Risk Factors for Development of Incisional Hernia after Aortic Aneurysm Repair: Secondary Analysis of the OVER Randomized Controlled Trial.

BACKGROUND: Since the risk of mortality from rupture is elevated, elective repair of abdominal aortic aneurysms (AAAs) is often recommended. Currently, over 80% of elective repairs are carried out using an endovascular approach. While open repair has similar late survival and fewer reintervention outcomes when compared to endovascular repair, incisional hernia is a frequent complication with morbidity and cost implications. The Open versus Endovascular Repair (OVER) trial was the largest randomized trial of endovascular versus open repair of AAA in the United States. The purpose of this study was to determine risk factors associated with incisional hernia development following AAA repair via secondary analysis of the OVER data. METHODS: This was a multisite trial conducted within the Veterans Affairs health-care system. Study participants (N = 881) were enrolled from 2002 to 2008 and followed until 2011 with additional administrative data collection until 2016. Eligible patients had AAA for which elective repair was planned and randomized 1:1 to either open or endovascular repair. Incisional hernia was a prespecified end point in the OVER protocol, specifically assessed at each protocol follow-up visit. Technical details were extracted from each operative report, repair case report form(s), and adverse event form(s). Patient demographics, comorbid conditions, reported preoperative activity level, and operative details including initial approach, blood loss, and closure methods were analyzed using Bayesian hierarchical Weibull survival regression modeling. RESULTS: Incisional hernias were recorded among 46 participants (5.2%). The average time to hernia diagnosis was 3.5 years. Of the 437 participants randomized to open treatment, 427 received an open repair including crossovers from endovascular treatment assignment. Transperitoneal repair was performed in 81%, running suture in 96%, and absorbable suture in 71% of cases. Randomization to endovascular repair was associated with reduced risk of hernia (hazard ratio [HR] 0.70, 95% credible interval [CI] 0.49-0.94). Higher activity level was associated with increased hernia risk (HR 1.39, 95% CI 1.06-1.84). Approach, suture closure techniques, body mass index, diabetes, and smoking status were not associated with increased risk of hernia development. CONCLUSIONS: Incisional hernia is a frequent complication associated with open repair of abdominal aortic aneurysm and commonly required reintervention. Endovascular repair was associated with reduced risk of hernia. Patients with increased activity experienced a higher incidence of hernia. However, no other modifiable patient, operative, or technical factors were found to be associated with hernia development.

The role of patch closure in current-day carotid endarterectomy.

BACKGROUND: It has long been debated whether it is preferable to perform conventional carotid endarterectomy (CEA) with or without patch closure. Although most contemporary surgeons patch, many still do not. Recent small studies have surfaced implying patching is unnecessary. The objective of our analysis was to determine the difference in short- and long-term outcomes according to patch use in a large modern, cross-specialty database. METHODS: Analyzing more than 118,000 records from the Vascular Quality Initiative, multimodel inference was used to evaluate the effect of patch use on important outcomes of conventional CEA. The composite short-term outcome included any ipsilateral neurological event, return to the operating room for a neurological event, and an increase in the Rankin score postoperatively. Late composite outcome incorporated restenosis as well as early and late ipsilateral neurological events. RESULTS: Patch use for conventional CEA closure was found to be a strong predictor of both early and late outcomes, as evidenced by its Akaike importance weight of 0.99. Examining predischarge events, patch closure is associated with a decrease in major negative events (odds ratio, 0.5; 95% confidence interval, 0.4-0.6). For long-term events, such closure offers a decrease in untoward outcome (odds ratio, 0.8; 95% confidence interval, 0.7-0.9). CONCLUSIONS: Analysis in a large current-day database suggests that patch closure of conventional CEA effects superior short- and long-term outcomes.

Effect of preservation of antegrade hypogastric flow on development of claudication following aortoiliac aneurysm repair.

