Cagri A. Uysal

Improved viability of random pattern skin flaps through the use of adipose-derived stem cells.

Background: Flap necrosis caused by inadequate blood supply is a common postoperative complication in reconstructive surgery. Because a putative stem cell population within the adipose tissue has been found to possess angiogenic potential, the authors sought to determine whether these cells might selectively induce neovascularization and increase the viability of random pattern skin flaps. Methods: Adipose-derived stem cells were isolated from the inguinal fat pads of ICR mice and expanded ex vivo for three passages. After the elevation of cranially based random pattern skin flaps (3 cm long and 1 cm wide), 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine (DiI)–labeled adipose-derived stem cells were then injected into the pedicle base (group A) or 1.5 cm distal to the pedicle (group B). Medium containing no adipose-derived stem cells, mature adipocytes, or basic fibroblast growth factor were injected in three other control groups separately. (n = 10 for each group). Millimetric measurements were taken at postoperative day 7 for evaluation of flap viability. Specimens were harvested for histologic analyses. Results: Adipose-derived stem cells led to a statistically significant increase in flap viability in both group A and group B compared with the control and the adipocyte groups. Histologic examination also demonstrated a statistically significant increase in capillary density in both group A and group B. Moreover, some of the endothelial cells were stained positively for DiI. Conclusions: These findings suggest that adipose-derived stem cells have a potential for enhancing the blood supply of random pattern skin flaps. This mechanism might be both the direct differentiation of adipose-derived stem cells into endothelial cells and the indirect effect of angiogenic growth factor released from adipose-derived stem cells.

Periodontal tissue regeneration by combined implantation of adipose tissue-derived stem cells and platelet-rich plasma in a canine model

BACKGROUND AIMS One goal of periodontal therapy is to regenerate periodontal tissues. Stem cells, growth factors and scaffolds and biomaterials are vital for the restoration of the architecture and function of complex tissues. Adipose tissue-derived stem cells (ASCs) are an ideal population of stem cells for practical regenerative medicine. In addition, platelet-rich plasma (PRP) can be useful for its ability to stimulate tissue regeneration. PRP contains various growth factors and may be useful as a cell carrier in stem cell therapies. The purpose of this study was to determine whether a mixture of ASCs and PRP promoted periodontal tissue regeneration in a canine model. METHODS Autologous ASCs and PRP were implanted into areas with periodontal tissue defects. Periodontal tissue defects that received PRP alone or non-implantation were also examined. Histologic, immunohistologic and x-ray studies were performed 1 or 2 months after implantation. The amount of newly formed bone and the scale of newly formed cementum in the region of the periodontal tissue defect were analyzed on tissue sections. RESULTS The areas of newly formed bone and cementum were greater 2 months after implantation of ASCs and PRP than at 1 month after implantation, and the radiopacity in the region of the periodontal tissue defect increased markedly by 2 months after implantation. The ASCs and PRP group exhibited periodontal tissue with the correct architecture, including alveolar bone, cementum-like structures and periodontal ligament-like structures, by 2 months after implantation. CONCLUSIONS These findings suggest that a combination of autologous ASCs and PRP promotes periodontal tissue regeneration that develops the appropriate architecture for this complex tissue.

Effect of mesenchymal stem cells on skin graft to flap prefabrication: an experimental study.

Angiogenetic potential has been reported for bone marrow-derived stem cells (BSCs) and adipose-derived stem cells (ASCs). The superficial femoral artery, vein, and fascia were used as a vascular crane for prefabrication model of skin graft to flap. BSCs or ASCs were injected before the adaptation of the graft to the vascular crane depending on the group. The prefabricated grafts were then transferred to inguinal region in every 7 days to observe the viability. In experiment part I (n = 18), the critical time for the prefabrication was found to be 1 week. In experiment part II (n = 12), the control and experiment assays were performed on the same animal to support the data of the experiment part I. The viability of flaps was evaluated. The vascular density was higher in BSC, and ASC groups. The Vascular Endothelial Growth Factor immunohistochemical staining was quantified. Furthermore, mesenchymal stem cells could be helpful in any prefabrication procedure in which neovascularization is indispensable.

Sciatic nerve anatomy in rat re-visited: a more proximal intervention

Figure 3 was found for anastomosis. In order to gain access to both veins for anastomosis the ear was retracted anteriorly, resulting in the ends of the veins meeting in the space created between the ear and the mastoid. As such the anastomosis would have to be performed in midair, and could not be sufficiently stabilised to facilitate appropriate suture. We placed a segment of green suture pack foil around a cut portion of a 1 ml syringe. This provided a suitably secure platform and an appropriately coloured background on which successful microanastomosis of the veins was performed (Figure 2), without which we believe the anastomosis would have failed. The ear completely survived (Figure 3). An appropriately sized syringe wrapped in suture foil makes a secure background for performing microanastomoses. We hope this demonstrates a solution to other microsurgeons struggling to anastomose tiny vessels in midair.

The efficacy of mesenchymal stem cell transplantation in caustic esophagus injury: an experimental study.

Introduction. Ingestion of corrosive substances may lead to stricture formation in esophagus as a late complication. Full thickness injury seems to exterminate tissue stem cells of esophagus. Mesenchymal stem cells (MSCs) can differentiate into specific cell lineages and have the capacity of homing in sites of injury. Aim and Methods. We aimed to investigate the efficacy of MSC transplantation, on prevention of esophageal damage and stricture formation after caustic esophagus injury in rats. 54 rats were allocated into four groups; 4 rats were sacrificed for MSC production. Group 1, untreated controls (n: 10). Group 2, membrane labeled MSCs-treated rats (n: 20). Group 3, biodistribution of fluorodeoxyglucose labeled MSCs via positron emission tomography (PET) imaging (n: 10). Group 4, sham operated (n: 10). Standard caustic esophageal burns were created and MSCs were transplanted 24 hours after. All rats were sacrificed at the 21st days. Results. PET scan images revealed the homing behavior of MSCs to the injury site. The histopathology damage score was not significantly different from controls. However, we demonstrated Dil labeled epithelial and muscle cells which were originating from transplanted MSCs. Conclusion. MSC transplantation after caustic esophageal injury may be a helpful treatment modality; however, probably repeated infusions are needed.

