Reliability of near-infrared angiography and micro-Doppler sonography for evaluating microvascular anastomoses.
BACKGROUND
Intraoperative fluorescence angiography has been reported to be a promising method, with rapid and high-quality image production at low cost when used for the detection of microvascular complications. The purpose of this study was to evaluate the reliability of intraoperative near-infrared indocyanine green angiography compared with microvascular Doppler testing in a standardized model in the rat with different vessel patencies.


METHODS
The carotid, aorta, and femoral vessels of 23 Wistar rats were used. Indocyanine green angiography and microvascular Doppler sonographic testing were performed to assess microanastomosis with a vessel patency randomly narrowed at the anastomosis to an outer patency of 100, 75, 50, 25, and 0 percent.


RESULTS
A total of 424 investigations were performed for 68 anastomoses, including both indocyanine green videoangiographic and microvascular Doppler sonographic examinations. The overall sensitivity and specificity of the microvascular Doppler sonographic testing at different degrees of stenoses were 100 and 86.9 percent, respectively. The positive predictive value for all observations was 95.8 percent, and the corresponding negative predictive value was 100 percent. Indocyanine green angiography revealed an overall sensitivity of 95.3 percent and a specificity of 100 percent. The positive predictive value for these observations was 100 percent, and the negative predictive value was 84 percent.


CONCLUSIONS
Indocyanine green angiography and microvascular Doppler sonography are quick and reliable methods for assessing blood flow in vessels in the laboratory model. The combined use of indocyanine green angiography and microvascular Doppler sonography can increase the accuracy of assessment of microvascular anastomoses intraoperatively. Indocyanine green can be used first, but followed by the microvascular Doppler in cases of a negative result to maximize accuracy.
München and Duisburg-Essen, Germany From the Department of Oral and Maxillofacial Surgery and the Institute for Medical Statistics and Epidemiology, Technische Universität München, Klinikum Rechts der Isar; the Graduate School of Information Science in Health, Technische Universität München; and the Department of Neurosurgery, Clinic of Duisburg, University Teaching Hospital Duisburg-Essen.
Thomas
T
Mücke
Klaus-Dietrich
KD
Wolff
Stefan
S
Wagenpfeil
Frank
F
Hölzle
Martin
M
Scholz
D000714:Anastomosis, Surgical; D000818:Animals; D004396:Coloring Agents; D003251:Constriction, Pathologic; D005451:Fluorescein Angiography; D007208:Indocyanine Green; D007259:Infrared Rays; D007432:Intraoperative Period; D055806:Microvessels / Q000000981:diagnostic imaging / Q000601:surgery*; D011237:Predictive Value of Tests; D011859:Radiography; D051381:Rats; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D014654:Vascular Patency
D004396:Coloring Agents; D007208:Indocyanine Green