En bloc TUR of bladder tumours: a new standard?
Trans urethral resection (TUR) of bladder tumor is one of the most frequent procedures performed in urology. Indeed, it is one of the most controversial . It clearly violates oncological basic principles inasmuch tumor must be fragmented to be resected and retrieved from the bladder. Fragmentation is at the base of two major flaws. First, the pathological examination of the specimen is frankly impaired. Margins cannot be properly assessed and infiltration of the sub-urothelial connective or of the muscular tissue may be underestimated or even missed. Second, seeding of urothelial cancerous cells, which may lead to recurrence, may easily occur after tumor resection and fragmentation. En bloc transurethral resection (EBTUR) is supposed to overcome the major flaws of conventional TUR. It is not a new procedure, since it has been described the first time in 1980 in Japan , but only in the last decade, the interest in technical improvements of TUR has been renewed . We performed a literature review to assess up to date results of EBTUR and to answer the question if EBTUR may be considered as the new golden standard for endoscopic treatment of bladder tumors
Materials and Methods
We performed a systematic review of the available literature about EBTUR. A search across PUBMED was performed with the following keys “bladder cancer” [MESH term] & “en bloc” and “en bloc resection bladder tumor” in July, 20th, 2016. Respectively, 132 and 160 papers were found. After reading the abstract, 118 and 141 were excluded by Authors because they were off topic, reviews and opinions. After matching the list of the remaining 14 and 20 items, 14 were excluded because duplicates, 2 because case reports, and 2 because not written in English. Thus, a list of 16 original papers was included in the review [3-18]. Finally, after reading thoroughly the references of the selected papers, one more significant item was added . Main outcomes were safety (complications rate), pathological assessment (incidence of detrusor muscle in the specimen and rate of appropriate staging), and oncological control (recurrence rate, surgical margins, rate of residual disease)
Overall, 895 patients have been submitted to EBTUR, accounting for 1191 lesions. Forty complications (4%) were computed. Only 10 (1%) were grade III, mostly bladder perforation or bleeding. Fifty-nine conversions (6.5%) to conventional TUR have been reported because of “difficult” locations of tumors or failure to extract the specimen. Several series, accounting for 763 patients, report about incidence of detrusor muscle in the specimen. Overall, 731 (96%) cases with detrusor muscle were computed. Tumor stage remained uncertain only in 12 (1.5%) cases. Follow up data were available for 544 patients. Mean follow up ranged from 9.3 to 40 months. Recurrence rate varied from 6% to 55%. Most of the recurrence occurred outside primary tumor site. Mean weighted follow up across all series was 20 months, whereas overall recurrence rate was 23%.
Conventional TUR of bladder tumor is generally performed with a 24/26 Ch continues flow resectoscope and standard loop. Tumor is fragmented in chips by the “incise and scatter” technique and extracted with a syringe or an Ellik evacuator through the working channel. Cell seeding may occur during resection as well as during extraction of tumor. Moreover, tumor fragmentation impairs pathological examination. There is no clear orientation of the specimen, muscular or sub connective tissue infiltration may be underestimated or even missed as well as a proper assessment of surgical margins is impossible, even if additional biopsies of the resection bed and of perilesional margins are performed. Conversely, EBTUR respects the oncological principle of specimen integrity with a safety margin of healthy tissue. Even if the first paper about EBTUR has been printed in the Eighties , it is yet in its infancy inasmuch only about a thousand of cases have been published up to date. Despite a similar surgical technique, a great variety of equipments for resection and for specimen extraction has been used, adding heterogeneity to the results interpretation [3-19]. Beyond technicalities, two main aspects must be underlined. First, EBTUR is safe; the risk of serious complications is negligible whereas the overall risk of complications is comparable to historical TUR series . Second, pathological assessment is by any means far more precise. The incidence of detrusor muscle in the specimen, about 95%, and the rate of appropriate staging, about 99%, are really high if compared to standard TUR [20,21].
EBTUR is safe and feasible. Pathological assessment of en bloc specimen makes the difference with respect to conventional TUR, even if a clear statement on the matter has still to be reported by pathologists, who should change their way of describing the specimen, including margins as in whatever oncological histology report. Indeed, no advantages in terms of recurrence rate have been yet disclosed. What we do really need now is a standardization of the technique, especially when it comes to specimen extraction, and larger randomized study, adequately designed to observe an oncological advantage. In the meanwhile, when it is possible, every urologist should adopt EBTUR to ensure the best histological assessment possible.
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