Peter A. Soden

Percutaneous versus femoral cutdown access for endovascular aneurysm repair

OBJECTIVE Prior studies suggest that percutaneous access for endovascular abdominal aortic aneurysm repair (pEVAR) offers significant operative and postoperative benefits compared with femoral cutdown (cEVAR). National data on this topic, however, are limited. We compared patient selection and outcomes for elective pEVAR and cEVAR. METHODS We identified all patients undergoing either pEVAR (bilateral percutaneous access, whether successful or not) or cEVAR (at least one planned groin cutdown) for abdominal aortic aneurysms from January 2011 to December 2013 in the Targeted Vascular data set from the American College of Surgeons National Surgical Quality Improvement Program database. Emergent cases, ruptures, cases with an iliac conduit, and cases with a preoperative wound infection were excluded. Groups were compared by χ(2) test or t-test or the Mann-Whitney test where appropriate. RESULTS We identified 4112 patients undergoing elective EVAR, 3004 cEVAR patients (73%) and 1108 pEVAR patients (27%). Of all EVAR patients, 26% had bilateral percutaneous access; 1.0% had attempted percutaneous access converted to cutdown (4% of pEVARs); and the remainder had a planned cutdown, 63.9% bilateral and 9.1% unilateral. There were no significant differences in age, gender, aneurysm diameter, or prior open abdominal surgery. Patients undergoing cEVAR were less likely to have congestive heart failure (1.5% vs 2.4%; P = .04) but more likely to undergo any concomitant procedure during surgery (32% vs 26%; P < .01) than patients undergoing pEVAR. Postoperatively, pEVAR patients had shorter operative time (mean, 135 vs 152 minutes; P < .01), shorter length of stay (median, 1 day vs 2 days; P < .01), and fewer wound complications (2.1% vs 1.0%; P = .02). On multivariable analysis, the only predictor of percutaneous access failure was performance of any concomitant procedure (odds ratio, 2.0; 95% confidence interval, 1.0-4.0; P = .04). CONCLUSIONS Currently, one in four patients treated at Targeted Vascular National Surgical Quality Improvement Program centers are getting pEVAR, which is associated with a high success rate, shorter operation time, shorter length of stay, and fewer wound complications compared with cEVAR.

Sex differences in mortality and morbidity following repair of intact abdominal aortic aneurysms

Objective: Medicare studies have shown increased perioperative mortality in women compared with men following endovascular and open abdominal aortic aneurysm (AAA) repair. However, a recent regional study of high‐volume centers, adjusting for anatomy but limited in sample size, did not show sex to be predictive of worse outcomes. This study aimed to evaluate sex differences after intact AAA repair in a national clinical registry. Methods: The targeted vascular module of the National Surgical Quality Improvement Program was queried to identify patients undergoing endovascular aneurysm repair (EVAR) or open repair for intact, infrarenal AAA from 2011 to 2014. Univariate analysis was performed using the Fisher exact test and Mann‐Whitney test. Multivariable logistic regression was used to account for differences in comorbidities, aneurysm details, and operative characteristics. Results: We identified 6661 patients (19% women) who underwent intact AAA repair (87% EVAR; 83% women vs 88% men; P < .001). Women were older (median age, 76 vs 73 years; P < .001), had smaller aneurysms (median, 5.4 vs 5.5 cm; P < .001), and had more chronic obstructive pulmonary disease (22% vs 17%; P < .001). Among patients undergoing EVAR, women had longer operative times (median, 138 [interquartile range, 103–170] vs 131 [106–181] minutes; P < .01) and more often underwent renal (6.3% vs 4.1%; P < .01) and lower extremity (6.6% vs 3.8%; P < .01) revascularization. After open repair, women had shorter operative time (215 [177–304] vs 226 [165–264] minutes; P = .02), but women less frequently underwent lower extremity revascularization (3.1% vs 8.2%; P = .03). Thirty‐day mortality was higher in women after EVAR (3.2% vs 1.2%; P < .001) and open repair (8.0% vs 4.0%; P = .04). After adjusting for repair type, age, aneurysm diameter, and comorbidities, female sex was independently associated with mortality (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1–2.6; P = .02) and major complications (OR, 1.4; CI, 1.1–1.7; P < .01) after intact AAA repair. However, after adjusting for aortic size index rather than for aortic diameter, the association between female sex and mortality (OR, 1.5; CI, 0.98–2.4; P = .06) and major complications (OR, 1.1; CI, 0.9–1.4; P = .24) was reduced. Conclusions: Women were at higher risk for 30‐day death and major complications after intact AAA repair. Some of this disparity may be explained by differences in aortic size index, which should be further evaluated to determine the ideal threshold for repair.

