Vasectomy reversal in humans

Vasovasostomy: A systematic review and meta-analysis comparing macroscopic, microsurgical, and robot-assisted microsurgical techniques

BACKGROUND AND OBJECTIVES

Vasovasostomy is a cost-effective procedure for the reversal of vasectomy. A water-tight adequately blood-supplied mucosal anastomosis is required for better outcomes. This review aimed to compare the outcome of vasovasostomy performed by three different techniques: macroscopic, pure microsurgical, and robot-assisted microsurgical techniques.

METHODS

Scopus, Web of Science, PubMed, Embase, and Cochrane library databases were searched for relevant studies from January 1901 to June 2023. We conducted our quantitative syntheses using the inverse variance method in OpenMeta software. The study's protocol was registered on PROSPERO.

RESULTS

This review involved 95 studies of different designs, with a total sample size of 48,132. The majority of operations were performed bilaterally, and participants were monitored for up to 10 years. The pooled patency rate was the highest following robot-assisted vasovasostomy (94.4%), followed by pure microsurgical vasovasostomy (87.5%), and macroscopic vasovasostomy (83.7%). The pooled pregnancy rate following purely microsurgical vasovasostomy was higher than that of macroscopic vasovasostomy (47.4 vs. 43.7%). Definitive pregnancy rates in robotic vasovasostomy are yet to be determined.

CONCLUSION

Patency outcomes for vasovasostomy were best with robot-assisted microsurgical technique, followed by pure microsurgical technique, and conventional macroscopic technique. Further investigations of robot-assisted microsurgical vasovasostomy outcomes and randomized control trials are required to support this evidence.

Epididymectomy as a novel surgical procedure; application in the domestic cat

Feline overpopulation raises issues concerning health, ecology, economy, and ethics. Procedures to limit overpopulation should carefully address animal welfare, efficiency, costs, and feasibility. Vasectomy in unowned cats is suggested as preferable to standard neutering as it maintains male sexual behaviour which may induce ovulation and pseudopregnancy in intact females and may prevent immigration of other males. Vasectomy is not performed routinely because it is fastidious, time consuming and requires more material than standard neutering. We describe epididymectomy as an alternative. In a first experiment, we analysed semen, testosterone, behaviour and pain in six experimental cats before and after epididymectomy, and after castration two months later. Excised tissues were analysed histologically. Testosterone concentrations did not differ significantly between intact and epididymectomised animals but were significantly different after castration. Sexual behaviour and testicular spermatogenesis persisted after epididymectomy, but with a marked drop in the semen count after 7 days. The Glasgow pain scores did not differ significantly after epididymectomy and castration. In a subsequent experiment, 20 privately owned cats were epididymectomised and castrated immediately afterwards, to analyse the learning curve and perioperative complications. The time required for an epididymectomy was significantly shorter than for castration. The study confirms that epididymectomy is quicker and less invasive than castration, it is associated with minimal risks and post-operative pain while easy to learn and inexpensive. Further field studies are required to test its efficiency for feline feral population control or in other species such as in bears, lions or deer, where infertility is required and castration not wanted.

One-layer macroscopic verus two-layer microscopic vasovasostomy: Our experience in two referral hospitals

Objective:

Vasovasostomy is the most common surgery to restore the fertility of vasectomized men. This study aimed to compare the outcomes of one-layer macroscopic VV (MOLVV) or two-layer microscopic VV (TLMVV)

Methods:

This study was performed on the medical records of 100 patients who underwent VV surgery in two tertiary hospitals from 2014 to 2017. All patient information, including demographic and sperm analysis, was collected. The chi-square test, independent t-test, and survival analysis using Kaplan–Meyer test and Cox regression were performed to analyze the data using SPSS software version 25, and the significance level was considered 0.05.

