A Pilot Study of Laparoscopic Doppler Ultrasound Probe to Map Arterial Vascular Flow within the Neurovascular Bundle during Robot-Assisted Radical Prostatectomy
Purpose. To report on the feasibility of a new Laparoscopic Doppler ultrasound (LDU) technology to aid in identifying and preserving arterial blood flow within the neurovascular bundle (NVB) during robotic prostatectomy (RARP). Materials and Methods. Nine patients with normal preoperative potency and scheduled for a bilateral nerve-sparing procedure were prospectively enrolled. LDU was used to measure arterial flow at 6 anatomic locations alongside the prostate, and signal intensity was evaluated by 4 independent reviewers. Measurements were made before and after NVB dissection. Modifications in nerve-sparing procedure due to LDU use were recorded. Postoperative erectile function was assessed. Fleiss Kappa statistic was used to evaluate inter-rater agreement for each of the 12 measurements. Results. Analysis of Doppler signal intensity showed maintenance of flow in 80% of points assessed, a decrease in 16%, and an increase in 4%. Plane of NVB dissection was altered in 5 patients (56%) on the left and in 4 patients (44%) on the right. There was good inter-rater reliability for the 4 reviewers. Use of the probe did not significantly increase operative time or result in any complications. Seven (78%) patients had recovery of erections at time of the 8-month follow-up visit. Conclusions. LDU is a safe, easy to use, and effective method to identify local vasculature and anatomic landmarks during RARP, and can potentially be used to achieve greater nerve preservation. 1. Introduction Erectile function after radical prostatectomy is predicated upon a number of factors, including the ability to carefully dissect and separate the cavernous nerves from the prostate [1–6]. Despite offering improved magnification of the operative field and precise surgical instrumentation, improvement in potency rates after robotic-assisted radical prostatectomy (RARP) remains of great interest, and there have been several efforts to introduce new nerve-sparing techniques to improve postoperative potency [7–9]. However, the reproducibility of these results remains controversial, with subsequent reports finding no difference in potency rates regardless of the nerve-sparing technique [10]. Regardless, visualization continues to be a hindrance in preserving the nerves and vessels around the prostate, and there remains a need for more accurate methods to correctly identify and preserve the neurovascular bundle (NVB) during surgery. There have been different attempts to provide better visualization of the NVB during dissection, including the use of intraoperative transrectal ultrasound
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