Relationships between 2-Year Survival, Costs, and Outcomes following Carotid Endarterectomy in Asymptomatic Patients in the Vascular Quality Initiative.

BACKGROUND: Carotid endarterectomy (CEA) for asymptomatic patients with limited life expectancy may not be beneficial or cost-effective. The purpose of this study was to examine relationships among survival, outcomes, and costs within 2 years following CEA among asymptomatic patients. METHODS: Prospectively collected data from 3097 patients undergoing CEA for asymptomatic disease from Vascular Quality Initiative VQI registry were linked to Medicare. Models were used to identify predictors of 2-year mortality following CEA. Patients were classified as low, medium, or high risk of death based on this model. Next, we examined costs related to cerebrovascular care, occurrence of stroke, rehospitalization, and reintervention within 2 years following CEA across risk strata. RESULTS: Overall, 2-year mortality was 6.7%. Age, diabetes, smoking, congestive heart failure (CHF), chronic obstructive pulmonary disease, renal insufficiency, absence of statin use, and contralateral internal carotid artery (ICA) stenosis were independently associated with a higher risk of death following CEA. In-hospital costs averaged $7500 among patients defined as low risk for death, and exceeded $10,800 among high risk patients. Although long-term costs related to cerebrovascular disease were 2 times higher in patients deemed high risk for death compared with low risk patents ($17,800 vs. $8800, P = 0.001), high risk of death was not independently associated with a high probability of high cost. Predictors of high cost at 2 years were severe contralateral ICA stenosis, dialysis dependence, and American Society for Anesthesia Class 4. Both statin use and CHF were protective of high cost. CONCLUSIONS: Greater than 90% of patients undergoing CEA live long enough to realize the benefits of their procedure. Moreover, the long-term costs are supported by the effectiveness of this procedure at all levels of patient risk.

Physician specialty and variation in carotid revascularization technique selected for Medicare patients.

OBJECTIVE: Carotid artery stenting (CAS) has become an alternative to carotid endarterectomy (CEA) for select patients with carotid atherosclerosis. We hypothesized that the choice of CAS vs CEA varies as a function of treating physician specialty, which would result in regional variation in the relative use of these treatment types. METHODS: We used Medicare claims (2002-2010) to calculate annual rates of CAS and CEA and examined changes by procedure type over time. To assess regional preferences surrounding CAS, we calculated the proportion of revascularizations by CAS, across hospital referral regions, defined according to the Dartmouth Atlas of Healthcare. We then examined relationships between patient factors, physician specialty, and regional use of CAS. RESULTS: The annual number of all carotid revascularization procedures decreased by 30% from 2002 to 2010 (3.2 to 2.3 per 1000; P = .005). Whereas rates of CEA declined by 35% during these 8 years (3.0 to 1.9 per 1000; P < .001), CAS utilization increased by 5% during the same interval (0.30 to 0.32 per 1000; P = .014). Variation in utilization of carotid revascularization varied across the Unites States, with some regions performing as few as 0.7 carotid procedure per 1000 beneficiaries (Honolulu, Hawaii) and others performing nearly 8 times as many (5.3 per 1000 in Houma, La). Variation in procedure type (CEA vs CAS) was evident as well, as the proportion of carotid revascularization procedures that were constituted by CAS varied from 0% (Casper, Wyo, and Meridian, Miss) to 53% (Bend, Ore). The majority of CAS procedures were performed by cardiologists (49% of all CAS cases), who doubled their rates of CAS during the study period from 0.07 per 1000 in 2002 to 0.15 per 1000 in 2010. CONCLUSIONS: Variation in rates of carotid revascularization exists. Whereas rates of carotid revascularization have declined by more than 30% in recent years, utilization of CAS has increased. The proportion of all carotid revascularization procedures performed as CAS varies markedly by geographic region, and regions with the highest proportion of cardiologists perform the most CAS procedures. Evidence-based guidelines for carotid revascularization will require a multidisciplinary approach to ensure uniform adoption across specialties that care for patients with carotid artery disease.

Use of a glucose management service improves glycemic control following vascular surgery: an interrupted time-series study.

