Brian S. Diggs

National Practice Patterns for Management of Adult Congenital Heart Disease Operation By Pediatric Heart Surgeons Decreases In-Hospital Death

Background— Surgery for grown-up (age ≥18 years) patients with congenital heart disease (GUCH) is frequently performed by surgeons without specialization in pediatric heart surgery. We sought to define national practice patterns and to determine whether outcomes for GUCH patients are improved if they are treated by specialized pediatric heart surgeons (PHSs) compared with non-PHSs. Methods and Results— We identified index cardiac procedures in patients with 12 congenital heart disease diagnostic groups using the Nationwide Inpatient Sample 1988 to 2003. PHSs were defined as surgeons whose annual practice volumes were made of >75% annual pediatric heart cases. GUCH operations were defined as operations within these 12 diagnoses occurring in patients ≥18 years of age. We identified 30 250 operations, yielding a national estimate of 152 277±7875 operations. Of these, 111 816±7456 (73%) were pediatric operations, and 40 461±1365 (27%) were GUCH operations. PHSs performed 68% of pediatric operations in all diagnostic groups, whereas non-PHSs performed 95% of GUCH operations within the same diagnostic groups (P<0.0001). In-hospital death rates for GUCH patients operated on by PHSs were lower than death rates for GUCH patients operated on by non-PHSs (1.87% [95% CI, 0.62 to 3.13] versus 4.84% [95% CI, 4.30 to 5.38%]; P<0.0001). Survival advantage increased with increasing surgeon annual pediatric volume (P=0.0031). Conclusions— Pediatric patients within specific diagnostic groups are more likely to undergo operation by PHSs, whereas GUCH patients within the same diagnostic groups are more likely to undergo operation by non-PHSs. In-hospital death rates are lower for GUCH patients operated on by PHSs. GUCH patients should be encouraged to obtain surgical operation by PHS.

Office-Based Unsedated Small-Caliber Endoscopy Is Equivalent to Conventional Sedated Endoscopy in Screening and Surveillance for Barrett's Esophagus: A Randomized and Blinded Comparison

OBJECTIVES:A major limitation to screening and surveillance of Barretts esophagus is the complexity, expense, and risk associated with sedation for upper endoscopy. This study examines the feasibility, accuracy, and patient acceptability of office-based unsedated endoscopy as an alternative.METHODS:Of 274 eligible adults scheduled for endoscopic screening for gastroesophageal reflux symptoms or surveillance of Barretts esophagus at a tertiary care center, 121 underwent unsedated small-caliber endoscopy and conventional endoscopy in a randomized crossover study. The two procedures were compared with regard to histological detection of Barretts esophagus and dysplasia and biopsy size. Patients answered questionnaires assessing the tolerability of the procedures.RESULTS:The prevalence of Barretts esophagus was 26% using conventional endoscopy and 30% using unsedated endoscopy (P = 0.503). The level of agreement between the two approaches was “moderate” (κ = 0.591). Each modality detected four cases of low-grade dysplasia with concordance on one case. The tissue samples collected with unsedated endoscopy were smaller than with conventional endoscopy (P < 0.001). The majority of subjects rated their experience with both procedures as being well tolerated with minimal or no difficulty. When asked which procedure they would prefer in the future, 71% (81/114) chose unsedated small-caliber endoscopy.CONCLUSIONS:Office-based unsedated small-caliber endoscopy is technically feasible, well tolerated, and accurate in screening for Barretts esophagus, despite yielding a smaller biopsy specimen. This approach bears the potential to eliminate the infrastructure and cost required for intravenous sedation in this application.

The Influence of Surgeon Specialty on Outcomes in General Thoracic Surgery: A National Sample 1996 to 2005

