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Dive into the research topics where Angela Cheng is active.

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Featured researches published by Angela Cheng.


Clinics in Plastic Surgery | 2012

Comparison of Different ADM Materials in Breast Surgery

Angela Cheng; Michel Saint-Cyr

This is a brief review of the history of the role of acellular dermal matrices in breast reconstruction surgery, with a summary of several currently available products, including a table of comparisons. Key features, including biologic tissue source, surgical preparation, sterility, polarity, contraindications, shelf life, and cost, are examined. A paucity of data exists to directly compare AlloDerm®, DermaMatrix®, Strattice™, Permacol™, DermACELL, FlexHD®, SurgiMend®, and ALLOMAX™ for breast reconstruction; most studies relate to hernia repair. An ideal acellular dermal matrix product is still unavailable but the information provided in this review should facilitate a breast surgeons decision-making process.


Plastic and Reconstructive Surgery | 2013

Treatment of capsular contracture using complete implant coverage by acellular dermal matrix: a novel technique.

Angela Cheng; Chrisovalantis Lakhiani; Michel Saint-Cyr

Background: Capsular contracture is a frequent complication of breast reconstruction that affects 2.8 to 15.9 percent of patients. Use of acellular dermal matrix has been reported for treatment of contracture, with a recurrence rate of 6.3 percent, but this was limited to partial implant coverage only. The authors describe a novel surgical technique using acellular dermal matrix to completely cover the implant anteriorly to treat and prevent capsular contracture. Methods: Charts were reviewed to identify patients who had received implant insertion with complete acellular dermal matrix coverage performed by a single surgeon. Patient demographic information, history of irradiation or capsular contracture, prior treatment, and postoperative complications were recorded. Results: Eleven patients (16 breasts) were identified. Mean age and body mass index were 52.3 ± 6.9 years and 23.6 ± 4.4 kg/m2, respectively. Four patients (five breasts) had a history of capsular contracture requiring previous capsulectomy and implant exchange. Ten cases were for correction of new-onset grade III (n = 2) or IV (n = 8) capsular contracture and one was to prevent future capsular contracture. Mean acellular dermal matrix size was 229.8 ± 46.5 cm2 (range, 144 to 256 cm2). Average follow-up was 9.2 months (range, 2.4 to 18.8 months). One patient (one breast) developed an infection requiring implant removal. No patients experienced recurrent capsular contracture. Conclusions: Capsular contracture may be treated successfully using complete acellular dermal matrix coverage. This technique may be a useful addition to therapies currently used to treat recalcitrant capsular contracture (early recurrence or refractory to standard therapy). CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Plastic and Reconstructive Surgery | 2012

The free descending branch muscle-sparing latissimus dorsi flap: vascular anatomy and clinical applications.

Shannon Colohan; Corrine Wong; Chrisovalantis Lakhiani; Angela Cheng; Munique Maia; Gary Arbique; Michel Saint-Cyr

Background: Increasing focus on reducing morbidity from latissimus dorsi flaps has led to the evolution of muscle-sparing variants and perforator-based flaps. This study aimed to investigate the vascular anatomy of the muscle-sparing variant and to describe its application as a free flap based on the descending branch of the thoracodorsal artery. Methods: Twelve fresh cadavers underwent anatomical dissection and angiographic injection studies of the thoracodorsal arterial system. The musculocutaneous territories of the descending and transverse branches to the latissimus dorsi muscle were identified and assessed using three-dimensional reconstruction software of computed tomography imaging results. In the clinical study, five patients underwent reconstruction of a variety of defects using the free descending branch muscle-sparing latissimus dorsi flap. Results: Three- and four-dimensional (computed tomography) angiography demonstrated perfusion of the latissimus dorsi muscle by the transverse and descending branches, with overlap of vascular territories via cross-linking vessels. The descending branch supplied a slightly greater cutaneous area overlying the muscle, although differences between both branches were not significant (p = 0.76). In the clinical study, the free muscle-sparing latissimus dorsi flap provided excellent coverage with no flap complications or seroma. Conclusions: The free muscle-sparing latissimus dorsi flap based on the descending branch of the thoracodorsal artery is a viable reconstructive option. Significant collateral flow between vessels allows for larger flap harvest than would be expected. The flap is technically simple to harvest, provides a large perfusion area, and is a reliable variant of the full latissimus dorsi flap. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.


Plastic and reconstructive surgery. Global open | 2016

No-drain DIEP Flap Donor-site Closure Using Barbed Progressive Tension Sutures.

