Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

BACKGROUND

Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.

METHODS

This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low-middle-income countries.

RESULTS

In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of 'single-use' consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low-middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.

CONCLUSION

This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high- and low-middle-income countries.

Surgery for acute subdural hematoma: the value of pre-emptive decompressive craniectomy by propensity score analysis

BACKGROUND

Acute subdural hematomas (ASDH) are found frequently following traumatic brain injury (TBI) and they are considered the most lethal type of mass lesions. The decision to perform a procedure to evacuate ASDH and the approach, either via craniotomy or decompressive craniectomy (DC), remains controversial.

METHODS

We reviewed a prospectively collected series of 343 moderate to severe TBI patients in whom ASDH was the main lesion (ASDH volumes ≥10 cc). Patients with early comfort measures (early mortality prediction >50% and not ICP monitored), bilateral ASDH or the presence of another intracranial hematoma with volumes exceeding two times the volume of the ASDH were excluded. Among them, 112 were managed conservatively, 65 underwent ASDH evacuation by craniotomy and 166 by DC (103 pre-emptive DC, 63 obligatory DC). We calculated the average treatment effect by propensity score (PS) analysis using the following covariates: age, year, hypoxia, shock, pupils, major extracranial injury, motor score, midline shift, ASDH volume, swelling, intraventricular and subarachnoid hemorrhage presence. Then, multivariable binary regression and ordinal logistic regression analysis were performed to estimate associations between predictors and mortality and 12 months-GOS respectively. The patients' inverse probability weights were included as an independent variable in both regression models.

RESULTS

The main variables associated with outcome were year, age, falls from patient´s own height, hypoxia, early deterioration, pupillary abnormalities, basal cistern effacement, compliance to ICP monitoring guidelines and type of surgical approach (craniotomy and pre-emptive DC).

CONCLUSIONS

According to sliding dichotomy analysis, we found that patients in the intermediate or worst bands of unfavorable outcome prognosis seemed to achieve better than expected outcome if they underwent pre-emptive DC rather than craniotomy.

Serum assessment of traumatic axonal injury: the correlation of GFAP, t-Tau, UCH-L1, and NfL levels with diffusion tensor imaging metrics and its prognosis utility

OBJECTIVE

Diagnosis of traumatic axonal injury (TAI) is challenging because of its underestimation by conventional MRI and the technical requirements associated with the processing of diffusion tensor imaging (DTI). Serum biomarkers seem to be able to identify patients with abnormal CT scanning findings, but their potential role to assess TAI has seldomly been explored.

METHODS

Patients with all severities of traumatic brain injury (TBI) were prospectively included in this study between 2016 and 2021. They underwent blood extraction within 24 hours after injury and imaging assessment, including DTI. Serum concentrations of glial fibrillary acidic protein, total microtubule-associated protein (t-Tau), ubiquitin C-terminal hydrolase L1 (UCH-L1), and neurofilament light chain (NfL) were measured using an ultrasensitive Simoa multiplex assay panel, a digital form of enzyme-linked immunosorbent assay. The Glasgow Outcome Scale-Extended score was determined at 6 months after TBI. The relationships between biomarker concentrations, volumetric analysis of corpus callosum (CC) lesions, and fractional anisotropy (FA) were analyzed by nonparametric tests. The prognostic utility of the biomarker was determined by calculating the C-statistic and an ordinal regression analysis.

RESULTS

A total of 87 patients were included. Concentrations of all biomarkers were significantly higher for patients compared with controls. Although the concentration of the biomarkers was affected by the presence of mass lesions, FA of the CC was an independent factor influencing levels of UCH-L1 and NfL, which positioned these two biomarkers as better surrogates of TAI. Biomarkers also performed well in determining patients who would have had unfavorable outcome. NfL and the FA of the CC are independent complementary factors related to outcome.

CONCLUSIONS

UCH-L1 and NfL seem to be the biomarkers more specific to detect TAI. The concentration of NfL combined with the FA of the CC might help predict long-term outcome.

Patients awaiting surgery for neurosurgical diseases during the first wave of the COVID-19 pandemic in Spain: a multicentre cohort study

OBJECTIVES

The large number of infected patients requiring mechanical ventilation has led to the postponement of scheduled neurosurgical procedures during the first wave of the COVID-19 pandemic. The aims of this study were to investigate the factors that influence the decision to postpone scheduled neurosurgical procedures and to evaluate the effect of the restriction in scheduled surgery adopted to deal with the first outbreak of the COVID-19 pandemic in Spain on the outcome of patients awaiting surgery.

