Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
Vet Surg. 2024 May;53(4):659-670. doi: 10.1111/vsu.14007. Epub 2023 Aug 3.
To determine the effect of indocyanine green (ICG) dose and timing of administration on near-infrared fluorescence (NIRF) imaging of the normal canine biliary tree.
Preclinical prospective study.
Eight purpose-bred beagles.
The dogs were randomized to receive two of four intravenous ICG dose (low [L]:0.05 mg/kg or high [H]:0.25 mg/kg)/time (0 and 3 h prior to NIRF) combinations. NIRF images were collected every 10 min for 120 min. Target (cystic duct)-to-background (liver) ratios were calculated for all timepoints and compared.
ICG cholangiography was successful in all dogs. The contrast ratio was above 1 in the L0 group by 20 min and reached its peak at 100 min. In the H0 group, the ratio was above 1 by 60 min and reached its peak at 90 min. Contrast ratios above 2 (fluorescence twice as bright in the cystic duct compared to the liver) were maintained from 180 to 300 min for L3 and H3 and was achieved after 80 min for L0.
Low dose ICG provided better ratios early after injection compared to the high dose which remained highly concentrated in the liver tissue after injection. Both doses provided excellent visualization of the biliary tree at 3 h post injection, low dose ICG provided better ratios from 3 to 5 h post injection. Based on these results, 0.05 mg/kg of ICG administered at anesthetic premedication, or as early as 3 h prior to laparoscopic surgery should yield optimal fluorescence images.
This study provides guidelines for NIRF cholangiography in clinically normal dogs.
确定吲哚菁绿（ICG）剂量和给药时间对正常犬胆管近红外荧光（NIRF）成像的影响。
临床前前瞻性研究。
8 只专门繁殖的比格犬。
将狗随机分为四组，每组接受两种静脉内 ICG 剂量（低 [L]：0.05mg/kg 或高 [H]：0.25mg/kg）/时间（NIRF 前 0 和 3 小时）组合。每隔 10 分钟收集 NIRF 图像，持续 120 分钟。计算所有时间点的目标（胆囊管）与背景（肝脏）比值并进行比较。
所有狗均成功进行了 ICG 胆管造影。L0 组在 20 分钟时对比度比 1 高，并在 100 分钟时达到峰值。在 H0 组，比值在 60 分钟时高于 1，并在 90 分钟时达到峰值。L3 和 H3 的对比度比 2 高（胆囊管中的荧光比肝脏亮两倍），从 180 到 300 分钟保持不变，而 L0 在 80 分钟后达到。
与注射后仍高度集中在肝组织中的高剂量相比，低剂量 ICG 注射后早期提供了更好的比值。两种剂量在注射后 3 小时均能很好地显示胆管树，低剂量 ICG 在注射后 3 至 5 小时提供更好的比值。基于这些结果，在麻醉前给药时给予 0.05mg/kg 的 ICG，或在腹腔镜手术前 3 小时内给予，应产生最佳荧光图像。
本研究为临床正常犬的 NIRF 胆管造影提供了指导。
