Proper Indication of Decompressive Craniectomy for the Patients with Massive Brain Edema after Intra-arterial Thrombectomy.

OBJECTIVE: Numerous studies have indicated that early decompressive craniectomy (DC) for patients with major infarction can be life-saving and enhance neurological outcomes. However, most of these studies were conducted by neurologists before the advent of intra-arterial thrombectomy (IA-Tx). This study aims to determine whether neurological status significantly impacts the final clinical outcome of patients who underwent DC following IA-Tx in major infarction. METHODS: This analysis included 67 patients with major anterior circulation major infarction who underwent DC after IA-Tx, with or without intravenous tissue plasminogen activator. We retrospectively reviewed the medical records, radiological findings, and compared the neurological outcomes based on the "surgical time window" and neurological status at the time of surgery. RESULTS: For patients treated with DC following IA-Tx, a Glasgow coma scale (GCS) score of 7 was the lowest score correlated with a favorable outcome (p=0.013). Favorable outcomes were significantly associated with successful recanalization after IA-Tx (p=0.001) and perfusion/diffusion (P/D)-mismatch evident on magnetic resonance imaging performed immediately prior to IA-Tx (p=0.007). However, the surgical time window (within 36 hours, p=0.389; within 48 hours, p=0.283) did not correlate with neurological outcomes. CONCLUSION: To date, early DC surgery after major infarction is crucial for patient outcomes. However, this study suggests that the indication for DC following IA-Tx should include neurological status (GCS ≤7), as some patients treated with early DC without considering the neurological status may undergo unnecessary surgery. Recanalization of the occluded vessel and P/D-mismatch are important for long-term neurological outcomes.

Association of Bypass Surgery and Mortality in Moyamoya Disease.

Background Patients with moyamoya disease (MMD) have a high risk of stroke or death. We investigated whether extracranial to intracranial bypass surgery can reduce mortality by preventing strokes in patients with MMD. Methods and Results This nationwide retrospective cohort study encompassed patients with MMD registered under the Rare Intractable Diseases program via the Relieved Co-Payment Policy between 2006 and 2019, using the Korean National Health Insurance Service database. Following a 4-year washout period, landmark analyses were employed to assess mortality and stroke occurrence between the bypass surgery group and the nonsurgical control group at specific time points postindex date (1 month and 3, 6, 12, and 36 months). The study included 18 480 patients with MMD (mean age, 40.7 years; male to female ratio, 1:1.86) with a median follow-up of 5.6 years (interquartile range, 2.5-9.3; mean, 6.1 years [SD, 4.0 years]). During 111 775 person-years of follow-up, 265 patients in the bypass surgery group and 1144 patients in the nonsurgical control group died (incidence mortality rate of 618.1 events versus 1660.3 events, respectively, per 105 person-years). The overall adjusted hazard ratio (HR) revealed significantly lower all-cause mortality in the bypass surgery group from the 36-month landmark time point, for any stroke mortality from 3- and 6-month landmark time points, and for hemorrhagic stroke mortality from the 6-month landmark time point. Furthermore, the overall adjusted HRs for hemorrhagic stroke occurrence were beneficially maintained from all 5 landmark time points in the bypass surgery group. Conclusions Bypass surgery in patients with MMD was associated with a lower risk of all-cause and hemorrhagic stroke mortality and hemorrhagic stroke occurrence compared with nonsurgical control.

Progressive postoperative slippage of titanium aneurysm clip confirmed by follow-up radiographic imaging studies and by reoperation: a case report.

We report a case of postoperative slippage of a titanium clip that was used for a small ruptured anterior communicating artery aneurysm. Clipping was successful with no remnant in the initial operation. Progressive slippage of the clip was observed in follow-up brain computed tomography angiography studies. Digital subtraction angiography confirmed this finding. Reoperation was performed 19 days after the initial craniotomy. The clinical course after reoperation was uneventful.

Effects of an Infection Control Protocol for Coronavirus Disease in Emergency Mechanical Thrombectomy.

