Project description:BackgroundTranscatheter mitral valve replacement (TMVR) may be a valuable treatment option for mitral annular calcification and severe mitral stenosis (MS) in patients at high operative risk. Pre-procedural virtual and printed simulations may aid in procedure planning, device sizing, and mitigate complications such as valve embolization or left ventricular outflow tract (LVOT) obstruction.Case summaryWe describe a case of TMVR in which multi-detector computed tomography (MDCT) derived, three-dimensional virtual planning and a 3D-printed model of the patients' left heart provided enhanced understanding of an individual patient's unique anatomy to determine feasibility, device sizing, and risk stratification. This resulted in deployment of an adequately sized valve. Post-TMVR LVOT obstruction was treated with LVOT balloon dilatation and percutaneous transluminal septal myocardial ablation.DiscussionAdvanced MDCT-derived planning techniques introduce consistent 3D modeling and printing to enhance understanding of intracardiac anatomical relationships and test device implantation. Still, static measurements do not feature haemodynamic factors, tissue, or device characteristics and do not predict device host interaction. Transcatheter mitral valve replacement is feasible in MS when adequately pre-procedurally planned. Multi-detector computed tomography-derived, 3D, virtual and printed models contribute to adequate planning in terms of determining patient eligibility, procedure feasibility, and device sizing. However, static 3D modeling cannot completely eliminate the risk of peri-procedural complications.
Project description:BackgroundTopical sinus irrigation plays a critical role in the management of sinonasal diseases. Yet, the penetration of irrigant to targeted sinuses may be highly variable and difficult to predict. Here, we investigate the use of 3D printing as a planning tool to optimize outcomes.MethodsEight post-operative models were 3D printed with a FormLabs Form3 printer based on individual CT scans. Irrigations were performed and video recorded with a squeeze bottle attached via silicon water-tight seal, in 4 head positions: 45° to-the-side, 90° to-the-side, 45° forward and 45° to-the-side, and 90° forward, with irrigation fluid entering the upper (conventional) or lower (backfill) nostrils.ResultsSignificant individual variations were observed in sinus penetration as a function of head position. In general, the maxillary sinus was the easiest to irrigate in most head positions (P < .05), followed by frontal and ethmoid, with sphenoid being the most difficult. Both the 90°-to-the-side and the 90°-forward positions were significantly more effective than the others (P < .05), with 90°-forward better for frontal sinuses and 90°-to-the-side superior for all other sinuses. The backfill was significantly superior to conventional technique in head positions involving a side tilt (P < .05).ConclusionVariations in technique and position significantly impacted irrigation outcome. Backfill irrigation that pushes fluid against gravity to pool around the ostium, seems to provide overall better outcomes. This study demonstrates the advantage of 3D printing as a rapid planning tool to guide irrigation strategies.
Project description:Over the last decades, bioprosthetic heart valves (BHV) have been increasingly implanted instead of mechanical valves in patients undergoing surgical aortic valve replacement (SAVR). Structural valve deterioration (SVD) is a common issue at follow-up and can justify the need for a reintervention. In the evolving landscape of interventional cardiology, valve-in-valve transcatheter aortic valve replacement (ViV TAVR) has emerged as a remarkable innovation to address the complex challenges of patients previously treated with SAVR and has rapidly gained prominence as a feasible technique especially in patients at high surgical risk. On the other hand, the expanding indications for TAVR in progressively younger patients with severe aortic stenosis pose the crucial question on the long-term durability of transcatheter heart valves (THVs), as patients might outlive the bioprosthetic valve. In this review, we provide an overview on the role of ViV TAVR for failed surgical and transcatheter BHVs, with a specific focus on current clinical evidence, pre-procedural planning, procedural techniques, and possible complications. The combination of integrated Heart Team discussion with interventional growth curve makes it possible to achieve best ViV TAVR results and avoid complications or put oneself ahead of time from them.
