The effect of social integration on outcomes after major lower extremity amputation.

OBJECTIVE: Major lower extremity (MLE) amputation is a common procedure that results in a profound change in a patient's life. We sought to determine the association between social support and outcomes after amputation. We hypothesized that patients with greater social support will have better post amputation outcomes. METHODS: From November 2011 to May 2013, we conducted a cross-sectional, observational, multicenter study. Social integration was measured by the social integration subset of the Short Form Craig Handicap Assessment and Reporting Technique. Systemic social support was assessed by comparing a United States and Tanzanian population. Walking function was measured using the 6-minute walk test and quality of life (QoL) was measured using the EuroQol-5D. RESULTS: We recruited 102 MLE amputees. Sixty-three patients were enrolled in the United States with a mean age of 58.0. Forty-two (67%) were male. Patients with low social integration were more likely to be unable to ambulate (no walk 39% vs slow walk 23% vs fast walk 10%; P = .01) and those with high social integration were more likely to be fast walkers (no walk 10% vs slow walk 59% vs fast walk 74%; P = .01). This relationship persisted in a multivariable analysis. Increasing social integration scores were also positively associated with increasing QoL scores in a multivariable analysis (ß, .002; standard error, 0.0008; P = .02). In comparing the United States population with the Tanzanian cohort (39 subjects), there were no differences between functional or QoL outcomes in the systemic social support analysis. CONCLUSIONS: In the United States population, increased social integration is associated with both improved function and QoL outcomes among MLE amputees. Systemic social support, as measured by comparing the United States population with a Tanzanian population, was not associated with improved function or QoL outcomes. In the United States, steps should be taken to identify and aid amputees with poor social integration.

Prospective, randomized, multi-institutional clinical trial of a silver alginate dressing to reduce lower extremity vascular surgery wound complications.

OBJECTIVE: Wound complications negatively affect outcomes of lower extremity arterial reconstruction. By way of an investigator initiated clinical trial, we tested the hypothesis that a silver-eluting alginate topical surgical dressing would lower wound complication rates in patients undergoing open arterial procedures in the lower extremity. METHODS: The study block-randomized 500 patients at three institutions to standard gauze or silver alginate dressings placed over incisions after leg arterial surgery. This original operating room dressing remained until gross soiling, clinical need to remove, or postoperative day 3, whichever was first. Subsequent care was at the provider's discretion. The primary end point was 30-day wound complication incidence generally based on National Surgical Quality Improvement Program guidelines. Demographic, clinical, quality of life, and economic end points were also collected. Wound closure was at the surgeon's discretion. RESULTS: Participants (72% male) were 84% white, 45% were diabetic, 41% had critical limb ischemia, and 32% had claudication (with aneurysm, bypass revision, other). The overall 30-day wound complication incidence was 30%, with superficial surgical site infection as the most common. In intent-to-treat analysis, silver alginate had no effect on wound complications. Multivariable analysis showed that Coumadin (Bristol-Myers Squibb, Princeton, NJ; odds ratio [OR], 1.72; 95% confidence interval [CI], 1.03-2.87; P = .03), higher body mass index (OR, 1.05; 95% CI, 1.01-1.09; P = .01), and the use of no conduit/material (OR, 0.12; 95% CI, 0.82-3.59; P < .001) were independently associated with wound complications. CONCLUSIONS: The incidence of wound complications remains high in contemporary open lower extremity arterial surgery. Under the study conditions, a silver-eluting alginate dressing showed no effect on the incidence of wound complications.

National variation in the utilization of alternative imaging in peripheral arterial disease.

OBJECTIVE: The value and cost-effectiveness of less invasive alternative imaging (AI) modalities (duplex ultrasound scanning, computed tomography angiography, and magnetic resonance angiography) in the care of peripheral arterial disease (PAD) has been reported; however, there is no consensus on their role. We hypothesized that AI utilization is low compared with angiography in the United States and that patient and hospital characteristics are both associated with AI utilization. METHODS: The Nationwide Inpatient Sample (2007-2010) was used to identify patients with an International Classification of Diseases-Ninth Edition diagnosis of claudication or critical limb ischemia (CLI) as well as PAD treatment (surgical, endovascular, or amputation). Patients with AI and those with angiography or expected angiography (endovascular procedures without imaging codes) were selected and compared. Multivariable logistic regression was performed for receiving AI stratified by claudication and CLI and adjusting for patient and hospital factors. RESULTS: We identified 290,184 PAD patients, of whom 5702 (2.0%) received AI. Patients with AI were more likely to have diagnosis of CLI (78.8% vs 48.6%; P < .0001) and receive open revascularizations (30.4% vs 18.8%; P < .0001). Van Walraven comorbidity scores (mean [standard error] 5.85 ± 0.22 vs 4.10 ± 0.05; P < .0001) reflected a higher comorbidity burden in AI patients. In multivariable analysis for claudicant patients, AI was associated with large bed size (odds ratio [OR], 3.26, 95% confidence interval [CI], 1.16-9.18; P = .025), teaching hospitals (OR, 1.97; 95% CI, 1.10-3.52; P = .023), and renal failure (OR, 1.52; 95% CI, 1.13-2.05; P = .006). For CLI patients, AI was associated with black race (OR, 1.53; 95% CI, 1.13-2.08; P = .006) and chronic heart failure (OR, 1.29; 95% CI, 1.04-1.60; P = .021) and was negatively associated with renal failure (OR, 0.80; 95% CI, 0.67-0.95; P = .012). The Northeast and West regions were associated with higher odds of AI in claudicant patients (OR, 2.41; 95% CI, 1.23-4.75; P = .011; and OR, 2.59; 95% CI, 1.34-5.02; P = .005, respectively) and CLI patients (OR, 4.31; 95% CI, 2.20-8.36; P < .0001; and OR, 2.18; 95% CI, 1.12-4.22; P = .021, respectively). Rates of AI utilization across states were not evenly distributed but showed great variability, with ranges from 0.31% to 9.81%. CONCLUSIONS: National utilization of AI for PAD is low and shows great variation among institutions in the United States. Patient and hospital factors are both associated with receiving AI in PAD care, and AI utilization is subject to significant regional variation. These findings suggest differences in systems of care or practice patterns and call for a clearer understanding and a more unified approach to imaging strategies in PAD care.

