Editorial Comment for Kaplan et al.

D uring transperitoneal minimally invasive (laparoscopic or robot-assisted) partial nephrectomy (PN), upper-pole posterior tumors are notoriously challenging to access. The authors describe a technique for accessing such tumors and share their early results. Their technique involves dissecting the kidney attachments circumferentially and rotating the kidney about its hilum. The aim of this transposition is to improve surgical access to posterior upper-pole tumors by putting them in a position similar to the less intimidating anterior lower-pole tumor.

The authors should be commended on their development and study of this technique. Robotic technology is increasing the use of PN, ¹ and the feasibility of resecting more complex tumors has been documented. ² There is certainly no one-size-fits-all approach to PN, and technical series such as this incrementally advance the field.

Our main concern with the described maneuver is that it necessitates extensive dissection of the ureter to the level of the renal pelvis, as well as twisting of the renal vessels. Although no ureteral or vascular injuries are noted in this series, Nouralizadeh and colleagues ³ reported a 33% transfusion rate, multiple urine leaks, and a higher overall complication rate in their series of kidney transposition during pure laparoscopic PN. In addition, the majority of those complications were early in that series, which should give pause to inexperienced, minimally-invasive surgeons before using this technique. The potential for hilar injury should be weighed against the benefit of improved exposure, because there are other reliable minimally invasive ways to access posterior upper-pole tumors. The kidney may be flipped medially, either inside or outside of the Gerota fascia, or a retroperitoneal approach may be used. It is our thinking that minimal dissection (especially early in one's experience) minimizes risk of ureteral or vessel injury and complications. It is not known whether twisting of the renal artery causes kinking, occlusion, and increased ischemic times. Furthermore, this technique as acknowledged by the authors, is not feasible in kidneys with accessory renal vessels. In our own single surgeon series of >400 minimally invasive PNs, of which a significant number included posterior upper-pole tumors, we have never had to use this technique. Instead we prefer “flipping” the kidney completely or a retroperitoneal approach. Nonetheless, transposition is a skill that may prove to be useful for surgeons and should be filed in the armamentarium of robotic PN techniques.