OBJECTIVE: The objective of this study was to compare the rate of development of buttock claudication in patients undergoing aortoiliac aneurysm repair with and without exclusion of antegrade hypogastric arterial flow. In the absence of convincing data, questions remain regarding the best management of hypogastric arterial flow to prevent the theoretical risk of buttock claudication. METHODS: The Veterans' Affairs Open Versus Endovascular Repair (OVER) Cooperative Study prospectively collected information on buttock claudication. Trial participants were specifically prompted both pre- and postoperatively to report the development of claudication symptoms at several anatomic levels. Of note, trial investigators were specifically trained to occlude the trunk hypogastric arterial, preserving the anterior and posterior divisions. Bayesian survival models were created to evaluate time to development of left, right, or bilateral buttock claudication according to the presence/absence of antegrade hypogastric perfusion. RESULTS: A total of 881 patients from the OVER trial with information regarding status of hypogastric flow were included in the analysis. Of these, 788 patients maintained bilateral antegrade hypogastric arterial perfusion, 63 had right hypogastric coverage/occlusion, and 27 had left hypogastric coverage/occlusion, whereas 3 patients had bilateral hypogastric coverage/occlusion. Just under 5% of all patients (n = 41) developed buttock claudication. After adjustment for smoking, chronic obstructive pulmonary disease, medications, study arm, preoperative activity level, body mass index, age, and diabetes, intervention-related changes to hypogastric perfusion had no effect on time to development of buttock claudication. A Maximum A Posteriori Kullback- Leibler misfit χ2 was 14.45 with 24 degrees of freedom, resulting in a goodness of fit P-value of P = .94, indicative of a good fit. CONCLUSIONS: OVER is the largest aneurysm treatment study to prospectively collect data related to the development of claudication as well as hypogastric preservation status. Despite this, we were unable to find evidence to support the assertion that preservation of antegrade hypogastric flow decreases the rate of development of buttock claudication symptoms. The low rate of development of buttock claudication overall and in the subgroups is striking.

Analysis of Repair Type and Hypogastric Artery Antegrade Perfusion and Erectile Function following Repair of Abdominal Aortic Aneurysms.

BACKGROUND: Published reports suggest that exclusion of antegrade hypogastric artery flow may have deleterious effects on erectile function after abdominal aortic aneurysm (AAA) repair. Off-label and open surgical hybrid procedures and, more recently, purpose-built branched devices have been developed to maintain antegrade pelvic perfusion in patients undergoing endovascular repair. Maintaining antegrade perfusion may reduce a spectrum of risks, including buttock claudication, colorectal ischemia, and spinal cord ischemia when patients undergo subsequent thoracic aortic procedures, as well as erectile dysfunction (ED). This project specifically focuses on erectile function, and analyzes baseline associations and relationships of hypogastric artery exclusion on changes in erectile function following aneurysm repair. METHODS: Male patients in the Veterans Affairs Open Versus Endovascular Repair (CSP#498; OVER) Trial had erectile function assessed preoperatively and postoperatively by administration of the International Index of Erectile Function-5 questionnaire. Bayesian mixed-effects regression models were created with the outcome variable (erectile function) treated as a latent variable. Primary effects of differences in erectile function between groups with and without preservation of bilateral antegrade hypogastric flow were compared. RESULTS: 876 men (442 randomized to endovascular repair) were enrolled in the trial and included in the analysis comparing treatment assignment. There is significant ED in elderly men with aortic aneurysm at baseline. Over 5 years of follow-up, there is modest decrease in erectile function and the endovascular group has improved function compared to open repair (0.082; 95% credible interval (CI) 0.008 and 0.155). A fifth of patients did not have bilateral preservation of antegrade hypogastric artery perfusion, with no difference in erectile function by univariate analysis. A more detailed regression analysis was applied--and after adjustment for baseline score, age, beta blocker use, diabetes, activity level, ejection fraction, preoperative ankle-brachial indices and time--preservation of both antegrade hypogastric arteries' perfusion showed transient improvement in survey scores compared to occlusion of at least 1 hypogastric artery at 6 months and 12 months after treatment, although this was not sustained at 60 months (score change: 0.046; 95% CI: -0.123, 0.215). Retesting this model in the cohort with complete data as a sensitivity analysis did not meaningfully change the conclusions. CONCLUSIONS: In this large prospective aneurysm treatment trial with systematic measurement of erectile function with a validated instrument, endovascular repair is associated with improved erectile function. Preservation of antegrade hypogastric flow with any repair is associated with early improved erectile function; however, it is not a sustained benefit. There is limited benefit of maintaining bilateral hypogastric artery perfusion for this specific indication in unselected men undergoing AAA repair.

Evaluating the Role of Major Lower Extremity Amputation in Nonagenarians.