DESIGN

This was an observational retrospective study.

SETTINGS

A tertiary-level multicentre study of neurosurgery activity between 1 March and 30 June 2020.

PARTICIPANTS

A total of 680 patients awaiting any scheduled neurosurgical procedure were enrolled. 470 patients (69.1%) were awaiting surgery because of spine degenerative disease, 86 patients (12.6%) due to functional disorders, 58 patients (8.5%) due to brain or spine tumours, 25 patients (3.7%) due to cerebrospinal fluid (CSF) disorders and 17 patients (2.5%) due to cerebrovascular disease.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was mortality due to any reason and any deterioration of the specific neurosurgical condition. Second, we analysed the rate of confirmed SARS-CoV-2 infection.

RESULTS

More than one-quarter of patients experienced clinical or radiological deterioration. The rate of worsening was higher among patients with functional (39.5%) or CSF disorders (40%). Two patients died (0.4%) during the waiting period, both because of a concurrent disease. We performed a multivariate logistic regression analysis to determine independent covariates associated with maintaining the surgical indication. We found that community SARS-CoV-2 incidence (OR=1.011, p<0.001), degenerative spine (OR=0.296, p=0.027) and expedited indications (OR=6.095, p<0.001) were independent factors for being operated on during the pandemic.

CONCLUSIONS

Patients awaiting neurosurgery experienced significant collateral damage even when they were considered for scheduled procedures.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

The influence of aneurysm morphology on the volume of hemorrhage after rupture

OBJECTIVE

Factors determining the risk of rupture of intracranial aneurysms have been extensively studied; however, little attention is paid to variables influencing the volume of bleeding after rupture. In this study the authors aimed to evaluate the impact of aneurysm morphological variables on the amount of hemorrhage.

METHODS

This was a retrospective cohort analysis of a prospectively collected data set of 116 patients presenting at a single center with subarachnoid hemorrhage due to aneurysmal rupture. A volumetric assessment of the total hemorrhage volume was performed from the initial noncontrast CT. Aneurysms were segmented and reproduced from the initial CT angiography study, and morphology indexes were calculated with a computer-assisted approach. Clinical and demographic characteristics of the patients were included in the study. Factors influencing the volume of hemorrhage were explored with univariate correlations, multiple linear regression analysis, and graphical probabilistic modeling.

RESULTS

The univariate analysis demonstrated that several of the morphological variables but only the patient's age from the clinical-demographic variables correlated (p < 0.05) with the volume of bleeding. Nine morphological variables correlated positively (absolute height, perpendicular height, maximum width, sac surface area, sac volume, size ratio, bottleneck factor, neck-to-vessel ratio, and width-to-vessel ratio) and two correlated negatively (parent vessel average diameter and the aneurysm angle). After multivariate analysis, only the aneurysm size ratio (p < 0.001) and the patient's age (p = 0.023) remained statistically significant. The graphical probabilistic model confirmed the size ratio and the patient's age as the variables most related to the total hemorrhage volume.

CONCLUSIONS

A greater aneurysm size ratio and an older patient age are likely to entail a greater volume of bleeding after subarachnoid hemorrhage.

Traumatic axonal injury: is the prognostic information produced by conventional MRI and DTI complementary or supplementary?

OBJECTIVE

A traumatic axonal injury (TAI) diagnosis has traditionally been based on conventional MRI, especially on those sequences with a higher sensitivity to edema and blood degradation products. A more recent technique, diffusion tensor imaging (DTI), can infer the microstructure of white matter (WM) due to the restricted diffusion of water in organized tissues. However, there is little information regarding the correlation of the findings obtained by both methods and their use for outcome prognosis. The main objectives of this study were threefold: 1) study the correlation between DTI metrics and conventional MRI findings; 2) evaluate whether the prognostic information provided by the two techniques is supplementary or complementary; and 3) determine the incremental value of the addition of these variables compared to a traditional prognostic model.

METHODS

The authors studied 185 patients with moderate to severe traumatic brain injury (TBI) who underwent MRI with DTI study during the subacute stage. The number and volume of lesions in hemispheric subcortical WM, corpus callosum (CC), basal ganglia, thalamus, and brainstem in at least four conventional MRI sequences (T1-weighted, T2-weighted, FLAIR, T2* gradient recalled echo, susceptibility-weighted imaging, and diffusion-weighted imaging) were determined. Fractional anisotropy (FA) was measured in 28 WM bundles using the region of interest method. Nonparametric tests were used to evaluate the colocalization of macroscopic lesions and FA. A multivariate logistic regression analysis was performed to assess the independent prognostic value of each neuroimaging modality after adjustment for relevant clinical covariates, and the internal validation of the model was evaluated in a contemporary cohort of 92 patients.