The effect of surgeon and hospital volume on mortality after open and endovascular repair of abdominal aortic aneurysms

Background: Higher hospital and surgeon volumes are independently associated with improved mortality after open repair of abdominal aortic aneurysms (AAAs) in the era before endovascular AAA repair (EVAR). The effects of both surgeon and hospital volume on mortality after EVAR and open repair in the current era are less well defined. Methods: We studied Medicare beneficiaries who underwent elective AAA repair from 2001 to 2008. Volume was measured by procedure type during the 1‐year period preceding each procedure and was further categorized into quintiles of volume for surgeon and hospital. Multilevel logistic regression models were used to evaluate the effect of surgeon volume, accounting for hospital volume, on mortality after adjusting for patient demographic and comorbid conditions as well as the analogous effect of hospital volume adjusting for surgeon volume. The multilevel models included random effects for surgeon and hospital to account for the clustering of multiple patients within the same surgeon and within the same hospital. Results: We studied 122,495 patients who underwent AAA repair (open: 45,451; EVAR: 77,044). After EVAR, perioperative mortality did not differ by surgeon volume (quintile 1 [0–6 EVARs]: 1.8%; quintile 5 [28–151 EVARs]: 1.6%; P = .29), but decreased with greater hospital volume (quintile 1 [0–9 EVARs]: 1.9%; quintile 5 [49–198 EVARs]: 1.4%; P < .01). After open repair, perioperative mortality decreased with both higher surgeon volume (quintile 1 [0–3 open repairs]: 6.4%; quintile 5 [14–62 open repairs]: 3.8%; P < .01) and hospital volume (quintile 1 [0–5 open repairs]: 6.3%; quintile 5 [14–62 open repairs]: 3.8%; P < .01). After adjustment for other predictors, surgeon volume was not associated with perioperative mortality after EVAR (odds ratio [OR], 0.9; 95% confidence interval [CI], 0.7–1.1); however, hospital volume was associated with higher perioperative mortality (quintile 1: OR, 1.5; 95% CI, 1.2–1.9; quintile 2: OR, 1.3; 95% CI, 1.02–1.6; and quintile 3: OR, 1.2; 95% CI, 1.01–1.5, compared with 5). After open repair, higher surgeon volume was also associated with lower mortality (quintile 1: OR, 1.5; 95% CI, 1.3–1.8; quintile 2: OR, 1.3; 95% CI, 1.1–1.6; and quintile 3: OR, 1.2; 95% CI, 1.1–1.4, compared with 5). Risk of mortality also was higher for patients treated at lower‐volume hospitals (quintile 1: OR, 1.3; 95% CI, 1.1–1.5; quintile 2: OR, 1.3; 95% CI, 1.1–1.5; and quintile 3: OR, 1.2; 95% CI, 1.1–1.4, compared with 5). Conclusions: After EVAR, hospital volume is minimally associated with perioperative mortality, with no such association for surgeon volume. After open AAA repair, surgeon and hospital volume are both strongly associated with mortality. These findings suggest that open surgery should be concentrated in hospitals and surgeons with high volume.

