WO2003103537A2

WO2003103537A2 - Apical penil implant for enlargement phalloplasty

Info

Publication number: WO2003103537A2
Application number: PCT/IT2003/000183
Authority: WO
Inventors: Salhi Jamal
Original assignee: Salhi Jamal
Priority date: 2002-06-05
Filing date: 2003-03-27
Publication date: 2003-12-18
Also published as: WO2003103537A3; ITRM20020314A1; AU2003226470A1; AU2003226470A8; ITRM20020314A0

Abstract

A surgically implanted penile prosthesis, including an apical prosthetic element (1) to be implanted as a pad in a sub-glans position, between the distal surface of the corpora cavernosa (2) and the glans (3), such apical prosthetic element (1) being of suitable size and shape to result, upon implant, in an overall increase in glans volume with no substantial alterations to the typical anatomical shape of the glans itself. The prosthesis can be associated with a pericavernous prosthesis (not shown) composed of two pericavernous prosthetic elements to be placed laterally, facing each other, outside the corpora cavernosa (2) along the whole penile length (5); the two pericavernous prosthetic elements are essentially semi-cylindrical or have the shape of a cylindrical segment of a reduced height, or have a crescent-shaped cross-section.

Description

APICAL PENILE IMPLANT FOR ENLARGEMENT PHALLOPLASTY

DESCRIPTION

The present invention concerns an apical penile implant for enlargement phalloplasty. More specifically, the invention concerns a penile prosthesis that can be surgically implanted between the distal surfaces of the corpora cavernosa and the glans in order to increase the latter's dimensions, and may be associated or not with a prosthetic element for penile shaft enlargement.

At present, many men turn to various specialists to obtain physical improvements not only as regards the functionality of their body, but also as regards physical appearance. The demand for cosmetic surgery, which was once considered to be a typically woman's prerogative, has been rising on the part of men as well, and has gradually extended to all parts of the body (hair transplants, rhinoplasty, facelifts, abdominoplasty, etc.). In this context, penile enlargement surgery - not correlated to problems of the organ's functionality - has seen a great development over the last ten years, due to socio-cultural developments and to increased confidence in plastic and reconstructive sur- gery techniques.

Apart from noting that the myth of a large penis has always accompanied the history of mankind and has been found in civilisations far apart from one another in time and space, one must acknowledge that, even for contemporary man, the size of one's penis is an integral part of a man's own image of personality, and critically influences the acceptance of one's body and value as an individual. In most cases, the desire to increase the dimensions of one's penis does not so much stem from any real handicap or lack of affection, as from the perception that the individual has of himself and of his own body. In cases like these, an individual perceives himself as inadequate and dispropor- tioned.

Even though, in most cases and especially in teenagers, the conviction of having a penis of inadequate dimensions is wholly devoid of any objec- tive grounds, in many cases a surgical intervention is seen as the only way to prevent psychological problems, which could also lead to forms of impotence. Increasing the size of a penis could thus act as a rebalancing factor for the individual's overall personality. As is known, a man's external sexual reproduction organ is composed of three parallel cylindrical masses of cavernous tissue covered by skin tissues. Two of these cylindrical masses, called corpora cavernosa, of a greater diameter than the third, are arranged like "gun barrels" and present two rounded distal tips. The third cylindrical mass, called the corpus spongiosum, is situated lower than the other two and in between. The corpus spongiosum contains the urethra, that distally ends with the external urethral meatus. The distal portion of the corpus spongiosum widens to form the glans, whose tissue goes to completely cover the tips of the two corpora cavernosa. Given the anatomical separation between the corpora cavernosa and the tissue of the glans, there is a cleavage plane between the distal ends of the corpora cavernosa and the deep face of the glans. Of the various overlapping subcutaneous fascias of the penile shaft, the innermost one, called Buck's fascia, surrounds both the two corpora cavernosa placed side by side as well as the corpus spongiosum of the urethra, but it also presents an internal sect (the intercav- ernous sect of Buck's fascia), that separates the two corpora cavernosa from the urethral corpus spongiosum. Each of the three membranes enclosing the two corpora cavernosa and the corpus spongiosum, inside Buck's fascia, is known as the tunica albuginea.

