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Kazuyoshi Korosue, Roberto C. Heros, Christopher S. Ogilvy, Akio Hyodo, Yong-Kwang Tu, and Robert Graichen

✓ Forty dogs were subjected to 6 hours of occlusion of the left internal carotid and middle cerebral arteries. They were divided into two “hemodilution groups” of 13 dogs each and a control “nonhemodiluted group” of 14 dogs. Thirty minutes after arterial occlusion, isovolemic hemodilution was performed by phlebotomy and infusions of low-molecular weight (MW) dextran in one group and of lactated Ringer's solution in the other group. The animals were sacrificed 1 week after temporary arterial occlusion.

Hemodilution reduced the hematocrit to a level of 33% to 34%, which lasted throughout the week in both groups. After hemodilution there was a very significant reduction in blood viscosity, plasma total protein content, and fibrinogen levels in both groups in the acute stage; these levels gradually returned to baseline by the end of the week. In the group with lactated Ringer's solution hemodilution, both osmotic and oncotic pressures were decreased by hemodilution in the acute stage. In the control and low-MW dextran groups, osmotic and oncotic pressure remained unaltered throughout the week. Hemodilution resulted in a slight decrease in mean arterial blood pressure in all groups in the acute stage, but there were no significant changes in central venous, pulmonary arterial, or pulmonary wedge pressures. During the week of study, there were no differences in the cardiac index and total blood volume between the groups, and no significant changes in hematological parameters with the exception of a slight increase in bleeding time immediately after hemodilution with low-MW dextran.

Daily neurological assessment showed consistently poorer condition during the first 5 days in the group with lactated Ringer's solution compared to either the control group or the group receiving low-MW dextran. Based on Mann-Whitney U-testing, the infarct volume of the lactated Ringer's solution recipients, expressed as a percentage of the total volume of that hemisphere (median 15.7%, range 6.6% to 25.2%) was significantly larger than that of the group receiving low-MW dextran (median 2.2%, range 0% to 15.8%) and that of the control group (median 11.9%, range 0% to 39.9%). The results indicate that, in this model, hemodilution with colloids was beneficial, whereas hemodilution with crystalloids was deleterious. It is likely that the decrease in oncotic pressure observed after hemodilution with lactated Ringer's solution is one of the most important reasons for its detrimental effect.

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Fon-Yih Tsuang, Abel Po-Hao Huang, Yi-Hsin Tsai, Jo-Yu Chen, Jing-Er Lee, Yong-Kwang Tu, and Kuo-Chuan Wang

Object

Traumatic subdural effusion (TSE) is a common sequela of traumatic brain injury. Surgical intervention is suggested only when TSE exerts mass effect. The authors have found that many patients with TSE exerting mass effect have concomitant hydrocephalus. Patient experiencing this occurrence were studied, and the pathogenesis of this phenomenon was discussed in the context of recent advances in the understanding of CSF circulation.

Methods

During a 2-year period, the authors' institution treated 14 patients with TSE who developed hydrocephalus, after 1 of the patients suffered subdural drainage and other 13 received subdural peritoneal shunt (SPSs). Thirteen of those who had SPSs received programmable ventriculoperitoneal shunts (VPSs) for the hydrocephalus. The clinical characteristics as well as the imaging and operative findings of these patients were reviewed.

Results

All patients with symptomatic TSE exerting mass effect received SPSs. All of these patients had a modified Frontal Horn Index of more than 0.33 at presentation, and high opening pressure on durotomy. Following a brief period (4–7 days) of clinical improvement, the condition of all patients deteriorated due to hydrocephalus. Programmable VPSs were inserted with the initial pressure set at approximately 8–10 cm H2O according to opening pressure at ventriculostomy. Shunt valve pressure was gradually decreased to 5–7 cm H2O, according to clinical and radiological follow-up.

Conclusions

Elevated modified Frontal Horn Index in patients with TSE is suggestive of concomitant hydrocephalus. The authors propose that tearing of the dura-arachnoid plane following trauma contributes to TSE and may also impede CSF circulation, causing hydrocephalus. Shunt pressure was adjusted to relative low pressure, indicating the old age of the patients and poor reexpansion of brain parenchyma after the mass effect. Subdural peritoneal shunts and VPSs are indicated in those patients with TSE exerting mass effect with concomitant hydrocephalus.

