WO1989000034A1

WO1989000034A1 - Correction of male impotence

Info

Publication number: WO1989000034A1
Application number: PCT/AU1988/000250
Authority: WO
Inventors: Rodney James Lane; Christopher Gordon Mcmahon; Peter Charles Spencer
Original assignee: Vaso Products Australia Pty. Limited
Priority date: 1987-07-07
Filing date: 1988-07-06
Publication date: 1989-01-12

Abstract

Male impotence is corrected by a variety of devices by either decreasing the outflow of blood or increasing the inflow of blood to the penis. The flexible biocompatible pads (10) are implanted between the tunica albuginea and Buck's fascia, the pads (10) being of sufficient volume so that when the patient initiates penile erectile tissue tumescence under normal physiological action, the additive volume of the pads with that of the tumescent erectile tissue is sufficient to cause an increase in venous vessel constriction.

Description

CORRECTION OF MALE IMPOTENCE FIELD OF INVENTION

This invention relates to the correction of male impotence which, in this specification, is defined as being 5 the inability of the male to be able to obtain and sustain a sufficiently rigid penis to allow vaginal penetration. BACKGROUND ART

Erection occurs when the pressure of blood in the erectile tissue or corpora cavernosa increases from the 10 resting level to greater than a critical level approaching diastolic blood pressure. This level is approximately 75mmHg (see Virag R: ARTERIAL AND VENOUS HEMODYNAMICS IN MALE IMPOTENCE, MANAGEMENT OF MALE IMPOTENCE, ed Bennett HA. Baltimore. Williams and Wilkins, Chapter 1, 1982). 15 Impotent males are not able to achieve and/or maintain this pressure in their erectile tissue for many reasons including psychogenic causes, arterial insufficiency and venous incompetence.

The increase in blood pressure in the corpora cavernosa 20 (erectile tissue) during erection occurs in response to several neurological and vascular phenomena. Although not well understood, the mechanism of erection is thought to ' ^• involve dilatation of arterial inflow vessels and the smooth muscles lining the corpora cavernosa as well as constriction 25 of venous outflow vessels.

Dilatation of arterial inflow vessels and the cavernosal tissue causes an erectile tissue blood pressure increase in response to increased blood inflow. Venous outflow constriction also causes an erectile tissue blood pressure rise which, in this case, is created by increasing the outflow resistance. In some impotent males one or both of these mechanisms fail to operate resulting in impotence. In the case of arterial insufficiency, impotence is most often due to arterial stenosis usually associated with atherosclerosis. The increase in venous outflow resistance is due to a constriction of the venous outflow vessels and is directly related to the increased volume of the erectile tissue during tumescence.

Ligation of venous outflow vessels including the deep dorsal vein increases the venous outflow resistance from the erectile tissue and has been used successfully in some patients to restore potency. At any given blood flow rate, increased outflow resistance results in increased erectile tissue blood pressure.

Following ligation, impotent men can obtain erections in response to sexual stimulation due to the increase in erectile tissue blood pressure. However, in the majority of cases the cure is only temporary. The most likely cause of the recurrence of impotence is due to the development of collateral circulation. DISCLOSURE OF INVENTION

One method of preventing collateral formation according to the invention is to intermittently occlude venous outflow vessels rather than to ligate them. A further extension of this method applies to some impotent men who can obtain partial penile tumescence. In these men, the blood pressure in the erectile tissue increases above the basal level but fails to reach the erectile level of approximately 75mmHg. According to one aspect of the present invention an implantable blood flow control device is used to cause erection in previously impotent males by increasing the erectile tissue blood pressure during sexual stimulation. The device is used to increase the resistance to venous blood outflow when an erection is desired. The device is automatically activated as the patient develops partial penile tumescence and increases the venous blood outflow resistance. The blood flow control device of the invention may be active or passive in the way it increases venous outflow resistance to cause an erection. BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings in whic :-

Fig. 1 is a cutaway diagrammatic view of a penis incorporating a blood flow control device according to one embodiment of the invention, Fig. 2 is a view taken along lines 2-2 of Fig. 1,

Fig. 3 is a view similar to Fig. 1 incorporating a blood flow control device according to a second embodiment of the invention, Fig. 4 is a side elevational view of a blood flow control device according to a third embodiment of the invention, Fig. 5 is a plan view of the device shown in Fig. 4 in position over the dorsal vein, Fig. 6 is a cross-sectional view of a flacid penis incorporating the device of Figs. 4 and 5, Fig. 7 is a view similar to Fig. 6 but with the penis erect,

