Search

Complications form a very significant element of the Oral Board Examination. The scoring system gives a grade for the handling of complications relevant to the treatment. The good news is that there are a limited number of complications in neurosurgery. Again, complications are expected on the Oral Board Examination. The most common complications are: postoperative neuropathic pain, postoperative wound infection, cerebrospinal fluid leak, C5 nerve palsy, postoperative cranial or spinal hematoma, hyponatremia, vasospasm, intraoperative aneurysm rupture (open or endovascular), major arterial injuries with cranial and spinal surgery, uncontrolled intracranial pressure, brain swelling during operative exposure, and esophageal injury. These are discussed in this chapter.

Dural arteriovenous fistulas are abnormal communications, within the dural leaflets, between meningeal arteries and dural venous sinuses and/or subarachnoid veins. Although many fistulas remain clinically silent and do not require treatment, presence of cortical venous reflux, intracranial bleed, and intolerable symptoms are the main indications for treatment. A thorough understanding of the natural history is of prime importance in the decision making and management of these lesions. In this chapter we discuss the epidemiology and natural history of intracranial dural arteriovenous fistulae.

Dural arteriovenous fistulas are abnormal communications, within the dural leaflets, between meningeal arteries and dural venous sinuses and/or subarachnoid veins. Although many fistulas remain clinically silent and do not require treatment, presence of cortical venous reflux, intracranial bleed, and intolerable symptoms are the main indications for treatment. A thorough understanding of the natural history is of prime importance in the decision making and management of these lesions. In this chapter we discuss the epidemiology and natural history of intracranial dural arteriovenous fistulae.

In the early years of open aneurysm surgery by craniotomy, which of course was done without the microscope, early surgery after subarachnoid hemorrhage (SAH) was performed frequently—and the results were disastrous! Then, Dr. Drake began to talk about the “red, angry, swollen brain” and taught us not to operate early. The results of aneurysm clipping began to improve, even before the microscope, in the hands of experienced surgeons. With the introduction of the microscope in neurosurgery, reports of very early surgery after aneurysmal SAH began to appear, particularly from Japan and then Europe. Neurosurgeons in North America began to understand that some patients who were in very good condition after SAH could be operated upon early, without the surgeon having to struggle with the swollen brain. It then became important to develop a grading scale that would allow us to communicate with each other about the condition of thepatient andtoanalyzeourresultsinrelationtothepreoperative

n the September/October 2011 issue of WORLD NEUROSURGERY, Lv et al. presented a retrospective analysis of 302 I consecutive cerebral arteriovenous malformations (AVMs) managed at the Beijing Neurosurgical Institute over a 9-year period. They attempted to identify patient andAVM-related factors that correlated with the presence of an associated intracranial aneurysm. Aneurysms were identified by selective and supraselective angiography and subsequently classified as intranidal, proximal flow-related, and unrelated circle of Willis aneurysms. Seventy-four (24.5%) patients were found to have a total of 77 aneurysms (47 intranidal, 26 proximal flow-related , and 10 unrelated aneurysms of the circle of Willis). Presentation with intracranial hemorrhage occurred in 159 (52.6%) patients and was determined to be caused by the aneurysm in 56. Proximal aneurysms were more likely to present with hemorrhage as compared to intranidal aneurysms. On both univariate and multivariate analyses, AVMs coexisting with aneurysms were found to be significantly associated with hemorrhage at initial presentation as well as infratentorial location. Older age also was found to correlate with presence of an aneurysm on multivariate analysis. There was no correlation between the presence of an associated aneurysm and patient sex, AVM size, and pattern of venous drainage.

