Publications by authors named "Lucas A Dvoracek"

13 Publications

  • Page 1 of 1

Posterior Cranial Vault Distraction Osteogenesis Utilizing a Posterior-Superior Distraction Vector in the Treatment of Mercedes Benz Pattern Craniosynostosis.

J Craniofac Surg 2021 Mar 24. Epub 2021 Mar 24.

Department of Plastic Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center Department of Plastic Surgery, University of Pittsburgh School of Medicine University of Pittsburgh School of Medicine, Pittsburgh, PA.

Abstract: Bilateral lambdoid and sagittal synostosis, or Mercedes Benz Syndrome, is a rare complex craniosynostosis resulting in frontal bossing, a tapered posterior fossa, and an anteriorly displaced cranial vertex. Its ideal surgical correction must result in posterior expansion, skull elongation, and caudal repositioning of the vertex. We present a craniometric analysis of skull changes with posterior-superior distraction and introduce a novel craniometric measure: vertex position. In this study, a retrospective review was performed to analyze outcomes of posterior cranial vault distraction osteogenesis (PVDO) using a posterior-superior distraction vector from 2016 to 2019. Cranial vertex position was measured as a fraction of the occipitofrontal diameter from rostral to caudal (0-1.0). Four patients underwent PVDO at mean age 10.61 ± 3.16 months utilizing a posterior-superior distraction vector. Linear distraction distance averaged 30.30 ± 0.90 mm with a mean consolidation period of 3.98 ± 0.72 months. Mean corrected change in intra-cranial volume was 236.30 ± 3.71 mL, at an average rate of 7.81 ± 2.00 mL/mm of distraction. Increases in anterior cranial height (7.83 ± 2.51 mm), middle cranial height (8.43 ± 4.21 mm), posterior cranial height (13.15 ± 7.45 mm), and posterior cranial fossa height (21.99 ± 8.55 mm) were observed. Cranial vertex demonstrated a mean posterior movement of 0.18 ± 0.13. PVDO utilizing a posterior-superior distraction vector for management of nonsyndromic bilateral lambdoid and sagittal synostosis effectively increases intracranial volume and height and provides an esthetic outcome with posterior movement of the cranial vertex.
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http://dx.doi.org/10.1097/SCS.0000000000007646DOI Listing
March 2021

Low-Cost, Three-Dimensionally-Printed, Anatomical Models for Optimization of Orbital Wall Reconstruction.

Plast Reconstr Surg 2021 Jan;147(1):162-166

From the Departments of Plastic Surgery and Radiology, University of Pittsburgh; the Division of Plastic and Reconstructive Surgery, University of Massachusetts Medical School-Baystate, Baystate Medical Center; and the Division of Otolaryngology, Yale School of Medicine.

Background: Orbital blowout fracture reconstruction often requires an implant, which must be shaped at the time of surgical intervention. This process is time-consuming and requires multiple placement trials, possibly risking complications. Three-dimensional printing technology has enabled health care facilities to generate custom anatomical models to which implants can be molded to precisely match orbital anatomy. The authors present their early experience with these models and their use in optimizing orbital fracture fixation.

Methods: Maxillofacial computed tomographic scans from patients with orbital floor or wall fractures were prospectively obtained and digitally reconstructed. Both injured-side and mirrored unaffected-side models were produced in-house by stereolithography printing technique. Models were used as templates for molding titanium reconstruction plates, and plates were implanted to reconstruct the patients' orbital walls.

Results: Nine patients (mean age, 15.5 years) were included. Enophthalmos was present in seven patients preoperatively and resolved in six patients with surgery. All patients had excellent conformation of the implant to the fracture site on postoperative computed tomographic scan. Postoperative fracture-side orbital volumes were significantly less than preoperative, and not significantly different from unfractured-side orbital volumes. Total model preparation time was approximately 10 hours. Materials cost was at most $21. Plate bending time was approximately 60 seconds.

Conclusions: Patient-specific orbital models can speed the shaping of orbital reconstruction implants and potentially improve surgical correction of orbital fractures. Production of these models with consumer-grade technology confers the same advantages as commercial production at a fraction of the cost and time.

Clinical Question/level Of Evidence: Therapeutic, IV.
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http://dx.doi.org/10.1097/PRS.0000000000007495DOI Listing
January 2021

Undiagnosed Normocephalic Pancraniosynostosis Presenting as Bilateral Abducens Nerve Palsy.