RESULTS

Differences in the lesion load between patients according to their severity and outcome were found. Colocalization of macroscopic nonhemorrhagic TAI lesions (not microbleeds) and lower FA was limited to the internal and external capsule, corona radiata, inferior frontooccipital fasciculus, CC, and brainstem. However, a significant association between the FA value and the identification of macroscopic lesions in distant brain regions was also detected. Specifically, lower values of FA of some hemispheric WM bundles and the splenium of the CC were related to a higher number and volume of hyperintensities in the brainstem. The regression analysis revealed that age, motor score, hypoxia, FA of the genu of the CC, characterization of TAI lesions in the CC, and the presence of thalamic/basal ganglia lesions were independent prognostic factors. The performance of the proposed model was higher than that of the IMPACT (International Mission on Prognosis and Analysis of Clinical Trials in TBI) model in the validation cohort.

CONCLUSIONS

Very limited colocalization of hyperintensities (none for microbleeds) with FA values was discovered. DTI and conventional MRI provide complementary prognostic information, and their combination can improve the performance of traditional prognostic models.

Apert syndrome: Cranial procedures and brain malformations in a series of patients

Background:

Apert syndrome is one of the most severe craniofacial disorders. This study aims to describe the craniofacial surgeries and central nervous system malformations of a cohort of children with Apert syndrome treated in the past 20 years and to compare these data with previously published data.

Methods:

Retrospective analysis of a series of patients with Apert syndrome treated between 1999 and 2019 in our hospital. Information was analyzed regarding craniofacial procedures, hydrocephalus and presence of shunts, Chiari malformation Type 1, and other brain malformations such as corpus callosum and septum pellucidum anomalies.

Results:

Thirty-seven patients were studied. Ventriculoperitoneal shunt prevalence was 24.3%, and 8.1% of patients required decompressive surgery for Chiari malformation. All of them needed at least one cranial vault remodeling procedure. The median age for this procedure was 8 months. In 69.7% of patients, the first cranial vault intervention was performed in the fronto-orbital region. In 36.4% of patients, a midface advancement had been performed at the time of this review, although this proportion was very dependent on the follow-up period and the age of the patients. The median age for the midface advancement procedure was 5.25 years. Anomalies of the corpus callosum and the septum pellucidum were reported in 43.2% and 59.5% of patients, respectively.

Conclusion:

Apert syndrome is a type of syndromic craniosynostosis, and patients usually require one or more cranial and facial surgeries. In comparison with other syndromic craniosynostosis types, Apert syndrome less frequently requires a VP shunt or treatment for a Chiari malformation.

Reliability and accuracy assessment of morphometric measurements obtained with software for three-dimensional reconstruction of brain aneurysms relative to cerebral angiography measures

OBJECTIVE

To analyze the reliability and accuracy of morphological measurements of software employed to three-dimensionally reconstruct aneurysms and vessels (VMTKlab, version 1.6.1,) with computed tomography angiography (CTA) as the source of images. Agreement with measurements from three-dimensional digital subtraction angiography (3 D-DSA) was evaluated.

METHODS

We evaluated 40 patients presenting with aneurysmal subarachnoid hemorrhage (aSAH). We analyzed four main variables of the aneurysm morphology: absolute height (size), neck (maximum neck width), perpendicular height, and maximum width. The CTA images were uploaded to the software and then segmented to reconstruct the aneurysm. This new method was compared to the current gold standard-3D reconstruction of pretreatment cerebral angiography. We used intraclass correlation coefficient (ICC) and Bland-Altman plot analyses to evaluate the agreement between these methods.

RESULTS

The ICCs obtained for absolute height, neck, perpendicular height, and maximum width were 0.85, 0.57, 0.85, and 0.89, respectively. This implied good agreement except for the neck of the aneurysm (moderate agreement). Bland-Altman plots are presented for the four indexes. The average of the differences was not significant in terms of absolute height, perpendicular height, and maximum width indicating good agreement. However, it was significant for the neck of the aneurysm.