BACKGROUND: The optimal method for obtaining good blood glucose control in noncritically ill patients undergoing peripheral vascular surgery remains a topic of debate for surgeons, endocrinologists, and others involved in the care of patients with peripheral arterial disease and diabetes. A prospective trial was performed to evaluate the impact of routine use of a glucose management service (GMS) on glycemic control within 24 hours of lower-extremity revascularization (LER). METHODS: In an interrupted time-series design (May 1, 2011-April 30, 2012), surgeon-directed diabetic care (Baseline phase) to routine GMS involvement (Intervention phase) was compared following LER. GMS assumed responsibility for glucose management through discharge. The main outcome measure was glycemic control, assessed by (1) mean hospitalization glucose and (2) the percentage of recorded glucose values within target range. Statistical process control charts were used to assess the impact of the intervention. RESULTS: Clinically important differences in patient demographics were noted between groups; the 19 patients in the Intervention arm had worse peripheral vascular disease than the 19 patients in the Baseline arm (74% critical limb ischemia versus 58%; p = .63). Routine use of GMS significantly reduced mean hospitalization glucose (191 mg/dL Baseline versus 150 mg/dL Intervention, p < .001). Further, the proportion of glucose values in target range increased (48% Baseline versus 78% Intervention, p = .05). Following removal of GMS involvement, measures of glycemic control did not significantly decrease for the 19 postintervention patients. CONCLUSIONS: Routine involvement of GMS improved glycemic control in patients undergoing LER. Future work is needed to examine the impact of improved glycemic control on clinical outcomes following LER.

Band removal and conversion to sleeve or bypass: are they equally safe?

INTRODUCTION: Patients who require laparoscopic adjustable gastric band (LAGB) removal are often converted to sleeve gastrectomy (SG) or roux-en-Y gastric bypass (RYGB). The relative safety of these salvage bariatric procedures is unclear. We hypothesized that LAGB removal with conversion to SG (BSG) or RYGB (BRYGB) would be associated with higher morbidity and mortality compared to primary SG or RYGB. METHODS: National Surgical Quality Improvement Project data (2005-2011) were analyzed. Patients undergoing SG, RYGB, BRYGB, and BSG were identified. The incidence of major complications, as well as mortality was compared between groups. Multivariate analysis was performed to identify patient factors and operation types associated with major complications or mortality. Odds ratios (OR) were calculated with 95 % confidence intervals (CI) with p value <0.05 considered statistically significant. RESULTS: A total of 51,609 patients were analyzed, consisting of primary RYGB (n = 46,153), BRYGB (495), primary SG (n = 4,831), and BSG (n = 130) patients. All groups had similar mean age (45 ± 11-years old). Salvage patients were more commonly female (89 vs. 79 %) and with lower body-mass index than primary bariatric patients (BMI 42 ± 8 vs. 46 ± 8 kg/m2). Major complication rates were 5.23 % (RYGB), 4.65 % (BRYGB), 3.95 % (SG) and 6.92 % (BSG), with 30-day mortality of 0.16 % (RYGB), 0.20 % (BRYGB), 0.08 % (SG) and 0.77 % (BSG). Multivariate analysis showed that compared to SG, RYGB, and BSG were independent predictors of major complications. Multivariate analysis of mortality showed BSG was an independent predictor of mortality compared to SG (OR 8.02, 95 % CI 1.08-59.34, p = 0.04). CONCLUSIONS: Band removal with conversion to RYGB is not associated with higher morbidity or mortality compared to primary RYGB. However, band removal with conversion to sleeve gastrectomy appears to be independently associated with a higher rate of major complications and mortality, and thus may not be the salvage procedure of choice.

Designation as "unfit for open repair" is associated with poor outcomes after endovascular aortic aneurysm repair.

BACKGROUND: Endovascular aortic aneurysm repair (EVAR) is often offered to patients with abdominal aortic aneurysms (AAAs) considered preoperatively to be unfit for open AAA repair (oAAA). This study describes the short- and long-term outcomes of patients undergoing EVAR with AAAs <6.5 cm who are considered unfit for oAAA. METHODS AND RESULTS: We analyzed elective EVARs for AAAs <6.5 cm diameter in the Vascular Study Group of New England (2003-2011). Patients were designated as fit or unfit for oAAA by the treating surgeon. End points included in-hospital major adverse events and long-term mortality. We identified patient characteristics associated with being unfit for open repair and predictors of survival using multivariable analyses. Of 1653 EVARs, 309 (18.7%) patients were deemed unfit for oAAA. These patients were more likely to have advanced age, cardiac disease, chronic obstructive pulmonary disease, and larger aneurysms at the time of repair (54 versus 56 mm, P=0.001). Patients unfit for oAAA had higher rates of cardiac (7.8% versus 3.1%, P<0.01) and pulmonary (3.6 versus 1.6, P<0.01) complications and worse survival rates at 5 years (61% versus 80%; log rank P<0.01) compared with those deemed fit for oAAA. Finally, patients designated as unfit for oAAA had worse survival, even adjusting for patient characteristics and aneurysm size (hazard ratio, 1.6; 95% confidence interval, 1.2-2.2; P<0.01). CONCLUSIONS: In patients with AAAs <6.5 cm, designation by the operating surgeon as unfit for oAAA provides insight into both short- and long-term efficacy of EVAR. Patients unable to tolerate oAAA may not benefit from EVAR unless their risk of AAA rupture is very high.