OBJECTIVE: Elderly patients with critical limb ischemia are an especially frail and vulnerable group of patients. There is little literature investigating outcomes and resource utilization in nonagenarians undergoing major lower extremity amputation (MLEA). This study aims to elucidate the outcomes of this unique set of patients for whom amputation may often be considered a "palliative" intervention. METHODS: Analyzing over 16,000 records from the Vascular Quality Initiative (VQI) database, we collected demographic, operative, and postoperative data on all patients who underwent an MLEA. We performed univariate analysis comparing nonagenarians to younger patients examining both short-term and long-term outcomes. Multimodel inference was used to analyze the effect of age on clinically meaningful outcomes: mortality and long-term living disposition. RESULTS: With 392 nonagenarians and 16,349 patients under the age of 90, we found nonagenarians were less comorbid and less likely to have a prior bypass or amputation. Despite experiencing lower rates of reoperation and individual postoperative complications, nonagenarians suffered higher long-term mortality (46% vs. 22%, P < 0.0005) and were more likely to be living in a facility at follow-up (34% vs. 15%, P < 0.0005). Incorporating important demographic and clinical factors, multimodel inference demonstrated that, the nonagenarian age group was a critical predictor of nonhome living status (Akaike Importance weight 0.99). CONCLUSIONS: Although nonagenarians were less comorbid than their younger counterparts and suffered fewer perioperative complications, MLEA leads to a poorer outcome with significant mortality and a higher likelihood of residing in a facility at long-term follow-up. These findings underscore the importance of frank goals of care discussions in nonagenarians considering major amputation.

Study protocol of a randomized controlled trial of fistula vs. graft arteriovenous vascular access in older adults with end-stage kidney disease on hemodialysis: the AV access trial.

BACKGROUND: Treatment of end-stage kidney disease (ESKD) with hemodialysis requires surgical creation of an arteriovenous (AV) vascular access-fistula (AVF) or graft (AVG)-to avoid (or limit) the use of a central venous catheter (CVC). AVFs have long been considered the first-line vascular access option, with AVGs as second best. Recent studies have suggested that, in older adults, AVGs may be a better strategy than AVFs. Lacking evidence from well-powered randomized clinical trials, integration of these results into clinical decision making is challenging. The main objective of the AV Access Study is to compare, between the two types of AV access, clinical outcomes that are important to patients, physicians, and policy makers. METHODS: This is a prospective, multicenter, randomized controlled trial in adults ≥ 60 years old receiving chronic hemodialysis via a CVC. Eligible participants must have co-existing cardiovascular disease, peripheral arterial disease, and/or diabetes mellitus; and vascular anatomy suitable for placement of either type of AV access. Participants are randomized, in a 1:1 ratio, to a strategy of AVG or AVF creation. An estimated 262 participants will be recruited across 7 healthcare systems, with average follow-up of 2 years. Questionnaires will be administered at baseline and semi-annually. The primary outcome is the rate of CVC-free days per 100 patient-days. The primary safety outcome is the cumulative incidence of vascular access (CVC or AV access)-related severe infections-defined as access infections that lead to hospitalization or death. Secondary outcomes include access-related healthcare costs and patients' experiences with vascular access care between the two treatment groups. DISCUSSION: In the absence of studies using robust and unbiased research methodology to address vascular access care for hemodialysis patients, clinical decisions are limited to inferences from observational studies. The goal of the AV Access Study is to generate evidence to optimize vascular access care, based on objective, age-specific criteria, while incorporating goals of care and patient preference for vascular access type in clinical decision-making. TRIAL REGISTRATION: This study is being conducted in accordance with the tenets of the Helsinki Declaration, and has been approved by the central institutional review board (IRB) of Wake Forest University Health Sciences (approval number: 00069593) and local IRB of each participating clinical center; and was registered on Nov 27, 2020, at ClinicalTrials.gov (NCT04646226).

Mycobacterium Bovis Causing Mycotic Aneurysm Secondary to Intravesical Treatment with Bacillus Calmette-Guérin: A Case Report.

BACKGROUND: Bacillus Calmette-Guerin (BCG) is a live, attenuated strain of Mycobacterium bovis that is used in the treatment of non-muscle invasive bladder cancer (NMIBC). Vascular complications, including mycotic aneurysms, after BCG therapy are exceedingly rare. In this patient population, the diagnosis of mycotic aneurysms can be delayed or missed due to their non-specific clinical and radiologic presentation. Literature review reveals management of mycotic aneurysms attributable to BCG therapy is widely varied.2,5-8,12,15 CASE REPORT: We report a patient who presented with mycotic aneurysm formation secondary to BCG treatment for bladder cancer that was repaired with in-line reconstruction utilizing cryoartery and buttressed with omental flap. We suggest this as an alternative treatment to in-line prosthetic graft or extra-anatomic reconstruction.

The Effect of Hypogastric Artery Revascularization on Ischemic Colitis in Endovascular Aneurysm Repair.

