Realization of Open Software Chain for 3D Modeling and Printing of Organs in Simulation Centers: Example of Renal Pelvis Reconstruction.

OBJECTIVE: Three-dimensional (3D) printing has many uses in healthcare such as in surgical training. It is becoming an interesting tool finding new pedagogical purposes in medical simulation. In this study, using a process consisting of 3D modeling, a simulator dedicated to pyeloplasty was designed, manufactured, and evaluated by experts. DESIGN: With the aid of open-source software and computer-aided design software, 3D models of a renal parenchyma, a renal pelvis and a ureter were created. This renal apparatus was processed and crafted with additive manufacturing using soft polymer materials. Polyvinyl alcohol material was used to print the components in order to make them dissectible and to evaluate their use in surgical teaching. SETTING AND PARTICIPANTS: Seven expert surgeons evaluated the model by performing a pyeloplasty sequence established in a previous work. An evaluation grid with 8 items related to surgical movement was rated on a 5-point Likert scale to assess how similar working with the model was to actual surgery. RESULTS: Three items were rated with a score greater than or equal to 4 (Needle penetration, Thread-sliding, and Cutting Strength). Suture strength was rated with a score above 3.5 for both renal pelvis and ureter, whereas elasticity was rated below 3. Handling and mobility properties were rated above 3 for the renal pelvis and below 3 for the ureter. The cost of the unit was $0.30 per renal unit. The primary difference identified was a difference in elongation between polyvinyl alcohol material and real biological tissue. CONCLUSIONS: It is feasible to generate and print a low cost upper urinary tract model from patient data imagery using environmentally friendly products that can be used effectively in surgical training. The simulator has been able to reproduce sensations related to surgical movements for a low cost. Hereafter, research into the pedagogical benefits provided to students, and through them, patients, should be performed. 3D printing models can offer new opportunities for healthcare simulation specific to different surgical fields.

Delayed prosthesis malposition after transcatheter aortic valve implantation causing coronaries obstruction.

A case of delayed malposition of a CoreValve device causing obstruction of coronary ostia is described. Nine months after the original implant, the patient developed an acute coronary syndrome and was readmitted to hospital. Angiogram demonstrated an ostial stenosis of both the left main stem and the right coronary ostia, which were filled by a paravalvular leakage of the bioprosthesis. Gated computed tomography scan with 3D reconstruction showed valve malposition with cusps situated 14 mm above the ostium of the right coronary and the presence of fibrous and calcific agglomerations associated to one of the cusp causing a tight stenosis of the left ostium. Computed tomography scan is a crucial imaging technique in the transcatheter aortic valve replacement field and in this case enabled us to identify an interesting phenomenon of fibrosis/calcification originating at the level of the misplaced valve, which was actually the triggering cause of the coronary obstruction. Considering the reported need for more accurate investigations regarding the predictors of negative outcomes and the selection of transcatheter aortic valve replacement candidates, the use of cardiac-gated computed tomography should be stimulated and promoted as a valuable aid for the diagnosis and further clinical decision making in those patients.

TAVR vs SAVR: Rising Expectations and Changing Indications for Surgery in Response to PARTNER II.

Despite the criticisms and concerns raised on the data published in the PARTNER II trial and related analyses, we are undeniably witnessing a revolution in the management of aortic valve disease, in which conventional full sternotomy surgical aortic valve replacement (SAVR), with all related complications and clinical burden, will soon become a nonviable option. Several of the findings described in the PARTNER II trial, although considerable as points of incongruence and study biases in comparison with SAVR, could be taken as lessons to found a new course in SAVR and redesign the respective roles of surgery and interventional procedures in aortic disease. In particular, the results of these trials can actually be considered as a stimulus to invest more effort to improve the current surgical practice that should embrace alternative solutions and least invasive approaches to provide a competitive advantage over percutaneous procedures. An analysis of these points in light of the more recent findings on transcatheter valve durability, thrombosis, and postprocedural complications is provided. Considerations on the parallel progress of SAVR and on the need for a behavioral change in the surgical community are discussed.

Septic rupture of an atherosclerotic plaque of the ascending aorta.

Infectious aortitis has become a rare disease thanks to the widespread use of antibiotics. We report the case of a patient who, 15 days after initiation of antibiotics for bacteraemia due to methicillin-resistant Staphylococcus aureus (MRSA), developed acute chest pain followed by haemodynamic instability. A tamponade due to a rupture into the pericardium of the ascending aorta at the site of an atherosclerotic plaque was diagnosed by an emergent chest contrasted computed tomography (CT). Intraoperatively, the septic nature of the rupture was suspected. All aortic atherosclerotic plaque samples grew MRSA. Postoperatively, the patient had an uneventful recovery after 12 weeks of antibiotic therapy. Transoesophageal echocardiography and chest CT were normal at 3 months after cessation of antibiotics. This case report permits the review of some characteristics of this disease, its physiopathology as well as the therapeutic implications.

Coronary computed tomography angiography: overview of technical aspects, current concepts, and perspectives.

Multidetector-row electrocardiogram (ECG)-gated cardiac computed tomography (CT) will probably be a major noninvasive imaging option in the near future. Recent developments indicate that this new technology is improving rapidly. This article presents an overview of the current concepts, perspectives, and technical capabilities in coronary CT angiography (CTA). We have reviewed the recent literature on the different applications of this technology; of particular note are the many studies that have demonstrated the high negative predictive value (NPV) of coronary CTA, when performed under optimal conditions, for significant stenoses in native coronary arteries. This new technology's level of performance allows it to be used to evaluate the presence of calcified plaques, coronary bypass graft patency, and the origin and course of congenital coronary anomalies. Despite a high NPV, the robustness of the technology is limited by arrhythmias, the requirement of low heart rates, and calcium-related artifacts. Some improvements are needed in the imaging of coronary stents, especially the smaller stents, and in the detection and characterization of noncalcified plaques. Further studies are needed to more precisely determine the role of CTA in various symptomatic and asymptomatic patient groups. Clinical testing of 64-slice scanners has recently begun. As the technology improves, so does the spatial and temporal resolution. To date, this is being achieved through the development of systems with an increased number of detectors and shorter gantry rotation time, as well as the development of systems equipped with 2 X-ray tubes and the eventual development of flat-panel technology. Thus further improvement of image quality is expected.