腹主动脉球囊阻断术在复杂盆腔肿瘤手术中的应用

目的:探讨腹主动脉球囊阻断术在复杂盆腔肿瘤手术中的安全性及临床应用价值。通过分析术中阻断时间、次数、失血量、术前术后血红蛋白、pH值等指标的变化,评估该技术在复杂盆腔肿瘤手术中应用的安全性及有效性,分析阻断次数和时间对手术出血等方面的影响,为该技术推广应用提供依据。方法:收集2013年3月至2019年11月间在湖北省肿瘤医院经腹主动脉球囊阻断术介导行骨盆、骶骨等盆腔肿瘤切除术患者的病例资料;按照阻断时间(≤60 min或>60 min)和阻断次数分成2组。A组(21例):阻断时间(≤60 min)、阻断次数1次,B组(9例):阻断时间(>60 min)、阻断次数1次或以上。其中A组10例、B组4例因瘤体较大或血供丰富行术前经皮造影瘤体栓塞;统计分析术中阻断时间、次数、失血量,手术前后血红蛋白及pH值等数据,比较阻断时间、次数等对失血量、血红蛋白等指标的的影响。结果:所有患者均完成肿瘤整块或分块切除及重建,重建方式包括3D打印半骨盆假体置换、普通假体和钉棒系统固定,所有病例中阻断次数最多达3次,最长累计阻断时间达140 min,平均阻断时间(57.30±26.88)min,手术出血量400~7500 mL,所有患者手术及术后恢复顺利。阻断时限在≤60 min的患者在术中出血量、血红蛋白降低等指标上明显优于阻断时间在>60 min和多次阻断的患者,差异具有统计学意义(P<0.05),阻断超过60 min以及多次阻断的患者手术平均出血量是阻断时限在≤60 min患者的1.5倍以上(P<0.05)。结论:腹主动脉球囊阻断术在骨盆环手术中有良好的安全性及可操作性,把握好阻断时间及阻断次数,尽量将累计阻断时间控制在60 min以内对于减少术中出血,降低出血相关风险有重要意义,应重视术前筛查、术中充分止血和血液相关指标的监测和管理,该技术具有良好的安全性,临床应用价值较高,值得推广。

Analysis and performance test on dynamic seed corn threshing and conveying process with variable diameter and spacing

In order to further reduce the damage rate in threshing seed corn,a seed corn threshing testbed with variable diameter and spacing that can realize dynamic adjustment of parameters,such as feed quantity,rotating speed of the threshing device,threshing spacing of the threshing units,was designed in this research.The software of finite element analysis ANSYS Workbench was applied to do modal analysis on the threshing axis designed for variable diameter and spacing of seed corn.The first 8 orders of natural frequencies were distributed in 201.12-1640.20 Hz,with corresponding vibration amplitude in 5.86-27.04 mm,showing reasonable structural design of the threshing axis,which could realize effective seed corn threshing and conveying.Discrete element method was applied to do simulation analysis on the seed corn threshing and conveying process with variable diameter and spacing.Under the condition of different feed quantity,different rotating speed of the thresher,the moving speed of corn clusters and contact force among clusters were measured through simulation,and the working characteristics of the threshing testbed for low-damage and dynamic threshing and conveying of seed corn with variable diameter and spacing were revealed.Working performance test results of the testbed of seed corn with variable diameter and spacing showed that,when the rotating speed of the threshing axis was 190-290 r/min,feed quantity was 1.80-3.80 kg/s,the damage rate of seed corn was 0.32%-0.63%,threshing rate was 99.20%-99.82%,and content impurity rate was 4.23%-5.86%,the mass of threshed corn grains first increased and then decreased along the axial direction.The test verification process was in line with the simulation results;thus,the test results could satisfy the requirements in design and actual operation.