The effect of surgeon specialization on outcomes after ruptured abdominal aortic aneurysm repair.

OBJECTIVE: Although mortality after elective abdominal aortic aneurysm (AAA) repair has steadily declined, operative mortality for a ruptured AAA (rAAA) remains high. Repair of rAAA at hospitals with a higher elective aneurysm workload has been associated with lower mortality rates irrespective of the mode of treatment. This study sought to determine the association between surgeon specialization and outcomes after rAAA repair. METHODS: The American College of Surgeons National Surgical Quality Improvement Project database from 2005 to 2010 was used to examine the 30-day mortality and morbidity outcomes of patients undergoing rAAA repair by vascular and general surgeons. Multivariable logistic regression analysis was performed for each death and morbidity, adjusting for all independently predictive preoperative risk factors. Survival curves were compared using the log-rank test. RESULTS: We identified 1893 repairs of rAAAs, of which 1767 (96.1%) were performed by vascular surgeons and 72 (3.9%) were performed by general surgeons. There were no significant differences between patients operated on by general vs vascular surgeons in preoperative risk factors or method of repair. Overall 30-day mortality was 34.3% (649 of 1893). After risk adjustment, mortality was significantly lower in the vascular surgery group compared with the general surgery group (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.30-0.86; P = .011). The risk of returning to the operating room (OR, 0.58; 95% CI, 0.35-0.97; P = .038), renal failure (OR, 0.54; 95% CI, 0.31-0.95; P = .034), and a cardiac complication (OR, 0.53; 95% CI, 0.28-0.99; P = .047) were all significantly less in the vascular surgery group. CONCLUSIONS: Despite similar preoperative risk factors profiles, patients who were operated on by vascular surgeons had lower mortality, less frequent returns to the operating room, and decreased incidences of postoperative renal failure and cardiac events. These data add weight to the case for further centralization of vascular services.

When to call it a day: incremental risk of amputation and death after multiple revascularization.

BACKGROUND: Patients with critical limb ischemia (CLI) often undergo revascularization before amputation. The exact relationship between multiple procedures and increased risk of amputation is unclear. We sought to determine the increased risk of amputation for each additional revascularization. METHODS: The 2007-2009 California State Inpatient Database (SID) was used to identify a cohort of CLI patients undergoing revascularization and conduct a time-to-event analysis for patients undergoing one or more revascularization procedures. One-year estimates were generated with Kaplan-Meier curves and compared with the log-rank test. The Wei-Lin-Weissfeld (WLW) marginal proportional hazards model was used to assess independent effects of number of revascularization procedures on amputation and death. RESULTS: A total of 11,190 patients with CLI underwent revascularization between July 2007 and December 2009. Their mean age was 71.0 years (interquartile range 62-80 years) and 6255 (55.9%) were male. Over half the subjects (55.2%) were smokers and there was a high burden of comorbidities in the cohort. One-year estimates of amputation by number of revascularizations (1: 23.3%; 2: 27.1%; 3: 30.3%; 4: 26.7%; 5(+): 28.6%; P < 0.001) and death (1: 18.7%; 2: 21.1%; 3: 26.3%; 4: 23.6%; 5+: 32.1%; P = 0.012) increased significantly as procedures increased. In the WLW model for amputation, the hazard increased significantly for patients with 2 revascularization versus 1 (HR = 1.22; 95% CI 1.09-1.37; P = 0.001) and 3 revascularizations versus 2 (HR = 1.33; 95% CI 1.10-1.62; P = 0.004). In the multivariable WLW models for death, the increase in revascularization procedures for 2 compared with 1 (HR = 1.18; 95% CI 1.04-1.34; P = 0.010) was significant. CONCLUSIONS: The risk of amputation increases with each additional revascularization procedure. These findings hold true for both percutaneous transluminal angioplasty only and lower extremity bypass only subsets. In addition, increased revascularization procedures appear to result in an increased risk of death. We advocate for continued communication between clinicians and patients on the true risks and benefits of additional revascularization procedures.

