Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): Guidelines for medical 3D printing and appropriateness for clinical scenarios

Este número da revista Cadernos de Estudos Sociais estava em organização quando fomos colhidos pela morte do sociólogo Ernesto Laclau. Seu falecimento em 13 de abril de 2014 surpreendeu a todos, e particularmente ao editor Joanildo Burity, que foi seu orientando de doutorado na University of Essex, Inglaterra, e que recentemente o trouxe à Fundação Joaquim Nabuco para uma palestra, permitindo que muitos pudessem dialogar com um dos grandes intelectuais latinoamericanos contemporâneos. Assim, buscamos fazer uma homenagem ao sociólogo argentino publicando uma entrevista inédita concedida durante a sua passagem pelo Recife, em 2013, encerrando essa revista com uma sessão especial sobre a sua trajetória

Context-aware learning for robot-assisted endovascular catheterization

Endovascular intervention has become a mainstream treatment of cardiovascular diseases. However, multiple challenges remain such as unwanted radiation exposures, limited two-dimensional image guidance, insufficient force perception and haptic cues. Fast evolving robot-assisted platforms improve the stability and accuracy of instrument manipulation. The master-slave system also removes radiation to the operator. However, the integration of robotic systems into the current surgical workflow is still debatable since repetitive, easy tasks have little value to be executed by the robotic teleoperation. Current systems offer very low autonomy, potential autonomous features could bring more benefits such as reduced cognitive workloads and human error, safer and more consistent instrument manipulation, ability to incorporate various medical imaging and sensing modalities. This research proposes frameworks for automated catheterisation with different machine learning-based algorithms, includes Learning-from-Demonstration, Reinforcement Learning, and Imitation Learning. Those frameworks focused on integrating context for tasks in the process of skill learning, hence achieving better adaptation to different situations and safer tool-tissue interactions. Furthermore, the autonomous feature was applied to next-generation, MR-safe robotic catheterisation platform. The results provide important insights into improving catheter navigation in the form of autonomous task planning, self-optimization with clinical relevant factors, and motivate the design of intelligent, intuitive, and collaborative robots under non-ionizing image modalities.Open Acces

Fluid Flow Characterization and in Silico Validation in a Rapid Prototyped Aortic Arch Model

Transcatheter aortic heart valve replacement (TAVR) is a procedure to replace a failing aortic valve and is becoming the new standard of care for patients that are not candidates for open-heart surgery [2]. However, this minimally invasive technique has shown to cause ischemic brain lesions, or “silent infarcts”, in 90% of TAVR patients, which can increase the patient’s risk for stroke by two to four times in future years [3]. Claret Medical Inc., a medical device company, has developed a cerebral protection system that filters and captures embolic debris released during endovascular procedures, such as TAVR. This thesis utilized CT scans from Claret Medical to create a physical construct of the aortic arch to experimentally validate a theoretical computer model through flow visualization. The hypothesis was that the empirical model can accurately mimic the fluid dynamic properties of the aortic arch in order validate an in silico model using the finite elements program COMSOL MultiPhysics® Modeling Software. The physical model was created from a patient CT scan of the aortic arch using additive manufacturing (3D printing) and polymer casting, resulting in the shape of the aortic arch within a transparent, silicone material. Fluid was pumped through the model to visualize and quantify the velocity of the fluid within the aortic arch. COMSOL MultiPhysics® was used to model the aortic arch and obtain velocity measurements, which were statistically compared to the velocity measurements from the physical model. There was no significant difference between the values of the physical model and the computer model, confirming the hypothesis. Overall, this study successfully used CT scans to create an anatomically accurate physical model that was validated by a computer model using a novel technique of flow visualization. As TAVR and similar procedures continue to develop, the need for experimental evaluation and visualization of devices will continue to grow, making this project relevant to many companies in the medical device industry

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Abstract Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.https://deepblue.lib.umich.edu/bitstream/2027.42/146524/1/41205_2018_Article_30.pd

Vascular remodeling after endovascular treatment: quantitative analysis of medical images with a focus on aorta

