Sophia Chia-Ning Chang

Injection molding of chondrocyte/alginate constructs in the shape of facial implants

Over one million patients per year undergo some type of procedure involving cartilage reconstruction. Polymer hydrogels, such as alginate, have been shown to be effective carriers for chondrocytes in subcutaneous cartilage formation. The goal of our current study was to develop a method to create complex structures (nose bridge, chin, etc.) with good dimensional tolerance to form cartilage in specific shapes. Molds of facial implants were prepared using Silastic ERTV. Suspensions of chondrocytes in 2% alginate were gelled by mixing with CaSO(4) (0.2 g/mL) and injected into the molds. Constructs of various cell concentrations (10, 25, and 50 million/mL) were implanted in the dorsal aspect of nude mice and harvested at times up to 30 weeks. Analysis of implanted constructs indicated progressive cartilage formation with time. Proteoglycan and collagen constructs increased with time to approximately 60% that of native tissue. Equilibrium modulus likewise increased with time to 15% that of normal tissue, whereas hydraulic permeability decreased to 20 times that of native tissue. Implants seeded with greater concentrations of cells increased proteoglycan content and collagen content and equilibrium and decreased permeability. Production of shaped cartilage implants by this technique presents several advantages, including good dimensional tolerance, high sample-to-sample reproducibility, and high cell viability. This system may be useful in the large-scale production of precisely shaped cartilage implants.

Donor site morbidity after suprafascial elevation of the radial forearm flap : A prospective study in 95 consecutive cases

From March of 1995 to November of 1997, 95 free radial forearm flaps for orofacial reconstructions were performed and included in this prospective study of donor site morbidity. All flaps were elevated using the suprafascial dissection technique. Donor site closure was performed with either split-thickness skin grafts (64 cases) or full-thickness skin grafts (31 cases). Among the 95 flaps, there were two complete flap losses and one partial flap loss because of arterial thrombosis. One orocutaneus fistula was successfully treated with a pedicled pectoralis major flap. At the donor site, the rate of complete take of skin graft was 94 percent in 95 patients. Functional and aesthetic results evaluated at least 6 months postoperatively in 50 patients revealed no significant change in grip power, pulp-to-pulp pinch power, or wrist movement in the complete skin graft take group (45 cases), whereas in the partial skin graft failure group (5 cases), both grip power and movement were significantly decreased. There was no remarkable cold intolerance in any of the 50 patients. Critical evaluations of sensory change revealed numbness distal to the donor site in 54 percent of the patients. However, dysesthesia was usually mild and improved spontaneously as time passed. Aesthetic outcome was rated as good or fair in 98 percent of the cases. The results of this prospective study show that suprafascial elevation of the radial forearm flap is superior to the classic elevation technique, particularly with regard to a higher rate of immediate complete take of skin grafts, thus avoiding impairment of range of motion and strength of the donor hand.

Tissue engineering of autologous cartilage for craniofacial reconstruction by injection molding.

Each year, more than one million patients undergo some type of procedure involving cartilage reconstruction. Polymer hydrogels such as alginate have been demonstrated to be effective carriers of chondrocytes for subcutaneous cartilage formation. The goal of this study was to develop a simple method to create complex structures with good three-dimensional tolerance in order to form cartilage in specific shapes in an autologous animal model. Six alginate implants that had been seeded with autologous chondrocytes through an injection molding process were implanted subcutaneously in sheep, harvested after 6 months, and analyzed histologically, biochemically, and biomechanically, in comparison with original auricular cartilage. Molds of craniofacial implants were prepared with Silastic E RTV (Dow Corning, Midland, Mich.). Chondrocytes were harvested from sheep auricular cartilage and suspended in 2% alginate at a concentration of 50 × 106 cells/ml. The mixture of cells and gel was injected into the Silastic molds and removed after 20 minutes. Chondrocyte-alginate constructs were implanted subcutaneously in the necks of the sheep from which the cells had originally been harvested, and the constructs were removed after 30 weeks. Analyses of the implanted constructs indicated cartilage formation with three-dimensional shape retention. The proteoglycan and collagen contents of the constructs increased with time to approximately 80 percent of the values for native tissue. The equilibrium modulus and the hydraulic permeability were 74 and 105 percent of those of native sheep auricular cartilage, respectively.

