Teaching Case

A 65-year-old male patient preseented with three epsiodes of self-resolving, short lasting ischaemic episodes in the left leg.

A 65-year-old man complained that after getting out of bed in the morning, he felt a sharp pain in his left calf, ascending up into the pelvis. He reported a feeling of pins and needles and noticed pale skin on the lower leg. He called an ambulance for transport to the local casualty department. About 30 min after he was admitted, all signs and symptoms had subsided. He presented as a previously healthy individual without any cardiovascular risk factors. Clinicially, an acute embolism was suspected and an intra-arterial angiography (DSA) was performed. This showed a slight irregularity of the left external iliac artery and an otherwise completely normal lower arterial system. The suspected diagnosis was an isolated dissection of the left external iliac artery. The next day, an MR-angiography was performed (Time of Flight MR-A), with an axial STIR-sequence. The MR image showed the dissecting membrane of the vessel and a perivascular oedema. The following day, the patient had another self-resolving symptomatic episode lasting 10 min. An angio-CT was done, which confirmed the presence of the dissecting membrane and a "thickening" of the vessel wall down to the level of the left common femoral artery, which was diagnosed to be the thrombosed false lumen of the dissected artery. By a CT scan, a dissection of the thoracic and abdominal aorta was excluded. As the patient was free of symptoms again, no indication for surgey was seen initially. Then, three weeks later, he was readmitted with another episode, and a bypass surgery was then performed. On that admission, he suddenly recalled that a few days before the first admission, he had been involved with some wood work in his house, when he had accidentally rammed a wooden-panel into his left groin. But since he did not have any severe pain, he had forgotten about this.

The isolated dissection of the external iliac artery is seen in conditions such as fibromusculuar dysplasia, cystic medi-necrosis (Erdheim–Gsell), hypertony,pregnancy, the Marfan-syndrome, in alpha-1-antitrypsin-deficiency, vasculitis and in trauma. In our patient, the reason was a time-related trauma, forgotten by the patient. Imaging diagnosis can be made by duplex-sonography or, as in our case, by DSA, MR-A or an angio-CT. According to the literature, a symptomatic dissection should be operated on due to the danger of a rupture, dilatation or an ischaemia. Alternative treatment may be interventional by stent or stent-graft. In any case, low-molecular heparin and platelet-inhibitors should be given.