Intra- and Early Postoperative Evaluation of Malperfused Areas in an Irradiated Random Pattern Skin Flap Model Using Indocyanine Green Angiography and Near-Infrared Reflectance-Based Imaging and Infrared Thermography

Abstract

Background: Assessment of tissue perfusion after irradiation of random pattern flaps still remains a challenge. Methods: Twenty-five rats received harvesting of bilateral random pattern fasciocutaneous flaps. Group 1 served as nonirradiated control group. The right flaps of the groups 2–5 were irradiated with 20 Gy postoperatively (group 2), 3 × 12 Gy postoperatively (group 3), 20 Gy preoperatively (group 4) and 3 × 12 Gy preoperatively (group 5). Imaging with infrared thermography, indocyanine green angiography and near-infrared reflectance-based imaging were performed to detect necrotic areas of the flaps. Results: Analysis of the percentage of the necrotic area of the irradiated flaps showed a statistically significant increase from day 1 to 14 only in group 5 (p < 0.05). Indocyanine green angiography showed no differences (p > 0.05) of the percentage of the nonperfused area between all days in group 1 and 3, but a decrease in group 2 in both the left and the right flaps. Infrared thermography and near-infrared reflectance-based imaging did not show evaluable differences. Conclusion: Indocyanine green angiography is more precise in prediction of necrotic areas in random pattern skin flaps when compared to hyperspectral imaging, thermography or clinical impression. Preoperative fractional irradiation with a lower individual dose but a higher total dose has a more negative impact on flap perfusion compared to higher single stage irradiation.

Comparison of Hyperspectral Imaging and Microvascular Doppler for Perfusion Monitoring of Free Flaps in an In Vivo Rodent Model

“…In addition, HSI was inferior to indocyanine green angiography (ICG) angiography in predicting necrotic areas in rat random pattern flaps. Furthermore, evaluation of the flaps by HSI was not even possible in the study, but this may have been due to the experimental design rather than the HSI technique itself [ 57 ]. In contrast, Thiem et al [ 1 ] used HSI successfully for perioperative monitoring of free and pedicled flaps.…”

Air-Pressure-Supported Application of Cultured Human Keratinocytes in a Fibrin Sealant Suspension as a Potential Clinical Tool for Large-Scale Wounds

“…In addition to combined two-step operations with a pretreatment of the wounds by allografting, composite grafts constructed in vitro have been used experimentally and clinically [ 29 ]. They are a crucial therapeutic option for large-scale wounds that cannot be repaired with tissue flaps and instead rely on skin transplants [ 30 , 31 ].…”

Effects of Different Pressure Levels in Topical Negative Pressure Application—Analysis of Perfusion Parameters in a Clinical Skin Model Using Multimodal Imaging Techniques

“…Near-infrared spectroscopy (Snapshot NIR ® ; KENT Imaging Inc., Calgary, AB, Canada) and thermographic imaging (FLIR ONE Pro, FLIR Systems, Inc., Wilsonville, OR, USA) were used for the measurement of the oxygenation and the temperature of the affected skin, respectively. The techniques have been explained in detail elsewhere [ 16 , 17 ].…”