Subarachnoid Hemorrhage Microchapters |
Diagnosis |
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Treatment |
AHA/ASA Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage (2012)
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Case Studies |
Subarachnoid hemorrhage surgery On the Web |
American Roentgen Ray Society Images of Subarachnoid hemorrhage surgery |
Risk calculators and risk factors for Subarachnoid hemorrhage surgery |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]; Sara Mehrsefat, M.D. [3]
Surgical clip of intracranial aneurysms was the primary modality of treatment before 1991. Occlusion of an aneurysm by an endovascular approach with electrolytically detachable coils was first described by Guglielmi.[1][2]
Surgical clip of intracranial aneurysms was the primary modality of treatment before 1991. Occlusion of an aneurysm by an endovascular approach with electrolytically detachable coils was first described by Guglielmi.[1][2]
Following a craniotomy, the small clip is placed across the base, or neck, of the aneurysm in order to block the normal blood flow. The main purpose of surgical clipping is to isolate an aneurysm from the normal circulation without blocking off nearby arteries.[1]
Endovascular coiling is a minimally invasive technique, which is not required craniotomy to treat the brain aneurysm. The catheter is used to reach the aneurysm in the brain and is passed through the groin up into the aneurysm. The coils, which made of platinum, induce clotting of the aneurysm and as a result it prevent blooding. The coil is left in place in the aneurysm and sometimes more than one coil may be needed to completely seal off the aneurysm.[1]
Those patients with a large hematoma, depressed level of consciousness or focal neurology may be candidates for urgent surgical removal of the blood or occlusion of the bleeding site. The remainder are admitted and stabilized more extensively, and undergo an transfemoral angiogram or CT angiogram at a later stage. In those where the bleeding is from an aneurysm (as opposed to non-aneurysmal perimesencephalic hemorrhage), most neurosurgical centers use either coiling or clipping of the aneurysm to prevent rebleeding. After the first 24 hours, rebleeding risk is about 40% over four weeks, suggesting that interventions should be aimed at reducing this risk.
Currently there are two treatment options for brain aneurysms: surgical clipping or endovascular coiling. Surgical clipping was introduced by Walter Dandy of the Johns Hopkins Hospital in 1937. It consists of performing a craniotomy, exposing the aneurysm, and closing the base of the aneurysm with a clip.[7] The surgical technique has been modified and improved over the years. Surgical clipping remains the best method to permanently eliminate aneurysms. Endovascular coiling was introduced by Guido Guglielmi at UCLA in 1991.[8] It consists of passing a catheter into the femoral artery in the groin, through the aorta, into the brain arteries, and finally into the aneurysm itself. Once the catheter is in the aneurysm, platinum coils are pushed into the aneurysm and released. These coils initiate a clotting or thrombotic reaction within the aneurysm that, if successful, will eliminate the aneurysm. In the case of broad-based aneurysms, a stent is passed first into the parent artery to serve as a scaffold for the coils ("stent-assisted coiling").
Presently it appears that the risks associated with surgical clipping and endovascular coiling, in terms of stroke or death from the procedure, are the same. The major problem associated with endovascular coiling, however, is the high recurrence rate and subsequent bleeding of the aneurysms. For instance, a major French study reported in 2007 indicates that 28.6% of aneurysms recurred within one year of coiling, and that the recurrence rate increased with time.[9] These results are similar to those previously reported by other endovascular groups; a series from Canada reported in 2003 found that 33.6% of aneurysms recurred within one year of coiling.[10] The long-term coiling results of one of the two prospective randomized studies comparing surgical clipping versus endovascular coiling (the International Subarachnoid Aneurysm Trial or ISAT), too, suggest that the need for late retreatment of aneurysms is 6.9 times more likely for endovascular coiling as compared to surgical clipping.[11]
Therefore it appears that although endovascular coiling is associated with a shorter recovery period as compared to surgical clipping, it is also associated with a significantly higher recurrence and bleeding rate after treatment. Patients who undergo endovascular coiling need to have annual studies (such as MRI/MRA, CTA, or angiography) indefinitely to detect early recurrences. If a recurrence is identified, the aneurysm needs to be retreated with either surgery or further coiling. The risks associated with surgical clipping of previously-coiled aneurysms are very high. Ultimately, the decision to treat with surgical clipping versus endovascular coiling should be made by a cerebrovascular team with extensive experience in both modalities. At present it appears that only older patients with aneurysms that are difficult to reach surgically are more likely to benefit from endovascular coiling. These generalizations, however, are difficult to apply to every case, which is reflected in the wide variabilty internationally in the use of surgical clipping versus endovascular coiling.
Medical treatment is available to both reduce the risk of repeat bleeding, and to treat a serious complication of SAH called vasospasm. In the case of spontaneous SAH from an aneurysm, there is a significant risk of repeat bleeding until definitive surgical intervention can be performed. During this waiting period medical treatments to control blood pressure, bed rest, and a quiet environment reduce the risk of rebleed.
Class I |
"1. Surgical clipping or endovascular coiling of the ruptured aneurysm should be performed as early as feasible in the majority of patients to reduce the rate of rebleeding after aSAH (Level of Evidence: B)" |
"2. Complete obliteration of the aneurysm is recom- mended whenever possible (Level of Evidence: B)" |
"3. Determination of aneurysm treatment, as judged by both experienced cerebrovascular surgeons and endovascular specialists, should be a multidisciplinary decision based on characteristics of the patient and the aneurysm (Level of Evidence: C)" |
"4. For patients with ruptured aneurysms judged to be technically amenable to both endovascular coiling and neurosurgical clipping, endovascular coiling should be considered (Level of Evidence: B)" |
"5. In the absence of a compelling contraindication, patients who undergo coiling or clipping of a ruptured aneurysm should have delayed follow-up vascular imaging (timing and modality to be individualized), and strong consideration should be given to retreatment, either by repeat coiling or microsurgical clipping, if there is a clinically significant (eg, growing) remnant (Level of Evidence: B)" |
Class III (Harm) |
"1. Stenting of a ruptured aneurysm is associated with increased morbidity and mortality, and should only be considered when less risky options have been excluded (Level of Evidence: C)" |
Class IIb |
"1. Microsurgical clipping may receive increased con- sideration in patients presenting with large (>50 mL) intraparenchymal hematomas and middle cerebral artery aneurysms. Endovascular coiling may receive increased consideration in the elderly (70 years of age), in those presenting with poor-grade (World Federation of Neurological Surgeons classi- fication IV/V) aSAH, and in those with aneurysms of the basilar apex (Level of Evidence: C)" |