Anna A Kuang

Oregon Health and Science University, Portland, Oregon, United States

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Publications (16)55.83 Total impact

  • Anna Kuang · Nathan R Selden
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    ABSTRACT: The mainstay of treatment for single-suture cranial synostosis is cranial vault reconstruction. After primary cranial vault remodeling, patients are at risk for cranial restenosis and delayed intracranial hypertension, which may result in developmental delay or blindness. Synostosis patients are therefore generally monitored periodically for signs and symptoms of intracranial hypertension that may indicate a second cranial expansion procedure. The authors present a carefully illustrated case of a patient who presented 2 years after primary cranial vault reconstruction for sagittal synostosis with a decrease in head circumference percentile, recurrent cranial dysmorphism, papilledema, headaches and computed tomographic imaging findings consistent with cranial restenosis. These findings resolved after secondary cranial vault remodeling. The authors advocate a protocol of prospective routine clinical and radiographic follow-up after primary cranial vault repair for single-suture cranial synostosis, and illustrate the specific clinical and radiographic findings suggestive of this late complication in a representative individual patient. © 2015 S. Karger AG, Basel.
    Pediatric Neurosurgery 03/2015; 50(2). DOI:10.1159/000380768 · 0.50 Impact Factor
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    ABSTRACT: Objective: Cranial vault remodeling for repair of craniosynostosis is associated with significant blood loss and need for blood transfusion. To reduce these events, our institution began using Tranexamic Acid (TXA) peri-operatively in 2012. We sought to quantify the impact TXA has had on reducing blood loss and the transfusion of all blood product components. Methods: With institutional review board approval, a retrospective study from 2006 to 2013 was performed for all patients undergoing surgical correction of craniosynostosis at our institution. All available records were reviewed, and patient data were collected from the time of preoperative evaluation until discharge. We focused our review on patients with non-syndromic single-suture synostosis, before and after the implementation of TXA into our program. Results: We identified a total of 220 patients with craniosynostosis, of which 176 had non-syndromic single-suture disease. Of these 176, a total of 48 received TXA. A single surgical team performed all operations. Median age at time of surgery was 9.1 months (IQR of 5.9-10.4 months). The TXA group had a significant reduction in estimated blood loss (29 vs. 37 ml/kg p<0.01), cell saver volume (46 vs. 83 ml p<0.01), red cell transfusion (33 vs. 42 ml/kg p<0.01), and exposure to plasma/cryoprecipitate transfusion (2% vs. 31% p<0.01). Reduction in platelet transfusion did not reach significance (2% vs. 9% p=0.18). Even with reduced red cell transfusion, the TXA-treated patients exhibited similar post-operative hematocrits to those not treated with TXA(30.1 vs. 30.9% p=0.508). We found that length of stay was reduced with the use of TXA (4 days IQR 3-4 vs. 4 days IQR 4-5, p<0.01), as was output from surgically placed drains (177 vs. 328 ml p<0.01). We found no difference in mortality or post-operative complications between groups. Conclusions: The introduction of TXA for non-syndromic single-suture synostosis repair at our institution resulted in significant reductions in blood loss and use of blood products. Postoperative hematocrits remained the same even with less red cell transfusion. TXA use nearly eliminated the need for plasma transfusion, and is associated with a shorter hospital stay. No difference in postoperative complications was observed. Our data provides further support for the continued use of TXA in our program and its wider acceptance for pediatric cranial vault remodeling.
