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Experience with potency preservation during radical prostatectomy
EXPERIENCE
WITH POTENCY PRESERVATION
DURING RADICAL PROSTATECTOMY Significance of Learning
*
Curve
BABU V SURYA, M.D. JOHN PROVET,
M.D.
GUIDO DALBAGNI, KARL-ERIC JORDAN
M.D.
JOHANSON,
BROWN,
M.D.
M.D.
From the Urology Service, Veterans Administration Medical Center, New York, and Department of Urology, New York University School of Medicine, New York, New York
ABSTRACT-Potency preservation after radical prostatectomy is relatively new. The efficacy of this procedure has not been widely documented. Twenty-four patients with full potency underwent nerve-sparing radical prostatectomy. A total of 12 patients retained potency after surgery. Analysis of data reveals there is a learning curve in doing this procedure, and once the initial learning phase is over good results can be obtained in a select group of patients.
Radical prostatectomy is a well accepted mode of therapy for the treatment of localized prostate cancer. 1.2 Subsequent erectile dysfunction has been one of the main factors discouraging both urologists and patients from pursuing this treatment option. Recent advances in understanding the role of corporeal nerves in erectile physiology and their anatomic relationship to the prostate have led to preservation of sexual function after radical prostatectomy. 3m5However, to date only a few medical centers have reported their results with this modified procedure, and thus the reproducibility of their initial success has not been widely documented.6.7 We herein describe our experience in preserving potency after radical prostatectomy in a small series of patients.
*Awarded prize at Ferdinand C. Valentine Essay Contest, York Academy of Medicine, March 30, 1988.
498
NW
Material and Methods Between January, 1985, and September, 1987, a total of 57 radical prostatectomies were performed for localized carcinoma of the prostate at this medical center. Of these, 24 patients underwent a nerve-sparing procedure using the technique of Walsh.B These patients form the basis of our report. Pre- and postoperative evaluations were personally supervised by one of us (BVS). The diagnosis of prostatic carcinoma was made either by transrectal core biopsy or by transurethral resection and graded as welldifferentiated, moderately or poorly differentiated tumor. All patients were staged by digital examination, intravenous pyelogram, cystoscopy, serum acid phosphatase level, computed tomography (CT) scan of the pelvis, and bone scan. When indicated by the bone scan, xray examinations of appropriate skeletal areas
UROLOGY
i
DECEMBER
1988
i
VOLUME
XXXII,
NUMBER
6
TABLEI. Pt. V.I? K.H. A.C. A.A. ;I LX R.M.R. ;:M. A.V. R.D. M.O. B.A. E.C. J.C. A.S. P.C.
E.B. L.G. V.D. E.W. RF. KEY WD
Results of potency-preserving
Age (Yrs.)
Date of Surgery
68 57 64 65 63 63 67 65 65 69 62 63 57 64 60 62 67 64 67 64 62 58 62 58
3185 3185 5185 8185 8185 9185 9185 10185 11185 12185 8186 8186 9186 9186 10186 12186 12186 12186 1187 l/87 7187 8187 8187 9187
= well differentiated
Final Path. Exam.
disease; MD = moderately differentiated
/ DECEMBER
1988
(n = 24)
Follow-Up (Mos.) 31 31 29 26 26 25 Lost to follow-up 24 23 22 14 14 13 13 12 10 10 10 9 9 3 2 2 2
B2 M-PD A2 WD A2 MD A2 MD B2 WD B2 WD A2 MD B2 MD Dl MD B2 MD Bl WD B2 MD A2 WD B2 WD B2 WD Bl MD B2 MD A2 MD C MD A2 MD B2 WD A2 WD A2 WD B2 MD
were obtained to exclude metastatic disease. Clinical stage was assigned according to the Whitmore-Jewett system.Q,lo All patients had clinically organ-confined disease. A detailed sexual history was obtained prior to surgery. Only those who had erections sufficient for penetration and were engaged in regular sexual intercourse were considered for the potency-preserving procedure. All surgery was done by the resident staff under the supervision of one faculty member (BVS). The procedure was performed as described by Walsh with a few modifications.” Briefly, the patient was placed in a modified lithotomy position providing access for an assistant to exert perineal pressure during the anastomosis of the bladder neck to the urethra. The dorsal vein complex was not ligated in bulk, but was thinned prior to suture ligation. This was accomplished in three steps. After incising the endopelvic fascia, lateral planes were developed only around the lower half of the prostatic apex, since we have noted that portions of the lateral venous plexus emanate from the 10 and 2 o’clock positions.