Regional variation in patient selection and treatment for lower extremity vascular disease in the Vascular Quality Initiative

Objective: Prior studies on the cause and effect of surgical variation have been limited by utilization of administrative data. The Vascular Quality Initiative (VQI), a robust national clinical registry, provides anatomic and perioperative details allowing a more robust analysis of variation in surgical practice. Methods: The VQI was used to identify all patients undergoing infrainguinal open bypass or endovascular intervention from 2009 to 2014. Asymptomatic patients were excluded. The 16 regional groups of the VQI were used to compare variation in patient selection, operative indication, technical approach, and process measures. χ2 analysis was used to assess for differences across regions where appropriate. Results: A total of 52,373 interventions were included (31%). Of the 16,145 bypasses, 5% were performed for asymptomatic disease, 26% for claudication, 56% for chronic limb‐threatening ischemia (CLI) (61% of these for tissue loss), and 13% for acute limb‐threatening ischemia. Of the 35,338 endovascular procedures, 4% were for asymptomatic disease, 40% for claudication, 46% for CLI (73% tissue loss), and 12% for acute limb‐threatening ischemia. Potentially unwarranted variation included proportion of prosthetic conduit for infrapopliteal bypass in claudication (13%‐41%, median, 29%; P < .001), isolated tibial endovascular intervention for claudication (0.0%‐5.0%, median, 3.0%; P < .001), discharge on antiplatelet and statin (bypass: 62%‐84%; P < .001; endovascular: 63%‐89%; P < .001), and ultrasound guidance for percutaneous access (claudication: range, 7%‐60%; P < .001; CLI: 5%‐65%; P < .001). Notable areas needing further research with significant variation include proportion of CLI vs claudication treated by bypass (38%‐71%; P < .001) and endovascular intervention (28%‐63%; P < .001), and use of closure devices in percutaneous access (claudication; 26%‐76%; P < .001; CLI: 30%‐78%; P < .001). Conclusions: Significant variation exists both in areas where evidence exists for best practice and, therefore, potentially unwarranted variation, and in areas of clinical ambiguity. Quality improvement efforts should be focused on reducing unwarranted variation. Further research should be directed at identifying best practice where no established guidelines and high variation exists.

Risk factors for 30-day unplanned readmission following infrainguinal endovascular interventions

Objective: Unplanned hospital readmissions following surgical interventions are associated with adverse events and contribute to increasing health care costs. Despite numerous studies defining risk factors following lower extremity bypass surgery, evidence regarding readmission after endovascular interventions is limited. This study aimed to identify predictors of 30‐day unplanned readmission following infrainguinal endovascular interventions. Methods: We identified all patients undergoing an infrainguinal endovascular intervention in the targeted vascular module of the American College of Surgeons National Surgical Quality Improvement Program between 2012 and 2014. Perioperative outcomes were stratified by symptom status (chronic limb‐threatening ischemia [CLI] vs claudication). Patients who died during index admission and those who remained in the hospital after 30 days were excluded. Indications for unplanned readmission related to the index procedure were evaluated. Multivariable logistic regression was used to identify preoperative and in‐hospital (during index admission) risk factors of 30‐day unplanned readmission. Results: There were 4449 patients who underwent infrainguinal endovascular intervention, of whom 2802 (63%) had CLI (66% tissue loss) and 1647 (37%) had claudication. The unplanned readmission rates for CLI and claudication patients were 16% (n = 447) and 6.5% (n = 107), respectively. Mortality after index admission was higher for readmitted patients compared with those not readmitted (CLI, 3.4% vs 0.7% [P < .001]; claudication, 2.8% vs 0.1% [P < .01]). Approximately 50% of all unplanned readmissions were related to the index procedure. Among CLI patients, the most common indication for readmission related to the index procedure was wound or infection related (42%), whereas patients with claudication were mainly readmitted for recurrent symptoms of peripheral vascular disease (28%). In patients with CLI, predictors of unplanned readmission included diabetes (odds ratio, 1.3; 95% confidence interval, 1.01‐1.6), congestive heart failure (1.6; 1.1‐2.5), renal insufficiency (1.7; 1.3‐2.2), preoperative dialysis (1.4; 1.02‐1.9), tibial angioplasty/stenting (1.3; 1.04‐1.6), in‐hospital bleeding (1.9; 1.04‐3.5), in‐hospital unplanned return to the operating room (1.9; 1.1‐3.5), and discharge other than to home (1.5; 1.1‐2.0). Risk factors for those with claudication were dependent functional status (3.5; 1.4‐8.7), smoking (1.6; 1.02‐2.5), diabetes (1.5; 1.01‐2.3), preoperative dialysis (3.6; 1.6‐8.3), procedure time exceeding 120 minutes (1.8; 1.1‐2.7), in‐hospital bleeding (2.9; 1.2‐7.4), and in‐hospital unplanned return to the operating room (3.4; 1.2‐9.4). Conclusions: Unplanned readmission after endovascular treatment is relatively common, especially in patients with CLI, and is associated with substantially increased mortality. Awareness of these risk factors will help providers identify patients at high risk who may benefit from early surveillance, and prophylactic measures focused on decreasing postoperative complications may reduce the rate of readmission.

