Christopher J. Abularrage

Endovascular management of patients with critical limb ischemia

BACKGROUND Although percutaneous intervention (PTA) is considered first-line therapy for peripheral vascular disease in many scenarios, its role in critical limb ischemia (CLI), wherein anatomic disease is more extensive, remains unclear. In the present study, late (5-year) clinical and patency data for PTA in CLI are defined. METHODS From January 2002 to December 2007, 409 patients underwent infrainguinal PTA ± stent for CLI (Rutherford IV-VI) of 447 limbs. Primary patency, assisted patency, limb salvage, and survival were assessed using Kaplan-Meier. Predictors of patency, limb salvage, and death were determined using multivariate models. RESULTS Demographics included age (70 ± 12 years old), diabetes (65.8%), and dialysis dependence (13%). The superficial femoral artery was treated in 58% of the patients, 16% were limited to the crural vessels, 38% had multilevel treatment, and stents were placed in 26%. Eighty percent of patients received postprocedure clopidogrel. Mean follow-up was 28 months (0-83). Five-year primary and assisted patency were 31% ± 0.04 and 75% ± 0.04, respectively. Limb salvage at 5 years was 74% ± 0.038. Sixty-three patients had major amputations. Survival at 5 years was 39% ± 0.03. Multivariate analysis identified dialysis dependence (P = .0005; 2.7 [1.6-4.8]), ≤1 vessel runoff (P = .02; 1.5 [1.1-2.0]), and warfarin use (P = .001; 1.7 [1.25-2.3]) as negative predictors of primary patency, but none of these were negative predictors of assisted patency. Dialysis dependence (P = .006; 2.5 [1.3-4.8]), female gender (P = .02; 2.0 [1.1-3.7]), and ≤1 vessel run-off (P = .04; 1.8 [1.0-3.2]) predicted limb loss. Dialysis dependence (P = .0003; 2.3 [1.5-3.5]), diabetes (P = .04; 1.5 [0.5-2.1]), and poor run-off (P = .04; 1.6 [1.2-2.1]) were predictors of mortality. CONCLUSION Although primary patency is low, excellent limb salvage rates can be achieved in patients with CLI through close follow-up and secondary interventions. These data, and the 12% annual death rate, validate PTA as first-line therapy in patients with CLI.

Preoperative functional status predicts perioperative outcomes after infrainguinal bypass surgery

OBJECTIVE Infrainguinal surgical bypass (BPG) is a durable method for lower extremity revascularization, but is accompanied by significant 30-day morbidity and mortality (MM). The goal of this study is to relate preoperative functional status, a defined metric in the National Surgical Quality Improvement Program (NSQIP) database, to perioperative MM. METHODS Between January 1, 2005 and December 31, 2007, all patients who underwent BPG from the NSQIP private sector database were reviewed. The primary end-point was 30-day MM. Patients were stratified by preoperative functional status: independent (IND) vs dependent (DEP). Associated patient demographic/clinical data were analyzed using univariate and multivariate methods. Composite odds ratios were constructed with clusters of high-risk comorbidities. RESULTS There were 5639 BPG patients (4600 [81.6%] IND and 1039 [18.4%]) DEP. DEP patients were significantly older (71.6 +/- 11.8 vs 66.8 +/- 11.8 years; P < .0001), had more chronic obstructive pulmonary disease (COPD) (16.7% vs 11.4%; P < .0001), diabetes (54.2% vs 40.7%; P < .0001), dialysis dependence (16.4% vs 5.6%; P < .0001), and critical limb ischemia (64.6% vs 44.0%; P < .0001). DEP patients had a higher incidence of death (6.1% vs 1.5%; P < .0001) and major complications (30.3% vs 14.2%; P < .0001). DEP was an independent predictor of major complications (odds ratio [OR]: 2.0; 95% confidence interval [CI]: [1.7-2.4]; P < .0001) major systemic complications (2.5 [1.9-3.2]; P < .0001), major operative site complications (1.6 [1.4-1.9]; P < .0001) and death (2.3[1.6-3.4]; P < .0001). The combination of DEP with emergency surgery, Cr > 1.8, or rest pain increased the odds of major complications by five, seven, or 11-fold, respectively. The combination of DEP with hemodialysis, emergency surgery, or age > or = 80 years increased the odds of death by 13, 38, or 87-fold, respectively. CONCLUSION Preoperative DEP is significantly correlated with all adverse 30-day outcomes in BPG patients. Furthermore, when combined in high-risk composites with specific preoperative clinical variables, DEP is associated with prohibitive MM, thereby identifying patient cohorts that may be unsuitable for BPG.

