The impact of current smoking on outcomes after infrainguinal bypass for claudication.

OBJECTIVE: Although smoking cessation is a benchmark of medical management of intermittent claudication, many patients require further revascularization. Currently, revascularization among smokers is a controversial topic, and practice patterns differ institutionally, regionally, and nationally. Patients who smoke at the time of revascularization are thought to have a poor prognosis, but data on this topic are limited. The purpose of this study was to evaluate the impact of smoking on outcomes after infrainguinal bypass for claudication. METHODS: Data from the national Vascular Quality Initiative from 2004 to 2014 were used to identify infrainguinal bypasses performed for claudication. Patients were categorized as former smokers (quit >1 year before intervention) and current smokers (smoking within 1 year of intervention). Demographic and comorbid differences of categorical variables were assessed. Significant predictors were included in adjusted Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) by smoking status for outcomes of major adverse limb event (MALE), amputation-free survival, limb loss, death, and MALE or death. Cumulative incidence curves were created using competing risks modeling. RESULTS: We identified 2913 patients (25% female, 9% black) undergoing incident infrainguinal bypass grafting for claudication. There were 1437 current smokers and 1476 former smokers in our study. Current smoking status was a significant predictor of MALE (HR, 1.27; 95% CI, 1.00-1.60; P = .048) and MALE or death (HR, 1.22; 95% CI, 1.03-1.44; P = .02). Other factors found to be independently associated with poor outcomes in adjusted models included black race, below-knee bypass grafting, use of prosthetic conduit, and dialysis dependence. CONCLUSIONS: Current smokers undergoing an infrainguinal bypass procedure for claudication experienced more MALEs than former smokers did. Future studies with longer term follow-up should address limitations of this study by identifying a data source with long-term follow-up examining the relationship of smoking exposure (pack history and duration) with outcomes.

Better survival for African and Hispanic/Latino Americans after infrainguinal revascularization in the Society for Vascular Surgery Vascular Quality Initiative.

OBJECTIVE: Inferior survival outcomes have historically been reported for African Americans with cardiovascular disease, and poorer outcomes have been presumed for peripheral arterial disease (PAD) as well. The current study evaluates the effect of race and ethnicity on survival of patients undergoing open or endovascular interventions for lower extremity PAD. METHODS: Data of patients from the Society for Vascular Surgery Vascular Quality Initiative database were obtained for patients undergoing open infrainguinal (INFRA) or suprainguinal (SUPRA) bypass, peripheral vascular intervention (PVI), and amputation (AMP). Patients were further stratified as suprainguinal (SupraPVI) if any of the first three interventions listed included the aorta or iliac vessels or infrainguinal (InfraPVI) if not. The primary outcome was the patient's death (overall mortality) as recorded in the database or determined by cross-reference with the Social Security Death Index (SSDI). The secondary outcome consisted of perioperative mortality during the index hospitalization. Generalized linear modeling provided multivariate analysis, with entry of variables dependent on results of univariate analysis. RESULTS: From January 2003 through September 2015, a total of 24,241 INFRA bypass, 8028 SUPRA bypass, 48,048 InfraPVI, 21,196 SupraPVI, and 3423 AMP patients met criteria for analysis, with a median follow-up of 18 (interquartile range, 8-33) months. Combining all procedures, overall mortality was lower among African Americans than among white Americans (12.4% vs 14.2%; P < .0001) but not death in the periprocedural period (1.1% vs 1.2%; P = .26). To account for differences in length of follow-up, Cox proportional hazards analysis confirmed that the African American race was independently associated with a significantly lower occurrence of overall mortality after INFRA bypass (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.70-0.88; P < .0009), InfraPVI (HR, 0.72; 95% CI, 0.67-0.78; P < .0001), and SupraPVI (HR, 0.77; 95% CI, 0.66-0.90; P = .0009) interventions but not after SUPRA bypass or AMP. Similarly, by Cox proportional hazards, Hispanic/Latino ethnicity was also independently associated with lower overall mortality after INFRA bypass (HR, 0.75; 95% CI, 0.62-0.91; P = .0030), InfraPVI (HR, 0.69; 95% CI, 0.62-0.78; P < .0001), and SupraPVI (HR, 0.68; 95% CI, 0.52-0.89; P = .0045) but not after SUPRA bypass or AMP. CONCLUSIONS: Contrary to the published data for other forms of cardiovascular disease, African American patients as well as patients identified with Hispanic/Latino ethnicity with PAD included in the Society for Vascular Surgery Vascular Quality Initiative undergoing INFRA revascularization for lower extremity PAD experienced better overall survival compared with white Americans.

Regional variation in outcomes for lower extremity vascular disease in the Vascular Quality Initiative.

