The authors report on 301 patients who underwent nephron sparing surgery for a localized renal tumor. Of these, 181 patients had renal artery occlusion with cold ischemia, while the remaining 120 patients were managed with external compression alone to control hemorrhage. Mean tumor size was 3.56cm and there was a higher incidence of centralized tumors in the arterial occlusion group (p less than 0.05). The authors noted no difference in blood loss, transfusion rates, tumor size, or complications between the two groups. Two renal units (1.2%) were “lost” due to ischemic damage in the renal artery occlusion group, which was not a complication in the external compression group. More importantly, there was a significantly higher incidence of positive margins in the external compression group (4.2%) relative to the group with renal artery occlusion during resection (0.6%), (p less than 0.05).
Renal artery occlusion during partial nephrectomy may result in ischemic damage to the remaining renal parenchyma, particularly if prolonged, but is clearly superior for optimal visualization during tumor resection. This study demonstrates that external compression (the “grip of death”) does not significantly minimize morbidity over renal artery clamping, and may, in fact, be associated with an increased positive margin rate due to poor visibility during tumor resection.
This was from an open surgical series, but points out the balance between better visualization to remove the cancer which can be done by stopping the blood supply, but the chance of permanent injury to the kidney.
I have usually favored complete blockage of blood flow to the kidney (artery and vein) in my open, as well as minimally invasive approaches.
The other actor that is important is the importance of positive margins, that was once considered an indication to remove the rest of the kidney, but now can often be observed.