A guide to interpreting systematic reviews and meta-analyses in neurosurgery and surgery.

INTRODUCTION: Systematic reviews (SRs) and meta-analyses (MAs) are methods of data analysis used to synthesize information presented in multiple publications on the same topic. A thorough understanding of the steps involved in conducting this type of research and approaches to data analysis is critical for appropriate understanding, interpretation, and application of the findings of these reviews. METHODS: We reviewed reference texts in clinical neuroepidemiology, neurostatistics and research methods and other previously related articles on meta-analyses (MAs) in surgery. Based on existing theories and models and our cumulative years of expertise in conducting MAs, we have synthesized and presented a detailed pragmatic approach to interpreting MAs in Neurosurgery. RESULTS: Herein we have briefly defined SRs sand MAs and related terminologies, succinctly outlined the essential steps to conduct and critically appraise SRs and MAs. A practical approach to interpreting MAs for neurosurgeons is described in details. Based on summary outcome measures, we have used hypothetical examples to illustrate the Interpretation of the three commonest types of MAs in neurosurgery: MAs of Binary Outcome Measures (Pairwise MAs), MAs of proportions and MAs of Continuous Variables. Furthermore, we have elucidated on the concepts of heterogeneity, modeling, certainty, and bias essential for the robust and transparent interpretation of MAs. The basics for the Interpretation of Forest plots, the preferred graphical display of data in MAs are summarized. Additionally, a condensation of the assessment of the overall quality of methodology and reporting of MA and the applicability of evidence to patient care is presented. CONCLUSION: There is a paucity of pragmatic guides to appraise MAs for surgeons who are non-statisticians. This article serves as a detailed guide for the interpretation of systematic reviews and meta-analyses with examples of applications for clinical neurosurgeons.

Towards zero infection for ventriculoperitoneal shunt insertion in resource-limited settings: a multicenter prospective cohort study.

INTRODUCTION: Shunting for hydrocephalus can lead to improvement in the quality of life although the latter has been subdued by complications like shunt infection. Established protocols have contributed to the reduction of ventriculoperitoneal shunt (VPS) infections. Previously, we retrospectively demonstrated a low infection rate despite some of the protocol recommendations not being implemented. The aim of this study was to prospectively establish the incidence of shunt infection in the early post-shunt period following our protocol and elucidate on associated risk factors. PATIENTS AND METHODS: A multicenter prospective descriptive cohort study of consecutive 209 under-5 children requiring VPS for hydrocephalus was conducted between January 2013 and November 2018. An innovative protocol insisting on intermittent application of povidone-iodine on the skin during the operation was implemented. The patients were followed-up for 3 months post-surgery. RESULTS: Included were 211 VPS procedures performed on 209 children. The median age was 9 months and 84 were males. Hydrocephalus was non-communicative in 72.0% and aqueductal stenosis was its most frequent cause (84.9%). Most surgeries were performed in the morning (90.5%), electively (95.3%), and for the first time (91%). The median duration of surgery was 65 min. Shunt infection rate was 1.9% (n = 4) (95% CI 0.7 to 5.0%) per procedure. CONCLUSION: The observed infection rate was low. This suggests that the protocol followed captured the most critical components necessary to ensure low infection rates and that simple measures implemented in economically challenged environments may achieve internationally acceptable infection rates.

Antimicrobial effects of craniopharyngioma cystic fluid.

BACKGROUND: Tumours are known to increase the risk of infections, especially those occurring in the central nervous system where insertion of surgical hardware/shunts such as in craniopharyngiomas may be required. However, infections are surprisingly scarce in craniopharyngioma cases. In this study, we explored the possibility of antimicrobial effects of craniopharyngioma cystic fluid. METHODS: The antibacterial effect of craniopharyngioma cystic fluid samples against selected human pathogens: Escherichia. coli, S. aureus and S. pneumoniae were determined using the agar disc diffusion method. Streptomycin and ampicillin were used as controls. The test organisms were cultured in Mueller-Hinton broth overnight at 37 °C. McFarland standard was used as a reference to adjust the inoculum size of each test organism to a concentration of 1 × 106 CFU/ml using sterile broth. RESULTS: The craniopharyngioma cystic fluid inhibited growth of Gram-positive bacteria S. aureus and S. pneumoniae, but not the Gram-negative bacteria, E. coli. The samples showed the highest zones of S. pneumoniae growth inhibition of up to 20.0 ± 1.0 mm compared with 18.0 ± 1.0 mm of streptomycin and 9.0 ± 0.0 mm of ampicillin. CONCLUSION: Craniopharyngioma cystic fluid showed significant antibacterial properties against Gram-positive bacteria. This novel finding has implications in the way we view infections in craniopharyngioma patients. More studies need to be carried out to further elucidate this unique finding and possibly exploit these antimicrobial properties.

Observational Studies in Neurosurgery: Structure, Functioning, and Uses.

