Hilar clamping versus off-clamp laparoscopic partial nephrectomy for T1b tumors

An off-clamp, or zero-ischemia, approach to laparoscopic partial nephrectomy has been a proposed means of preserving global renal function by preventing ischemia to normal renal parenchyma. However, for clinical stage T1b tumors this provides a unique challenge as the large size of these tumors further complicates an already difficult procedure. This review provides an overview of outcomes for laparoscopic partial nephrectomies performed with or without hilar clamping for clinical stage T1b tumors.

There is a paucity of data for laparoscopic partial nephrectomies for this larger tumor size. The feasibility of performing laparoscopic partial nephrectomy for renal tumors 4-7 cm in size has clearly been demonstrated. Not unexpectedly, using an off-clamp technique during laparoscopic partial nephrectomy has variably shown increased intraoperative blood loss when compared to hilar controlled procedures. This does not, however, seem to translate into increased risk of transfusion or loss of visualization leading to compromise in oncologic outcomes. Lastly, some data suggest improved short-term and long-term preservation of renal function as estimated by estimated glomerular filtration rate.

With accumulating data pointing to the long-term health benefits of nephron sparing surgery over radical nephrectomy and its oncologic equivalency confirmed, there is an increased push to perform partial nephrectomy for larger tumors. As demonstrated in the setting of a solitary kidney, every minute of warm ischemia counts and ischemia is an important modifiable variable that impacts renal function. As such, off-clamp dissection has potential advantages. The reviewed data show that foregoing hilar clamping for T1b tumors is not only feasible, but is likely beneficial with respect to renal function and does not appear to carry an increased risk of transfusion despite increased blood loss.