Neurosurgery Blog

Eur Spine J (2011) 20:1596–1606.DOI 10.1007/s00586-011-1873-8
Despite an increasing implantation rate of interspinous process distraction (IPD) devices in the treatment of intermittent neurogenic claudication (INC), definitive evidence on the clinical effectiveness of implants is lacking. The main objective of this review was to perform a meta-analysis of all systematic reviews, randomized clinical trials and prospective cohort series to quantify the effectiveness of IPDs and to evaluate the potential sideeffects.
Methods  Data from all studies prospectively describing clinical results based on validated outcome scales and reporting complications of treatment of patients with INC with IPD placement. We searched MEDLINE, EMBASE, Web of Science, Cochrane (CENTRAL), CINAHL, Academic Search Premier, Science Direct up to July 2010. Studies describing patients with INC caused by lumbar stenosis, reporting complication rate and reporting based on validated outcome scores, were eligible. Studies with only instrumented IPD results were excluded.
Results  Eleven studies eligible studies were identified. Two independently RCTs and eight prospective cohorts were available. In total 563 patients were treated with IPDs. All studies showed improvement in validated outcome scores after 6 weeks and 1 year. Pooled data based on the Zurich Claudication Questionnaire of the RCTs were more in favor of IPD treatment compared with conservative treatment (pooled estimate 23.2, SD 18.5–27.8). Statistical heterogeneity after pooled data was low (I-squared 0.0, p =  0.930). Overall complication rate was 7%.
Conclusion  As the evidence is relatively low and the costs are high, more thorough (cost-) effectiveness studies should be performed before worldwide implementation is introduced.

J Neurosurg Spine 15:295–310, 2011.DOI: 10.3171/2011.4.SPINE10330

The authors compared the effectiveness of instrumented posterior lumbar interbody fusion (iPLIF) and instrumented posterolateral fusion (iPLF) for the treatment of low-back pain (LBP) due to degenerative lumbar disease.

Methods. Relevant randomized controlled trials (RCTs) and comparative observational studies through December 2009 were identified using a retrieval strategy of sensitive and specific searches. The study design, participant characteristics, interventions, follow-up rate and period, and outcomes were abstracted after the assessment of methodological quality of the trials. Analyses were performed following the method guidelines of the Cochrane Back Review Group.
Results. Nine studies were identified—3 RCTs and 6 comparative observational studies. No significant difference was found between the 2 fusion procedures in the global assessment of clinical outcome (OR 1.51, 95% CI 0.71–3.22, p = 0.29) and complication rate (OR 0.55, 95% CI 0.16–1.86, p = 0.34). Both techniques were effective in reducing pain and improving functional disability, as well as restoring intervertebral disc height. Instrumented PLIF was more effective in achieving solid fusion (OR 2.60, 95% CI 1.35–5.00, p = 0.004), a lower reoperation rate (OR 0.20, 95% CI 0.03–1.29, p = 0.09), and better restoration of segmental angle and lumbar lordotic angle than iPLF. There were no significant differences between the fusion methods regarding blood loss (weighted mean difference –179.63, 95% CI –516.42 to 157.15, p = 0.30), and operating time (weighted mean difference 8.03, 95% CI –45.46 to 61.53, p = 0.77).

Conclusions. The authors’ analysis provided moderate-quality evidence that iPLIF has the advantages of higher fusion rate and better restoration of spinal alignment over iPLF. No significant differences were identified between iPLIF and iPLF concerning clinical outcome, complication rate, operating time, and blood loss.

Neurosurgery 69:255–260, 2011 DOI: 10.1227/NEU.0b013e31821a45ba

Ventriculostomy placement is an important diagnostic and therapeutic tool for neurosurgeons. Multiple authors have presented retrospective series of patients evaluating periprocedure hemorrhage.

OBJECTIVE: We performed a meta-analysis of existing studies to determine a more accurate rate of hemorrhage.

METHODS: A MEDLINE and PubMed search was performed to find all studies of 25 or more patients conducted since 1970 that found a hemorrhagic complication rate from placement of a ventriculostomy. Studies in which a non-neurosurgeon placed the ventriculostomy and studies involving premature infants were excluded.

RESULTS: Sixteen studies were used to obtain data from 2428 ventriculostomy procedures. Hemorrhage was found after 203 procedures, and 52 of these hemorrhages were deemed significant by the authors. The cumulative rate of hemorrhage was 7.0% (95% confidence interval: 4.5%-9.4%), with P , .05. The cumulative rate of significant hemorrhage was 0.8% (95% confidence interval: 0.2%-1.4%) with P , .05.

