Use of acellular dermal matrix in peripheral nerve reconstruction: an experimental study on rat sciatic nerve defect.

BACKGROUND: In patients with nerve tissue defects, the use of autologous nerve grafts is the standard method of treatment. Alternatives to autologous, nerve grafts have attracted the attention of reconstructive surgeons. In this study, the results of nerve repairs using acellular dermal matrix (ADM) in an experimental rat sciatic nerve defect model are presented. METHODS: Thirty-six Sprague-Dawley rats were randomized into 5 groups: Group 1: control group, Group 2: negative control group (n = 6), Group 3: autologous nerve graft group (n = 10), Group 4: donor site entubulated with ADM group (n = 10); and Group 5: nerve graft entubulated with ADM group (n = 10). The animals in each group were evaluated for electrophysiologic functions, gastrocnemius muscle weight and histomorphology on the 3rd and 6th month. RESULTS: The compound muscle action potential was observed to be distinctly lower in Groups 3, 4 and 5 in comparison to the control group. In Group 4, the gastrocnemius ratio (GCR) values on the 6th month were statistically significantly lower than the GCR values in Group 3 and Group 5, The histological scores and myelinated axonal counts in Group 5 were statistically significantly higher than the values in Group 3 and Group 4. CONCLUSION: The results of this study showed that wrapping ADM around nerve grafts resulted in better outcomes with respect to nerve healing.

A Study on the Effects of the Use of Propofol in Experimental Model Inferior Epigastric Island Flap on Ischemia-Reperfusion Injury.

Problems concerning vascular blood flow are the most frequently encountered ones after flap applications. The flap tissue starts to develop ischemia in patients with a vascular blood flow insufficiency. And reperfusion starts in those patients in whom the ischemia is temporary, triggering an ischemia-reperfusion injury depending on the duration of the ischemia. The aim of this study was to evaluate the effect of propofol, which is an anesthetic agent known to have an antioxidant effect and a free radical scavenging feature on the ischemia-reperfusion injury created on an experimental epigastric island flap.Thirty Sprague-Dawley rats were used in the study. The rats were divided into 3 groups of 10 rats each. Inferior epigastric artery-based abdominal flaps were prepared in all the groups. In group 1 (sham), the flap was elevated but no ischemia was applied. In groups 2 (control) and 3 (propofol), the flap was exposed to ischemia for 2 hours after it was elevated. All the rats were sacrificed and biochemical and histopathological assessments were made on the tissue samples taken on the 14th day. As a result of a comparison between the groups, the flap viability rates and the superoxide dismutase, total antioxidant capacity, and catalase values were found to be significantly higher (P < 0.001) in the propofol group while the malondialdehyde and total oxidative stress values were lower (P < 0.001). Based on the data obtained from the present study, the use of propofol was observed to have a protective effect against ischemia-reperfusion injuries in flap surgeries.

An unusual etiology in cold injury: Liquefied petroleum gas.

Cold injury is a condition that causes reversible and irreversible damage when tissues are exposed to cold. This injury occurs due to various etiologies, and the most commonly observed ones include contact with liquefied petroleum gas (LPG) used in households, vehicles, and industry. LPG is a type of gas stored in liquid state under high pressure within cylinders. LPG contains a mixture of propane and butane gases. Direct contact of these gases with the tissues has the potential to cause metabolic, toxic, and respiratory damage. In this study, we present the cases of four patients with cold injury in the face and upper extremity caused by a pressurized jet stream of liquid gas that escaped out of the valves of the LPG cylinders. The patients had bullous lesions in the upper extremities and the face and second- and third-degree cold injuries with fibrotic and necrotic areas. The superficial defects secondarily healed with minimal scarring, while the necrotic finger had to be amputated. Cold injury on the skin caused by high-pressure jet streams of liquid gas as in our study is a rare occurrence. Our patients are important cases due to the rare etiology of cold injury.

Extended lateral thoracic fasciocutaneous biosynthetic flap for reconstruction of full-thickness partial external ear defects: an experimental study.

External ear reconstruction is a controversial topic in reconstructive plastic surgery. Here, we prepared a pedicled biosynthetic flap for full-thickness, partial ear defects in rabbits. We operated on six adult female New Zealand rabbits weighing 3-4 kg. The dimensions of the lateral thoracic fasciocutaneous flap were 7 × 6 cm. The flap was elevated based on one of the bilaterally located internal thoracic arteries, which were dissected proximally. The pedicled flap was folded in two, and polypropylene mesh was sandwiched in the middle. The flap was adapted to a defect of 3.5 × 3 cm in diameter. In fact, the defect was created before elevation of the flap. Rabbits were followed up for 4 weeks, at the end of which they were killed and their ears were evaluated histopathologically. The survival rate of the rabbits was 100 %. All pedicled biosynthetic flaps were viable, but one showed partial (20 %) necrosis (1/6) and one was partially detached (1/6). Macroscopic (color, thickness, texture) and histological (polymorphonuclear leukocyte invasion in the skin, subcutaneous tissue, and at the junction between the polypropylene mesh and the flap) features of the flap were compared to the ipsilateral ear. A new technique was developed for partial external ear reconstruction with sufficient inner skeletal support and outer skin lining. Level of evidence Level NA.

Polypropylene mesh for nasal septal perforation repair: an experimental study.

