Abstract:

Objective

Exploring the clinical application value of the combination of 3D digital subtraction angiography （3D-DSA） and color Doppler flow imaging （CDFI） for positioning precisely on the perforator vessels in the preoperative evaluation of the anterolateral thigh perforator flap （ALTFP） for repairing lower limb defects after leg salvage surgery.

Methods

From June 2022 to June 2023， 25 cases of wounds after lower leg limb-sparing surgery were covered with ALTFP in Department of Traumatic Orthopedics of Suzhou Ruihua Orthopedic Hospital. Prior to surgery， 3D-DSA combined with CDFI was used to locate the perforator vessels of ALTFP and the vessels in the affected area of the leg wound. The preoperative location of the perforator vessels in the skin flap， the number， diameter， and type of perforator were recorded， as well as the type and diameter of the vessels in the affected area of the leg wound were recorded. The number， diameter， type of perforations of the skin flap during surgery， as well as the compatibility rate between the vascular pedicle of the skin flap and the diameter of the blood vessels in the affected area of the leg wound were recorded， to verify the accuracy of preoperative combined positioning and the efficiency of skin flap harvesting. Postoperative flap survival rate and complications in the flap donor site were collected.

Results

In this series of 25 cases， the combination of 3D-DSA and CDFI was used to identify 70 perforators， of which 40 were actually utilized during surgery. The remaining unused perforators were not traced back to their origins. All the perforators used in the surgery were the preoperatively localized ones， with a positive predictive value of 100%. The average length of the vascular pedicles measured intraoperatively was 12.96 （8-18）cm， and the average predicted length of the vascular pedicles before surgery was 13.76 （7-19）cm， with the difference within 1-3 cm. The average proximal caliber of the main vessel was 1.77（1.55-1.90）mm， which could be matched and anastomosed with the recipient area vessels.According to the preoperative design， the flaps met the requirements for intraoperative wound repair. The preoperative angiography exposure time was 45（30-70）seconds. The time spent on harvesting the flap was 25（10-60）minutes. All 25 flaps survived successfully， with primary healing of both the donor and recipient sites， and no vascular complications occurred in the flaps postoperatively. Length of hospitalization was 14-60 days after flap coverage， with an average of 25 days. Postoperative follow-up was conducted 6-18 months， with no wound infections observed. The flaps exhibited healthy reddish color， no significant hyperpigmentation， soft texture， and good appearance. All postoperative fractures achieved union.

Conclusion

3DDSA combined with CDFI can accurately locate the blood vessels of ALTPF and recipient vessels in the lower leg wound area. This approach provides excellent preoperative plan for transplantation of free ALTPF to repair the wound after limb salvage in the lower leg， which is worth reference in clinical applications.

Key words: Wound, Anterolateral thigh perforator flap, Angiography，digital subtraction, Positioning technology