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Priapism: An Avoidable Complication of Pharmacologically Induced Erection
0022-534 7 /89/1424-0995$02.0G/O
VoL 142, October Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1989 by AMERICAN UROLOGICAL ASSOCIATION, !NC.
PRIAPISM: AN AVOIDABLE COMPLICATION OF PHARMACOLOGICALLY INDUCED ERECTION A. FOUDA, M. HASSOUNA, E. BEDDOE, D. KALOGEROPOULOS, Y. M. BINIK AND M. M. ELHILALI From the Urology Center, Royal Victoria Hospital, and Department of Psychology, McGill University, Montreal, Quebec, Canada
ABSTRACT
Priapism is an alarming complication during treatment of erectile dysfunction with vasoactive drugs, particularly papaverine alone or in combination with phentolamine mesylate. An investigational protocol was designed to identify patients who are more susceptible to priapism after intracavernous injection ofpapaverine alone or with phentolamine. The protocol was applied in 331 men with impotence of various etiology. The association of a positive response to visual sexual stimulation and penile brachial index of more than 0.8 represented a higher risk for post-injection priapism. We were able to reduce the incidence of this compliance to 1 % in the last 101 patients. (J. Ural., 142: 995-997, 1989) The use of intracavernous injection of vasoactive drugs to induce erection is increasingly popular in the management of erectile dysfunction. Papaverine alone or with phentolamine is used widely, with a success rate of nearly 80% in achieving erection. Many patients have expressed satisfaction with this alternative to penile implantation. This modality, although simple, has the risk of prolonged sustained erection and priapism. The incidence of pharmacologically induced priapism varied from 4 to 8.7%. 1' 2 In a review of the literature we could find no data regarding parameters that could predict the risk of priapism before injection therapy is begun. We compared all of the evaluation criteria in an attempt to identify those that could predict individuals with high risk for priapism after injection therapy. MATERIALS AND METHODS
From June 1986 until August 1987 230 patients with erectile failure were enrolled at our sexual dysfunction clinic. These patients represent referrals from several peripheral clinics, and they were evaluated for sexual function and psychologically by 1 of us (D. K.). The protocol of investigation included history taking in the form of a self-completed questionnaire with special emphasis on sexual history (duration of impotence, quality of erection, vascular or neurological symptoms, diabetes, intake of drugs and/or medication). Physical examination was done with emphasis on signs of endocrinological, vascular or neurological deficits, length of the penis and any abnormal fibrous plaques, as well as size and consistency of the testes, Routine blood chemistry studies were done and a hormonal profile was requested when necessary for follicle-stimulating hormone, testosterone, luteinizing hormone and prolactin levels. The patient then underwent routine investigations, including determination of the penile brachial index and sacral evoked potential, and recording of the penile tumescence and rigidity during visual sexual stimulation. The penile brachial index is evaluated with the penis in the flaccid state as described previously. 3 In brief, the brachial arterial systolic blood pressure is taken from the right arm with the patient in the supine position. A specially designed inflatable cuff is wrapped around the base of the penis, and connected to a sphygmomanometer and a manual pump. Penile arterial pulsation is monitored with a 5 MHz. Doppler stethoscope by placing it at a 45-degree angle on the side of the penile shaft. Accepted for publication April 5, 1989.
