Soria Federico, Sánchez Francisco M, Sun Fei, Ezquerra Javier, Durán Esther, Usón Jesús
Endoscopy Department, Minimally Invasive Surgery Centre, Campus Universitario, Av. de la Universidad s/n, Cáceres, Spain.
Cardiovasc Intervent Radiol. 2005 Nov-Dec;28(6):773-8. doi: 10.1007/s00270-004-0266-3.
The aim of the study was to determine the optimal stent size and stenting duration following retrograde endoureterotomy of experimental ureteral strictures. Twenty healthy Large White female pigs were randomly divided into four groups, depending on stent size (7F vs 14F) and stenting duration (3 weeks vs 6 weeks). Three additional pigs were used as the control group. The internal ureteral diameter was measured 2 cm below the lower pole of the right kidney. Histopathological changes of the urinary tract, ultrasonographic and fluoroscopic studies, urine culture, and serum urea and creatine levels were analyzed during the different phases of the study. The study was divided into three phases. Phase I included premodel documentation of the normal urinary tract and laparoscopic ureteral stricture creation. During the second phase 1 month later, the diagnosis and endourologic treatment of strictures were performed. Phase III began 4 weeks after stent removal; follow-up imaging studies and postmortem evaluation of all animals were performed. Ureteral strictures developed in all animals 4 weeks after model creation. Results from ureteral diameter measurements and pathological studies revealed no statistically significant intergroup differences. However, prevalence of urinary infection proved to be directly related to stent size (14F) and permanence (6 weeks). The chi square results suggest a statistically significant relationship between the urinary tract infection and recurrent strictures (alpha = 0.046). We recommend the use of 7F stents for a period of 3 weeks or less, as these are more easily positioned and result in the reduction of secondary side effects (lower infection rate, less intramural ureteral lesions). A significant relationship between urinary tract infection and stricture recurrence was found in this experimental study.
本研究的目的是确定实验性输尿管狭窄逆行输尿管内切开术后的最佳支架尺寸和支架置入持续时间。20只健康的大白母猪根据支架尺寸（7F与14F）和支架置入持续时间（3周与6周）被随机分为四组。另外三只猪作为对照组。在右肾下极下方2厘米处测量输尿管内径。在研究的不同阶段分析了尿路的组织病理学变化、超声和荧光透视检查、尿培养以及血清尿素和肌酐水平。该研究分为三个阶段。第一阶段包括正常尿路的模型前记录和腹腔镜输尿管狭窄的创建。在1个月后的第二阶段，对狭窄进行诊断和腔内泌尿外科治疗。第三阶段在取出支架4周后开始；对所有动物进行随访影像学研究和尸检评估。模型创建4周后所有动物均出现输尿管狭窄。输尿管直径测量和病理学研究结果显示组间无统计学显著差异。然而，尿路感染的发生率被证明与支架尺寸（14F）和留置时间（6周）直接相关。卡方检验结果表明尿路感染与复发性狭窄之间存在统计学显著关系（α = 0.046）。我们建议使用7F支架3周或更短时间，因为这些支架更容易放置，并能减少继发性副作用（感染率更低，输尿管壁内病变更少）。在本实验研究中发现尿路感染与狭窄复发之间存在显著关系。