Use of surveillance imaging following treatment of small renal masses.

PURPOSE: With the increasing incidence of small renal masses, there is greater use of ablation, nephron sparing surgery and surveillance compared to radical nephrectomy. However, patterns of care in the use of posttreatment imaging remain uncharacterized. The purpose of this study is to determine the rate of posttreatment imaging after various treatments for small renal mass. MATERIALS AND METHODS: Using SEER (Surveillance, Epidemiology and End Results)-Medicare data during 2005 to 2009, we identified 1,682 subjects diagnosed with small renal mass and treated with open partial nephrectomy (330), minimally invasive partial nephrectomy (160), open radical nephrectomy (404), minimally invasive radical nephrectomy (535), thermal ablation (212) and surveillance (42). Use of imaging was compared within 24 months of treatment and multivariate regression models were constructed to identify factors associated with increased imaging use. RESULTS: On adjusted analyses thermal ablation was associated with almost eightfold greater odds of surveillance imaging compared with open radical nephrectomy (OR 7.7, 95% CI 1.01-59.4). Specifically, thermal ablation was associated with increased computerized tomography (OR 5.28) and magnetic resonance imaging (OR 2.19) use and decreased ultrasound use (OR 0.59). Minimally invasive partial nephrectomy (OR 3.28) and open partial nephrectomy (OR 3.19) were also associated with increased computerized tomography use to a lesser extent. CONCLUSIONS: Subjects undergoing nephron sparing surgery undergo more posttreatment imaging compared to open radical nephrectomy. Although possibly associated with lower morbidity, thermal ablation is associated with significantly greater use of imaging compared to other small renal mass treatments. This may increase costs and radiation exposure, although further study is needed for confirmation.

Comparative methods for handling missing data in large databases.

OBJECTIVE: Analysis of complex survey databases is an important tool for health services researchers. Missing data elements are challenging because the reasons for "missingness" are multifactorial, especially categorical variables such as race. We simulated missing data for race and analyzed the bias from five methods used in predicting major amputation in patients with critical limb ischemia (CLI). METHODS: Patient discharges with fully observed data containing lower extremity revascularization or major amputation and CLI were selected from the 2003 to 2007 Nationwide Inpatient Sample, a complex survey database (weighted n = 684,057). Considering several random missing data schemes, we compared five missing data methods: complete case analysis, replacement with observed frequencies, missing indicator variable, multiple imputation, and reweighted estimating equations. We created 100 simulated data sets, with 5%, 15%, or 30% of subjects' race drawn to be missing from the full data set. Bias was estimated by comparing the estimated regression coefficients averaged over 100 simulated data sets (ß(miss)) from each method vs estimates from the fully observed data set (ß(full)), with relative bias calculated as (ß(full) - ß(miss)/ß(full)) × 100%. RESULTS: Our results demonstrate that reweighted estimating equations produce the least biased and the missing indicator variable produces the most biased coefficients. Complete case analysis, replacement with observed frequencies, and multiple imputation resulted in moderate bias. Sensitivity analysis demonstrated the optimal method choice depends on the quantity and type of missing data encountered. CONCLUSIONS: Missing data are an important analytic topic in research with large databases. The commonly used missing indicator variable method introduces severe bias and should be used with caution. We present empiric evidence to guide method selection for handling missing data.

The effect of postoperative stroke and myocardial infarction on long-term survival after carotid revascularization.

INTRODUCTION: The largest randomized controlled trial that compared the efficacy of carotid endarterectomy (CEA) with carotid artery stenting (CAS) showed equivalent outcomes for the composite end point of postoperative stroke, myocardial infarction (MI), or death. However, CAS had a higher risk of postoperative stroke, and CEA had a higher risk of MI. We hypothesize that there is a differential association of postoperative stroke, compared with that of postoperative MI, with reduced long-term survival after carotid revascularization when compared with neither complication. METHODS: The Vascular Study Group of New England database was used to identify all CEA and CAS procedures performed between 2003 and 2011. Patients were stratified according to whether they experienced an in-hospital postoperative stroke (minor or major), MI (troponin elevation, electrocardiographic changes, or clinical symptoms), or neither. Primary study end point was survival during the first year and the first 5 years postoperatively. Multivariable Cox proportional hazards models compared the magnitude of association of stroke and MI on survival. RESULTS: Of 8315 patients, 81 (0.97%) experienced postoperative MI, and 63 (0.76%) experienced stroke. During the first year after operation, survival significantly differed among the three groups: neither, 96%; MI, 84%; stroke, 77% (log-rank P < .0001). After adjusting for confounders, survival after postoperative stroke (hazard ratio [HR], 6.6; 95% confidence interval [CI], 3.7-12; P < .0001) was nearly twofold less than that after postoperative MI (HR, 3.6; 95% CI, 2-6.8; P < .0001). During the first 5 years postoperatively, multivariable modeling showed postoperative stroke and postoperative MI remained independent predictors of decreased survival, but the magnitude of association was similar (HR, 2.7; 95% CI, 1.7-4.3 [P < .0001] vs HR, 2.8; 95% CI, 1.8-4.3 [P < .0001]). CONCLUSIONS: During the first year after operation, postoperative stroke conferred a twofold lower survival than that after postoperative MI. By 5 years after operation, these survival curves converged, and the survival disadvantage associated with stroke became similar to that of MI. These data suggest that different postoperative complications after carotid revascularization have different implications for patients, with decreased short-term survival in patients experiencing a postoperative stroke. These findings help to inform our interpretation of studies that have used a composite end point in order to evaluate the comparative effectiveness of revascularization strategies.

