes were 20.5% for AKI, 4.1% for new-onset RRT, 4.9% for 30-day mortality, and 8.3% for 1-year mortality. On adjusted analyses, independent of ischemia time, suprarenal clamping relative to clamping above a single renal artery had higher odds of postoperative AKI (adjusted odds ratio [aOR], 1.50; 95% confidence interval; 95% CI, CI, 1.28-1.75), but similar odds for new-onset RRT (aOR, 1.27; 95% CI, 0.79-2.06) and 30-day mortality (aOR, 1.12; 95% CI, 0.79-1.58) and hazards for 1-year mortality (adjusted hazard ratio, 1.12; 95% CI, 0.86-1.45). However, every 10 minutes of prolonged intraoperative ischemia time was associated with an increase in odds or hazards ratio of postoperative AKI by 7% (IQR, 3%-11%), new-onset RRT by 11% (IQR, 4%-17%), 30-day mortality by 11% (IQR, 6%-17%), and 1-year mortality by 7% (IQR, 2%-13%). Patients with more than 40 minutes of ischemia time had notably higher rates of all four outcomes. CONCLUSIONS: Suprarenal clamping relative to clamping above a single renal artery was associated with AKI, but not new-onset RRT or 30-day mortality. However, the intraoperative renal ischemia time was independently associated with all four postoperative outcomes. Although further studies are warranted, our findings suggest that an expeditious proximal anastomosis creation is more important than trying to maintain clamp position below one renal artery, suggesting that suprarenal clamping may be the best strategy for open AAA repair when needed to efficiently perform the proximal anastomosis.

A systematic review of thromboelastography utilization in vascular and endovascular surgery.

OBJECTIVE: Thromboelastography (TEG) is diagnostic modality that analyzes real-time blood coagulation parameters. Clinically, TEG primarily allows for directed blood component resuscitation among patients with acute blood loss and coagulopathy. The utilization of TEG has been widely adopted in among other surgical specialties; however, its use in vascular surgery is less prominent. We aimed to provide an up-to-date review of TEG utilization in vascular and endovascular surgery. METHODS: Using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, a literature review with the Medical Subject Headings (MeSH) terms "TEG and arterial events", "TEG and vascular surgery", "TEG and vascular", "TEG and endovascular surgery", "TEG and endovascular", "TEG and peripheral artery disease", "TEG and prediction of arterial events", "TEG and prediction of complications ", "TEG and prediction of thrombosis", "TEG and prediction of amputation", and "TEG and amputation" was performed in Cochrane and PubMed databases to identify all peer-reviewed studies of TEG utilization in vascular surgery, written between 2000 and 2021 in the English language. The free-text and MeSH subheadings search terms included diagnosis, complications, physiopathology, surgery, mortality, and therapy to further restrict the articles. Studies were excluded if they were not in humans or pertaining to vascular or endovascular surgery. Additionally, case reports and studies with limited information regarding TEG utilization were excluded. Each study was independently reviewed by two researchers to assess for eligibility. RESULTS: Of the 262 studies identified through the MeSH strategy, 15 studies met inclusion criteria and were reviewed and summarized. Literature on TEG utilization in vascular surgery spanned cerebrovascular disease (n = 3), peripheral arterial disease (n = 3), arteriovenous malformations (n = 1), venous thromboembolic events (n = 7), and perioperative bleeding and transfusion (n = 1). In cerebrovascular disease, TEG may predict the presence and stability of carotid plaques, analyze platelet function before carotid stenting, and compare efficacy of antiplatelet therapy after stent deployment. In peripheral arterial disease, TEG has been used to predict disease severity and analyze the impact of contrast on coagulation parameters. In venous disease, TEG may predict hypercoagulability and thromboembolic events among various patient populations. Finally, TEG can be utilized in the postoperative setting to predict hemorrhage and transfusion requirements. CONCLUSIONS: This systematic review provides an up-to-date summarization of TEG utilization in multiple facets of vascular and endovascular surgery.

Late Type 1A Endoleaks: Associated Factors, Prognosis and Management Strategies.