J Craniofac Surg 2021 Jan-Feb 01;32(1):270-272

Department of Plastic Surgery, University of Pittsburgh, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA.

Abstract: Primary pancraniosynostosis is a rare variant of craniosynostosis in which the major cranial sutures prematurely fuse. Single-suture craniosynostosis is often recognized early in life due to an abnormal head shape. In contrast, primary pancraniosynostosis may be diagnosed later in life due to a grossly normal head shape and size. As such, these children can present with symptoms related to chronically elevated intracranial pressure (eg, vision loss or cognitive impairment). This report highlights a patient with primary pancraniosynostosis associated with unique neurologic sequelae-namely, bilateral abducens nerve palsy. A 9-year-old boy presented to the ophthalmologist with a 1-month history of double vision, drifting of his right eye toward the nasal bridge, and intracranial hypertension evident with papilledema. Physical examination was notable for mild bitemporal narrowing. A computed tomography study demonstrated radiologic thumbprinting, diffuse osseous sclerosis, and fusion of the bilateral coronal, sagittal, metopic, and lambdoid sutures. The patient underwent emergent cranial vault expansion with fronto-orbital advancement. Papilledema had resolved 4 months following surgery. At 2-year follow-up, abducens nerve palsy and head shape were significantly improved. This study brings attention to an unreported presenting symptom of pancraniosynostosis (bilateral abducens nerve palsy). This information may lead to quicker diagnosis and treatment of pancraniosynostosis-induced intracranial hypertension, which is critical to prevent long-term sequelae.
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http://dx.doi.org/10.1097/SCS.0000000000007018DOI Listing
September 2020

Improved Testing and Design of Intubation Boxes During the COVID-19 Pandemic.

Ann Emerg Med 2021 01 3;77(1):1-10. Epub 2020 Sep 3.

Department of Plastic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA.

Study Objective: Throughout the coronavirus disease 2019 pandemic, many emergency departments have been using passive protective enclosures ("intubation boxes") during intubation. The effectiveness of these enclosures remains uncertain. We sought to quantify their ability to contain aerosols using industry standard test protocols.

Methods: We tested a commercially available passive protective enclosure representing the most common design and compared this with a modified enclosure that incorporated a vacuum system for active air filtration during simulated intubations and negative-pressure isolation. We evaluated the enclosures by using the same 3 tests air filtration experts use to certify class I biosafety cabinets: visual smoke pattern analysis using neutrally buoyant smoke, aerosol leak testing using a test aerosol that mimics the size of virus-containing particulates, and air velocity measurements.

Results: Qualitative evaluation revealed smoke escaping from all passive enclosure openings. Aerosol leak testing demonstrated elevated particle concentrations outside the enclosure during simulated intubations. In contrast, vacuum-filter-equipped enclosures fully contained the visible smoke and test aerosol to standards consistent with class I biosafety cabinet certification.

Conclusion: Passive enclosures for intubation failed to contain aerosols, but the addition of a vacuum and active air filtration reduced aerosol spread during simulated intubation and patient isolation.
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http://dx.doi.org/10.1016/j.annemergmed.2020.08.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7470714PMC
January 2021

Decompressive Cranial Vault Remodeling in Osteosclerotic Robinow Syndrome.

Cleft Palate Craniofac J 2021 Jan 6;58(1):126-130. Epub 2020 Aug 6.

Department of Plastic Surgery, 6619Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.

We present a novel application of endocranial burr contouring for cranial vault expansion as a surgical adjunct during decompressive craniectomy in patients with cranial osteosclerosis. A 16-year-old female with osteosclerotic Robinow syndrome complicated by slit ventricle syndrome presented with refractory intracranial hypertension following external ventricular drain placement. Symptoms included severe headaches and altered mental status. Given the severe intracranial volume restriction secondary to massive calvarial thickening (2.5 cm), the patient was taken to the operating room for urgent surgical decompression. After frontal and parietal craniectomy, burr and osteotome contouring were used to remove two-thirds of the endocranial calvarial bone flap thickness resulting in a 9% cranial vault expansion while preserving an overall normal head size. There were no immediate postoperative complications. At over 3 years postoperatively, the patient had reduced headaches, maintained adequate shunt function, and has not required further vault reconstruction.
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http://dx.doi.org/10.1177/1055665620946573DOI Listing
January 2021

Reply: Demineralized Bone Matrix and Resorbable Mesh Bilaminate Cranioplasty Is Ineffective for Secondary Reconstruction of Large Pediatric Cranial Defects.

