Dominique B. Buck

Long-Term Outcomes of Abdominal Aortic Aneurysm in the Medicare Population

BACKGROUND Randomized trials and observational studies have shown that perioperative morbidity and mortality are lower with endovascular repair of abdominal aortic aneurysm than with open repair, but the survival benefit is not sustained. In addition, concerns have been raised about the long-term risk of aneurysm rupture or the need for reintervention after endovascular repair. METHODS We assessed perioperative and long-term survival, reinterventions, and complications after endovascular repair as compared with open repair of abdominal aortic aneurysm in propensity-score-matched cohorts of Medicare beneficiaries who underwent repair during the period from 2001 through 2008 and were followed through 2009. RESULTS We identified 39,966 matched pairs of patients who had undergone either open repair or endovascular repair. The overall perioperative mortality was 1.6% with endovascular repair versus 5.2% with open repair (P<0.001). From 2001 through 2008, perioperative mortality decreased by 0.8 percentage points among patients who underwent endovascular repair (P=0.001) and by 0.6 percentage points among patients who underwent open repair (P=0.01). The rate of conversion from endovascular to open repair decreased from 2.2% in 2001 to 0.3% in 2008 (P<0.001). The rate of survival was significantly higher after endovascular repair than after open repair through the first 3 years of follow-up, after which time the rates of survival were similar. Through 8 years of follow-up, interventions related to the management of the aneurysm or its complications were more common after endovascular repair, whereas interventions for complications related to laparotomy were more common after open repair. Aneurysm rupture occurred in 5.4% of patients after endovascular repair versus 1.4% of patients after open repair through 8 years of follow-up (P<0.001). The rate of total reinterventions at 2 years after endovascular repair decreased over time (from 10.4% among patients who underwent procedures in 2001 to 9.1% among patients who underwent procedures in 2007). CONCLUSIONS Endovascular repair, as compared with open repair, of abdominal aortic aneurysm was associated with a substantial early survival advantage that gradually decreased over time. The rate of late rupture was significantly higher after endovascular repair than after open repair. The outcomes of endovascular repair have been improving over time. (Funded by the National Institutes of Health.).

Clinical Relevance of Cranial Nerve Injury following Carotid Endarterectomy

OBJECTIVES The benefit of carotid endarterectomy (CEA) may be diminished by cranial nerve injury (CNI). Using a quality improvement registry, we aimed to identify the nerves affected, duration of symptoms (transient vs. persistent), and clinical predictors of CNI. METHODS We identified all patients undergoing CEA in the Vascular Study Group of New England (VSGNE) between 2003 and 2011. Surgeon-observed CNI rate was determined at discharge (postoperative CNI) and at follow-up to determine persistent CNI (CNIs that persisted at routine follow-up visit). Hierarchical multivariable model controlling for surgeon and hospital was used to assess independent predictors for postoperative CNI. RESULTS A total of 6,878 patients (33.8% symptomatic) were included for analyses. CNI rate at discharge was 5.6% (n = 382). Sixty patients (0.7%) had more than one nerve affected. The hypoglossal nerve was most frequently involved (n = 185, 2.7%), followed by the facial (n = 128, 1.9%), the vagus (n = 49, 0.7%), and the glossopharyngeal (n = 33, 0.5%) nerve. The vast majority of these CNIs were transient; only 47 patients (0.7%) had a persistent CNI at their follow-up visit (median 10.0 months, range 0.3-15.6 months). Patients with perioperative stroke (0.9%, n = 64) had significantly higher risk of CNI (n = 15, CNI risk 23.4%, p < .01). Predictors for CNI were urgent procedures (OR 1.6, 95% CI 1.2-2.1, p < .01), immediate re-exploration after closure under the same anesthetic (OR 2.0, 95% CI 1.3-3.0, p < .01), and return to the operating room for a neurologic event or bleeding (OR 2.3, 95% CI 1.4-3.8, p < .01), but not redo CEA (OR 1.0, 95% CI 0.5-1.9, p = .90) or prior cervical radiation (OR 0.9, 95% CI 0.3-2.5, p = .80). CONCLUSIONS As patients are currently selected in the VSGNE, persistent CNI after CEA is rare. While conditions of urgency and (sub)acute reintervention carried increased risk for postoperative CNI, a history of prior ipsilateral CEA or cervical radiation was not associated with increased CNI rate.

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.

Endovascular treatment of abdominal aortic aneurysms

Patients with abdominal aortic aneurysms (AAAs) are usually treated with endovascular aneurysm repair (EVAR), which has become the standard of care in many hospitals for patients with suitable anatomy. Clinical evidence indicates that EVAR is associated with superior perioperative outcomes and similar long-term survival compared with open repair. Since the randomized, controlled trials that provided this evidence were conducted, however, the stent graft technology for infrarenal AAA has been further developed. Improvements include profile downsizing, optimization of sealing and fixation, and the use of low porosity fabrics. In addition, imaging techniques have improved, enabling better preoperative planning, stent graft placement, and postoperative surveillance. Also in the past few years, fenestrated and branched stent grafts have increasingly been used to manage anatomically challenging aneurysms, and experiments with off-label use of stent grafts have been performed to treat patients deemed unfit or unsuitable for other treatment strategies. Overall, the indications for endovascular management of AAA are expanding to include increasingly complex and anatomically challenging aneurysms. Ongoing studies and optimization of imaging, in addition to technological refinement of stent grafts, will hopefully continue to broaden the utilization of EVAR.

