The aorta is the largest blood vessel in the body, delivering blood from the heart to the brain, organs and extremities. Aortic dissection is a separation of the aortic wall, caused by injuries that result in blood to flow into the vessel's wall. The ascending aorta starts at the top of the heart's left ventricle, If the ascending aorta is not involved in the aortic dissection, it is known as 'complicated type B'. People with complicated type B aortic dissection may present with aortic rupture or impending rupture, persistent hypertension despite full medication, symptoms of partial paralysis of the lower limbs (paraparesis), insufficient blood supply of organs (organ malperfusion) and chest or abdominal pain which is hard to control (refractory pain). Thoracic endovascular aortic repair (TEVAR; a minimally invasive procedure to repair the aorta) has become the first-line choice for treating complicated type B aortic dissection. However, favourable outcomes of the repaired aorta are usually only seen in the area covered by the stent. The PETTICOAT technique extends the covered segment by using a bare metal stent to obtain a better outcome. It is unclear whether PETTICOAT is better than TEVAR.
Study characteristics and key results
We performed a comprehensive literature search on 5 November 2018 for all randomised controlled trials addressing this review question. We found no randomised controlled trials on this topic.
Quality of the evidence
We were unable to assess the quality of evidence because of the absence of studies included in this review.
Randomised controlled trials are needed to provide solid evidence on this topic. Evidence from non-randomised studies with large sample sizes would also be helpful in guiding clinical practice.
We identified no randomised controlled trials and therefore cannot draw any definite conclusion on this topic. Evidence from non-randomised studies appears to be favourable in the short-term, for combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) to solve the problem of unfavourable distal aortic remodeling. Randomised controlled trials are warranted to provide solid evidence on this topic. Evidence from cohort studies with large sample sizes would also be helpful in guiding clinical practice.
Aortic dissection is a separation of the aortic wall, caused by blood flowing through a tear in the inner layer of the aorta. Aortic dissection is an infrequent but life-threatening condition. The incidence of aortic dissection is 3 to 6 per 10,000 per year in the Western population, and can be up to 43 per 10,000 per year in the Eastern population. Over 20% of people with an aortic dissection do not reach a hospital alive. After admission, the mortality rates for people with an aortic dissection are between 10% and 20% for those who received endovascular treatment, and between 20% and 30% for those who had open surgery.
Thoracic endovascular aortic repair (TEVAR) is the standard endovascular method to treat complicated type B aortic dissection (aortic dissections without involvement of the ascending aorta). Although TEVAR is less invasive than open surgery and has a better long-term aortic remodeling effect than conservative medical treatment, favourable aortic remodelling is usually limited to the thoracic aortic segment. TEVAR cannot be extended into the abdominal aorta because it could cover the ostia of the reno-visceral arteries. Thus, the abdominal aorta is still at risk of progressive aneurysmal degeneration. The PETTICOAT (provisional extension to induce complete attachment) technique, with proximal endograft and distal bare metal stent, was proposed in 2006 to address this issue. The concept of this technique was to implant a distal bare metal stent into the aortic true lumen, distal to the proximal endograft, to stabilize the distal collapsed intimal flap, while allowing blood flow to reno-visceral arteries. Therefore, the PETTICOAT technique was considered to be related to a more extensive aortic remodelling for people with type B aortic dissection, especially in the area of the abdominal aorta. However, it is still unclear whether the PETTICOAT technique is superior to standard TEVAR.
To assess the effects of combined proximal descending aortic endografting plus distal bare metal stenting versus conventional proximal descending aortic stent graft repair for treating complicated type B aortic dissections.
The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 November 2018. We also undertook reference checking and citation searching to identify additional studies.
We considered all randomised controlled trials which compared the outcome of complicated type B aortic dissection, when treated by combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair.
Two independent review authors assessed all references identified by the Cochrane Vascular Information Specialist. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions.
We found no trials that met the inclusion criteria for this review.