Results:

The fertility rate in patients of both groups was 15%. The findings showed a statistically significant difference between the mean percentage of normal sperm morphology according to the type of surgery ( p = 0.045). There was no statistically significant difference between the mean sperm count, sperm motility percentage, and mean hospital costs according to the type of surgical procedure ( p > 0.05). The incidence of spouse pregnancy in the TLMVV method after 15 and 24 months was 87.5% and 58.3%, respectively. In patients with unilateral anastomosis, the incidence of pregnancy at 13 and 15 months after surgery was 98.7% and 95.8%, respectively. The mean and median time of pregnancy in the spouses of patients with each surgical shower were 24 and 25 months. Other variables had no significant effect on spouse pregnancy.

Conclusion:

Vasovasostomy with the one and two-layer methods had equal results. The number, movement, and normal morphology of sperm after surgery were low. Therefore, these people will need assisted reproductive techniques.

Physiological Characterization of the Transporter-Mediated Uptake of the Reversible Male Contraceptive H2-Gamendazole Across the Blood-Testis Barrier

The blood-testis barrier (BTB) is formed by a tight network of Sertoli cells (SCs) to limit the movement of reproductive toxicants from the blood into the male genital tract. Transporters expressed at the basal membranes of SCs also influence the disposition of drugs across the BTB. The reversible, nonhormonal contraceptive, H2-gamendazole (H2-GMZ), is an indazole carboxylic acid analog that accumulates over 10 times more in the testes compared with other organs. However, the mechanism(s) by which H2-GMZ circumvents the BTB are unknown. This study describes the physiologic characteristics of the carrier-mediated process(es) that permit H2-GMZ and other analogs to penetrate SCs. Uptake studies were performed using an immortalized human SC line (hT-SerC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Uptake of H2-GMZ and four analogs followed Michaelis-Menten transport kinetics (one analog exhibited poor penetration). H2-GMZ uptake was strongly inhibited by indomethacin, diclofenac, MK-571, and several analogs. Moreover, H2-GMZ uptake was stimulated by an acidic extracellular pH, reduced at basic pHs, and independent of extracellular Na+, K+, or Cl- levels, which are intrinsic characteristics of OATP-mediated transport. Therefore, the characteristics of H2-GMZ transport suggest that one or more OATPs may be involved. However, endogenous transporter expression in wild-type Chinese hamster ovary (CHO), Madin-Darby canine kidney (MDCK), and human embryonic kidney-293 (HEK-293) cells limited the utility of heterologous transporter expression to identify a specific OATP transporter. Altogether, characterization of the transporters involved in the flux of H2-GMZ provides insight into the selectivity of drug disposition across the human BTB to understand and overcome the pharmacokinetic and pharmacodynamic difficulties presented by this barrier. SIGNIFICANCE STATEMENT: Despite major advancements in female contraceptives, male alternatives, including vasectomy, condom usage, and physical withdrawal, are antiquated and the widespread availability of nonhormonal, reversible chemical contraceptives is nonexistent. Indazole carboxylic acid analogs such as H2-GMZ are promising new reversible, antispermatogenic drugs that are highly effective in rodents. This study characterizes the carrier-mediated processes that permit H2-GMZ and other drugs to enter Sertoli cells and the observations made here will guide the development of drugs that effectively circumvent the BTB.

Vasectomy reversal: a review on outcomes using a loupe-assisted vasovasostomy approach

INTRODUCTION

Vasectomy is a popular choice of contraception worldwide. In the UK, vasectomy reversal is not usually licensed under the NHS with reports on outcomes being limited. Microsurgical reversal is a technique commonly performed under the operating microscope. Loupe magnification, however, is emerging as a safe and reliable technique to perform microsurgery.

METHOD

Loupe-assisted microsurgical vasovasotomies were performed on 14 men in a 3-year period. Indications for the procedure were for fertility only. Semen analysis variables were measured against European Association of Urologists (EAU) guidelines at six weeks. Patients were followed-up at clinic in three months. Data were collated using operation notes and cytology results, and analysed using descriptive statistics. Pearson's correlation coefficient was used to compare years after vasectomy, and age to sperm count.

RESULTS

The average sperm count in our group was 41.3 million per millilitre (median 29.95, range 2.7-107.8) at 6 weeks. Seventy-five per cent were found to have positive sperm motility, and all had acceptable sperm morphology at follow-up. A very low to weak correlation between time after vasectomy and age, with sperm count.