Plast Reconstr Surg 2020 09;146(3):378e

Department of Plastic Surgery, University of Pittsburgh, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pa.

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http://dx.doi.org/10.1097/PRS.0000000000007132DOI Listing
September 2020

Quantifying the Severity of Metopic Craniosynostosis: A Pilot Study Application of Machine Learning in Craniofacial Surgery.

J Craniofac Surg 2020 May/Jun;31(3):697-701

Department of Plastic Surgery, UPMC Children's Hospital, University of Pittsburgh Medical Center, Pittsburgh, PA.

The standard for diagnosing metopic craniosynostosis (CS) utilizes computed tomography (CT) imaging and physical exam, but there is no standardized method for determining disease severity. Previous studies using interfrontal angles have evaluated differences in specific skull landmarks; however, these measurements are difficult to readily ascertain in clinical practice and fail to assess the complete skull contour. This pilot project employs machine learning algorithms to combine statistical shape information with expert ratings to generate a novel objective method of measuring the severity of metopic CS.Expert ratings of normal and metopic skull CT images were collected. Skull-shape analysis was conducted using ShapeWorks software. Machine-learning was used to combine the expert ratings with our shape analysis model to predict the severity of metopic CS using CT images. Our model was then compared to the gold standard using interfrontal angles.Seventeen metopic skull CT images of patients 5 to 15 months old were assigned a severity by 18 craniofacial surgeons, and 65 nonaffected controls were included with a 0 severity. Our model accurately correlated the level of skull deformity with severity (P < 0.10) and predicted the severity of metopic CS more often than models using interfrontal angles (χ = 5.46, P = 0.019).This is the first study that combines shape information with expert ratings to generate an objective measure of severity for metopic CS. This method may help clinicians easily quantify the severity and perform robust longitudinal assessments of the condition.
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http://dx.doi.org/10.1097/SCS.0000000000006215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7202995PMC
September 2020

Cone-Beam Computed Tomography Incidental Findings in Individuals With Cleft Lip and Palate.

Cleft Palate Craniofac J 2020 04 22;57(4):404-411. Epub 2020 Jan 22.

UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA.

Objectives: The use of cone-beam computed tomography (CBCT) is well-established in clinical practice. This study seeks to categorize and quantify the incidental finding (IF) rate on CBCT in patients with cleft lip and palate (CLP) prior to orthodontic or surgical treatment.

Methods: This is systematic retrospective review of head and neck CBCTs in patients with nonsyndromic CLP taken between 2012 and 2019 at a single tertiary referral center. All assessments were performed independently by 4 observers (a head and neck radiologist and 3 orthodontists, including 2 fellowship-trained cleft-craniofacial orthodontists ). The images were divided into 9 anatomical areas and screened using serial axial slices and 3D reconstructions. The absolute number of IFs was reported for each area and statistical analysis was performed.

Results: Incidental findings were found in 106 (95.5%) of the 111 patients. The most common sites were the maxilla (87.4%, principally dental anomalies), paranasal sinuses (46.8%, principally inflammatory opacification), and inner ear cavities (18.9%, principally inflammatory opacification). Eleven patients had skull malformations. Thirty-three patients had IFs in 1 anatomical area, 49 patients in 2 anatomical areas, 19 patients in 3 areas, and 5 patients presented with IFs in 4 of the 9 anatomical areas.

Discussion: In patients with CLP, IFs on CBCT exam were present in the majority of cases. Most patients with IFs had them in multiple anatomical areas of the head and neck. The maxillary dental-alveolar complex was the most common area. Inflammatory changes in the inner ear cavities and paranasal sinuses were also common; however, cervical spine and skull abnormalities were also identified. Clinicians caring for patients with CLP should be aware of IFs, which may warrant further investigation and treatment.
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http://dx.doi.org/10.1177/1055665619897469DOI Listing
April 2020

An Intraoperative Salvage After Transection of the Greater Palatine Artery During Cleft Palate Repair: A Case for Buccal Fat and Buccal Myomucosal Flaps.

