Effect of Platelet-Derived Concentrated Growth Factor on Single-Layer, Multi-Layer, and Crushed Onlay Cartilage Grafts.

BACKGROUND: The main concern with utilizing cartilage grafts to achieve structural integrity and volume restoration is the loss of volume over time and their unpredictable viability. Preservation of the volume of cartilage grafts is necessary to ensure their long-term success. OBJECTIVES: The main aim of this study was to investigate the effect of concentrated growth factor (CGF) sheet on single-layer, multi-layer, and crushed block cartilage grafts. METHODS: Cartilage grafts obtained from the ears of rabbits were prepared in 3 different forms: single-layer, triple-layer, and crushed. After measuring the weight and thickness of the cartilage grafts, the grafts in the experimental group were wrapped with the prepared autologous CGF. These cartilage grafts were placed in subcutaneous pouches created on the backs of the rabbits. After 4 months, the rabbits were killed. The weight and thickness of the cartilage grafts were measured and the cartilage viability and peripheral changes were examined microscopically. RESULTS: The percentage changes in the weights and thicknesses of the single-layer, multi-layer, and crushed cartilage grafts wrapped with CGF were found to be statistically significantly lower than in the control group. When the cartilage viability and changes in peripheral tissue were evaluated, CGF-wrapped cartilage groups did not achieve statistically significantly better scores than the untreated control groups. CONCLUSIONS: In cases planned to receive a block cartilage graft, especially if graft resorption is not desired or should be minimized, wrapping the graft with autologous CGF is a feasible option.

The Effect of Astaxanthin on Random Pattern Skin Flaps.

BACKGROUND: Skin flaps are the first-line treatment modality for skin defect reconstruction. With the increased importance and use of flap surgery, a growing number of studies have investigated the ways for the prevention of ischemia-reperfusion injury. The aim of this study was to investigate the effect of astaxanthin, which is an antioxidant molecule from the xanthophyll family, on the survival of random pattern skin flaps. METHODS: Thirty-two Sprague-Dawley rats with a caudally based random pattern skin flap (3 × 9 cm) were divided into 4 groups: group A (astaxanthin orally 1 mg/kg per day), group B (astaxanthin orally 4 mg/kg per day), group C (astaxanthin orally 16 mg/kg per day), and the control group. On postoperative day 7, the flaps were evaluated by photographic, scintigraphic, and histological methods. Photographs were taken to investigate the total flap, necrotic flap, and surviving flap areas. A scintigraphic evaluation was undertaken to analyze the surviving area. The flaps were evaluated histopathologically for vascularization, acute inflammation, and chronic inflammation. RESULTS: The rate of surviving flap areas was observed to increase in parallel to the increase in the astaxanthin dose. Surviving flap areas and flap perfusion values were higher in group C compared with the control group and group A (P < 0.05). The values were also significantly higher in group B compared with control group (P < 0.05). All study groups were shown to have statistically significantly higher vascular density than the control group (P < 0.05), whereas lymphocyte and neutrophil densities were similar among all groups (P > 0.05). The photographic and scintigraphic evaluations for the viable area percentages of the flaps correlated with each other (rs = 0.913, P < 0.001). CONCLUSIONS: Orally administered astaxanthin, if given at doses higher than 4 mg/kg, increases flap viability rates and vascularization and can be used as an adjunctive agent.

Biomechanical analysis of a modified suture technique for septal extension grafts: Transloop suture.

BACKGROUND: A successful rhinoplasty procedure requires a well-defined and properly projected nasal tip; however, surgical control of the nasal tip is difficult. The aim of this investigation was to assess the efficacy and safety of a modified suture technique, which can be used to fix the caudal septal extension graft during primary rhinoplasty of the Asian population and revision septorhinoplasties of the Caucasian population, and to compare it with those of other commonly used techniques. METHODS: After peeling of perichondrium of scapular cartilages, cartilage pieces of 3 × 1 cm in size and 2 mm in thickness were divided into two from the midline. These pieces were repaired end-to-end using three different repair techniques: two simple interrupted in Group A (n = 40), vertical figure-of-eight in Group B (n = 40) and modified vertical figure-of-eight (transloop) in Group C (n = 40). All repaired cartilage specimens were subjected to a biomechanical analysis, in which four different forces were applied: tension, lateral bending, shearing and buckling. RESULTS: According to the tensile test, Group C had statistically significantly higher strength than Group A at 2 mm range. The lateral bending test similarly revealed that Group C had statistically significantly higher strength at 1.5 mm and 2 mm range than Group A. However, there was no statistically significant difference between the three groups in the assessment of shearing and buckling forces. CONCLUSION: The modified transloop suture technique provides a more stable repair, and we consider that it can be used as an alternative suture repair method.

Effect of platelet-rich plasma on reconstruction with nerve autografts.

Despite advances in understanding of peripheral nerve injuries and regeneration and advances in surgical techniques, successful outcomes cannot be guaranteed after reconstructive surgery. Platelet-rich plasma (PRP) has been reported to have positive effects on nerve regeneration, as well as on tissue healing. The present study was designed to evaluate the effect of PRP on nerve-grafted defects. Sprague-Dawley rats were divided into four surgery groups (n=7 in each). A 1-cm long nerve defect was created in the upper thigh and then reconstructed using a nerve autograft in all groups. The wet muscle weights, electromyographic findings, and histomorphologic changes were evaluated 10 weeks later. As shown by both the electromyographic (p<0.001) and histomorphologic findings (p<0.001), PRP had more positive effects on nerve gap reconstruction in Group 3 then Group 4 as compared to the control groups. The present study is novel in that it evaluated the regeneration effect of PRP on a large nerve defect reconstructed with a nerve graft rather than primary repair. The results are encouraging for further experimental studies on the role of PRP in nerve healing.