UROLOGY
modified radical prostatectomy
Current Status Impotent Impotent Impotent Impotent Impotent Potent Impotent Potent Impotent Potent Impotent Potent Potent Impotent Impotent Potent Impotent Impotent Potent Potent Potent Potent Potent Potent
disease.
Next, the puboprostatic ligaments were divided between sutures to prevent inadvertent injury to the dorsal venous plexus. Following this, the prostate drops off the pubis and can be retracted to expose the lateral venous tributaries. These were then cauterized and cut. Consequent to these maneuvers, the dorsal plexus bundle is considerably thinned and allows placement of a more secure suture. The complex is then easily ligated using the Reiner and Walsh technique. l2 The dorsal plexus bundle is then divided with the cautery to minimize back bleeding. In our experience, this modification has resulted in a considerable reduction in blood loss and allows for accurate visualization of the prostatic apex which is essential for preserving the corporeal nerves. The remainder of the procedure is performed as described by Walsh. A urethral catheter was left indwelling for fourteen days after surgery at which time a voiding cystourethrogram was performed to demonstrate the integrity of the anastomosis. All patients were followed in the outpatient clinic at three-month intervals. A detailed history as to continence and erectile function was
I VOLUME XxX11, NUMBER 6
499
8
A m Potent 0
Impotent
FIGURE 1. (A) Denotes first half and (B) second half of study population. Shaded areas indicate number of patients who regained potency.
obtained. Erection sufficient for penetration and intercourse was considered a successful result. Pathologic specimens were evaluated with respect to final disease grade, capsular penetration, seminal vesicle and nodal involvement. Results A total of 24 men underwent potencypreserving modified radical prostatectomy. All were potent preoperatively and were capable of penetration. Nine patients were followed up for more than fifteen months, 5 patients for more than twelve months, 5 for more than six months, and 4 for more than three months. One patient was lost to follow-up and was considered a failure. Patient data are summarized in Table I. Patients’ ages at surgery ranged from fiftyseven to sixty-nine years (median 63.3 years). All except 2 had tumor confined to the prostate on final pathologic examination. One patient (RMR) with seminal vesicle invasion and one positive lymph node was impotent at twentythree months of follow-up. Another (PC) who regained potency six months after prostatectomy had focal capsular penetration. In addition, 1 patient (LG) underwent resection of the neurovascular bundle on one side for presumed extra-prostatic extension suspected during
500
surgery. l3 This patient retained potency, and the disease proved to be organ-confined in the final specimen. There were 9 patients with surgical Stage A2 disease, 2 with Bl disease, and 11 with B2 disease of which 44 percent, 50 percent, and 54 percent, respectively, regained potency. One of the 2 patients with extra-prostatic extension regained potency for a final potency rate of 50 percent (12 of 24). When the patients who underwent nervesparing radical prostatectomy are stratified by their time of entry into the study, 3 of the first 11 (27%) and 9 of the subsequent 13 (69.2%) are potent, for an overall potency rate of 50 percent (Fig. 1). These two groups were otherwise comparable with regard to stage, grade, and age. One patient (AV) was potent for six months and then complained of gradual loss of erection, Another patient (AA) had erections but was not able to penetrate. The time to return of potency also correlated with order of entry into the study (Fig. 2). The 3 patients of the first 11 group were potent at twelve months, fifteen months, and nine months, respectively, after surgery. In the second group potency returned much sooner. Three patients in the second group had return of erectile function within three months after surgery. One of the patients (VD) had goodquality erections prior to discharge from the hospital within three weeks of undergoing surgery. All patients remain continent. One patient suffered a wound dehiscence. In 2 patients anastomotic strictures developed. One required a single dilation and the other required endoscopic incision. There have been no tumor recurrences to date.
16r
‘1 Ll
2’
31
4’
5I
61
Patient
7’
8I
91
IO I
III
12 ’
Number
Time taken to regain sexual potency after surgery. Patient number denotes order of entry into study. FIGURE 2.
