Spontaneous dissection of the celiac trunk : report of three cases and review of the literature

Spontaneous dissection of the celiac trunk is quite an uncommon medical condition, with few case reports in the medical literature. Sudden epigastric abdominal pain is the most common complaint reported by patients, but due to the rarity of this disease in clinical practice and the nonspecific nature of its symptoms, a high degree of clinical suspicion is needed to establish diagnosis. However, improvements in imaging techniques are facilitating diagnosis of this clinical entity, increasing its detection rate. The ideal treatment has not yet been fully established in the literature and the available therapeutic strategies are conservative medical treatment, surgical revascularization or endovascular intervention. In this article we report on three cases of spontaneous dissection of the celiac trunk and conduct a review of the literature on this disease


INTRODUCTION
Spontaneous dissection of visceral arteries is a rare event, affecting the superior mesenteric artery and sometimes the celiac trunk, the splenic artery and the inferior mesenteric artery. 1 Although the condition is rare, its incidence may have been underestimated in the past and it has historically been associated with poor prognosis.3][4][5] Abdominal pains are the most common symptom in people who have suffered spontaneous dissection of the celiac trunk, but patients may also exhibit nonspecific symptoms such as weight loss. 1,5As imaging methods have continually improved, diagnosis of this condition has been facilitated and it should be taken into account during differential diagnosis of epigastric abdominal pain. 1,42][3][4][5] There are three possible treatment options available: conservative clinical treatment, surgical revascularization or endovascular treatment. 1The objective of this article is to describe three cases of spontaneous dissection of the celiac trunk and to conduct a review of the current literature on the subject.

CASE REPORTS Case 1
FGS, a 52-year-old male patient with poorly controlled chronic systemic arterial hypertension, presented with sudden epigastric pain and nausea with onset 24 hours previously.Abdominal ultrasonography findings were normal, but angiotomographic investigation identified a dissection flap in the celiac trunk (Figure 1).The condition was treated clinically and the patient was referred for outpatients follow-up, free from symptoms.