CONCLUSIONS

We report good agreement between the values generated using VMTKlab and cerebral angiography for three of the four main variables. Discrepancies in neck diameter are not surprising and its underestimation with a traditional delineation from cerebral angiography has been reported before.

Endoscopic Transnasal Trans-Sphenoidal Approach for Pituitary Adenomas: A Comparison to the Microscopic Approach Cohort by Propensity Score Analysis

BACKGROUND

Despite some evidence for the adoption of endoscopic transnasal trans-sphenoidal surgery (ETSS) for pituitary adenomas, the advantages of this technique over the traditional approach have not been robustly confirmed.

OBJECTIVE

To compare ETSS with the microscopic sublabial trans-septal trans-sphenoidal surgery (MTSS) for pituitary adenomas.

METHODS

We retrospectively reviewed 2 cohorts of ETSS and MTSS performed at our institution from 1995 to 2017. Patient characteristics, surgical data, and outcomes were recorded prospectively. We performed a univariate and multivariable analysis to determine the best surgical approach. To improve the quality of the results, we matched the distribution of patient characteristics between groups by propensity score (PS) method.

RESULTS

A total of 187 procedures (90 MTSS, 97 ETSS) were reviewed. We found better results in the ETSS group in terms of gross total resection (P = .002) and hormone-excess secretion control (P = .014). There was also a lower incidence of cerebrospinal fluid leakage (P = .039), transitory diabetes insipidus (P = .028), and postoperative hypopituitarism (P = .045), as well as a shorter hospital length of stay (P < .001). After PS matching, we confirmed by multivariable logistic regression analysis an increased odds ratio of gross total resection for the ETSS (3.910; 95% CI 1.720-8.889; P = .001).

CONCLUSION

By PS method, our results suggest that the ETSS provides advantages over the traditional MTSS approach for tumor resection. Better control of secreting tumors and a lower rate of most complications also support the selection of the ETSS approach for the treatment of pituitary adenomas.

Opening of unusual vascular collaterals leads to early recanalization of a giant intracavernous carotid artery aneurysm following common carotid artery occlusion: A Case report and literature review

Background:

Parent artery occlusion (PAO) with or without bypass surgery is a feasible treatment for large intracavernous carotid artery (ICCA) aneurysms. The ideal occlusion site (internal or common carotid artery [CCA]) and ischemic complications after PAO have received special attention since the description of the technique. Unfrequently, some patients can also develop unusual external carotid artery-internal carotid artery collateral pathways distal to the ligation site that can explain the failure to aneurysm size reduction.

Case Description:

We describe a rare case of delayed refilling of a large ICCA aneurysm partially thrombosed which early recanalized after surgical ligation of the cervical CCA through an unusual collateral pathway.

Conclusion:

Based on our experience, we recommend periodic long-term follow-up neuroimaging, especially in those cases where potential collateral branches have not been clearly identified in the preoperative studies.

Sixto Obrador SENEC prize 2019: Utility of diffusion tensor imaging as a prognostic tool in moderate to severe traumatic brain injury. Part I. Analysis of DTI metrics performed during the early subacute stage

BACKGROUND AND OBJECTIVES

Traumatic axonal injury (TAI) contributes significantly to mortality and morbidity after traumatic brain injury (TBI). Its identification is still a diagnostic challenge because of the limitations of conventional imaging techniques to characterized it. Diffusion tensor imaging (DTI) can indirectly identify areas of damaged white matter integrity by detecting water molecule diffusion alterations. Our main objective is to characterize the TAI using DTI at the early subacute stage in our series of moderate to severe TBI patients and to evaluate if there is a relationship between the information provided by the DTI and patient's outcome.

MATERIALS AND METHODS

We have obtained DTI data from 217 patients with moderate to severe TBI acquired at a median of 19 days after TBI, and patient DTI metrics were compared with data obtained from 58 age-matched healthy controls. Region of interest method was applied to obtain mean fractional anisotropy (FA) value in 28 white matter fiber bundles susceptible to TAI.

RESULTS

Our main results were that when we compared patients with controls, patients, regardless of TBI severity, showed significantly reduced mean FA in almost all region of interest measured. We found statistically significant correlation between FA metrics and some clinical characteristics. Additionally, the FA values of the three portions of Corpus callosum, Cingulum and cerebral peduncles measured at the early subacute stage were highly associated with outcome assessed at hospital discharge and at 6 and 12 months after TBI.

CONCLUSIONS

We conclude that DTI is a useful tool to characterize TAI and the detection of FA reduction in the subacute stage after TBI is associated with long-term unfavorable outcome.

