Jong Woo Choi

Clinical application of human adipose tissue-derived mesenchymal stem cells in progressive hemifacial atrophy (Parry-Romberg disease) with microfat grafting techniques using 3-dimensional computed tomography and 3-dimensional camera.

BackgroundParry-Romberg disease is a rare condition that results in progressive hemifacial atrophy, involving the skin, dermis, subcutaneous fat, muscle, and, finally, cartilage and bone. Patients have been treated with dermofat or fat grafts or by microvascular free flap transfer. We hypothesized that adipose-derived stem cells (ASCs) may improve the results of microfat grafting through enhancing angiogenesis. We evaluated the utility of ASC in microfat grafting of patients with Parry-Romberg disease by measuring the change in the hemifacial volumes after injection of ASCs with microfat grafts or microfat grafts alone. MethodsIn April 2008, this investigation was approved by the Korean Food and Drug Administration and the institutional review board of the Asan Medical Center (Seoul, Korea) that monitor investigator-initiated trials. Between May 2008 and January 2009, 10 volunteers with Parry-Romberg disease (5 men and 5 women; mean age, 28 y) were recruited; 5 received ASC and microfat grafts and 5 received microfat grafts only. The mean follow-up period was 15 months. Adipose-derived stem cells were obtained from abdominal fat by liposuction and were cultured for 2 weeks. On day 14, patients were injected with fat grafts alone or plus (in the test group) 1 × 107 ASCs. Patients were evaluated postoperatively using a 3-dimensional camera and 3-dimensional CT scans, and grafted fat volumes were objectively calculated. ResultsSuccessful outcomes were evident in all 5 patients receiving microfat grafts and ASCs, and the survival of grafted fat was better than in patients receiving microfat grafts alone. Before surgery, the mean difference between ipsilateral and contralateral hemiface volume in patients receiving microfat grafts and ASCs was 21.71 mL decreasing to 4.47 mL after surgery. Overall resorption in this ASC group was 20.59%. The mean preoperative difference in hemiface volume in those receiving microfat grafts alone was 8.32 mL decreasing to 3.89 mL after surgery. Overall resorption in this group was 46.81%. The preoperative and postoperative volume differences between the groups was statistically significant (P = 0.002; random-effects model [SAS 9.1]). ConclusionsAdipose-derived stem cells enhance the survival of fat grafted into the face. A microfat graft with simultaneous ASC injection may be used to treat Parry-Romberg disease without the need for microvascular free flap transfer.

The search for the ideal thin skin flap: superficial circumflex iliac artery perforator flap--a review of 210 cases.

Background: The superficial circumflex iliac artery perforator flap is a thin skin flap that can be harvested reliably and quickly from the groin. It is ideal for single-stage resurfacing of cutaneous defects. The donor site heals well and is easily concealed. The authors clarify the anatomy, simplify the flap harvest technique, and outline the modifications to expand the applications of this flap. Methods: Between January of 2011 and January of 2014, 210 superficial circumflex iliac artery perforator flaps were performed at Asan Medical Center. The flaps were used for head and neck reconstruction (n = 13), upper extremity reconstruction (n = 19), lower limb reconstruction (n = 176), and reconstruction in the trunk region (n = 2). All flaps were raised suprafascially using a free-style approach. The anatomy of the flap, the elevation technique, and the results of the reconstruction were assessed. Results: The average flap size was 86 cm2, ranging from 17.5 to 216 cm2 (mean vertical width, 6.3 cm; mean transverse length, 13.5 cm). Total flap loss occurred in 10 flaps (4.8 percent). Two patients developed complications at the donor site. Debulking surgery was performed in five patients (2.4 percent). The average follow-up period was 400 days (range, 30 to 1690 days). Conclusions: The superficial circumflex iliac artery perforator flap enables accurate resurfacing of moderate-size cutaneous defects. It is vascularly robust and versatile for use in different sites. This is the thinnest skin flap presently available and has the potential to become the new workhorse flap for resurfacing moderate-size skin defects. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

In vivo differentiation of undifferentiated human adipose tissue-derived mesenchymal stem cells in critical-sized calvarial bone defects.