The hitherto known phalloplasty operations not intended to treat prob- lems of impotence can firstly be divided into interventions aimed at mainly increasing only the length of the organ (lengthening phalloplasty) and those aiming at increasing the volume thereof (enlargement phalloplasty). The techniques used in the first case mainly involve the severing of the pubic-penile suspensory ligament that anchors the penis to the pubis, making it adhere to the lower surface of the pubic bone. The result of this operation is a protrusion of part of the inner section of the penis, and this normally does not interfere with the organ's functionality, even if its arrangement is slightly altered during erection.

In most cases, however, the specialist is not just asked for a mere lengthening of the penile shaft, but also an overall increase in its volume, which mainly means increasing penile diameter. Among the techniques cur- rently available, the most common one in use involves removing fatty tissue from the patient himself, by liposuction from other parts of the body (such as the lower abdomen and the inner thigh) and then injecting it into the subcutaneous tissue of the penis circumferentially. A variation of this technique envisages the use of flaps of autologous fatty tissue (Free Fat Flap). This transplant of fatty tissue provides considerable increases in penile dimensions, but the effects are very often temporary because the injected fat can be reabsorbed very quickly (six months). As a result, this solution requires a series of follow-up maintenance interventions. Moreover, there is the added risk of infection, inflammation and the formation of abscesses, and even the outflow of the injected material, with the consequent adher- ences, retractions and difficulties in skin flow. Furthermore, there is the risk of secondary phimosis and pain during sexual intercourse, as well as the formation of oedemas and haematomas. Finally, the treated parts of the penis could present irregular surfaces and defects due to inadequate fills, owing to the uneven distribution of the fatty material, as well as gross alterations of penile symmetry.

Another kind of intervention involves rotating some pedunculate muscle flaps. This technique, the most commonly used by plastic surgeons, involves the overturning on the penis of some vascularised muscle flaps from the abdominal wall, without severing the flap base, in order to maintain blood flow in the transferred tissues. Alternatively, the surgery can entail the implanting of free dermal grafts, appropriately pre-treated, or also in this case pedunculate. However, this kind of intervention could also result in the complications mentioned above as regards fatty tissue transplants, and may even lead to the flaps necrosis and retraction, with a deformity of the penis during an erection (very broad base and very fine tip).

Alternatively, enlargement phalloplasty can be carried out using sili- cone or other inert fillers (silicone gel, water polymers, formacryl and the like), that are injected in the pericavernous tissues in order to increase penile volume. Other materials, such as lyophilised dermal tissue, duramadre, silastec and goretex, are made into strips and implanted inside the corpora cavernosa by making an incision in the tunica albuginea. The main drawbacks with these techniques are the risk of rejection and of infection with skin perforations, as well as the formation of capsula around the implant and sclerosis. This results in deformation of the penis and possible arching, besides the possibility of pain during sexual intercourse. Penile enlargement surgery techniques also include the methods and implants described in US patents No. 5445584 and No. 5669870, both in the name of James J. Elist. These patents concern penile prostheses for enlarging and lengthening the penis in patients who, in any case, still keep a normal erection capacity. US patent No. 5445584 concerns an inflatable prosthesis of an essentially tubular shape, to be implanted beneath the skin layers and around the corpora cavernosa, extending from the base of the glans to the base of the penis. The implant is soft and flexible, and is shaped like a cylindrical hose that is interrupted lengthways by a non-inflatable bellow-like section, to be positioned on the side of the urethral canal and of the corpus spongiosum. In order to adapt it as much as possible to the various conditions of an erect and flaccid penis, the implant is equipped with devices to assure pressurisation and these can be operated externally. In order to maintain the proper arrangement of the internal sheath of the hose when the prosthesis is deflated, the implant is equipped with an internal reinforcement composed of a spiral made of flexible material.

In the version described in the second US patent No. 5669870, the inflatable prosthesis is designed with partially tubular bellow-like body with loops transversal to the main axis of the tubular body. This shape is designed to adapt to penile expansion and, above all, to the lengthening of the penile shaft during an erection, and to avoid an unnatural retraction inside the prosthesis when the penis is flaccid. This second patent also discloses alternative embodiments where the tubular prosthesis is composed of two or three paral- lei longitudinal sections put under pressure by corresponding independent connections.

