{'fraction_non_alphanumeric': 0.015762925598991173, 'fraction_numerical': 0.0018915510718789407, 'mean_word_length': 4.966165413533835, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Arteriovenous fistula of the jugular vein: detection and follow-up with color-coded duplex ultrasound].

A 71-year-old man presented with a pulsating swelling in the lower right neck region. On clinical examination palpation revealed a local thrill and auscultation the typical systolic vascular sounds. On sonography the typical findings for an AV fistula with large widening of the jugular vein and entry of an extremely rapid jet stream into the vein were detected. The entry point was under a venous valve whose movements apparently influenced the jet stream since the inflow was only seen intermittently and only in the systolic phase. The shunt volume of the fistula was apparently small: indirect signs of an arteriovenous short circuit could not be seen on duplex sonography. The low-flow fistula was not demonstrated by arterial DSA. Thus, the arterial sources could not be identified. Sonographic monitoring over 5 years at first showed no changes while at the last follow-up the fistula was no longer detectable. The suspected cause of the arteriovenous fistula was a vascular wall perforation effected some years previously during insertion of a central venous catheter. We further assume that the anticoagulation therapy with Marcumar started at that time had prevented spontaneous closure of the fistula over a period of several years. This case illustrates the value of colour-coded duplex sonography for the differentiation of pulsating tumors in the neck. In individual cases of AV fistulas with low shunt volumes the method is apparently superior even to angiography.