Eul Je Cho’s research while affiliated with Yonsei University and other places

Improvement of flap survival represents an ongoing challenge in reconstructive surgery. The angiogenic potential of adipose-derived stem cells (ASCs) offers a promising approach to improve the viability of random pattern flaps. Recently, to maximize the therapeutic effects of ASCs, increasing focus is being placed on how to deliver the stem cells to target lesions. The purpose of the present study was to compare the effectiveness of different administration routes of ASCs to improve the viability of the random pattern skin flap. ASCs labelled with PKH26 were applied via four methods to the cranially-based random pattern skin flaps of rats: (a) intravenous injection; (b) subcutaneous injection; (c) application with collagen sponge seeding; and (d) application with fibrin glue seeding. ASCs led to a significant increase in flap viability in the subcutaneous injection group and the collagen sponge group. Cutaneous blood flow was increased in the intravenous injection, subcutaneous injection and collagen sponge groups. Capillary density in the intravenous injection group and collagen sponge group was significantly greater than in the control group (no treatment). PKH26-positive cells via the collagen sponge were distributed more densely within the flap than in other groups. This study demonstrated that the collagen sponge method delivered ASCs most effectively within the flap and increased flap vascularity. The clinical therapeutic effects of ASCs can therefore be maximized when the optimal delivery route is chosen. Copyright © 2012 John Wiley & Sons, Ltd.

Background: Although double eyelid surgery is one of the most common cosmetic surgeries among Asians, there are few reports to confirm the physiology of eye blinking after such surgeries. This study analyzed eyelid dynamics and supratarsal crease appearance after double eyelid surgery using a high-speed digital camera to provide precise movement detection. Methods: Twenty healthy volunteers and 15 patients who underwent double eyelid surgery with tarsodermal fixation were studied. Using the slow-motion replay setting of a high-speed digital camera, the patients' spontaneous eye blinking was analyzed for (1) blink duration, (2) peak eyelid velocity, (3) blink rate, and (4) supratarsal crease appearance. Results: After double eyelid surgery, there were no significant differences in blink duration, peak eyelid velocity, or blink rate compared with the control group. Regarding supratarsal crease appearance, dynamic creases were created in 6 of 15 patients, whereas 9 patients showed static creases. Conclusions: Double eyelid surgery with tarsodermal fixation does not alter lid dynamics of spontaneous eye blinking. Furthermore, the tarsodermal fixation method, which is known to create a static crease, could also lead to the development of a dynamic crease.

Rigid external distraction osteogenesis is regarded as a standard treatment for congenital midfacial hypoplasia. However, external distraction for the upper portion of the midface is not as effective and tends to rotate the midfacial segment in a counterclockwise direction. Moreover, patients poorly tolerate it because of the device's bulkiness. To prevent such drawbacks of an external distractor, both external and internal distractors were synchronously applied to patients with Crouzon syndrome. In 6 patients with Crouzon syndrome in whom a dual-distraction technique was applied, distraction of the midfacial region was performed for up to a mean length of 15.3 mm. The external distractor was removed after a 1-month consolidation period, but the internal distractor was maintained for more than 6 months. The degree of advancement of the midface and ossification was measured with lateral cephalometry and 3-dimensional computed tomography imaging, respectively. At long-term follow-up (mean, 4.6 years), the facial contours retained the initial distraction geometry with almost no relapse, showing that the ideal facial contour and occlusion could be obtained. Bone deposition was found to be continually progressing even 6 months postoperatively, and more than 6 months of consolidation was required for complete ossification that mainly occurred in the pterygomaxillary junction and lateral orbital wall. The dual-distraction technique can induce balanced growth without the recurrence of hypoplasia, and it may eventually yield satisfactory outcomes in Crouzon syndrome.

According to previous reports about the experimental study of transport disk distraction osteogenesis (TDDO) for the reconstruction of bone defects, TDDO showed great feasibility of successful bone regeneration. However, those studies had some limitations in their design and analysis of the results, either. In this report, we intended to verify the effect of TDDO in the reconstruction of skull defects with a combined result of distraction osteogenesis and bone graft of transported disk (TD). Six female dogs were operated on and were given a 35×15-mm bilateral skull defect. In the experimental group, TDDO with internal distractors (7×14-mm TD) was performed. On the other side, in the control group, the bone defects were left to heal naturally. The distraction was performed from the postoperative fifth day at a rate of 1 mm/d. The distraction progressed for 14 days, and then the TD was maintained in the middle of the bone defect area. The 40% of the original bone defect area was left the same as the control side. The TD was expected to be survived as a bone graft during the consolidation period. After 3½ months of a consolidation period, the remained bone defects were measured by three-dimensional computed tomography. The solidity of the new bone was compared with the bone tissue of the normal skull bone. In the study group, the new bone formation was estimated to be 62.3% (SD, 25.1%) of the defect area, and in the control group, it was 44.8% (SD, 27.3%). The difference between the 2 groups was significant (P=0.04). The solidity of the newly generated bone by TDDO was not different from the normal skull (P=0.74). In this study, the concept of TDDO and bone graft seemed to promote new bone formation. The role of the TD could include bone regeneration from distraction osteogenesis as well as autogenous bone graft, although it needs more investigation. The relationship between the duration of distraction and the positive role of the TD as an autogenous bone graft in TDDO for better clinical application may be investigated.