One‐day penile prosthesis surgery by penile block

Since penile prosthesis surgery is conducted under general, spinal, epidural and other forms of anesthesia, it is a highly invasive procedure. Consequently, many elderly patients decline treatment. Furthermore, because hospitalization is required, many patients refuse to have penile prosthetic surgery treatment, particularly if they are resistant to hospital admission or have severe time-related restrictions. This surgical modality is not covered by the national medical insurance system, which places a heavy financial burden on the patient as the hospitalization and treatment are expensive. For these reasons, in order to reduce the physical, psychological and economic burden on the patient, we have been conducting non-inflatable penile prosthesis surgery by means of a penile block (local anesthesia) since April 1993. The subjects of the present study were 20 organic impotence patients who visited the Reproduction Center at Toho University School of Medicine. Their ages ranged from 25 to 80 years and their mean age was 53.5 years. Differential diagnosis was conducted by a variety of tests, including questioning, urinalysis, hemanalysis, endocrine tests, psychological tests, nocturnal tumescence recordings, examination of the peripheral nerves of the penis using a vibrometer (SMV-5 biothesiometer; Medicine Co. Ltd, Tokyo, Japan), measurement of bulbocavernosus reflex latency, audiovisual sexual stimulation tests, intracavernosal injection tests, color Doppler, dynamic infusion cavernosometry and cavernosography (DICC). The results of these tests revealed 11 vaso-neurogenic cases, five vasogenic cases, two endocrinogenic cases, one neurogenic case and one cavernosal case (intracavernosal fibrosis due to papaverine hydrochloride). Prior to the operation, an external vacuum device was used to evaluate the feasibility of using the technique, and the consent of the patient’s partner was obtained. Anesthesia was conducted by injecting 0.5% bupivacaine hydrochloride using a 27G (27-gauge) needle at four sites between the tunica albuginea of the phallobase and the Buck’s fascia (Fig. 1a). We injected approximately 2 mL of the anesthetic per site using a total of 8–10 mL. The following measures were employed to minimize the discomfort caused by injection: (i) the patient was reassured about the procedure, (ii) we used the finest needle possible (27-gauge or less), (iii) the area to be injected was pinched between the fingers, (iv) penetration of the injection needle through the skin was rapid, (v) the anesthetic was infused as slowly as possible, and (vi) the site of anesthetic infusion was massaged thoroughly.1 After making a subcoronal skin incision (Fig. 1b), the Colle’s fascia and Buck’s fascia were released, the neurovascular bundle was displaced medially, and an approximately 2 cm lengthways cut was made in the tunica albuginea of the corpus cavernosum of the penis using a number 11 scalpel after elevating the tunica albuginea with a 2-0 silk suture. Dilatation of the corpus cavernosum was conducted slowly using long scissors and a sizer (proximal to the crus penis) (Fig. 1c,d). Hegar was not used for the dilatation. The prosthesis was an AMS600 (American Medical Systems Inc., Minnetonka, MN, USA) or a DURA-II (Timm Medical Technologies, West Parkway, MN, USA; Fig. 2). Before insertion, the prosthesis and the lumen of the corpus cavernosum were flushed with physiological saline solution using an antibiotic (phosphomycin). The prosthesis was first inserted proximal to the corpus cavernosum, then inserted distally using a small retractor. The tunica albuginea was continuously sutured with 2-0 Vicryl. The Colle’s fascia and Buck’s fascia were sutured with 4-0 Vicryl, and the skin was sutured with 4-0 nylon. Postoperatively, a urethral catheter was employed in the first ten patients treated; however, in subsequent cases, the urethral catheter was not used and the patients returned home with the penis in an elevated state. The following day, the balloon catheter was withdrawn and the wound was sterilized with antiseptic during a visit to the out-patient clinic. The patients subsequently conducted antiseptic sterilization themselves at home, then underwent suture removal at about one week to ten days after the operation. Sexual intercourse was proscribed for two months after the operation. (a) Anesthesia was conducted by injecting 0.5% bupivacaine using a 27-gauge needle at four sites between the tunica albuginea of the phallobase and the Buck’s fascia. (b) Subcoronal skin incision. (c,d) Dilatation of the corpus cavernosum was conducted slowly using long scissors and a sizer (proximal to the crus penis). The two types of prostheses, (a) an AMS600, (b) a DURA-II, (c) a diagram of an inserted prosthesis. The operation time was about 1 h and none of the patients experienced operative pain. Anesthesia was effective for a period of 2–4 h. The 10 patients in whom an urethral catheter was inserted experienced urethralgia. Eighteen patients underwent surgery as out-patients and two as in-patients (because of the need for blood sugar control by insulin). Five patients received an AMS600 and 15 a DURA-II prosthesis (Fig. 3). The lengths of the prostheses were either the same as that of the corpus cavernosum, or 5 mm shorter. Prostheses widths were 9.5 mm in one case, 11.5 mm in four cases and 10 mm in 15 cases, and lengths were 14 cm in two cases, 15.5 cm in one case, 16 cm in five cases, 17 cm in three cases, 18 cm in six cases and 19 cm in three cases. The follow-up period ranged from one year to five years and seven months, and the mean follow-up period was three years and five months. Complications consisted of unilateral spontaneous prolapse in four cases (ranging from six to 30 months after the operation, with a mean period of one year and nine months) and a persistent sensation of the presence of a foreign body in one case. However, all of these patients were able to