New concept parameters of RigiScan in differentiation of vascular erectile dysfunction: Is it a useful test?

BACKGROUND: The aim of this study is to investigate the value of new nocturnal penile tumescence recording parameters, such as tumescence activity unit and rigidity activity unit values, total erection number and erection times, in differentiating between psychogenic erectile dysfunction and organic erectile dysfunction. We also aimed to determine the role of these parameters in differentiating arterial erectile dysfunction from veno-occlusive dysfunction. METHODS: Eighty-seven consecutive patients were allocated into three groups as psychogenic, arterial and venous erectile dysfunction after investigations. Nocturnal penile tumescence recording parameters between psychogenic and vascular erectile dysfunction and arterial and veno-occlusive dysfunction were compared. Mann-Whitney U-test, Pearson's chi2 test and correlation coefficient tests were used for statistical analysis. RESULTS: Depending on intracavernous injection, penile Doppler ultrasonography and cavernosometry tests, 37 patients (43%) had psychogenic impotence while 50 (57%) had organic pathologies. Of the 50 patients diagnosed with vascular impotence, 29 (48%) had arterial failure and 21 (42%) had veno-occlusive dysfunction. Nocturnal penile tumescence recording revealed psychogenic erectile dysfunction in 34 patients (39%) and vascular erectile dysfunction in 53 patients (61%). Nocturnal penile tumescence recording has been regarded as the gold standard and, in our series, it showed 90.6% sensitivity and 88.2% specificity in differentiating the cause of erectile dysfunction. Values of rigidity activity unit and tumescence activity unit were significantly higher in patients with psychogenic impotence (P < 0.001), when compared with vascular impotence. In patients with a vascular cause, no difference was found between arterial failure and veno-occlusive dysfunction with regard to tip tumescence activity unit, base tumescence activity unit, tip rigidity activity unit, base rigidity activity unit and erection time (P > 0.001). However, patients with arterial failure had less erection than patients with veno-occlusive dysfunction (P < 0.001). CONCLUSION: New recording parameters of nocturnal penile tumescence can differentiate organic and psychogenic erectile dysfunction more precisely. However, these recording parameters cannot distinguish subgroups with a vascular cause of erectile dysfunction.     

Evaluation of erectile dysfunction with continuous monitoring of penile rigidity

Measurement of nocturnal penile tumescence or circumferential expansion is a valuable method for the diagnosis of erectile impotence. However, only a few investigations have been made of penile rigidity during tumescence with a single isolated measurement. A new method of continuous and simultaneous recording of nocturnal penile rigidity and circumferential expansion (tumescence) was used in 105 patients with erectile impotence. The method provided several findings concerning nocturnal penile erection. Circumferential expansion was not always accompanied by penile rigidity. A dissociation of rigidity between the tip and base of the penis was observed in some patients. Shortened episodes and low amplitude of rigidity also were seen. Of 11 patients with psychogenic impotence diagnosed by conventional methods 3 (27.3 per cent) showed abnormal nocturnal rigidity and 8 of 94 (8.5 per cent) with organic impotence diagnosed by conventional methods showed normal nocturnal rigidity. Because of its ambulatory character the continuous measurement of nocturnal penile rigidity is of value in defining features of nocturnal penile erection and differentiating psychogenic from organic impotence.     

Sildenafil improves nocturnal penile erections in organic impotence.

We studied the effects of sildenafil on nocturnal penile erections. We prospectively evaluated 36 patients with organic or psychogenic impotence and 5 normal, potent men. All patients completed 3 sessions of consecutive nights using the RigiScan Plus device. The first two nights the patients were asked to take placebo before the session and to take 50 mg of sildenafil before the third session. In the organic impotence group the use of sildenafil induced a significant improvement in time of rigidity 60-100%, rigidity and tumescence activity unit values and rigidity and tumescence activity unit values per hour in the tip and base. In the psychogenic impotence group it caused significant improvement only in rigidity activity unit per hour in the tip. In the potent men, changes were statistically insignificant. Sildenafil improves nocturnal penile erectile activity in organic impotence. Our study shows that phosphodiesterase inhibitors can improve penile erections not induced by sexual stimulation.     

