Gamma knife radiosurgery for benign tumors with symptoms from brainstem compression.

PURPOSE: This study evaluated the role of radiosurgery in the management of symptomatic patients with brainstem compression from benign basal tumors. METHODS AND MATERIALS: Over a 17-year, period 246 patients (202 vestibular schwannomas and 44 meningiomas) with brainstem compression from benign skull-base tumors were managed with Gamma Knife radiosurgery. Median tumor volumes were 3.9 cm(3) (range, 0.8-39.0 mL) and 6.6 mL (range, 1.6-25.1 mL) for vestibular schwannomas and meningiomas, respectively. For both tumors, a median marginal dose of 13 Gy was prescribed. Median follow-up of patients was 65 months for vestibular schwannomas and 60 months for meningiomas. Patients were categorized into four groups on the basis of the tumor-brainstem relationship on neuroimaging. RESULTS: Preservation of function was stratified according to grade of brainstem compression. We analyzed the effect of radiosurgery on symptoms of brainstem compression. The tumor control rate was 100 % for meningioma and 97% for vestibular schwannomas (although 5% required an additional procedure such as a ventriculoperitoneal shunt). In patients with vestibular schwannoma, serviceable hearing was preserved in 72.0%. Balance improved in 31.9%, remained unchanged in 56.5%, and deteriorated in 11.6% of patients who had imbalance at presentation. Balance improved significantly in patients who had less tumor compression (p = 0.0357) after radiosurgery. Symptoms improved in 43.2% of patients with meningioma. CONCLUSION: Radiosurgery is a minimally invasive option for patients with benign basal tumors that indent or distort the brainstem. A high tumor growth control rate and satisfactory rate of neurological preservation and symptom control can be obtained with radiosurgery.

Low incidence of symptomatic strokes after carotid stenting without embolization protection devices for extracranial carotid stenosis: a single-institution retrospective review.

OBJECTIVE: Carotid angioplasty and stenting (CAS) remains the primary modality of treating individuals with carotid stenosis and significant comorbidities or anatomically difficult lesions. The use of embolization protection devices (EPD) has been mandated by the cerebrovascular community even though the ability of these devices to prevent symptomatic strokes is not supported by the current literature. Our goal was to assess the clinical and radiological outcomes of patients who underwent CAS without EPDs at our hospital from 1996 to 2006. METHODS: We performed a retrospective chart analysis of all patients who underwent CAS without EPDs at the Jefferson Hospital for Neuroscience in Philadelphia, PA. The clinical and angiographic outcomes of these patients were studied retrospectively using chart reviews and operative, angiographic, and radiological reports. The mean clinical and radiological follow-up period was 18.6 months. RESULTS: One hundred five patients (97.2%) had clinical follow-up at 1 month. During this period, the following complications were observed: cerebrovascular accidents in 2 patients (1.9%), myocardial infarctions in 2 patients (1.9%), femoral hematoma in 1 patient (0.9%), retroperitoneal hematomas in 3 patients (2.8%), and cervical carotid dissections in 4 patients (3.7%); 2 patients (1.9%) died. Seventy-six patients (80.9%) had a mean clinical follow-up period of 18.6 months. During this period, 2 patients (2.6%) had cerebrovascular accidents, 1 of which was fatal. The long-term morbidity and mortality rate was 2.6%. In the same follow-up period, the restenosis (>50% stenosis from baseline) rate was 9.2% (7 patients). Three (3.9%) of these patients went on to require repeat CAS. CONCLUSION: Our experience reveals that CAS can be performed safely with risks similar to those reported in series in which EPDs were used. Any procedure or device that adds risk and cost to the patient should be evaluated with a randomized, controlled trial to evaluate its efficacy, especially in situations in which published data provide conflicting results. The use of EPDs should be no exception to this paradigm.

Initial experience with bioactive cerecyte detachable coils: impact on reducing recurrence rates.

