Impact of early surgery after aneurysmal subarachnoid haemorrhage.

OBJECTIVES: To investigate the effect of early aneurysm surgery (<72 h) on outcome in patients with subarachnoid haemorrhage (SAH). MATERIALS AND METHODS: We studied two consecutive series of patients with aneurysmal SAH [postponed surgery (PS) cohort, n = 118, 1989-1992: surgery was planned on day 12 and early surgery (ES) cohort, n = 85, 1996-1998: ES was performed only in patients with Glasgow Coma Scale (GCS) >13]. We used multivariable logistic regression analysis to assess outcome at 3 months. RESULTS: Favourable outcome (Glasgow Outcome Scale 4 or 5) was similar in both cohorts. Cerebral ischemia occurred significantly more often in the ES cohort. The occurrence of rebleeds was similar in both cohorts. External cerebrospinal fluid (CSF) drainage was performed more often in the ES cohort (51% vs 19%). Patients with cisternal sum score (CSS) of subarachnoid blood <15 on admission [adjusted odds ratio (OR) for favourable outcome: 6.4, 95% confidence interval (CI) 1.0-39.8] and patients with both CSS <15 and GCS > 12 on admission benefited from the strategy including ES (OR 10.5, 95% CI 1.1-99.4). CONCLUSIONS: Our results support the widely adopted practice of ES in good-grade SAH patients.

Risk factors for infections related to external ventricular drainage.

BACKGROUND: External ventricular drainage (EVD) is frequently used in neurosurgery for cerebrospinal fluid (CSF) drainage in patients with raised intracranial pressure. The major complication of this procedure is an EVD-related infection, i.e., meningitis or ventriculitis. The purpose of the present retrospective single centre study is to assess the possible causes of these infections. PATIENTS AND METHODS: Two hundred and twenty-eight patients were included in the period from January 1993 until April 2005. Patient and disease demographics, as well as EVD data, and the occurrence of infection were reviewed, compared, and included in a risk-analysis study. RESULTS: The population's mean age was 56 +/- 15 years and the sexes were equally distributed. Most frequently, the indication for EVD was hydrocephalus due to intraventricular haemorrhage (48.2%). An infection was documented in 23.2% of all patients. Duration of EVD drainage appeared to be a risk factor for infection (>11 days: OR 4.1; 95% CI 1.8-9.2, p = 0.001). CSF sampling frequency was also a significant risk-factor (no sampling: OR 0.2, 95% CI 0.2-0.5, p = 0.003). CONCLUSIONS: We found a relatively high percentage of EVD-related infections. After multivariate analysis there appears to be a relation with duration of drainage and frequent CSF sampling. As a result, a new EVD protocol is proposed in our institution that we believe will decrease the number of EVD-related infections to a minimum.

Safety and efficacy of frameless and frame-based intracranial biopsy techniques.

BACKGROUND: Frameless stereotaxy or neuronavigation has evolved into a feasible technology to acquire intracranial biopsies with good accuracy and little mortality. However, few studies have evaluated the diagnostic yield, morbidity, and mortality of this technique as compared to the established standard of frame-based stereotactic brain biopsy. We report our experience of a large number of procedures performed with one or other technique. PATIENTS AND METHODS: We retrospectively assessed 465 consecutive biopsies done over a ten-year time span; Data from 391 biopsies (227 frame-based and 164 frameless) were available for analysis. Patient demographics, peri-operative characteristics, and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and of it being followed by death. RESULTS: On average, nine tissue samples were taken with either stereotaxy technique. Overall, the biopsy led to a diagnosis on 89.4% of occasions. No differences were found between the two biopsy procedures. In a multiple regression analysis, it was found that left-sided lesions were less likely to result in a non-diagnostic tissue sample (p = 0.023), and cerebellar lesions showed a high risk of negative histology (p = 0.006). Postoperative complications were seen after 12.1% of biopsies, including 15 symptomatic haemorrhages (3.8%). There was not a difference between the rates of complication after either a frame-based or a frameless biopsy. Overall, peri-operative complications (p = 0.030) and deep-seated lesions (p = 0.060) increased the risk of biopsy-related death. Symptomatic haemorrhages resulting in death (1.5% of all biopsies) were more frequently seen after biopsy of a fronto-temporally located lesion (p = 0.007) and in patients with a histologically confirmed lymphoma (p = 0.039). CONCLUSIONS: The diagnostic yield, complication rates, and biopsy-related mortality did not differ between a frameless biopsy technique and the established frame-based technique. The site of the lesion and the occurrence of a peri-operative complication were associated with the likelihood of failure to achieve a diagnosis and with death after biopsy. We believe that using intraoperative frozen section or cytologic smear histology is essential during a stereotactic biopsy in order to increase the diagnostic yield and to limit the number of biopsy specimens that need to be taken.

