The impact of indocyanine green on tumor visualization and procedural adjustment in minimally invasive liver surgery.

backgroundMinimally invasive hepatobiliary surgery is performed increasingly either with robotic assistance or conventional laparoscopy. The lack of haptic feedback is one of the main challenges which has to be addressed during these procedures. Especially in oncological minimally invasive liver surgery Indocyanine green (ICG) can help to gain additional information for improved oncological quality.

methodsPatients who underwent minimally invasive liver surgery for liver tumors between 01/2019 and 09/2022 and matched the study criteria were selected from the Magdeburg Registry of Minimally invasive liver surgery (MD-MILS). Patient demographics, tumor characteristics and perioperative data were analyzed retrospectively. The benefit of ICG for tumor identification and the resection procedure was assessed as 'very helpful', 'helpful' and 'not helpful' depending on the surgeon´s estimation.

resultsSeventy-two patients who met the selection criteria were included in the analysis. Of these, 49 patients received ICG for intraoperative tumor visualization (ICG). Twenty-three patients with comparable demographics did not receive ICG and served as comparison group (nICG). A total of 69.4% robotic and 30.6% laparoscopic procedures were performed. In the ICG group procedural adjustments were significantly more frequent intraoperatively (p = 0.023). Intraoperative frozen section analysis on additional biopsies of ICG positive lesions were performed in 37% in the ICG group. In the nICG group suspect lesions, identified by ultrasound, went to frozen section in 17% (p = 0.006). Histopathological tumor positivity was identified in 12.2% in the ICG cohort vs no tumor positivity in the nICG cohort. This was one factor which led to the termination of surgery in 8% in the ICG vs the nICG 4.3% group (p = 0.485). In 88% intraoperative ICG visualization was scored as "helpful" when injected on preoperative day 4-7 with respect to the liver parenchyma structure and hepatocellular function.

conclusionICG can improve oncological quality in minimally invasive liver resections. It provides additional visual information which can help to compensate the loss of haptics and tumor identification during liver tissue palpation. The intraoperative use of ICG was associated with no adverse events and did not prolong operative time. We recommend its routine use during minimally invasive liver surgery.