Longitudinal Analysis of Corpus Callosum Diffusion Tensor Imaging Metrics and Its Association with Neurological Outcome

Traumatic axonal injury (TAI) is the main cause of cognitive and psychological disfunction after a traumatic brain injury (TBI). Diffusion tensor imaging (DTI) is considered a useful technique for indirect assessment of white matter (WM) integrity after a TBI. Scattered WM alterations and its relationship with patient severity have been discovered in normal appearing conventional magnetic resonance imaging (MRI) studies based on DTI sequences. However, there is a lack of large sample studies on the longitudinal changes of DTI metrics to be used to determine the temporal profile after head injury and its association with patient outcome. We performed a prospective observational study in 118 moderate-to-severe TBI patients. The study included clinical outcome assessment based on the Glasgow Outcome Scale Extended (GOSE) and serial DTI studies in the early subacute setting (< 60 days) and 6 and 12 months after injury. Fractional anisotropy (FA) and axial and radial diffusivities (AD and RD, respectively) were measured in the three portions of corpus callosum (genu, body, splenium) at each time-point and compared with normalized values from an age-matched control group. Longitudinal FA analysis and its correlation with patient improvement also was done by non-parametric testing and ordinal regression analysis. Our main results indicated that between all the time-points, dynamic changes in DTI metrics in all three portions of corpus callosum were detected, but TBI patients continued to show significantly lower FA and AD values and higher RD values compared with controls. We also have discovered differences in the change of DTI metrics among different time-points in patient subgroups according with their outcome improvement. In conclusion, even without normalization of DTI metrics in the long-term, knowledge of the temporal profile of change in DTI metrics can provide important information about patients' clinical recovery after TBI.

[Assessment of the correlation between histological degeneration and radiological and clinical parameters in a series of patients who underwent lumbar disc herniation surgery]

BACKGROUND AND OBJECTIVE

The use of histological degeneration scores in surgically-treated herniated lumbar discs is not common in clinical practice and its use has been primarily restricted to research. The objective of this study is to evaluate if there is an association between a higher grade of histological degeneration when compared with clinical or radiological parameters.

PATIENTS AND METHOD

Retrospective consecutive analysis of 122 patients who underwent single-segment lumbar disc herniation surgery. Clinical information was available on all patients, while the histological study and preoperative magnetic resonance imaging were also retrieved for 75 patients. Clinical variables included age, duration of symptoms, neurological deficits, or affected deep tendon reflex. The preoperative magnetic resonance imaging was evaluated using Modic and Pfirrmann scores for the affected segment by 2 independent observers. Histological degeneration was evaluated using Weiler's score; the presence of inflammatory infiltrates and neovascularization, not included in the score, were also studied. Correlation and chi-square tests were used to assess the association between histological variables and clinical or radiological variables. Interobserver agreement was also evaluated for the MRI variables using weighted kappa.

RESULTS

No statistically significant correlation was found between histological variables (histological degeneration score, inflammatory infiltrates or neovascularization) and clinical or radiological variables. Interobserver agreement for radiological scores resulted in a kappa of 0.79 for the Pfirrmann scale and 0.65 for the Modic scale, both statistically significant.

CONCLUSIONS

In our series of patients, we could not demonstrate any correlation between the degree of histological degeneration or the presence of inflammatory infiltrates when compared with radiological degeneration scales or clinical variables such as the patient's age or duration of symptoms.

Symptomatic ptosis cerebelli after suboccipital craniectomy in a patient with severe brain trauma

PRIMARY OBJECTIVE

To report the first case of symptomatic cerebellar ptosis after a large suboccipital craniectomy in a patient with severe brain trauma and a review of the literature.

PATIENT AND METHODS

A 36-year-old man suffered severe traumatic brain injury after a four-metre fall. He underwent a large suboccipital craniectomy because his computed tomography scan revealed a posterior fossa subdural haematoma and cerebellar swelling. Four weeks after admission, he developed communicating hydrocephalus, and a ventriculoperitoneal shunt was placed. Although he experienced good recovery, seven months after the trauma he complained of cephalea, dizziness, recurrent vomiting and diplopia. Magnetic resonance imaging (MRI) showed descent of the cerebellum through a wide bone defect.

RESULTS

We performed a posterior fossa cranioplasty after other causes of delayed worsening were ruled out, such as shunt malfunction, overdrainage and ischaemic lesions. The patient improved, and a post-operative MRI confirmed the upward migration of the cerebellum.

