Objective:To explore a reasonable relationship between the survival of descending genicular artery (chimeric) perforator flap [DGAPF (-Ch)] and the preservation of the great saphenous vein (GSV), so as to optimise the protection and reduction of a damage to the donor site in clinical applications.Methods:From June 2015 to October 2022, the Division of Orthopaedics and Traumatology of Department of Orthopaedics of Nanfang Hospital, Southern Medical University, conducted cadaver perfusion studies on 15 fresh specimens of human lower extremity, and then on 31 patients who received free DGAPF (-Ch) transfer surgery. Among the patients, 13 had soft tissue defects in hand or forearm, 17 had soft tissue defects in foot or ankle and 1 had early femoral head necrosis after internal fixation for femoral neck fracture. Among them, 6 patients were complicated with bone defect. The size of soft tissue defect was 5.5 cm×3.0 cm-13.0 cm×6.5 cm, the size of flaps was 6.5 cm×3.5 cm-14.5 cm×7.5 cm, and bone flap volume was 3.5 cm×1.5 cm×1.5 cm-5.0 cm×1.5 cm×1.5 cm. All patients underwent preoperative evaluation of donor site by computed tomography angiography (CTA), and the CTA data were processed with Mimics 20.0 to design the flaps. Intraoperatively, the location of the descending genicular artery (DGA) was detected using Doppler ultrasound. When harvesting the flap, the P point (SP-p) was used as the centre to form an arteriovenous pedicle. A matching medial femoral condyle flap was designed to reconstruct the bone defect. The free flap (25 patients) or chimeric flap (6 patients) was transferred to the recipient site, and end-to-end vessel anastomoses were performed to establish the blood supply. After surgery, the patients were kept in bed for 7-9 days. Antibiotics were routinely administered to prevent infection, together with a symptomatic anticoagulation and anti-spasm treatment. The colour, temperature, capillary refilling and tension of the flap were closely observed. All patients were entered in postoperative follow-up at outpatient clinic for review at 1, 3, and 6 months after surgery to observe the appearance, texture and function of the flaps and the condition of the donor sites.Results:Through anatomy observation, cutaneous perforating branch of DGA was located in front of the main trunk of the GSV at the plane of medial femoral condyle. It was found that both of the perforators of cutaneous artery and the branches of osteoarticular artery originated from the DGA. Distance between SP-p and S-p(DSPS) of fresh samples was 2.9-4.1 (3.6±0.5) cm. The DSPS of 31 patients measured in surgery was 2.9-4.3 (3.7±0.4) cm. A total of 30 flaps survived completely. One flap had partial necrosis, which healed at 2 weeks after skin grafting. The postoperative follow-up lasted for 6-48 (mean, 11.23) months. X-rays of 5 patients with chimeric bone flaps showed the healing of bone defects at 3 months after surgery. All donor sites were directly sutured and left with linear scars after healing, except 5 donor sites that received skin grafting. Eight patients received further flap thinning surgery at 3 to 12 months after primary surgery without any complication. All donor sites healed well without numbness.Conclusion:If the GSV is preserved during harvest of a DGAPF(-Ch), it causes less damage to the donor site and does not affect the survival of the flap. The DGAPF(-Ch) without GSV is a better method in the surgical treatment of complex tissue defects.

Objective:To explore a reasonable relationship between the survival of descending genicular artery (chimeric) perforator flap [DGAPF (-Ch)] and the preservation of the great saphenous vein (GSV), so as to optimise the protection and reduction of a damage to the donor site in clinical applications.Methods:From June 2015 to October 2022, the Division of Orthopaedics and Traumatology of Department of Orthopaedics of Nanfang Hospital, Southern Medical University, conducted cadaver perfusion studies on 15 fresh specimens of human lower extremity, and then on 31 patients who received free DGAPF (-Ch) transfer surgery. Among the patients, 13 had soft tissue defects in hand or forearm, 17 had soft tissue defects in foot or ankle and 1 had early femoral head necrosis after internal fixation for femoral neck fracture. Among them, 6 patients were complicated with bone defect. The size of soft tissue defect was 5.5 cm×3.0 cm-13.0 cm×6.5 cm, the size of flaps was 6.5 cm×3.5 cm-14.5 cm×7.5 cm, and bone flap volume was 3.5 cm×1.5 cm×1.5 cm-5.0 cm×1.5 cm×1.5 cm. All patients underwent preoperative evaluation of donor site by computed tomography angiography (CTA), and the CTA data were processed with Mimics 20.0 to design the flaps. Intraoperatively, the location of the descending genicular artery (DGA) was detected using Doppler ultrasound. When harvesting the flap, the P point (SP-p) was used as the centre to form an arteriovenous pedicle. A matching medial femoral condyle flap was designed to reconstruct the bone defect. The free flap (25 patients) or chimeric flap (6 patients) was transferred to the recipient site, and end-to-end vessel anastomoses were performed to establish the blood supply. After surgery, the patients were kept in bed for 7-9 days. Antibiotics were routinely administered to prevent infection, together with a symptomatic anticoagulation and anti-spasm treatment. The colour, temperature, capillary refilling and tension of the flap were closely observed. All patients were entered in postoperative follow-up at outpatient clinic for review at 1, 3, and 6 months after surgery to observe the appearance, texture and function of the flaps and the condition of the donor sites.Results:Through anatomy observation, cutaneous perforating branch of DGA was located in front of the main trunk of the GSV at the plane of medial femoral condyle. It was found that both of the perforators of cutaneous artery and the branches of osteoarticular artery originated from the DGA. Distance between SP-p and S-p(DSPS) of fresh samples was 2.9-4.1 (3.6±0.5) cm. The DSPS of 31 patients measured in surgery was 2.9-4.3 (3.7±0.4) cm. A total of 30 flaps survived completely. One flap had partial necrosis, which healed at 2 weeks after skin grafting. The postoperative follow-up lasted for 6-48 (mean, 11.23) months. X-rays of 5 patients with chimeric bone flaps showed the healing of bone defects at 3 months after surgery. All donor sites were directly sutured and left with linear scars after healing, except 5 donor sites that received skin grafting. Eight patients received further flap thinning surgery at 3 to 12 months after primary surgery without any complication. All donor sites healed well without numbness.Conclusion:If the GSV is preserved during harvest of a DGAPF(-Ch), it causes less damage to the donor site and does not affect the survival of the flap. The DGAPF(-Ch) without GSV is a better method in the surgical treatment of complex tissue defects.