continue to engage in sexual intercourse. Prostheses were removed surgically from two patients, one of whom was not able to engage in sexual intercourse and the other because of the sensation of the presence of a foreign body. Complaints about the insertion of the prosthesis included feelings of narrowness, smallness and coldness of the penis, lack of flexibility at times other than during sexual intercourse (AMS600), bending of the phallobase during sexual intercourse, and the occurrence of an audible sound when the penis was bent (DURA-II). Post operation, erection and non-erection. Penile prosthesis surgery is the most reliable treatment among the therapeutic modalities available for organic erectile dysfunction. However, surgery conducted on inpatients under any form of anesthesia other than local anesthesia, places a substantial physical, psychological, economic and time-consuming burden on the patient. In many cases, this burden causes the patient to abandon surgical treatment and to depend exclusively on chemotherapy, the efficacy of which is limited. However, surgery conducted under local anesthesia lessens the burden on the patient. After the initial decision to operate is made, an adequate number of pre-operative tests should be conducted. For example, if the patient has been diagnosed as having organic impotence, then a test using an external vacuum device should be performed prior to making the final decision regarding penile prosthesis surgery. Moreover, some patients are resistant to surgery because of the influence of their partners, hence it is essential to discuss the treatment fully with the patient and their partner. It is also important to ascertain the patient’s psychological status with the help of psychological tests. The decision to conduct surgery should be based on an overall judgement that considers pre-operative tests and consultations. In our series, anesthesia was conducted with 0.5% bupivacaine hydrochloride. It is not unusual for bupivacaine hydrochloride, which is a long-acting anesthetic, to cause a nerve block for as long as 5–7 h. It has a strong pain-killing action and its effect on motor nerves weakens over time. Marcaine hydrochloride is used frequently in the field of obstetrics as it has a very low tendency to penetrate the placenta, thereby reducing the possibility of elevation of the fetal blood anesthetic level.2 The strength of the blood plasma protein-binding capacity of a local anesthetic is high in bupivacaine, with decreasing strengths in etidocaine, mepivacaine and lidocaine, all of which exhibit long-term action. With respect to the toxicity of local anesthesia, many commonly used local anesthetics can lead to convulsions, respiratory insufficiencies and eventually, cardiac arrests. However, these adverse effects can be largely prevented by early respiratory management through the administration of an anticonvulsive. Despite this countermeasure, however, it has been reported that the local anesthetics, marcaine and etidocaine, which have come into use recently, have high lipid-lysing properties. These properties may result in a cardiac arrest, irrespective of the occurrence of convulsion,3 and the resuscitation required for cardiac arrests induced by these anesthetics is extremely time-consuming (45 min or longer may be needed to recover a heart beat). Experiments using sheep showed that although arrhythmia is not observed in convulsive cases anesthetized with lidocaine, all animals given marcaine exhibited arrhythmia, thereby indicating that marcaine is more potently cardiotoxic.4 However, there is a body of opinion that opposes the view that local anesthetics, such as marcaine and etidocaine, have more potent cardiosuppressive effects than other local anesthetics.5 Moreover, the results of a study in dogs, in which the dose of local anesthetic that caused cardiovascular collapse and the dose that caused convulsion were compared, revealed that etidocaine and marcaine did not show vasosuppressive effects that were any more potent than those of other local anesthetics.6 Although the recommended maximum single dose of marcaine is reported to be 2 mg/kg, we used one-third of that amount. In addition, we carefully checked the ECG monitor for the occurrence of arrhythmia during the operation. Koper and Pearson used a method of local anesthesia in which four anesthetic methods were combined.7 In this combined method, firstly, 0.5% bupivacaine and 0.5% lidocaine are mixed in equal amounts, then 6–8 mL of the mixture is injected into the tuber ischiadicum to induce a penile nerve block. Secondly, a Penrose drain is used to ligate the phallobase, and 0.25% lidocaine is infused into the corpus cavernosum of the penis until a complete erection is achieved. Thirdly, 1–2 mL of the same anesthetic mixture used to induce the penal nerve block is injected into the area of the incision. Finally, the same anesthetic is infused into the corpus cavernosum. Mulcahy injected 2 mL of 1% lidocaine into each of four sites in the phallobase, then applied a tourniquet to ligature the phallobase and injected the corpus cavernosum with 30–40 mL of physiological saline containing 0.25% lidocaine.7 Kelami, Claro and other researchers have injected anesthetic into the corpus cavernosum.8,9 Dos Reis achieved a penal nerve block using 10 mL of 1% lidocaine, then injected 20 mL of 0.5% lidocaine into the phallobase for intracavernosal infusion.10 In our study, we injected 8 mL of 0.5% marcaine into the phallobase and conducted the operation by applying pain-free pressure without the combined use of intracavernosal infusion and a penal nerve block. However, the patients experienced pain on insertion of the balloon catheter immediately after the operation, suggesting that the anesthetic was not effective to the level of the urethra. The results of our 20 surgical experiences suggest that penile prosthesis surgery with a low dose of anesthetic can be conducted safely and almost without pain.