The cuff is inflated above the systolic blood pressure and gradually deflated until the perception of penile pulsation, which indicates the systolic penile blood pressure. The ratio between the systolic penile and brachia! systolic blood pressure is termed the penile brachial index. We accept a penile brachial index of 0.65 as being the lower limit of normal. 3 The sacral evoked potential tests the integrity of the somatic component of the sacral arc. Our technique has been described previously.• In brief, the stimulation electrodes are placed on the glans penis. The electromyographic response is obtained at the external anal sphincter, The stimulus and response are displayed on an oscilloscope 4-channel recorder, The average of 16 stimulations is recorded on each channel. The latency between the stimulus and onset of the response is calculated, and the upper limit is considered to be 40 msec. The response in penile tumescence is measured with a mercury strain gauge electrode wrapped around the middle of the shaft of the penis. After 5 minutes has elapsed to stabilize the baseline to zero, the penile tumescence is monitored during visual sexual stimulation and after intracavernous injection of the vasoactive drug (papaverine hydrochloride with or without phentolamine mesylate). Visual sexual stimulation is performed in a special room in which the patient is seated comfortably and allowed to view an erotic videotape for 10 minutes. The patient is asked to concentrate on the movie and changes in penile circumference (tumescence) are recorded. An increase in tumescence is shown as upward deflection and evaluated as percentile increase from the baseline during tumescence. At the end of the session the penile rigidity is evaluated by patient description, palpation and by the angle of the penis from the vertical while the patient is standing. An angle of 90 degrees or more is considered consistent with good rigidity. Intracavernous injection then is performed with papaverine alone or mixed with phentolamine mesylate. The initial intracavernous injection dose contains 9,75 mg, papaverine and 0.5 mg. phentolamine mesylate in a 1 ml. tuberculin syringe, An elastic band is applied at the base of the penis. Under aseptic conditions the skin on the penile shaft is kept stretched and the tuberculin needle is inserted perpendicularly deep to the corpus cavernosum, avoiding any visible vessels, Pressure is applied for 2 to 3 minutes at the site of injection and then the elastic band is removed. The strain gauge is put around the penis and any tumescence is recorded for 10 minutes. In some patients visual sexual stimulation was repeated after intracavernous injection to evaluate the degree of rigidity and tumescence.
995
996
FOUDA AND ASSOCIATES
The patient is sent home and encouraged to engage in sexual activity within 1 hour after intracavernous injection. The patient is instructed clearly to report to the emergency room if the erection persists for more than 4 hours. He is telephoned the next day and interviewed in regard to sexual performance. In case of success the patient is enrolled in the program of selfinjection. He is taught all of the precautions for an aseptic technique of injection. Papaverine and phentolamine are supplied in 2 separate multiuse vials and the patient is instructed how to prepare the mixture within the limit of the effective dose determined previously. The upper limit of frequency of intracavernous injection is 3 times per week. The patient is warned about the risks of prolonged erection. He is followed every 3 months and examined for evidence of any penile lesion as long as he is on the self-injection program. Liver enzyme determinations also are performed every 3 months. If there was no response to the initial dose the injection is increased by increments of 6.5 mg. papaverine and 0.5 mg. phentolamine mesylate at each subsequent visit until a satisfactory response or the upper limit of 60 mg. papaverine and 5 mg. phentolamine is reached. At this point the patient who did not respond is offered other alternatives, such as a penile prosthesis. Between August and December 1987 we reviewed the charts of 101 additional patients with organic impotence who followed the same protocol of investigation but who had a slight modification in the sequence of injections. In the first 2 doses papaverine hydrochloride was given alone at doses of 9. 75 and 19.5 mg. Phentolamine mesylate was withheld until visit 3, when it was given at a dose of 0.5 mg. with 9. 75 mg. papaverine (table 1). RESULTS
The response to visual sexual stimulation was assessed in 226 patients of whom 15 (12%) had a positive response. In 4 patients the response was graded excellent (85% increase in penile tumescence), and they were considered to be ineligible TABLE
1. Schedule of dosage in last 101 patients
Visit
1 2
6
9.75 19.5 9.75 13 19.5 32.5
7
60
3 4 5
TABLE 2.
Phentolamine Mesylate (mg.)
Papaverine (mg.)
0.5 1 1.5 2.5 5
Evaluation of response to visual sexual stimulation in 266 patients Penile Tumescence ( % increase)
TABLE 4.
(%)
Response to visual sexual stimulation in 101 patients with modified protocol Penile Tumescence(% increase)
No. Pts.
Excellent (>85) Moderate (75-85) Fair (50-75) No response (<50)
5 10 85
4 (1.8) 8 (3.5) 3 (1.3)
211 (93.3)
TABLE
Mean age (yrs.) Antihypertensive (No. pts.) History of transurethral prostatic resection (No. pts.) Paraplegic (No. pts.) Mean penile brachia! index Sacral evoked potentials lntracavernous injection dose
* Statistically significant.
