Management of deep sacral and ischial pressure injuries with free-style local perforator flaps: A D+P+DPD model.

BACKGROUND: Previous reports on the treatment of sacral and ischial pressure injuries have not provided clear algorithms for surgical therapies. The objective of this study was to establish a reconstruction algorithm to guide the selection of an ideal free-style perforator flap that can be tailored to the defect in question. METHODS: We used 23 perforator flaps to reconstruct 14 sacral and 8 ischial defects in 22 patients over 5 years. A reconstruction algorithm system was developed based on the anatomical features of the perforator vessels (diameter, D; pulsatility [++∼+++], P) and their position in the skin island (DPD) (ie, D+P+DPD). A perforator-based propeller flap was applied as the first-line choice; if this plan was not feasible, we applied an altered V-Y advancement model or another second-choice technique. RESULTS: All flaps survived, and only 1 patient experienced partial wound dehiscence, which healed by secondary intention. After an average follow-up period of 11.2 months, no patient experienced recurrence or infection. CONCLUSIONS: Free-style perforator flap selection is determined by pressure injury and the desired advantage of a specific approach. The use of free-style perforator-based propeller flaps allows a surgeon to transfer healthy tissue into the defect, shifts the suture line away from the bony prominence, and preserves additional future donor sites. In cases where unexpected variations are encountered, the V-Y advancement model or another technique can be used. The simplified surgical algorithm (D+P+DPD) can provide versatility and reliability, achieve a durable, natural esthetic outcome, and minimize injuries to future donor sites.

A modified perforator-based stepladder V-Y advancement flap in the Achilles tendon area for coverage of larger posterior heel defects.

BACKGROUND: Posterior heel defect coverage is challenging because of the paucity of suitable flaps. The traditional local stepladder V-Y advancement flap is recommended only for small defects because of the lack of an axial pedicle. This study reports our experience of using the perforator-based stepladder V-Y advancement flaps in a larger posterior heel defect repair. METHODS: Twenty-two patients with posterior heel defects were treated with modified perforator-based stepladder V-Y advancement flaps in the Achilles tendon area for 11 years. Sixteen males and six females aged 3-74 years underwent surgery. The defect size, perforator characteristics, flap size, flap movement, sural nerve, lesser saphenous vein, deep fascia, flap survival, and outcome quality were analyzed. RESULTS: The perforators were found to predominate within two 2-cm intervals: 0-2 cm and 4-6 cm proximal to the tip of the lateral malleolus. Twenty-one perforator-based flaps healed uneventfully, and only one developed tip necrosis on the lower edge, which healed by secondary intention. The maximum distance of distal movement was 5.0 cm for the modified flap in contrast to 2.5 cm for the traditional flap. All flaps allowed adequate and durable reconstruction to be achieved, with excellent contouring after 2-28 months of follow-up. CONCLUSIONS: The perforator-based stepladder V-Y advancement flap resulted in good outcomes for larger posterior heel defects compared with conventional transfer methods. The flap is a reliable, well-vascularized, sensate, and pliable local flap option that uses similar tissue from adjacent skin for defect repair and creates an internal gliding surface for the Achilles tendon.

A new skin flap from the zygomaticotemporal region: Anatomical study and clinical application to eyelid reconstruction.

BACKGROUND: Eyelid reconstruction is a demanding task faced by plastic surgeons. Island flaps from the zygomaticotemporal region, where the zygomatico-orbital artery predominates in vascularization, represent the recent local approaches to this problem. Questions exist as to where and on what element the flap should be based, and whether or not they should be adapted in relation to the behavior of the zygomatico-orbital artery. METHODS AND MATERIALS: A total of 22 fresh-frozen adult cadaver heads were employed. The fasciocutaneous perforators of the zygomatico-orbital artery and their anastomoses with the surrounding arteries, especially those in the upper palpebra, were investigated. On this basis, a distally based perforator flap was created and executed for eyelid reconstruction in 7 patients. RESULT: The zygomatico-orbital artery was interconnected through its perforators with the subdermal plexus over the zygomaticotemporal region and with the arteries in the surroundings. The transverse facial artery took the place of zygomatico-orbital artery where it was absent. Both the arteries anastomosed consistently with the superficial orbital arcade at a predictable site. All 7 flaps survived completely. CONCLUSION: A new distally based perforator flap from the zygomaticotemporal region is described regarding its anatomical basis and clinical applications to eyelid reconstruction. With a vascular axis consistently present and a pivot adjacent to the defects, the flap is more reliable in vascularization, and less harm to its donor site than orbicularis oculi myocutaneous flaps, and poses no concern about whether the zygomatico-orbital artery is present or not.

Flap failure prediction in microvascular tissue reconstruction using machine learning algorithms.