OBJECTIVE: Despite proven safety of endovascular coil embolization of intracranial aneurysms, the potential need for retreatment remains criticized. The goal of this prospective study was to assess the safety, durability, and effect on recanalization rates of the Cerecyte (Micrus Corp., Sunnyvale, CA) bioactive coil. METHODS: Two hundred twelve ruptured and unruptured aneurysms in 176 patients were prospectively enrolled in a database registry during a 12-month period. Adverse clinical outcomes directly attributed to the use of the Cerecyte coil were documented. Angiographic outcomes were determined immediately after coil embolization and during follow-up studies. All patients who received stent assistance or a non-Cerecyte coil were excluded. Two independent endovascular surgeons reviewed follow-up films. Any discrepancy was deemed a recurrence. RESULTS: After exclusion criteria, 81 patients with 89 aneurysms were available for a minimum of 6 months of follow-up. Of those 89 aneurysms, 65% were ruptured aneurysms and were treated in the acute setting. The mean size of the aneurysm was 7 mm. The mean angiographic follow-up period was 11.2 months. Recurrences requiring retreatment as a result of dome filling were identified in six aneurysms (6.7%). Four aneurysms (4%) developed compaction of more than 20%, which was defined as interstitial filling of the fundus. There was one thromboembolic event leading to permanent neurological deficit. No cases of chemical meningitis or delayed hydrocephalus occurred. CONCLUSION: The Cerecyte bioactive coil seems to be safe and effective for use in both ruptured and unruptured aneurysms. The bioactive polymer within the coils allows similar handling characteristics of a bare platinum coil. Studies to assess long-term outcomes with direct comparison to platinum coils and alternative bioactive coils are warranted.

Endovascular coil embolization of ruptured and unruptured posterior circulation aneurysms: review of a 10-year experience.

OBJECTIVE: Treatment of posterior circulation aneurysms poses a great technical challenge for the practicing neurosurgeon. The advent of endovascular techniques has made such treatment more feasible. We report our experience with the endovascular management of ruptured and unruptured posterior circulation aneurysms during the past 10 years. METHODS: A retrospective analysis was performed on all patients with posterior circulation aneurysms undergoing endovascular treatment at Jefferson Hospital for Neuroscience between July 1995 and December 2005. This yielded 275 patients (67 men and 208 women). The degree of aneurysm occlusion was determined by the operating endovascular neurosurgeon at the time of the procedure. Successful embolization was defined as greater than 95% occlusion of the dome without any coil prolapsing into the parent vessel. Clinical outcome was evaluated using the modified Glasgow Outcome Scale. Clinical follow-up data was obtained for 262 patients (95.3%); the follow-up period ranged from 1 to 94 months (mean, 31.8 mo for procedures performed before 2004 and 13.3 mo for procedures performed during 2004 and 2005). Angiographic follow-up data was obtained for 224 patients (84.8%) for periods ranging from 6 to 94 months (mean, 31.3 mo for procedures performed before 2004 and 13.7 mo for procedures performed during 2004 and 2005). RESULTS: Based on the Hunt and Hess grading scale, the patient population included 106 patients (38.5%) with unruptured aneurysms, 43 patients (15.6%) with Grade I aneurysms, 16 patients (5.8%) with Grade II aneurysms, 56 patients (20.5%) with Grade III aneurysms, and 54 patients (19.6%) with Grade IV aneurysms. The locations of the posterior circulation aneurysms included 189 (68.7%) in the basilar apex or posterior cerebral artery, 23 (8.4%) in the basilar trunk/anterior inferior cerebellar artery, 22 (8%) in the superior cerebellar artery, and 41 (14.9%) in the vertebral artery or posterior inferior cerebellar artery. Of the 275 patients, 208 (76%) were women and 67 (24%) were men. The mean age at the time of treatment was 53.9 years (range, 7-90 yr). Of all patients treated, 237 patients (87.8%) had successful embolization (>95% occlusion of the dome). On angiographic follow-up, 55 patients (24.5%) developed recanalization of at least 5%. Retreatment was required in 11 patients (4.9%; 0.01%/patient yr) and rehemorrhage occurred in three patients (1.1%; 0.003%/patient yr). Clinical follow-up was graded using the modified Glasgow Outcome Scale (mGOS) and revealed 229 patients (87.4%) in the mGOS I category, 12 patients (4.6%) in the mGOS II category, eight patients (3%) in the mGOS III category, two patients (0.8%) in the mGOS IV category, and 11 patients (4.2%) were deceased (mGOS V). Clinically significant vasospasm requiring angioplasty occurred in 11 patients (6.5%) with subarachnoid hemorrhage, and 120 patients (71%) with subarachnoid hemorrhage required ventricular shunts. Complications causing clinical morbidity occurred in 14 patients (5.1%) and ranged from postoperative ischemia to recurrent subarachnoid hemorrhage. Of all clinical factors evaluated, Hunt and Hess grade was the strongest predictor of good clinical outcome (P < 0.0001). CONCLUSION: Endovascular coil embolization of posterior circulation aneurysms is an effective treatment in the short term but is associated with recurrence, which requires close surveillance, possible retreatment, and can, albeit very rarely, lead to rehemorrhage. Future technological advancements such as the development of biologically active coils will be essential in the permanent obliteration of aneurysms.