The effect of endovascular treatment on isolated iliac artery aneurysm treatment and mortality

OBJECTIVE Isolated iliac artery aneurysms are rare, but potentially fatal. The effect of recent trends in the use of endovascular iliac aneurysm repair (EVIR) on isolated iliac artery aneurysm-associated mortality is unknown. METHODS We identified all patients with a primary diagnosis of iliac artery aneurysm in the National Inpatient Sample from 1988 to 2011. We examined trends in management (open vs EVIR, elective and urgent) and overall isolated iliac artery aneurysm-related deaths (with or without repair). We compared in-hospital mortality and complications for the subgroup of patients undergoing elective open and EVIR from 2000 to 2011. RESULTS We identified 33,161 patients undergoing isolated iliac artery aneurysm repair from 1988 to 2011, of which there were 9016 EVIR and 4933 open elective repairs from 2000 to 2011. Total repairs increased after the introduction of EVIR, from 28 to 71 per 10 million United States (U.S.) population (P < .001). EVIR surpassed open repair in 2003. Total isolated iliac artery aneurysm-related deaths, due to rupture or elective repair, decreased after the introduction of EVIR from 4.4 to 2.3 per 10 million U.S. population (P < .001). However, urgent admissions did not decrease during this time period (15 to 15 procedures per 10 million U.S. population; P = .30). Among elective repairs after 2000, EVIR patients were older (72.4 vs 69.4 years; P = .002) and were more likely to have a history of prior myocardial infarction (14.0% vs 11.3%; P < .001) and renal failure (7.2% vs 3.6%; P < .001). Open repair had significantly higher rate of in-hospital mortality (1.8% vs 0.5%; P < .001) and complications (17.9% vs 6.7%; P < .001) and a longer length of stay (6.7 vs 2.3 days; P < .001). CONCLUSIONS Treatment of isolated iliac artery aneurysms has increased since the introduction of EVIR and is associated with lower perioperative mortality, despite a higher burden of comorbid illness. Decreasing iliac artery aneurysm-attributable in-hospital deaths are likely related primarily to lower elective mortality with EVIR rather than rupture prevention.

Management and outcomes of isolated renal artery aneurysms in the endovascular era

OBJECTIVE Isolated renal artery aneurysms are rare, and controversy remains about indications for surgical repair. Little is known about the impact of endovascular therapy on selection of patients and outcomes of renal artery aneurysms. METHODS We identified all patients undergoing open or endovascular repair of isolated renal artery aneurysms in the Nationwide Inpatient Sample from 1988 to 2011 for epidemiologic analysis. Elective cases were selected from the period 2000 to 2011 to create comparable cohorts for outcome comparison. We identified all patients with a primary diagnosis of renal artery aneurysms undergoing open surgery (reconstruction or nephrectomy) or endovascular repair (coil or stent). Patients with concomitant aortic aneurysms or dissections were excluded. We evaluated patient characteristics, management, and in-hospital outcomes for open and endovascular repair, and we examined changes in management and outcomes over time. RESULTS We identified 6234 renal artery aneurysm repairs between 1988 and 2011. Total repairs increased after the introduction of endovascular repair (8.4 in 1988 to 13.8 in 2011 per 10 million U.S. population; P = .03). Endovascular repair increased from 0 in 1988 to 6.4 in 2011 per 10 million U.S. population (P < .0001). However, there was no concomitant decrease in open surgery (5.5 in 1988 to 7.4 in 2011 per 10 million U.S. population; P = .28). From 2000 to 2011, there were 1627 open and 1082 endovascular elective repairs. Patients undergoing endovascular repair were more likely to have a history of coronary artery disease (18% vs 11%; P < .001), prior myocardial infarction (5.2% vs 1.8%; P < .001), and renal failure (7.7% vs 3.3%; P < .001). In-hospital mortality was 1.8% for endovascular repair, 0.9% for open reconstruction (P = .037), and 5.4% for nephrectomy (P < .001 compared with all revascularization). Complication rates were 12.4% for open repair vs 10.5% for endovascular repair (P = .134), including more cardiac (2.2% vs 0.6%; P = .001) and peripheral vascular complications (0.6% vs 0.0%; P = .014) with open repair. Open repair had a longer length of stay (6.0 vs 4.6 days; P < .001). After adjustment for other predictors of mortality, including age (odds ratio [OR], 1.05 per decade; 95% confidence interval [CI], 1.0-1.1; P = .001), heart failure (OR, 7.0; 95% CI, 3.1-16.0; P < .001), and dysrhythmia (OR, 5.9; 95% CI, 2.0-16.8; P = .005), endovascular repair was still not protective (OR, 1.6; 95% CI, 0.8-3.2; P = .145). CONCLUSIONS More renal artery aneurysms are being treated with the advent of endovascular techniques, without a reduction in operative mortality or a reduction in open surgery. Indications for repair of renal artery aneurysms should be re-evaluated.

