Method For Achieving Reversible Male Sterilization

Abstract

A method for obtaining reversible male sterilization by occlusion of the vas deferens to block passage of the sperm produced in the testes. A portion of the vas deferens is exposed by a high midscrotal incision for the insertion of an intravasal plug. The plug has a filiform thread attached to one of its ends and is introduced into the vas by a straight needle from the testicular side of the epididymal side of the vas with the filiform threads allowed to extend through the wall of the vas at the epididymal side. The filiform thread is then tied around the vas at the epididymal side in order to hold the intravasal plug in place thereby creating a mechanical obstruction to the passage of the sperm.

Description

This invention relates to a method for obtaining male sterilization, more particularly, to a method for achieving reversible male sterilization by the mechanical blocking of the passage of sperm in the vas deferens with the passage of sperm being readily restored upon removal of the mechanical blocking device.

The conventional method for obtaining male sterilization is the vasectomy which is generally performed on a permanent basis. The permanency of the vasectomy and the present difficulty of restoring fecundity has prevented this method of male sterilization from being generally acceptable. attempts have been made therefore to achieve reversible male sterilization by vas occlusion rather than the vasectomy. A number of animal experiments have been carried out along these lines using various means such as; and injection of Biowax, the insertion of a piece of plastic material, electrocoagulation, chemical cauterization, a nonoperative vasoligature and the placement of nonreactive suture material. The findings of these experiments were reported by Dr. H. Y. Lee in The Journal of the Korean Medical Association, Vol. 10 No. 12: 914--918, 1967. It was reported there that the most satisfactory method for reversible vas occlusion was the introduction of nonreactive suture material. However, as stated in Dr. Lee's report, the insertion of the nonreactive suture material caused an undesirable dilatation of the vas due to an increased intravasal pressure caused by deposition or stasis of continued sperm production. This dilatation allowed sperm to pass through the dilatated lumen of the vas even though the material was still in place. Furthermore, difficulty was also encountered in restoring the patency of the vasal lumen upon removal of the suture material from the vas deferens thereby creating doubt as to the reversibility of the method.

An object of the present invention is to remedy the deficiencies of the prior attempts in obtaining male sterilization as outlined above. In particular, an object of the invention is to provide a method for achieving reversible male sterilization that will successfully prevent passage of sperm from the testes through the vas deferens. A further object of the invention is to provide a method of obtaining reversible male sterilization by vas occlusion that will block passage of sperm through a dilated vasal lumen. A further object of the invention is to achieve reversible vas occlusion that upon removal of the blocking device the patency of the vasal lumen will be successfully restored.

The foregoing and other objects of the invention are obtained by a method of inserting an intravasal plug having filiform threads attached to one of its ends into the noncilated scrotal portion of the vas. The ends of the filiform threads are extended through the wall of the vas deferens around which they are tied to retain the plug in place. The intravasal plug and filiform threads are made of surgical nylon thread. The plug is inserted into the vasal lumen by means of a straight needle to which the filiform nylon threads are fixed, the needle is forced through the wall of the exposed vas from the distal (testes) end to the proximal (epididymal) end of the vas thereby permitting the plug to be pulled into the vasal lumen by the filiform threads which are left extending through the proximal end of the vas wall. The needle is thereafter disengaged from the filiform threads which are then tied around the vas to maintain the plug in place. The above described procedure is then immediately carried out on the other side of the vas deferens and after completion of that portion of the operation the scrotal incision is closed.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which:

FIG. 1 is a prospective view of the intravasal plug and filiform threads.

FIG. 1a is a prospective view of the intravasal plug attached to a straight needle.

FIG. 2 is a view of the vas deferens exposed through the scrotal incision.

FIG. 3 is a view of the intravasal thread attached to the straight needle being inserted into the distal end of the vas.

FIG. 4 is a view of the intravasal thread being pulled into the vas with the straight needle being forced through the wall of the vas at the proximal end.

FIG. 5 is a view of the intravasal thread located within the vas with the filiform nylon threads protruding through the wall of the vas.

FIG. 6 is a view of the intravasal thread situated in its proper position in the vas with the filiform threads tied around the vas.

FIG. 7 is a view of the exposed vas deferens with the filiform threads being cut in order to remove the plug.