Object As endovascular techniques have become more advanced, preoperative embolization has become an increasingly used intervention in the management of meningiomas. To date, however, no consensus has been reached on the use of this technique. To clarify the role of preoperative embolization in the management of meningiomas, the authors conducted a systematic review of case reports, case series, and prospective studies to increase the current understanding of the management options for these common lesions and complications associated with preoperative embolization. Methods A PubMed search was performed to include all relevant studies in which the management of intracranial meningiomas with preoperative embolization was reported. Immediate complications of embolization were reported as major (sustained) or minor (transient) deficits, death, or no neurological deficits. Results A total of 36 studies comprising 459 patients were included in the review. Among patients receiving preoperative embolization for meningiomas, 4.6% (n = 21) sustained complications as a direct result of embolization. Of the 21 patients with embolization-induced complications, the incidence of major complications was 4.8% (n = 1) and the mortality rate was 9.5% (n = 2). Conclusions Preoperative embolization is associated with an added risk for morbidity and mortality. Preoperative embolization may be associated with significant complications, but careful selection of ideal cases for embolization may help reduce any added morbidity with this procedure. Although not analyzed in the authors' study, embolization may still reduce rates of surgical morbidity and mortality and therefore may still have a potential benefit for selected patients. Future prospective studies involving the use of preoperative embolization in certain cases of meningiomas may further elucidate its potential benefit and risks.

Complications form a very significant element of the Oral Board Examination, and questions about complications should be expected. The scoring system gives a grade for the handling of complications relevant to the treatment. The good news is that there are a limited number of complications in neurosurgery. The most common complications are postoperative neuropathic pain, postoperative wound infection, cerebrospinal fluid leak, C5 nerve palsy, postoperative cranial or spinal hematoma, hyponatremia, vasospasm, intraoperative aneurysm rupture—open or endovascular, major arterial injuries with cranial and spinal surgery, uncontrolled intracranial pressure, brain swelling during operative exposure, and esophageal injury; all these are discussed in this chapter.

Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome characterized by disturbed gait, cognition, and urinary symptoms in the context of enlargement of the ventricular system. Typically, gait impairment is the most prominent feature, yet cognitive decline can predate other symptoms and contribute to functional impairments.1 The cognitive profile of iNPH is generally characterized by frontal-systems dysfunction, which includes executive deficits, compromised learning and recall, and reduced information processing and psychomotor speed. Improvement in gait has been well documented after shunt placement,2,3 yet controversy remains regarding the extent and pattern of postsurgical cognitive changes. Some studies report no change in mental status; others suggest improvement in up to 90% of patients.4–7 Conflicting findings may be explained by variations in the depth of cognitive examination, the way in which cognitive improvement is defined, and study follow-up intervals. Furthermore, most investigations lack a control group, making it difficult to disentangle practice effects from a true treatment effect. One recent study on iNPH treatment response used comparison data from a control sample and found that iNPH patients improved on most tasks; however, effects of prior exposure to test material could not be examined because the control subjects were tested at only 1 time point.7 Neuropsychological test performance can change as a result of measurement error, statistical considerations (ie, regression to the mean), or the effects of prior exposure to the testing material (ie, practice effects). Although the use of alternative test forms can alleviate some concerns regarding repeat testing, the most rigorous methodology involves a controlled study design in which both patients and control subjects undergo repeat assessment. We sought to examine postshunt changes in a sample of well-characterized iNPH participants compared with a group of age- and education-matched healthy control subjects.

Background Optimal treatment of intracranial aneurysms involves complete occlusion of the aneurysm with preservation of the parent artery and all of its branches. Attempts to occlude the aneurysm and preserve the parent artery may be associated with a higher level of risk than parent vessel occlusion or trapping. Objective To evaluate our series of patients with large and giant aneurysms who underwent treatment via endovascular coiling with parent artery sacrifice or surgical ligation of the common carotid artery (CCA) and gain insight into the advantages and risks of each of these alternatives. Methods We retrospectively reviewed all patients with aneurysms who underwent carotid sacrifice via endovascular occlusion or surgical CCA ligation during an 8-year period at our institution. Results Twenty-seven patients with large and giant aneurysms of the internal carotid artery underwent carotid artery sacrifice via endovascular occlusion (n = 15) or CCA ligation (n = 12). Of the patients who underwent endovascular occlusion, 3 developed groin complications, 1 developed a new sixth nerve palsy, 1 died from vasospasm related to subarachnoid hemorrhage, and 1 died secondary to rupture of an associated 3-mm anterior communicating artery aneurysm 5 days postoperatively. Of the patients undergoing CCA ligation, 1 patient developed a partial hypoglossal palsy. Clinical improvement of presenting symptoms was observed in all surviving patients regardless of the method of treatment. Complete aneurysm obliteration was documented in all patients during the initial hospital stay. The mean radiographic long-term follow-up was 14.2 months, which was available in 20 of the 25 surviving patients (80%). Complete obliteration was confirmed at follow-up in all but 2 patients with large cavernous aneurysms; 1 was initially treated with endovascular occlusion and the other with carotid ligation. Conclusion Parent artery sacrifice is still a viable treatment for some complex aneurysms of the internal carotid artery. CCA ligation is a reasonable alternative to endovascular arterial sacrifice.