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.

The impact of endovascular repair on specialties performing abdominal aortic aneurysm repair

BACKGROUND Abdominal aortic aneurysm (AAA) repair has been performed by various surgical specialties for many years. Endovascular aneurysm repair (EVAR) may be a disruptive technology, having an impact on which specialties care for patients with AAA. Therefore, we examined the proportion of AAA repairs performed by various specialties over time in the United States and evaluated the impact of the introduction of EVAR. METHODS The Nationwide Inpatient Sample (2001-2009) was queried for intact and ruptured AAA and for open repair and EVAR. Specific procedures were used to identify vascular surgeons (VSs), cardiac surgeons (CSs), and general surgeons (GSs) as well as interventional cardiologists and interventional radiologists for states that reported unique treating physician identifiers. Annual procedure volumes were subsequently calculated for each specialty. RESULTS We identified 108,587 EVARs and 85,080 open AAA repairs (3011 EVARs and 12,811 open repairs for ruptured AAA). VSs performed an increasing proportion of AAA repairs during the study period (52% in 2001 to 66% in 2009; P < .001). GSs and CSs performed fewer repairs during the same period (25% to 17% [P < .001] and 19% to 13% [P < .001], respectively). EVAR was increasingly used for intact (33% to 78% of annual cases; P < .001) as well as ruptured AAA repair (5% to 28%; P < .001). The proportion of intact open repairs performed by VSs increased from 52% to 65% (P < .001), whereas for EVAR, the proportion went from 60% to 67% (P < .001). The proportion performed by VSs increased for ruptured open repairs from 37% to 53% (P < .001) and for ruptured EVARs from 28% to 73% (P < .001). Compared with treatment by VSs, treatment by a CS (0.55 [0.53-0.56]) and GS (0.66 [0.64-0.68]) was associated with a decreased likelihood of undergoing endovascular rather than open AAA repair. CONCLUSIONS VSs are performing an increasing majority of AAA repairs, in large part driven by the increased utilization of EVAR for both intact and ruptured AAA repair. However, GSs and CSs still perform AAA repair. Further studies should examine the implications of these national trends on the outcome of AAA repair.

The impact of endovascular repair on management and outcome of ruptured thoracic aortic aneurysms

Background: Thoracic endovascular aortic repair (TEVAR) has become an alternative to open repair for the treatment of ruptured thoracic aortic aneurysms (rTAAs). The aim of this study was to assess national trends in the use of TEVAR for the treatment of rTAA and to determine its impact on perioperative outcomes. Methods: Patients admitted with an rTAA between 1993 and 2012 were identified from the National Inpatient Sample. Patients were grouped in accordance with their treatment: TEVAR, open repair, or nonoperative treatment. The primary outcomes were treatment trends over time and in‐hospital death. Secondary outcomes included perioperative complications and length of stay. Trend analyses were performed using the Cochran‐Armitage test for trend, and adjusted mortality risks were established using multivariable logistic regression analysis. Results: A total of 12,399 patients were included, with 1622 (13%) undergoing TEVAR, 2808 (23%) undergoing open repair, and 7969 (64%) not undergoing surgical treatment. TEVAR has been increasingly used from 2% of total admissions in 2003‐2004 to 43% in 2011‐2012 (P < .001). Concurrently, there was a decline in the proportion of patients undergoing open repair (29% to 12%; P < .001) and nonoperative treatment (69% to 45%; P < .001). The proportion of patients undergoing surgical repair has increased for all age groups since 1993‐1994 (P < .001 for all) but was most pronounced among those aged 80 years with a 7.5‐fold increase. After TEVAR was introduced, procedural mortality decreased from 36% in 2003‐2004 to 27% in 2011‐2012 (P < .001); mortality among those undergoing nonoperative treatment remained stable between 63% and 60% (P = .167). Overall mortality after rTAA admission decreased from 55% to 42% (P < .001). Since 2005, mortality for open repair was 33% and 22% for TEVAR (P < .001). In adjusted analysis, open repair was associated with a twofold higher mortality than TEVAR (odds ratio, 2.0; 95% confidence interval, 1.7‐2.5). Conclusions: TEVAR has replaced open repair as primary surgical treatment for rTAA. The introduction of endovascular treatment appears to have broadened the eligibility of patients for surgical treatment, particularly among the elderly. Mortality after rTAA admission has declined since the introduction of TEVAR, which is the result of improved operative mortality as well as the increased proportion of patients undergoing surgical repair.