CONCLUSION

We have demonstrated that fertility and post-operative outcomes using a loupe-assisted microsurgical vasovasotomy approach are favourable as per EAU guidelines.

Toxicity and Mutagenicity Evaluation Following RISUG Contraception Reversal in Rats

Reestablishment of fertility, after a male contraceptive method, is of great concern. In this context, RISUG (Reversible Inhibition of Sperm Under Guidance) has been evaluated for its mutagenicity following reversibility with dimethyl sulfoxide (DMSO)/sodium bicarbonate (NaHCO3) in Wistar albino rats. Animals were divided into 7 groups, namely, sham-operated control, vas occlusion with RISUG for 90 and 360 days, reversal with DMSO and NaHCO3 after 90 and 360 days, respectively. The testis, cauda epididymis, cauda epididymal spermatozoa, and serum were evaluated for apoptosis and hormonal status through various assays. RISUG was subjected to Ames test at dose levels of 10, 50, and 100 µL. Results of terminal deoxynucleotidyl transferase nick end labeling and caspase-3 assays in testes and cauda epididymis revealed that the percentage of positive cells in the experimental groups was comparable to sham-operated control. Annexin V assay in cauda epididymal spermatozoa showed slight elevation in group II ( P < 0.05), whereas in the remaining groups, minimum numbers of positive sperms were found. Hormone profile, namely, testosterone, prolactin, cortisol, prostate-specific antigen, and sperm antibody concentration, remained unchanged. In Ames test, no significant increase was observed in the number of revertant colonies on plates containing RISUG in the presence and absence of S9 mix in all 3 strains. Therefore, the reversal of RISUG-induced contraception by solvent vehicle DMSO/NaHCO3 was successful without any toxicity at the cellular levels.

Retrospective Review of Surgical Outcomes and Pair-housing Success in Vasectomized Rhesus Macaques (Macaca mulatta)

Providing social housing for adult male macaques can be challenging. One successful strategy for long-term social housing of adult male macaques is to pair them with adult females; however, unwanted breeding must be prevented by sterilization of the male or female. Vasectomy is a simple, highly effective, and minimally invasive method of contraception that is used at our institution to facilitate social housing. We performed a retrospective review to analyze the surgical outcomes and rate of postoperative complications after vasectomy of adult rhesus macaques at our research facility. In addition, we evaluated the success rate of pairing vasectomized macaques with female partners. Over 10 y, 16 macaques were vasectomized, of which 5 developed postoperative complications such as orchitis, epididymitis, or surgical site infection. These complications resolved completely and without incident after antibiotic and analgesic therapy; an additional male had postoperative incisional swelling that resolved quickly after NSAID treatment. This complication rate is consistent with that in humans by surgeons who perform open vasectomies relatively infrequently. In addition, 5 of the vasectomized macaques (31%) developed sperm granulomas, which are a common and generally benign complication in humans and have been reported to develop in 40% of macaques after vasectomy. Successful pair housing with a female partner was achieved for 13 of 16 (81%) of the vasectomized macaques. We conclude that surgical vasectomy is a safe and simple procedure that can be used as a highly effective method to facilitate social housing of adult male rhesus macaques in research facilities.

Incidence of Y-chromosome microdeletions in children whose fathers underwent vasectomy reversal or in vitro fertilization with epididymal sperm aspiration: a case-control study

Objective

To evaluate the incidence of Y-chromosome microdeletions in individuals born from vasectomized fathers who underwent vasectomy reversal or in vitro fertilization with sperm retrieval by epididymal aspiration (percutaneous epididymal sperm aspiration).

Methods

A case-control study comprising male children of couples in which the man had been previously vasectomized and chose vasectomy reversal (n=31) or in vitro fertilization with sperm retrieval by percutaneous epididymal sperm aspiration (n=30) to conceive new children, and a Control Group of male children of fertile men who had programmed vasectomies (n=60). Y-chromosome microdeletions research was performed by polymerase chain reaction on fathers and children, evaluating 20 regions of the chromosome.