DISCUSSION
lntracavernous pharmacological agents used to manage erectile dysfunction have been gaining widespread acceptance. The main drawback of this method is the development of priapism. It is of prime importance to predict patients at high risk for priapism after injection. Some neurological disorders have been more prone to association with priapism, such as multiple sclerosis and paraplegia. 5 We evaluated the risk factors that could predict priapism after intracavernous injection of papaverine. The response to visual sexual stimulation was graded to differentiate the high from low responders. The fact that none of the patients with no response to visual sexual stimulation had priapism indicates the importance of this simple screening procedure, which can replace nocturnal penile tumescence. 6 The other parameters for evaluation of penile vasculature, such as penile brachial index, and innervation, such as sacral evoked potential, were studied in all patients in an attempt to determine if they could be helpful to predict high risk patients. The penile brachial index is a good predictor, particularly if it is higher than 0. 7 and associated with a good to moderate response to visual sexual stimulation. The prolonged latency (more than 80 msec.) found on the sacral evoked potential study in 3 patients with priapism is not conclusive as a risk factor in this series because of the small number, although some investigators attribute the priapism to be a result of a "denervation supersensitivity". 5
No. Pts.
Excellent (>85) Moderate (75-85) Fair (50-75) No response (<50)
Hrs. of erection
for intracavernous injection and referred for psychiatric evaluation (table 2). Of the remaining 11 patients 6 had priapism after intracavernous injection of 9.25 mg. papaverine and 0.5 mg. phentolamine: in 5 the priapism was treated by corporeal aspiration and 1 required a cavernospongiosal shunt. None of the patients with a negative response to visual sexual stimulation had priapism after intracavernous injection. The 6 patients with priapism after intracavernous injection were compared to the 5 who responded to visual sexual stimulation without having subsequent priapism after injection of a similar dose (table 3). There was a delay in the latency of the sacral evoked potential in 3 patients with priapism. Moreover, the mean penile brachial index was 0.8 in the priapism group compared to 0.51 in the patients without priapism. The response to visual sexual stimulation in the 101 patients who followed the modified protocol of investigation mentioned previously is shown in table 4. Only 1 patient had post-injection priapism that lasted for 5 hours. On closer questioning this patient injected 19.5 mg. papaverine twice in the same night. The episode of priapism was controlled by corporeal aspiration with the patient under local anesthesia.
1
3. Comparison between patients with and without priapism Priapism (6 pts.)
No Priapism (5 pts.)
54.3 1
51 1 1 1 0.51*
2 0
0.8* Prolonged in 3 pts. 10 mg. papaverine, 0.5 mg. phentolamine 6-36
Normal 10 mg. papaverine, 0.5 mg. phentolamine
1-3
PRIAPISM:
Since we recognized the of visual sexual stimulation we included this test in ail prospective evaluations of impotent men. Any patient with a 50% or more increase in penile tumescence after visual sexual stimulation is monitored closely after intracavern.ous injection for 2 hours. With this protocol of investigation the incidence of post-injection priapism has decreased to 1 % in our series. The papaverine dose for intracavernous injection preferably is begun at 9.75 mg. and is followed by doubling the dose. We defer the combination with phentolamine mesylate to a subsequent visit if papaverine alone is not helpful to obtain erection. In conclusion, priapism may be predicted and avoided if the patients are screened with visual sexual stimulation and penile brachial index, and phentolamine mesylate may be avoided in
the initial injections. REFERENCES l. Zorgniotti, A. W. and Lefleur, R. S.: Auto-injection of the corpus cavemosum with a vasoactive drug combination for vasculogenic impotence. J. Urol., 133: 39, 1985. 2. Nellans, R. E., Ellis, L. R. and Kramer-Levien, D.: Pharmacological erection: diagnosis and treatment applications in 69 patients. J. Uro!., 138: 52, 1987. 3. Elhilali, M. M., Hassouna, M., Abdel-Hakim, A. and Teijeira, J.: Urethral stricture following cardiovascular surgery: role of urethral ischemia. J. Urol., 135: 275, 1986. 4. Hassouna, M., Lebel, M. and Elhilali, M. M.: The evoked potential of the sacral reflex arc: technical aspects. Neurourol. Urodynam., 5: 543, 1986. 5. Padma-Nathan, H., Goldstein, I. and Krane, R. J.: Treatment of prolonged or priapistic erections following intracavernosal papaverine therapy. Sem. Urol., 4: 236, 1986. 6. Giesbers, A. A.G. M., Bruins, J. L., Kramer, A. E. J. L. and Jonas, U.: New methods in the diagnosis of impotence: rigiscan penile tumescence and 1·igidity monitoring and diagnostic papaverine hydrochloride injection. World J. Urol., 5: 173, 1987.