Preoperative variables predict persistent type 2 endoleak after endovascular aneurysm repair

OBJECTIVE Persistent type 2 endoleaks (PT2, present >or=6 months) after endovascular aneurysm repair (EVAR) are associated with adverse outcomes. This study evaluated the preoperative risk factors and natural history of PT2 in order to define a population at high risk. METHODS From January 1999 to December 2007, 595 of 832 EVAR patients had long-term computed tomography follow-up and comprised the study cohort. Preoperative anatomic and clinical variables were correlated with PT2 using Cox regression. Composite hazard ratios (HRs) were constructed with clusters of high-risk preoperative variables. Primary end points, including spontaneous resolution, sac enlargement >5 mm, and freedom from reintervention, were evaluated using Kaplan-Meier analysis. RESULTS There were 136 PT2 patients (23%) with a median follow-up of 34.8 months (range, 6.4-121.2 months). Positive predictive factors included patent inferior mesenteric artery (IMA; HR, 4.00; 95% confidence interval [CI], 1.62-9.90; P = .003), increasing number of patent lumbar arteries (HR, 1.24; 95% CI, 1.10-1.41; P = .0006), increasing age (HR, 1.04; 95% CI, 1.01-1.06; P = .005), and increasing luminal diameter on CT-contrast opacified lumen (HR, 1.03; 95% CI, 1.02-1.05; P = .0001). During follow-up, spontaneous PT2 resolution occurred in 34 patients (25%), sac diameter remained stable in 63 (46%), and rupture occurred in 2 (1.5%). Kaplan-Meier analysis estimated that 35.2% +/- 5.6% (95% CI, 23.8%-46.2%) of PT2 resolve spontaneously at 5 years after the index procedure. Freedom from sac enlargement >5 mm was 54.6% +/- 7.2% (95% CI, 40.6%-69.4%) at 5 years. Fifty-nine reinterventions were performed in 39 patients with PT2. Freedom from reintervention was 67.3% +/- 5.0% (95% CI, 57.0%-77.0%) at 5 years. The combination of a patent IMA and one risk factor of more than six patent lumbar arteries, maximum luminal diameter >30 mm, or age >70 years increased the odds of PT2 approximately ninefold. The combination of a patent IMA and any two risk factors increased the odds of PT2 approximately 18-fold. CONCLUSIONS Several readily identifiable preoperative variables are associated with PT2 whose natural history was benign in but 35% of patients. On the basis of the composite high-risk HRs, there is accordingly a cohort of patients in whom perioperative interventions to preclude PT2 should be considered.

Comparison of open and endovascular treatment of acute mesenteric ischemia

INTRODUCTION Acute mesenteric ischemia (AMI) is a commonly fatal result of inadequate bowel perfusion that requires immediate evaluation by both vascular and general surgeons. Treatment often involves vascular repair as well as bowel resection and the possible need for parenteral nutrition. Little data exist regarding the rates of bowel resection following endovascular vs open repair of AMI. METHODS Using the National Inpatient Sample database, admissions from 2005 through 2009 were identified according to International Classification of Diseases, Ninth Revision codes correlating to both AMI (557.0) and subsequent vascular intervention (39.26, 38.16, 38.06, 39.9, 99.10). Patients with a diagnosis of AMI but no intervention or nonemergent admission status were excluded. Patient level data regarding age, gender, and comorbidities were also examined. Outcome measures included mortality, length of stay, the need for bowel resection (45.6, 45.71-9, 45.8), or infusion of total parenteral nutrition (TPN; 99.10) during the same hospitalization. Statistical analysis was conducted by χ(2) tests and Wilcoxon rank-sum comparisons. RESULTS Of 23,744 patients presenting with AMI, 4665 underwent interventional treatment from 2005 through 2009. Of these patients, 57.1% were female, and the mean age was 70.5 years. A total of 679 patients underwent vascular intervention; 514 (75.7%) underwent open surgery and 165 (24.3%) underwent endovascular treatment overall during the study period. The proportion of patients undergoing endovascular repair increased from 11.9% of patients in 2005 to 30.0% in 2009. Severity of comorbidities, as measured by the Charlson index, did not differ significantly between the treatment groups. Mortality was significantly more commonly associated with open revascularization compared with endovascular intervention (39.3% vs 24.9%; P = .01). Length of stay was also significantly longer in the patient group undergoing open revascularization (12.9 vs 17.1 days; P = .006). During the study time period, 14.4% of patients undergoing endovascular procedures required bowel resection compared with 33.4% for open revascularization (P < .001). Endovascular repair was also less commonly associated with requirement for TPN support (13.7% vs 24.4%; P = .025). CONCLUSIONS Endovascular intervention for AMI had increased significantly in the modern era. Among AMI patients undergoing revascularization, endovascular treatment was associated with decreased mortality and shorter length of stay. Furthermore, endovascular intervention was associated with lower rates of bowel resection and need for TPN. Further research is warranted to determine if increased use of endovascular repair could improve overall and gastrointestinal outcomes among patients requiring vascular repair for AMI.

