Mehmet Veli Karaaltin

Generation of Skin Tissue Using Adipose Tissue-Derived Stem Cells.

Background: The aim of this study was to generate skin tissue using adipose tissue-derived mesenchymal stem cells. Methods: Thirty Wistar albino rats were used. A 2-cm-diameter full-thickness skin defect on the back of each rat was formed. A secondary wound healing model was constituted in group 1, fibrin matrix only was applied in group 2, a keratinocyte-coated fibrin matrix was applied in group 3, an adipose tissue-derived mesenchymal stem cell–seeded fibrin matrix was applied in group 4, and a keratinocyte-coated and adipose tissue-derived mesenchymal stem cell–seeded fibrin matrix was applied to the defects in group 5. Results: A similar form of wound healing, with contraction from the edges and ulceration at the center, was observed in groups 1, 2, and 3. The wound contraction was reduced in group 4, and the epidermis was creeping from the surrounding tissue but with some ulcerations in the central part of the wounds. In group 5, the defect area was almost totally epithelialized, with minimal wound contraction. By microscopic analysis, significant increases in the collagen volume ratios and vascular volume ratios were determined in groups 4 and 5. From the fluorescent micrographs, fibroblastic differentiation and extracellular matrix synthesis, endothelial differentiation of stem cells, and neoangiogenesis and epithelium derived from marked keratinocytes were observed in group 5. Conclusion: Formation of the adipose tissue-derived mesenchymal stem cell–seeded and keratinocyte-coated autologous fibrin scaffold leads to significant skin replacement.

Human olfactory stem cells for injured facial nerve reconstruction in a rat model

The purpose of this study was to show the efficacy of olfactory stem cells for injured facial nerve reconstruction in a rat model.

Effects of Open Technique Rhinoplasty on Mimicry: Electroneurographic Evaluation.

Objective:This study was designed to investigate the effects of open technique rhinoplasty on facial nerve terminal branches more concerned with mimicry via electroneurography (ENoG). Methods:Twenty patients ages between 24 and 36 years were included in the study. Five nasal mimicry muscles were used to evaluate axonal loss of the facial nerve: bilateral transverse nasal, levator labii superioris alaeque nasi (LLSAN), and procerus muscles of all patients were evaluated preoperatively and postoperative third month by ENoG. The patients that have abnormalities regarding the amplitude and latency at third month were reevaluated at sixth month postoperatively. Results:Mean latencies of the facial nerve were calculated to be increased for all muscles at third postoperative month, but this increase was significant only for left LLSAN (P = 0.002). Amplitudes of the facial nerve decreased in all of the groups, but this decrease was not significant (P > 0.05). Two patients with exceptionally long latency facial nerve response of transverse nasal muscle and 11 muscle recordings with abnormal low amplitudes of the facial nerve at the third month was reevaluated at sixth postoperative month and the values were improved. Conclusions:This study demonstrated that facial nerve integrity is minimally affected after rhinoplasty, yet all affected muscles were recovered on the long term.

Total Scalp Replantation: Surgical Tricks and Pitfalls.

Background:Two patients were successfully operated on for total scalp avulsions. Methods:Ages were between 11and 35 years, and both patients were female. Bilateral temporal artery and veins were used as the recipient pedicles. Interpositional vein graft harvested from the left forearm was used in 1 patient. No nerve repair was performed. Results:The scalp was successfully replanted in both cases. Venous congestion and arterial insufficiency were observed in 1 patient. Successful revision of the vascular anastomosis was performed. Total necrosis of the upper helical rim was observed in 1 patient. A mean size of 3 × 3 cm of tissue necrosis was observed in the occipital region of all patients. One patient was treated with split-thickness skin grafting, whereas the other one was left for secondary healing. Conclusions:The “replace like tissue with like tissue” represents the philosophy in replantation surgery. Although reconstructive surgeries imply advanced surgical methods, scalp replantation remains the only ideal surgical modality to create an embellishing natural-looking hair-bearing scalp. In this article, we present some tricks and pitfalls of total avulsed scalp replantation as well as our skills and literature review.

The multiple osteotomized free iliac osteocutaneous flap for reconstructions of complex maxillofacial and oromandibular defects.