The aim of this study is to determine the effectiveness and biocompatibility of polypropylene mesh for the repair of nasal septal perforations in an animal model on rabbits. A full-thickness nasal septal perforation with a diameter of nearly 10 × 10 mm was created on 12 rabbits, and then the perforation was reconstructed with two different methods. We used mucosal flaps and polypropylene mesh as an interpositional graft in group 1. Only mucosal flaps were used for reconstruction and are identified as group 2. After 4 weeks, we removed the nasal septum of the rabbits and performed histopathological examinations for acute rejection, infection, inflammatory response, fibrosis, and granuloma formation. We found perforation closure rates of 75 and 25 % in groups 1 and 2, respectively. Inflammatory response was seen in all specimens of group 1 (100 %). The inflammatory response was +1 in five of the specimens (62.5 %), +2 in one specimen (12.5 %), and +3 in two specimens (25 %). Mild fibrosis around the mesh was detected in four specimens (50 %), medium-level fibrosis was detected in one (12.5 %), and no fibrosis was detected in three (37.5 %). Severe fibrosis was not seen in any specimens. The foreign-body reaction was limited to a few giant cells, and granuloma formation was seen in two specimens (25 %). The propylene mesh showed excellent biocompatibility with the septal mucosa, and it can, therefore, be used for the repair of septal perforation as an interpositional graft safely.

Comparison of tooth-borne and hybrid devices in surgically assisted rapid maxillary expansion: A randomized clinical cone-beam computed tomography study.

PURPOSE: The objective of this 2-arm, parallel, single-center trial was to compare the skeletal, dental, and periodontal effects of tooth-borne (TB) and hybrid devices in surgically assisted rapid maxillary expansion (SARME). MATERIALS AND METHODS: Twenty consecutive patients (9 male and 11 female) with skeletal transverse maxillary deficiency seeking treatment at the Department of Orthodontics at Istanbul University in Istanbul, Turkey, were randomly assigned to 2 groups (10 patients each). Hybrid devices were inserted in the first group and TB (Hyrax) devices in the second. All of the patients had undergone SARME operations, which were carried out by the same surgeons using the same procedure (a Le Fort I osteotomy with pterygomaxillary dysjunction). All of the patients had similar transverse deficits, and 7 mm of expansion was achieved in all of them over 14 days. CBCT was carried out preoperatively (T0), at the end of the active expansion phase (T1), and after 6 months of retention (T2). Measurements were made using Mimics 16.0. RESULTS: Anterior skeletal maxillary widening parameters increased significantly in the T0-T1 and T0-T2 periods in the 2 groups (P = 0.001). There was significantly less dental expansion anteriorly with the hybrid devices (T0-T2: 4.03 mm vs. 6.29 mm). The first molars tipped buccally more in the group with TB devices during the T0-T1 phase (P = 0.029) and moved upright more than those in the group with hybrid devices during the retention phase (P = 0.035). Dental tipping, buccal alveolar bone resorption, and root resorption were observed significantly more often with the TB devices. CONCLUSION: Hybrid RME devices, with similar skeletal effects, different dental movement patterns, and fewer dental and periodontal side effects, thus appear to be a beneficial alternative to TB devices for SARME procedures.

Evaluation of the Retro-Orbital Fatty Tissue Volume in Delayed Orbital Blow-Out Fractures.

PURPOSE: In patients where diplopia and enophthalmia are manifest, surgical intervention is usually necessary. The pathogenesis of these symptoms usually includes the prolapse of orbital tissues into the sinus or compression by the surrounding bone structures. Although the retro-orbital fatty tissue, orbital fascia, and the muscle tissue can be reduced to the original place after being incarcerated into the maxillary space, it is obvious that the procedure can lead to significant fibrosis in these structures. The authors have aimed to carry out a quantitative evaluation of the fatty tissue volumes in patients with repair delayed for more than two weeks. METHODS: The preoperative and postoperative fatty tissue volumes and the changes in total orbital volume were evaluated by using CT on the patients (n = 9) who were consulted to the authors' clinic from other health centers. RESULTS: Although no significant correlation was observed between the prolapsed volume and the postoperative reduction in the fatty tissue, the reduction in the retro-orbital fatty tissue was statistically significant. CONCLUSION: Evaluating postoperative retro-orbital fatty tissue volumes may have implications for surgical intervention in the future.

Autologous fat injection into the pectoralis major as an adjunct to surgical correction of gynecomastia.

BACKGROUND: Correction of gynecomastia in males is a frequently performed aesthetic procedure. Various surgical options involving the removal of excess skin, fat, or glandular tissue have been described. However, poor aesthetic outcomes, including a flat or depressed pectoral area, limit the success of these techniques. OBJECTIVES: The authors sought to determine patient satisfaction with the results of upper chest augmentation by direct intrapectoral fat injection in conjunction with surgical correction of gynecomastia. METHODS: In this prospective study, 26 patients underwent liposuction and glandular excision, glandular excision alone, or Benelli-type skin excision. All patients received intramuscular fat injections in predetermined zones of the pectoralis major (PM). The mean volume of fat injected was 160 mL (range, 80-220 mL per breast) bilaterally. Patients were monitored for an average of 16 months (range, 8-24 months). RESULTS: Hematoma formation and consequent infraareolar depression was noted in 1 patient and was corrected by secondary lipografting. Mean patient satisfaction was rated as 8.4 on a scale of 1 (unsatisfactory) to 10 (highly satisfactory). CONCLUSIONS: Autologous intrapectoral fat injection performed simultaneously with gynecomastia correction can produce a masculine appearance. The long-term viability of fat cells injected into the PM needs to be determined. LEVEL OF EVIDENCE: 4 Therapeutic.