J Craniofac Surg 2020 Mar/Apr;31(2):e133-e135

Department of Plastic Surgery, University of Pittsburgh Medical Center, PA.

Recently, several adjunctive procedures have gained traction to aid cleft surgeons in repairing especially challenging palatal clefts. Buccal fat flaps and buccal myomucosal flaps have demonstrated particular utility in reinforcing thin palatal flaps or tissue deficits. Although their use has not been widely accepted, they may be particularly helpful in the setting of significant scarring or vascular compromise. Here the authors describe the case of an intraoperative salvage using bilateral buccal fat flaps and a right buccal myomucosal flap after transection of the right Greater Palatine artery (GPA) during palatoplasty on a 14-month old female with Pierre Robin Sequence and a wide Veau II cleft palate. For this operative salvage, bilateral buccal fat flaps were used to reinforce the hard-soft palate junction and a 4 cm × 2 cm flap of the right-sided buccal mucosa and buccinator muscle was inset along the majority of the right-sided soft and posterior hard palate. At 2 years follow-up, the patient had no significant complications and was doing well with healthy-appearing palatal tissue and age-appropriate speech.
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http://dx.doi.org/10.1097/SCS.0000000000006037DOI Listing
June 2020

Demineralized Bone Matrix and Resorbable Mesh Bilaminate Cranioplasty Is Ineffective for Secondary Reconstruction of Large Pediatric Cranial Defects.

Plast Reconstr Surg 2020 01;145(1):137e-141e

From the Department of Plastic Surgery, University of Pittsburgh, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center; the University of Massachusetts-Baystate, Baystate Medical Center; and the Drexel University College of Medicine.

Replacement of the autologous bone flap after decompressive craniectomy can be complicated by significant osteolysis or infection with large defects over scarred dura. Demineralized bone matrix is an alternative to autologous reconstruction, effective when reconstructing large defects using a resorbable mesh bilaminate technique in primary cranioplasty, but this technique has not been studied for revision cranioplasty and the setting of scarred dura. Retrospective review was performed of patients receiving demineralized bone matrix and resorbable mesh bilaminate cranioplasty for postdecompressive craniectomy defects. Seven patients (mean age, 4.2 years) were identified with a mean follow-up of 4.0 years. Computed tomography before the demineralized bone matrix and resorbable mesh bilaminate cranioplasty and at least 1 year postoperatively were compared. Defects were characterized and need for revision was assessed. All patients had craniectomy with associated hemidural scarring. Five patients had autologous bone flap cranioplasty associated with nearly total osteolysis, and two patients had deferral of bone flap before demineralized bone matrix and resorbable mesh bilaminate cranioplasty. Demineralized bone matrix and resorbable mesh bilaminate cranioplasty demonstrated unpredictable and poor ossification, with bony coverage unchanged at postoperative follow-up. All patients required major revision cranioplasty at a mean time of 2.5 years. Porous polyethylene was successfully used in six of the revisions, whereas exchange cranioplasty was used in the remaining patient, with a mean follow-up of 1.4 years. Although demineralized bone matrix and resorbable mesh bilaminate is appropriate for primary cranioplasty, it should be avoided in the setting of scarred or infected dura in favor of synthetic materials or exchange cranioplasty. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.
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http://dx.doi.org/10.1097/PRS.0000000000006386DOI Listing
January 2020

Quick Calculation of Breast Resection Mass Using the Schnur Scale.

Ann Plast Surg 2019 03;82(3):316-319

From the Department of Plastic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA.

In 1991, Dr Paul Schnur and his colleagues published an article correlating the weight of breast tissue to be removed in a breast reduction operation with the total body surface area (BSA) of the patient. They presented a very cogent argument for selecting three groups of patients: those with medical indications for operation, those who merit review, and those whose operation could be considered cosmetic. The Schnur Sliding Scale is widely used by insurance companies in the western United States in the process of preauthorizing breast reduction operations, and its use may be spreading eastward. The Schnur group presented a nomogram for calculating BSA and a scale in the form of a table for guiding a determination of whether the patient is a reconstructive patient as opposed to an aesthetic patient. We have combined the scale and the BSA nomogram for a simplified nomogram calculator that facilitates rapid determination of anticipated tissue weight of resection for a patient of a given size. This calculator yields the required weight of tissue to remove with just knowledge of the patient's height and weight and the use of a straight edge. We demonstrate and compare performance of this calculation by hand and by nomogram. There is ample evidence that the practice of applying the Schnur Sliding Scale may be prohibitive to symptomatic patients seeking reduction mammaplasty and should be abandoned. While this practice continues, our simplified Schnur Sliding Scale nomogram is meant to help easily determine the insurer-required minimum breast resection weight and thereby both improve patient counseling prior to planning surgery and assist the surgeon with achieving insurer reimbursement for the procedure while avoiding rejected claims.
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http://dx.doi.org/10.1097/SAP.0000000000001643DOI Listing
March 2019

