Workflow to develop 3D designed personalized neonatal CPAP masks using iPhone structured light facial scanning.

BACKGROUND: Continuous positive airway pressure (CPAP) is a common mode of respiratory support used in neonatal intensive care units. In preterm infants, nasal CPAP (nCPAP) therapy is often delivered via soft, biocompatible nasal mask suitable for long-term direct skin contact and held firmly against the face. Limited sizes of nCPAP mask contribute to mal-fitting related complications and adverse outcomes in this fragile population. We hypothesized that custom-fit nCPAP masks will improve the fit with less skin pressure and strap tension improving efficacy and reducing complications associated with nCPAP therapy in neonates. METHODS: After IRB approval and informed consent, we evaluated several methods to develop 3D facial models to test custom 3D nCPAP masks. These methods included camera-based photogrammetry, laser scanning and structured light scanning using a Bellus3D Face Camera Pro and iPhone X running either Bellus3D FaceApp for iPhone, or Heges application. This data was used to provide accurate 3D neonatal facial models. Using CAD software nCPAP inserts were designed to be placed between proprietary nCPAP mask and the model infant's face. The resulted 3D designed nCPAP mask was form fitted to the model face. Subsequently, nCPAP masks were connected to a ventilator to provide CPAP and calibrated pressure sensors and co-linear tension sensors were placed to measures skin pressure and nCPAP mask strap tension. RESULTS: Photogrammetry and laser scanning were not suited to the neonatal face. However, structured light scanning techniques produced accurate 3D neonatal facial models. Individualized nCPAP mask inserts manufactured using 3D printed molds and silicon injection were effective at decreasing surface pressure and mask strap pressure in some cases by more than 50% compared to CPAP masks without inserts. CONCLUSIONS: We found that readily available structured light scanning devices such as the iPhone X are a low cost, safe, rapid, and accurate tool to develop accurate models of preterm infant facial topography. Structured light scanning developed 3D nCPAP inserts applied to commercially available CPAP masks significantly reduced skin pressure and strap tension at clinically relevant CPAP pressures when utilized on model neonatal faces. This workflow maybe useful at producing individualized nCPAP masks for neonates reducing complications due to misfit.

Surgical Simulation in East, Central, and Southern Africa: A Multinational Survey.

BACKGROUND: High-income countries have increased the use of simulation-based training and assessment for surgical education. Learners in low- and middle-income countries may have different educational needs and levels of autonomy but they and their patients could equally benefit from the procedural training simulation provides. We sought to characterize the current state of surgical skills simulation in East, Central, and Southern Africa and determine residents' perception and future interest in such activities. METHODS: A survey was created via collaboration and revision between trainees and educators with experiences spanning high-income countries and low- and middle-income countries. The survey was administered on paper to 76 trainees (PGY2-3) who were completing the College of Surgeons of East, Central, and Southern Africa (COSECSA) Membership of the College of Surgeons examination in Kampala, Uganda in December 2019. Data from paper responses were summarized using descriptive statistics and frequencies. RESULTS: We received responses from 43 trainees (57%) from 11 countries in sub-Saharan Africa who participated in the examination. Fifty-eight percent of respondents reported having dedicated space for surgical skills simulation training, and most (91%) had participated in some form of simulation activity at some point in their training. However, just 16% used simulation as a regular part of training. The majority of trainees (90%) felt that surgical skills learned in simulation were transferrable to the operating room and agreed it should be a required part of training. Seventy-one percent of trainees felt that simulation could objectively measure technical skills, and 73% percent of respondents agreed that simulation should be integrated into formal assessment. However, residents split on whether proficiency in simulation should be achieved prior to operative experience (54%) and if nontechnical skills could be measured (51%). The most common cited barriers to the integration of surgical simulation into residents' education were lack of suitable tools and models (85%), funding (73%), and maintenance of facilities (49%). CONCLUSIONS: Residents from East, Central, and Southern Africa strongly agree that simulation is a valuable educational tool and ought to be required during their surgical residency. Barriers to achieving this goal include availability of affordable tools, adequate funding and confidence in the value of the educational experience. Trainees affirm further efforts are necessary to make simulation more widely available in these contexts.

Three-Dimensional-Printed Liver Model Helps Learners Identify Hepatic Subsegments: A Randomized-Controlled Cross-Over Trial.

