Spinal arteriovenous malformations associated with Klippel-Trenaunay-Weber syndrome: a literature search and report of two cases.

SUMMARY: Patients with Klippel-Trenaunay-Weber syndrome present with venous varices, cutaneous capillary malformations, and tissue hypertrophy, usually involving an extremity. A small but important subset also harbors arteriovenous malformations (AVMs) of the spine. We report 2 such cases, 1 with 3 concurrent spinal arteriovenous fistulas. These cases and our review of the literature emphasize the importance of screening the spine for AVMs. In addition, it is also important to investigate for the presence of multiple spinal AVMs.

Acute physiological derangement is associated with early radiographic cerebral infarction after subarachnoid haemorrhage.

BACKGROUND: Cerebral infarction after aneurysmal subarachnoid haemorrhage (SAH) is presumed to be due to cerebral vasospasm, defined as arterial lumen narrowing from days 3 to 14. METHODS: We reviewed the computed tomography scans of 103 patients with aneurysmal SAH for radiographic cerebral infarction and controlled for other predictors of outcome. A blinded neuroradiologist reviewed the angiograms. Cerebral infarction from vasospasm was judged to be unlikely if it was visible on computed tomography within 2 calendar days of SAH or if angiography showed no vasospasm in a referable vessel, or both. RESULTS: Cerebral infarction occurred in 29 (28%) of 103 patients with SAH. 18 patients had cerebral infarction that was unlikely to be due to vasospasm because it was visible on computed tomography by day 2 (6 (33%)) or because angiography showed no vasospasm in a referable artery (7 (39%)), or both (5 (28%)). In a multivariate model, cerebral infarction was significantly related to World Federation of Neurologic Surgeons grade (odds ratio (OR) 1.5/grade, 95% confidence interval (CI) 1.1 to 2.01, p = 0.006) and SAH-Physiologic Derangement Score (PDS) >2 (OR 3.7, 95% CI 1.4 to 9.8, p = 0.01) on admission. Global cerebral oedema (OR 4.3, 95% CI 1.5 to 12.5, p = 0.007) predicted cerebral infarction. Patients with cerebral infarction detectable by day 2 had a higher SAH-PDS than patients with later cerebral infarction (p = 0.025). CONCLUSIONS: Many cerebral infarctions after SAH are unlikely to be caused by vasospasm because they occur too soon after SAH or because angiography shows no vasospasm in a referable artery, or both. Physiological derangement and cerebral oedema may be worthwhile targets for intervention to decrease the occurrence and clinical impact of cerebral infarction after SAH.

Quantifying Intracranial Aneurysm Wall Permeability for Risk Assessment Using Dynamic Contrast-Enhanced MRI: A Pilot Study.

BACKGROUND AND PURPOSE: Pathological changes in the intracranial aneurysm wall may lead to increases in its permeability; however the clinical significance of such changes has not been explored. The purpose of this pilot study was to quantify intracranial aneurysm wall permeability (K(trans), VL) to contrast agent as a measure of aneurysm rupture risk and compare these parameters against other established measures of rupture risk. We hypothesized K(trans) would be associated with intracranial aneurysm rupture risk as defined by various anatomic, imaging, and clinical risk factors. MATERIALS AND METHODS: Twenty-seven unruptured intracranial aneurysms in 23 patients were imaged with dynamic contrast-enhanced MR imaging, and wall permeability parameters (K(trans), VL) were measured in regions adjacent to the aneurysm wall and along the paired control MCA by 2 blinded observers. K(trans) and VL were evaluated as markers of rupture risk by comparing them against established clinical (symptomatic lesions) and anatomic (size, location, morphology, multiplicity) risk metrics. RESULTS: Interobserver agreement was strong as shown in regression analysis (R(2) > 0.84) and intraclass correlation (intraclass correlation coefficient >0.92), indicating that the K(trans) can be reliably assessed clinically. All intracranial aneurysms had a pronounced increase in wall permeability compared with the paired healthy MCA (P < .001). Regression analysis demonstrated a significant trend toward an increased K(trans) with increasing aneurysm size (P < .001). Logistic regression showed that K(trans) also predicted risk in anatomic (P = .02) and combined anatomic/clinical (P = .03) groups independent of size. CONCLUSIONS: We report the first evidence of dynamic contrast-enhanced MR imaging-modeled contrast permeability in intracranial aneurysms. We found that contrast agent permeability across the aneurysm wall correlated significantly with both aneurysm size and size-independent anatomic risk factors. In addition, K(trans) was a significant and size-independent predictor of morphologically and clinically defined high-risk aneurysms.

