The effect of secondary operations on mortality following abdominal aortic aneurysm repair in the United States: 1988-2001.

Certain complications following open repair of abdominal aortic aneurysms (AAAs) require additional operations or invasive procedures. The purpose of this study was to determine the effect of secondary interventions on mortality rate following open repair of intact and ruptured AAAs in the United States. Clinical data on 98,193 patients treated from 1988 to 2001 with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) primary procedure code 38.44 (resection of the abdominal aorta with replacement) were analyzed. Demographic factors, types of secondary interventions, and in-hospital mortality rates were assessed by univariate and multivariate logistic regression analysis (SPSS Version 11.0, Chicago, IL). The database utilized in this study was The Nationwide Inpatient Sample (NIS). The mortality rate was 4.5% in the intact AAA group and 45.5% in the ruptured AAA group. The rate of secondary operations and procedures was much higher in the ruptured AAA group, especially related to renal failure (5.52% vs 1.49%, p <0.001); respiratory failure (3.67% vs 0.71%, p <0.001); postoperative bleeding (2.41% vs 0.81%, p <0.001); or colonic ischemia (2.38% vs 0.36%, p <0.001). Increased mortality following open repair of intact AAAs accompanied: peripheral artery angioplasty/stenting (OR, 1.25; 95% CI, 1.04-1.51; p = 0.018); coronary artery angioplasty/stenting (OR, 1.68; 95% CI, 1.05-2.70; p = 0.031); inferior vena cava (IVC) filter placement (OR, 2.02; 95% CI, 01.31-3.1; p = 0.001); vascular reconstruction or thromboembolectomy (OR, 2.05; 95% CI, 1.9-2.22; p <0.001); lower extremity amputation (OR, 4.09; 95% CI, 2.78-6.0; p <0.001); coronary artery bypass (OR, 6.71; 95% CI, 3.74-12.03; p <0.001); operations for postoperative bleeding (OR, 6.92; 95% CI, 5.71-8.4; p <0.001); initiation of hemodialysis (OR, 10.52; 95% CI, 9.22-12.01; p <0.001); tracheostomy (OR, 11.9; 95% CI, 9.86-14.37; p <0.001); and colectomy (OR, 16.22; 95% CI, 12.55-20.95; p <0.001). Increased risk of mortality following open repair of ruptured AAAs accompanied the following: operations for postoperative bleeding (OR, 1.5; 95% CI, 1.22-1.85; p <0.001); colectomy (OR, 1.63; 95% CI, 1.32-2.01; p <0.001); and initiation of hemodialysis (OR, 2.66; 95% CI, 2.30-3.08; p <0.001). The only independent variable in this group associated with decreased risk of in-hospital mortality was IVC filter placement (OR, 0.41; 95% CI, 0.27-0.64; p <0.001). This study confirms the perception that additional operations or invasive procedures following open repair of AAA entail significantly worse in-hospital mortality rates, especially when related to colonic ischemia, respiratory failure, and renal failure.

Payer status is related to differences in access and outcomes of abdominal aortic aneurysm repair in the United States.

BACKGROUND: The hypothesis of this study was that differences exist among patients with private insurance compared with patients with Medicaid or no insurance, regarding access to the timely treatment of abdominal aortic aneurysms (AAAs) and the outcomes of AAA repair. METHODS: The study comprised 5363 patients aged less than 65 years (mean age, 59 years) with a diagnostic code for intact or ruptured AAA and a procedure code for AAA repair in the National Inpatient Sample for 1995 to 2000. Dependent variables included ruptured AAA, intact AAA, and in-hospital postoperative mortality rates. Independent variables included payer status, median income, race, gender, age, and comorbid disease. Risk-adjusted analyses were performed with the use of binary logistic regression. RESULTS: AAA rupture was most likely (P <.001) to affect patients with no insurance (36%) or Medicaid (18%), compared with patients with private insurance (13%). After an adjustment for case-mix had been made, data showed that patients without insurance had an increased risk of rupture compared with patients with private insurance (odds ratio, 2.3; 95% CI, 1.5-3.5; P <.001). Operative mortality rates after elective AAA repair were greater (P =.04) for patients with no insurance (2.6%) or Medicaid (2.7%), compared with patients with private insurance (1.2%). Similarly, operative mortality rates for AAA repair after rupture were greater (P =.001) in patients without insurance (45.3%) or Medicaid (31.3%), compared with patients with private insurance (26.2%). CONCLUSIONS: Uninsured patients more often seek treatment of ruptured AAAs compared with patients with private insurance. Operative mortality rates in uninsured patients are greater for elective and emergent AAA repair. These data support the tenet that payer status is associated with mortality rates after AAA repair.

