Figure 1
CT angiography - axial plane
CTA scan shows the circumference of the intimal intussusception in the aortic arch.
Intimo-intimal intussusception: an unusual presentation of aortic dissection
SectionCardiovascular
Case TypeClinical Cases
AuthorsP. Hernández, J. Ferreirós
Connected authors
85 years, male
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 ).
Discussion
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.
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.
References
[1] Castan, E., Mata, J. M., & Pallardo, Y. (2003) CT in Nontraumatic Acute Thoracic Aortic Disease : Typical and Atypical Features and Complications. Radiographics 23:S93–S110 (PMID: 14557505)
[2] Touati G, Carmi D, Trojette F, et al. (2003) Intimo-intimal intussusception: a rare clinical form of aortic dissection. Eur J Cardiothorac Surg 23:119-21. (PMID: 12493521)
[3] I. Vilacosta a,V. Cañadas a, P. Aragoncillo. (2006) Aspectos morfológicos de la disección aórtica. Angiología 58: S49-S57
[4] Kastan DJ, Sharma RP, Keith F, Shetty PC, Burke MW. (1988) Intimo-intimal intussusception: an unusual presentation of aortic dissection. American Journal of Roentgenology 151(3):603-4. (PMID: 3261524)
[5] Fan, Z. M., Zhang, Z. Q., Ma, X. H., & Guo, X. (2006) Acute Aortic Dissection with Intimal Intussusception: MRI Appearances. American Journal of Roentgenology 186(3), 841–843. (PMID: 16498118)
[6] Hagan PG et al. (2000) The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA 283(7):897-903. (PMID: 10685714)
[7] Loebe M, Ren D, Rodriguez L, La Francesca S, Bismuth J, Lumsden A. (2012) Acute and chronic thoracic aortic disease: surgical considerations. HSR Proc Intensive Care Cardiovasc Anesth 4(4):243-50. (PMID: 23439669)
Case information
| URL: | https://www.eurorad.org/case/11419 |
| DOI: | 10.1594/EURORAD/CASE.11419 |
| ISSN: | 1563-4086 |
Figure 2
CT angiography - sagittal MPR
Intimo-intimal intussusceotion with intimal flap detached and wrapped in the arotic arch (arrow), the ascending aorta being the false lumen (*). Proximal flap in the aortic root (arrowhead).
Figure 3
CT angiography - sagittal MPR
In addition to the invaginated flap in the aortic arch, dissection of the supraaortic branches dissection (arrow) and of the descending aorta (arrowhead) is also detected. Proximal flap in the aortic root (short arrow).
Figure 4
CT angiography - sagittal MPR
There is aneurysmal dilatation of the ascending aorta, invagination of the intimomedial flap in the aortic arch (arrow) and aortic dissection with two lumens in the descending aorta (arrowhead).
CT angiography - axial plane
CTA scan shows the circumference of the intimal intussusception in the aortic arch.
P. Hernández, Department of Radiology, Hospital Clínico San Carlos, Madrid, Spain.
P. Hernández, Department of Radiology, Hospital Clínico San Carlos, Madrid, Spain.
CT angiography - sagittal MPR
Intimo-intimal intussusceotion with intimal flap detached and wrapped in the arotic arch (arrow), the ascending aorta being the false lumen (*). Proximal flap in the aortic root (arrowhead).
P.Hernández, Hospital Clínico San Carlos, Madrid, Spain
P.Hernández, Hospital Clínico San Carlos, Madrid, Spain
CT angiography - sagittal MPR
In addition to the invaginated flap in the aortic arch, dissection of the supraaortic branches dissection (arrow) and of the descending aorta (arrowhead) is also detected. Proximal flap in the aortic root (short arrow).
P.Hernández, Hospital Clínico San Carlos, Madrid, Spain.
P.Hernández, Hospital Clínico San Carlos, Madrid, Spain.
CT angiography - sagittal MPR
There is aneurysmal dilatation of the ascending aorta, invagination of the intimomedial flap in the aortic arch (arrow) and aortic dissection with two lumens in the descending aorta (arrowhead).
P. Hernández, Hospital Clínico San Carlos, Madrid, Spain.
P. Hernández, Hospital Clínico San Carlos, Madrid, Spain.