OBJECTIVE: Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, neurointerventionists have been increasingly concerned regarding the prevention of infection and time delay in performing emergency thrombectomy procedures in patients with acute stroke. This study aimed to analyze the effects of changes in mechanical thrombectomy protocol before and after the COVID-19 pandemic on procedure time and patient outcomes and to identify factors that significantly impact procedure time. METHODS: The last-normal-to-door, first-abnormal-to-door, door-to-imaging, door-to-puncture, and puncture-to-recanalization times of 88 patients (45 treated with conventional pre-COVID-19 protocol and 43 with COVID-19 protection protocol) were retrospectively analyzed. The recanalization time, success rate of mechanical thrombectomy, and modified Rankin score of patients at discharge were assessed. A multivariate analysis was conducted to identify variables that significantly influenced the time delay in the door-to-puncture time and total procedure time. RESULTS: The door-to-imaging time significantly increased under the COVID-19 protection protocol (p=0.0257) compared to that with the conventional pre-COVID-19 protocol. This increase was even more pronounced in patients who were suspected to be COVID-19-positive than in those who were negative. The door-to-puncture time showed no statistical difference between the conventional and COVID-19 protocol groups (p=0.5042). However, in the multivariate analysis, the last-normal-to-door time and door-to-imaging time were shown to affect the door-to-puncture time (p=0.0068 and 0.0097). The total procedure time was affected by the occlusion site, last-normal-to-door time, door-to-imaging time, and type of anesthesia (p=0.0001, 0.0231, 0.0103, and 0.0207, respectively). CONCLUSION: The COVID-19 protection protocol significantly impacted the door-to-imaging time. Shortening the door-to-imaging time and performing the procedure under local anesthesia, if possible, may be required to reduce the door-to-puncture and doorto- recanalization times. The effect of various aspects of the protection protocol on emergency thrombectomy should be further studied.

Changes in Blood Pressure and Heart Rate during Decompressive Craniectomy.

OBJECTIVE: Rapid increase in intracranial pressure (ICP) can result in hypertension, bradycardia and apnea, referred to as the Cushing phenomenon. During decompressive craniectomy (DC), rapid ICP decreases can cause changes in mean atrial blood pressure (mABP) and heart rate (HR), which may be an indicator of intact autoregulation and vasomotor reflex. METHODS: A total of 82 patients who underwent DC due to traumatic brain injury (42 cases), hypertensive intracerebral hematoma (19 cases), or major infarction (21 cases) were included in this prospective study. Simultaneous ICP, mABP, and HR changes were monitored in one minute intervals during, prior to and 5-10 minutes following the DC. RESULTS: After DC, the ICP decreased from 38.1±16.3 mmHg to 9.5±14.2 mmHg (p<0.001) and the mABP decreased from 86.4±14.5 mmHg to 72.5±11.4 mmHg (p<0.001). Conversly, overall HR was no significantly changed in HR, which was 100.1±19.7 rate/min prior to DC and 99.7±18.2 rate/min (p=0.848) after DC. Notably when the HR increased after DC, it correlated with a favorable outcome (p<0.001), however mortality was increased (p=0.032) when the HR decreased or remained unchanged. CONCLUSION: In this study, ICP was decreased in all patients after DC. Changes in HR were an indicator of preserved autoregulation and vasomotor reflex. The clinical outcome was improved in patients with increased HR after DC.

Clinical Significance of Decompressive Craniectomy Surface Area and Side.

OBJECTIVE: Decompressive craniectomy (DC) can partially remove the unyielding skull vault and make affordable space for the expansion of swelling brain contents. The objective of this study was to compare clinical outcome according to DC surface area (DC area) and side. METHODS: A total of 324 patients underwent different surgical methods (unilateral DC, 212 cases and bilateral DC, 112 cases) were included in this retrospective analysis. Their mean age was 53.4±16.6 years (median, 54 years). Neurological outcome (Glasgow outcome scale), ventricular intracranial pressure (ICP), and midline shift change (preoperative minus postoperative) were compared according to surgical methods and total DC area, DC surface removal rate (DC%) and side. RESULTS: DC surgery was effective for ICP decrease (32.3±16.7 mmHg vs. 19.2±13.4 mmHg, p<0.001) and midline shift change (12.5±7.6 mm vs. 7.8±6.9 mm, p<0.001). The bilateral DC group showed larger total DC area (125.1±27.8 cm2 for unilateral vs. 198.2±43.0 cm2 for bilateral, p<0.001). Clinical outcomes were nonsignificant according to surgical side (favorable outcome, p=0.173 and mortality, p=0.470), significantly better when total DC area was over 160 cm2 and DC% was 46% (p=0.020 and p=0.037, respectively). CONCLUSION: DC surgery is effective in decrease the elevated ICP, decrease the midline shift and improve the clinical outcome in massive brain swelling patient. Total DC area and removal rate was larger in bilateral DC than unilateral DC but clinical outcome was not influenced by DC side. DC area more than 160 cm2 and DC surface removal rate more than 46% were more important than DC side.

