John A. Cowan

Surgical treatment of intact thoracoabdominal aortic aneurysms in the United States: Hospital and surgeon volume-related outcomes

OBJECTIVE Surgical treatment of intact thoracoabdominal aortic aneurysm (TAAA) is crucial to prevent rupture but is associated with high perioperative mortality. We tested the hypothesis that provider volume of surgical treatment of TAAA is an important determinant of operative outcome. Patients and methods Clinical information regarding repair of intact TAAA in 1542 patients from 1988 to 1998 was obtained from the Nationwide Inpatient Sample (NIS), a stratified discharge database of a representative 20% of US hospitals. Demographic data included age, sex, race, nature of admission, and comorbid conditions. Annual hospital volume of TAAA treated was grouped into terciles and defined as low (LVH; 1-3 cases [median, 1]), medium (MVH; 2-9 cases [median, 4]), or high (HVH; 5-31 cases [median, 12]). Annual surgeon volume was defined as low (LVS; 1-2 cases [median, 1]) or high (HVS; 3-18 cases [median, 7]). The primary outcome measure was in-hospital postoperative mortality. Secondary outcome measures included length of stay, and cardiac, pulmonary, and renal complications. Adjusted and unadjusted analyses were conducted. RESULTS Overall mortality was 22.3%. Mortality improved over time. LVH and HVH differed in mortality rates (27.4% vs 15.0%; P <.001). Mortality between LVS and HVS also differed significantly (25.6% vs 11.0%; P <.001). When controlling for patient demographic data, comorbid conditions, and postoperative complications, both hospital and surgeon volume were significant predictors of mortality for intact TAAA repair (LVS: odds ratio [OR] 2.6, P <.001; LVH: OR 2.2, P <.001; and MVH: OR 1.7, P =.004). CONCLUSIONS Greater hospital and surgeon TAAA treatment volumes contribute to better outcome. Given the relative high perioperative mortality associated with TAAA repair, regionalization of care to high-volume providers with consistently lower postoperative mortality deserves consideration by patients, physicians, and health care planners.

Surgeon volume as an indicator of outcomes after carotid endarterectomy: An effect independent of specialty practice and hospital volume

BACKGROUND High-volume hospitals have been shown to have superior outcomes after carotid endarterectomy (CEA), but the contribution of surgeon volume and specialty practice to CEA outcomes in a national sample is unknown. STUDY DESIGN Using the National Inpatient Sample for 1996 and 1997, 35,821 patients who underwent CEA (ICD-9-CM code 3812) and had data for unique surgeon identification were studied. Surgeons were categorized in terms of annual CEA volume as low-volume surgeons (< 10 procedures), medium-volume surgeons (10 to 29), and high-volume surgeons (> or = 30). Data from cardiac, general, neurologic, and vascular surgical practices were analyzed. In-hospital mortality, postoperative stroke, and prolonged length of stay (> 4 days) were the primary outcomes variables. Unadjusted and case-mix adjusted analyses were performed. RESULTS The overall in-hospital mortality was 0.61%. CEA was performed annually by high-volume surgeons in 52% of patients, by medium-volume surgeons in 30% of patients, and by low-volume surgeons in 18% of patients. Observed mortality by surgeon volume was 0.44% for high-volume surgeons, 0.63% for medium-volume surgeons, and 1.1% for low-volume surgeons (p < 0.001). The postoperative stroke rate was 1.14% for high-volume surgeons, 1.63% for medium-volume surgeons, and 2.03% for low-volume surgeons (p < 0.001). Surgeon specialty had no statistically significant effect on mortality or postoperative stroke. In the logistic regression model, increased risk of mortality was associated with emergent admission (odds ratio [OR] = 2.1; 95% confidence interval [CI] 1.6 to 2.8, p < 0.001), patient age > 65 years (OR = 2.0; 95% CI 1.3 to 3.1, p = 0.001), low-volume surgeon (OR = 1.9; 95% CI 1.4 to 2.5, p < 0.001), and COPD (OR = 1.8; 95% CI 1.3 to 2.5, p = 0.001). Low hospital CEA volume (< 100) was not a significant risk factor in the multivariate analysis. CONCLUSIONS More than 50% of the CEAs in the United States are performed by high-volume surgeons with superior outcomes. Health policy efforts should focus on reducing the number of low-volume surgeons, regardless of surgeon specialty or total hospital CEA volume.