Who performs endocrine operations in the United States?

BACKGROUND: Endocrine surgery is a discipline that is dedicated to high-quality care of patients with endocrine surgical disease. The relationship between its "identity" as a separate field and clinical practice patterns is not known. METHODS: The National Inpatient Sample was searched by the International Classification of Diseases-9th revision-Clinical Modification codes for parathyroidectomy, thyroidectomy, and adrenalectomy for the years 1988 through 2000. The surgeons who performed these operations were profiled by 2 methods: Method A, by the percentage of the total primary International Classification of Diseases-9th revision-Clinical Modification procedure codes that were the selected endocrine procedures; method B, by absolute number of index endocrine procedures performed per year. Only patients with complete coding data for the surgeons were included. RESULTS: In this sample, surgeons whose practice was comprised of 25% or less of these endocrine procedures performed 11,071 parathyroidectomies (78% of total), 46,210 thyroidectomies (82% of total), and 4209 adrenalectomies (94% of total). In contrast, surgeons whose practice was comprised of more than 75% of these endocrine procedures performed 769 parathyroidectomies (5% of total), 1560 thyroidectomies (3% of total), and 128 adrenalectomies (3% of total). CONCLUSION: If these data can be extrapolated to indicate generalized practice patterns, the majority of common operations for endocrine disease are performed by surgeons whose practice is not focused on endocrine surgery. However, much of this effect is due to the fact that non-endocrine surgeons far outnumber endocrine surgeons. This understanding of clinical practice patterns will be important to consider during future studies that seek to determine the relationship between surgeon volume and patient outcomes.

Diffusion of new technology in health care: the case of aorto-iliac occlusive disease.

BACKGROUND: The objective of the current study was to characterize temporal trends in the treatment of aorto-iliac occlusive disease (AIOD) and the impact of the introduction of less invasive therapy on overall intervention rates. METHODS: Patients with diagnostic codes for AIOD, and procedure codes for aortofemoral bypass (AFB) or iliac artery angioplasty and stenting were selected from the Nationwide Inpatient Sample for 1996 to 2000. Utilization rates of both intervention types were determined. Outcome variables including in-hospital mortality and duration of stay were assessed. RESULTS: The rate of iliac artery angioplasty and stenting increased 850%, from 0.4 to 3.4 cases per 100,000 adults (P <.001). The rate of AFB declined 15.5%, from 5.8 to 4.9 cases per 100,000 adults (P <.005). Older age, white race, and higher-income patients were more likely to undergo angioplasty and stenting. AFB had a higher mortality rate, longer duration of stay, and higher hospital charges compared to angioplasty and stenting. CONCLUSIONS: Iliac artery angioplasty and stenting has rapidly gained a large market share in the treatment of AIOD. Acceptable clinical outcomes have likely lowered the threshold for treatment and contributed to the rapid diffusion of this technology for the treatment of AIOD.

National variation in operative mortality rates for esophageal resection and the need for quality improvement.