BACKGROUND: The objective of the study was to examine the effect of hypogastric revascularization maneuvers on the rate of postoperative ischemic colitis among patients undergoing endovascular aortoiliac aneurysm repair. METHODS: Using the 2011-2018 Endovascular Aneurysm Repair Procedure-Targeted American College of Surgeons National Surgical Quality Improvement Program Participant Use Files, we analyzed patients undergoing elective endovascular infrarenal aortoiliac aneurysm repairs. Using multivariable modeling techniques, a cohort of patients at high risk for postoperative ischemic colitis was identified. The outcomes of this group were then compared using Pearson's chi-square testing in accordance with whether or not they underwent hypogastric revascularization. RESULTS: Of 4753 patients undergoing endovascular aortoiliac aneurysm repair in the National Surgical Quality Improvement Program cohort, 1161 had concomitant hypogastric revascularization procedures. High-risk predictors of ischemic colitis included chronic obstructive pulmonary disease and concurrent renal artery or external iliac artery stenting. There was not a significant association between pelvic revascularization and postoperative ischemic colitis [1.0% with versus 0.5% without pelvic revascularization; adjusted odds ratio of ischemic colitis with revascularization 2.07 (0.96, 4.46); P = 0.06] after adjustment for patient- and procedure-related factors. In a subgroup analysis of patients with a distal aneurysm extent beyond the common iliac artery, the incidence of ischemic colitis was significantly lower in patients without pelvic revascularization (0.1% versus 1.6%, P = 0.004). CONCLUSIONS: Our analysis of patients undergoing elective endovascular repair of infrarenal aortoiliac aneurysmal disease did not find a reduced incidence of postoperative ischemic colitis in patients who received a concomitant pelvic revascularization procedure, suggesting instead that such procedural adjuncts may actually increase risk for this complication.

Patterns of opioid use in dialysis access procedures.

BACKGROUND: Overprescription of opioids after surgical procedures is recognized as an important contributor to opioid misuse. Dialysis access procedures are commonly performed outpatient operations with few data or guidelines to inform prescription pain management practices. We sought to characterize opioid pain medication use after dialysis access surgery to promote a conservative approach to postoperative opioid prescriptions. METHODS: We performed a retrospective review of patients who underwent surgical dialysis access procedures from August 2018 through January 2019. Patient-reported opioid use information was captured in a brief questionnaire administered during routine follow-up appointments or phone calls and recorded in the electronic medical record. The procedure, type of intraoperative anesthesia or analgesia, postoperative prescription provided, and patient factors (including age, sex, dialysis type, history of chronic pain, and preoperative opioid or benzodiazepine use) were recorded. All procedures were classified by type (arteriovenous fistula or graft with a short incision [AVF-S], arteriovenous fistula or graft with a long incision [AVF-L], or peritoneal dialysis [PD] catheter), and descriptive statistics were performed using R (R Foundation for Statistical Computing, Vienna, Austria). RESULTS: Eighty-six patients underwent dialysis access procedures in the study time frame, of whom 63 were administered the pain questionnaire and 58 quantified opioid use; 85% of patients received a prescription, but 31% took no opioids and 71% used opioids for ≤2 days. Interquartile ranges (25th-75th percentile) of prescription and consumption quantities for patients who underwent AVF-L procedures were 10 to 28 pills and 2.5 to 20 pills; for patients who underwent AVF-S, quantities were 4.0 to 8.4 pills and 0 to 4.3 pills; and PD quantities were 10 pills and 3.3 to 9 pills. Thirty-one patients (53%) reported receiving more pain medication than they used, which resulted in a median of 8 excess pills per patient with an unused pill interquartile range of 0 to 22 pills for AVF-L procedures, 0 to 4.2 pills for AVF-S procedures, and 1.3 to 6.7 pills for PD procedures. Patients who were prescribed oxycodone or had a repeated operation had significantly increased opioid use. CONCLUSIONS: This investigation of opioid use after surgical dialysis access procedures suggests that most patients use relatively few opioid pills after surgery, which translates into overprescription and leftover medication for >50% of patients. A conservative approach to postoperative prescription guidelines using lower prescription quantities would encourage opioid-related risk reduction while providing adequate postoperative analgesia. Recommended quantities for postoperative prescriptions were generated using the 80th percentile consumed and were 0 to 6 pills for brachiobasilic or brachiocephalic fistulas, 0 to 5 pills for basilic vein transposition, 0 to 5 pills for radiocephalic AVF, 0 to 15 pills for upper arm grafts, and 0 to 10 pills for PD catheter placement.

Locoregional anesthesia is associated with lower 30-day mortality than general anesthesia in patients undergoing endovascular repair of ruptured abdominal aortic aneurysm.

