Failure to achieve clinical improvement despite graft patency in patients undergoing infrainguinal lower extremity bypass for critical limb ischemia

OBJECTIVE: Studies of infrainguinal lower extremity bypass for critical limb ischemia (CLI) have traditionally emphasized outcomes of patency, limb salvage, and death. Because functional outcomes are equally important, our objectives were to describe the proportion of CLI patients who did not achieve symptomatic improvement 1 year after bypass, despite having patent grafts, and identify preoperative factors associated with this outcome. METHODS: The prospectively collected Vascular Study Group of Northern New England database was used to identify all patients with elective infrainguinal lower extremity bypass for CLI (2003 to 2007) for whom long-term follow-up data were available. The primary composite study end point was clinical failure at 1 year after bypass, defined as amputation or persistent or worsened ischemic symptoms (rest pain or tissue loss), despite a patent graft. Variables identified on univariate screening (inclusion threshold, P \u3c .20) were included in a multivariable logistic regression model to identify independent predictors. RESULTS: Long-term follow-up data were available for 1012 patients who underwent infrainguinal bypasses for CLI, of which 788 (78%) remained patent at 1 year. Of these, 79 (10%) met criteria for the composite end point of clinical failure: 21 (2.7%) for major amputations and 58 (7.4%) for persistent rest pain or tissue loss. In multivariable analysis, significant predictors of clinical failure included dialysis dependence (odds ratio [OR], 3.74; 95% confidence interval [CI], 1.84-7.62; P \u3c .001) and preoperative inability to ambulate independently (OR, 2.17; 95% CI, 1.26-3.73; P = .005). A history of coronary artery bypass graft or percutaneous coronary intervention was protective (OR, 0.52; 95% CI, 0.29-0.93; P = .03). CONCLUSIONS: After infrainguinal lower extremity bypass for CLI, 10% of patients with a patent graft did not achieve clinical improvement at 1 year. Preoperative identification of this specific patient subgroup remains challenging. To improve surgical decision making and the overall care of CLI patients, further emphasis needs to be placed on functional outcomes in addition to traditional surgical end points. Inc. All rights reserved

Protamine reduces bleeding complications associated with carotid endarterectomy without increasing the risk of stroke

OBJECTIVES: Controversy persists regarding the use of protamine during carotid endarterectomy (CEA) based on prior conflicting reports documenting both reduced bleeding as well as increased stroke risk. The purpose of this study was to determine the effect of protamine reversal of heparin anticoagulation on the outcome of CEA in a contemporary multistate registry. METHODS: We reviewed a prospective regional registry of 4587 CEAs in 4311 patients performed by 66 surgeons from 11 centers in Northern New England from 2003-2008. Protamine use varied by surgeon (38% routine use, 44% rare use, 18% selective use). Endpoints were postoperative bleeding requiring reoperation as well as potential thrombotic complications, including stroke, death, and myocardial infarction (MI). Predictors of endpoints were determined by multivariate logistic regression after associated variables were identified by univariate analysis. RESULTS: Of the 4587 CEAs performed, 46% utilized protamine, while 54% did not. Fourteen patients (0.64%) in the protamine-treated group required reoperation for bleeding compared with 42 patients (1.66%) in the untreated cohort (P = .001). Protamine use did not affect the rate of MI (1.1% vs 0.91%, P = .51), stroke (0.78% vs 1.15%, P = .2), or death (0.23% vs 0.32%, P = .57) between treated and untreated patients, respectively. By multivariate analysis, protamine (odds ratio [OR] 0.32, 95% confidence interval [CI], 0.17-0.63; P = .001) and patch angioplasty (OR 0.46, 95% CI, 0.26-0.81; P = .007) were independently associated with diminished reoperation for bleeding. A single center was associated with a significantly higher rate of reoperation for bleeding (OR 6.47, 95% CI, 3.02-13.9; P \u3c .001). Independent of protamine use, consequences of reoperation for bleeding were significant, with a four-fold increase in MI, a seven-fold increase in stroke, and a 30-fold increase in death. CONCLUSION: Protamine reduced serious bleeding requiring reoperation during CEA without increasing the risk of MI, stroke, or death, in this large, contemporary registry. In light of significant complications referable to bleeding, liberal use of protamine during CEA appears warranted