Endovascular management of intracranial aneurysms: current experience and future advances.

OBJECTIVE: The past 15 years have seen a revolution in the treatment of intracranial aneurysms. Endovascular technology has evolved rapidly since the Food and Drug Administration approval of Guglielmi detachable coils in 1995, which now allows successful treatment of most aneurysms. The authors provide a review of their 11-year experience at Jefferson Hospital for Neuroscience with endovascular embolization of intracranial aneurysms and discuss clinical trial outcomes and future directions of this treatment method. METHODS: The authors reviewed the clinical and angiographic outcomes for 1307 patients undergoing endovascular treatment of intracranial aneurysms. Their analysis focuses on posterior circulation and middle cerebral artery aneurysms, as well as cases of stent-assisted coil embolization. They review their procedural protocol and patient selection criteria for endovascular management. RESULTS: Several large clinical trials have demonstrated the safety and efficacy of endovascular treatment of intracranial aneurysms. The International Subarachnoid Aneurysm Trial provides Level I evidence demonstrating a significant reduction in disability or death with endovascular treatment compared with surgical clipping. The most common procedural complications include intraprocedural rupture and thromboembolic events; avoidance strategies are also discussed. Vasospasm after subarachnoid hemorrhage causes neurological morbidity and mortality and can be successfully managed by early recognition and interventional treatment with angioplasty, pharmacologic agents, or both. CONCLUSION: Long-term studies evaluating experience with aneurysm coil embolization during the past decade indicate that this is a safe and durable treatment method. The introduction of stent-assist techniques has improved the management of wide-neck aneurysms. Future technology developments will likely improve the durability of endovascular treatment further by delivering bioactive agents that promote aneurysm thrombosis beyond the coil mass alone. It is clear that endovascular therapy of both ruptured and unruptured aneurysms is becoming a mainstay of practice in this patient population. Although not replacing open surgery, the continued improvements have allowed aneurysms that previously were amenable only to open clip ligation to be treated safely with durable long-term outcomes.

Radiosurgery for dural arteriovenous fistulas.

