In surgical treatment of non-muscle-invasive bladder cancer (BC) the en bloc resection technique – removal of tumour in a single piece with the subjacent muscle (detrusor) – is becoming more widely used. The objective of this review was to assess the oncological efficacy (relapse incidence) and safety (of peri- and post-operative complications) of this technique for various tumour sizes. This systematic review was written in accordance with the PRISMA criteria. The relevant literature published over the past 20 years was chosen in two databases (Medline and Scopus) with the use of the search query “en bloc” and “bladder cancer”. We selected publications that assessed the efficacy and safety of en bloc resection of the bladder wall with non-muscle-invasive tumour, and also publications comparing the efficacy of en bloc резекции resection with that of transurethral resection (TUR) of the bladder. Based on analysis of 18 studies (1592 patients after en bloc resection), the following conclusions were made: the incidence of BC relapses after en bloc resection of the bladder wall (with non-muscle-invasive tumour) is significantly lower than after conventional TUR of the bladder; a practically 100-percent presence of muscle fibers is found in the histological tumour specimen; the frequency of peri- and post-operative complications in en bloc resection is significantly lower as compared with classical TUR; the choice of a power source does not influence the oncological outcomes, but laser en bloc resection is safer than electrical; extraction of tumours with sizes up to 2-3 cm is possible in one piece; tumours of larger diameters should be preliminary fragmented in the bladder cavity; comparison of tumours of various diameters did not reveal any statistical differences between the oncological outcomes of patients. The technique of en bloc resection of the bladder wall with non-muscle-invasive tumour is effective and safe for removal of smaller tumours (~ to 2 cm); as some authors point out, it is also effective in larger tumours but there are no literature evidence sufficient for such an. Key words: systematic review, en bloc resection, non-muscle-invasive bladder cancer