Failure of surgery to improve outcome in hypertensive putaminal hemorrhage. A prospective randomized trial.

Hypertensive putaminal hemorrhage remains a major cause of hemorrhagic stroke carrying extremely high morbidity. Considerable controversy remains regarding the optimal form of therapy. Between 1983 and 1989 we conducted a prospective randomized trial with three treatment strategies: best medical management, best medical management plus intracranial pressure monitoring, and surgical evacuation. Only patients with significant deficit harboring a putaminal hematoma at least 3.0 cm in diameter were entered. The study was interrupted after 21 patients had been studied (9, best medical management; 4, intracranial pressure monitoring; and 8, surgical evacuation). No differences were found among groups for age, admission blood pressure, and time interval between onset of symptoms and arrival at hospital. None of the subjects were capable of returning to prestroke activity. Fifteen (71%) died or remained vegetative at 6 months, and only 4 (19%) were capable of independent life at home. Of the 9 patients in the best medical management arm, 7 were dead or vegetative. In the surgical group, 4 patients died and only 2 were capable of independent life. These results suggest that current medical and neurosurgical therapies remain ineffective in preventing the devastating neurologic consequences of hypertensive putaminal hemorrhage.

Preoperative embolization of cerebral arteriovenous malformations with polyvinyl alcohol particles: experience in 51 adults.

In order to determine possible risk factors and to assess the value of platinum microcoils added to polyvinyl alcohol particles in preoperative embolization of cerebral arteriovenous malformations in adults, we reviewed our experience with this procedure. Between September 1985 and June 1989, we performed embolizations in 54 patients with cerebral arteriovenous malformations. Of these, procedures in 51 adults involved the use of polyvinyl alcohol particles, either alone (n = 29) or in combination with platinum microcoils (n = 21). A complication during catheterization precluded embolization in another patient. Beginning as flow-directed embolizations via carotid artery catheterizations (n = 12), newer catheters allowed progression to superselective intracerebral catheterizations (n = 38). Embolization has led to shorter surgical procedures, more clearly defined operative margins, and less bloody operative fields. We have not found recanalization to significantly hinder embolization results with polyvinyl alcohol when resection is undertaken within 1-4 weeks of embolization. Its relative safety and ease of manipulation at surgery argue for its use. We found no significant increase in complications based on patient age, venous drainage of the arteriovenous malformation, or the circulation embolized. Embolization results in cerebral arteriovenous malformations were improved with superselective catheterization and most improved with the combined use of polyvinyl alcohol for nidus embolization followed by occlusion of the feeding vessel with microcoils.

Treatment of traumatic arterial vasospasm with intraarterial papaverine infusion.

We report a case of severe posttraumatic arterial vasospasm treated with repetitive intraarterial papaverine infusions. The salient features of the mechanism of action of papaverine are included.

Calcium 45 autoradiography and dual-isotope single-photon emission CT in a canine model of cerebral ischemia and middle cerebral artery occlusion.

