MR Cranial Bone Imaging: Evaluation of Both Motion-Corrected and Automated Deep Learning Pseudo-CT Estimated MR Images.

BACKGROUND AND PURPOSE: CT imaging exposes patients to ionizing radiation. MR imaging is radiation free but previously has not been able to produce diagnostic-quality images of bone on a timeline suitable for clinical use. We developed automated motion correction and use deep learning to generate pseudo-CT images from MR images. We aim to evaluate whether motion-corrected pseudo-CT produces cranial images that have potential to be acceptable for clinical use. MATERIALS AND METHODS: Patients younger than age 18 who underwent CT imaging of the head for either trauma or evaluation of cranial suture patency were recruited. Subjects underwent a 5-minute golden-angle stack-of-stars radial volumetric interpolated breath-hold MR image. Motion correction was applied to the MR imaging followed by a deep learning-based method to generate pseudo-CT images. CT and pseudo-CT images were evaluated and, based on indication for imaging, either presence of skull fracture or cranial suture patency was first recorded while viewing the MR imaging-based pseudo-CT and then recorded while viewing the clinical CT. RESULTS: A total of 12 patients underwent CT and MR imaging to evaluate suture patency, and 60 patients underwent CT and MR imaging for evaluation of head trauma. For cranial suture patency, pseudo-CT had 100% specificity and 100% sensitivity for the identification of suture closure. For identification of skull fractures, pseudo-CT had 100% specificity and 90% sensitivity. CONCLUSIONS: Our early results show that automated motion-corrected and deep learning-generated pseudo-CT images of the pediatric skull have potential for clinical use and offer a high level of diagnostic accuracy when compared with standard CT scans.

Conceptual Principles in Pediatric Craniomaxillofacial Reconstruction.

Pediatric craniomaxillofacial reconstruction must be approached through the lens of growth and durability. A systematic approach of matching defects to donor tissue drives the selection of autologous reconstructive technique. The menu of available methods for reconstruction can be organized in a manner similar to adults, with special considerations for growth and development. Reconstructive surgeons have the opprtunity to promote and maintain young patients' sense of identity during psychosocial development.

Pediatric Cranial Vault Pathology.

A wide variety of diagnoses can be approached with a common framework for diagnosis, extirpation, and reconstruction of pediatric cranial vault pathologies. Durability of reconstruction is critical for the range of pediatric patients from infancy to adolescence. Rigid reconstruction, preferably with autologous tissue when possible, promotes brain protection and satisfactory aesthetic outcome. Careful planning can allow for immediate definitive reconstruction of defects without need for further surgical intervention.

Multidisciplinary Optimal Outcomes Reporting and Team Clinic Retention in Isolated Nonsyndromic Cleft Palate.

OBJECTIVE: Optimal Outcomes Reporting was recently introduced to categorize outcomes after cleft palate repair. We seek to propose an expanded version of Optimal Outcomes Reporting and to determine if correlation exists between the expanded outcomes and persistence with team care follow-up through age 9. DESIGN: Retrospective cohort study. SETTING: Cleft team at large pediatric hospital. PATIENTS: Patients with isolated nonsyndromic cleft palate (n = 83) born from 2001-2012. MAIN OUTCOME MEASURES: Patients who continued to present at age 5 or greater were assessed for optimal outcomes. Optimal outcomes were: surgery - no fistula or velopharyngeal insufficiency; otolaryngology - no obstructive sleep apnea or signs of chronic middle ear disease; audiology - no hearing loss; speech-language pathology - no assessed need for speech therapy. RESULTS: Of the 83 patients identified, 41 were assessed for optimal outcomes. Optimal outcome in any discipline was not associated with follow-up through age 9 (0.112 ≤ p ≤ 0.999). For all disciplines, the group with suboptimal outcomes had a higher proportion of patients from geographic areas in the most disadvantaged quartile of social vulnerability index, with the strongest association in the group with suboptimal speech outcome (OR 6.75, 95% CI 0.841-81.1). CONCLUSIONS: Optimal outcomes and retention in team clinic were not statistically significantly associated, but clinically relevant associations were found between patients in the most disadvantaged quartile of social vulnerability and their outcomes. A patient-centered approach, including caregiver education about long-term care for patients with cleft palate, would allow for enhanced resource utilization to improve retention for patients of concern.

Improving the Care of Our Patients: Twenty-Three Years of the James Barrett Brown Resident Research Day.

BACKGROUND: James Barrett Brown was one of the founders of Plastic and Reconstructive Surgery as a specialty in the United States. Susan Mackinnon started the James Barrett Brown Resident Research Day in 1997 in his honor to serve as an annual opportunity for trainees to present their research to the Division and a visiting contemporary leader in plastic surgery. We sought to determine the proportion of Resident Research Day projects that have progressed to publication. METHODS: Available internal records from 1998 to 2019 were used to identify presenters and projects. Academic productivity of presenters was estimated with the h-index from the Scopus database. RESULTS: One hundred forty-five students, residents, and fellows presented 276 projects at Resident Research Day from 1998 to 2019. These presentations were associated with 144 unique peer-reviewed publications, representing 52% of the presented projects. They were published an average of 1.8 years after presentation, and the presenter was the first or last author on 67% of them. The current average h-index of trainees who published at least 1 project (8.3) is significantly higher than the h-index of those who did not (5.0, P < 0.001). CONCLUSIONS: The James Barrett Brown Resident Research Day not only honors the legacy of Brown but also enhances scholarly activity of trainees. The opportunity to present and publish research teaches project planning, implementation, and data analysis, followed by manuscript preparation and the publication process. This important skill set can provide the foundation for the academic careers of future leaders in plastic surgery.