Improved results using Onyx glue for the treatment of persistent type 2 endoleak after endovascular aneurysm repair.

OBJECTIVE Persistent type 2 (PT2) endoleaks (present ≥ 6 months) after endovascular aneurysm repair are associated with adverse outcomes, and selective secondary intervention is indicated in those patients with an expanding aneurysm sac. This study evaluated the outcomes of secondary intervention for PT2. METHODS From 1999 to 2007, 136 patients who underwent endovascular aneurysm repair developed PT2 and comprised the study cohort. Primary end points included PT2 resolution (secondary interventional success) and survival, and were evaluated using multiple logistic regression and Kaplan-Meier analyses, respectively. RESULTS Fifty-one patients underwent a total of 68 secondary interventions for PT2 with expanding aneurysm sacs with a median postsecondary interventional follow-up of 13.7 months. Secondary interventions included 20 inferior mesenteric artery coil embolizations, 17 Onyx glue embolizations, 11 aneurysm sac coil embolizations, 10 non-Onyx glue embolizations, 7 lumbar artery coil embolizations, 2 open lumbar ligations, and 1 graft explant. The overall secondary interventional success rate was 43% (29 of 68). Onyx glue embolization was associated with a greater success rate when used as the initial secondary intervention (odds ratio, 59.61; 95% confidence interval, 4.78-742.73; P < .001). There was no difference in success between the different techniques when multiple secondary interventions were required. Five-year survival was 72% ± 0.08% and was unrelated to any of the secondary interventional techniques. CONCLUSIONS Secondary intervention for PT2 is associated with success in less than half of all cases. Onyx glue embolization was associated with greater long-term success when used as the initial secondary intervention.

Long-Term Outcomes of Diabetic Patients Undergoing Endovascular Infrainguinal Interventions

OBJECTIVE Diabetes mellitus (DM) has traditionally predicted poor outcomes after lower extremity revascularization for peripheral vascular disease (PVD). This study assessed the influence of DM on long-term outcomes of percutaneous transluminal angioplasty, with or without stenting (PTA/stent), in patients with PVD. METHODS From January 2002 to December 2007, 920 patients underwent 1075 PTA/stent procedures. Patients were stratified into DM and non-DM cohorts. Study end points included primary patency (PP), assisted patency (AP), limb salvage, and survival and were evaluated using Kaplan-Meier and Cox regression analyses. RESULTS There were 533 DM and 542 non-DM limbs. Median follow-up was 34 months. Overall, the 5-year actuarial PP was 42% +/- 2.4%, AP was 81% +/- 2.0%, limb salvage was 89% +/- 1.6%, and survival was 60% +/- 2.4%. On univariate analysis, DM vs non-DM was associated with inferior 5-year PP (37% +/- 3.4% vs 46% +/- 3.3%; P = .009), limb salvage (84% +/- 2.6% vs 93% +/- 1.8%, P < .0001), and survival (52% +/- 3.5% vs 68% +/- 3.1%, P = .0001). AP did not differ between DM and non-DM patients (P = .18). In the entire cohort, DM (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.01-1.54; P = .04), single-vessel peroneal runoff (HR, 1.54; 95% CI, 1.16-2.08; P = .003), and dialysis (HR, 1.59; 95% CI, 1.10-2.33; P = .02) were associated with decreased PP on multivariate analysis. The only variables on multivariate analysis to predict limb loss and death were critical limb ischemia (HR, 9.09; 95% CI, 4.17-20.00; P < . 0001; HR, 2.99; 95% CI, 2.01-4.44; P < .0001, respectively) and dialysis (HR, 2.94; 95% CI, 1.39-5.00; P = .003; HR, 4.24; 95% CI 2.80-6.45; P < .0001, respectively). CONCLUSIONS DM is an independent predictor of decreased long-term primary patency after PTA/stent. Although acceptable assisted patency rates can be achieved with close surveillance and reintervention, long-term limb salvage remains inferior in diabetic patients compared with non-diabetic patients due to a more severe clinical presentation and poor runoff.

