[A comparative study of color Doppler ultrasound and CT angiography for preoperative evaluation of perforator vessels in free posterior interosseous artery flap].

Objective: To investigate the accuracy of color Doppler ultrasound (CDU) and CT angiography (CTA) in the preoperative evaluation of perforator vessels in free posterior interosseous artery perforator (PIAP) flaps.

Methods: Between January 2020 and December 2023, 19 patients with hand skin and soft tissue defects caused by trauma were admitted. There were 11 males and 8 females, with a median age of 45 years (range, 26-54 years). The interval between injury and admission was 5-11 days (mean, 7.2 days). The skin and soft tissue defects were located on the dorsum of the hand in 8 cases and on the fingers in 11 cases. The size of defect ranged from 4.0 cm×2.5 cm to 7.5 cm×3.5 cm. After locating the perforator vessels through CDU and CTA before operation, the free PIAP flaps were designed to repair hand defects, with the size of 4.5 cm×3.0 cm-7.5 cm×4.0 cm. The defects of donor sites were directly sutured. The number and diameter of perforator vessels in the posterior interosseous artery detected by CDU and CTA were compared. The differences in localization of perforator vessels using CDU and CTA and their clinical effects were also compared to calculate the accuracy and recognition rate. During follow-up, the survival of the skin flap was observed, and the Vancouver scar scale (VSS) score was used to evaluate the healing of the donor site, while the visual analogue scale (VAS) score was used to evaluate the patient's satisfaction with the appearance of the skin flap.

Results: The number and the diameter of PIAP vessels was 5.8±1.2 and (0.62±0.08) mm assessed by CDU and 5.2±1.0 and (0.60±0.07) mm by CTA, showing no significant difference between the two methods ( P>0.05). The number, course, and distribution of perforator vessels of the PIAP vessels observed during operation were basically consistent with those detected by preoperative CDU and CTA. Compared with intraoperative observation results, the recognition rates of dominant perforating vessels by CDU and CTA were 95.0% (18/19) and 89.5% (17/19), respectively, and the accuracy rates were 100% (19/19) and 84.2% (16/19), with no significant difference between the two methods ( P>0.05). All flaps survived after operation, and all wounds and incisions at donor sites healed by first intention. All patients were followed up 6-13 months (mean, 8.2 months). At last follow-up, the skin flaps had elasticity and soft texture，with the patient satisfaction VAS score of 9.2±0.8. The donor sites had no obvious scar hyperplasia with the VSS score of 11.7±0.9.

Conclusion: CDU and CTA accurately identify the dominant perforator vessels and provide reliable information for vessel localization, facilitating precise flap harvesting and minimizing donor site injury. However, CDU offers superior visualization of distal end of perforator vessels in the forearm compared to CTA.