Factors predicting resource utilization and survival after major amputation.

OBJECTIVE: Major amputation is associated with increased short-term healthcare resource utilization (RU), early mortality, and socioeconomic status (SES) disparities. Our objective is to study patient-specific and SES-related predictors of long-term RU and survival after amputation. METHODS: This retrospective analysis identified 364 adult patients who underwent index major amputation for critical limb ischemia from January 1995 through December 2000 at two tertiary centers with outcomes through December 2010. Age, gender, SES (race, income, insurance, and marital status), comorbidities (congestive heart failure [CHF], diabetes, diabetes with complications, and renal failure [RF]), subsequent procedures, cumulative length of stay (cLOS), and mortality were analyzed. Bivariate and multivariate Poisson regression for subsequent procedures and cLOS and Cox proportional hazard modeling for all-cause mortality were undertaken. RESULTS: During a mean follow-up of 3.25 years, amputation patients had mean cLOS of 71.2 days per person-year (median, 17.6), 19.5 readmissions per person-year (median, 2.1), 0.57 amputation-related procedures (median, 0), and 0.31 cardiovascular procedures (median, 0). Below-knee amputation as the index procedure was performed in 70% of patients, and 25% had additional amputation procedures. Of readmissions at ≤ 30 days, 52% were amputation-related. Overall mortality during follow-up was 86.9%; 37 patients (10.2%) died within 30 days. Among patients surviving >30 days, multivariate Poisson regression demonstrated that younger age (incidence rate ratio [IRR], 0.98), public insurance (IRR, 1.63), CHF (IRR, 1.60), and RF (IRR, 2.12) were associated with increased cLOS. Diabetes with complications (IRR, 1.90) and RF (IRR, 2.47) affected subsequent amputation procedures. CHF (IRR, 1.83) and RF (IRR, 3.67) were associated with a greater number of cardiovascular procedures. Cox proportional hazard modeling indicated older age (hazard ratio [HR], 1.04), CHF (HR, 2.26), and RF (HR, 2.60) were risk factors for decreased survival. Factors associated with SES were not significantly related to the outcomes. CONCLUSIONS: This study found that RU is high for amputees, and increased RU persists beyond the perioperative period. Results were similar across SES indices, suggesting higher SES may not be protective against poor outcomes when limb salvage is no longer attainable. These findings support the hypothesis that SES disparities may be more modifiable during earlier stages of care for critical limb ischemia.

Outcomes of lower extremity bypass performed for acute limb ischemia.

OBJECTIVE: Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. METHODS: All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. RESULTS: Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function, and respiratory complications. Patients who underwent lower extremity bypass for acute limb ischemia had no difference in rates of graft occlusion (18.1% vs 18.5%; P = .77), but did have significantly higher rates of limb loss (22.4% vs 9.7%; P < .0001) and mortality (20.9% vs 13.1%; P < .0001) at 1 year. On multivariable analysis, acute limb ischemia was an independent predictor of both major amputation (hazard ratio, 2.16; confidence interval, 1.38-3.40; P = .001) and mortality (hazard ratio, 1.41; confidence interval, 1.09-1.83; P = .009) at 1 year. CONCLUSIONS: Patients who present with acute limb ischemia represent a less medically optimized subgroup within the population of patients undergoing lower extremity bypass. These patients may be expected to have more complex operations followed by increased rates of perioperative adverse events. Additionally, despite equivalent graft patency rates, patients undergoing lower extremity bypass for acute ischemia have significantly higher rates of major amputation and mortality at 1 year.

Impact of hospital market competition on endovascular aneurysm repair adoption and outcomes.

