Ruptured Splenic Artery Aneurysm
From the Department of Radiology, Salmania Medical Complex, Bahrain.
NS Jamsheer, N Malik, Ruptured Splenic Artery Aneurysm. 2001; 21(5-6): 340-341
The splenic artery is the third most common site of intraabdominal aneurysm formation after the abdominal aorta and iliac arteries. Splenic artery aneurysms (SAAs) constitute approximately 60% of all visceral arterial aneurysms.1 They are usually discovered incidentally, either at autopsy or during imaging studies of the upper abdomen. Rupture is the main complication leading to massive intraperitoneal hemorrhage. This report describes our experience in the diagnosis and management of a ruptured SAA in a young male patient.
Case
Case Report
A previously healthy 30-year-old male was brought to the Emergency Department after collapsing at his workplace. Prior to the occurrence of the cardiovascular collapse, he had had a sudden onset of severe pain in the left hypochondrium. There was no significant past history of any medical illness. On admission, he was in shock, dyspneic and hypotensive. His pulse was 135/min. and blood pressure was 80/50 mm Hg. He responded to volemic resuscitation and was urgently assessed by the surgeon. No abdominal mass was palpable on physical examination. A portable bedside ultrasound revealed free fluid in the abdomen. An urgent CT scan of the abdomen was performed which revealed massive hemoperitoneum. A rounded, well-defined 4x5 cm mass with heterogeneous attenuation was seen in the region of the splenic hilum posterior to the gastric fundus (Figure 1A). In the pre-contrast scan, the lesion was hyperdense. After contrast injection, intense enhancement was seen along the periphery of the lesion, which was in relation to the distal part of splenic artery (Figure 1B). Large areas of splenic infarction were noted. On the basis of CT findings, a diagnosis of ruptured splenic artery aneurysm with splenic infarction was made. At the subsequent surgery, a partially thrombosed 5 cm aneurysm of splenic artery was removed together with the spleen. The patient's postoperative course was uneventful. Histological examination of the specimen confirmed the diagnosis of aneurysm of the splenic artery.
Discussion
Since the first report of splenic artery aneurysm by Beaussier at necropsy in 1770, incidence rates varying between 0.02% and 0.1% have been reported in large autopsy series.2 They may be found in all age groups, but the peak incidence is in the fifth and sixth decades of life, and they occur more frequently in women.3 The majority of SAAs are single and saccular in shape, and are located in the middle and distal parts of the splenic artery.
The pathogenesis of SAAs is not fully understood, but multiparity and portal hypertension seem to promote aneurysmal dilatation.4 The strong association between SAA and multiple pregnancies is possibly due to hormonal and hemodynamic effects on the arterial wall during pregnancy.
Patients with SAAs are usually asymptomatic. Acute left upper quadrant pain and shock usually indicate rupture of the aneurysm, which occurs in 5%-10% of the cases.2 SAAs are diagnosed when a curvilinear calcification is seen in relation to the splenic artery on conventional abdominal radiographs, or incidentally during ultrasound or CT examination of the abdomen. On ultrasound examination, SAAs appear as hypoechoic masses in the left upper part of the abdomen. Duplex ultrasound examination may show a holosystolic waveform. On CT scans, SAAs appear as well-defined low-density masses with or without calcifications. Intense enhancement within the residual patent lumen following the administration of intravenous contrast medium confirms the diagnosis of an aneurysm. If intense enhancement is not present due to thrombosed lumen of the aneurysm, the differentiation of an SAA from other tumors of the pancreas becomes difficult. MRI in helpful is such rare cases.5
SAAs larger than 2 cm, particularly in women of childbearing age, are treated surgically because of the high mortality rate if rupture occurs during pregnancy.6Surgical treatment includes ligation of the splenic artery or resection of the aneurysm. Once the rupture has occurred, aneurysm is resected along with the spleen, sometimes together with partial distal pancreatectomy as well. Super-selective embolization of the splenic artery is an important alternative method of treatment in high-risk patients.7
In conclusion, the diagnosis of SAA rests upon a high index of suspicion. In ruptured SAA, the mortality rate is low if immediate resuscitation is performed and an aggressive surgical approach is undertaken.
References
1. Trastek VF, Pairolero PC, Joyce JW, et al. Splenic artery aneurysms. Surgery 1982;91:694-9.
2. Perrot MD, Buhler L, Deleaval J, et al. Management of true aneurysms of the splenic artery. Am J Surg 1998;175:466-8.
3. Spittel JA Jr, Faurbourn JF II, Kincaid DW, et al. Aneurysm of the splenic artery. J Am Med Assoc 1961;175:452-6.
4. Caillouette JC, Merchant EB. Ruptured splenic artery aneurysm in pregnancy: twelfth reported case with maternal and fetal survival. Am J Obstet Gynecol 1993;168:1810-3.
5. Kehagias DT, Tzalonikos MT, Moulopoulos LA, et al. MRI of a giant splenic artery aneurysm. Br J Radiol 1998;71;444-6.
6. Carr S, Pearce W, Vogelzang R, McCarthy W, Nemcek A, Yao J. Current management of visceral artery aneurysms. Surgery 1996; 120:627-34.
7. McDermott V, Shlansky-Goldberg R, Copec C. Endovascular management of splenic artery aneurysms and pseudoaneurysms. Cardiovasc Intervent Radiol 1994;17:179-84.
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