Daniel C. Merrill

Clinical Experience with the Mentor Inflatable Penile Prosthesis in 301 Patients

The Mentor inflatable penile prosthesis has been implanted in 301 patients during the last 60 months, of whom 3 died of unrelated causes and 13 have been lost to followup. Of the remaining 285 patients 96.8 per cent are presently using the device. A life table analysis of 253 implantations performed since 1983 shows that 97 per cent of the prostheses presently being implanted will survive 48 months without mechanical failure. There have been no wear-induced leaks or aneurysms in the 602 cylinders implanted. Complications that resulted in permanent device loss or necessitated a second operation were owing to mechanical problems in 3 per cent, infection in 2.3 per cent and surgeon error in 1.7 per cent of the cases. This clinical study demonstrates the 5-year reliability of cylinders constructed from polyurethane, the reliability of the Mentor snap-on connector system and the increased durability of nylon-reinforced silicone tubing.

The Treatment of Detrusor Incontinence by Electrical Stimulation

Cystometrograms were done on 20 patients before and during transrectal stimulation to determine if electrical stimulation increased the detrusor reflex threshold. In 4 patients the detrusor reflex threshold was increased during stimulation and urinary continence was restored. However, each patient became incontinent when transrectal stimulation was discontinued for 1 to 5 days. Thus, cyclic periods of stimulation were necessary to maintain the beneficial effects of electrical stimulation and a permanent pelvic floor stimulator was implanted since chronic transrectal stimulation was inconvenient.

Laboratory comparison of urethral profilometry techniques.

A comparison of urethral pressure profiles performed with the air infusion, water infusion, membrane catheter, and transducer tip catheter techniques was made in a canine model. The gas and water infusion methods gave statistically identical results if the gas studies were performed at flow rates of 100 ml./min. and pull rates of 5 cm./min. The transducer tip catheter and the gas and water infusion techniques gave accurate recordings of peak urethral pressure but were incapable of detecting multiple areas of urethral compression. The transducer tip catheter measurements often were difficult to interpret because of rotation and flexion artifact. The membrane catheter was capable of recording multiple areas of urethral compression but gave spuriously high recordings of peak urethral pressure. We conclude that none of the methods tested will give accurate recordings of urethral pressure in all clinical situations.

Experience with the Small-carrion Penile Prosthesis

The Small-Carrion prosthesis has been implanted successfully in 14 of 15 patients. These prostheses are implanted through a dorsal midline penile incision which simplifies the procedure. The perineal approach is preferred for keloid formers and paraplegics who will use a condom catheter. Operative failure may be decreased by paying particular attention to the size of prosthesis implanted and the positioning of its distal tip.

Effect of baclofen and dantrolene on bladder stimulator-induced detrusor-sphincter dyssynergia in dogs.

The effect of baclofen (Lioresal) and dantrolene (Dantrium) on bladder stimulation-induced detrusor-sphincter dyssynergia was studied in normal and chronic T-10 paraplegic dogs. Dantrolene, which depresses skeletal muscle contractility, had little effect on electrically evoked contractions of the urethral sphincter in dogs. Baclofen, which acts centrally by potentiating presynaptic inhibition, depressed the pudendal to pudendal nerve reflex and decreased urethral resistance during bladder stimulation.

USE OF NEGATIVE PRESSURE SUCTION IN UROLOGY

Abstract Our results substantiate those of others who have found that hemovac negative pressure suction provides superior drainage of surgical wounds than does the Penrose drain. Better wound drainage encourages primary wound healing and eliminates serosanguineous and uriniferous dressings. The use of negative pressure suction also decreases morbidity rate and hospital stay which more than compensates for the initial cost of the hemovac unit.

Clinical evaluation of FasTENS, an inexpensive, disposable transcutaneous electrical nerve stimulator designed specifically for postoperative electroanalgesia.

Previous studies have shown that electroanalgesia is an effective method of reducing postoperative pain in patients who have urologic surgery. All prior studies of postperative transcutaneous electrical nerve stimulation (TENS) have employed TENS stimulators which were designed for the control of chronic pain. Disadvantages to the use of standard TENS stimulators in postoperative patients include the high cost of the devices and their operative complexity which make it difficult for staff and patients to use them. FasTENS is a lightweight, relatively inexpensive disposable TENS stimulator which has been designed specifically for use in postoperative patients. We evaluated the effectiveness of FasTENS in patients who had implantation of an inflatable penile prosthesis, radical retropubic prostatectomy, or radical nephrectomy. Patients treated with FasTENS used 60 percent less pain medication (P less than 0.001) and made 61 percent fewer requests for Demerol injections (P less than 0.001) than did control patients who were not treated with postoperative electroanalgesia. FasTENS was most effective in patients who had radical prostatectomy or penile prosthetic surgery. FasTENS was not cost-effective or practical in patients who had radical nephrectomy.

Failure to control postprostatectomy urinary incontinence by urethral compression

A modification of Kaufmans urinary incontinence device was implanted unsuccessfully in 5 patients. This device achieved passive urinary continence in each of these patients; however, all patients continued to experience moderate to severe stress incontinence. The results of this study challenge the concept that static urethral compression can achieve total urinary continence in patients with postprostatectomy incontinence.

Modified Thoracoabdominal Approach to the Kidney and Retroperitoneal Tissue

Exposure to the retroperitoneal space may be improved by performing thoracotomy through the 8th rib bed rather than the 9th or 10th and by combining a subcostal incision with the standard longitudinal abdominal incision. This modification of the standard thoracoabdominal incision has been used to remove giant hypernephromas, to perform radical nephrectomies with node dissection and to remove retroperitoneal lymphatic structures in non-seminomatous testis tumors.

Mineral oil granulomatosis of scrotum

Abstract An unusual case of mineral oil granulomatosis of the scrotum in an elderly male patient is presented. Failure to consider the diagnosis of foreign-body granuloma in any nonulcerating lesion of the external genitalia may result in erroneous preoperative diagnosis and unnecessary surgical procedures.