CASE 11419 Published on 10.02.2014

Intimo-intimal intussusception: an unusual presentation of aortic dissection



Case Type

Clinical Cases


P. Hernández, J. Ferreirós

Hospital Clínico San Carlos, Madrid (Spain);

85 years, male

Area of Interest Arteries / Aorta, Cardiovascular system ; Imaging Technique CT-Angiography
Clinical History
An 85-year-old man was admitted to the hospital with left-sided hemiparesis, hypoventilation, and unconsciousness. Under clinical suspicion of pulmonary embolism (PE) a computed tomography angiography (CTA) was requested.
Imaging Findings
A computed tomography angiography was performed resulting negative for PE, but revealed indirect signs of aortic dissection (intimal calcification displacement). Considering this findings another CTA scan was performed with systemic arterial phase revealing a Stanford Type A aortic dissection showing the intimal flap invaginated in the aortic arch and no flap in the ascending aorta (Figures 1-4 ).
Intimal intussusception is an atypical manifestation of aortic dissection produced by circumferential dissection of the intimal layer, which subsequently invaginates like a windsock. In intimointimal intussusception, CTA scans may show one lumen wrapped around the other lumen in the aortic arch, with the inner lumen being the true lumen and the false lumen being peripheral. In these unusual cases of intussusception, the intimal tear usually begins near the coronary ostia [1].

Aortic dissection with intimo-intimal intussusception is an unusual presentation of aortic dissection with less than 50 cases published in the literature. It was first described by Chiari in 1909 as an “ inversion of the internal cylinder”, being posteriorly denominated as “intimo-intimal intussusception” by Hufnagel and Conrad in 1962 [2]. It has also been denominated as circumferential dissection with “absent flap”.

In this type of dissection, the medial layer occupies completely the aortic circumference, and two different flaps become detached, one proximal and another distal; the proximal one can prolapse into the left ventricle in diastole causing massive aortic insufficiency, while the distal one is rejected to the aortic arch in systole, leading to the intussusception of this flap in the true aortic lumen and sometimes provoking the obstruction of some supraaortic branches [3].

Imaging plays an important role in establishing the diagnosis of this entity, and computed tomography angiography is the technique of choice. It reveals an aneurysmal dilatation of the ascending aorta, the presence of one or more intimal flaps in the aortic root, absence of flap in the ascending aorta and the presence of an invaginated flap in the aortic arch [4]. Post-processing methods are very useful tools that help characterise these kind of lesions.

This is a rare type of aortic dissection with very poor prognosis requiring urgent surgery [5, 6]. Due to the absence of the intimal flap in the ascending aorta this atypical condition can be challenging, thereby delaying its identification and diagnosis.
The treatment of choice is emergency surgery for replacement of the ascending aorta and/or the aortic arch, generally with a synthetic graft [7].

Intimal intussusception is an atypical and infrequent manifestation of aortic dissection with high morbi-mortality and, not only a higher rupture risk, but also a higher rate of complications than classic aortic dissection. It is very important to identify this condition as early as possible as patient´s prognosis depends on it.
Differential Diagnosis List
Aortic dissection with intimo-intimal intussusception.
Typical Aortic Dissection Type A
Ascending Aorta Aneurysm with associated dissection
Final Diagnosis
Aortic dissection with intimo-intimal intussusception.
Case information
DOI: 10.1594/EURORAD/CASE.11419
ISSN: 1563-4086