A new surgical method of vasoepididymostomy for epididymal obstructive azoospermia to improve the success rate in the rat

Abstract

Background: Two-suture longitudinal intussusception vasoepididymostomy (LIVE) surgery has been confirmed by many studies in the treatment of epididymal obstruction; however, the success rate and anastomotic patency rate are not high, which cannot meet the modern human demand for a cure rate for this disease. Based on our preliminary research, we have reason to speculate that the new 2-suture circular intussusception vasoepididymostomy (CIVE) surgery group can greatly improve the anastomosis rate and success rate of treating epididymal obstruction patients. LIVE has become the preferred technique for epididymal and vas deferens anastomosis in North America, Europe, and globally for 22 years. Compared with LIVE, CIVE can greatly improve the anastomosis and success rate of treating epididymal obstruction patients. The aim of this study is to make CIVE the preferred technique for treating epididymal obstruction in North America, Europe, and globally. CIVE ultimately benefits more patients.

Methods: Thirty-three male rats (type: Sprague-Dawley, SD) were randomly divided into control (group I) and experimental groups (groups II and III). After 3 weeks of epididymal obstruction, bilateral vasoepididymostomy was performed. In group II, the epididymal tubules (the epididymal tubules, which were cut into circular incisions) were punctured and lifted with a suture under a microscope, the vas deferens was incised obliquely at 45° for CIVE. In group III: LIVE was performed. After 3 months, patency was assessed in a blinded manner.

Results: The rates of functional patency (presence of motile sperm in the vas deferens) were 90.9% and 63.6% in groups II and III, respectively (single-tailed test, P=0.042). On retrograde methylene blue vasography of the epididymis, the mechanical patency rate was similar to the functional patency rate. The incidence of sperm granulomas in postoperative groups II and III was 0% and 18.2%, respectively, with a single-tailed test P value of 0.24. Due to insufficient sample size, the sample size can be expanded for further verification in the later stage.

Conclusions: Compared with LIVE, CIVE at a 45° oblique incision of the vas deferens provides a larger anastomotic area and has a higher recanalization rate, which is worthy of further investigation. The aim of this study is to propose a new surgical approach called 'CIVE'. By expanding the anastomotic area to reduce the risk of traditional surgical failure, the ultimate goal is to provide patients with safer and more efficient treatment options.

Keywords: Microscopic vasoepididymostomy; epididymis; microsurgery; obstructive azoospermia (OA).

Figure 1

Schematic diagram of the new surgical procedure CIVE. (A) The vas deferens was cut obliquely at 45°, enlarged by 4×. (B) Another 10-0 stitch was sutured in the middle of the two stitches, enlarged by 15×. (C) The knot was tied and the epididymal duct was lifted, enlarged by 15×. (D) Microscopic scissors were used to cut open the epididymal duct. The circular incision was made, enlarged by 15×. CIVE, 2-suture circular intussusception vasoepididymostomy.

Figure 2

Schematic diagram of suture sequence for new and traditional surgeries. Vas deferens a1 and b1 are the entry points, and a2 and b2 are the exit points. Two 10-0 single-needle nylon sutures were passed from the outside to the inside through the lumen of the vas deferens at the marked points (a1 and b1) and from the inside to the outside through the muscle layer at the marked points (a2 and b2); c: elliptical incision; d: 45° oblique resection of the vas deferens; e: the surgical incision for the epididymal duct was innovatively changed from the traditional linear surgical incision to the circular surgical incision in the new surgical method.

Figure 3

Schematic diagram of traditional LIVE surgical procedures. (A) The vas deferens was cut vertically at 90°, enlarged by 4×. (B) Two needles were inserted and guided in parallel through the epididymal duct, enlarged by 15×. (C) A sharp blade was used to longitudinally cut through the wall of the epididymal duct between the two needles, enlarged by 15×. (D) The linear incision was made, enlarged by 15×. LIVE, 2-suture longitudinal intussusception vasoepididymostomy.

Figure 4

Comparison diagram of CIVE and LIVE anastomosis. A₁', A₂', B₁', and B₂' are the injection points for CIVE, and the red circle represents the CIVE anastomotic site; A₁, A₂, B₁, and B₂ are the injection points for LIVE, and CDC1E is the anastomotic site after the LIVE epididymal duct is pulled into the vas deferens; CC₁ is the linear incision line of the LIVE anastomosis. CIVE, 2-suture circular intussusception vasoepididymostomy; LIVE, 2-suture longitudinal intussusception vasoepididymostomy.

Figure 5

Schematic diagram comparing the anastomosis area between CIVE and LIVE. (A) Retrograde injection of methylene blue into the distal vas deferens, showing the epididymal duct. This represents successful surgery after epididymal vas deferens anastomosis, enlarged by 15×. (B) Retrograde injection of methylene blue into the distal vas deferens, with the epididymal duct not shown, enlarged by 15×. This represents surgical failure. CIVE, 2-suture circular intussusception vasoepididymostomy; LIVE, 2-suture longitudinal intussusception vasoepididymostomy.