Transcutaneous procedures for male sterilization.

Outside the People's Republic of China transcutaneous methods of male sterilization are not widely used, even though there are advantages of these methods over surgical vasectomy procedures. Methods of transcutaneous sterilization (intratesticular, intraepididymal, and intravasal) that have been evaluated in men are reviewed.

Transcutaneous male sterilization.

PIP: This report reviews and summarizes the results of current animal and human research studies for each of the 3 approaches to transcutaneous sterilization: intratesticular injection of chemical agents to affect spermatogenesis; intraepididymal injection of chemical agents to affect sperm transport; and obstruction of the vas lumen by the intravasal injection of chemical (sclerosing) agents or by electrocoagulation of the vas lumen. Wiebe and Barr evaluated the effects of the direct injection of aqueous 1, 2, 3-trihydroxypropane (THP; glycerol), a normal component of living cells, into the testes of Sprague-Dawley rats. Spermatogenesis was inhibited by a direct and local action of THP on the seminiferous tubules. The only other intratesticular method that has been investigated is the use of ultrasonic energy. Although the injection of sclerosing agents directly into the epididymis is technically simpler than injection into the vas lumen, the intraepididymal approach to nonsurgical sterilization has been evaluated in only 3 studies. The advantages of intraepididymal over intravasal injections are that the cauda epididymis is easily palpated and intraluminal placement of the needle in the epididymis is not necessary. The appeal of the intraepididymal approach to transcutaneous sterilization is that it is easier to inject a chemical into the epididymis than into the vas lumen. Limitated evaluations of the intraepididymal injection of chemical agents has shown this to be an unsatisfactory approach to male sterilization. Whether improved results can be obtained with other chemical agents remains to be evaluated. Numerous chemical agents have been injected into the vasa of rats, dogs, and rabbits to evaluate their effects in producing vas occulsion. A table lists the agents that have been evaluated. Only 2 chemical agents are known to have been tested in man: 3.6% formaldehyde in 90% ethanol and 4% formaldehyde in 90% ethanol and a carbolic acid, n-butyl alpha cyanoacrylate mixture. The mode of action of all of the sclerosing agents tested is thought to be similar: they produce local necrosis and fibrosis and vasal closure through scarring. A main objective in choosing a chemical agent for use in human sterilization procedures is to select one that has minimal toxic effects and will produce a minimal amount of damage if injected onto structures other than the vas. The transcutaneous intravasal sterilization procedure developed by the Chinese and which has been widely and successfully used since 1972 is described. To further advance the electrocoagulation procedure developed by Schmidt in 1966, bipolar electrodes have been developed. Black, at the Marie Stopes Clinic in the UK, is currently investigating a transcutaneous electrocoagulation procedure. Black believes that improvement of the electrodes and some changes in the technique of performing the electrocoagulation will result in an effective procedure.^ieng

[Contraceptive development for the future]. / La contraception de l'avenir.

PIP: This article provides background on worldwide contraceptive usage as an introduction to its main topic, new methods of fertility regulation now under development in terms of their intervention in specific reproductive processes. A large number of chemical compounds and steroidal or nonsteroidal pharmacologic agents have been shown to interfere directly of indirectly with the processes of spermatogenesis, but most are associated with undesirable side effects. Nitrofuranes, alpha-chlorohydrine and othr chlorinated sugars, cyproterone acetate, estrogen, progestins, testosterone alone or in combination with other hormonal agents, and the cotton seed derivative gossypol have all been tested. Although research on some of them continues, questions questions of side effects, toxicity, and reversibility have arisen. Luteinizing hormone releasing hormone analogs and especially antagonists offer promise as a male contraceptive use in conjunction with testosterone, but further research on efficacy and reversibility is needed. Percutaneous vas occlusion using chemical substances including a mixture of ethannol and formaldehyde, and occlusion of the vas by electrocautery are norsurgical techniques of vas occlusion that are expected to be more acceptable to men than current surgical techniques. Various removable devices for vas occlusion have been studies, such as silicone or nylon threads, valves of different kinds, polymers, and threads of metal, especially copper, but thus far all have posed serious technical problems. Methods under development which block sperm transport in the female genital tract include enzyme sperm inhibitors and long-acting steroids, spermicides, improved vaginal sponges, disposable diaphragms impregnated with spermicide, vaginal rings, water soluble spermicidal condoms, a latex cervical cap kept in place by suction, an intracervical device that would liberate progesterone, transcervical approaches to sterilization by occlusion of the salpingo-uterine junction using quinacrine or methylcyanocrylate, and reversible methods of obstructing the salpingo-uterine junction. Research is underway to develop IUDs that would remain effective longer and reduce incidences of bleeding and expulsion, possibly through use of substances such as quinacrine, luteolytic agents, immunologic or spermicidal substances, or antifibrinolytic agents. Long-acting methods including injectable steroids and biodegradable or non-biodegradable implants, pregnancy vaccines, and other immunological approaches are at various stages of research.^ieng

Gossypol: a possible male antifertility agent. Report of a workshop.