Treatment and outcomes of aortic endograft infection

OBJECTIVE This study examined the medical and surgical management and outcomes of patients with aortic endograft infection after abdominal endovascular aortic repair (EVAR) or thoracic endovascular aortic repair (TEVAR). METHODS Patients diagnosed with infected aortic endografts after EVAR/TEVAR between January 1, 2004, and January 1, 2014, were reviewed using a standardized, multi-institutional database. Demographic, comorbidity, medical management, surgical, and outcomes data were included. RESULTS An aortic endograft infection was diagnosed in 206 patients (EVAR, n = 180; TEVAR, n = 26) at a mean 22 months after implant. Clinical findings at presentation included pain (66%), fever/chills (66%), and aortic fistula (27%). Ultimately, 197 patients underwent surgical management after a mean of 153 days. In situ aortic replacement was performed in 186 patients (90%) using cryopreserved allograft in 54, neoaortoiliac system in 21, prosthetic in 111 (83% soaked in antibiotic), and 11 patients underwent axillary-(bi)femoral bypass. Graft cultures were primarily polymicrobial (35%) and gram-positive (22%). Mean hospital length of stay was 23 days, with perioperative 30-day morbidity of 35% and mortality of 11%. Of the nine patients managed only medically, four of five TEVAR patients died after mean of 56 days and two of four EVAR patients died; both deaths were graft-related (mean follow-up, 4 months). Nineteen replacement grafts were explanted after a mean of 540 days and were most commonly associated with prosthetic graft material not soaked in antibiotic and extra-anatomic bypass. Mean follow-up was 21 months, with life-table survival of 70%, 65%, 61%, 56%, and 51% at 1, 2, 3, 4, and 5 years, respectively. CONCLUSIONS Aortic endograft infection can be eradicated by excision and in situ or extra-anatomic replacement but is often associated with early postoperative morbidity and mortality and occasionally with a need for late removal for reinfection. Prosthetic graft replacement after explanation is associated with higher reinfection and graft-related complications and decreased survival compared with autogenous reconstruction.

Racial/Ethnic Disparities Associated With Initial Hemodialysis Access

IMPORTANCE Superior outcomes have been established with the use of an arteriovenous fistula (AVF) at first hemodialysis. However, considering the influence of comorbidities, medical insurance, and specialist care, racial/ethnic differences in the patterns of utilization of AVFs are unknown and deserve evaluation. OBJECTIVE To assess national trends in initial hemodialysis access with respect to race/ethnicity stratified by comorbid disease, nephrology care, and medical insurance status within the US Renal Data System. DESIGN, SETTING, AND PARTICIPANTS A retrospective analysis of all patients with end-stage renal disease in the US Renal Data System who initiated hemodialysis between January 1, 2006, and December 31, 2010. Univariable statistics (χ² test and analysis of variance) and logistic regression were used to compare racial/ethnic groups (white vs black vs Hispanic). Multivariable logistic regression and propensity score-matching techniques were used to evaluate hemodialysis access rates between patients of different races/ethnicities with comparable characteristics. MAIN OUTCOMES AND MEASURES Utilization rates of AVF, arteriovenous graft, and intravascular hemodialysis catheter. RESULTS In this cohort of 396,075 patients, more white patients initiated hemodialysis with an AVF than black patients or Hispanic patients (18.3% vs 15.5% and 14.6%, respectively; P < .001). Black patients and Hispanic patients initiated hemodialysis with an AVF less frequently despite being younger and having less coronary artery disease, chronic obstructive pulmonary disease, and cancer than white patients with an AVF. When stratified by medical insurance status, black patients (odds ratios, 0.90 [95% CI, 0.82-0.98] for uninsured and 0.85 [95% CI, 0.84-0.87] for insured) and Hispanic patients (odds ratios, 0.72 [95% CI, 0.65-0.81] for uninsured and 0.81 [95% CI, 0.79-0.84] for insured) persistently initiated hemodialysis with an AVF less frequently than white patients (P < .05 for all). Arteriovenous fistula utilization at initial hemodialysis was lower among black patients (odds ratio, 0.81 [95% CI, 0.78-0.84]) and Hispanic patients (odds ratio, 0.86 [95% CI, 0.82-0.90]) compared with white patients within the category of patients who had nephrology care for longer than 1 year (P < .001 for all). CONCLUSIONS AND RELEVANCE Black patients and Hispanic patients tend to initiate hemodialysis with an AVF less frequently than white patients despite being younger and having fewer comorbidities. These disparities persisted independent of factors that drive health access for fistula placement, such as medical insurance status and nephrology care. The sociocultural underpinnings of these disparities deserve investigation and redress to maximize the benefits of initiating hemodialysis via fistula in patients with end-stage renal disease irrespective of race/ethnicity.

