Evaluation of viscoelastic parameters and photo-based assessment of newly developed dermal substitutes modified with thermostabilized fibroblast growth factor 2.

BACKGROUND: The purpose of dermal substitutes is to mimic the basic properties of the extracellular matrix of human skin. The application of dermal substitutes to the defect reduces the formation of hypertrophic scars and improves the scar quality. This study aims to develop an original dermal substitute enriched with stable fibroblast growth factor 2 (FGF2-STAB®) and test it in an animal model. METHODS: Dermal substitutes based on collagen/chitosan scaffolds or collagen/chitosan scaffolds with nanofibrous layer were prepared and enriched with FGF2-STAB® at concentrations of 0, 0.1, 1.0, and 10.0 µg ‧ cm-2. The performance of these dermal substitutes was tested in vivo on artificially formed skin defects in female swine. The outcomes were evaluated using cutometry at 3 and 6 months. In addition, visual appearance was assessed based on photos of the scars at 1-month, 3-month and 6-month follow-ups using Yeong scale and Visual Analog Scale. RESULTS: The dermal substitute was fully integrated into all defects and all wounds healed successfully. FGF2-STAB®-enriched matrices yielded better results in cutometry compared to scaffolds without FGF2. Visual evaluation at 1, 3, and 6 months follow-ups detected no significant differences among groups. The FGF2-STAB® effectiveness in improving the elasticity of scar tissues was confirmed in the swine model. This effect was independently observed in the scaffolds with nanofibres as well as in the scaffolds without nanofibres. CONCLUSION: The formation of scars with the best elasticity was exhibited by addition 1.0 µg ‧ cm-2of FGF2-STAB® into the scaffolds, although it had no significant effect on visual appearance at longer follow-ups. This study creates the basis for further translational studies of the developed product and its progression into the clinical phase of the research.

Comparison of contraction-type and noncontraction-type lymphatic vessels in lymphaticovenous anastomosis for cancer-related unilateral lower limb lymphedema: a retrospective cohort propensity-score-matched outcome analysis.

BACKGROUND: Contraction-type lymphatic vessels (LV) are considered suboptimal for lymphaticovenous anastomosis (LVA). However, despite these pathological changes, their functionality and link to outcomes have not been fully elucidated. The aim of this study was to determine the impact on outcomes when contraction-type LVs were used for LVA compared to the noncontraction-type (normal + ectatic) counterpart for treating lower limb lymphedema. STUDY DESIGN: Eighty-three patients with gynecologic cancer-related unilateral lower-limb lymphedema who underwent LVA as their primary treatment were enrolled in this study. The study group included 20 patients who used only contraction-type LVs. An additional 63 patients (control group) received noncontraction-type LVs only. Patients with a history of LVA, liposuction, or excisional therapy were excluded. Patient characteristics, intraoperative findings, functional parameters, and pre-LVA and post-LVA volume changes were recorded and matched using propensity scores. The primary endpoint was the volume change at 6/12 months after LVA. RESULTS: After matching, 20 patients were included in each group. All parameters were matched, except that the study group still had a significantly inferior indocyanine green (ICG)-positive ratio, lymph flow-positive ratio, and washout-positive ratios ( P <0.001, P =0.003, and P <0.001, respectively) when compared to the control group after matching. However, at 1-year follow-up, the postoperative percentage volume reduction was comparable between the groups ( P= 0.619). CONCLUSION: The use of contraction-type LVs for LVA is encouraged when no other LVs are available.

An Algorithm in Managing Deep Inferior Epigastric Vessel Interruption in Free Flap Breast Reconstruction.