PURPOSE: To determine whether transient ischemia can be separated from permanent ischemia via calcium 45 autoradiography and to assess the applicability of dual isotope single-photon emission CT (SPECT) in the evaluation of cerebral blood flow. METHODS: We examined calcium influx in 12 dogs (group A) by using whole-brain calcium 45 autoradiography: Animals received 250 microCi/kg 24 hours after 30-minute (n = 6) or permanent (n = 6) middle cerebral artery (MCA) occlusion. Forty-eight hours after MCA occlusion, 5-mm coronal brain sections were fixed for either autoradiography or pathologic examination. In a separate study, 9 mongrel dogs (group B) were given 250 microCi/kg calcium 45 and a mean dose of 700 microCi/kg technetium Tc 99m hexamethylpropyleneamine oxime intravenously. A silicone plug was then injected into the internal carotid artery and angiography was performed to verify MCA occlusion. A 10th (control) animal did not undergo occlusion. In an 11th animal, placement of the plug could not be achieved and a slurry of microfibrillar collagen was injected into the carotid artery. No angiography was performed in animals 10 and 11. After occlusion, each animal was injected with a mean dose of 126 microCi/kg simultaneous acquisition for technetium 99m and 123I-iodoamphetamine. RESULTS: In group A, all animals who had permanent MCA occlusion showed infarction and increased calcium 45 uptake in infarcted territories. None of the animals who had 30-minute occlusion had either increased calcium 45 uptake or infarction at 48 hours. In group B, 7 or 10 dogs had SPECT findings that were consistent with the calcium autoradiographic marker for ischemia. One animal died during the procedure and 1 dog served as a control. CONCLUSION: Calcium 45 autoradiography allowed distinction between areas of temporary and permanent occlusion. Iodoamphetamine imaging was not consistently sensitive to that level of ischemia. Timing of calcium influx may lead to insight that could impact timing of pharmacologic or endovascular intervention.

Emergent aneurysm surgery without cerebral angiography for the comatose patient.

Neurologically based clinical grading scales offer excellent prognostic information for the patient suffering diffuse subarachnoid hemorrhage (SAH). These grading scales are less applicable to patients with life-threatening intraparenchymal hematomas after aneurysmal rupture. During the last 3 years, four patients in a comatose state with brain stem compression syndromes documented by computed tomographic scans have undergone emergent operation in our neurosurgical service. Each patient was so critically ill that we believed it unwise to delay craniotomy for diagnostic angiography. The average delay from the onset of coma to skin incision was 3.02 hours (range, 1.67-6.5 hours), and the average delay from arrival in our unit until skin incision was 1.8 hours (range, 0.75-2.5 hours). The condition of two arousable patients deteriorated while they were in the emergency room, presumably from new bleeding. Each patient underwent craniotomy for hematoma evacuation, definitive aneurysm clipping, and lobectomy for decompression. Temporary clipping was employed in one patient, and intraoperative rupture occurred in two others. Three patients survived but retain significant disability. Emergent craniotomy with empiric exploration of appropriate subarachnoid cisterns after hematoma decompression may be life-saving in some cases. The delay imposed for diagnostic angiography may be avoided in attempts to save vital minutes of severe brain stem compression.

The use of acetazolamide-enhanced regional cerebral blood flow measurement to predict risk to arteriovenous malformation patients.

Regional hemodynamic disturbances may complicate the treatment of certain cerebral arteriovenous malformations (AVM) and occasionally produce life-threatening situations. Acetazolamide-enhanced quantitative regional cerebral blood flow studies were performed preoperatively in 35 patients to determine if patterns of vasoreactivity could be identified that might be markers for postoperative morbidity. Ipsilateral and contralateral regions of hypoperfusion were identified on resting studies, and a steal index was calculated by dividing the regional cerebral blood flow in the steal region by the flow in a normal cerebellar region. Flow in these regions of interest was again quantitated after the administration of acetazolamide, a known cerebral vasodilator. A delta value was calculated by subtracting the resting index values from the acetazolamide indices. Abnormally enhanced vasoreactivity (vasodilation) to acetazolamide stimulation was noted in these threatened territories in AVM that had perforating vessel feeding and angiographic steal phenomena, that developed hyperemic disturbances, and that resulted in poor outcomes. These findings call into question traditional theories of AVM-related hemodynamic decompensation and suggest unique smooth muscle derangements in cerebral vasculature in some AVM patients.

Causes of morbidity and mortality from surgery of aneurysms of the distal basilar artery.

