Optimization of near-infrared fluorescence cholangiography  for open and laparoscopic surgery.
BACKGROUND
During laparoscopic cholecystectomy, common bile duct (CBD) injury is a rare but severe complication. To reduce the risk of injury, near-infrared (NIR) fluorescent cholangiography using indocyanine green (ICG) has recently been introduced as a novel method of visualizing the biliary system during surgery. To date, several studies have shown feasibility of this technique; however, liver background fluorescence remains a major problem during fluorescent cholangiography. The aim of the current study was to optimize ICG dose and timing for NIR cholangiography using a quantitative intraoperative camera system during open hepatopancreatobiliary (HPB) surgery. Subsequently, these results were validated during laparoscopic cholecystectomy using a laparoscopic fluorescence imaging system.


METHODS
Twenty-seven patients who underwent NIR imaging using the Mini-FLARE image-guided surgery system during open HPB surgery were analyzed to assess optimal dosage and timing of ICG administration. ICG was intravenously injected preoperatively at doses of 5, 10, and 20 mg, and imaged at either 30 min (early) or 24 h (delayed) post-injection. Next, the optimal doses found for early and delayed imaging were applied to two groups of seven patients (n = 14) undergoing laparoscopic NIR fluorescent cholangiography during laparoscopic cholecystectomy.


RESULTS
Median liver-to-background contrast was 23.5 (range 22.1–35.0), 16.8 (range 11.3–25.1), 1.3 (range 0.7–7.8), and 2.5 (range 1.3–3.6) for 5 mg/30 min, 10 mg/30 min, 10 mg/24 h, and 20 mg/24 h, respectively. Fluorescence intensity of the liver was significantly lower in the 10 mg delayed-imaging dose group compared with the early imaging 5 and 10 mg dose groups (p = 0.001), which resulted in a significant increase in CBD-to-liver contrast ratio compared with the early administration groups (p < 0.002). These findings were qualitatively confirmed during laparoscopic cholecystectomy.


CONCLUSIONS
This study shows that a prolonged interval between ICG administration and surgery permits optimal NIR cholangiography with minimal liver background fluorescence.
Floris P R
FP
Verbeek
Boudewijn E
BE
Schaafsma
Quirijn R  J  G
QR
Tummers
Joost R
JR
van der Vorst
Wendeline J
WJ
van der Made
Coen I  M
CI
Baeten
Bert A
BA
Bonsing
John V
JV
Frangioni
Cornelis J  H
CJ
van de Velde
Alexander L
AL
Vahrmeijer
Rutger-Jan
RJ
Swijnenburg
D000328:Adult; D000368:Aged; D001649:Bile Duct Diseases / Q000175:diagnosis* / Q000601:surgery; D002758:Cholangiography / Q000592:standards*; D017081:Cholecystectomy, Laparoscopic / Q000379:methods*; D004396:Coloring Agents; D003952:Diagnostic Imaging / Q000592:standards*; D005260:Female; D005453:Fluorescence; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000379:methods*
D004396:Coloring Agents; D007208:Indocyanine Green