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Meng-Fai Kuo, Yihsin Tsai, Wen-Ming Hsu, Ruei-Sheng Chen, Yong-Kwang Tu, and Huei-Shyong Wang

Object

Vertebral defects, anal atresia, cardiovascular anomalies, tracheoesophageal fistulas (TEFs), renal anomalies, and limb defects (most often of the radius) are commonly associated and known collectively by the acronym VACTERL. The authors studied these nonrandomly associated birth defects to determine if a further relationship exists between VACTERL association and the presence of a tethered spinal cord (TSC).

Methods

From 2001 to 2004, 12 patients with VACTERL association who were treated operatively by a single pediatric surgeon underwent magnetic resonance (MR) imaging to evaluate the intraspinal abnormalities that may cause tethering. Three patients were excluded from the study due to complications after surgery for TEF. Coincidentally, these three patients did not have imperforate ani. In the remaining nine patients, seven had associated urogenital anomalies, and six of these also had high-type imperforate ani. Five of the six patients and the one patient with low-type imperforate anus and a urogenital anomaly were found to have TSCs. In the remaining two patients without urogenital anomalies there was a high-type imperforate anus without a TSC in one patient and a low-type imperforate anus with a TSC in the other. All seven patients with TSCs underwent successful untethering. The lesions contributing to TSC included terminal filum lipomas (TFLs) in five patients, an intramedullary ependymal cyst in one patient, and a lipomeningomyelocele in another patient.

Conclusions

The authors found that in patients with VACTERL association there was a high incidence of TSC (seven of nine patients) if an imperforate anus was present as one of the anomalies. In patients with VACTERL association and urogenital anomalies, the incidence of TSC was even higher (86%). Five of the seven cases of TSC in the present study were caused by a TFL, a lesion that can be easily and safely managed surgically. The authors conclude that MR imaging is essential for ruling out the possibility of a TSC in patients with VACTERL association combined with urogenital anomalies or an imperforate anus.

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Fon-Yih Tsuang, I-Chang Su, Jo-Yu Chen, Jing-Er Lee, Dar-Ming Lai, Yong-Kwang Tu, and Kuo-Chuan Wang

Object

The object of this study was to identify the clinical features and outcomes of a subgroup of patients with aneurysmal subarachnoid hemorrhage (SAH) who had active contrast extravasation from a ruptured aneurysm during initial cerebral CT angiography (CTA).

Methods

The authors performed a retrospective study of spontaneous SAH cases involving patients treated at their institute. They identified 9 cases in which active contrast extravasation was evident on the initial CT angiogram. Another 12 similar cases were also identified in a literature review and data was gathered from these cases to evaluate the outcomes.

Results

Analysis of all 21 cases revealed that the overall outcomes in cases characterized by active aneurysmal bleeding during CTA were poor. Seventy-six percent of patients had unfavorable results. Patients who showed poor neurological status at presentation died no matter what kind of treatment they received. In contrast, patients who presented with good neurological status initially had a chance of favorable outcome. Among the patients with good initial neurological status, most demonstrated rapid deterioration of their condition during the CTA examination; only those who received immediate and effective decompressive surgery and aneurysm obliteration had good results.

Conclusions

Active aneurysmal rebleeding during CTA is an uncommon but devastating event. Though the mortality of this distinct group of patients remains high, a clinical subgroup may benefit from immediate surgery. Patients with good initial neurological status who show rapid neurological deterioration may still have a favorable outcome if they undergo timely and successful decompressive surgery and proper aneurysm obliteration. Patients who present with poor neurological status do badly, and there is no effective treatment for such patients.

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I-Chang Su, Chi-Cheng Yang, Wei-Han Wang, Jing-Er Lee, Yong-Kwang Tu, and Kuo-Chuan Wang

The authors present a rare case of an infarction complication 15 days following acute intraventricular bleeding due to moyamoya disease. Before the infarction occurred, perfusion CT imaging disclosed early but reversible ischemic injury on the day of hemorrhage. Dehydration and hypotension are both possibly contributing factors of progressive injury from reversible ischemia due to infarction. Although the patient underwent successful bypass surgery, 1 month after the ictus the neurobehavior evaluation still showed marked executive dysfunction. The authors address that, in hemorrhagic-type moyamoya disease, early perfusion CT scanning is not only a powerful tool to identify the high-risk group of patients who could experience subacute infarction, but also alarms neurosurgeons to eliminate any predisposing factors when it shows reversible ischemic injuries.