Previous surgical procedures in the abdomen are no longer contra-indications for free flap breast reconstruction using the deep inferior epigastric artery perforator flap. Nonetheless, a possible consequence of previous surgical procedures may be trauma to the deep inferior epigastric (DIE) pedicle, leading to interruption. In these cases, a modification in operative strategy may be required. Methods: A study was performed across two centers, during a 10-year period between January 1, 2010 and December 2019. Patient and outcome data were collected from the patient file and operation notes. Results: Four cases with clear evidence of DIE pedicle interruption were found, with an average age of 54 years and an average body mass index of 28.9. Three patients had a preoperative diagnosis of DIE pedicle interruption on CT angiography, whereas in one case this was found peroperatively. For three cases, unilateral reconstruction was performed, and for one, bilateral reconstruction. Four flaps (in three cases) were unipedicled; the contralateral DIE pedicle was used in three, and the superficial system was used in one. For the bipedicled case, two hemiflaps were used, with the interrupted DIE pedicle anastomosed to a branch of the contralateral DIE pedicle. Conclusions: Interrupted DIE vessels remain a challenge for free flap breast reconstruction. The four cases demonstrated in this article highlight different surgical strategies, with an emphasis on detailed preoperative planning, including CT angiography. We present an algorithm to aid the reader in approaching cases with an interrupted DIE pedicle.

Accelular nanofibrous bilayer scaffold intrapenetrated with polydopamine network and implemented into a full-thickness wound of a white-pig model affects inflammation and healing process.

Treatment of complete loss of skin thickness requires expensive cellular materials and limited skin grafts used as temporary coverage. This paper presents an acellular bilayer scaffold modified with polydopamine (PDA), which is designed to mimic a missing dermis and a basement membrane (BM). The alternate dermis is made from freeze-dried collagen and chitosan (Coll/Chit) or collagen and a calcium salt of oxidized cellulose (Coll/CaOC). Alternate BM is made from electrospun gelatin (Gel), polycaprolactone (PCL), and CaOC. Morphological and mechanical analyzes have shown that PDA significantly improved the elasticity and strength of collagen microfibrils, which favorably affected swelling capacity and porosity. PDA significantly supported and maintained metabolic activity, proliferation, and viability of the murine fibroblast cell lines. The in vivo experiment carried out in a domestic Large white pig model resulted in the expression of pro-inflammatory cytokines in the first 1-2 weeks, giving the idea that PDA and/or CaOC trigger the early stages of inflammation. Otherwise, in later stages, PDA caused a reduction in inflammation with the expression of the anti-inflammatory molecule IL10 and the transforming growth factor ß (TGFß1), which could support the formation of fibroblasts. Similarities in treatment with native porcine skin suggested that the bilayer can be used as an implant for full-thickness skin wounds and thus eliminate the use of skin grafts.

Use of free radial forearm and pronator quadratus muscle flap: Anatomical study and clinical application.

The authors present an anatomical study and clinical experience with radial forearm flap (RFF) and pronator quadratus muscle (PQM) application in the reconstruction of various body areas. The aim was to describe the anatomical placement and proportions of the PQM, the anatomical location of the major arterial branch of the radial artery supplying the PQM, and the application of this knowledge in clinical practice. The anatomical study was based upon an analysis of 13 fresh adult cadaver upper extremities, of which nine were female and four male; both arms from the same donors were used in four cases. The study of the PQM was performed using a dye-containing intraarterial injection, standard macro- and micro-preparation techniques, and chemical digestion. The data on the PQM size in males and females, thickness of the radial artery branch (the principal artery nourishing the muscle), and its position were analysed. The radial artery branch nourishing the PQM was identified in all cadaveric specimens of the anatomical study. In addition, 12 patients underwent reconstructions of soft and bony tissue defects using a RFF + PQM (pedicled or free flap). The radial artery branch perfusing the PQM was identified in all cases. The flap was used for the management of defects of the head (seven cases), arm (three cases) and lower leg (two cases). The harvest site healed well in all cases and, with the exception of one case in which a partial necrosis of the flap was observed, all flaps remained viable, which demonstrated the safety of the method.

Development of a questionnaire for a patient-reported outcome after nasal reconstruction.

