Preclinical Assessment of Tissue Effects by Gastrointestinal Endoscope Tip Temperature.

BACKGROUND: Endoscope tips are heated by their electrical and illuminating components. During the procedure, they might get in close or even direct contact with intestinal tissues.

OBJECTIVE: To assess endoscope tip and tissue temperature as well as histopathologic changes of gastrointestinal (GI) tissues when exposed to the heated tip of GI endoscopes.

METHODS: The endoscope tip temperatures of four GI endoscopes were measured for 30 minutes in a temperature-controlled chamber. The temperature of ex vivo porcine GI tissues was measured for 5-, 15-, and 120-minute exposure to endoscope tips within a climate chamber to control environmental factors (simulation of fever as worst-case). Exposed tissues were histopathologically examined afterward. Control samples included untreated mucosa, tissue samples exposed to endoscope tips for 120 minutes, as well as tissue samples thermally coagulated with a bipolar high-frequency probe.

RESULTS: Actual endoscope tip temperatures of 59 to 86°C, dependent on the endoscope type, were measured. After 10 to 15 minutes, the maximum temperatures were reached. Maximum tissue temperatures of 44 to 46°C for 5 and 15 minutes, as well as up to 50°C for 120 minutes, were recorded dependent on tissue and endoscope type. No direct heat-induced histopathologic tissue alterations were observed in the 5- and 15-minute samples.

CONCLUSIONS: Both clinically relevant and a worst-case control were tested. Even though elevated temperatures were recorded, no heat-related tissue alterations were detected. This overall supports the safety profile of GI endoscopy; however, the study findings are limited by the ex vivo setting (no metabolic tissue alterations accessible, no blood flow) and small sample number.