Elke Munch

Management of severe traumatic brain injury by decompressive craniectomy.

OBJECTIVE The beneficial effect of decompressive craniectomy in the treatment of head trauma patients is controversial. The aim of our study was to assess the value of unilateral decompressive craniectomy in patients with severe traumatic brain injury. METHODS We retrospectively investigated 49 patients who underwent decompressive craniectomy. Intracranial pressure, cerebral perfusion pressure, therapy intensity level, and cranial computed tomographic scan features (midline shift, visibility of ventricles, gyral pattern, and mesencephalic cisterns) were evaluated before and after craniectomy. The gain of intracranial space was calculated from cranial computed tomographic scans. Patient outcome was graded using the Glasgow Outcome Scale. RESULTS Thirty-one patients (63.3%) underwent rapid surgical decompression within 4.5 +/- 3.8 hours after trauma; in 18 patients (36.7%), delayed surgical decompression was performed 56.2 +/- 57.0 hours after injury. Patients younger than 50 years or patients who underwent rapid surgical decompression had a significantly better outcome than older patients or patients who underwent delayed surgical decompression. Craniectomy significantly decreased midline shift and improved visibility of the mesencephalic cisterns. The state of the mesencephalic cisterns correlated with the distance of the lower border of the craniectomy to the temporal cranial base. Alterations in intracranial pressure, cerebral perfusion pressure, and therapy intensity level were not significant. The overall mortality of the patients corresponded to the reports of the Traumatic Coma Data Bank (1991). CONCLUSION Although there was a significant decrease in midline shift after craniectomy, this did not translate into decompressive craniectomy demonstrating a beneficial effect on patient outcome.

HYPERTONIC SALINE SOLUTION FOR CONTROL OF ELEVATED INTRACRANIAL PRESSURE IN PATIENTS WITH EXHAUSTED RESPONSE TO MANNITOL AND BARBITURATES

Critically elevated intracranial pressure (ICP) represents the most important cause of morbidity and mortality in patients suffering from severe traumatic brain injury (TBI) and is a serious complication after subarachnoid hemorrhage (SAH). Thus new strategies for the control of ICP are required. Based on the evidence available hypertonic saline solution (HSS) may be a promising approach. It was therefore the aim of the present study to evaluate in a prospective manner the effects of HSS on ICP and cerebral perfusion pressure (CPP) in patients with therapy-resistant elevation of ICP. A total of 48 bolus infusions of HSS (7.5%, 2 ml kg-1 b.w.; infusion rate 20 ml min-1) were given intravenously (range 1-15 per patient) to 10 patients (age 41 +/- 6 years) with TBI and SAH. Only patients with ICP > 25 mmHg not responding to standard ICP-management protocol and plasma sodium (Na+) concentration < 150 mmol l-1 were included in the study. Within the first hour after HSS application, ICP decreased from 33 +/- 9 mmHg to 19 +/- 6 mmHg (p < 0.05) and further to 18 +/- 5 mmHg at the time of maximum effect (98 +/- 11 min post bolus). Decrease of ICP was accompanied by a rise of CPP from 68 +/- 11 mmHg to 79 +/- 11 mmHg (p < 0.05) after 1 h and further to 81 +/- 11 mmHg at the time of maximum effect. Plasma Na+ concentration was 141 +/- 6 mmol l-1 before and 143 +/- 5 mmol l-1 1 h after HSS bolus. Corresponding values for plasma osmolality were 302 +/- 11 and 308 +/- 12 mOsm l-1. When the ICP lowering effect was transient, subsequent HSS bolus was necessary 163 +/- 54 min after previous dosing. The present results indicate that repeated bolus application of HSS (7.5% NaCl, 2 ml kg-1 b.w.) is an effective measure to decrease ICP which is otherwise refractory to standard therapeutic approaches. Whether or not the therapy scheme is also suited as primary measure for the control of ICP remains to be established.