BACKGROUND While general thoracic surgical procedures are performed by several different surgical subspecialties, debate remains as to whether surgeon specialty impacts outcomes. METHODS The Nationwide Inpatient Sample (NIS) was queried for procedure codes for pneumonectomy, lobectomy, limited lung resection, and decortication. We constructed multivariate logistic regression models to calculate odds of hospital mortality or length-of-stay (LOS) greater than 14 days (a marker of morbidity), adjusted for age, sex, patient comorbidities, hospital setting, and surgeon specialty. A surgeon was considered general thoracic if they performed greater than 75% general thoracic operations and less than 10% cardiac operations, Cardiac if greater than 10% cardiac operations, and general surgeon if less than 75% general thoracic and less than 10% cardiac operations. A second set of models additionally adjusted for procedure-specific hospital and surgeon volume. RESULTS From 1996 to 2005, the NIS estimates 41,808 pneumonectomies, 321,767 lobectomies, 75,200 limited lung resections, and 149,318 decortications were performed in the United States. For all procedures studied, general thoracic surgeons had significantly decreased odds-of-death and LOS greater than 14 days compared with general surgeons. Cardiac surgeons had significantly decreased LOS greater than 14 days for all operations and decreased odds-of-death for decortications, lobectomy, and limited lung resection compared with general surgeons. When further adjusted for surgeon volume, most differences in odds-of-death were no longer present; however, significantly decreased LOS greater than 14 days largely persisted for both general thoracic and cardiac surgeons. CONCLUSIONS The majority of general thoracic surgical operations in the United States are performed by surgeons not specializing in thoracic surgery. Both general thoracic surgeons and cardiac surgeons achieve better outcomes than general surgeons. Differences in mortality may be more dependent on surgeon volume than subspecialty. Differences in morbidity are significantly impacted by surgeon specialty and volume.

Systemic inflammation and insulin sensitivity in obese IFN-γ knockout mice

Adipose tissue macrophages are important mediators of inflammation and insulin resistance in obesity. IFN-γ is a central regulator of macrophage function. The role of IFN-γ in regulating systemic inflammation and insulin resistance in obesity is unknown. We studied obese IFN-γ knockout mice to identify the role of IFN-γ in regulating inflammation and insulin sensitivity in obesity. IFN-γ-knockout C57Bl/6 mice and wild-type control litter mates were maintained on normal chow or a high fat diet for 13 weeks and then underwent insulin sensitivity testing then sacrifice and tissue collection. Flow cytometry, intracellular cytokine staining, and QRTPCR were used to define tissue lymphocyte phenotype and cytokine expression profiles. Adipocyte size was determined from whole adipose tissue explants examined under immunofluorescence microscopy. Diet-induced obesity induced systemic inflammation and insulin resistance, along with a pan-leukocyte adipose tissue infiltrate that includes macrophages, T-cells, and NK cells. Obese IFN-γ-knockout animals, compared with obese wild-type control animals, demonstrate modest improvements in insulin sensitivity, decreased adipocyte size, and an M2-shift in ATM phenotype and cytokine expression. These data suggest a role for IFN-γ in the regulation of inflammation and glucose homeostasis in obesity though multiple potential mechanisms, including effects on adipogenesis, cytokine expression, and macrophage phenotype.

Ten-year trend in the national volume of bile duct injuries requiring operative repair

BackgroundThe objectives of this study were to determine the national proportions and mortality rate for bile duct injuries resulting from laparoscopic cholecystectomy (LC) that required operative reconstruction for repair over a 10-year period and to investigate the major factors associated with the mortality rate in this group of patients.MethodsUsing the Nationwide Inpatient Sample (NIS) of >7 million patient records per year, we extracted and analyzed data for LC during the years 1990–2000. Procedures that involved biliary reconstructions performed as part of another primary procedure were excluded. Using the Statistical Package for the Social Sciences (SPSS), we used procedure-specific codes that enabled us to calculate national estimates for LC for the time period under review. We then calculated biliary reconstruction procedures that occurred after LC for this cohort of patients. Finally, we analyzed in-hospital mortality, as well as the patient, institutional, and outcome characteristics associated with biliary reconstructions.ResultsThe percentage of cholecystectomies performed laparoscopically has increased over the years for which data are available (from 52% in 1991 to 75% in 2000). Despite this increase, the mortality rate for this group of patients has remained consistently low over the study period (mean, 0.45%; range 0.33–0.58%). Within this group of patients, the average rate of bile duct injuries requiring operative repair was 0.15% for the years under study. The reconstruction rates ranged from 0.25% in 1992 to 0.09% in 1999. For 2000, the most recent year for which data are available, biliary reconstruction was performed in 0.10% of all patients who underwent LC. The average mortality rate for patients undergoing biliary reconstruction for the years 1991 to 2000 was 4.5%. After multivariate analysis, age, African American ethnicity, type of admission, source of admission, and hospital location, and teaching status were all found to correlate significantly with death after-biliary reconstruction.ConclusionsThese data show an increase in the percentage of cholecystectomies performed laparoscopically over the years under study and an associated low mortality rate. In contrast, although the number of bile duct injuries appears to be decreasing, these procedures continue to be associated with a significant mortality rate.