OBJECTIVE: Dural arteriovenous fistulas (DAVFs) comprise 10% to 15% of all arteriovenous malformations. Recent studies have demonstrated promising results when radiosurgery is used for DAVFs. We retrospectively analyzed our patients with DAVFs who received stereotactic radiosurgery with or without embolization. METHODS: Between 1991 and 2002, 18 patients with 23 angiographically confirmed symptomatic DAVFs underwent gamma knife radiosurgery, either alone (n = 8) or in combination with embolization (n = 10). A retrospective chart review was performed to identify DAVF location, venous drainage pattern, radiosurgery dosimetry, clinical outcomes, and imaging results. The series included 9 men and 9 women with a mean age of 65 (range 50-89) years. Nine patients received particulate, coil, and/or absolute ethanol embolization before radiosurgery, and 1 patient received particulate embolization after radiosurgery. The mean duration of clinical follow-up was 43 (range 2-116) months. The mean margin radiosurgery dose was 20 (range 15-30) Gy. RESULTS: Nine patients had complete resolution of their presenting symptoms, and 9 patients had resolution of all but 1 of their presenting symptoms. Angiographic follow-up (mean 46 months) was performed on 8 patients demonstrating complete obliteration in all the cases. Seven patients evaluated by magnetic resonance angiography or computed tomography angiography showed no evidence of DAVF (4 patients) or decreased DAVF size (3 patients). After radiosurgery, 1 patient developed a temporary hemiparesis. Two permanent neurological deficits occurred after embolization before radiosurgery. No patient had an intracranial hemorrhage after treatment. CONCLUSION: Stereotactic radiosurgery provides effective long-term relief of symptoms in selected patients with DAVFs.

The role of carotid angioplasty and stenting in carotid revascularization.

OBJECTIVES: The gold standard procedure for carotid revascularization has been carotid endarterectomy. Several randomized trials demonstrate that it is more efficacious than medical management in stroke prevention for both symptomatic and asymptomatic patients when performed with low surgical morbidity. However, many high-risk patients not included in these trials are now being referred for carotid revascularization. Endovascular treatment of carotid stenosis with angioplasty and stenting has become an established alternative to carotid endarterectomy (CEA) for these patients. We provide a review of the current role of carotid stent and angioplasty. METHODS: We reviewed our procedural techniques for carotid artery stenting (CAS) with an emphasis on the need for medical therapy before and after the procedure to reduce thromboembolic complications. We also retrospectively analysed our clinical outcomes and incidence of restenosis after CAS. RESULTS: We evaluated 139 of 252 patients treated over a 10-year period who had a minimum of 6-month clinical and imaging (ultrasound and/or angiography) follow-up (average f/u=60 months). Our rate of major stroke, MI or death was 3%, and rate of peri-operative TIAs was 2%. Morbidity related to femoral sheath placement has been 1.5%, with one 'cold foot' resolved with heparin and one retroperitoneal hematoma requiring transfusion. Recurrent stenosis after CAS occurred in 4% of patients, predominately following radiation treatment where it was 15%. DISCUSSION: Although CEA is the gold standard procedure to prevent stroke from carotid stenosis, CAS has an expanding role for revascualrization, particularly in high-risk patients. Several randomized prospective trials are ongoing to better define the indications for CAS versus CEA.

Periprocedural morbidity and mortality associated with endovascular treatment of intracranial aneurysms.