A Case of Nonsyndromic Craniosynostosis in an Infant Child of Jehovah's Witness Parents: Is Surgical Correction Appropriate?

An infant with nonsyndromic craniosynostosis is brought to clinic by his Jehovah's Witness parents to discuss treatment. Five potential courses of action are discussed in the context of biomedical ethics principles. The potential conflict between parents' autonomy to make decisions for their child and the surgeon's ethical duty of beneficence to the patient is explored.

Systemic Preoperative Antibiotics with Mandible Fractures: Are They Indicated at the Time of Injury?

Mandible fractures are the most common result of facial trauma. The proximity of oral flora to the site of both the injury and resulting surgical instrumentation makes managing infection a unique challenge. The benefit of antibiotic prophylaxis at the time of surgical treatment of mandible fractures is well established. However, the routine use of antibiotics between the time of injury and surgery is of unclear benefit. We aim to define the role of antibiotics in the preoperative period: from the time of injury to surgical intervention. Demographic and clinical data were collected retrospectively on all patients who were treated for mandible fracture by the Division of Plastic and Reconstructive Surgery at our institution between 2003 and 2013. The use of both preoperative (between injury and surgery) and perioperative (at the time of surgery) systemic antibiotics was recorded along with the incidence of postoperative infections and other complications. Complete data were available for 269 patients. Of the 216 patients who received preoperative antibiotics, 22 (10%) developed an infection postoperatively. Of the 53 patients who did not receive preoperative antibiotics, 2 (4%) developed infection ( p = 0.184). Likewise, preoperative antibiotics were not significantly associated with hardware complication rates. In our retrospective review, the use of antibiotics between injury and surgical repair had no impact on postoperative infection rates. These data suggest that preoperative antibiotic use may actually be associated with an increased incidence of postoperative infection. Our results do not support the routine use of antibiotics between injury and surgical repair in patients with mandible fractures.

Structural basis for VEGF-C binding to neuropilin-2 and sequestration by a soluble splice form.

Vascular endothelial growth factor C (VEGF-C) is a potent lymphangiogenic cytokine that signals via the coordinated action of two cell surface receptors, Neuropilin-2 (Nrp2) and VEGFR-3. Diseases associated with both loss and gain of VEGF-C function, lymphedema and cancer, respectively, motivate studies of VEGF-C/Nrp2 binding and inhibition. Here, we demonstrate that VEGF-C binding to Nrp2 is regulated by C-terminal proteolytic maturation. The structure of the VEGF-C C terminus in complex with the ligand binding domains of Nrp2 demonstrates that a cryptic Nrp2 binding motif is released upon proteolysis, allowing specific engagement with the b1 domain of Nrp2. Based on the identified structural requirements for Nrp2 binding to VEGF-C, we hypothesized that the endogenous secreted splice form of Nrp2, s9Nrp2, may function as a selective inhibitor of VEGF-C. We find that s9Nrp2 forms a stable dimer that potently inhibits VEGF-C/Nrp2 binding and cellular signaling. These data provide critical insight into VEGF-C/Nrp2 binding and inhibition.

Effect of C-terminal sequence on competitive semaphorin binding to neuropilin-1.

Neuropilins (Nrp) are type I transmembrane proteins that function as receptors for vascular endothelial growth factor (VEGF) and class III Semaphorin (Sema3) ligand families. Sema3s function as potent endogenous angiogenesis inhibitors but require proteolytically processing by furin to compete with VEGF for Nrp binding. This processing liberates a C-terminal arginine (CR) that is necessary for binding to the b1 domain of Nrp, a common feature shared by Nrp ligands. The CR is necessary but not sufficient for potent Nrp inhibition, and the role of upstream residues is unknown. We demonstrate that the second-to-last residue (C-1), immediately upstream of the CR, plays a significant role in controlling competitive ligand binding by orienting the C-terminus for productive Nrp binding. With the use of a peptide library derived from Sema3F, C-1 residues that preferentially adopt an extended bound-like conformation, including proline and ß-branched amino acids, were found to produce the most avid competitors. Consistent with this, analysis of the binding thermodynamics revealed that more favorable entropy is responsible for the observed binding enhancement of C-1 proline. We further tested the effect of the C-1 residue on Sema3F processing by furin and found an inverse relationship between processing and inhibitory potency. Analysis of all Sema3 family members reveals two non-equivalent furin processing sites differentiated by the presence of either a C-1 proline or a C-1 arginine and resulting in up to a 40-fold difference in potency. These data reveal a novel regulatory mechanism of Sema3 activity and define a fundamental mechanism for preferential Nrp binding.

Function of members of the neuropilin family as essential pleiotropic cell surface receptors.

The neuropilin (Nrp) family consists of essential multifunctional vertebrate cell surface receptors. Nrps were initially characterized as receptors for class III Semaphorin (Sema3) family members, functioning in axon guidance. Nrps have also been shown to be critical for vascular endothelial growth factor-dependent angiogenesis. Intriguingly, recent data show that Nrp function in these seemingly divergent pathways is critically determined by ligand-mediated cross-talk, which underlies Nrp function in both physiological and pathological processes. In addition to functioning in these two pathways, Nrps have been shown to specifically function in a number of other fundamental signaling pathways as well. Multiple general mechanisms have been found to directly contribute to the pleiotropic function of Nrp. Here we review critical general features of Nrps that function as essential receptors integrating multiple molecular cues into diverse cellular signaling.