HYPOTHESIS: Operative mortality rates for esophageal resection vary across hospital volume groups in a nationally representative sample of hospitals. DESIGN: Cross-sectional study of all adult patients in the Nationwide Inpatient Sample who underwent esophageal resection from 1995 through 1999 (N = 3023). Operative mortality was determined for hospital volume quartiles (low, <3 per year; medium, 3-5 per year; high, 6-16 per year; very high, >16 per year). Multiple logistic regression of in-hospital mortality was used for case-mix adjusted analyses. SETTING: Hospitals performing at least 1 esophageal resection from 1995 through 1999 in the Nationwide Inpatient Sample. PATIENTS: Patients having esophageal resection from 1995 through 1999 in the Nationwide Inpatient Sample. RESULTS: Overall mortality was 8.2% and varied 3-fold from 11.8% to 3.7% across hospital volume groups (P<.001). In the case-mix-adjusted multivariate analysis, having surgery at a low-volume hospital (odds ratio, 2.9; 95% confidence interval, 1.7-4.9; P<.001) or medium-volume hospital (odds ratio, 2.4; 95% confidence interval, 1.4-4.3; P =.002) was associated with an increased risk of mortality compared with the reference group of very high-volume hospitals. The effect of volume on mortality was significant for both malignant and benign disease. Given the absolute risk difference of 8.1% between very high- and low-volume hospitals, only 12 patients would need to be referred to prevent 1 death after esophageal resection. CONCLUSIONS: The operative mortality rate for esophageal resection varies across hospitals in the United States. To improve the quality of care and reduce operative mortality rates for patients in need of esophageal surgery, patients should either be referred to higher-volume hospitals, or quality improvement should be directed at lower-volume hospitals.

National trends in the use and outcomes of hepatic resection.

BACKGROUND: Hepatic resection is increasingly performed for primary and metastatic tumors. Reports from tertiary care centers show improved outcomes over time with lower operative mortality rates. The objective of this investigation was to characterize trends in the use and outcomes of hepatic resection in the US during a recent 13-year period. STUDY DESIGN: Adult patients with a procedures code for hepatic resection in the Nationwide Inpatient Sample (NIS) from 1988 to 2000 were included. The Nationwide Inpatient Sample is a 20% representative sample of all discharges in the US. Outcomes variables included in-hospital mortality and length of stay. High volume hospitals performed 10 or more (>50th percentile) procedures per year. RESULTS: During the 13-year period, 16,582 patients underwent hepatic resection. The number of procedures performed increased nearly twofold, from 820 per year in 1988 to 1,420 per year in 2000. Similar changes in use were seen for each indication for operation. The overall mortality rate declined from 10.4% (1988 to 1989) to 5.3% (1999 to 2000) during the study period (p < 0.001). The mortality rate was lower at high volume centers than at lower volume centers (5.8% versus 8.9%, p < 0.001), and the decline in mortality over time was greater at high volume centers (10.1% to 3.9%, p < 0.001) compared with to low volume centers (10.6% to 7.4%, p = 0.01). CONCLUSIONS: The number of hepatic resections performed in the US has increased significantly. Short-term outcomes have also improved over the same time period, with more improvement seen at higher volume centers than in lower volume centers.

Epidemiology of surgically treated gastric cancer in the United States, 1988-2000.

The incidence of gastric cancer and the need for subsequent surgery has been decreasing in the United States. However, very few population-based studies on the magnitude of these changes are available. The objective of the present study was to characterize temporal trends in the use of gastric resection in the treatment of gastric cancer. Patients with a primary diagnosis code for gastric cancer (N=105,887) and a procedure code for gastric resection (N=23,690) in the Nationwide Inpatient Sample for 1988-2000 were included. The Nationwide Inpatient Sample represents a 20% stratified random sample representative of all United States hospitals. Outcome variables included the overall incidence, in-hospital mortality rate, and length of stay. Rates of surgery are shown as the number of cases per 100,000 hospital discharges. Hospital volume was defined as follows: low volume (1 to 4 cases per year), medium volume (5 to 8 cases per year), and high volume (9 or more cases per year). Rates of gastric resection have shown a 20% decline from 30 cases per 100,000 (1988-1989) to 24 cases per 100,000 (1999-2000) (P=0.001). In-hospital mortality has not changed over the 13-year period and remains at 7.4%. There was significant variation in mortality across hospitals, with very low-volume centers having an 8.9% mortality rate, whereas very high-volume centers had a 6.4% mortality rate (P<0.001). The market share of gastric resections performed at high-volume centers increased a small amount from 43% (1988-1989) to 48% (1999-2000) (P=0.023). Over the 13-year period, length of stay decreased from 15 days (interquartile range [IQR] 11-23) in 1988 to 11 days (interquartile range [IQR] 8-16) in 2000 (P<0.001). Rates of gastric resection for cancer have shown a modest decline over the past 13 years in the United States. Although the length of stay for these patients has decreased, no significant changes to in-hospital mortality have occurred. Given the declining rates of gastric cancer surgery, and the superior outcomes at high-volume centers, regionalization of care may improve mortality rates for this high-risk surgical procedure.