Functional outcomes following catheter-based iliac vein stent placement.

OBJECTIVES: Although previous reports have demonstrated the efficacy of catheter-directed thrombolytic therapy and iliac vein stent placement for the management of iliofemoral deep vein thrombosis (DVT), functional outcomes remain undefined. The purpose of this study was to determine midterm outcomes and functional quality of life among patients treated with iliac vein stenting. METHODS: Records of all the patients treated with iliac vein stent placement between March 2004 and March 2011 were examined for primary patency, assisted primary patency, and secondary patency. Midterm functional outcomes were measured quantitatively, including ongoing symptoms and return to work status. RESULTS: Over the study interval, 32 patients (33 limbs) underwent iliac vein stent placement. In all, 72% (n = 23) of these patients were female, with an average age of 43 years. In all, 78% (n = 25) of the patients were diagnosed with acute DVT, 89% of which occurred in the left leg. Catheter-directed thrombolysis was utilized in 92% (23 of 25) of the patients with acute DVT. All patients treated with thrombolysis and stent placement presented with pain and edema in the affected limb. One-year primary, assisted primary, and secondary patencies were 75%, 96%, and 96%, respectively. Freedom from reintervention at 1 year was 83%. Treatment was associated with a sustained significant reduction in pain (91% vs 6%, P < .001) and edema (97% vs 12%, P < .001) at a mean follow-up of 29 months (range 5-83 months), at which time 89% of the patients reported to be at their pre-DVT functional status. CONCLUSIONS: Aggressive therapy of symptomatic iliac vein stenosis or occlusion with venography, catheter-directed thrombolysis, and iliac vein stent placement provides durable patency and freedom from reintervention. Most patients can anticipate good functional recovery with decreased pain, decreased edema, and high likelihood of returning to work.

Optimal selection of asymptomatic patients for carotid endarterectomy based on predicted 5-year survival.

OBJECTIVE: Although carotid endarterectomy (CEA) is performed to prevent stroke, long-term survival is essential to ensure benefit, especially in asymptomatic patients. We examined factors associated with 5-year survival following CEA in patients with asymptomatic internal carotid artery (ICA) stenosis. METHODS: Prospectively collected data from 4114 isolated CEAs performed for asymptomatic stenosis across 24 centers in the Vascular Study Group of New England between 2003 and 2011 were used for this analysis. Late survival was determined with the Social Security Death Index. Cox proportional hazard models were used to identify risk factors for mortality within the first 5 years after CEA and to calculate a risk score for predicting 5-year survival. RESULTS: Overall 3- and 5-year survival after CEA in asymptomatic patients were 90% (95% CI 89%-91%) and 82% (95% CI 81%-84%), respectively. By multivariate analysis, increasing age, diabetes, smoking history, congestive heart failure, chronic obstructive pulmonary disease, poor renal function (estimated glomerular filtration rate <60 or dialysis dependence), absence of statin use, and worse contralateral ICA stenosis were all associated with worse survival. Patients classified as low (27%), medium (68%), and high risk (5%) based on number of risk factors had 5-year survival rates of 96%, 80%, and 51%, respectively (P < .001). CONCLUSIONS: More than four out of five asymptomatic patients selected for CEA in the Vascular Study Group of New England achieved 5-year survival, demonstrating that, overall, surgeons in our region selected appropriate patients for carotid revascularization. However, there were patients selected for surgery with high risk profiles, and our models suggest that the highest risk patients (such as those with multiple major risk factors including age ≥ 80, insulin-dependent diabetes, dialysis dependence, and severe contralateral ICA stenosis) are unlikely to survive long enough to realize a benefit of prophylactic CEA for asymptomatic stenosis. Predicting survival is important for decision making in these patients.