UROLOGY
i
DECEMBER
1988
i
VOLUME XxX11, NUMBER 6
Comment Reproducibility is one of the main criteria by which the results of any new procedure are judged. Radical nerve-sparing prostatectomy was developed only recently. Experience with this technique has been reported from only a few major medical centers. Introduction of a new surgical technique is associated with a learning curve. l4 We herein describe a series of patients who were operated on in a teaching hospital. Our data support the contention that preservation of potency during radical prostatectomy can become a widespread surgical practice once some degree of familiarity with the procedure is obtained. Our overall potency rate of 50 percent is considerably lower than that reported by Walsh15 (72 % ) but does compare with that of Catalona and Dressner’ (52 % ), Considering that less than 9 percent of our patients had pathologic Stage Bl disease and 87 percent of patients were over sixty years old, the overall potency rate compares favorably with other series. Catalona reported a potency rate of 43 percent in patients over sixty years of age. Walsh reports an overall potency rate of 60 percent for patients sixty to seventy years old. The results of this series illustrate the effect of a learning curve in performing this procedure. Only 3 of our first 12 patients were potent, whereas 9 of the next 12 achieved potency. The time taken for erectile function to return was also considerably improved in the latter half of the series. This learning curve is important in adopting a new procedure, and it probably predicts the results one can expect when the procedure is utilized more widely. Evidence supporting the standardization of a technique is provided by obtaining repeated similar results by different practitioners. In our series, the procedure was performed by different residents under supervision of one staff surgeon, pointing to the reproducibility of the technique. Twenty-two of 24 of our patients had organconfined disease. Other series have reported an 18 to 38 percent incidence of periprostatic extension in clinical Bl lesions. This discrepancy is probably a reflection of the small number of patients in our series and a strong bias in the selection of operative candidates. Only 1 patient (LG) was thought to have periprostatic extension during surgery, and his left neurovascu-
UROLOGY
/
DECEMBER
1988
/
VOLUME
lar bundle was excised widely. This patient had organ-confined disease on final sections and remains potent. In conclusion, this series supports the applicability of nerve-sparing radical prostatectomy under different conditions. Our experience indicates that there is a definite learning curve in performing this procedure, but once the initial phase is passed, good results can be obtained in a select group of patients. Urology Service, 112 VA Medical Center First Avenue at East 24th Street New York, New York 10010 (DR. SURYA) References 1. Walsh PC: Radical prostatectomy for the treatment of localized prostatic carcinoma, Urol Clin North Am 7: 523 (1980). 2. Paulson DF, Lin GH, Hinshaw W, Stephani S, and the UroOncology Research Croup: Radical surgery versus radiotherapy for adenocarcinoma of the prostate, J Ural 128: 502 (1982). 3. Lue TF, Zeineh SJ, Schmidt RA, and Tanagho EA: Neuroanatomy of penile erection: its relevance to iatrogenic impotence, J Urol 131: 273 (1984). 4. Lepor H, et al: Precise localization of the autonomic nerves from the pelvic plexus to the corpora cavernosa: a detailed anatomical study of the adult male pelvis, J Urol 133: 207 (1985). 5. Walsh PC, and Donker PJ: Impotence following radical prostatectomy: insight into etiology and prevention, J Urol 128: 492 (1982). 6. Eggleston JC, and Walsh PC: Radical prostatectomy with preservation of sexual function: pathological findings in the first 100 cases. I Urol 134: 1146 (1985). 7. Cataiona WJ, and Dressner SM: Nerve-sparing radical prostatectomy: extraprostatic extension and preservation of sexual function, J Urol 134: 1149 (1985). 8. Walsh PC: Radical retropubic prostatectomy and cystoprostatectomy: surgical technique for preservation of sexual function (motion picture), Norwich, New York, Norwich Eaton Pharmaceuticals, 1984. 9. Whitmore WF Jr: Hormone therapy in prostate cancer, Am J Med 21: 697 (1956). 10. Jewett HJ: The present status of radical prostatectomy for stages A and B prostatic cancer, Urol Clin North Am 2: 105 (1975). 11. Surya BV, Dalbagni G, Johanson KE, and Brown JS: Modified approach to dorsal vein ligation during radical prostatectomy, (in preparation). 12. Reiner WG, and Walsh PC: An anatomic approach to the surgical management of the dorsal vein and Santorini’s plexus during radicalyetropubic surgery, J Urol 121: 198 (1979). 13. Walsh PC. Eustein II. and Lowe FC: Potencv following radical prostatectomy with wide unilateral excision of neurovascular bundle. J Urol 138: 823 (1987). 14. Smith AD, White E, and Lee W: The learning curve of percutaneous stone extraction (Abstr. 205), J Urol 131: 155A (1984). 15. Walsh PC: Radical prostatectomy, preservation of sexual function, cancer control: the controversy, Urol Clin North Am 14: 663 (1987).
XXXII, NUMBER
6
501
WITH POTENCY PRESERVATION
DURING RADICAL PROSTATECTOMY Significance of Learning
*
Curve
BABU V SURYA, M.D. JOHN PROVET,
M.D.
GUIDO DALBAGNI, KARL-ERIC JORDAN
M.D.
JOHANSON,
BROWN,
M.D.
M.D.
From the Urology Service, Veterans Administration Medical Center, New York, and Department of Urology, New York University School of Medicine, New York, New York
ABSTRACT-Potency preservation after radical prostatectomy is relatively new. The efficacy of this procedure has not been widely documented. Twenty-four patients with full potency underwent nerve-sparing radical prostatectomy. A total of 12 patients retained potency after surgery. Analysis of data reveals there is a learning curve in doing this procedure, and once the initial learning phase is over good results can be obtained in a select group of patients.
Radical prostatectomy is a well accepted mode of therapy for the treatment of localized prostate cancer. 1.2 Subsequent erectile dysfunction has been one of the main factors discouraging both urologists and patients from pursuing this treatment option. Recent advances in understanding the role of corporeal nerves in erectile physiology and their anatomic relationship to the prostate have led to preservation of sexual function after radical prostatectomy. 3m5However, to date only a few medical centers have reported their results with this modified procedure, and thus the reproducibility of their initial success has not been widely documented.6.7 We herein describe our experience in preserving potency after radical prostatectomy in a small series of patients.
*Awarded prize at Ferdinand C. Valentine Essay Contest, York Academy of Medicine, March 30, 1988.
498
NW
Material and Methods Between January, 1985, and September, 1987, a total of 57 radical prostatectomies were performed for localized carcinoma of the prostate at this medical center. Of these, 24 patients underwent a nerve-sparing procedure using the technique of Walsh.B These patients form the basis of our report. Pre- and postoperative evaluations were personally supervised by one of us (BVS). The diagnosis of prostatic carcinoma was made either by transrectal core biopsy or by transurethral resection and graded as welldifferentiated, moderately or poorly differentiated tumor. All patients were staged by digital examination, intravenous pyelogram, cystoscopy, serum acid phosphatase level, computed tomography (CT) scan of the pelvis, and bone scan. When indicated by the bone scan, xray examinations of appropriate skeletal areas
UROLOGY
i
DECEMBER
1988
i
VOLUME
XXXII,
NUMBER
6
TABLEI. Pt. V.I? K.H. A.C. A.A. ;I LX R.M.R. ;:M. A.V. R.D. M.O. B.A. E.C. J.C. A.S. P.C.
E.B. L.G. V.D. E.W. RF. KEY WD
Results of potency-preserving
Age (Yrs.)
Date of Surgery
68 57 64 65 63 63 67 65 65 69 62 63 57 64 60 62 67 64 67 64 62 58 62 58
3185 3185 5185 8185 8185 9185 9185 10185 11185 12185 8186 8186 9186 9186 10186 12186 12186 12186 1187 l/87 7187 8187 8187 9187
= well differentiated
Final Path. Exam.
disease; MD = moderately differentiated
/ DECEMBER
1988
(n = 24)
Follow-Up (Mos.) 31 31 29 26 26 25 Lost to follow-up 24 23 22 14 14 13 13 12 10 10 10 9 9 3 2 2 2
B2 M-PD A2 WD A2 MD A2 MD B2 WD B2 WD A2 MD B2 MD Dl MD B2 MD Bl WD B2 MD A2 WD B2 WD B2 WD Bl MD B2 MD A2 MD C MD A2 MD B2 WD A2 WD A2 WD B2 MD
were obtained to exclude metastatic disease. Clinical stage was assigned according to the Whitmore-Jewett system.Q,lo All patients had clinically organ-confined disease. A detailed sexual history was obtained prior to surgery. Only those who had erections sufficient for penetration and were engaged in regular sexual intercourse were considered for the potency-preserving procedure. All surgery was done by the resident staff under the supervision of one faculty member (BVS). The procedure was performed as described by Walsh with a few modifications.” Briefly, the patient was placed in a modified lithotomy position providing access for an assistant to exert perineal pressure during the anastomosis of the bladder neck to the urethra. The dorsal vein complex was not ligated in bulk, but was thinned prior to suture ligation. This was accomplished in three steps. After incising the endopelvic fascia, lateral planes were developed only around the lower half of the prostatic apex, since we have noted that portions of the lateral venous plexus emanate from the 10 and 2 o’clock positions.