Class I obesity is paradoxically associated with decreased risk of postoperative stroke after carotid endarterectomy.

INTRODUCTION Although obesity is a risk factor for vascular disease, previous studies have shown an obesity paradox with decreased mortality in obese patients undergoing vascular surgery. This study examined the relationship between body mass index (BMI) and outcomes after carotid endarterectomy (CEA). METHODS The 2005-2009 American College of Surgeons National Surgical Quality Improvement Program database was queried to evaluate 30-day outcomes after isolated CEA across National Institutes of Health-defined obesity classes. χ(2) analysis was used to assess the unadjusted relationship of BMI category to postoperative outcomes. The independent association of BMI with morbidity and mortality was assessed with multivariable logistic regression, adjusting for preoperative and operative characteristics. RESULTS In the cohort of 23,652 CEA, 1.8% of patients were underweight (BMI <18.5), 26.6% were normal weight (BMI 18.5-24.9), 39.4% were overweight (BMI 25.0-29.9), 21.1% were class I obese (BMI 30.0-34.9), 7.5% were class II obese (BMI 35.0-39.9), and 3.5% were class III obese (BMI ≥ 40). The overall stroke and mortality rates were 1.4% and 0.6%, respectively. On univariable analysis, there were U-shaped relationships between death (P = .017) and stroke (P = .029), with the lowest incidence in overweight and class I obese patients. The incidence of surgical site infection (SSI) (P = .021) increased incrementally with increasing BMI. On multivariable analysis, class I obesity was the only variable associated with decreased risk of stroke (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.31-0.83; P = .007). Independent risk factors for stroke were previous transient ischemic attack (OR, 1.97; P = .006), American Society of Anesthesiologists class 4 to 5 (OR, 1.62; P = .010), surgery performed by a nonvascular surgeon (OR, 1.85; P = .015), and hemiplegia (OR, 1.97; P = .018). There was also a trend, although not statistically significant, toward decreased mortality risk associated with class I obesity (OR, 0.53; 95% CI, .26-1.08; P = .080). Class II obesity was associated with an increased risk of SSI compared with normal weight (OR, 2.21; 95% CI, 1.01-4.82; P = .047). BMI category was not associated with the risk of myocardial infarction. CONCLUSIONS An obesity paradox exists for stroke and mortality after CEA; for stroke, but not mortality, this protective association was independent of patient demographics and comorbidities. Obesity is not a contraindication to CEA, and surgeons may safely undertake CEA in obese patients when indicated.

Preoperative smoking is associated with early graft failure after infrainguinal bypass surgery.

OBJECTIVE Smoking has been implicated as the single most important risk factor for the development of peripheral arterial disease. Whereas previous studies have found poor long-term outcomes in smokers undergoing lower extremity bypass, there is a lack of consistent reports describing the effects of persistent tobacco abuse on early outcomes after infrainguinal bypass. METHODS The American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2011 was queried for primary infrainguinal bypasses. A bivariate analysis was done to assess preoperative and intraoperative risk factors for the primary outcome of 30-day graft failure comparing active smokers with nonsmokers, defined as patients who did not smoke within the 12 months before surgery. Multivariable logistic regression was conducted to assess the independent association of active smoking with graft failure. RESULTS In 6614 (40.0%) active smokers and 9920 (60.0%) nonsmokers, 16,534 infrainguinal bypasses were performed. Active smokers were more likely to be younger, male, and of nonwhite race and to have a history of chronic obstructive pulmonary disease (P < .001, all). Nonsmokers were more likely to be functionally dependent and had significantly more comorbidities (ie, hypertension, diabetes, obesity, congestive heart failure, history of previous cardiac surgery or intervention, and dialysis; P < .001, all). The presence of critical limb ischemia was similar in both groups (53.1% of active smokers vs 53.5% of nonsmokers; P = .61). More nonsmokers received a tibial-level bypass than did active smokers (47.8% vs 33.9%; P < .001). There was a trend toward increased early graft failure in active smokers compared with nonsmokers (5.3% vs 4.7%; P = .08). With adjustment for other variables, especially bypass level and graft type, there was an independent association between active smoking and early graft failure (adjusted odds ratio, 1.21; 95% confidence interval, 1.02-1.43; P = .03). CONCLUSIONS Although nonsmokers were significantly older, had more comorbidities, and required more distal revascularization, active smokers still had an increased risk for development of early graft failure. These results stress the need for immediate smoking cessation before lower extremity bypass. Further research is warranted to determine an optimal period of abstinence among smokers with peripheral arterial disease to reduce their risk for early graft failure.