    Plastic &amp Reconstructive Surgery 10/2014; 134(4S-1 Suppl):22. DOI:10.1097/01.prs.0000455342.16278.23 · 3.33 Impact Factor
  • Journal of the American College of Surgeons 10/2014; 219(4):e128. DOI:10.1016/j.jamcollsurg.2014.07.727 · 4.45 Impact Factor
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    ABSTRACT: Excess scar formation after cutaneous injury can result in hypertrophic scar (HTS) or keloid formation. Modern strategies to treat pathologic scarring represent nontargeted approaches that produce suboptimal results. Mammalian target of rapamycin (mTOR), a central mediator of inflammation, has been proposed as a novel target to block fibroproliferation. To examine its mechanism of action, we performed genomewide microarray on human fibroblasts (from normal skin, HTS, and keloid scars) treated with the mTOR inhibitor, rapamycin. Hypertrophic scar and keloid fibroblasts demonstrated overexpression of collagen I and III that was effectively abrogated with rapamycin. Blockade of mTOR specifically impaired fibroblast expression of the collagen biosynthesis genes PLOD, PCOLCE, and P4HA, targets significantly overexpressed in HTS and keloid scars. These data suggest that pathologic scarring can be abrogated via modulation of mTOR pathways in procollagen and collagen processing.
    Annals of Plastic Surgery 06/2014; 72(6):711-9. DOI:10.1097/SAP.0b013e31826956f6 · 1.46 Impact Factor
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    ABSTRACT: The American Academy of Pediatrics Back to Sleep program in 1992 dramatically increased the incidence of posterior plagiocephaly in infants. In 2000, the craniofacial disorders program at Oregon Health & Science University established a plagiocephaly screening clinic staffed by pediatric nurse practitioners. Electronic medical records of patients seen in a single accredited craniofacial disorders clinic from 2005 to 2011 were reviewed retrospectively to identify patients screened independently by pediatric nurse practitioners for positional plagiocephaly versus synostosis. Over a 7-year period, 1228 patients were independently screened. Over half [638 patients (52 percent)] were followed through subsequent visits for craniofacial disorders without any direct surgeon input. Of these, 169 (26 percent) were treated with orthotic consultation for a molding helmet, 385 (60 percent) received a combination of counseling and/or physical therapy for torticollis, and 84 (13 percent) were lost to follow-up. No patient managed by pediatric nurse practitioners was identified to have cranial synostosis and no patient underwent early or delayed surgery. All returning patients [n = 554 (86 percent)] showed improvement in, or resolution of, their presenting deformity. The remaining 590 patients (48 percent) were referred by the pediatric nurse practitioner for surgical consultation. Computed tomographic imaging revealed synostosis in 121 patients. Pediatric nurse practitioners accurately screened over half of patients referred to a high-volume craniofacial disorders program for positional plagiocephaly versus synostosis, without surgeon input. Based on available information, no synostosis diagnosis was overlooked using this approach. With specific training, pediatric nurse practitioners working in a craniofacial disorders program can safely and independently screen for positional versus synostotic plagiocephaly. Diagnostic, III.
    Plastic and Reconstructive Surgery 08/2013; 132(2):414-8. DOI:10.1097/PRS.0b013e3182958a89 · 3.33 Impact Factor
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    ABSTRACT: Whether cranial vault remodeling surgery for nonsyndromic, isolated sagittal suture synostosis affects the patency of initially normal, unaffected sutures is unknown. The influence of coronal and lambdoidal suture patency after cranial vault remodeling on the trajectory of subsequent cranial growth is also unknown. Disruption of normal sutural anatomy during cranial vault reconstruction could influence the incidence of secondary craniosynostosis and need for reoperation in a small proportion of these patients.We performed a retrospective review of patients younger than 1 year with nonsyndromic sagittal synostosis treated at a single tertiary referral pediatric hospital from September 2005 to January 2010 by an interdisciplinary team. Computed tomographic images obtained preoperatively, immediately postoperatively, and 2 years postoperatively were evaluated for the occurrence of secondary synostosis of initially nonsynostotic sutures. Craniofacial disorders clinic and ophthalmologic follow-up records were also analyzed for the occurrence of radiographic cranial restenosis, clinical or ophthalmologic signs of intracranial hypertension (ICH), and reoperation.Fifty-one patients younger than 1 year underwent primary surgical repair of isolated, nonsyndromic sagittal suture synostosis during the study period. Thirty-seven of these patients (71%) had completed 2-year clinical and radiographic follow-up by the time of analysis, constituting the study population. The average age at surgery was 5.4 months (range, 3.1-11.5 months). Thirty-three (89%) of the 37 study patients showed radiographic evidence of bilateral secondary coronal synostosis (SCS). Five patients (15%) additionally showed partial lambdoid synostosis. One patient with radiographic SCS (3%) required reoperation for radiographic cranial restenosis, clinical signs and symptoms of ICH, and papilledema first noted 1 year after primary cranial vault reconstruction.There is a high incidence of secondary coronal suture synostosis following cranial vault remodeling for isolated, nonsyndromic sagittal synostosis. Postoperative SCS was only rarely associated with secondary radiographic cranial stenosis, clinical or ophthalmologic signs of ICH, and the need for reoperation.