Nocturnal penile tumescence predicting response to intracorporeal pharmacological erection testing

Although response to intracorporeal pharmacological erection testing has been proposed to determine the etiology of impotence, physiological criteria predicting this response have not been established and the literature includes conflicting results regarding which patients respond to pharmacological erection therapy. In this study 37 impotent patients underwent a diagnostic nocturnal penile tumescence evaluation (including measurements of rigidity, pulsations and bulboischiocavernosus muscle activity) and the results were correlated with subsequent response to intracorporeal pharmacological testing. Most but not all patients with psychogenic impotence and all with neurogenic impotence responded with good erections. For vasculogenic impotence response rate depended upon impairment severity determined from nocturnal penile tumescence measurements; none of the severe cases versus 90 per cent of the milder cases responded. The results indicate that response to intracorporeal pharmacological testing does not accurately distinguish psychogenic from organic impotence, is best for neurogenic impotence and worst for severe vasculogenic impotence, and can be predicted accurately by nocturnal penile tumescence measurements.     

Combination therapy: medicated urethral system for erection enhances sexual satisfaction in sildenafil citrate failure following nerve-sparing radical prostatectomy

The objective of our study was to assess the effectiveness of combining medicated urethral system for erection (MUSE) with sildenafil citrate in men unsatisfied with the sildenafil alone. Baseline and follow-up data from 23 patients (mean age, 62.5 +/- 5.23 years) unsatisfied with the use of the sildenafil citrate alone for the treatment of erectile dysfunction following nerve-sparing radical prostatectomy (mean use, 4 attempts/100-mg dose) was obtained. All patients started oral sildenafil citrate more than 6 months after radical prostatectomy. Combination therapy was initiated using 100 mg sildenafil citrate orally 1 hour prior to intercourse. Patients used combination therapy for a minimum of 4 attempts prior to assessment with the Sexual Health Inventory of Men (International Index for Erectile Function-5) and visual analog scale to gauge rigidity (0-100). The effect of therapy on the total International Index for Erectile Function (IIEF) score and penile rigidity score was assessed. Of the 23 patients, 4 (17%) had no improvement with the addition of medicated urethral system for erection and discontinued the drug, while 19 (83%) reported improvement with the penile rigidity and sexual satisfaction. The IIEF scores of these 19 patients showed significant improvements in each sexual domain, and the patients reported that erection was sufficient for vaginal penetration 80% of the time. Rigidity scores on a scale of 0-100 with sildenafil alone averaged 38% (23-53) for men and 46% (26-67) for their partners. With the addition of MUSE, scores increased to 76% for men and 62% for their partners. We conclude that the addition of MUSE to sildenafil improved sexual satisfaction and penile rigidity in patients unsatisfied with sildenafil alone.     

Sildenafil citrate significantly improves nocturnal penile erections in sildenafil non-responding patients with psychogenic erectile dysfunction

Effects of sildenafil citrate on nocturnal penile tumescence and rigidity (NPTR) were evaluated among sildenafil non-responding patients with psychogenic erectile dysfunction. All patients (n=30), equally divided into groups I and II, completed four consecutive nights using the RigiScan Plus device. Sildenafil citrate (50 mg) was given in the third night in group I and in the fourth in group II, whereas a placebo was given in the remaining nights. Additional patients (n=12) receiving only a placebo served as a control group. Results of NPTR recordings revealed neither significant differences between the control and non-sildenafil nights of both test groups, nor between the corresponding values of both groups (P>0.05). On the other hand, when sildenafil citrate nights of groups I and II taken together were compared with placebo nights, a significant increase of total events duration (P<0.001), average rigidity of the tip (P<0.05) and base (P<0.01), and rigidity activity unit (RAU) and tumescence activity unit (TAU) of tip and base (P<0.001) was observed. These results suggest that performance anxiety may be responsible for failure of response during awakening.     