The solution proposed in the two aforesaid US patents to some extent takes into account the variations in penile shaft size when erect and flaccid; however, it suffers from the complexity of the implant pressurisation system. Moreover, the single element version (the only one envisaged in the first of the two patents) can give rise to a poor attachment of the prosthesis, or to detachment, as well as a reduction in sensitivity.

Alternatively, and still with the main aim of increasing penile size in patients with a normal erection, some proposals have concerned semi-rigid prostheses, also to be implanted in the pericavernous position. These pros- theses are composed of two separate half-shells or specular side-pieces that laterally wrap around the penis from the base of the glans and for the whole visible length of the penis. The patent application DE 19925162 (Michael et al.) describes one such prosthesis, created using an elastic, flexible and soft material with a smooth surface, that is inserted between the superficial penile fascia and the deeper one. The distal end of each of the two half-shells, nearest the glans, is resistant enough to be sutured to the tissues.

The device of this type which has been most widely divulged is the one described in European patent application EP 719528 (L. Subrini). This is essentially similar to the previous one and of earlier date. The implant, which was also marketed under the Volumis^® trade name, is composed of two complementary opposing half-shells of an essentially semi-cylindrical shape or a cylindrical segment of a smaller height, or even with a crescent-shaped cross-section, to be applied laterally to the two corpora cavernosa in order to increase the overall circumference of the penile shaft. The thickness of the two half-shells decreases towards the distal tip, and their distal edge can be cut obliquely in order to fit perfectly in the balano-preputial sulcus.

According to the description, the prosthesis may be composed of a suitable biocompatible synthetic material, which is flexible silicone in the commercially available version, but can also be a gel, appropriately enclosed within a flexible sheath. Over and beyond the actual validity of the aforesaid phalloplasty techniques, it is important to note that none of them intervenes on the apical part of the penis - the glans being left unchanged whatever the method adopted. On the other hand, for a successful penis enlargement phalloplasty operation, the pre-existing proportions of the organ must be respected. Any change in shape could lead to an imbalance and the resulting non-acceptance of the organ itself by the patient, who may perceive his penis as something disproportionate and foreign to the rest of his body. This does not solve the uneasiness that had led to the decision to undergo the operation in the first place. In general, the glans is in most cases volumetrically harmonious and consistent with the volume of the penis shaft. However, in a certain percentage of cases, the glans volume is undersized, mainly due to its congenital underdevelopment or because previous penile shaft enlargement surgery increased the volume of the penile circumference. Both in the case of con- genital underdevelopment and in the case of a disproportion accruing from enlargement phalloplasty, the present invention thus aims at providing a penile prosthesis to be implanted in the apical position in order to stably enlarge the volume of the glans in order to restore a harmonious or, in any case, an aesthetically pleasing proportion with respect to the rest of the organ. To this end, the present invention provides for an implant - on the apex of the corpora cavernosa and beneath the glans tissue - of a suitably shaped internal prosthetic element whose volume is added to the existing glans tissues in order to make the glans longer and broader and thus increase its overall dimensions. The present invention thus specifically provides a surgically implanted penile prosthesis comprising an apical prosthetic element to be implanted as a pad in a sub-glans position, between the distal surface of the corpora cavernosa and the glans, the said apical prosthetic element being of suitable size and shape to result, upon implant, in an overall increase in glans volume with no substantial alterations to the typical anatomical shape of the glans itself. Since it is to be implanted inside the tissues of the glans so as to take up room, while maintaining the glans normal anatomical shape, the apical pros- thetic element may have a substantially hemispherical, semi-ellipsoidal, sphere segment or ellipsoid segment shape. It can also be shaped like a "button": i.e. with a round shape as seen in front view and largely flat but with curved edges as seen in side view; or even "bean-shaped", i.e. with an oblong oval shape that is curved in front view and largely semi-oval in side view.

According to some preferred embodiments of the present invention, as well as having one of the general shapes mentioned above, the apical prosthetic element is anatomically shaped on the side designed to rest on the intercavemous sect, showing a rib corresponding to the groove formed by the said sect on the distal surface of the corpora cavernosa. In this way, the prosthesis perfectly fits the anatomical configuration of the site it is implanted in.

In order to anchor it stably in its final position, the apical prosthetic element according to the present invention is provided with two side appendages of reduced thickness for suturing it to the glans tissues or to the tips of the corpora cavernosa.