Eagle syndrome is an uncommon entity but is well known in the otorhinolaryngology and oral surgery literature. This syndrome results from the compression of cranial nerves in the neck by an elongated styloid process causing unilateral cervical and facial pain. The styloid process can also cause compression of the cervical carotid arteries leading to the so-called carotid artery syndrome together with carotidynia or neurological symptoms due to flow reduction in these arteries. The authors discuss the case of a 70-year-old man who suffered from transient ischemic attacks on turning his head to the left, with immediate remission of symptoms when his head returned to the neutral position. The patient was studied with dynamic angiography, which clearly showed focal flow restriction. Once a diagnosis was made, the styloid process was removed surgically and the patient completely recovered from his symptoms. A postoperative angiogram demonstrated complete resolution of the pathology. Neurosurgeons might encounter patients with Eagle syndrome and should be aware of the symptoms and signs. Once the diagnosis is made, the treatment is clear and very effective.

Object The management of non–life threatening spontaneous intraparenchymal hemorrhage with no obvious medical etiology in patients and the lack of findings on images has not been clearly defined. In general, the current practice is to treat these patients conservatively and repeat studies to rule out a treatable cause 6 weeks to 3 months later; more often than not these repeated studies fail to reveal any findings, and the patient is treated conservatively. For years, the senior author (R.C.H.) has treated these patients with early surgical exploration. This study was undertaken prospectively to ascertain the frequency of positive findings during surgical exploration. Methods Between 2000 and 2007, the authors prospectively collected data from 9 cases (4 cerebellar, 4 lobar, and 1 caudate head) of unexplained intraparenchymal hemorrhages. The patient age ranged from 18 to 45 years (mean 31.2 years). All patients were normotensive, had no underlying medical problems explaining such a hemorrhage, and failed to exhibit findings on cerebral angiograms. Magnetic resonance images with contrast showed no abnormal vasculature or enhancement. Eight patients underwent elective surgical exploration in the subacute stage, and urgent decompression of the clot was necessary in 1. Results In 7 (77.8%) of the 9 cases, histopathological examination revealed a cause for the hemorrhage (3 “cryptic” arteriovenous malformations, 3 cavernomas, and 1 neoplasm). A good outcome was achieved in all 8 patients who underwent elective surgery. Conclusions The authors recommend elective surgical exploration of intracerebral hematomas of unknown etiology provided that the hematoma is surgically accessible and the patient is relatively young and healthy. Early exploration and resection can provide a cure and eliminate the risk of rebleeding when a vascular lesion is found or guide further treatment in cases of tumor.

