PCNL has very high stone-free rates that reach up to 95% and is thus considered the first line of treatment for large kidney stones [1]. Although, PCNL still has considerable complication rates due to its invasive nature [6]. In addition, the effect of using a percutaneous approach on renal function has not been fully studied and defined [7, 8]. While miniaturized PCNL techniques can decrease complication rates, this comes with a decrease in stone-free rate [9, 10].
The technological advances in flexible ureterorenoscopy have led to the miniaturization of equipment, superior vision and improved deflective capability [11], which enhanced the effectiveness of retrograde intrarenal surgery in managing a wider range of renal stones. A metanalysis on nine retrospective non-comparative studies including over 400 patients reported a stone-free rate between 77%-96% with a mean number of procedures of 1.6, a mean operation time of 82 (range 28–215) minutes and a complication rate of up to 10%. In the study, Steinstrasse, pyelonephritis and subcapsular hematoma were the major complications reported. The metanalysis also showed decreased stone-free rates and increased complication rates in larger stone sizes [12]. These results encouraged various centers to carry out randomized studies where they compared RIRS and PCNL in the management of large renal stones. They reported a lower stone-free rate of 73% after the first session of RIRS and lower complication rates, operation time and hospital stay, similar to our study [3, 13].
Although it was introduced quite early, the LP method did not gain much popularity due to its steep learning curve compared to the well-described PCNL [4]. Hence, the use of LP has only been reported in cases with renal anomaly or cases accompanying ureteropelvic obstruction without clear criteria or consensus [14]. However, recent studies have reported LP to have higher stone-free rates, lower bleeding and longer operation times and hospital stay compared to PCNL in the management of large and complex kidney stones [5, 15, 16]. In the current study, our stone-free rates and complication rates in LP were similar to the literature, with no conversions to open surgery. We associated this result with the good selection of patients and the high experience of our center in laparoscopic surgery. Moreover, LP achieved higher stone-free rates than RIRS despite the larger stone burden in the LP group.
Other than better clinical outcomes, LP may also have additional advantages over RIRS and PCNL. Firstly, in LP, the entire stone is extracted, unlike RIRS, where the stone is broken down into very small fragments and left for spontaneous passage, which may lead to Steinstrasse and urinary tract infections after surgery [17]. Another advantage of LP is not using fluoroscopy, as it constitutes a potential risk for genetic mutation and malignancy for both the patients and the physician’s [18]. While some studies have reported the use of fluoroscopy-free RIRS, this may not be available in all centers or applicable for all patients [19]. Finally, with the reported negative effect of economic downturn on various surgical procedures, the high cost and short lifespan of the basic equipment used in RIRS (laser lithotripter and FURS) constitute major obstacles for its widespread use and availability [20, 21]. On the other hand, the main limitation of LP is its steep learning curve and requirement of great experience [22]. Another limitation is its possible side effects and complications after surgery. One of these complications is urinary leakage, with a reported incidence of 0–12%, similar to the prolonged urine leakage reported for PCNL [23]. Another possible complication in LP is bleeding, although at lower rates than PCNL. In our study, urinary leakage was observed only in one patient (2%), while bleeding was not reported in any patient. We associated this with the fact that the procedures were carried out by a surgeon with great expertise.
Our study had some limitations, the main one being its retrospective and comparative nature. In addition, we could not provide any information on the differences between the two groups in terms of postoperative pain management. Still, this study represents the first series that compares LP and RIRS in English literature. Our study revealed that LP had higher stone-free rates and lower complication rates after a single session compared to RIRS in the management of kidney stones sized ≥ 2 cm. The study also showed LP to achieve a combination of the high stone-free rates of PCNL and the low complication rates of RIRS within experienced hands. Further large-scale, prospective, randomized and controlled trials are needed to confirm these results.