Coiling versus Clipping Subarachnoid Haemorrhages

Coiling versus Clipping Subarachnoid Haemorrhages

A 40 year old female presented with a severe sudden onset headache, and deteriorated in the emergency department with worsening agitation and confusion requiring intubation and ventilation for her own safety. A CT scan diagnosed a Fisher Grade 4 subarachnoid haemorrhage and obstructive hydrocephalus. Clinical presentation was scored as Hunt and Hess grade 4 or World Federation of Neurosurgeons grade 4. The patient was transferred to the local tertiary Neurocritical care unit where an extra-ventricular drain was inserted overnight. The following day the patient underwent coiling of her right middle cerebral artery aneurysm in the radiology suite. A Magnesium infusion and Nimodipine therapy were commenced to reduce the risk of vasospasm. On initial sedation hold she woke up agitated so she had an early tracheostomy placed to allow controlled wake up. She had a straightforward respiratory wean from the ventilator over the next few days. Neurological recovery was good (Glasgow coma score improved to 14/15) and the patient was discharged to the ward for on-going neuro rehabilitation and repatriation to the base hospital.

What are the risks of clipping vs coiling subarachnoid haemorrhages?

Katherine Francis

Subarachnoid haemorrhage carries up to a 50% mortality rate, with 15% of patients not surviving to hospital admission. It drives a surge in catecholamine release, which can lead to multi-organ injury. The cause of acute subarachnoid haemorrhage is predominantly traumatic but can be due to berry aneurysms.

The securing of an intracerebral aneurysm is vital to reduce the risk of re-bleeding. Two options are available, radiological coiling or surgery and the placement of clips across the neck of the aneurysm. Clipping requires a craniotomy to locate the aneurysm, followed by the placement of clips around the neck of the aneurysm. Coiling is performed endovascularly: a catheter is inserted into the femoral artery in the groin and advanced through the aorta to the arteries (both carotid arteries and both vertebral arteries) that supply the brain. When the aneurysm has been located, platinum coils are deployed that cause a blood clot to form in the aneurysm, obliterating it.

Whilst interventional radiology is a growing speciality, and far less invasive than neurosurgical intervention, there are various contra-indications to endovascular treatment. The decision regarding the modality of treatment is dependent on many factors, including the age and condition of the patient, the size of the aneurysm, the shape of the aneurysm, and the location of the aneurysm.

Kunz et al (1) studied the impact of intra-procedural rupture (IAR) and peri-procedural ischaemia with respect to both radiological and surgical treatment in 563 patients (200 surgical, 363 endovascular). The risks of intra-procedural rupture and peri-procedural ischaemia are linked with a morbidity rate of 4.9 and 6% respectively (1). The study showed a mortality rate of 0.7% with endovascular treatment (4 patients), but no procedure related death linked to microsurgery. Intra-procedural aneurysm rupture occurred in 9.4% of the surgical cases, a significant difference from the 4% for endovascular procedures, and risk factors for IAR were age, aneurysm diameter, symptomatic aneurysms, smoking (surgery only) and hypertension. Peri-procedural ischaemia (12.1 vs. 9 %) resulted in significantly worse outcome in both groups. Risk factors for peri-procedural ischaemia were IAR during microsurgery, aneurysm diameter, symptomatic aneurysms and smoking in either group. Whilst endovascular treatment had a lower incidence of aneurysmal rupture in the study, the outcome was significantly worse than if rupture occurred during neurosurgical intervention, with associated increased mortality.

Molyneux and the International Subarachnoid Aneurysm Trial (ISAT) Collaborative group undertook a randomized multicenter trial to look at the safety and efficacy of endovascular coiling compared to the standard neurosurgical clipping specifically in ruptured aneurysms (2). 2143 patients were recruited, with approximately equal study arms (1070 underwent surgical clipping, 1073 had endovascular coiling). The outcome was defined in terms of survival free from disability, and this was significantly better with endovascular coiling (23.7% compared to 30.6%). Although there was a small long term risk of re-bleed with either therapy, this was slightly higher with endovascular coiling.

Previously aneurysms with a branch artery incorporated in the sac of the aneurysm have been a contraindication for coiling, because of the risk of occlusion. Kim et al (3) looked retrospectively at coiling of aneurysms involving a branch artery incorporated into the sac. They achieved successful coiling in 78 of 79 aneurysms (26 ruptured, 52 unruptured) with the abandonment of one procedure due to incorporated branch occlusion. Acceptable outcomes were achieved in 89%, with 6 major recurrences in follow up angiography, all of which were retreated successfully.

Mortality in ruptured SAH remains high, although it is slightly skewed by those patients that don’t survive to hospital admission. A review in Thailand (4) of 225 cases concluded that patients with a WFNS grade 3-5 only had a favourable outcome (classed as good recovery/ moderate disability) in 34% of cases, with 66% of patients left with severe disability, persistent vegetative state or died.

In Qian’s study of 664 patients (5), a statistical significance was shown in good outcome between those who were treated with early endovascular therapy (within 24 hours) compared with those who waited 4-10 days for their coiling procedure. (78% vs 57% retrospectively.)


Lessons learnt

This was an interesting case because on paper the initial presentation, CT scan (Fisher grade 4) and presence of hydrocephalus indicated high chance of a poor neurological recovery. However the patient received swift resuscitation care from the emergency department and early transfer to a neurosurgical centre. As a relatively young patient to suffer a subarachnoid haemorrhage, she was treated aggressively and her aneurysm was secured early, with the least invasive option. This allowed a sedation hold and assessment of her neurological status. She suffered no obvious complications and made a good recovery.


References

  1. Kunz M, Bakhshai Y, Zausinger S et al. Interdisciplinary treatment of unruptured intracranial aneurysms: impact of intraprocedural rupture and ischemia in 563 aneurysms. J Neurol. 2012 Dec 23.
  2. A Molyneux, ISAT collaborative group. International Subaracnhoid Aneurysm Trial of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomized trial. Lancet 2002 Oct: 360; 1267-74
  3. B M Kim, S I Park, D J Kim et al. Endovascular coil embolisation of aneurysms with a branch incorporated into the sac. AJNR 2010 31: 145-151
  4. W Watcharasaksilp, K Limpastan, T Norasathada et al. The result of surgical treatment in patients with cerebral aneurysms in Maharaj Nakorn Chiang Mai Hospital: a report of 225 cases. J Med Assoc Thai 2013 Jul;96(7):814-8.
  5. Z Qian, T Peng, A Liu et al. Early timing of Endovascular Treatment for aneurysmal Subarachnoid Haemorrhage improves outcomes. Curr Neurovasc Res 2013 Dec 9 (EPub).
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