Mark D. Duncan

Hospital Volume Can Serve as a Surrogate for Surgeon Volume for Achieving Excellent Outcomes in Colorectal Resection

OBJECTIVE To examine the association of surgeon and hospital case volumes with the short-term outcomes of in-hospital death, total hospital charges, and length of stay for resection of colorectal carcinoma. METHODS The study design was a cross-sectional analysis of all adult patients who underwent resection for colorectal cancer using Maryland state discharge data from 1992 to 1996. Cases were divided into three groups based on annual surgeon case volume--low (< or =5), medium (5 to 10), and high (>10)--and hospital volume--low (<40), medium (40 to 70), and high (> or =70). Poisson and multiple linear regression analyses were used to identify differences in outcomes among volume groups while adjusting for variations in type of resections performed, cancer stage, patient comorbidities, urgency of admission, and patient demographic variables. RESULTS During the 5-year period, 9739 resections were performed by 812 surgeons at 50 hospitals. The majority of surgeons (81%) and hospitals (58%) were in the low-volume group. The low-volume surgeons operated on 3461 of the 9739 total patients (36%) at an average rate of 1.8 cases per year. Higher surgeon volume was associated with significant improvement in all three outcomes (in-hospital death, length of stay, and cost). Medium-volume surgeons achieved results equivalent to high-volume surgeons when they operated in high- or medium-volume hospitals. CONCLUSIONS A skewed distribution of case volumes by surgeon was found in this study of patients who underwent resection for large bowel cancer in Maryland. The majority of these surgeons performed very few operations for colorectal cancer per year, whereas a minority performed >10 cases per year. Medium-volume surgeons achieved excellent outcomes similar to high-volume surgeons when operating in medium-volume or high-volume hospitals, but not in low-volume hospitals. The results of low-volume surgeons improved with increasing hospital volume but never equaled those of the high-volume surgeons.

Patterns of PD-L1 expression and CD8 T cell infiltration in gastric adenocarcinomas and associated immune stroma

Objective Recent data supports a significant role for immune checkpoint inhibitors in the treatment of solid tumours. Here, we evaluate gastric and gastro-oesophageal junction (G/GEJ) adenocarcinomas for their expression of programmed death-ligand 1 (PD-L1), infiltration by CD8+ T cells and the relationship of both factors to patient survival. Design Thirty-four resections of primary invasive G/GEJ were stained by immunohistochemistry for PD-L1 and CD8 and by DNA in situ hybridisation for Epstein–Barr virus (EBV). CD8+ T cell densities both within tumours and at the tumour–stromal interface were analysed using whole slide digital imaging. Patient survival was evaluated according to PD-L1 status and CD8 density. Results 12% of resections showed tumour cell membranous PD-L1 expression and 44% showed expression within the immune stroma. Two cases (6%) were EBV positive, with one showing membranous PD-L1 positivity. Increasing CD8+ densities both within tumours and immune stroma was associated with increasing percentage of tumour (p=0.027) and stromal (p=0.005) PD-L1 expression. Both tumour and immune stromal PD-L1 expression and high intratumoral or stromal CD8+ T cell density (>500/mm2) were associated with worse progression-free survival (PFS) and overall survival (OS). Conclusions PD-L1 is expressed on both tumour cells and in the immune stroma across all stages and histologies of G/GEJ. Surprisingly, we demonstrate that increasing CD8 infiltration is correlated with impaired PFS and OS. Patients with higher CD8+ T cell densities also have higher PD-L1 expression, indicating an adaptive immune resistance mechanism may be occurring. Further characterisation of the G/GEJ immune microenvironment may highlight targets for immune-based therapy.

Is endovascular stent-graft treatment of primary aortoesophageal fistula worthwhile?

Aortoesophageal fistula (AEF) as a result of prolonged nasogastric intubation is rare and certainly fatal, without prompt surgical intervention. We report the case of a 41-year-old man with morbid obesity who was admitted after suffering 55% of total body surface area burns. After several skin graft operations over the course of 12 weeks, he was rushed into surgery because of the acute onset of severe upper gastrointestinal bleeding. Exploratory laparotomy and esophagogastroduodenoscopy (EGD) suggested an AEF, which was then quickly confirmed by a diagnostic angiogram. An endovascular aortic stent graft repair was performed that successfully stopped the bleeding. We include a review of the literature pertaining to cases of AEF treated by endovascular surgery, which appears to be a promising alternative to open surgery in the unfit patient.

Inpatient survival after gastrectomy for gastric cancer in the 21st century

BACKGROUND Surgical treatment for gastric cancer has evolved substantially. To understand how changes in patient- and hospital-level factors are associated with outcomes over the last decade, we examined a nationally representative sample. METHODS Retrospective cross-sectional discharge data from the 2001-2010 Nationwide Inpatient Sample were analyzed using cross tabulation and multivariable regression modeling. Patients with a primary diagnosis of gastric cancer undergoing gastrectomy as primary procedure were included. We examined relationships between patient- and hospital-level factors, surgery type, and outcomes including in-hospital mortality and length of stay (LOS). RESULTS A total of 67,327 patients with gastric cancer undergoing gastrectomy nationwide with complete information were included. Compared with patients treated in 2001, patients in 2010 were younger, more likely admitted electively, treated in a teaching hospital, or at an urban center. There was no difference in the type of procedure performed over time. Factors associated with an increased risk of in-hospital mortality included older age, male gender, and nonelective admission (P<0.05). In multivariable analysis, patients undergoing gastrectomy in 2010 demonstrated 40% lower odds of in-hospital mortality (odds ratio, 0.60; P=0.008). Overall mean LOS was 13.9 d (standard error, 0.1) without change over time. Factors associated with longer LOS included procedure type, hospital location, nonelective admission, and comorbid disease (all P<0.05). CONCLUSIONS The adjusted odds of in-hospital mortality among surgically treated patients with gastric cancer decreased >40% between 2001 and 2010. Further research is warranted to determine if these findings are due to better patient selection, regionalization of care, or improvement of in-hospital quality of care.