An Analysis of Current Techniques Used for Intraoperative Flap Evaluation.

Background: Over the last decade, microsurgeons have used a greater variety of more complex flaps. At the same time, microsurgeons have also become more interested in technology, such as indocyanine green (ICG) angiography, dynamic infrared thermography (DIRT), and photospectrometry, for preoperative planning and postoperative monitoring. These technologies are now migrating into the operating room, and are used to optimize flap design and to identify areas of hypoperfusion or problems with the anastomoses. Although relatively more has been published about ICG angiography, information is generally lacking about the intraoperative role of these techniques.

Methods: A systematic analysis of articles discussing intraoperative ICG angiography, DIRT, and photospectrometry was performed to better define the sensitivity, specificity, expected outcomes, and potential complications associated with these techniques.

Results: For intraoperative ICG angiography, the sensitivity was 90.9% (95% CI: 77.5-100) and the accuracy was 98.6% (95% CI: 97.6-99.7). The sensitivity of DIRT was 33% (95% CI: 11.3-64.6), the specificity was 100% (95% CI: 84.9-100), and the accuracy was 80% (95% CI: 71.2-89.7). The sensitivity of intraoperative photospectrometry was 92% (95% CI: 72.4-98.6), the specificity was 100% (95% CI: 98.8-100), and the accuracy was also 100% (95% CI: 98.7-100).

Conclusion: These technologies for intraoperative perfusion assessment have the potential to provide objective data that may improve decisions about flap design and the quality of microvascular anastomoses. However, more work is needed to clearly document their value.