Evaluation of diagnostic accuracy using preoperative handheld Doppler in identifying the cutaneous perforators in the anterolateral thigh flap: a systematic review.

cord and anastomosed them to the pampiniform venous plexus, which also runs beside the spermatic cord.2 Anatomical lymphatic mapping of the male genital region is described in detail by Sappey3 and Mascagni4 (Fig. 2). Two different lymphatic pathways, the superficial and deep lymphatic routes, contribute to lymphatic drainage in the male genital region. According to these anatomical findings, there are two options for creating a lymphovenous shunt: using the superficial lymphatic pathway or the deep lymphatic pathway. We performed both methods in three patients at different time points. In our experience, the diameters of the superficial lymphatic vessels were smaller (0.2 to 0.5 mm) compared with those of the deep lymphatic vessels (0.5 to 1 mm); therefore, creating a lymphovenous shunt was technically more reliable using the deep lymphatic vessel. Another advantage of selecting the deep lymphatic vessels is that these vessels could be identified constantly beside the pampiniform veins. After the obstruction of lymphatic vessels, the structure of the lymphatic vessel is altered. These changes are more significant in the proximal region near the obstruction site than in the distal region.5 There is a possibility that lymphovenous bypass using the superficial lymphatic vessels may not improve symptoms because they degenerate in male genital lymphedema. Our preliminary experiences suggest that creating lymphovenous bypasses using the deep lymphatic vessel may be a more effective treatment for male genital lymphedema than selecting the superficial lymphatic vessels. DOI: 10.1097/PRS.0b013e318245ea3c

The effects of antileukotriene agents on capsular contracture: an evidence-based analysis.

1. Komorowska-Timek E, Gurtner GC. Intraoperative perfusion mapping with laser-assisted indocyanine green imaging can predict and prevent complications in immediate breast reconstruction. Plast Reconstr Surg. 2010;125:1065–1073. 2. Newman MI, Samson MC, Tamburrino JF, Swartz KA. Intraoperative laser-assisted indocyanine green angiography for the evaluation of mastectomy flaps in immediate breast reconstruction. J Reconstr Microsurg. 2010;26:487–492. 3. Murray JD, Jones GE, Elwood ET, Whitty LA, Garcia C. Fluorescent intraoperative tissue angiography with indocyanine green: Evaluation of nipple-areola vascularity during breast reduction surgery. Plast Reconstr Surg. 2010;126:33e–34e. 4. Pestana IA, Coan B, Erdmann D, Marcus J, Levin LS, Zenn MR. Early experience with fluorescent angiography in free-tissue transfer reconstruction. Plast Reconstr Surg. 2009;123:1239–1244. 5. Francisco BS, Kerr-Valentic MA, Agarwal JP. Laser-assisted indocyanine green angiography and DIEP breast reconstruction. Plast Reconstr Surg. 2010;125:116e–118e.

Functional and aesthetic approach to adult unoperated Möbius syndrome: orthognathic surgery followed by bilateral free gracilis muscle transfers.