Project description:BackgroundRecent literature highlights the importance of treating hallux valgus (HV) as a 3-dimensional (3D) deformity. Although 3D printing may enhance visualization of the multiplanar aspects of HV, its influence on surgical planning remains unclear. This study assessed changes in surgical plans when surgeons sequentially reviewed 2D radiographs, 3D weightbearing computed tomography (WBCT), and 3D-printed models, hypothesizing that 3D printing would have the greatest impact.MethodsA single HV case (a 40-year-old woman, intermetatarsal angle [IMA] 21 degrees, HV angle [HVA] 47 degrees) was evaluated by 30 surgeons in a masked, stepwise manner. Surgical plans were recorded at each stage. Surgeons rated the influence of WBCT and 3D printing using a 5-point Likert scale. A follow-up survey examined the effect of these technologies on correction amplitudes.ResultsThe participants were mostly early career surgeons (median age 35.5 years, 2 years in practice). WBCT was accessible to 43.3% and used in 30% of HV cases, whereas 3D printing was accessible to 23.3% and used in 6.6%. Changes in the treatment algorithm occurred in 30% of cases after WBCT and in 43.3% after 3D printing. Significant differences (P < .05) were observed for the Lapicotton procedure between radiography and WBCT, and between WBCT and 3D printing. Surgeons performing <50 HV cases annually or with >70% Foot and Ankle specialization were more influenced by WBCT. Follow-up data (n = 23) indicated that WBCT and 3D printing influenced correction amplitudes, particularly for pronation and distal metatarsal articular angle (DMAA), more than for the IMA.DiscussionBoth WBCT and 3D printing influenced surgical planning, mostly explained by changes in first ray tarsometatarsal procedures. The rotational components (pronation and DMAA) were perceived as the most significantly affected. Future studies should explore cost-effectiveness, patient outcomes, and the utility of combining WBCT and 3D printing in other deformities requiring multiplanar corrections.Level of Evidence: Level IV, cross-sectional survey.
Project description:Magnetic resonance imaging is increasingly being used to evaluate the lymphatic system. Advances in magnetic resonance (MR) software and hardware allow improved visualization of lymph nodes and lymphatic vessels. We describe how MR lymphangiography can be used to diagnose central lymphatic system anatomy and pathology, which can be used for diagnostic purposes or for pre-procedural planning.
Project description:Advances in our knowledge of cardiovascular disorders coupled with technological innovations have enabled the increased use of minimally invasive cardiovascular surgeries and transcatheter interventions, with resultant reduced morbidity and hospital stay. Three-dimensional imaging, particularly computed tomography (CT) is increasingly used for patient selection, providing a roadmap of the anatomy and identifying factors that may complicate these procedures. Advantages of CT are the rapid turnaround time, good spatial and temporal resolutions, wide field of view and three-dimensional multi-planar reconstruction capabilities. This pictorial review describes the role of CT in the pre-operative evaluation of patients undergoing cardiovascular surgeries and intervention. Main Messages • CT scan is valuable in pre-operative evaluation for cardiac surgeries • Cardiovascular structures, including bypass grafts should be located >10 mm from the sternum in patients for reoperative cardiothoracic surgeries • Knowledge of variations in pulmonary venous anatomy are essential for planning radiofrequency ablation.
Project description:Three-dimensional printing is a valuable modality with broad clinical applications. Hip preservation surgery outcomes are dependent on correction of morphological abnormalities that may be optimally visualized with three-dimensional models. To assess the efficacy of three-dimensional models for patient and trainee education and to determine its benefits during pre-operative planning in hip preservation surgery. Sixteen patients with hip pathology were selected. Computed tomography was utilized to generate three-dimensional models. Customized Likert-style questionnaires were given to 10 hip preservation surgeons, 11 orthopedic surgery residents and 10 patients. All residents strongly agreed or agreed that the three-dimensional hip models helped them to understand patients' pathology. All but one patient agreed that the models assisted in their understanding of the treatment plan. Surgeons concurred that although they do not routinely order three-dimensional models, their use would improve trainee and patient education, especially when treating atypical osseous pathomorphologies. Three-dimensional models are tools that can help surgeon, trainee and patient understanding and participation in treatment of complex hip disorders. Patients and trainees agree that the prototypes enhanced their educational experience, as the surgeon can directly demonstrate complex morphological abnormalities. Trainees can therefore gain a better understanding of hip pathologies and treatment. As patients better understand their hip disorder, they can more fully participate in shared treatment decision-making.Level of evidenceLevel IV, Retrospective Case Series.
