The use of flexible ureteroscopy and minimally-invasive percutaneous techniques, which utilize smaller tract sizes, has been established as a way to decrease the invasiveness of procedures and improve patient outcomes compared to conventional percutaneous nephrolithotomy (PCNL) and flexible mini-PCNL has emerged as a novel technique previously first as an auxiliary procedure and then as a standalone technique. This study aims to assess the feasibility and effectiveness of flexible nephoscopy in improving stone clearance compared to standard retrograde intrarenal surgery using a flexible ureteroscope.
Urinary stones are one of the most common rising health concerns around the world. Urolithiasis is particularly common in high-income countries, with more than 10% of people suffering from it. Renal stones often manifest as colicky loin pain, often known as renal colic. Percutaneous nephrolithotomy (PCNL) is highly recommended by international guidelines as the primary treatment for renal stones larger than 20 mm. However, for stones ranging from 10 to 20 mm in size, treatment options may include shock wave lithotripsy (SWL), PCNL, or retrograde intrarenal surgery (RIRS). Significant advancements have been achieved in surgical techniques recently, leading to the emergence of minimally invasive percutaneous nephrolithotomy (mini-PCNL) as a viable and effective treatment option for the removal of large renal and proximal ureteral stones. In recent years, there has been a consistent reduction in the size of endoscopic instruments. The primary objective of these tools is to minimize the amount of blood lost during surgery, lower the occurrence of complications both during and after the operation, and ultimately reduce the length of hospital stays. Despite the use of a smaller nephroscope, the rigidity of the mini-nephroscope poses a limitation in maneuvering into renal calyces at acute angles. This limitation may necessitate the creation of additional tracts, leading to an increase in morbidity. To tackle this challenge, a new technique flexible mini-nephroscope has been developed. This innovative instrument allows for access to all regions of the pelvi-caliceal system through a single access tract. Retrograde Intrarenal Surgery (RIRS) is a prominent approach utilized to eliminate kidney stone disease. In contrast to PCNL, RIRS offers the benefit of utilizing a natural orifice, thereby eliminating the need for an additional pathway for lithotripsy. Consequently, this treatment option ensures enhanced safety and facilitates a more favorable postoperative recovery process. RIRS has some significant limitations that make it challenging to retrieve a large number of fragments after the lithotripsy of large stones. Additionally, there is a complicated balance between irrigation and intrarenal pressure that must be maintained. While continuous rinsing of renal cavities is necessary to improve visibility, an imbalanced fluid evacuation can lead to a rise in pressure within the collecting system. Due to these limitations, large stones cannot be treated with a single RIRS procedure, and multiple sessions may be required. This exposes the patient to repeated anesthesia and the risk of ureteral damage and stenosis, making it important to limit operative time and prevent complications. This study aims to compare the clinical outcome in the form of safety and efficacy between flexible mini-nephroscopy in minimally-invasive PCNL and retrograde intra-renal surgery in patients with symptomatic renal stones.
In Group A (flexible mini-PCNL cases), a puncture will be done under fluoroscopic guidance medial to the posterior axillary line using an 18-gauge puncture needle. The puncture will be directed horizontally or with a slight upward inclination towards the lower or middle calyx. After a successful puncture, a 0.035 Fr Super Stiff guidewire will be inserted. Tract dilatation with amplatz dilator followed by access sheath insertion. Stone disintegration will be done with the flexible mini-nephroscopy (WiScope Digital Endoscope System by OTU Medical, California, USA) which has a shaft length of 38 cm, distal tip diameter is 15.3 F tapering to 10 F, working channel inner diameter is 6.6 F, and the angle of deflection of the distal tip is 210 degrees.
n Group B, Flexible ureteroscopy will be used with a ureteral access sheath and laser fragmentation of renal stones will be done
Ain Shams University Hospitals
Cairo, Cairo Governorate, Egypt
stone-free rate
patients will be considered stone free, if the stone residual in the follow up is less than 4mm
Time frame: 1 month postoperative
Operative time
time from starting the procedure with the cystoscopy till termination with catheter insertion. intraoperative finding in minutes
Time frame: 24 hour postoperative
Hospital Stay
duration of hospital stay since admission on the day of the procedure till discharge
Time frame: 1 month postoperative
Cost analysis
evaluation of the procedure cost, the additional cost of hospital stay, complication and auxiliary procedure needed for stone residual.
Time frame: 1 month postoperative
infection rate
evaluation of postoperative urinary tract infection
Time frame: up to 1 month postoperative
Hemoglobin drop
evaluation of hemoglobin drop in the procedure by CBC
Time frame: 1 day postoperative
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Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
130