OBJECTIVE: The share of total abdominal aortic aneurysm (AAA) repairs performed by endovascular aneurysm repair (EVAR) increased rapidly from 32% in 2001 to 65% in 2006 with considerable variation between states. We hypothesized that hospitals in competitive markets were early EVAR adopters and had improved AAA repair outcomes. METHODS: Nationwide Inpatient Sample and linked Hospital Market Structure (HMS) data was queried for patients who underwent repair for nonruptured AAA in 2003. In HMS, the Herfindahl Hirschman Index (HHI, range 0-1) is a validated and widely accepted economic measure of competition. Hospital markets were defined using a variable geographic radius that encompassed 90% of discharged patients. We conducted bivariate and multivariable linear and logistic regression analyses for the dependent variable of EVAR use. A propensity score-adjusted multivariable logistic regression model was used to control for treatment bias in the assessment of competition on AAA repair outcomes. RESULTS: A weighted total of 21,600 patients was included in our analyses. Patients at more competitive hospitals (lower HHI) were at increased odds of undergoing EVAR vs open repair (odds ratio, 1.127 per 0.1 decrease in HHI; P < .0127) after adjusting for patient demographics, comorbidities, and hospital level factors (bed size, teaching status, AAA repair volume, and ownership). Competition was not associated with differences in in-hospital mortality or vascular, neurologic, or other minor postoperative complications. CONCLUSIONS: Greater hospital competition is significantly associated with increased EVAR adoption at a time when diffusion of this technology passed its tipping point. Hospital competition does not influence post-AAA repair outcomes. These results suggest that adoption of novel vascular technology is not solely driven by clinical indications but may also be influenced by market forces.

Comparative effectiveness, costs and trends in treatment of small renal masses from 2005 to 2007.

UNLABELLED: What's known on the subject? and what does the study add?: Retrospective data have suggested an increased survival benefit for patients undergoing partial nephrectomy compared to radical nephrectomy, possibly as a result of the avoidance of long-term renalin sufficiency and subsequent sequelae. However, recent level-one evidence has questioned this benefit. Both retrospective studies and randomized controlled trials are not without limitations. There are few population-based data available with respect to the outcomes of partial nephrectomy vs radical nephrectomy. Additionally, there are no population-based studies analyzing the surgical approach (minimally-invasive vs open), as well as other modalities, such as ablation and surveillance. Finally, there is very little information available on the potential differences in cost for each approach. The present study comprises the first comprehensive population-based analysis of the trends, outcomes and costs of all treatment modalities for T1a renal masses from 2005 to 2007. OBJECTIVE: To perform a comprehensive analysis of the outcomes and costs for treatments for small renal masses (SRM) using a population-based approach. Partial nephrectomy may be associated with improved survival, although level-one evidence has questioned this survival advantage. PATIENTS AND METHODS: Using Surveillance, Epidemiology and End Results-Medicare data, we identified 1682 subjects who were diagnosed with SRM from 2005 to 2007. Treatment included open radical nephrectomy (ORN; n = 404), minimally-invasive radical nephrectomy (MIRN; n = 535), open partial nephrectomy (OPN; n = 330), minimally-invasive partial nephrectomy (MIPN; n = 160), ablation (n = 211) and surveillance (n = 42). Postoperative complications, renal insufficiency diagnosis, overall mortality, cancer-specific mortality and postoperative costs were compared. Covariates were balanced before outcomes analysis using propensity score methods. RESULTS: Although the use of nephron-sparing surgery (NSS) increased over the study period, radical nephrectomy remained the predominant approach for SRM in 2007. Minimally-invasive approaches had shorter lengths of stay (P < 0.001), whereas open approaches had more overall complications, respiratory complications and intensive care unit admissions (all P < 0.003). MIRN and ORN were associated with more peri-operative medical complications, acute renal failure, haemodialysis use and long-term chronic renal insufficiency diagnosis vs NSS (all P < 0.001). Ablation, MIRN and ORN were associated with the highest overall mortality rates (P < 0.001), whereas MIRN and ORN were associated with the highest cancer-specific mortality rates (P < 0.001). Treatment costs were lowest for surveillance ($2911) followed by ablation ($10730), MIRN ($15373), MIPN ($15695), OPN ($16986) and ORN ($17803). CONCLUSIONS: Although not the predominant treatment approach for SRM over the study period, the use of NSS increased and was associated with improved survival, fewer complications and less renal insufficiency. Minimally-invasive approaches confer lower costs.

Effect of minimizing tension during robotic-assisted laparoscopic radical prostatectomy on urinary function recovery.