Papaverine testing of impotent patients following nerve-sparing radical prostatectomy

To investigate the etiology of impotence following nerve-sparing radical retropubic prostatectomy we performed papaverine testing on 23 patients who did not regain erections sufficient for vaginal penetration. Intervals from surgery to testing ranged from 3 to 30 months, with an average of 9 months. All patients achieved some degree of tumescence. In response to intracavernous papaverine injection only 1 patient (5 per cent) obtained an erection equivalent to the preoperative state. Of 18 patients who were fully potent preoperatively 8 (44 per cent) achieved an erection less than normal but judged to be sufficient for intercourse by the examining physician. Twelve patients, including 2 who were not fully potent preoperatively, had erections of poor quality insufficient for vaginal penetration. The results suggest that in most of these patients postoperative erectile dysfunction is predominantly vasculogenic in origin. Thus, factors other than injury to the neurovascular bundles may be responsible for postoperative impotence.     

Sildenafil citrate vs intracavernous alprostadil for patients with arteriogenic erectile dysfunction: a randomised placebo controlled study

We compared the effectiveness of sildenafil citrate and alprostadil in improving arterial penile inflow (peak systolic velocity (PSV)) and penile rigidity in 55 patients with erectile dysfunction caused by atherosclerosis. A total of 35 patients with pure vasculogenic impotency were randomly assigned to alprostadil (Av group; n=11), sildenafil (Sv group; n=12), or placebo (P group; n=12), and 20 patients with nonvasculogenic impotency were randomly assigned to alprostadil (A group; n=10) or Sildenafil (S group; n=10): Av and A used alprostadil injection (capable of giving a full erection) once a week for 1 month, Sv and S took daily oral sildenafil (25 mg) for 1 month, and P took daily oral placebo for one month. The PSV was measured with Duplex sonography and penile rigidity was assessed using the IIEF-15 questionnaire, both of which were administered before and after treatment. Although both treatments improved penile rigidity, they increased PSV only in the Av and Sv groups. Our results suggest that alprostadil and oral therapy should be the starting therapy in men with vasculogenic impotency, whereas alprostadil should be avoided as the first-line approach in men with nonvasculogenic impotency.     

CAVERNOUS ARTERIAL AND ARTERIOLAR CIRCULATION IN PATIENTS WITH ERECTILE DYSFUNCTION: A POWER DOPPLER STUDY

Purpose

We assessed the morphodynamic features of cavernous arteries and helicine arterioles by power Doppler sonography in vasculogenic and nonvasculogenic impotent men.

Materials and Methods

A total of 40 impotent patients with and without definite vascular risk factors were studied by penile power Doppler sonography. The test was performed during penile flaccidity, after intracavernous injection of 20 mcg. alprostadil and after subsequent genital and audiovisual sexual stimulation. A second injection and stimulation were given if the erectile response observed after the initial injection was less than the maximum erection seen during sexual activity. Morphodynamic parameters evaluated by power Doppler imaging included vessel course, shape, wall thickness and pulsatility, peak systolic velocity, end diastolic velocity, acceleration time and resistance index.

Results

In the nonvasculogenic group all patients who achieved rigid erection showed normal cavernosal artery and helicine arteriole inflow. In these cases the arteriolar picture was characterized by the presence of 3 orders of distal ramifications originating from the cavernous arteries with an acute angle, systolic diastolic flow during penile tumescence and systolic flow alone at full rigidity. In the vasculogenic group patients with normal cavernous artery inflow showed an arteriolar tree that was pathological in 50% and was characterized by a reduced number of ramifications originating perpendicularly from the cavernous arteries and irregular caliber (arteriolar impotence). In the same group patients with reduced cavernous artery inflow also showed normal or pathological arteriolar components (pre-penile arterial impotence and diffused penile arterial impotence).

Conclusions

Power Doppler sonography allows a precise study of the morphodynamics of the cavernous arteries and helicine arterioles. Our preliminary data suggest that the intracavernous arteriolar component may have a significant role in the genesis of some forms of vasculogenic impotence.     