AbstractAdult stem cells have recently drawn considerable attention for potential cell therapy applications. However, critical details about their specific in vivo environments and cellular activities are unclear. Adipose tissue-derived mesenchymal stem cells (ASCs) are attractive candidates for treating bone defects, but most studies focus on delivery of in vitro-differentiated cells. We assessed various scaffolding materials for the ability to support osteogenic differentiation of undifferentiated human ASCs in vivo, in athymic nude rat calvaria. Twenty-four 9- to 10-week-old athymic nude Sprague-Dawley rats (250 g) were used in these experiments. Fat tissue from 3 patients was harvested from abdominal tissue discarded during reconstructive breast surgery by transverse rectus abdominis myocutaneous flap, performed at the Asan Medical Center after resection of breast cancer. Human ASCs were extracted from discarded adipose tissue and isolated based on standard International Society for Cellular Therapy protocols. Adipose tissue-derived mesenchymal stem cells were seeded on polylactic glycolic acid, atelocollagen, and hydroxyapatite scaffolds, and osteogenesis was evaluated using bone mineral densitometry, histology, immunohistochemistry, and reverse transcription polymerase chain reaction. The gross appearance of scaffolds seeded with ASCs was strikingly different from that of scaffolds alone. Bone mineral densitometry analysis revealed a 2- to 3-fold increase in mineral density in ASC-seeded scaffolds. In addition, undifferentiated ASCs seeded onto hydroxyapatite scaffolds, but not onto collagen or polylactic glycolic acid scaffolds, expressed human messenger RNA for osteogenic markers such as alkaline phosphatase, osteopontin, osteocalcin, and osteonectin. These results indicate that undifferentiated human ASCs can differentiate into osteocytes or osteoblasts in athymic nude rat calvaria, and the importance of appropriate scaffolding for in vivo ASC differentiation.

The reliability of a surgery-first orthognathic approach without presurgical orthodontic treatment for skeletal class III dentofacial deformity.

BackgroundOrthognathic surgery with presurgical and postsurgical orthodontic treatment is the most widely accepted method for the correction of skeletal or dentoalveolar malocclusion. However, recent advancements in presurgical orthodontic simulations and postsurgical orthodontic treatments using miniscrews have shown remarkable stability and control of the occlusion after orthognathic surgery. Thus, we have adopted a surgery-first orthognathic approach without presurgical orthodontic treatment, based on a novel presurgical simulation process using a dental model. We hypothesized that this treatment modality will be feasible for skeletal class III dentofacial deformity patients. Materials and MethodsThis prospective study investigated intervention outcomes in 24 standard and 32 surgery-first approaches for patients with skeletal class III dentofacial deformity. The patients underwent orthognathic surgery between December 2007 and July 2010. In the surgery-first approach, a dental model was created and a novel preoperative orthodontic simulation of the standard presurgical orthodontic treatment was performed to determine the final occlusion between the maxilla and mandible. Changes in cephalometric landmarks were compared between the standard and surgery-first groups in the preoperative, immediate postoperative, and postoperative periods. The Student t test, Kruskal-Wallis test, and a linear mixed model were used for statistical analysis. ResultsThe follow-up period ranged from 12 to 36 months (average, 20.5 months). The average age of the patients was 22.4 years, with 16 male and 40 female patients. We found that a surgery-first approach without presurgical orthodontic treatment is possible and can give similar results to standard orthognathic surgery. The statistical analysis showed that changes in skeletal cephalometric landmarks were similar between the surgery-first and standard approach groups, according to each period. However, the cephalometric landmarks relating to the dental component showed changes between treatment groups at different time points but similar final values. This suggests that the benefits of postsurgical orthodontic treatment after the surgery-first approach could be similar to those obtained via the standard approach. ConclusionsThe surgery-first orthognathic approach without presurgical orthodontic treatment was found to be predictable and applicable to treat class III dentofacial deformities, and we recommend consideration of the technique as an effective alternative for treating this condition.

Are polytetrafluoroethylene (Gore-Tex) implants an alternative material for nasal dorsal augmentation in Asians?