The prognostic value of clinical characteristics and parameters of cerebrospinal fluid hydrodynamics in shunting for idiopathic normal pressure hydrocephalus.

BACKGROUND: It is difficult to predict which patients with symptoms and radiological signs of normal pressure hydrocephalus (NPH) will benefit from a shunting procedure and which patients will not. Risk of this procedure is also higher in patients with NPH than in the overall population of hydrocephalic patients. The aim of this study is to investigate which clinical characteristics, CT parameters and parameters of cerebrospinal fluid dynamics could predict improvement after shunting. METHODS: Eighty-three consecutive patients with symptoms and radiological signs of NPH were included in a prospective study. Parameters of the cerebrospinal fluid dynamics were measured by calculation of computerised data obtained by a constant-flow lumbar infusion test. Sixty-six patients considered candidates for surgery were treated with a medium-pressure Spitz-Holter valve; in seventeen patients a shunting procedure was not considered indicated. Clinical and radiological follow-up was performed for at least one year postoperatively. FINDINGS: The odds ratio, the sensitivity and specificity as well as the positive and negative predictive value of individual and combinations of measured parameters did not show a statistically significant relation to clinical improvement after shunting. CONCLUSIONS: We conclude that neither individual parameters nor combinations of measured parameters show any statistically significant relation to clinical improvement following shunting procedures in patients suspected of NPH. We suggest restricting the term normal pressure hydrocephalus to cases that improve after shunting and using the term normal pressure hydrocephalus syndrome for patients suspected of NPH and for patients not improving after implantation of a proven well-functioning shunt.

[High level of satisfaction among patients despite persistent symptoms in the mid-long-term following surgery for lumbosacral radicular syndrome]. / Na operatie wegens lumbosacraal radiculair syndroom bij meer dan de helft van de patiënten nog klachten op middellange termijn, maar wel grote tevredenheid.

OBJECTIVE: To determine the mid-long-term outcomes after surgery in patients with lumbosacral radicular syndrome (LRS) and to identify prognostic factors for persisting LRS symptoms. DESIGN: Descriptive retrospective and prospective. METHOD: A total of 250 consecutive patients operated on by 7 neurosurgeons in four hospitals between May and December 2001 were selected from medical records. They were asked to take part in a telephone questionnaire at 6 and 19 months after operation. They had all undergone discectomy for LRS at L4-L5 or L5-S1 and were aged from 18 to 65. RESULTS: Of the 250 patients, 163 participated in the study: 63% reported that they still had LRS-related symptoms 19 months after surgery. However, severe leg pain had decreased in 83% of the patients. In general the patients were satisfied with their treatment. Female gender and an age of 51-65 were prognostic factors for persistent LRS symptoms. CONCLUSION: More than half of the patients reported LRS symptoms 19 months after surgery.

Do neurosurgeons subscribe to the guideline lumbosacral radicular syndrome?

BACKGROUND: This study presents a survey of the opinion of neurosurgeons on the multidisciplinary clinical guideline 'lumbosacral radicular syndrome'. The aim was to describe to what extent neurosurgeons in the Netherlands endorse the content of this guideline. The guideline was issued in 1996 by the Netherlands Institute of Quality Health Care and this is the first attempt to evaluate the implementation of this guideline. METHODS: All active neurosurgeons (n=92) in the Netherlands were invited to complete a questionnaire investigating to what extent they agree with the 26 recommendations in the guideline 'lumbosacral radicular syndrome'. The results are represented in frequencies (%) in order to express the magnitude of their consent or dissent with the recommendations. RESULTS: Overall, 75% of the neurosurgeons responded and, of these, 94% agreed (at least partially) with the content of the guideline. Of the 26 recommendations in the guideline, seven were not fully endorsed by the neurosurgeons. Three of these seven recommendations may need revision based on newly published data. CONCLUSION: This survey shows that almost all neurosurgeons subscribed (at least partially) to the multidisciplinary LRS guideline. Therefore, one important aspect of the implementation process has been fulfilled, i.e. acceptance of the content of the guideline.