Surgeon specialty and provider volumes are related to outcome of intact abdominal aortic aneurysm repair in the United States.

OBJECTIVE This study was undertaken to determine the relative importance of surgeon specialty, hospital volume, and surgeon volume on outcome after abdominal aortic aneurysm (AAA) repair. METHODS Data were reviewed for 3912 patients undergoing AAA repair in the Nationwide Inpatient Sample during 1997. In-hospital mortality was compared between high-volume hospitals and low-volume hospitals and between high-volume surgeons and low-volume surgeons. High-volume hospitals performed more than 35 AAA repairs per year, and high-volume surgeons performed more than 10 AAA repairs per year. Vascular, cardiac, and general surgery specialization was identified by analysis of other procedures performed by each surgeon. RESULTS Overall, AAA repair mortality was 4.2%, and was lower at high-volume hospitals (3.0%) than at low-volume hospitals (5.5%) (P <.001). Lowest mortality was associated with operations performed by vascular surgeons (2.2%) compared with cardiac surgeons (4.0%) and general surgeons (5.5%) (P <.001). Mortality rates were also lower for high-volume hospitals (2.5%) compared with low-volume hospitals (5.6%) (P <.001). In a risk-adjusted analysis, high-volume hospital, vascular surgery specialty, and high-volume surgeon were all independently associated with lower risk of in-hospital mortality. In this analysis, risk reduction was 30% for high-volume hospitals (95% confidence interval [CI], 2%-51%; P <.05) and 40% for surgery by a high-volume surgeon (95% CI, 12%-60%; P =.01). AAA repair by general surgeons compared with vascular surgeons was associated with 76% greater risk for death (95% CI, 10%-190%; P =.02). No significant difference in mortality was found between cardiac and vascular surgeons. CONCLUSIONS High surgeon volume and hospital volume of AAA repair were both associated with lower mortality compared with low-volume providers. Increased specialization in vascular surgery was associated with markedly decreased mortality independent of AAA repair volume. Health policy in support of selective referral for AAA repair should consider surgical specialization in addition to provider volume thresholds.

Variation in postoperative complication rates after high-risk surgery in the United States

OBJECTIVE Our goal was to characterize variation in complication rates across hospitals with differing volumes for select high-risk operations in the United States. METHODS Data from the Nationwide Inpatient Sample for 1996 and 1997 were analyzed for 3 high-risk operations: esophagectomy (n=1,226), pancreatectomy (n=4,789), and intact abdominal aortic aneurysm repair (n=11,863). Complications evaluated included aspiration, cardiac complications, infection, pneumonia, pulmonary failure, renal failure, septicemia, and others. The risk of complications was calculated by hospital volume deciles, as well as for high-volume hospitals (HVH) and low-volume hospitals (LVH) defined by median hospital volume. RESULTS Rates of any postoperative complication varied nearly 2-fold across hospital volume groups. The proportion of patients across hospital deciles having at least one complication ranged from 30% to 51% for esophageal resection, 6% to 12% for pancreatic resection, and 9% to 18% for abdominal aortic aneurysm repair. HVH had lower rates of one or more complications after pancreatic resection (OR, 0.71; 95% CI, 0.57 to 0.83; P=.002), esophageal resection (OR, 0.68; 95% CI, 0.52 to 0.90; P=.008), and intact abdominal aortic aneurysm (AAA) repair (OR, 0.67; 95% CI, 0.59 to 0.76; P<.001). Patients with one or more complications after pancreatic resection had a mortality of 18.8% versus only 5.2% for those without complications (P<.001). Esophageal resection mortality was 16.9% for patients with at least one complication and 2.5% for those without complications (P<.001) and AAA repair mortality was 10.4% for patients with at least one complication and 2.9% for those without complications (P<.001). CONCLUSIONS High-risk operations have a decreased rate of postoperative complications when performed at HVH. Variation in complication rates may contribute to the volume-outcome relationship and provide a focus for quality improvement at LVH.

Surgical volume and quality of care for esophageal resection: do high-volume hospitals have fewer complications?