Effect of Nicardipine Prolonged-Release Implants on Cerebral Vasospasm and Clinical Outcome After Severe Aneurysmal Subarachnoid Hemorrhage A Prospective, Randomized, Double-Blind Phase IIa Study

Background and Purpose— The purpose of this study was to investigate the effect of nicardipine prolonged-release implants (NPRIs) on cerebral vasospasm and clinical outcome after severe subarachnoid hemorrhage. Methods— Thirty-two patients with severe subarachnoid hemorrhage and undergoing aneurysm clipping were included into this single center, randomized, double-blind trial. Sixteen patients received NPRIs implanted into the basal cisterns in direct contact to the exposed proximal blood vessels; in 16 control patients, the basal cisterns were opened and washed out only without leaving implants. Angiography was performed preoperatively and at day 8±1. Computed tomography imaging was analyzed for the incidence of territorial infarcts unrelated to surgery. Patient outcome was assessed using the modified Rankin and National Institute of Health Stroke scales. Results— The incidence of angiographic vasospasm in proximal vessel segments was significantly reduced after implantation of NPRIs (73% control versus 7% NPRIs). Significant differences occurred also for the majority of distal vessel segments. Computed tomography scans revealed a lower incidence of delayed ischemic lesions (47% control versus 14% NPRIs). The NPRI group demonstrated more favorable modified Rankin and National Institute of Health Stroke scales as well as a significantly lower incidence of deaths (38% control versus 6% NPRIs). Conclusions— Implantation of NPRIs reduces the incidence of cerebral vasospasm and delayed ischemic deficits and improves clinical outcome after severe subarachnoid hemorrhage.

Effect of Intra-Arterial Papaverine on Regional Cerebral Blood Flow in Hemodynamically Relevant Cerebral Vasospasm

Background and Purpose — It remains controversial whether the intra-arterial administration of papaverine (IAP) is effective in reversing vasospasm-associated cerebral hypoperfusion after aneurysmal subarachnoid hemorrhage. The aim of the present study was to continuously assess regional cerebral blood flow (rCBF) during and after IAP with the use of quantitative, bedside thermal diffusion flowmetry. Methods — Eight patients with cerebral vasospasm after subarachnoid hemorrhage (mean flow velocity >120 cm/s; angiographic vessel constriction >33%; hemispheric cerebral blood flow [CBF] <32 mL/100 g per minute) were prospectively entered into the study. Before IAP, thermal diffusion microprobes were implanted into the white matter of each affected vascular territory (n=10) for rCBF monitoring. During and after IAP (300 mg papaverine/50 mL saline over 1 hour), mean arterial blood pressure, intracranial pressure, cerebral perfusion pressure, thermal diffusion rCBF (TD-rCBF), and cerebrovascular resistance (CVR) were recorded continuously. Results — IAP significantly increased TD-rCBF from 7.3±1.6 to 37.9±6.6 mL/100 g per minute (mean±SEM), indicating reversal of cerebral hypoperfusion. This TD-rCBF response was dependent on the degree of cerebral vasospasm and reduced perfusion within the vascular territory. Long-term analysis of TD-rCBF, however, demonstrated that this beneficial effect of IAP on cerebral hypoperfusion was only transient: within 3 hours after treatment, TD-rCBF and CVR returned to baseline values. Furthermore, a lack of correlation between transcranial Doppler sonography and thermal diffusion flowmetry suggested that transcranial Doppler sonography is not suited for CBF-based neuromonitoring after IAP. Conclusions — IAP is not effective in permanently reversing cerebral hypoperfusion in patients with cerebral vasospasm. The need to validate alternative therapeutic strategies that seek to improve cerebral perfusion in vasospasm warrants continued development of CBF-based neuromonitoring strategies.

The CAMINO Intracranial Pressure Device in Clinical Practice: Reliability, Handling Characteristics and Complications

