Innovative Use of an Injectable, Self-Healing Drug-Loaded Pectin-Based Hydrogel for Micro- and Supermicro-Vascular Anastomoses.

Microvascular surgery plays a crucial role in reconnecting micrometer-scale vessel ends. Suturing remains the gold standard technique for small vessels; however, suturing the collapsed lumen of microvessels is challenging and time-consuming, with the risk of misplaced sutures leading to failure. Although multiple solutions have been reported, the emphasis has predominantly been on resolving challenges related to arteries rather than veins, and none has proven superior. In this study, we introduce an innovative solution to address these challenges through the development of an injectable lidocaine-loaded pectin hydrogel by using computational and experimental methods. To understand the extent of interactions between the drug and the pectin chain, molecular dynamics (MD) simulations and quantum mechanics (QM) calculations were conducted in the first step of the research. Then, a series of experimental studies were designed to prepare lidocaine-loaded injectable pectin-based hydrogels, and their characterization was performed by using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and rheological analysis. After all the results were evaluated, the drug-loaded pectin-based hydrogel exhibiting self-healing properties was selected as a potential candidate for in vivo studies to determine its performance during operation. In this context, the hydrogel was injected into the divided vessel ends and perivascular area, allowing for direct suturing through the gel matrix. While our hydrogel effectively prevented vasospasm and facilitated micro- and supermicro-vascular anastomoses, it was noted that it did not cause significant changes in late-stage imaging and histopathological analysis up to 6 months. We strongly believe that pectin-based hydrogel potentially enhanced microlevel arterial, lymphatic, and particularly venous anastomoses.

Use of Dorsal Nasal Flap in Combination With Nasolabial Perforator Propeller Flap for Reconstruction of Nasal Skin Defects of Medium to Large Size; A Simpler Alternative to Frontal Flap.

ABSTRACT: Nasal reconstruction is one of the most challenging procedures in plastic surgery. To get optimal aesthetic and functional results, the surgeon should know all the options well. Forehead flap is the gold standard technique for closure of medium to large defects of the nose. Although it provides a very good color and texture match, it may become a difficult option in patients with poor condition. The aim of this study was to define a simpler technique for nasal reconstruction using combined local flaps.Twelve patients, operated using a dorsal nasal flap combined with a nasolabial perforator propeller flap, were presented in the study. Properties of the patients, defect size and locations, and complications were evaluated.The mean size of the reconstructed defects was 10.1 cm2. No flap loss was observed. Venous congestion was the most common complication and resolved spontaneously in all cases. Two cases had partial distal necrosis, which also healed spontaneously.Closure was achieved successfully in all cases with a medium to large nasal defect using a combined dorsal nasal flap and nasolabial perforator propeller flap. This method can be used as an alternative to forehead flap.

Effects of Insulin, Metoprolol and Deferoxamine on Fat Graft Survival.

BACKGROUND: The main problem faced with fat grafting is unpredictable resorption rates. Many substances have been reported to increase the survival of fat grafts. The aim of this study was to compare the effects of insulin, metoprolol and deferoxamine on fat graft survival. METHODS: Inguinal fat pads of male Sprague-Dawley rats were harvested and split into four parts as grafts. The grafts were placed in subcutaneous pockets in four quadrants on the back area of the rats. The insulin and metoprolol group fat grafts were incubated in regular insulin and metoprolol solutions, until they were placed. Deferoxamine and control group fat grafts were placed without incubation. After surgery, the control group fat grafts were injected with 10 doses of NaCl solution once every 3 days, and the deferoxamine group fat grafts were injected with 10 doses of deferoxamine solution once every 3 days. After a graft maturation period of 3 months, the grafts were harvested for weight measurements and histological and immunohistochemical evaluation. RESULTS: According to the rate of perilipin staining, the metoprolol group had 30% more mature viable adipocytes than the control and insulin group fat grafts (p < 0.05 and p < 0.01, respectively). CD31 activation rates were significantly higher in the deferoxamine and insulin group than in the metoprolol group (p < 0.05). CD34 staining rates did not differ between any groups (p > 0.05). CONCLUSIONS: In this experimental study, we have shown that there was no significantly increased fat graft survival rate seen in any drug treatment group. Low survival rates of stem cells demonstrated that the adipogenesis period ended at 3 months. Treatment of fat grafts with the selective ß1-blocker metoprolol resulted in good quality better graft take with more viable mature adipocytes. However, better viability of adipocytes did not result in increased weight of the fat graft. Studies aiming to compare the effects on fat graft survival of beta-blockers with long or short durations of action, different potencies and different receptor selectivity may be designed in the future. In addition, further studies may be performed, in which immunohistochemical markers used to assess inflammation and fibrosis are added to the study after the completion of the fat graft maturation period at the end of the first year to test the permanence of the results. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors - www.springer.com/00266 .