Abstract The vascularized iliac osteocutaneous flap has been used successfully for jaw reconstruction. To obtain a better contour of the reconstructed area in large upper and lower jaw resections, the transferred bone actually needs to be osteotomized. Single closing-wedge osteotomy of the iliac flap for mandibular reconstruction has been previously described. In this article, the modified multiple osteotomized perforator-based versatile free iliac osteocutaneous flap is described. Eleven cases were enrolled. Seven patients had wide anterior mandibular resections due to oral cavity and mandibular tumors; 3 patients had a defect due to explosive injury and 1 patient had complicated orbitomaxillary defect due to blast injury. Skin paddle was based on the perforators. In 8 patients, the bony segment was divided into 3 segments by 2 osteotomies, whereas in 2 patients the bony segment was divided into 4 segments by 3 osteotomies. In 10 cases, the flap was used for anterior mandibular defects, whereas in 1 case the flap was customized to fit an L-shaped defect at the naso-orbito-maxillary region. The overall flap success rate was 100%. No resorption or morbidity related to the osteotomy of the bony segments was observed. The size of perforator skin paddle was 6 to 8 × 15 to 18 cm. Physical and radiologic examinations showed proper bone healing without any additional complications. The modified multiple osteotomized free osteocutaneous iliac flap can provide a safe and versatile bony segment to be arranged and adapted to reconstruct complex mandibular and maxillofacial defects.

Decellularization of Trachea With Combined Techniques for Tissue-Engineered Trachea Transplantation

Objectives The purpose of this study is to shorten the decellularization time of trachea by using combination of physical, chemical, and enzymatic techniques. Methods Approximately 3.5-cm-long tracheal segments from 42 New Zealand rabbits (3.5±0.5 kg) were separated into seven groups according to decellularization protocols. After decellularization, cellular regions, matrix and strength and endurance of the scaffold were followed up. Results DNA content in all groups was measured under 50 ng/mg and there was no significant difference for the glycosaminoglycan content between group 3 (lyophilization+deoxycholic acid+de-oxyribonuclease method) and control group (P=0.46). None of the decellularized groups was different than the normal trachea in tensile stress values (P>0.05). Glucose consumption and lactic acid levels measured from supernatants of all decellularized groups were close to group with cells only (76 mg/dL and 53 mg/L). Conclusion Using combination methods may reduce exposure to chemicals, prevent the excessive influence of the matrix, and shorten the decellularization time.

Thoracoacromial artery perforator flap based on the clavicular branch: A new option in regional reconstruction

Thoarcoacromial artery‐based perforator flaps are rarely used in clinical practice, especially for the reconstruction of head, neck and axillary regions. In the present study, we present a case with an anterior chest wall soft tissue defect that was reconstructed using a thoarcoacromial artery‐based perforator flap based on the clavicular branch.

‘Auto‐supercharge’ of the anterolateral thigh flap during the reconstruction of lower extremity defects: A turbocharge technique for flow‐through flaps

The anterolateral thigh flap is a workhorse perforator flap option that can be used as a flow‐through flap in the reconstruction of defects with vascular insufficiency. In the present study, the flow‐through concept was introduced in terms of preserving blood inflow of the flap and establishing blood flow to the distal portion of the flap as a supercharge technique.

The double scalpel flap: a new technique for the closure of circular skin defects.

Abstract Reconstruction needs to be designed attentively to obtain a functional and a good aesthetic consequence for closing skin defects. Numerous local flaps have been defined to conceal skin defects. However, new techniques are still required, especially for circular type of skin defects. This study describes a new technique that has been well defined to repair the circular type of skin defects. The technique basically uses extra skin relaxation provided with 2 opposing flaps’ rotation maneuver in favor of the defect closure. The objective of this technique is for the flaps to start from one border of the defect and extend just to the other border, not invading beyond the defect borders. This enables us to apply the procedure on defects that are close to important anatomical structures because it is sufficient to use only the opposing 2 sides of the defect for its closure. With this method, 2 opposing flaps that resemble the tip of a scalpel were rotated to the existing circular defect; and by suturing these 2 flaps at the midline, the defect was closed. This technique was applied to 17 patients between the ages of 48 and 83 years. Defect sizes were between 2.5 × 2.5 and 5 × 5 cm. With the use of opposing flaps designed narrower than half-width of the defect, a tension-free closure could be achieved on both the donor and the recipient site. No flap necrosis was detected on any patients. After a mean follow-up of 11 months (3–26 months), it was realized that a good aesthetic appearance could be achieved in all the patients about 2 to 3 months postoperatively.