Outcomes after cerebral aneurysm clip occlusion in the United States: the need for evidence-based hospital referral.

OBJECT: In an age of multimodality and multidisciplinary treatment of cerebral aneurysms, patient outcomes have improved significantly. For a number of complex surgical procedures, hospitals with high case volumes yield superior outcomes. The effect of hospital volume on the mortality rate after emergency and elective cerebral aneurysm clip occlusion in a nationally representative sample of patients is unknown. METHODS: Using clinical data derived from the Nationwide Inpatient Sample for the years from 1995 through 1999, 12,023 patients who underwent clip occlusion of a cerebral aneurysm (International Classification of Diseases, Ninth Revision, Clinical Modification code 3951) were included. Patient age, comorbid conditions, nature of admission, and diagnosis of subarachnoid hemorrhage were abstracted. Hospital case volume was grouped into quartiles. Unadjusted and case-mix adjusted analyses were performed. The mean patient age was 53.2 +/- 13.5 years. The overall crude postoperative mortality rates for emergency and elective aneurysm clip occlusion were 12.2 and 6.6%, respectively. Very low volume hospitals demonstrated higher mortality rates than very high volume hospitals for both emergency (14.7 compared with 8.9%, p < 0.001) and elective (9.4 compared with 4.5%, p < 0.001) aneurysm surgery. Patient-specific predictors of death in the multivariate model were renal disease (odds ratio [OR] 3.32, p < 0.042); age (> 60 years, OR 2.36, p < 0.001; 51-60 years, OR 1.63, p < 0.001; 40-50 years, OR 1.25, p = 0.047); chronic obstructive pulmonary disease (present, OR 1.52, p < 0.001); and nature of admission (emergency, OR 1.18, p = 0.03). Provider-specific predictors of death included very low volume (OR 1.59, p < 0.001); low-volume (OR 1.37, p = 0.001); and high-volume (OR 1.45, p < 0.001) hospitals compared with very high volume hospitals. CONCLUSIONS: A significant volume-outcome effect exists for surgical treatment of cerebral aneurysms in the US. Factors influencing this effect should be investigated to guide future healthcare policy and evidence-based referral. Whenever possible, healthcare practitioners should refer patients to centers in which superior outcomes are consistently demonstrated.

Hemiarthroplasty for femoral neck fracture in the elderly surgeon and hospital volume-related outcomes.

The elderly patient with a displaced femoral neck fracture is commonly treated via hemiarthroplasty. The objectives of this study were to: 1) determine the rates of in-hospital mortality, complications, and prolonged length of stay (LOS) in such patients; 2) elucidate the patient characteristics that predict these occurrences; and 3) investigate the influence of surgeon and hospital volumes on these outcomes. Using the Nationwide Inpatient Sample (NIS), 173,508 cases of hemiarthroplasty for femoral neck fracture were identified in patients > or =65 years of age. Univariate and multivariate analysis demonstrated that hospitals with low caseload volumes were associated with increased patient risk for prolonged LOS, pulmonary embolism, urinary tract infection, and pneumonia. Surgeons with low caseload volumes were associated with increased risk for mortality and prolonged LOS. Quality-improvement initiatives would benefit from consideration of these factors.

