Shao Jiang

The osteogenic potential of adipose-derived stem cells for the repair of rabbit calvarial defects

Introduction: Bone replacement is often necessary during reconstruction of craniofacial anomalies or trauma. Adipose-derived stem cells (ASCs) possess osteogenic potential and are a promising cell source for bone tissue engineering. The present study was designed to assess the osteogenic potential and utility of using ASCs to regenerate bone in a rabbit calvarial defect model. Methods: Rabbit ASCs were seeded on gelatin foam (GF) scaffolds and induced in osteogenic medium containing bone morphogenetic protein (BMP)-2. Thirty-four 8-mm calvarial defects were randomly treated with autograft, no treatment, GF scaffold, GF + ASCs, or GF + osteoinduced ASCs. After 6 weeks, calvaria were harvested and underwent histologic and radiologic analyses to compare healing between the treatment groups. Results: Defects treated with autograft underwent complete healing. Radiologically, there were no significant (P > 0.05) differences in healing among empty defects, and those treated with GF alone or GF plus osteoinduced ASCs. Osteoinduced ASCs exhibited significantly (P < 0.05) greater healing than noninduced ASCs. Conclusion: Preimplantation osteoinduction of ASCs enhances their osteogenic capacity. Lack of a significant osteogenic effect of ASCs on calvarial healing at 6 weeks may be secondary to use of noncritical-sized defects. Larger defects would likely demonstrate the osteogenic potential of ASCs more definitively.

500 Consecutive Patients with Free TRAM Flap Breast Reconstruction : A Single Surgeon's Experience

Background: This study reports on the longitudinal experience and outcomes of one surgeon performing free transverse rectus abdominis musculocutaneous (TRAM) flaps on 500 consecutive patients between 1992 and 2003. Methods: A retrospective review of hospital and outpatient records was performed. Specific risk factors for successful reconstruction were reviewed, including American Society of Anesthesiologists class, obesity, smoking, medical comorbidities, and irradiation and chemotherapy history. Outcomes measured included the length of hospital stay and the incidence of complications including both thrombotic and nonthrombotic complications. Results: Five hundred sixty-nine free TRAM breast reconstructions were performed in a total of 500 patients. Preoperative patient risk factors included obesity, smoking, hypertension, diabetes, and cardiac disease, with three-fourths of the patients being American Society of Anesthesiologists class II or III. Intraoperative or postoperative thrombosis occurred in 35 reconstructions (6.2 percent). Only one patient had a total flap loss, for a flap success rate of 99.7 percent. Significant nonthrombotic complications occurred in 67 patients (13.4 percent). The most common nonthrombotic complications included wound infection (3 percent), fat necrosis (3 percent), and delayed healing (3 percent). Revision procedures after free TRAM reconstruction were performed in 14.4 percent of cases. Conclusions: The free TRAM flap is a highly reliable method of autogenous breast reconstruction in a broad spectrum of patients. This free flap has a very low thrombotic complication rate, and abdominal donor defect problems have been limited. Finally, this method of reconstruction can be reliably offered to a wide group of patients, including those considered at high risk for a pedicled TRAM flap reconstruction.

A Successful Algorithm for Limiting Postoperative Fistulae following Palatal Procedures in the Patient with Orofacial Clefting