BACKGROUND: Increased focus has been placed on perioperative and long-term outcomes in the treatment of peripheral artery disease (PAD), both for purposes of quality improvement and for assessment of performance at a surgeon and institutional level. This study evaluates regional variation in outcomes after treatment for PAD within the Vascular Quality Initiative (VQI). By describing the variation in practice patterns and outcomes across regions, we hope that each regionally based quality group can select which areas are most important for them to focus on as they will have access to their regional data to compare. METHODS: We identified all patients in the VQI who had infrainguinal bypass or endovascular intervention from 2009 to 2014. We compared variation in perioperative and 1-year outcomes stratified by symptom status and revascularization type among the 16 regional groups of the VQI. We analyzed variation in perioperative end points using χ2 analysis, and 1-year end points were analyzed using Kaplan-Meier and life-table analysis. RESULTS: We identified 15,338 bypass procedures for symptomatic PAD: 27% for claudication, 59% for chronic limb-threatening ischemia (CLI; 61% of these for tissue loss), and 14% for acute limb ischemia. We identified 33,925 endovascular procedures for symptomatic PAD: 42% for claudication, 48% for CLI (73% of these for tissue loss), and 10% for acute limb ischemia. Thirty-day mortality varied significantly after endovascular intervention for CLI (0.5%-3%; P < .001) but not for claudication (0.0%-0.5%, P = .77) or for bypass for claudication (0.0%-2.6%; P = .37) or CLI (0.0%-5.0%; P = .08). After bypass, rates of >2 units transfused red blood cells (claudication, 0.0%-13% [P < .001]; CLI, 6.9%-27% [P < .001]) varied significantly. In-hospital major amputation was variable after bypass for CLI (0.0%-4.3%; P = .004) but not for claudication (0.0%-0.6%; P = .98), as was postoperative myocardial infarction (claudication, 0.0%-4% [P = .36]; CLI, 0.8%-6% [P = .001]). One-year survival varied significantly for endovascular interventions for claudication (92%-100%; P < .001), bypass for CLI (85%-94% [P < .001]), and endovascular interventions for CLI (77%-96%; P < .001) but not after bypass for claudication (95%-100%; P = .57). CONCLUSIONS: In this real-world comparison among VQI regions, we found significant variation in perioperative and 1-year end points for patients with PAD undergoing bypass or endovascular intervention. This study highlights opportunities for quality improvement efforts to reduce variation and to improve outcomes.

Regional variation in patient selection and treatment for lower extremity vascular disease in the Vascular Quality Initiative.

OBJECTIVE: Prior studies on the cause and effect of surgical variation have been limited by utilization of administrative data. The Vascular Quality Initiative (VQI), a robust national clinical registry, provides anatomic and perioperative details allowing a more robust analysis of variation in surgical practice. METHODS: The VQI was used to identify all patients undergoing infrainguinal open bypass or endovascular intervention from 2009 to 2014. Asymptomatic patients were excluded. The 16 regional groups of the VQI were used to compare variation in patient selection, operative indication, technical approach, and process measures. χ2 analysis was used to assess for differences across regions where appropriate. RESULTS: A total of 52,373 interventions were included (31%). Of the 16,145 bypasses, 5% were performed for asymptomatic disease, 26% for claudication, 56% for chronic limb-threatening ischemia (CLI) (61% of these for tissue loss), and 13% for acute limb-threatening ischemia. Of the 35,338 endovascular procedures, 4% were for asymptomatic disease, 40% for claudication, 46% for CLI (73% tissue loss), and 12% for acute limb-threatening ischemia. Potentially unwarranted variation included proportion of prosthetic conduit for infrapopliteal bypass in claudication (13%-41%, median, 29%; P < .001), isolated tibial endovascular intervention for claudication (0.0%-5.0%, median, 3.0%; P < .001), discharge on antiplatelet and statin (bypass: 62%-84%; P < .001; endovascular: 63%-89%; P < .001), and ultrasound guidance for percutaneous access (claudication: range, 7%-60%; P < .001; CLI: 5%-65%; P < .001). Notable areas needing further research with significant variation include proportion of CLI vs claudication treated by bypass (38%-71%; P < .001) and endovascular intervention (28%-63%; P < .001), and use of closure devices in percutaneous access (claudication; 26%-76%; P < .001; CLI: 30%-78%; P < .001). CONCLUSIONS: Significant variation exists both in areas where evidence exists for best practice and, therefore, potentially unwarranted variation, and in areas of clinical ambiguity. Quality improvement efforts should be focused on reducing unwarranted variation. Further research should be directed at identifying best practice where no established guidelines and high variation exists.

Predicting outcomes for infrapopliteal limb-threatening ischemia using the Society for Vascular Surgery Vascular Quality Initiative.

