Communicating with the flowing blood, pseudoaneurysm is a collection of blood outside the vessel lumen . The absence of a 3-layered arterial wall differentiates it from a true aneurysm. Intercostal artery pseudoaneurysms are rare, as far as we know, there are 24 cases reported in the English literature [2–25]. The clinical findings of these cases are summarized in the Table. Ten patients were women and 14 were men. Their age ranged from 9 to 86 years (mean,55). Symptoms were hemothorax in 10 patients, pulsatile mass in 4 patients, hemoptysis in 2 patients, hematoma in 2 patients, acute chest or back pain in 3 patients, and hematemesis in 1 patient. The rest 2 patients without any symptoms were found accidentally by radiological examination. Aetiology of the cases described was iatrogenic in 17 patients, and traumatic in 6 patients. Cause of one patient without any medical history and chest trauma was unclear and ,as well as this case, might be spontaneous.
Hemothorax was the most common presenting symptom in almost all the cases reported previously. So patients with massive hemothorax should be suspected to have an intercostal artery pseudoaneurysm, especially when they had chest trauma or underwent a surgical procedure via the intercostal space. The rupture of intercostal artery pseudoaneurysm causes
brisk bleeding which may lead to shock or death. But, as reported, delayed hemothorax might occur two to four weeks after trauma or surgical procedures, so early diagnosis was possible and essential. Traditionally, diagnosis of an intercostal artery pseudoaneurysm was usually made by means of arteriography which allows endovascular treatment in a single procedure. But doppler ultrasound and CT are the two most primary diagnostic modality for intercostal artery pseudoaneurysm. In our case, intraoperative findings and pathology on resected tissues were also important in the diagnosis of intercostal artery pseudoaneurysm. Because, as for differential diagnosis, initially, we took pulmonary sequestration and mediastinal tumor into consideration.
The ruptured intercostal artery pseudoaneurysm was a good indication for endovascular intervention. Embolisation was considered to be the preferred treatment of a ruptured pseudoaneurysm. Many successful cases have been reported [8, 11, 14–16, 19, 22–25]. Generally speaking, microcoils were the first choice for embolisation [8, 14, 15, 19, 22, 14, 25], but glue-lipiodol mixture , polyvinyl alcohol particles and gelfoam slurry [11, 23] could also serve as alternatives. Callaway et al  reported a patient cured with covered stent. Conservative management [6, 20] and ultrasound-guided thrombin injection [9, 13, 17] had also been described. Only few cases involved open excision [2, 4, 7, 10]. Although endovascular intervention was often chosen, sekino et al  suggested that a pseudoaneurysm might have multiple blood supplies which sometimes lead to treatment failure. Actually, in our case, the covered stent did not interrupt the blood supply into the pseudoaneurysm completely. Furthermore, atelectasis occured because the thoracic cavity was filled with the hematoma that was difficult to absorb. Surgical removal of the gross hematoma should be performed to prevent infection and release the compressed lungs. So we formulated a two-step therapeutic schedule which was proved to be feasible.