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Biomedical subjects

D A Mhoon

Publications and source records attributed to D A Mhoon.

5 recordsLinked to original sources

Does the CaverMap device help preserve potency?

Erectile dysfunction remains a common complication following radical prostatectomy. The CaverMap Surgical Aid (UroMed, Boston, MA) was designed to aid the surgeon in identifying and preserving neurovascular bundles (NVBs). However, the size of the CaverMap nerve stimulator may make it difficult to trace the cavernous nerves before the prostate is removed, particularly in obese men or in patients who have a large prostate or a narrow pelvis. In a randomized, controlled study, the use of the CaverMap during radical prostatectomy resulted in improved nocturnal erections, but did not lead to improved overall sexual function. The CaverMap device, however, may be useful as a research tool in that it helps determine whether the NVBs have been successfully preserved after removing the prostate. However, preservation of the NVB does not guarantee recovery of potency, which may be prolonged despite successful stimulation of the cavernous nerves intraoperatively. This suggests that erectile dysfunction following radical prostatectomy is multifactorial.

Erectile Dysfunction↗

Sildenafil in the treatment of erectile dysfunction after radical prostatectomy.

OBJECTIVES: To evaluate the efficacy of sildenafil for the treatment of erectile dysfunction after radical prostatectomy and to determine whether age, preservation of the neurovascular bundles (NVBs), or the interval between surgery and the initiation of sildenafil therapy influences the response to sildenafil. METHODS: We began this study in April 1998, immediately after the Food and Drug Administration approved sildenafil. We surveyed 170 men who had undergone radical retropubic prostatectomy, had not recovered natural erections sufficient for intercourse, and subsequently received sildenafil between 3 and 24 months postoperatively. The data were collected through a confidential mail survey conducted by a clinical nurse. The men used a dose of 50 mg sildenafil and increased this to 100 mg if they did not obtain an adequate response. RESULTS: In the 120 men who began taking sildenafil at least 12 months after surgery, the overall response rate was 29%. Results varied markedly by patient age and number of NVBs preserved. In men younger than 55 years in whom both NVBs had been preserved, the response rate was 80%. In contrast, no patient older than 55 years in whom only one NVB had been preserved reported an adequate response. Regardless of age, no patient in whom both NVBs had been excised reported success with sildenafil. Of the 50 patients who began taking sildenafil less than 9 months after surgery and who had not recovered natural sexual function, none reported erections adequate for intercourse using sildenafil. CONCLUSIONS: Sildenafil is an effective treatment for men with erectile dysfunction after radical retropubic prostatectomy, particularly in younger men in whom both NVBs have been preserved. It is ineffective in men in whom both NVBs have been excised, and it is also ineffective in older men in whom only one NVB has been preserved. Sildenafil appears ineffective in the first 9 months after prostatectomy.

Age Factors↗

Effect of preoperative biofeedback/pelvic floor training on continence in men undergoing radical prostatectomy.

OBJECTIVES: To determine whether preoperative biofeedback training improves urinary continence overall or the rate of return of continence in men undergoing radical prostatectomy. METHODS: One hundred men scheduled to undergo radical prostatectomy were randomized to receive graded pelvic muscle exercise training with biofeedback 2 to 4 weeks before surgery or to a control group performing pelvic muscle exercises without biofeedback. The biofeedback group was instructed to continue exercises four times per day until surgery and to resume exercises when the urethral catheter was removed following surgery. The control group received written and brief verbal instructions in pelvic muscle exercises before surgery and again after catheter removal. Urinary continence was assessed by personal or phone interviews. RESULTS: Six months following surgery, the continence rates, as defined by the use of one pad or less per day, were 94% (44 of 47) and 96% (48 of 50) in the biofeedback and control groups, respectively (P = 0.596). Also, the rate of return as determined at time points 1, 2, 3, and 4 months after surgery was not significantly different between the two groups. CONCLUSIONS: Preoperative biofeedback training did not improve the outcome of pelvic muscle exercises on overall continence or the rate of return of urinary control in men undergoing radical prostatectomy.

Biofeedback, Psychology↗

A positive caver map response poorly predicts recovery of potency after radical prostatectomy.

OBJECTIVES: To determine whether preservation of the neurovascular bundles (NVBs), defined by a positive CaverMap response, correlates with the recovery of potency after radical prostatectomy. METHODS: We studied a group of 60 men who were potent preoperatively who underwent radical retropubic prostatectomy by one surgeon. The CaverMap was used after removal of the prostate to assess the integrity of the NVBs. Postoperative potency was assessed by a postal questionnaire and telephone interview, administered independently of the treating surgeon. Men were considered potent if they reported postoperative erections consistently sufficient for vaginal penetration with or without the use of sildenafil. RESULTS: The mean patient age was 59 years, and the median follow-up was 365 days. A positive CaverMap response was obtained in 73 (77%) of the 95 NVBs tested. The overall potency rate was 18%. No patients with a bilateral negative CaverMap response were potent, and 2 (22%) of 9 with a unilateral CaverMap response (negative versus unilateral response, P = 0.46) and 6 (27%) of 22 with bilateral CaverMap responses (negative versus bilateral response, P = 0.32) were potent. CONCLUSIONS: A positive CaverMap response, suggesting that a successful nerve-sparing prostatectomy had been performed, was obtained in 77% of the NVBs tested. Nevertheless, with a median follow-up of 12 months, most patients with a positive CaverMap response remained impotent. This suggests that other factors are critical to the recovery of sexual function after radical prostatectomy.

Diagnostic Techniques, Neurological↗

A new technique for securing a foley catheter.

We describe a new technique to secure a urethral catheter using a horizontal drain tube stabilizer. This device is reliable, inexpensive, and more comfortable for patients than either adhesive tape or leg straps.

Humans↗