OBJECTIVE: The outcomes of open surgical or endovascular intervention for limb-threatening ischemia (LTI) involving the infrapopliteal vessels are dependent on complex anatomic, demographic, and disease factors. To assist in decision-making, we used the Vascular Quality Initiative (VQI) to derive a model using only preoperatively available factors to predict important outcomes for open or endovascular revascularization. METHODS: National VQI data for the infrainguinal bypass and peripheral vascular intervention (PVI) modules were reviewed in a blinded fashion for patients who underwent intervention for LTI of the infrapopliteal vessels. Primary outcomes consisted of major adverse limb event (MALE) and amputation-free survival (AFS). Generalized linear modeling was used for the multivariate analyses, with entry of variables dependent on results of univariate analysis. RESULTS: From January 2003 through August 2014 a total of 19,053 infrainguinal open bypass and 48,739 PVI procedures were identified, among which 5264 and 5252, respectively, represented infrapopliteal (tibial-peroneal-pedal) revascularization for LTI. From these, 3036 infrapopliteal open bypass patients and 1319 infrapopliteal PVI patients had sufficient follow-up data for study inclusion. For open surgery, the reduced generalized linear model revealed that American Society of Anesthesiologists class 4 or 5, previous major amputation, living at home, and female sex had the greatest adverse effect on MALE, and dialysis dependence, low body mass index, and lack of great saphenous vein as a conduit had the greatest negative effect on AFS. For PVI, lesion length from 10 to 15 cm, treatment of three or more arteries, and classification other than A on the Trans-Atlantic Inter-Society Consensus demonstrated the largest adverse effects on MALE, and dialysis dependence, low body mass index, and congestive heart failure most negatively affected AFS. CONCLUSIONS: This study on a cross-section of patients selected for intervention in academic and community hospitals offers a "real world" glimpse of factors predictive of outcome. The VQI can be used to derive models that predict the outcomes of open surgical bypass or PVI for LTI involving the infrapopliteal vessels.

A comparative evaluation of risk-adjustment models for benchmarking amputation-free survival after lower extremity bypass.

BACKGROUND: Providing patients and payers with publicly reported risk-adjusted quality metrics for the purpose of benchmarking physicians and institutions has become a national priority. Several prediction models have been developed to estimate outcomes after lower extremity revascularization for critical limb ischemia, but the optimal model to use in contemporary practice has not been defined. We sought to identify the highest-performing risk-adjustment model for amputation-free survival (AFS) at 1 year after lower extremity bypass (LEB). METHODS: We used the national Society for Vascular Surgery Vascular Quality Initiative (VQI) database (2003-2012) to assess the performance of three previously validated risk-adjustment models for AFS. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL), Finland National Vascular (FINNVASC) registry, and the modified Project of Ex-vivo vein graft Engineering via Transfection III (PREVENT III [mPIII]) risk scores were applied to the VQI cohort. A novel model for 1-year AFS was also derived using the VQI data set and externally validated using the PIII data set. The relative discrimination (Harrell c-index) and calibration (Hosmer-May goodness-of-fit test) of each model were compared. RESULTS: Among 7754 patients in the VQI who underwent LEB for critical limb ischemia, the AFS was 74% at 1 year. Each of the previously published models for AFS demonstrated similar discriminative performance: c-indices for BASIL, FINNVASC, mPIII were 0.66, 0.60, and 0.64, respectively. The novel VQI-derived model had improved discriminative ability with a c-index of 0.71 and appropriate generalizability on external validation with a c-index of 0.68. The model was well calibrated in both the VQI and PIII data sets (goodness of fit P = not significant). CONCLUSIONS: Currently available prediction models for AFS after LEB perform modestly when applied to national contemporary VQI data. Moreover, the performance of each model was inferior to that of the novel VQI-derived model. Because the importance of risk-adjusted outcome reporting continues to increase, national registries such as VQI should begin using this novel model for benchmarking quality of care.

Preoperative antiplatelet and statin treatment was not associated with reduced myocardial infarction after high-risk vascular operations in the Vascular Quality Initiative.

