Objective To explore the feasibility and effectiveness of mixed reality technology for localizing perforator vessels in the repair of mandibular defects using free fibular flap. Methods Between June 2020 and June 2023, 12 patients with mandibular defects were repaired with free fibular flap. There were 8 males and 4 females, with an average age of 61 years (range, 35-78 years). There were 9 cases of ameloblastomas and 3 cases of squamous cell carcinomas involving the mandible. The disease duration ranged from 15 days to 2 years (median, 14.2 months). The length of mandibular defects ranged from 5 to 14 cm (mean, 8.5 cm). The area of soft tissue defects ranged from 5 cm×4 cm to 8 cm×6 cm. Preoperative enhanced CT scans of the maxillofacial region and CT angiography of the lower limbs were performed, and the data was used to create three-dimensional models of the mandible and lower limb perforator vessels. During operation, the mixed reality technology was used to overlay the three-dimensional model of perforator vessels onto the body surface for harvesting the free fibular flap. The length of the fibula harvested ranged from 6 to 15 cm, with a mean of 9.5 cm; the size of the flap ranged from 6 cm×5 cm to 10 cm×8 cm. The donor sites were sutured directly in 7 cases and repaired with free skin grafting in 5 cases. Results Thirty perforator vessels were located by mixed reality technology before operation, with an average of 2.5 vessels per case; the distance between the exit point of the perforator vessels located before operation and the actual exit point ranged from 1 to 4 mm, with a mean of 2.8 mm. All fibular flaps survived; 1 case had necrosis at the distal end of flap, which healed after dressing changes. One donor site had infection, which healed after anti-inflammatory dressing changes; the remaining incisions healed by first intention, and the grafts survived smoothly. All patients were followed up 8-36 months (median, 21 months). The repaired facial appearance was satisfactory, with no flap swelling. Among the patients underwent postoperative radiotherapy, 2 patients had normal bone healing and 1 had delayed healing at 6 months. Conclusion In free fibular flap reconstruction of mandibular defects, the use of mixed reality technology for perforator vessel localization can achieve three-dimensional visualization, simplify surgical procedures, and reduce errors.
Objective To compare the effectiveness of poly ether ether ketone (PEEK) positioning devices combined with mixed reality technology versus color doppler ultrasound guidance for the localization of vessels in anterolateral thigh perforator flap. Methods A retrospective analysis was conducted on 40 patients with tissue defects after oral cancer resection who underwent repair using the anterolateral thigh perforator flap between January 2022 and June 2023. According to the different intraoperative positioning methods of the anterolateral thigh perforator flap, they were randomly divided into PEEK group (mixed reality technology positioning with PEEK positioning device combined with CTA data) and color ultrasound group (using color ultrasound guided positioning), with 20 cases in each group. There was no significant difference in gender, age, etiology, and disease duration in the two groups (P>0.05). The number of perforator vessels actually detected in the two groups of regions of interest was recorded, and compared them with the intraoperative identified number to calculate the success rate of perforator vessels; the distance between the perforating point and the actual puncture point was measured, the operation time of the two groups of flaps was recorded. ResultsP In the PEEK group, 32 perforator vessels were identified, 34 were found by intraoperative exploration, and the success rate was 94.1% (32/34); in the color ultrasound group, 29 perforator vessels were identified, 33 were found by intraoperative exploration, and the success rate was 87.8% (29/33); there was a significant difference in the success rate of identifying perforator vessels between the two groups (P<0.05). The distance between the perforating point and the actual puncture point and the operation time in PEEK group were significantly shorter than those in color ultrasound group (P<0.05). Patients in both groups were followed up 6-30 months, with a median of 17 months; there was no significant difference in the follow-up time between the two groups (P>0.05). In the PEEK group, there was 1 case of flap necrosis at the distal edge and delayed healing after trimming and dressing change. In the color ultrasound group, there was 1 case of flap necrosis at 7 days after operation and pectoralis major myocutaneous flap was selected for repair after removal of the necrotic flap. In the rest, the flap survived and the incision healed by first intention. Donor site infection occurred in 1 case in PEEK group and healed after anti-inflammatory treatment. The maxillofacial appearance of the two groups was good, the flap was not obviously bloated, and the patients were satisfied with the repair effect. Conclusion Compared with the traditional color ultrasound positioning, the positioning marker made of PEEK combined with CTA data to locate the vessels in anterolateral thigh perforator flap has higher success rate and positioning accuracy, and the flap production time is short, which has high clinical application value.