CONCLUSION: Based on our meta-analysis, the overall hemorrhagic complication rate from ventriculostomy placement by neurosurgeons is approximately 7%. The rate of significant hemorrhage from ventriculostomy placement is approximately 0.8%. Further prospective studies are warranted to better address this question.

Neurosurgery 68:996–1005, 2011 DOI: 10.1227/NEU.0b013e3182096d84

Ventriculostomy-related infection (VRI) is a severe complication of external ventricular drain use, occurring in 5% to 23% of patients. Preventive measures for VRI include prolonged prophylactic systemic antibiotics (PSAs) and an antibioticcoated external ventricular drains (ac-EVDs).

OBJECTIVE: We performed a systematic review of all studies evaluating PSAs and ac-EVD for VRI prevention through July 2010.

METHODS: Two reviewers independently assessed eligibility and evaluated study quality based on pre-established criteria. Observational studies and randomized clinical trials (RCTs) that fulfilled inclusion criteria were included in the meta-analysis.

RESULTS: Three RCTs and 7 observational studies met our inclusion criteria and were included in the analysis. The type of antibiotics and VRI definitions varied among these studies. Pooled analysis showed a protective effect of PSAs and ac-EVDs for VRI (risk ratio: 0.32; 95% CI: 0.18-0.56). Results showed moderate heterogeneity (I2 = 53%) explained by the difference in quality among the studies and the inclusion of 1 large positive cohort study. The effect of PSAs and ac-EVDs was unrelated to the type of study (RCT or observational, P for interaction = .55), the route of antibiotic administration (PSAs or ac-EVDs, P = .13), or the quality of the studies (suboptimal vs good/excellent, P = .55).

CONCLUSION: RCTs and observational-derived evidence support the use of PSAs throughout the duration of external ventricular drainage; similarly, the use of ac-EVDs to prevent VRI seems to be beneficial. Available data are heterogeneous and of suboptimal quality. Further research is needed to confirm the findings of this meta-analysis. There are not sufficient data to compare the protective effect of ac-EVDs and PSAs.

Neurosurgery 68:571–581, 2011 DOI: 10.1227/NEU.0b013e3182093145

Randomized clinical trials (RCTs) have usually supported using heparin prophylaxis against venous thromboembolism (VTE) in patients undergoing cranial neurosurgery. The tradeoff between benefit and bleeding risk, however, has not been adequately characterized.

OBJECTIVE: To conduct a systematic review and meta-analysis assessing the extent to which low-dose unfractionated heparin (LDUH) or low-molecular-weight heparin (LMWH) prophylaxis reduces the rate of VTE and increases the rate of intracerebral hemorrhage (ICH) and other bleeding in patients undergoing elective cranial neurosurgery.

METHODS: We selected RCTs that evaluated LDUH or LMWH prophylaxis of VTE in patients undergoing elective cranial neurosurgery. A meta-analysis assessing heparins vs no heparin (either with or without mechanical methods) was performed.

RESULTS: Eight RCTs were identified. Six RCTs involving 1170 patients evaluated LDUH or LMWH vs a control group. Five of 6 trials found a significant reduction in the risk of symptomatic and asymptomatic VTE with heparin prophylaxis. The pooled risk ratio was 0.58 (95% confidence interval, 0.45-0.75). ICH was more common in those receiving heparin, but not statistically significantly. For every 1000 patients who receive heparin prophylaxis, 91 VTE events will be prevented (approximately 35 of which are proximal deep vein thrombosis or pulmonary embolism and 9 to 18 of which are symptomatic), whereas 7 ICHs and 28 more minor bleeds will occur.

CONCLUSION: Heparin prophylaxis for patients undergoing elective cranial neurosurgery reduces the risk of VTE but may also increase bleeding risks with a ratio of serious or symptomatic VTE relative to serious bleeding that is only slightly favorable.

Neurosurgery 66:1153-1160, 2010 DOI: 10.1227/01.NEU.0000369189.09182.5F

A meta-analysis was performed to evaluate whether a beneficial clinical effect of cervical disk prostheses over conventional cervical diskectomy with fusion exists.

