EW" DEJA V U - - A G A I N : AND LIMITATIONS OF METHODS PENILE ARTERIAL FLOW
Le field of vaseulogenie impoarisen in the interpretation of ~d to assess penile blood flow. faced by urologic surgeons have eviously by vascular surgeons in fion of extremities. The probre similar in some ways but in relation to penile hemoharks are offered to clarify adions of methods of penile blood timately, the practicing urolo~ese tests for treatment of vascuFhe tests considered are penile ;ure index (PBPI), penile pulse PVR), cavernosal artery closing duplex scanning. ial Blood Pressure Index Ratio (PBPI) ratio between systolic pressure er probe distal to a penile cuff or braehial arterial pressure. A em in size should be used in 'I expresses the difference in syspressure detected in the distal ;al penile arteries as a ratio. A :gests that no major obstacle exta and the distal measurement related quantitatively to major in the aortoiliae bed. The ated based on measurements in ~es not tell us what pressure is m. Values below 0.75 confirm [esions involving the distal vesd pudendal and penile arteries. F this limitation can be under;sure gradients across stenoses or when flow through the stenosis Lough rate to cause a pressure of stating this is that pressure if the resistance offered by the han peripheral resistance. In rge vessels provide blood flow to
extensive pelvic collaterals as well as to the lower extremities. These are large areas of the arterial bed with a low peripheral resistance. Therefore, the flow phenomena usually produce decreased distal pressure. On the other hand, the penile arteries exclusively and the internal pudendals, almost exclusively, supply the corpora eavernosa which, in the flaccid state, offer high peripheral resistance. Many lesions of these arteries are not detected by PBPI; these can become hemodynamieally significant at the time demand is placed on this bed by the process of penile erection. Penile Pulse Volume Recording (PPVR) Plethysmographie recordings show the total penile expansion with each pulsation and the contribution of all elements of arterial flow in the form of a pulse wave. Variables assessed are crest time, wave form, and presence or absence of a diastolic notch. Empirically, PPVR is effective in separating impotent from potent patients when the PBPI ranges 0.60.7. To obtain pulse volume recordings, an aireontaining plethysmographie cuff standardized to the particular laboratory should be used. The transducer is contained within the cuff and applied directly to the penile wall; otherwise there will be damping of the pulse wave signals. Criteria of abnormal pulse volume recordings in the flaccid state have been described and are similar to those obtained in lower extremities. This test detects more sensitively both large and small artery flow defects. It is not capable of giving i n f o r m a t i o n about location since it measures total penile pulsation as a sum and also can be affected by eavernosal fibrosis, In rare instances the penis may be too small to properly fit a cuff, and wave-form analyses are more subject to variability because multiple factors must be assessed. Cavernosal Artery Closing Pressure This test requires invasive testing to measure intraeavernosal pressure by a needle inserted in the cavernous bodies. Loss of Doppler ultrasound signals during artificial erection are detected by a
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Doppler probe which is placed at the base of the penis and direeted toward each erus, respectively. The value obtained tells us what pressure is available for erection. Closing pressure is the intraeavernous pressure measured at the moment during" artifP eial erection that deep cavernosal artery flow disappears. At this time, the distended corpora and the tuniea albuginea act exactly like a blood pressure cuff applied to the arm as the arterial pulsation disappears at systolic pressure. The Doppler signal disappears completely at the moment of equilibrium between eavernosal artery systolic pressure and intraeavernous pressure~ Duplex Measurements of Cavernosal Artery Flow Using duplex scans, it is possible to visualize both deep eavernosal arteries at various times before and after injection of agents which produce artificial erection. A knowledge of the diameter and flow veloeity detected by the Doppler ultrasound signal provides an estimate of total flow. Application of this test is likely to be technically demanding. More experience is needed in its application to relate the findings to timing of the changes occurring during
9,00
the erectile process and to anatomic v~ penile and cavernous arteries. ~lbgether with cavernosometry, the~ aminations provide quantitative dat~ hemodynamies of the erectile proces comprehensive study cannot be totall, The anatomy underlying the disord played by these tests. Angiography i rational planning of operative proce graphic examination of the afferent graphy) and r u n o f f bed (caverr drainage--eavernosography) deline~ tomie location and nature of the d erectile failure. Both physiologic me assess penile flow and eomprehensiw during artificial erection are required tive procedures. tlalph G. 1 The George Washington University 2150 Pennsylvan Washingt Vaclav Mieh~ Institute for Clinical and Experin Vizer 14000 Praha 4,