BACKGROUND: Unlike periprocedural Type 1A endoleaks, late appearing proximal endoleaks have been poorly described. METHODS: We studied all elective EVAR from 2010 -2018 in a single institution. Late endoleaks were defined as those appearing after 1 year. We used Cox regression to study factors associated with late Type 1A endoleaks and survival. RESULTS: Of 477 EVAR during the study period, 411 (86%) had follow-up imaging, revealing 24 Type 1A endoleaks; 4 early and 20 late. Freedom from Type 1A endoleaks was 99%, 92-81% at 1, 5 and 8 years with a median time to occurrence of 2.5 years (.01-8.2 years). On completion angiogram, only 10% of patients with a late Type 1A had a proximal endoleak, and 60% had no endoleak. Only 21% of late Type 1As were diagnosed on routine 1-year CT angiogram, but 79% had stable or expanding sacs. Two thirds (65%) of the patients eventually diagnosed with late Type 1A endoleaks had previously been treated for other endoleaks, mostly Type 2 (10/13). Age (HR 1.07/year [1.02-1.12], P = 0.01), neck diameter >28mm (HR 3.5 [1.2-10.3], P = 0.02), neck length <20mm (HR 3.0 [1.1-8.6], P = 0.04), and neck angle>60 degrees (HR 3.4 [1.5-7.9], P = 0.004) were associated with higher rates of Type 1A endoleak, but not female sex, endograft, or the use of suprarenal fixation. 2 patients had proximal degeneration and 5 experienced graft migration. There were 2 ruptures (10%), and 13 patients underwent repair with 5 open conversions. Median survival after late Type 1A repair was 6.6 years (0-8.4 years). CONCLUSION: Late appearing Type 1A endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful surveillance is needed in patients with hostile neck anatomy and those who undergo intervention for other endoleaks. Adverse neck anatomy may be better suited for open repair or fenestrated/branched devices rather than conventional EVAR.

The Effect of Retrograde External Iliac Artery Runoff on Aortofemoral Bypass Limb Patency.

BACKGROUND: Superficial femoral artery and profunda patency has been shown to affect aortofemoral bypass (AFB) limb patency. However, the effect of retrograde flow through the external iliac artery (EIA) is unknown and is the subject of this analysis. METHODS: Institutional AFB data from 2000 to 2017 were gathered, excluding that where Superficial femoral artery /EIA patency could not be determined. The cohort was divided into limbs with and without EIA occlusion; primary outcome was limb-based primary patency. Kaplan-Meier estimated patency; cox proportional-hazards model evaluated EIA patency while controlling for other factors. RESULTS: Over the study period, there were AFB 557 limbs in 281 patients. Of the 435 AFB limbs in 220 patients that met inclusion criteria and were included in the analysis, 162 had EIA occlusion and 273 had a patent EIA. Mean age was 69.6 ± 9.0. EIA occlusions were more common in male patients (59.9% vs. 44.6%; P = 0.001), patients with CAD (43.8% vs. 34.1%; P = 0.042), COPD (34.6% vs. 20.5%; P = 0.001), and CHF (14.8% vs. 5.9%; P = 0.002). Limbs with EIA occlusions more often underwent end-to-side proximal anastomosis (40.7% vs. 24.2%; P < 0.001) and simultaneous infrainguinal bypass (7.4% vs. 0.7%; P < 0.001). Median clinical follow-up was 4.4 years (IQR: 1.6-8.4). Five-year primary patency was 83.1% (95% CI: 74.5-90.0%) for EIA occlusion limbs and 85.9% (95% CI: 80.2-90.0%) with patent EIA limbs (P = 0.96). While controlling for other factors, EIA stenosis or occlusion did not affect primary patency. For patients with a proximal occlusion (occluded aorta, occluded common iliac, or end-to-end proximal anastomosis) and occluded SFA (N = 73), EIA occlusion had a HR of 1.92 for loss of patency, but this was not statistically significant. CONCLUSIONS: EIA patency did not influence primary patency in the overall cohort Further investigation on the topic in specific patient subgroups is warranted to determine the effect of EIA patency.

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.

Prognostication of Asymptomatic Penetrating Aortic Ulcers: A Modern Approach.

