Bilateral Nerve-sparing Procedure Research Articles

Post-Radical Prostatectomy Penile Blood Flow: Assessment with Color Flow Doppler Ultrasound

Cadaveric dissections have revealed that accessory blood vessels to the penis often arise near or through the apex of the prostate. These accessory vessels may be easily injured during radical prostatectomy. Increasing attention since the 1980s has focused on preserving potency after radical prostatectomy with a nerve sparing technique. However, many patients are impotent even after a nerve sparing procedure. An arterial, venous or psychological mechanism may be involved. A prospective study was designed to assess cavernous artery diameter, peak systolic flow velocity, penile blood flow, end diastolic flow velocity and resistance index preoperatively and postoperatively in patients undergoing radical prostatectomy. Ten patients with a mean age of 60 years were evaluated, of whom 8 underwent a unilateral nerve sparing procedure, 1 bilateral nerve sparing procedure and 1 bilateral nonnerve sparing procedure. Mean penile blood flow as calculated by the formula penile blood flow = peak systolic flow velocity × π (diameter/2)2 increased 0.33ml. per second (+26%) on the nerve spared side, while diminishing 0.68ml. per second (−41%) on the nonspared side. Overall penile blood flow was diminished. End diastolic flow velocity increased on spared and nonspared sides after surgery. The resistance index for all radical prostatectomy patients diminished 7% from 0.83 preoperatively to 0.77 postoperatively (p = 0.16). While these findings were not statistically significant, they suggest that arterial insufficiency and corporeal venous occlusive dysfunction may be involved in sexual dysfunction after nerve sparing radical prostatectomy.

Nerve-Sparing Radical Prostatectomy: Evaluation of Results after 250 Patients

To examine the efficacy of nerve-sparing radical retropubic prostatectomy in preserving sexual potency and urinary continence, and in providing complete tumor excision we analyzed the records of the first 250 consecutive patients with clinical stage A or B prostate cancer treated since this operation was adopted at our institution. Over-all, sexual potency was preserved in 71 of 112 patients (63%) who underwent bilateral nerve-sparing prostatectomy and 13 of 33 (39%) who underwent a unilateral nerve-sparing procedure with a minimum of 6 months of followup. Preservation of potency correlated with patient age (p equals 0.0035, chi-square) and was significantly (p less than 0.001, chi-square) higher in patients with pathologically organ-confined tumors (72%) than in those with pathologically extracapsular tumors (51%). Of 192 patients followed for at least 6 months 188 (98%) achieved urinary continence postoperatively. Over-all, apparent complete tumor excision as defined by organ-confined tumor with negative surgical margins and undetectable postoperative prostate specific antigen levels was achieved in 14 preoperatively potent patients (42%) who underwent a unilateral and 67 (59%) who underwent a bilateral nerve-sparing procedure. Completeness of tumor excision correlated with tumor stage. In approximately 45% of the patients incomplete tumor excision was owing to seminal vesicle and/or lymph node involvement or positive bladder neck margins that could not be attributed to the nerve-sparing modification. However, improper application of the nerve-sparing technique may have contributed in the others. We were unable to detect microscopic penetration of the capsule or distinguish between gross extracapsular tumor extension and periprostatic fibrosis at operation.We conclude that with proper application of nerve-sparing radical retropubic prostatectomy, potency can be preserved in the majority of patients without compromising the adequacy of tumor excision. The completeness of tumor excision appears to be determined primarily by the extent of the tumor. Therefore, patient selection is important. Patients with focal, well differentiated tumors are ideal candidates for a nerve-sparing procedure, while those with high volume, poorly differentiated tumors may be at a higher risk for positive surgical margins. The benefits of wide excision of the neurovascular bundles remain to be demonstrated formally.