Tissue Sensor to Reduce the Need for Controlled Apnea During Retrograde Intrarenal Surgery

Retrograde intrarenal surgery is an established minimally invasive treatment for renal stones. During laser lithotripsy, respiratory motion causes the kidney, renal collecting system, and stone to move relative to the distal tip of the laser fiber. This can impair precise fiber positioning, reduce operative-field stability, and increase the risk of unintended laser exposure of the urothelium of the renal collecting system. To reduce respiratory motion of the kidney, the surgeon may ask the anesthesiologist to temporarily pause mechanical ventilation. Controlled apnea can briefly stabilize the operative field; however, it requires interruption of ventilation and may cause oxygen desaturation, carbon dioxide accumulation, hemodynamic changes, and increased anesthetic burden. Tissue Sensor is a technology that automatically terminates laser emission when contact between the distal tip of the laser fiber and tissue is detected. Tissue Sensor is expected to reduce the risk of unintended laser exposure of the renal collecting-system mucosa during respiratory motion of the kidney. Greater surgeon confidence in the safety of laser activation may reduce the need to stabilize the kidney with controlled apnea. At the same time, brief automatic interruptions of laser emission may increase lithotripsy time and total operative time.