Radiology

Non operative treatment of cerebral aneyrysms by Endovascular coiling (GDC) using interventional neuroradiological techniques.

Dr. Manish Shrivastav

(Patients are cautioned that this information is for general use only. In case you have queries or need further details, please contact us at the telephone numbers given at the end of this note)

Aneurysms can be described as weaknesses in the arterial wall causing them to bulge and ultimately rupture. At times, these aneurysms involve the entire circumference of the vessel and result in what is called "Fusiform" aneurysm (fig.) When only a part of the circumference (i.e. one of the walls) is involved the result is a "Saccular" or a "Berry" aneurysm. (fig.)

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Once subarachnoid hemorrhage occurs, the patient usually suffers "The worst headache of his/her life", which may or may not be associated with nausea, vomiting, double vision, neck stiffness, focal neurological deficits, drowsiness and loss of consciousness.

Aneurysmal SAH is a medial emergency. Approximately 1/10th of these patients do not survive till they reach the hospital. One half of them succumb with in first 30 days after the SAH. Of the survivors, about half will suffer a permanent stroke. Strokes in SAH usually occur 8-15 days after the hemorrhage itself. This happens because the blood with in the subarachnoid space irritates the blood vessels on the surface of the brain causing them to become narrow and ultimately shut down unless treated. Treatment of patients with aneurysmal SAH therefore consists of blockage of the aneurysm so that it will not bleed again and preventing / treating vasospasm of brain blood vessels in order to maintain blood flow to the brain.

At times, the blood with in the subarachnoid space or the ventricular system of the brain may cause obstruction to the flow of cerebra spinal fluid (CSF) and result in a condition which is known as "Hydrocephalus".

Diagnosis of SAH is usually clinical and confirmed on a CT Scan, less commonly on MRI and rarely by lumbar puncture.

Digital Subtraction Angiography

Once a patient is diagnosed to have non traumatic SAH, he/ she needs to undergo an Cerebral Angiogram to find the cause of it. A cerebral angiogram can be a CT angiogram, MR angiogram (MRA). As of today DSA remains the "Gold-Standard" for diagnosis and planning of further treatment of aneurysms.

Cerebral DSA is a minimally invasive procedure which is usually performed by an "Interventional Neuroradiologist". During cerebral angiography a thin, flexible tube called a catheter is introduced into an artery (usually at the groin i.e. femoral artery) then steered through the vessels of the body into the artery involved by the aneurysm. This is performed in an angiography suite, under guidance of X-ray imaging to see the position of the catheter tip. A liquid medicine containing iodine salts (contrast) that can be seen on X-ray is injected through the catheter and radiographic pictures are taken. This gives detailed information about the location, size and shape of the aneurysm as well as a detailed anatomy of the artery from which the aneurysm arises. Once this information has been obtained, it can used to decide as to how that particular aneurysm needs to be treated.

Treatment options for Aneurysms

Two types of approaches are available for treatment of aneurysms i.e. one from outside (after opening the skull) using open surgical techniques (clipping) and the other from with in the blood vessel using 'Endovascular' techniques (coiling).

A surgical approach requires cutting the skull bone & creating an opening through which the surgeon's instruments can enter. The surgeon can then place a clip across the neck of the aneurysm, preventing it from rebleeding.

Endovascular treatment of an aneurysm is performed in the angiography suite and is called coiling. During this procedure a larger catheter (similar to the one used for diagnostic angiography) called "Guiding catheter" is placed in the artery in the neck after inserting it through a blood vessel in the graoin.. A smaller catheter called "microcatheter" is now passed through the guiding catheter into the aneurysm. This microcatheter is usually guided by a by a wire called "microguide wire". Once the microcatheter is placed in to the aneurysm, it is packed using Detachable platinum coils (fig.) so that the aneurysm is totally excluded from the circulation and the patient is protected from its rerupture. If the neck (i.e. the junction of the aneurysm with the main artery) of the aneurysm is narrow coiling can be done safely as described above. But if the neck is wide there are chances that the coils may fall back into the main artery and compromise the flow in the artery. In such cases the neck may be protected by using a balloon or a stent placed across the neck during coiling.

Once the coiling is done there are 2 important questions that need to be answered:
A) Will all symptoms go away after the aneurysm is coiled?

It is extremely important to understand that coiling of aneurysm doesn't repair areas of brain already injured by haemorrhage. The procedure of coiling would protect the aneurysm from rerupture.
This patient who has had a severe stroke due to subarachnoid haemorrhage may continue to need intensive medical care even after the aneurysm has been coiled. In addition there are 2 important sequels of SAH i.e.
1. Vasospasm which results in irritation and narrowing of blood vessels supplying the brain; This in turn may further damage the brain tissue. Vasospasm may need treatment by angioplasty (Mechanical - using balloon or chemical using medicine (Nimodepine)).
2. Hydrocephalus results from obstruction to flow of fluid with in the brain and may need treatment by drainage or shunting.

Here are two reports of treatment of cerebral aneurysms by endovascular coiling.

Case: 1

Clinical Profile:-
A 54-year-old lady presented to us with complaints of headache and giddiness over six days. She had a MRI of the brain which revealed subarachnoid hemorrhage.

Fig. 1

Following this, she was referred to us for cerebral angiography and further management.

Cerebral Angiography:-
The cerebral angiogram shows a small, saccular, narrow necked, berry aneurysm on the anterior-communicating artery.

Fig. 2a	Fig. 2b	Fig. 2c

The fundus of this aneurysm is seen to point superiorly and to the right. The right A1 segment was seen to be hypoplastic.

Management:-
After consulting the patient's relative, it was decided to treat the aneurysm by endovascular route i.e. by coiling

Under general anesthesia, a 6F guiding catheter was placed in the left ICA. SL-10 microcatheter was now navigated over a Dasher-14 wire into the aneurysm.

Fig. 3

The aneurysm was now packed using 4 detachable platinum coils. Post coiling angiogram shows complete exclusion of the aneurysm from the circulation with all arteries and their branches remaining patent.

Fig. 4a	Fig. 4b	Fig. 4c

Fig. 5a	Fig. 5b

Case: 1

Clinical Profile:

A 65-year-old lady presented with acute onset, severe and persistent headaches associated with neck pain for 2-3 days. She underwent a CT Scan of the brain, which did not show any significant abnormality. Following this, a lumbar puncture was done which showed the CSF to be xanthochromic i.e. strongly suspicious of subarachnoid hemorrhage. She was subjected to a cerebral angiogram that revealed a fairly large and wide necked, left PCoM aneurysm with the fundus pointing postero-laterally.

Fig. 1a	Fig. 1b	Fig. 1c

At this stage it was decided to treat her by surgical clipping. But the surgery was not successful due to technical difficulties and the patient was referred to for endovascular management.

Management:

A 6F guiding catheter was placed in the left ICA. A SL-10 microcatheter was navigated over a Dasher-14 wire into the aneurysm. The aneurysm was packed using seven detachable platinum coils. Post coiling angiogram showed an almost complete exclusion of the aneurysm from the circulation with a tiny neck residual

Fig. 2a	Fig. 2b	Fig. 2c

Fig. 3a	Fig. 3b

The patient tolerated the procedure well and was discharged on the 2nd postoperative day.

For further information, please contact Dr. Uday Limaye, Dr. W. Siddhartha or Dr. Manish Shrivastav at 24103906 or e-mail websitecontact@kem.edu