[Application of computer-assisted design for anterolateral thigh flap in oral and maxillofacial reconstruction]

To investigate the feasibility and accuracy of using digital technology to design anterolateral thigh flap (ALTF) in oral and maxillofacial defect reconstruction.

Ten cases underwent oral and maxillofacial defects reconstruction with ALTFs in Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from June 2019 to Oct. 2019 were enrolled. There were 7 males and 3 females with the mean age of 47.1 years. Preoperative high frequency color Doppler ultrasound examination was performed to detect the perforators of ALTF. CT data of the thigh was imported in DICOM (digital imaging and communications in medicine) format to the Proplan CMF 3.0 software (Materalise, Belgium), then virtual harvest of ALTF was performed according to the points of perforators detected by high frequency color Doppler ultrasound and the virtual flap volume was calculated by Proplan CMF 3.0 software. ALTF was harvested followed by preoperative virtual design, and the actual flap volume of ALTF was measured by the draining method during the surgery. Finally, the accuracy rate of using high frequency color Doppler ultrasound to detect perforators of ALTFs was calculated, and the differences between the virtual flap volume measured by Propaln CMF 3.0 software and the actual volume of ALTF by the draining method were compared using paired samples T test.

Fifteen perforators in the flaps area of 10 patients who underwent oral and maxillofacial defects reconstruction with ALTFs were detected by high frequency color Doppler ultrasound, and 16 perforators were identified during the surgery, with the accuracy rate of 87.5%. The flaps size ranged from 5 cm×7 cm to 8 cm×15 cm, all the 10 flaps survived. The donor sites were primarily closed without skin graft, and no surgery complication was found on the donor site. The mean flap volume measured by Propaln CMF 3.0 software was 71.4 cm³ (range: 36.1-188.4 cm³), and the mean volume measured by the draining method was 70.7 cm³ (range: 38.3-172.5 cm³). There was no significant difference between the virtual flap volume measured by Propaln CMF 3.0 software and the actual volume measured by draining method (t=0.318; P=0.758).

Preoperative virtual design of ALTF has good feasibility and accuracy and can be used to guide the harvest of ALTF during operation.