An Unusual Complication of Aortic Dissection
Article Outline
Hepatic artery aneursyms are rare and are often caused by trauma and following surgical and radiological procedures. We report the imaging findings and management of a case of hepatic artery pseudo aneurysm (HAPA) secondary to extending aortic dissection, presenting with hemobilia and obstructive jaundice HAPA carries high mortality, when it ruptures into the bile duct presenting as hemobilia. When this happens due to dissection of aorta, management becomes challenging. In our patient, HAPA was successfully managed by trans-catheter embolisation of both proximal and distal arteries.
Keywords: Aneurysm, Dissecting, Aorta, Abdominal, Hemobilia, Hepatic Artery, Embolization, Therapeutic
Introduction
Aneurysm or pseudo aneurysms of the hepatic artery (HAPA) make up about 20% of all splanchic aneurysms. Spontaneous rupture of HAPA leading to life threatening haemorrhage is a known complication and Transcatheter embolisation (TCE) using metallic coils has been effectively used as an alternate to open surgery. An extra hepatic HAPA secondary to aortic dissection is extremely rare and only three such cases have been reported in the literature. We present one such case of HAPA due to aortic dissection presenting with hemobilia and obstructive jaundice that was managed by TCE using metallic coils.
Case Report
A 56 year old man presented with two months history of upper abdominal pain associated with hemetemesis, melaena and jaundice. He was a hypertensive on regular medication. At presentation his blood pressure was under control. He was jaundiced and abdominal examination revealed a palpable liver. Biochemical tests showed low hemoglobin and altered liver function tests. Computerized tomography of the abdomen with contrast showed an aortic dissection extended 2
cm above the celiac artery to the common iliac bifurcation. The celiac artery was arising from the true lumen and IMA from the false lumen. The dissection extended into the Superior Mesenteric Artery (SMA). The common hepatic artery (CHA) was arising from the SMA with extension of the dissection into it. Just proximal to the origin of the gastro-duodenal artery, there was a pseudo aneurysm measuring 4 cms, partially filled with thrombus. Hyper densities suggestive of blood clots were found within the dilated CBD due to a fistulous communication with the pseudo aneurysm (Fig. 1). There was associated marked intra and extra hepatic biliary dilatation. Management was prioritized to obliterate the fistula of the HAPA with the CBD. Resection and bypass of the aneurysm was deferred due to associated co-morbid condition of the patient. As placement of a covered stent was technically difficult, coil embolisation was prefered. Philips CT Brilliance 3D workstation was used for image reconstruction. A ‘scroll’ tool bar from the GE PACS was also used while interpreting the anatomy before the intervention. Aortic dissection was not considered for treatment as exit foraminae were identified clearly on imaging and patient did not have any related symptoms. Through a right femoral access, CHA was selectively cannulated. There was faint opacification of the pseudo aneurysm as it was possibly a low pressure area. Using the glide vertebral catheter (Terumo) and Progret catheter (Terumo), the gastro duodenal, hepatic artery segment proximal and distal to the HAPA were embolised using 22 “Hilal embolisation coils” 0.018 thickness, size varying from 5–7 mms. Post embolisation check angiogram showed no opacification of the pseudo aneurysm (Fig. 2). Angiogram of the celiac artery showed filling of the hepatic arteries through collaterals from the left gastric artery. Doppler examination on the following day showed total thrombosis of the pseudo aneurysm. After the intervention, hematemesis settled and liver function improved markedly over the subsequent days without needing biliary drainage. There was no evidence of liver necrosis or abscess, two weeks after the procedure. Patient has been advised to follow up at 6 monthly intervals for the first two years to monitor the aneurysm exclusion and the dissection of the aorta.
Fig. 1
CT Contrast showing Aortic dissection extending into the SMA with a pseudo aneurysm filled with partial clot arising from the replaced Hepatic artery. Dilated bile duct was displaced posteriorly and filled with clots.
Fig. 2
DSA image showing residual filling of the pseudo aneurysm after coil embolisation of gastro duodenal and hepatic artery proximal and distal to HAPA.
Discussion
Pseudo aneurysms represent contained hematomas that result from localized arterial disruption, with a persistent channel to arterial lumen, so that they are pulsatile. More than 3000 splanchnic artery aneurysms are reported in the literature with HAPA constituting 20% of them.1, 2, 3, 4, 5 Infected aneurysms, previously considered the most common etiology following drug abuse is now replaced by atherosclerotic aneurysms (32%), trauma (22%), radiological intervention procedures, polyarteritis nodosa, cystic medial necrosis, amphetamine use, following liver transplant, localized inflammation caused by cholecystitis and pancreatitis.1 This patient presented with rupture of an extrahepatic pseudo aneursym into the CBD caused by dissection of SMA, extending from the aorta. A similar presentation, but as hemosuccus pancreaticus, is reported recently.4
Average size of a HAPA reported in the literature is 3.5 cms. Common hepatic artery (40%) is the commonest site followed by RHA (28%) and LHA (5%).4 Most of the patients present with chronic upper abdomen pain radiating to the back. Rupture of the HAPA is a known complication occurring in 20–44%, either into the general peritoneal cavity or the CBD. Rupture into the bile duct results in hematemesis, jaundice, fever and hemobilia, where the mortality is high-35%.1, 2, 3, 4, 6 Rarely the HAPA can undergo spontaneous thrombosis.7 Apart from the traditional surgical management of the extra hepatic HAPA,3 super selective microcoil embolisation has been effectively used in the management.5 Many kinds of material have been tried including gelatin sponges, coils, PVA, detachable balloons, cyanoacrylate and thrombin.4 The liver can tolerate considerable arterial ischemia as alternate collateral routes develop. In our patient, hepatic artery proximal and distal to pseudo aneurysm and the gastroduodenal artery were embolised without any complication. A reported 42% recanalisation rate after TCE mandates proper technique to be employed and further long term follow up of the patient.1 The potential for migration of embolic material resulting in central lobular necrosis and abscess formation is reported.1 Percutaneous injection of thrombin and stents have also been tried for post-operative HAPA.1
We present this case due to its rare etiology and to highlight the effective use of radiological intervention thus avoiding surgery.
References
- . Splanchnic artery aneursyms. In: Cronenwett G editors. Vascular Surgery by Robert B. Rutherford. 6th ed.. Philadelphia, Pennsylvania: Elsevier Saunders; 2005;p. 1569–1570
- . Hemobilia from ruptured hepatic artery aneurysm. Report of a case and review of the literature. Am J Surg. 1977;133(2):229–232
- . Obstructive jaundice by a dissecting aneurysm of celiac axis and hepatic artery. Dig Dis Sci. 1987;32(12):1431–1434
- Transarterial embolization of common hepatic artery pseudoaneurysm secondary to aortic dissection. Cardiovasc Intervent Radiol. 2006;29(4):713–716
- . Embolization of hepatic artery pseudo-aneurysm facilitated by selective injection of thrombin and thrombin-soaked coils. Australas Radiol. 1995;39(3):257–259
- . The diagnosis and management of visceral artery aneurysms. Surgery. 1980;88(5):619–624
- . Spontaneous thrombosis of hepatic posttraumatic pseudoaneurysms: sonographic and computed tomographic features. J Ultrasound Med. 2003;22(1):99–103
PII: S1533-3167(07)00033-7
doi:10.1016/j.ejvsextra.2007.09.003
© 2007 Published by Elsevier Inc.
