Author reply: Wei Gan JJ, Lia Gan JJ, Hsien Gan JJ, Lee KT. Lateral percutaneous nephrolithotomy: A safe and effective surgical approach. Indian J Urol 2018;34:45-50.

Dear Editor,

We thank the readers for their comments to our article.[1] We fully agree that the optimal access for pelvic/lower pole/upper ureteric stones (in fact, in a majority of large renal stones) is through an upper pole puncture, preferably using the safer subcostal approach. However, this approach can be difficult to achieve in prone/supine percutaneous nephrolithotomy (PCNL) due to inherent anatomical limitations. Often, a longer, more dangerous supracostal approach is needed when upper pole puncture is deemed necessary.

From the comparative experiences with prone and lateral PCNL, we feel that the use of a “kidney break” (only possible in lateral position) is a major factor in reducing the need for supracostal access; the lateral flexion of the spine moves the 12th rib cranially widening the lumbodorsal space, allowing easier access to the upper pole subcostally. This is reflected in the much higher rate of successful subcostal access in our series. In fact, lateral PCNL also seemed to make lower pole access easier and better aligned with the renal axis by moving the pelvis caudally, especially in short, fat patients.

We believe and like to emphasize that the lateral position confers numerous other advantages, especially a faster and more efficient stone clearance rate-fragments fall out/easily flushed from (sometimes difficult to access) calyces into pelvis by gravity.

In the 4 cases abandoned in this series, three had very turbid urine, suspicious of pus during the initial puncture-these kidneys were drained, patients treated with adequate antibiotics before returning for definitive PCNL. In one patient, a large upper ureteric stone was too impacted with a somewhat “kinked/distorted” pelviureteric junction (PUJ), rendering the attempted PCNL difficult. Conversion to an open ureterolithotomy was a breeze as the patient was already in the standard position for an open ureteric/renal surgery!

Kind Regards,