Continuous Video-Rate Laser Speckle Imaging for Intra- and Postoperative Cutaneous Perfusion Imaging of Free Flaps

Abstract

Background Success of free tissue transfer depends on standardized intraoperative flap design, microsurgical technique, and postoperative monitoring. We sought to investigate whether laser speckle imaging (LSI) is suitable for optimization of intraoperative flap design and postoperative monitoring of free flaps with skin paddles. Methods Skin perfusion was assessed with LSI in 27 free flaps after dissection at the donor site, after anastomosis at the recipient site, after inset and on postoperative days (POD) 1, 5, and 10. Skin perfusion of the whole flap (ROI [region of interest]-1) and the area over the pedicle (ROI-2) were compared between patients with and without postoperative complications (POC+ and POC − , respectively). A receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff for perfusion during LSI-guided microsurgery. Results In flaps without or only minor POC, intraoperatively measured perfusion over ROI-2 was significantly higher compared with ROI-1, whereas no significant differences were found for flaps with major POC. Perfusion of ROI-1 and 2 intraoperatively and on POD 1 was significantly lower in the POC+ compared with the POC− group (p < 0.05). ROC analysis yielded a threshold of 107 perfusion units (PU) at ROI-2 with an area under the curve (AUC) of > 0.8 for identification of flaps with major POC. Conclusion LSI is an easy to use, noninvasive technique for identification of malperfused areas in free flaps, thus allowing for intraoperative decision-making on flap dimensions and postoperative monitoring. LSI therefore is a valuable tool for perfusion assessment with a high potential to become an established part of microsurgical practice.

A Structured, Microsurgical Training Curriculum Improves the Outcome in Lower Extremity Reconstruction Free Flap Residency Training: The Ludwigshafen Concept

“…10 Partial flap loss can be avoided by standardized intraoperative application of Indocyanine-Green Fluorescence Angiography or the Continuous Video-Rate Laser Speckle Imaging, and safely allows adapting the flap design to the defect as well as to the angiosom. 11,12 Unfortunately, this formal and consistent approach does not exist for continuous microsurgical education of the PGY.…”

Flap Monitoring Using Transcutaneous Oxygen or Carbon Dioxide Measurements

“…47 Laser speckle imaging involves capturing reflected laser light of a tissue as speckles on a video-camera detector array which correlates with blood flow as the speckles move in relation to the red blood cells moving. 49 This technology is fast, easy to use, noninvasive, and may be a valuable adjunct for use intra- and postoperatively for evaluating tissue perfusion of free flaps. 7 Another relatively new technology for monitoring free flaps is use of thermal imaging cameras.…”

Imaging for thinned perforator flap harvest: current status and future perspectives

“…In contrast to ICGA, laser speckle contrast imaging (LSCI) allows wide-field imaging of 24 × 24 cm for continuous perfusion monitoring of a large flap without repetitive dye injection [ 57 ]. Its efficacy has been reported in intraoperative cutaneous perfusion imaging of thin flaps, including full-thickness eyelid [ 16 ] and ALT flaps [ 58 ], and thus might be appropriate for thinned perforator flap perfusion assessment.…”