Value of indocyanine green angiography in monitoring blood perfusion of free perforator flap during repair surgery of limb soft tissue defect / 中华创伤杂志

ABSTRACT

Objective:To analyze the effectiveness of indocyanine green angiography in monitoring blood perfusion of free perforator flap during repair surgery of limb soft tissue defect.Methods:A retrospective case series study was conducted to analyze the clinical data of 26 patients who underwent free perforator flap repair of soft tissue defects in the limbs in Xingtai General Hospital of North China Medical and Health Group from August 2019 to October 2022. The patients included 21 males and 5 females, aged 20-59 years [(39.5±4.1)years]. The wound size ranged from 2.0 cm×5.0 cm to 12.0 cm×16.0 cm. The time from injury to surgery was 5-30 days [(16.2±1.9)days]. During the surgery, indocyanine green angiography was used to evaluate the blood perfusion in the flap area after the free perforator flap was completely cut but before the vascular pedicle was not cut off, and immediately after the free perforator flap was anastomosed with the recipient area′s blood vessels and sutured with surrounding tissues. Consistency testing was performed on the degree of blood perfusion of the skin flap displayed by two indocyanine green angiography tests to determine whether the anastomosis of the skin flap was unobstructed after transplantation. On 14 days after surgery, the second indocyanine green angiography technique was applied to measure the survival of flaps in patients with sufficient blood perfusion. The difference between the poor blood perfusion in the flap arearevealed by indocyanine green angiography technique and the actual necrosis occurrence in this part was compared. The sensitivity, specificity, accuracy, negative predictive value, and positive predictive value of indocyanine green angiography were calculated for evaluating blood perfusion in the flap area.Results:All the patients were followed up for 14-21 days [(17.4±3.5)days]. Two indocyanine green angiography tests showed strong consistency in blood perfusion in the flap area, with no statistically significant difference (Kappa coefficients of 1.00, P<0.01). All the patients had unobstructed anastomosis after flap transplantation. On 14 days after surgery, the second indocyanine green angiography test showed all skin flap areas as grade 1 in 11 patients, with the worst developed areas as grade 2 in 7 patients, grade 3 in 5, and grade 4 in 3. All the flaps survived in the 18 patients with flaps showing grade 1 development and the worst part showing grade 2 development; among the 8 patients with the worst developed areas being grade 3 and grade 4, 5 patients were found with skin flap necrosis (full thickness or superficial) in the areas with poor blood supply, and the skin flap survived well in 3 patients. Indocyanine green angiography in evaluating blood perfusion in the flap area showed the sensitivity of 100% (95% CI 0.46, 1.00), the specificity of 85.71% (95% CI 0.63, 0.96), the accuracy of 88.46% (95% CI 0.76, 1.00), the negative predictive value of 100% (95% CI 0.78, 1.00), and the positive predictive value of 62.50% (95% CI 0.26, 0.90). Conclusion:Indocyanine green angiography has good real-time imaging effect, with high sensitivity, specificity and accuracy, making it an objective method for monitoring the blood flow status of skin flaps and predicting skin flap necrosis.