BACKGROUND: Previous reports have shown a potential causal impact of vasectomy on prostate cancer (PCa). The objective of this study was to investigate the association between vasectomy and PCa, while evaluating the influence of confounding factors such as prostate-specific antigen (PSA) screening and body mass index (BMI).
METHODS: Mendelian randomization (MR) study using summary statistics from genome-wide associations of vasectomy (462,933 European ancestry), ever had PSA test (200,410 European ancestry), time since last PSA test (46,104 European ancestry), BMI (152,893 European males) and PCa (79,148 cases, 61,106 controls, European ancestry). This study was conducted using summary statistic data from large, previously described cohorts. Data analyses were conducted from November 2022 to June 2023.
RESULTS: Genetic liability to vasectomy was not associated with PCa (OR = 0.07, 95% CI: 2.95  ×  10-3 , 1.54, p = 0.09). Genetic liability to vasectomy was not associated with ever had PSA test (OR = 1.08, 95% CI: 0.49-2.39, p = 0.83) and time since last PSA test (OR = 2.49, 95% CI: 0.71-8.79, p = 0.16). After controlling for PSA test and BMI, there remains no causal relationship between vasectomy and PCa risk (OR = 5.56  ×  10-4 , 95% CI: 7.29  ×  10-8 , 4.24, p = 0.10). The reverse MR results showed a weak association between PCa and vasectomy patients (OR = 1.00, 95% CI: 1.0003-1.0033, p = 0.02).
CONCLUSIONS: Based on the available evidence from MR analysis, the current findings did not support vasectomy being a risk factor for PCa. Further work is required to provide additional confirmation and validation of the potential link.

Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.

OBJECTIVE: To quantitatively assess the performance of the new robotic visualization system (Zeiss, KINEVO 900) in terms of visual imaging effect and evaluate its potential application in microscopic vasectomy reversal.
METHODS: We made a parallel comparison between the effects of the plane and stereo visual images of KINEVO 900 and optical surgical microscopy (Zeiss, S7), and performed microscopic vasectomy reversal on the rat model using KINEVO 900.
RESULTS: Compared with S7, KINEVO 900 provided an even longer working distance (200－625 mm), a 3－4 times larger effective field area and a 1.5－2 times deeper front depth of field with the same working distance of 200 mm. No statistically significant difference was observed in the average anastomosis time and immediate patency rate between the two platforms (P > 0.05).
CONCLUSIONS: The 4K3D video image stream outputted by KINEVO 900 is not inferior to that of the optical surgical microscope represented by S7 and is sufficient for microsurgeries in urology and andrology. More prospective randomized clinical animal experiments are needed to further evaluate its application value in andrology.

To date, there is little information about the demography of vasectomy reversal (VR) patients or the factors currently influencing VR effectiveness in China, especially after the universal two-child policy was released in 2015. In this research, demographic data and perioperative medical records of VR patients were extracted from seven major hospitals in different provinces or municipalities of China. Meanwhile, a telephone survey of the patients was conducted to collect follow-up information. Eventually, 448 VR cases from the past 13 years were included. The results were analyzed by stratified comparison to investigate factors that can influence postoperative vas deferens patency and pregnancy rate. Appropriately statistical methods were used, and all of the protocols were approved by the Ethics Committees of the institutes in this research. The results showed that the annual operation volume of VR quadrupled after the two-child policy was implemented. Nonmicrosurgery and a long duration of vasectomy were significantly associated with a lower patency rate. A follow-up survey showed that the general postoperative pregnancy rate was 27.2%. For female partners over the age of 35 years, the postoperative pregnancy rate showed a more severe decline, but only 35.5% of them had been given a fertility examination before their husbands\' VR surgery. Our work revealed that more patients in China have been demanding VR in recent years. High-quality microsurgery and a short duration of vasectomy are crucial for restoring patency by VR. Clinical andrologists should perform a preoperative fertility evaluation of the patients\' female partners.

The debate over the association between vasectomy and prostate cancer has been lasted about 40 years and there is no sign of stopping. In the present study, we aimed to evaluate whether vasectomy is associated with prostate cancer based on the most comprehensive and up-to-date evidence available.
The PubMed, Cochrane Library, and EMBASE databases were systematically searched inception to March 14, 2021 without year or language restriction. Multivariable adjusted risk ratios (RRs) were used to assess each endpoint. Risk of bias was assessed using the Newcastle-Ottawa scale.
A total of 58 studies involving 16,989,237 participants fulfilled inclusion criteria. There was significant association of vasectomy with risk of any prostate cancer (risk ratio, 1.18, 95% CI, 1.07-1.31). Association between vasectomy and advanced prostate cancer (risk ratio, 1.06, 95% CI, 1.01-1.12), low-grade prostate cancer (risk ratio, 1.06, 95% CI, 1.02-1.10), and intermediate-grade prostate cancer (risk ratio, 1.12, 95% CI, 1.03-1.22) were significant. There was no significant association between vasectomy and prostate cancer-specific mortality (risk ratio, 1.01, 95% CI, 0.93-1.10).
This study found that vasectomy was associated with the risk of any prostate cancer and advanced prostate cancer. From the current evidence, patients should be fully informed of the risk of prostate cancer before vasectomy.