Perioperative outcome of endovascular repair for complex abdominal aortic aneurysms

Background: As endovascular aneurysm repair (EVAR) continues to advance, eligibility of patients with anatomically complex abdominal aortic aneurysms (AAAs) for EVAR is increasing. However, whether complex EVAR is associated with favorable outcome over conventional open repair and how outcomes compare with infrarenal EVAR remains unclear. This study examined perioperative outcomes of patients undergoing complex EVAR, focusing on differences with complex open repair and standard infrarenal EVAR. Methods: We identified all patients undergoing nonruptured complex EVAR, complex open repair, and infrarenal EVAR in the American College of Surgeons National Surgical Quality Improvement Program Targeted Vascular Module. Aneurysms were considered complex if the proximal extent was juxtarenal or suprarenal or when the Zenith Fenestrated endograft (Cook Medical, Bloomington, Ind) was used. Independent risks were established using multivariable logistic regression analysis. Results: Included were 4584 patients, with 411 (9.0%) undergoing complex EVAR, 395 (8.6%) undergoing complex open repair, and 3778 (82.4%) undergoing infrarenal EVAR. Perioperative mortality was 3.4% after complex EVAR, 6.6% after open repair (P = .038), and 1.5% after infrarenal EVAR (P = .005). Postoperative acute kidney injuries occurred in 2.3% of complex EVAR patients, in 9.5% of those undergoing complex open repair (P < .001), and in 0.9% of infrarenal EVAR patients (P = .007). Compared with complex EVAR, complex open repair was an independent predictor of 30‐day mortality (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.1‐4.4), renal function deterioration (OR, 4.8; 95% CI, 2.2‐10.5), and any complication (OR, 3.7; 95% CI, 2.5‐5.5). When complex vs infrarenal EVAR were compared, infrarenal EVAR was associated with favorable 30‐day mortality (OR, 0.5; 95% CI, 0.2‐0.9), and renal outcome (OR, 0.4; 95% CI, 0.2‐0.9). Conclusions: In this study assessing the perioperative outcomes of patients undergoing repair for anatomically complex AAAs, complex EVAR had fewer complications than complex open repair but carried a higher risk of adverse outcomes than infrarenal EVAR. Further research is warranted to determine whether the benefits of EVAR compared with open repair for complex AAA treatment are maintained during long‐term follow‐up.

Predictors of renal dysfunction after endovascular and open repair of abdominal aortic aneurysms

Objective: Renal complications after repair of abdominal aortic aneurysms (AAAs) have been associated with increased morbidity and mortality. However, limited data have assessed risk factors for renal complications in the endovascular era. This study aimed to identify predictors of renal complications after endovascular AAA repair (EVAR) and open repair. Methods: Patients who underwent EVAR or open repair of a nonruptured infrarenal AAA between 2011 and 2013 were identified in the National Surgical Quality Improvement Project Targeted Vascular module. Patients on hemodialysis preoperatively were excluded. Renal complications were defined as new postoperative dialysis or creatinine increase >2 mg/dL. Patient demographics, comorbidities, glomerular filtration rate (GFR), operative details, and outcomes were compared using univariate analysis between those with and without renal complications. Multivariable logistic regression was used to identify independent predictors of renal complications. Results: We identified 4503 patients who underwent elective repair of an infrarenal AAA (EVAR: 3869, open repair: 634). Renal complication occurred in 1% of patients after EVAR and in 5% of patients after open repair. There were no differences in comorbidities between patients with and without renal complications. A preoperative GFR <60 mL/min/1.73m2 occurred more frequently among patients with renal complications (EVAR: 81% vs 37%, P < .01; open: 60% vs 34%, P < .01). The 30‐day mortality was also significantly increased (EVAR: 55% vs 1%, P < .01; open: 30% vs 4%, P < .01). After adjustment, renal complications were strongly associated with 30‐day mortality (odds ratio [OR], 38.3; 95% confidence interval [CI], 20.4–71.9). Independent predictors of renal complications included GFR <60 mL/min/1.73m2 (OR, 4.6; 95% CI, 2.4–8.7), open repair (OR, 2.6; 95% CI, 1.3–5.3), transfusion (OR, 6.1; 95% CI, 3.0–12.6), and prolonged operative time (OR, 3.0; 95% CI, 1.6–5.6). Conclusions: Predictors of renal complications include elevated baseline GFR, open approach, transfusion, and prolonged operative time. Given the dramatic increase in mortality associated with renal complications, care should be taken to use renal protective strategies, achieve meticulous hemostasis to limit transfusions, and to use an endovascular approach when technically feasible.

