Hyperspectral Imaging for Microcirculatory Assessment of Patients undergoing Transcatheter and Surgical Aortic Valve Replacement-a Prospective Observational Pilot Study

This prospective, observational study evaluated Hyperspectral Imaging (HSI) to assess the effects of cardiac surgery and cardiopulmonary bypass (CPB) on microcirculation. 40 Patients with severe aortic stenosis were enrolled. 20 patients underwent transapical/transaxillary/transaortic aortic valve replacement (TAVR), 20 underwent an open surgical approach with CPB (SAVR). HSI was used to determine tissue oxygenation (StO₂ and NIR), hemoglobin (THI) and water content (TWI) at the palm before/after surgery (T1/T2), and on the third postoperative day (T3). TAVR patients showed no significant changes of microcirculatory parameters during surgery. TWI significantly increased until T3. SAVR patients showed an increase of TWI and a decrease of THI, while StO₂ and NIR remained unchanged at T2. In SAVR patients, StO₂ and NIR correlated negatively with the duration of CPB and StO₂ correlated with intraoperative urine output at T2. HSI was able to detect microcirculatory changes during cardiac surgery. CPB duration seemed to affect tissue oxygenation. Clinical trial registration: (German Clinical Trial Register): DRKS00024765.