Arteriovenous haemangioma of the vas deferens is an extremely rare entity in clinical practice. To date, there have been no clinical or pathological cases reported in Medline, Embase or other published English literature. Herein, a 50-year-old male who presented with right scrotal pain for 4 years after vasectomy was admitted to our hospital. One painful nodule was palpable in the right scrotum on physical examination. Color Doppler ultrasound merely showed dilation of the epididymis and no additional information concerning the painful nodule in the right scrotum. Moreover, the laboratory test results were all within normal limits. Ibuprofen was administered to the patient for 2 months with a poor effect, and then spermatic cord block significantly relieved his symptoms. This patient underwent resection of the right painful nodule of the vas deferens under medical advice. Postoperative pathological examinations showed arteriovenous haemangioma of the vas deferens. There were no obvious complications after arteriovenous haemangioma excision, and the right scrotal pain was significantly relieved 1 month later. This article reminds urologists and oncologists that haemangioma can involve the vas deferens and, in addition to spermatic granuloma, might be a cause of post-vasectomy pain syndrome. Cauterization of the vas deferens might have a potential relationship with haemangioma.

BACKGROUND: Unintended pregnancy is popular all over the world, accounting for 40% to 50% of all pregnancies. The condition not only exerts pressure on the relationship of couples and severely impacts the quality of life, but also imposes a heavy burden on the health of women and child. Recently, more than 220 million couples have chosen to be sterilized to obtain contraception, 47.3% of married couples select sterilization, of which vasectomy accounts for 17.1%. Vasectomy is currently the most convenient and effective method of male contraception. We will perform the systematic review and meta-analysis to assess the correlation between vasectomy and male sex dysfunction and provide evidence-based evidence for the couple METHODS:: The electronic databases of MEDLINE, PubMed, Web of Science, EMBASE, Clinicaltrials.org., China National Knowledge Infrastructure Database (CNKI), Wan fang Database, China Biology Medicine Database (CBM), VIP Science Technology Periodical Database, Chinese Clinical Trial Registry, and Cochrane Library will be retrieved before November 20, 2021. We will search English literature and Chinese literature with proper Medical Subject Heading or text key words. RevMan 5.3 and Stata 14.0 will be used for Systematic review and Meta-analysis. This protocol reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement, and we will report the systematic review by following the PRISMA statement.
UNASSIGNED: The aim of this study was to evaluate the effect of vasectomy on the sexual function of patients after operation. The results will be published in a public issue journal to provide evidence-based medical evidence for urologists and andrologists to make clinical decisions.
UNASSIGNED: INPLASY202080014.

Vasectomy is a simple, safe, effective, and economical method used worldwide for long-term male contraception. As a surgical operation, it has short-term and long-term complications such as hematoma formation, infection, sterilization failure, sperm granulomas, short-term postoperative pain (nodal pain, scrotal pain, and ejaculation pain), and chronic pain syndrome. Whether it increases the risk of autoimmune disease, cardiovascular disease, testicular cancer, or prostate cancer is still controversial. Changes in plasma concentrations of luteinizing hormone, follicle-stimulating hormone, and testosterone after vasectomy have also been studied, as well as the relation between vasectomy and sexual function. Sperm quality decreases very slowly after vasectomy, and vasovasostomy and intracytoplasmic sperm injection could help a couple achieve a pregnancy if they change their minds at any point. We include a follow-up strategy and suggestions for follow-up care at the end of this review.

Epidemiological cohort studies investigating the association between vasectomy and prostate cancer risk have yielded inconsistent results. The aim of the present meta-analysis is to update the evidence on the association between vasectomy and prostate cancer. A comprehensively literature search of relevant studies was performed in December 2019 using PubMed. A DerSimonian and Laird random-effects model was used to calculate the summary relative risk (RR) and its 95% confidence interval (CI). A total of 15 eligible cohort studies (16 data sets) with more than four million of participants were eventually included in this meta-analysis. There was a statistically significant higher risk of prostate cancer among men who underwent vasectomy (RR: 1.09, 95% CI: 1.04-1.13) with obvious heterogeneity among included studies (P < 0.001, I2 = 64.2%). Vasectomy was also associated with the risk of advanced prostate cancer (RR: 1.07, 95% CI: 1.02-1.13), which is less likely to be affected from detection bias. In conclusion, findings from this meta-analysis of prospective studies indicate that vasectomy may be positively associated with the risk of prostate cancer. Further large prospective studies with long follow-up are warranted to verify the findings from this meta-analysis. In addition, the potential underlying molecular mechanism needed further exploration with in vitro and animal studies.

This study aimed to evaluate a simplified vasovasostomy procedure that shortens the operative time. This was a retrospective (non-randomized) study of men who underwent bilateral vasectomy and consulted for vasovasostomy (02/2014-08/2016). Eight interrupted sutures were used for one-layer full-thickness vasal anastomosis over a 20 or 22 G catheter temporarily inserted in the lumen of the anastomotic site as a stent. Control patients underwent double-layer vasovasostomy. The surgery was significantly shorter in the one-layer group (n = 23) (62 ± 8 vs. 133 ± 15 min, P < 0.001 vs. the two-layer group, (n = 19)). There was no difference in patency between the two groups (95.7 vs. 94.7%, P > 0.999). There was one case of epididymitis in each group. There were no complications like bleeding, scrotal hematoma, hydrocele, or infection. Low-power microscopic one-layer vasovasostomy with stent was simple and had a short operation time. The patency could be similar to that of two-layer vasovasostomy, but prospective studies are necessary for confirmation.