Type II endoleak
A type II endoleak is a commonest form of endoleak are after an abdominal aortic repair.
They may occur in 10-44% of patients having reparis and can comprise around half of all endoleaks 1.
They may be simple of complex. Simple leak usually occur secondary to backflow (retrograde) from collateral arteries, most notably the inferior mesenteric and lumbar vasculature. They may also occur from other aortic collaterals such as the internal iliac, median sacral or accessory renal arteries.
CT has the advantage of having the ability to acquire seqeuntial images from a number of different “phases”.
- non-contrast phase: acquired first to detect high attenuating structures such as calcium or mural thrombus.
- arterial and delayed phases: used to visualize arterial structures and “late” events such as endoleaks, which are not necessarily visible during the arterial phase
Dual energy CT
Dual-energy CT acquires datasets at two different photon spectra in a single acquisition, and have give both enhanced and nonenhanced data. It can be used to detect endoleaks with good accuracy and at a reduced radiation exposure
- aortic aneurysm rupture: a rupture after EVAR secondary to an isolated type II endoleak is rare (less than 1 %, but over a third are thought to occur in the absence of sac expansion 3
Treatment and prognosis
It usually resolves spontaneously over time and requires no treatment. Some recommend intervention in patients with type II endoleak when the sac diameter is more than 10 mm 1. Embolisation of the branch vessel is indicated if the aneurysm sac continues to expand in size. Such options include
- transarterial embolotherapy
- translumbar and direct sac embolotherapy
- percutaneous transcaval embolisation
Endoleaks with a stable or decreased aneurysmal sac size may be followed up with CT given the generally high rates of spontaneous resolution and a low risk of rupture in published literature 5.
- 1. Brown A, Saggu GK, Bown MJ, Sayers RD, Sidloff DA. Type II endoleaks: challenges and solutions. Vascular health and risk management. 12: 53-63. doi:10.2147/VHRM.S81275 - Pubmed
- 2. Steinmetz E, Rubin BG, Sanchez LA, Choi ET, Geraghty PJ, Baty J, Thompson RW, Flye MW, Hovsepian DM, Picus D, Sicard GA. Type II endoleak after endovascular abdominal aortic aneurysm repair: a conservative approach with selective intervention is safe and cost-effective. Journal of vascular surgery. 39 (2): 306-13. doi:10.1016/j.jvs.2003.10.026 - Pubmed
- 3. Sidloff DA, Stather PW, Choke E, Bown MJ, Sayers RD. Type II endoleak after endovascular aneurysm repair. The British journal of surgery. 100 (10): 1262-70. doi:10.1002/bjs.9181 - Pubmed
- 4. Avgerinos ED, Chaer RA, Makaroun MS. Type II endoleaks. Journal of vascular surgery. 60 (5): 1386-91. doi:10.1016/j.jvs.2014.07.100 - Pubmed
- 5. Tolia AJ, Landis R, Lamparello P, Rosen R, Macari M. Type II endoleaks after endovascular repair of abdominal aortic aneurysms: natural history. Radiology. 235 (2): 683-6. doi:10.1148/radiol.2352040649 - Pubmed
- 6. Güntner O, Zeman F, Wohlgemuth WA, Heiss P, Jung EM, Wiggermann P, Pfister K, Stroszczynski C, Müller-Wille R. Inferior mesenteric arterial type II endoleaks after endovascular repair of abdominal aortic aneurysm: are they predictable?. Radiology. 270 (3): 910-9. doi:10.1148/radiol.13130489 - Pubmed