EDITORIAL COMMENTS The authors have presented an evaluation scheme using visual sexual stimulation followed by measurement of the penile brachia! index and sacral evoked potential. Since all patients with priapism had either a fair (50 to 75% increase in penile tumescence) or moderate (75 to 85% increase) response to visual sexual stimulation one wonders whether measurement of the penile brachia! index or sacral evoked potential is necessary. It would seem that these patients should be presumed to have a lesser degree of organic impotence and be tested directly with a low dose of pharmacological agents. Previous studies have shown that patients with milder degrees of vasculogenic impotence, and particularly those with neurogenic impotence, are more prone to have priapism after pharmacological erection testing. Neurogenic impotence often is suspected from the history and can be confirmed by a number of tests, including sacral evoked potential and measurement of buibocavemosus-ischiocavernosus muscle activity. The degree of vascular insuffi-
997
ciency is determined better by measurement of arterial pulsations and penile rigidity during sleep or visual sexual stimulation rather than by measurement of the penile brachia! index. It would appear that the findings of visual sexual stimulation or nocturnal penile tumescence alone should indicate the potential risk of priapism and that such patients should be tested with lowe1· doses of medication. In such patients we have used an initial dose of 6 mg. papavei·ine and 0.1 mg. phentolamine. All injections are given in the early morning so that should priapism develop the patient can be treated promptly later that afternoon. However, with this decreased dosage we have encountered no episodes of priapism within the last 2 years.
Charles B. Brend/er Department of Urology The Johns Hopkins Hospital Baltimore, Maryland The introduction of intracavemous vasodilator injection for diagnosis and treatment of impotence has revolutionized its management. Since its widespread use began in 1983, thousands of patients have benefited and only a small number have been harmed. The incidence ofpriapism is reported to be as high as 8.7%. The authors report their experience with intracavernous vasodilator injections in 331 impotent patients. By carefully monitoring those with a good response to visual sexual stimulation and a penile brachia! index of more than 0.8 (the so-called high risk patients) they were able to reduce the incidence of priapism to 1 % in the last 101 patients. This welcome report clearly demonstrates that injection-induced priapism can be prevented. I do have a different preventive approach that may be of some interest to the readers of the Journal. I give every patient a comprehensive instruction and consent form that includes the possible complications and specifically emphasizes the seriousness of priapism. If, after intracavemous injection of a vasodilator, the response is not a fully rigid erection I do not send the patient home but ask him to stimulate the penis manually behind a closed door in my office and observe the response for 1 to 2 hours. If the patient still has a fairly good erection by 1 hour a preventive intracavernous injection of diluted phenylephrine hydrochloride or epinephrine solution is given to reverse the erection. (This possibility is stated clearly in the consent form.) All candidates for home therapy receive injections in the office at least twice with the same precautions until the lowest dosage that produces adequate erection is determined. The patient always is instructed to use this low dosage and not to increase it without consulting the physician. During the last 5½ years I have used intracavernous vasodilator injections for diagnosis in more than 1,350 patients, of whom 5 had priapism more than 6 hours in duration, which was resolved by aspiration alone or with injection of an a-adrenergic agent (4 of these occurred among the first 200 patients). Among more than 300 patients who currently perform home injection therapy no incidence of priapism has occurred to date. My results are similar to those of the authors and echo their message that injection-induced priapism definitely is preventable.