New methods in the diagnosis of impotence: RigiScan® penile tumescence and rigidity monitoring and diagnostic papaverine hydrochloride injection

Summary In 26 patients with erectile impotence and 8 healthy volunteers the value of continuous monitoring of penile tumescence and rigidity by means of the RigiScan was tested. Based on history and routine screening tests the patients were divided into 3 groups of preliminary diagnosis: psychogenic (5 patients), organic (10 patients), mixed (11 patients). Real-time measurements of tumescence and rigidity were performed during direct visual stimulation and after intracorporeal injection of 80 mg papaverine hydrochloride according to a specific protocol. A total of 21 patients were monitored during sleep studies for 2 or 3 consecutive nights. The rigidity figures of the volunteers correlated well with their subjective interpretation of the erection. Evaluation of the recordings of the impotent patients enabled reclassification of the mixed group into 3 patients with mainly organic and 8 patients with mainly psychogenic impotence. RigiScan recording of penile tumescence and rigidity appears to be of great value in the diagnosis of impotent patients. Real-time monitoring during direct visual stimulation and after papaverine injection can generally replace nocturnal measurements. If the patient shows a positive response on visual sexual stimulation (VSS) alone, then his impotence is of psychogenic origin. Failing rigidity during VSS after injection indicates vascular impotence. In patients who show negative results during VSS alone, and positive response after injection or during subsequent VSS, nocturnal monitoring will differentiate between psychogenic and neurogenic impotence.     

Intracavernous injections of papaverine and phentolamine: correlation with penile brachial index

Eighty-two patients were evaluated for erectile failure with a comprehensive history, physical examination, hormonal testing, noninvasive Doppler examination (PBI), and nocturnal penile tumescence (NPT). After these studies all patients received intracavernous injection with a combination of papaverine (50 mg) and phentolamine (1.66 mg), and both tumescence and rigidity were monitored. Rigidity response was compared with the PBI. The number of patients with a poor rigidity response in each PBI category were: 3 of 5 with a PBI of less than 0.6 (vasculogenic), 7 of 11 with a PBI of 0.6-0.75 (ambiguous), and 25 of 66 with a PBI of 0.75-1.0 (normal). These results indicate only a marginally significant association between PBI and intracavernous injection. The procedure was safe with no long-term sequelae from injection observed, and no surgical intervention was required. Complications of injections included reversible priapism in 11 patients (13.4%), transient dizziness in 10 patients (12.2%), and hematoma in 5 patients (6.2%). This study suggests that intracavernous injection with a drug combination may be a more sensitive screening test for vasculogenic impotence than noninvasive Doppler studies because it more closely simulates the erectile response.     

Analysis of nocturnal penile tumescence with continuous monitoring of penile rigidity

By continuous and simultaneous recording of nocturnal penile rigidity and circumferential expansion (tumescence), nocturnal penile rigidity and tumescence have been classified into 6 patterns: normal, dissociation, uncoupling, short episode, low amplitude and flat trace. The monitoring will be helpful to diagnose underlying disorders involving erectile impotence, if the pattern of nocturnal penile rigidity and tumescence are related with the disorders. This study analyzed the relationship between the pattern of nocturnal penile rigidity and tumescence and associated disorders in 105 patients with erectile impotence. Of 15 patients with central nervous system disorders, 9 (60%) had a pattern of short episode of rigidity. In 29 patients with cardiovascular disorders, the patterns of dissociation, low amplitude and flat trace were the main findings and observed in 41, 41, 35% of the group, respectively. No patients with diabetes mellitus showed normal pattern. Although the group of non insulin dependent diabetes mellitus (21 patients) had various patterns of rigidity and tumescence, the insulin dependent group (14 patients) mainly showed patterns of low amplitude (21%) and/or flat trace (71%). The continuous and simultaneous monitoring of penile rigidity and tumescence will be helpful, with an integral analysis of its pattern and other examinations, for accurate diagnosis of underlying disorders of organic impotence, besides for differentiation of organic impotence from psychogenic one.     

