Endovascular Implants
Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos in McDonald's Blood Flow in Arteries, 2022
The vessel wall can also dissect when, similar to aneurysms, hemodynamic forces lead to tear initiation of the aortic wall, allowing blood to flow within its layers (Criado, 2011) and creating two rather than one lumen: the true lumen that is anatomo-physiologically correct and the false lumen. Aortic dissection is a significant and growing condition in aging populations. The extension of aortic dissection determines the severity of the disease and is a determinant mortality factor (Fattori et al., 2013). Dissections are classified by their involvement of ascending and transverse as opposed to the descending aorta (Mokashi and Svensson, 2019). Their treatment involves eliminating the false lumen and restoring the physiologic flow to the true lumen. Those that involve the ascending aorta can be repaired surgically; however, once the tear extends distally into the descending aorta critical branch vessels limit surgical approaches. Endovascular aneurysm repair techniques have been introduced, and new devices, such as branched and fenestrated aortic stent-grafts, have been developed (Wong et al., 2011; Ruffino and Rabbia, 2012; Rikhtegar Nezami et al., 2018; Stefanov et al., 2017; Sultan et al., 2016a).
Vascular Surgery
Tjun Tang, Elizabeth O'Riordan, Stewart Walsh in Cracking the Intercollegiate General Surgery FRCS Viva, 2020
Aneurysms: The UK endovascular aneurysm repair (EVAR) trials22 showed a clear operative mortality benefit of EVAR over open repair in patients fit for both procedures. However, no long-term survival advantage was found. For patients unfit for open repair, EVAR reduces long-term AAA-related mortality but not all-cause mortality.DREAM is a Dutch study similar to EVAR-1OVER is a USA study similar to EVAR-1IMPROVE is a multicentre study to compare rupture AAA with open and endovascular stenting. The study treats all comers with a rupture aneurysm. Overall survival is very similar.
Diseases of the Aorta
Mary N. Sheppard in Practical Cardiovascular Pathology, 2022
The natural history of AAAs is to expand and the rate is accelerated by hypertension. Routine echocardiography of the abdominal aorta shows that dilatation of more than 5 cm occurs in up to 5% of healthy individuals over 50 years of age. These subjects, who are usually male, need annual checks to follow the expansion to forestall rupture by surgery. A rate of increase of more than 0.5 cm per annum or a value of over 5.5 cm is an indication for prophylactic surgery. Nationwide screening programmes, as in the UK and Sweden, show that it is safe to leave these small aneurysms (<5.5 cm diameter) under surveillance and that the operative mortality of larger screen-detected aneurysms is very low. We do not know the diameter threshold at which the risk of rupture exceeds the risk of elective surgery and competing mortality. In the past, bypass surgery with Dacron grafts were the norm (Fig. 8.38), but now percutaneous insertion of covered stents is more popular (Fig. 8.39). In many countries, endovascular aneurysm repair is used preferentially (in about three-quarters of cases) with open repair often only considered when stenting is not feasible. The benefits lie mainly in the lower operative mortality associated with this procedure and the rapid recovery. Over the past few years, there has been increasing concern about the rate of secondary ruptures after endovascular repair which may affect about 5% of patients and can occur at any time after the procedure. Other concerns include the extent of surveillance and the radiation burden incurred. Open repair is associated with durable results and aneurysm rupture from proximal or distal anastomoses and progression is rare.
Identifying and addressing the limitations of EVAR technology
Published in Expert Review of Medical Devices, 2018
Viony M Belvroy, Ignas B Houben, Santi Trimarchi, Himanshu J Patel, Frans L Moll, Joost A. Van Herwaarden
The treatment for abdominal aortic aneurysm (AAA) repair has long been open repair, which was first introduced by Dubost in 1951 [1]. Open surgical repair requires aortic cross-clamping and a large surgical incision to expose the abdominal aorta. Because open surgical repair came with a morbidity and mortality of 3.0–7.5%, less-invasive alternatives were introduced [2–5]*. Volodos et al. introduced the concept of endovascular aneurysm repair (EVAR)[6]. Since 1991, after Parodi reported about EVAR, it has become widely accepted as a safe technique for the treatment of AAA [7,8]. Laparoscopic aortic surgery was introduced as another less-invasive alternative to open surgery in 1993, but never gained popularity. This is due to the steep learning curve, the necessary experience from surgeons, and the required aortic cross-clamping making it inferior to EVAR. A recent propensity-matched prospective trial comparing 228 consecutive AAAs and occlusive aorto-iliac disease cases, non-randomly treated with laparoscopy or open surgery, suggested that even with a well-trained surgical team, the laparoscopic approach increases the risk for adverse events observed during aortic surgery [9].
A cardio-abdominal dilemma
Published in Acta Cardiologica, 2018
Sofie Rosier, Jan Breuls, Philippe Dewolf, Koen Ameloot
A 75-year-old man known with COPD and peripheral arterial disease was brought to our ER after an episode of typical thoracic pain and syncope. His vital signs on arrival were BP 60/30 mmHg, pulse 78/min and oxygen saturation 98%. He was cold, pale, clammy and had distended jugular veins. He had distant heart sounds, normal lung auscultation and a pulsatile mass in the abdomen. ECG did not show signs of ischemia. Given the clinical picture of obstructive shock with an abdominal aortic problem, an urgent CT-scan was performed to rule out type A aortic dissection with pericardial breakthrough. Surprisingly, CT-scan showed both an acute haemorrhagic pericardiac tamponade and a 7.8 cm wide abdominal aortic aneurysm with radiological signs of imminent rupture (Figure 1). After an urgent pericardial phenestration hemodynamic parameters recovered. Endovascular aneurysm repair (EVAR) procedure was successfully performed immediately thereafter. The cause of the tamponade could not be determined. Pathology was negative, staged coronary angiography did not show significant stenosis and cMRI did not show increased pericardial signal intensity. We could not establish a link between the cryptogenic tamponade and the aneurysm. To the best of our knowledge, no similar case has been published previously. Despite presenting as severe circulatory shock with two life-threatening causes, the patient recovered well.
Profile of the Ovation ALTO abdominal stent graft for the treatment of abdominal aortic aneurysms: overview of its safety and efficacy
Published in Expert Review of Medical Devices, 2021
Mark Gregory, Matt Metcalfe, Kate Steiner
The 5-year follow up data from the ENCORE database are highly satisfactory, demonstrating a freedom from aneurysm related mortality rate of 99.3%. Freedom from type 1A endoleak was found to be 95.8% and freedom from sac expansion 84.9% [48]. Of the patients in the database, 50% were found to have complex aortic anatomy, (defined as one of: neck length <10 mm, neck angle >60°, reverse neck taper >10%, distal common iliac artery diameter <10 mm, or external iliac artery diameter <6 mm). Despite the high rate of complex anatomy, technical success was achieved in 99.7% of cases and the 30-day mortality rate only 0.3% [48]. Direct comparative data between devices in comparable aneurysm anatomy is highly limited, however it is useful to note that in one multicentre study endovascular aneurysm repair with the Ovation stent graft achieved favorable 5-year results, where 41% of the patients had anatomy deemed unsuitable for other stent grafts [47].
Related Knowledge Centers
- Abdominal Aortic Aneurysm
- Aorta
- Embolism
- Renal Artery
- Vascular Surgery
- Thoracic Aorta
- Pathology
- Pain
- Stent
- Open Aortic Surgery