Yong Chen Por

Recombinant Human BMP-2 Enhances the Effects of Materials Used for Reconstruction of Large Cranial Defects

PURPOSE Cranial defect reconstruction presents 2 challenges: induction of new bone formation, and providing structural support during the healing process. This study compares quantity and quality of new bone formation based on various materials and support frameworks. MATERIALS AND METHODS Eighteen dogs underwent surgical removal of a significant portion of their cranial vault. Demineralized bone matrix was used to fill the defect in all animals. In 9 dogs, recombinant human bone morphogenetic protein-2 (rhBMP-2) was added, while the other 9 served as the non-rhBMP-2 group. In each group, 3 animals were fixed with cobalt chrome plates, 3 with adding platelet-rich plasma, and 3 fixed with a Lactosorb (Walter Lorenz Surgical, Inc, Jacksonville, FL) resorbable mesh. Necropsy was done at 12 weeks postoperative. Histomorphometry, density, and mechanical properties of the regenerate were analyzed. RESULTS The non-rhBMP-2 groups showed minimal substitution of demineralized bone matrix with new bone, while only sporadic remnants of demineralized bone matrix were present in the rhBMP-2 groups. The defect showed more new bone formation (P < .001) and density (P < .001) in the rhBMP-2 groups by Kruskal-Wallis test. The area of new bone was not significantly different among the rhBMP-2 subgroups. The resorbable mesh struts showed no sign of bone invasion or substitution. In the non-rhBMP-2 resorbable mesh group, demineralized bone matrix almost totally disintegrated without replacement by new bone. CONCLUSIONS The addition of rhBMP-2 to demineralized bone matrix accelerated new bone formation in large cranial defects, regardless of the supporting framework or the addition of platelet-rich plasma. The use of a resorbable mesh in such defects is advisable only if rhBMP-2 is added.

Sustained release of hydrophobic drugs by the microfluidic assembly of multistage microgel/poly (lactic-co-glycolic acid) nanoparticle composites

The poor solubility of many newly discovered drugs has resulted in numerous challenges for the time-controlled release of therapeutics. In this study, an advanced drug delivery platform to encapsulate and deliver hydrophobic drugs, consisting of poly (lactic-co-glycolic acid) (PLGA) nanoparticles incorporated within poly (ethylene glycol) (PEG) microgels, was developed. PLGA nanoparticles were used as the hydrophobic drug carrier, while the PEG matrix functioned to slow down the drug release. Encapsulation of the hydrophobic agents was characterized by fluorescence detection of the hydrophobic dye Nile Red within the microgels. In addition, the microcomposites prepared via the droplet-based microfluidic technology showed size tunability and a monodisperse size distribution, along with improved release kinetics of the loaded cargo compared with bare PLGA nanoparticles. This composite system has potential as a universal delivery platform for a variety of hydrophobic molecules.

In Vivo Tissue Engineering Over Wounds With Exposed Bone and Tendon: Autologous Dermal Grafting and Vacuum-assisted Closure

Flap coverage is ideal for wounds exposing bone and tendon, but technically less demanding and speedier options might be considered for small shallow wounds and for wounds with adjacent tissue loss precluding local flaps. We revisited the use of autologous dermal grafting-in combination with vacuum-assisted closure (VAC)-for such wounds.Five small- to medium-sized wounds exposing bone, joint, and/or tendon were each covered using an autologous meshed dermal graft followed by VAC application to induce granulation. Closure was completed at 2 weeks by split-thickness skin grafting over the granulating dermis graft.Complete and stable wound healing was achieved in all cases within 4 weeks of dermal grafting over exposed bone with excellent outcome at 1 year in terms of donor site healing and return to function. All healed wounds had a nearly flush profile with no bulkiness in the foot and toe region.Autologous dermal grafting with VAC is an integrated in vivo tissue engineering system in which the meshed dermis acts as an attractive scaffold for granulation within the conducive VAC-medium. As an alternative to flap surgery or dermal substitutes, the technique is simple, swift, and cost-effective for immediate closure of small shallow wounds and even multiple small wounds, exposing bone and tendon particularly in the lower legs, feet, and toes.

Bone generation in the reconstruction of a critical size calvarial defect in an experimental model.

