Background: Whether standard lymphadenectomy or extended lymphadenectomy should be performed is still under debate during pancreaticoduodenectomy (PD). We aimed to compare their morbidity and mortality rates among patients with pancreatic head cancer (PHC). Material and methods: In this retrospective study, a total of 322 patients were enrolled. According to the scope of intraoperative lymph node dissection, patients were divided into extended lymphadenectomy group (n=120) and standard lymphadenectomy group (n=202). Based on the resectability of the tumor, there were 198 cases of resectable PHC and 124 cases of boardline resectable PHC, respectively, in which further stratified analysis was carried out according to the extent of lymph node dissection.Results: All patients completed the operation successfully, with a perioperative morbidity rate of 27.9% and mortality rate of 0.9%. As for the overall patients, patients in the extended lymphadenectomy group had higher NLR, longer operation time, more intraoperative blood loss, lymph node dissection and patients with BRPHC. (P<0.05) The 1-, 2- and 3-year overall survival rates of patients with extended lymphadenectomy and standard lymphadenectomy were 71.9%, 50.6%, 30.0% and 70.0%, 32.9%, 21.5%, respectively. (P=0.068) With regards to patients with BRPHC, the number of lymph node dissection in the extended lymphadenectomy group was more, (P<0.05) and the 1-, 2- and 3-year overall survival rates of patients with extended lymphadenectomy and standard lymphadenectomy were 60.7%, 43.3%, 27.4% and 43.2%, 17.7%, 17.7%, respectively. (P=0.007)Conclusions: Patients with BRPHC tended to have vast lymph node metastasis. Extended lymphadenectomy can improve their long-term survival.

Background: We aimed to investigate the clinical course, possible transmission routes and the potential risk factors of Pneumocystis pneumonia in liver transplant recipients.Methods: The study was performed by collecting and analyzing the clinical, epidemiological, and molecular data from patients with Pneumocystis pneumonia as well as from matched controls.Results: There were a total of ten patients diagnosed with Pneumocystis pneumonia containing prospectively included six patients and retrospectively collected four patients, of which seven were transferred to the surgical intensive care unit and four died. The transmission map revealed inter-patient transmission of Pneumocystis jirovecii was impossible. Pneumocystis jirovecii detection was negative in all air samples. It was positive only in one sample from the twelve healthcare workers with close contact to diseased patients. Five out of 79 liver transplant recipients during the outbreak were colonized with Pneumocystis jirovecii compared to two out of 94 after the outbreak upon admission (P > 0.05). Liver transplant recipients with Pneumocystis pneumonia had totally different genotypes based on multilocus sequence typing. Additionally, we found an unreported mutation at the cytochrome b gene (566 C/T and C838C/T). The absolute CD19+ B-cell counts (odds ratio: 1.028; 95% confidence interval: 1.000-1.057; P = 0.049) was defined to be the only significant independent risk factor using multivariable conditional logistic regression. Conclusions: Pneumocystis pneumonia is a severe complication following liver transplantation. The outbreak may not be caused by nosocomial transmission. A decrease in absolute CD19+ B-cell counts may play an important role in the development of Pneumocystis pneumonia.