An interventional study of RIRS without Tissue Sensor and RIRS with Tissue Sensor in Tissue Sensor, sponsored by Botkin Hospital. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-01.
Sponsored by Botkin Hospital · Not applicable, Interventional, and Treatment
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.
Botkin Hospital is the lead sponsor of 8 studies on the registry; 6 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
RIRS will be performed using a thulium fiber laser with Tissue Sensor activated. All automatic system trigger events will be recorded and, whenever possible, synchronized with the procedure video recording.
Procedure: RIRS without Tissue Sensor · Procedure: RIRS with Tissue Sensor
RIRS will be performed using the same TFL system with Tissue Sensor deactivated. Visually confirmed contacts between the activated laser fiber and the mucosa will be recorded from the procedure video.
RIRS will be performed using a thulium fiber laser with Tissue Sensor activated. All automatic system trigger events will be recorded and, whenever possible, synchronized with the procedure video recording. * total number of Tissue Sensor trigger events; * Tissue Sensor trigger events per minute of laser activation.
Proportion of patients requiring at least one episode of controlled intraoperative apnea during laser lithotripsy.
Time frame: intraoperative
• number of apnea episodes;
Time frame: intraoperative
total apnea duration;
Time frame: intraoperative
mean number of apnea episodes per patient;
Time frame: intraoperative
maximum duration of a single apnea episode;
Time frame: intraoperative
minimum SpO2;
Time frame: intraoperative
incidence of desaturation;
Time frame: intraoperative
visible laser-induced mucosal
Time frame: intraoperative
No study locations are listed for this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Botkin Hospital