Background: Palatal procedures include (1) primary palatoplasty, (2) oronasal fistulas repair, and (3) secondary palatoplasty for velopharyngeal insufficiency. Any time a palatal procedure is performed, postoperative fistulas remain potential consequences. Presented here is a successful algorithm for performing palatal procedures and decreasing the rate of postoperative fistulas in a large, single-surgeon, consecutive series. Methods: A retrospective review of all consecutive palatal procedures performed between 2002 and 2006 including (1) primary palatoplasty, (2) oronasal fistulas repair, and (3) secondary palatoplasty for velopharyngeal insufficiency was performed. Cleft Veau type, surgical technique, and outcomes are reviewed. The algorithm included (1) relaxing incisions, (2) complete intravelar veloplasty, (3) total release of the tensor tendon, (4) dissection of the neurovascular bundle with optional osteotomy of the foramen, and (5) incorporation of acellular dermal matrix to achieve complete nasal lining reconstruction. Results: Two hundred sixty-eight palatal procedures were performed: (1) 132 primary Furlow palatoplasties yielding one symptomatic post–Furlow palatoplasty fistula (0.76 percent) (acellular dermal matrix was used in 39.4 percent of primary palatoplasties); (2) 55 oronasal fistula repairs yielding two symptomatic postoperative fistulas (3.6 percent) (acellular dermal matrix was used in 90.9 percent of fistula repairs); and (3) 81 secondary palatoplasties for velopharyngeal insufficiency resulting in no postoperative fistulas. Acellular dermal matrix was used in 14.8 percent of secondary palatoplasties for velopharyngeal insufficiency. No recommendations for speech surgery followed palatoplasty. Conclusions: Using the proposed algorithm in this single-surgeon consecutive series of 268 cases, the authors achieved the lowest reported incidence of postoperative fistulas in all forms of palatal procedures, including the lowest incidence (0.76 percent) of symptomatic palatal fistulas following primary Furlow palatoplasty.

Demineralized bone matrix and resorbable mesh bilaminate cranioplasty: a novel method for reconstruction of large-scale defects in the pediatric calvaria.

Background: Pediatric patients with large-scale calvarial defects often lose the osteogenic potential of their dura before developing a diploic space sufficient to facilitate harvest of split-thickness calvarial grafts. The authors present their experience using demineralized bone matrix and resorbable mesh bilaminate for the repair of large-scale cranial defects in pediatric patients. Methods: A retrospective review of the Cleft-Craniofacial Center database at Children’s Hospital of Pittsburgh was performed from 2003 through 2007. Patients who underwent cranioplasties using demineralized bone matrix and resorbable mesh bilaminate were identified. Indications, defect size, quantity of demineralized bone matrix used, complications, follow-up, and computed tomographic scans were reviewed. Results: Eleven patients underwent 13 skull reconstructions using demineralized bone matrix and resorbable mesh bilaminate cranioplasty. Mean age was 3.6 years (range, 2.1 to 4.9 years); average defect size was 30.8 cm2 (range, 6.6 to 80.0 cm2). Mean clinical follow-up was 29.3 months (range, 13.4 to 41.8 months). All patients had follow-up computed tomographic scans. The average time of follow-up scan was 18.7 months postoperatively (range, 6.9 to 32.6 months). Seven patients had immediate postoperative scans in addition to long-term follow-up scans, facilitating the calculation of a 98 percent average defect healing (range, 95 to 100 percent). All patients had clinically stable cranial reconstructions at follow-up. Conclusions: When autogenous bone is not available, demineralized bone matrix and resorbable mesh bilaminate cranioplasty is an alternative method of calvarial reconstruction when used in a healthy site free of scarring or infection. This cranioplasty technique has provided consistent bony regeneration, with no donor-site morbidity.

Open reduction and internal fixation of dislocated condylar fractures in children: long-term clinical and radiologic outcomes.

The purpose of this study was to investigate the long-term clinical and radiologic outcomes of treating dislocated condylar fractures sustained in childhood with open reduction and internal fixation (ORIF). Six children 14 years or younger with a condylar neck or subcondylar fracture with dislocation of the condyle from the glenoid fossa were treated with ORIF. Patients were followed for 27 to 92 months post-ORIF (mean: 67.6 months) with routine clinical and radiologic examinations. On the dislocated side, all patients radiographically showed signs of remodeling of the condylar process and shortening of the ramus. Subsequent to their fractures, 3 patients were classified with Angle class II malocclusion, retrognathism, and deviation of the mandibular symphysis. Four patients had objective and/or subjective signs of temporomandibular (TMJ) dysfunction. Until open surgery demonstrates a consistent functional advantage, nonsurgical management should be considered the first treatment option for the dislocated pediatric condylar fracture.

Diagnosis and treatment of velopharyngeal insufficiency: clinical utility of speech evaluation and videofluoroscopy.

