This study focuses on comparing three distinct treatments for lower pole renal stones: Flexible Ureteroscopy (F-URS), Extracorporeal Shock Wave Lithotripsy (ESWL), and Mini Percutaneous Nephrolithotomy (Mini-PCNL). These techniques vary in invasiveness, with newer approaches like F-URS and Mini-PCNL aiming for decreased morbidity while ESWL remains less invasive but potentially less effective [9, 10]. The research aligns with established guidelines and concentrates on the complexities posed by hard stones and anatomical variations in the lower pole, seeking to address treatment challenges within this specific context.

One striking observation was the differing SFR among the modalities, with newer methods like F-URS and Mini-PCNL showing promise in reducing morbidity and enhancing stone clearance, while ESWL, though less invasive, also demonstrates certain advantages [11]. This study provides a comprehensive assessment tailored to guidelines treatment strategies, considering the intricate interplay of anatomical variations and stone characteristics in managing lower pole renal stones.

The Stone Free Rate (SFR) was notably different among the treatment modalities in this study Flexible Ureteroscopic Lithotripsy (FURS) exhibited the highest SFR at 90.2%, significantly surpassing both Extracorporeal Shock Wave Lithotripsy (ESWL) at 61.5% and Mini Percutaneous Nephrolithotomy (Mini PCNL) at 83.3% (P-value < 0.001). These findings corroborate with previous studies, like Kruck et al. [7] found relatively higher SFRs for FURS and Mini PCNL compared to ESWL. However, studies by Kumar et al., Aboutaleb et al., and Resorlu et al. demonstarte higher SFRs for Mini PCNL over ESWL and FURS, diverging from the predominant observations [5, 12, 13].

Sedation is important to optimize the patients tolerance during the procedures which will improve the stone free rate and procedure outcome. Shock wave lithotripsy (SWL) can be effectively performed using either oral analgesia or general anesthesia. Although general anesthesia can enhance stone targeting, oral analgesia offers the benefit of a minimally invasive and outpatient approach to stone management. Various studies have shown that oral opioids and NSAIDs are effective in alleviating pain during ESWL [14]. Despite in our study, we used Topical anesthesia not sedation.

The requirement for auxiliary procedures varied significantly among the treatment groups in this study. In the Mini PCNL group, 15.7% required additional procedures, including ESWL sessions, FURS, or Mini Percutaneous Nephrolithotomy (Mini PCNL). In the ESWL group, 38.5% needed further interventions, primarily subsequent ESWL sessions, FURS, or Mini PCNL. Conversely, In the Flexible Ureteroscopic Lithotripsy (FURS) group, only 9.8% underwent additional procedures, all involving ESWL. (P-value < 0.001).

This contrast with Dhayal’s study, where Mini PCNL had the lowest need for additional procedures at 1.7%, compared to FURS at 10% and ESWL at 18.33% (P = 0.031) [15]. Resorlu et al. similarly reported a higher incidence of auxiliary procedures after ESWL (21.9%) compared to PCNL (5.7%) and FURS (8.7%) (p < 0.001) [13].

The choice of auxiliary procedure depends on several factors, including stone composition, residual stone size and location, patient BMI, renal anatomy, and preferences of both the patient and urologist. These factors collectively influence the decision-making process regarding the type of additional intervention required to manage residual stones effectively.

