Intra-vas Device Research Articles

Vasectomy occlusion techniques for male sterilization

Vasectomy is an increasingly popular and effective family planning method. A variety of vasectomy techniques are used worldwide, including vas occlusion techniques (excision and ligation, thermal or electrocautery, and mechanical and chemical occlusion methods), as well as vasectomy with vas irrigation or with fascial interposition. Vasectomy guidelines largely rely on information from observational studies. Ideally, the choice of vasectomy techniques should be based on the evidence from randomized controlled trials (RCTs). The objective of this review was to compare the effectiveness, safety, acceptability and costs of vasectomy techniques for male sterilization. In February 2014, we updated the searches of CENTRAL, MEDLINE, POPLINE and LILACS. We looked for recent clinical trials in ClinicalTrials.gov and the International Clinical Trials Registry Platform. Previous searches also included EMBASE. For the initial review, we searched the reference lists of relevant articles and book chapters. We included RCTs comparing vasectomy techniques, which could include suture ligature, surgical clips, thermal or electrocautery, chemical occlusion, vas plugs, vas excision, open-ended vas, fascial interposition, or vas irrigation. We assessed all titles and abstracts located in the literature searches. Two reviewers independently extracted data from articles identified for inclusion. Outcome measures include contraceptive efficacy, safety, discontinuation, and acceptability. Peto odds ratios (OR) with 95% confidence intervals (CI) were used for dichotomous outcomes, such as azoospermia. The mean difference (MD) was used for the continuous variable of operating time. Six studies met the inclusion criteria. One trial compared vas occlusion with clips versus a conventional vasectomy technique. No difference was found in failure to reach azoospermia (no sperm detected). Three trials examined vasectomy with vas irrigation. Two studies looked at irrigation with water versus no irrigation, while one examined irrigation with water versus the spermicide euflavine. None found a difference between the groups for time to azoospermia. However, one trial reported that the median number of ejaculations to azoospermia was lower in the euflavine group compared to the water irrigation group. One high-quality trial compared vasectomy with fascial interposition versus vasectomy without fascial interposition. The fascial interposition group was less likely to have vasectomy failure. Fascial interposition had more surgical difficulties, but the groups were similar in side effects. Lastly, one trial found that an intra-vas was less likely to produce azoospermia than was no-scalpel vasectomy. More men were satisfied with the intra-vas device, however. For vas occlusion with clips or vasectomy with vas irrigation, no conclusions can be made as those studies were of low quality and underpowered. Fascial interposition reduced vasectomy failure. An intra-vas device was less effective in reducing sperm count than was no-scalpel vasectomy. RCTs examining other vasectomy techniques were not available. More and better quality research is needed to examine vasectomy techniques.

A randomized, controlled, multicenter contraceptive efficacy clinical trial of the intravas device, a nonocclusive surgical male sterilization

Because of unavoidable complications of vasectomy, this study was undertaken to assess the efficacy and safety of male sterilization with a nonobstructive intravas device (IVD) implanted into the vas lumen by a mini-surgical method compared with no-scalpel vasectomy (NSV). IVDs were categorized into two types: IVD-B has a tail used for fixing to the vas deferens (fixed wing) whereas IVD-A does not. A multicenter prospective randomized controlled clinical trial was conducted in China. The study was comprised of 1459 male volunteers seeking vasectomy who were randomly assigned to the IVD-A (n = 487), IVD-B (n = 485) or NSV (n = 487) groups and underwent operation. Follow-up included visits at the 3rd–6th and 12th postoperative months. The assessments of the subjects involved regular physical examinations (including general and andrological examinations) and semen analysis. The subjects’ partners also underwent monitoring for pregnancy by monthly interviews regarding menstruation and if necessary, urine tests. There were no significant differences in pregnancy rates (0.65% for IVD-A, 0 for IVD-B and 0.21% for NSV) among the three groups (P > 0.05). The cumulative rates of complications at the 12th postoperative month were zero, 0.9% and 1.7% in the three groups, respectively. In conclusion, IVD male sterilization exhibits a low risk of long-term adverse events and was found to be effective as a male sterilization method, similar to the NSV technique. IVD male sterilization is expected to be a novel contraceptive method.