Significant regional variation exists in morbidity and mortality after repair of abdominal aortic aneurysm.

Objective: Limited data exist comparing perioperative morbidity and mortality after open and endovascular abdominal aortic aneurysm (AAA) repair (EVAR) among regions of the United States. This study evaluated the regional variation in mortality and perioperative outcomes after repair of AAAs. Methods: The Vascular Quality Initiative (VQI) was used to identify patients undergoing open AAA repair and EVAR between 2009 and 2014. Ruptured and intact aneurysms were evaluated separately, and the analysis of intact aneurysms was limited to infrarenal AAAs. All 16 regions of the VQI were deidentified, and those with <100 open repairs were combined to eliminate the effect of low‐volume regions. Regional variation was evaluated using χ2 and Fisher exact tests. Regional rates were compared against current quality benchmarks. Results: Perioperative outcomes from 14 regions were compared. After open repair of intact aneurysms, no significant variation was seen in 30‐day or in‐hospital mortality; however, multiple regions exceeded the Society for Vascular Surgery benchmark for in‐hospital mortality after open repair of intact aneurysms of <5% (range, 0%‐7%; P = .55). After EVAR, all regions met the Society for Vascular Surgery benchmark of <3% (range, 0%‐1%; P = .75). Significant variation in in‐hospital mortality existed after open (14%‐63%; P = .03) and endovascular (3%‐32%; P = .03) repair of ruptured aneurysms across the VQI regional groups. After repair of intact aneurysms, wide variation was seen in prolonged length of stay (>7 days for open repair: 32%‐53%, P = .54; >2 days for EVAR: 16‐43%, P < .01), transfusion (open: 10%‐35%, P < .01; EVAR: 7%‐18%, P < .01), use of vasopressors (open: 19%‐37%, P < .01; EVAR: 3%‐7%, P < .01), and postoperative myocardial infarction (open: 0%‐13%, P < .01; EVAR: 0%‐3%, P < .01). After open repair, worsening renal function (6%‐18%; P = .04) and respiratory complications (6%‐20%; P = .20) were variable across regions. The frequency of endoleak at completion of EVAR also had considerable variation (15%‐38%; P < .01). Conclusions: Despite limited variation, multiple regions do not meet current benchmarks for in‐hospital mortality after open AAA repair for intact aneurysms. Significant regional variation exists in perioperative outcomes and length of stay, and mortality is widely variable after repair for rupture. These data identify important areas for quality improvement initiatives and clinical practice guidelines.

Clinical presentation, management, follow-up, and outcomes of isolated celiac and superior mesenteric artery dissections