Similarly to the already known intracavemous and pericavernous prostheses, the apical penile prosthesis may be made of one or more biocompatible synthetic or natural materials, and in particular of a solid flexible material or a gel or liquid material enclosed in a flexible sheath consisting of one or more layers. Preferably, the said biocompatible material is composed of a three-layered silicone elastomer sheath filled with a silicone gel of parenchy- mal consistency. According to a further preferred solution, the elastomer sheath has a texturised external surface, i.e. a surface worked in such a way as to be extremely irregular, in order to improve implant bonding with the sur- rounding tissues and to reduce the formation of a rigid fibrotic capsule as much as possible.

According to another aspect of the present invention, the aforesaid apical prosthesis may be associated with a pericavernous prosthesis essentially similar to that used in the closest prior art. In this case, the aim of the phalloplasty is not to harmonise glans dimensions with those of the penile shaft, to deal with a congenital glans underdevelopment or a disproportion following enlargement phalloplasty of the penile shaft, but to achieve a com- plete enlargement phalloplasty with harmonious results, by acting at the same time on penile shaft size as well as on glans size.

According to some further preferred embodiments of the present invention, therefore, the surgically implanted penile prosthesis also includes two pericavernous prosthetic elements to be placed laterally facing one another along the whole length of the penile shaft, in contact with the tunica albuginea of the corpora cavernosa and under Buck's fascia. These pericavernous prosthetic elements are essentially semi-cylindrical or have the shape of a cylindrical segment of a reduced height, or have a crescent-shaped cross-section. Preferably, each of the two pericavernous prosthetic elements has a distal tip of a gradually decreasing thickness and with rounded edges, and each of the two said distal tips can be provided with an appendage of reduced thickness, for suturing the respective prosthetic element to the tip of the homolateral corpus cavernosum and/or to the glans and/or to the said apical prosthetic element.

In the version of the apical prosthesis combined with the two pericavernous prostheses, the apical prosthetic element can be provided with two lateral appendages of reduced thickness, each one to be used for the attachment to the distal tip of the homolateral pericavernous prosthetic element. The materials which may be used in manufacturing the pericavernous prosthetic elements can be selected in the same group of materials already described for the apical prosthesis, even though it is not necessary for the said elements, when used in combination, to be of exactly the same material.

Further structural and functional features of the penile implant accord- ing to the present invention, as well as the advantageous aspects of its application, will be more evident with reference to some specific embodiments thereof, illustrated by way of example in the attached drawings, where:

Figure 1 is a top plan view of a penile shaft prior to phalloplasty;

Figure 2 is a top plan view, partially cut-away, of the same penile shaft shown in figure 1 , after a phalloplasty operation with the implant of the apical prosthesis according to the present invention;

Figure 3 is a side elevation view, partially cut-away, of the same im- plant shown in figure 2.

Figure 4 is a cross-section taken along the A-A plane, of the same implant shown in figure 3;

Figure 5 is a plan view from the bottom, partially cut-away, of the same implant shown in figure 2;

Figure 6 is a top plan view, partially cut-away, of the same penile shaft shown in figure 1 , after a phalloplasty operation with the implant of the apical and pericavernous prostheses according to the present invention;

Fugure 7 is a plan view from the bottom, partially cut-away, of the same implant shown in figure 6;

Figure 8 is a side elevation view, partially cut-away, of the same implant shown in figure 6;

Figure 9 is a cross-section taken along the B-B plane, of the same implant shown in figure 8; Figure 10 is a perspective exploded view of the implant of figures 6-9;

Figure 11 is a perspective view of the same implant of figure 10, with the prosthetic elements in their final position;

Figure 12 is a perspective view of the implant of figures 2-5, with the prosthetic element in its final position; Figure 13 schematically shows some apical prosthetis configurations alternative to the one shown in figures 2-12, seen in cross-section along planes corresponding to the A-A plane of figure 3; and

Figure 14 schematically shows the cross-sectional views of the same configurations of figure 13 along orthogonal planes. As shown in figures 2-5 and 12, a first version of the penile implant according to the present invention consists of a single apical prosthetic element (1 ), suitably shaped for being implanted near the tip of the two corpora cavernosa (2) and below the glans (3). The surgical implanting of the apical prosthetic element (1 ) is made possible by the fact that, between the two ad- jacent masses of the corpora cavernosa (2), each lined with the relative tunica albuginea, and the lower face of the glans (3), made of the same tissue as the corpus spongiosum of the urethra (4), there is a cleavage surface along which the detachment of the tissues is relatively easy.