INTRODUCTION: Our face plays an important role in communication and social life. Defects of the face have a big impact on socializing and psychics of patients with its deformities. A good esthetic outcome is an important task of each reconstructive surgery. With a modern concept of nose reconstruction, it is possible to achieve a better esthetic and functional outcome than it was possible with one phase reconstructions before. There was a specific tool missing to measure patients reported outcome and objectively evaluate benefits of nose reconstruction from a patients point of view and get reliable feedback about the whole procedure.  The goal of this paper is to develop such a questionnaire. MATERIALS AND METHODS: A pilot questionnaire was developed with literature input. The questionnaire was tested on five patients. Based on patients feedback and a review from a psychologist, the second version of the questionnaire was made. It was sent to 39 patients, who underwent nose reconstruction in the years 2016-2020. After two appeals, 34 completed questionnaires were sent back (87,2%). The final version of the questionnaire was developed after a thorough mathematic and statistical analysis of collected data. RESULTS: The group of patients who completed the questionnaire consisted of 16 females (47%) and 18 males (53%). On average, the patients were 69 years old (17-88 years). The final questionnaire is structured into six categories from A to F: A - general information defining the patient and purpose for reconstruction, B - satisfaction with esthetic outcome, C - satisfaction with function and stability, D - satisfaction with medical treatment, E - social and psychological impact, F - overall satisfaction. Most of the questions use a 5-point rating scale. CONCLUSION: The questionnaire enables the patients to provide feedback on particular aspects of the treatment and their overall satisfaction with the whole procedure and its outcome. With statistical analysis, it is possible to discover specific treatment aspects that have crucial impact on overall satisfaction with the whole procedure. A patient-reported outcome helps to improve the quality of provided health care and the quality of patient life.

Long-term donor-site morbidity after thumb reconstruction with twisted-toe technique.

BACKGROUND: Traumatic thumb loss is a serious injury affecting patient´s ability to work and participate in activities of daily life. The main goal for a plastic surgeon is to restore hand grip, often by microsurgical methods. However, patients should be informed of all effects associated with tissue harvesting. The aim of the study was to assess the impact on donor foot and gait cycle in patients who have undergone thumb reconstruction using twisted-toe technique modified by Kempný. MATERIAL AND METHODS: Twelve patients participated in the study: all suffered a thumb loss between the years 2003 and 2011 and the twisted-toe technique for thumb reconstruction was utilized. The changes in foot pressure distribution and lower extremity joint loading were evaluated. RESULTS: The differences in total maximal plantar pressure, pressure time integral, contact area, and maximum force between the affected and non-affected foot were statistically significant (P 0.1). No significant differences of temporal gait parameters between the affected and non-affected extremity were observed; however, statistically significant differences in kinetics parameters, frontal ankle and knee moments were detected. CONCLUSION: Donor limb functionality and anatomical disability were assessed using pedobarography systems and 3D-gait analysis. The recorded differences in plantar pressure distribution (increased pressure in I., IV. and V. metatarsal areas) and overload of the medial compartment of the knee joint were the most significant findings. Therefore, wearing individually adapted shoe insoles as prevention of osteoarthrosis might be beneficial for patients after thumb reconstruction by a twisted-toe technique.

Healing and Angiogenic Properties of Collagen/Chitosan Scaffolds Enriched with Hyperstable FGF2-STAB® Protein: In Vitro, Ex Ovo and In Vivo Comprehensive Evaluation.

Wound healing is a process regulated by a complex interaction of multiple growth factors including fibroblast growth factor 2 (FGF2). Although FGF2 appears in several tissue engineered studies, its applications are limited due to its low stability both in vitro and in vivo. Here, this shortcoming is overcome by a unique nine-point mutant of the low molecular weight isoform FGF2 retaining full biological activity even after twenty days at 37 °C. Crosslinked freeze-dried 3D porous collagen/chitosan scaffolds enriched with this hyper stable recombinant human protein named FGF2-STAB® were tested for in vitro biocompatibility and cytotoxicity using murine 3T3-A31 fibroblasts, for angiogenic potential using an ex ovo chick chorioallantoic membrane assay and for wound healing in vivo with 3-month old white New Zealand rabbits. Metabolic activity assays indicated the positive effect of FGF2-STAB® already at very low concentrations (0.01 µg/mL). The angiogenic properties examined ex ovo showed enhanced vascularization of the tested scaffolds. Histological evaluation and gene expression analysis by RT-qPCR proved newly formed granulation tissue at the place of a previous skin defect without significant inflammation infiltration in vivo. This work highlights the safety and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® protein. Moreover, these sponges could be used as scaffolds for growing cells for dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration.