The following letter was written by Dr. Patrick Walsh, Urologist-in-Chief at Johns Hopkins to one of his patients in which he defends the use of the "nerve sparing technique" for performing radical prostate surgery. The operation has been criticized by Dr. Thomas Stamey, Former Chairman of the Department of Urology at Stanford University School of Medicine.
Dr. Walsh developed the nerve sparing procedure in part to try to save the nerves that are responsible for erections. Dr. Stamey takes issue with the technique because he believes it compromises the outcome of surgery, which he says should be performed with the sole purpose of curing the patient. Walsh wrote the letter in September 1994 in reply to an article Stamey wrote in April 1994, "Prostate Cancer: Who Should Be Treated?"
This operation has been perfected over the past 15 years and essentially involves 3 steps:
Prior to the advent of this procedure, the nerves were never excised - they were just cut and left in place. With the development of an anatomical approach to radical prostatectomy, it is now possible to preserve the nerves where feasible or excise them widely where necessary to provide an adequate surgical margin. When Dr. Stamey talks about wide excision of the nerves, he is referring to a technique that I developed. (1)
In Dr. Stamey's paper, he states that The Johns Hopkins group is "aggressive at sparing the nerves for erections". In actuality, both neurovascular bundles are only spared in only 58% of patients. He goes on to state that we have the highest rate of positive surgical margins. The paper he is referring to reports on our experience with the first 507 men who underwent this operation between 1982 and 1988 (2) The reason for the high rate of positive surgical margins is two-fold:
Dr. Stamey infers that nerve-sparing was responsible for the positive surgical margins. That conclusion is not correct. Dr. Epstein, in another publication, analyzed the influence of nerve-sparing on the presence of positive margins in this series of patients. He found that 24 (4.7%) of the patients potentially had positive margins caused by attempts to preserve the neurovascular bundle. "Of these 24 patients 4 had progressive disease after radical prostatectomy. Three of these patients have manifested elevated PSA levels as their only evidence of progression and 1 has a proven local recurrence. These 4 patients represent 0.8% of the total population who underwent radical prostatectomy. The 20 patients without evidence of disease have follow-ups ranging from 3 to 8 years with a mean and median of 5.5 years".
Thus, I am very careful when and where I spare nerves and for this reason nerve sparing rarely interferes with excellent cancer control. Conversely, most patients with positive surgical margins have extensive cancers which cannot be cured with surgery. Fortunately, with the development of PSA for the early diagnosis of prostate cancer, more patients are being detected at an earlier curable stage. In my last 200 consecutive patients, the frequency of positive surgical margins was 12%, similar to the 18% reported by Dr. Stamey in his most recent series. Thus, I believe that Dr. Stamey's comparison was unfair because he compares patients operated on a decade ago when tumors were more advanced than they are today.
Dr. Stamey reports a very high frequency of urinary incontinence. Indeed, 5% of his patients are totally incontinent! In contrast, I have never had a patient who was totally incontinent following a radical prostatectomy. In the near future I will be publishing the results of my 10-year series in THE JOURNAL OF UROLOGY. (4) In the first 593 consecutive patients, complete urinary control was achieved in 92%. Stress incontinence was present in 8%; 6% wore 1 or fewer pads per day; stress incontinence was sufficient to require placement of an artificial sphincter in 2 men (0.3%). No patient was totally incontinent. In the most recent 700 men, no one has experienced total urinary incontinence nor stress incontinence severe enough to warrant placement of an artificial sphincter. Recently, 8 men in this series who had the most severe incontinence requiring more than 1 pad per day were evaluated. The average bladder capacity was 450 cc, in 5 of 8 men leakage could not be demonstrated at full bladder capacity with the patient straining, and in 3 others the average leak point pressure was 65 cm of water. When urinary pads were weighed, the average 24-hour urinary loss in my most severe patients was only 9% of the total urinary output.
Finally, I do not agree with Dr. Stamey's comments on recovery of
sexual function. His statement "these reports in the literature
are based on the answer to only one question: have you had successful
intercourse with vaginal penetration at least once in the past year"
is not true of the way we evaluate patients. In Dr. Stamey's series
only 30% of his patients with bilateral nerve-sparing have preservation
of sexual function and only 15% if one nerve is spared. We define
potency as the ability to have an unassisted erection sufficient
for vaginal penetration and orgasm on a regular basis. (5) Beginning
in 1985 men have been offered treatment with pharmacological erection
therapy or vacuum erection devices. Men with weaker erections will
use one of these alternatives and thus are classified as impotent.
In men less than 50 years of age sexual function is preserved in
91%, in men 50-60 years in 75%, in men 60- 70 years in 58%, and
in men 70 or older in only 25%. In men under the age of 50 potency
was similar in men who had both neurovascular bundles preserved
and in patients in whom one neurovascular bundle was widely excised.
With advancing age, sexual function was better in patients in whom
both neurovascular bundles were preserved then in patients in whom
on neurovascular bundle was excised. Recently patients and their
wives underwent an extensive questionnaire 18 months following surgery
inquiring about the status of sexual function. When potent patients
were asked to estimate the quality of their erection compared to
their preoperative status, patients stated that it averaged 79%
of preoperative status (range 60-95%). Furthermore, they stated
that the average duration of erection was 9 minutes.
In summary, an anatomical approach to radical prostatectomy in our hands has made it possible to cure prostate cancer today with fewer side effects than in the past. We have recently evaluated 955 men with clinically localized prostate cancer who underwent radical prostatectomy between 1982 and 1991. (4) At 10 years 70% had an undetectable serum PSA, 23% had an isolated elevation of PSA, 7% developed distant metastases, and 4% developed local recurrence. From reviewing the literature, these are the best results on cancer control that have ever been reported.
I do agree with Dr. Stamey that radical prostatectomy is not an easy operation and is best performed by a very experienced surgeon. However, for the right patient in the hands of the right surgeon it is the right way to cure prostate cancer.
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Patrick C. Walsh, M.D., Urologist-in-Chief.