A comparison of figure 1 with figures 2-5 shows the increase in glans volume after implanting the apical prosthesis (1 ) according to the present invention, as well as the resulting lengthening of the overall penile shaft (5). In general, bearing in mind the normal sizes of the anatomical parts concerned, the apical prostheses (1 ) preferably have a maximum thickness (in the central part) of 0.5-1.5 cm, thus assuring corresponding increases in the overall penile length. The apical prostheses (1 ) can be manufactured in various sizes to perfectly fit the patient's sizes, and can preferably have a diameter ranging between 1.5 and 2.5 cm (in the widest part of the prosthesis, if it is a prosthesis with a non-circular section).

As shown, above all, in figure 2 and in the perspective view of figure 10 (even though, in this case, with reference to a prosthesis that also includes the pericavernous elements, which will be dealt with below), the configuration of the apical prosthesis (1 ) is "anatomical" in the case depicted, since it is provided with a ribbing (6) on its lower face that corresponds to the groove formed by the intercavemous sect at the tip of the two corpora cavernosa (2).

In the case of the embodiment illustrated in figures 6-9 and 10-1 1 (in which the same reference numbers are used to show the same elements as in figures 2-5 and 12), the apical prosthesis (1) is associated with a penile shaft (5) enlargement prosthesis, composed of two pericavernous prosthetic elements (7), which are implanted on both sides, and facing each other, along the whole length of the penile shaft (5). As with the pericavernous prostheses of the prior art, the ones shown in the attached drawings can have semicircu- lar cross-section or a reduced height circular segment section, but they are preferably configured in order to perfectly adapt to the penile shaft (5) on which they are implanted. Thus, they preferably present a crescent-shape cross-section, which may be seen in the perspective view of figure 10 and, in the external view, in the cross-section of the glans (3) of figure 9. Preferably, the two distal tips (8) of the pericavernous prosthetic elements (7) gradually become thinner towards the glans (3) and their edges are rounded. Although this is not shown in the figures, the pericavernous pros- thetic elements (7), as well as the apical prosthesis (1), can be provided with thin "strip-like" appendages or terminal edges to allow the prosthesis attachment to the underlying tissues and/or the connection of the apical prosthesis (1 ) to the two pericavernous prosthetic elements (7). The external surface of the two pericavernous prosthetic elements (7) can be smooth or made anatomical with ribbing that simulates the vein system of the penis. It is important to note that the length of the prosthesis must be the same as the erect penis in order to avoid the feeling of a step, and a shrinking of the section, should the prosthesis not exactly terminate at the base of the penile shaft at the proximal end and at the level of the balano- preputial sulcus at the distal end. For the penile shaft not to have an unnatural aspect when flaccid, it is extremely advantageous for the two pericavernous prosthetic elements (7) to be made of a gel or liquid material enclosed in a flexible sheath, of the type already in use for mammary prostheses, instead of using a solid flexible material. In this way, the two pericavernous prosthetic elements (7) can adapt to dimensional variations of the erect or flaccid penis by inflating laterally when flaccid and extending more lengthways when erect.

Figures 2-12 show for the apical prosthesis (1) an "anatomical" shape, which is substantially "bean-shaped", in order to follow the configuration of the urethral canal, but with a ribbing (6) on the side where the prosthesis rests on the corpora cavernosa (2) in order to better fit the tips of the latter at the inter- cavernous sect, However, many other shapes are possible, generally of a pad type, such as the ones illustrated in figures 13 and 14. Especially in the case where also the apical prosthesis (1 ) is made of a gel or liquid material en- closed in a flexible sheath, these shapes will easily fit the space in which the apical prosthesis (1 ) is implanted, thus allowing the glans (3) to move forward and outward thereby increasing its size.