UROLOGY
modified radical prostatectomy
Current Status Impotent Impotent Impotent Impotent Impotent Potent Impotent Potent Impotent Potent Impotent Potent Potent Impotent Impotent Potent Impotent Impotent Potent Potent Potent Potent Potent Potent
disease.
Next, the puboprostatic ligaments were divided between sutures to prevent inadvertent injury to the dorsal venous plexus. Following this, the prostate drops off the pubis and can be retracted to expose the lateral venous tributaries. These were then cauterized and cut. Consequent to these maneuvers, the dorsal plexus bundle is considerably thinned and allows placement of a more secure suture. The complex is then easily ligated using the Reiner and Walsh technique. l2 The dorsal plexus bundle is then divided with the cautery to minimize back bleeding. In our experience, this modification has resulted in a considerable reduction in blood loss and allows for accurate visualization of the prostatic apex which is essential for preserving the corporeal nerves. The remainder of the procedure is performed as described by Walsh. A urethral catheter was left indwelling for fourteen days after surgery at which time a voiding cystourethrogram was performed to demonstrate the integrity of the anastomosis. All patients were followed in the outpatient clinic at three-month intervals. A detailed history as to continence and erectile function was
I VOLUME XxX11, NUMBER 6
499
8
A m Potent 0
Impotent
FIGURE 1. (A) Denotes first half and (B) second half of study population. Shaded areas indicate number of patients who regained potency.
obtained. Erection sufficient for penetration and intercourse was considered a successful result. Pathologic specimens were evaluated with respect to final disease grade, capsular penetration, seminal vesicle and nodal involvement. Results A total of 24 men underwent potencypreserving modified radical prostatectomy. All were potent preoperatively and were capable of penetration. Nine patients were followed up for more than fifteen months, 5 patients for more than twelve months, 5 for more than six months, and 4 for more than three months. One patient was lost to follow-up and was considered a failure. Patient data are summarized in Table I. Patients’ ages at surgery ranged from fiftyseven to sixty-nine years (median 63.3 years). All except 2 had tumor confined to the prostate on final pathologic examination. One patient (RMR) with seminal vesicle invasion and one positive lymph node was impotent at twentythree months of follow-up. Another (PC) who regained potency six months after prostatectomy had focal capsular penetration. In addition, 1 patient (LG) underwent resection of the neurovascular bundle on one side for presumed extra-prostatic extension suspected during
500
surgery. l3 This patient retained potency, and the disease proved to be organ-confined in the final specimen. There were 9 patients with surgical Stage A2 disease, 2 with Bl disease, and 11 with B2 disease of which 44 percent, 50 percent, and 54 percent, respectively, regained potency. One of the 2 patients with extra-prostatic extension regained potency for a final potency rate of 50 percent (12 of 24). When the patients who underwent nervesparing radical prostatectomy are stratified by their time of entry into the study, 3 of the first 11 (27%) and 9 of the subsequent 13 (69.2%) are potent, for an overall potency rate of 50 percent (Fig. 1). These two groups were otherwise comparable with regard to stage, grade, and age. One patient (AV) was potent for six months and then complained of gradual loss of erection, Another patient (AA) had erections but was not able to penetrate. The time to return of potency also correlated with order of entry into the study (Fig. 2). The 3 patients of the first 11 group were potent at twelve months, fifteen months, and nine months, respectively, after surgery. In the second group potency returned much sooner. Three patients in the second group had return of erectile function within three months after surgery. One of the patients (VD) had goodquality erections prior to discharge from the hospital within three weeks of undergoing surgery. All patients remain continent. One patient suffered a wound dehiscence. In 2 patients anastomotic strictures developed. One required a single dilation and the other required endoscopic incision. There have been no tumor recurrences to date.
16r
‘1 Ll
2’
31
4’
5I
61
Patient
7’
8I
91
IO I
III
12 ’
Number
Time taken to regain sexual potency after surgery. Patient number denotes order of entry into study. FIGURE 2.
