Hyperspectral Evaluation of the Human Liver During Major Resection.

OBJECTIVE

This study investigates the effects of PVE and vascular inflow control (VIC) on liver microperfusion and tissue oxygenation using hyperspectral imaging (HSI) technology.

BACKGROUND

Mechanisms triggering future liver remnant (FLR) augmentation introduced by PVE have not been sufficiently studied in humans. Particularly, the arterial buffer response (ABR) of the liver might play a vital role.

METHODS

Hyperspectral datacubes (TIVITA) acquired during 58 major liver resections were qualitatively and quantitatively analyzed for tissue oxygenation (StO%), near-infrared (NIR) perfusion, organ-hemoglobin indices (OHI), and tissue-water indices (TWI). The primary study endpoint was measurement of hyperspectral differences in liver parenchyma subject to PVE and VIC before resection.

RESULTS

HSI revealed parenchyma specific differences in StO% with regard to the underlying disease ( < 0.001). Preoperative PVE (n = 23, 40%) lead to arterial hyperoxygenation and hyperperfusion of corresponding liver segments (StO: 77.23% ± 11.93%, NIR: 0.46 ± 0.20[I]) when compared with the FLR (StO: 66.13% ± 9.96%, NIR: 0.23 ± 0.12[I]; < 0.001). In a case of insufficient PVE and the absence of FLR augmentation hyperspectral StO and NIR differences were absent. The hyperspectral assessment demonstrated increased liver tissue-oxygenation and perfusion in PVE-segments (n = 23 cases) and decreased total VIC in nonembolized FLR hemilivers (n = 35 cases; < 0.001). Intraoperative HSI analysis of tumor tissue revealed marked tumor specific differences in StO, NIR, OHI, and TWI ( < 0.001).

CONCLUSIONS

HSI allows intraoperative quantitative and qualitative assessment of microperfusion and StO% of liver tissue. PVE lead to ABR-triggered tissue hyperoxygenation and cross-talk FLR augmentation. HSI furthermore facilitates intraoperative tumor tissue identification and enables image-guided liver surgery following VIC.