[Clinical effects of flaps or myocutaneous flaps transplantation after titanium mesh-retaining debridement in repairing the wounds with exposed titanium mesh after cranioplasty]

Objective: To explore the clinical effects of flaps or myocutaneous flaps transplantation after debridement to repair the wounds with exposed titanium mesh after cranioplasty on the premise of retaining the titanium mesh. Methods: This study was a retrospective observational study. From February 2017 to October 2022, 22 patients with titanium mesh exposure after cranioplasty who met the inclusion criteria were admitted to the Department of Plastic, Aesthetic & Maxillofacial Surgery of the First Affiliated Hospital of Xi'an Jiaotong University, including 15 males and 7 females, aged from 19 to 68 years. After admission, treatments such as bacterial culture of wound exudate sample, anti-infection, and dressing change were carried out. Thorough surgical debridement was performed when the wound improved, and the wound area was 3.0 cm×2.0 cm to 11.0 cm×8.0 cm after debridement. The wound was repaired with local flaps, expanded flaps, or free latissimus dorsi myocutaneous flaps according to the size, location, severity of infection, and surrounding tissue condition of the wounds, and the areas of flaps or myocutaneous flaps were 5.5 cm×4.0 cm to 18.0 cm×15.0 cm. The donor areas of flaps were sutured directly or repaired by split-thickness skin grafts from head. The wound repair method was recorded. The survivals of flaps or myocutaneous flaps after surgery and wound healing in 2 weeks after surgery were recorded. During postoperative follow-up, recurrence of infection or titanium mesh exposure in the implanted area of titanium mesh was observed; the head shapes of patients, scar formation of the operative incision, and baldness were observed. At the last follow-up, the satisfaction of patients with the treatment effect (dividing into three levels: satisfied, basically satisfied, and dissatisfied) was evaluated. The total treatment costs of patients during their hospitalization were calculated. Results: The wounds in 11 cases were repaired with local flaps, the wounds in 5 cases were repaired with expanded flaps, and the wounds in 6 cases were repaired with free latissimus dorsi myocutaneous flaps. All flaps or myocutaneous flaps survived completely after surgery, and all wounds healed well in 2 weeks after surgery. Follow up for 6 to 48 months after operation, only one patient with local flap grafting experienced a recurrence of infection in the titanium mesh implanted area at more than one month after surgery, and the titanium mesh was removed because of ineffective treatment. Except for one patient who had a local depression in the head after removing the titanium mesh, the rest of the patients had a full head shape. Except for myocutaneous flap grafting areas in 6 cases and skin grafting area in 1 case with local flaps grafting had no hair growth, the other patients had no baldness. All the scars in surgical incision were concealed. At the last follow-up, 19 cases were satisfied with the treatment effects, 2 cases were basically satisfied, and 1 case was dissatisfied. The total treatment cost for patients in this group during hospitalization was 11 764-36 452 (22 304±6 955) yuan. Conclusions: For patients with titanium mesh exposure after cranioplasty, on the premise of adequate preoperative preparation and thorough debridement, the wound can be repaired with appropriate flaps or myocutaneous flaps according to the wound condition. The surgery can preserve all or part of the titanium mesh. The postoperative wound healing is good and the recurrence of infection or titanium mesh exposure in the titanium mesh implanted area is reduced, leading to good head shape, reduced surgical frequency, and decreased treatment costs.

[Clinical effects of free pre-expanded internal thoracic artery perforator pedicled deltopectoral flap transfer in facial scar reconstruction]

