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Up and Down arrows will open main level menus and toggle Woman looking nsa Walls sub tier links. Enter and space open menus and escape closes them as well. Tab will move on to the next part of the site rather than go through menu items. A cerebral or intracranial aneurysm is an abnormal focal dilation of an artery in the brain that from a weakening of the inner muscular layer the intima of a blood vessel wall. The vessel develops a "blister-like" dilation that can become thin and rupture without warning.
The resultant bleeding into the space around the brain is called a subarachnoid hemorrhage SAH. Aneurysms are usually found at the base of the brain just inside the skull, in an area called the subarachnoid space. In fact, 90 percent of SAHs are attributed to ruptured cerebral aneurysms and the two terms are often used synonymously. Aneurysms larger than one inch are called giant aneurysms, pose a particularly high risk and are difficult to treat.
The exact mechanisms by which cerebral aneurysms develop, grow and rupture are unknown. However, a of factors are believed to contribute to the formation of cerebral aneurysms, including:.
Patients with intracranial aneurysms can present with SAH from aneurysmal rupture or with un-ruptured aneurysms, which may have been discovered incidentally or resulted in neurological symptoms. An aneurysm ruptures when a hole develops in the sac of the aneurysm.
The hole can be small, in which case only a small amount of blood leaks, or large, leading to a major hemorrhage. An un-ruptured aneurysm is the one whose sac has not ly leaked.
Every year approximately 30, patients in the U. The management of both ruptured and un-ruptured cerebral aneurysms poses a ificant challenge for patients and their treating physicians 1. There is little doubt on the treatment for ruptured cerebral aneurysms, which are typically secured with clips or coils to prevent re-rupture.
The treatment for un-ruptured cerebral aneurysms has been a matter of debate for decades. For posterior circulation and posterior communicating artery aneurysms these rates were higher: 2. This study could not make recommendations regarding the modality of treatment because the characteristics of patients in the endovascular cohort differed greatly from those in the surgical group 3.
This study has been criticized for selection bias and study de. In clinical practice SAH from aneurysms smaller than 7 mm is not infrequently encountered. Over the years a of factors have Woman looking nsa Walls reported which can influence rupture rates of the aneurysms. Factors such as family history of intracranial aneurysms, history of smoking, excessive alcohol consumption, female sex, SAH, symptomatic aneurysm, its location and size have shown negative correlations.
Inbased on the critical analysis of the literature available at that time Komotar et al 4 recommended that:. Broadly, three treatment options for people with the diagnosis of cerebral aneurysm include:. Medical therapy is usually only an option for the treatment of un-ruptured intracranial aneurysms.
Strategies include smoking cessation and blood pressure control. Both patient and doctor can work together to de an individualized smoking cessation program that is both practical and feasible for the patient's lifestyle. Woman looking nsa Walls the mechanisms of aneurysm rupture are incompletely understood, and because even aneurysms of very small size may rupture, the role of serial imaging for cerebral aneurysm is undefined.
InWalter Dandy, MD, a Woman looking nsa Walls American neurosurgeon, introduced the method of "clipping" an aneurysm when he applied a V-shaped, silver clip to the neck of an internal carotid artery aneurysm. Since that time, aneurysm clips have evolved into hundreds of varieties, shapes and sizes. The mechanical sophistication of available clips, along with the advent of the operating microscope in the s have made surgical clipping the gold standard in the treatment of both ruptured and un-ruptured cerebral aneurysms.
In spite of these advances, surgical clipping remains an invasive and technically challenging procedure. An aneurysm is clipped through a craniotomy, which is a surgical procedure in which the brain and the blood vessels are accessed through an opening in the skull. After the aneurysm is identified, it is carefully dissected separated from the surrounding brain tissue. A small metal clip usually made from titanium is then applied to the neck base of the aneurysm.
Aneurysm clips come in all different shapes and sizesand the choice of a particular clip is based on the size and location of an aneurysm. The clip has a spring mechanism which allows the two "jaws" of the clip to close around either side of the aneurysm, thus occluding separating the aneurysm from the parent origin blood vessel. In the ideal clipping, normal blood vessel anatomy is physically restored by excluding the aneurysm sac from the cerebral circulation. Endovascular techniques for treating aneurysms date back to the s with the introduction of proximal balloon occlusion by Fjodor A.