FIG. 8 is a view of the intravasal thread being removed from the vas deferens.

FIG. 1 illustrates an intravasal blocking device 10 which consists of a plug portion 12 1 centimeter in length which is made of surgical nylon thread of size No. 1 to No. 5 chromic catgut. It is to be noted that the diameter of the plug is a function of the inner diameter of the vasal lumen. Attached to the plug are two filiform nylon threads 14 approximately 8 centimeters in length and of size 6-0 chromic catgut. A number of different mechanical devices were tested in attempting to obtain vas occlusion but it was found that a physiologically inert material, such as nylon thread, produced the best results. In order to insert the intravasal plug into the vas deferens the filiform threads are attached to a straight needle 16, as shown in FIG. 1a. The use of a straight needle 16, as shown in FIG. 1a allows the intravasal plug to be inserted into the vasal lumen without the incision of the vas. The filiform nylon threads not only provide a means of attaching the plug to the straight needle but also aid in retaining the plug in its blocking position and further prevents the dilatation of the vas as will be discussed below.

The first step in the method of inserting an intravasal plug is to expose the vas deferens 18 through a high midscrotal incision approximately 2 centimeters long as shown in FIG. 2. The vas 18 is lifted above the surface of the scrotum by threads 20 which are pulled by mosquito forceps 22. Once the vas has been properly exposed the straight needle 16 to which the intravasal thread is attached is inserted through the wall of the vas into the vasal lumen 19. The initial insertion at point 24 of the vas is at the distal (testes) side of the vas. The needle after entering the vas at the distal end continues through the vasal lumen and is brought through the wall of the vas at point 25 which is the proximal (epididymal) side of the vas as shown in FIG. 4. Once the needle protrudes through the wall of the vas it is continuously pulled thereby drawing the plug 12 into the vasal lumen as shown in FIG. 5. With the plug 12 in place in the vasal lumen the straight needle 16 is severed from the ends of the filiform nylon threads which are protruding through the wall of the vas. The filiform nylon threads are then tied (FIG. 6) around the epididymal side of the vas in order to hold the intravasal plug in place. Care should be taken not to tie the filiform threads around the vas too tightly which would choke the vas. Experiments have shown that if the vas is tied too tightly it will be severely damaged and the continuity may not be restored due to excessive ligation with the threads.

After the filiform nylon threads have been tied the same procedure is immediately carried out on the other side of the vas deferens in order to obtain complete blockage of the sperm passage. After completion of the insertion of the intravasal thread in the other vas deferens the scrotal incision is closed in the usual manner with silk sutures by layers following clamping and tying of bleeders as required.

The above method was used on three different groups of adult male dogs. The three groups tested used different mechanical devices for the vas occlusion. The first group consisted of nine dogs with surgical nylon threads placed in the vas. The second group consisted of nine dogs with surgical silk thread in the vas and the third group comprised seven dogs which had a small piece of plastic material inserted in the vas. 3 to 6 months after the insertion of the intravasal thread, semen analysis showed that no sperm was found in the ejaculates except in one case of faulty insertion of the intravasal thread. These results are tabulated below. ##SPC1##

Vasography examinations also substantiated the success of the vasal occlusion in that the lumen in the vas were completely occluded without leakage under pressure 3 months after the thread had been in place. Again, the only leakage that was found was with the faulty insertion. The results of these tests are shown below: ##SPC2##

There were variations, however, of the amount of tissue reaction found in the different groups. Histologic examinations indicated that there was moderate to mild tissue reaction in the group that used plastic as an intravasal blocking device. The group that used silk thread showed only a mild reaction. The group that utilized nylon as in intravasal blocking device showed minimal destruction of the cells in the vas and very few abnormal inflammatory cells were found. The results of the histologic tests are shown below: ##SPC3##

In order to remove the intravasal thread from the vas deferens the vas is exposed in a similar manner as for the intravasal thread insertion. The filiform nylon threads that are tied around the vas are then cut, as shown in FIG. 7, and the intravasal plug 12 is then removed by pulling the filiform nylon threads with a pair of mosquito forceps (FIG. 8). The plug, upon being removed, passes through the same opening that the straight needle made upon insertion of the intravasal thread thereby eliminating the need for the incision of the vas to remove the plug. Once the plug is removed the patency of the vasal lumen is restored. In order to prevent kinking of the vas after removal of the plug due to extensive fibrotic contracture of surrounding tissues, a nylon thread, 2-0 in size, is introduced into the previously occluded vasal lumen as an internal splint with one end of the thread connected to the scrotal skin. After the splint is introduced, the incision is closed in the usual manner. The splint can normally be removed on the 10th post operative day.