Microsurgical anatomy of the facial nerve.

The facial nerve connections and pathways from the cortex to the brainstem are intricate and complicated. The extra-axial part of the facial nerve leaves the lateral part of the pontomedullary sulcus and enters the temporal bone through the internal acoustic meatus. In the temporal bone, the facial nerve branches into fibers innervating the glands and tongue. After it emerges from the temporal bone it supplies various facial muscles. It contains a motor, general sensory, special sensory, and autonomic components. The physician needs comprehensive knowledge of the anatomy and courses of the facial nerve to diagnose and treat lesions and diseases of it so that surgical complications due to facial nerve injury can be avoided. This review describes the microsurgical anatomy of the facial nerve and illustrates its anatomy in relation to the surrounding bone, connective, and neurovascular structures.

Temperature Difference between Brain and Axilla according to Body Temperature in the Patient with Brain Injury.

OBJECTIVE: Commonly, brain temperature is estimated from measurements of body temperature. However, temperature difference between brain and body is still controversy. The objective of this study is to know temperature gradient between the brain and axilla according to body temperature in the patient with brain injury. METHODS: A total of 135 patients who had undergone cranial operation and had the thermal diffusion flow meter (TDF) insert were included in this analysis. The brain and axilla temperatures were measured simultaneously every 2 hours with TDF (2 kinds of devices: SABER 2000 and Hemedex) and a mercury thermometer. Saved data were divided into 3 groups according to axillary temperature. Three groups are hypothermia group (less than 36.4°C), normothermia group (between 36.5°C and 37.5°C), and hyperthermia group (more than 37.6°C). RESULTS: The temperature difference between brain temperature and axillary temperature was 0.93±0.50°C in all data pairs, whereas it was 1.28±0.56°C in hypothermia, 0.87±0.43°C in normothermia, and 0.71±0.41°C in hyperthermia. The temperature difference was statistically significant between the hypothermia and normothermia groups (p=0.000), but not between the normothermia and hyperthermia group (p=0.201). CONCLUSION: This study show that brain temperature is significantly higher than the axillary temperature and hypothermia therapy is associated with large brain-axilla temperature gradients. If you do not have a special brain temperature measuring device, the results of this study will help predict brain temperature by measuring axillary temperature.

Current Status of Neurosurgical and Neurointensive Care Units in Korea : A Brief Report on Nationwide Survey Results.

OBJECTIVE: The purpose of this study is identify the operation status of the neurosurgical care units (NCUs) in neurosurgical residency training hospitals nationwide and determine needed changes by comparing findings with those obtained from the Korean Neurosurgical Society (KNS) and Korean Society of Neurointensive Care Medicine (KNIC) survey of 2010. METHOD: This survey was conducted over 1 year in 86 neurosurgical residency training hospitals and two neurosurgery specialist hospitals and focused on the following areas : 1) the current status of the infrastructure and operating systems of NCUs in Korea, 2) barriers to installing neurointensivist team systems, 3) future roles of the KNS and KNIC, and 4) a handbook for physicians and practitioners in NCUs. We compared and analyzed the results of this survey with those from a KNIC survey of 2010. RESULTS: Seventy seven hospitals (87.5%) participated in the survey. Nineteen hospitals (24.7%) employed a neurointensivist or faculty member; Thirty seven hospitals (48.1%) reported high demand for neurointensivists, and 62 hospitals (80.5%) stated that the mandatory deployment of a neurointensivist improved the quality of patient care. Forty four hospitals (57.1%) believed that hiring neurointensivist would increase hospital costs, and in response to a question on potential earnings declines. In terms of potential solutions to these problems, 70 respondents (90.9%) maintained that additional fees were necessary for neurointensivists' work, and 64 (83.1%) answered that direct support was needed of the personnel expenses for neurointensivists. CONCLUSION: We hope the results of this survey will guide successful implementation of neurointensivist systems across Korea.

Compare the Intracranial Pressure Trend after the Decompressive Craniectomy between Massive Intracerebral Hemorrhagic and Major Ischemic Stroke Patients.