The contraceptive effect of a novel filtering‐type nano‐copper complex/polymer composites intra‐vas device on male animals

Contraceptive techniques which target vas deferens have been paid great attention for their good efficacy, safety and reversibility. We have made a filtering-type intra-vas device (IVD) using nano-copper complex/polymer composites. Twenty male adult Beagle dogs and 40 male rabbits were randomly assigned to four groups (sham-operation, IVD, reversal and vasectomy groups). Dogs' semen parameters, concentration of α-glucosidase, copper and zinc ions were tested pre-operation and 1, 3, 6 and 12 months post-operation. The pregnancy rates of the rabbits were evaluated by mating trials after the IVDs were implanted. The histology of testis, epididymides and vas deferens of the animals was examined using an electron microscope. Apoptosis of the cells in the testes, epididymides and vas deferens was detected by TUNEL method. There was no sperm in the semen of dogs, which had been inserted IVD and vasectomized at 1, 3, 6 and 12 months post-operation. The concentration of α-glucosidase in the IVD group, reversal group and sham-operation group was not significantly different between pre- and post-operation. The pregnancy rates of the female rabbits in the vasectomy, IVD and reversal groups were all zero, but the pregnancy rate in the reversal group, after taking out IVD, and that of the sham-operation group was 60% and 80%, respectively. The ultrastructures of the testes, epididymides and vas deferens of the male animals in the IVD group and sham-operation group were in normal ranges compared with the vasectomy group. The apoptosis of the cells in the testes, epididymides and vas deferens in the vasectomy group of both dogs and rabbits was obvious compared with the other groups. No significant changes in the quantities of copper and zinc ions were found in semen of the male dogs both pre- and post-operation. Our studies demonstrated that the filtering-type nano-copper complex/polymer composites intra-vas device may be an efficacious, safe and reversible male contraceptive device.

Biological evaluation of a novel copper-containing composite for contraception

To investigate the biocompatibility of a novel copper-containing composite to provide preclinical data for clinical application of intrauterine device (IUD) or intra-vas device (IVD). Prospective experimental study. Good laboratory practices laboratories. Twenty healthy adult mice (SPF grade Kunming white mice, animal code SCXK 2003-0005). Cytotoxicity tests in vitro were conducted to evaluate the influence of the materials on the morphology, growth, and proliferation of cultured L929 mouse fibroblasts. Acute systemic toxicity tests were conducted to investigate the acute systemic toxic reaction with mice, and then the materials were implanted into the spinal muscle of rabbits (n = 15). The rabbits were sacrificed for pathologic examination at 1, 4, and 12 weeks after surgery. Evaluation of cytotoxicity by MTT assay, cytotoxicity test by direct contact assay, acute systemic toxicity test, and material implantation test. The cytotoxicity grade of the copper-containing composite was 0-1, suggesting that the material was free of cytotoxicity; no acute systemic toxicity was found in any mice; mild inflammatory reaction was observed in the surrounding tissues of the implanted material in the early implantation stage, which was similar to that of the sham-operated sides. Twelve weeks after implantation, the inflammatory reaction was completely disappeared in the implanted tissue, similarly to the sham-operated sides. The fibrosis membrane surrounding the material became stable gradually over time. The copper-containing composite has excellent biocompatibility, which is feasible and safe for the clinical application as a novel contraceptive material.

Initial studies on a novel filtering-type intra-vas device in male dogs

Background To relieve the side effects induced by the complete obstruction of the vas deferens, we created a filtering-type intra-vas device (IVD) which is made of materials composed of nano-SiO 2-copper complex cross-linking polymer composites. Study Design Eight male beagle dogs were grouped into nonimplanted control group and IVD-implanted group. We tested the efficacy of the sperm filtering effect of the new IVD material for 12 months and examined the influence of the IVD materials on the cells of the vas deferens, epididymis and testis. Results The densities of sperm were reduced significantly after the IVD was implanted; no motile sperm were found after the third month. No obvious morphological changes were found in the cells of the vas deferens, epididymis and testis in the IVD-implanted group. Conclusions The filtering-type nano-SiO 2-copper complex/polymer composite IVD is able to filter the sperm of the male dogs, and the IVD material did not cause obvious damage to the cells of the male reproductive organs after 1 year of implantation.

Studies with an intravas nylon device in rat.

Contraceptive efficacy of an intravas device (IVD) was investigated in rat. The IVD used consisted of a nylon suture which did not occlude the lumen of the vas completely and permitted a free passage of spermatozoa. Its presence for periods ranging from 15 to 180 days did not produce any changes in the histology of the testis and epididymis; In the vas deferens the tall columnar ciliated epithelium was replaced by squamous epithelium. A spermatic granuloma developed on the vas at the entry of the IVD and its frequency of occurrence and size increased with the passage of time. The device caused an increase in the vasal protein, sialic acid and phospholipid content, and a decrease in the level of glycogen and alkaline phosphatase activity at 15 days. The level of portein, glycogen and alkaline phosphatase activity returned to normalcy at 90 days but the sialic acid and phospholipid content remained elevated. Notwithstanding these alterations the device failed to affect the spermatozoal number, morphology, motility and their fertilizing ability. The significance of these findings is discussed.

