Evaluation of Spinal Cord Blood Supply with Hyperspectral Imaging of the Paraspinous Musculature During Staged Endovascular Repair of Thoracoabdominal Aortic Aneurysm: A Sub-Study of the Prospective Multicenter PAPA-ARTiS Trial

<b>Background/Objectives</b>: Our aim was to assess the feasibility of hyperspectral imaging (HSI) to detect changes in tissue oxygenation (StO₂) of the back, as non-invasive spinal cord collateral network (CN) monitoring during staged endovascular repair (ER) of thoracoabdominal aortic aneurysm (TAAA). <b>Methods</b>: Between September 2019 and June 2021, 20 patients were treated for TAAA and underwent HSI. They were randomized 1:1 to minimally invasive staged segmental artery coil embolization (MIS2ACE) (<i>n</i> = 10) and staged stentgraft implantation (<i>n</i> = 10) as priming methods. HSI of paravertebral regions was taken during each procedure and up to 10 days after. The primary endpoint was the identification of StO₂ changes after ER of TAAA. <b>Results</b>: TAAA Crawford Type II (<i>n</i> = 17) and Type III (<i>n</i> = 3) were treated. After stentgrafting, StO₂ increased immediately (<i>p</i> < 0.001), followed by a decrease after 5 days (<i>p</i> < 0.001) and 10 days (<i>p</i> = 0.028). StO₂ was significantly higher in the thoracic compared to the lumbar region. There was no significant difference between MIS2ACE and the first stentgrafting for StO₂ (<i>p</i> = 0.491). Following MIS2ACE, definitive ER caused a significant decrease in StO₂ after 5 days (<i>p</i> = 0.021), which recovered to baseline after 10 days (<i>p</i> = 0.130). After stentgraft priming, definitive ER caused a significant decrease in StO₂ after 24 h (<i>p</i> = 0.008), which did not return to baseline after 5 (<i>p</i> < 0.001) and 10 days (<i>p</i> = 0.019). <b>Conclusions</b>: HSI detected significant changes in StO₂ in the thoracic and lumbar paravertebral regions during ER of TAAA. These preliminary data suggest the efficacy of MIS2ACE in priming the CN before ER of TAAA.