Purushottam Nagarkar; Chrisovalantis Lakhiani; Angela Cheng; Michael R. Lee; Sumeet S. Teotia; Michael Saint-Cyr

Background: The use of progressive tension sutures has been shown to be comparable to the use of abdominal drains in abdominoplasty. However, the use of barbed progressive tension sutures (B-PTSs) in deep inferior epigastric artery perforator (DIEP) flap donor-site closure has not been investigated. Methods: A retrospective chart review was performed on patients with DIEP flap reconstruction in a 3-year period at 2 institutions by 2 surgeons. Patients were compared by method of DIEP donor-site closure. Group 1 had barbed running progressive tension sutures without drain placement. Group 2 had interrupted progressive tension closure with abdominal drain placement (PTS-AD). Group 3 had closure with only abdominal drain placement (AD). Data collected included demographics, perioperative data, and postoperative outcomes. Results: Seventy-five patients underwent DIEP reconstruction (25 B-PTS, 25 PTS-AD, and 25 AD). Patient characteristics—age, body mass index, comorbidities, smoking status, and chemotherapy—were not significantly different between groups. Rate of seroma was 1.3% (B-PTS = 0%, PTS-AD = 4%, AD = 0%), wound dehiscence 16% (B-PTS = 8%, PTS-AD = 16%, AD = 24%), and umbilical necrosis 5.3% (B-PTS = 0%, PTS-AD = 0%, AD = 16%). No hematomas were observed in any patients. No statistically significant difference was found between complication rates across groups. Conclusions: Use of B-PTSs for abdominal closure after DIEP flap harvest can obviate the need for abdominal drains. Complication rates following this technique are not significantly different from closure using progressive tension suture and abdominal drain placement. This practice can prevent the use of abdominal drains, which can promote patient mobility, increase independence upon discharge, and contribute to patient satisfaction.


Plastic and Reconstructive Surgery | 2013

Nerve transfers for facial transplantation: a cadaveric study for motor and sensory restoration.

Thorir Audolfsson; Andres Rodriguez-Lorenzo; Corrine Wong; Angela Cheng; Morten Kildal; Daniel Nowinski; Shai M. Rozen

Background: Restoration of facial animation and sensation is highly important for the outcome after facial allotransplantation. The identification of healthy nerves for neurotization is of particular importance for successful nerve regeneration within the allograft. However, because of the severity of the initial injury and resultant scar formation, a lack of healthy nerve stumps in the recipient is a commonly encountered problem. In this study, the authors evaluate the technical feasibility of performing nerve transfers in facial transplantation for both sensory and motor neurotization. Methods: Fifteen fresh cadaver heads were used in this study. The study was divided into two parts. First, the technical feasibility of nerve transfer from the cervical plexus to the mental nerve and the masseter nerve to the buccal branches of the facial nerve was assessed. Next, the authors performed nerve transfers in simulated face transplants to describe the surgical technique, focusing on sensory restoration of the midface and upper lip by neurotization of the infraorbital nerve, sensory restoration of the lower lip by neurotization of the mental nerve, and smile reanimation by neurotization of the buccal branches of the facial nerve. Results: In all specimens, coaptation of at least one of the branches of the cervical plexus to the mental nerve and between the masseter nerve to the buccal branch of the facial nerve was possible. In simulated face transplant procedures, nerve transfers of the supraorbital nerve to the infraorbital nerve, cervical plexus branches to the mental nerve, and masseter nerve to facial nerve are all technically possible. Conclusions: Nerve transfers are a technically feasible option that could theoretically be used in face transplantation either as a primary nerve reconstruction when there are no available healthy nerves, or as a secondary procedure for enhancement of functional outcomes.


Journal of Plastic Reconstructive and Aesthetic Surgery | 2013

A reliable anatomic approach for identification of the masseteric nerve

Angela Cheng; Thorir Audolfsson; Andres Rodriguez-Lorenzo; Corrine Wong; Shai M. Rozen

