HEMODYNAMIC PATTERNS OF PHARMACOLOGICALLY INDUCED ERECTION - EVALUATION BY COLOR DOPPLER SONOGRAPHY

Purpose: Penile erection is achieved through hemodynamic mechanisms th at can be assessed best with color flow imaging and Doppler waveform a nalysis, We performed dynamic studies using computer assisted analysis to assess the hemodynamic patterns of pharmacologically induced erect ion. Materials and Methods: A total of 73 color Doppler ultrasound stu dies was performed in 66 patients with erectile dysfunction. Various b lood flow parameters, including peak systolic velocity, end diastolic velocity, mean flow rate, resistive index and artery diameter, were ob served continuously and recorded frequently for about 30 minutes after intracorporeal injection of papaverine/phentolamine/prostaglandin E1 mixture, A computerized Doppler waveform analysis of 3 curves or great er was performed for each recording to minimize error, A second inject ion was administered if the first injection failed to induce a rigid e rection. Status of the erection was observed and recorded throughout t he study. A computerized graph was generated for each corpus. Results: After intracorporeal injection the time to reach normal or peak veloc ity varied from 1 to 24 minutes. Among 146 corpus units in 73 color Do ppler ultrasound studies we observed the following hemodynamic pattern s: I-normal maximal peak systolic velocity (35 cm. per second or great er), sustained; Ia-end diastolic velocity 0 or less with complete erec tion response (19 units); Ib-end diastolic velocity greater than 0 or incomplete erection response (14 units); II-normal maximal peak systol ic velocity (35 cm, per second or greater), transient; IIa-end diastol ic velocity 0 or less with complete erection response (21 units); IIb- end diastolic velocity greater than 0 or incomplete erection response (12 units); III-borderline maximal peak systolic velocity (30 to 35 cm , per second); IIIa-end diastolic velocity 0 or less with complete ere ction response (10 units); IIIb-end diastolic velocity greater than 0 or incomplete erection response (8 units); IV-low maximal peak systoli c velocity (less than 30 cm. per second); IVa-end diastolic velocity 0 or less with complete erection response (24 units); and IVb-end diast olic velocity greater than 0 or incomplete erection response (38 units ). Conclusions: Erection is a complex and dynamic process. A new class ification of hemodynamic patterns is presented that aids in assessing and interpreting more thoroughly blood flow parameters to stratify mor e precisely the hemodynamic patterns of erectile dysfunction.