Neurosurgery Blog

Acta Neurochir (2013) 155:345–353

Monitoring of brain function and metabolism during surgery may be of benefit for patient outcome. Microdialysis is the only sampling technique to date that allows continuous monitoring of drug or metabolite concentrations in the extracellular fluid of multiple tissues in the brain. This qualitative systematic review aimed to determine whether microdialysis is a valid tool for detecting changes in tissue composition as would be expected upon changes in (induced) tissue metabolic composition during brain surgery.

Methods A systematic review was conducted by performing a MEDLINE search using the terms “Intraoperative Period” (Medical Subject Heading [MeSH]) OR “Surgery” [Subheading] OR “Monitoring, Intraoperative” [MeSH] AND “Microdialysis” [MeSH] AND “Brain” [MeSH]. Two reviewers independently assessed the methodological quality of the studies. For each study the grades of recommendation were determined.

Results The search strategy yielded 46 publications in Medline. Data extraction was performed on 16 studies. The methodological quality of studies was low, with overall scores of 4 or 5. A quantitative analysis could not be performed because of lack of sufficient data. A qualitative analysis was positive with regard to the detection of different states of tissue composition by microdialysis. However, the levels of recommendation on the outcome statements were low, resulting in a grade D level of recommendation on all statements.

Conclusions The available evidence for the validity of cerebral microdialysis as a diagnostic tool during brain surgery is of low scientific quality. In order to develop cerebral microdialysis as a valid instrument for monitoring of brain metabolism during surgery, standardised clinical prospective studies in homogeneous patient populations are required.

 Spine 2013 ; 38 : 24 – 36

Study Design. Systematic literature review.

Objective. To assess the effect of total disc replacement for chronic low back pain due to lumbar degenerative disc disease compared with fusion or other treatment options.

Summary of Background Data. There is an increasing use in disc replacement devices for degenerative disc disease, but their effectiveness compared with other interventions such as fusion of the motion segment or conservative treatment remains unclear.

Methods. A comprehensive search in PubMedCentral, MEDLINE, EMBASE, BIOSIS, ClinicalTrials.gov, and FDA trials register was conducted. Randomized controlled trials comparing total disc replacement with any other intervention for degenerative disc disease were included. Risk of bias was assessed using the criteria of the Cochrane Back Review Group. Quality of evidence was graded according to the GRADE approach. Two review authors independently selected studies, assessed risk of bias, and extracted data. Results and upper bounds of confidence intervals were compared with predefined clinically relevant differences.

Results. We included 7 randomized controlled trials with a follow-up of 24 months. There is risk of bias in the included studies due to sponsoring and absence of any kind of blinding. One study compared disc replacement with rehabilitation and found a signifi cant advantage in favor of surgery, which, however, did not reach the predefi ned threshold. Six studies compared disc replacement with fusion and found that the mean improvement in visual analogue scale score of back pain was 5.2 mm higher (2 studies; 95% confidence interval 0.2–10.3) with a low quality of evidence. The improvement of Oswestry disability index score at 24 months in the disc replacement group was 4.3 points more than in the fusion group (5 studies; 95% confidence interval 1.85–6.68) with a low quality of evidence. Both upper bounds of the confidence intervals were below the predefined clinically relevant difference.

Conclusion. Although statistically significant, the differences in clinical improvement were not beyond generally accepted boundaries for clinical relevance. Prevention of adjacent level disease and/or facet joint degeneration was not properly assessed. Therefore, because we think that harm and complications may occur after some years, the spine surgery community should be prudent to adopt this technology on a large scale, despite the fact that total disc replacement seems to be effective in treating low back pain in selected patients, and in the short term is at least equivalent to fusion surgery.

Key words: s.

J Neurosurg 114:1250–1256, 2011. DOI: 10.3171/2010.12.JNS101623

Despite the increased detection of incidental or small meningiomas, the lesion’s natural history is largely unknown.

Methods. One year or longer of follow-up was conducted in 244 patients with 273 meningiomas managed conservatively by a single surgeon between 2003 and 2008. Data were stratified according to age, sex, tumor location, symptoms, initial tumor diameter, calcification, MR imaging intensity, and edema. Linear tumor growth was defined as a 2-mm or larger increase in the maximum diameter in any direction of the tumor. Volumetric analysis (ImageJ version 1.43) was also conducted in 154 of 273 meningiomas for which complete radiological data were available in the form of DICOM files throughout the follow-up period. A volume increase greater than 8.2% was regarded as significant because the preliminary volumetry based on 20 randomly selected meningiomas showed that the average SD was 4.1%.

Results. Linear growth was observed in 120 tumors (44.0%) with a mean follow-up of 3.8 years. Factors related to tumor growth were age of 60 or younger (p = 0.0004), absence of calcification (p = 0.027), MR imaging T2 signal hyperintensity (p = 0.021), and edema (p = 0.018). Kaplan-Meier analysis and Cox proportional hazards regression analysis revealed that age 60 or younger (hazard ratio [HR] 1.54, 95% CI 1.05–2.30, p = 0.026), initial tumor diameter greater than 25 mm (HR 2.23, 95% CI 1.44–3.38, p = 0.0004), and the absence of calcification (HR 4.57, 95% CI 2.69–8.20, p < 0.0001) were factors associated with a short time to progression. Volumetric growth was seen in 74.0% of the cases. Factors associated with a higher annual growth rate were male sex (p = 0.0002), initial tumor diameter greater than 25 mm (p < 0.0001), MR imaging T2 signal hyperintensity (p = 0.0001), presence of symptoms (p = 0.037), and edema (p < 0.0001).

