The authors, in an effort to avoid this problem, have routinely employed a BK ultrasound unit (Peabody, MA) to assess the absence of flow upon clamping the renal hilum. In this report of 20 patients, they noted a 10% incidence of continued blood flow to a renal mass after renal hilar clamping. Further, they studied an inexpensive Doppler probe system (Vascular Technology, Nashua, NH) to evaluate whether this inexpensive system ($998.00 one time purchase price and $137.00 for a disposable end effector probe per case) would compare favorably with the BK unit (purchase price of $85,000). This device, like the BK unit, similarly detected both cases of continued flow after presumed renal hilar clamping. In both of these patients, further dissection was done enabling subsequent ischemia-inducing clamping of the hilum.
In my experience, the use of this simple intraoperative Doppler probe is a valuable adjunct to partial nephrectomy. In our practice, we have used this device to delineate the major vascular supply to the renal mass itself. By circumferentially dissecting the renal mass and then marking the area of vascular inflow with an electrocautery probe, we have been able to selectively isolate this area during the excision of the lesion allowing for the use of a bipolar device to straddle the area of the presumed vessel thereby effectively coagulating it prior to its incision. Indeed, this has enabled an increase in the number of wedge excision procedures that we have been able to do without any hilar clamping at all. Furthermore, Sundaram and colleagues have used this same device to aid with rapid identification of the renal hilum, thereby facilitating hilar dissection in 40% of their cases.
To be sure, the introduction of a simple, inexpensive ultrasound unit into the operating room is a positive advance providing the surgeon with an “augmented” reality experience as one can now identify major hilar vessels deep to the perirenal fat, detect a crossing vessel in the case of a ureteropelvic junction obstruction, and ultrasonically “dissect” a renal mass to delineate its vascular supply. As with the aforementioned narrow-band imaging, better technology brings better surgery for our patients.
(Disclosure: Dr. Clayman has served as a consultant and worked on product development with Vascular Technology.)
Mues AC, Okhunov Z, Badani K, Gupta M, Landman J
J Endourol. 2010 Dec;24(12):1953-6