Bowstring Phenomenon in Renal Artery Aneurysm Exclusion Using a Viabahn Stent Graft

A 77-year-old man presented with an incidental finding of right renal artery aneurysm without symptoms. Computed tomography revealed a 22 mm saccular aneurysm with a wide neck at the main renal artery trunk. An 8 × 100 mm Viabahn stent graft (W. L. Gore, Flagstaff, AZ) was deployed by fully pulling back the guiding sheath. However, the deployment knob was not able to be pulled. We returned the guiding sheath to the original position and confirmed the cause was the bowstring phenomenon. Because avoidance of this phenomenon required straightening of the tortuous vessel, the stent graft was deployed by short pull-back of the guiding sheath. Computed tomography after a year revealed no opacification of the aneurysm and the patency of the stent graft.

Accordion effect: A red herring during percutaneous angioplasty of arteriovenous dialysis access

Accordion or concertina effect is the angiographic appearance of pseudostenosis caused by interaction of a stiff guidewire with a tortuous vessel during endovascular procedures. This phenomenon may often mislead the interventionist into performing unnecessary and potentially harmful procedures in a bid to treat the ‘stenotic’ lesion. The resolution of ‘stenosis’ on withdrawal of the guidewire clinches the diagnosis. While well described in coronary vessels, the occurrence of this phenomenon in arteriovenous fistula or graft has not been reported. We describe a case of accordion effect observed during endovascular intervention for arteriovenous graft salvage.

Concertina Phenomenon in the Left Anterior Descending Artery: An Unexpected Circumstance in an Unexpected Vessel

The concertina phenomenon is the occurrence of new and transient angiographic series of pseudolesions in a tortuous vessel induced mainly by a stiff guide wire. Here, we describe a 53-year-old man who experienced a concertina effect in the left anterior descending coronary artery (LAD) during an elective percutaneous coronary intervention. After the diagnosis of the concertina phenomenon in the LAD, a percutaneous coronary intervention was performed following the withdrawal of the soft guide wire to the mid level of the LAD. After the intervention, the patient remained in very good clinical status and was discharged on the third postprocedural day.

Dopplervelocimetric evaluation of portal vein as a diagnostic tool for portosystemic shunt diagnosis in dogs

The objective of this research was to verify if the study of portal hemodynamic parameters through duplex Doppler ultrasonography (DUS) is able to help to detect portosystemic shunt (PSS) and the shunted vessel origin. It was detected PSS in 20 dogs by abdominal DUS and confirmed at surgery or necropsy from March of 2004 until March 2007. Main ultrasonographic findings were: identification of a tortuous vessel shunting portal flow being: portocaval shunt (16/20 or 80%), esplenocaval shunt (2/20 or 10%), gastrocaval shunt (1/20 or 5%), portoazigo shunt (1/20 or 5%); 2) elevated portal flow velocity before shunt (17/20 or 81%), 3) lower portal flow velocity after shunt (17/20 or 81%), 4) turbulence in the caudal vena cava (10/20 or 47,5%) and 5) reduced liver size (15/20 or 71%). The others ultrasonographic findings associated with clinical records were similar to that described in literature. With this work we could conclude that hemodynamic assessment of portal vein with DUS may be a useful tool for PSS diagnosis and to detect the shunted vessel origin.

Stenting Both before and after Coiling of a Ruptured Fusiform Basilar Aneurysm to Overcome Mechanical Occlusion Caused by Thrombosis within the Coil Mass

Tortuous vessel anatomy reconstructed by stent-assisted coiling may be kinked by thrombus expansion within the coil mass. This can be overcome by placement of a second stent.

A Case of Vertebrovertebral Arteriovenous Fistula Presenting with Subarachnoid Haemorrhage

A rare paediatric case of vertebrovertebral arteriovenous fistula presented with a subarachnoid haemorrhage. A 12 year-old boy, who fell on his back at school, presented with a one week history of headache, vomiting, and double vision. Computed tomography (CT) scan revealed subarachnoid haemorrhage. Magnetic resonance imaging (MRI) demonstrated a tortuous vessel on the anterior surface of the spinal cord. Selective angiography showed an arteriovenous fistula of the left vertebral artery at the level of C1. The venous drainage of the fistula refluxed into the medullary vein at the level of C6-7, and drained upwards into the posterior fossa veins. An endovascular detachable balloon technique was employed and complete occlusion of the fistula was achieved.