National trends in outcomes for esophageal resection.

BACKGROUND: Case-series reports from tertiary centers report improved outcomes for esophageal resection in recent years. The objective of the current study was to determine trends in short-term outcomes after esophageal resection in a representative sample of United States (US) hospitals. METHODS: Observational study of all adult patients in the Nationwide Inpatient Sample who underwent esophageal resection from 1988 to 2000 (N = 8,657). Temporal trends of in-hospital mortality and prolonged length of stay were determined. Analyses were performed for all hospitals after stratifying by hospital volume. The proportion of patients having surgery at high volume hospitals was used to assess changes in referral patterns. RESULTS: The overall mortality rate was 11.3% and revealed a modest but significant decline from 13.6% to 10.5% during the study period (p = 0.001). Low volume hospitals had markedly higher mortality rates and showed no improvement over time (15.3% vs 14.5%). In contrast, high volume hospitals indicated significant reduction in mortality over time (11.0% vs 7.5%, p = 0.003). Referral patterns changed over time with the proportion of esophageal resections performed at high volume hospitals increasing from 40% (1988 to 1991) to 57% (1997 to 2000). CONCLUSIONS: The operative mortality rate for esophageal resection has declined over the past 13 years, particularly at high volume hospitals. Efforts should be made to understand the processes of care underlying this improvement.

Variation in outcomes after percutaneous coronary intervention in the United States and predictors of periprocedural mortality.

The objective of this study was to characterize variation in mortality rates across hospitals performing percutaneous coronary intervention (PCI) in the United States. For this purpose, data (n = 735,022) from the Nationwide Inpatient Sample from 1996 to 2001 were analyzed. The primary outcome for the analysis was postprocedural in-hospital mortality. Mortality rates were calculated by race, gender, geographic region, comorbid status and hospital volume. There were significant variations in mortality across gender groups, comorbid status, regions and by hospital volume status. Independent predictors of mortality in this large cohort were older age, female gender, lower income and lower hospital volume. The data suggests targets for quality improvement initiatives for patients undergoing PCI particularly in the elderly, females, lower income patients and low volume hospitals. Even in the contemporary era of adjunctive pharmacological therapies and ubiquitous use of stents, hospital volume remains a significant independent predictor of in-hospital mortality.

Trends in utilization of adrenalectomy in the United States: have indications changed?

Minimally invasive approaches have dramatically reduced morbidity associated with adrenalectomy. There has been concern that an increased frequency of adrenal imaging along with the advantages of less morbidity could influence the indications for adrenalectomy. We tested the hypothesis that adrenalectomy has become more common over time and that benign diseases have been increasingly represented among procedural indications. The Nationwide Inpatient Sample (NIS) database was utilized to determine the incidence of adrenalectomy and the associated surgical indications in the United States between 1988 and 2000. All discharged patients were identified whose primary ICD-9-CM procedure code was for adrenalectomy, regardless of the specific surgical approach (laparoscopic adrenalectomy was not reliably coded). This subset was then queried for associated ICD-9-CM diagnostic codes. Linear regression and t-tests were utilized to determine the significance of trends. The total number of adrenalectomies increased significantly, from 12.9 per 100,000 discharges in 1988 to 18.5 per 100,000 discharges in 2000 (p = 0.000003). The total number of adrenalectomies with a primary ICD-9-CM code for malignant adrenal neoplasm did not increase significantly: from 1.2 per 100,000 discharges in 1988 to 1.6 per 100,000 discharges in 2000 (p = 0.47). The total number of adrenalectomies with a primary ICD-9-CM diagnostic code for benign adrenal neoplasm increased significantly, from 2.8 per 100,000 discharges in 1988 to 4.8 per 100,000 discharges in 2000 (p = 0.00002). The average percentage of adrenalectomies performed for malignant neoplasm was significantly higher during the period 1988--1993 when compared to 1994--2000 (11% vs. 9%; p = 0.002). The average percentage of adrenalectomies performed for benign neoplasm was significantly lower during 1988--1993 when compared to 1994--2000 (25% vs. 28%; p = 0.015). Adrenalectomy is being performed with increasing frequency. This is associated with an increase in the proportion of adrenalectomies performed for benign neoplasms. Assuming no significant change in disease prevalence during the study period, these data suggest that indications for adrenalectomy may have changed somewhat over that period.