OBJECTIVE: Massive intracerebral hemorrhage (ICH) and major infarction (MI) are devastating cerebral vascular diseases. Decompression craniectomy (DC) is a common treatment approach for these diseases and acceptable clinical results have been reported. Author experienced the postoperative intracranaial pressure (ICP) trend is somewhat different between the ICH and MI patients. In this study, we compare the ICP trend following DC and evaluate the clinical significance. METHODS: One hundred forty-three patients who underwent DC following massive ICH (81 cases) or MI (62 cases) were analyzed retrospectively. The mean age was 56.3±14.3 (median=57, male : female=89 : 54). DC was applied using consistent criteria in both diseases patients; Glasgow coma scale (GCS) score less than 8 and a midline shift more than 6 mm on brain computed tomography. In all patients, ventricular puncture was done before the DC and ICP trends were monitored during and after the surgery. Outcome comparisons included the ictus to operation time (OP-time), postoperative ICP trend, favorable outcomes and mortality. RESULTS: Initial GCS (p=0.364) and initial ventricular ICP (p=0.783) were similar among the ICH and MI patients. The postoperative ICP of ICH patients were drop rapidly and maintained within physiological range if greater than 80% of the hematoma was removed. While in MI patients, the postoperative ICP were not drop rapidly and maintained above the physiologic range (MI=18.8 vs. ICH=13.6 mmHg, p=0.000). The OP-times were faster in ICH patients (ICH=7.3 vs. MI=40.9 hours, p=0.000) and the mortality rate was higher in MI patients (MI=37.1% vs. ICH=17.3%, p=0.007). CONCLUSION: The results of this study suggest that if greater than 80% of the hematoma was removed in ICH patients, the postoperative ICP rarely over the physiologic range. But in MI patients, the postoperative ICP was above the physiologic range for several days after the DC. Authors propose that DC is no need for the massive ICH patient if a significant portion of their hematoma is removed. But DC might be essential to improve the MI patients' outcome and timely treatment decision.

Determining the Lower Limit of Cerebral Perfusion Pressure in Patients Undergoing Decompressive Craniectomy Following Traumatic Brain Injury.

BACKGROUND: In patients with severe traumatic brain injury (TBI), maintaining systolic blood pressure >90 mm Hg, intracranial pressure (ICP) <20 mm Hg and cerebral perfusion pressure (CPP) >60-70 mm Hg is recommended to improve clinical outcomes. A recommended CPP value for patients treated with decompressive craniectomy (DC) has not been clearly studied. We aimed to determine whether the targeted CPP can be lowered in patients treated with DC. METHODS: This retrospective analysis included 191 patients who underwent DC for TBI. All patients were monitored for ICP and blood pressure during and after DC. CPP was calculated every 2 hours after DC. Patient outcomes were evaluated 6 months after initial treatment. RESULTS: Mean patient age was 50.8 years (median 52 years), and 79.1% of patients were male. Initial Glasgow Coma Scale score was 6.2 (median 6). Comparing clinical outcome based on postoperative ICP >25 mm Hg and <25 mm Hg, Extended Glasgow Outcome Scale score was 1.4 (>25 mm Hg) and 4.9 (<25 mm Hg) (P = 0.000). In patients maintained at ICP <25 mm Hg, mortality was increased significantly with CPP between 35 mmHg and 30 mm Hg (χ2, P = 0.029 vs. P = 0.062). CONCLUSIONS: Patients with TBI who underwent DC with postoperative ICP maintained <25 mm Hg and CPP >35 mm Hg may have similar mortality as patients with CPP >60-70 mm Hg who did not undergo DC. For patients with TBI who undergo DC, targeted CPP might be lowered to 35 mm Hg if ICP is maintained <25 mm Hg.

Clinical Results of the Intra-Arterial Thrombolysis with Stent Retriever Device Weather Perfusion Diffusion Mismatching and Intravenous Tissue Plasminogen Activator Administration.