Serbinenko, MD, a Russian neurosurgeon. During the s, endovascular treatment of aneurysms with balloon occlusions was associated with high procedural rate of rupture and complications. Guido Guglielmi, MD, an American-based neuroradiologist, invented the platinum detachable microcoil, which was used to treat the first human being in The development of Guglielmi detachable coils GDCsand their FDA approval inrevolutionized endovascular treatment of cerebral aneurysms. The common goal of both surgical clipping and endovascular coiling is to eliminate blood flow into the aneurysm.
Efficacy long-term success or effectiveness of the treatment is measured by evidence of aneurysm obliteration failure to be demonstrated by conventional or noninvasive angiographywithout evidence of recanalization any blood flow into the aneurysm or recurrence reappearance. Guglielmi detachable coils, known as GDCs, are soft wire spirals originally made out of platinum. These coils are deployed released Woman looking nsa Walls an aneurysm via a microcatheter that is inserted through the femoral artery of the leg and carefully advanced into the brain.
The microcatheter is selectively advanced into the aneurysm itself, and the microcoils are released in a sequential manner. Once the coils are released into the aneurysm, the blood flow pattern within the aneurysm is altered, and the slow or sluggish remaining blood flow le to a thrombosis clot of the aneurysm.
A thrombosed aneurysm resists the entry of liquid blood, providing a seal in a manner similar to a clip. Endovascular coiling is an attractive option for treating aneurysms because it does not require opening of the skull, and is generally accomplished in a shorter time frame, which lessens the anesthesia given. Nevertheless, important differences remain between clipping and coiling, including the nature of the seal created.
Because coiling does not physically re-approximate the inner blood vessel lining endotheliumrecanalization may occur through the eventual compaction of the coils into the aneurysm by the bloodstream. One of the largest, randomized controlled trials comparing surgical clipping and endovascular coiling — International Subarachnoid Aneurysm Trial ISAT — randomly allocated the patients to either neurosurgical clipping or endovascular coiling after a SAH.
In the first report published in2, participants were enrolled and randomly ased to the endovascular coiling group and the surgical clipping group. They concluded that survival free of disability at one year was better with endovascular coiling. Long-term risk of further bleeding from treated aneurysm was low with either therapy, but higher with endovascular coiling, as compared to surgical clipping 5.
The investigators recently published the long-term outcomes from 1, patients enrolled from 22 U. At long-term follow-up rates of increased dependency alone did not differ between groups, the probability of death or dependency was ificantly greater in the neurosurgical group and re-bleeding was more likely after endovascular coiling 6. However, this study, like many other stroke trials, has many shortcomings and should be interpreted with caution 7. Meta-analyses of randomized trials comparing endovascular coiling and surgical clipping including ISAT conducted later were unable to show a ificant difference between endovascular treatment and neurosurgical clipping in mortality and reported that endovascular treatment was associated with higher rates of re-bleeding 8, 9.
Often endovascular coiling may need to be performed with stent — or balloon assistance — for complex aneurysms such as wide-necked aneurysms with lower dome-to-neck ratios, large and giant aneurysms. Stent — or balloon-assisted coiling — is done to prevent herniation of the coil mass into the parent artery which can result in stroke. For balloon-assisted coiling, the balloon is temporarily inflated at the neck of the Woman looking nsa Walls while the coils are placed into the aneurysm.
For stent-assisted coiling, the stent is permanently placed across the aneurysm neck. There are advantages and disadvantages of both approaches. The patients who have the stent placed need to be on anti-platelets medicationslimiting their use in ruptured aneurysms, although stent-assisted coiling has been used in ruptured aneurysms with good outcomes.
Stents have also been shown to reduce aneurysm recanalization and Woman looking nsa Walls in further occlusion of incompletely coiled aneurysms 10, A literature review on stent-assisted coiling in reported the overall complication rate of 19 percent with an overall death rate of 2. Flow diverter FD stents were introduced about 7 years ago into the clinical armamentarium of the neuro-interventionists as an additional tool for aneurysm treatment. They have higher metal surface area coverage about percent as compared to the generation stents which have about percent metal surface-area coverage FDs are tubular stent-like implants with a low porosity metal-free to metal-covered area and a high pore density with two main work mechanisms 14 :.