Should older patients be selectively referred to high-volume centers for abdominal aortic surgery?

The objective of the current study was to determine the effect of hospital volume on outcomes of abdominal aortic surgery for patients older than and younger than 65 years. In order to perform this investigation, information on all adult patients who underwent abdominal aortic surgery in Maryland from 1994 to 1996 (N = 2,987 patients) in 45 acute care hospitals was obtained. Hospitals were designated as low (< 20/year), medium (20 to 36/year), or high (> 36/year) volume according to the annual number of procedures performed. The relationship of hospital volume and mortality was determined for patients less than or greater than 65 years old. Two separate multiple logistic regression models were used to adjust for patient case-mix in each age category. Of the 2,987 patients, 2,067 (69%) were older than 65 years and 920 (31%) were younger. The crude in-hospital mortality rates according to hospital volume were 2.7% (low), 2.1% (medium), and 2.7% (high) for patients younger than 65 years old (p = .8). For patients older than 65 years, in-hospital mortality rates were 11.9% (low), 9.9% (medium), and 6.9% (high) (p = .005). After adjusting for patient case-mix in a multivariate analysis, high hospital volume was associated with a decreased risk of in-hospital mortality for patients older than 65 years (OR 0.57; 95% CI 0.37 to 0.86; p = .008) but not for patients under 65 years old. In conclusion, hospital volume was associated with decreased in-hospital mortality after abdominal aortic surgery only for patients greater than 65 years old. Because of this differential effect, targeting elderly patients for regionalization would achieve most potentially avoidable deaths for this common high-risk surgical procedure.

Epidemiology of surgically treated abdominal aortic aneurysms in the United States, 1988 to 2000.

Abdominal aortic aneurysm (AAA) repair is a complex procedure about which little information exists regarding trends in surgical practice in the United States. This study was undertaken to define benchmark data regarding performance and outcomes of conventional AAA repair that might be used in comparisons with endovascular AAA repair data. Patients undergoing repair of intact (n = 87,728) or ruptured (n = 16,295) AAAs in the Nationwide Inpatient Sample (NIS) for 1988 to 2000 were studied. The NIS represents a 20% stratified random sample of all discharges from US hospitals. Unadjusted and case mix-adjusted analyses of in-hospital mortality and length of stay were performed. The overall frequency of intact AAA repair remained relatively stable during the study period, ranging from 18.1 to 16.3 operations/100,000 adults between 1988 and 2000, respectively. The operative mortality rate for intact AAA repair decreased significantly (p < .001) from 6.5% in 1988 to 4.3% in 2000. Length of stay following intact AAA repair also declined significantly (p < .001) from a median of 11 days in 1988 (interquartile range [IQR] 9-15 days) to 7 days in 2000 (IQR 5-10 days). The incidence of ruptured AAA repair decreased significantly (p < .001) from 4.2 to 2.6 operations/100,000 adults between 1988 and 2000, respectively. Mortality for ruptured AAA repair, averaging 45.6%, did not decrease significantly during the study period. Intact AAA repair by conventional means has become increasingly safe, with decreased operative mortality and shorter hospital stays. Ruptured AAA repair by conventional means has not become safer but has decreased in incidence, suggesting possible reductions in risk factors contributing to rupture, coupled with more timely intact AAA repairs.

Venous thromboembolism: regional differences in the nationwide inpatient sample, 1993 to 2000.

