Laparoscopic pelvic lymph node dissection system based on preoperative primary tumour stage (T stage) by computed tomography in urothelial bladder cancer: results of a single-institution prospective study

Abstract

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Bladder cancer (BC) is a public health problem throughout the world, and now radical cystectomy (RC) has been introduced as a standard treatment for BC invading muscle and some BCs not invading muscle. Pelvic lymph node dissection (PLND) is considered an integral part of RC for its prognostic and therapeutic significance, but the extent of the PLND has not been precisely defined. Computed tomography is considered one of the most preferable methods to assess the BC stage preoperatively because of its high sensitivity and specificity. However, there are few articles referring to CT as an aid in deciding the extent of lymphadenectomy during RC. In the present study, we prospectively studied the clinical value of preoperative CT staging of primary tumours in deciding the extent of PLND during laparoscopic RC in the management of BC. The preliminary findings suggested that all patients with higher preoperative CT stage should be given super-extended PLND during RC. For those with lower CT stage, careful and thorough clearance of all lymphatic and adipose tissues within the true pelvis could be more helpful than super-extended PLND.

Objective: To study prospectively the clinical value of preoperative spiral computed tomography (CT) staging of primary tumours in deciding the extent of pelvic lymph node dissection (PLND) during laparoscopic radical cystectomy (RC) in the management of bladder cancer (BC).

Patients and methods: Between January 2010 and December 2011, a total of 63 patients with urothelial BC received laparoscopic RC, super-extended PLND and ileac conduit. The super-extended PLND removed all lymphatic tissues in the boundaries at the level of the inferior mesenteric origin from the aorta (cephalad), the pelvic floor (distally), the genitofemoral nerve (laterally) and the sacral promontory (posteriorly). All of the operations were performed by one experienced surgeon, and all harvested lymph nodes were submitted separately. CT was used to evaluate the preoperative CT stage (CTx) of each primary bladder tumour.

Results: All patients were divided into five categories according to their CTx stages: three at CT1, seven at CT2a, 38 at CT2b, seven at CT3b, and eight at CT4a. All 63 procedures were completed successfully without any conversion to open surgery. The mean estimated blood loss was 450 mL, and 14 patients (22.2%) had postoperative lymphatic leakage. Each case was pathologically confirmed as transitional cell carcinoma with negative margins at the urethral and ureteric stumps. None of the patients with a low CTx stage (CT1-CT2a) had positive lymph nodes above the level of the common iliac artery bifurcation. There was no jump lymph node metastasis, and no positive lymph node was detected above the level of aortic bifurcation in all cases.

Conclusion: Based on the preoperative CT staging, urological surgeons can determine the boundaries of PLND to reduce intraoperative injury and postoperative complications in patients with BC, especially those at the lower CTx stages (CT1 and CT2a).