V1561: Utilization of a laparoscopic Doppler ultrasound probe to improve arterial vascular preservation within the neurovascular bundle during robot-assisted radical prostatectomy

Video

Introduction and Objectives
Preservation of the neurovascular bundle (NVB) during robot-assisted radical prostatectomy (RARP) is essential to optimize potency outcomes but is hampered by difficulty in visually identifying its exact anatomic location. Laparoscopic Doppler ultrasound (LDU) technology has been used for radical and partial nephrectomy and varicocelectomy and can potentially provide auditory confirmation of anatomic NVB location. This video demonstrates the feasibility of using LDU technology to preserve arterial blood flow within the NVB.

Methods
Vascular Technology Inc 20mHz laparoscopic Doppler probe was placed in the surgical field. The probe was manipulated by the console surgeon using a needle driver. Doppler signal intensity was characterized as follows: absent, low, moderate, and high. The intensity level was assessed by the surgeon and four independent observers at two time points (before NVB release and after prostate removal) at three anatomic locations – base, midgland, and apex – bilaterally. Any resulting modifications in the nerve-sparing procedure and NVB dissection were recorded.

Results
Nine patients were enrolled in this prospective feasibility study. All participants had baseline normal potency (SHIM>21) and met criteria for a bilateral nerve sparing procedure. There were no complications associated with LDU use. Median age was 57 and median PSA was 4.3 ng/mL. By D’Amico classification, the patient cohort was categorized as 25% low, 62.5% intermediate, and 12.5% high risk. Mean time for LDU use was 9.5 minutes (SD 3.3 min). Signal intensity concordance before and after NVB dissection was 0.625. Doppler signal intensity was maintained in 80% of locations assessed and decreased in 16% of locations. Use of LDU altered the anatomical plane of dissection during nerve sparing in 60% of patients on the left side and 40% of patients on the right side. There was no learning curve and use was independent of the bedside assistant.

Conclusions
This video demonstration illustrates the technique for LDU use during RARP to aid in preservation of arterial blood flow within the NVB. LDU technology appears to impact preservation of local vasculature and enhance the quality of nerve-sparing by providing anatomical landmarks for dissection. Moreover, the video details the ease of use with the da Vinci robot. Promising early results suggest that LDU technology is feasible and beneficial in RARP, and warrants further study. Long term follow-up is needed to assess the impact of LDU on potency outcomes.

Funding: None.