Insurance status, stone composition, and 24-hour urine composition.

UNLABELLED: Abstract Purpose: We examined the stone composition, 24-hour urinary risk factors, and insurance status in patients evaluated in two regional stone clinics to further investigate the relationship between the socioeconomic status and kidney stone formation. MATERIALS AND METHODS: We performed a retrospective review of stone formers who completed a 24-hour urinalysis as part of a metabolic evaluation for nephrolithiasis. Insurance status was determined by billing records and those with state-assisted insurance (SAI) were compared to patients with private insurance (PI). Multivariate analyses were performed adjusting for known risk factors for stones. RESULTS: Three hundred forty-six patients were included. Patients with SAI (16%) were significantly more likely to be female (55% vs.38%, p=0.026) and younger (43.5 vs.49.2, p=0.003). Among those with stone composition data (n=200), SAI patients were as likely to form calcium phosphate (CaPhos) as calcium oxalate (CaOx) stones (46.9% vs.31.3%, p=0.44). PI patients were significantly less likely to form CaPhos than CaOx stones (10.1% vs.77.4%, p<0.001). On multivariate analysis, among those with calcium stones, the odds of forming CaPhos stones over CaOx stones were ten times higher among SAI patients compared to PI, odds ratio 10.2 (95% CI 3.6, 28.6, p<0.001). Further, patients with SAI had significantly higher urine sodium, pH, and supersaturation of CaPhos, and a lower supersaturation of uric acid compared to patients with PI. CONCLUSIONS: SAI was associated with a greater likelihood of a CaPhos stone composition and increased urinary risk factors for CaPhos stones. These findings may reflect dietary or other unmeasured differences, and have important implications for resource allocation and counseling, as treatment may differ for these groups.

Venous thromboembolism after surgery for inflammatory bowel disease: are there modifiable risk factors? Data from ACS NSQIP.

BACKGROUND: Although it is commonly reported that IBD patients are at increased risk for venous thromboembolic events, little real-world data exist regarding their postoperative incidence and related outcomes in everyday practice. OBJECTIVE: We aimed to identify the rate of venous thromboembolism and modifiable risk factors within a large cohort of surgical IBD patients. DESIGN: We performed a retrospective review of IBD patients who underwent colorectal procedures. PATIENTS: Patient data were obtained from the American College of Surgeons National Surgical Quality Improvement Program 2004 to 2010 Participant Use Data Files. MAIN OUTCOME MEASURES: The primary outcomes measured were short-term (30-day) postoperative venous thromboembolism (deep vein thrombosis and pulmonary embolism). Clinical variables were analyzed by univariate and multivariate analyses to identify modifiable risk factors for these events. RESULTS: A total of 10,431 operations were for Crohn's disease (52.1%) or ulcerative colitis (47.9%), and 242 (2.3%) venous thromboembolic events occurred (178 deep vein thromboses, 46 pulmonary embolisms, 18 both) for a combined rate of 1.4% in Crohn's disease and 3.3% in ulcerative colitis. Deep vein thrombosis and pulmonary embolism each occurred at a mean of 10.8 days postoperatively (range for each, 0-30 days). A multivariate model found that bleeding disorder, steroid use, anesthesia time, emergency surgery, hematocrit <37%,malnutrition, and functional status were potentially modifiable risk factors that remained associated (p < 0.05) with venous thromboembolism on regression analysis. Patients with thromboembolism had longer length of stay (18.8 vs 8.9 days), more complications (41% vs 18%), and a higher risk of death (4% vs 0.9%). LIMITATIONS: This study was limited by its retrospective design and its limited generalizability to nonparticipating hospitals. CONCLUSIONS: Inflammatory bowel disease patients are at increased risk for postoperative venous thromboembolism. Reducing preoperative anemia, steroid use, malnutrition, and anesthesia time may also reduce venous thromboembolism in this at-risk population. Risk-reducing, preventative strategies are needed in this at-risk population.

Impact of screening versus symptomatic measurement of deep vein thrombosis in a national quality improvement registry.