Patient and Hospital Characteristics on the Variance of Perioperative Outcomes for Pancreatic Resection in the United States: A Plea for Outcome-Based and Not Volume-Based Referral Guidelines

HYPOTHESIS There is an effect of patient and hospital characteristics on perioperative outcomes for pancreatic resection in the United States. DESIGN Retrospective cohort study. SETTING Academic research. PATIENTS Patient data from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project from January 1988 to January 2003. MAIN OUTCOME MEASURES In-hospital mortality, perioperative complications, and mortality following a major complication. RESULTS A total of 103 222 patients underwent major pancreatic surgery. The annual number of pancreatic resections increased 15.0% during the 16-year study period. Resection for benign pancreatic disease increased 26.8%. Overall in-hospital mortality, perioperative complications, and mortality following a major complication were 6.5%, 35.6%, and 15.6%, respectively. Multivariate analysis demonstrated that significant independent predictors for these 3 perioperative outcomes were advancing age, male sex, medical comorbidity, and hospital volume for each type of pancreatic resection. The in-hospital mortality for pancreatoduodenectomy increases with age and ranges from 1.7% to 13.8% (P < .001). After adjusting for other confounders, the odds of in-hospital mortality for pancreatoduodenectomy, distal pancreatectomy, and total pancreatectomy in those 65 years or older were 4.78-fold, 3.84-fold, and 2.60-fold, respectively, lower in the high-volume hospitals compared with those in the lower-volume hospitals. CONCLUSIONS Perioperative complications derived from this population-based study were higher than those reported in many case series. A significant disparity was noted in perioperative outcomes among surgical centers across the United States. An outcome-based referral guideline may have an immediate effect on improving the quality of care in patients who undergo pancreatic resection for benign and malignant disease.

Alterations in T-Cell Subset Frequency in Peripheral Blood in Obesity

Background: Obesity affects the regulation of immune and inflammatory responses. This study characterizes differences in peripheral blood lymphocyte phenotype in obese humans. Methods: Frequencies of lymphocyte subsets among peripheral blood mononuclear cells were compared between 10 obese (BMI ≥35) and 10 lean subjects, as determined by antibodies directed against cluster differentiation (CD) markers. Results: Obese patients demonstrated an increased frequency of CD3+CD4+ T-cells (mean difference 12%, P=0.004), a decreased frequency of CD3+CD8+ T-cells (mean difference 9.4%, P=0.016) and an increased frequency of CD3+CD8+CD95+ T-cells (mean difference 13.3%, P=0.032). No other differences among T-cell or monocyte subsets were noted. Conclusions: Obesity is associated with alterations in frequencies of peripheral CD4+ and CD8+ T-cells and aberrations in the expression of CD95 among CD8+ T-cells. These data suggest both CD4+ and CD8+ T-cell compartments, as well as the regulation of CD95 expression on CD8+ T-cells, as targets for further study into obesitys effects on the immune system.

Patient and peri-operative predictors of morbidity and mortality after esophagectomy: American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), 2005-2008.

PurposeOur aim was to determine what specific patient and peri-operative factors contribute to major complications after esophagectomy.MethodsUsing the American College of Surgeons National Surgical Quality Improvement Program database, data for esophagectomies between the years 2005 and 2008 were extracted and analyzed. Thirty-day post-operative complications were classified into seven major groups: (1) wound infections, (2) respiratory complications (pneumonia, intubation), (3) cardiac complications, (4) deep venous thrombosis, (5) sepsis/septic shock, (6) re-operation, and (7) death. Univariate analysis and logistic regression modeling were performed to determine if a significant association existed between patient factors or peri-operative factors and these post-operative complications.ResultsOne thousand thirty-two patients who underwent esophagectomy were identified. Diabetes was the strongest pre-operative independent predictor of death (odds ratio (OR) 10.98; 95% confidence interval (CI) 1.37–1.15, p < 0.1) or respiratory (OR 1.86; 95% CI 1.03–3.29, p = 0.04) or cardiac (OR 5.14; 95% CI 1.93–13.20, p < 0.01) complications following esophagectomy. Thoracotomy performed during the operation was not associated with an increased risk of respiratory or cardiac complications.ConclusionsThe major predictors of morbidity after an esophagectomy are the patient factors of diabetes, dyspnea, peripheral vascular disease, and cerebrovascular accident while the peri-operative factors are pre-operative international normalized ratio, contaminated wound classification, and American Society of Anesthesiologists class. Similarly, the major predictors of mortality are diabetes, dyspnea, and age for patient factors and contaminated wound classification for peri-operative factors.