UROLOGY / AUGUST1990 / VOLUMEXXXVI,
Le field of vaseulogenie impoarisen in the interpretation of ~d to assess penile blood flow. faced by urologic surgeons have eviously by vascular surgeons in fion of extremities. The probre similar in some ways but in relation to penile hemoharks are offered to clarify adions of methods of penile blood timately, the practicing urolo~ese tests for treatment of vascuFhe tests considered are penile ;ure index (PBPI), penile pulse PVR), cavernosal artery closing duplex scanning. ial Blood Pressure Index Ratio (PBPI) ratio between systolic pressure er probe distal to a penile cuff or braehial arterial pressure. A em in size should be used in 'I expresses the difference in syspressure detected in the distal ;al penile arteries as a ratio. A :gests that no major obstacle exta and the distal measurement related quantitatively to major in the aortoiliae bed. The ated based on measurements in ~es not tell us what pressure is m. Values below 0.75 confirm [esions involving the distal vesd pudendal and penile arteries. F this limitation can be under;sure gradients across stenoses or when flow through the stenosis Lough rate to cause a pressure of stating this is that pressure if the resistance offered by the han peripheral resistance. In rge vessels provide blood flow to
extensive pelvic collaterals as well as to the lower extremities. These are large areas of the arterial bed with a low peripheral resistance. Therefore, the flow phenomena usually produce decreased distal pressure. On the other hand, the penile arteries exclusively and the internal pudendals, almost exclusively, supply the corpora eavernosa which, in the flaccid state, offer high peripheral resistance. Many lesions of these arteries are not detected by PBPI; these can become hemodynamieally significant at the time demand is placed on this bed by the process of penile erection. Penile Pulse Volume Recording (PPVR) Plethysmographie recordings show the total penile expansion with each pulsation and the contribution of all elements of arterial flow in the form of a pulse wave. Variables assessed are crest time, wave form, and presence or absence of a diastolic notch. Empirically, PPVR is effective in separating impotent from potent patients when the PBPI ranges 0.60.7. To obtain pulse volume recordings, an aireontaining plethysmographie cuff standardized to the particular laboratory should be used. The transducer is contained within the cuff and applied directly to the penile wall; otherwise there will be damping of the pulse wave signals. Criteria of abnormal pulse volume recordings in the flaccid state have been described and are similar to those obtained in lower extremities. This test detects more sensitively both large and small artery flow defects. It is not capable of giving i n f o r m a t i o n about location since it measures total penile pulsation as a sum and also can be affected by eavernosal fibrosis, In rare instances the penis may be too small to properly fit a cuff, and wave-form analyses are more subject to variability because multiple factors must be assessed. Cavernosal Artery Closing Pressure This test requires invasive testing to measure intraeavernosal pressure by a needle inserted in the cavernous bodies. Loss of Doppler ultrasound signals during artificial erection are detected by a
T 1990 / VOLUMEXXXVt, NUMBER2
199
Doppler probe which is placed at the base of the penis and direeted toward each erus, respectively. The value obtained tells us what pressure is available for erection. Closing pressure is the intraeavernous pressure measured at the moment during" artifP eial erection that deep cavernosal artery flow disappears. At this time, the distended corpora and the tuniea albuginea act exactly like a blood pressure cuff applied to the arm as the arterial pulsation disappears at systolic pressure. The Doppler signal disappears completely at the moment of equilibrium between eavernosal artery systolic pressure and intraeavernous pressure~ Duplex Measurements of Cavernosal Artery Flow Using duplex scans, it is possible to visualize both deep eavernosal arteries at various times before and after injection of agents which produce artificial erection. A knowledge of the diameter and flow veloeity detected by the Doppler ultrasound signal provides an estimate of total flow. Application of this test is likely to be technically demanding. More experience is needed in its application to relate the findings to timing of the changes occurring during
9,00
the erectile process and to anatomic v~ penile and cavernous arteries. ~lbgether with cavernosometry, the~ aminations provide quantitative dat~ hemodynamies of the erectile proces comprehensive study cannot be totall, The anatomy underlying the disord played by these tests. Angiography i rational planning of operative proce graphic examination of the afferent graphy) and r u n o f f bed (caverr drainage--eavernosography) deline~ tomie location and nature of the d erectile failure. Both physiologic me assess penile flow and eomprehensiw during artificial erection are required tive procedures. tlalph G. 1 The George Washington University 2150 Pennsylvan Washingt Vaclav Mieh~ Institute for Clinical and Experin Vizer 14000 Praha 4,
UROLOGY / AUGUST1990 / VOLUMEXXXVI,
