Accuracy of Ultrasound for Detecting Residual Fragments During RIRS

Diagnostic Accuracy of Ultrasound Versus Fluoroscopy for Detecting Residual Fragments During Retrograde Intrarenal Surgery: a Randomized Controlled Trial

The purpose of this study is to assess the accuracy of ultrasound and traditional fluoroscopy to find the residual fragments before retrograde intrarenal surgery is complete. This would ultimately limit the need for radiation exposure and improve the quality of clinical care given to patients and healthcare teams.

Ultrasound is currently gaining popularity as an alternative imaging modality for the diagnosis and treatment of urolithiasis. However, the benefit of ultrasound on the diagnostic accuracy of detecting residual fragments during retrograde intrarenal surgery (RIRS) has never been evaluated in a randomized study. Its use would reduce radiation exposure for patients and care team members as well as improve stone free clearance rates for surgery. Therefore, The investigators plan to conduct a randomized trial to assess the diagnostic accuracy of ultrasound and fluoroscopy in conjunction with endoscopic examination for detecting residual stone fragments during retrograde intrarenal surgery. After admission, approximately 172 subjects will be randomized in a 1:1 ratio to receive ultrasound or fluoroscopy before completing RIRS. Subsequently, four weeks after the operation, the investigators will compare with routine low-dose non-contrast computed tomography as a gold standard for detecting residual fragments. If ultrasound is more accurate than fluoroscopy in detecting residual fragments, the investigators will encourage this approach as it can reduce radiation exposure for patients and healthcare professionals.

Before completing retrograde intrarenal surgery, a complete endoscopic examination will be performed along with ultrasound by the same endourologist to determine the size of the largest residual fragment.

Standard of care, control Before completing retrograde intrarenal surgery, a complete endoscopic examination will be performed along with fluoroscopy by the same endourologist to determine the size of the largest residual fragment.

Before completing retrograde intrarenal surgery, a complete endoscopic examination will be performed along with ultrasound instead of fluoroscopy by the same endourologist to determine the size of the largest residual fragment.

The diagnostic accuracy of ultrasound and fluoroscopy will be measured in conjunction with endoscopic examination for detecting residual fragments during retrograde intrarenal surgery for renal stones treatment by the same endourologist to determine the size of the largest residual fragment, categorizing them as stone free, ≤ 2 mm, or >2 mm, and compared with routine low-dose non-contrast computed tomography by a radiologist blinded to surgery and intraoperative imaging, categorizing them as stone free, ≤ 2 mm, or >2 mm. The results will be compared for accuracy.

The sensitivity of ultrasound and fluoroscopy will be measured in conjunction with endoscopic examination for detecting residual fragments during retrograde intrarenal surgery for renal stones treatment by the same endourologist to determine the size of the largest residual fragment, categorizing them as stone free, ≤ 2 mm, or >2 mm, and compared with routine low-dose non-contrast computed tomography by a radiologist blinded to surgery and intraoperative imaging, categorizing them as stone free, ≤ 2 mm, or >2 mm. The results will be compared for sensitivity.

The specificity of ultrasound and fluoroscopy will be measured in conjunction with endoscopic examination for detecting residual fragments during retrograde intrarenal surgery for renal stones treatment by the same endourologist to determine the size of the largest residual fragment, categorizing them as stone free, ≤ 2 mm, or >2 mm, and compared with routine low-dose non-contrast computed tomography by a radiologist blinded to surgery and intraoperative imaging, categorizing them as stone free, ≤ 2 mm, or >2 mm. The results will be compared for specificity.

The positive predictive value of ultrasound and fluoroscopy will be measured in conjunction with endoscopic examination for detecting residual fragments during retrograde intrarenal surgery for renal stones treatment by the same endourologist to determine the size of the largest residual fragment, categorizing them as stone free, ≤ 2 mm, or >2 mm, and compared with routine low-dose non-contrast computed tomography by a radiologist blinded to surgery and intraoperative imaging, categorizing them as stone free, ≤ 2 mm, or >2 mm. The results will be compared for positive predictive value.

The negative predictive value of ultrasound and fluoroscopy will be measured in conjunction with endoscopic examination for detecting residual fragments during retrograde intrarenal surgery for renal stones treatment by the same endourologist to determine the size of the largest residual fragment, categorizing them as stone free, ≤ 2 mm, or >2 mm, and compared with routine low-dose non-contrast computed tomography by a radiologist blinded to surgery and intraoperative imaging, categorizing them as stone free, ≤ 2 mm, or >2 mm. The results will be compared for negative predictive value.

The operative time will be measured from the time the endoscope is inserted into the urethra until the end of the procedure.

Surgical complications into grade I to V on the modified Clavien-Dindo classification from operation, up to 4 weeks.

Surgical complications will be categorized according to the modified Clavien-Dindo classification consisted of 5 severity grades. Complications are within 4 weeks post-operation ranging from Grade I to V. Grade I include any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic, and radiological interventions. Grade II complications are defined as complications requiring pharmacological treatment with drugs other than such allowed for grade I complications. Grade III complications are defined as complications requiring surgical, endoscopic or radiological intervention; IIIa intervention not under general anesthesia and IIIb intervention under general anesthesia. Grade IV complications are defined as life-threatening complication requiring IC/ICU management; IVa single organ dysfunction (including dialysis) and IVb multiorgan dysfunction. Grade V complications indicated death of a patient due to a complication.

Inclusion Criteria: Patients over the age of 18. Consecutive patients with a diagnosis of renal stone or ureteral stone with a plan to undergoing RIRS for stone removal. Exclusion Criteria: Patients who decline informed consent. Pregnancy Kidney transplantation Ectopic kidney Patients undergoing concurrent bilateral stone removal surgery. Patients whose pain cannot be controlled when presenting at the Emergency Department.

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