The study compared operative times among different techniques, revealing varying durations. Mini Percutaneous Nephrolithotomy (Mini PCNL) was an average of 50.75 ± 13.37 min, while Extracorporeal Shock Wave Lithotripsy (ESWL) and Flexible Ureteroscopic Lithotripsy (FURS) showed shorter durations of 36.05 ± 5.98 min and 40.0 ± 6.36 min respectively (P = 0.001). Other studies echoed these differences, demonstrating shorter times for ESWL, longer durations for FURS, and Mini PCNL, highlighting the variations influenced by surgeon expertise, calculation methods, and managing diverse kidney stone locations. In our study, the fluoroscopy durations for ESWL, FURS, and Mini PCNL revealed marked differences in imaging times. ESWL exhibited a notably longer median duration of 9.15 min (6.5–11.18 min), significantly exceeding Mini PCNL(4.34 min, 3.25–5 min) and FURS (3 min, 2.67–3.33 min) with a substantial P-value of < 0.001. Also, Resorlu et al. found PNL to have a longer duration (57.5 ± 22.1 s) than FURS (43.1 ± 17) with a significant difference (p < 0.001) [13]. Moreover, another study highlighted the extensive fluoroscopy time in Mini PCNL (170.8 ± 1.5 s) compared to FURS (31.5 ± 1.7 s) (p < 0.01) [5]. These diverse results underscore considerable variations in imaging durations across these stone management procedures, emphasizing substantial differences in fluoroscopy times between ESWL, FURS, and Mini PCNL techniques in different research investigations.

The study demonstrate time to radiation exposure during stone management with three modalities The duration of radiation exposure was notably longer for ESWL compared to both flexible ureteroscopy (URS) and Mini PCNL (percutaneous nephrolithotomy). To overcome this problem, Chang et al. developed a real-time tracking ultrasound-based system for renal stones achieving real time tracking of the stone without excessive radiation exposure to the patient [16]. In our study, we use fluoroscopy for stone localization as ultrasound localization for renal stone not available in our institute.

This study assessed post-operative complications using the Clavien-Dindo Classification for three procedures: FURS, ESWL, and Mini PCNL. Although the complication rates varied—17.6% for FURS, 18% for ESWL, and 27.1% for Mini PCNL—there was no significant difference in the overall incidence of postoperative complications among these groups. These findings were consistent with Kumar’s study, which noted a higher but non-significant incidence of complications in Mini PCNL compared to ESWL and FURS [5].

Contrasting outcomes were found in Dhayal IR et al.‘s research, highlighting significant differences in complication rates between the groups [15]. Similar studies by Kruck et al. and Resorlu et al. [7, 13] echoed higher complication rates associated with PCNL compared to ESWL and FURS. The occurrences of fever, UTI, and steinstrasse-related severe renal colic demonstrated variances across these procedures in different studies, showcasing discrepancies in complication profiles among them. These diverse findings emphasize the necessity of understanding complications linked to different stone treatment methods based on individual patient characteristics.

Hospital stays varied significantly across renal stone treatments: FURS showed a median of 60 h, ESWL at 2 h, and Mini PCNL the longest at 72 h. Previous studies echoed these differences: Aboutaleb’s 2012 research outlined shorter ESWL stays (average of 0.73 days) compared to PCNL and FURS, emphasizing diverse durations. Kruck et al.‘s findings emphasized extended stays for FURS and Miniperc, averaging 2.2 h, 4.5 days, and 2.3 days, respectively (p < 0.001) [7].

This research delved into the economic aspects of stone treatments, dissecting expenses per patient involving procedure charges, in-patient care, and management of associated complications. Findings pinpointed ESWL as a cost-efficient method with fewer complications. Conversely, FURS demonstrated higher expenses compared to other modalities, while Mini-PCNL emerged as the most cost-effective approach for 1–2 cm renal stones treated in a single session. Despite its lower cost, shock wave lithotripsy was found to be less effective. However, another perspective from Wymer et al. favored FURS as the most cost-effective surgical intervention for 1–2 cm renal stones, regardless of their location within the kidney [17].

We used dusting mode with mini PCNL of the same laser settings of flexible URS which may take longer operative time than traditional fragmentation.

The study needs to include more variety of stone compositions to standardize the most suitable approach.

ESWL may require a longer follow up for stone free than other interventions, such as URS or PCNL to achieve complete stone clearance. So, the two weeks follow up may have underestimated the true stone free rate for ESWL group as some patients may have require a longer duration of follow up to fully clear stone fragments.

Variables such as infundibulo-pelvic angle, calyceal length, skin-to-stone distance, infundibulum neck width, and stone composition are known to influence ESWL outcomes. These factors warrant consideration in future studies to optimize patient selection and improve treatment efficacy.