Testicular vasal diameter: A new intra-operative predictor of vasectomy reversal success?

Background: Vasectomy reversal (VR) can be a challenging surgery and numerous factors have been identified to guide surgical decision-making to optimize success.

Objectives: The objective of this study was to identify pre-operative and intra-operative factors associated with VR surgical method and success. Additionally, we aimed to investigate the role of testicular vas deferens diameter in surgical decision-making and success.

Materials and methods: This study was a retrospective cohort of men >18 years of age who underwent a VR at our Institution from January 2008 to June 2023. Qualified patients underwent chart review and details recorded included age, obstructive interval, surgical technique, vasal lumen diameters, presence of sperm granuloma or surgical clips, sperm quality, and vasal fluid quality. Semen analysis (SA) parameters were also recorded. Pregnancy outcomes were ascertained via telephone interview. Descriptive statistics and correlations were analyzed with two-sample t-tests for continuous and chi-square or Fisher's exact tests for categorical characteristics. Logistic regression using generalized estimating equation (GEE) methods was used to estimate associations of diameter with surgery types unadjusted and adjusted for patient and intra-operative fluid characteristics.

Results: A total of 710 patients underwent VR during the study period and 326 post-operative semen analyses were available for review. Average patient was 38 years old, with an obstructive interval of 10 years. Vasoepididymostomy (VE) had modestly larger observed mean testicular vasal lumen diameter (0.94 mm) versus vasovasostomy (VV; 0.88 mm; p = 0.10). However, diameter ≥1 mm was associated with >2 times higher odds of VE versus VV (odds ratio [OR] 2.12; p < 0.01) adjusted for several patient characteristics. VE was associated with lower frequency of positive post-operative semen analyses (64.4% VV/VE or bilateral VE vs. 92.4% bilateral VV), and longer obstructive interval (11.5 years VV/VE or bilateral VE vs. 7.84 years bilateral VV). There were higher rates of spermatozoa on post-operative SAs when bilateral VV was performed (VV/VV 92.3%; VV/VE 73.3%; VE/VE 51.5%; p < 0.001). Of the 207 patients with pregnancy data, 103 (49.8%) experienced pregnancy following VR.

Discussion and conclusion: Intra-operative measurements of testicular vasal lumen diameter can be an adjunctive factor that may influence choice of VR technique. This finding can help guide pre-operative surgical counseling and VR success rates.