TomF. Lue Department of Urology University of California San Francisco, California
VoL 142, October Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1989 by AMERICAN UROLOGICAL ASSOCIATION, !NC.
PRIAPISM: AN AVOIDABLE COMPLICATION OF PHARMACOLOGICALLY INDUCED ERECTION A. FOUDA, M. HASSOUNA, E. BEDDOE, D. KALOGEROPOULOS, Y. M. BINIK AND M. M. ELHILALI From the Urology Center, Royal Victoria Hospital, and Department of Psychology, McGill University, Montreal, Quebec, Canada
ABSTRACT
Priapism is an alarming complication during treatment of erectile dysfunction with vasoactive drugs, particularly papaverine alone or in combination with phentolamine mesylate. An investigational protocol was designed to identify patients who are more susceptible to priapism after intracavernous injection ofpapaverine alone or with phentolamine. The protocol was applied in 331 men with impotence of various etiology. The association of a positive response to visual sexual stimulation and penile brachial index of more than 0.8 represented a higher risk for post-injection priapism. We were able to reduce the incidence of this compliance to 1 % in the last 101 patients. (J. Ural., 142: 995-997, 1989) The use of intracavernous injection of vasoactive drugs to induce erection is increasingly popular in the management of erectile dysfunction. Papaverine alone or with phentolamine is used widely, with a success rate of nearly 80% in achieving erection. Many patients have expressed satisfaction with this alternative to penile implantation. This modality, although simple, has the risk of prolonged sustained erection and priapism. The incidence of pharmacologically induced priapism varied from 4 to 8.7%. 1' 2 In a review of the literature we could find no data regarding parameters that could predict the risk of priapism before injection therapy is begun. We compared all of the evaluation criteria in an attempt to identify those that could predict individuals with high risk for priapism after injection therapy. MATERIALS AND METHODS
From June 1986 until August 1987 230 patients with erectile failure were enrolled at our sexual dysfunction clinic. These patients represent referrals from several peripheral clinics, and they were evaluated for sexual function and psychologically by 1 of us (D. K.). The protocol of investigation included history taking in the form of a self-completed questionnaire with special emphasis on sexual history (duration of impotence, quality of erection, vascular or neurological symptoms, diabetes, intake of drugs and/or medication). Physical examination was done with emphasis on signs of endocrinological, vascular or neurological deficits, length of the penis and any abnormal fibrous plaques, as well as size and consistency of the testes, Routine blood chemistry studies were done and a hormonal profile was requested when necessary for follicle-stimulating hormone, testosterone, luteinizing hormone and prolactin levels. The patient then underwent routine investigations, including determination of the penile brachial index and sacral evoked potential, and recording of the penile tumescence and rigidity during visual sexual stimulation. The penile brachial index is evaluated with the penis in the flaccid state as described previously. 3 In brief, the brachial arterial systolic blood pressure is taken from the right arm with the patient in the supine position. A specially designed inflatable cuff is wrapped around the base of the penis, and connected to a sphygmomanometer and a manual pump. Penile arterial pulsation is monitored with a 5 MHz. Doppler stethoscope by placing it at a 45-degree angle on the side of the penile shaft. Accepted for publication April 5, 1989.
