Background
The aorta is the main artery in the body. It supplies blood to all parts of the body and originates from the heart. Aortic dissection is a disease that involves a tear in the wall of the aorta. There are two types of aortic dissection: Type A, which occurs in a region of the aorta that is close to the heart (ascending aorta and aortic arch), and Type B, which occurs in a region of the aorta farther from the heart (distal to the left subclavian artery). If Type B aortic dissection occurs and no immediate surgery is required, the dissection ages and is referred to as a chronic dissection (older than six weeks). Complications may develop after this time, which may require surgical intervention, depending on the relative severity of the complication and risk of the intervention. The combination of age of dissection and presence of complications requiring intervention is why this is referred to as complicated chronic Type B aortic dissection.
For many years, the only treatment option for this was open surgical repair. Despite its widespread use, there remain significant issues with this approach, such as kidney failure, loss of movement (paraplegia), further surgeries, and death.
In recent years, advances in biomedical engineering have allowed for the development of stent grafts, which can be mounted onto catheters to be inserted through minimally invasive techniques. This is referred to as thoracic endovascular aortic repair (TEVAR), and it has been considered by some to be a more attractive treatment due to its minimally invasive nature. Stent grafts are different from grafts used in open surgery, and so information is needed to measure if this method is better compared to open surgery.
Study characteristics and key results
We carried out a thorough literature search (good to 2 August 2021) to identify all randomised and controlled clinical trials that investigated this review question. We did not find any randomised or controlled clinical trials that met our inclusion criteria.
Certainty of evidence
We were unable to assess the certainty of evidence because of the absence of studies included in this review.
Conclusion
We are unable to report any evidence to help healthcare professionals or patients make decisions on the best way to manage complicated chronic Type B aortic dissection. High-quality randomised or controlled clinical trials addressing this question are needed. Due to the nature of this life-threatening condition, conducting such studies will be challenging.
Due to lack of RCTs or CCTs investigating the effectiveness and safety of TEVAR compared to OSR for patients with complicated CBAD, we are unable to provide any evidence to inform decision-making on the optimal intervention for these patients. High-quality RCTs or CCTs addressing this objective are necessary. However, conducting such studies will be challenging for this life-threatening disease.
Type B aortic dissection can lead to serious and life-threatening complications such as aortic rupture, stroke, renal failure, and paraplegia, all of which require intervention. Traditionally, these complications have been treated with open surgery. Recently however, endovascular repair has been proposed as an alternative.
To assess the effectiveness and safety of thoracic aortic endovascular repair versus open surgical repair for treatment of complicated chronic Type B aortic dissection (CBAD).
The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, and AMED databases, as well as the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers, to 2 August 2021. We searched references of relevant articles retrieved through the electronic search for additional citations.
We considered all randomised controlled trials (RCTs) and controlled clinical trials (CCTs) assessing the effects of thoracic aortic endovascular repair (TEVAR) versus open surgical repair (OSR) for treatment of complicated chronic Type B aortic dissection (CBAD). Outcomes of interest were mortality (all-cause, dissection-related), neurological sequelae (stroke, spinal cord ischaemia/paresis-paralysis, vertebral insufficiency), morphological outcomes (false lumen thrombosis, progression of dissection, aortic diameters), acute renal failure, ischaemic symptoms (visceral ischaemia, limb ischaemia), re-intervention, and health-related quality of life.
Two review authors independently screened all titles and abstracts identified by the searches to identify those that met the inclusion criteria. From title and abstract screening, we did not identify any trials (RCTs or CCTs) that required full-text assessment. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions. We planned to assess the certainty of evidence using GRADE.
We did not identify any trials (RCTs or CCTs) that met the inclusion criteria for this review.