Fig. 8 is a schematic diagram of a blood flow control system according to one embodiment of the invention, Fig. 9 is a schematic diagram of a blood flow control system according to a second embodiment of the invention, Fig. 10 is a schematic diagram of a blood flow control system according to a third embodiment of the invention, and, Fig. 11 is a schematic diagram of a blood flow control system according to a fourth embodiment of the invention. DESCRIPTION OF PREFERRED EMBODIMENTS

The blood flow control system shown in Figs. 1 and 2 utilises a passive control device which consists of one or more thin flexible biocompatible pads 10 which, in this instance, are inserted between the tunica albuginea 11 and the buck's fascia 12. The pads 10 are of sufficient volume such that when the patient initiates penile erectile tissue tumescence under normal physiological action, the additive volume of the pads with that of the tumescent erectile tissue is sufficient to cause an increase in venous vessel constriction. This increased constriction provides a sufficient resistance to blood outflow to increase erectile tissue blood pressure to the level required to obtain an erection. The pads may be implanted in other areas of the penis to achieve the same results.

The blood flow control system of Fig. 3 utilises an active control device. In this case, the device consists of at least one thin biocompatible fluid filled reservoir 13 which is implanted between the tunica albuginea 11 and the buck's fascia 12. The reservoir 13 is connected by SILASTIC tubing 16 to one or more cuffs 14 placed around major venous outflow vessels, such as the deep dorsal vein 15. Initiation of tumescence causes movement of fluid from the reservoir 13 into the cuff 14. The cuff constricts the venous vessel(s) which in turn increases venous outflow resistance. The higher outflow resistance increases erectile tissue blood pressure to the level required to obtain an erection.

The blood flow control system shown in Figs. 4 to 7 utilises a flexible band 20 of biocompatible material (such as silicone or polyurethane) to increase resistance to venous outflow. Embedded within the band 20 is a metal or plastic spring 21 which acts as a shape memory for the device. At each end of the band 20 there are suture points 22.

The device of Figs. 4 and 5 is implanted against a major corpora cavernosa venous outflow vessel such as the dorsal vein 23 at the base of the penis as shown in Fig. 6. The band 20 is, in this instance, sutured in place to the tunica albuginea 24 in the vicinity of the dorsal arteries and nerves 25. At erection, as shown in Fig. 7, the dorsal vein 23 is occluded between the band 20 and the rigid corpora cavernosa 26. Amplification of the venous outflow constriction process occurs automatically in patients who achieve some tumescence naturally. During tumescence, the suture points 22 hold the band 20 in place.

As the tunica albuginea 24 stretches, the two sutured ends of the band 20 are pulled apart to straighten the device and thereby compress the dorsal vein to increase the resistance to venous outflow. In addition, the impotent male may achieve increased resistance to venous outflow by manually, transcutaneously, pressing the band 20 against the dorsal vein 23. Manual activation may be used until tumescence has begun or erection obtained. Detumescence is spontaneous and caused by the natural erectile physiological mechanism. The techniques described above show three ways in which an implantable device can be used to increase erectile tissue blood pressure and thereby cause an erection.

The device of Figs. 8 to 11 may be used to control blood flow along a naturally occurring blood vessel or a fistula created to revascularize the erectile tissue. The blood pressure increase may be accomplished by increasing the resistance to blood outflow from the erectile tissue or increasing the blood inflow rate to the erectile tissue or by a combination of both.

The devices of this aspect of the invention control blood flow to or from the erectile tissue by causing constriction of a blood vessel or vessels. Activation of the device causing vessel constriction occurs only when an erection is desired and remains deactivated at all other times. Reverse function is possible but not recommended because of the likelihood of thrombosis or the development of collaterals. It has been shown that intermittent vessel occlusion using a device external to the vessel can safely occlude blood vessels for several hours at a time without causing vessel damage or thrombosis.