OBJECTIVE: Intraarterial thrombolysis (IA-Tx) with stent retriever is accepted as an additional treatment for selected patients and the clinical benefit is well reported. Each intravenous tissue plasminogen activator administration (IV-tPA) and perfusion diffusion mismatching (P/D-mismatching) is well known the beneficial effects for recanalization and clinical outcomes. In this report, authors analyzed the clinical outcomes of additional IA-Tx with retrieval stent device, according to the combined IV-tPA and P/D-mismatching or not. METHODS: Eighty-one treated IA-Tx with the Solitaire stent retriever device, diagnosed as anterior circulation larger vessel occlusion were included in this study. Computed tomography-angiography (CTA) was done as an initial diagnostic image and acute stroke magnetic resonance image (MRI) followed after the IV-tPA. Forty-two patients were in the tPA group and 39 patients were in the non-tPA group. Recanalization rate, clinically significant hemorrhagic (sICH) and clinical outcomes were recorded according to the IV-tPA and P/D-mismatching. RESULTS: Recanalization rate was 81.0% in IV-tPA group, and it was 69.2% in non-tPA group (p = 0.017). While sICH were 19.9% and 25.6%, respectively (p = 0.328). Neurologic outcomes did not influence by IV-tPA administration or not. But according to the P/D-mismatching, the recanalization rate and sICH were 91.9% and 16.7% in the mismatched group and 46.7% and 46.7% in the matched group (p = 0.008 and p = 0.019, respectively). CONCLUSION: For patients treated with IA-Tx with retrieval stent, IV-tPA infusion does not influence on the sICH, recanalization rate and neurologic outcomes. But P/D-mismatching was correlated well with sICH, recanalization rate and clinical outcomes.

Brain Metastases of Papillary Thyroid Carcinoma with Horner's Syndrome.

Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy and has relatively favorable prognosis. Blood-borne metastases of PTC are very rare among the thyroid malignancies. Moreover a case of blood-borne central nervous system metastasized PTC with only unilateral Horner's syndrome, and without any abnormalities in laboratory or physical examinations has not been described before. A 53-year-old female patient had been managed in ophthalmologic clinic due to vague symptoms of right monocular blurred vision with eye dryness for 3 months, but showed no signs of improvement. So it was performed a magnetic resonance imaging and magnetic resonance angiography to evaluate the possibilities of cerebral lesion. And a left frontal mass was incidentally found, and the tumor turned out to be a PTC that had metastasized to brain, regional lymph node, cervical, thoracic spine, and lung. We describe a PTC with extraordinary initial symptoms that metastasized to an unusual site. We recommend that if a papillary thyroid tumor with unusual symptoms or at an advanced stage is found, further investigation should be performed for distant metastasis.

Spontaneous spinal subdural hematoma concurrent with cranial subdural hematoma.

A 39-year old female presented with chronic spinal subdural hematoma manifesting as low back pain and radiating pain from both legs. Magnetic resonance imaging (MRI) showed spinal subdural hematoma (SDH) extending from L4 to S2 leading to severe central spinal canal stenosis. One day after admission, she complained of nausea and severe headache. Computed tomography of the brain revealed chronic SDH associated with midline shift. Intracranial chronic SDH was evacuated through two burr holes. Back pain and radiating leg pain derived from the spinal SDH diminished about 2 weeks after admission and spinal SDH was completely resolved on MRI obtained 3 months after onset. Physicians should be aware of such a condition and check the possibility of concurrent cranial SDH in patients with spinal SDH, especially with non-traumatic origin.

The clinical efficacy of repeat brain computed tomography in patients with traumatic intracranial haemorrhage within 24 hours after blunt head injury.

This study was performed to determine the usefulness of repeated brain computed tomography (CT) within 24 hours of blunt head trauma in patients with traumatic intracranial haemorrhages (ICH) and who were initially treated nonsurgically. Factors associated with the worsening of lesions on repeat CT were evaluated. Medical records of all blunt head trauma patients with traumatic ICH admitted to our hospital from January 2003 to December 2006 were retrospectively reviewed. Patients older than 16 years of age with an initial Glasgow Coma Scale (GCS) of 8 or greater were included. From the results of the repeat CT, patients were categorized as Group 1 (improved or unchanged condition) or Group 2 (worsened condition). A total of 168 patients (mean age of 44.8 +/- 19.2; mean admission GCS of 13.42 +/- 2.07; male to female ratio 2.1:1) were included. In 161 patients, repeat CT was obtained on a routine basis. In the remaining 7, it was prompted by a worsening neurological condition. The mean time from initial to repeat CT was 10.10 +/- 7.25 hours. Based on the results of the repeat CT, 108 patients were included in Group 1 and 60 in Group 2. The mean initial GCS was lower in patients from Group 2 versus those from Group 1 (11.9 +/- 2.6 compared with 14.3 +/- 0.96; p < 0.001). After repeat CT, 28 (47%) of the patients in Group 2 underwent neurosurgical interventions. Of the 28 surgically treated patients from Group 2, 6 (10%) exhibited neurological worsening and 22 (37%) appeared neurologically stable. According to our data, we suggest that routine repeat CT within 24 hours after blunt head trauma might minimize potential neurological deterioration in patients with either a GCS lower than 12 or with an epidural haematoma or multiple lesions as indicated on initial CT.

