Objective To compare the safety of laparoscopic pancreatoduodenectomy(LPD)and open pancreatoduodenectomy(OPD)and analyze the learning curve and safety at different stages of LPD.Methods A retrospective analysis was conducted on the clinical data of 50 LPD patients and 54 OPD patients in the Department of Hepatopancreatobiliary Surgery of Suzhou Hospital Affiliated to Nanjing Medical University from January 2020 to June 2024,and intraoperative and postoperative conditions were compared.The Cumulative Sum(CUSUM)analysis method was used to analyze the technical nodes of the LPD learning curve.Results There were no significant differences in operation time and intraoperative blood loss between the LPD group and the OPD group(P＞0.05).There was also no significant difference in the incidence rates of pancreatic fistula(grade B and C),delayed gastric emptying,postoperative bleeding,biliary fistula and intra-abdominal infection between the LPD group and the OPD group(P＞0.05).A time series plot of operation time was drawn based on the patient's operation time and surgical sequence,yielding a fitted curve.Curve analysis showed initial stage and stable stage were finished at the 17th and 24th cases.The LPD learning curve could be divided into three stages:stage Ⅰ characterized as the initial stage(cases 1 to 17),stage Ⅱ characterized as the stable stage(cases 18 to 24),and stage Ⅲ characterized as the proficient stage(cases 25 to 50).The operation time in stages Ⅱ and Ⅲ was significantly shorter than that in stage Ⅰ,and the intraoperative blood loss in stage Ⅰ was significantly higher than that in stage Ⅲ(P＜0.05).There was no significant difference in the incidence of complications among the three stages(P＞0.05).Conclusion LPD and OPD show no significant differences in indications and safety.The LPD learning curve can be divided into three stages.As the number of surgeries completed increa-ses,the operation time of physicians gradually shortens,and the incidence of complications of patients gradually decreases.

Objective:To compare the changes of biliary microbiota after enteral extended biliary stents (EEBS) implantation with that of conventional plastic stents in animal experiment, and to preliminarily investigate its possible mechanism in preventing stents occlusion.Methods:A total of 12 healthy Bama minipigs were randomly assigned to the conventional plastic stent group ( n=6) and the EEBS group ( n=6) using simple random method. The bile samples of all pigs were collected before stents implantation and 4 weeks after stents placement. The biliary microbiota composition and diversity before and after different stents implantation were analyzed by 16S rRNA gene sequencing and compared. Results:No complications including acute cholangitis, perforation, bleeding, or death occurred in 12 pigs. Eight days after stents implantation, stents were out of bile duct in all pigs under endoscopy, while the bile samples were collected again for analysis. The main composition of biliary microbiota at the phylum level were Proteobacteria, Firmicutes and Bacteroidota. Alpha-diversities revealed the Shannon ( P=0.004) and Simpson index ( P=0.008) significantly decreased in the conventional stent group after stents placement, and Bata diversity analysis also showed a significant difference in microbial composition (Anosim: R=0.514 8, P=0.011). There was no significant difference in Observed species index ( P=0.095), Chao1 index ( P=0.136), Shannon index ( P=0.353), Simpson index ( P=0.227) or Bata diversity (Anosim: R=0.059 3, P=0.187) in the EEBS group before and after stents placement. LEfSe algorithm indicated Bacteroides_ fragilis and Proteobacteria- Gammaproteobacteria- Enterobacterales- Enterobacteriaceae- scherichia_ Shigella- Escherichia_ coli significantly increased in the conventional stent group, and Desulfobacterota- Desulfovibrionia- Desulfovibrionales- Desulfovibrionaceae- Bilophila significantly increased in the EEBS group after stents placement. Conclusion:The biliary microbiota change slightly after EEBS implantation in the short-term, and EEBS may prevent duodenobiliary reflux by prolonging the reflux path.

Objective To investigate the feasibility of urethral reconstruction by using stretched electrospun silk fibroin matrices.Methods Stretched electrospun silk fibroin matrix was prepared,and the structure of the material was assessed by electron microscopy.Canine urothelial cells were isolated,expanded and seeded onto the material for 1 week to obtain a tissue-engineered graft.The tissue-engineered graft was assessed using HE staining and electron microscopy scanning.A dorsal urethral mucosa defect was created in 9 female beagle dogs.In the experimental group,tissue-engineered mucosa was used to repair urethral mucosa defects in 6 dogs.No substitute was used in the 3 dogs of the control group.Retrograde urethrography was performed at 1,2 and 6 months after grafting.The urethral grafts were analyzed grossly and histologically.Results Electron microscopy scanning revealed that the material had a 3 dimensional porous structure.Urothelial cells grew on the material and showed good biocompatibility with the stretched silk fibroin matrices.Canines implanted with tissue-engineered mucosa voided without difficulty.Retrograde urethrography revealed no signs of stricture,and histological staining showed gradual epithelial cell development and stratified epithelial layers at 1,2 and 6 months.The canines in the control group showed difficulty in voiding.Retrograde urethrography showed urethral stricture,and histological staining showed that no or only one layer of epithelial cells developed.A severe inflammatory reaction was also observed in the control group.Conclusion Stretched electrospun silk fibroin matrices have good biocompatibility with urothelial cells,and could be a potential material for urethral reconstruction.