Julie E. Adams

Gender differences in abdominal aortic aneurysm presentation, repair, and mortality in the Vascular Study Group of New England

OBJECTIVE Prior studies of gender differences in abdominal aortic aneurysm (AAA) repair suggest there may be differences in presentation, suitability for endovascular aneurysm repair (EVAR), and outcomes between men and women. METHODS We used the Vascular Study Group of New England database to identify all patients undergoing EVAR or open AAA repair. We analyzed demographics, comorbidities, and procedural, and perioperative data. Results were compared using the Fisher exact test and the Student t-test. Multivariable logistic regression and Cox proportional hazards modeling were performed to identify predictors of mortality. RESULTS We identified 4026 patients (78% men) who underwent AAA repair (54% EVAR). Women were less likely than men to undergo EVAR for intact aneurysms (50% vs 60% of intact AAA repair; P < .001) but not for ruptured aneurysms (26% vs 20%; P = .23). Women were older (median age, 75 vs 72 years for intact; P < .001; 78 vs 73 years for rupture; P < .001) with smaller aortic diameters (57 vs 59 mm for elective; P < .001; 71 vs 79 mm for rupture; P < .001). Arterial injury was more common in women (5.4% vs 2.7%; P = .013) among patients undergoing EVAR for intact aneurysms. Women stayed in the hospital longer (4.3 vs 2.7 days; P = .018) and had lower odds of being discharged home, even after adjusting for age. Among patients undergoing open repair for intact aneurysms, women more frequently experienced leg ischemia/emboli (4% vs 1%; P = .001) and bowel ischemia (5% vs 3%; P = .044). Women had higher 30-day mortality after OAR for intact (4% vs 2%; P = .03) and rupture (48% vs 34%; P = .03) repairs. However, 30-day mortality after EVAR was similar for intact (1% in men vs 1% in women; P = .57) and rupture (29% in men vs 27% in women; P > .99) repairs. Late survival was worse in women than men only for patients undergoing open repair of ruptured aneurysms (hazard ratio, 1.8; 95% confidence interval, 1.0-3.1; P = .04). After controlling for age, type of repair, urgency at presentation (ie, elective/intact vs ruptured), comorbidities, and other relevant risk factors, gender was not predictive of 30-day or 1-year mortality. CONCLUSIONS Women with AAAs are being treated at older ages and smaller AAA diameters and are undergoing rupture repair at smaller diameters than men. Women are more likely to experience perioperative complications as a result of less favorable vascular anatomy. Age >80 years, comorbidity, presentation, and type of repair are more important predictors of mortality than gender.

Clopidogrel is not associated with major bleeding complications during peripheral arterial surgery

OBJECTIVES Persistent variation in practice surrounds preoperative clopidogrel management at the time of vascular surgery. While some surgeons preferentially discontinue clopidogrel citing a perceived risk of perioperative bleeding, others will proceed with surgery in patients taking clopidogrel for an appropriate indication. The purpose of this study was to determine whether preoperative clopidogrel use was associated with significant bleeding complications during peripheral arterial surgery. METHODS We reviewed a prospective regional vascular surgery registry recorded by 66 surgeons from 15 centers in New England from 2003 to 2009. Preoperative clopidogrel use within 48 hours of surgery was analyzed among patients undergoing carotid endarterectomy (CEA), lower extremity bypass (LEB), endovascular abdominal aortic aneurysm repair (EVAR), and open abdominal aortic aneurysm repair (oAAA). Ruptured AAAs were excluded. Endpoints included postoperative bleeding requiring reoperation, as well as the incidence and volume of blood transfusion. Statistical analysis was performed using analysis of variance, Fisher exact, χ(2), and Wilcoxon rank-sum tests. RESULTS Over the study interval, a total of 10,406 patients underwent surgery, including 5264 CEA, 2883 LEB, 1125 EVAR, and 1134 oAAA repair. Antiplatelet use among all patients varied, with 19% (n = 2010) taking no antiplatelet agents, 69% (n = 7132) taking aspirin (ASA) alone, 2.2% (n = 229) taking clopidogrel alone, and 9.7% (n = 1017) taking both ASA and clopidogrel. Clopidogrel alone or as dual antiplatelet therapy was most frequently used prior to CEA and least frequently prior to oAAA group (CEA 16.1%, LEB 9.0%, EVAR 6.5%, oAAA 5%). Reoperation for bleeding was not significantly different among patients based on antiplatelet regimen (none 1.5%, ASA 1.3%, clopidogrel 0.9%, ASA/clopidogrel 1.5%, P = .74). When analyzed by operation type, no difference in reoperation for bleeding was seen across antiplatelet regimens. There was also no difference in the incidence of transfusion among antiplatelet treatment groups (none 18%, ASA 17%, clopidogrel 0%, ASA/clopidogrel 24%, P = .1) and none when analyzed by individual operation type. Among patients who did require transfusion, there was no significant difference in the mean number of units of packed red blood cells required (none 0.7 units, ASA 0.5 units, clopidogrel 0 units, ASA/clopidogrel 0.6 units, P = .1) or when stratified by operation type. CONCLUSIONS Patients undergoing peripheral arterial surgery in whom clopidogrel was continued either alone or as part of dual antiplatelet therapy did not have significant bleeding complications compared with patients taking no antiplatelet therapy or ASA alone at the time of surgery. These data suggest that clopidogrel can safely be continued preoperatively in patients with appropriate indications for its use, such as symptomatic carotid disease or recent drug-eluting coronary stents.