Venous thromboembolism (VTE) is a costly complication of hospitalization. The sequelae make it a concern for public health planners. The Nationwide Inpatient Sample (NIS) contains data for hospital discharges in the United States. These data were reviewed to determine their suitability for health policy planning. International Classification of Diseases, Ninth Revision, Clinical Modification codes for VTE were applied to the NIS data. The sample was queried for demographic information, mortality, length of hospital stay, diagnosis, and treatment. The rates were standardized for geographic region and disease acuity. Statistical analysis included descriptive reporting of means and event rates; analysis of variance and logistic regression were used for regional effects and modeling of mortality. Between 1993 and 2000, 636,814 discharges involved VTE (1.2%). This rate was consistent over time and within regions. Regional differences existed in the acceptance of new technology and hospital charges. Mortality varied from 6.3% (Midwest) to 7.9% (Northeast) and was associated with admission type, comorbidities, pulmonary embolism, and discharge from the Northeast region. White race, chronic venous insufficiency, and female gender were protective variables. The NIS data report a consistent mortality rate despite improved therapy. Regional diagnostic, treatment, and economic differences exist. The data are useful for the purposes of public health care planning and stimulating clinical trial questions.

Ruptured thoracoabdominal aortic aneurysm treatment in the United States: 1988 to 1998.

OBJECTIVE: Thoracoabdominal aortic aneurysm (TAAA) rupture usually results in death. The outcome remains poor for patients who reach the operating room. The objective of this investigation was to define contemporary surgical experience with ruptured TAAA in the United States. Patients and methods Clinical data derived from the Nationwide Inpatient Sample on patients who underwent repair of a ruptured TAAA from 1988 to 1998 were analyzed. Age, sex, race, nature of admission, comorbid conditions, and provider volume were abstracted from the database. In-hospital mortality, postoperative complications, and length of stay were the principal outcome measures. RESULTS: Three hundred twenty-one patients were identified for the study. Mean age was 71.5 years; men outnumbered women (63% vs 37%). Crude overall surgical mortality was 53.8% and did not improve over time. Operative mortality was most likely (51%) to occur within the first 24 hours postoperatively. Median length of stay for surviving patients was 16 days. Renal failure (28%) and cardiac complications (18%) were the most common complications. In a logistic regression model, age greater than 77 years was predictive of death (odds ratio [OR], 2.5; P =.005), and nonwhite race appeared protective (OR, 0.53; P =.013). CONCLUSIONS: Mortality after surgical treatment of ruptured TAAA is high. Surviving patients experience many postoperative complications and have lengthy hospital stays. Given the lack of significant improvement in contemporary surgical practice, new techniques of repair deserve the attention of clinicians.

Effect of increasing patient age on complication rates following intact abdominal aortic aneurysm repair in the United States.

INTRODUCTION: Advanced age is generally acknowledged as a risk factor for adverse surgical outcomes, but little information exists to define the magnitude of this association from a population-based perspective. This study was undertaken to determine the relation of patient age to complications following abdominal aortic aneurysm (AAA) repair in a population-based experience. METHODS: This study was based upon data from 6397 patients with a primary diagnosis of intact AAA and a procedure code for repair of AAA from the Nationwide Inpatient Sample (NIS) in 2000. The NIS is a 20% stratified random sample representative of all United States hospitals. Primary outcome variables were postoperative complications determined from secondary diagnostic codes. Adjustment for confounding variables was performed using multiple logistic regression. RESULTS: At least one complication affected 29% of patients. Increasing age correlated with a higher risk of having one or more complications (51-60 years, 18.8%; 61-70 years, 27.3%; 71-80 years, 31.2%; >80 years, 34.3%; P < 0.01). Comparison of the oldest to the youngest age group revealed an increased incidence of pulmonary insufficiency (13.9% versus 6.4%), pneumonia (7.7% versus 3.0%), reintubation (9.5% versus 3.9%), acute renal failure (8.8% versus 2.5%), myocardial infarction (4.3% versus 1.6%), and mortality (7.9% versus 1.1%). The association of increasing age to complications and mortality persisted after adjusting for patient case-mix. CONCLUSIONS: Older patient age is independently associated with an increased risk of major postoperative complications after AAA repair. The increasing age of the United States population will compound this healthcare problem. Quality improvement efforts must focus on minimizing complication rates in elderly patients undergoing common vascular surgical procedures including AAA repair.

