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.

Finite Element Analysis of the Septal Cartilage L-Strut.

Importance: Septoplasty is one of the most commonly performed operations in the head and neck. However, the reasons for septoplasty failure and the additional stress of performing a chondrotomy on the septal cartilage are not well understood. Design, Setting, and Participants: A finite element model of the nasal septum was created using a microcomputed tomography scan of the nasoseptal complex that was reconstructed into a three-dimensional model in silico. Testing included four common chondrotomy designs: traditional L-strut, double-cornered chondrotomy (DCC), curved L-strut, and the C-curve. Tip displacement was applied in a vector parallel to the caudal strut to simulate nasal tip palpation. Main Outcomes and Measures: With finite element analysis, the maximum principal stress (MPS), von Mises stress (VMS), harvested cartilage volume, and surface area were recorded. Results: The highest MPS for the L-strut, DCC, curved L-strut, and C-curve was identified at the corner of the chondrotomy. The MPS at the corner of the chondrotomy was reduced 44% when comparing the C-curve with the traditional L-strut. The VMS patterns showed compressive stress along the caudal septum in all models, but at the corner, the stresses were highest in the chondrotomies designed with sharp-angled corners. The VMS showed a 76% decrease when comparing the C-curve with the traditional L-strut. The stress across the anterior septal angle is also higher in models with sharp-angled corners. Cartilage harvest volumetric and surface area assessments did not show meaningful differences between shapes. Conclusions and Relevance: The highest area of stress is near the transition of the dorsal to caudal septum in all models. Stresses are relatively higher in chondrotomy shapes that contain sharp-angled corners. The relative reduction in MPS and VMS utilizing a C-curve instead of an L-strut may decrease the likelihood that the septum will deform or fail in this region. The volume and surface area of the C-curve are similar to that of the L-strut technique. Avoiding sharp-angled corners reduces the stresses at the corner of the chondrotomy and across the anterior septal angle. Using a C-curve may be an improved septoplasty design.

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.

Clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: adult cardiac conditions.

BACKGROUND: Medical 3D printing as a component of care for adults with cardiovascular diseases has expanded dramatically. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides appropriateness criteria for adult cardiac 3D printing indications. METHODS: A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with a number of adult cardiac indications, physiologic, and pathologic processes. Each study was vetted by the authors and graded according to published guidelines. RESULTS: Evidence-based appropriateness guidelines are provided for the following areas in adult cardiac care; cardiac fundamentals, perioperative and intraoperative care, coronary disease and ischemic heart disease, complications of myocardial infarction, valve disease, cardiac arrhythmias, cardiac neoplasm, cardiac transplant and mechanical circulatory support, heart failure, preventative cardiology, cardiac and pericardial disease and cardiac trauma. CONCLUSIONS: Adoption of common clinical standards regarding appropriate use, information and material management, and quality control are needed to ensure the greatest possible clinical benefit from 3D printing. This consensus guideline document, created by the members of the RSNA 3D printing Special Interest Group, will provide a reference for clinical standards of 3D printing for adult cardiac indications.

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.

Use of 3D-Printed and 2D-Illustrated International Frontal Sinus Anatomy Classification Anatomic Models for Resident Education.

OBJECTIVE: To examine the impact of 2-dimensional (2D) illustrations and 3-dimensonal (3D)-printed anatomic models of the frontal sinuses according to the International Frontal Sinus Anatomy Classification in the education of otolaryngology and radiology residents. STUDY DESIGN: A crossover study design with half of the study participants randomized to the 2D illustration intervention first and the other half randomized to the 3D-printed model first. SETTING: Regularly scheduled resident didactic lectures at a tertiary care center. SUBJECTS AND METHODS: Forty-one otolaryngology and radiology residents were assessed with pre- and postintervention questionnaires that included subjective and objective methods of assessment. RESULTS: Overall, there was a statistically significant improvement in total number of answers correct and in confidence score between the pre- and postintervention assessments (P < .0001). The primary outcome of order of intervention (ie, 2D → 3D vs 3D → 2D) did not result in statistically significant differences in postevaluation scores. In regard to the secondary outcome of learner preference for educational modality, radiology residents favored the 2D illustrations to understand anatomic relationships, while otolaryngology residents preferred the 3D model to be more helpful in surgical planning (P = .0075). CONCLUSION: There is no difference between 2D-illustrated and 3D-printed International Frontal Sinus Anatomy Classification anatomic models in overall educational outcome, despite the preference of learners. Together, these models can be used as helpful tools in frontal sinus education for otolaryngology and radiology trainees.

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.

Simulation of Endovascular Aortic Repair Using 3D Printed Abdominal Aortic Aneurysm Model and Fluid Pump.