UROLOGY
i
DECEMBER
1988
i
VOLUME XxX11, NUMBER 6
Comment Reproducibility is one of the main criteria by which the results of any new procedure are judged. Radical nerve-sparing prostatectomy was developed only recently. Experience with this technique has been reported from only a few major medical centers. Introduction of a new surgical technique is associated with a learning curve. l4 We herein describe a series of patients who were operated on in a teaching hospital. Our data support the contention that preservation of potency during radical prostatectomy can become a widespread surgical practice once some degree of familiarity with the procedure is obtained. Our overall potency rate of 50 percent is considerably lower than that reported by Walsh15 (72 % ) but does compare with that of Catalona and Dressner’ (52 % ), Considering that less than 9 percent of our patients had pathologic Stage Bl disease and 87 percent of patients were over sixty years old, the overall potency rate compares favorably with other series. Catalona reported a potency rate of 43 percent in patients over sixty years of age. Walsh reports an overall potency rate of 60 percent for patients sixty to seventy years old. The results of this series illustrate the effect of a learning curve in performing this procedure. Only 3 of our first 12 patients were potent, whereas 9 of the next 12 achieved potency. The time taken for erectile function to return was also considerably improved in the latter half of the series. This learning curve is important in adopting a new procedure, and it probably predicts the results one can expect when the procedure is utilized more widely. Evidence supporting the standardization of a technique is provided by obtaining repeated similar results by different practitioners. In our series, the procedure was performed by different residents under supervision of one staff surgeon, pointing to the reproducibility of the technique. Twenty-two of 24 of our patients had organconfined disease. Other series have reported an 18 to 38 percent incidence of periprostatic extension in clinical Bl lesions. This discrepancy is probably a reflection of the small number of patients in our series and a strong bias in the selection of operative candidates. Only 1 patient (LG) was thought to have periprostatic extension during surgery, and his left neurovascu-
UROLOGY
/
DECEMBER
1988
/
VOLUME
lar bundle was excised widely. This patient had organ-confined disease on final sections and remains potent. In conclusion, this series supports the applicability of nerve-sparing radical prostatectomy under different conditions. Our experience indicates that there is a definite learning curve in performing this procedure, but once the initial phase is passed, good results can be obtained in a select group of patients. Urology Service, 112 VA Medical Center First Avenue at East 24th Street New York, New York 10010 (DR. SURYA) References 1. Walsh PC: Radical prostatectomy for the treatment of localized prostatic carcinoma, Urol Clin North Am 7: 523 (1980). 2. Paulson DF, Lin GH, Hinshaw W, Stephani S, and the UroOncology Research Croup: Radical surgery versus radiotherapy for adenocarcinoma of the prostate, J Ural 128: 502 (1982). 3. Lue TF, Zeineh SJ, Schmidt RA, and Tanagho EA: Neuroanatomy of penile erection: its relevance to iatrogenic impotence, J Urol 131: 273 (1984). 4. Lepor H, et al: Precise localization of the autonomic nerves from the pelvic plexus to the corpora cavernosa: a detailed anatomical study of the adult male pelvis, J Urol 133: 207 (1985). 5. Walsh PC, and Donker PJ: Impotence following radical prostatectomy: insight into etiology and prevention, J Urol 128: 492 (1982). 6. Eggleston JC, and Walsh PC: Radical prostatectomy with preservation of sexual function: pathological findings in the first 100 cases. I Urol 134: 1146 (1985). 7. Cataiona WJ, and Dressner SM: Nerve-sparing radical prostatectomy: extraprostatic extension and preservation of sexual function, J Urol 134: 1149 (1985). 8. Walsh PC: Radical retropubic prostatectomy and cystoprostatectomy: surgical technique for preservation of sexual function (motion picture), Norwich, New York, Norwich Eaton Pharmaceuticals, 1984. 9. Whitmore WF Jr: Hormone therapy in prostate cancer, Am J Med 21: 697 (1956). 10. Jewett HJ: The present status of radical prostatectomy for stages A and B prostatic cancer, Urol Clin North Am 2: 105 (1975). 11. Surya BV, Dalbagni G, Johanson KE, and Brown JS: Modified approach to dorsal vein ligation during radical prostatectomy, (in preparation). 12. Reiner WG, and Walsh PC: An anatomic approach to the surgical management of the dorsal vein and Santorini’s plexus during radicalyetropubic surgery, J Urol 121: 198 (1979). 13. Walsh PC. Eustein II. and Lowe FC: Potencv following radical prostatectomy with wide unilateral excision of neurovascular bundle. J Urol 138: 823 (1987). 14. Smith AD, White E, and Lee W: The learning curve of percutaneous stone extraction (Abstr. 205), J Urol 131: 155A (1984). 15. Walsh PC: Radical prostatectomy, preservation of sexual function, cancer control: the controversy, Urol Clin North Am 14: 663 (1987).
XXXII, NUMBER
6
501