PIP: Clinical studies on the antifertility effect; site of action; pharmacokinetics and toxicity of gossypol, a yellowish pigment occurring in certain species of cotton plant with a reputed contraceptive effect, were first carried out in 1972. Some 4000 Chinese men had used gossypol contraceptive pill for at least 6 months, and some for more than 4 years. Reported efficacy rate of the pill was 99.89%. Male fertility returned by 3 months after discontinuation of the pill, and there were no apparent serious side effects on the babies borne by the wives of the men who had stopped using gossypol. A study by Lee and Malling suggests that gossypol works by inhibiting an enzyme that has a crucial role in the metabolism of sperm and sperm-generating cells. Gossypol is toxic to nonruminant animals, including humans. This toxicity has precluded the economic utilization of cottenseed product for human nutrition. Cottenseed oil, however, is used in food preparation and cooking as salad oil, shortening, and margarine. The mechanism of gossypol's toxicity is not well understood. Toxicity may be due to the action of gossypol on specific enzymes, or interference with amino acid, protein, or iron metabolism. Clinical research suggest that increasing the dietary level of quality of protein minimizes or eliminates the physiologic effects of ingested gossypol within limits. If human reaction to gossypol is similar to that of animal reaction, a diet lacking adequate levels of protein, iron or certain minerals could adversely affect its efficacy and safety, and malnutrition could severely affect gossypol toxicity and its antifertility factors. Carefully designed clinical trials should be done to determine dose-response, efficacy, side effects, metabolic effects, and reversibility potential of gossypol. If gossypol is found to be a new non-steroidal contraceptive method which could be highly effective and reversible, fully safe and inexpensive, it could very well be the answer to the world's population problem.^ieng

Puerperal tubal ligation morbidity, histology and bacteriology.

PIP: To assess the relationship of morbidity to the time interval between delivery and puerperal tubal ligation, 76 women were studied after receiving a tubal ligation. The women were divided into 4 subgroups relating to the time interval of the tubal ligation after delivery from 12-108 hours. Morbidity was defined as (1) puerperal morbidity: a temperature of 100.4 degrees F which occurs on any 2 of the first 10 post-partum days, and (2) other morbidity: a temperature of greater than 100 degrees F on any 1 of the first 10 post-partum days. Endometrial and tubal specimens were taken and tested for the presence of bacteria. In addition, tubal specimens were tested for salpingitis, edema, and perivascular infiltrate. There was no correlation between the time interval and post-operative morbidity. Positive endometrial cultures were found in 39.5% of the patients involved, and positive tubal cultures in 28.9%, which showed no correlation with time delay. There was significantly less histologic salpingitis in cases done within 36 hours after delivery. There was a correlation between salpingitis and positive tubal cultures. Post-operative morbidity did not correlate with either abnormal tubal histology or positive tubal cultures.^ieng

Family planning; postpartum approach.

PIP: In early 1966, the Population Council established the International Postpartum Family Planning Program which aimed to provide contraceptive information and supplies to urban, low-income women in public hospitals. 26 hospitals in 19 cities in 15 countries around the world were involved in the program. Each women delivering or aborting at these hospitals was given contraceptive information. Follow-up work was done with women who did not return for their postpartum examination. Supplies were provided free of charge. In the first 2 years of the prog ram, more than 236,000 women have accepted contraception, over 40% of total hospitalized cases. Word-of-mouth contacts have entered the program also. After 18 months, continuance was 82%. These acceptors were young, had few children, and were using contraception for spacing. This hospital approach is as cost efficient as other more general family planning programs. The program stimulated greater concern for maternal health too. The program will soon expand to 200 hospitals in 25 countries in the developing world. Later the program can be carried to rural areas through establishment of primary health centers and maternal/child health clinics.^ieng

Family planning via the postpartum approach.

PIP: Since motivation for family planning is extremely high after delivery or abortion, women should be consulted about the use of contraception within 3 months postpartum. The International Postpartum Family Planning Program began in 1966 and now provides family planning information and services in 26 urban hospitals in 15 countries for women of low socioeconomic status. In the first 2 years, 236,000 acceptors were enrolled in the program out of an estimated target in developing countries of 1,870,000 women. Home visit follow up surveys found that 82% were continuing some method of contraception 18 months after initial acceptance. The cost has been $3.20 per acceptor. The rates of postpartum return visits have increased since the initiation of the postpartum family planning program. The Population Council is now extending the program to other countries of the developing world to work in rural as well as in urban areas.^ieng