Sildenafil taken at bedtime significantly increases nocturnal erections: results of a placebo-controlled study

Objectives. Nighttime erections occur at all ages and contribute to the maintenance of the morphodynamic integrity of smooth muscle cells within the corpora cavernosa. This study was aimed at evaluating the effect on nocturnal erections of sildenafil versus a placebo taken at bedtime.Methods. A double-blind, crossover, placebo-controlled study design was used to examine the effects of sildenafil and placebo on sleep-related erectile activity. Thirty selected patients with erectile dysfunction (vasculogenic etiology, 22 patients [73%]; psychogenic etiology, 8 patients [27%]) were submitted to a polysomnographic recording of nocturnal erections, using a RigiScan device during 3 consecutive nights. After a first night of adaptation, the 2 following nights were used to study patients after the administration of sildenafil (100 mg) or a placebo taken at bedtime.Results. Twenty-three patients (77%) showed a significantly improved nocturnal erectile activity (according to the calculation of rigidity and tumescence activity units) after the administration of sildenafil (P <0.01), 5 patients (17%) showed comparable nocturnal erections with sildenafil and placebo, and 2 patients (6%) showed a significantly improved nocturnal erectile activity after taking the placebo (P <0.05). Overall, mean rigidity and tumescence activity values at the tip and base of the penis were significantly improved after sildenafil rather than placebo administration (P <0.001). The duration of tip rigidity greater than 60% was significantly longer during the night with sildenafil (P <0.001). Although the number of erectile episodes was greater during the sildenafil night, this did not reach statistical significance.Conclusions. In most patients with good sleep efficiency and who have erectile dysfunction, sildenafil, rather than a placebo, taken at bedtime produces a significantly improved nocturnal erectile activity. Further studies are needed to verify whether this preliminary finding may constitute the basis for the use of sildenafil as a tool for preventing erectile dysfunction.     

Venous incompetence: critical study of the organic basis of high maintenance flow rates during artificial erection test

We tested whether the necessity for high flow rates of saline to maintain an artificial erection actually corresponds to an organic abnormality able to induce impotence as claimed recently. A total of 56 patients with presumed vascular impotence and 13 with typical psychogenic impotence underwent dynamic cavernosography followed by the artificial erection test. The former 56 patients also underwent bilateral selective internal iliac arteriography. A severely elevated maintenance flow rate (more than 120 ml. per minute) was found in 19 of the 56 patients with vascular and none of the 13 with psychogenic impotence, while a moderately elevated maintenance flow rate (80 to 120 ml. per minute) was found in 11 and 3, respectively. In most cases a severely elevated maintenance flow rate was associated with arterial (16 patients) or neurological abnormalities able to disturb erection. However, a severely elevated maintenance flow rate seemed to correspond to an organic abnormality able to induce impotence or to worsen erectile failure induced by other organic factors. Indeed, we found no severely elevated maintenance flow rates among our 13 patients with psychogenic impotence and the nocturnal penile tumescence test was normal in only 1 of 12 tested patients, although 7 had no other organic impairment sufficient to induce impotence (only moderate arterial stenoses in 4). In addition, sexual treatment succeeded in only 1 of the 13 patients, while our success rate is 43 per cent among patients with arterial impotence exclusively and this treatment succeeded in 6 of 10 patients with a moderately elevated maintenance flow rate. On the contrary, a moderately elevated maintenance flow rate does not seem to correspond to a genuine organic abnormality able to induce impotence. Indeed, we found it in 3 of 13 patients with psychogenic impotence, and every patient with a moderately elevated maintenance flow rate and normal arteries had a normal nocturnal penile tumescence test or was cured by sexual therapy. In conclusion, a maintenance flow rate exceeding 120 ml. per minute seems to reveal a genuine venous incompetence but in most cases this abnormality is only the cofactor of an arterial obstruction.     

Comparative value of prostaglandin E1 and papaverine in treatment of erectile failure: double-blind crossover study among Egyptian patients.