Despite modern neurosurgical technology and neuroanesthetic care, treatment of aneurysms of the distal basilar artery remains fraught with complications. Between 1982 and 1988, 126 patients with aneurysms of the distal basilar artery who had been treated by 2 surgeons were retrospectively analyzed to determine the causes of morbidity and mortality from this disease and its treatment. Ten patients (8%) died, and 14 patients (11%) suffered permanent neurological disability after treatment. The causes of failed management could be grouped into the following categories: 1) direct effects of hemorrhage; 2) errors in surgical timing; 3) conceptual errors; 4) technical errors; 5) morbidity from delayed cerebral ischemia; and 6) complications of hypertensive/hypervolemic therapy for symptomatic vasospasm; a small group of patients who died despite having received what we consider excellent management were grouped under a seventh category, "bad luck." Frequently, patients who did poorly suffered from multiple complications, each of which contributed to their overall morbidity. It is our hope that increased awareness of these potential pitfalls and the further evolution of intravascular technique in selected cases will, in time, improve the outlook for patients suffering from these dangerous lesions.

Enlarging thrombosed aneurysm of the distal basilar artery.

The case of a 65-year-old man who had partial left third nerve palsy is reported. Radiographic examination disclosed a completely thrombosed giant suprasellar aneurysm. Although an angiogram appeared to indicate that his aneurysm arose from the distal basilar artery, he was also noted to have an unusual and ectatic distal internal carotid artery on the left side, and this was also felt to be a potential source of the aneurysm. Operative exploration was performed and confirmed the basilar artery as the sight of origin, and definitive therapy was deferred. The patient's progress was monitored, and for 3 years his neurological course was stable and there was no change in his radiographic abnormalities. During the 6 months following this period, the patient developed signs and symptoms of progressing hydrocephalus and was found to have significant enlargement of his still completely thrombosed giant aneurysm. This complicated case highlights the controversy regarding the management of this difficult condition, particularly with regard to endovascular therapies, and also provides insight into the evolution of this dynamic disease process.

Resolution of a recurrent/residual bacterial aneurysm during antibiotic therapy.

Management of patients harboring infectious intracranial aneurysms remains controversial because of the technical problems associated with the obliteration of these lesions as well as their frequent regression during antibiotic therapy. A case of a ruptured bacterial aneurysm of the distal middle cerebral artery in which a segment of the artery was found to be inflamed and necrotic is presented. The ruptured portion of the sac was clipped, leaving a small tag of aneurysmal tissue. Five days later, this tag was found to have expanded into a second aneurysm. This second lesion resolved with antibiotic therapy. Because of the responsiveness of infected cerebral arteries to the appropriate antibiotics, a less than radical surgical tactic may be a successful alternative to excision of the diseased arterial segment followed by distal revascularization in treating these lesions.

Intravenous perflubron emulsion administration improves the recovery of auditory evoked potentials after temporary brain stem ischemia in dogs.

Oxygent, a second-generation perfluorocarbon (Perflubron) emulsion (Alliance Pharmaceutical Corporation, San Diego, CA) with superior oxygen delivery characteristics and greater stability than previous perfluorocarbon emulsions, was evaluated as a cerebroprotective agent in a dog model of partial brain stem ischemia. Six dogs were exposed to 20 minutes of isolated brain stem ischemia after receiving an intravenous bolus of Oxygent at a dose of 1.5 ml/kg. Brain stem auditory evoked potentials (BAEP) and regional cerebral blood flow were measured before and during the ischemia and for 5 hours after reperfusion. Changes in BAEP in this group were compared with those in four control dogs that experienced an identical ischemic period but that did not receive Oxygent. During the ischemic period, both control and Oxygent-treated animals experienced a dramatic decline in BAEP to under 10% of the baseline value. After reperfusion, the BAEP increased in both groups to between 50 and 70% of the baseline. In the Oxygent-treated group, the BAEP continued to recover to a final sustained level of over 80% of baseline. In contrast, the control animals suffered a drop in BAEP to 23% of baseline after the brief postischemic peak. The continued improvement in the BAEP in the Oxygent-treated group compared with the control groups suggests that Oxygent may be of some value as a protective agent to the brain stem during ischemia. This effect may be the result of improved oxygen delivery to the brain stem or may be related to other effects of Oxygent, such as reduction of reperfusion injury. Results suggest that Oxygent may be useful as a cerebroprotectant during cerebrovascular surgeries that require temporarily reducing blood flow to the brain stem.