INTRODUCTION: The purpose of this study was to find out whether 3-dimensional (3D)-printed models improved the learners' ability to identify liver segments. METHODS: A total of 116 physicians from 3 disciplines were tested in a cross-over trial at baseline and after teaching with 3D models and 2-dimensional (2D) images. Adjusted multilevel-mixed models were used to compare scores at baseline and after 3D and 2D. RESULTS: Accuracy in identifying hepatic segments was higher with 3D first than 2D (77% vs 69%; P = 0.05) and not significantly improved by a combination of 3D and 2D. Increased confidence in segment identification was highest in trainees after 3D (P = 0.04). DISCUSSION: 3D-printed models facilitate learning hepatic segmental anatomy.

Coordinated approach to spinal and tracheal reconstruction in a patient with morquio syndrome.

Morquio syndrome (Mucopolysaccharidosis IVA) is an autosomal recessive lysosomal storage disease with manifestations ranging from mild to severe phenotype. Mechanical spinal cord injury and airway insufficiency are major causes of mortality. A 17-year-old male patient with severe Morquio syndrome presented with cervical and upper thoracic spinal stenosis with spinal cord myelopathy, and progressive severe tracheal stenosis. Coordinated care among otolaryngology, orthopedic surgery, neurosurgery, anesthesiology, cardiovascular surgery, radiology, and pulmonology teams facilitated the successful planning and execution of two major surgical interventions in rapid succession. This is the first description of a successful coordinated spine and airway repair in the literature.

3D printed modeling contributes to reconstruction of complex chest wall instability.

BACKGROUND: Three-dimensional printed models are increasingly used in many fields including medicine and surgery, but their use in the planning and execution of complex chest wall reconstruction has not been adequately described. In cases of non-union or prior attempts at chest wall reconstruction which have failed, there can be substantial deviations from expected chest wall anatomy. We report a novel technique for pre-operative planning and surgical execution of complex chest wall reconstruction, assisted by 3D printing. Our objective was to utilize 3-D volumetric modeling coupled with 3-D printing to produce patient-specific models for chest wall reconstruction in complex cases. METHODS: Soft tissue reconstruction 0.75 mm slice thickness computed tomography (CT) imaging data was loaded into medical CAD software for segmentation. Lung, muscle, foreign bodies, and bony structureswere separated due to the differences in density between them. The 3D volumetric mesh was then quality checked and stereolithography files (STL) were made which were able to be utilized by the 3D printer. The STL files were exported to a Objet 500 material jetting printer that utilized several UV light cured photopolymers. RESULTS: As an example case, we discuss a 55 year old male who underwent resuscitative thoracotomy. In the early post-operative period, he developed a pulmonary hernia in the 6th intercostal space, repaired with wire cerclage reapproximation of ribs. He developed a symptomatic mobile chest wall at the site of prior repair with additional concern for dissociated anterior cartilage. In preparation for operative repair, a 3D printed model was created, demonstrating fractured cartilage anteriorly as well a saw effect through the six and seventh ribs. An additional model was created using the normal ribs from the right side in mirror image reflection to quantify the degree and precise geometry of mal-alignment to the left chest. These models were then utilized to determine the operative approach via a thoracotomy incision to remove the cerclage wires, followed by parasternal incision, reduction and plating of the sternocostal non-union bursa Rib non-unions were plate stabilized. Repeat imaging in follow-up has demonstrated continued appropriate alignment and the patient reported improvement in his symptoms. CONCLUSION: At present, the cost of 3-D printing remains substantial, but given the improved planning in complex cases, this cost may be recaptured in the reduction of operative time and improved outcomes with reduced re-operation rates. We believe that the early adoption of this technology by surgeons can help improve surgical quality and provide enhanced individualized patient care. These patient-specific models facilitate identification of features which are often not detected with standard 3-D reconstructed CT rendering. Centers should pursue the integration of 3-D printed models into their practice and active collaborations between surgeons and modeling experts should be sought at every available opportunity.

Imaging for Acute and Chronic Scaphoid Fractures.

The scaphoid is the most commonly fractured bone in the wrist but 20% to 40% of scaphoid fractures are radiographically occult. Delayed or misdiagnosis can have significant consequences with late complications such as nonunion, malunion, or the development of avascular necrosis in the proximal pole. After initial negative radiographs, advanced cross-sectional imaging, including CT and MRI, ultimately may provide more accurate and rapid diagnosis than conventional radiography. With chronic fractures, the preferred modality depends on the clinical question. New techniques are evolving that will further advance imaging for diagnosis and treatment of scaphoid fractures.

Preoperative Planning Using 3-Dimensional Printing for Complex Paraspinal Schwannoma Resection: 2-Dimensional Operative Video.