In the last years, the convergence of advanced imaging techniques and endovascular procedures has revolutionized the practice of vascular surgery. However, regardless the anatomical district, several complications still occur after endovascular treatment and the impact of endovascular repair on vessel morphology remains unclear. Starting from this background, the aim of this thesis is to ll the gaps in the eld of vessel remodeling after endovascular procedure. Main focus of the work will be the repair of the aorta and, in particular thoracic and thoracoabdominal treatments. Furthermore an investigation of the impact of endovascular repair on femoro-popliteal arterial segment will be reported in the present work. Analyses of medical images will been conducted to extract anatomical geometric features and to compare the changes in morphology before treatment and during follow-up. After illustrating in detail the aims and the outline of the dissertation in Chapter 1, Chapter 2 will concern the anatomy and the physiology of the aorta along with the main aortic pathologies and the related surgical treatments. Subsequently, an overview of the medical image techniques for segmentation and vessel geometric quantication will be provided. Chapter 3 will introduce the concept of remodeling of the aorta after endovascular procedure. In particular, two types of aortic remodeling will be considered. On one side remodeling can be seen as the shrinkage of the aneurysmal sac or false lumen thrombosis. On the other side, aortic remodeling could be seen as the changes in the aortic morphology following endograft placement which could lead to complications. Chapter 4 will illustrate a study regarding the analysis of medical images to measure the geometrical changes in the pathological aorta during follow-up in patients with thoracoabdominal aortic aneurysms treated with endovascular procedure using a novel uncovered device, the Cardiatis Multilayer Flow Modulator. Chapter 5 will focus on the geometrical remodeling of the aortic arch and descending aorta in patients who underwent hybrid arch treatment to treat thoracic aneurysms. The goal of the work is to develop a pipeline for the processing of pre-operative and post-operative Computed Tomography images in order to detect the changes in the aortic arch physiological curvature due to endograft insertion. Chapter 6 will focuse on the use of 3D printing technology as valuable tool to support patient's follow-up. In particular, we report a case of a patient originally treated with endovascular procedure for type B aortic dissection and which experimented several complications during follow-up. 3D printing technology is used to show the remodeling of the aortic vasculature during time. Chapter 7 will concern patient-specic nite element simulations of aortic endovascular procedure. In particular, starting from a clinical case where complication developed during followup, the predictive value of computational simulations will be shown. Chapter 8 will illustrate a study concerning the evaluation of morphological changes of the femoro-popliteal arterial segment due to limb exion in patients undergoing endovascular treatment of popliteal artery aneurysms

Simulation training approaches in intracranial aneurysm surgery-a systematic review.

BACKGROUND With the increasing complexity and decreasing exposure to intracranial aneurysm surgery, training and maintenance of the surgical skills have become challenging. This review elaborated on simulation training for intracranial aneurysm clipping. METHODS A systematic review was performed according to the PRISMA guidelines to identify studies on aneurysm clipping training using models and simulators. The primary outcome was the identification of the predominant modes of the simulation process, models, and training methods associated with a microsurgical learning curve. The secondary outcomes included assessments of the validation of such simulators and the learning capability from the use of such simulators. RESULTS Of the 2068 articles screened, 26 studies met the inclusion criteria. The chosen reports used a wide range of simulation approaches including ex vivo methods (n = 6); virtual reality (VR) platforms (n = 11); and static (n = 6) and dynamic (n = 3) 3D-printed aneurysm models (n = 6). The ex vivo training methods have limited availability, VR simulators lack haptics and tactility, while 3D static models lack important microanatomical components and the simulation of blood flow. 3D dynamic models including pulsatile flow are reusable and cost-effective but miss microanatomical components. CONCLUSIONS The existing training methods are heterogenous and do not realistically simulate the complete microsurgical workflow. The current simulations lack certain anatomical features and crucial surgical steps. Future research should focus on developing and validating a reusable, cost-effective training platform. No systematic validation method exists for the different training models, so there is a need to build homogenous assessment tools and validate the role of simulation in education and patient safety