OBJECTIVE: Medical management with antiplatelet (AP) and statin therapy is recommended for nearly all patients undergoing vascular surgery to reduce cardiovascular events. We assessed the association between preoperative use of AP and statin medications and postoperative in-hospital myocardial infarction (MI) in patients undergoing high-risk open surgery. METHODS: We studied patients who underwent elective suprainguinal (n = 3039) and infrainguinal (n = 8323) bypass and open infrarenal abdominal aortic aneurysm repair (n = 3007) in the Vascular Quality Initiative (VQI, 2005-2014). We assessed the association between AP or statin use and in-hospital postoperative MI and MI/death. Multivariable logistic analyses were performed to identify the patient, procedure, and preoperative medication factors associated with postoperative MI and MI/death across procedures and patient cardiac risk strata. Secondary end points included bleeding, transfusion, and thrombotic complications. RESULTS: Most patients were taking both AP and statin preoperatively (56% both agents vs 19% AP only, 13% statin only, and 12% neither agent). Use of both agents was more common for patients in the highest cardiac risk stratum (low, 54%; intermediate, 59%; high, 61%; P < .01). Increased cardiac risk was associated with higher MI rates (1.8% vs 3.8% vs 6.5% for low, intermediate, and high risk; P < .01). By univariate analysis, MI rate was paradoxically higher for patients taking both agents (3.7%, vs statin only 2.8%, AP only 2.6%, or neither AP nor statin 2.4%; P = .003). After multivariable adjustment, rates of MI in patients taking preoperative AP only (odds ratio [OR], 0.9; 95% confidence interval [CI], 0.7-1.2) and statin only (OR, 0.8; 95% CI, 0.6-1.2) were not different from those in patients taking either or neither medication (neither agent compared with taking both agents: OR, 1.0; 95% CI, 0.7-1.4; P > .05 for all). Similarly, rates of MI/death were not associated with medication status after multivariable adjustment. Estimated blood loss >1 liter (OR, 2.4; 95% CI, 1.6-3.7; P < .01) and transfusions of 1 or 2 units (OR, 2.5; 95% CI, 2.0-3.3; P < .01) and ≥3 units (OR, 4.0; 95% CI, 3.1-5.3; P < .01) were highly associated with MI, with similar findings related to composite MI/death in multivariable analysis. Rates of blood loss were slightly higher with AP use for all procedures; however, increased transfusions occurred only for infrainguinal bypass with AP use. Rates of reoperation for bleeding, graft thrombosis, or graft revision did not differ by preoperative AP use. CONCLUSIONS: Preoperative AP and statin medications as used in VQI were not associated with the rate of in-hospital MI/death after major open vascular operations. Rather, predicted cardiac risk and operative blood loss were significantly associated with in-hospital MI or MI/death. AP and statin medications appear to be more useful in reducing late mortality than early postoperative MI/death in VQI. However, they were not harmful, so their long-term benefit argues for continued use.

Participation in the Vascular Quality Initiative is associated with improved perioperative medication use, which is associated with longer patient survival.

OBJECTIVE: Medical management (MM) with antiplatelet (AP) and statin therapy is recommended for most patients undergoing vascular surgery and has been advocated by the Vascular Quality Initiative (VQI). We analyzed the effect of VQI participation on perioperative (preoperative and postoperative) MM use over time and the effect of discharge MM on patient survival. METHODS: We studied VQI patients treated with MM preoperatively and at discharge from 2005 to 2014, including all elective carotid endarterectomy/carotid stenting (n = 28,092), suprainguinal/infrainguinal bypass (n = 11,362), peripheral vascular interventions (n = 24,476), open/endovascular abdominal aortic aneurysm repair (n = 13,503), and thoracic endovascular aneurysm repair (n = 702). We examined trends of MM use over time, as well as the effect of duration of VQI participation on MM use. Multivariable logistic regression analysis was performed to identify factors associated with MM use. In addition, the Cox proportional hazards model was used to identify factors associated with 5-year survival. RESULTS: MM with AP and statin preoperatively and postoperatively across VQI centers improved from 55% in 2005 to 68% in 2009, with a subsequent overall decline to 62% by 2014, coincident with many new centers with lower MM rates joining VQI in 2010. Longer center participation in VQI was associated with improved perioperative MM overall. This was also noted across all procedure types, with MM increasing from 47% to 82% for aneurysm repairs and 69% to 83% for carotid procedures from 1 to 12 years of participation in VQI. After multivariable adjustment, centers in VQI ≥3 years were 30% more likely to have patients on MM (odds ratio, 1.3, 95% confidence interval [CI], 1.3-1.4). Importantly, discharge on AP and statin therapy was associated with improved 5-year survival, compared with discharge on neither medication (82% [95% CI, 81%-83%] vs 67% [95% CI, 62%-72%]), and an adjusted hazard ratio for death of 0.6 (95% CI, 0.5-0.7; P < .001). Discharge on a single medication was associated with intermediate survival at 5 years (AP only: 77% [95% CI, 75%-79%]; statin only: 73% [95% CI, 68%-77%]). CONCLUSIONS: These data demonstrate that MM is associated with improved survival after a number of vascular procedures. Importantly, VQI participation improves the use of MM, demonstrating that involvement in an organized quality effort can affect patient outcomes.

Regional quality groups in the Society for Vascular Surgery® Vascular Quality Initiative.