BACKGROUND: Abdominal aortic aneurysm (AAA) models can be manufactured with 3D printing technology. This study describes detailed methodology and validation of endovascular aortic repair (EVAR) simulation using 3D printed AAA model connected to hemodynamic pump. METHOD: The AAA model was printed with Objet500 Connex3 (Stratasys, Eden Prairie, MN) and connected to BDC PD-0500 fluid pump (BDC Laboratories, Wheat Ridge, CO). EVAR procedure metrics were benchmarked in two expert implanters and compared to 20 vascular surgical trainees with different levels of EVAR experience (< 20 or ≥ 20 cases). All simulations were performed using commercially available stent grafts, guidewires, catheters, fluoroscopic guidance and digital subtraction angiography. Studied outcomes included ability to complete the procedure independently, time to deploy aortic component, ability to cannulate contralateral gate and complete the repair, and total fluoroscopy and procedure times. RESULTS: A total of 22 EVAR simulation procedures were performed with mean procedure time of 37 ± 12 min. Experienced trainees had significantly lower total procedural time (32 ± 9 vs. 44 ± 6 min, P = 0.003) and fluoroscopic time (13 ± 5 vs. 23 ± 8 min, P = 0.005). All experienced trainees completed the procedure independently in < 45 min, compared to six (46%) of those with less EVAR experience (P = 0.016). Among less experienced trainees, only two (15%) completed the entire procedure independently (P < 0.001). Benchmark implanters performed significantly better than both trainee groups in nearly all EVAR metrics. CONCLUSION: EVAR simulation was feasible and simulated all procedural steps with high fidelity. This model may be applicable for assessment of technical competencies and standard endovascular skill acquisition within vascular surgery training curricula.

Creating patient-specific anatomical models for 3D printing and AR/VR: a supplement for the 2018 Radiological Society of North America (RSNA) hands-on course.

Advanced visualization of medical image data in the form of three-dimensional (3D) printing continues to expand in clinical settings and many hospitals have started to adapt 3D technologies to aid in patient care. It is imperative that radiologists and other medical professionals understand the multi-step process of converting medical imaging data to digital files. To educate health care professionals about the steps required to prepare DICOM data for 3D printing anatomical models, hands-on courses have been delivered at the Radiological Society of North America (RSNA) annual meeting since 2014. In this paper, a supplement to the RSNA 2018 hands-on 3D printing course, we review methods to create cranio-maxillofacial (CMF), orthopedic, and renal cancer models which can be 3D printed or visualized in augmented reality (AR) or virtual reality (VR).

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.

Impact of a 3D printed model on patients' understanding of renal cryoablation: a prospective pilot study.

PURPOSE: To determine whether a 3D printed model improves patients' understanding of renal cryoablation and the involved anatomy. METHODS: This prospective study included 25 control patients, who received standard of care renal cryoablation education (verbal explanation accompanied by review of relevant 2D imaging) and 25 experimental patients, who received education using a 3D printed renal cryoablation model in addition to standard of care. Subsequent patient surveys included 5 anatomy and 5 procedural knowledge questions. The experimental cohort also subjectively graded the importance of the 3D model for understanding the renal cryoablation procedure and associated anatomy. RESULTS: Mean percent of anatomy questions answered correctly was significantly higher in the experimental cohort than that in the control group (87.2% vs. 72.8%; p = 0.007). After adjusting for the physician providing the education, however, the 3D model was no longer significantly associated with patient anatomy knowledge (p = 0.22). Mean percent of procedure-related questions answered correctly was higher in the experimental cohort (93.6%) than that in the control group (89.6%) (p = 0.16). The experimental cohort graded the importance of the 3D model for understanding their renal tumor anatomy and upcoming procedure to be very high (mean 9.4 and 9.5, respectively, on a 0-10 point scale). Twenty-three (92%) patients "definitely recommended" continued use of the 3D model as a patient educational tool. CONCLUSIONS: Although patients' objective anatomy and procedural knowledge was not significantly improved with the 3D renal cryoablation model in this small pilot study, patients' high perceived value of the model supports investigation in a larger study.

Virtual surgical planning and three-dimensional printing in multidisciplinary oncologic chest wall resection and reconstruction: A case report.

INTRODUCTION: Primary sarcomas of the sternum are extremely rare and present the surgical teams involved with unique challenges. Historically, local muscle flaps have been utilized to reconstruct the resulting defect. However, when the resulting oncologic defect is larger than anticipated, local tissues have been radiated, or when preservation of chest wall muscles is necessary to optimize function, local reconstructive options are unsuitable. PRESENTATION OF CASE: Virtual surgical planning (VSP) and in house three-dimensional (3D) printing provides the platform for improved understanding of the anatomy of complex tumours, communication amongst surgeons, and meticulous pre-operative planning. We present the novel use of this technology in the multidisciplinary surgical care of a 35 year old male with primary sarcoma of the sternum. Emphasis on minimizing morbidity, maintaining function of chest wall muscles, and preservation of the internal mammary vessels for microvascular anastomosis are discussed. DISCUSSION: While the majority of patients at our institution receive local or regional flaps for reconstruction of thoracic defects, advances in microvascular surgery allow the reconstructive surgeon the latitude to choose other flap options if necessary. VSP and 3D printing allowed the surgical team involved to utilize free tissue transfer to reconstruct the defect with free tissue transfer from the thigh. Perseveration of the internal mammary vessels was paramount during tumor extirpation. CONCLUSION: Virtual surgical planning and rapid prototyping is a useful adjunct to standard imaging in complex chest wall resection and reconstruction.

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.

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.

Preoperative planning and tracheal stent design in thoracic surgery: a primer for the 2017 Radiological Society of North America (RSNA) hands-on course in 3D printing.

In this work, we provide specific clinical examples to demonstrate basic practical techniques involved in image segmentation, computer-aided design, and 3D printing. A step-by-step approach using United States Food and Drug Administration cleared software is provided to enhance surgical intervention in a patient with a complex superior sulcus tumor. Furthermore, patient-specific device creation is demonstrated using dedicated computer-aided design software. Relevant anatomy for these tasks is obtained from CT Digital Imaging and Communications in Medicine images, leading to the generation of 3D printable files and delivery of these files to a 3D printer.