Towards better patient safety: Patient Injuries in vascular surgery

Safe care is a prime priority for all health care professionals. Surgical care is associated with potentially high risks. Patient injuries can cause significant suffering to the patients and major costs to health-care systems. The aim of this doctoral thesis was to describe patient injuries in vascular surgery in Finland: their causes, consequences, and whether they could have been prevented. The study analyzed all patient injuries compensated by the Patient Insurance Center in vascular surgery in Finland for 1997–2017 inclusive. During that time period, 142 patient injuries were compensated of which the majority were related to the operative care of patients. Patients were mostly elderly with multiple co-morbidities. Typical injuries involved errors in surgical technique, nerve injuries, injuries to adjacent organs or tissues and intraoperative burns. Delays and errors in diagnosis and treatment, and also errors in medication were compensated. Patient injuries in vascular surgery were rare but their consequences were severe. For 5 patients, death was compensated as a patient injury. Ten patients required either a partial or complete amputation of the upper or lower limb. Twenty-one patients were left with permanent nerve injuries and 3 suffered a major stroke. More than half of the patients required additional surgical operations, the majority of whom were left with permanent impairment. Injuries in vascular surgery occurred in all stages of care and under the care of several different groups of medical professionals. Almost 90% of the cases were evaluated to have been potentially preventable. Safety procedures already in use such as surgical safety checklists could potentially have prevented more than 10% of the injuries. Prevention of patient injuries requires continuing efforts in health care and the heightened risks involved with surgery should be recognized. National quality registry in vascular surgery could present possibilities for improving care and help to provide accurate statistics on vascular procedures. The information learned from patient injuries should be used to educate health care staff to prevent injuries from reoccurring.Kohti parempaa potilasturvallisuutta: Verisuonikirurgiset potilasvahingot Turvallinen hoito on kaikkien terveydenhuollon työntekijöiden tärkeä yhteinen tavoite. Kirurgiaan liittyy korostunut potilasturvallisuusriski. Potilasvahingot aiheuttavat potilaille huomattavaa kärsimystä ja terveydenhuollolle merkittäviä kuluja. Tämän väitöskirjan tavoitteena oli kuvata Suomessa tapahtuneita verisuonikirurgiaan liittyviä potilasvahinkoja ja niihin vaikuttaneita tekijöitä. Tarkoituksena oli myös selvittää vahinkojen seuraukset potilaille ja arvioida, olisivatko potilasvahingot olleet ehkäistävissä. Tutkimuksessa analysoitiin Potilasvakuutuskeskuksen vuosina 1997–2017 korvaamat verisuonikirurgian erikoisalan potilasvahingot. Kyseisenä ajanjaksona korvattiin 142 potilasvahinkoa, joista valtaosa liittyi potilaan leikkaushoitoon. Potilaat olivat useimmiten iäkkäitä ja monisairaita. Tyypillisimmät potilasvahingot liittyivät leikkaustekniikan virheisiin, hermovammoihin, viereisten kudosten tai elinten vaurioitumiseen ja leikkauksen aikaisiin palovammoihin. Myös diagnoosin tai hoidon viivästymiseen ja lääkitysvirheisiin liittyviä vahinkoja korvattiin. Verisuonikirurgiaan liittyvät potilasvahingot olivat harvinaisia, mutta niiden seuraukset vakavia. Vahingon kärsineistä potilaista viisi kuoli ja 10:lle tehtiin osittainen tai täydellinen amputaatio ylä- tai alaraajaan. 21 potilasta sai vahingon seurauksena pysyvän hermovamman ja kolme merkittävän aivohalvauksen. Yli puolet potilaista joutui vahingon seurauksena ylimääräiseen leikkaukseen. Valtaosa potilaista sai vahingon seurauksena pysyviä vaurioita. Potilasvahinkoja tapahtui kaikissa verisuonikirurgisen potilaan hoidon vaiheissa ja useat potilasta hoitaneet ammattiryhmät olivat niihin osallisia. Lähes 90 %:ssä tapauksista arvioitiin, että vamma olisi ollut mahdollista estää. Pelkästään jo tällä hetkellä käytössä olevilla apuvälineillä, kuten leikkaustiimin tarkistuslistan käytöllä, vammoista olisi saatu estettyä yli 10 %. Potilasvahinkojen ehkäisyyn tulee kiinnittää terveydenhuollossa erityistä huomiota ja kirurgiseen toimintaan liittyvä korostunut riski on tiedostettava. Kansallinen verisuonikirurginen laaturekisteri voisi tarjota mahdollisuuksia potilasturvallisuuden kehittämiseen ja parempiin tilastoihin verisuonitoimenpiteistä. Potilasvahingoista saatavaa tietoa voidaan käyttää hyödyksi terveydenhuollon ammattilaisten koulutuksessa uusien vammojen ehkäisemiseksi