Summary Intracranial pressure monitoring has a key role in the management of patients developing increased intracranial pressure (ICP). We adopted the Camino fiberoptic system for intracranial pressure measurement in 1993 in our neurosurgical department. The aim of this study was to investigate reliability, handling characteristics and complication rate of the Camino intracranial pressure device. In an eighteen month period, we prospectively investigated 118 patients with intracranial pathology undergoing Camino fiberoptic intraparenchymal or intraventricular ICP monitoring. The assessment of reliability of ICP monitoring according to patients clinical condition, to cranial computed tomography (CCT) findings and ICP waveform was carried out. Position of the probe and intracranial bleeding complications related to probe insertion were confirmed by CCT. Technical complications, as well as infections due to the device, were documented. In vivo recalibration was performed in 22 patients. At the end of the measuring period the drift of the probe was evaluated and the accuracy of the fiberoptic device was measured by performing a two point calibration. Recordings of intracranial pressure were carried out with 136 Camino devices (104 parenchymal, 32 ventricular) in 118 patients with an average measuring time of 94.1±79.1 hrs. One hundred and fifteen Camino intracranial pressure devices (85.2%) demonstrated reliability according to the predetermined clinical parameters. The actual mean drift after removal of the devices was 3.4 mmHg±3.2 with an actual daily drift of 3.2±17.2 mmHg. Recorded complications included infection (0.7%), intraparenchymal haematoma (5.1%), and a high complication rate (23.5%) with regard to technical aspects. The Camino intracranial pressure system offers reliable ICP measurements in an acceptable percentage of devices, and the advantage of in vivo recalibration. The high incidence of technical complications identifies a need for improvement in the fiberoptic cable and the fixation system.

Therapy of malignant intracranial hypertension by controlled lumbar cerebrospinal fluid drainage.

ObjectivesTo evaluate the effect of controlled lumbar cerebrospinal fluid drainage in adult patients with refractory intracranial hypertension. DesignProspective, pre- vs. postintervention study. SettingSurgical intensive care unit of a university hospital. PatientsTwenty-three patients with severe traumatic brain injury or delayed ischemia after subarachnoid hemorrhage with intracranial hypertension refractory to aggressive treatment, including repeated applications of tromethamine, hypertonic saline solution, barbiturate coma, and decompressive craniectomy. Patients were considered for controlled lumbar cerebrospinal fluid drainage if basal cisterns on computerized tomography scan were discernible. InterventionsAfter institution of a lumbar drain, cerebrospinal fluid was gradually aspirated, and then, continuous cerebrospinal fluid drainage was maintained under control of intracranial pressure (ICP) and pupillary status. Measurements and Main Results ICP and cerebral perfusion pressure before and after initiation of lumbar cerebrospinal fluid drainage and related complications were documented. The neurologic outcome of the patients was assessed according to the Glasgow Outcome Scale 6 months after injury. As a result of lumbar cerebrospinal fluid drainage, all patients demonstrated an immediate and lasting decrease of ICP and a concomitant increase of cerebral perfusion pressure. Two patients temporarily showed a unilateral fixed and dilated pupil 6 and 8 hrs after onset of lumbar cerebrospinal fluid drainage, respectively. Ten patients showed a favorable outcome, four patients survived with a severe permanent neurologic deficit, one patient remained in a persistent vegetative state, and eight patients died. ConclusionsControlled lumbar cerebrospinal fluid drainage significantly reduces refractory intracranial hypertension. The danger of transtentorial or tonsillar herniation is minimized by considering lumbar drainage in the presence of discernible basilar cisterns only.

Effects of the selective endothelin A (ET(A)) receptor antagonist Clazosentan on cerebral perfusion and cerebral oxygenation following severe subarachnoid hemorrhage - preliminary results from a randomized clinical series.

SummaryObjective. To study the effects of clazosentan, a new selective endothelin receptor subtype A antagonist, on cerebral perfusion and cerebral oxygenation following severe aneurysmal subarachnoid haemorrhage (aSAH). Methods. All 12 patients treated at our institution in the context of a phase IIa, multicenter, randomized trial on clazosentan’s safety and efficacy in reducing the incidence of angiographic cerebral vasospasm were included in this substudy. The phase IIa study (n = 34) consisted of two parts: a double-blind, randomized Part A (clazosentan 0.2 mg/kg/h versus placebo) and an open-label Part B (clazosentan 0.4 mg/kg/h for 12 h followed by 0.2 mg/kg/h) for patients with established vasospasm. In parallel to the phase IIa study protocol, which included assessment of vasospasm by angiography and transcranial Doppler sonography, we determined regional cerebral blood flow (rCBF), cerebrovascular resistance, and regional tissue oxygenation. Results. Cerebral perfusion was comparable between treatment groups during the early post-bleeding period (rCBF placebo, 22.6 ± 3.5 ml/100 g/min versus rCBF clazosentan, 23.9 ± 1.1 ml/100 g/min). By the time of control angiography (day 8 after aSAH), rCBF decreased by 50% in the placebo group (11.3 ± 6.7 ml/ 100 g/min) while it remained stable in the clazosentan group (23.5 ± 12.9 ml/100 g/min). During Part B of the study, all 3 patients who developed haemodynamically relevant vasospasm during placebo treatment, showed a sustained improvement in rCBF upon conversion to clazosentan. Conclusions. These preliminary data suggest that clazosentan reduces the extent of vasospasm-associated impairment of cerebral perfusion following aSAH. Furthermore, clazosentan may exert beneficial actions on overt vasospasm-associated hypoperfusion.