Hospital volume-related differences in aorto-bifemoral bypass operative mortality in the United States.

PURPOSE: Aorto-bifemoral bypass (AFB) is commonly performed in US hospitals. Durable long-term outcome is achieved after AFB performed to treat aortoiliac occlusive disease. However, short-term outcome for complex surgical procedures is not uniform across medical centers. The objective of the current study was to define the relationship of hospital volume to operative mortality after AFB. METHODS: The study included 3073 patients with a primary procedure code for AFB and a diagnostic code for peripheral vascular occlusive disease who received treatment during 1997 at 483 hospitals in the Nationwide Inpatient Sample (NIS). The NIS represents a 20% stratified random sample representative of all US hospitals. Unadjusted and case mix-adjusted analyses were performed. RESULTS: Overall AFB-related mortality was 3.3%. Hospitals that performed more than 25 AFB per year (33% of patients at 37 hospitals in the NIS) had a lower crude mortality rate (3.7% vs 2.2%) compared with hospitals that performed fewer AFB. In a multivariate analysis adjusting for case mix, AFB at a high- volume hospital was associated with 42% decreased risk for in-hospital mortality (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.34-0.97; P =.04) compared with low-volume hospitals. Two other important risk factors associated with increased mortality in the multivariate analysis included age more than 65 years (OR, 3.3; 95% CI, 2.0-5.4) and history of chronic pulmonary disease (OR, 1.9; 95% CI, 1.2-2.9). CONCLUSIONS: AFB operative mortality was significantly lower at high-volume hospitals in this nationally representative database. The effect of hospital volume of AFB procedures on outcome should be of importance to patients, providers, and health policy makers.

A national and single institutional experience in the contemporary treatment of acute lower extremity ischemia.

OBJECTIVE: To determine the contemporary clinical relevance of acute lower extremity ischemia and the factors associated with amputation and in-hospital mortality. SUMMARY BACKGROUND DATA: Acute lower extremity ischemia is considered limb- and life-threatening and usually requires therapy within 24 hours. The equivalency of thrombolytic therapy and surgery for the treatment of subacute limb ischemia up to 14 days duration is accepted fact. However, little information exists with regards to the long-term clinical course and therapeutic outcomes in these patients. METHODS: Two databases formed the basis for this study. The first was the National Inpatient Sample (NIS) from 1992 to 2000 of all patients (N = 23,268) with a primary discharge diagnosis of acute embolism and thrombosis of the lower extremities. The second was a retrospective University of Michigan experience from 1995 to 2002 of matched ICD-9-CM coded patients (N = 105). Demographic factors, atherosclerotic risk factors, the need for amputation, and in-hospital mortality were assessed by univariate and multivariate logistic regression analysis. RESULTS: In the NIS, the mean patient age was 71 years, and 54% were female. The average length of stay (LOS) was 9.4 days, and inflation-adjusted cost per admission was $25,916. The amputation rate was 12.7%, and mortality was 9%. Decreased amputation rates accompanied: female sex (0.90, 0.81-0.99), age less than 63 years (0.47, 0.41-0.54), angioplasty (0.46, 0.38-0.55), and embolectomy (0.39, 0.35-0.44). Decreased mortality accompanied: angioplasty (0.79, 0.64-0.96), heparin administration (0.50, 0.29-0.86), and age less than 63 years(0.27, 0.23-0.33). The University of Michigan patients' mean age was 62 years, and 57% were men. The LOS was 11 days, with a 14% amputation rate and a mortality of 12%. Prior vascular bypasses existed in 23% of patients, and heparin use was documented in 16%. Embolectomy was associated with decreased amputation rates (0.054, 0.01-0.27) and mortality (0.07, 0.01-0.57). CONCLUSIONS: In patients with acute limb ischemia, the more widespread use of heparin anticoagulation and, in select patients, performance of embolectomy rather than pursuing thrombolysis may improve patient outcomes.