目的：膀胱癌是泌尿系统最常见的恶性肿瘤之一，发病率常年居全球癌症的前十位。对于肌层浸润性膀胱癌，根治性膀胱切除术 (radical cystectomy，RC) 仍为标准术式。RC存在较多并发症，主要包括：术后腹胀（postoperative abdominal distention，PAD）、术后肠梗阻（postoperative ileus，POI）和术后感染等，其中术后感染可大致表现为两次高峰。目前已知研究主要聚焦在POI的危险因素分析和预防，以及基于血、尿培养监测的术后第一次感染高峰，忽略了PAD的发生发展及其与POI的关系，以及拔除输尿管支架管后继发的泌尿系感染（urinary tract infection，UTI）出现。本研究分两个部分，第一部分旨在通过回顾性研究，分析RC术后PAD、POI发生的危险因素，验证PAD与POI发生的关系。第二部分目的为呈现输尿管支架管拔除后UTI发生的危险因素，总结致病菌谱及敏感药物。

方法：第一部分研究，通过回顾性病例队列研究总结临床、实验室检查资料，分析RC术后PAD、POI发生危险因素，探究POI发生与PAD之间的联系。第二部分研究，通过前瞻随机队列比较药敏实验结果差异，分析拔管后UTI发生的危险因素，呈现具备统计学意义的临床药物治疗方案及拔管后泌尿系感染的致病菌谱。

结果：PAD的发生率为38.06%，多元Logistic回归分析显示，慢性便秘史、泻药剂量增加和术后延迟下地活动是PAD发生独立危险因素；POI的发生率为30.77%，慢性便秘史、泻药剂量增加、既往腹部手术史和术后延迟下地活动是POI的发生独立危险因素。共计94人发生了PAD，76人发生POI。50人为合并POI与PAD，PAD与POI的发生存在联系（P＜0.001）。感染方面，实验组导管尖端培养阳性17人（56.67%），最终发生感染8人（26.67%）；对照组导管尖端培养阳性19人（63.33%），实际发生感染14人（46.67%），拔管6小时内应用碳青霉烯类抗生素可以显著降低拔管后UTI发生的风险（P=0.038，OR=2.414）。体重指数增加、糖尿病史、术前白蛋白水平降低、术后返回ICU是拔管后UTI发生的独立危险因素。最常见的拔管后UTI致病菌为大肠埃希菌及肠球菌。拔管后血培养找致病菌，存在一定假阳性率和滞后性。

结论：通过对慢性便秘的纠正及适当减少术前肠道准备用药量，敦促患者下地活动，可能有助于减少PAD和POI的发生。拔管时应用碳青霉烯抗生素可以降低拔管后UTI发生的风险。对于肠道尿流改道的RC术后患者，推荐在拔管同时留取导管尖端培养及药敏，以便指导后续治疗。

Objective Bladder cancer is one of the most common malignancies in the urinary system, with an incidence ranking among the top ten cancers worldwide. Radical cystectomy (RC) remains the standard procedure for muscle invasive bladder cancer. However, RC is associated with several complications, including postoperative abdominal distention (PAD), postoperative ileus (POI), and infection. While the first peak of infection is typically monitored via blood and urine cultures, research has primarily focused on identifying the risk factors for and prevention of POI, overlooking the relationship between PAD and POI, as well as the occurrence of the second peak of infection, which majorly is urinary tract infection (UTI) after the removal of the ureteral stent. This study aims to analyze the risk factors for PAD and POI after RC through a retrospective study and summarize the prevention and treatment strategies for POI. Additionally, this study aims to identify the risk factors for UTI after the removal of ureteral stents, characterize the spectrum of pathogens causing UTI, and evaluate the effectiveness of sensitive antibiotics.

Methods The first part of the study involved a retrospective analysis to summarize clinical and laboratory data, identify the risk factors for PAD and POI after RC, and explore the relationship between PAD and POI. The second part of the study involved a prospective randomized trial to compare intervention outcomes, analyze the statistical significance of the interventions, and identify the risk factors for UTI after the removal of ureteral stents. The spectrum of pathogens causing UTI and their sensitivity to antibiotics were also characterized.

Results The incidence of PAD was 38.06%. Multivariate logistic regression analysis showed that a history of chronic constipation, increased laxative dose, and delayed ambulation after surgery were independent risk factors for PAD. The incidence of POI was 30.77%. Independent risk factors for POI included a history of chronic constipation, increased laxative dose, previous abdominal surgery, and delayed ambulation after surgery. A total of 94 patients developed PAD, while 76 patients developed POI. Among them, 50 patients had both POI and PAD, indicating an association between the occurrence of PAD and POI (P<0.001). Regarding infections, 17 patients (56.67%) in the experimental group had positive cultures at the catheter tip, and 8 patients (26.67%) eventually developed infections. In the control group, 19 patients (63.33%) had positive cultures at the catheter tip, and 14 patients (46.67%) developed infections. The use of carbapenem antibiotics within six hours of ureteral stents removal significantly reduced the risk of UTI (P=0.038, OR=2.414). Increased body mass index, history of diabetes, preoperative hypoalbuminemia, and postoperative return to the ICU were independent risk factors for it. The most common pathogens causing UTI were Escherichia coli and Enterococcus. The blood culture for identifying pathogenic bacteria after catheter removal may have a certain false positive rate and lag time.

Conclusion Correcting chronic constipation, reducing the use of preoperative bowel preparation drugs, and promoting postoperative mobilization may help reduce the incidence of PAD and POI. The use of carbapenem antibiotics during ureteral stents removal could reduce the risk of UTI, and for patients undergoing RC with intestine related urinary diversion, collecting and testing the tips of the ureteral catheters while removing stents is recommended.