The Society for Vascular Surgery Vascular Quality Initiative (SVS VQI) is designed to improve the quality, safety, effectiveness, and cost of vascular health care. The SVS VQI is uniquely organized as a distributed network of regional quality improvement groups across the United States. The regional approach allows for the involvement of a variety of health care professionals, the pooling of available resources and expertise, and serves as a motivating factor for each participating institution. Regional quality group sizes, administrative structure, and meeting logistics vary according to geography and regional needs. This review describes the process of forming, growing, and maintaining a regional quality improvement group of the SVS VQI.

The role of amputation as an outcome measure in cellular therapy for critical limb ischemia: implications for clinical trial design.

BACKGROUND: Autologous bone marrow-derived stem cells have been ascribed an important therapeutic role in No-Option Critical limb Ischemia (NO-CLI). One primary endpoint for evaluating NO-CLI therapy is major amputation (AMP), which is usually combined with mortality for AMP-free survival (AFS). Only a trial which is double blinded can eliminate physician and patient bias as to the timing and reason for AMP. We examined factors influencing AMP in a prospective double-blinded pilot RCT (2:1 therapy to control) of 48 patients treated with site of service obtained bone marrow cells (BMAC) as well as a systematic review of the literature. METHODS: Cells were injected intramuscularly in the CLI limbs as either BMAC or placebo (peripheral blood). Six month AMP rates were compared between the two arms. Both patient and treating team were blinded of the assignment in follow-up examinations. A search of the literature identified 9 NO-CLI trials, the control arms of which were used to determine 6 month AMP rates and the influence of tissue loss. RESULTS: Fifteen amputations occurred during the 6 month period, 86.7% of these during the first 4 months. One amputation occurred in a Rutherford 4 patient. The difference in amputation rate between patients with rest pain (5.6%) and those with tissue loss (46.7%), irrespective of treatment group, was significant (p = 0.0029). In patients with tissue loss, treatment with BMAC demonstrated a lower amputation rate than placebo (39.1% vs. 71.4%, p = 0.1337). The Kaplan-Meier time to amputation was longer in the BMAC group than in the placebo group (p = 0.067). Projecting these results to a pivotal trial, a bootstrap simulation model showed significant difference in AFS between BMAC and placebo with a power of 95% for a sample size of 210 patients. Meta-analysis of the literature confirmed a difference in amputation rate between patients with tissue loss and rest pain. CONCLUSIONS: BMAC shows promise in improving AMP-free survival if the trends in this pilot study are validated in a larger pivotal trial. The difference in amp rate between Rutherford 4 & 5 patients suggests that these patients should be stratified in future RCTs.

Early results and lessons learned from a multicenter, randomized, double-blind trial of bone marrow aspirate concentrate in critical limb ischemia.

OBJECTIVES: Despite advances in endovascular therapies, critical limb ischemia (CLI) continues to be associated with high morbidity and mortality. Patients without direct revascularization options have the worst outcomes. We sought to explore the feasibility of conducting a definitive trial of a bone marrow-derived cellular therapy for CLI in this "no option" population. METHODS: A pilot, multicenter, prospective, randomized, double-blind, placebo-controlled trial for "no option" CLI patients was performed. The therapy consisted of bone marrow aspirate concentrate (BMAC), prepared using a point of service centrifugation technique and injected percutaneously in 40 injections to the affected limb. Patients were randomized to BMAC or sham injections (dilute blood). We are reporting the 12-week data. RESULTS: Forty-eight patients were enrolled. The mean age was 69.5 years (range, 42-93 years). Males predominated (68%). Diabetes was present in 50%. Tissue loss (Rutherford 5) was present in 30 patients (62.5%), and 18 (37.5%) had rest pain without tissue loss (Rutherford 4). Patients were deemed unsuitable for conventional revascularization based on multiple prior failed revascularization efforts (24 [50%]), poor distal targets (43 [89.6%]), and medical risk (six [12.5%]). Thirty-four patients were treated with BMAC and 14 with sham injections. There were no adverse events attributed to the injections. Renal function was not affected. Effective blinding was confirmed; blinding index of 61% to 85%. Subjective and objective outcome measures were effectively obtained with the exception of treadmill walking times, which could only be obtained at baseline and follow-up in 15 of 48 subjects. This pilot study was not powered to demonstrate statistical significance but did demonstrate favorable trends for BMAC versus control in major amputations (17.6% vs 28.6%), improved pain (44% vs 25%), improved ankle brachial index (ABI; 32.4% vs 7.1%), improved Rutherford classification (35.3% vs 14.3%), and quality-of-life scoring better for BMAC in six of eight domains. CONCLUSIONS: In this multicenter, randomized, double-blind, placebo-controlled trial of autologous bone marrow cell therapy for CLI, the therapy was well tolerated without significant adverse events. The BMAC group demonstrated trends toward improvement in amputation, pain, quality of life, Rutherford classification, and ABI when compared with controls. This pilot allowed us to identify several areas for improvement for future trials and CLI studies. These recommendations include elimination of treadmill testing, stratification by Rutherford class, and more liberal inclusion of patients with renal insufficiency. Our strongest recommendation is that CLI studies that include Rutherford 4 patients should incorporate a composite endpoint reflecting pain and quality of life.