Objective: To explore the clinical effects of free pre-expanded deltopectoral flap transfer in facial scar reconstruction by selecting appropriate internal thoracic artery perforator as the pedicle through preoperative color Doppler ultrasonic vascular assessment. Methods: A retrospective observational study was conducted. From September 2017 to March 2021, 11 patients with facial scar who met the inclusion criteria were admitted to the First Affiliated Hospital of Xi'an Jiaotong University, including 6 males and 5 females, aged 16-58 (31±12) years. The scar with area ranging from 7 cm×5 cm to 14 cm×9 cm was reconstructed by free pre-expanded internal thoracic artery perforator pedicled deltopectoral flap transfer. The operation was performed in 2 or 3 stages. Before operation, color Doppler ultrasonography was performed to evaluate the internal thoracic artery perforator. In the first stage, skin and soft tissue expander (hereinafter referred to as expander) implantation was performed, and a cylindrical expander with rated capacity of 400 to 600 mL was placed in the chest wall. The expansion time was 3 to 4 months, and the water injection volume reached 1.2-1.5 times of the rated capacity of expander. In the second stage, scar excision+free pre-expanded deltopectoral flap transfer was performed, with harvested flap area ranging from 9 cm×7 cm to 16 cm×10 cm. The vascular pedicle of flap (intercostal perforator of internal thoracic artery) was anastomosed end-to-end to the facial artery and vein or superficial temporal artery and vein. The wound in donor site was closed directly. Third stage operation thinning was performed at 3-6 months after the second stage operation in 5 patients because of bloated flap pedicle. At 6 months after the last operation, the flap survival and complications were recorded, the sensation of flap was evaluated by Semmes-Weinstein monofilament test, the color of flap was evaluated by color contrast of the flap to surrounding normal skin, and the curative effect satisfaction degree of patients was evaluated by 5-grade Likert scale. Results: At 6 months after the last operation, all the flaps of 11 patients survived well. One patient experienced venous congestion after flap transplantation, but the flap survived after re-anastomosis. One patient experienced hematoma after the first stage operation of expander implantation, but the rest treatment was not influenced after hematoma removal. No complications such as infection or expander exposure occurred in any patient. At 6 months after the last operation, the sensation of flap of patient was as follows: 9 cases recovered to protective sensation decrease or better, 1 case had protective sensation defect, and 1 case only had deep touch and pressure sensation; the color of flap of patient was as follows: 3 cases were very close to the color of surrounding normal skin, 6 cases were close to the color of surrounding normal skin, and 2 cases were different to the color of surrounding normal skin; the curative effect satisfaction degree of patients was as follows: 2 patients were very satisfied, 6 patients were satisfied, 2 patients were somewhat satisfied, and 1 patient was a little not satisfied. Conclusions: The large area facial scar can be treated safely and effectively by free pre-expanded deltopectoral flap with appropriate single internal thoracic artery perforator as vascular pedicle selected through vascular assessment by color Doppler ultrasonography before operation. After operation, the color of flap of patients is close to the surrounding normal skin and the sensation of flap can be partially recovered, with high curative effect satisfaction degree of patients.

VEGF gene therapy for the survival of transplanted fat tissue in nude mice

The objective of this study was to determine the effects of adenovirus-mediated vascular endothelial growth factor (Ad-VEGF) on the angiogenesis and survival of free-fat tissue transplantation in nude mice. Thirty 6-week-old CD-1 nude male mice were injected with 1ml fat tissue (harvested by suction-assisted lipectomy from the breast of humans) in the subcutaneous of scalp and were randomised into three groups of 10 animals each. Group 1 was the study group, in which Ad-VEGF was mixed with transplanted fat tissue and injected into mice. In group 2, adenovirus-mediated green fluorescent protein (Ad-GFP) gene was mixed with transplanted fat tissue and injected into the mice. In group 3, normal saline alone was used. Both group 2 and group 3 are control groups. The animals were euthanised 15 weeks after the procedure. The fat survival weight and volume of the study group were significantly greater than those of two control groups (p<0.05). Light microscopical examination of haematoxylin and eosin-stained slides of the dissected fat 15 weeks after injection was performed in group 1 and group 2. Less cyst formation and fibrosis, indicating improved quality of the injected fat, can be obtained by the addition of Ad-VEGF. Vascular density was evaluated at the microvascular level through the use of light microscopic sections of the central part of the fat tissue at 15 weeks after injection by von Willebrand factor staining. Histological evaluation showed that capillary density increased markedly in the study group mice. Mice of the study group disclosed significantly higher VEGF protein levels detected by ELISA assay of plasma samples obtained from the mice after the fat injection (day 1, 4, 7 and 28; p<0.01) at each time point than the mice of the two control groups. The findings reported in this study indicate that the VEGF gene therapy can enhance the survival and the quality of grafted fat tissue, which may be due to induction of angiogenesis.