OBJECTIVE: The objective of this study was to compare 30-day postoperative mortality for patients undergoing endovascular repair of ruptured abdominal aortic aneurysm (rAAA) using locoregional vs general anesthesia. Unlike the open approach, endovascular repair of rAAA can be performed using either locoregional or general anesthesia. We hypothesize that mortality after endovascular repair of rAAA is lower when locoregional rather than general anesthesia is used. METHODS: Propensity score matching techniques were used to compare the 30-day postoperative outcomes of patients from the 2007 to 2015 American College of Surgeons National Surgical Quality Improvement Program database who underwent endovascular repair of rAAA under locoregional vs general anesthesia. RESULTS: Of the 1382 endovascular rAAA repair procedures in our overall study population, 132 (9.5%) were performed using locoregional anesthesia. Our propensity score matching algorithm yielded a cohort of 130 general anesthesia patients who were well matched with their locoregional anesthesia counterparts for known patient and procedure characteristics. The 30-day postoperative mortality rates for patients in the matched cohort were 14.6% for patients in the locoregional anesthesia group compared with 29.2% for patients in the general anesthesia group (P = .002). CONCLUSIONS: Locoregional rather than general anesthesia is associated with a significantly lower 30-day mortality after endovascular repair of rAAA. The designs of future trials comparing endovascular and open rAAA repair should include stratification of endovascular procedures by anesthesia modality.

Most patients experiencing 30-day postoperative stroke after carotid endarterectomy will initially experience disability.

OBJECTIVE: Although modern rates of stroke after carotid endarterectomy (CEA) have been low, the functional outcomes of stroke after CEA are unclear. Our goal was to assess the degree of initial disability in patients without baseline stroke-related impairment who had undergone CEA and experienced an early postoperative stroke. METHODS: The National Surgical Quality Improvement Program CEA-targeted database was queried for CEA cases from 2011 to 2014. Patients who had experienced a postoperative stroke were included, and the modified Rankin scale (mRS) was used to assess the degree of initial disability from stroke (0, none; 1, no significant; 2, slight; 3, moderate; 4, moderately severe; 5, severe disability; 6, dead). The mRS score was categorized as not applicable (NA) in the absence of any stroke. Patients were excluded if they had had a preoperative mRS score >1. The 30-day outcomes among the cohorts with a postoperative mRS score of NA/0 to 1, 2 to 3, and 4 to 5 were compared. Multivariable analysis was used to determine the predictors of higher initial postoperative mRS scores. RESULTS: A total of 8797 patients with CEA and preoperative mRS scores of NA/0 to 1 were identified. Their mean age was 71 ± 8.8 years, and 61% were men. Most were asymptomatic (88%) and had been taking antiplatelet agents (90%) and statins (82%) preoperatively. At 30 days, the postoperative stroke rate was 1.1% and mortality was 0.6%. Of the patients with a postoperative stroke after CEA, 35.4% had had stable initial postoperative mRS scores of NA/0 to 1, and most had had increased initial postoperative disability with mRS scores of 2 to 3 (32.3%) or 4 to 5 (32.3%). The cohorts with greater initial postoperative mRS scores exhibited a longer length of stay (2.2 ± 3.3 vs 5.8 ± 3.9 vs 11.9 ± 18.8 days; P < .001) and greater rates of major adverse cardiac events (2.7% vs 100% vs 100%; P < .001). Multivariable analysis showed that the initial postoperative disability, determined by a greater mRS score, was independently associated with preoperative bleeding disorder/chronic anticoagulation (odds ratio, 1.79; 95% confidence interval, 1.04-3.11; P = .037) and operative time by hour (odds ratio, 1.38; 95% confidence interval, 1.11-1.7; P = .003). CONCLUSIONS: Although the rate of stroke after CEA has been low, almost two thirds of patients who experienced a stroke within 30 days postoperatively developed some degree of initial postoperative disability and one third developed initial moderately severe to severe disability. These findings provide an evidence base for improved informed consent and risk-benefit discussions with patients.

Carotid artery stenting is associated with a higher incidence of major adverse clinical events than carotid endarterectomy in female patients.

BACKGROUND: The optimal approach to carotid revascularization in female patients with carotid artery stenosis is widely debated. Information available is largely derived from clinical trials that include only highly selected patients. The goal of this study was to compare the early clinical outcomes in women who undergo carotid artery stenting (CAS) vs carotid endarterectomy (CEA). METHODS: Female patients undergoing CAS or CEA between January 1, 2012 and December 31, 2015, and who were included in the Procedure Targeted American College of Surgeons National Surgical Quality Improvement Program were assessed for their incidence of early postoperative complications. The primary outcome measure was 30-day incidence of a major adverse clinical event (MACE; defined as death, stroke, transient ischemic attack, or myocardial infarction/arrhythmia). Univariable analyses were used to compare results between female patients undergoing CEA and those undergoing CAS. Propensity score matching techniques were used to create a cohort of 125 CAS and CEA patients who were well matched for all known patient-, disease-, and procedure-related factors. Analysis of comparative outcomes between the propensity-matched groups was then performed. RESULTS: The overall study population consisted of 5620 female CEA patients and 131 female CAS patients. Of these patients, 290 (5.2%) from the CEA group and 16 (12.2%) from the CAS group sustained a MACE in the first 30 days after their procedures. Within the propensity-matched cohort, the 30-day incidence of postoperative MACE in the CAS group of this cohort was 11.2% (14 patients) compared with 4.0% (5 patients; odds ratio, 1.01 [95% confidence interval, 1.01-7.77]; P = .04) in the CEA group. CONCLUSIONS: Our analysis of a "real-world" clinical registry suggests that CAS may be inferior to CEA in female patients who require carotid artery revascularization.