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Isovolemic hemodilution in experimental focal cerebral ischemia

Part 1: Effects on hemodynamics, hemorheology, and intracranial pressure

Yong-Kwang Tu, Roberto C. Heros, Guillermo Candia, Akio Hyodo, Karen Lagree, Ronald Callahan, Nicholas T. Zervas, and Dimitris Karacostas

✓ A total of 76 splenectomized dogs were entered in a study of the value and effects of isovolemic hemodilution. Of these, seven were not included in the analysis because of technical errors. Of the remaining 69 dogs, 35 were treated with hemodilution; 28 were subjected to a 6-hour period of temporary occlusion of the distal internal carotid artery and the proximal middle cerebral artery, and seven underwent a sham operation only, with arterial manipulation but no occlusion. The other 34 dogs were not subjected to hemodilution; 26 of these underwent temporary arterial occlusion and eight had a sham operation only. In each group the animals were about equally divided into 1) an acute protocol with regional cerebral blood flow measurements by a radioactive microsphere technique and sacrifice at the end of the acute experiment, and 2) a chronic protocol with survival for 1 week to permit daily neurological assessment and final histopathological examination but without blood flow measurements. Isovolemic hemodilution was performed about 1 hour after the arterial occlusion or sham operation and was accomplished by phlebotomy and infusions of low molecular weight dextran to bring the hematocrit to a level of 30% to 32%. This treatment resulted in a very significant reduction in viscosity and fibrinogen levels. The decrease in hematocrit lasted throughout the week in the animals in the chronic protocol. The decrease in viscosity correlated almost linearly with the decrease in hematocrit. There was a slight decrease in systemic arterial pressure with hemodilution but there were no significant changes in central venous pressure or in pulmonary arterial or wedge pressure. There was a slight decrease in cardiac index in both the hemodilution and control groups, which may have been due to the effects of barbiturate anesthesia. There was a slight increase in the measured blood volume in both groups, which was probably artifactual and related to the method of calculation. Intracranial pressure increased significantly with time in all animals subjected to arterial occlusion, but this increase was less severe in the hemodilution group. There was no significant change in intracranial pressure in sham-operated animals, whether hemodiluted or not. The results of cerebral blood flow measurements, assessment of neurological condition, and measurement of infarct size are given in Part 2 of this report.

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Isovolemic hemodilution in experimental focal cerebral ischemia

Part 2: Effects on regional cerebral blood flow and size of infarction

Yong-Kwang Tu, Roberto C. Heros, Dimitris Karacostas, Ted Liszczak, Akio Hyodo, Guillermo Candia, Nicholas T. Zervas, and Karen Lagree

✓ Seventy-six splenectomized dogs were entered in a study of the value and effects of isovolemic hemodilution. Of these, seven were not included in the analysis because of technical errors. Of the remaining 69 dogs, 35 were treated with hemodilution; 28 were subjected to a 6-hour period of temporary occlusion of the distal internal carotid artery and the proximal middle cerebral artery, and seven underwent a sham operation only, with arterial manipulation but no occlusion. The other 34 dogs were not subjected to hemodilution; 26 of these underwent temporary arterial occlusion and eight had a sham operation only. In each group the animals were about equally divided into 1) an acute protocol with regional cerebral blood flow measurements by a radioactive microsphere technique and sacrifice at the end of the acute experiment, and 2) a chronic protocol with survival for 1 week to permit daily neurological assessment and final histopathological examination but without blood flow measurements. The general experimental protocol, the hemodynamic and rheological measurements, and the changes in intracranial pressure are described in Part 1 of this report.

In the animals with arterial occlusion, blood flow decreased significantly in the territory of the ischemic middle cerebral artery. This decrease was partially reversed by hemodilution in the animals so treated. When the changes in blood flow before and after hemodilution in treated animals are compared with the changes at equivalent times in animals without hemodilution, the increases in flow in the gray matter of the ischemic hemisphere brought about by hemodilution are statistically significant. The neurological condition of the animals in the chronic protocol (sacrificed 1 week after occlusion) with hemodilution, as evaluated by daily neurological assessment, was significantly better than that of the control animals.