Case 2
SJSS, a 50-year-old female who had been healthy until 3 months previously, suffered a single episode of sudden, high intensity, postprandial pain in the epigastric area.Once pain had been managed using a nonsteroidal anti-inflammatory and intravenous tramadol, the patient was investigated further using angiotomography of the thoracoabdominal aorta, which showed that the celiac trunk had undergone traumatic dissection due to extrinsic pressure exerted by the median arcuate ligament of the diaphragm (Figure 2) and revealed thrombosis of the common hepatic artery with a chronic appearance (Figure 3).The patient was referred for outpatients follow-up.two elastic layers. 1,5,6Spontaneous arterial dissection is more common among men (at a proportion of five men to each woman) and the mean age of patients is approximately 55 years. 3Arterial dissection is described as isolated when there is no related aortic dissection and is more often observed in the renal and carotid arteries, but rarely seen in visceral arteries. 4,5he most common types of extra-aortic dissection, in descending order of frequency, are: renal artery, coronary artery, cerebral artery, carotid artery, vertebral artery and visceral artery dissections. 5pontaneous dissection of the visceral arteries was first described by Baurersfeld in 1947 and is an extremely uncommon condition. 2Spontaneous dissection of the renal artery has been reported more often in the literature than dissection of the celiac artery. 2 Only 55 cases of spontaneous dissection of visceral arteries had been reported up to 2007. 3 Of these, just 11 cases of spontaneous dissection of the celiac trunk had been reported since 1959. 3solated spontaneous dissection of the celiac trunk is a rare entity.The majority of these cases have been observed in young patients and were managed using surgery or conservative treatment.Histology has shown that dissection occurs between the internal and the external elastic lamina, in contrast with dissection of the aorta, where the cleavage plane runs between the first and second parts of the tunica intima. 2 Conditions that have been identified as causing arterial dissection include arterial hypertension, atherosclerosis, trauma, iatrogeny, pregnancy, syphilis, polyarteritis nodosa, fibromuscular dysplasia, cystic degeneration of the media (Marfan Syndrome) and other congenital disorders of vessel walls (Ehlers-Danlos Syndrome, for example). 5,7ther precipitating events can include mechanical stretching and microtraumas caused by effort or by rapid increases in intra-abdominal pressure, such as, for example, sneezing or standing up.However, in the majority of cases of isolated spontaneous dissection of the celiac trunk the cause remains unknown. 3lthough rare, isolated dissection of visceral arteries has historically conferred poor prognosis.To date, the natural history of the disease is unpredictable and prognosis is dependent on the degree of compromise of subsegmental branches.Acute signs of hepatic ischemia or hemorrhage are indicative of poor prognosis. 3he most common initial clinical manifestation is sudden abdominal pain in the epigastric area. 3linical diagnosis is difficult because symptoms are relatively nonspecific and overlap with other conditions; making a high degree of clinical suspicion necessary.Some authors have suggested that a triad comprising sudden epigastric pain, weight loss and an epigastric systolic murmur is pathognomonic of this clinical condition. 4,6espite the reports that the majority of patients suffer abdominal pain, there is often a discrepancy between the symptoms reported and the signs detected during physical examination, with the first being more intense than the second.Chronic dissection of the celiac artery can manifest with symptoms of postprandial abdominal pains and weight loss. 2 In rare cases, dissection of the celiac trunk can also manifest as obstructive jaundice or pancreatitis. 1,3tomography.This finding may be predictive of a predisposition for the dissection to extend to adjacent vessels. 3he ideal treatment for dissection of the celiac artery is still a controversial subject, in part because of the condition's rarity, but also because treatment options are dependent on the patient's hemodynamic status, on involvement of other vessels, on response to conservative treatment and on development of complications. 5 A range of vascular complications have been described, such as propagation of the dissection to adjacent vessels causing visceral infarcts and development of aneurysms.The cause of this aneurysm formation is not yet clear, but it may reflect an individual genetic predisposition to weakening of the artery wall, vascular rupture and mesenteric ischemia. 3here patients are hemodynamically stable, conservative management has generally been attempted.The objectives of conservative clinical treatment do not only include preventing progression of the dissection by controlling arterial blood pressure, but also extend to avoiding thromboembolic complications through administration of anticoagulants. 3,4,8In view of this, 3 to 6 months' treatment with anticoagulant agents or antiplatelet drugs, aiming for a target international normalized ratio (INR) of 2.0 to 3.0, in combination with strict control of arterial blood pressure 5,7 have been recommended for prevention of thromboembolic complications.Administration of an anticoagulant immediately after diagnosis induces healing of the dissection and dissolution of the mural hematoma while preventing thromboembolic complications. 5,8dditionally, secondary antiplatelet treatment is recommended to prevent thrombosis in patients who have stenotic lesions. 2 Conservative treatment may also include antihypertensive and antiinflammatory drugs and corticosteroids in addition to the anticoagulants. 2,3urgical or endovascular interventions should be considered in the following situations: when the patient is hemodynamically unstable or has persistent abdominal pain, when conservative medical treatment fails to control arterial blood pressure and when the dissection is progressing further. 2,3,7This can be investigated through serial follow-up using imaging methods, but to date there is no established consensus on the frequency with which these examinations should be conducted. 2f angiotomography shows active contrast leakage from the celiac trunk, emergency laparotomy is the treatment of choice. 3,4,8Sadly, even when immediate The nonspecific symptoms and clinical signs and the need to confirm the hypothesis of dissection, determine its extension or even identify other pathological conditions mean that diagnosis is generally established using imaging exams.Invasive angiography has traditionally been considered the gold standard examination for diagnosis, but recently computed tomography (CT) has acquired increasing importance. 3,4,8,9As more advanced CT equipment has been developed along with image acquisition techniques that allow high-quality twodimensional and three-dimensional reconstructions, CT with injection-pump administration of contrast, or angiotomography, has become one of the most useful diagnostic techniques for investigating visceral artery dissections and providing details on the path of the dissection and its propagation into arterial system branches. 4,5,8Furthermore, angiotomography offers the possibility of comparing measurements of the extent of involvement with high reproducibility and accuracy for followup. 5,8Several different studies have suggested that angiotomography is a precise method for diagnosis and serial follow-up images of arterial dissection that is less invasive than angiography. 5,8,10In support of this position, recent research has shown that angiotomographic diagnosis and follow-up is associated with a significant reduction in morbidity compared with angiography. 3,4,8,10In view of this, angiotomography is now considered the first choice imaging exam for diagnosis of celiac trunk dissection, although magnetic resonance angiography, Doppler ultrasonography and conventional angiography can also be used. 2,10issection of the celiac trunk can occur with concomitant formation of an arterial aneurysm. 3,5,9im et al. state that intimal delamination in angiotomographic images is a pathognomonic diagnostic finding, while observation of an eccentric mural thrombus in the artery lumen should raise a suspicion of dissection. 2,11Observation of a mural thrombus may be the only clue to the existence of a dissection since intimal delamination is not always visible. 2,3,5,11In such circumstances, misdiagnosis of a dissection as a thromboembolic occlusion may lead to unnecessary prescription of pharmacological thrombolysis. 2,3,5,11Silvestre et al. described a case of simultaneous aneurysm and dissection of the celiac trunk in which the dissection was identified on angiotomography as a failure of linear filling compatible with a laminar dissection. 12Spontaneous dissection cases may also exhibit densification of the fat planes surrounding the celiac trunk on

Figure 1 .
Figure 1.Axial angiotomography image showing failure of linear filling compatible with a dissection flap (arrow) of the celiac trunk, which is mildly dilated.

Figure 2 .
Figure 2. Angiotomography with maximum intensity projection reconstruction in the sagittal plane showing an elongated failure to fill the celiac trunk interior (arrowhead) corresponding to the dissection flap.There is mild compensatory dilation downstream (arrow).

Figure 3 .
Figure 3. Angiotomography with volume rendering reconstruction showing the celiac trunk (*), the common hepatic artery (arrow) and an abrupt interruption in flow (arrowhead) compatible with obstruction by post-dissection thrombosis.

Figure 4 .
Figure 4. T1-weighted coronal magnetic resonance angiography image with contrast showing a failure of linear filling compatible with a dissection flap (arrow) in the celiac trunk.The superior mesenteric artery (arrow head) remains pervious with no signs of dissection.