The cuff is inflated above the systolic blood pressure and gradually deflated until the perception of penile pulsation, which indicates the systolic penile blood pressure. The ratio between the systolic penile and brachia! systolic blood pressure is termed the penile brachial index. We accept a penile brachial index of 0.65 as being the lower limit of normal. 3 The sacral evoked potential tests the integrity of the somatic component of the sacral arc. Our technique has been described previously.• In brief, the stimulation electrodes are placed on the glans penis. The electromyographic response is obtained at the external anal sphincter, The stimulus and response are displayed on an oscilloscope 4-channel recorder, The average of 16 stimulations is recorded on each channel. The latency between the stimulus and onset of the response is calculated, and the upper limit is considered to be 40 msec. The response in penile tumescence is measured with a mercury strain gauge electrode wrapped around the middle of the shaft of the penis. After 5 minutes has elapsed to stabilize the baseline to zero, the penile tumescence is monitored during visual sexual stimulation and after intracavernous injection of the vasoactive drug (papaverine hydrochloride with or without phentolamine mesylate). Visual sexual stimulation is performed in a special room in which the patient is seated comfortably and allowed to view an erotic videotape for 10 minutes. The patient is asked to concentrate on the movie and changes in penile circumference (tumescence) are recorded. An increase in tumescence is shown as upward deflection and evaluated as percentile increase from the baseline during tumescence. At the end of the session the penile rigidity is evaluated by patient description, palpation and by the angle of the penis from the vertical while the patient is standing. An angle of 90 degrees or more is considered consistent with good rigidity. Intracavernous injection then is performed with papaverine alone or mixed with phentolamine mesylate. The initial intracavernous injection dose contains 9,75 mg, papaverine and 0.5 mg. phentolamine mesylate in a 1 ml. tuberculin syringe, An elastic band is applied at the base of the penis. Under aseptic conditions the skin on the penile shaft is kept stretched and the tuberculin needle is inserted perpendicularly deep to the corpus cavernosum, avoiding any visible vessels, Pressure is applied for 2 to 3 minutes at the site of injection and then the elastic band is removed. The strain gauge is put around the penis and any tumescence is recorded for 10 minutes. In some patients visual sexual stimulation was repeated after intracavernous injection to evaluate the degree of rigidity and tumescence.
995
996
FOUDA AND ASSOCIATES
The patient is sent home and encouraged to engage in sexual activity within 1 hour after intracavernous injection. The patient is instructed clearly to report to the emergency room if the erection persists for more than 4 hours. He is telephoned the next day and interviewed in regard to sexual performance. In case of success the patient is enrolled in the program of selfinjection. He is taught all of the precautions for an aseptic technique of injection. Papaverine and phentolamine are supplied in 2 separate multiuse vials and the patient is instructed how to prepare the mixture within the limit of the effective dose determined previously. The upper limit of frequency of intracavernous injection is 3 times per week. The patient is warned about the risks of prolonged erection. He is followed every 3 months and examined for evidence of any penile lesion as long as he is on the self-injection program. Liver enzyme determinations also are performed every 3 months. If there was no response to the initial dose the injection is increased by increments of 6.5 mg. papaverine and 0.5 mg. phentolamine mesylate at each subsequent visit until a satisfactory response or the upper limit of 60 mg. papaverine and 5 mg. phentolamine is reached. At this point the patient who did not respond is offered other alternatives, such as a penile prosthesis. Between August and December 1987 we reviewed the charts of 101 additional patients with organic impotence who followed the same protocol of investigation but who had a slight modification in the sequence of injections. In the first 2 doses papaverine hydrochloride was given alone at doses of 9. 75 and 19.5 mg. Phentolamine mesylate was withheld until visit 3, when it was given at a dose of 0.5 mg. with 9. 75 mg. papaverine (table 1). RESULTS
The response to visual sexual stimulation was assessed in 226 patients of whom 15 (12%) had a positive response. In 4 patients the response was graded excellent (85% increase in penile tumescence), and they were considered to be ineligible TABLE
1. Schedule of dosage in last 101 patients
Visit
1 2
6
9.75 19.5 9.75 13 19.5 32.5
7
60
3 4 5
TABLE 2.
Phentolamine Mesylate (mg.)
Papaverine (mg.)
0.5 1 1.5 2.5 5
Evaluation of response to visual sexual stimulation in 266 patients Penile Tumescence ( % increase)
TABLE 4.
(%)
Response to visual sexual stimulation in 101 patients with modified protocol Penile Tumescence(% increase)
No. Pts.
Excellent (>85) Moderate (75-85) Fair (50-75) No response (<50)
5 10 85
4 (1.8) 8 (3.5) 3 (1.3)
211 (93.3)
TABLE
Mean age (yrs.) Antihypertensive (No. pts.) History of transurethral prostatic resection (No. pts.) Paraplegic (No. pts.) Mean penile brachia! index Sacral evoked potentials lntracavernous injection dose
* Statistically significant.