Comparison of Traditional versus Normative Cephalic Index in Patients with Sagittal Synostosis: Measure of Scaphocephaly and Postoperative Outcome.

Plast Reconstr Surg 2015 Sep;136(3):541-548

St. Louis, Mo. From the Division of Plastic and Reconstructive Surgery and the Department of Neurosurgery, Washington University in St. Louis.

Background: Preoperative severity and postoperative success for patients with sagittal synostosis are measured by cephalic index, but this metric does not describe the appropriateness of euryon location. The authors hypothesize that cephalic index in patients with sagittal synostosis is an inaccurate measure of scaphocephaly.

Methods: Preoperative and 1-year postoperative cranial computed tomographic scans of children with sagittal synostosis treated before 6 months of age by either total calvarial reconstruction or endoscope-assisted craniectomy and helmet therapy (n = 10 for each) were reviewed retrospectively. The location of euryons in age-matched controls was measured as a fraction of the glabella-opisthocranion distance (horizontal point of maximum width) and as the fraction of the nasion-vertex vertical distance (vertical point of maximum width). Cephalic index at this ideal location (normative cephalic index) and traditional cephalic index were determined in all patients.

Results: Ideal euryon location from preoperative controls was 56 percent by the horizontal point of maximum width and 56 percent by the vertical point of maximum width. Normative cephalic index (0.60) was significantly less than traditional cephalic index (0.66) in patients preoperatively (p < 0.001) and remained smaller postoperatively (0.68 versus 0.73) for patients who underwent open reconstruction (p < 0.001). Patients treated endoscopically also had a smaller normative cephalic index (0.71) than traditional cephalic index (0.76) postoperatively (p < 0.001).

Conclusions: Anterocaudal displacement of euryon in patients with sagittal synostosis influences cephalic index. Normative cephalic index, assessed at ideal euryon location, is a more accurate measure of preoperative severity and postoperative outcome.

Clinical Question/level Of Evidence: Diagnostic, III.
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http://dx.doi.org/10.1097/PRS.0000000000001505DOI Listing
September 2015

Lovastatin inhibits oxidized L-A-phosphatidylcholine B-arachidonoyl-gamma-palmitoyl (ox-PAPC)-stimulated interleukin-8 mRNA and protein synthesis in human aortic endothelial cells by depleting stores of geranylgeranyl pyrophosphate.

Atherosclerosis 2010 Jan 18;208(1):50-5. Epub 2009 Jun 18.

Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV 26074, USA.

Human aortic endothelial cells (HAEC) exposed to 50 microg/ml oxidized L-A-phosphatidylcholine B-arachidonoyl-gamma-palmitoyl (ox-PAPC) for 6h increased in interleukin-8 mRNA and protein levels. Preincubation of HAEC with the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA) inhibitor, (20 microM), significantly inhibited ox-PAPC-stimulated interleukin-8 mRNA and protein levels. Mevalonate (200 microM) reversed the inhibition of ox-PAPC-stimulated mRNA and protein levels by lovastatin, indicating the inhibitory effect of lovastatin was due to inhibition of mevalonate synthesis. Addition of the geranylgeraniol (GGOL, 10 microM) but not farnesol (FOL, 10 microM), reversed the inhibitory effect of lovastatin on interleukin-8 mRNA and protein levels stimulated by ox-PAPC, indicating that lovastatin exerted its effect by inhibiting stores of geranylgeranyl pyrophosphate (GGPP) which are necessary for geranylgeranylation of proteins. These results suggest a new mechanism for lovastatin in preventing atherosclerosis by inhibiting the inflammatory response that takes place in the vascular wall.
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http://dx.doi.org/10.1016/j.atherosclerosis.2009.06.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813419PMC
January 2010