Less is more in the difficult gallbladder: recent evolution of subtotal cholecystectomy in a single HPB unit.

INTRODUCTION: Subtotal cholecystectomy (SC) is a technique to manage the difficult gallbladder and avoid hazardous dissection and biliary injury. Until recently it was used infrequently. However, because of reduced exposure to open total cholecystectomy in resident training, we recently adopted subtotal cholecystectomy as the bail-out procedure of choice for resident teaching. This study reports our experience and outcomes with subtotal cholecystectomy in the years immediately preceding adoption and since adoption. METHODS: A retrospective analysis was conducted of patients undergoing SC from July 2010 to June 2019. Outcomes, including bile leak, reoperation and need for additional procedures, were analyzed. Complications were graded by the Modified Accordion Grading Scale (MAGS). RESULTS: 1571 cholecystectomies were performed of which 71 were SC. Subtotal cholecystectomy patients had several indicators of difficulty including prior attempted cholecystectomy and previous cholecystostomy tube insertion. The most common indication for SC was marked inflammation in the hepatocystic triangle (51%). As our experience increased, fewer patients required open conversion to accomplish SC and SC was completed laparoscopically, usually subtotal fenestrating cholecystectomy (SFC). Most patients (85%) had a drain placed and 28% were discharged with a drain. The highest MAGS complication observed was grade 3 (11 patients, 15%). Six patients had a bile leak from the cystic duct resolved by ERCP. At mean follow-up of about 1 year no patient returned with recurrent symptoms. CONCLUSIONS: Subtotal fenestrating cholecystectomy is a useful technique to avoid biliary injury in the difficult gallbladder and can be performed with very satisfactory rates of bile fistula, ERCP, and reoperation.

Qualitative imaging features of pancreatic neuroendocrine neoplasms predict histopathologic characteristics including tumor grade and patient outcome.

OBJECTIVES: To identify PanNEN imaging features associated with tumor grade and aggressive histopathological features. METHODS: Associations between histopathological and imaging features of resected PanNEN were retrospectively tested. Histopathologic features included WHO grade, lymphovascular invasion (LVI), growth pattern (infiltrative, circumscribed), and intratumoral fibrosis (mature, immature). Imaging features included size, degree/uniformity of enhancement, progressive enhancement, contour, infiltrative appearance (infiltrativeim), calcifications, cystic components, tumor thrombus, vascular occlusion (VO), duct dilatation, and atrophy. Multinomial logistic regression analyses evaluated the magnitude of associations. Association of variables with outcome was assessed using Cox-proportional hazards regression. RESULTS: 133 patients were included. 3 imaging features (infiltrativeim, ill-defined contour [contourill], and VO) were associated with all histopathologic parameters and poor outcome. Increase in grade increased odds of contourill by 15.6 times (p = 0.0001, 95% CI 3.8-64.4). PanNEN with VO were 51.1 times (p = 0.0002, 6.5-398.6) more likely to demonstrate LVI. For PanNEN with contourill, infiltrative growth pattern was 51.3 times (p < 0.0001, 9.1-288.4), and fibrosis was 14 times (p = 0.0065, 2.1-93.7) more likely. Contourill was associated with decreased recurrence-free survival (p = 0.0003, HR 18.29, 3.83-87.3) and VO (p = 0.0004, HR6.08, 2.22-16.68) with decreased overall survival. CONCLUSIONS: Infiltrativeim, contourill, and VO on imaging are associated with higher grade/histopathological parameters linked to tumor aggression, and poor outcome.

Intratumoral Fibrosis and Tumor Growth Pattern as Prognostic Factors in Optimally Resected Pancreatic Neuroendocrine Neoplasms: An Analysis of 168 Cases.

OBJECTIVES: Pancreatic neuroendocrine neoplasms (PanNENs) can recur after curative resection. We sought to establish the significance of tumor fibrosis and tumor growth pattern as predictors of recurrence-free survival and overall survival. METHODS: A retrospective query of an institutional surgical database was performed from 2000 to 2018 to identify optimally resected PanNENs. All eligible slides were reviewed by an experienced gastrointestinal pathologist for established histopathologic prognostic factors, as well as fibrosis and tumor growth pattern. We evaluated the effect of the interested variables through Cox proportional hazards models. RESULTS: One hundred sixty-eight cases were considered. The majority of patients (90%) had grade 1 or 2 tumors, 46% showed significant fibrosis, and 22% demonstrated an infiltrative growth pattern. Twenty-one percent of patients had a recurrence. In multivariable analysis, lymphovascular invasion with a hazard ratio (HR) of 5.1 and infiltrative growth pattern (HR, 2.8) were significantly associated with increased risk of recurrence and increased risk of death (HR, 3.6 and 2.7, respectively). There was a significant decrease in recurrence-free survival and overall survival for fibrosis and infiltrative growth pattern. CONCLUSIONS: In optimally resected PanNENs, the presence of fibrosis and infiltrative growth pattern are significant risk factors for recurrence and/or decreased survival.

Vector-host interactions governing epidemiology of West Nile virus in Southern California.

Southern California remains an important focus of West Nile virus (WNV) activity, with persistently elevated incidence after invasion by the virus in 2003 and subsequent amplification to epidemic levels in 2004. Eco-epidemiological studies of vectors-hosts-pathogen interactions are of paramount importance for better understanding of the transmission dynamics of WNV and other emerging mosquito-borne arboviruses. We investigated vector-host interactions and host-feeding patterns of 531 blood-engorged mosquitoes in four competent mosquito vectors by using a polymerase chain reaction (PCR) method targeting mitochondrial DNA to identify vertebrate hosts of blood-fed mosquitoes. Diagnostic testing by cell culture, real-time reverse transcriptase-PCR, and immunoassays were used to examine WNV infection in blood-fed mosquitoes, mosquito pools, dead birds, and mammals. Prevalence of WNV antibodies among wild birds was estimated by using a blocking enzyme-linked immunosorbent assay. Analyses of engorged Culex quinquefasciatus revealed that this mosquito species acquired 88.4% of the blood meals from avian and 11.6% from mammalian hosts, including humans. Similarly, Culex tarsalis fed 82% on birds and 18% on mammals. Culex erythrothorax fed on both birds (59%) and mammals (41%). In contrast, Culex stigmatosoma acquired all blood meals from avian hosts. House finches and a few other mostly passeriform birds served as the main hosts for the blood-seeking mosquitoes. Evidence of WNV infection was detected in mosquito pools, wild birds, dead birds, and mammals, including human fatalities during the study period. Our results emphasize the important role of house finches and several other passeriform birds in the maintenance and amplification of WNV in southern California, with Cx. quinquefasciatus acting as both the principal enzootic and "bridge vector" responsible for the spillover of WNV to humans. Other mosquito species, such as Cx. tarsalis and Cx. stigmatosoma, are important but less widely distributed, and also contribute to spatial and temporal transmission of WNV in southern California.