Volume-outcome relationships in lower extremity arterial bypass surgery.

OBJECTIVE: We sought to investigate whether a volume-outcome relationship exists for lower extremity arterial bypass (LEAB) surgery. METHODS: All LEAB procedures performed in England between 2002 and 2006 were identified from Hospital Episode Statistics data. A Charlson-type risk profile, including operating hospital annual case volume, was identified per patient. Outcome measures of revision bypass, amputation, death and a composite measure were established during the index admission and at 1 year.Quintile analysis and multilevel multivariate modeling were used to identify the existence of a volume-outcome relationship and allow adjustment of results for significant determinants of outcome. RESULTS: A total of 27,660 femoropopliteal bypass and 4161 femorodistal bypass procedures were identified.As volume increased, in-hospital mortality after popliteal bypass decreased from 6.5% to 4.9% (P = 0.0045), with a corresponding odds ratio of 0.980 [95% confidence interval (CI), 0.929-0.992; P = 0.014] for every increase of 50 patients per year. Major amputation decreased from 4.1% to 3.2% (P = 0.006) in high-volume hospitals, with a reduction in risk of 0.955 (95% CI, 0.928-0.983; P = 0.002) at 1 year.For distal bypass, in-hospital mortality decreased from 9.8% to 5.5% (P = 0.004) and 1-year major amputation decreased from 25.4% to 18.2% (P < 0.001), with a corresponding odds ratio of 0.658 (95% CI, 0.517-0.838; P < 0.0001) as the volume increased.An increase in the chance of revision surgery (10.6% vs 8.2%, P < 0.001) was seen with higher volume, with an increased odds ratio of 1.031 (95% CI, 1.005-1.057; P = 0.018). CONCLUSIONS: A positive volume-outcome relationship exists for LEAB procedures even after employing multilevel risk adjustment models. There are benefits in terms of mortality and limb salvage both in the short-term and at 1 year postsurgery.

Locoregional anesthesia for endovascular aneurysm repair.

OBJECTIVE: This was a systematic review and meta-analysis of the mode of anesthesia and outcome after endovascular aneurysm repair (EVAR). METHODS: Review methods were according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Published and unpublished literature was searched. The primary outcome was 30-day mortality. Secondary outcomes were categorized for patient selection, perioperative outcomes, and postoperative outcomes. Weighted mean differences (WMD) were calculated for continuous variables, such as length of stay, and pooled odds ratios (OR) were calculated for discrete variables such as major morbidity. RESULTS: Ten studies of 13,459 patients given local anesthesia (LA) or general anesthesia (GA) were eligible for analysis. There was no difference in 30-day mortality. The LA patients were older than the GA patients (WMD, 0.17; P = .006), with an increased burden of cardiac (LA vs GA: OR, 1.28; P = .011) and respiratory (LA vs GA: OR, 1.28; P = .006) comorbidity. LA EVAR was reported with shorter operative time (WMD, -0.54; P = .001) and hospital stay (WMD, -0.27; P = .001) vs GA. LA patients developed fewer postoperative complications than GA patients (OR, 0.54; P < .001). CONCLUSIONS: The absence of randomized data is a major hurdle to understanding the effect of anesthetic technique on morbidity after EVAR. The data presented are encouraging in selected patients. The use of locoregional anesthesia for EVAR should be further investigated with better reporting of aneurysm morphology to clarify its potential benefits and identify the subgroups that will derive greatest benefit.