A phase II randomized controlled trial of a novel male contraception, an intra‐vas device

The aim of this study was to introduce a novel male contraceptive method, an intra-vas device (IVD), and to assess the efficacy, safety and satisfaction of recipients compared with no-scalpel vasectomy (NSV). A phase II randomized controlled trial was conducted in China in 2003. Two hundred and eighty-eight male subjects seeking vasectomy were randomly assigned to the IVD or NSV group. Follow up included a telephone questionnaire on the 14th postoperative day and visits at the third and 12th postoperative months. The follow-up rates at the three time points were 100%, 100% and 96.5% respectively. There was no technical failure in any subject. The surgical conditions were similar in both groups, but the IVD group experienced an additional 5 min of operative time (p<0.001). The IVD group recovered normal activity and sexual intercourse more rapidly (both p<0.05). The azoospermia rate was lower in the IVD group than in the NSV group at the third and 12th postoperative months. The rate of contraceptive success based on semen analyses was similar in both groups, especially at the 12th postoperative month (94.3% in the IVD group vs. 98.6% in the NSV group; p=0.054). The IVD group had less risk of complications (i.e. pain, congestive epididymitis and sperm granuloma). More subjects reported satisfaction with IVD sterilization than with NSV. The two procedures were similar in terms of surgical complications. The IVD was slightly less effective, but had a lower risk of later adverse events than the NSV technique. The IVD group also reported a higher level of satisfaction.

Copper intravas device (IVD) and male contraception

An alternative method of male contraception is crucial at this stage of increasing population in the developing world. A non-obstructive, non-hormonal, reversible method of male contraception would find acceptance in oriental communities. Our experience with copper IVD in small animals has been encouraging. We present here an extension of the use of the copper IVD in the rhesus monkey. Treated male rhesus ejaculate showed fifteen-to thirty-five-fold increase in copper levels up to 10 months after insertion of Cu IVD. Semen analysis showed an increase of dead sperm (23.0%–52.3%; control 4.5%–14.0%) and decrease in percentage of motile sperm (10–30%; control 70–80%). Fertility studies using treated male rhesus of proven fertility from the breeding colony mated with cycling females of proven fertility showed highly significant reduction of fertility up to 13 months ( P < 0.001). Reduction in fertility of the treated rhesus was also significant up to a period of 23 months ( P < 0.01). A reversal of contraceptive effect and increase in sperm count and motility is observed after 13 months post-treatment. Studies are required to achieve an increase in the effective life span of the IVD.

Intravas device studies in rabbits: II. Effects on sperm output, fertility and histology of the reproductive tract

Solid (rod) and open (tube) prototype gold-platinum intravas device housings of three different surface designs were surgically inserted into the vasa deferentia of rabbits to test the feasibility of controlling male fertility. The devices were inserted through a short longitudinal slit in each vas deferens, secured with 4-0 silk suture and remained in situ for various periods ranging from 56–426 days. The solid devices completely inhibited the fertility of 6 rabbits in 20 of 21 matings. The fertile mating resulted after the loss of a device in one animal. In contrast, 7 of 9 rabbits receiving identical, but open (i.d. 0.8 mm), devices were fertile in numerous matings. Reduced sperm numbers or sperm-free ejaculates were usually obtained for 2–3 weeks after surgery, but returned to normal following this period. However, sperm blockage due to connective tissue infiltration and eventual encapsulation of the open devices was subsequently observed in about 50% of the animals. Histological changes of the vas deferens at the sites of some of the devices included occasional sperm granulomas, mild focal submucosal edema, mucosal erosion and mild mucosal hyperplasia due to fibroblastic proliferation.

Intravas device studies in rabbits: I. Effect of surgical procedures on adrenergic innervation of the vas deferens

The effect of intravas device placement on the adrenergic innervation of the vas deferens was studied in the rabbit. Utilizing varying methods for intravas device insertion (non-transected vs. transected vas), segments of vasa were removed at autopsy and examined histologically for the fluorescent histochemical demonstration of norepinephrine. In each surgical procedure, fluorescence was maintained above the device site or area of transection. Intraluminal placement of an intravas device without vas transection reduced, but did not abolish, innervation below the device site; fluorescence below the device was abolished, however, if the vasa were transected. Comparative studies with vasectomized rabbits resulted in a similar loss of fluorescence below the area of transection.It is concluded that transection of the rabbit vas deferens for intravas device insertion results in a loss of adrenergic innervation below the point of transection; this effect can be mimicked by vasectomy. Intravas device insertion without transection retained some of the neuromuscular integrity of the vas smooth musculature.

Biochemical and Contraceptive Effects of an Intravas Device in the Rat

A study to determine whether a foreign body an intravas device (IVD) in the vasal lumen in rats would lead to any biochemical changes in the vas deferens that affect the fertilizing capacity of spermatozoa without affecting their morphology motility or transport is presented. On the side containing the IVD there were increases in protein sialic acid and phospholipids. Glycogen concentration and alkaline phosphates were significantly (p<.001) decreased. The fertilizing capacity of the vasal spermatozoa was unaffected.