The masseteric nerve remains a reliable option in facial reanimation procedures in patients whom have no facial nerve donor (i.e. Moebius syndrome), previously failed cross-facial nerve grafts, prefer a one-stage procedure, or have a guarded lifespan. There is minimal donor site morbidity, it is conveniently located within the region of dissection, and has a shorter distance for re-innervation with a more rapid and powerful clinical recovery of function. However, surgeons encounter difficulty locating the nerve due to a variety of described branching patterns and variability of facial measurements on which some surgical approaches are based upon. We present a technique to identify the nerve in a 1.5 cm area defined by constant anatomical landmarks e the zygomatic arch, condyle, coronoid process, and mandibular notch. To demonstrate variability of the nerve location based on facial measurements, cadaveric dissections were performed and compared to previous studies. Since facial measurements were occasionally unreliable, mainly in the anterioreposterior dimension, an alternative surgical approach was developed. A pre-tragal incision is used to elevate a cheek flap in the subcutaneous plane for approximately 1 cm and then transition into the sub-SMAS plane to expose the parotid-masseteric fascia, facial vessels, modiolus, and zygomatic arch. Palpation of the anatomic landmarks, zygomatic arch, coronoid process, and mandibular condyle, helps identifying the triangular zone. The mandibular or sigmoid notch is also confirmed as the caudal apex of the triangular zone. Opening and closing the mouth may facilitate identification of the coronoid. Dissection begins in the center of this triangular region. If the parotid gland extends over this area (not uncommon), dissection proceeds gently through the parotid with fine hemostats directed in an anterior posterior course, while preserving the facial nerve branches. An assistant gently


Emerging Digital Micromirror Device Based Systems and Applications V | 2013

In-vivo quantitative evaluation of perfusion zones and perfusion gradient in the deep inferior epigastric artery perforator flap

Michel Saint-Cyr; Chrisovalantis Lakhiani; Angela Cheng; Michael Mangum; Jinyang Liang; Sumeet S. Teotia; Edward H. Livingston; Karel J. Zuzak

The selection of well-vascularized tissue during DIEP flap harvest remains controversial. While several studies have elucidated cross-midline perfusion, further characterization of perfusion to the ipsilateral hemiabdomen is necessary for minimizing rates of fat necrosis or partial fat necrosis in bilateral DIEP flaps. Eighteen patients (29 flaps) underwent DIEP flap harvest using a prospectively designed protocol. Perforators were marked and imaged with a novel system for quantitatively measuring tissue oxygenation, the Digital Light Hyperspectral Imager. Images were then analyzed to determine if perforator selection influenced ipsilateral flap perfusion. Flaps based on a single lateral row perforator (SLRP) were found to have a higher level of hemoglobin oxygenation in Zone I (mean %HbO2 = 76.1) compared to single medial row perforator (SMRP) flaps (%HbO2 = 71.6). Perfusion of Zone III relative to Zone I was similar between SLRP and SMRP flaps (97.4% vs. 97.9%, respectively). These differences were not statistically significant (p>0.05). Perfusion to the lateral edge of the flap was slightly greater for SLRP flaps compared SMRP flaps (92.1% vs. 89.5%, respectively). SMRP flaps had superior perfusion travelling inferiorly compared to SLRP flaps (88.8% vs. 83.9%, respectively). Overall, it was observed that flaps were better perfused in the lateral direction than inferiorly. Significant differences in perfusion gradients directed inferiorly or laterally were observed, and perforator selection influenced perfusion in the most distal or inferior aspects of the flap. This suggests broader clinical implications for flap design that merit further investigation.


European Journal of Plastic Surgery | 2014

Maximizing aesthetic outcome in autologous breast reconstruction with implants and lipofilling

Chrisovalantis Lakhiani; Ziyad S. Hammoudeh; Johnathon M. Aho; Michael R. Lee; Yvonne Rasko; Angela Cheng; Michel Saint-Cyr

BackgroundFree flap breast reconstruction is an option widely sought in postmastectomy breast reconstruction. However, the volume of autologous tissue from the patient is often not sufficient for symmetrical reconstruction. In these cases, flaps can be used in combination with implants or autologous fat injections to augment volume and achieve shape, symmetry, and contour.MethodsA retrospective chart review was performed on patients who underwent postmastectomy free flap reconstruction with secondary augmentation using autologous fat grafting or implant from 2008 to 2011.ResultsTwenty-four patients (39 breasts) received further augmentation of autologous tissue reconstruction during this period. Sixteen patients (26 breasts) had fat graft augmentation only, four patients (eight breasts) had implant augmentation only, and three patients (five breasts) had both procedures. Among patients who had fat grafting, operative intervention was required twice for fat necrosis. Contrastingly, of patients who received implants, one patient required operative intervention for implant malpositioning. These differences were not significant (P = 0.57). The group with both fat grafting and implant augmentation had significantly higher aesthetic scores regarding overall appearance, contour, and volume, but not projection, than the group with fat grafting only and the group with implant only.ConclusionsAutologous fat grafting offers several contouring aesthetic advantages, including selectively augmenting areas of hollowness to improve contour and maximize symmetry. However, implant augmentation generally allows for a larger increase in projection in a single procedure, with similar rates of postaugmentation complications. Use of both autologous fat grafting and implant augmentation may allow for superior aesthetic results.Level of Evidence: Level IV, therapeutic study.