A historical prospective cohort study of carotid artery stenosis after radiotherapy for head and neck malignancies.

PURPOSE: To determine carotid artery stenosis incidence after radiotherapy for head-and-neck neoplasms. METHODS AND MATERIALS: This historical prospective cohort study comprised 44 head-and-neck cancer survivors who received unilateral neck radiotherapy between 1974 and 1999. They underwent bilateral carotid duplex ultrasonography to detect carotid artery stenosis. RESULTS: The incidence of significant carotid stenosis (8 of 44 [18%]) in the irradiated neck was higher than that in the contralateral unirradiated neck (3 of 44 [7%]), although this difference was not statistically significant (p = 0.13). The rate of significant carotid stenosis events increased as the time after radiotherapy increased. The risk of ipsilateral carotid artery stenosis was higher in patients who had undergone a neck dissection vs. those who had not. Patients with significant ipsilateral stenosis also tended to be older than those without significant stenosis. No other patient or treatment variables correlated with risk of carotid artery stenosis. CONCLUSIONS: For long-term survivors after neck dissection and irradiation, especially those who are symptomatic, ultrasonographic carotid artery screening should be considered.

Incidental renal artery stenosis among a prospective cohort of hypertensive patients undergoing coronary angiography.

OBJECTIVE: To determine the feasibility, safety, and clinical yield of angiographic screening among hypertensive patients undergoing coronary angiography. PATIENTS AND METHODS: This study was a prospective cohort analysis of hypertensive patients who underwent cardiac catheterization at a tertiary care referral center from July 1998 to March 1999. Abdominal aortography was performed to screen for renal artery stenosis, the percentage of which was measured. RESULTS: The mean +/- SD age of the 297 study patients was 64.9+/-10.2 years; 58.6% were male, and 98.0% were white. Mean +/- SD systolic/diastolic blood pressure was 142.8+/-22.5/79.6+/-11.4 mm Hg. Aortography required a mean incremental dose of 62+/-9 mL of nonionic contrast agent. No complications were attributable to aortography. Of 680 renal arteries, 611 (90%) were visualized adequately. Also, 53% of patients had normal renal arteries, 28% had stenoses less than 50%, and 19.2% had stenoses of 50% or more. Renal artery stenosis was bilateral in 3.7% of patients and high grade (>70% stenosis) in 7%. Patients with renal artery stenosis were more likely to have had a previous coronary intervention. In multivariate analysis, systolic blood pressure (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.03-138; P=.02), history of stroke or transient ischemic attack (OR, 2.7; 95% CI, 1.27-5.78; P=.01), and cancer (OR, 2.0; 95% CI, 1.02-3.82; P=.04) independently correlated with renal artery stenosis of 50% or more. CONCLUSION: The prevalence of incidental renal artery stenosis among hypertensive patients undergoing coronary catheterization is significant. Therefore, screening abdominal aortography should be considered in these patients to better define their risk of cardiovascular complications.

Acute aortic dissection: population-based incidence compared with degenerative aortic aneurysm rupture.

OBJECTIVES: To ascertain whether acute aortic dissection (AAD) remains the most common aortic catastrophe, as generally believed, and to detect any improvement in outcomes compared with previously reported population-based data. PATIENTS AND METHODS: We determined the incidence, operative intervention rate, and long-term survival rate of Olmsted County, Minnesota, residents with a clinical diagnosis of AAD initially made between 1980 and 1994. The incidence of degenerative thoracic aortic aneurysm (TAA) rupture was also delineated. We compared these results with other population-based studies of AAD, degenerative TAA, and abdominal aortic aneurysm (AAA) rupture. RESULTS: During a 15-year period, we identified 177 patients with thoracic aortic disease. We focused on 39 patients with AAD (22% of the entire cohort) and 28 with TAA rupture (16%). The annual age- and sex-adjusted incidences were 3.5 per 100,000 persons (95% confidence interval, 2.4-4.6) for AAD and 3.5 per 100,000 persons (95% confidence interval, 2.2-4.9) for TAA rupture. Thirty-three dissections (85%) involved the ascending aorta, whereas 6 (15%) involved only the descending aorta. Nineteen patients (49%) underwent 22 operations for AAD, with a 30-day case fatality rate of 9%. Among all 39 patients with AAD, median survival was only 3 days. Overall 5-year survival for those with AAD improved to 32% compared with only 5% in this community between 1951 and 1980. CONCLUSIONS: In other studies, the annual incidences of TAA rupture and AAA rupture are estimated at approximately 3 and 9 per 100,000 persons, respectively. This study indicates that AAD and ruptured degenerative TAA occur with similar frequency but less commonly than ruptured AAA. Although timely recognition and management remain problematic, these new data suggest that recent diagnostic and operative advances are improving long-term survival in AAD.