BACKGROUND Previous studies have shown that high-volume hospitals (HVHs) have lower mortality rates than low-volume hospitals (LVHs). However, little is known regarding the relationship of morbidity to hospital volume. The objective of the current study was to investigate the relative incidence of postoperative complications after esophageal resection at HVHs and LVHs. METHODS All patients discharged from a nonfederal, acute-care hospital in Maryland after esophageal resection from 1994 to 1998 were included (n = 366). Rates of 10 postoperative complications were compared at HVHs and LVHs. Risk-adjusted analyses were performed using multiple logistic regression. RESULTS High-volume hospitals had a mortality rate of 2.5% compared with 15.4% at LVHs (p < 0.001), with a case-mixed adjusted odds ratio (OR) of death equal to 5.7 (95% confidence interval [CI], 2.0 to 16; p < 0.001). Low-volume hospitals had a profound increase in the risk of several complications after adjusting for case-mix: renal failure (OR, 19; 95% CI, 1.9 to 178; p = 0.01), pulmonary failure (OR, 4.8; 95% CI, 1.6 to 14; p = 0.002), septicemia (OR, 4.0; 95% CI, 1.1 to 15; p = 0.04), reintubation (OR, 2.9; 95% CI, 1.4 to 6.1; p = 0.004), surgical complications (OR, 3.3; 95% CI, 1.6 to 6.9; p = 0.001), and aspiration (OR, 1.8; 95% CI, 1.0 to 3.3; p = 0.04). CONCLUSIONS Patients undergoing esophageal resection at LVHs were at a markedly increased risk of postoperative complications and death. Pulmonary complications are particularly prevalent at LVHs and contribute to the death of patients having surgery at those centers.

The role of radiation therapy after surgical resection of nonfunctional pituitary macroadenomas.

OBJECTIVE:Radiotherapy after aggressive surgical resection of nonfunctional macroadenoma (NFA) of the pituitary remains controversial. Historically, immediate postoperative radiotherapy has been recommended to decrease risk of recurrence. With the availability of high-resolution imaging, most neurosurgeons now withhold radiation until recurrence. There is relatively little evidence to support this practice, however. This study reviews postoperative results in a large number of patients with NFA, the majority of whom did not undergo prophylactic radiation. METHODS:Of the 258 patients who underwent surgery from 1979 to 1999 for NFA, medical records were available for 176. Forty-four patients were treated with immediate postoperative radiotherapy after tumor resection, and the remaining 132 patients were followed up with serial imaging studies and treated with radiotherapy only when a recurrence was documented by follow-up imaging. RESULTS:Patients in the group that received immediate postoperative radiotherapy at time of initial diagnosis and surgery did not differ significantly with respect to age or sex from those in the group that was observed. Five- and 10-year recurrence rates were 2.3 and 2.3%, respectively, for patients who received immediate postoperative radiotherapy, as compared with 15.2 and 50.5%, respectively, for patients who were followed up and did not receive radiotherapy unless there was evidence of recurrence or progression. No patient had symptomatic recurrence in the group that was observed if consistent follow-up was performed. Of the 26 patients who received radiotherapy at time of tumor recurrence or progression, 18 had adequate follow-up, and in all cases, the tumors either remained stable or regressed. CONCLUSION:Withholding radiotherapy after a high-percentage resection of NFA leads to a higher recurrence rate, but it avoids exposing all patients to the risks of radiation. Deferring radiotherapy for patients with complete or near-complete resection seems to be a safe and prudent approach, as our data suggest that recurrences may be detected early with high-resolution imaging and treated effectively with radiation at time of recurrence. Therefore, immediate postoperative radiotherapy may be eliminated for patients with complete or near complete resection of NFA and who agree to undergo close follow-up for a long period.

Complications and costs after high-risk surgery: Where should we focus quality improvement initiatives?

BACKGROUND Data on the relative clinical and economic impact of postoperative complications are needed in order to direct quality improvement efforts. STUDY DESIGN Patients undergoing two high-risk surgical procedures, hepatectomy (n = 569) and esophagectomy (n = 366), from 1994 to 1998 were included. Data were abstracted from the Maryland hospital discharge database. Relative resource use was determined using median regression, adjusting for patient comorbidities and other case-mix variables. RESULTS A total of 935 patients were studied. Overall in-hospital mortality was 6.1%; complication rate was 38.4%. Median cost for all patients was

Changes in the utilization of spinal fusion in the United States

14,527 (interquartile range

A National and Single Institutional Experience in the Contemporary Treatment of Acute Lower Extremity Ischemia

10,936-

Hospital volume and surgical outcomes for elderly patients with colorectal cancer in the United States.

21,412) and length of stay 9 days (interquartile range 7-13 days). Median hospital cost was increased for patients with complications (