Adipose-derived Stem Cells Enhance Axonal Regeneration through Cross-facial Nerve Grafting in a Rat Model of Facial Paralysis

Background: Cross-face nerve grafting combined with functional muscle transplantation has become the standard in reconstructing an emotionally controlled smile in complete irreversible facial palsy. However, the efficacy of this procedure depends on the ability of regenerating axons to breach two nerve coaptations and reinnervate endplates in denervated muscle. The current study tested the hypothesis that adipose-derived stem cells would enhance axonal regeneration through a cross-facial nerve graft and thereby enhance recovery of the facial nerve function. Methods: Twelve rats underwent transection of the right facial nerve, and cross-facial nerve grafting using the sciatic nerve as an interpositional graft, with coaptations to the ipsilateral and contralateral buccal branches, was carried out. Rats were divided equally into two groups: a grafted but nontreated control group and a grafted and adipose-derived stem cell–treated group. Three months after surgery, biometric and electrophysiologic assessments of vibrissae movements were performed. Histologically, the spectra of fiber density, myelin sheath thickness, fiber diameter, and g ratio of the nerve were analyzed. Immunohistochemical staining was performed for the evaluation of acetylcholine in the neuromuscular junctions. Results: The data from the biometric and electrophysiologic analysis of vibrissae movements, immunohistochemical analysis, and histologic assessment of the nerve showed that adipose-derived stem cells significantly enhanced axonal regeneration through the graft. Conclusion: These observations suggest that adipose-derived stem cells could be a clinically translatable route toward new methods to enhance recovery after cross-facial nerve grafting.

ISOLATED UPPER EYELID COLOBOMA

Etiology of congenital eyelid coloboma is still unclear. It is a formation anomaly of complete or partial eyelid defect that can accompany other systemic diseases. 19 month old girl had an isolated congenital upper eyelid coloboma without any additional medical conditions. Defect was corrected with pentagonal incisions and advancement flaps. In our study we like to emphasize the importance of systemic analyze for additional conditions and to show that single stage repair is adequate.

Platelet-Rich Plasma Increases Pigmentation.

Platelet-rich plasma (PRP) is an autologous solution of plasma containing 4 to 7 times the baseline concentration of human platelets. Platelet-rich plasma has been widely popular in facial rejuvenation to attenuate wrinkles and has been practically used. The authors have been encountering various patients of increased hiperpigmentation following PRP applications that were performed to attenuate the postinflammatory hiperpigmentation especially after laser treatment. The authors have been using PRP for facial rejuvenation in selected patients and in 1 patient the authors have encountered increased pigmentation over the pigmented skin lesions that were present before the application. The authors recommend that the PRP might increase pigmentation especially in the face region and precautions might be taken before and after the application. Platelet-rich plasma should not be used for the treatment of post inflammatory hiperpigmentation.

Effect of mesenchymal stem cells on skin graft to flap prefabrication: reply.

To the Editor: I would like to thank the authors for writing a letter to the editor about my article “Effect of mesenchymal stem cells on skin graft to flap prefabrication.” It is gratifying to know that the article still elicits a response, although it has been a long time since it was published. We have been performing studies using mesenchymal stem cells (MSCs) since 2005. We have tried different kinds of labeling techniques and 1,1′-dioctadecyl-3,3,3′,3′tetramethylindocarbocyanine perchlorate (DiI) was one of them. We labeled the cells by incubating in the cell-labeling solution at 37°C according to the manual as mentioned by the authors. This protocol and manual was only for frozen sections. Thus, the sections had to be thicker with less successful resolution for any microscope. It seems the authors of the letter did not notice that, in our studies, the specimens were embedded in paraffin to make thinner slices for better visualization. In addition, it is well known that paraffin section has been the first choice in immunohistological specimens whenever possible.We used themanual described by Pavlidis et al and FluoProbes, which designated incubation of the cells in the cell-labeling solution at 4°C. It was mentioned that this method was as effective as incubation at 37°C. Nevertheless, in thinking that this might lead to decreased cell labeling, this would not have indicated a negative result. On the contrary, this technique has helped us to observe the specific differentiation of the cells, and the indirect effect of the MSCs was observed by discarding the contact labeling of the cells by DiI. The main disadvantage of

Asymmetric Z-plasty for telephone deformity in prominent ear correction.

Abstract There have been plenty of surgical techniques for the correction of prominent ears. “Telephone deformity” or “reverse telephone ear” has been described as the undesired result of the inappropriate correction of the prominent ear, mainly the deficient correction of the lobule. We have performed an asymmetric Z-plasty to the lobule to overcome this deformity not only by excision of the excess skin but also by transposition of the soft tissue. Between 2005 and 2011, the technique currently described was performed in 19 patients. Preoperative, intraoperative, and postoperative standardized photographs were taken, and measurements were done on postoperative first week, first month, and first year. The measurements include ear height at 3 different horizontal planes as follows: (1) the most cranial point of the ear, (2) the middle point of the ear, and (3) the most caudal point of the ear. The angle between the vertical plane of the head and the ear was measured at these previously defined 3 points. These measurements were used for indication and preoperative planning. There were statistically significant differences between preoperative and postoperative values (P < 0.05). The postoperative first year results indicated the effectiveness of this alternative technique for the long-term maintenance of the position of the lobule.