Guidelines for the treatment of abdominal aortic aneurysms. Report of a subcommittee of the Joint Council of the American Association for Vascular Surgery and Society for Vascular Surgery.

Decision-making in regard to elective repair of abdominal aortic aneurysms (AAA) requires careful assessment of factors that influence rupture risk, operative mortality, and life expectancy. Individualized consideration of these factors in each patient is essential, and the role of patient preference is of increasing importance. It is not possible or appropriate to recommend a single threshold diameter for intervention which can be generalized to all patients. Based upon the best available current evidence, 5.5 cm is the best threshold for repair in an "average" patient. However, subsets of younger, good-risk patients or aneurysms at higher rupture risk may be identified in whom repair at smaller sizes is justified. Conversely, delay in repair until larger diameter may be best for older, higher-risk patients, especially if endovascular repair is not possible. Intervention at diameter <5.5 cm appears indicated in women with AAA. If a patient has suitable anatomy, endovascular repair may be considered, and it is most advantageous for older, higher-risk patients or patients with a hostile abdomen or other technical factors that may complicate standard open repair. With endovascular repair, perioperative morbidity and recovery time are clearly reduced; however, there is a higher reintervention rate, increased surveillance burden, and a small but ongoing risk of AAA rupture. There is no justification at present for different indications for endovascular repair, such as earlier treatment of smaller AAA. Until long-term outcome of endoluminal repair is better defined and results of randomized trials available, the choice between endovascular and open repair will continue to rely heavily on patient preference.

Trends in rehabilitation after amputation for geriatric patients with vascular disease: implications for future health resource allocation.

OBJECTIVE: To assess the effect of demographic changes on rehabilitation of geriatric patients after amputation and the implications for future health resource allocation. DESIGN: Population-based study. SETTING: Olmsted County, MN. PARTICIPANTS: Residents over the age of 65 years who had a major lower-extremity amputation because of peripheral arterial disease between 1956 and 1995. Patients who had amputations between 1956 and 1973 (earlier cohort) were compared with those who had amputations between 1974 and 1995 (later cohort). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Demographic and clinical features, total number of amputations, amputation rates, and rate of successful prosthetic fitting over time. RESULTS: Of 292 patients, 93 had amputations between 1956 and 1973 and 199 between 1974 and 1995. Amputation rates declined after 1985, but the total number of amputations was unchanged. Patients in the later cohort were more likely to have a below-knee amputation (P<.001) and cerebrovascular disease (P=.008) and to be discharged to a nursing home (P<.001). There was no significant difference in median age at amputation, survival, or rates of successful prosthetic fitting over time. CONCLUSION: Although amputation rates have declined, the total number of amputations has increased. The rate of successful prosthetic fitting in the geriatric population has not changed significantly over 40 years. Amputations in the geriatric population in the United States will probably double from 28,000 to 58,000 per year by 2030, requiring considerable resources.

Human leukocyte antigen class II immune response genes, female gender, and cigarette smoking as risk and modulating factors in abdominal aortic aneurysms.

OBJECTIVE: Aortic inflammation and the genes that regulate the immune response play an important role in abdominal aortic aneurysm pathogenesis. However, the modulating effects of such genetic and other environmental factors on the severity on aneurysm inflammation is not known. The objective of this study was to determine the influence of the human leukocyte antigen (HLA) class II genes, gender, and environmental factors on degree of abdominal aortic aneurysm tissue inflammation. METHODS: Aneurysm specimens were obtained at the time of operation from 96 consecutive patients who underwent abdominal aortic aneurysm repair and were graded for degree of histologic inflammation. Multivariate analysis was used to determine the association of genetic and environmental factors with degree of inflammation and to determine the HLA-associated disease risk for aneurysm. RESULTS: Active cigarette smoking and female gender were independently associated with high-grade tissue inflammation identified histologically (odds ratio [OR], confidence interval [CI]: 5.6, 1.6 to 19.3; and 6.0, 1.4 to 26.2, respectively), and a specific HLA allele (DR B1(*)01) was inversely associated with inflammation (OR, CI: 0.2, 0.04 to 0.7). Overall, the HLA-DR B1(*)02 and B1(*)04 alleles were significantly associated with disease risk, more than doubling risk for abdominal aortic aneurysm (OR, CI: 2.5, 1.4 to 4.3; and 2.1, 1.2 to 3.7, respectively). CONCLUSION: Active cigarette smoking and female gender are significant disease-modulating factors associated with increased abdominal aortic aneurysm inflammation. In addition, the HLA class II immune response genes possess both disease modulating and disease risk properties, which may be useful in early aneurysm detection and surveillance.

