Abstract
In this article, Ghani and colleagues have reported on their initial experience with robot-assisted anatrophic nephrolithotomy (RANL) with renal hypothermia for treating patients with staghorn calculi. The authors should be commended on their effort for using a new technique for a common challenging clinical situation. The aim of the discussed approach is to provide an alternative in cases where percutaneous nephrolithotomy (PCNL) is unlikely to achieve complete stone clearance with a single procedure.
Fully recognizing that this was the initial experience for this procedure, the stone-free rate for the current RANL article is only 33% (only one patient achieved complete stone-free status after a single procedure). When comparing PCNL with open anatrophic nephrolithotomy Al-Kohlany and associates 1 showed that the stone-free rate is similar between the two groups, but PCNL was associated with significantly less morbidity and shorter length of hospital stay. There was also a trend toward less significant stone volume residual in the PCNL group. With the use of ancillary procedures PCNL can achieve stone-free rates of 74% to 80% 2,3 in patients with staghorn calculi.
The second factor that needs to be addressed is the morbidity associated with each procedure. Although RANL is a minimally invasive procedure, it is unlikely to offer a less invasive solution than PCNL. Opening the collecting system within the peritoneal cavity can be associated with urine extravasation and urinoma formation. Stent placement in the system postprocedure reduces but does not eliminate this risk. Another disadvantage of any anatrophic nephrolithotomy technique is that unlike post-PCNL, an immediate ancillary procedure is not feasible and some necessary healing time needs to pass before further procedures can be performed to manage any residual stone burden. Also the potential nephron loss associated with this procedure needs further assessment with larger studies and intermediate- to long-term functional data. PCNL in patients with staghorn stones is not without its own morbidity and has been associated with significant bleeding in 10% of the cases. 4 In the same series, 9% of patients needed a blood transfusion after PCNL for a staghorn stone.
The final remark is with regard to the cost of the procedure. Even if the RANL is as safe and as effective as PCNL in the treatment of patients with staghorn calculi, what is the cost of this procedure and can we justify its use in the current environment of contracting healthcare spending? The cost of RANL and the need for subsequent ancillary procedures would need to be compared with similar factors for PCNL as well as rates and cost of complications and length of hospital stay.
In a few words, PCNL remains the standard of care for treatment of patients with staghorn calculi. With more advancement of PCNL techniques such as use of a tubeless technique, modified patient positioning, and more advanced intracorporeal lithotripsy technology, we are likely to observe further improvement in all the key end points for this procedure. 5
The authors should be congratulated for demonstrating the feasibility of these new techniques that recapitulate the classic open procedure. Nevertheless, a return to anatrophic nephrolithotomy even with a minimally invasive approach should be evaluated critically before being considered for widespread adoption.