BACKGROUND AND PURPOSE: Despite experience and technological improvements, endovascular treatment of intracranial aneurysms still has inherent risks. We evaluated cerebral complications associated with this treatment. METHODS: From October 1998 to October 2002, 180 consecutive patients underwent 131 procedures for 118 ruptured aneurysms and 79 procedures for 72 unruptured aneurysms. We retrospectively reviewed their records and images to evaluate their morbidity and mortality. RESULTS: Thirty-seven (17.6%) procedure-related complications occurred: 27 and six with initial embolization of ruptured and unruptured aneurysms, respectively, and four with re-treatment. Complications included 22 cerebral thromboembolisms, nine intraprocedural aneurysm perforations, two coil migrations, two parent vessel injuries, one postprocedural aneurysm rupture, and one cranial nerve palsy. Fourteen complications had no neurologic consequence. Three caused transient neurologic morbidity; 10, persistent neurologic morbidity; and 10, death. Procedure-related neurologic morbidity and mortality rates, respectively, were as follows: overall, 4.8% and 4.8%; ruptured aneurysms, 5.9% and 7.6%; unruptured aneurysms, 1.4% and 1.4%; and re-treated aneurysms, 10% and 0%. Combined procedure-related morbidity and mortality rates for ruptured, unruptured, and re-treated aneurysms were 13.5%, 2.8%, and 10%, respectively. Nonprocedural complications attributable to subarachnoid hemorrhage in 118 patients with ruptured aneurysm were early rebleeding before coil placement (0.9%), symptomatic vasospasm (5.9%), and shunt-dependent hydrocephalus (5.9%); mortality from complications of subarachnoid hemorrhage itself was 11.9%. CONCLUSION: Procedural morbidity and mortality rates were highest in ruptured aneurysms and lowest in unruptured aneurysms. Morbidity rates were highest in re-treated aneurysms and lowest in unruptured aneurysms. No procedural mortality occurred with re-treated aneurysms. The main cause of morbidity and mortality was thromboembolism.

Carotid artery angioplasty and stent placement for recurrent stenosis.

OBJECT: The use of endovascular management for recurrent carotid artery (CA) stenosis is rapidly expanding due to the increased surgical risk associated with repeated carotid endarterectomy (CEA). Carotid artery angioplasty and stent placement for recurrent CA stenosis offers a less invasive strategy with fewer procedural complications and may provide a more durable treatment. The authors report on their experience with this procedure in the management of recurrent CA stenosis. METHODS: A retrospective review was performed to evaluate clinical and ultrasound imaging outcomes after CA angioplasty and stent placement. Twenty-three vessels in 22 patients with severe recurrent stenosis (> 80%) post-CEA were treated with balloon angioplasty and stent placement without distal protection. There were no perioperative neurological or cardiac complications in this series. Over a mean follow-up period of 36 months, one patient (5%) suffered recurrent stenosis requiring retreatment with angioplasty alone. CONCLUSIONS: The use of CA angioplasty and stent placement provides a safe and effective treatment for recurrent CA stenosis. The use of drug-eluting and/or bioactive stents in the future will likely further improve the efficacy of this procedure for recurrent CA stenosis.

Frequency and management of recurrent stenosis after carotid artery stent implantation.

OBJECT: To determine the rate of hemodynamically significant recurrent carotid artery (CA) stenosis after stent-assisted angioplasty for CA occlusive disease, the authors analyzed Doppler ultrasonography data that had been prospectively collected between October 1998 and September 2002 for CA stent trials. METHODS: Patients included in the study participated in at least 6 months of follow-up review with serial Doppler studies or were found to have elevated in-stent velocities (> 300 cm/second) on postprocedure Doppler ultrasonograms. Hemodynamically significant (> or = 80%) recurrent stenosis was identified using the following Doppler criteria: peak in-stent systolic velocity at least 330 cm/second, peak in-stent diastolic velocity at least 130 cm/second, and peak internal carotid artery/common carotid artery velocity ratio at least 3.8. Follow-up studies were obtained at approximate fixed intervals of 1 day, 1 month, 6 months, and yearly. Angiography was performed in the event of recurrent symptoms, evidence of hemodynamically significant stenosis on Doppler ultrasonography, or both. Treatment was repeated because of symptoms, angiographic evidence of severe (> or = 80%) recurrent stenosis, or both of these. Stents were implanted in 142 vessels in 138 patients (all but five patients were considered high-risk surgical candidates and 25 patients were lost to follow-up review). For the remaining 112 patients (117 vessels), the mean duration of Doppler ultrasonography follow up was 16.42+/-10.58 months (range 4-54 months). Using one or more Doppler criteria, severe (> or = 80%) in-stent stenosis was detected in six patients (5%). Eight patients underwent repeated angiography. Six patients (three with symptoms) required repeated intervention (in four patients angioplasty alone; in one patient conventional angioplasty plus Cutting Balloon angioplasty; and in one patient stent-assisted angioplasty). CONCLUSIONS: In a subset of primarily high-risk surgical candidates treated with stent-assisted angioplasty, the rates of hemodynamically significant restenosis were comparable to surgical restenosis rates cited in previously published works. Treatment for recurrent stenosis incurred no instance of periprocedure neurological morbidity.

