Contrast extravasation

The neurointerventionalist should limit the number of microcatheter injections performed during the exam, as there is growing evidence that this may increase the chances of hemorrhagic transformation of the infarcted tissue. Direct injection of contrast into stagnant vessels, which contains injured glial cells and thus breakdown of the blood-brain barrier, allows for contrast extravasation. Contrast is readily visualized on the immediate post-thrombolysis CT as an area of high attenuation in the parenchyma. In some instances, MRI with susceptibility-weighted sequences may be useful to differentiate contrast extravasation from Such a distinction... 

Table 5.2. Contrast extravasation/aneurysm in upper GIH technique of embolization according to vascular anatomy...

Particulate embolization is an option when contrast extravasates and the bleeding branch is beyond the reach of superselective catheterization (Fig. 5.7). Non-calibrated polyvinyl alcohol particles (PVA) in sizes of 150-250 [i to 250-350 p or even larger should be used. The amount of particles should be kept as low as possible to avoid diffuse distal embolization. After each injection of 0.1-0.2 ml (up to a maximum of 1 ml) of a dilution of PVA, control arteriography should verify that the bleeding point has been... 

When discussing the results of LGI embolization one must understand the difference between technical and clinical success. The successful deposition of embolic material in the intended target artery, with occlusion of flow and termination of contrast extravasation is the general definition of technical success. Clinical success on the other hand is successful termination of bleeding as evidenced by no further bloody output, stable vital signs without pressors, and a stable hematocrit. 

A transient encephalopathy has been reported after the use of an iodinated contrast medium in a neurointerventional procedure with development of psychomotor agitation, disorientation, and progressive left faciobrachial hemiparesis 30 minutes after successful treatment of a right carotid-ophthalmic fusiform aneurysm [6 ]. A CT scan showed marked cortical enhancement and edema in the right cerebral hemisphere, thought to be due to contrast extravasation after disruption of the blood-brain barrier. Treatment with dexa-methasone and maimitol produced complete recovery. 

Fig. 10.8a,b. Postraumatic high-flow priapism. Imaging features with multidetector-row CT angiography, a Coronal image showing iodinated contrast extravasation within the right corpus cavernosum (arrowhead), b 3D reconstruction of the vascular supply to the penis on the right side, from the pudendal artery to the cavernosal artery tear (arrowhead)... 

Proximal Embolization In the absence of active contrast extravasation, the splenic artery is proximally embolized. We typically utilize either a 5F Cobra catheter or a 5F Omni-2 catheter to catheterize the celiac axis. Depending on the tortuosity of the vessel, we then either use the Cobra catheter or a microcatheter with a 0.021 inner luminal diameter for more selective catheterization. Once the catheter is in place, just distal to the dorsal pancreatic artery, coils are deposited. The size of the coils chosen depends on the size of the vessel. 

Fig 5.1a,b. Fifty-year-old female was an restrained driver involved in a road traffic accident traveling at 50 mph. She was hemodynamically stable when the initial pelvic CT was performed, a Contrast-enhanced CT of the pelvis shows right pelvic fractures and active contrast extravasation (arrow) with mass effect on the bladder. This finding prompted angiographic study of the internal iliac arteries, b Selective angiogram of the right internal iliac shows no contrast extravasation. As the patient was hemodynamically stable, no embolization was performed. 

Once abdominal hemorrhage has been ruled out by FAST, CT, or DPI with continued hemodynamic instability or if contrast extravasation is demonstrated on CT the patient should be transferred to the angiography suite. It is imperative that the resus-citative process is not impeded by this transfer, and that a full complement of clinical staff accompany the patient during angiography and embolization. 

Arterial cut-off Mural irregularities or flap Laceration Thrombosis Dissection Free-flow contrast extravasation Stagnant intraparenchymal accumulation of contrast Parenchymal blush Stagnant arterial or venous flow Diffuse vasoconstriction Pseudoaneurysm Arteriovenous fistula Vessel displacement Free-flow contrast extravasation Stagnant intraparenchymal accumulation of contrast Disruption of visceral contour Displaced organ Intraparenchymal avascular zones... 

Fig. 8.4. a Nonselective celiac angiogram in a patient with a large splenic pseudoaneurysm after trauma. Note the marked vasospasm and contrast pooling in the left upper quadrant, b Coaxial use of a microcatheter to obtain access distal to the neck of the pseudoaneurysm despite the vasospasm, c Follow-up splenic angiogram after coil embolization of the splenic artery. No further contrast extravasation was noted and the patient s vitals stabilized. (Courtesy of James R. Duncan, MD)... 

Embolization of massively bleeding duodenal ulcers constituted 5% of endoscopically treated duodenal ulcers and as little as 0.6% of all cases with upper gastrointestinal bleeding who underwent emergency endoscopy in one large series. Contrast extravasation was demonstrated in only half of these cases. Embolization did however induce haemostasis in 90% of cases (Toyoda et al. 1995). Prophylactic embolization of the GDA is sometimes performed with success (as in this series) even when no angiographic abnormality is demonstrated despite a proven endoscopic source of haemorrhage. 

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