Schwannomas are benign peripheral nerve sheath tumors that are typically round, smooth, and straightforward to resect. Occasionally they are more complicated to resect because of their size, location, degree of bony erosion, and vascular or neural compression. These complex lesions frequently require multidisciplinary surgical teams in order to decrease surgical morbidity. Historically, surgical planning consisted of imaging review and verbal communication among team members. 3-dimensional (3D) printing offers a new method for preoperative planning and is becoming more popular in Neurosurgery. This video demonstrates the use of 3D printing for complex paraspinal tumors in the cervical, thoracic, and sacral regions. The Institutional Review Board Office for Human Research Protection does not require approval for single participant case studies, or a case series with multiple participants. The subjects involved in this study were not identifiable and the general surgical consent form included permission for intraoperative photos.

The Various Applications of 3D Printing in Cardiovascular Diseases.

PURPOSE OF REVIEW: To highlight the various applications of 3D printing in cardiovascular disease and discuss its limitations and future direction. RECENT FINDINGS: Use of handheld 3D printed models of cardiovascular structures has emerged as a facile modality in procedural and surgical planning as well as education and communication. Three-dimensional (3D) printing is a novel imaging modality which involves creating patient-specific models of cardiovascular structures. As percutaneous and surgical therapies evolve, spatial recognition of complex cardiovascular anatomic relationships by cardiologists and cardiovascular surgeons is imperative. Handheld 3D printed models of cardiovascular structures provide a facile and intuitive road map for procedural and surgical planning, complementing conventional imaging modalities. Moreover, 3D printed models are efficacious educational and communication tools. This review highlights the various applications of 3D printing in cardiovascular diseases and discusses its limitations and future directions.

The breadth of the diaphragm: updates in embryogenesis and role of imaging.

The diaphragm is an unique skeletal muscle separating the thoracic and abdominal cavities with a primary function of enabling respiration. When abnormal, whether by congenital or acquired means, the consequences for patients can be severe. Abnormalities that affect the diaphragm are often first detected on chest radiographs as an alteration in position or shape. Cross-sectional imaging studies, primarily CT and occasionally MRI, can depict structural defects, intrinsic and adjacent pathology in greater detail. Fluoroscopy is the primary radiologic means of evaluating diaphragmatic motion, though MRI and ultrasound also are capable of this function. This review provides an update on diaphragm embryogenesis and discusses current imaging of various abnormalities, including the emerging role of three-dimensional printing in planning surgical repair of diaphragmatic derangements.

Three-dimensional prototyping for procedural simulation of transcatheter mitral valve replacement in patients with mitral annular calcification.

INTRODUCTION: Three-dimensional (3D) prototyping is a novel technology which can be used to plan and guide complex procedures such as transcatheter mitral valve replacement (TMVR). METHODS: Eight patients with severe mitral annular calcification (MAC) underwent TMVR. 3D digital models with digital balloon expandable valves were created from pre-procedure CT scans using dedicated software. Five models were printed. These models were used to assess prosthesis sizing, anchoring, expansion, paravalvular gaps, left ventricular outflow tract (LVOT) obstruction, and other potential procedure pitfalls. Results of 3D prototyping were then compared to post procedural imaging to determine how closely the achieved procedural result mirrored the 3D modeled result. RESULTS: 3D prototyping simulated LVOT obstruction in one patient who developed it and in another patient who underwent alcohol septal ablation prior to TMVR. Valve sizing correlated with actual placed valve size in six out of the eight patients and more than mild paravalvular leak (PVL) was simulated in two of the three patients who had it. Patients who had mismatch between their modeled valve size and post-procedural imaging were the ones that had anterior leaflet resection which could have altered valve sizing and PVL simulation. 3D printed model of one of the latter patients allowed modification of anterior leaflet to simulate surgical resection and was able to estimate the size and location of the PVL after inserting a valve stent into the physical model. CONCLUSION: 3D prototyping in TMVR for severe MAC is feasible for simulating valve sizing, apposition, expansion, PVL, and LVOT obstruction.

Skull base plasmacytoma: A unique case of POEMS syndrome with a plasmacytoma causing craniocervical instability.