In a double-blind, crossover designation penile intracavernous prostaglandin E1 and papaverine hydrochloride were compared in regard to effectiveness and safety in 52 patients investigated and treated for sexual erectile dysfunction. In evidence of the reliable effectiveness, prostaglandin E1 (20 micrograms/ml.) induced significant positive erectile response in 42 of 52 patients (81%). This rate reached 100% with neurogenic, hyperprolactinemic and/or psychogenic impotence. However, with papaverine hydrochloride (30 mg./ml.) and exclusively in cases of vasculogenic (most probably arteriogenic) impotence, negative erectile response was revealed as absent erection in 6 of 52 patients (11.5%) and nonrigid tumescence in 13 (25%) versus 2 (3.8%) and 8 (15.4%), respectively, with prostaglandin E1. Moreover, with prostaglandin E1 the regional pain was tolerable and transient, and the positive erectile response was not attended by priapism even in patients who formerly had priapism with papaverine hydrochloride. However, presently with prostaglandin E1 the relatively higher cost and shorter expiration period would probably limit its diagnostic and therapeutic use in Egypt, and probably in other developing countries.     

Rationale for combination therapy of intraurethral prostaglandin E(1) and sildenafil in the salvage of erectile dysfunction patients desiring noninvasive therapy

Corpus cavernosum smooth muscle relaxation and hence penile erection are regulated in part by increases in smooth muscle synthesis of the second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). The object of this study was to determine 30-month follow-up results in motivated patients desiring noninvasive medical therapy using sildenafil citrate (Viagra) in combination with intraurethral prostaglandin E(1) (PGE(1)) (Medicated Urethral System for Erection [MUSE]). Twenty-eight patients (mean +/- s.d. age, 59 +/-7.3 y; 17 who had undergone radical prostatectomy and 11 who had a diagnosis of organic erectile dysfunction) were included in this study. Detailed history taking and physical examinations were performed and vascular risk factors noted. In these patients, treatment with either 100 mg of sildenafil citrate and/or 1000 microg of MUSE had failed. None of these patients desired intracavernosal injection. Duplex Doppler ultrasonography after redosing was carried out on all patients. Dynamic infusion corpus cavernosography/cavernosometry was obtained in 17 of 28 patients, and combination therapy was initiated using 100 mg of sildenafil citrate orally 60 min before intercourse and 500 microg of MUSE intraurethrally immediately before intercourse. Independently, either 100 mg of sildenafil citrate or 1000 microg of MUSE was not efficacious in inducing an erection sufficient for vaginal penetration in any of the 28 patients. After initiating a combination therapy, at 30 months, all 28 patients were reporting erections sufficient for vaginal penetration, with 3.6 intercourse episodes per month. None of the patients crossed over to intracavernosal therapy or penile prosthesis. During therapy, eight of 28 patients reduced the dose of sildenafil citrate to 50 mg. Combination therapy with MUSE and sildenafil may be more efficacious in the salvage of patients who desire noninvasive therapy but in whom single-treatment modalities fail. Although both cAMP- and cGMP-mediated vasodilation can lead to penile erection, combining therapies that incorporate both pathways may succeed when single therapies fail.     

Visual sexual stimulation plethysmography: complementary test to nocturnal penile plethysmography

Diurnal penile plethysmography under visual sexual stimulation (VSS) and nocturnal penile tumescence (NPT) plethysmography have been performed in 5 healthy volunteers and 195 consecutive men complaining of impotence. Our study demonstrates that VSS plethysmography may compensate at least partially for the shortcomings of classic NPT plethysmography, by allowing direct clinical estimation of "erectile performance." Twenty percent of the patients had full erection under VSS. These patients do not need further testing. VSS is a noninvasive and useful "first-line" investigation in erectile dysfunction.     