Assessment of the CAMINO Intracranial Pressure Device in Clinical Practice

The purpose of this study was to investigate reliability, handling characteristics and complication rate of the CAMINO-ICP-monitor-system in clinical routine. In a case controlled study 82 patients with intracranial pathology necessitating ICP-monitoring received either a ventricular or a parenchymal CAMINO-device. Clinical assessment of curve shape and apparent reliability of the measurement was documented. Probe position and presence of hematoma was evaluated in all patients with a CT after probe insertion. Handling complications, i.e. dislocation were recorded. At the end of the measuring period the drift of the probe was checked ex vivo and a two point calibration was performed using a water column. During one year 82 patients received 95 probes (parench, 73. ventric. 22). The average measuring period was 91.3 +/- 70.6 hrs. Catheter position was verified by CCT for 67 (70.5%) probes. 92.5% of the devices were placed correctly. Clinically 88.4% of the measurements were assessed plausible, in 8.2% the displayed ICP-values were judged to be too high, in 2.1% too low. Probe drift after explanation was -0.21 mmHg/24 hrs. The mean value of the recalibrated probes in the water column corresponding to 15.8 mmHg was 14.7 +/- 1.9 mmHg. There was no correlation between neither drift nor function in the water column and the duration of the measurement. Technical complications exclusively related to the construction of the CAMINO-system like kinking of the cable, dislocation (probe pulled out) or dislocated fixation screw were too high (25.3%).

Current advances in the diagnosis of vasospasm

Abstract Symptomatic vasospasm leading to delayed ischemia and neurological deficits is one of the most serious complications after aneurysmal subarachnoid hemorrhage (SAH). Reliable and early detection of symptomatic vasospasm is one of the major goals in the management of patients with SAH. In awake patients, the close clinical neurological examination still remains the most important diagnostic measure. In comatous or sedated patients, cerebral angiography remains the mainstay of the diagnostic workup for vasospasm. However, angiography does not allow assessing the hemodynamic relevance of vasospasm and is not suited for early identification of cerebral hypoperfusion and ischemia. Therefore, a large panel of new monitoring techniques for the assessment of regional cerebral perfusion has been recently introduced into the clinical management of SAH patients. This article briefly reviews the most relevant methods for monitoring cerebral perfusion and discusses their clinical predictive value for the diagnosis of vasospasm. On the basis of the currently available monitoring technologies, an algorithm for the diagnosis of vasospasm is presented.

Penetrating craniocerebral injuries in a civilian population in mid-Europe

Our current neurosurgical understanding of civilian penetrating craniocerebral injuries is based on US metropolitan series. It is unknown whether all principles applied to these patients are relevant in the Mid-European setting with its distinct epidemiology. The objective of this study was to characterize our patients with penetrating craniocerebral injuries, to analyze their outcome, and to identify relevant prognostic factors. Thirty-two patients with penetrating craniocerebral injuries were entered into the study. Patient evaluation comprised neurological, laboratory and radiographic analyses. Motivating factors were suicide (75%), assault (13%), and accident (9%). Initial GCS score, coagulopathy on admission, and radiographic extent of injury could be identified as outcome predictors (P < 0.001). An aggressive therapeutic approach to patients with GCS 3-7 reduced mortality when compared to a conservative management (67 vs. 91%). Due to major differences in epidemiology and outcome of our penetrating craniocerebral injury patients when compared to major US metropolitan series, current therapeutic strategies applied to this patient population in mid-Europe should be reconsidered. The results of our study justify an aggressive neurosurgical approach even in those patients that are thought to have a deleterious prognosis. Predictive variables identified in this study and a novel CT-grading algorithm may help in decision making.