Results

The results showed no Y-chromosome microdeletions in any of the studied subjects. The incidence of Y-chromosome microdeletions in individuals born from vasectomized fathers who underwent vasectomy reversal or in vitro fertilization with spermatozoa recovered by percutaneous epididymal sperm aspiration did not differ between the groups, and there was no difference between control subjects born from natural pregnancies or population incidence in fertile men.

Conclusion

We found no association considering microdeletions in the azoospermia factor region of the Y chromosome and assisted reproduction. We also found no correlation between these Y-chromosome microdeletions and vasectomies, which suggests that the assisted reproduction techniques do not increase the incidence of Y-chromosome microdeletions.

Relative suitability of DMSO and NaHCO3 for reversal of RISUG® induced long-term contraception

Among the vas-based methods on trial, reversible inhibition of sperm under guidance (RISUG(®) ), a co-polymer of styrene and maleic anhydride is being projected as an effective alternative to No Scalpel Vasectomy. RISUG offers long-term contraception with safety, efficacy in human trials and can be delivered by no-scalpel injection. Currently, the procedure is under phase-III clinical trial. However, reversal of this vas-based drug-induced contraception needs to be established in animal models prior to clinical trials to ensure its claim as an effective alternative for vasectomy. In the present investigation, the relative suitability of dimethyl sulphoxide (DMSO) and NaHCO3 for RISUG induced long-term vas occlusion reversal was carried out in albino rats. Animals were allocated into four groups (n = 10), viz., sham-operated control (group-I), vas occlusion with RISUG for 360 days (group-II), vas occlusion with RISUG for 360 days and reversal with DMSO (group-III) and vas occlusion with RISUG for 360 days and reversal with NaHCO3 (group-IV). A variable response in fertility was observed in different groups. Absolute sterility in group III at all mating intervals, while, zero percent fertility in groups II and IV following 90 days of occlusion was observed. Following reversal restoration of fertility with DMSO at 45 days, whereas, reversal by NaHCO3 at 30 days was noticed. Ejaculated spermatozoa of RISUG injected and initial intervals of reversed animals exhibited various degrees of abnormalities. The testes exhibited focal degeneration in vas occluded animals. The occluded lumen of the vas deferens contained an eosinated polymer with exfoliated epithelium. Following vas occlusion reversal, a complete regeneration in the vas epithelium was seen. All other parameters remained unaltered. The reversal with NaHCO3 resulted into an early resumption of fertility when compared with DMSO and the procedure found to be successful, feasible and safe up to F1 generation. Thus, RISUG provides a hope for reversible male contraceptives.

Vasectomy reversal: A review of the evaluation, techniques, and outcomes

This review highlights the evaluation and treatment of men who have undergone vasectomy and desire vasectomy reversal to father children. For surgeons offering this treatment, the appropriate evaluation and treatment are crucial for acceptable outcomes. Although variations on surgical approaches have evolved over the years, one constant is the need for a high level of training and skill in microsurgical techniques.

Interpositional substitution of free vas deferens segment autografts in rat: feasibility and potential implications

Background

Insufficient vas length for performing a tension-free vasovasostomy is a problem occasionally encountered by microsurgeons. Herein we evaluated utilization of a non-vascularized vas deferens autograft in a rat model.

Methods

Segments of isolated vas deferens, 2.5 cm in length, were used as bilateral autografts in 15 rats. Each autograft was implanted between the two transected ends of vas deferens using end-to-end anastomosis. Fertility, sperm motility, and graft survival was evaluated and compared with the control group.

Results

At the end of the 3 months, 9/15 (60%) rats were able to breed successfully and 24 (80%) vas grafts were patent and viable. Large granulomata developed at the proximal anastomosis sites in 6 (20%) autografts that failed. Unilateral minimal fluid leakage was observed in 6 (20%) of the proximal (testicular end) anastomosis sites in those rats that were able to breed. Histological evaluations demonstrated that graft survival was associated with mild to severe changes in the structure of the vas autograft. On semen analysis 76% of the sperms in the experimental group had forward motility compared to 78% in the control group (p > 0.05).

Conclusions

Vas autograft can successfully be performed in a rat model with ultimate breeding capability.