En-bloc Resection: The standard technique of tumor resection in fractions ignores the oncologic principle of negative surgical margins. This theoretically, causes liberation of tumour cells into the irrigation fluid, which facilitates their implantation, and potential leads to early recurrence. Furthermore, this can significantly impair pathological assessment and staging. In contrast, the En-bloc resection offers complete removal of the tumor in one piece, with safe oncologic margins, and enabling simple pathologic staging (Figure 1). Different En-bloc resection techniques utilizing monopolar or bipolar current, Thulium-YAG or Holmium-YAG laser have been described. Hydro dissection using a submucosal injection via needle or water jet, might facilitate resection within the right layer. This will enable immediate differentiation between T1 and T2 tumours, due to the elevation of the mucosa when no muscle infiltration or scarring is present.
In the En-block technique a circular incision is made in the mucosa around the tumour. Subsequently, the tumour is dissected En-bloc including its muscle layer. Afterwards, the specimen is retrieved using a forceps, basket or extraction bag. The technique is characterized by high quality resected specimens with the presence of detrusor muscle in 96-100% of cases [1-4]. Additional advantages include decreased bleeding and obturator nerve perforation rates. According to a recent meta-analysis, En bloc resection is associated with shorter hospitalization and catheterization times [5]. However, the size and location of the tumor will affect the success rate of this En block technique. Harvesting larger tumors and treatment of tumours located near the bladder neck, are particularly challenging. Randomized controlled studies are needed to objectively asses and demonstrate the superiority of this technique.
Figure 1: Moving from the standard incision and fragmentation TURBT technique to the En-block technique:
Speaker: Udo Nagele, MD, Professor, Department of Urology and Andrology. General Hospital Hall in Tirol, Austria
Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan at The 15th Meeting of the EAU Section of Oncological Urology ESOU18 - January 26-28, 2018 - Amsterdam, The Netherlands
References
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4. Zhang XR, Feng C, Zhu WD, Si JM, Gu BJ, Guo H, Song LJ, Li C (2015) Two Micrometer Continuous-Wave Thulium Laser Treating Primary Non-Muscle-Invasive Bladder Cancer: Is It Feasible? A Randomized Prospective Study. Photomedicine and laser surgery 33 (10):517-523. doi:10.1089/pho.2015.3913
5. Wu YP, Lin TT, Chen SH, Xu N, Wei Y, Huang JB, Sun XL, Zheng QS, Xue XY, Li XD (2016) Comparison of the efficacy and feasibility of en bloc transurethral resection of bladder tumor versus conventional transurethral resection of bladder tumor: A meta-analysis. Medicine 95 (45):e5372. doi:10.1097/md.0000000000005372