Early abdominal closure with mesh reduces multiple organ failure after ruptured abdominal aortic aneurysm repair: guidelines from a 10-year case-control study.

OBJECTIVE: The objectives of this study were the comparison of patients who needed mesh closure of the abdomen with patients who underwent standard abdominal closure after ruptured abdominal aortic aneurysm repair and the determination of the impact of timing of mesh closure on multiple organ failure (MOF) and mortality. METHODS: We performed a case-control study of patients who needed mesh-based abdominal closure (n = 45) as compared with patients who underwent primary closure (n = 90) after ruptured abdominal aortic aneurysm repair. RESULTS: Before surgery, the patients who needed mesh abdominal closure had more blood loss (8 g versus 12 g of hemoglobin; P <.05), had prolonged hypotension (18 minutes versus 3 minutes; P <.01), and more frequently needed cardiopulmonary resuscitation (31% versus 2%; P <.01) than did the patients who underwent primary closure. During surgery, the patients who needed mesh closure also had more severe acidosis (base deficit, 14 versus 7; P <.01), had profound hypothermia (32 degrees C versus 35 degrees C; P <.01), and needed more fluid resuscitation (4.0 L/h versus 2.7 L/h; P <.01). With this adverse clinical profile, the patients who needed mesh closure had a higher mortality rate than did the patients who underwent primary closure (56% versus 9%; P <.01). However, the patients who underwent mesh closure at the initial operation (n = 35) had lower MOF scores (P <.05), a lower mortality rate (51% versus 70%), and were less likely to die from MOF (11% versus 70%; P <.05) than the patients who underwent mesh closure after a second operation in the postoperative period for abdominal compartment syndrome (n = 10). CONCLUSION: This study reports the largest experience of mesh-based abdominal closure after ruptured abdominal aortic aneurysm repair and defines clinical predictors for patients who need to undergo this technique. Recognition of these predictors and initial use of mesh closure minimize abdominal compartment syndrome and reduce the rate of mortality as the result of MOF.

Current results of open revascularization for chronic mesenteric ischemia: a standard for comparison.

OBJECTIVE: Questions remain concerning the optimal site of graft origin and the extent of revascularization necessary to achieve excellent results for chronic mesenteric ischemia (CMI). Endovascular therapy also is performed for CMI. These factors prompted us to review our results to provide a current standard. METHODS: Ninety-eight patients who underwent operation for CMI from 1989 to 1998 were reviewed. Patients with acute ischemia and arcuate ligament syndrome were excluded. RESULTS: Seventy-six women (78%) and 22 men (22%), with an average age of 66 years (range, 36 to 87 years), participated in the study. Abdominal pain was present in 95 patients (97%), and weight loss in 92 patients (94%). The superior mesenteric artery was severely diseased (70% to 99% stenosis or occlusion) in 90 patients (92%), the celiac artery in 81 patients (83%), and both arteries in 76 patients (78%). Bypass grafts were performed in 91 patients (93%), 77 antegrade and 14 retrograde. Of the other seven patients, five had endarterectomies, one reimplantation, and one patch angioplasty. Multivessel reconstruction was performed in 79 patients (81%), and single-vessel reconstruction in 19 (19%). Twelve patients had concomitant aortic reconstruction. Three early graft thromboses were seen. Five hospital deaths occurred (5.1%); one case had concomitant aortic reconstruction (1/12 versus 4/86; P = not significant). All five patients who died were older than 70 years (5/41 versus 0/57; P =.011). The median follow-up period was 1.9 years (range, 0 to 9.6 years). Follow-up was complete in all survivors. The 1-year, 5-year, and 8-year survival rates were 83%, 63%, and 55%, respectively. These rates were worse than the rates of the age-matched/gender-matched control subjects (P <.001). Survival was worse in patients greater than 70 years of age (P =.0013). Survival was unaffected by the number of vessels revascularized. The patients with retrograde grafts had decreased median survival rates (4.0 versus 5.7 years; P =.026), but they were older (75 versus 65 years; P =.0013). The 1-year and 5-year symptom-free survival rates were 95% and 92%, respectively. Symptoms recurred in six patients (6%): four had recurrent stenosis/occlusion and two had patent grafts. Symptom-free survival was unaffected by the number of vessels revascularized or by graft orientation. CONCLUSION: Operation for CMI was successful for most patients, with low operative mortality and excellent long-term relief of symptoms. Selective concomitant aortic procedures did not increase mortality rates. The rate of symptomatic recurrences was not different for single-vessel versus multiple-vessel reconstructions or for antegrade versus retrograde grafts. Patients older than 70 years had increased operative mortality and decreased survival rates. Endovascular therapy may be appropriate for this subset of patients.