BACKGROUND: Deep vein thrombosis (DVT) is a quality measure recorded by initiatives such as the National Surgical Quality Improvement Program (NSQIP). However, because surveillance-detected DVT rates may be higher than symptomatic DVT rates, we examined how differences in the method of DVT detection may affect the use of this quality measure. METHODS: Using the NSQIP database (2007-2009), we compared DVT rates of vascular (amputation, open aortic procedures, and lower extremity bypass) and nonvascular (prostatectomy, gastric bypass [GBP], and hip arthroplasty) operations. Using a predefined literature search strategy, we compared the incidence of DVT in NSQIP to the incidence of DVT reported in published literature, diagnosed by symptomatic status or by surveillance studies. RESULTS: Within NSQIP, the overall incidence of postoperative DVT was 0.7%. This varied from 0.3% after GBP to 1.8% after open aortic surgery. Across all procedures except amputation, the incidence of DVT in NSQIP was similar to the incidence of DVT reported in our literature survey of "symptomatic" DVTs. The relative rate (RR) of literature-derived symptomatic DVTs to NSQIP ranged from 0.7 for aortic cases (95% confidence interval [CI], 0.3-1.7) to 1.4 (95% CI, .7-3.1) for GBP. Overall, surveillance studies had 11.6 higher RR of DVT compared to NSQIP (95% CI, 10.5-13), ranging from 2.6 for GBP (95% CI, 1.4-5) to 14 .5 for hip arthroplasty (95% CI, 10.5-20). CONCLUSIONS: The incidence of DVT reported in NSQIP is similar to the reported incidence of symptomatic DVT for many high-risk procedures but is much lower than rates of DVT reported in surveillance studies. Clear delineation of symptomatic vs surveillance detection of DVT would improve the usefulness of this measurement in quality improvement registries.

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.

Carotid endarterectomy in asymptomatic patients with limited life expectancy.

BACKGROUND AND PURPOSE: Data from randomized trials assert that asymptomatic patients undergoing carotid endarterectomy (CEA) must live 3 to 5 years to realize the benefit of surgery. We examined how commonly CEA is performed among asymptomatic patients with limited life expectancy. METHODS: Within the American College of Surgeons National Quality Improvement Project we identified 8 conditions associated with limited life expectancy based on survival estimates using external sources. We then compared rates of 30-day stroke, death, and myocardial infarction after CEA between asymptomatic patients with and without life-limiting conditions. RESULTS: Of 12,631 CEAs performed in asymptomatic patients, 2525 (20.0%) were in patients with life-limiting conditions or diagnoses. The most common conditions were severe chronic obstructive pulmonary disease and American Society of Anesthesiologists Class IV designation. Patients with life-limiting conditions had significantly higher rates of perioperative complications, including stroke (1.8% versus 0.9%, P<0.001), death (1.4% versus 0.3%, P<0.001), and stroke/death (2.9% versus 1.1%, P<0.001). Even after adjustment for other comorbidities, patients with life-limiting conditions were nearly 3 times more likely to experience perioperative stroke or death than those without these conditions (OR, 2.8; 95% CI, 2.1-3.8; P<0.001). CONCLUSION: CEA is performed commonly in asymptomatic patients with life-limiting conditions. Given the high rates of postoperative stroke/death in these patients as well as their limited life expectancy, the net benefit of CEA in this population remains uncertain. Health policy research examining the role of CEA in asymptomatic patients with life-limiting conditions is necessary and may serve as a potential source for significant healthcare savings in the future.

Variation in thromboembolic complications among patients undergoing commonly performed cancer operations.

