Endovascular treatment of ruptured cerebral bacterial aneurysm: Parent artery occlusion with Glue.

Case 12 : contributed by Dr. Sharad

Other Cases

Case Report :

A 17-year-old lady presented with sudden onset giddiness and headache. On MRI examination, she had a left parietal hematoma with minimal mass effect and perilesional edema .There was a flow void noted within the hematoma (fig.1 and 2). She was drowsy with Glasgow coma scale of 10/15 .On diagnostic angiogram, we found a small aneurysm on the posterior parietal branch of the left MCA compatible in appearance with a mycotic aneurysm with an area of avascularity around - this being consistent with the heamatoma (fig.3,4) In consultation with the neurosurgeon, it was decided to go ahead with endovascular treatment. The necessary consent was obtained.

Fig 1	Fig. 2
Fig. 3	Fig. 4

Endovascular procedure:

The procedure was done under general anesthesia and systemic heparinisation. Right femoral arterial access was secured. A 6F Guiding catheter (CORDIS-Envoy) was placed in the left internal carotid artery. A 1.5F micro catheter (MTI- Flowryder) was negotiated and placed in the posterior parietal branch of the left MCA close to the aneurysm. The aneurysm and short segment of the parent vessel were selectively embolised using Histacryl Glue (B-Braun, Germany) ( fig.5 ). Post embolisation angiogram showed complete exclusion of the aneurysm from the circulation ( fig.6 ). Following the procedure, the patient did not have any neurological deficit. She was put on broad spectrum antibiotics. Echocardiography was normal. There was no sign of sinusitis or mastoiditis. CSF study was suggestive of pyogenic meningitis. A follow up CT scan was done two days after the embolisation. It showed the glue cast in the aneurysm, with resolving heamatoma (fig. 7).

	Fig 5	Fig 6
	F7

Discussion :

Endovascular therapy for ruptured mycotic aneurysms has been reported in three cases by Khayala et al; in one case by Frizell et al and three cases by G. Scotti et al. The aim is to treat both the ruptured aneurysm and it's cause. Traditionally, these have been treated by surgical evacuation of the heamatoma with parent artery ligation. Surgical management is not always possible in case of distal or deep location .Endovascular management includes occlusion of the aneurismal sac and a segment of parent artery. The modes of treatment available are GDC , glue and autologous clot embolisation.

Bacterial intracranial aneurysms occur most frequently on the middle cerebral artery or it's distal branches , less commonly on the posterior and anterior cerebral arteries. Large arteries are rarely affected. They constitute 2.5-6.2% of all intracranial aneurysms, appearing clinically in 2% of cases of bacterial endocarditis and 5-15% at autopsy. The pathogenesis of bacterial aneurysm is believed to start when an infected embolus lodges at some point in the vessel wall. The wall gets weakened by the propagation of infectious process into the media and adventitia. The pulsations against the necrotic ,weakened wall further damages the wall leading to aneurysmal dilatation. These aneurysms can be further divided into three types: embolic origin aneurysms secondary to bacterial endocarditis, affecting mainly the middle cerebral artery; extra vascular origin aneurysms secondary to extension of infection from a neighboring septic focus affecting mainly large arteries such as the intracavernous carotid artery and primary bacterial aneurysms occurring in the absence of an obvious inflammatory focus elsewhere in the body.

In an experimental study in dogs, bacterial aneurysms formed in 1-3days after lodging of an infected embolus in a cerebral vessel without antibiotics treatment .With treatment aneurysms develop in 7-10 days.

In same patients, aneurysms may resolve or decrease in size with medical treatment alone .However Bohmfalk et al pointed out the high mortality (44%) in patient treated with antibiotics alone and lower mortality (23%) in patient who were treated by antibiotics and elective surgery.

With rapidly improving catheter technology, distal intravascular navigation is now becoming possible with safety and efficacy. Endovascular obliteration of distal mycotic aneurysms is now a feasible, safe and effective treatment option. It avoids craniotomy, surgical dissection and handling of swollen brain. In our opinion it should be the primary treatment option in mycotic aneurysms which require surgical therapy.