    The Journal of craniofacial surgery 05/2013; 24(3):937-940. DOI:10.1097/SCS.0b013e31828dcf24 · 0.68 Impact Factor
  • Victor W Wong · F You · M Januszyk · GC Gurtner · AA Kuang
    Plastic &amp Reconstructive Surgery 05/2013; 131:136. DOI:10.1097/01.prs.0000430126.25993.8c · 3.33 Impact Factor
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    ABSTRACT: BACKGROUND: The purpose of this study was to investigate the effects of tacrolimus on human fibroblasts derived from unwounded skin, hypertrophic scars (HTS), and keloids. We hypothesized that tacrolimus, a potent anti-inflammatory and immunosuppressant drug known to attenuate solid organ transplant fibrosis, would block collagen expression in human dermal fibroblasts. METHODS: We performed genomewide microarray analysis on human dermal fibroblasts treated with tacrolimus in vitro. We used principal component analysis and hierarchical clustering to identify targets regulated by tacrolimus. We performed quantitative polymerase chain reaction to validate the effect of tacrolimus on collagen 1 and 3 expression. RESULTS: We identified 62, 136, and 185 gene probes on microarray analysis that were significantly regulated (P < 0.05) by tacrolimus in normal, HTS, and keloid fibroblasts, respectively. Collagen pathways were not blocked after tacrolimus exposure in any of the fibroblast groups; we validated these findings using quantitative polymerase chain reaction for collagen 1 and 3. Microarray gene expression of NME/NM23 nucleoside diphosphate kinase 1 and heterogeneous nuclear ribonucleoprotein H3-2H9 were significantly downregulated (P < 0.05) by tacrolimus in both HTS and keloid fibroblast populations but not normal fibroblasts. CONCLUSIONS: Tacrolimus does not modulate the expression of collagen 1 or 3 in human dermal fibroblasts in vitro. Microarray gene expression of NME/NM23 nucleoside diphosphate kinase 1 and heterogeneous nuclear ribonucleoprotein H3-2H9 are blocked by tacrolimus in pathologic fibroblasts but not normal fibroblasts, and may represent novel genes underlying HTS and keloid pathogenesis. Tacrolimus-based anti-fibrotics might prove more effective if non-fibroblast populations such as inflammatory cells and keratinocytes are targeted.
    Journal of Surgical Research 04/2013; 184(1). DOI:10.1016/j.jss.2013.04.006 · 2.12 Impact Factor
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    ABSTRACT: Object Delayed intracranial hypertension may occur after cranial vault remodeling for synostosis and may result in visual loss and developmental delay. Delayed intracranial hypertension is relatively common in children with syndromic, multisuture synostosis, but the incidence is poorly defined in children with single-suture nonsyndromic synostosis. This study evaluates the frequency of reoperation for delayed intracranial hypertension after single-suture synostosis repair. Methods Patients who had undergone cranial vault remodeling for nonsyndromic single-suture synostosis and were treated at a single tertiary pediatric hospital between July 2000 and December 2010 were analyzed for the occurrence of delayed intracranial hypertension and reoperation for cranial vault remodeling. Results Eighty-one patients with clinical follow-up of at least 3 years were analyzed from a total of 156 consecutive patients. The average patient age at the initial operation was 9.1 months. Five (6.2%) of 81 patients presented with delayed clinical and ophthalmological signs and symptoms of intracranial hypertension following initial cranial vault reconstruction, confirmed indirectly in each case by CT findings and directly by intracranial pressure monitoring. These 5 patients underwent repeat cranial vault reconstruction. Conclusions Calvarial growth restriction and intracranial hypertension occur sporadically following primary cranial vault reconstruction for single-suture nonsyndromic cranial synostosis. In this series, delayed intracranial hypertension occurred only in male patients who underwent primary repair of isolated sagittal synostoses at an age less than or equal to 5 months.
