Factors affecting polyglycolic acid sheet engraftment success for covering mucosal defects from head and neck surgery.

BACKGROUND: Polyglycolic acid (PGA) sheets have been used with fibrin glue to cover extensive mucosal defects in oral and pharyngeal surgery; however, the sheets can fall off before wound healing is completed. Hence, prolonged fasting is often recommended in such patients. However, there are few studies on the factors that shape PGA sheet engraftment. We studied sheet engraftment rates considering these factors. METHODS: All consecutive cases of oral surgery in 2013-21 in which the defect was covered with fibrin glue and Neoveil® or Neoveil Nano® PGA sheets were identified. The loss of all sheets was defined as an engraftment failure. Multiple logistic regression analysis was conducted to identify whether the PGA-sheet type, application site, defect size and postoperative fasting duration predicted engraftment. RESULTS: Overall, 137 patients were identified (mean age, 73 years; 57% male). The surgeries were conducted with Neoveil® in 66% of the patients; the most common site was the buccal mucosa (25%), and the mean defect size and fasting duration were 709 mm2 and 4 days, respectively. The engraftment rate was 76%. Neoveil Nano® PGA sheets were associated with a 2.8-fold better engraftment rate than Neoveil® (univariate: 87 vs. 70%, P = 0.032; multivariate: 95% confidence intervals = 1.067-7.410, P = 0.036). Other variables, including fasting duration, were not predictive of engraftment. CONCLUSIONS: This is the largest case series of patients with head and neck cancer who underwent fibrin glue-PGA sheet defect coverage. The fasting duration did not influence engraftment. Therefore, early oral intake is not contraindicated in such patients.

Clinical assessment of early mobilization after head and neck free flap reconstruction: A retrospective case-control study.

PURPOSE: We examined whether there were any differences in perioperative complications between patients who mobilized on the first postoperative day (early mobilization) and those who mobilized on the second postoperative day after head and neck reconstruction using free tissue transfer. METHODS: In the control group (n = 74), patients were instructed to mobilize on the second postoperative day (April 2019-March 2020), while in the early mobilization group (n = 101), patients were instructed to mobilize on the first postoperative day (April 2020-March 2021). Mobilization was defined as maintaining a standing position or walking. Clinical data were collected from medical records and retrospectively analyzed. RESULTS: There were no significant differences in clinical background factors, with the exception of intraoperative blood loss volume. The proportion of patients who successfully mobilized on the day of instruction was significantly lower in the early mobilization group (89.1% vs. 98.7%). One case of total flap loss and four cases of partial flap loss occurred in the control group, and three cases of partial flap loss occurred in the early mobilization group. There was no significant difference in partial or total flap loss between the two groups. There were no significant differences in other perioperative complications (wound infection, postoperative bleeding, and delirium) between the two groups. The median postoperative hospital stay was 24.5 and 25.0 days in the control and early mobilization groups, respectively. CONCLUSION: In this study, early mobilization on the first day after head and neck free flap reconstruction was safe and feasible.

Anterior Neck-scar Contracture Reconstruction Using a Long Skin-pedicled Flap.

We previously reported cases of anterior-neck reconstruction using super-thin and perforator-supercharged skin-pedicled flaps harvested from the pectoral area and back. Here, we reconstructed a neck-scar contracture with a long skin-pedicled flap from the pectoral area that survived without congestion despite not being supercharged with a perforator, as planned. The patient, a 67-year-old man, was admitted to our hospital due to neck-scar contracture after a chemical burn 3 years previously. During surgery, the scar was resected above the platysma. A large, 19 × 6-cm skin-pedicled flap was elevated from the left pectoral area. We planned to supercharge the flap by anastomosing the second intercostal perforator to the flap periphery but could not confirm the perforator intraoperatively. To promote flap survival, we did not elevate the flap pedicle more than absolutely necessary and then manipulated the flap very carefully. The flap survived fully and the contracture was effectively released. Thin flaps are useful for reconstructing exposed areas such as the face, neck, and dorsum of the hands that require good outcomes in terms of both function and aesthetics. However, if the flap is too large, ischemia/congestion could arise in the periphery unless the blood flow is stabilized by attaching a perforator. In our case, supercharging was not possible and we had to resort to careful intraoperative maneuvers to ensure flap survival. This approach was successful and suggests that although supercharging of thin and large flaps is preferred, unexpectedly unsuperchargeable flaps can be rescued by careful and finely tuned surgical judgment and techniques.

The Immunosuppressant Fingolimod (FTY720) for the Treatment of Mechanical Force-Induced Abnormal Scars.

AIM: Abnormal scars such as hypertrophic scars (HSs) and keloids are excessively growing scars that exhibit chronic inflammation and capillary vasculogenesis. The lipid mediator sphingosine-1-phosphate (S1P) is important in inflammatory cell recruitment and angiogenesis. Fingolimod (FTY720) is an analog of S1P and thus functionally antagonizes S1P receptors and inhibits the enzyme that produces S1P. We examined the effects of topical FTY720 injections on mechanical force-induced HS progression. METHODS: Mechanical force-induced HSs were generated in C57BL6/J mice by suturing a dorsal incision and applying a stretching device on Days 6, 8, 10, and 12. On Days 8, 10, and 12, intracutaneous FTY720 (10 µM) or control vehicle injections were performed. On Day 14, scar tissues and blood were procured and subjected to histology and flow cytometry. RESULTS: Flow cytometry showed that FTY720 decreased the frequencies of macrophages with M2 predominance in the scars but had no effect on total, CD4+, or CD8a+ T cell frequencies. FTY720 also decreased the vascular endothelial cell frequencies in the scar along with the microvessels, as determined by immunohistochemistry. Compared to the vehicles, FTY720 treatment significantly reduced the gross scar area and the cross-sectional scar area on histology. On the other hand, FTY720 tended to reduce white blood cells and significantly reduced the lymphocyte frequencies in the blood. CONCLUSION: Topical FTY720 induces M2 predominance and impairs angiogenesis. Therefore, its local immunosuppressive mechanisms differ from those of conventional immunosuppressive agents. Topical FTY720 can be a novel therapeutic option for abnormal scars that are difficult to control with corticosteroids. Its lymphocytopenic effects may be limited by careful optimization of the treatment regimen.