Outcomes of symptomatic abdominal aortic aneurysm repair

OBJECTIVE: Operative mortality of patients undergoing symptomatic abdominal aortic aneurysm (Sx-AAA) repair has been reported at 6% to 30% during the past 25 years. We used a multicenter regional database to describe the contemporary outcomes of patients undergoing repair of Sx-AAA. METHODS: All patients undergoing infrarenal AAA repair in 11 hospitals comprising the Vascular Study Group of Northern New England (VSGNNE) between 2003 and 2009 were studied. Sx-AAA was prospectively defined as an AAA accompanied by abdominal or back pain or tenderness, but without rupture. The primary study end point was in-hospital mortality. Secondary end points included in-hospital postoperative major adverse events (MAE) and late survival. These outcomes were compared between symptomatic patients and contemporary VSGNNE cohorts of elective (E-AAA) and ruptured AAAs (R-AAAs) treated within the same study period. RESULTS: During the study period, 2386 AAA repairs were performed, comprising 1959 (82%) E-AAAs, 156 (7%) Sx-AAAs, and 271 (11%) R-AAAs. Repair was endovascular in 945 (48%) E-AAAs, 60 (38%) Sx-AAAs, and 33 (12%) R-AAAs. Hospital mortality was 1.7% for E-AAA repair and 1.3% for Sx-AAA repair, but was 34.7% for R-AAA repair (P \u3c .001). The MAE rates were 20%, 35%, and 63%, respectively, for E-AAA, Sx-AAA, and R-AAA repairs (P \u3c .001). The mean Glasgow Aneurysm Score (GAS) for Sx-AAA patients who survived was 79 +/- 12. Those who died had an average score of 92 +/- 7, and 83% of all Sx-AAA and R-AAA patients who died had a GAS \u3e85. Kaplan-Meier analysis demonstrated that at 1 and 4 years, Sx-AAA repair was associated with intermediate survival (83% and 68%) compared with E-AAA repair (89% and 73%) and R-AAA repair (49% and 35%; P \u3c .001). CONCLUSION: The operative mortality of patients with Sx-AAA in contemporary practice appears better than that previously reported in the literature. Despite low operative mortality, MAE and late survival are intermediate compared with E-AAA and R-AAA repair. Review of previous series shows a trend for lower operative mortality after Sx-AAA repair in more recent series, which likely reflects improved perioperative care and more use of endovascular aneurysm repair. All rights reserved

Factors associated with death 1 year after lower extremity bypass in Northern New England

BACKGROUND: Using 30-day operative mortality reported with lower extremity bypass (LEB) in preoperative decision making may underestimate the actual death rate encountered before patients have truly recovered from surgery, especially in elderly, debilitated patients with significant tissue loss. Therefore, we examined preoperative, patient-level risk factors that predict survival within the first year following LEB. METHODS: Using our regional quality improvement initiative in 11 hospitals in Northern New England, we studied 2306 LEB procedures performed in 2031 patients between January 2003 and December 2007. Sixty surgeons contributed to our database, and over 100 demographic and clinical variables were abstracted by trained researchers. Cox proportional hazards models were used to generate hazard ratios (HR) and surrounding 95% confidence intervals (CI) for our combined outcome measure of death occurring within the first year postoperatively. RESULTS: We found that within our cohort of 2306 bypass procedures, 11% of patients died within 1 year of surgery (2% prior to discharge, 9% prior to 1-year follow-up). We identified six preoperative patient characteristics associated with higher risk of death in multivariate analysis: congestive heart failure (HR 1.3, 95% CI 1.0-1.8), diabetes (HR 1.5, 95% CI 1.1-2.1), critical limb ischemia (CLI) (HR 1.7, 95% CI 1.3-2.4), lack of single-segment saphenous vein (HR 1.9, 95% CI 1.5-2/5), age over 80 (HR 2.0, 95% CI 1.5-2.7), dialysis dependence (HR 2.7, 95% CI 1.9-3.6), and emergent nature of the procedure (HR 3.4, 95% CI 1.7-6.8). While patients with no risk factors had 1-year death rates that were less than 5%: patients with three or more risk factors had a 28% chance of dying before 1 year postoperatively. When we compared risk-adjusted survival across centers, we found that one center in our region performed significantly better than expected (observed-to-expected outcome ratio 0.7, 95% CI 0.6-0.9, P = .04). CONCLUSIONS: Preoperative risk factors allow surgeons to predict survival in the first year following LEB, and to more precisely inform patients about their operative risk with LEB. Additionally, our model facilitates benchmarking comparison of risk-adjusted outcomes across our region. We believe quality improvement measures such as these will allow surgeons to identify best practices and thereby improve outcomes with LEB across centers. rights reserved