To our knowledge, our retrospective study is the only available clinical evidence comparing in a significant population, and with a long-term follow-up, a nerve-sparing RP performed with and without the use of an energy device, specifically ultrasonic shears.5 Although we found a significantly better recovery of EF after 3 months of follow-up in the cohort of patients receiving cautery-free dissection (p=0.002), in the long term, we could not find a statistically significant difference in terms of potency recovery between the cohorts (p=0.09 at 12 months, and p=0.14 at 24 months). The only variables significantly associated with postoperative erection recovery at multivariate analysis were age (p<0.001), and extension of neural preservation, being those undergoing bilateral nerve-sparing laparoscopic RP (p<0.001) more likely to regain potency.
The type of energy device used during surgery is relevant. Several scientific reports agree in demonstrating that ultrasonic instruments spread less thermal energy and cause smaller damage to surrounding tissue.6-8 In fact, an ultrasonic device was used in the present study whenever performing a thermal dissection of the neurovascular bundle. Importantly, we employed specific actions to avoid thermal damage, specifically, the neurovascular bundle was incised as close as possible to the periprostatic fascia, keeping the active blade twisted toward the prostate; during the time of energy delivery, the suction device was used to irrigate and disperse the heat within the interfascial plane.
Therefore, the use of an ultrasonic energy device, coupled with other means to increase heat dispersion, may explain the comparable recovery results observed in our study. Nonetheless, other factors such as nerve stretch and compression may be involved in the mechanism of nerve damage. We believe, although cannot support any evidence, that during an athermal dissection the cavernous nerves are more often exposed to these injuries when compared to ultrasonic dissection.
Written by: Vincenzo Pagliarulo, Department of Urology, DETO, University “Aldo Moro," Bari, Italy
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