Multiple head injuries in rats: Effects on behavior

BACKGROUND Evidence suggests that mild head injuries in humans can result in cumulative damage. No investigation to date has considered the effects of multiple subacute mild head injuries in an animal model. METHODS Forty-one male Long-Evans hooded rats were trained in a Morris water maze. All animals were fitted with a hollow intracranial screw. Concussions were generated using a fluid percussion device. Animals were then evaluated in the water maze until performance returned to baseline. Control animals received no concussions. The remaining animals were randomized to receive one, two, or three concussions. Animals were allowed to return to baseline after each concussion and were then killed. Motor performance was evaluated on a balance beam both before and after concussions. RESULTS After one concussion, 85% of animals showed performance deviation from baseline as measured by time to reach the platform, returning to baseline within a mean of 14.0 trials. After two concussions, 48% of animals showed deviation, with a mean return to baseline of 6.8 trials. After three concussions, 25% of animals showed deviation, with a mean return to baseline of 2.3 trials. Of postconcussive animals, 42% developed new inconsistent baseline levels of performance. Balance beam performance was unaffected. CONCLUSION Multiple concussions cause immediate transient impairment in spatial recognition and have extended effects on baseline performance in rats. Motor performance is not affected.

Perioperative management with antiplatelet and statin medication is associated with reduced mortality following vascular surgery

OBJECTIVE Many patients undergoing vascular surgical procedures are not on appropriate medical therapy. This study sought to examine the variation and impact of antiplatelet (AP) and statin therapy on early and late mortality in patients undergoing vascular surgery in our region. METHODS We studied all patients (n = 14,489) undergoing elective carotid endarterectomy (n = 6978), carotid stenting (n = 524), and suprainguinal (n = 763) and infrainguinal bypass (n = 3053), as well as patients with known coronary risk factors undergoing open (n = 1044) and endovascular (n = 2127) abdominal aortic aneurysm repair from 2005 to 2012 in the Vascular Study Group of New England. Optimal medical management was defined as treatment with both AP and statin agents, preoperatively and at discharge. We analyzed temporal, procedural, and center variation of medication use. Multivariable analyses were used to determine the adjusted impact of AP and statin therapy on 30-day mortality and 5-year survival. RESULTS Optimal medical management improved over the study interval (55% in 2005 to 68% in 2012; P trend < .01) with carotid interventions having the highest rates of optimal medications use (carotid artery stenting, 78%; carotid endarterectomy, 74%) and abdominal aortic aneurysm repair in patients with known cardiac risk factors having the lowest (open, 57%; endovascular aneurysm repair, 56%). Optimal medication use varied by center as well (range, 40%-86%). Preoperative AP and statin use was associated with reduced 30-day mortality (odds ratio, 0.76; 95% confidence interval [CI], 0.5-1.05; P = .09). AP and statin prescription at discharge was additive in survival benefit with improved 5-year survival (hazard ratio, 0.5; 95% CI, 0.4-0.7; P < .01) that was consistent across procedure types. Patients prescribed AP and statin at discharge had 5-year survival of 79% (95% CI, 77%-81%) compared with only 61% (95% CI, 52%-68%; P < .001) for patients on neither medication. CONCLUSIONS AP and statin therapy preoperatively and at discharge was associated with reduced 30-day mortality and an absolute 18% improved 5-year survival after vascular surgery. However, one-third of patients are suboptimally managed in real world practice. This demonstrates an opportunity for quality improvement that can substantially improve survival after vascular surgery.

The impact of diabetes on postoperative outcomes following lower-extremity bypass surgery.