Project description:3D printing can produce intuitive, precise, and personalized anatomical models, providing invaluable support for precision medicine, particularly in areas like surgical training and preoperative planning. However, conventional 3D printed models are often significantly more rigid than human organs and cannot undergo repetitive resection, which severely restricts their clinical value. Here we report the stereolithographic 3D printing of personalized liver models based on physically crosslinked self-healing elastomers with liver-like softness. Benefiting from the short printing time, the highly individualized models can be fabricated immediately following enhanced CT examination. Leveraging the high-efficiency self-healing performance, these models support repetitive resection for optimal trace through a trial-and-error approach. At the preliminary explorative clinical trial (NCT06006338), a total of 5 participants are included for preoperative planning. The primary outcomes indicate that the negative surgery margins are achieved and the unforeseen injuries of vital vascular structures are avoided. The 3D printing of liver models can enhance the safety of hepatic surgery, demonstrating promising application value in clinical practice.
Project description:PURPOSE:The technology of 3D printing (3DP) exists for quite some time, but it is still not utilized to its full potential in the field of orthopaedics and traumatology, such as underestimating its worth in virtual preoperative planning (VPP) and designing various models, templates, and jigs. It can be a significant tool in the reduction of surgical morbidity and better surgical outcome avoiding various associated complications. METHODS:An observational study was done including 91 cases of complex trauma presented in our institution requiring operative fixation. Virtual preoperative planning and 3DP were used in the management of these fractures. Surgeons managing these cases were given a set of questionnaire and responses were recorded and assessed as a quantitative data. RESULTS:In all the 91 cases, where VPP and 3DP were used, the surgeons were satisfied with the outcome which they got intraoperatively and postoperatively. Surgical time was reduced, with a better outcome. Three dimensional models of complex fracture were helpful in understanding the anatomy and sketching out the plans for optimum reduction and fixation. The average score of the questionnaire was 4.5, out of a maximum of 6, suggesting a positive role of 3DP in orthopaedics. CONCLUSION:3DP is useful in complex trauma management by accurate reduction and placement of implants, reduction of surgical time and with a better outcome. Although there is an initial learning curve to understand and execute the VPP and 3DP, these become easier with practice and experience.
Project description:Adeno-Associated Virus based vectors (rAAV) are advantageous for human gene therapy due to low inflammatory responses, lack of toxicity, natural persistence, and ability to transencapsidate the genome allowing large variations in vector biology and tropism. Over sixty clinical trials have been conducted using rAAV serotype 2 for gene delivery with a number demonstrating success in immunoprivileged sites, including the retina and the CNS. Furthermore, an increasing number of trials have been initiated utilizing other serotypes of AAV to exploit vector tropism, trafficking, and expression efficiency. While these trials have demonstrated success in safety with emerging success in clinical outcomes, one benefit has been identification of issues associated with vector administration in humans (e.g. the role of pre-existing antibody responses, loss of transgene expression in non-immunoprivileged sites, and low transgene expression levels). For these reasons, several strategies are being used to optimize rAAV vectors, ranging from addition of exogenous agents for immune evasion to optimization of the transgene cassette for enhanced therapeutic output. By far, the vast majority of approaches have focused on genetic manipulation of the viral capsid. These methods include rational mutagenesis, engineering of targeting peptides, generation of chimeric particles, library and directed evolution approaches, as well as immune evasion modifications. Overall, these modifications have created a new repertoire of AAV vectors with improved targeting, transgene expression, and immune evasion. Continued work in these areas should synergize strategies to improve capsids and transgene cassettes that will eventually lead to optimized vectors ideally suited for translational success.