For merely illustrative purposes and by way of example, some cases of enlargement phalloplasty using the prosthetic elements according to the present invention are reported below, together with an evaluation of the results obtained. 1 st case - Apical prosthesis implant

A 29-year-old confectioner, married for the last 7 years and with a son, a non smoker and moderate drinker, with regular intestinal function and diuresis, complained of an undersized glans penis. In the preliminary interview with the psycho-sexologist, he did not show signs of any sexual deficiency; indeed, the sexual relations were satisfying for both partners.

The patient's worry solely concerned the size of his glans which, in his view, was smaller than the norm, also because he had been circumcised around the age of 14 for a congenital phimosis. The fact that his glans was always uncovered and visible made him very frustrated and gave him a feeling of inadequacy both during intimate moments with his wife and during his everyday life, such as when using the communal changing rooms and showers of sports clubs.

The objective examination showed a circumcised penis about 13.5 cm long and 9 cm in circumference. The glans appeared in a proportionally smaller size, also during an erection (obtained via Video Sex Stimulation).

After a careful psycho-sexological evaluation and lengthy discussion with the patient, he underwent the apical penile implant according to the present invention. After administering a local anaesthetic and light sedation, a small right-lateral sub-coronal incision of about 1.5 cm was made, following the old scar of the previous circumcision. After opening Buck's fascia and via an artificially induced erection by an infusion of a physiological solution to facilitate surgical dissection, the operation proceeded with the dissection of the glans from the tips of the corpora cavernosa, creating a small pocket rang- ing from the distal surfaces of the corpora cavernosa to proximally the rear surface of the glans. The other adjacent anatomical structures (dorsal vas- culo-nervous fascia and ventral spongio-urethral corpus) were not touched. The pocket formed in this case had a single aperture, and its preparation took into account the symmetry of the terminal end of the penis. After inserting an apical prosthesis of the "button-shaped" type of a suitable size, the surgical cut was closed with separate stitches, reattaching the posterior surface of the glans to the distal tunica albuginea of the right-side corpus cavemosum and reconstructing the anatomical planes.

The medication used was of the light elasto-compressive type. Moreover, a systemic antibiotic was administered in the intra-operation period and was continued in the next 5 days. The result 15 days after the operation was very satisfactory, with a volumetric increase of the glans penis and also a lengthening thereof by about 7 mm. Forty days later, the patient could resume normal sexual relations and a later psycho-sexological evaluation showed a considerable improvement.

2nd case - Apical prosthesis implant associated with pericavernous prosthesis The patient was a 27-year-old professional who was a non-smoker and moderate drinker, with regular intestinal function and diuresis, and enjoyed excellent overall health. He was 1.83 m tall and weighed 79 kg. He had a 25-year-old girlfriend of three years standing, but they did not live together and did not have very frequent sexual relations (1-3 times a month). He reported having a normal erection and in most cases a premature ejaculation.

The patient complained that he had a small penis. The objective examination showed a penis about 4 cm long and 6 cm in circumference when flaccid, with an abundant foreskin. In erection the penis reached about 13 cm in length and 10.5 cm in circumference. The volume of the glans was proportionally smaller than the penile volume, with a latero-lateral diameter of 2.5 cm and a height of 2 cm.

The patient was interviewed by a psycho-sexologist who gave a favourable opinion to the surgical operation for enlargement phalloplasty. After being completely informed of the surgical technique, the materials used, the benefits and the possible risks or complications, the patient gave his informed written consent to the operation.

The operation was carried out under general anaesthetic. After making a circular sub-coronal incision, the operation proceeded with the total "de- gloving" of the penis: the suspensory ligament of the penis was severed and then a pericavernous sub-fascia tunnel was prepared (under Buck's fascia) proximal to the tunica albuginea, bilaterally, for the whole length of the penis. This tunnelling extended to the tips of the corpora cavernosa, finding a cleavage plane between the tunica albuginea and the posterior face of the glans tissue. The partial detachment of the glans did not concern the dorsal side or ventral side. Two service incisions were made on Buck's fascia on each side, a sub-glans one and a mid-penile one. After introducing and attaching the apical prosthesis according to the present invention, the two half-shells of the associated pericavernous prosthesis were implanted and fixed at both apical and proximal ends. The implanted components were secured by using stitches transfixed in the underlying tunica albuginea and by covering the prosthesis with Buck's fascia.