Prognostic value of intra-operative lateral spread response monitoring during microvascular decompression in patients with hemifacial spasm.

Hemifacial spasm (HFS) has characteristic and specific electrophysiological features, primarily the lateral spread response (LSR). The aim of this study was to evaluate the correlation between changes in the lateral spread response during microvascular decompression (MVD) and the clinical outcome after MVD. Seventy-two patients with HFS who were treated with MVD were included in this study. Intra-operative facial electromyography (EMG) was performed and brainstem auditory evoked potentials were monitored. In 32 (44.4%) patients, the LSR persisted after MVD. Among these 32 patients, 11 had mild HFS at discharge and six had mild HFS at the 6 month follow up. Out of the 40 patients in whom the LSR disappeared intra-operatively after MVD, five had mild HFS at discharge and four had mild HFS at the 6-moth follow up. The clinical outcome of HFS after MVD does not always correlate with intra-operative EMG abnormality. Therefore, the prognostic value of intra-operative LSR monitoring with respect to long-term results is questionable.

Delayed diagnosis, due to the associated radiological abnormalities, of spontaneous intracranial hypotension caused by cerebrospinal fluid leakage at C1-2.

Spontaneous intracranial hypotension (SIH) is an uncommon clinical entity that is often diagnosed after a delay, or it is misdiagnosed due to the variety of clinical presentations and the associated radiological findings. We present here a case of SIH associated with chronic subdural haematoma (SDH) and subarachnoid haemorrhage. Following the diagnosis of the SIH, the patient underwent injection of an epidural blood patch for the SIH and burr hole trephination was done for treating the chronic subdural haematoma.

Peritumoral brain edema in meningiomas: correlations between magnetic resonance imaging, angiography, and pathology.

BACKGROUND: The purpose of this study was to evaluate the radiologic characteristics and pathology related to the formation of peritumoral edema in meningiomas. METHODS: Seventy-nine patients with meningioma were examined by MRI and cerebral angiography. The predictive factors possibly related to peritumoral edema, such as patient age, sex, tumor location, tumor size, peritumoral rim (CSF cleft), shape of tumor margin, signal intensity of tumor in T2WI, pial blood supply, and pathology, were evaluated. We defined the edema-tumor volume ratio as EI and used this index to evaluate peritumoral edema. RESULTS: Male sex (P = .009), tumor size (P = .026), signal intensity of tumor in T2WI (P = .016), atypical and malignant tumor (P = .004), and pial blood supply (P = .001) correlated with peritumoral edema on univariate analyses. However, in multivariate analyses, pial blood supply was statistically significant as a factor for peritumoral edema in meningioma (P = .029). Male sex (P = .067, P < .1) and hyperintensity in T2WI (P = .075, P < .1) might have statistical probability in peritumoral edema. CONCLUSIONS: In our results, male sex, hyperintensity on T2WI, and pial blood supply were associated with peritumoral edema in meningioma that influence the clinical prognosis of patients.

Assessment of cerebrovascular reserve before and after STA-MCA bypass surgery by SPECT and SPM analysis.

OBJECTIVE: The purpose of this study was to objectively assess the efficacy of superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery using Technetium (Tc)-99m-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) in patients who underwent STA-MCA bypass surgery. MATERIALS AND METHODS: Brain perfusion SPECT images obtained at baseline and after the administration of acetazolamide were reconstructed using statistical parametric mapping in 23 patients, both before and after STA-MCA bypass surgery. The clinical outcomes of the surgery were also recorded and compared with the hemodynamic changes. A voxel with an uncorrected p-value of less than 0.001 was considered to be statistically significant. RESULTS: SPECT images of the territory supplied by the bypass graft showed an increase in both cerebrovascular flow and reserve at baseline, and the increase was significantly higher following the administration of acetazolamide. All patients showed improvement of clinical symptoms and increased blood flow to the left temporal, parietal, and frontal cortices as well as the thalamus. CONCLUSION: Brain SPECT effectively and objectively demonstrated the improved outcomes of STA-MCA bypass surgery, and thus may be used in postoperative analyses.

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.