Pipeline embolization device PED is currently used most often in the U. The PED is a Woman looking nsa Walls microcatheter-delivered self-expanding cylindric construct composed of 48 braided strands of cobalt chromium and platinum. The Food and Drug Administration FDA approved the PED for the treatment of large or giant wide-necked intracranial aneurysms from the petrous to the superior hypophyseal segments of the internal carotid artery ICAwhich is a section of the artery that supplies the blood to the brain.
The concept behind the treatment is the same with all four FDs. Flow diversion is generally performed for the treatment of aneurysms that are challenging and less amenable to traditional endovascular coiling; such as complex aneurysms, including large and giant aneurysms, wide-neck aneurysms, fusiform aneurysms and recanalized aneurysms after coiling.
Stent-assisted coiling and balloon-assisted coiling are alternative endovascular options for such aneurysms; however, some studies reported their limited efficacy due to high recanalization rates Dual antiplatelet therapy with Plavix Clopidogrel and aspirin ASA is recommended starting prior to the placement of the device and continued afterwards for three to Woman looking nsa Walls months followed by aspirin monotherapy lifelong. That is why most aneurysms treated are un-ruptured although there are cases where they were used for ruptured aneurysms also.
Most centers still limit their use to the un-ruptured aneurysms. For adequate anticoagulation and to lower the thromboembolic complications prior to device placement, Plavix assays are checked at baseline before the administration of Plavix and then again just before the procedure. The percentage of inhibition is calculated and the dosage is adjusted to achieve adequate platelet inhibition before the procedure.
Patients with resistance to Plavix are switched to a different anti-platelet drug. After the routine groin access and placement of a sheath, the microcatheter is navigated inside the larger guide catheter to the desired position across the aneurysm neck. FD stent is then passed through the microcatheter and deployed across the aneurysm neck carefully under the angiographic guidance.
The from the large retrospective and prospective single- and multi-center studies have shown an excellent feasibility of the treatment with a high efficacy and acceptable periprocedural complications occurring soon before, during or after the performance of a medical procedure as well as morbidity and mortality rates 17, Besides the important complications such as thromboembolic events and the intra-procedural aneurysm rupture, which are also seen with traditional aneurysm coiling, other complications seen with the use of FDs include delayed aneurysmal rupture causing hemorrhage and distant away from aneurysm intraparenchymal hemorrhage.
The mechanisms for delayed hemorrhage and distant intraparenchymal hemorrhage are not well understood. The hypotheses suggested include the inflammation associated with thrombus formation weakens the aneurysmal wall causing rupture or the hemodynamic changes within the aneurysm causing stress and rupture Intrasaccular flow disruption with a WEB device is one of the latest technological advancements in management of wide-necked aneurysms especially at the bifurcation Woman looking nsa Walls an artery.
The WEB device is placed within an aneurysm in contrast to the FDs which are placed in the parent artery.
One of the biggest advantages is the reduced need for antiplatelet medications, especially for the ruptured aneurysms, which is particularly helpful in patients with SAH. The clinical experience with its use is currently limited; however, the preliminary retrospective multicenter series reported percent technical feasibility, 4. Surgical clipping of a cerebral aneurysm is Woman looking nsa Walls performed by a neurosurgeon, often one with expertise in cerebrovascular disease. Most cerebrovascular neurosurgeons have had five to seven years of general neurosurgery training and an additional one to two years of specialized cerebrovascular training.
Endovascular coiling is done either by a neurosurgeon or by an interventional neuroradiologist. An interventional radiologist has undergone extensive training three to five years in both radiology and interventional invasive procedures involving the brain and spinal cord. All neurosurgeons that perform endovascular coiling have undergone additional training in endovascular techniques in addition to full Woman looking nsa Walls training five to seven years of residency.
Although the frequencies of certain complications vary according to the intervention, both clipping and coiling share the same complications. Rupture of the aneurysm is one of the most serious complications seen in either procedure. Exact frequencies of ruptures are not well documented, but reported rupture rates range from 2 percent to 3 percent for both coiling and clipping. Rupture can cause massive intracerebral hemorrhage hemorrhagic stroke or bleeding into the brain and subsequent coma or death.
Although rupture can have catastrophic consequences during either procedure, surgery probably provides a better opportunity to control hemorrhage because of direct access to the ruptured aneurysm and the supplying vessels.Woman looking nsa Walls
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