Objective: Isolated visceral artery dissections are rare entities with no current consensus guidelines for treatment and follow‐up. This study aims to evaluate the presentation, management, outcomes, and follow‐up practices for patients with isolated visceral artery dissections and to compare those with and without symptoms. Methods: In this retrospective analysis, we identified all patients with isolated celiac artery and/or isolated superior mesenteric artery dissections at a single institution between September 2006 and December 2014. Patients with concomitant aortic dissections were excluded. Cases were stratified by symptom status. Presentation, anatomic findings, treatment, outcomes, and follow‐up imaging were then compared between symptomatic and asymptomatic patients. Results: We identified 25 patients including 15 with symptoms and 10 without. There were no differences in patient comorbidities; however, symptomatic patients more frequently presented with thrombus (n = 10; 67% vs n = 1; 10%; P = .01) and inflammation (n = 8; 53% vs n = 1; 10%; P = .04), and trended toward increased stenosis (n = 12; 80% vs n = 4; 40%; P = .09) compared with asymptomatic patients. All asymptomatic patients were treated with observation alone with vessel diameter enlargement noted in 33% (n = 2) of patients on follow‐up imaging. Among symptomatic patients, standard treatment included a short course of anticoagulation (mean, 4.5 months) with lifelong antiplatelet therapy. Three patients underwent operative intervention for persistent or worsening symptoms, two during the index admission and one 10 months after presentation for chronic abdominal pain. Approximately 70% (n = 17) of patients in each group had follow‐up imaging (computed tomography angiography: n = 14; 56%; magnetic resonance angiography: n = 4; 16%; ultrasound: n = 13; 52%). Among patients treated nonoperatively, no patients complained of symptoms at follow‐up, and 50% of those with inflammation on initial imaging had resolution. Twenty‐five percent (n = 4) of patients had an increase in vessel size; however, all vessels remained less than 2 cm in maximal diameter. There were no ruptures or related deaths in either group. Conclusions: Among patients with visceral artery dissection, no ruptures occurred but diameter enlargement was documented. This disease progression suggests that routine surveillance may be appropriate; however, transitioning early to ultrasound imaging should be considered to decrease radiation, contrast, and associated costs.

Results for primary bypass versus primary angioplasty/stent for lower extremity chronic limb-threatening ischemia

Background: Long‐term results comparing percutaneous transluminal angioplasty with or without stenting (PTA/S) and open surgical bypass for chronic limb‐threatening ischemia (CLTI) in patients who have had no prior intervention are lacking. Methods: All patients undergoing a first‐time lower extremity revascularization for CLTI by vascular surgeons at our institution from 2005 to 2014 were retrospectively reviewed. Outcomes included perioperative complications, wound healing, restenosis, primary patency, reintervention, major amputation, RAS events (ie, reintervention, major amputation, or stenosis), and mortality. Outcomes were evaluated using χ2, Kaplan‐Meier, and Cox regression analyses. Results: Of the 2869 total lower extremity revascularizations performed between 2005 and 2014, there were 1336 that fit our criteria of a first‐time lower extremity intervention for CLTI (668 bypass procedures and 668 PTA/S procedures). Bypass patients were younger (71 vs 72 years; P = .02) and more often male (62% vs 56%; P < .02). Total mean hospital length of stay (LOS) was significantly longer after a first‐time bypass (10 vs 8 days; P < .001), as were mean preoperative LOS (4 vs 3 days; P < .01) and postoperative LOS (7 vs 5 days; P < .001). There was no difference in perioperative mortality (3% vs 3%; P = .63). Surgical site infection occurred in 10% of bypass patients. Freedom from reintervention was significantly higher in patients undergoing a first‐time bypass procedure (62% vs 52% at 3 years; P = .04), as was freedom from restenosis (61% vs 45% at 3 years; P < .001). Complete wound healing at 6‐month follow‐up was significantly better after an initial bypass (43% vs 36%; P < .01). A Cox regression model of all patients showed that reintervention was predicted by a first‐time PTA/S (hazard ratio, 1.6; 95% confidence interval, 1.3‐2.1) and both preoperative femoropopliteal TransAtlantic Inter‐Society Consensus (TASC) C and TASC D lesions (2.0 [1.3‐3.1] and 1.8 [1.3‐2.7], respectively). Major amputation among all patients was predicted by an initial presentation of gangrene (2.5 [1.3‐5.0]), dialysis dependence (1.9 [1.3‐2.9]), diabetes (2.0 [1.1‐3.8]), and preoperative femoropopliteal TASC D lesions (2.1 [1.1‐4.0]) and was not predicted by procedure type. Conclusions: In this retrospective analysis, bypass for the primary treatment of CLTI showed improved 6‐month wound healing, higher freedom from restenosis, improved patency rates, significantly fewer reinterventions, and higher survival than PTA/S within 3 years; however, a bypass‐first approach was associated with increased total hospital LOS and wound infection. Perioperative mortality and amputation rates were similar between procedure types.