Utilization of laparoscopic colectomy in the United States before and after the clinical outcomes of surgical therapy study group trial.

Objective: To evaluate the utilization of laparoscopic colectomy (LC) in the United States before and after prospective data supported its use for the treatment of colon cancer. Methods: The Nationwide Inpatient Sample 2001–2003 [before Clinical Outcomes of Surgical Therapy (COST)] and 2005–2007 (after COST) was queried for elective colectomies for both benign and malignant disease. The COST trial was published in 2004; therefore, 2004 data were excluded. Univariate analyses including patient-specific, hospital-specific, and outcome variables were performed. Multivariate logistic regression models and subset analyses were used to evaluate these variables and operative approach by time frame. Results: The query yielded 741,817 elective colectomies (684,969 open and 56,848 laparoscopic). The percentage of elective colectomies performed laparoscopically has increased over time. Laparoscopic colectomy for benign disease increased from 6.2% in 2001–2003 to 11.8% in 2005–2007, while those for colon cancer have increased by a larger percentage, 2.3% to 8.9%. In a multivariate model of patients with colon cancer, the odds ratio (OR) for having a laparoscopic approach after COST was 4.55 (confidence interval 3.81–5.44) compared with before COST. In contrast, for benign disease, the OR was 2.10 (confidence interval 1.79–2.46). Factors predictive of having a laparoscopic approach for cancer have changed very little over time: Patients are more likely to be male, insured, live in areas with the highest incomes, and undergo resection at urban teaching hospitals. Conclusions: Within 3 years after publication of the COST trial, the use of laparoscopic resection for colon cancer approached that of benign disease. However, almost 90% of cases are still performed open and utilization remains influenced by socioeconomic factors.

The Relationship Between Hospital Surgical Case Volumes and Mortality Rates in Pediatric Cardiac Surgery: A National Sample, 1988–2005

BACKGROUND Overall surgical volumes and raw mortality rates are frequently used to compare pediatric cardiac surgical programs, but unadjusted comparisons are potentially unreliable. We sought to quantify the relationship between hospital volume and pediatric cardiac surgical mortality. METHODS Pediatric cardiac operations assigned to Risk Adjustment for Congenital Heart Surgery, version 1 (RACHS-1) categories were retrospectively identified by International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) coding from the Nationwide Inpatient Sample, 1988-2005. Hospitals were grouped by yearly pediatric cardiac surgical volume (very small, <or= 20; small, 21 to 100; medium, 101 to 200; large, > 200). Mortality rates were adjusted for surgical volume, case mix (RACHS-1 categories), patient age, and year of operation by logistic regression. RESULTS We identified 55,164 operations from 307 hospitals; 188 (61%) performed 20 or fewer cases per year. The unadjusted mortality rate at very small hospitals was no different than at large hospitals (odds ratio, 1.0, 95% confidence interval [CI] 0.7 to 1.4). After adjustment for RACHS-1 category and age, large hospitals performed significantly better than all other volume groups. As a discriminator of mortality, volume performed significantly worse than a model with RACHS-1 category and age (receiver operating characteristic [ROC] curve area, 0.60 vs 0.81). CONCLUSIONS As a discriminator of mortality, volume alone was only marginally better than a coin flip (ROC curve area of 0.50). However, large-volume hospitals performed more complex operations and achieved superior results; therefore, the use of overall, unadjusted mortality rates to evaluate institution quality is misleading. Hospital comparisons and pay-for-performance initiatives must be based on robust risk-adjusted comparisons.