Gamma knife radiosurgery for trigeminal schwannomas.

BACKGROUND: Trigeminal schwannomas are uncommon tumors that may be microsurgically removed in selected cases, albeit with significant risk for new neurological morbidity. We evaluated the role of stereotactic radiosurgery as an alternative for patients with newly diagnosed or residual trigeminal schwannomas. METHODS: The records of 23 patients who underwent radiosurgery for trigeminal schwannoma were reviewed. The most frequent presenting symptoms were facial numbness (11 patients), diplopia (6 patients), and facial pain (3 patients). One patient presented with partial complex seizures as the first symptom. Twelve patients had undergone one or more prior resections. Eleven underwent radiosurgery on the basis of imaging diagnosis only. The mean tumor volume was 4.5 mL (range 0.46-11.2 cc). Radiosurgery was performed using a median marginal dose of 15 Gy (range, 13-20 Gy). RESULTS: At a median imaging follow-up of 40 months (range, 12-146), 20 of 22 evaluable patients (91%) had tumor growth control (regression in 15 and no further tumor growth in 5). One 80-year-old patient died of unrelated cause 4 months after radiosurgery. Two patients with enlarged tumors were treated effectively with repeat radiosurgery. Twelve of 23 patients (52%) reported improvement and 9 (39%) had no change in their symptoms. Two patients noted new neurological complaints (transient facial weakness in 1 patient and worsening of the preradiosurgery facial numbness in another patient). CONCLUSIONS: Radiosurgery is an effective minimally invasive management option for patients with residual or newly diagnosed trigeminal schwannomas.

A rare case of a ruptured middle meningeal aneurysm causing intracerebral hematoma in a patient with moyamoya disease.

Moyamoya disease is infrequently associated with intracranial aneurysms arising from the circle of Willis vessels or from "peripheral" branches of choroidal and meningeal vessels. We present a rare case of a moyamoya-related aneurysm arising along the dural junction of multiple meningeal branches from the external carotid artery causing intracerebral hemorrhage. Endovascular coil embolization of the middle meningeal artery (MMA) and occipital artery (OA) led to delayed aneurysm obliteration without rehemorrhage.

Stent-assisted coil placement for unruptured cerebral aneurysms.

OBJECT: The treatment of wide-necked cerebral aneurysms represents a challenging problem for neurosurgeons. The recent development of stents has provided clinicians with the ability to treat these aneurysms while keeping the parent vessel patent. The long-term occlusion rate of aneurysms treated with stent-assisted coil placement has yet to be investigated. The authors report the use of a new intracranial stent-the Neuroform microstent-in the treatment of unruptured wide-necked cerebral aneurysms. METHODS: Thirty-two patients harboring unruptured wide-necked intracranial aneurysms underwent a stent-assisted coil placement procedure. Patients were pretreated with antiplatelet agents, and a stent was positioned across the neck of the aneurysm. The next step was the insertion of coils into the aneurysm cavity. Patients received anticoagulation therapy for 24 hours after the procedure. All 32 patients with unruptured wide-necked cerebral aneurysms were suitable candidates for this procedure. Occlusion of at least 90% of the aneurysm was achieved in 24 patients (75%) and 0% occlusion was observed in five patients (15%). Two patients experienced thromboembolic events, one of which was directly related to the stent. The overall complication rate was 6.3%. CONCLUSIONS: Intracranial stents will be used more frequently in the new era of endovascular management of widenecked cerebral aneurysms. With some technical improvements and more data on long-term occlusion rates, this new modality should improve the occlusion of wide-necked cerebral aneurysms while protecting the parent vessel.

