Can Selective Arterial Clamping With Fluorescence Imaging Preserve Kidney Function During Robotic Partial Nephrectomy?

Abstract

Objectives To compare renal functional outcomes in robotic partial nephrectomy (RPN) with selective arterial clamping guided by near infrared fluorescence (NIRF) imaging to a matched cohort of patients who underwent RPN without selective arterial clamping and NIRF imaging. Methods From April 2011 to December 2012, NIRF imaging-enhanced RPN with selective clamping was utilized in 42 cases. Functional outcomes of successful cases were compared with a cohort of patients, matched by tumor size, preoperative eGFR, functional kidney status, age, sex, body mass index, and American Society of Anesthesiologists score, who underwent RPN without selective clamping and NIRF imaging. Results In matched-pair analysis, selective clamping with NIRF was associated with superior kidney function at discharge, as demonstrated by postoperative eGFR (78.2 vs 68.5 ml/min per 1.73m2; P=0.04), absolute reduction of eGFR (−2.5 vs −14.0 ml/min per 1.73m2; P<0.01) and percent change in eGFR (−1.9% vs −16.8%, P<0.01). Similar trends were noted at three month follow up but these differences became non-significant (P[eGFR]=0.07], P[absolute reduction of eGFR]=0.10, and P[percent change in eGFR]=0.07). In the selective clamping group, a total of four perioperative complications occurred in three patients, all of which were Clavien I-III. Conclusion Utilization of NIRF imaging was associated with improved short-term renal functional outcomes when compared to RPN without selective arterial clamping and NIRF imaging. With this effect attenuated at later follow-up, randomized prospective studies and long-term assessment of kidney-specific functional outcomes are needed to further assess the benefits of this technology.

The future of partial nephrectomy

“…Compared to standard arterial clamping, early results showing significantly superior post-operative kidney function at discharge, and a trend towards significance at 3 months [8].…”

“…A fluorescent contrast agent is administered intravenously, which emits light in the near-infrared wavelength (700-850 nm) after activation by a light emitting diode [8]. The light, not visible to the human eye, is recorded using a charge-coupled device camera.…”

“…The selection process is aided by NIRF, to identify renal vasculature, assess renal perfusion and dictate the arteries that are to be clamped. The technique allows the surgeon to only clamp off arteries supplying areas of the renal parenchyma that supply the tumour and its immediate margin, while maintaining perfusion of unclamped segments [8].…”

“…There have been many techniques described to induce renal cooling including peri-renal ice slush, cold saline surface irrigation, endoscopic retrograde renal cooling, and trans-arterial renal hypothermia, with varying degrees of success. Kaouk et al, described intracorporeal cooling which placement of the kidney inside an Endocatch II bag filled with ice slush to achieve a temperature of [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] degrees [23]. A recent method that avoids the use of a cumbersome bag, and is not limited to the retroperitoneal approach was by placing ice on the psoas muscle and then over the renal parenchyma, with a laparoscopic sponge placed on the small bowel to prevent bowel cooling ( [23].…”

Surgical and Minimally Invasive Therapies for the Management of the Small Renal Mass

“…A recent study assessing the intraoperative use of NIR with indocyanine green reported benefit, in terms of short-term renal function, when NIR imaging was utilised to enable selective renal arterial clamping, although this benefit was attenuated at later follow-up [45]. However, a separate study from the same group found that NIR with indocyanine green was unreliable in identifying malignancy, as correlated with final histology [46].…”