Intraoperative ventricular puncture.

Modern neuroanesthetic techniques frequently provide the neurosurgeon with adequate brain relaxation for an atraumatic frontotemporal or transylvian dissection. Circumstances such as recent subarachnoid hemorrhage with brain edema and acute hydrocephalus can mandate significant frontal lobe retraction before access to cerebrospinal fluid (CSF) drainage from the basal cisterns is gained. A simple technique can give the "early" aneurysm surgeon reliable access to the frontal horn of the lateral ventricle for intraoperative drainage of CSF before brain retraction.

The protective effects of thiopental on brain stem ischemia.

Thiopental, a barbiturate anesthetic, which at high doses suppresses cortical electroencephalogram activity, was evaluated as a neuroprotective agent in a dog model of reversible, hindbrain ischemia. Fourteen dogs were exposed to 20 minutes of isolated brain stem ischemia after pretreatment with 35 mg per kg of thiopental or placebo. Brain stem auditory evoked potentials (BAEPs) and regional cerebral blood flow were measured before and during the ischemia and for 5 hours after reperfusion. During the ischemic period, both control and thiopental-treated animals experienced dramatic declines in the BAEPs to less than 10% of baseline. On reperfusion for 30 minutes, the BAEPs increased in both groups to near 40% of baseline. In the thiopental-treated animals, the BAEPs continued to recover variably to a mean of 70% of baseline by 5 hours of reperfusion. In contrast, untreated animals showed a decline in BAEPs after 30 minutes of reperfusion. The improved recovery of BAEPs in the thiopental-treated animals suggests that thiopental may be of some value as a cerebroprotective agent, although the mechanism remains unclear. The variability in recovery in this group implies that other factors play a significant role in mediating functional recovery from ischemic brain stem damage.

Current results of the surgical management of aneurysms of the basilar apex.

OBJECTIVE: To provide current information regarding the expected clinical outcomes and sources of morbidity and mortality in the modern surgical management of basilar apex aneurysms. METHOD: A retrospective review was conducted of 303 cases of such aneurysms that were treated surgically during 18 years at one institution. Postoperative angiography was performed in 81% of the cases. Clinical grading using the Glasgow Outcome Scale was conducted at the time of hospital discharge and for 91% of the surviving patients at 6 months after surgery. The preoperative parameters that were linked statistically to poor clinical outcome were identified through the use of single and multivariate analyses. RESULTS: More than 80% of the patients were operated on using some modification of the trans-sylvian exposure, and temporary arterial occlusion was used routinely. Good outcomes (Glasgow Outcome Scale scores of 4 or 5) were achieved in 76% of the patients at the time of discharge and in 81% of the patients at 6 months after surgery. There was no incidence of postoperative subarachnoid hemorrhage. Residual aneurysm was revealed by postoperative angiography in 6% of the cases. Factors found to be statistically linked to poor outcome included poor admission grade (Hunt and Hess Grades IV and V), patient age older than 65 years, computed tomographic demonstration of thick basal cistern clot, aneurysm size greater than 20 mm, and symptoms attributable to brain stem compression. CONCLUSION: Direct microsurgical repair of basilar apex aneurysms should result in good clinical outcomes in 80 to 85% of cases, with reliable prevention of subarachnoid bleeding and routine elimination/reduction of symptoms secondary to mass effect. Those patients who are at high risk for poor outcomes can be identified by the presence of certain clinical, radiographic, and demographic features before undergoing surgery and can be considered for alternative or adjunctive modes of therapy if long-term efficacy of such treatment is demonstrated.

Use of the extracranial-intracranial arterial bypass in the management of refractory vasospasm: a case report.