The blood flow control devices of Figs 8 to 11 may be used to control blood flow in vessels which are introduced at operation to revascularise the erectile tissue or in combination with naturally occurring blood vessels. The blood flow control system shown in Fig. 8 utilises two fistulae in combination with an occluding device. An inflow blood supply to the penis 100 is created between the cavernosal tissue shown diagramatically by numeral 101 and an arterial vessel 102 such as the femoral artery or inferior epigastric artery using a first saphenous vein graft fistula 103 or any other appropriate graft. An outflow or second fistula 104 is created between the cavernosal tissue 101 and the femoral venous system 105. The outflow fistula (known as a Graysacks procedure) may be created using a saphenous vein graft between the cavernosal tissue 101 and the femoral vein 105.

An occluding device consisting of a cuff 106 and reservoir 107 is implanted to occlude the Graysacks fistula. At operation, the arterial supply is created through the first fistula 103 so that it results in sufficient erectile tissue pressure increase to cause erection. Following the Graysacks procedure, the erection subsides in response to the decreased erectile tissue blood outflow resistance. Post operative activation of the occluding device by transcutaneously operating reservoir 107 closes the cuff 106 around the Graysacks fistula 104 to restrict outflow of blood from the cavernosal tissue 101 resulting again in an erection.

SUBSTITUTESHEET The blood flow control system shown in Fig. 9 is also a two fistulae system. One fistula 108 is used to arterialise one of the main venous outflow vessels from the corpora cavernosa 101 such as the deep dorsal vein 109. A saphenous vein graft may be used to connect the femoral artery 102 to the deep dorsal vein 109. A secondary fistula 110 connects the first fistula 108 to the venous system 111. The secondary fistula 110 may consist of a saphenous vein graft to the femoral vein 105. An occluding device consisting of an inflatable cuff 106 around the secondary fistula 110 and an operating reservoir 107 is implanted to occlude the secondary fistula 110.

When the secondary fistula 110 is occluded, the primary fistula increases erectile tissue blood outflow resistance and may cause retrograde flow of blood from the fistula into the erectile tissue. This occurs only when the occluding device is activated thereby preventing blood flow along the secondary fistula system to the venous system 111. When the device is not activated blood preferentially flows into the femoral vein 105 rather than the cavernosal tissue 101.

Another embodiment of the invention is shown in Fig. 10 where a saphenous vein graft fistula 112 is created between the deep dorsal vein 109 and the femoral artery 102. The cuff 106 of the occluding device is located above the junction of the fistula 112 and the deep dorsal vein 109. When the cuff 106 is actuated by pressing the reservoir 107, the deep dorsal vein 109 is occluded and blood flow from the femoral artery 102 through the fistula 112 arterialises the outflow vessels from the corpora cavernosa. The occluding device may be used to occlude one or more of the naturally occurring venous outflow vessels. It is known that ligation of the deep dorsal vein cures impotence in some men. However, in the majority of cases the cure is only temporary. The most likely cause of the recurrence is due to formation of collateral vessels. The ligation causes an increase in venous outflow resistance thereby increasing erectile tissue blood pressure during sexual stimulation in comparison to the pre-ligation value. Erection, occurs following increased arterial inflow due to sexual stimulation and as a result of the increased outflow resistance. Development of collaterals decreases the blood outflow resistance thereby decreasing erectile tissue blood pressure at a given blood inflow rate.

Intermittent dorsal vein occlusion shown in Fig. 11 has the same effect on venous outflow resistance as dorsal vein ligation. The cuff 106 of the occluding device is positioned around the deep dorsal vein 109 and is actuated by the reservoir 107. However, evidence suggests that collateral formation will either not be stimulated by intermittent occlusion or at least stimulated at a much slower rate. Therefore the cure will be either permanent or

for a much longer period than currently occurring with ligation.

The occluding device shown in Figs. 8 to 11 may be of the type described in our Australian Patent Application No. 48,016/85 which consists of a transcutaneously activated cuff which is placed around the vessel to be controlled.

Inflation of the cuff causes vessel occlusion.

The techniques described above show several ways in which an implantable occluding device in combination with a revascularisation procedure can be used to increase erectile tissue blood pressure and thereby cause erection. Other device and revascularisation technique combinations may be used without departing from the scope and ambit of the invention. Other device combinations may be used without departing from the scope and ambit of the invention.

