Human Thiel cadaveric flow model for training aortic endovascular interventional techniques

Transcription

1 Human Thiel cadaveric flow model for training aortic endovascular interventional techniques Poster No.: C-2618 Congress: ECR 2015 Type: Educational Exhibit Authors: H. M. McLeod, A. Melzer, J. Robertson, R. Eisma, B. F. Cox, G. Houston; Dundee/UK Keywords: Interventional vascular, Arteries / Aorta, Professional issues, Fluoroscopy, CT, CT-Angiography, Arterial access, Angioplasty, Education, Aneurysms, Education and training, Grafts DOI: /ecr2015/C-2618 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 18

2 Learning objectives The purpose of this presentation is to introduce a novel human cadaveric training model, which offers a high fidelity training model for clinicans training in complex endovascular techniques. endovascular stent graft delivery to thoracic aorta endovascular stent graft delivery to infra renal location Page 2 of 18

3 Images for this section: Fig. 1: Dr Hadwen Trust are an organisation who promote scientific research to replace the use of animals in science Dr Hadwen Trust Page 3 of 18

4 Fig. 2: University of Dundee, Institute for Medical Science and Technology Imaging facility, The clinical environment is replicated to provide a realistic training experience. Page 4 of 18

5 Background Training of clinicans in highly technical tasks such as endovascular interventions coupled with reduced copportunity ot achieve competency, necessitates a move away from training on the job to simulator and model training in many fields of medicine. The human aorta has no animal equivalent with realistic anatomy and physiology, whilst simulators lack the realism required. Human Thiel embalmed cadaveric models with added function (extracorporeal vascular flow and respiratory motion) provide a high fidelity model, which when installed in a mock clinical environment this set up can mimic the realistic clinical experience required for training. Human cadavers embalmed by the method of Thiel (Thiel 1992, 2002) have the advantage of retaining many "in life" properties, such as flexibility, colour. Early studies at University of Dundee, established the patency of the vascular system. As such, Thiel embalmed cadavers represent the breadth of anatomical variance, offering an unparalled training experience, in comparison to animal models and simulators. Three human Thiel emabalmed cadavers (2 male and 1 female) were connected to an extracorporeal pump to prefuse the aorta. This model was used to to demonstrate the deployment of aortic devices. Two throacic stent grafts, one abodminal stent graft and one bifurcating abdominal stent graft, were deployed by interventional radiologists. Page 5 of 18

6 Findings and procedure details MODEL DESIGN To perfuse the aorta and large vessels, connection to an extracorporeal pump was established (Heart Lung Machine HL30, Maquet, Germany). This was achieved by locating an endotracheal tube (Size 8, Portex, USA) directly into the aorta via the left ventricle. The cadavers used in these experiments had previously recieved postmortem thoracotomy and or sternotomy, which provided direct access to the heart. In cadavers which had not had this previous treatment, the heart was accessed by adaption of a a minimally invasive technique described by Hill et al (Hill 2000). Heart Lung machine (HL30, Maquet, Germany) facilitated extracorporeal introduction of Thiel moistening solution directly into the connection located in the aortic bulb, to perfuse the arterial system with antegrade pulsatile flow. Flow rates of between 0.5 L per min to 2.5 L per min were achieved with pulsatile flow of 60 beats per minute the standard setting for these experiments. This flow rate was sufficient to maintain vessel patency and facilitated guidewire and catheter interventions under fluoroscopic guidance, evaluated with Digital subtraction angiography. INTERVENTIONS CONDUCTED ON THE MODEL All endovascular procedures were conducted under fluoroscopic guidance with or without contrast (GE OEC 9900, Bayer Omnipaque). Left common femoral arteriotomy was created by incision, vessel was accessed by seldinger technique to insert a 22 Fr Dry seal sheath (Gore). Stent grafts (Medtronic, Valient) were located over guidewire (Boston Scientific) to target locations using standard interventional techniques. Devices were deployed according to manufacturer instructions and stent graft balloon catheters (Medtronic) used to ensure full deployment (Fig 5-10). Post procedural CT scanning ensured the devices were appropriately deployed. Page 6 of 18

7 Images for this section: Fig. 3: External view of Endotracheal tube connection. Minimal incision to reduce damage to cadaver. Page 7 of 18

8 Fig. 4: Schematic representation of Endotracheal tube connection in aorta of heart. Approach via apex of heart into left ventricle, through the aortic valve, where balloon in inflated to secure connection location. Page 8 of 18

9 Fig. 5: Thoracic aortic Digital Subtraction Angiography of aorta, Captivia Delivery system carrying Valiant Thoracic stent graft evident in descending aorta. Aortic arch and great vessels are visible landmarks to locate graft. Page 9 of 18

10 Fig. 6: Fluoroscopic image of captivia Delivery system is situ in aorta, carrying Valiant Thoracic stent graft (Medtronic, USA), being moved into location on guide wire (Amplatz Super Stiff, Boston Scientific). Page 10 of 18

11 Fig. 7: post procedure Digital subtraction aortogram. Stent graft successfully deployed, vessel patent. Page 11 of 18

12 Fig. 8: Fluoroscopic image of Captivia delivery system in situ in abdominal aorta carrying valiant abdominal stent graft. Page 12 of 18

13 Fig. 11: Digital Spot Image of stent graft balloon catheter to expand abdominal stent graft (Reliant Balloon, Medtronic, USA). Page 13 of 18

14 Fig. 9: Location of catheter and guidewire into right leg of bifurcating stent graft(endurant II, Medtronic, USA), to locate right iliac stent. Page 14 of 18

15 Fig. 10: Digital Spot image of bifurcating stent graft in situ. Page 15 of 18

16 Conclusion Human Thiel cadaveric aortic perfusion model provided a realistic model to train complex interventional techniques. The interventional radiologists who used the model commented that the model was highly realistic, and fully emulated the clinical scenario. The cadaver was perfused for prolonged durations, was robust with repeated applications possible, depending upon the intervention conducted. In comparison to fresh cadavers, Thiel cadavers have the advantage of extended shelf life, where the model can be reused on many occasions depending upon the nature of the intervention. Page 16 of 18

17 Personal information This work is supported by Dr Hadwen Trust, an organization who promote research in fields to reduce and ultimately replace the use of animals in research. This project aims to develop cadaveric models to replace animals used when training in complex procedures. Page 17 of 18

18 References J D Hill, G J Avery, G Egrie, K Turley, S Reichenbach. Less Invasive Thoratec LVAD Insertion: A surgical Technique. The Heat Surg Forum 2000:3(3): Thiel W. The preservation of the whole corpse with natural colour. Ann Anat. 1992;174(3): Thiel W. Supplement to the conservation of an entire cadaver. Ann Anat. 2002;184: Page 18 of 18