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Aneurysm – Coiling and Stent


Brain aneurysms are commonly treated using endovascular techniques with placement of coils within the aneurysm or stents inside blood vessels in the brain. This means that aneurysms are not treated using conventional surgery (i.e. via incision in the skull) and placement of a clip on the outside of an aneurysm. Coils, stents or other devices inside the aneurysm or surrounding blood vessels are delivered using a catheter (a thin tube) travelling internally through the blood vessel system. Access into the blood vessel is typically through the femoral artery in the groin / hip.

Apart from the small incision in the groin to access a blood vessel, no other incision is required. The procedure is classified as a minimally invasive technique and uses specialised X-ray equipment to guide catheters and other devices into the aneurysm.


Endovascular coiling and brain stents are both used to treat ruptured and unruptured brain aneurysms. Studies have shown that this endovascular approach leads to improved outcomes over alternative approaches, such as aneurysm clipping (at least over the short term, i.e. within a year of treatment), especially in ruptured aneurysms. The best approach in each case is based upon an assessment of the size, shape and location of the aneurysm, as well as the age and general health of the patient (clipping for example may be a better option for younger, healthier patients and broad-based aneurysms).

Preoperative Instructions

Where the procedure is to treat an unruptured aneurysm (a ruptured aneurysm is treated as a medical emergency), you should…

  • Stop eating or drinking anything after midnight the night before the procedure (You can still take medications with small sips of water before the procedure.
  • Let our office know if you take regular blood thinners. Some blood thinners (such as aspirin and Plavix) may be continued, while other medications (such as warfarin) may need to be stopped. Your doctor will advise you about taking these blood thinners ahead of the procedure.
  • For stent procedures, you will need to take specific blood thinners at least 1 week prior to surgery. Your neuro-interventional surgeon will instruct you on these medications.
  • As much as possible, postpone dental treatment (within three weeks) or any other form of surgery (within three months) until after the planned procedure.
  • If you develop any symptoms of infection, e.g. a cold or flu, before surgery, or if you are receiving treatment for an infection, you may need to postpone your procedure, so please inform our office as soon as possible.


The procedure can be carried out under general anaesthesia. A tube or sheath is placed in the groin artery as an entry point. The catheter is inserted via this entry point and gently guided into position near the aneurysm using real time x-ray images from an angiogram. Another small catheter (called a microcatheter) is then pushed through the main catheter, and gently placed into the inside of the aneurysm. Through the microcatheter, a series of soft, miniscule platinum coils (these are made of wire roughly the width of a human hair in diameter) is moved into the aneurysm itself. These coils remain permanently in the aneurysm and induce clotting of blood inside the aneurysm (‘thrombosis’), which prevents any more blood from entering the aneurysm. Sometimes, a microcatheter balloon is placed parallel to the coiling microcatheter to support the coils as they are delivered (‘balloon-assisted coiling), and the balloon is removed once the aneurysm coiling is completed. When the surgeon has verified that blood flow into the aneurysm has stopped, the catheter is gently withdrawn and the entry point incision is closed with a small stitch or plug.

Where the 'neck' of the aneurysm is wide, a stent (a hollow tube made of metal mesh) may be inserted in the affected section of the blood vessel to make sure the coils remain secure inside the aneurysm. Recently, more advanced stents (‘flow-diverter’) have been developed that promote blood flow away from aneurysms, leading to gradual clotting of the aneurysm without placement of coils at all.

Newer technologies are becoming available, such as ‘intrasaccular devices’, but the long-term effectiveness of these devices is not fully known yet.

Postoperative Instructions

Where the aneurysm has not ruptured, patients are generally able to return home the day after the procedure; if the aneurysm has ruptured the hospital stay is longer, generally 2-3 weeks.

It is advisable…

  • Not to go swimming or take hot baths or similar for 3 days after the procedure (showering after 24 hours is permissible).
  • Not to drive until the 3-days post operatively.
  • Not to lift anything heavier than 4kg for 1 week.
  • Not to return to work for 1-2 weeks.

You should seek immediate medical assistance if any of the following occur after returning home…

  • Sudden severe headache (symptoms of a brain aneurysm rupture).
  • Nausea (symptoms of a brain aneurysm rupture).
  • Vomiting (symptoms of a brain aneurysm rupture).
  • Stiff neck (symptoms of a brain aneurysm rupture).
  • 'Popping' sensation in the head (symptoms of a brain aneurysm rupture).
  • Bleeding or large bruising in the groin near the entry point (these are signs of leaking from the femoral artery).
  • Redness / swelling / pain / discharge near the entry point incision (these are signs of possible infection).


The risks listed below are uncommon with this procedure, however they may occur…

  • Blood clots within the brain blood vessels, leading to stroke.
  • Rupture of aneurysm.
  • Rupture of aneurysm.
  • Coil/s moving out of position.
  • Coil/s not fully blocking the neck of the aneurysm.
  • Consequences of ruptured aneurysm – Vasospasm (narrowing of an artery) or Hydrocephalus (Blockage of cerebrospinal fluid flow).

Treatment Alternatives

Aneurysm clipping is an alternative surgical treatment for brain aneurysms.

Related Information

Brain Aneurysms