The current indications for cerebral bypass surgery are unquestionably diminishing. As a result of rapid and progressive advances, endovascular techniques are now capable of dealing with more and more challenging aneurysms that could have been optimally managed only with open surgical techniques just afewyearsago. Similarly, therecent resultsof the Carotid Occlusion Surgery Study (COSS) have emphasized the effectiveness of modern medical therapy for the management of intracranial ischemia and dampened enthusiasm for bypass surgery (3). However, despite these advances, there still remains a subset of patients who benefit from revascularization surgery. InapaperrecentlypublishedinWORLD NEUROSURGERY, Kalanietal. attempt to define the current indications and outcomes of bypass surgery in the modern endovascular era. The authors present a contemporary series of direct cerebrovascular revascularization procedures performed at the Barrow Neurological Institute (BNI) over a 7-year period (2006e2013). There were 131 direct bypass procedures performed in 121 patients. Indications for bypass surgery included moyamoya disease in 40 patients (47 bypasses), complex aneurysms in 54 patients (56 bypasses), and occlusive vascular disease in27 patients (28 bypasses).Amongpatients with moyamoya angiopathy, revascularization resulted in improvement of symptomsin 77.5%.Morbidity and mortality rates were 5%and 0%, respectively. Long-term angiographic follow-up was available in only 60% of the patients and demonstrated graft patency in 96.8%. Among the patients with complex aneurysms, 81.5% of the patients had afavorable outcome. Morbidity and mortality rates were 16.6% and 13%, respectively. Long-term angiographic follow-up was available in 94.4% of the surviving patients and demonstrated graft patency in 76.7%. Among patients with occlusive vascular disease, symptom improvement was seen in 55.5%. Morbidity and mortality rates were 14.8% and 0%, respectively. Long-term angiographic follow-up was available in 59.3% of patients and showed a 100% graft patency rate. It is always useful to hear the experience of such a renowned center as the BNI. The article has some limitations, such as the retrospective nature of the review; the heterogeneous group of patients; and the limited long-term angiographic follow-up, particularly in the patients with moyamoya disease and vascular occlusive disease. This single-institution experience limits the general applicability of the results; very few surgeons in the world can hope to achieve the generally excellent results reported in this study. The authors use the Glasgow Outcome Scale, which was originally designed for assessment of outcomes in patients with severe head trauma. Although a Glasgow Outcome Scale score of 4 may be a “good” result for a patient with a severe head injury, such an outcome (“independent withmildto moderateneurologic deficit”) maynot be a “good” outcome for an intact patient presenting with an asymptomatic complex aneurysm. Use of the modified Rankin Scale, which is a more accurate indicator of outcomes, may have been

The middle cerebral artery (MCA) is the most common location for giant aneurysms of the anterior circulation. The contemporary management of giant aneurysms of the MCA lies largely in the surgical domain. Clipping is the first surgical option for these aneurysms. In about half the cases, the aneurysm neck is amenable to clipping, usually in conjunction with aneurysmorraphy. However, clipping is unsuitable for aneurysms without a well-defined neck or for fusiform giant aneurysms. For these cases, indirect treatment options include aneurysm trapping or proximal occlusion. Although frequently an M4 and occasionally an M3 branch can be sacrificed without the need for a distal bypass, we always recommend distal bypass whenever M1 or M2 must be sacrificed. There are several choices for distal bypass, but we prefer a high-flow bypass with a saphenous vein or radial artery graft whenever M1 is sacrificed and usually when M2 is occluded. With M3 or M4 occlusion, a low-flow superficial temporal artery distal bypass usually suffices. Recurring themes in the surgical treatment of these lesions are preservation of lenticulostriate perforators and keeping vessel reconstructions as simple as possible to reduce the length of temporary occlusion.

✓ In his 2003 Presidential Address to the American Association of Neurological Surgeons, Dr. Heros discusses his personal additions to the six basic competencies for which all neurosurgical residents must be tested. The basic competencies are as follows: 1) patient care; 2) medical knowledge; 3) practice-based learning and improvement; 4) interpersonal and communication skills; 5) professionalism; and 6) system-based practice. To these, Dr. Heros proposes to add six supplemental competencies: 1) intellectual honesty, which involves frank discussions about patient complications and admissions of the physician's frailties; 2) scholarship—the art and science of medicine, which recognizes the value of evidence-based medicine but does not discount knowledge derived from experience; 3) practicing in a hyperlegalistic society, which involves tailoring informed consent to fit individual patients' circumstances; 4) time- and cost-efficient practices, in which the physician strives to conserve time and resources by forgoing testing that is not strictly necessary, doing only what is needed to return patients to wellness; 5) approach to patients, which entails acknowledging and respecting the dignity of all patients; and 6) pride in being a neurosurgeon, which carries a sense of elitism without arrogance.

The management of cerebral arteriovenous malformations (AVMs) is one of the most important challenges for neurosurgeons. In this article, the authors discuss the preoperative issues that may lead to complications and intraoperative and postoperative complications of AVM surgery, as well as how to avoid them.

