Bladder perforation during transurethral resection of bladder tumour is not a result of a deficient structure of the bladder wall

Background Transurethral resection of the bladder tumour (TUR) is associated with a risk of bladder perforation. The underlying mechanisms and risk factors are not fully understood. The aim of this study was to determine if the bladder wall structure affects the risk of bladder perforation during TUR. Methods Fifteen patients who underwent TUR complicated by a bladder perforation (group 1) and fifteen matched controls who underwent uncomplicated TUR (group 2) were retrospectively enrolled in this morphological analysis. Surgical specimens were collected from all participating patients to describe the quality and architecture of urothelium and bladder submucosa. Immunohistochemical studies were performed with primary mouse anti-human E-cadherin, beta-catenin, type IV collagen, cytokeratin 20 and epithelial membrane antigen antibodies. The intensity of the immunohistochemical reaction was assessed using an immunoreactive score (IRS). Ultrastructural examinations were performed by transmission electron microscopy. The microscopic assessment was focused on the intensity of fibrosis in the bladder submucosa and the presence of degenerative changes in the urothelium. Results Patients' age, sex distribution, tumour diameters, surgeon experience or cancer stage did not differ between study groups. The immunohistochemical analysis did not reveal statistically significant differences between group 1 and group 2. From a clinical point of view, ultrastructural analysis by electron microscopy showed a higher rate of severe fibrosis in group 1 (63.6% vs. 38.5%), with no differences in the rate and degree of urothelial changes. However, these differences were not statistically significant (p= 0.32). Conclusions Bladder perforation during TUR is not a result of a deficient structure of the bladder wall. Based on available evidence, the surgical technique seems to play the most important role in its prevention.