BACKGROUND: Literature detailing the natural history of asymptomatic penetrating aortic ulcers (PAUs) is sparse and lacks long-term follow-up. This study sought to determine the rate of asymptomatic PAU growth over time and adverse events from asymptomatic PAU. METHODS: A cohort of patients with asymptomatic PAU from 2005 to 2020 was followed. One ulcer was followed per patient. Primary end points were change in size over time and the composite of symptoms, radiographic progression, rupture, and intervention; cumulative incidence function estimated the incidence of the composite outcome. Ulcer size and rate of change were modeled using a linear mixed-effects model. Patient and anatomic factors were evaluated as potential predictors of the outcomes. RESULTS: There were 273 patients identified. The mean age was 75.5±9.6 years; 66.4% were male. The majority of ulcers were in the descending thoracic aorta (53.9%), followed by abdominal aorta (41.4%) and aortic arch (4.8%). Fusiform aneurysmal disease was present in 21.6% of patients at a separate location; 2.6% had an associated intramural hematoma; 23.6% had at least 1 other PAU. Symptoms developed in 1 patient who ruptured; 8 patients (2.9%) underwent an intervention for PAU (1 for rupture, 2 for radiographic progression, 5 for size/growth) at a median of 3.1 years (interquartile range, 1.0-6.5) after diagnosis. Five- and 10-year cumulative incidence of the primary outcome, adjusted for competing risk of death, was 3.6% (95% CI, 1.6%-6.9%) and 6.5% (95% CI, 3.1%-11.4%), respectively. For 191 patients with multiple computed tomography scans (760 total computed tomographies) with a median radiographic follow-up of 3.50 years (interquartile range, 1.20-6.63 years), mean initial ulcer width, ulcer depth, and total diameter were 13.6 mm, 8.5 mm, and 31.4 mm, respectively. A small but statistically significant change over time was observed for ulcer width (0.23 mm/y) and total diameter (0.24 mm/y); ulcer depth did not significantly change over time. Hypertension, hyperlipidemia, diabetes, initial ulcer width >20 mm, thrombosed PAU, and associated saccular aneurysm were associated with larger changes in ulcer size over time; however, the magnitude of difference was small, ranging from 0.4 to 1.9 mm/y. CONCLUSIONS: Asymptomatic PAU displayed minimal growth and infrequent complications including rupture. Asymptomatic PAU may be conservatively managed with serial imaging and risk factor modification.

The long-term fate of renal and visceral vessel reconstruction after open thoracoabdominal aortic aneurysm repair.

OBJECTIVES: In the ever-advancing era of endovascular thoracoabdominal aneurysm (TAAA) repair, understanding long-term patency of renovisceral reconstructions after open TAAA repair provides important benchmarks. METHODS: Institutional open TAAA repair patient data were queried. Patients dying during index admission or with incomplete operative detail were excluded. Visceral and renal reconstructions were categorized as bypass, incorporation into a proximal or distal beveled aortic anastomosis, inclusion button, Carrel patch, or hybrid stent along with endarterectomy/stent adjuncts. Axial imaging or angiography determined long-term patency. Vessel event was defined as new occlusion or reintervention after repair. Overall time-to-event analysis was performed as well as separate analyses for each vessel (celiac, superior mesenteric artery [SMA], right renal, left renal) by reconstruction type utilizing Kaplan-Meier methods. Log-rank testing was employed to compare reconstructive strategies. RESULTS: Over 28 years, 604 repairs (type I, 106 [18%]; type II, 73 [12%]; type III, 195 [32%]; and type IV, 230 [38%]) were identified. Follow-up (median, 500 days) was available in 410/570 (72%) celiac, 406/573 (71%) SMA, 379/532 (71.2%) right renal, and 370/515 (72%) left renal reconstructions. There were five celiac, one SMA, eight right renal, and 10 left renal events. No type of reconstruction or adjunct was significantly associated with event. Overall 5-year patency of all renal/visceral reconstructions was 94% (95% confidence interval, 90%-96%). Estimated 5-year patency of the celiac, SMA, left renal, and right renal were similar, and were 99%, 100%, 97%, and 96%, respectively (P = .09). CONCLUSIONS: Visceral and renal long-term patency after open TAAA repair is excellent regardless of reconstructive technique. No differences are appreciated even when target vessel disease is addressed at the time of reconstruction. These findings continue to substantiate the effective long-term durability of open TAAA repair and are particularly germane to the ongoing evolution of endovascular strategies.

Comparison of treatment options for aortic necks outside standard endovascular aneurysm repair instructions for use.