INTRODUCTION: Plasmacytomas, considered to be the solitary counterparts of multiple myeloma, are neoplastic monoclonal plasma cell proliferations within soft tissue or bone. Plasmacytomas often present as a collection of findings known as POEMS-syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, M-Protein spike, and Skin changes). CASE DESCRIPTION: We present a report of a 47 yo male diagnosed with POEMS-syndrome secondary to a skull base plasmacytoma. The mass resulted in marked instability of the cranio-cervical junction due to bony erosion. Following an induction course of chemotherapy, he showed clinical improvement with a marked reduction in tumor size and underwent an autologous peripheral blood stem cell transplant for systemic treatment of his POEMS-syndrome. Following completion of systemic treatment, he then underwent a definitive occipital-cervical fusion without complications. His neurologic exam upon dismissal was stable with subjective improvement in left upper extremity strength. Postoperative radiographs confirmed spinal alignment and pathological examination of a small biopsy from C1 revealed benign fibrous tissue. CONCLUSION: To the best of our knowledge, this is the first report of a skull-base plasmacytoma associated with POEMS-syndrome, causing cranio-cervical instability. The approach of systemic therapy combined with temporary external fixation, followed by definitive occipital cervical fusion resulted in a good outcome for this patient.

Management of pediatric hepatocellular carcinoma: A multimodal approach.

HCC is rare in the pediatric population, but is the second most common liver malignancy in children. Survival rates for primary unresectable HCC have been dismal. The objective of this study was to describe our experience with a multimodal approach for the management of unresectable HCC in two adolescent patients and to review the literature. Both patients are currently alive with no recurrence at 51 and 29 months post-transplant. Multimodality treatment involving chemotherapy with doxorubicin, cisplatin, and sorafenib; TACE; timely liver transplantation; and post-transplant therapy with sorafenib and mTOR inhibitors may help improve outcomes and prolong survival in pediatric patients with unresectable HCC.

The Utility of Magnetic Resonance Imaging in the Evaluation of Accessory Scrotum in the Newborn.

Accessory scrotum, a rare form of congenital scrotal anomaly that is often associated with other genitourinary and anorectal anomalies, is characterized by ectopic scrotal tissue in the presence of a normal, orthotopic scrotum. Here, we present a case of accessory scrotum in a newborn male. We describe our experience with the utilization of preoperative pelvic magnetic resonance imaging to characterize the complex relationship between the accessory scrotum and ano-sphincteric complex, as well as identify associated genitourinary abnormalities. We also provide a brief literature review.

Melorheostosis: A Retrospective Clinical Analysis of 24 Patients at the Mayo Clinic.

BACKGROUND: Current understanding of the clinical features of persons with melorheostosis is restricted primarily to individual case reports and small case series. OBJECTIVE: To assess the clinical features of patients with melorheostosis treated at our institution from 1972 through 2010. DESIGN: Chart review. SETTING: Tertiary academic medical center. PARTICIPANTS: Twenty-three patients with "definite" and one patient with "probable" melorheostosis based on radiographic criteria. METHODS: The eligible study cohort was identified through the Rochester Medical Index database. Further diagnostic confirmation of patients with melorheostosis was performed by radiographic review. MAIN OUTCOME MEASUREMENTS: We evaluated age at first visit to our institution, gender, affected body area, number of bones affected, presenting symptoms, surgical evaluation, and therapies provided. RESULTS: The average age at first evaluation at our clinic was 36.5 years (median 41.5 years, range 3-68 years). The female to male ratio was 4:1. The lower extremity was most commonly affected (66.6%), followed by upper extremity (33.3%), spine (16.6%), and head (8.3%). One-third of patients had involvement of a single bone; two-thirds had multiple bone involvement. Pain was the most common presenting concern (83.3%), followed by deformity (54.1%), limitation of movement (45.8%), numbness (37.5%), and weakness (25.0%). Most patients had a physician evaluation (87.5%); patients also underwent orthopedic surgery (45.8%), physical therapy (33.3%), and occupational therapy (12.5%). CONCLUSIONS: Melorheostosis is a rare sclerotic bone disease resulting in pain, deformity, and dysfunction. An interdisciplinary approach to care should include nonoperative and operative evaluation, as well as appropriate therapies. A prospective approach to evaluation, including imaging and physical examinations, would provide valuable longitudinal data. LEVEL OF EVIDENCE: IV.

Three-dimensional printed models in multidisciplinary planning of complex tracheal reconstruction.

Three-dimensional printed models are increasingly used in medicine and surgery, but applications of these models in the planning of operative procedures is not well described. In particular, their benefits have not been documented in complex, multiservice, high-risk operations. We describe five cases of complex pediatric tracheal reconstruction for which three-dimensional models had specific benefits in planning as well as in education of trainees, operating room staff, and patient families. We also describe our method for producing models so that others can adopt the technology if desired. Laryngoscope, 127:967-970, 2017.