The tip of the pericavernous prosthesis was positioned in the sub- glans location. After a layered reconstruction and partial postectomy, the skin was sutured with catgut and an elasto-compressive medication was applied. The patient was given an antibiotic in the intra-operation phase.

Immediately after the operation there was an increase of about 3 cm in penis size during erection and the circumference of the penis when flaccid was about 11 cm. The volume of the glans had increased overall and was now proportionate for the new size of the penis. The latero-lateral diameter of the glans had increased to 3.5 cm and was now 2.6 cm high.

The patient's follow-up lasted one year, during which he underwent periodic checks. He did not have any complications and the results of the operation were stable. After the initial period of convalescence, the patient did not have any impediment in his sex life and there was considerable improve- ment also at the psychological level.

The present invention has been disclosed with particular reference to some specific embodiments thereof, but it should be understood that modifications and changes may be made by the persons skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims

1. A surgically implanted penile prosthesis comprising an apical prosthetic element (1) to be implanted as a pad in a sub-glans position, between the distal surface of the corpora cavernosa (2) and the glans (3), the said apical prosthetic element (1 ) being of suitable size and shape to result, upon implant, in an overall increase in glans volume with no substantial alterations to the typical anatomical shape of the glans itself.

2. A penile prosthesis according to claim 1 , wherein the said apical prosthetic element (1) has a substantially hemispherical, semi-ellipsoidal, sphere segment or ellipsoid segment shape, or is button-shaped or bean- shaped.

3. A penile prosthesis according to claims 1 or 2, wherein the said apical prosthetic element (1 ) is anatomically shaped on the side designed to rest on the intercavernous sect, showing a rib (6) corresponding to the groove formed by the said sect on the distal surface of the corpora cavernosa (2).

4. A penile prosthesis according to any one of claims 1-3, wherein the said apical prosthetic element (1 ) is provided with two side appendages of reduced thickness for suturing the said apical prosthetic element (1 ) to the tissues of the glans (3) or to the tips of the corpora cavernosa (2).

5. A penile prosthesis according to any one of claims 1-4, wherein the said apical prosthetic element (1 ) is made of one or more biocompatible synthetic or natural materials.

6. A penile prosthesis according to claim 5, wherein the said biocom- patible material is a solid flexible material or a gel or liquid enclosed within a flexible sheath consisting of one or more layers.

7. A penile prosthesis according to claim 6, wherein the said biocompatible material is composed of a three-layered silicone elastomer sheath filled with a silicone gel of parenchymal consistency.

8. A penile prosthesis according to claim 7, wherein the said elastomer sheath has an external texturised surface.

9. A surgically implanted penile prosthesis according to any one of the preceding claims, also including two pericavernous prosthetic elements (7) to be placed laterally facing one another along the whole length of the penile shaft (5), in contact with the tunica albuginea of the corpora cavernosa (2) and under Buck's fascia; the pericavernous prosthetic elements (7) being essen- tially semi-cylindrical or having the shape of a cylindrical segment of a reduced height, or having a crescent-shaped cross-section.

10. A penile prosthesis according to claim 9, wherein each of the said two pericavernous prosthetic elements (7) has a distal tip (8) of a gradually decreasing thickness and with rounded edges.

11. A penile prosthesis according to claim 10, wherein each of the said two distal tips (8) is provided with an appendage of reduced thickness for suturing the respective prosthetic element to the tip of the homolateral corpus cavernosum (2) and/or to the glans (3) and/or to the said apical prosthetic element (1 ).

12. A penile prosthesis according to claims 9-11 , wherein the said apical prosthetic element (1) is provided with two side appendages of reduced thickness, each one for attachment to the distal tip (8) of the homolateral pericavernous prosthetic element (7).

13. A penile prosthesis according to claims 9-12, wherein each of the said two pericavernous prosthetic elements (7) is made of one or more biocompatible synthetic or natural materials.

14. A penile prosthesis according to claim 13, wherein the said biocompatible material is a solid flexible material or a gel or liquid enclosed within a flexible sheath consisting of one or more layers.

15. A penile prosthesis according to claim 14, wherein the said biocompatible material is composed of a three-layered silicone elastomer sheath filled with a silicone gel of parenchymal consistency.

16. A penile prosthesis according to claim 15, wherein the said elastomer sheath has an external texturised surface.