Current practice of thoracic outlet decompression surgery in the United States.

BACKGROUND: Thoracic outlet syndrome (TOS) and its management are relatively controversial topics. Most of the literature reporting the outcomes of surgical decompression for TOS derives from single-center experiences. The objective of our study was to describe the current state of TOS surgery among hospitals that participate in the American College of Surgeons National Surgical Quality Improvement Program database. METHODS: Our study sample consisted of patients from the 2005 to 2014 American College of Surgeons National Surgical Quality Improvement Program database who underwent first or cervical rib resection as their index procedure and whose constellation of diagnosis and procedure codes identified them as having neurogenic, arterial, or venous TOS. Patient and procedure characteristics were determined, as were the 30-day incidence of specific complications including nerve injury. Multimodel inference was used for multivariable analysis of the composite outcome of readmission or reoperation ≤30 days. RESULTS: We identified 1431 patients undergoing operation for TOS: 83% for neurogenic TOS, 3% for arterial TOS, and 12% for venous TOS. Vascular surgeons performed 90% of procedures. Only four patients (0.3%) demonstrated evidence of nerve injury. The rate of bleeding complication requiring transfusion was also quite low, at 1.4%. The 30-day incidence of readmission or reoperation, or both, in our study cohort was 8.6%. The risk of this outcome was increased in patients with a higher American Society of Anesthesiologists Physical Status Classification, those whose procedure was for non-neurogenic symptoms, and those whose procedure took longer to complete. CONCLUSIONS: The findings of our study will provide surgeons who advocate for the surgical management of TOS with reassurance that such intervention is associated with an extremely low risk of disability resulting from iatrogenic nerve injury and major bleeding events.

Predictors of 30-day postoperative major adverse clinical events after carotid artery stenting: An analysis of the procedure-targeted American College of Surgeons National Surgical Quality Improvement Program.

BACKGROUND: Information about carotid artery stenting (CAS) is largely derived from clinical trials, consensus statements, and outcomes comparisons between CAS and carotid endarterectomy. Given these limitations, the goal of this study was to identify risk factors for adverse outcomes after CAS among hospitals participating in the CAS-targeted American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). METHODS: Our study sample consisted of patients from the 2012 to 2015 CAS-targeted ACS NSQIP data set. The primary outcome variable was 30-day postoperative incidence of major adverse clinical events (MACEs; death, myocardial infarction/arrhythmia, ipsilateral stroke/transient ischemic attack). Univariable and multivariable analyses were performed to identify patient and procedural characteristics associated with MACEs. RESULTS: A total of 448 patients undergoing CAS for carotid artery stenosis were identified in the 2012 to 2015 CAS-targeted ACS NSQIP data set as eligible for analysis. The incidence of postoperative MACEs was 8.4% for symptomatic patients and 5.4% for asymptomatic patients. On multivariable analysis, independent predictors of MACEs included age ≥80 years, female sex, black race, presence of chronic obstructive pulmonary disease, active tobacco use (protective), and use of more than one stent. CONCLUSIONS: The rate of major postoperative events in preoperatively asymptomatic patients is higher than the threshold recommended by the American Heart Association guidelines. Elderly patients (≥80 years), female patients, and black patients as well as those receiving more than one stent are at increased risk of negative outcome after CAS.

Targeting the most important complications in vascular surgery.

