Endoscopic Management of Submucosal Renal Stones

Abstract

Introduction: The prevalence of kidney stones in the United States is estimated at 5%–10% and increasing. Stone disease can lead to pain, renal obstruction, and renal injury. Papillary calcifications may also cause chronic flank pain, which can be relieved in up to 85% of cases, with durable outcomes in 60% of cases, by ureteroscopic laser papillotomy. In this study, we aim to describe the endoscopic technique to treat submucosal renal stones. Patients and Methods: A 57-year-old man presented with intermittent left flank pain. Otherwise healthy, his only medical issue has been nephrolithiasis. One previous left ureteroscopy documented the presence of submucosal stones. The patient was first evaluated with a noncontrast computed tomography. Imaging revealed multiple calcifications in the upper, middle, and lower pole, with the largest being 1.0 cm, located on the lower pole. Blood work showed normal serum creatinine and electrolytes, and 24-hour urine collections had high urinary sodium, calcium, oxalate, and uric acid. After an initial consultation, a decision was made to treat the stone burden through flexible ureteroscopy. Results: Several visible papillary calcifications were fragmented with a 200-μm laser fiber set at 800 Hz and 0.8 J until they were released from the papilla. Once free, stones were basketed and removed. When no more papillary calcifications or submucosal stones were identified through endoscopy, fluoroscopy was used to find which renal papilla contained submucosal stones and the procedure was repeated to treat all radiopaque stones. At the end of the surgery, a Double-J stent was placed. The operative time was 2 hours, blood loss was minimal, and there were no intra/postoperative complications. The stent was removed after 1 week and the patient remained asymptomatic at a 2-month follow-up. Stone composition analysis revealed pure calcium stone. Conclusion: Endoscopic management of submucosal renal stones is feasible and safe, it may improve stone-related symptoms, and can provide a stone-free status. No competing financial interests exist. Runtime of video: 6 mins 35 secs