Expanded polytetrafluoroethylene implants for soft-tissue augmentation: 5-year follow-up and literature review

Heparin/Collagen-REDV Modification of Expanded Polytetrafluoroethylene Improves Regional Anti-thrombosis and Reduces Foreign Body Reactions in Local Tissues

Prosthetic implants of expanded polytetrafluoroethylene (ePTFE) in the cardiovascular system have a high failure rate over the long term because of thrombosis and intimal hyperplasia. Although multiple surface modification methods have been applied to improve the anti-thrombotic and in situ endothelialization abilities of ePTFE, none have delivered outstanding results in vivo. Our previous study combined heparin/collagen multilayers and REDV peptides to modify ePTFE, and the in-vitro results showed that modification ePTFE with heparin/collagen-REDV can promote the cytocompatibility and antiplatelet property. This study illustrated the physical change, selective endothelial cells capture ability, and in vivo performance in further. The physical test demonstrated that this modification improved the hydrophilicity, flexibility and strength of ePTFE. A competition experiment of co-cultured endothelial cells and vascular smooth muscle cells verified that the heparin/collagen-REDV modification had high specificity for endothelial cell capture. A rabbit animal model was constructed to evaluate the in vivo performance of modified ePTFE implanted in the right ventricular outflow tract. The results showed that heparin/collagen-REDV modification was safe, promoted endothelialization, and successfully achieved regional anti-thrombosis without influencing body-wide coagulation function. The pathologic manifestations and mRNA expression pattern in tissues in contact with modified ePTFE indicated that this modification method may reduce M2-type macrophage infiltration and the expression of genes related to immune and inflammatory responses. The heparin/collagen-REDV modification may lower the incidence of complications related to ePTFE implantation and has good prospects for clinical use.

Palliative Surgical Management of a Metastatic Lesion of the Tibia with Extension into the Popliteal Fossa Using Polytetrafluoroethylene Felt and Bone Cement

The treatment of metastatic bony lesions with the involvement of adjacent neurovascular structures presents a surgical challenge. We present—to the best of our knowledge—the first case of a patient suffering from a metastatic lytic lesion at the proximal tibia who underwent palliative treatment with the use of a polytetrafluoroethylene (PTFE) felt as a liner in order to preserve the adjacent vasculature and nerves. An 82-year-old female patient was diagnosed with multiple lytic bone metastases from renal cell carcinoma. One of these metastatic lesions was located at the proximal metaphysis of the left tibia. The lesion destructed the proximal metaphyseal part and the posterior cortex, and it was extending into the popliteal fossa. As a result, the patient was unable to bear weight. The patient was not fit to undergo radical operative treatment. As a means of palliative therapy, she underwent intralesional curettage and instillation of Poly-Methyl-Methacrylate (PMMA) bone cement using an alternative novel surgical technique with the use of a PTFE felt as a liner in order to protect the adjacent vasculature and nerves. This technique has proven to be successful in preventing cement leak into the popliteal cavity and efficient in allowing the patient to bear weight and walk independently until she demised 14 months later. The use of a PTFE felt as a liner, when treating lytic lesions, in order to protect the adjacent vasculature and nerves from PMMA leakage, is a helpful novel surgical option in cases when a radical treatment cannot be implemented.

Use of a Hyaluronic Acid Soft-tissue Filler to Correct Congenital and Post-traumatic Lip Asymmetry

Background:

The use of hyaluronic acid soft-tissue fillers for enhancement of lip features is a popular and minimally invasive office-based procedure used worldwide due to its relative simplicity and favorable safety profile.

Materials and Methods:

Hyaluronic acid was used in illustrative cases to attempt correction of congenital and acquired lip asymmetries.

Results:

In the cases presented, accurate and cosmetically acceptable results were attained and maintained for the duration of the product life.

Conclusions:

Hyaluronic acid may be used successfully when lip asymmetry is evident and is a relatively simple nonsurgical alternative.