1. Chou EK, Cheung DC, Ko EW, Chen YR, Chang SC. Functional and aesthetic approach to adult unoperated Möbius syndrome: Orthognathic surgery followed by bilateral free gracilis muscle transfers. Plast Reconstr Surg. 2010;125:58e–60e. 2. Guijarro-Martı́nez R, Hernández-Alfaro F. Management of maxillofacial hard and soft tissue discrepancy in Möbius sequence: Clinical report and review of the literature. J Craniomaxillofac Surg. Epublished ahead of print February 25, 2011. 3. Bianchi B, Copelli C, Ferrari S, Ferri A, Sesenna E. Facial animation in patients with Moebius and Moebius-like syndromes. Int J Oral Maxillofac Surg. 2010;39:1066–1073. 4. Bianchi B, Copelli C, Ferrari S, Ferri A, Bailleul C, Sesenna E. Facial animation with free-muscle transfer innervated by the masseter motor nerve in unilateral facial paralysis. J Oral Maxillofac Surg. 2010;68:1524–1529.

Diagnostic efficacy of preoperative 64-section multidetector computed tomographic angiography in identifying the cutaneous perforators in the anterolateral thigh flap: an evidence-based review.

Diagnostic Efficacy of Preoperative 64-Section Multidetector Computed Tomographic Angiography in Identifying the Cutaneous Perforators in the Anterolateral Thigh Flap: An Evidence-Based Review Sir: T anterolateral thigh flap has become a workhorse flap in the reconstruction of various soft-tissue defects. Because of its inconsistent vascular anatomy, preoperative assessment of perforators has been performed using several devices. Among them, computed tomographic angiography combines the use of x-rays with computerized analysis of the images. The number of detector rows determines how fast a scan can be performed and the extent to which details can be revealed.1 Use of 64-section multidetector computed tomographic angiography has allowed clinicians to experience images with excellent resolution and high accuracy. To determine the diagnostic performance of 64-section multidetector computed tomographic angiography in identifying the cutaneous perforators in the anterolateral thigh flap, we conducted a systematic review for trials comparing 64-section multidetector computed tomographic angiography with intraoperative findings as reference standards. We searched the PubMed database from January of 2001 to February of 2012. We used the following keywords: “anterolateral thigh flap” and “computed tomography angiography.” Two reviewers independently extracted data in two steps: titles and abstracts, and then the full-text articles. This search was supplemented by a review of reference lists of potentially eligible studies. We excluded studies not using 64-section computed tomographic angiography, operated or computed tomographic angiography cases fewer than 3, duplicated reports of the same patient population, and studies with incomplete or no presentation of intraoperative findings (Fig. 1). Perforators found both by 64-section multidetector computed tomographic angiography and intraoperatively were defined as true-positive. Perforators found by computed tomographic angiography but not identified intraoperatively were defined as false-positive. Additional perforators found intraoperatively were regarded as false-negative. Three studies were included for a total of 60 anterolateral thigh flaps studied (Table 1).2–4 Use of 64-section multidetector computed tomographic angiography identified a total of 125 perforators, and all were identified intraoperatively (i.e., true-positive, n 125). It did not show perforators that were not actually present intraoperatively (i.e., false-positive, n 0). There were a total of 27 additional perforators found intraoperatively (i.e., false-negative, n 27). The pooled false-negative rate as for the presence or absence of the perforators is calculated to be 17.8 percent (27 of 152). The pooled sensitivity is 82.2 percent (95 percent confidence interval, 75.0 to 87.8 percent). In our previous systematic review, the handheld Doppler device demonstrated a pooled false-negative rate of 10.3 percent (23 of 224) and a pooled sensitivity of 89.7 percent (95 percent confidence interval, 85.0 to 93.0 percent) in identifying the cutaneous perforators in the anterolateral thigh flap.5 The authors concluded that the 64-section multidetector computed tomographic angiography device may be considered no more than an op-

Free-flap salvage by thrombolytic agents? An evidence-based systemic analysis.

INTRODUCTION: Despite the advances in microsurgery and the experience gained in clinical practice, failures caused by thrombosis at the site of microanastomosis remains a challenge to plastic surgeons. The failure rate of approximately 5% of all free-flap surgeries clinically suggested that there may be a place for pharmacological intervention at the time of threatened flap failure. But there was no consensus on the role of thrombolytic agents in free-flap salvage.