OBJECTIVE The effect of diabetes type (noninsulin dependent vs insulin dependent) on outcomes after lower-extremity bypass (LEB) has not been clearly defined. Therefore, we analyzed associations between diabetes type and outcomes after LEB in patients with critical limb ischemia. METHODS We performed a retrospective analysis of 1977 infrainguinal LEB operations done for critical limb ischemia between 2003 and 2010 within the Vascular Study Group of New England. Patients were categorized as nondiabetic (ND), noninsulin-dependent diabetic (NIDD), or insulin-dependent diabetic (IDD) based on their preoperative medication regimen. Our main outcome measures were in-hospital mortality and major adverse events (MAEs)--a composite outcome, including myocardial infarction, dysrhythmia, congestive heart failure, wound infection, renal insufficiency, and major amputation. We compared crude and adjusted rates of mortality and MAEs using logistic regression across diabetes categories. RESULTS Overall, 41% of patients were ND, 28% were NIDD, and 31% were IDD. Crude rates of in-hospital mortality were similar across these groups (1.7% vs 3.1% vs 2.1%; P = .211). Adjusted analyses accounting for differences in patient characteristics showed that diabetes is not associated with increased risk of in-hospital mortality. However, type of diabetes was associated with a higher risk of MAEs in both crude (15.1% for ND; 21.1% for NIDD; and 25.2% for IDD; P < .001) and adjusted analyses (odds ratio for NIDD, 1.41; 95% confidence interval, 1.2-1.7; odds ratio for IDD, 1.53; 95% confidence interval, 1.3-1.8). CONCLUSIONS Diabetes is a significant contributor to the risk of postoperative complications after LEB surgery, and insulin dependence is associated with higher risk. Quality measures aimed at limiting complications after LEB may have the most impact if these initiatives are focused on patients who are IDD.

Evaluation of Simulation-Based Training Model on Vascular Anastomotic Skills for Surgical Residents

Introduction Reduced work hours and concerns over patient safety have encouraged surgical educators to find methods to advance resident skills more efficiently. Simulation provides the opportunity to improve technical surgical skills outside the operating room. We hypothesized that practice on surgical task simulators would improve residents’ technical performance of vascular anastomotic technique. Methods Senior general surgery residents at an academic medical center completed pretests and posttests on 3 vascular surgery simulators: femoral-popliteal bypass, carotid endarterectomy, and abdominal aortic aneurysm repair. The initial training sessions began with a 15-minute instructional video on how to perform the procedures, followed by supervised sessions in anastomotic technique with attending vascular surgeons. Initial individual sessions were videotaped as a pretest, and the final attempt was videotaped as the posttest. Each test was evaluated by a single experienced attending vascular surgeon blinded to the examinees. Anastomoses were graded using a performance rating and a modified objective structured assessment of technical skill rating. Results were analyzed using mixed model P values. Results The residents showed statistically significant improvement between the pretest and the posttest in both their performance rating (1.9 vs. 2.4, P = 0.02) and the objective structured assessment of technical skill (2.6 vs. 3.1, P = 0.01), as well as in most subsets of each assessment scale. Conclusions We conclude that practice using simulated anastomotic models leads to measurable improvement in vascular anastomotic technique in senior general surgery residents.

The influence of gender on functional outcomes of lower extremity bypass

OBJECTIVE Our aim was to evaluate the effect of gender on early and late procedural and functional outcomes of lower extremity bypass (LEB). METHODS We reviewed the records of 2576 patients (828 women; 32%) who underwent LEB for claudication or critical limb ischemia (CLI) in the Vascular Study Group of New England from 2003 to 2010. Logistic regression and proportional hazards models were used to adjust for potential confounding differences between genders. Morbidity, mortality, graft patency, freedom from major amputation, ambulation, and living status were analyzed postoperatively and over 1 year. RESULTS Women were older (70 vs 68 years; P < .001), had more hypertension (89% vs 85%; P = .006), less coronary artery disease (35% vs 39%; P = .03), smoking (73% vs 88%; P < .001), and preoperative statin use (60% vs 64%; P = .04). Women were more likely to have CLI (76% vs 71%; P = .003), and ambulate with assistance at presentation (19% vs 16%; P = .02). Morbidity was similar except women had higher rates of reoperation for thrombosis (4% vs 2%; P < .001) without differences in major amputation (2% vs 1%; P = .13) or in-hospital mortality (1.7% vs 1.7%; P = .96). Women and men with claudication had similar 1-year graft patency rates. Women with CLI had lower rates of primary (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.03-1.48; P = .02), assisted primary (HR, 1.42; 95% CI, 1.15-1.76; P = .001) and secondary patency (HR, 1.40; 95% CI, 1.10-1.77; P = .006) during the first year compared with men. Freedom from amputation was similar for men and women with CLI (HR, 1.17; 95% CI, 0.84-1.63; P = .36). There were no differences in late survival between women and men with claudication (HR, 0.89; 95% CI, 0.60-1.31; P = .36) or CLI (HR, 0.94; 95% CI, 0.81-1.09; P = .39). More female claudicants were not independently ambulatory at discharge (30% vs 19%; P = .002) and were discharged to a nursing home (15% vs 5%; P < .001) but these differences did not persist at 1 year. Women with CLI were more likely to be nonambulatory at discharge (13% vs 9%; P = .006) and at 1 year (13% vs 8%; P < .001). More women with CLI were discharged to a nursing home (44% vs 35%; P = .01) and resided there at 1 year (11% vs 7%; P = .02). CONCLUSIONS Women have complication rates similar to men with inferior early and late functional outcomes after LEB. The reduced patency rates in women with CLI did not translate into differences in limb salvage. These findings might help define physician and patient expectations for women before revascularization.

