Cognitive Damage from SAH May be Less with Coiling Than Clipping
Abstract & Commentary
Source: Hadjivassiliou M, et al. Aneurysmal SAH. Cognitive outcome and structural damage after clipping or coiling. Neurology. 2001;56:1672-1677.
Hadjivassiliou and colleagues compared cognitive outcome and structural damage in patients with aneurysmal subarachnoid hemorrhage (SAH) treated in a nonrandomized manner either by surgical clipping (SC) or endovascular coiling (EC).
Forty case-matched pairs of patients with SAH who underwent SC or EC at 2 university hospitals in the United Kingdom during 1995 and 1996 were followed prospectively. Case matching was based on the following: World Federation of Neurologic Surgeons grade (Drake CG. J Neurosurg. 1998;68:985-986) on admission, age, location of aneurysm, and extent of SAH on CT scan. All patients underwent neuropsychological assessments at 1 year after treatment. Twenty-three case-matched pairs also underwent brain MRI at 1 year (see Table).
| Table: MRI Results at 1 Year | |||
| Brain Lesion | Surgery (n = 23) |
Coiling (n = 23) |
P |
| Infarction | 20 | 13 | < 0.05 |
| Surgical Damage (Focal Encephalomalacia) | 19 | 0 | < 0.001 |
| White Matter Hyperintensities |
15 | 19 | NS |
Both SC and EC groups were impaired in all cognitive domains when compared with age-matched healthy control subjects. The surgical group scored significantly worse than the endovascular group in 4 tests: the semantic fluency test, the vocabulary subtest of the WAIS-R (Weschsler D. WAIS-R Manual. New York: The Psychological Corporation, 1981), the complex figure recall test, and the extradimensional stage of the intradimensional/extradimensional shift test from the Cambridge Automated Neuropsychological Test Battery (Sahakian BJ, Owen AM. JR Soc Med. 1992;85:399-402).
On MRI, the prevalence of large vessel infarcts probably caused by vasospasm-induced ischemia was the same in both groups (SC, n = 8; EC, n = 9).
The surgical group, however, had a significantly larger number of patients with a single or multiple small infarcts (SC, n = 12; EC, n = 6) possibly due to compromise of adjacent perforating arteries during exposure and clipping of the aneurysm.
Hadjivassiliou et al conclude that although overall cognitive outcome after SAH primarily is determined by the characteristics of the initial hemorrhage, SC causes more structural damage and cognitive defects than EC.
Commentary
The results of this study are sure to be embraced by interventional radiologists and patients’ advocacy groups, just as they will be disputed by neurosurgeons. Nevertheless, the small number of patients enrolled and the major design flaws of the study (all patients having surgery were treated at Sheffield and all patients having endovascular procedures were at Oxford; all MRIs were read by the same neuroradiologist who could not be blinded because of the characteristic MRI appearances produced by the 2 procedures) should temper enthusiasms and prevent a firm clinical judgment at this time.
This interesting report is a foretaste of a larger, multicenter, randomized comparison of SC and EC—the International Subarachnoid Hemorrhage Trial that may revolutionize our approach to SAH. —John J. Caronna
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