OBJECTIVE: There is widespread evidence that cancer confers an increased risk of deep venous thrombosis (DVT). This risk is thought to vary among different cancer types. The purpose of this study is to better define the incidence of thrombotic complications among patients undergoing surgical treatment for a spectrum of prevalent cancer diagnoses in contemporary practice. METHODS: All patients undergoing one of 11 cancer surgical operations (breast resection, hysterectomy, prostatectomy, colectomy, gastrectomy, lung resection, hepatectomy, pancreatectomy, cystectomy, esophagectomy, and nephrectomy) were identified by Current Procedural Terminology and International Classification of Diseases, Ninth Revision codes using the American College of Surgeons National Surgical Quality Improvement Program database (2007-2009). The study endpoints were DVT, pulmonary embolism (PE), and overall postoperative venous thromboembolic events (VTE) within 1 month of the index procedure. Multivariate logistic regression was utilized to calculate adjusted odds ratios for each endpoint. RESULTS: Over the study interval, 43,808 of the selected cancer operations were performed. The incidence of DVT, PE, and total VTE within 1 month following surgery varied widely across a spectrum of cancer diagnoses, ranging from 0.19%, 0.12%, and 0.28% for breast resection to 6.1%, 2.4%, and 7.3%, respectively, for esophagectomy. Compared with breast cancer, the incidence of VTE ranged from a 1.31-fold increase in VTE associated with gastrectomy (95% confidence interval, 0.73-2.37; P = .4) to a 2.68-fold increase associated with hysterectomy (95% confidence interval, 1.43-5.01; P = .002). Multivariate logistic regression revealed that inpatient status, steroid use, advanced age (≥60 years), morbid obesity (body mass index ≥35), blood transfusion, reintubation, cardiac arrest, postoperative infectious complications, and prolonged hospitalization were independently associated with increased risk of VTE. CONCLUSIONS: The incidence of VTE and thromboembolic complications associated with cancer surgery varies substantially. These findings suggest that both tumor type and resection magnitude may impact VTE risk. Accordingly, such data support diagnosis and procedural-specific guidelines for perioperative VTE prophylaxis and can be used to anticipate the risk of potentially preventable morbidity.

A meta-analysis of anticoagulation for calf deep venous thrombosis.

OBJECTIVE: This meta-analysis was initiated to assess the efficacy and safety of anticoagulation therapy for adult patients with isolated calf vein deep venous thrombosis (DVT). METHODS: We searched MEDLINE (1950-October 2010), the Cochrane Library (1993-October 2010), trial registries, meeting abstracts, and selected references, using no limits. Included studies compared the results of anticoagulation (vitamin K antagonist or therapeutic heparin) for a minimum of 30 days vs the results of no anticoagulation in adults with calf vein DVT proved by ultrasound imaging or venograph who were monitored for at least 30 days. Two independent reviewers extracted data using a piloted standardized form. Methodologic quality was assessed using the Cochrane Risk of Bias tool for randomized controlled trials (RCTs) and the Newcastle-Ottawa Quality Assessment Scale for cohort and case-control studies. Discrepancies were resolved by consensus or by a third reviewer. Authors were contacted for additional information if necessary. Outcomes were pooled using Peto fixed-effects models. RESULTS: Of 2328 studies identified, two RCTs and six cohorts (126 patients treated with anticoagulation and 328 controls) met selection criteria. The methodologic quality of most studies was poor. Pulmonary embolism (PE; odds ratio, 0.12; 95% confidence interval, 0.02-0.77; P = .03) and thrombus propagation (odds ratio, 0.29; 95% confidence interval, 0.14-0.62; P = .04) were significantly less frequent in those who received anticoagulation. Significant heterogeneity existed in studies reporting mortality rates, but these demonstrated a trend toward fewer deaths with anticoagulation. When limited to randomized trials, the protective effect of anticoagulation for PE was no longer statistically significant, but the benefit for preventing thrombus progression persisted. Adverse events such as bleeding were sparsely reported but favored controls (P = .65). CONCLUSIONS: Our review suggests that anticoagulation therapy for calf vein DVT may decrease the incidence of PE and thrombus propagation. However, due to poor methodologic quality and few events among included studies for PE, this finding is not robust. Thrombus propagation appears reduced with anticoagulation treatment. A rigorous RCT will assist in treatment decisions for calf vein DVT.

Impact of practice patterns in shunt use during carotid endarterectomy with contralateral carotid occlusion.