Journal of Plastic Reconstructive and Aesthetic Surgery | 2015

Influence of using a single facial vein as outflow in full-face transplantation: A three-dimensional computed tomographic study

Andres Rodriguez-Lorenzo; Thorir Audolfsson; Corrine Wong; Angela Cheng; Gary Arbique; Daniel Nowinski; Shai M. Rozen

BACKGROUND The aim of this study was to evaluate the contribution of a single unilateral facial vein in the venous outflow of total-face allograft using three-dimensional computed tomographic imaging techniques to further elucidate the mechanisms of venous complications following total-face transplant. METHODS Full-face soft-tissue flaps were harvested from fresh adult human cadavers. A single facial vein was identified and injected distally to the submandibular gland with a radiopaque contrast (barium sulfate/gelatin mixture) in every specimen. Following vascular injections, three-dimensional computed tomographic venographies of the faces were performed. Images were viewed using TeraRecon Software (Teracon, Inc., San Mateo, CA, USA) allowing analysis of the venous anatomy and perfusion in different facial subunits by observing radiopaque filling venous patterns. RESULTS Three-dimensional computed tomographic venographies demonstrated a venous network with different degrees of perfusion in subunits of the face in relation to the facial vein injection side: 100% of ipsilateral and contralateral forehead units, 100% of ipsilateral and 75% of contralateral periorbital units, 100% of ipsilateral and 25% of contralateral cheek units, 100% of ipsilateral and 75% of contralateral nose units, 100% of ipsilateral and 75% of contralateral upper lip units, 100% of ipsilateral and 25% of contralateral lower lip units, and 50% of ipsilateral and 25% of contralateral chin units. CONCLUSION Venographies of the full-face grafts revealed better perfusion in the ipsilateral hemifaces from the facial vein in comparison with the contralateral hemifaces. Reduced perfusion was observed mostly in the contralateral cheek unit and contralateral lower face including the lower lip and chin units.


Plastic and Reconstructive Surgery | 2013

Obturator nerve anatomy and relevance to one-stage facial reanimation: Limitations of a retroperitoneal approach

Shai M. Rozen; Andres Rodriguez-Lorenzo; Thorir Audolfsson; Corrine Wong; Angela Cheng

Background: Single-stage facial reanimation with a partial gracilis muscle coapted to the contralateral facial nerve seems an optimal surgical solution yet has not supplanted the two-stage approach. Insufficient obturator nerve length may limit reach to sizable contralateral facial nerve branches (possibly necessitating interposition nerve grafting), compromise optimal muscle positioning, or risk nerve coaptation under tension. This study evaluates whether retroperitoneal obturator nerve dissection would effectively lengthen the nerve, thus obviating the aforementioned limitations. Methods: Ten hemifaces and obturator nerves of five cadavers were dissected. Facial measurements included modiolus to contralateral facial nerve branches of sufficient size at the vertical line of the lateral orbital rim. Obturator nerve measurements included gracilis neurovascular hilum to (1) obturator canal entry point (ab), (2) intraobturator canal point where additional adductor branches are inseparable by internal neurolysis (ac), and (3) retroperitoneal point of separation between anterior and posterior obturator branches (ad). Obturator nerve reach for cross-facial nerve coaptation was assessed. Results: Successful coaptation was achieved with obturator nerve dissection to point b approximately 20 percent of the time, to point c 60 to 70 percent of the time, and to retroperitoneal point d 90 to 100 percent of the time Conclusions: Successful coaptation to large contralateral facial nerve branches is feasible in 90 to 100 percent of cases if the entire anterior obturator branch is harvested. However, the increased risk of retroperitoneal dissection and sacrifice of additional adductor branches decreases the viability of this approach. Obturator canal dissection (point c) provides reach in 60 to 70 percent of cases, but short interposition nerve grafting may prove necessary.

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Michel Saint-Cyr

University of Texas Southwestern Medical Center

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Chrisovalantis Lakhiani

University of Texas Southwestern Medical Center

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Corrine Wong

University of Texas Southwestern Medical Center

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Thorir Audolfsson

Uppsala University Hospital

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Shai M. Rozen

University of Texas Southwestern Medical Center

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Michael R. Lee

University of Texas Southwestern Medical Center

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Daniel Nowinski

Uppsala University Hospital

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Sumeet S. Teotia

University of Texas Southwestern Medical Center

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Edward H. Livingston

University of Texas Southwestern Medical Center

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