AB213. Study on the applied anatomy of the ejaculatory duct region

Objective: The anatomic and physiological data of ejaculatory duct area are controversial in previous reports. The technique of seminal vesiculoscopy depends on the correct and deeper understanding of the anatomical characteristics of this region. The goal of the study is to achieve the accurate physiological data of the ejaculatory duct area.

Methods: Forty six cases of intact postoperative histological specimens come from 35 cases of prostate cancer (Pca) and 11 cases of bladder cancer (Bca) treated by laparoscopic radical prostatectomy (LRP) or cystectomy (LRC) since October 2012 to February 2015 were acquired and their anatomical data of the seminal vesicle, vas deferens ampulla and ejaculatory duct were carefully measured. The morphological characteristics of prostatic utricle and the relationship with the bilateral ejaculatory duct orifice were observed under transurethral endoscopy by using 109 BPH patients when they treated by TURP in our hospital since June 2013 to August 2014.

Results: The measurement to the 46 cases of Pca or Bca specimens showed that: the lengths of the seminal vesicle are (39.7±7.4) mm on left side and (41.4±8.6) mm on right side; the widths of the seminal vesicle are (16.5±3.3) mm on left side and (16.4±3.0) mm on right side; the thickness of the seminal vesicle are (7.8±2.4) mm on left side and (7.8±2.3) mm on right side. The lengths of the vas deferens ampulla are (16.7±2.4) mm on left side and (16.2±2.3) mm on right side; the circumference of the vas deferens ampulla are (11.3±2.2) mm on left side and (11.4±2.2) mm on right side. The lengths of ejaculatory duct are (15.0±2.5) mm on left side and (14.9±2.4) mm on right side; the diameter of ejaculatory duct are (1.2±0.2) mm on left side and (1.1±0.2) mm on right side. The prostatic utricle could be found in 47.8% (22/46) cases with the depth of (6.7±1.7) mm. Prostatic utricle is usually located at the midline of prostate near the verumontanum level and at the plane between the bilateral ejaculatory ducts. The endoscopic observation to 109 cases of BPH patients showed that 78.9% (86/109) cases have obvious prostate utricle openings located at the top of the verumontanum, while 21.1% (23/109) cases did not show obvious prostate utricle openings. The ejaculatory duct orifices were located at bilateral sides with about 2 mm away from the prostatic utricle openings and they formed a triangular or being linear arrangement. Equilateral triangle location accounted for 44.2% (38/86) of cases, inverted triangle location accounted for 25.6% (22/86) and transverse or oblique rectilinear accounted for 30.2% (26/86) of cases.

Conclusions: The physiological data of ejaculatory duct area is valuable for the differentiation of physiological and pathological situation. The anatomical structure especially the prostatic utricle and ejaculatory duct is dedicated and may be variable which need to be pay more attention when perform the seminal vesiculoscopy or related procedure in this region.

Keywords: Seminal vesicle; ejaculatory duct; anatomy; cyst