Written by Emily Majorkiewicz
An aneurysm is defined as a weakened blood vessel wall that bulges in response to blood vessel damage. If ruptured, aneurysms can lead to haemorrhaging that causes confusion, changes in cognition, and in extreme cases, brain death [1]. In the last decade, a number of treatments have become available to treat aneurysms before they burst and potentially hemorrhage. In this review, traditional clipping and coiling treatments will be compared with the newer pipeline embolization technique for both new and recurrent aneurysms.
Although these procedures have become common for treating aneurysms, both pose considerable risks. For the clipping treatment, a neurosurgeon makes an incision in the scalp and then dissects the necessary layers of bone and brain to reach the location of the aneurysm [2]. A clip is then placed across the aneurysm at the location where it begins to bulge out, relieving pressure and preventing blood flow from entering the bulge. For the coiling procedure, an angiogram is used to insert a catheter into a blood vessel around the hip area and then navigated into the blood vessels of the brain [3]. Through this passageway, a coil is packed tightly into the aneurysm to prevent blood flow into the bulge.
Initial clipping or coiling treatment for a never-before treated aneurysm may lead to different post-operative symptoms. After receiving the initial clipping procedure, 68 patients were found to take up to one year to fully recover when compared to coiling patients, who only needed about 30 days [4]. Complications were also more prevalent among the clipping patients. Such findings suggest that although both forms of treatment can be effective, there are still risks, especially for the clipping procedure. However, one new procedure developed within the last decade may be a better option.
The Pipeline Embolization device, designed to treat large neck intracranial aneurysms, is a new procedure that aims to divert blood flow away from the weakened portion of the blood vessel through a braided mesh pipe [5]. Through time, the original artery is reconstructed and the natural blood flow is restored. Unlike the previous treatments, the pipeline device promotes restructuring of the original blood vessel, which aims to eliminate future necessity of treatment. In a clinical study, out of 108 patients who had a large intracranial aneurysm within the internal carotid artery, none experienced recurrence of an aneurysm after blood vessel occlusion [5]. Furthermore, none of those patients had experienced any stroke or neurological death when they were evaluated from the time period of 6 months to 5 years post-procedure, and after 5 years the originally weakened blood vessel had undergone 95% occlusion [5].
Such an ideal outcome may seem almost too good to be true. But clinical trials have proven this device extremely effective, especially in treating large aneurysms that can be greater than 20 to 25 millimeters in size. All in all, it seems that compared to traditional clipping and coiling treatments, the Pipeline Embolization device is promising to patients who have recurrent and new aneurysms. However, more long-term studies will be necessary to explore the lasting results for patients who have undergone pipeline embolization.
References:
[1] Macon, B.L., Sloan, M. “Aneurysm: Causes, Symptoms, and Diagnosis.” Healthline. Healthline Media, 11 Dec. 2015. Web. 10 June 2017.
[2] Yue, W. Endovascular Treatment of Unruptured Intracranial Aneurysms. Interv Neuroradiol. 2011. 17(4): 420-424.
[3] Johnston S.C., Dudley, R.A., Gress, D.R., Ono, L. Surgical and Endovascular Treatment of Unruptured Cerebral Aneurysms at University Hospitals. Neurology. 1999. 52: 1799-1805.
[4] Johnston S.C., Wilson, C.B., Halbach, V.V., Higashida, R.T., Dowd, C.F., McDermott, M.W., Applebury, C.B., Farley, T.L., Gress, D.R. Endovascular and surgical treatment of unruptured cerebral aneurysms: comparison of risks. Ann Neurol. 2000. 48(1): 11-9.
[5] Medtronic Internal Report FD3456B, PUFS 5 Year CSR.
[6] “Pipeline Flex Embolization Device.” Medtronic. Medtronic, Jan. 2017. Web. 01 June 2017.