    Journal of Neurosurgery Pediatrics 04/2013; 11(6). DOI:10.3171/2013.3.PEDS12525 · 1.37 Impact Factor
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    ABSTRACT: Exuberant fibroproliferation is a common complication after injury for reasons that are not well understood. One key component of wound repair that is often overlooked is mechanical force, which regulates cell-matrix interactions through intracellular focal adhesion components, including focal adhesion kinase (FAK). Here we report that FAK is activated after cutaneous injury and that this process is potentiated by mechanical loading. Fibroblast-specific FAK knockout mice have substantially less inflammation and fibrosis than control mice in a model of hypertrophic scar formation. We show that FAK acts through extracellular-related kinase (ERK) to mechanically trigger the secretion of monocyte chemoattractant protein-1 (MCP-1, also known as CCL2), a potent chemokine that is linked to human fibrotic disorders. Similarly, MCP-1 knockout mice form minimal scars, indicating that inflammatory chemokine pathways are a major mechanism by which FAK mechanotransduction induces fibrosis. Small-molecule inhibition of FAK blocks these effects in human cells and reduces scar formation in vivo through attenuated MCP-1 signaling and inflammatory cell recruitment. These findings collectively indicate that physical force regulates fibrosis through inflammatory FAK-ERK-MCP-1 pathways and that molecular strategies targeting FAK can effectively uncouple mechanical force from pathologic scar formation.
    Nature medicine 12/2011; 18(1):148-52. DOI:10.1038/nm.2574 · 28.05 Impact Factor
  • Tina F Jenq · Stuart M Hilliard · Anna A Kuang
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    ABSTRACT: Objective: Novel use of osmotic tissue expanders to recruit local palatal mucoperiosteum for the treatment of difficult anterior palatal fistulas. Design: This is a retrospective review of our experience with osmotic tissue expanders for closure of secondary palatal fistulas. Setting: The study occurred at Oregon Health and Science University, a tertiary care level academic hospital. Patients, Participants: All patients were treated for combined cleft lip and palate by the Oregon Health and Science University Craniofacial Disorders multidisciplinary team. They were determined to be appropriate candidates due to the anterior location of the fistula and symptomatic nature. Patients complained of significant nasal regurgitation of liquid and solids. Interventions: All patients underwent a two-stage procedure under general anesthesia. The first stage was placement of the expanders. The second stage was 1 week later, with removal of the expanders, palatal revision, and closure of the oronasal fistula. Main Outcome Measure: The primary outcome measures determined before data collection were treatment of symptoms and decreased size of fistula. Results: Seven patients with palatal fistulas were treated with osmotic tissue expanders. Five patients had complete closure of the fistula. Two patients demonstrated slit-like fistulas that were no longer symptomatic and were amenable to closure at time of alveolar bone grafting. No complications were observed. Conclusions: The use of osmotic tissue expanders is a viable alternative for repair of large anterior palatal fistulas, especially in a scarred or previously operated palate. Patients were also no longer symptomatic.
