Abstract: Objective： To assess the relationship between recovery of urinary continence after laparoscopic radical prostatectomy (LRP) and prostatic volume (PV) and intravesical prostatic protrusion length (IPPL) on preoperative magnetic resonance imaging (MRI). Methods: 88 patients with pathologic confirmed prostate carcinoma who were underwent LRP were included in this study. MRI examination was performed in 1 week before the biopsy. The patients were divided into two groups according to PV (＜50 mL, ≥50 mL) on preoperative MRI. The patients were divided into two groups according to IPPL (＜5 mm, ≥5 mm), IPPL was measured on MRI as the vertical distance from the tip of the protru-ding prostate to the base of the urinary bladder. After surgery we recorded and analyzed recovery of urinary continence of the patients for one year. Results: All the 88 patients received extra-peritoneal LRP successfully. The average operation time was (155±67) min, and the estimated blood volume was (145±159) mL. There was a significant difference between group PV＜50 mL and ≥50 mL in the operation time (P=0.045). All the patients who underwent MRI preoperatively showed that their mean PV was (44.54±26.58) mL and mean IPPL was (5.2±5.7) mm. The continence rate for all the patients after LRP was 53.4%, 84.1% and 94.3% in their follow-up of 3, 6 and 12 months. Three months after LRP, the continence rate for group PV＜50 mL and ≥50 mL were 61.5% and 30.4%, which were completely continent (P=0.010). Six or twelve months after surgery, the continence rate was 87.7％ and 73.9％ (P=0.120), 96.9％ and 87.0％ (P=0.076) for group PV＜50 mL and ≥50 mL separately. Three months after LRP, the continence rate for group IPPL＜5 mm and ≥5 mm were 66.1% and 31.3%, which were completely continent (P=0.002). Six months after surgery, the continence rate was 92.6％ and 68.8％ (P=0.003), and one year after surgery, the continence rate was 98.2％ and 87.5％ for group IPPL＜5 mm and ≥5 mm separately (P=0.037). There was a significant difference between group PV＜50 mL and ≥50 mL in the urinary continence curve (P=0.017), and the same significant difference between group IPPL＜5 mm and ≥5 mm (P=0.001). Conclusion: The PV and IPPL on preoperative MRI were associated with significantly slower return of urinary continence, especially for early recovery (3 months) of continence after LRP.

Key words: Prostatic neoplasms, Prostatectomy, Incontinence