DISCUSSION
lntracavernous pharmacological agents used to manage erectile dysfunction have been gaining widespread acceptance. The main drawback of this method is the development of priapism. It is of prime importance to predict patients at high risk for priapism after injection. Some neurological disorders have been more prone to association with priapism, such as multiple sclerosis and paraplegia. 5 We evaluated the risk factors that could predict priapism after intracavernous injection of papaverine. The response to visual sexual stimulation was graded to differentiate the high from low responders. The fact that none of the patients with no response to visual sexual stimulation had priapism indicates the importance of this simple screening procedure, which can replace nocturnal penile tumescence. 6 The other parameters for evaluation of penile vasculature, such as penile brachial index, and innervation, such as sacral evoked potential, were studied in all patients in an attempt to determine if they could be helpful to predict high risk patients. The penile brachial index is a good predictor, particularly if it is higher than 0. 7 and associated with a good to moderate response to visual sexual stimulation. The prolonged latency (more than 80 msec.) found on the sacral evoked potential study in 3 patients with priapism is not conclusive as a risk factor in this series because of the small number, although some investigators attribute the priapism to be a result of a "denervation supersensitivity". 5
No. Pts.
Excellent (>85) Moderate (75-85) Fair (50-75) No response (<50)
Hrs. of erection
for intracavernous injection and referred for psychiatric evaluation (table 2). Of the remaining 11 patients 6 had priapism after intracavernous injection of 9.25 mg. papaverine and 0.5 mg. phentolamine: in 5 the priapism was treated by corporeal aspiration and 1 required a cavernospongiosal shunt. None of the patients with a negative response to visual sexual stimulation had priapism after intracavernous injection. The 6 patients with priapism after intracavernous injection were compared to the 5 who responded to visual sexual stimulation without having subsequent priapism after injection of a similar dose (table 3). There was a delay in the latency of the sacral evoked potential in 3 patients with priapism. Moreover, the mean penile brachial index was 0.8 in the priapism group compared to 0.51 in the patients without priapism. The response to visual sexual stimulation in the 101 patients who followed the modified protocol of investigation mentioned previously is shown in table 4. Only 1 patient had post-injection priapism that lasted for 5 hours. On closer questioning this patient injected 19.5 mg. papaverine twice in the same night. The episode of priapism was controlled by corporeal aspiration with the patient under local anesthesia.
1
3. Comparison between patients with and without priapism Priapism (6 pts.)
No Priapism (5 pts.)
54.3 1
51 1 1 1 0.51*
2 0
0.8* Prolonged in 3 pts. 10 mg. papaverine, 0.5 mg. phentolamine 6-36
Normal 10 mg. papaverine, 0.5 mg. phentolamine
1-3
PRIAPISM:
Since we recognized the of visual sexual stimulation we included this test in ail prospective evaluations of impotent men. Any patient with a 50% or more increase in penile tumescence after visual sexual stimulation is monitored closely after intracavern.ous injection for 2 hours. With this protocol of investigation the incidence of post-injection priapism has decreased to 1 % in our series. The papaverine dose for intracavernous injection preferably is begun at 9.75 mg. and is followed by doubling the dose. We defer the combination with phentolamine mesylate to a subsequent visit if papaverine alone is not helpful to obtain erection. In conclusion, priapism may be predicted and avoided if the patients are screened with visual sexual stimulation and penile brachial index, and phentolamine mesylate may be avoided in
the initial injections. REFERENCES l. Zorgniotti, A. W. and Lefleur, R. S.: Auto-injection of the corpus cavemosum with a vasoactive drug combination for vasculogenic impotence. J. Urol., 133: 39, 1985. 2. Nellans, R. E., Ellis, L. R. and Kramer-Levien, D.: Pharmacological erection: diagnosis and treatment applications in 69 patients. J. Uro!., 138: 52, 1987. 3. Elhilali, M. M., Hassouna, M., Abdel-Hakim, A. and Teijeira, J.: Urethral stricture following cardiovascular surgery: role of urethral ischemia. J. Urol., 135: 275, 1986. 4. Hassouna, M., Lebel, M. and Elhilali, M. M.: The evoked potential of the sacral reflex arc: technical aspects. Neurourol. Urodynam., 5: 543, 1986. 5. Padma-Nathan, H., Goldstein, I. and Krane, R. J.: Treatment of prolonged or priapistic erections following intracavernosal papaverine therapy. Sem. Urol., 4: 236, 1986. 6. Giesbers, A. A.G. M., Bruins, J. L., Kramer, A. E. J. L. and Jonas, U.: New methods in the diagnosis of impotence: rigiscan penile tumescence and 1·igidity monitoring and diagnostic papaverine hydrochloride injection. World J. Urol., 5: 173, 1987.