OBJECTIVE/BACKGROUND: Endovascular aneurysm repair (EVAR) is associated with worse outcomes in patients whose anatomy does not meet the device instructions for use (IFU). However, whether open surgical repair (OSR) and commercially available fenestrated EVAR (Zenith Fenestrated [ZFEN]) represent better options for these patients is unknown. METHODS: We identified all patients without prior aortic surgery undergoing elective repair of abdominal aortic aneurysms with neck length ≥4 mm at a single institution with EVAR, OSR, and ZFEN. We applied device-specific aneurysm neck-related IFU to EVAR patients, and a generic EVAR IFU to ZFEN and OSR patients. Long-term outcomes were studied using propensity scores with inverse probability weighting. We compared outcomes in patients undergoing EVAR by adherence to IFU and outcomes by repair types in the subset of patients not meeting IFU. RESULTS: Of 652 patients (474 EVAR, 34 ZFEN, 143 OSR), 211 had measurements outside of standard EVAR IFU (109 EVAR [23%], 27 ZFEN [80%], and 74 OSR [52%]). Perioperative mortality was 0.5% overall. For EVAR, treatment outside the IFU was associated with significantly higher adjusted rates of long-term type IA endoleak (22% at 5 years compared to 2% within IFU, hazard ratio [HR]: 5.8 [3.1-10.9], P < .001), and lower survival (5- and 10-year survival: 56% and 34% vs 81% and 53%, HR: 2.3 [1.2-4.3], P = .01). There was no difference in reinterventions or open conversion. In patients not meeting IFU, ZFEN was associated with higher adjusted rates of reinterventions (EVAR as referent: HR: 2.6 [1.5-4.4, P < .001), whereas OSR and EVAR patients experienced similar reintervention rates (HR: 0.7 [0.4-1.1], P = .13). Patients outside the IFU experienced lower mortality with OSR compared with either EVAR (HR: 0.4 [0.2-0.9], P = .005) or ZFEN (HR: 0.3 [0.1-0.7], P = .002). When restricted to patients outside the IFU deemed fit for open repair, OSR patients remained associated with lower adjusted mortality compared with ZFEN (HR: 0.2 [0.1-0.5], P < .001), but statistical significance was lost in the comparison to EVAR (HR: 0.6 [0.3-1.1], P = .1). CONCLUSIONS: Treatment outside device-specific IFU is associated with adverse long-term outcomes. Open surgical repair is associated with higher long-term survival in patients who fall outside of the EVAR IFU and should be favored over EVAR or ZFEN in suitable patients. A three-vessel-based fenestrated strategy may not be a durable solution for difficult aortic necks, but more data are needed to evaluate the performance of newer, four-vessel devices.

Addition of common carotid intervention increases the risk of stroke and death after carotid artery stenting for asymptomatic patients.

BACKGROUND: A recent review of Vascular Study Group of New England data suggested that simultaneous endovascular treatment of tandem carotid lesions (TCAL: common carotid artery + internal carotid artery) is associated with a fourfold increase in perioperative neurologic events and death. However, given the small cohort, the effect of symptomatic status could not be evaluated. This study sought to determine the risk of simultaneous TCAL stenting in cohorts stratified by symptom status. METHODS: Vascular Quality Initiative data (2005-2020) were queried for carotid stenting procedures (CAS). Emergent and bilateral procedures, patients with prior ipsilateral CAS, internal carotid artery lesions with stenosis <50%, and hybrid transcarotid procedures were excluded. The cohort was stratified by symptomatic status. The primary outcome was the composite of perioperative stroke and death. Predictors of stroke/death were determined with multivariable logistic regression for symptomatic and asymptomatic patients with TCAL forced into the models. RESULTS: There were 18,886 carotid arteries stented (18,441 patients): 18,077 (96%) with isolated carotid artery lesions and 809 (4%) with TCAL. Mean age was 70.0 ± 9.7. Symptomatic lesions were present in 58.9% of cases (isolated carotid artery lesions: 59.1% vs TCAL: 52.5%; P < .001). More TCAL arteries had a prior carotid endarterectomy (38.3% vs 23.8%; P < .001). TCAL had a higher perioperative stroke/death (3.4% vs 1.8%; P = .026) for asymptomatic lesions, but not symptomatic lesions (4.5% vs 3.7%; P = .41). TCAL were independently associated with stroke/death in asymptomatic patients (odds ratio, 1.85; 95% confidence interval, 1.03-3.33; P = .039) but not symptomatic patients (odds ratio, 1.22; 95% confidence interval, 0.76-1.97; P = .42). CONCLUSIONS: The addition of endovascular treatment of common carotid artery lesions with CAS is associated with almost double the risk of perioperative stroke/death in asymptomatic patients and should be avoided if possible. Treatment of TCAL is not associated with an increased risk of stroke/death for symptomatic lesions.