Objective To investigate the feasibility and application value of digital technology in establishing the micro-vessels model of cross-boundary perforator flap in rat. Methods Twenty 8-week-old female Sprague Dawley rats, weighing 280-300 g, were used to established micro-vessels model. The cross-boundary perforator flaps of 10 cm×3 cm in size were prepared at the dorsum of 20 rats; then the flaps were suturedin situ. Ten rats were randomly picked up at 3 and 7 days after operation in order to observe the necrosis of flap and measure the percentage of flap necrosis area; the lead-oxide gelatin solution was used for vessels perfusion; flaps were harvested and three-dimensional reconstruction of micro-vessel was performed after micro-CT scanning. Vascular volume and total length were measured via Matlable 7.0 software. Results The percentage of flap necrosis area at 3 days after operation was 19.08%±3.64%, which was significantly lower than that at 7 days (39.76%±3.76%;t=10.361, P=0.029). Three-dimensional reconstruction via the micro-CT clearly showed the morphological alteration of micro-vessel of the flap. At 3 days after operation, the vascular volume of the flap was (1 240.23±89.71) mm3 and the total length was (245.94±29.38) mm. At 7 days after operation, the vascular volume of the flap was (1 036.96±88.97) mm3 and the total length was (143.20±30.28) mm. There were significant differences in the vascular volume and the total length between different time points (t=5.088, P=0.000; t=7.701, P=0.000). Conclusion The digital technology can be applied to visually observe and objectively evaluate the morphological alteration of the micro-vessels of the flap, and provide technical support for the study of vascular model of flap.
Objective To investigate the effectiveness of the digital technology in repairing tiny hand wounds with superficial lateral sural artery perforator flap. Methods Between August 2013 and October 2016, 10 cases of tiny hand wounds were treated with the superficial lateral sural artery perforator flap. There were 6 males and 4 females, aged 19 to 47 years (mean, 31.2 years). The causes included crushing injury by machine in 6 cases, traffic accident injury in 3 cases, and electric burning injury in 1 case. The location of the soft tissue defect was the first web in 2 cases, the thumb pulp in 3 cases, the index finger pulp in 1 case, the dorsal palms in 3 cases, and the dorsum of finger in 1 case. The time from injury to hospitalization was 4 hours to 10 days (mean, 3.5 days). The size of wound was from 4 cm×3 cm to 8 cm×7 cm. All defects were associated with exposure of tendon and bone. CT angiography (CTA) from aortaventralis to bilateral anterior and posterior tibial arteries was performed before operation, and the appropriate donor site as well as perforator was selected. Then the CTA data were imported into the Mimics15.0 software to reconstruct the three dimensional structure of the perforator artery, bone, and skin; according to flap size, the flap design and harvesting process were simulated. The flap was obtained on the basis of preoperative design during operation. The size of flaps varied from 5 cm×4 cm to 10 cm×8 cm. The donor site was sutured directly in 9 cases and repaired with skin grafting in 1 case. Results Superficial medial sural artery peforator was cut in 3 patients whose superficial lateral sural artery was too narrow, and the flaps were obtained to repair defects smoothly in the others. Venous crisis occurred in 1 flap, which survived after exploration of the vessel, thrombus extraction, and thrombolysis; the other flaps survived successfully. All wounds and incisions healed by first intention. All cases were followed up 3-18 months (mean, 10 months). The flaps had good shape. At last follow-up, the results were excellent in 6 cases, good in 3 cases, and fair in 1 case according to total active motion (TAM). Conclusion The preoperative individualized design of the superficial lateral artery perforator flap can realize through CTA digital technology and Mimics15.0 software; it can reduce the operation risk and is one of better ways to repair the tiny hand wounds.