Comparison of penile duplex ultrasonography with nocturnal penile tumescence monitoring for the evaluation of erectile impotence

A total of 50 patients with erectile dysfunction underwent comprehensive evaluation, including vascular evaluation with penile duplex ultrasonography and papaverine injection, as well as nocturnal penile tumescence monitoring. The latter was performed in a sleep laboratory setting in all patients. The results of penile duplex ultrasonography with papaverine injection were classified as 18 patients with normal vascular findings, 22 with arterial insufficiency, 3 with the pelvic steal syndrome and 7 with isolated venous leakage. Of the patients 15 had normal ultrasonographic and nocturnal penile tumescence findings, 29 had abnormal ultrasonographic vascular and nocturnal penile tumescence findings, 3 had abnormal ultrasonographic vascular findings and normal nocturnal penile tumescence (including 1 with the pelvic steal syndrome as evidenced by penile brachial index) and 3 had normal ultrasonographic vascular findings and abnormal nocturnal penile tumescence (including 2 with neurogenic erectile dysfunction). Penile duplex ultrasonography with papaverine injection appears to be a useful objective method to evaluate vasculogenic impotence and to correlate favorably with nocturnal penile tumescence monitoring. It also may have a higher yield than nocturnal penile tumescence monitoring in patients with the pelvic steal syndrome. While nocturnal penile tumescence is impaired in patients with neurogenic impotence, penile duplex ultrasonography with papaverine injection reveals, as expected, normal findings in patients with neurogenic impotence and normal vascular systems.     

Is intracavernous injection of papaverine a reliable screening test for vascular impotence?

To determine whether intracavernous injection of papaverine can discriminate vascular versus psychogenic impotence 80 mg. papaverine were injected intracorporeally into 27 impotent patients without any hormonal or neurological abnormality. The patients also underwent dynamic cavernosography, the artificial erection test and selective internal iliac arteriography. In addition, 21 of the patients underwent nocturnal penile tumescence monitoring. The response to intracavernous papaverine injection was noted as positive (fully rigid erection), intermediate or negative (soft or absent erection). Among 14 patients with severe arterial lesions and/or severe venous leakage the response was negative in 11 and positive in none. Among the remaining 13 patients (moderate or absent vascular abnormalities) the response was positive in 4 but negative in 4. Of 15 patients with an abnormal nocturnal penile tumescence test the response to intracavernous papaverine injection was negative in 12 and positive in none. However, of 6 patients with a normal nocturnal penile tumescence test the response was positive in only 1. Over-all, the results of the intracavernous papaverine injection test are correlated only fairly with those of the nocturnal penile tumescence test and the vascular investigations. This test could be useful to save some nocturnal penile tumescence tests in cases of suspected vascular impotence. However, the safety of this procedure must be confirmed in larger series. Indeed, 1 of our patients suffered priapism after a second intracavernous papaverine injection performed for a therapeutic purpose.     

Recovery of erectile function after nerve-sparing radical prostatectomy: improvement with nightly low-dose sildenafil

OBJECTIVE

To evaluate the effect of low‐dose sildenafil for rehabilitating erectile function after nerve‐sparing radical prostatectomy (NSRP), as the delay to recovery of erectile function after NSRP remains under debate.

PATIENTS AND METHODS

Forty‐three sexually active patients had a NSRP; at 7–14 days after surgery they had a Rigiscan® (Dacomed Corporation, Minneapolis, MN, USA) measurement of nocturnal penile tumescence and rigidity (NPTR). To support the recovery of spontaneous erectile function, 23 patients with preserved nocturnal erections received sildenafil 25 mg/day at night. A control group of 18 patients were then followed but had no phosphodiesterase‐5 inhibitors. The International Index of Erectile Function (IIEF)‐5 questionnaire was completed 6, 12, 24, 36 and 52 weeks after NSRP.

RESULTS

Of the 43 patients, 41 (95%) had one to five erections during the first night after catheter removal. In the group using daily sildenafil the mean IIEF‐5 score decreased from 20.8 before NSRP to 3.6, 3.8, 5.9, 9.6 and 14.1 at 6, 12, 24, 36 and 52 weeks after NSRP, respectively. In the control group the respective scores were 21.2, decreasing to 2.4, 3.8, 5.3, 6.4 and 9.3. There was a significant difference in IIEF‐5 score and time to recovery of erectile function between the groups (P < 0.001), with potency rates of 86% vs 66%.

CONCLUSION

The measurement of NPTR after NSRP showed erectile function even the ‘first’ night after catheter removal. In cases of early penile erection, daily low‐dose sildenafil leads to a significant improvement in the recovery of erectile function.