The surgical management of kidney stones has been performed with high success rates in recent years with the technological advancements in the endourological field. Although PNL is the gold standard treatment for renal calculi larger than 20 mm, the use of f-URS in the therapy of these stones has also increased in recent years. There are many studies in the literature which compared f-URS and mPNL procedures for the treatment of 1–2 cm renal stones In a meta-analysis that has been published recently, both treatment modalities are found to be effective with high success and low complication rates . From this point of view, our study will provide a different perspective to the literature by evaluating the advantages and disadvantages of these two surgical options for patient with failed ureteral access sheath placement during f-URS.
With the developments in the field of endourology, both f-URS and mPNL operations are applied today with high stone-free rates. In their series, Kiremit et al. reported 86.1% success rate for f-URS, and 83.6% success rate for mPNL procedure. . Also, Akbulut et al. reported that the success of f-URS and mPNL for lower calyceal stones of 2 cm or less was shown to be 85.7% and 90.3%, respectively . In our study, both treatment methods had a high success rate, and no significant difference was observed between the two treatment methods.
The time spent on both positioning the patient and gaining percutaneous access to the kidney prolongs the operation time for mPNL. Fluoroscopy is used in f-URS procedure during access sheath insertion and stone localization. In the mPNL operation, fluoroscopy is used for varying periods of time during the access, and fluoroscopy assistance is used for evaluation of stone-free status. When the studies in the literature were evaluated, it was observed that the operative and fluoroscopy times were longer in the mPNL operation [9, 10]. In a study conducted by Ergin et al. in 2018 with a high patient volume, both fluoroscopy time and operative time were found to be significantly higher for the mPNL group . In our study, in accordance with the literature, f-URS seems to be more advantageous in terms of operative and fluoroscopy time.
For the treatment of kidney stones, both f-URS and mPNL operations are minimally invasive procedures and are safely performed with low complication rates. Postoperative complications have been compared in many studies using the Clavien-Dindo classification [11, 12]. In a study conducted by Wang et al. in 2021, no significant difference was found between f-URS and mPNL in terms of postoperative complications . In another recent study, Coskun et al. reported higher complication rates in the mPNL group than in the f-URS group . In a multicenter randomized controlled study published in 2018, complication rates of mPNL and f-URS were found to be similar . According to our results, both operations can be performed safely with low and similar complication rates.
Kidney stone disease impairs the quality of life of patients physically, socially, and mentally. The SF-36 is an internationally accepted questionnaire used in the assessment of the quality of life. Bensalah et al. reported that physical functioning, emotional role, general health, and bodily pain parameters were found to be lower in patients with kidney stone disease compared to the normal population . In a study conducted by Perez-Fentez et al., the SF-36 values of the patients before and after the mPNL operation were compared. It was observed that the physical function, physical limitation, pain, and social function values of the patients improved significantly after the procedure . According to the results of our study, removal of kidney stones by surgery had positive effects on the quality of life of the patients. SF-36 parameters such as physical function, pain, limitation of physical role, and general health parameters improved significantly after the procedures in both f-URS and mPNL groups.
Although it is known that both types of operations improve the quality of life of the patients, it has not been debated in the literature until now which surgery shows a better improvement in the patients. In our study, the differences between the pre- and post-procedure SF-36 parameters of both groups were evaluated and compared between the groups. Although bodily pain decreased in both groups, this difference was higher in the mPNL group than in the f-URS group. Also, the mPNL group had better results in the physical function parameter, similar to pain parameter. In the f-URS group, irritation of the JJ stent and the spontaneous passage of the fragmented calculi can be responsible for these results.
There are some limitations of our study. The cost of the procedures has not been calculated. Pain assessment was not performed with the visual analog scale (VAS) score of the patients in the early post-procedure period. Stone analyses were not taken into consideration. We think that our results should be supported by studies to be conducted with higher patient numbers.