PENILE RIGIDITY PROSTHESIS

Abstract: A penile rigidity prosthesis for the treatment of erectile impotence in men includes at least one penile implant comprising an elongated maleable cylindrical body adapted to be surgically implanted in the corpus cavernosum of the penis; said body having a rounded front tip and an anatomical design at the end; the outer sheet of the cylinder is made of harder elastic material while the inner of considerably softer one; embedded in this material there is a core of twisted metal wires. In the variable size type the wires are fixed into a screw, allowing intermediate small cylinder extensions and a tail end to be screwed all together.

Description: TECHNICAL FIELD A penile rigidity prosthesis which is adapted to be surgically implanted into the corpus cavernosum of the penis in men for the treatment of erectile impotence. BACKGROUND ART Some cases of erectile impotence do not respond to conventional therapy and , as a result , the surgical implantation of a penile prosthesis may be the only practical way of remedying the impotence. In the past, several different types of - penile rigidity prosthesis have been employed. It started with pure silicone rods which , whatever be its hardness , always left the user in extreme situations : if hard enough to allow natural intercourse it revealed its presence due to its straight forward position at anytime ; if too soft , to easily bend in "micturation position", out of sexual intercourse , it lost its desirable rigidity and appearance for intromission. Some improvements have been obtained with the use of metal rods or wires in the core of silicone cylinders with some achievements on the maleability aspect. Nevertheless the forced compromise among the full maleability of appropiate metals the back force of just one type of silicone and the rigidity of the entire system have not been well succeeded. Most of the penis becomes bended in a curve position instead of its natural hang on the plane of the body . While this curved position brings some discretion in a dressed body , the abnormal curvature seems to be a reason of real embarassment when undressed. Furthermore a maximal silicone hardness of 50 shore A , usually employed on those prosthesis is low enough and permits the prosthesis silicone tip and/or tail to fracture during surgical manipulation of the implant. The present invention relates to a novel implantable penile rigidity prosthesis, More particularly it relates to a double silicone sheet and metal wires core which makes it more maleable and less harder and also resitant to rupture achieving the desirable longitudinal rigidity of the penis for vaginal intromission. A variable size type is also provided. References: - Trim, Gerald W. USA 626373 1975 DT 2646323 A1 - Gerow, S.F. USA 637557 1975 DT 2648234 A1 - Finley, Roy P. USA 729251 1976 DE 2744265 A1 - Koss , Walter DE 8031230 U BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side section view along the midline of the entire penile rigidity prosthesis,in one preferred embodiment, the fixed lenght model. Figure 2 is a enlarged cross sectional view taken along the midportion of the implant. Figure 3 is a tridi ensional and a cross sectional view of the proximal end or the prosthesis tail. Figure 4 is a tridimensional and a cross sectional view of the distal end or the prosthesis tip. Figure 5 is a side view of one penile rigidity prosthesis in one preferred embodiment of the variable size model. Left : the main body with its rounded front tip , the metal wires fixed into the screw . Middle: a spare cylinder extension with its screw and inside and outside threads. Right : the tail of the prosthesis with its single inner thread screw. Figure 6 is a tridimensional and cross sectional view of parts of the variable size prosthesis. Left : partial view of the main body with the metal wires incasing the screw. Middle : a spare cylinder extension. Right : the tail and its screw. DISCLOSURE OF THE INVENTION It is the general object of the present invention to disclose a novel implantable penile rigidity prosthesis of superior maleability. Regadless its proper longitudinal rigidity it has the sufficient lateral elasticity and hardness to avoid silicone fracture due to the bending of the silicone on the metal edges. It is of further object to disclose in such implants the provision of a variable size model by employing intermediate cylinders between the tail and the prosthesis main body. In the preferred embodiment the penile rigidity prosthesis consists of two identical and independent rods that can be surgically implanted completely into the penis through the most usual surgical techniques. Each rod has a cylindrical body with a round tip and a quasi-conical tail. The external wall of the cylinder is made of elastic harder material, preferentially medical grade silicone with a ir nimum hardness of 60 shore A and a elongation capability of at least 700% . The core is made of metal wires occupying about 60% of the total lenght of the implant. Between the core and the external wall there are sheets of softer material with a hardness of approximately 20 shore A and ' a smaller elongation capability. On those prosthesis that a provision for a variable lenght exist the metal core extremities attaches into a screw; its thread determines the border of the implant main body. The tail also has a screw with a internal thread that matches the screw of the main body. There are small cylinders with, a screw, internal and external threads , that can be interposed between the main body and the tail of the prosthesis thus allowing a modification of the total lenght. BEST MODE OF CARRYING OUT THE INVENTION As better seen in figure 1 the implant has an inteimediate cylinder portion, a rounded tip and a quasi-conical tail. According to figure 2 the inner portion of the prosthesis core is made of twisted metal wires (3) . Its outer shelf (1) is made of harder elastic material, preferably medical grade silicone rubber, having a hardness around 60 shore A and at least 700% of elongation. Between the metal core and the outer shelf there sheets of softer material, preferably medical grade silicone rubber with a hardness between 20 and 40 shore A. The elongation of this material should be greater than 350% . Ideally the size of the central metal core should be 60% of the total prosthesis lenght being nearer the tip than the tail (figures 3 and 4) . This allows manual trimming size facilities on surgery time. Also the remoteness of the metal wires from the extremities help the pure silicone ends to absorb better the stresses of those regions. The metal wire core can