This study was designed to investigate the optimal combination of known osteogenic biomaterials with shape conforming struts to achieve calvarial vault reconstruction, using a canine model. Eighteen adolescent beagles were divided equally into 6 groups. A critical-size defect of 6 x 2 cm traversed the sagittal suture. The biomaterials used for calvarial reconstruction were demineralized perforated bone matrix (DBM), recombinant human bone morphogenetic protein 2 (rhBMP2), and autogenous platelet-rich plasma (PRP). The struts used were cobalt chrome (metal) or resorbable plate. The groupings were as follows: 1) DBM + metal, 2) DBM + PRP + metal, 3) DBM + PRP + resorbable plate, 4) DBM + rhBMP2 + metal, 5) DBM + rhBMP2 + PRP + metal, and 6) DBM + rhBMP2 + resorbable plate. Animals were killed at 3 months after surgery. There was no mortality or major complications. Analysis was performed macroscopically and histologically and with computed tomography. There was complete bony regeneration in the rhBMP2 groups only. Non-rhBMP2 groups had minimal bony ingrowth from the defect edges and on the dural surface, a finding confirmed by computed tomographic scan and histology. Platelet-rich plasma did not enhance bone regeneration. Shape conformation was good with both metal and resorbable plate. rhBMP2, but not PRP, accelerated calvarial regeneration in 3 months. The DBMs in the rhBMP2 groups were substituted by new trabecular bone. Shape molding was good with both metal and resorbable plate.This study was designed to investigate the optimal combination of known osteogenic biomaterials with shape conforming struts to achieve calvarial vault reconstruction, using a canine model. Eighteen adolescent beagles were divided equally into 6 groups. A critical-size defect of 6 × 2 cm traversed the sagittal suture. The biomaterials used for calvarial reconstruction were demineralized perforated bone matrix (DBM), recombinant human bone morphogenetic protein 2 (rhBMP2), and autogenous platelet-rich plasma (PRP). The struts used were cobalt chrome (metal) or resorbable plate. The groupings were as follows: 1) DBM + metal, 2) DBM + PRP + metal, 3) DBM + PRP + resorbable plate, 4) DBM + rhBMP2 + metal, 5) DBM + rhBMP2 + PRP + metal, and 6) DBM + rhBMP2 + resorbable plate. Animals were killed at 3 months after surgery. There was no mortality or major complications. Analysis was performed macroscopically and histologically and with computed tomography. There was complete bony regeneration in the rhBMP2 groups only. Non-rhBMP2 groups had minimal bony ingrowth from the defect edges and on the dural surface, a finding confirmed by computed tomographic scan and histology. Platelet-rich plasma did not enhance bone regeneration. Shape conformation was good with both metal and resorbable plate. rhBMP2, but not PRP, accelerated calvarial regeneration in 3 months. The DBMs in the rhBMP2 groups were substituted by new trabecular bone. Shape molding was good with both metal and resorbable plate.

Results of Primary Repair of Submucous Cleft Palate With Furlow Palatoplasty in Both Syndromic and Nonsyndromic Children.

Objective We hypothesize that primary repair of submucous cleft palate (SMCP) with Furlow palatoplasty will not lead to significant differences in speech outcomes for syndromic and nonsyndromic children. Design Retrospective analysis of patients with primary Furlow repair of SMCP between 2004 and 2012. Setting Tertiary care center. Patients/Participants Thirty-four patients (15 boys; 44%) satisfied our inclusion criteria: multidisciplinary consensus on diagnosis of SMCP, failed trial of speech-language rehabilitation, at least 4 years old at the time of primary surgery, at least 6 months follow-up with a repeat set of postoperative speech assessments. Interventions Primary Furlow palatoplasty for SMCP. Main Outcome Measures Primary outcomes were based on postoperative perceptual speech assessments and the need for revision surgery. Secondary outcomes included improvement in nasalance scores, postoperative complications, and change in and time to normalization of velar closing ratios. Results Mean age at surgery = 7.7 years. Of the patients, 17 (50%) were syndromic and 11 (32%) had associated hearing loss. Mean follow-up = 48 months. No patients had postoperative complications, such as wound dehiscence or fistula; however, two patients (one syndromic, one nonsyndromic) required secondary procedures. Velar closing ratios for all patients increased (P < .05) and approached normal at an average of 1.3 years postoperatively. Conclusions Although the Furlow palatoplasty can correct anatomic anomalies, it cannot achieve normal perceptual resonance in syndromic patients, possibly because of inherent higher-order deficiencies that affect speech production. Further studies with greater patient numbers are necessary to achieve population statistical significance.