OBJECTIVE: This study was conducted to identify the most clinically relevant and costly perioperative complications occurring in vascular surgery patients. METHODS: The analysis included patients in the 2012 to 2014 National Surgical Quality Improvement Program database undergoing one of four high-risk vascular procedures. The procedures-aortic reconstruction, lower extremity bypass, lower extremity amputation, and carotid endarterectomy (CEA)-were selected because they have been established as high risk in the literature, rendering them natural targets for quality improvement initiatives. Population-attributable fractions (PAFs) were used to estimate the impact of seven prespecified complications on 30-day outcomes in the study population. The PAF predicts the reduction in outcome anticipated if a particular complication were to be prevented across the study population. Unadjusted and adjusted PAFs were reported. CEA was analyzed separately from the other procedures. RESULTS: The analysis included 72,805 National Surgical Quality Improvement Program patients. Pneumonia had the largest impact on the incidence of end-organ dysfunction in CEA patients (adjusted PAF, 24.4%; 95% confidence interval, 20.6-28.1), and cerebrovascular accident had the largest impact on mortality in these patients (adjusted PAF, 23.1%; 95% confidence interval, 18.5-27.3). In patients undergoing abdominal or lower extremity vascular surgery, bleeding and pneumonia had the largest impact on clinical outcomes and need for prolonged hospitalization, and surgical site infection had the largest impact on hospital readmission. In contrast, prevention of venous thromboembolism, urinary tract infection, and myocardial infarction do not demonstrate substantial impact on patient outcomes or resource utilization in either group of vascular surgery patients. CONCLUSIONS: Quality initiatives that can successfully reduce the occurrence of postoperative stroke, bleeding, and pneumonia will have the greatest clinical impact on the outcomes of vascular surgery patients. Initiatives that target complications such as venous thromboembolism, urinary tract infection, or myocardial infarction will have little impact on this patient population.

Validated prediction model for severe groin wound infection after lower extremity revascularization procedures.

BACKGROUND: Groin wound infection is a costly and morbid event after lower extremity revascularization. To date, a comprehensive and validated method for identifying patients who are at greatest risk for this complication has yet to be developed. METHODS: Our retrospective analysis included all patients at a single institution who underwent lower extremity revascularization using a groin incision from 2009 through 2012. Patients were randomly assigned to one of two groups: a test group, which was used to develop a predictive model for our primary outcome; and a validation group, which was used to test that model. The primary outcome for our analysis was severe groin wound infection, which we defined as postoperative groin infection that required operative intervention. Multimodel inference methods were used to evaluate all possible combinations, interactions, and transformations of potential predictor variables from the test group of patients. The resulting model that exhibited the lowest Akaike information criterion was then selected for testing with the validation group of patients. RESULTS: A total of 284 patients who underwent lower extremity revascularization procedures were included in our study (140 in the test group, 144 in the validation group). In the test group, 17 patients (12.1%) developed severe groin wound infection requiring operative intervention. The best-fit predictive model developed from this group identified the following independent risk factors for severe groin wound infection: prior ipsilateral groin incision, female gender, body mass index, end-stage renal disease, malnutrition, and urgent or emergency procedure status. The correct classification rate of this model in the test group was 88.6%. The incidence of severe groin wound infection in the validation group was 13.9%, and application of our predictive model to this group yielded a correct classification rate of 86.1%. CONCLUSIONS: We have developed and validated a statistical model that accurately predicts those patients who are likely to sustain severe groin wound infection after lower extremity revascularization.

S-nitrosylation therapy to improve oxygen delivery of banked blood.

From the perspectives of disease transmission and sterility maintenance, the world's blood supplies are generally safe. However, in multiple clinical settings, red blood cell (RBC) transfusions are associated with adverse cardiovascular events and multiorgan injury. Because ∼85 million units of blood are administered worldwide each year, transfusion-related morbidity and mortality is a major public health concern. Blood undergoes multiple biochemical changes during storage, but the relevance of these changes to unfavorable outcomes is unclear. Banked blood shows reduced levels of S-nitrosohemoglobin (SNO-Hb), which in turn impairs the ability of stored RBCs to effect hypoxic vasodilation. We therefore reasoned that transfusion of SNO-Hb-deficient blood may exacerbate, rather than correct, impairments in tissue oxygenation, and that restoration of SNO-Hb levels would improve transfusion efficacy. Notably in mice, administration of banked RBCs decreased skeletal muscle pO2, but infusion of renitrosylated cells maintained tissue oxygenation. In rats, hemorrhage-induced reductions in muscle pO2 were corrected by SNO-Hb-repleted RBCs, but not by control, stored RBCs. In anemic awake sheep, stored renitrosylated, but not control RBCs, produced sustained improvements in O2 delivery; in anesthetized sheep, decrements in hemodynamic status, renal blood flow, and kidney function incurred following transfusion of banked blood were also prevented by renitrosylation. Collectively, our findings lend support to the idea that transfusions may be causally linked to ischemic events and suggest a simple approach to prevention (i.e., SNO-Hb repletion). If these data are replicated in clinical trials, renitrosylation therapy could have significant therapeutic impact on the care of millions of patients.

The impact of functional dependency on outcomes after complex general and vascular surgery.