OBJECTIVES: Although most prostatectomy studies emphasize optimal nerve-sparing dissection planes, subtle technical variation also affects functional outcomes. The impact of minimizing assistant/surgeon tension on urinary function has not been quantified. We assess urinary function after attenuating neurovascular bundle (NVB) and rhabdosphincter tension during robotic-assisted radical prostatectomy (RARP). METHODS: Retrospective study of prospectively collected data for 268 (RARP-T) versus 342 (RARP-0T) men with versus without tension on the NVB and rhabdosphincter during RARP. Outcomes compared include Expanded Prostate Cancer Index (EPIC) urinary function, estimated blood loss (EBL), operative time, and positive surgical margins (PSM). RESULTS: In unadjusted analysis, men undergoing RARP-T versus RARP-0T were older, had higher biopsy and pathologic Gleason grade, and higher preoperative prostate specific antigen (all p ≤ 0.023). Baseline urinary function was similar. Postoperatively, RARP-0T versus RARP-T was associated with higher 5-month urinary function scores (69.7 versus 64, p = 0.049). In adjusted analyses, RARP-0T versus RARP-T was associated with improved 5-month urinary function [Parameter Estimate (PE) 7.37, Standard Error (SE) 2.67, p = 0.006], while bilateral versus non-/unilateral nerve-sparing was associated with improved 12-month urinary function and continence (both p ≤ 0.035). RARP-0T versus RARP-T was associated with shorter operative times (PE 6.66, SE 1.90, p = 0.001) and higher EBL (PE 20.88, SE 6.49, p = 0.001). There were no significant differences in PSM. CONCLUSIONS: While the use of tension aids in dissection of anatomic planes, avoidance of NVB counter-traction and minimizing tension on the rhabdosphincter during apical dissection attenuates neuropraxia and leads to earlier urinary function recovery. Bilateral versus non-/unilateral nerve-sparing also improves urinary function recovery.

Use, costs and comparative effectiveness of robotic assisted, laparoscopic and open urological surgery.

PURPOSE: Although robotic assisted laparoscopic surgery has been aggressively marketed and rapidly adopted, there are few comparative effectiveness studies that support its purported advantages compared to open and laparoscopic surgery. We used a population based approach to assess use, costs and outcomes of robotic assisted laparoscopic surgery vs laparoscopic surgery and open surgery for common robotic assisted urological procedures. MATERIALS AND METHODS: From the Nationwide Inpatient Sample we identified the most common urological robotic assisted laparoscopic surgery procedures during the last quarter of 2008 as radical prostatectomy, nephrectomy, partial nephrectomy and pyeloplasty. Robotic assisted laparoscopic surgery, laparoscopic surgery and open surgery use, costs and inpatient outcomes were compared using propensity score methods. RESULTS: Robotic assisted laparoscopic surgery was performed for 52.7% of radical prostatectomies, 27.3% of pyeloplasties, 11.5% of partial nephrectomies and 2.3% of nephrectomies. For radical prostatectomy robotic assisted laparoscopic surgery was more prevalent than open surgery among white patients in high volume, urban hospitals (all p≤0.015). Geographic variations were found in the use of robotic assisted laparoscopic surgery vs open surgery. Robotic assisted laparoscopic surgery and laparoscopic surgery vs open surgery were associated with shorter length of stay for all procedures, with robotic assisted laparoscopic surgery being the shortest for radical prostatectomy and partial nephrectomy (all p<0.001). For most procedures robotic assisted laparoscopic surgery and laparoscopic surgery vs open surgery resulted in fewer deaths, complications, transfusions and more routine discharges. However, robotic assisted laparoscopic surgery was more costly than laparoscopic surgery and open surgery for most procedures. CONCLUSIONS: While robotic assisted and laparoscopic surgery are associated with fewer deaths, complications, transfusions and shorter length of hospital stay compared to open surgery, robotic assisted laparoscopic surgery is more costly than laparoscopic and open surgery. Additional studies are needed to better delineate the comparative and cost-effectiveness of robotic assisted laparoscopic surgery relative to laparoscopic surgery and open surgery.

Stepwise description and outcomes of bladder neck sparing during robot-assisted laparoscopic radical prostatectomy.

PURPOSE: While bladder neck sparing may improve post-prostatectomy urinary continence, there is concern that it may lead to more positive surgical margins and compromise cancer control. We compared the continence and cancer control outcomes of bladder neck sparing vs nonsparing techniques during robot-assisted laparoscopic radical prostatectomy. MATERIALS AND METHODS: Data were prospectively collected on 1,067 robot-assisted laparoscopic radical prostatectomies done from September 2005 through October 2011. We compared the procedures according to bladder neck sparing (791) and nonsparing (276). Continence was defined by zero pad responses on the EPIC (Expanded Prostate Cancer Index) item quantifying daily use. Biochemical recurrence was defined as prostate specific antigen 0.1 ng/ml or greater. Cox regression was performed to assess factors associated with post-prostatectomy continence and biochemical recurrence-free survival. RESULTS: Median followup for bladder neck sparing vs nonsparing was 25.8 vs 51.7 months. Men treated with bladder neck sparing were more likely to have clinical T1c tumors (p <0.001) and less likely to have biopsy Gleason grade 6 or less disease (p = 0.023). They experienced fewer urinary leaks (p = 0.009) and shorter length of stay (p = 0.006). Regarding cancer control outcomes, there was no difference in bladder neck sparing vs nonsparing base (1.2% vs 2.6%, p = 0.146) and overall surgical margin positivity (each 13.8%, p = 0.985). On adjusted analyses bladder neck sparing vs nonsparing was associated with better continence (HR 1.69, 95% CI 1.43-1.99) and similar biochemical recurrence-free survival (HR 1.20, 95% CI 0.62-2.31, p = 0.596). CONCLUSIONS: Bladder neck sparing is associated with fewer urinary leak complications, shorter hospitalization and better post-prostatectomy continence without compromising cancer control compared to bladder neck nonsparing.