Introduction: The workup of velopharyngeal insufficiency (VPI) includes speech pathology evaluation and examination of velopharyngeal anatomy and physiology. This study sought to determine whether perceptual speech symptoms were predictive of velopharyngeal closure. Patients and Methods: A retrospective chart review of patients with VPI following primary palatoplasty was performed. All patients underwent perceptual speech evaluation using the Pittsburgh Weighted Speech Scale (PWSS) and examination of velopharyngeal anatomy by videofluoroscopy. PWSS scores were correlated to velopharyngeal closure. Results: All patients exhibited clinical VPI (PWSS = 5–27). No patient demonstrated complete velopharyngeal closure on videofluoroscopy. Velopharyngeal closure on the lateral view showed a statistically significant, moderate correlation with both the PWSS total score (rs = −0.424; P = 0.03) and the phonation subscore (rs = −0.405; P = 0.04). Conclusions: Although certain aspects of speech are related to velopharyngeal anatomy, speech and videofluoroscopic studies each provide unique information in the workup of VPI. Selection of surgical approach often depends on anatomic factors, and improvement in speech postoperatively indicates successful treatment.

Free Tissue Transfer: Comparison of Outcomes between University Hospitals and Community Hospitals

Background: In university hospitals, free tissue transfer has become a standard method of reconstruction for a broad spectrum of defects. Because of its complexity, free tissue transfer has not been routinely performed in a community hospital setting. This study reports the outcomes of two equal groups of free tissue transfer performed by the same surgeons, comparing the university versus the community hospital setting. Methods: A total of 735 free tissue transfers were performed at one university hospital and six community hospitals in our region over a 10-year study period. Outcome parameters used in this study included wound complications such as infection, dehiscence, delayed healing, hematoma, and fat necrosis. Results: A total of 674 operations were performed using 735 free tissue transfers: 386 free tissue transfers were performed at the university hospital (53 percent) and 349 (47 percent) were performed at the community hospital. Categories of free tissue transfer reconstruction included breast, lower extremity, head and neck, and upper extremity reconstructions. Most of the breast reconstructions were performed in the community hospital, whereas most of the lower extremity and head and neck reconstructions were performed at the university hospital. Fifty-one major postoperative complications occurred in the university hospital (14 percent), while 31 (10 percent) occurred in the community hospital. Complication rates did not differ significantly between settings; however, there was a trend toward more wound infections in the university hospital and more cases of fat necrosis in the community hospital, most likely reflected in the differing case mix between hospital settings. Conclusion: Free tissue transfer is an effective and practical method of reconstruction that has been safely performed in both university and community hospital settings.

Leporine-derived adipose precursor cells exhibit in vitro osteogenic potential.

Adipose-derived stem cells (ASCs) possess osteogenic potential and have been shown to undergo in vitro osteoblastic differentiation and promote bone regeneration in vivo. In this study, we describe the isolation and osteoblastic differentiation of rabbit ASCs and their behavior on a gelatin foam scaffold. These studies will form the basis of future in vivo studies of the osteogenic potential of rabbit ASCs for calvarial defect repair. Adipose-derived stem cells were isolated from New Zealand White rabbits and cultured in osteogenic medium ± bone morphogenetic protein 2. Osteoblastic differentiation was assessed via histochemical stains for alkaline phosphatase (AP) and extracellular matrix (ECM) calcification. Reverse transcriptase polymerase chain reaction was performed to evaluate the expression of AP and the osteogenic transcription factor Runx2. Adipose-derived stem cells were seeded onto gelatin foam scaffolds at various densities, and cell proliferation was measured fluorometrically. Cells isolated from rabbit adipose tissue exhibited classic ASC morphology. Adipose-derived stem cells cultured in osteogenic medium exhibited more robust staining for AP and ECM calcification compared with ASCs in control medium. Furthermore, this staining was more marked in male ASCs versus female ASCs and also enhanced by bone morphogenetic protein 2. mRNA for AP and Runx2 were also increased in the osteoinduced cells. Theoptimal seeding density was 1 × 105 ASCs on an 8-mm gelatin foam scaffold. We have shown that rabbit ASCs have in vitro osteogenic potential and are compatible with a gelatin foam scaffold. Characteristic features of osteoblasts, such as ECM mineralization and expression of osteogenic genes, were demonstrated in this cell population. In vitro osteoblastic differentiation and scaffold studies are necessary before in vivo trials. The mechanism underlying the sex-based variation in osteoblastic differentiation is unknown but may involve signaling via factors such as estrogen.