EDITORIAL COMMENTS The authors have presented an evaluation scheme using visual sexual stimulation followed by measurement of the penile brachia! index and sacral evoked potential. Since all patients with priapism had either a fair (50 to 75% increase in penile tumescence) or moderate (75 to 85% increase) response to visual sexual stimulation one wonders whether measurement of the penile brachia! index or sacral evoked potential is necessary. It would seem that these patients should be presumed to have a lesser degree of organic impotence and be tested directly with a low dose of pharmacological agents. Previous studies have shown that patients with milder degrees of vasculogenic impotence, and particularly those with neurogenic impotence, are more prone to have priapism after pharmacological erection testing. Neurogenic impotence often is suspected from the history and can be confirmed by a number of tests, including sacral evoked potential and measurement of buibocavemosus-ischiocavernosus muscle activity. The degree of vascular insuffi-
997
ciency is determined better by measurement of arterial pulsations and penile rigidity during sleep or visual sexual stimulation rather than by measurement of the penile brachia! index. It would appear that the findings of visual sexual stimulation or nocturnal penile tumescence alone should indicate the potential risk of priapism and that such patients should be tested with lowe1· doses of medication. In such patients we have used an initial dose of 6 mg. papavei·ine and 0.1 mg. phentolamine. All injections are given in the early morning so that should priapism develop the patient can be treated promptly later that afternoon. However, with this decreased dosage we have encountered no episodes of priapism within the last 2 years.
Charles B. Brend/er Department of Urology The Johns Hopkins Hospital Baltimore, Maryland The introduction of intracavemous vasodilator injection for diagnosis and treatment of impotence has revolutionized its management. Since its widespread use began in 1983, thousands of patients have benefited and only a small number have been harmed. The incidence ofpriapism is reported to be as high as 8.7%. The authors report their experience with intracavernous vasodilator injections in 331 impotent patients. By carefully monitoring those with a good response to visual sexual stimulation and a penile brachia! index of more than 0.8 (the so-called high risk patients) they were able to reduce the incidence of priapism to 1 % in the last 101 patients. This welcome report clearly demonstrates that injection-induced priapism can be prevented. I do have a different preventive approach that may be of some interest to the readers of the Journal. I give every patient a comprehensive instruction and consent form that includes the possible complications and specifically emphasizes the seriousness of priapism. If, after intracavemous injection of a vasodilator, the response is not a fully rigid erection I do not send the patient home but ask him to stimulate the penis manually behind a closed door in my office and observe the response for 1 to 2 hours. If the patient still has a fairly good erection by 1 hour a preventive intracavernous injection of diluted phenylephrine hydrochloride or epinephrine solution is given to reverse the erection. (This possibility is stated clearly in the consent form.) All candidates for home therapy receive injections in the office at least twice with the same precautions until the lowest dosage that produces adequate erection is determined. The patient always is instructed to use this low dosage and not to increase it without consulting the physician. During the last 5½ years I have used intracavernous vasodilator injections for diagnosis in more than 1,350 patients, of whom 5 had priapism more than 6 hours in duration, which was resolved by aspiration alone or with injection of an a-adrenergic agent (4 of these occurred among the first 200 patients). Among more than 300 patients who currently perform home injection therapy no incidence of priapism has occurred to date. My results are similar to those of the authors and echo their message that injection-induced priapism definitely is preventable.
TomF. Lue Department of Urology University of California San Francisco, California