1,027 research outputs found
Optimization of CT scanning protocol of Type B aortic dissection follow-up through 3D printed model
This research aims to develop and evaluate a human tissue-like material 3D printed model used as a phantom in determining optimized scanning parameters to reduce the radiation dose for Type B aortic dissection patients after thoracic endovascular aortic repair. The results show that radiation risk for follow-up Type B aortic dissection patients can be potentially reduced. Further, the value of using 3D printed model in studying CT scanning protocols was further validated
Image-guided therapy system for interstitial gynecologic brachytherapy in a multimodality operating suite
In this contribution, an image-guided therapy system supporting gynecologic
radiation therapy is introduced. The overall workflow of the presented system
starts with the arrival of the patient and ends with follow-up examinations by
imaging and a superimposed visualization of the modeled device from a PACS
system. Thereby, the system covers all treatments stages (pre-, intra- and
postoperative) and has been designed and constructed by a computer scientist
with feedback from an interdisciplinary team of physicians and engineers. This
integrated medical system enables dispatch of diagnostic images directly after
acquisition to a processing workstation that has an on-board 3D Computer Aided
Design model of a medical device. Thus, allowing precise identification of
catheter location in the 3D imaging model which later provides rapid feedback
to the clinician regarding device location. Moreover, the system enables the
ability to perform patient-specific pre-implant evaluation by assessing the
placement of interstitial needles prior to an intervention via virtual template
matching with a diagnostic scan.Comment: 7 pages, 3 figure
A Survey on the Current Status and Future Challenges Towards Objective Skills Assessment in Endovascular Surgery
Minimally-invasive endovascular interventions have evolved rapidly over the past decade, facilitated by breakthroughs in medical
imaging and sensing, instrumentation and most recently robotics. Catheter based operations are potentially safer and applicable to
a wider patient population due to the reduced comorbidity. As a result endovascular surgery has become the preferred treatment
option for conditions previously treated with open surgery and as such the number of patients undergoing endovascular interventions
is increasing every year. This fact coupled with a proclivity for reduced working hours, results in a requirement for efficient training
and assessment of new surgeons, that deviates from the “see one, do one, teach one” model introduced by William Halsted, so
that trainees obtain operational expertise in a shorter period. Developing more objective assessment tools based on quantitative
metrics is now a recognised need in interventional training and this manuscript reports the current literature for endovascular skills
assessment and the associated emerging technologies. A systematic search was performed on PubMed (MEDLINE), Google Scholar,
IEEXplore and known journals using the keywords, “endovascular surgery”, “surgical skills”, “endovascular skills”, “surgical training
endovascular” and “catheter skills”. Focusing explicitly on endovascular surgical skills, we group related works into three categories
based on the metrics used; structured scales and checklists, simulation-based and motion-based metrics. This review highlights the
key findings in each category and also provides suggestions for new research opportunities towards fully objective and automated
surgical assessment solutions
In Vitro and Computational Analyses of Blood Flow at Aortoiliac Bifurcation for Patients with Atherosclerotic Plaque Treated with Endovascular Procedures
This research has developed an appropriate approach allowing for more accurate assessment of haemodynamic changes following implantation of endovascular stent graft to treat patients with occlusive aortoiliac disease. Two different endovascular techniques involving the use of different types of stent grafts were analysed and compared with regard to haemodynamics associated with these techniques. Results improved understanding of the flow characteristics of these endovascular techniques
Haemodynamic changes in visceral hybrid repairs of type III and type V thoracoabdominal aortic aneurysms
The visceral hybrid procedure combining retrograde visceral bypass grafting and completion endovascular stent grafting is a feasible alternative to conventional open surgical or wholly endovascular repairs of thoracoabdominal aneurysms (TAAA). However, the wide variability in visceral hybrid configurations means that a priori prediction of surgical outcome based on haemodynamic flow profiles such as velocity pattern and wall shear stress post repair remain challenging. We sought to appraise the clinical relevance of computational fluid dynamics (CFD) analyses in the setting of visceral hybrid TAAA repairs. Two patients, one with a type III and the other with a type V TAAA, underwent successful elective and emergency visceral hybrid repairs, respectively. Flow patterns and haemodynamic parameters were analysed using reconstructed pre- and post-operative CT scans. Both type III and type V TAAAs showed highly disturbed flow patterns with varying helicity values preoperatively within their respective aneurysms. Low time-averaged wall shear stress (TAWSS) and high endothelial cell action potential (ECAP) and relative residence time (RRT) associated with thrombogenic susceptibility was observed in the posterior aspect of both TAAAs preoperatively. Despite differing bypass configurations in the elective and emergency repairs, both treatment options appear to improve haemodynamic performance compared to preoperative study. However, we observed reduced TAWSS in the right iliac artery (portending a theoretical risk of future graft and possibly limb thrombosis), after the elective type III visceral hybrid repair, but not the emergency type V repair. We surmise that this difference may be attributed to the higher neo-bifurcation of the aortic stent graft in the type III as compared to the type V repair. Our results demonstrate that CFD can be used in complicated visceral hybrid repair to yield potentially actionable predictive insights with implications on surveillance and enhanced post-operative management, even in patients with complicated geometrical bypass configurations
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