INTRODUCTION: Although randomized interventional studies are the gold standard of clinical study designs, they are not always feasible or necessary. In such cases, observational studies can bring insights into critical questions while minimizing harm and cost. There are numerous observational study designs, each with strengths and demerits. Unfortunately, it is not uncommon for observational study designs to be poorly designed or reported. In this article, the authors discuss similarities and differences between observational study designs, their application, and tenets of good use and proper reporting focusing on neurosurgery. METHODS: The authors illustrated neurosurgical case scenarios to describe case reports, case series, and cohort, cross-sectional, and case-control studies. The study design definitions and applications are taken from seminal research methodology readings and updated observational study reporting guidelines. RESULTS: The authors have given a succinct account of the structure, functioning, and uses of common observational study designs in Neurosurgery. Specifically, they discussed the concepts of study direction, temporal sequence, advantages, and disadvantages. Also, they highlighted the differences between case reports and case series; case series and descriptive cohort studies; and cohort and case-control studies. Also, they discussed their impacts on internal validity, external validity, and relevance. CONCLUSION: This paper disambiguates widely held misconceptions on the different observational study designs. In addition, it uses case-based scenarios to facilitate comprehension and relevance to the academic neurosurgery audience.

Truncal complex regional pain syndrome, myth or reality: Case report.

INTRODUCTION: Complex regional pain syndrome (CRPS) is an under diagonised, chronic pain condition commonly described occurring in the extremities. Its occurrence in the trunk is rarely reported and is thought by some to be non existent. CASE PRESENTATION: We report an unusual case of trunkul CRPS post appendectomy which presented with debilitating pain and review relevant literature. DISCUSSION AND CONCLUSION: We recommend that subsequent descriptions and diagnostic criteria should include the trunk as a site of occurrence of CRPS and not just the extremities. This will help reduce under diagnosis of this important condition.

Spontaneous chronic subdural hematomas in human immunodeficiency virus-infected patients with normal platelet count and no appreciable brain atrophy: Two case reports and review of literature.

BACKGROUND: Chronic subdural hematomas (CSDHs) usually occur in elderly patients following minor head trauma. Their occurrence is usually linked to cerebral atrophy secondary to alcohol, old age, or human immunodeficiency virus (HIV) infection. Spontaneous CSDHs have also been documented but are rare. They are usually caused by coagulopathies and various pathologies resulting in intracranial hypotension. CASES: We have observed a number of spontaneous CSDHs in HIV patients with normal platelet counts and no appreciable cerebral atrophy possibly caused by platelet dysfunction, hence we report about two such cases. To the best of our knowledge, no such cases have been reported in literature before. CONCLUSION: It is important to include CSDHs in the differential diagnosis of HIV patients presenting with neurological deficits even without a history of trauma.

Capillary hemangioma in the superior sagittal sinus as a rare cause of intracranial hypertension in a child: case report.

OBJECTIVE AND IMPORTANCE: The etiological factors involved in idiopathic intracranial hypertension are not easy to identify. This case of idiopathic intracranial hypertension was associated with a capillary hemangioma growing in the lumen of the superior sagittal sinus. CLINICAL PRESENTATION: A 10-year-old girl had experienced progressive headaches and abdominal pain. Fundoscopic examination disclosed bilateral papilledema and high intrathecal pressure, suggesting idiopathic intracranial hypertension. Magnetic resonance imaging, including magnetic resonance angiography as well as digital angiography, revealed a 3-cm mass protruding into the superior sagittal sinus lumen above the torcular. INTERVENTION: A capillary hemangioma attached to the internal dural wall of the sagittal sinus lumen was microsurgically removed. The symptoms resolved in several days and no additional treatment was required. CONCLUSION: A tumor growing into a venous sinus is a rare cause of venous outflow impairment and may generate the clinical signs of idiopathic intracranial hypertension. This case emphasizes the importance of multiple complementary imaging modalities and the efficacy of a direct surgical approach, which allowed resolution of symptoms.

The surgeon and human immunodeficiency virus.

The moral dilemmas faced by surgeons worldwide who treat patients infected with the human immunodeficiency virus (HIV) can be viewed against the background of experience in sub-Saharan countries, where the community prevalence is in excess of 25% (90% of hospital inpatients). When seeking consent for an HIV test before surgery, frank communication regarding the surgeons' perspective of risks to themselves and the patient is helpful. When consent for a test must be obtained from a substitute decision-maker, the surgeon should consider if the patient would want the decision-maker to know the result. Understanding the natural history of HIV in the surgical setting can help deal with the uncertainties encountered and should be a research priority for developing countries. International professional organizations are useful platforms for the exchange of ideas when surgeons encounter uncertainty by increasing access to journals and creating opportunities for discussion. Although supervisory bodies in some parts of the world prevent HIV-infected surgeons from putting patients at risk by offering surgery, the withdrawal of their services in developing countries can cause more harm than good. Surgeons in that position may be entitled to offer surgery but only with full disclosure of the risk of HIV infection to the patient. The decision-making process known as "accountability for reasonableness" allows surgeons to determine fairness, legitimacy, and acceptability when making resource allocation decisions involving patients with HIV.