In the animals sacrificed acutely (8 hours after arterial occlusion), the volume of infarction as estimated by the tetrazolium chloride histochemical method was 7.36% of the total hemispheric volume in the control animals and 1.09% in the hemodiluted animals, showing a statistically significant difference (p < 0.005). In the chronic animals these values were 9.84% and 1.26%, respectively (p < 0.005), as calculated by fluorescein staining. By histopathological examination the volume of infarction in the chronic animals was calculated as 10.92% in the control animals and 1.20% in the hemodiluted animals (p < 0.005). There was good correlation between the size of infarction and the decrease in hematocrit and viscosity, and excellent correlation between the size of infarction estimated by fluorescein and that determined by histopathological examination in each animal in the chronic group.

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Lu-Ting Kuo, Chien-Min Chen, Chien-Hsun Li, Jui-Chang Tsai, Hsiu-Chu Chiu, Ling-Chun Liu, Yong-Kwang Tu, and Abel Po-Hao Huang

Object

Currently, the effectiveness of minimally invasive evacuation of intracerebral hemorrhage (ICH) utilizing the endoscopic method is uncertain and the technique is considered investigational. The authors analyzed their experience with this method in terms of case selection, surgical technique, and long-term results.

Methods

The authors performed a retrospective analysis of the clinical and radiographic data obtained in 68 patients treated with endoscope-assisted ICH evacuation. Rebleeding, morbidity, and mortality were recorded as primary end points. Hematoma evacuation rate was calculated by comparing the pre- and postoperative CT scans. Glasgow Coma Scale scores and scores on the extended Glasgow Outcome Scale (GOSE) were recorded at the 6-month postoperative follow-up. The technical aspect of this report explains details of the procedure, the instruments that are used, the methods for hemostasis, and the role of hemostatic agents in the management of intraoperative hemorrhage. The pertinent literature was reviewed and summarized.

Results

All surgeries were performed within 12 hours of ictus, and 84% of the surgeries were performed within 4 hours. The mortality rate was 5.9%, and surgery-related morbidity occurred in 3 cases (4.4%). The hematoma evacuation rate was 93% overall—96% in the putaminal group, 86% in the thalamic group, and 98% in the subcortical group. The rebleeding rate was 1.5%. The mean operative time was 85 minutes, and the average blood loss was 56 ml. The mean GOSE score was 4.9 at 6-month follow-up. The authors acknowledge the limitations of these preliminary results in a small number of patients.

Conclusions

The data suggest that early endoscope-assisted ICH evacuation is safe and effective in the management of supratentorial ICH. The rebleeding, morbidity, and mortality rates are low compared with rates reported in the literature for the traditional craniotomy method. This study also showed that early and complete evacuation of ICH may lead to improved outcomes in selected patients. However, the safety and efficacy of endoscope-assisted ICH evacuation should be further investigated in a large, prospective, randomized trial.

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Kuo-Chuan Wang, Sung-Chun Tang, Jing-Er Lee, Dar-Ming Lai, Sheng-Jean Huang, Sung-Tsang Hsieh, Jiann-Shing Jeng, and Yong-Kwang Tu

Object

Experimental studies have demonstrated the crucial role of posthemorrhagic erythrocyte catabolism in the pathogenesis of subarachnoid hemorrhage (SAH). The authors of this study aimed to investigate the prognostic value of a series of CSF biomarkers linked to heme metabolism in SAH patients.

Methods

Patients with Fisher Grade III aneurysmal SAH undergoing early aneurysm obliteration were enrolled. The levels of heme oxygenase–1 (HO-1), oxyhemoglobin, ferritin, and bilirubin in intrathecal CSF were measured on the 7th day posthemorrhage. The associations of functional outcome with clinical and CSF parameters were analyzed.

Results

The study included 41 patients (mean age 59 ± 14 years; 16 male, 25 female), 17 (41.5%) of whom had an unfavorable outcome (Glasgow Outcome Scale score ≤ 3) 3 months after SAH. In terms of the clinical data, age > 60 years, admission World Federation of Neurosurgical Societies Grade ≥ III, and the presence of acute hydrocephalus were independent factors associated with an unfavorable outcome. After adjusting for clinical parameters, a higher level of HO-1 appeared to be the most significant CSF parameter related to an unfavorable outcome among all tested CSF molecules (OR 0.934, 95% CI 0.883–0.989, p = 0.018). Further analysis using a generalized additive model identified a cutoff HO-1 value of 81.2 μM, with higher values predicting unfavorable outcome (82.4% accuracy).

Conclusions

The authors propose that the level of intrathecal CSF HO-1 at Day 7 post-SAH can be an effective outcome indicator in patients with Fisher Grade III aneurysmal SAH.