Vasoepididymostomy (VE) is one of representative methods of vasal repair to get natural conception for patients with obstructive azoospermia (OA). The surgical procedures and techniques of VE are constantly innovated and improved. Several modified single-armed VE techniques with high patency and pregnancy rates have been reported (8–11). In our center, we also attempted to explore modified surgical techniques to improve the rate of spontaneous pregnancy rate (7, 8, 12).
Epididymal obstruction is considered as a common cause of OA, and quite a large part of these patients has an epididymitis history. In a cohort of 110 patients underwent VE, 42% of the patients had a history of epididymitis (13). What’s worse, Binsaleh reported that 83.3% (10/12) of the patients could only underwent unilateral VE due to genitourinary infection (14). With surgical techniques modified and improved, high patency can be also achieved in patients underwent unilateral VE. Recently, multiple reports have showed a patency rate of 45.8–66.7% in unilateral VE (10, 13, 15). In the present study, an overall patency rate of 50.0% (23/46) was achieved, which was consistent with previous studies.
To date, most studies upon unilateral VE have been conducted with small samples. And seldom studies focused on intraoperative findings for unilateral VE. In 2017, Peng et al reported a retrospective study including 51 patients underwent unilateral VE. Contralateral intratesticular obstruction (n = 26) was the main cause of unilateral reconstruction, followed by distal vas deferens obstruction (n = 14), contralateral absent vas deferens (n = 6) and cryptorchidism (n = 5) (16). Different from their research, the current study showed that obstruction in distal of unilateral vas deferens (16/46) was the most common cause, while unilateral intratesticular obstruction was found in only two patients. Notably, 28.4% (13/46) of the OA patients performing unilateral single-armed VE presented with CUAVD, suggesting that CUAVD patients with OA seeking for natural conception is not a small population.
Several studies have compared the clinical outcomes between unilateral VE and bilateral VE (13, 17, 18), however no studies have focused on the efficacy of unilateral VE in OA of different causes. To the best of our knowledge, this is the first study reporting the clinical outcomes of unilateral VE between congenital and acquired OA patients. Our results showed the patency and natural pregnancy rates in CUAVD group and acquired group were 38.5% and 54.5%, 20.0% and 33.3%, respectively. There was no statistical significance of patency and pregnancy rates between the two groups (p > 0.05). These findings suggest unilateral single-armed VE is a feasible option for OA patients with different causes.
Apart from high rates of patency and natural pregnancy, VE has potential benefits over assisted reproductive technology (ART), including low costs, no additional risks to the female partner and fetus and can achieve multiple pregnancies (13, 19). It is suggested that VE should be the first option for epididymal obstruction, not an alternative treatment after ART failure (16). Our results showed unilateral VE could also achieve a satisfactory result, whether in patients with CUAVD-associated or acquired OA. However, ART should be taken into account when making intraoperative and postoperative decisions. In the current study, the epididymal and testicular sperms were cryopreserved during VE as a backup of the procedure. And 13 patients underwent ART after surgery, including 2 couples achieved pregnancy through ICSI using the sperm in the fresh ejaculate. Thus, ART can be a remedy after unilateral single-armed VE for patients.
Our study has several limitations. Given the retrospective design, potential information bias is possible. We failed to collect some important surgical variables, such as operation and patency time. Due to the low incidence of CUAVD, this study contained a small number of patients in CUAVD group. Thus, a prospective, multicenter, and large sample cohort study is needed.