Alcohol embolization of carotid-cavernous indirect fistulae.

OBJECTIVE: Carotid-cavernous fistulae (CCFs) are abnormal communications between the carotid artery and cavernous sinus that may present with rapid visual deterioration and extraocular paresis as a result of increasing intraocular pressure requiring emergent treatment to preserve vision. We present a technique of balloon-assisted ethanol embolization of the cavernous carotid artery supply to indirect CCFs providing immediate reduction in intraocular pressure with symptomatic improvement. METHODS: We reviewed clinical and angiographic data and present a retrospective case series illustrating six patients who underwent endovascular embolization because of worsening visual acuity and extraocular motility disorder caused by CCFs. Cerebral angiography revealed significant blood supply from the cavernous carotid artery to these CCFs. We performed ethanol embolization of these branches with distal balloon protection. RESULTS: Five of the six patients experienced immediate and sustained (mean follow-up, 21 mo) decreases in intraocular pressure, with significant symptom improvement. One patient experienced cavernous sinus thrombosis after conclusion of embolization, which caused a temporary worsening of symptoms that improved gradually over time. CONCLUSION: Many surgical and endovascular options are available to treat indirect CCFs. Absolute ethanol is a liquid agent that causes immediate vessel sclerosis and occlusion, which makes it a dangerous but potent liquid embolic agent. With distal temporary balloon protection to prevent migration of ethanol, we achieved excellent clinical and angiographic results using absolute ethanol to embolize the cavernous carotid supply to indirect CCFs. This represents a safe and effective method of endovascular management of this complex vascular anomaly.

Target-specific multimodality endovascular management of carotid artery blow-out syndrome.

We describe a novel multimodality endovascular approach to safely control hemorrhage from a carotid artery pseudoaneurysm and tumor vasculature associated with a squamous cell carcinoma. This approach was used in the case of a 68-year-old man who had previously undergone a laryngectomy, chemotherapy, and brachytherapy and who subsequently experienced acute oropharyngeal bleeding. Angiography detected a carotid artery pseudoaneurysm and significant tumor vascularity. A target-specific multimodality approach was taken to embolize the potential etiologies for both the current and any future hemorrhages. Stent-assisted coiling of the pseudoaneurysm was successful. The tumor blush was treated with polyvinyl alcohol particles and both retrievable and nonretrievable coils. Endovascular surgeons have become increasingly involved in the management of patients with carotid injuries and with neoplasms in and around the skull base. Current endovascular technology provides a rapid target-specific approach to the treatment of carotid artery blow-out syndrome and has a greater potential to lower morbidity than does carotid sacrifice.

Lumbar microdiscectomy: a historical perspective and current technical considerations.

A historical review is presented of the original descriptions of lumbar discectomy, focusing on the evolution toward a less invasive surgical approach following the introduction of the operating microscope. From the initial work in Europe by Yasargil and Caspar to the popularization of microdiscectomy by Williams and Wilson in the United States, this procedure has successfully reduced operative time, surgical morbidity, and incision size while allowing patients to return to work faster. Emphasis is placed on the importance of a careful preoperative clinical and radiographic evaluation by identifying factors that may help in the prediction of a successful surgical outcome. A modification of the lumbar microdiscectomy technique is described including patient positioning in the lateral position as well as minimal disc space and nerve root manipulation. In their experience performing more than 3000 microdiscectomies, the authors have produced good-to-excellent clinical results in nearly 90% of patients, with the majority returning to work within 1 month. The complication rate of dural tears, discitis, or root injury has been less than 2%, with a reoperation rate of 5%. The authors believe that lumbar microdiscectomy remains the gold standard with which all other discectomy techniques must be compared.