Subunit Principle of Vulvar Reconstruction: Algorithm and Outcomes

Background Vulvar defects result chiefly from oncologic resection of vulvar tumors. Reconstruction of vulvar defects restores form and function for the purpose of coitus, micturition, and defecation. Many surgical options exist for vulvar reconstruction. The purpose of this article is to present our experience with vulvar reconstruction. Methods From 2007 to 2013, 43 women presented to us with vulvar defects for reconstruction. Their mean age at the time of reconstruction was 61.1 years. The most common cause of vulvar defect was from resection of vulvar carcinoma and extramammary Pagets disease of the vulva. Method s of reconstruction ranged from primary closure to skin grafting to the use of pedicled flaps. Results The main complications were that of long term hypertrophic and/or unaesthetic scarring of the donor site in 4 patients. Twenty-two patients (51%) were able to resume sexual intercourse. There were no complications of flap loss, wound dehiscence, and urethral stenosis. Conclusions We present a subunit algorithmic approach to vulvar reconstruction based on defect location within the vulva, dimension of the defect, and patient age and comorbidity. The gracilis and gluteal fold flaps are particularly versatile and aesthetically suited for reconstruction of a variety of vulvar defects. From an aesthetic viewpoint the gluteal fold flap was superior because of the well-concealed donor scar. We advocate the routine use of these 2 flaps for vulvar reconstruction.

Efficacy of Topical Timolol as Primary Monotherapy in Cutaneous Facial Infantile Hemangiomas.

AbstractRecent studies have shown that infantile hemangiomas (IHs) undergo a rapid growth phase between 5.5 and 7.5 weeks of life and do not usually proliferate beyond 6 months; growth thereafter is usually proportionate to the childs growth. This review assesses the evidence for topical timolol as primary monotherapy for cutaneous facial IHs before 12 months of age, and to determine the differences in outcome between early (before 6 months) and late initiation (after 6 months) of timolol. A review of English language articles published up to November 2015 was performed using selected key words. Articles identified were further reviewed for relevance. The full text of studies included for final analysis was perused to include pertinent patient details, treatment protocol with timolol, complications (if any) reported, and response to treatment. Four studies met the inclusion criteria. In children before 12 months of age, the efficacy of topical timolol for the treatment of cutaneous facial IHs in achieving clinically significant improvement as defined by a standardized Global Assessment Score score of 3 and above ranged from 47% to 88%. One study also showed that IH regression was greater in patients started on timolol before 6 months of age compared with those started later (P <0.05). Topical timolol initiated in children before 12 months of age appears to be safe and clinically effective. There was insufficient data for detailed analysis of outcomes in patients who commenced treatment before and after 6 months of age.

Distally Based Sural Artery Adipofascial Flap based on a Single Sural Nerve Branch: Anatomy and Clinical Applications

Background The distally based sural artery flap is a reliable, local reconstructive option for small soft tissue defects of the distal third of the leg. The purpose of this study is to describe an adipofascial flap based on a single sural nerve branch without sacrificing the entire sural nerve, thereby preserving sensibility of the lateral foot. Methods The posterior aspect of the lower limb was dissected in 15 cadaveric limbs. Four patients with soft tissue defects over the tendo-achilles and ankle underwent reconstruction using the adipofascial flap, which incorporated the distal peroneal perforator, short saphenous vein, and a single branch of the sural nerve. Results From the anatomical study, the distal peroneal perforator was situated at an average of 6.2 cm (2.5-12 cm) from the distal tip of the lateral malleolus. The medial and lateral sural nerve branches ran subfascially and pierced the muscle fascia 16 cm (14-19 cm) proximal to the lateral malleolus to enter the subcutaneous plane. They merged 1-2 cm distal to the subcutaneous entry point to form the common sural nerve at a mean distance of 14.5 cm (11.5-18 cm) proximal to the lateral malleolus. This merging point determined the pivot point of the flap. In the clinical cases, all patients reported near complete recovery of sensation over the lateral foot six months after surgery. All donor sites healed well with a full range of motion over the foot and ankle. Conclusions The distally based sural artery adipofascial flap allowed for minimal sensory loss, a good range of motion, an aesthetically acceptable outcome and can be performed by a single surgeon in under 2 hours.

A unique presentation of epignathus.

Palatal clefts in conjunction with space-occupying lesions of the oral or nasal cavities are of interest because they may represent a developmental etiology of palatal clefts. Epignathus is a rare space-occupying tumor of the nasopharynx that can arise from the upper jaw, palate, and sphenoid. It can protrude through the mouth, causing respiratory embarrassment and death. The pathogenesis of epignathus is unknown, but several theories have been proposed. Management depends on the size of the tumor and requires a multidisciplinary approach.

Abstract 95: results of primary repair of submucous cleft palate with furlow palatoplasty in both syndromic and non-syndromic children.

PurPose: Submucous cleft palate (SMCP) is an oftenmissed diagnosis until the child has developed abnormal speech. This often results as a consequence of aberrant anatomy, leading to velopharyngeal insufficiency and/or articulation errors. While the latter can usually be corrected with speech therapy, much controversy persists with regard to the optimal technique for surgical repair in the former. Moreover, when SMCP occurs as part of a syndrome, surgery has yielded mixed results. This study therefore aims to investigate outcomes of primary SMCP repair with Furlow palatoplasty in both syndromic and non-syndromic children.