Three months after the removal of the intravasal plug, vasography examination revealed that the patency of nine out of 11 vasa in group 2 and four out of eight vasa in group 3 had returned almost to normal. In eight of the dogs, two from group 1, two from group 2 and four from group 3, the intravasal thread was found to be too large thereby causing tissue damage which resulted in vasal strictures. The results of the vasography examination are summarized below: ##SPC4##

Histological tests were also made 6 months after the placement of the intravasal thread and from 1 to 3 months after removal with the following results: ##SPC5##

This method has clearly achieved a proven reversibility not present in the standard vasectomy. The relative permanency of a vasectomy, even in light of some present day successful anastmosis of the vas deferens, has been the greatest drawback to its acceptance and, consequently, its failure to be the answer to the world's problem of birth control. Furthermore, this method has also solved the problems of previous attempts at vas occlusion (Study on Vasectomy--VI Reversible Vas Occlusion Method on Experimental Animals--Ibid.) in that the tying of the intravasal plug to the vas deferens by the filiform threads has: 1. Prevented migration of the internal plug upward in the vas, 2. stopped sperm escape by preventing dilatation of the vasal lumen due to continued sperm production and 3. avoids an incision of the vas for insertion and/or removal. The method was reported in The Journal of the Korean Medical Association Vol. II No. 9 Sept. 20, 1968 in an article entitled "Studies on Vasectomy--VII Experimental Studies on Reversible Vas Occlusion by Intravasal Thread."

The method may be carried out in other specific forms without departing from the spirit or essential characteristics thereof. The present described method is therefore to be considered in all respects as illustrative and not restrictive, the scope of the method being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

What I claim:

1. A method for achieving reversible male sterilization by vas occlusion comprising the steps of exposing a portion of the vas deferens, inserting a physiologically inert elongated plug having transverse dimensions of luminal size into the vasal lumen thereby blocking passage of sperm, said plug having at least one physiologically inert thread attached to its end thereof, fixing said plug in said vasal lumen by tying said thread around the epididymal side thereof and, restoring said vas deferens to its original unexposed position.

2. A method as in claim 1 wherein said step of exposing a portion of said vas deferens is accomplished by a high midscrotal incision thereby exposing the nonciliated scrotal portion of said vas deferens.

3. A method as in claim 1 wherein said plug consists of a cylindrical plug of luminal diameter having at least one filiform thread attached to one of its ends.

4. A method as in claim 3 wherein said plug is made of nonreactive and nonabsorbable surgical nylon thread.

5. A method as in claim 1 wherein said plug is inserted into said vasal lumen by means of a straight needle to which said mechanical device is attached.

6. A method as in claim 1 wherein said plug is inserted into the exposed vas deferens from the testes side to the epididymal side.

7. A method as in claim 1 wherein said filiform thread is tied around the circumference of the vas deferens at the epididymal side.

8. In a method for reversing male sterilization achieved by vas occlusion which comprises the steps of exposing a portion of the vas deferens by a midscrotal incision, inserting into the vasal lumen a physiologically inert plug of luminal diameter having at least one physiologically inert thread attached to one of its ends and extending through the wall of said vas deferens, fixing said plug within said vasal lumen by tying said thread around said vas deferens and restoring said vas deferens to its original unexposed position and closing said scrotal incision, in which said sterilization is reversed by exposing said portion of said vas deferens containing said intravasal plug, cutting said thread tied around said vas deferens thereby releasing said plug, removing said plug from said vasal lumen by pulling said thread, introducing one end of a splint thread into said previously occluded vasal lumen, attaching said other end of said splint thread to the scrotal skin and restoring said vas deferens to its original unexposed position and closing said scrotal incision.