Unusual fistulas and connections in the cardiovascular system: A pictorial review

A fistula is an abnormal vascular connection leading to diversion of blood from a high resistance arterial circuit to low resistance venous circuit. Coronary artery fistulas are abnormal communications of the coronary artery with a chamber of the heart, or with any segment of systemic or pulmonary circulation, bypassing the myocardial capillaries. Other unusual fistulas include connection between aorta and the right atrium/superior vena cava, aorta and the inferior vena cava or between a coronary artery bypass graft and a cardiac vein. Abnormal connections also include origin of the coronary artery from the pulmonary artery. In this article, we review the imaging, particularly computed tomography and magnetic resonance imaging of unusual fistulas and connections involving the cardiovascular system, particularly the coronary arteries and the aorta.     

Unusual pleural involvement after exposure to amorphous silicates (Liparitosis): report of two cases

Liparitosis is a rare pneumoconiosis determined by inhalation of pumice, an amorphous complex silicate extracted in the quarries of Lipari (Aeolian Archipelago, Italy). We describe two cases of subjects occupationally exposed to pumice dust in which high-resolution computed tomography (HRCT) revealed the presence of pleural lesions without parenchymal involvement.     

Aortocaval fistulas]

Aortocaval fistulas most frequently occur as a consequence of ruptured abdominal aortic aneurysms due to the additional trauma, spontaneous or iatrogenic. The basic symptomatology is the consequence of local irritation of spinal nerves, and major hemodynamic disturbances. In this paper we have presented two cases of aortocaval fistulas, treated at the Military Medical Academy with presentation of their preoperative status, performed diagnostic procedures, applied surgical procedures, and postoperative course and outcome.     

CT of aortoenteric fistulas

We compared CT findings with endoscopic, angiographic and surgical results in ten patients suspected of having an aortoenteric fistula (AEF) because of gastrointestinal bleeding (seven) or recurrent sepsis (three). CT correctly diagnosed AEF in six patients and excluded it in the other four. CT findings of AEF consisted of perigraft fluid (PGF) (5/6) and/or gas within the bed of the graft (4/6) later than three months after graft surgery. All six patients with AEF had perigraft infections; PGF with gas was found in 50%, PGF alone in 33%, and in one patient perigraft gas alone was found. Angiography and endoscopy failed to identify AEF. Our findings indicate that CT should be the initial imaging procedure in patients with suspected AEF who do not require immediate surgical intervention.     

Marginal sinus arteriovenous fistulas mimicking carotid cavernous fistulas: diagnostic and therapeutic considerations

Marginal sinus fistulas (MSFs) are uncommon vascular anomalies. Occasionally, the dominant venous drainage is forced retrograde up the inferior petrosal sinus and into the cavernous sinus, causing chemosis, proptosis, and ocular hypertension, mimicking a carotid cavernous fistula. This atypical clinical presentation may lead to misdiagnosis and inappropriate hazardous treatment of an MSF. Identifying the site of the fistula and understanding the anatomy of the venous drainage are critical in providing appropriate, safe, and efficacious endovascular treatment.     

Endovascular management of carotid-cavernous fistulas

Objective To investigate endovascular treatment of traumatic direct carotid-cavernous fistulas （CCF） and their complications such as pseudoaneurysms. Methods： Over a five-year period, 22 patients with traumatic direct CCFs were treated endovascularly in our institution. Thirteen patients were treated once with the result of CCF occluded, 8 twice and 1 three times. Treatment modalities included balloon occlusion of the CCF, sacrifice of the ipsilateral internal carotid artery with detachable balloon, coll embolization of the cavernous sinus and secondary pseudoaneurysms, and covered-stem management of the pseudoaneurysms. Results All the direct CCFs were successfully managed endovascularly. Four patients developed a pseudoaneurysm after the occlusion of the CCF with an incidence of pseudoaneurysm formation of 18.2% （4/22）. A total number of 8 patients experienced permanent occlusion of the ICA with a rate of ICA occlusion reaching 36.4% （8/22）. Followed up through telephone consultation from 6 months to 5 years, all did well with no recurrence of CCF symptoms and signs. Conclusion Traumatic direct CCFs can be successfully managed with endovascular means. The pseudoaneurysms secondary to the occlusion of the CCFs can be occluded with stent-assisted coiling and implantation of covered stents.     

Benign esophagorespiratory fistulas in adults

Four benign esophagorespiratory fistulas, three secondary to granulomatous disease and one presumed to be congenital, have been diagnosed in adults at the authors' institution in the past year. The patients had symptoms of chronic or recurrent pulmonary infections, and two experienced coughing after swallowing. Chest radiographs demonstrated refractory consolidation, with or without cavitation and frequently accompanied by an air-distended esophagus. Barium studies were diagnostic. All patients responded well to antibiotic and surgical therapy.     

Atypical pleural tuberculosis presenting as an isolated pleural tuberculoma

Pleural tuberculosis is the most common extrapulmonary manifestation of tuberculosis, and is generally characterized by an effusion. The effusion is usually unilateral and residual pleural thickening or calcification is also observed in some cases. Manifestations of multiple pleural tuberculomas without associated effusion and history of tuberculosis or antituberculous therapy are rare and an isolated pleural tuberculoma is exceedingly rare. Herein, we report the first documented case of an isolated pleural tuberculoma, diagnosed by chest CT and pathological findings. Although rare, an isolated pleural tuberculoma should be added to the differential diagnosis of focal nodular pleural tumors, particularly in areas of high tuberculosis prevalence.     

Double spinal dural arteriovenous fistulas

We present a patient with double spinal dural arteriovenous fistulas revealed by progressive myelopathy. Numerous dilated veins extending along the entire length of the spinal cord were found on MR imaging. Angiography showed a first spinal dural fistula at the level of T7 with descending venous drainage and a second spinal dural fistula at the level of T5 with ascending venous drainage. Both fistulas were cured by therapeutic embolization.     

Treatment of vertebral arteriovenous fistulas

Twenty patients with vertebral arteriovenous fistulas (eight spontaneous, six traumatic without vertebral artery transection, and six traumatic with vertebral artery transection) were treated by transvascular embolization techniques, resulting in complete fistula closure in all patients. The fistulas were located at C1-C2 in 45%, C2-C3 in 25%, C4-C5 in 15%, C5-C6 in 10%, and C6-C7 in 5%. Trauma was the most common cause: 30% followed knife wounds, 20% followed gunshot injuries, and 10% followed blunt trauma. Eight patients had spontaneous fistulas, two associated with fibromuscular dysplasia. Three patients-all with large, long-standing fistulas-developed neurologic deficits coincident with the abrupt closure of the fistula, which resolved with reestablishment of fistula flow. Two of these patients were treated by staged closure; the other one by gradual closure. In all three cases the result was complete fistula closure without neurologic sequelae. The remaining spontaneous fistulas were all closed by balloon embolization with preservation of the vertebral artery and without deficits. The six patients with traumatic fistulas without transection were cured by balloon embolization, without deficits; in four there was also preservation of vertebral flow. The other six patients had traumatic fistulas with transection and were all cured by balloon embolization with preservation of flow in two. Four patients required bilateral approaches to the fistula to achieve complete fistula closure. The only complication was a mild residual Wallenberg syndrome after occlusion of the posterior inferior cerebellar artery in the treatment of a transection located at C1. In our opinion, transvascular techniques are the treatment of choice for vertebral arteriovenous fistulas.