PURPOSE: This study investigated the association between surgeon practice pattern in shunt placement and 30-day stroke/death in patients undergoing carotid endarterectomy (CEA) with contralateral carotid occlusion (CCO). METHODS: Among 6379 CEAs performed in the Vascular Study Group of New England (VSGNE) between 2002 and 2009, we identified 353 patients who underwent CEA with CCO and compared the 30-day stroke/death rate with 5279 patients who underwent primary, isolated CEA with a patent contralateral carotid artery. Within patients with CCO, we examined the 30-day stroke/death rate across the reason for shunt placement and two distinct surgeon practice patterns in shunt placement: surgeons who selectively used a shunt (≤95% of CEAs) or routinely used a shunt (>95% of CEAs). We used observed/expected (O/E) ratios to provide risk-adjusted comparisons across groups. RESULTS: Of 353 patients with CCO, 118 (33%) underwent CEA without a shunt, 173 (49%) underwent CEA using a shunt placed routinely, and 62 (18%) had a shunt placed for a neurologic indication. Rates of 30-day stroke/death across categories of reason for shunt use were no shunt, 3.4%; routine shunt, 4.0%; and shunt for indication, 4.8% (P = .891). The risk of 30-day stroke/death was higher for surgeons who selectively placed shunts (5.6%) in all their CEAs and lower for surgeons who routinely placed shunts (1.5%, P = .05). The risk of 30-day stroke/death was >1 in patients undergoing selective shunting (O/E ratio, 1.4; 95% confidence interval [CI], 1.1-1.7) and <1 for surgeons who placed shunts routinely (O/E ratio, 0.4; 95% CI, 0.2-0.9). Stroke/death rates were lowest when individual surgeons' intraoperative decisions reflected their usual pattern of practice: 1.5% stroke/death rate when "routine" surgeons placed a shunt, 3.4% when "selective" surgeons did not place a shunt, and 7.6% stroke/death rate for "selective" surgeons who placed a shunt (P = .05 for trend). CONCLUSIONS: The risk of 30-day stroke/death is higher in CEA in patients with CCO than with a patent contralateral carotid artery. Surgeons who place shunts selectively during CEA have higher rates of stroke/death in patients with CCO. This suggests that shunt use for CCO during CEA is associated with fewer complications, but only if the surgeon uses a shunt as part of his or her routine practice in CEA. Surgeons should preoperatively consider their own practice pattern in shunt use when faced with a patient who may require shunt placement.

Completion imaging after carotid endarterectomy in the Vascular Study Group of New England.

OBJECTIVES: We studied surgeons' practice patterns in the use of completion imaging (duplex or arteriography), and their association with 30-day stroke/death and 1-year restenosis after carotid endarterectomy (CEA). METHODS: Using a retrospective analysis of 6115 CEAs, we categorized surgeons based on use of completion imaging as rarely (<5% of CEAs), selective (5% to 90%), or routine (≥90%). Crude and risk-adjusted 30-day stroke/death and 1-year restenosis rates were examined across surgeon practice patterns. Finally, we audited 90 operative reports of patients who underwent re-exploration and characterized findings and interventions. We analyzed the effect of re-exploration on outcomes. RESULTS: Practice patterns in completion imaging varied: 51% of surgeons performed completion imaging rarely, 22% selectively, and 27% routinely. Crude 30-day stroke/death rates were highest among surgeons who routinely used completion imaging (rarely: 1.7%; selectively: 1.2%, routinely: 2.4%; P = .05). However, after adjusting for patient characteristics predictive of stroke/death, the effect of surgeon practice pattern was not statistically significant (odds ratio [OR] for routine-use surgeons, 1.42; 95% CI, 0.93-2.17; P = .10; selective-use surgeons, 0.75; 95% CI, 0.40-1.41; P = .366). Stenosis >70% at 1 year showed a trend toward lowest rates for surgeons who performed completion imaging (rarely: 2.8%, selectively: 1.1%, and routinely: 1.1%; P = .09). This effect became statistically significant for selective-use surgeons after adjustment (hazard risk [HR] for selective-use surgeons, 0.52; 95% CI, 0.29-0.92; P = .02). Overall, 178 patients (2.9%) underwent operative re-exploration. Routine-use surgeons were most likely to perform re-exploration (7.6% routine, 0.8% selective, 0.9% rare; P < .001). An audit of 90 re-explored patients demonstrated technical problems, the most common being flap, debris, and plaque. Rates of stroke/death were higher among patients who underwent re-exploration (3.9% vs 1.7%; P = .03); however, this affect was attenuated after adjustment (OR, 2.1; 95% CI, 0.9-5.0; P = .08). CONCLUSIONS: The use of completion imaging during CEA varies widely across our region. There is little evidence that surgeons who use completion imaging have lower rates of 30-day stroke/death, although selective use of completion imaging is associated with a small but a significant reduction in stenosis 1 year after surgery. We also demonstrate an association between re-exploration and higher risk of 30-day stroke/death, although this effect was attenuated after adjustment for patient-level predictors of stroke/death. Future work is needed to direct the selective use of completion imaging to prevent stroke, rather than cause unnecessary re-exploration.