CONCLUSIONS

Cerebellar ptosis must be considered in cases of delayed symptoms after large suboccipital craniectomy regardless of pathology. Posterior fossa cranioplasty to provide structural support to slumped cerebellum can improve or resolve symptoms.

[Selection of medical graduates for residency posts. A comparative study of the methodologies used in different countries]

INTRODUCTION

The design of an appropriate method for the selection of medical graduates for residency posts is extremely important, not only for the efficiency of the method itself (accurate identification of most competent candidates), but also for its influence on the study and teaching methodologies operating in medical schools. Currently, there is a great variation in the criteria used in different countries and there is no definitively appropriate method. The use of isolated or combined criteria, such as the marks obtained by students in medical schools, their performance in tests of theoretical knowledge and evaluations of clinical competence, or personal interviews, have a limited value for identifying those candidates who will perform better during the residency and later on during independent practice.

OBJECTIVES

To analyse the variability in the methodologies used for the selection of residents employed in different countries, in particular those used in the United Kingdom and USA, where external agencies and medical schools make systematic analyses of curriculum development. The advantages and disadvantages of national or transnational licensing examinations on the process of convergence and harmonization of medical degrees and residency programmes through Europe are discussed. The present analysis is used to design a new and more efficient multi-criteria methodology for resident selection in Spain, which will be published in the next issue of this journal.

CONCLUSIONS

Since the multi-criteria methods used in UK and USA appear to be most consistent, these have been employed for designing the new methodology that could be applied in Spain. Although many experts in medical education reject national examinations for awarding medical degrees or ranking candidates for residency posts, it seems that, when appropriately designed, they can be used to verify the level of competence of graduating students without necessarily distorting curriculum implementation or improvement.

Endovascular treatment of a true posterior communicating artery aneurysm

BACKGROUND

Posterior communicating artery (PCoA) aneurysms are most commonly located at the junction of the internal carotid artery and the PCoA. "True" PCoA aneurysms, which originate from the PCoA itself, are rarely encountered. Most previously reported cases were treated surgically mainly before the endovascular option became available.

CASE DESCRIPTION

A 53-year-old male presented with sudden onset of right hemiparesis and aphasia. Left middle cerebral artery stroke was diagnosed. Further studies revealed a 3 mm left PCoA aneurysm arising from the PCoA itself, attached to neither the internal carotid artery nor the posterior cerebral artery. Endovascular treatment was performed and the aneurysm was coiled completely.

CONCLUSION

Technical advances in endovascular interventional technology have permitted an additional approach to these lesions. The possible endovascular significance of the treatment of true PCoA aneurysms is discussed.

Dorsal myelopathy secondary to epidural fibrous scar tissue around a spinal cord stimulation electrode

The authors describe a patient with delayed thoracic spinal cord compression due to fibrous scar tissue around an epidural electrode used in spinal cord stimulation (SCS). One year after implantation of the system the stimulation became ineffective, and 1 year later the patient developed progressive paraparesis. There was no evidence of device-related complications on plain radiographs and CT scans, so the system was removed to perform MRI studies. These studies showed a dorsal myelopathy secondary to scar tissue around the electrode. At surgery thick scar tissue was resected, and the patient's neurological symptoms improved. The histological examination confirmed fibrosis, and microbiological studies excluded chronic infection. As far as the authors are aware, this complication has never been reported before at the thoracic level. Scarring around SCS electrodes should be considered as a late complication and as a possible cause of the tolerance phenomenon.

Acute neurological deterioration as a result of two synchronous hemorrhagic spinal ependymomas

Background:

Ependymomas are the most common intramedullary tumors in adults and are the most common in mid-adult years. The presence of synchronous ependymomas in different sites of the spine is not common and it is even more infrequent to find hemorrhage from a spinal ependymoma as a cause of neurological deterioration.

Case Description:

A 32-year-old man presented with back pain and progressive paraparesia. Magnetic resonance (MR) showed two intradural extramedullary lesions on spinal canal with signs of acute hemorrhage. The patient underwent emergent surgical decompression and resection. Pathology revealed myxopapillary ependymomas.

Conclusion:

To our knowledge, we report the first case of a patient with acute neurological deterioration as a consequence of synchronous bleeding of two spinal ependymomas located at different levels in the spinal cord. This study illustrates the importance of recognizing the rare, but known occurrence of acute neurological deterioration after spontaneous hemorrhage in spinal ependymomas.