Brain tissue oxygen response in severe traumatic brain injury.

OBJECTIVE: To investigate clinical relevance and prognostic value of brain tissue oxygen response (TOR: response of brain tissue pO(2) to changes in arterial pO(2)) in traumatic brain injury (TBI). PATIENTS AND METHODS: In a prospective cohort study TOR was investigated in 41 patients with severe TBI (Glasgow Coma Score < or =8) in whom continuous monitoring of brain tissue oxygen pressure (PbrO(2)) was performed.TOR was investigated each day over a five day period for 15 minutes by increasing FiO(2) on the ventilator setting. FiO(2) was increased directly from baseline to 1.0 for a period of 15 minutes under stable conditions (145 tests). In 34 patients the effect of decreasing PaCO(2) was evaluated on TOR by performing the same test after increasing inspiratory minute volume on the ventilator setting to 20% above baseline. Arterial blood gas analysis was performed before and after changing ventilator settings. Multimodality monitoring, including PbrO(2) was performed in all patients. Outcome at six months was evaluated according to the Glasgow Outcome Scale. For statistical analysis the Mann-whitney U-test was used for ordinally distributed variables, and the Chi-square test for categorical variables. Predictive value of TOR was analyzed in a multivariable model. RESULTS: 145 tests were available for analysis. Baseline PbrO(2) varied from 4.0 to 50 mmHg at PaO(2) values of 73-237 mmHg. At FiO(2) settings of 1.0, PbrO(2) varied from 9.1-200 mmHg and PaO(2) from 196-499 mmHg. Three distinct patterns of response were noted: response type A is characterized by a sharp increase in PbrO(2), reaching a plateau within several minutes; type B by the absence of a plateau, and type C by a short plateau phase followed by a subsequent further increase in PbrO(2). Patterns characterized by a stable plateau (type A), considered indicative of intact regulatory mechanisms, were seen more frequently from 48 hours after injury on. If present within the first 24 hours after injury such a response was related to more favorable outcome (p = 0.06). Mean TOR of all tests was 0.73 +/- 0.59 with an median TOR of 0.58. Patients with an unfavourable outcome had a higher TOR (1.03 +/- 0.60) during the first 24 hours, compared to patients with a favorable outcome (0.61 +/- 0.51; p = 0.02). Multiple logistic regression analysis supported the independent predictive value of tissue oxygen response for unfavorable outcome (odds ratio 4.8). During increased hyperventilation, mean TOR decreased substantially from 0.75 +/- 0.54 to 0.65 +/- 0.45 (p = 0.06; Wilcoxon test). Within the first 24 hours after injury a decrease in TOR following hyperventilation was significantly related to poorer outcome (p = 0.01). CONCLUSIONS: Evaluation of TOR affords insight in (disturbances in) oxygen regulation after traumatic brain injury, is of prognostic value and may aid in identifying patients at (increased) risk for ischemia.

Serial transcranial Doppler measurements in traumatic brain injury with special focus on the early posttraumatic period.

BACKGROUND: Cerebral ischemia is considered a key factor in the development of secondary damage after Traumatic Brain Injury (TBI). Studies on Cerebral Blood Flow (CBF) have documented decreased flow in over 50% of patients with TBI, studied in the acute phase. Transcranial Doppler (TCD) sonography is a non-invasive technique, permitting frequent or continuous measurements of blood flow velocity in the basal cerebral arteries. OBJECTIVES: To investigate the potential of TCD to detect decreased blood flow velocity in the early phase after TBI;To investigate whether flow velocity differs between hemispheres in patients with focal lesions versus those with more diffuse injuries;To investigate if decreased blood flow velocity is indicative of cerebral ischemia, as evidenced by measurements of brain tissue pO(2). METHODS: TCD examinations were performed in 57 patients with severe TBI (GCS