ORIGINAL
PAPER
Penile perfusion index (PPI) for the non-invasive evaluation of the vascularization of the penis Marco Grasso 1, Salvatore Ivano Blanco 1, Caterina Lania 2, Emanuele Grasso 3, Vittorio Segramora 3. 1 2 3
Dept of Urology, San Gerardo Hospital Monza (MB), Italy; Dept of Urology, San Raffaele Institute, Milano, Italy; Dept of Vascular Surgery, San Gerardo Hospital Monza (MB), Italy.
Objectives. The aim of the study is to define if PPI can be considered a sensitive, noninvasive parameter to predict the effectiveness of therapy. Material and Methods. From June 2003 to September 2016 we evaluated 422 patients for ED. We performed vascular penile evaluation with a non invasive method. In basal condition we considered the ratio between penile and humeral pressure and the response to PDE5in during follow-up. The values of PPI were compared to the recovery of erection. Results. the results show that the recovery of valid erections both after taking the drug and spontaneously occurs mainly with PPI higher than 0.8. Conclusion. A PPI value > of 0.8 proved to be an effective “predictor” of a valid response to phosphodiesterase inhibitors and therefore an indicator of correct vascularization. A value of IPP <0.8 should lead to a complete cardio-vascular study. We believe that it is no longer motivated to submit the patient to the risks of color Doppler with FIC, not producing any further diagnostic element useful to the patient.
SUMMARY
KEY WORDS: Penile, ED, PDE5in, Doppler.
INTRODUCTION The spread of phosphodiesterase inhibitors (PDE5in) has completely changed the approach strategies to erectile dysfunction (ED). It is still considered important in the first approach to the patient to rule out hormonal or metabolic problems and evaluate the vascularization of the penis. In the diagnosis of ED, Doppler ultrasound with drug induced erection is now performed all over the world. We believe that this examination can be replaced by a less invasive test which is the evaluation of the PPI (Penile Perfusion Index). Since the early 1980s, the evaluation of the vascularization of the penis using Doppler technology has entered in the common practice for diagnosing erectile dysfunction (1). At the beginning, simple velocimeters with pencil probes were used. Subsequently, with the development of an increasingly advanced technology designed for other districts in which lumen diameter and flow velocity are essential parameters, we switched to the use of eco-color / power doppler instrumentation. With these more modern tools, the evidence of morphological parameters (patency and diameter) as well as
dynamics (flow velocity) have been used in the evaluation of the single dorsal and cavernous arteries. This method, however, involves the use of drugs injected into the corpora cavernosa to induce a pharmacological erection, without which these evaluations are not possible in the penile area where, in conditions of rest, the vessels are small. The development of increasingly valid drugs for the treatment of erectile dysfunction (we refer to phosphodiesterase inhibitor drugs) has in fact remodeled the therapeutic approach to ED that today benefits from the use of these drugs, also tailoring the choice according to the patient`s performance requests. We have wondered whether it is still appropriate to submit patients to an examination that requires time, highly qualified personnel and high-tech and cost-effective tools, but above all, that requires mandatory invasive intracavernous injection of prostaglandins. This procedure, besides being painful, can lead to local complications, especially the fearful post-injection priapism. For this purpose, expert staff must be available for 24 hours after the exam. In the early 1980s we started using a new parameter which is the relationship between humeral pressure and cavernous pressure. We have Advances in Urological Diagnosis and Imaging - 2021; 4,2
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