Acellular dermal matrix in the treatment and prevention of exposed vertical expandable prosthetic titanium ribs.

Study Design. Case series. Objective. To illustrate the use of acellular dermal matrix (ADM) in treatment and prevention of exposed vertical expandable prosthetic titanium rib (VEPTR) implants. Summary of Background Data. In the pediatric population with severe kyphoscoliosis, VEPTR is an effective tool during growth for the correction of ribcage deformity. Prolonged VEPTR therapy can result in wound breakdown, implant exposure, and infection. Treatment includes the use of prolonged antibiotics, muscle flaps, and, when salvage fails, removal of the VEPTR. The use of ADM in the treatment and prevention of VEPTR exposure has not been previously described. Methods. Between January 2002 and January 2010, eight patients who underwent placement of ADM for the treatment and prevention of exposed VEPTR devices were identified. Their records were reviewed for diagnosis, sex, age of patient at initial VEPTR placement, position of VEPTR placement, number of VEPTR expansions, wound complications, ADM use, adjunct procedures, and length of wound follow-up. Results. ADM was used in eight patients. In five patients ADM was used for compromised soft tissue overlying the VEPTR and threatened exposure of the hardware. In these cases, subsequent expansions occurred without incident and the wound remained stable with an average follow-up of 7.6 months. In three patients, ADM was used for exposed VEPTR hardware secondary to wound breakdown. Average follow-up was 3.3 months. In two of the three cases of exposed and contaminated hardware, stable soft tissue coverage was achieved and continued VEPTR therapy was achieved. One of the three cases of exposure involved infected and prominent hardware with purulence. This patient failed to clear the infection and required complete device removal. Conclusion. ADM can treat and prevent exposed VEPTR, allowing subsequent VEPTR expansions and minimizing the need for muscle flap coverage and/or implant removal and replacement.

Magnetic resonance imaging as a predictor of submucous cleft palate severity and guide for surgical intervention.

BackgroundDiagnosis of submucous cleft palate (SMCP) is frequently delayed, adversely affecting speech outcomes. Previous studies show that MRI reliably identifies structural abnormalities in velopharyngeal musculature. This information has potential to assist with diagnosis and treatment decisions. AimsThe objectives of this study were to (1) develop a clinician-friendly MRI grading scale of SMCP anatomy, (2) identify correlations between radiographic cleft severity and clinical severity using Pittsburgh Weighted Speech Scores (PWSS), and (3) determine if MRI is a predictor of surgical efficacy in improving PWSS. DesignThirty patients presenting to our Cleft Palate-Craniofacial Clinic for evaluation of velopharyngeal insufficiency (VPI) and suspected SMCP were reviewed. VPI severity was clinically graded using PWSS. All patients underwent MRI to grade palatal abnormalities, using a novel MRI grading scale. PWSS and cleft severity on MRI were compared. A subgroup of patients (n = 19) underwent palatoplasty. Preoperative and postoperative PWSS were compared. Degree of PWSS improvement was then correlated with the preoperative MRI grade. ResultsTwenty-nine out of 30 MRIs demonstrated abnormal palate anatomy. Of the 30 patients evaluated, 5 clinically improved with speech therapy alone. In this subgroup, MRI severity did not correlate with PWSS (P = 0.06–0.6). Nineteen patients underwent palatoplasty. Of these, 14 demonstrated improved postoperative PWSS. There were no significant correlations between severity of cleft on imaging and preoperative PWSS or score improvement (P = 0.056–0.65). ConclusionWhile MRI accurately identifies structural abnormalities of the soft palate, these abnormalities do not reliably correspond to clinical severity. Clinical examination including speech scores and dynamic speech testing, rather than static MRI, should guide treatment decisions and surgical indications.