BACKGROUND: Microvascular tissue reconstruction is a well-established, commonly used technique for a wide variety of the tissue defects. However, flap failure is associated with an additional hospital stay, medical cost burden, and mental stress. Therefore, understanding of the risk factors associated with this event is of utmost importance. AIM: To develop machine learning-based predictive models for flap failure to identify the potential factors and screen out high-risk patients. METHODS: Using the data set of 946 consecutive patients, who underwent microvascular tissue reconstruction of free flap reconstruction for head and neck, breast, back, and extremity, we established three machine learning models including random forest classifier, support vector machine, and gradient boosting. Model performances were evaluated by the indicators such as area under the curve of receiver operating characteristic curve, accuracy, precision, recall, and F1 score. A multivariable regression analysis was performed for the most critical variables in the random forest model. RESULTS: Post-surgery, the flap failure event occurred in 34 patients (3.6%). The machine learning models based on various preoperative and intraoperative variables were successfully developed. Among them, the random forest classifier reached the best performance in receiver operating characteristic curve, with an area under the curve score of 0.770 in the test set. The top 10 variables in the random forest were age, body mass index, ischemia time, smoking, diabetes, experience, prior chemotherapy, hypertension, insulin, and obesity. Interestingly, only age, body mass index, and ischemic time were statistically associated with the outcomes. CONCLUSION: Machine learning-based algorithms, especially the random forest classifier, were very important in categorizing patients at high risk of flap failure. The occurrence of flap failure was a multifactor-driven event and was identified with numerous factors that warrant further investigation. Importantly, the successful application of machine learning models may help the clinician in decision-making, understanding the underlying pathologic mechanisms of the disease, and improving the long-term outcome of patients.

The effect of inhibiting exosomes derived from adipose-derived stem cells via the TGF-ß1/Smad pathway on the fibrosis of keloid fibroblasts.

BACKGROUND: The main mechanism of keloid formation is that keloid fibroblasts (KFs) apoptosis is inhibited, leading to excessive proliferation. Transforming growth factor-ß1 (TGF-ß1) is a key signal molecule in the process of regulating cell fibrosis. This paper discusses the effect of adipose-derived stem cell exosomes (ADSCs-EXO) on the proliferation and apoptosis of KFS and its possible mechanism, in order to provide reference for the clinical intervention of hypertrophic scar. METHODS: ADSCs were isolated and cultured from human adipose tissue, the supernatant was collected, and the exosomes secreted by ADSCs-EXO were extracted by ultracentrifugation. At the same time, KFs were cultured from human keloid tissue to P3 generation, and then divided into four groups: control group, experimental group A, experimental group B and experimental group C. KFs were then cultured with four concentrations of ADSCs-EXO (0, 1, 10, and 100 µg/mL, respectively). After 24 hours, cells in each group were taken to detect the following: proliferation of cells in each group using the cell counting Kit 8 (CCK-8) method, cell migration ability via the Transwell test, cell apoptosis by flow cytometry, collagen synthesis using the hydroxyproline method, messenger ribonucleic acid (mRNA) expression of fibrosis-related genes in each group by real-time fluorescent polymerase chain amplification, and the expression of fibrosis-related proteins in the cells of each group by western blotting. RESULTS: Compared with the control group, the proliferation rate, migration rate, and collagen synthesis levels in the three experimental groups decreased with the increase of ADSCs-EXO concentration, while the apoptosis rate in the three experimental groups increased with the increase of ADSCs-EXO concentration, and the differences were statistically significant (P<0.05). Also, compared with the control group, the relative mRNA and protein expression of alpha-smooth muscle actin (α-SMA), TGF-ß1, and Smad3 in the three groups decreased significantly, while the expression of three kinds of mRNA and protein decreased with the increase of ADSCs-EXO concentration, and the differences were statistically significant (P<0.05). CONCLUSIONS: ADSCs-EXO may inhibit the proliferation and migration, and promote the apoptosis of KFs by inhibiting the expression of the TGF-ß1/Smad pathway.

Lateral calcaneal artery perforator-based skin flaps for coverage of lower-posterior heel defects.

BACKGROUND: Perforator-based flaps have been explored across almost all of the lower leg except in the Achilles tendon area. This paper introduced a perforator flap sourced from this area with regard to its anatomic basis and clinical applications. METHODS: Twenty-four adult cadaver legs were dissected to investigate the perforators emerging along the lateral edge of the Achilles tendon in terms of number and location relative to the tip of the lateral malleolus, and distribution. Based on the anatomic findings, perforator flaps, based on the perforator(s) of the lateral calcaneal artery (LCA) alone or in concert with the perforator of the peroneal artery (PA), were used for reconstruction of lower-posterior heel defects in eight cases. Postoperatively, subjective assessment and Semmes-Weinstein filament test were performed to evaluate the sensibility of the sural nerve-innerved area. RESULTS: The PA ended into the anterior perforating branch and LCA at the level of 6.0 ± 1.4 cm (range 3.3-9.4 cm) above the tip of the lateral malleolus. Both PA and LCA, especially the LCA, gave rise to perforators to contribute to the integument overlying the Achilles tendon. Of eight flaps, six were based on perforator(s) of the LCA and two were on perforators of the PA and LCA. Follow-up lasted for 6-28 months (mean 13.8 months), during which total flap loss and nerve injury were not found. Functional and esthetic outcomes were good in all patients. CONCLUSION: The integument overlying the Achilles tendon gets its blood supply through the perforators of the LCA primarily and that of through the PA secondarily. The LCA perforator(s)-based and the LCA plus PA perforators-based stepladder flap is a reliable, sensate flap, and should be thought of as a valuable procedure of choice for coverage of lower-posterior heel defects in selected patients.