Conclusions. Although the authors could obtain variable results depending on the measurement method, the data demonstrate patients younger than 60 years of age and those with meningiomas characterized by hyperintensity on T2-weighted MR imaging, no calcification, diameter greater than 25 mm, and edema need to be observed more closely. Volumetry was more sensitive to detecting tumor growth than measuring the linear diameter.

Stroke. 2010;41:2108-2129. DOI: 10.1161/STR.0b013e3181ec611b

Purpose—The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of acute spontaneous intracerebral hemorrhage.

Methods—A formal literature search of MEDLINE was performed. Data were synthesized with the use of evidence tables. Writing committee members met by teleconference to discuss data-derived recommendations. The American Heart Association Stroke Council’s Levels of Evidence grading algorithm was used to grade each recommendation. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statements Oversight Committee and Stroke Council Leadership Committee. It is intended that this guideline be fully updated in 3 years’ time.

Results—Evidence-based guidelines are presented for the care of patients presenting with intracerebral hemorrhage. The focus was subdivided into diagnosis, hemostasis, blood pressure management, inpatient and nursing management, preventing medical comorbidities, surgical treatment, outcome prediction, rehabilitation, prevention of recurrence, and future considerations.

Conclusions—Intracerebral hemorrhage is a serious medical condition for which outcome can be impacted by early, aggressive care. The guidelines offer a framework for goal-directed treatment of the patient with intracerebral hemorrhage.

J Neurosurg Spine 13:144–157, 2010.DOI: 10.3171/2010.3.SPINE09369

The overall incidence of complications or adverse events in spinal surgery is unknown. Both prospective and retrospective analyses have been performed, but the results have not been critically assessed. Procedures for different regions of the spine (cervical and thoracolumbar) and the incidence of complications for each have been reported but not compared. Authors of previous reports have concentrated on complications in terms of their incidence relevant to healthcare providers: medical versus surgical etiology and the relevance of perioperative complications to perioperative events. Few authors have assessed complication incidence from the patient’s perspective. In this report the authors summarize the spine surgery complications literature and address the effect of study design on reported complication incidence.

Methods. A systematic evidence-based review was completed to identify within the published literature complication rates in spinal surgery. The MEDLINE database was queried using the key words “spine surgery” and “complications.” This initial search revealed more than 700 articles, which were further limited through an exclusion process. Each abstract was reviewed and papers were obtained. The authors gathered 105 relevant articles detailing 80 thoracolumbar and 25 cervical studies. Among the 105 articles were 84 retrospective studies and 21 prospective studies. The authors evaluated the study designs and compared cervical, thoracolumbar, prospective, and retrospective studies as well as the durations of follow-up for each study.

Results. In the 105 articles reviewed, there were 79,471 patients with 13,067 reported complications for an overall complication incidence of 16.4% per patient. Complications were more common in thoracolumbar (17.8%) than cervical procedures (8.9%; p < 0.0001, OR 2.23). Prospective studies yielded a higher incidence of complications (19.9%) than retrospective studies (16.1%; p < 0.0001, OR 1.3). The complication incidence for prospective thoracolumbar studies (20.4%) was greater than that for retrospective series (17.5%; p < 0.0001). This difference between prospective and retrospective reviews was not found in the cervical studies. The year of study publication did not correlate with the complication incidence, although the duration of follow-up did correlate with the complication incidence (p = 0.001).

Conclusions. Retrospective reviews significantly underestimate the overall incidence of complications in spine surgery. This analysis is the first to critically assess differing complication incidences reported in prospective and retrospective cervical and thoracolumbar spine surgery studies

Acta Neurochir (2010) 152:87–97 DOI 10.1007/s00701-009-0552-6

Objective The purpose of the study was to define and identify prognostic indicators within an elderly population of patients suffering from intracranial meningiomas. The clinical presentation of the patient with meningioma is diverse, manifesting as a different clinical entity in the elderly patient compared to a similar type of tumor in a young patient.

Methods Two hundred fifty patients aged over 65 years admitted to RAMBAM Medical Center with meningiomas from 1995–2005 were characterized. We report the present- ing symptoms, chronic illnesses, perioperative and long- term follow-up results for a 5-year period.

Results Based on univariate and multivariate analysis, significant prognostic indicators were identified and were implemented into a new geriatric scoring system (GSS) including tumor size and location, peritumoral edema, neurological deficits, Karnofsky score (Clancey J Neurosci Nurs 27:220, 1995; Crooks et al. J Gerontol 46:M139– M144, 1991), and associated diabetes, hypertension or lung disease. Seven outcome parameters were retrospectively tested using the scoring system, namely mortality, Barthel Index score (Mahoney and Barthel Md State Med J 14:61–65, 1965), Karnofsky score and consciousness expressed by the Glasgow Coma Scale score (Jennett and Bond Lancet 1:480–484, 1975) 5 years after surgery, as well as recurrence within and beyond 12 months. Age proved to inversely correlate with outcome. Morbidity and mortality were significantly lower in women. The extent of surgical resection (Simpson J Neurol Neurosurg Psychiatry 20:22–39, 1957) had no influence on function- al outcome, although radical resection was associated with significantly lower mortality. Generally, a GSS score higher than 14 was associated with a significantly more favorable outcome.

Conclusion The present results suggest that common experience-based considerations may be optimized and implemented into a simple scoring system that in turn may allow for outcome prediction and evidence-based decision making.