OBJECTIVE Although anterior circulation disease has both medical and surgical treatment options, management of vertebrobasilar disease has predominantly had only medical options. Some patients remain symptomatic despite medical treatment, and angioplasty has been demonstrated to relieve critical stenoses. However, the relative safety and effectiveness of medical and surgical treatments is not clearly known. This report reviews the clinical characteristics, indications, and procedural risks of intracranial angioplasty in a series of patients with symptomatic posterior circulation ischemia. METHODS All patients undergoing angioplasty for critical intracranial vertebral or basilar artery stenosis at the University of California at San Francisco Medical Center between June 1986 and July 1999 were included in a retrospective record review. Clinical features and procedural complications were recorded. RESULTS Angioplasty was performed on 25 vessel lesions in 25 patients in whom medical therapy had failed. The patients ranged in age from 50 to 87 years. Of the 25 stenoses, 10 were intracranial vertebral, 9 vertebrobasilar junction, and 6 basilar in location. Angioplasty was effective in reducing the degree of stenosis by more than 40% in all 25 vessels. The overall risk of stroke or death was 28%, and the risk of disabling stroke or death was 16%. CONCLUSION Intracranial posterior circulation angioplasty is effective in the reduction of stenosis and can be performed with relative safety. Angioplasty can be considered as a treatment option in patients with recurrent ischemic symptoms despite medical therapy.

INTRODUCTION First of all, I would like to apologize in advance for writing this chapter more as an essay reecting my personal biases rather than as a scientiŽc paper. In this context, the following will be devoid of scientiŽc quotations. I would also apologize for my personal lack of vision for what the future would be like beyond the next few years. Like Yogi Berra, I do have major difŽculties with predictions, particularly if they refer to the future. Clearly, those of us who lived through the ‘golden days’ of cerebrovascular surgery cannot help but be somewhat nostalgic about the past, which does not necessarily mean that we are pessimistic about the future. I would roughly date the beginnings of the golden era of cerebrovascular surgery to the early 70s when two deŽning trends entered neurosurgery. Firstly, the microscope and microsurgical techniques began to be applied widely in neurosurgery. Secondly, neurosurgeons became adept at microvascular suturing techniques and the EC–IC bypass graft operation was developed and began to be used widely by neurosurgeons. Before the 70s, several pioneers began to use the microscope and microsurgical techniques in neurosurgery and there were already a number of individuals who had developed a reputation as cerebrovascular surgeons. However, in general, all of these individuals did more than cerebrovascular surgery and in fact, were generally very well respected already as excellent and experienced neurosurgeons who could, in addition to doing many other things, clip an aneurysm or extirpate an AVM with good results. What was so important about the early 70s, in my opinion, was the emergence of a cadre of dedicated cerebrovascular surgeons. The microscope allowed this generally young group of surgeons to become technically proŽcient in a short period of time. Before that time, it took many years of experience to be able to clip an aneurysm successfully. With the microscope, many if not most neurosurgeons could clip a ‘routine’ aneurysm satisfactorily during their chief residency or during the Žrst few years in practice. The introduction of microvascular suturing techniques, which was rapidly mastered by those of us who became interested in the vascular area, deŽned those young surgeons (there were a few ‘older’ ones, but by and large they were the exception) as being doted with unique surgical talent. Our professors simply found it incredible that we were able to complete successfully an anastomosis to a vessel that was less than 1 mm in diameter. Coupled with these factors was the rich opportunity for doing cerebrovascular research allowed to those individuals who became interested in this area early on in their career. Cerebrovascular physiology was then, as it remains now, a fascinating topic to those of us interested in the nervous system and a young neurosurgeon at that time had opportunities in research that unfortunately are less prevalent today. To a large degree, this was due to the reimbursement system which was generous enough to allow academic departments to invest some of the clinical revenues in the support of research laboratories. It was in this fashion that many of us had the opportunities to develop the substantial preliminary data that was necessary for successful future NIH funding. This coupling of the perception of unique surgical technical talent and a track record of investigation in the laboratory opened the door to substantial academic opportunities for the majority of this early cadre of dedicated cerebrovascular surgeons. It is interesting that as important as the bypass was in the early career of these individuals, the ending of the bypass era, with the publication of the EC–IC study, did very little to discourage or terminate the dedication to cerebrovascular surgery of this early cadre of individuals. There were still plenty of aneurysms, AVMs and carotid endarterectomies to go around and the research opportunities continued to abound. There were still extremely important questions to be answered in the clinic and in the laboratory about vasospasm, the causes and thresholds of ischemic damage, the value of neuroprotective agents, etc. Even after the publication of the bypass study, I recall that a good number of the better qualiŽed resident applicants were still interested in the cerebrovascular Želd. Obviously, to deŽne a ‘golden era’, one must have seen its decline. What, then, are the factors involved in the decline of this golden era? They are obvious, but not irreversible and in fact, some of these very factors may lead to a revitalization of cerebrovascular surgery. Radiosurgery came into being and, following the trend Correspondence and reprint requests to: Roberto C. Heros, MD, Department of Neurosurgery, University of Miami School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA. Accepted for publication December 2001.