Backgrounds: Augmentation rhinoplasty is a relatively common procedure in Korea. Alloplastic materials such as silicone, supramid mesh, Proplast, Mersiline, Medpor, and hydroxyapatite are frequently used for dorsal augmentation. Alloplastic implants have advantages, such as ready availability and no donor-site morbidity, but are associated with higher infection and extrusion rates than are autogenous materials. Although polytetrafluoroethylene (Gore-Tex) implants have recently been introduced, such implants are yet to be established as an alternative for nasal augmentation because of a lack of relevant reports. Methods: From March 1998 to March 2007, we operated on 873 nasal dorsum augmentation patients using hard-type Gore-Tex implants. The patients were all of Korean ethnicity. There were 826 female and 47 male patients and aged ranging from 18 to 57 years (mean, 24 y). The Gore-Tex implant thicknesses were 3.1 to 4.9 mm (used in 59% of cases), 2 to 3 mm (8%), or 5 to 6 mm (33%). The Gore-Tex implants were used only for dorsal augmentation, whereas conchal or septal cartilage was used for nasal tip plasty. Results: Of the total of 873 patients, 257 received long-term follow-up (mean follow-up, 34 mo). Apart from 34 patients with revision, no patient reported dissatisfaction, and there were no reports of problems with nasal contour, implant migration, or resorption of the implant material. The overall complication rate was 3.8%. Of the 257 long-term follow-up patients, 34 (13.5%) required revision. Four of these patients involved minor complications that were managed conservatively, whereas 30 patients required implant removal and revision procedures. These 30 cases included irregularity, infection, deviation, unfavorable dorsum height, and apparent implant silhouette, in addition to obvious supratip deformity. A review of the literature revealed that Gore-Tex implants seemed to have a lower implant removal rate than silicone implants. However, the overall complication rates seemed to be similar when Gore-Tex and silicone implants were used for nasal dorsum augmentation in Asian patients. We found that Gore-Tex implants were effective and safe for use in primary and revision rhinoplasty in Asians. Gore-Tex implants seem to have an overall complication rate similar to that of silicone implants. Thus, Gore-Tex can be considered as an alternative material for dorsal augmentation rhinoplasty but turned out not to have definite advantages over the silicone implants.

Applications of medial sural perforator free flap for head and neck reconstructions.

Oropharyngeal defects left after tumor resection are usually reconstructed with radial forearm or anterolateral thigh (ALT) perforator free flaps, but these flaps can be too thin or too thick. In this study, medial sural perforator free flaps with intermediate volumes were used for oropharyngeal reconstruction. Of the 243 patients with oropharyngeal cancer who underwent head and neck reconstruction between October 2006 and October 2011, the medial sural perforator free flap was used 20 times. The number and locations of the main sizable perforators, the dimensions and thickness of the flap, and the length of the pedicle were recorded. Satisfactory results were achieved in 18 patients. The flaps in the two remaining cases failed. The vertical locations of the main sizable medial sural perforators were 6 to 15 cm away from the popliteal crease. The medial sural perforator free flaps ranged from 4 to 10 mm in thickness. Medial sural perforator free flaps may be an alternative for medium-sized defects that cannot be properly reconstructed with radial forearm or ALT perforator free flaps because of their inappropriate flap volume.

Changes in graft thickness after skull defect reconstruction with autogenous split calvarial bone graft.

Abstract The ideal material for primary reconstruction of skull defect would be the autogenous bone. However, the long-term evaluation regarding the change in bone graft thickness has not been reported. In this article, we analyzed the thickness changes of the graft according to the time period. Between March 2005 and February 2011, a total of 29 patients underwent skull reconstruction with autogenous split calvarial bone grafts. After applying exclusion criteria, computed tomographic (CT) images of 15 patients were analyzed. The donor bone was harvested in full thickness as 1 piece and then as split. One half of the bone plate was transferred to the defect site; the other half, to the donor site. Both halves were fixed with titanium plates. To compare graft thickness changes, immediate postoperative and follow-up CT scans were analyzed by a single researcher. An anatomic reference was appointed for each patient, and the thickness of the graft on the same level was measured on time-series CT images. Collected data were analyzed with a polynomial random coefficient model. The main causes of the skull defects were trauma and tumor excision. In all cases, the graft thickness was not decreased but even increased in both the donor and recipient sites. The mean graft thicknesses between 6 months and 1 year after the surgery as well as those between 2 and 3 years after the surgery were 1.24-times and 1.56-times thicker than the immediate postoperative thickness, respectively. Graft thickness turned out to be either maintained or increased over time.

Midfacial degloving approach for resectioning and reconstruction of extensive maxillary fibrous dysplasia.

