Reappraisal of Malignant Risk Assessment for Small (≤20 mm) Non-functioning Pancreatic Neuroendocrine Tumors.

BACKGROUND: Optimal management of non-functioning pancreatic neuroendocrine tumors (PanNETs) ≤20 mm is controversial. The biological heterogeneity of these tumors poses challenges when deciding between resection and observation. METHODS: In this multicenter, retrospective cohort study, we analyzed all patients (n = 78) who underwent resection of non-functioning PanNETs ≤20 mm at three tertiary medical centers from 2004 to 2020 to assess the utility of preoperatively available radiological features and serological biomarkers of non-functioning PanNETs in choosing an optimal surgical indication. The radiological features included non-hyper-attenuation pattern on enhancement computed tomography (CT; hetero/hypo-attenuation) and main pancreatic duct (MPD) involvement, and serological biomarkers included elevation of serum elastase 1 and plasma chromogranin A (CgA) levels. RESULTS: Of all small non-functioning PanNETs, 5/78 (6%) had lymph node metastasis, 11/76 (14%) were WHO grade II, and 9/66 (14%) had microvascular invasion; 20/78 (26%) had at least one of these high-risk pathological factors. In the preoperative assessment, hetero/hypo-attenuation and MPD involvement were observed in 25/69 (36%) and 8/76 (11%), respectively. Elevated serum elastase 1 and plasma CgA levels were observed in 1/33 (3%) and 0/11 (0%) patients, respectively. On multivariate logistic regression analysis, hetero/hypo-attenuation (odds ratio [OR] 6.1, 95% confidence interval [CI] 1.7-22.2) and MPD involvement (OR 16.8, 95% CI 1.6-174.3) were significantly associated with the high-risk pathological factors. The combination of the two radiological worrisome features correctly predicted non-functioning PanNETs with high-risk pathological factors, with about 75% sensitivity, 79% specificity, and 78% accuracy. CONCLUSIONS: This combination of radiological worrisome features can accurately predict non-functioning PanNETs that may require resection.

Assessment of serum and drain fluid bilirubin concentrations in liver transplantation patients.

BACKGROUND: Bile leakage is a major complication after liver transplantation and remains as a significant source of morbidity and mortality. In 2011, the International Study Group of Liver Surgery (ISGLS) defined bile leakage as a drain/serum bilirubin ratio ≥3. However, to our knowledge there is no literature assessing serum and drain bilirubin concentrations after liver transplantation. The aim of this study was to describe the natural postoperative changes in serum and drain fluid bilirubin concentrations in patients after liver transplantation. METHODS: We included 32 patients who underwent liver transplantation at Kobe University Hospital from January 2007 to December 2020. We enrolled 34 living donors who had no complications as the control group. RESULTS: The recipient serum total/direct bilirubin concentration were higher compared with the donors from postoperative day (POD) 1 to 5 with a statistical difference (P < .05). The recipient drain/serum total bilirubin ratio was lower than donors on POD 3 (0.89 ± 0.07 vs 1.53 ± 0.07: P < .0001), which was also confirmed by the recipient drain/serum direct bilirubin ratio (0.64 ± 0.10 vs 1.18 ± 0.09: P < .0001). On POD 3, the drain fluid volume (647.38 ± 89.47 vs 113.43 ± 86.8 mL: P < .001) and serum total bilirubin concentration (6.73 ± 0.61 vs 1.23 ± 0.60 mg/dL: P < .001) was higher in the recipients than in donors. Categorized in 2 groups, the higher drain fluid volume and bilirubin concentration recipients showed lower drain/serum total bilirubin ratio compared with the other group (P = .03) CONCLUSION: The drain/serum bilirubin ratio in the transplanted patients could be calculated lower compared with the hepatectomy patients because of high drain fluid volume and hyperbilirubinemia. Great care should be taken when assessing the bile leakage in liver transplant recipients using the ISGLS definition.

Pancreatic volumetric assessment as a predictor of new-onset diabetes following distal pancreatectomy.

INTRODUCTION: Pancreatogenic diabetes after pancreatectomy is of growing importance due to the increasing life expectancy of pancreatectomized patients. Although reduction of pancreatic volume is thought to affect glucose metabolism, a consistent relationship has yet to be determined. This study aimed to investigate functional consequences of distal pancreatectomy (DP) in preoperatively non-diabetic patients. METHODS: This study included 61 non-diabetic patients who underwent DP. Clinical data were obtained, and the percent resected volume (PRV) of each pancreas was determined via multi-detector row computed tomography volumetry. RESULTS: During the follow-up period (median 26 months), 22 patients (36 %) developed new-onset diabetes within a median onset time of 8 months (range 0.5-42 months) postoperatively. The remaining 39 patients also showed impaired glucose metabolism. Multivariate analysis identified preoperative hemoglobin A1c ≥ 5.7 % (odds ratio 15.6, p = 0.001) and PRV > 44 % (odds ratio 11.3, p = 0.004) as independent risk factors for new-onset diabetes. CONCLUSIONS: Key determinants of postoperative glycemic control include preoperative functional reserve of the endocrine pancreas and the volume reduction of pancreatic parenchyma. Our findings enable reliable preoperative evaluation of the risk of postoperative diabetes and appropriate postoperative surveillance, which is helpful for early intervention in high risk patients.