OBJECTIVE: To describe the outcomes of functionally dependent patients who undergo major general or vascular surgery and to determine the relationship between functional health status and early postoperative outcomes. BACKGROUND: In contrast to frailty, functional health status is a relatively easy entity to define and to measure and therefore may be a more practical variable to assess in patients who are being considered for major surgery. To date, few studies have assessed the impact of functional health status on surgical outcomes. METHODS: Patients undergoing 1 of 10 complex general or vascular operations were extracted from the 2005 to 2010 America College of Surgeons National Surgical Quality Improvement Program database. Propensity score techniques were used to match patients with and without preoperative functional dependency on known patient- and procedure-related factors. The postoperative outcomes of this matched cohort were then compared. RESULTS: A total of 10,246 functionally dependent surgical patients were included for analysis. These patients were more acutely and chronically ill than functionally independent patients, and they had higher rates of mortality and morbidity for each of the 10 procedures analyzed. Propensity-matching techniques resulted in the creation of a cohort of functionally independent and dependent patients who were well matched for known patient- and procedure-related variables. Dependent patients from the matched cohort had a 1.75-fold greater odds of postoperative death (95% confidence interval: 1.54-1.98, P < 0.0001) than functionally independent patients. CONCLUSIONS: Preoperative functional dependency is an independent risk factor for mortality after major operation. Functional health status should be routinely assessed in patients who are being considered for complex surgery.

Predictors of 30-day postoperative stroke or death after carotid endarterectomy using the 2012 carotid endarterectomy-targeted American College of Surgeons National Surgical Quality Improvement Program database.

OBJECTIVE: This study used a recently released procedure-targeted multicenter data source to determine independent predictors of postoperative stroke or death in patients undergoing carotid endarterectomy (CEA) for carotid artery stenosis. METHODS: The 2012 CEA-targeted American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was used for this study. Patient, disease, and procedure characteristics of patients undergoing CEA were assessed. Multivariate logistic regression analysis was used to determine independent risk factors for 30-day postoperative stroke/death or other major complications. RESULTS: The analysis included 3845 patients undergoing CEA (58.1% with asymptomatic and 41.9% with symptomatic carotid disease). The overall 30-day postoperative stroke/death rate was 3.0% (1.9% in asymptomatic patients, 4.6% in symptomatic patients). The variables that maintained an independent association with postoperative stroke/death after adjustment for other known patient-related and procedure-related factors were age ≥80 years, active smoking, contralateral internal carotid artery stenosis of 80% to 99%, emergency procedure status, preoperative stroke, presence of one or more ACS NSQIP-defined high-risk characteristics (including any or all of New York Heart Association class III/IV congestive heart failure, left ventricular ejection fraction <30%, recent unstable angina, or recent myocardial infarction), and operative time ≥150 minutes. CONCLUSIONS: After adjustment for a comprehensive array of patient-related and procedure-related variables of particular import to patients with carotid artery stenosis, we have identified several factors that are independently associated with early stroke or death after CEA. These factors are generally related to the comorbid condition of CEA patients and to specific characteristics of their carotid disease, and not to technical features of the CEA procedure. Knowledge of these factors will assist surgeons in selecting appropriate patients for this procedure.

Risk factors for cranial nerve injury after carotid endarterectomy.

BACKGROUND: Although numerous studies have described the incidence of postoperative cranial nerve injury (CNI) after carotid endarterectomy (CEA), there have been few attempts to identify risk factors for this complication. METHODS: The 2012 CEA-targeted American College of Surgeons National Surgical Quality Improvement Program database was used to determine the incidence of CNI after CEA. Multivariate logistic regression analysis was performed to identify independent predictors of CNI after CEA, using a comprehensive array of patient-, carotid disease-, and procedure-related factors as potential predictor variables. RESULTS: Of the 3762 CEA patients who were included in our analysis, 84 (2.2%) were noted to have sustained CNI in the first 30 days after their operation. Independent predictors of this complication included age ≥80 years (reference group, <70 years; adjusted odds ratio [AOR] for CNI, 1.74; 95% confidence interval [CI], 1.00-3.03; P = .05), presence of a preoperative bleeding disorder (including patients in whom preoperative nonaspirin anticoagulation therapy was not stopped before CEA; AOR, 1.66; 95% CI, 1.03-2.68; P = .04), duration of operation (AOR, 1.15 for each 30-minute interval beyond an operative time of 90 minutes; 95% CI, 1.06-1.25; P = .001), and need for reoperation (AOR, 2.65; 95% CI, 1.03-6.80; P = .04). CONCLUSIONS: Our study demonstrates clinically evident CNI to be a relatively uncommon event after CEA at institutions that participate in the CEA-targeted American College of Surgeons National Surgical Quality Improvement Program and identifies four separate factors that are independently associated with an increased risk of CNI.