Laparoscopic Kasai portoenterostomy can be a standard surgical procedure for treatment of biliary atresia

BACKGROUND Biliary atresia(BA)is a rare pediatric disease.AIM To compare the outcomes of laparoscopic portoenterostomy(Lap-PE)with those of laparotomy(Open-PE)at a single institution.METHODS The surgical outcomes of PE were retrospectively analyzed for patients with a non-correctable type of BA from 2003 to 2020.RESULTS Throughout the assessment period,119 patients received PE for BA treatment,including 66 Open-PE and 53 Lap-PE cases.Although the operation duration was longer(medians:for Open-PE,242 min;for Lap-PE,341 min;P<0.001),blood loss was considerably less(medians:for Open-PE,52 mL;for Lap-PE,24 mL;P<0.001)in the Lap-PE group than in the Open-PE group.The postoperative recovery of the Lap-PE group was more favorable;specifically,both times to resume oral intake and drain removal were significantly shorter in the Lap-PE group.Complete resolution of jaundice was observed in 45 Open-PE cases and 42 Lap-PE cases,with no statistically significant difference(P=0.176).Native liver survival rates were>80%for both groups for the first half year post surgery,followed by a gradual decrease with time;there were no statistically significant differences in the native liver survival rates for any durations assessed.CONCLUSION Lap-PE could be a standard therapy for BA.

Novel zinc alloys for biodegradable surgical staples

BACKGROUND The development of biodegradable surgical staples is desirable as non-biodegradable Ti alloy staples reside in the human body long after wound healing, which can cause allergic/foreign-body reactions, adhesion, or other adverse effects. In order to develop a biodegradable alloy suitable for the fabrication of surgical staples, we hypothesized that Zn, a known biodegradable metal, could be alloyed with various elements to improve the mechanical properties while retaining biodegradability and biocompatibility. Considering their biocompatibility, Mg, Ca, Mn, and Cu were selected as candidate alloying elements, alongside Ti, the main material of clinically available surgical staples.AIM To investigate the in vitro mechanical properties and degradation behavior and in vivo safety and feasibility of biodegradable Zn alloy staples.METHODS Tensile and bending tests were conducted to evaluate the mechanical properties of binary Zn alloys with 0.1–6 wt.% Mg, Ca, Mn, Cu, or Ti. Based on the results,three promising Zn alloy compositions were devised for staple applications(wt.%): Zn-1.0Cu-0.2Mn-0.1Ti(Zn alloy 1), Zn-1.0Mn-0.1Ti(Zn alloy 2), and Zn-1.0Cu-0.1Ti(Zn alloy 3). Immersion tests were performed at 37℃ for 4 wk using fed-state simulated intestinal fluid(Fe SSIF) and Hank’s balanced salt solution(HBSS). The corrosion rate was estimated from the weight loss of staples during immersion. Nine rabbits were subjected to gastric resection using each Zn alloy staple, and a clinically available Ti staple was used for another group of nine rabbits. Three in each group were sacrificed at 1, 4, and 12 wk post-operation.RESULTS Additions of ≤1 wt.% Mn or Cu and 0.1 wt.% Ti improved the yield strength without excessive deterioration of elongation or bendability. Immersion tests revealed no gas evolution or staple fracture in any of the Zn alloy staples. The corrosion rates of Zn alloy staples 1, 2, and 3 were 0.02 mm/year in HBSS and 0.12, 0.11, and 0.13 mm/year, respectively, in Fe SSIF. These degradation times are sufficient for wound healing. The degradation rate is notably increased under low pH conditions. Scanning electron microscopy and energy dispersive spectrometry surface analyses of the staples after immersion indicated that the component elements eluted as ions in Fe SSIF, whereas corrosion products were produced in HBSS, inhibiting Zn dissolution. In the animal study, none of the Zn alloy staples caused technical failure, and all rabbits survived without complications. Histopathological analysis revealed no severe inflammatory reaction around the Zn alloy staples.CONCLUSION Staples made of Zn-1.0Cu-0.2Mn-0.1Ti, Zn-1.0Mn-0.1Ti, and Zn-1.0Cu-0.1Ti exhibit acceptable in vitro mechanical properties, proper degradation behavior,and in vivo safety and feasibility. They are promising candidates for biodegradable staples.