Hospital volume, utilization, costs and outcomes of robot-assisted laparoscopic radical prostatectomy.

PURPOSE: Although robot-assisted laparoscopic radical prostatectomy has been aggressively marketed and rapidly adopted, there is a paucity of population based utilization, outcome and cost data. High vs low volume hospitals have better outcomes for open and minimally invasive radical prostatectomy (robotic or laparoscopic) but to our knowledge volume outcomes effects for robot-assisted laparoscopic radical prostatectomy alone have not been studied. MATERIALS AND METHODS: We characterized robot-assisted laparoscopic radical prostatectomy outcome by hospital volume using the Nationwide Inpatient Sample during the last quarter of 2008. Propensity scoring methods were used to assess outcomes and costs. RESULTS: At high volume hospitals robot-assisted laparoscopic radical prostatectomy was more likely to be done on men who were white with an income in the highest quartile and age less than 50 years than at low volume hospitals (each p <0.01). Hospitals at above the 50th volume percentile were less likely to show miscellaneous medical and overall complications (p = 0.01). Low vs high volume hospitals had longer mean length of stay (1.9 vs 1.6 days) and incurred higher median costs ($12,754 vs $8,623, each p <0.01). CONCLUSIONS: Demographic differences exist in robot-assisted laparoscopic radical prostatectomy patient populations between high and low volume hospitals. Higher volume hospitals showed fewer complications and lower costs than low volume hospitals on a national basis. These findings support referral to high volume centers for robot-assisted laparoscopic radical prostatectomy to decrease complications and costs.

Influence of surgeon and hospital volume on radical prostatectomy costs.

PURPOSE: While higher radical prostatectomy hospital and surgeon volume are associated with better outcomes, the effect of provider volume on health care costs remains unclear. We performed a population based study to characterize the effect of surgeon and hospital volume on radical prostatectomy costs. MATERIALS AND METHODS: We used SEER (Surveillance, Epidemiology and End Results)-Medicare linked data to identify 11,048 men who underwent radical prostatectomy from 2003 to 2009. We categorized hospital and surgeon radical prostatectomy volume into tertiles (low, intermediate, high) and assessed costs from radical prostatectomy until 90 days postoperatively using propensity adjusted analyses. RESULTS: Higher surgeon volume at intermediate volume hospitals (surgeon volume low $9,915; intermediate $10,068; high $9,451; p = 0.021) and high volume hospitals (surgeon volume low $11,271; intermediate $10,638; high $9,529; p = 0.002) was associated with lower radical prostatectomy costs. Extrapolating nationally, selective referral to high volume radical prostatectomy surgeons at high and intermediate volume hospitals netted more than $28.7 million in cost savings. Conversely, higher hospital volume was associated with greater radical prostatectomy costs for low volume surgeons (hospital volume low $9,685; intermediate $9,915; high $11,271; p = 0.010) and intermediate volume surgeons (hospital volume low $9,605; intermediate $10,068; high $10,638; p = 0.029). High volume radical prostatectomy surgeon costs were not affected by varying hospital volume, and among low volume hospitals radical prostatectomy costs did not differ by surgeon volume. CONCLUSIONS: Selective referral to high volume radical prostatectomy surgeons operating at intermediate and high volume hospitals nets significant cost savings. However, higher radical prostatectomy hospital volume was associated with greater costs for low and intermediate volume radical prostatectomy surgeons.

An integrated biochemical prediction model of all-cause mortality in patients undergoing lower extremity bypass surgery for advanced peripheral artery disease.