The EPIC Nitinol Stent System in the Treatment of Iliac Artery Lesions: One-Year Results From the ORION Clinical Trial

Purpose To report the 1-year results of a pivotal study for a new-generation nitinol stent for the treatment of iliac atherosclerotic lesions. Methods The ORION trial ( ClinicalTrials.gov identifier NCT00896337) was a single-arm, non-randomized, prospective, multicenter clinical trial that enrolled 125 patients (81 men; mean age 61.1±9.3 years) implanted with the EPIC self-expanding nitinol stent system in 166 de novo or restenotic iliac artery lesions ≤13 cm long. The primary endpoint was the 9-month major adverse event rate [i.e., device- or procedure-related death within 30 days, myocardial infarction during the index hospitalization, target vessel revascularization (TVR), or index limb amputation]. Follow-up occurred at hospital discharge and at 1, 9, and 12 months. An independent core laboratory evaluated ultrasound results at 1, 9, and 12 months. Results The primary endpoint met the prespecified performance goal, with only 3.4% (4/117) of patients experiencing a major adverse event by 9 months (p<0.0001). By 12 months, 6 (5.4%) of 111 patients had TVR; none had an index limb amputation. The ankle-brachial index, Walking Impairment Questionnaire, and Rutherford classifications all showed sustained improvements through 12 months. Primary patency was 94.4% with comparable results for lesions classified as complex (TASC II C/D 95.5%) or non-complex (TASC II A/B 95.0%). Conclusion The EPIC stent system demonstrated safety and effectiveness through 12 months, including improvements for complex lesions. The EPIC stent is a viable alternative to surgery for patients with either complex or non-complex lesions.

Use of a postoperative insulin protocol decreases wound infection in diabetics undergoing lower extremity bypass

OBJECTIVE Strict glucose control in patients undergoing coronary bypass grafting has been shown to decrease infectious complications, arrhythmias, and mortality. Our objective was to determine if strict glucose control reduced morbidity after lower extremity bypass (LEB). METHODS A prospective pilot study at a single institution within the Vascular Study Group of New England was conducted from January 2009 to December 2010. Patients with diabetes and without undergoing LEB were placed on an intravenous (IV) insulin infusion for 3 days after surgery with titration of blood glucose from 80 to 150 mg/dL. The IV insulin study group (n = 104) was compared to a historic control group (n = 189) that received standard insulin treatment from the preceding 3 years. The Fisher exact test, t-tests, Wilcoxon rank-sum tests, χ(2), and logistic regression analyses were used to compare in-hospital morbidity. Stratified analyses were conducted to determine if findings differed based on the presence or absence of diabetes. RESULTS There was no difference in postoperative complications between the two groups with regard to graft infection, myocardial infarction, dysrhythmia, primary patency at discharge, or mortality. Patients in the IV insulin group had significantly fewer in-hospital wound infections (4% vs 11%; odds ratio [OR], 0.32; 95% confidence interval [CI], 0.11-0.96; P = .047). This association strengthened after adjusting for potentially confounding baseline differences in gender, body mass index, and smoking status (adjusted OR, 0.22; 95% CI, 0.05-0.84; P = .03). When stratified by presence of diabetes, wound infections were decreased in the IV insulin group (0/44 [0%] vs 9/90 [10%]; P = .03). In patients without diabetes treated with IV insulin, there was no significant difference in wound infections (7% vs 12%; P = .42). CONCLUSIONS Strict glucose control with a postoperative insulin infusion protocol significantly decreased the incidence of postoperative in-hospital wound infection in the diabetic population. These previously unreported findings from this single-institution prospective study warrant further investigation.