be made of any maleable metal wire, according its biocompatibility, being the wires thinner as the metal becomes less maleable. Preferably the metal wires shall be twisted all together. The thickness of the harder outer shell shall be kept between 1.5 and 2.3 mm. Providing the need for a variable size lenght penile prosthesis a modification on the simpler preferred embodiment may be performed. As better seen in figure 5 the central metal core ends into a screw with its thread (10) off the main body of the prosthesis. A cylinder spare extension with a screw having an inner thread at one side and an outer thread at the other (9) is covered (6) with the same sheet of hard material as the main body and has the same final thickness and outer diameter. The tail has also an inner thread (Figure 6., 11),that matches either the main body or the cylinder extension , and desirably a quasi-conical shape with the same materials employed on the main body. On figure 6 those described parts can be better visualized on the lateral sections of the tridimensional drawings. On the left a partial view of the main body with the screw, its protused thread, and the metal core attached to it. In the middle one spare cylindrical extension (7) with its screw that has inner and outer threads (8). On the right the tail with its screw having an- inner thread (11) attached to the cylindrical extension or only to the main body. Thus, by changing the number of spare cylinders the total lenght of the implant can be altered. It is recommended that the total lenght of the cylinders be kept at 1.5 cm and that the size of the tail be shorter than 3.0 cm . It is also recommended to use up to three extension cylinders for each prosthesis The size of the human penis varies ; so must do the prosthesis. Moreover because a part of the corpus cavernosu is hidden into the pelvis its exact size can only be estimated through external measurements. The prosthesis needs to occupy the entire lenght of the corpus cavernosum. Accordingly to present techniques a large number of prosthesis sizes must be supplied at surgery room ; if that request is not attended, as the most current error overestimates the. size , the penile prosthesis will be too tight and consequently painful to the patient or can be even rejected or extruded due to excessive compression. With the preferred embodiment of the fixed size model its extremities can be trimmed down to 25% of its initial lenght on surgery room with scalps or scissors. This facility avoids the above described inconvenient and consequent cost. One of the most used surgical techniques for penile prosthesis implant accesses the corpora cavernosum at the glans penis shaft. After dilating it down to the pubis and up to the glans , the prosthesis is introduced first into the pubis ; than the glans penis must be dressed up and the surgeon to do so compresses and bends the tip of the prosthesis. Usually breakage of the tip occurs at this surgical step on those prosthesis made up of a single kind of silicone. The double sheet prosthesis described in this application reduces this trouble to zero due to its greater elasticity and the reinforced external wall . Furthermore the remoteness of the metal wire core from the extremities let them softer and more capable of receiving stresses or pressure specially during sexual intercourse. Finally, due to its double sheet material build up the total back up force of the elastic material is reduced allowing a efficient bending of the metal core which angles further than 90° leaving the penis at its natural hang on position along the plane of the body. On the other hand the problem of underestimation may occur. A too small prosthesis leaves the penis in a poor cosmetic and functional situation. The glans penis stays loose during sexual intercourse creating embarassment and a poor quality contact with the vaginal tissue. To overcome even this possibility the other preferred embodiment the variable size is fitted. If yhe size of the implant is determined by external conventional measurements - the size of the distended penis from the midglans to the pubic bone, plus seven centimenters (expectation on the lenght of the inner region of the corpus cavernosum) - it is recommended a kit consisting of main body , two spare extensions and a tail - which mounted all together fits that expectation - supplied with one additional spare extension. If in the surgery room an underestimation is revealed another extension may be added. If occurs an overestimation up .to two spare-cylinders can be removed with no compromise on the anatomy of the implant " . Calculations on this recommended kit reveals that the rigid part of the prosthesis (three screws and the tail) will have up to seven centimeters and will be always into the inner region of the corpus cavernosum. ' Nevertheless , if further reducement of the lenght is needed, its tip , as in the fixed size model , can also be manualy trimmed , up to 1.5 cm , although loosing its smoothness and a perfect frontal anatomical fitness. It must be clear that the invention is not to be limited by any of the specific embodiments described but only by the claims which follows. INDUSTRIAL APPLICATION Although the limited medical field of penile implants r its importance is unquestionable. As organic impotence deseases are being more recognized and the prosthetic treatment better accepted each new development on the prosthetic devices will contribute to its widespread use. We are very confident that the good results obtained with its use during the experimental period will reflect on the industrial application.

Claims: CLAIMS 1. The penile rigidity prosthesis comprises an elongated body having a tip portion at one end and a tail at the other both made up of two elastic materials being the outer sheet significantly harder than the inner , and maleable metal wires located at the core of the softer sheet. A. The maleable metal core wires are away from the extremities extending itself along the lenght of the implant no more than 70%. 2. A system of screwable spare cylinders were designed to be placed between the tail and the main body for changing the lenght of the penile implant of claim 1. A. The screwable spare cylinder has equal inner and outer threads. B. The main body and the tail of the penile prosthesis have screws to match the cylinders.

Inventors: AYRES MARQUES HELIO JOSE, MOREIRA DE AZEREDO FERNANDO AN, AYRES MARQUES, HELIO, JOSE, MOREIRA DE AZEREDO, FERNANDO, ANTONIO
Applicants: AYRES MARQUES HELIO JOSE, MOREIRA DE AZEREDO F A, AYRES MARQUES, HELIO, JOSE
Application year: 1985
Main classification: A61F5
IPC codes: A61F2