Figure 3: Frame from the operating room video showing the dissection of the aneurysm.
An aortic aneurysm is an abnormal dilatation of the luminal wall of the aorta with bulging or ballooning of the vessel.
Aneurysms of the aorta are rare in the very young, and infrarenal aneurysms are even less common4. No aortic aneurysms of this type have been accurately diagnosed in utero preceding this patient.
The presence of color flow Doppler easily differentiates a vascular lesion from any of the cysts that might have occurred in the region (mesenteric, ovarian, renal...). In addition, the differential diagnosis between an arteriovenous fistula and an aneurysm can be made by the different type of flow in the two lesions. In an arteriovenous fistula, one would expect high diastolic flow due to the shunting. Conversely, in an aneurysm, the lesion is exposed to the same resistance as the rest of the vessel, and a low diastolic flow or a flow similar to that of the aorta is expected. Further, due to the poor cardiac reserve of the fetus, shunting lesions (chorioangioma, vein of Galen aneurysm, angioma of the liver) present rapidly with right-sided overload and failure. This is not expected to be found in aneurysms. A more difficult problem may arise when more than one vessel is involved. In this particular case, the question of arteriovenous malformation could not be excluded because the aortic aneurysm was bulging around the inferior vena cava.
If no other anomalies exist, routine prenatal management need not be altered. Postnatal management: Surgical excision is indicated after stabilization to avoid complications from rupture. Coagulopathy is another potential complication that should be assessed.
Prognosis may depend on the age at which this anomaly is detected, its size and location. Authors have reported a poor outcome for young patients that become symptomatic before a diagnosis is made.5
1. Tilson MD: Histochemistry of aortic elastin in patients with non specific abdominal aortic aneurysmal disease. Arch Surg 123:503-5, 1988.
2. Rolfes DB, Towbin R, Bove KE: Vascular dysplasia in a child with tuberous sclerosis. Pediatr-Pathol 3:359-73, 1985.
3. Sarkar R, Coran AG, Cilley RE, et al: Arterial aneurysms in children: clinicopathologic classification. J Vasc Surg 13:47-56; 1991
4. Roques X, Choussat A, Bourdeaud"hui A, et al: Aneurysms of the abdominal aorta in the neonate and infant. Ann Vasc Surg 3:335-40, 1989.
5. Lobe TE, Richardson CJ, Boulden TF, et al: Mycotic thromboaneurysmal disease of the abdominal aorta in preterm infants: its natural history and its management. J Pediatr Surg 27:1054-9, 1992.