Objective The traditional unilateral or bilateral buccogingival or bicoronal approach often seems to impose limitations on achieving complete resection and reconstruction of the extensive midfacial fibrous dysplasia. Therefore, we hypothesized that the midfacial degloving approach could be used for the correction of maxillary fibrous dysplasia, which has been primarily used for paranasal sinus lesions or nasopharyngeal tumor. Methods The study involved 5 maxillofacial fibrous dysplasia patients who underwent a midfacial degloving surgical procedure. There were 4 male patients and 1 female patient with a mean age of 16.8 years. The average, mean follow-up duration was 17.8 months. A wide, subperiosteal dissection was made along the anterior wall of the maxilla and pyriform aperture over the level of the infraorbital foramen. A bilateral, circumferential, nasal vestibular incision and dissection allowed for bilateral degloving of the middle third of the face over the infraorbital rim. Then total or subtotal resection, followed by reconstruction using an iliac bone graft, was performed. Results The midface, degloving approach provided visualization of the medial maxillary wall, the pterygoid junction, nasofrontal suture, infraorbital rim, and laterally to the temporal process of the zygoma. Subtotal or total resection of the lesions and reconstruction with bone grafts was possible in all 5 patients, and there were no complications. There was also no visible facial scarring and all patients expressed satisfaction with the cosmetic outcome. Conclusions The midfacial, degloving approach was found to be safe and effective for maxillofacial fibrous dysplasia, and nearly total resection was possible. This approach allows for a wider dissection and resection compared with the traditional buccogingival approaches, and there was no visible facial scarring.

Total nose reconstruction using superselective embolisation and a forehead flap: overlooked in recurrent massive vascular malformations of the nose.

OBJECTIVESnMassive vascular malformations of the nose cause serious cosmetic, functional and psychological problems. Generally, no single treatment modality to date has provided satisfactory results. Therefore, multidisciplinary treatment approaches are being standardised. In spite of standard multidisciplinary treatments, especially postoperative outcomes in massive nasal vascular malformation cases are often aesthetically and functionally unsatisfactory due to the unique characteristics of the nose. While several studies report on the management of facial vascular malformations using local and distant flaps, none is specific to the nasal region.nnnMATERIALS AND METHODSnThe present article describes the treatment of four patients with recurrent massive nasal vascular malformation (which invades more than two-thirds of the nose) using a combined-procedure approach involving preoperative superselective embolisation, extensive (en bloc) malformation resection and nasal reconstruction using a paramedian forehead flap. Patients were followed up for a mean of 19 months. Preoperative assessments included MR angiography, selective angiography and physical examination, including Doppler sonography. Preoperative superselective embolisation was then performed by a radiologist. On post-embolisation day 2, patients underwent en bloc resection and total nasal reconstruction with paramedian forehead flap hitherto overlooked in the treatment of nasal vascular malformation.nnnRESULTSnSatisfactory results were achieved in all four patients. Three patients suffered a high-flow malformation and one suffered a low-flow malformation. As confirmed by the radiologist, no recurrences were noted. Colour matching and nasal contouring were satisfactory in all cases. There were no major complications such as serious infection, recurrent ulceration, postoperative bleeding or flap failure. All patients responded positively.nnnCONCLUSIONSnThe present novel treatment of massive vascular malformations of the nose using selective embolisation, en bloc resection and a paramedian forehead flap was successful. The findings indicate that this treatment of massive nasal vascular malformations leads to successful functional and aesthetic outcomes. The patients were followed up for an average of 2 years and ongoing follow-up is scheduled.

Appropriate and Effective Dosage of Bmp-2 for the Ideal Regeneration of Calvarial Bone Defects in Beagles.

BACKGROUNDnAlthough bone morphogenetic protein-2 (BMP-2) is a potent growth factor, the appropriate and effective dosages for ideal bone formation according to defect size and type remain to be established. This study was designed to measure the effects of BMP-2 on calvarial defects in the beagle dog, by means of three-dimensional computed tomographic imaging.nnnMETHODSnEight beagles of equal age and weight were divided into one control and three experimental groups. After creating four circular 20-mm diameter defects, a BMP-2/tricalcium phosphate scaffolding mixture with concentrations of BMP-2 was introduced. The defect filling response was assessed until 16 weeks by three-dimensional computed tomograpy for the thickness, area, and density of the regenerating bone.nnnRESULTSnStatistically significant responses to BMP-2 were observed. The mean thicknesses of the regenerated bone were 1.6 mm for the control group and 1.6, 2.1, and 2.8 mm for 10, 50, and 200 µg/ml, respectively. As the original mean thickness of the calvarial bone in the beagles was 2.0 mm, a 50-µg quantity of BMP-2 proved to be ideal for 2-cm calvarial defects. The original surface area of the defect created was 314 mm. The mean surface areas of the regenerated bone were 181.94 mm for the control group, and 237, 276, and 288 mm for 10, 50, and 200 µg/ml.nnnCONCLUSIONSnBMP-2 promotes anatomically significant bone regeneration in critical-size cranial defects in this model, with an optimal dose-response at 50 µg/ml and without hyperosteogenesis or hypo-osteogenesis.