METHODS: A literature search was completed ending February 4, 2009, that included the abstract books of recent major spine congresses. All studies reported the results of singlelevel cervical disease without myelopathy. The Visual Analog Score (VAS) of the arm, VAS of the neck, Neck Disability Index, Physical Composite Scores of the Short Form 36, and Mental Composite Score of the Short Form 36, as well as adverse events, were evaluated.

RESULTS: Nine records were found, totaling 1533 patients. Of these, 1165 were evaluable at the last follow-up at 12 or 24 months. As an effect measure, a pooled odds ratio (OR) was calculated at 12 and 24 months. At 12 months, the VAS arm reached statistical significance (OR = 0.698; 95% confidence interval [CI], 0.571-0.853), as did the VAS neck (OR = 0.690; 95% CI, 0.562-0.847), and the Physical Composite Scores (OR = 1.362; 95% CI, 1.103-1.682) and the Mental Composite Score (OR = 1.270; 95% CI, 1.029-1.569) of the Short Form 36, favoring arthroplasty. The Neck Disability Index at 24 months also reached statistical difference (OR = 0.794; 95% CI, 0.641-0.984). All other measurements did not reveal any statistical difference. The number of complications, including secondary surgeries for adjacent segment disease, did not differ.

CONCLUSION: A clinical benefit for the cervical disk prosthesis is not proven. Because none of the studies were blinded, bias of the patient or researcher is a probable explanation for the differences found. Therefore, these costly devices should not be used in daily clinical practice.

J Neurosurg 112:1020–1032, 2010. DOI: 10.3171/2009.7.JNS09758

The aim of this study was to answer the question whether quality of life and progression-free and overall survival are increased in adults with supratentorial malignant glioma who are treated with cytoreductive resection as compared with those who only undergo biopsy.

Methods. A literature search of the electronic databases MEDLINE, EMBASE, and CENTRAL was performed to identify relevant studies published before May 2008. Hand-searching of reference lists of the identified studies and relevant review articles was also performed. A study was considered eligible, regardless of study design (prospective or retrospective), if: 1) quality of life and/or progression-free and/or overall survival was compared among adult patients undergoing biopsy or resection, and 2) patient age and Karnofsky Performance Scale scores were not significantly different among the 2 groups compared.

Results. One randomized controlled trial and 4 retrospective studies (involving a total of 1111 patients) were found eligible for this systematic review. A meta-analysis of the eligible studies demonstrated a significant increase in overall survival in the patients treated with resection instead of biopsy (hazard ratio 0.61, 95% CI 0.52–0.71, p < 0.0001, fixed-effect model). Although statistical pooling was not feasible, the available data suggest that quality of life was increased in patients treated with resection rather than biopsy, while there did not seem to be any significant difference in progression-free survival between the 2 groups.

Conclusions. Based on the best available evidence, it appears that cytoreductive resection in adults with supratentorial malignant glioma is associated with improved overall survival as compared with biopsy. However, well designed prospective studies are needed for more solid conclusions to be drawn.

DOI: 10.3171/2009.7.JNS09758

The aim of this study was to answer the question whether quality of life and progression-free and overall survival are increased in adults with supratentorial malignant glioma who are treated with cytoreductive resection as compared with those who only undergo biopsy.

Methods. A literature search of the electronic databases MEDLINE, EMBASE, and CENTRAL was performed to identify relevant studies published before May 2008. Hand-searching of reference lists of the identified studies and relevant review articles was also performed. A study was considered eligible, regardless of study design (prospective or retrospective), if: 1) quality of life and/or progression-free and/or overall survival was compared among adult patients undergoing biopsy or resection, and 2) patient age and Karnofsky Performance Scale scores were not significantly different among the 2 groups compared.

Results. One randomized controlled trial and 4 retrospective studies (involving a total of 1111 patients) were found eligible for this systematic review. A meta-analysis of the eligible studies demonstrated a significant increase in overall survival in the patients treated with resection instead of biopsy (hazard ratio 0.61, 95% CI 0.52–0.71, p <0.0001, fixed-effect model). Although statistical pooling was not feasible, the available data suggest that quality of life was increased in patients treated with resection rather than biopsy, while there did not seem to be any significant difference in progression-free survival between the 2 groups.

Conclusions. Based on the best available evidence, it appears that cytoreductive resection in adults with supratentorial malignant glioma is associated with improved overall survival as compared with biopsy. However, welldesigned prospective studies are needed for more solid conclusions to be drawn.