Despite the rapid development of ultrasound medicine, semen analysis and radiology, it is still not possible to clearly diagnose the cause and location of obstruction in obstructive azoospermia preoperatively, so intraoperative vas deferens exploration with a logical exploration strategy is imperative. Obstruction can occur in any part of the entire vas deferens tract, starting from the testicular network, the caudal part of the epididymal head and body, and the vas deferens to the ejaculatory duct. Congenital bilateral vasovagal agenesis with typical clinical features, inaccessible vas deferens or epididymis on examination, low semen volume, low semen pH, and normal testicular volume, is not difficult to diagnose [6]. However, patients with unilateral vasovagal agenesis can also have obstruction of the vas deferens tract on the healthy side due to acquired factors and present with obstructive azoospermia [7]. It is suggested that azoospermia patients with CUAVD may be due to acquired obstruction of the contralateral vas deferens tract and still have a chance of surgical recanalization. Intraoperative exploration revealed that CUAVD could be combined with distal obstruction of the healthy vas deferens or obstruction of the healthy epididymis, and there could be a chance to perform vasovas deferens (V-V) anastomosis or vasovas deferens-epidididymis (V-E) anastomosis, and two out of the five patients obtained natural pregnancy, meanwhile, three cases underwent sperm retrieval + freezing due to the impossibility of anastomosis, so the patients with CUAVD should be carefully identified preoperatively according to the characteristics of the semen and ultrasonography, etc., to avoid unnecessary surgical Probing. Inguinal hernia surgery in children is a common medical cause of vas deferens obstruction, and the incidence of spermatic obstruction in infertility-seeking men with a previous history of inguinal hernia surgery was 26.7%, and the distal end of the vas deferens may be in the internal inguinal ring or the internal ring (56.7%), or there may be a defect, which may be concomitantly secondary to epididymal obstruction [8]. We have reported OA due to medically induced vas deferens injury after surgery in the inguinal region, where the ends of the obstruction site were explored directly through the original incision and vasovasostomy was performed [5]. Inguinal hernia surgery may not always be the cause of OA, and there may be primary or secondary obstruction of the epididymis following vas deferens injury. Since obstruction of the inguinal segment of the vas deferens is not identified preoperatively, it is debatable whether to directly explore the inguinal segment. The first exploration through scrotal incision, the surgical access is simple, if the distal end of the vas deferens is patent then there is no need to open the groin, if it is obstructed, then consider another inguinal canal incision to explore the spermatic tract. The severed end of the vas deferens after injury may retract above the internal ring opening, making exploration and anastomosis more difficult and requiring laparoscopic assistance to free the vas deferens stump [9]. Vas deferens injury due to inguinal hernia surgery is not only due to severance, clamping or electrocoagulation, but also fibrosis due to tension-free repair of the patch may cause obstruction of the spermatic tract, and how to protect the vas deferens during inguinal hernia surgery deserves attention [10]. The small caliber of the distal vas deferens found during exploration may be due to the inability of growth factors or androgens in the semen to act locally. Surgical exploration revealed postoperative OA after inguinal hernia alone in 15 cases, postoperative inguinal hernia combined with epididymal obstruction in 5 cases, and combined with CUAVD in 3 cases. Postoperative recanalization was observed in 11 cases and spontaneous pregnancy in 5 cases. OA without clear vasovagal factors is often difficult to determine the cause of obstruction by auxiliary examination preoperatively, and the 12 cases of OA without obvious cause of obstruction preoperatively in this study had different locations of obstruction on intraoperative exploration. If the distal vas deferens obstruction detected by intraoperative exploration, the site of obstruction could be detected by epidural catheter, and the surgical incision could be changed to continue the exploration according to the location of obstruction. For complex OA with multiple obstructions in the vas deferens or asymmetry between the two sides, the recanalization rate can be improved by using cross anastomosis according to the intraoperative exploration. A distal vas deferens obstruction with a proximal contralateral vas deferens obstruction suggests the use of a vas crossover anastomosis (see Fig. 2), which can result in a higher recanalization rate compared with vas deferens epididymal anastomosis, and one of the three patients with a crossover VV anastomosis achieved a spontaneous pregnancy. In OA that was confirmed to be unsuitable for recanalization after exploration, testicular sperm retrieval was recommended to be frozen for assisted reproductive use to avoid re-surgical sperm retrieval [11]. Due to the limitation of double-needle sutures in China, single-needle vasovaso-epididympanic anastomosis is more widely used, and considerable surgical success rates have been obtained as surgical skills have improved [3, 12, 13]. Micro VE anastomosis for OA has been gradually carried out in several units in China [12, 14, 15], which has enriched the treatment of OA and accumulated more and more experience in complex OA. In our group, cross VE anastomosis was used in 2 cases: 1 case of distal vas deferens with ipsilateral epididymal caudal obstruction and contralateral epididymal head obstruction was treated with caudal vas deferens epididymal anastomosis (see Fig. 3), and recanalization was confirmed by postoperative semen examination; 1 case of distal vas deferens with ipsilateral epididymal somatic obstruction and contralateral epididymal head obstruction was treated with vas deferens epididymal somatic anastomosis and no sperms were seen in the postoperative semen examination. No spermatozoa were seen. The different postoperative prognosis may be related to the different sites of epididymal anastomosis [16].Sabanegh [2] used vaso-epidididympanic cross-anastomosis in 10 patients with unilateral vasovasal obstruction with contralateral testicular pathology, and 8 cases were recanalized postoperatively. Obstructive azoospermia after inguinal hernia surgery was handled with vasovaginal anastomosis according to intraoperative exploration, and some recanalization rate could be obtained by vasovaginal cross-anastomosis and vasovaginal epididymal cross-anastomosis [13]. When anastomosis is not possible, testicular sperm retrieval and freezing for assisted reproductive use is recommended to avoid re-surgical sperm retrieval [11]. Complex obstructive azoospermia with vasovagal factors can be treated with microscopic recanalization based on strict preoperative evaluation and intraoperative exploration, and the chances of obtaining a spontaneous pregnancy after the operation, and cross-microscopic anastomosis is an effective means of recanalization of the complex spermatic ducts, which is worthy of further promotion and application.