Intraoperative Identification of Perforator Spasm and Decreased Pulsation Using Video-capillaroscopy during Free Flap...

Temporary or prolonged vascular spasm can be appreciated when perivascular dissection is performed for microvascular reconstruction. Due to a lack of reliable assessment modalities, the resolution of spasm at the periphery of perforators cannot be determined by naked eyes or surgical loupes. To address this conundrum, we aimed to observe the state of perforator vessel spasm after flap elevation using video-capillaroscopy. Between November 2021 and February 2022, seven free flaps were evaluated with video-capillaroscopy to determine the incidence of vasospasm in less than 1 mm-diameter perforators. The type of perforator spasm after flap elevation was divided into six types according to the video-capillaroscopy findings: type A, no spasm/decreased pulsation (S/DP); type B, S/DP with recovery within 5 minutes; type C, S/DP requiring papaverine hydrochloride spraying and hot water treatment (PHS+HWT) resulting in recovery within 5 minutes; type D, S/DP requiring PHS+HWT resulting in recovery within 10 minutes; type E, S/DP requiring PHS+HWT resulting in recovery within 15 minutes; and type F, S/DP with no recovery of pulsation even after PHS+HWT. Twenty-five perforators were evaluated, 3.57 perforators (range, 3-4) per flap. Using our classification for perforator vessel spasms on video-capillaroscopy, observations of five perforating branches were classified as type A, seven as type B, six as type C, five as type D, and two as type E. No type F spasm was observed. With video-capillaroscopy it is possible to confirm if blood flow deterioration occurs even in areas that are difficult to determine macroscopically. Video-capillaroscopy, a noninvasive imaging modality, is a useful alternative for the intraoperative evaluation of perforator flow and spasm.