    The Cleft Palate-Craniofacial Journal 03/2011; 48(2):217-21. DOI:10.1597/09-215 · 1.11 Impact Factor
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    ABSTRACT: Children are exposed to ionizing radiation during pre- and post-operative evaluation for craniofacial surgery. The primary purpose of the study was to decrease effective radiation dose while preserving the diagnostic quality of the study. In this prospective study 49 children were positioned during craniofacial CT (CFCT) imaging with their neck fully extended into an exaggerated sniff position, parallel to the CT gantry, to eliminate the majority of the cervical spine and the thyroid gland from radiation exposure. Image-quality and effective radiation dose comparisons were made retrospectively in age-matched controls (n = 49). When compared to CT scans reviewed retrospectively, the prospective examinations showed a statistically significant decrease in z-axis length by 16% (P < 0.0001) and delivered a reduced effective radiation dose by 18% (P < 0.0001). The subjective diagnostic quality of the exams performed in the prospective arm was maintained despite a slight decrease in the quality of the brain windows. There was statistically significant improvement in the quality of the bone windows and three-dimensional reconstructed images. Altering the position of the head by extending the neck during pediatric craniofacial CT imaging statistically reduces the effective radiation dose while maintaining the diagnostic quality of the images.
    Pediatric Radiology 12/2010; 40(12):1910-7. DOI:10.1007/s00247-010-1788-2 · 1.65 Impact Factor
  • Journal of the American College of Surgeons 09/2010; 211(3):S127. DOI:10.1016/j.jamcollsurg.2010.06.338 · 4.45 Impact Factor
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    ABSTRACT: PURPOSE/AIM The purpose of this poster is to describe and illustrate craniofacial syndromes, preoperative computed tomography (CT) imaging, operative procedures used to correct each syndrome and the immediate and late post-surgical radiographic findings. 2D & 3D craniofacial CT images are used to illustrate the radiographic and surgical findings. CONTENT ORGANIZATION A multitude of craniofacial syndromes affect the skull and face; commonly Crouzon’s, Apert’s, Hemifacial microsomia/Goldenhaar, and Treacher Collins Syndrome. CT imaging is diagnostic and is used to guide surgical repair. Corrective surgeries include frontal orbital advancement, cranial vault remodeling, monobloc advancement, midface advancement, and mandibular surgery. With IRB approval, we reviewed CT images of children who had undergone surgical correction of craniofacial deformity. SUMMARY We have illustrated the characteristic radiographic findings of the most common craniofacial malformation syndromes, reviewed the corrective surgical procedures utilizing radiographic correlation, along with the post-operative radiographic findings.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM The purpose of this poster is to illustrate the role of computed tomography (CT) in diagnosis of non-syndromic single suture craniosynostosis; preoperative imaging, operative procedures used to correct them, and the early and late post-surgical radiographic findings. CONTENT ORGANIZATION Craniosynostosis is associated with developmental and speech delay, increased intracranial pressure and blindness. Craniofacial CT is the foundation of diagnostic imaging. In radiology literature, description of operative techniques and postoperative findings are scarce. Following IRB approval, we reviewed CT images and surgical history of children who have undergone CT and surgical repair at a tertiary academic medical center. 2D & 3D CT images are used to illustrate these craniosynostoses. SUMMARY We have described and illustrated the characteristic radiographic findings of the non-syndromic single suture craniosynostoses, their respective corrective surgical procedures and expected post-operative early and late radiographic findings.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM The purpose of this poster is to describe and illustrate the radiographic and surgical anatomy of facial clefts based on the clinically relevant Tessier classification system which is based on a numerical system from 0-14. Information given to the observer will teach embryology, epidemiology and key points to describe in radiology reports. CONTENT ORGANIZATION Facial clefts occur due to complete/partial failure of embryonic facial plates to merge/fuse. Complications of facial clefts necessitate early surgical repair. Tessier described an anatomical classification system of facial clefts using a numerical system from 0-14 which designates the location, direction, and/or extent of the cleft relative to the ipsilateral orbit. 2D &3D craniofacial CT images are used to illustrate the radiographic findings of each cleft. SUMMARY After reading this exhibit the observer should comprehend these key points: Understand facial embryology as it pertains to facial maldevelopment (facian clefting). Recognize the anatomy of facialclefts based on the numerical classification system described by Tessier. The observer should be able to accurately describe the relevant anatomy in the radiology report.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;