Congenital kinking of the internal carotid artery in twin brothers.

We report magnetic resonance (MR) angiographic evidence of congenital kinking of the internal carotid artery in 4-year-old twin brothers. The first twin presented with a left pulsating laterocervical mass '2 cm in diameter. On examination, the mass had a palpable thrill and a systolic murmur. An echo-Doppler examination showed a loop of the left internal carotid artery with no hemodynamic changes. MR angiography disclosed a left internal carotid artery loop with kinking just after the bifurcation. No arteriovenous fistula was noted (Figure 1.) The second twin was completely asymptomatic. Clinical examination was normal, but an echo-Doppler examination revealed carotid loops on both sides, especially the right, with no hemodynamic changes. MR angiography showed kinking of the right internal carotid artery with a very acute internal angle close to the tonsil. The left carotid presented with an S-shaped tortuosity. No arteriovenous fistula was noted (Figure 2). We decided not to treat these patients surgically.