In this issue of the Journal of Neurosurgery, Kellner and colleagues4 present an excellent retrospective analysis of their experience with surgical proximal basilar artery (BA) occlusion for complex BA aneurysms. Over a 22-year period a total of 15 patients were treated in this manner. Patients underwent this procedure if direct surgical clipping or endovascular coiling were believed to be unsafe and there was good collateral flow to the posterior circulation through at least 1 robust posterior communicating artery (PCoA). Considering the difficult lesions treated, the results were excellent: 80% of the patients were neurologically intact 1 month after surgery, there was no postoperative aneurysmal bleeding during an average follow-up of 3 years (range 2 months to 18 years), and 57% of the surviving patients were found to have their aneurysm completely occluded on late angiographic follow-up. As the authors will agree, the limitations of the study include its retrospective nature, its inherent selection bias, the small cohort of patients, and the heterogeneity of the lesions treated. However, we believe this is an important article because it reminds us that the time-honored technique of proximal artery (Hunterian) ligation remains a viable and effective treatment option. Despite advances in modern microsurgical and endovascular techniques, aneurysm obliteration with preservation of the parent artery may not always be possible, may carry significant morbidity, or may be unlikely to provide durable results. In such cases proximal artery occlusion is a reasonable alternative, provided there is adequate collateral circulation. We would like to make some comments emphasizing certain aspects of the article. Although the authors do not elaborate on their intraoperative decision making, they state that BA occlusion was used as a fallback treatment after direct clipping was aborted because of anatomical concerns. We completely agree with this approach and cannot overemphasize that clinical decision making does not stop once a decision has been made to operate; rather, it is a continuous process assessing the risks and benefits throughout the procedure up to the point of definitive treatment. On many occasions during his career, the senior author of this editorial (R.C.H.) has deviated from his original surgical plan or aborted a procedure after finding an unexpected morphological feature, such as calcification at the neck of an unruptured aneurysm, that in his opinion increased the surgical morbidity as compared with his preoperative estimation.3 We also agree with the authors that in many instances surgical clip occlusion in the BA is safer than endovascular coil occlusion. A long vessel segment is frequently required to place a solid occlusive coil mass during endovascular proximal artery sacrifice. Such long segments devoid of critical branches and/or perforators are found in the internal carotid arteries (ICAs) and vertebral arteries (VAs); however, endovascular coil occlusion of the BA is problematic due to the lack of such a perforatorand branch-free zone. Furthermore, the risk of coil migration remains a concern. In contrast to coil occlusion, surgical clip occlusion in the BA has the advantage of directly visualizing the perforating vessels, which are frequently not visualized on angiography, and placing the clip in a segment of the artery devoid of any branches. The authors use the term “point occlusion,” which in our opinion nicely describes the selective nature of clip occlusion. We would like to comment on the authors’ decision to delay proximal vessel occlusion in patients presenting with subarachnoid hemorrhage. Although the authors do not specifically mention the reason, we presume this delay in treatment was to minimize the potential ischemic complications in patients who would develop vasospasm. Patients who demonstrate robust collaterals or have tolerated balloon test occlusion (BTO) early after rupture of the aneurysm may not tolerate occlusion if vasospasm develops several days later. This is why we prefer, in the setting of subarachnoid hemorrhage, to treat patients conservatively and wait until the period at risk for vasospasm has subsided before proximal artery occlusion is undertaken. The authors frequently performed a preoperative Editorial See the corresponding article in this issue, pp 319–327.