Lillemoe, Keith D.

Objective: We comparatively analyzed the longitudinal outcomes of conversion to open procedure, laparoscopic subtotal cholecystectomy (CCY), and laparoscopic cholecystostomy tube placement. Background: Severe cholecystitis often causes dense inflammation that distorts the hepatocystic anatomy and can make safe dissection during CCY challenging. However, controversy exists regarding the optimal bailout procedure in such situations. Methods: The New York and Florida State all-claims databases were queried for patients who underwent laparoscopic CCY for acute cholecystitis from 2012 to 2021. Hierarchical logistic regression models were used to obtain adjusted estimates, with fixed effects assigned to patient-level variables and random effects assigned to hospital identifiers to adjust for intraclass correlation. Results: Of 384,948 laparoscopic CCYs performed, 5448 (1.4%) were not completed laparoscopically; 1370 underwent conversion to open procedure, 2646 underwent laparoscopic subtotal CCY, and 1432 underwent laparoscopic cholecystostomy tube placement. The conversion to open rate decreased from 0.6% in 2012 to 0.3% in 2021, while the laparoscopic subtotal CCY rate increased from 0.2% in 2012 to 1.4% in 2021. The 1-year bile duct injury (BDI) rate was highest for the conversion to open group (4.4%), followed by the laparoscopic subtotal CCY (0.8%) and laparoscopic cholecystostomy tube groups (0.3%, P<0.001). On adjusted analyses with the conversion to open group as the control, laparoscopic subtotal CCY (OR: 0.17, P<0.001) and laparoscopic cholecystostomy tube were associated with lower BDI rates (OR: 0.08, P<0.001, Figure). The 1-year postoperative endoscopic biliary intervention rate was lowest for the conversion to open group (4.2%), followed by the laparoscopic subtotal CCY (8.4%) and the laparoscopic cholecystostomy tube groups (8.8%, P<0.001). The completion CCY rates for the laparoscopic subtotal CCY and laparoscopic cholecystostomy tube groups were 2.1% and 23.4%, respectively. Among completion CCYs, the open rates were 56.4% in the laparoscopic subtotal CCY group versus 24.5% in the laparoscopic cholecystostomy tube group (P<0.001). Conclusions: In patients with severe cholecystitis requiring a bailout procedure, the BDI rate was highest after conversion to open procedure. Laparoscopic subtotal CCY and laparoscopic cholecystostomy tube were associated with lower BDI rates at the cost of higher postoperative endoscopic biliary intervention rates. Completion CCYs were required in 2.1% and 23.4% of patients who underwent laparoscopic subtotal CCY and laparoscopic cholecystostomy tube placement, respectively, of which the former group’s CCY was more likely to require an open operation.

Objective: To determine the prevalence of clinical significance reporting in contemporary comparative effectiveness research (CER). Background: In CER, a statistically significant difference between study groups may or may not be clinically significant. Misinterpreting statistically significant results could lead to inappropriate recommendations that increase health care costs and treatment toxicity. Methods: CER studies from 2022 issues of the Annals of Surgery , Journal of the American Medical Association , Journal of Clinical Oncology , Journal of Surgical Research , and Journal of the American College of Surgeons were systematically reviewed by 2 different investigators. The primary outcome of interest was whether the authors specified what they considered to be a clinically significant difference in the “Methods.” Results: Of 307 reviewed studies, 162 were clinical trials and 145 were observational studies. Authors specified what they considered to be a clinically significant difference in 26 studies (8.5%). Clinical significance was defined using clinically validated standards in 25 studies and subjectively in 1 study. Seven studies (2.3%) recommended a change in clinical decision-making, all with primary outcomes achieving statistical significance. Five (71.4%) of these studies did not have clinical significance defined in their methods. In randomized controlled trials with statistically significant results, sample size was inversely correlated with effect size ( r = −0.30, P = 0.038). Conclusions: In contemporary CER, most authors do not specify what they consider to be a clinically significant difference in study outcome. Most studies recommending a change in clinical decision-making did so based on statistical significance alone, and clinical significance was usually defined with clinically validated standards.

Objective: The ISGPS aimed to develop a universally accepted definition for PPAP for standardized reporting and outcome comparison. Background: : PPAP is an increasingly recognized complication after partial pancreatic resections, but its incidence and clinical impact, and even its existence are variable because an internationally accepted consensus definition and grading system are lacking. Methods: The ISGPS developed a consensus definition and grading of PPAP with its members after an evidence review and after a series of discussions and multiple revisions from April 2020 to May 2021. Results: We defined PPAP as an acute inflammatory condition of the pancreatic remnant beginning within the first 3 postoperative days after a partial pancreatic resection. The diagnosis requires (1) a sustained postoperative serum hyperamylasemia (POH) greater than the institutional upper limit of normal for at least the first 48 hours postoperatively, (2) associated with clinically relevant features, and (3) radiologic alterations consistent with PPAP. Three different PPAP grades were defined based on the clinical impact: (1) grade postoperative hyperamylasemia, biochemical changes only; (2) grade B, mild or moderate complications; and (3) grade C, severe life-threatening complications. Discussions: The present definition and grading scale of PPAP, based on biochemical, radiologic, and clinical criteria, are instrumental for a better understanding of PPAP and the spectrum of postoperative complications related to this emerging entity. The current terminology will serve as a reference point for standard assessment and lend itself to developing specific treatments and prevention strategies.

Abstract Purpose: The initiation, progression, and maintenance of pancreatic ductal adenocarcinoma (PDAC) results from the interplay of genetic and epigenetic events. While the genetic alterations of PDAC have been well characterized, epigenetic pathways regulating PDAC remain, for the most part, elusive. The goal of this study was to identify novel epigenetic regulators contributing to the biology of PDAC. Experimental Design: In vivo pooled shRNA screens targeting 118 epigenetic proteins were performed in two orthotopic PDAC xenograft models. Candidate genes were characterized in 19 human PDAC cell lines, heterotopic xenograft tumor models, and a genetically engineered mouse (GEM) model of PDAC. Gene expression, IHC, and immunoprecipitation experiments were performed to analyze the pathways by which candidate genes contribute to PDAC. Results: In vivo shRNA screens identified BRD2 and BRD3, members of the BET family of chromatin adaptors, as key regulators of PDAC tumor growth. Pharmacologic inhibition of BET bromodomains enhanced survival in a PDAC GEM model and inhibited growth of human-derived xenograft tumors. BET proteins contribute to PDAC cell growth through direct interaction with members of the GLI family of transcription factors and modulating their activity. Within cancer cells, BET bromodomain inhibition results in downregulation of SHH, a key mediator of the tumor microenvironment and canonical activator of GLI. Consistent with this, inhibition of BET bromodomains decreases cancer-associated fibroblast content of tumors in both GEM and xenograft tumor models. Conclusions: Therapeutic inhibition of BET proteins offers a novel mechanism to target both the neoplastic and stromal components of PDAC. Clin Cancer Res; 22(16); 4259–70. ©2016 AACR.