BACKGROUND: Patients with advanced peripheral artery disease (PAD) have a high prevalence of cardiovascular (CV) risk factors and shortened life expectancy. However, CV risk factors poorly predict midterm (<5 years) mortality in this population. This study tested the hypothesis that baseline biochemical parameters would add clinically meaningful predictive information in patients undergoing lower extremity bypass operations. METHODS: This was a prospective cohort study of patients with clinically advanced PAD undergoing lower extremity bypass surgery. The Cox proportional hazard model was used to assess the main outcome of all-cause mortality. A clinical model was constructed with known CV risk factors, and the incremental value of the addition of clinical chemistry, lipid assessment, and a panel of 11 inflammatory parameters was investigated using the C statistic, the integrated discrimination improvement index, and Akaike information criterion. RESULTS: The study monitored 225 patients for a median of 893 days (interquartile range, 539-1315 days). In this study, 50 patients (22.22%) died during the follow-up period. By life-table analysis (expressed as percent surviving ± standard error), survival at 1, 2, 3, 4, and 5 years, respectively, was 90.5% ± 1.9%, 83.4% ± 2.5%, 77.5% ± 3.1%, 71.0% ± 3.8%, and 65.3% ± 6.5%. Compared with survivors, decedents were older, diabetic, had extant coronary artery disease, and were more likely to present with critical limb ischemia as their indication for bypass surgery (P < .05). After adjustment for the above, clinical chemistry and inflammatory parameters significant (hazard ratio [95% confidence interval]) for all-cause mortality were albumin (0.43 [0.26-0.71]; P = .001), estimated glomerular filtration rate (0.98 [0.97-0.99]; P = .023), high-sensitivity C-reactive protein (hsCRP; 3.21 [1.21-8.55]; P = .019), and soluble vascular cell adhesion molecule (1.74 [1.04-2.91]; P = .034). Of the inflammatory molecules investigated, hsCRP proved most robust and representative of the integrated inflammatory response. Albumin, eGFR, and hsCRP improved the C statistic and integrated discrimination improvement index beyond that of the clinical model and produced a final C statistic of 0.82. CONCLUSIONS: A risk prediction model including traditional risk factors and parameters of inflammation, renal function, and nutrition had excellent discriminatory ability in predicting all-cause mortality in patients with clinically advanced PAD undergoing bypass surgery.

Socioeconomic and hospital-related predictors of amputation for critical limb ischemia.

OBJECTIVE: Disparities in limb salvage procedures may be driven by socioeconomic status (SES) and access to high-volume hospitals. We sought to identify SES factors associated with major amputation in the setting of critical limb ischemia (CLI). METHODS: The 2003-2007 Nationwide Inpatient Sample was queried for discharges containing lower extremity revascularization (LER) or major amputation and chronic CLI (N = 958,120). The Elixhauser method was used to adjust for comorbidities. Significant predictors in bivariate logistic regression were entered into a multivariate logistic regression for the dependent variable of amputation vs LER. RESULTS: Overall, 24.2% of CLI patients underwent amputation. Significant differences were seen between both groups in bivariate and multivariate analysis of SES factors, including race, income, and insurance status. Lower-income patients were more likely to be treated at low-LER-volume institutions (odds ratio [OR], 1.74; P < .001). Patients at higher-LER-volume centers (OR, 15.16; P <.001) admitted electively (OR, 2.19; P < .001) and evaluated with diagnostic imaging (OR, 10.63; P < .001) were more likely to receive LER. CONCLUSIONS: After controlling for comorbidities, minority patients, those with lower SES, and patients with Medicaid were more likely receive amputation for CLI in low-volume hospitals. Addressing SES and hospital factors may reduce amputation rates for CLI.

Validation of the Society for Vascular Surgery's objective performance goals for critical limb ischemia in everyday vascular surgery practice.

BACKGROUND: To develop standardized metrics for expected outcomes in lower extremity revascularization for critical limb ischemia (CLI), the Society for Vascular Surgery (SVS) has developed objective performance goals (OPGs) based on aggregate data from randomized trials of lower extremity bypass (LEB). It remains unknown, however, if these targets can be achieved in everyday vascular surgery practice. METHODS: We applied SVS OPG criteria to 1039 patients undergoing 1039 LEB operations for CLI with autogenous vein (excluding patients on dialysis) within the Vascular Study Group of New England (VSGNE). Each of the individual OPGs was calculated within the VSGNE dataset, along with its surrounding 95% confidence intervals (CIs) and compared to published SVS OPGs using χ(2) comparisons and survival analysis. RESULTS: Across most risk strata, patients in the VSGNE and SVS OPG cohorts were similar (clinical high-risk [age >80 years and tissue loss]: 15.3% VSGNE; 16.2% SVS OPG; P = .58; anatomic high risk [infrapopliteal target artery]: 57.8% VSGNE; 60.2% SVS OPG; P = .32). However, the proportion of VSGNE patients designated as conduit high-risk (lack of single-segment great saphenous vein) was lower (10.2% VSGNE; 26.9% SVS OPG;P < .001). The primary safety endpoint, major adverse limb events (MALE) at 30 days, was lower in the VSGNE cohort (3.2%; 95% CI, 2.3-4.6) than the SVS OPG cohort (6.2%; 95% CI, 4.2-8.1; P = .05). The primary efficacy OPG endpoint, freedom from any MALE or postoperative death within the first year (MALE + postoperative death [POD]), was similar between VSGNE and SVS OPG cohorts (77%; 95% CI, 74%-80%) SVS OPG, 74% (95% CI, 71%-77%) VSGNE, P = .58). In the remaining safety and efficacy OPGs, the VSGNE cohort met or exceeded the benchmarks established by the SVS OPG cohort. CONCLUSION: Community and academic centers in everyday vascular surgery practice can meet OPGs derived from centers of excellence in LEB. Quality improvement initiatives, as well as clinical trials, should incorporate OPGs in their outcome measures to facilitate communication and comparison of risk-adjusted outcomes in the treatment of CLI.