Cerebral arterial vasospasm after aneurysmal subarachnoid hemorrhage remains one of the major causes of morbidity and mortality in patients surviving the initial hemorrhage. Once established, no known method has been shown to reverse this process in humans. Although intravascular volume expansion and induced arterial hypertension have been shown to be effective in the reversal of neurological deficits secondary to vasospasm, a large proportion of patients remain refractory to these methods. We report one such case successfully managed by the establishment of an extracranial-intracranial anastomosis in an attempt to augment collateral flow.

A canine model of acute hindbrain ischemia and reperfusion.

Animal models of brain stem ischemia are needed for pathophysiological study and evaluation of treatment; few such models are available currently. A new canine model of hindbrain ischemia and reperfusion is introduced in this article. Through an anterior cervical approach, the basilar artery was surgically exposed in 18 dogs. The posterior communicating and superior cerebellar arteries were embolized with cyanoacrylate glue to isolate the posterior circulation from the anterior circulation. Reversible hindbrain ischemia was induced in 14 dogs by the temporary clipping of the vertebral and ventral spinal arteries for various periods (10-30 min), then the clips were removed and reperfusion was achieved for 5 hours. In all 14 dogs, the hindbrain ischemia was confirmed by the decreased perfusion pressure in the basilar artery (< 10 mm Hg), the diminished regional cerebral blood flow as measured with a laser Doppler flowmeter at the medulla oblongata (< 10 ml/100 g/min), the flattened brain stem auditory evoked potentials, and the increased leakage of Evans blue dye from tissue. These parameters did not change in the four control dogs. The changes in brain stem auditory evoked potentials were closely related to the length of ischemic interval; after 10 minutes of ischemia, reperfusion fully reversed the changes in brain stem auditory evoked potentials, but 20-minute and 30-minute ischemic intervals partially or totally depleted the brain stem auditory evoked potentials. Delayed postischemic hypoperfusion occurred in all five dogs that underwent the 30-minute ischemic interval. The early physiological changes in this model allowed us to estimate the severity of brain stem ischemia and the resulting damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Subtemporal transdural use of detachable balloons for traumatic carotid-cavernous fistulas.

Endovascular use of detachable balloons has revolutionized the management of carotid-cavernous fistulas so that the goals of angiographic elimination of fistula and preservation of carotid patency can usually be achieved nonsurgically. Certain circumstances of flow dynamics and anatomy, however, make an endovascular approach difficult for even an experienced interventional neuroradiologist. Fistulas involving the posterior carotid wall at its proximal cavernous entry and the anterior carotid wall in its initial horizontal intracavernous segment, as well as very low flow fistulas at other sites, have posed particular problems. Three patients with such traumatic fistulas whose endovascular treatment failed were managed by the direct transdural introduction of balloons. Intraoperative angiography was accomplished with open internal carotid artery (ICA) catheterization and the use of a portable C-arm with a 6-in. image intensifier. After temporal craniectomy and subtemporal exposure, the course of the cavernous ICA was mapped out with spinal needles and the site of the fistula was localized by intraoperative angiography. An incision was then made in the lateral wall of the cavernous sinus, and latex balloons were manually introduced via a 7 French introducer sheath. The balloons were inflated under angiographic control and detached when the fistula was obliterated. This simple technique was initially successful in three patients; the fistula was eliminated with preservation of carotid patency. One patient suffered a recurrence of his fistula 2 months postoperatively while lifting weights, and one patient developed a new 3rd nerve palsy after operation.

Hemodynamic assessment of the spinal cord arteriovenous malformation with intraoperative microvascular Doppler ultrasound: case report.

Microvascular Doppler recordings were taken from the nidus and draining system of a dural spinal cord arteriovenous malformation during operative treatment. Doppler signals readily showed the direction of blood flow in the draining vein and the hemodynamic effects of surgical maneuvers. Recording during alterations of mean arterial blood pressure and partial carbon dioxide pressure (pCO2) demonstrated lack of autoregulation and impaired CO2 reactivity in the AVM nidus. Microvascular Doppler techniques provide useful intraoperative assessment of the hemodynamics of arteriovenous malformations of the spinal cord.