Implementation of iterative metal artifact reduction in the pre-planning-procedure of three-dimensional physical modeling.

BACKGROUND: To assess the impact of metal artifact reduction techniques in 3D printing by evaluating image quality and segmentation time in both phantom and patient studies with dental restorations and/or other metal implants. An acrylic denture apparatus (Kilgore Typodent, Kilgore International, Coldwater, MI) was set in a 20 cm water phantom and scanned on a single-source CT scanner with gantry tilting capacity (SOMATOM Edge, Siemens Healthcare, Forchheim, Germany) under 5 scenerios: (1) Baseline acquisition at 120 kV with no gantry tilt, no jaw spacer, (2) acquisition at 140 kV, (3) acquisition with a gantry tilt at 15°, (4) acquisition with a non-radiopaque jaw spacer and (5) acquisition with a jaw spacer and a gantry tilt at 15°. All acquisitions were reconstructed both with and without a dedicated iterative metal artifact reduction algorithm (MAR). Patients referred for a head-and-neck exam were included into the study. Acquisitions were performed on the same scanner with 120 kV and the images were reconstructed with and without iterative MAR. Segmentation was performed on a dedicated workstation (Materialise Interactive Medical Image Control Systems; Materialise NV, Leuven, Belgium) to quantify volume of metal artifact and segmentation time. RESULTS: In the phantom study, the use of gantry tilt, jaw spacer and increased tube voltage showed no benefit in time or artifact volume reduction. However the jaw spacer allowed easier separation of the upper and lower jaw and a better display of the teeth. The use of dedicated iterative MAR significantly reduced the metal artifact volume and processing time. Same observations were made for the four patients included into the study. CONCLUSION: The use of dedicated iterative MAR and jaw spacer substantially reduced metal artifacts in the head-and-neck CT acquisitions, hence allowing a faster 3D segmentation workflow.

Technique for 3-Dimesional (3D) Modeling of Osteoarticular Medial Femoral Condyle Vascularized Grafting to Replace the Proximal Pole of Unsalvagable Scaphoid Nonunions.

This study describes a novel technique for the preoperative surgical planning for an osteoarticular medial femoral condyle (MFC) graft to replace the proximal pole of a scaphoid. In cases of proximal pole scaphoid nonunion or in Preiser disease, fragmentation of the articular surface can occur, leading to significant pain and disability. Osteoarticular MFC bone grafting can be used to treat these injuries by providing a vascularized osteoarticular surface. Using 3-dimensional imaging and printing we are able to precisely model the injured scaphoid, and also accurately plan the harvest of MFC osteoarticular graft. This technique allows for accurate preoperative planning of a complex 3-dimensional bone, and has improved our execution of the plan intraoperatively.

Use of Personalized Printed 3-Dimensional Kidney Models for Simulation before Nephron Sparing Surgery: Methodology and Examples from a Case Series.

INTRODUCTION: Nephron sparing surgery may be challenging in cases of complex or aberrant renal anatomy. 3-Dimensional printing technology has allowed the creation of 3-dimensional models that can aid in preoperative surgical planning and simulation. We describe the construction of personalized 3-dimensional kidney models, and present a series of patients with complex surgical anatomy to illustrate their use in surgical planning and performance of complex nephron sparing surgery. METHODS: Three patients with complex renal masses were identified. Contrast enhanced computerized tomography studies were used to create segmentation images based on separate scan phases, which were overlaid to create virtual 3-dimensional models. High-fidelity 3-dimensional physical models were then created using 3-dimensional printing technology. The 3-dimensional models were used as an aid in the surgical planning and performance of nephron sparing surgery. RESULTS: Three patients with complex renal anatomy presented with T1b or T2 renal masses. Two patients had absolute or relative indications for nephron sparing surgery and in 1 patient a benign mass was suspected on imaging. The 3-dimensional kidney models were constructed based on preoperative cross-sectional imaging to evaluate the feasibility of nephron sparing surgery and to simulate the surgical approach. All patients underwent successful nephron sparing surgery with negative surgical margins and preservation of renal function at followup. CONCLUSIONS: We describe the creation of personalized 3-dimensional kidney models to facilitate the visualization of the renal mass and its relationship with surrounding structures, the identification of renal and tumor vasculature, and the evaluation of aberrant anatomy. These 3-dimensional models represent a valuable tool for preoperative planning and simulation in cases with complex anatomical considerations.