Claims

1. A blood flow control device for causing erection in previously impotent males by increasing the erectile tissue blood pressure during sexual stimulation, said device comprising a flexible biocompatible pad adapted to be implanted within the penis, said pad being of sufficient volume so that when the patient initiates penile erectile tissue tumescence under normal physiological action, the additive volume of the pad with that of the tumescent erectile tissue is sufficient to cause an increase in venous vessel constriction.

2. -A blood flow control device according to claim 1 wherein the pad is inserted between the tunica albuginea and Buck's fascia.

3. A blood flow control device according to claim 1 wherein the pad is a first pad and there is provided a second pad.

4. A blood flow control device according to claim 1 wherein the pad comprises a fluid filled reservoir.

5. A blood flow control device according to claim 4 and further including an inflatable cuff adapted to be positioned around a venous outflow vessel and means for connecting the reservoir to the cuff whereby initiation of tumescence causes movement of fluid from the reservoir to the cuff.

6. A blood flow control device according to claim 5 wherein the cuff is a first cuff and there is provided a second cuff, each of said cuffs being positioned around a venous outflow vessel.

7. A blood flow control device for causing erection in previously impotent males by increasing the erectile tissue blood pressure, said device comprising a fluid filled reservoir adapted to be implanted within the penis, a cuff adapted to be positioned around a venous outflow vessel of the penis and means connecting the reservoir to the cuff whereby initiation of tumescence causes movement of fluid from the reservoir to the cuff.

8. A blood flow control device for causing erection in previously impotent males by increasing the erectile tissue blood pressure, said device comprising a flexible band of biocompatible material adapted to be implanted within the penis so as to constrict a venous outflow vessel of the penis.

9. A method of controlling the flow of blood in a penis ^~c cause an erection in previously impotent males comprising implanting blood flow restrictor means within the penis adapted upon initiation of penile erectable tissue tumescence to provide a sufficient resistance to blood outflow to increase erectile tissue blood pressure to the level required to obtain an erection.

10. A method according to claim 9 wherein the restrictor means comprises a flexible pad of biocompatible material, the pad being of sufficient volume so that when the patient initiates penile erectile tissue tumescence under normal physiological action, the additive volume of the pad with that of the tumescent erectile tissue causes an increase in venous vessel constriction.

11. A method according to claim 9 wherein the pad is inserted between the tunica albuginea and Buck's fascia.

12. A method according to claim 9 wherein the restrictor means comprises a fluid filled reservoir, a cuff adapted to be positioned around a venous outflow vessel of the penis and means connecting the reservoir to the cuff.

13. A method according to claim 9 wherein the cuff is placed around the deep dorsal vein.

14. A method according to claim 9 wherein the restrictor means comprises a flexible band of biocompatible material.

15. A method according to claim 14 wherein the band includes embedded spring means which acts as a shape memory for the band.

16. A method according to claim 14 wherein the band is sutured to the tunica albuginea in the vicinity of the dorsal vein.

17. A method according to claim 16 wherein the dorsal vein is occluded between the band and the rigid corpora cavernosa.

18. A blood flow control system for causing erection in previously impotent males by increasing the erectile tissue blood pressure comprising means for increasing the resistance to blood outflow from the erectile tissue or for increasing the blood inflow rate to the erectile tissue or a combination of both.

19. A blood flow control system according to claim 18 and including a blood inflow path, a blood outflow path and means for occluding the blood outflow path.

SUBSTITUTESHEET

20. A blood flow control system according to claim 19 wherein the blood inflow path comprises a fistula between an arterial vessel external of the penis and the cavernosal tissue.

21. A blood flow control system according to claim 19 wherein the blood outflow path comprises a fistula between the cavernosal tissue and a venous vessel external of the penis.

22. A blood flow control system according to claim 21 and including a cuff adapted to occlude the fistula.

23. A blood flow control system according to claim 18 and including a first fistula between an arterial vessel external to the penis and a venous outflow vessel of the penis whereby the fistula arterialises the outflow vessel, a secondary fistula connecting the first fistula to the venous system external of the penis, an inflatable cuff around the secondary fistula and means for inflating the cuff.

24. A blood flow control system according to claim 18 and including a fistula between a venous outflow vessel of the penis and an arterial vessel external of the penis, an inflatable cuff around the outflow vessel beyond the fistula and means for inflating the cuff so as to arterialise the outflow vessel.

25. A blood flow control system according to claim 18 and including an inflatable cuff around a venous outflow vessel and means for inflating the cuff.