The spine intra-abdominal pressure (SIAP) trial. A prospective, observational, single arm, monocenter study looking at the evolutions of the IAP prior, during and after spine surgery.

BACKGROUND AND AIMS: Both anaesthesiologists and spine surgeons consider the intra-abdominal pressure (IAP) as an important peri-operative factor affected by patient positioning. We assessed the change in IAP caused by using a thoraco pelvic support (inflatable prone support, IPS) with the subject under general anesthesia. The IAP was measured before, during and immediately after surgery. METHODS: The Spine Intra-Abdominal Pressure study (SIAP trial) is a prospective, single-arm, monocenter, observational study looking at changes in IAP prior, during and after spine surgery. The objective is to assess the change in IAP, measured via an indwelling urinary catheter, using the inflatable prone support (IPS) device during prone positioning of patients in spinal surgery. RESULTS: Forty (40) subjects requiring elective lumbar spine surgery in prone position were enrolled after providing informed consent. The inflation of the IPS results in a significant decrease of IAP (from a median of 9.2 mmHg to 6.46 mmHg (p < 0.001)) in patients undergoing spine surgery in prone position. This decrease in IAP was maintained throughout the procedure despite the discontinuation of muscle relaxants. No serious adverse events or unexpected adverse events occurred. CONCLUSION: The use of the thoraco-pelvic support IPS device was able to significantly lower the IAP during spine surgery.

Comparing radiation dose of image-guided techniques in lumbar fusion surgery with pedicle screw insertion; A systematic review.

Background Context: Fluoroscopic devices can be used to visualize subcutaneous and osseous tissue, a useful feature during pedicle screw insertion in lumbar fusion surgery. It is important that both patient and surgeon are exposed as little as possible, since these devices use potential harmful ionizing radiation. Purpose: This study aims to compare radiation exposure of different image-guided techniques in lumbar fusion surgery with pedicle screw insertion. Study Design: Systematic review. Methods: Cochrane, Embase, PubMed and Web of Science databases were used to acquire relevant studies. Eligibility criteria were lumbar and/or sacral spine, pedicle screw, mGray and/or Sievert and/or mrem, radiation dose and/or radiation exposure. Image-guided techniques were divided in five groups: conventional C-arm, C-arm navigation, C-arm robotic, O-arm navigation and O-arm robotic. Comparisons were made based on effective dose for patients and surgeons, absorbed dose for patients and surgeons and exposure. Risk of bias was assessed using the 2017 Cochrane Risk of Bias tool on RCTs and the Cochrane ROBINS-I tool on NRCTs. Level of evidence was assessed using the guidelines of Oxford Centre for Evidence-based Medicine 2011. Results: A total of 1423 studies were identified of which 38 were included in the analysis and assigned to one of the five groups. Results of radiation dose per procedure and per pedicle screw were described in dose ranges. Conventional C-arm appeared to result in higher effective dose for surgeons, higher absorbed dose for patients and higher exposure, compared to C-arm navigation/robotic and O-arm navigation/robotic. Level of evidence was 3 to 4 in 29 studies. Risk of bias of RCTs was intermediate, mostly due to inadequate blinding. Overall risk of bias score in NRCTs was determined as 'serious'. Conclusions: Ranges of radiation doses using different modalities during pedicle screw insertion in lumbar fusion surgery are wide. Based on the highest numbers in the ranges, conventional C-arm tends to lead to a higher effective dose for surgeons, higher absorbed dose for patients and higher exposure, compared to C-arm-, and O-arm navigation/robotic. The level of evidence is low and risk of bias is fairly high. In future studies, heterogeneity should be limited by standardizing measurement methods and thoroughly describing the image-guided technique settings.

Cost-effectiveness of anterior surgical decompression surgery for cervical degenerative disk disease: a systematic review of economic evaluations.

PURPOSE: No clear consensus exists on which anterior surgical technique is most cost-effective for treating cervical degenerative disk disease (CDDD). One of the most common treatment options is anterior cervical discectomy with fusion (ACDF). Anterior cervical discectomy with arthroplasty (ACDA) was developed in an effort to reduce the incidence of clinical adjacent segment pathology and associated additional surgeries by preserving motion. This systematic review aims to evaluate the evidence regarding the cost-effectiveness of anterior surgical decompression techniques used to treat radiculopathy and/or myelopathy caused by CDDD. METHODS: The search was conducted in PubMed, EMBASE, Web of Science, CINAHL, EconLit, NHS-EED and the Cochrane Library. Studies were included if healthcare costs and utility or effectivity measurements were mentioned. RESULTS: A total of 23 studies were included out of the 1327 identified studies. In 9 of the 13 studies directly comparing ACDA and ACDF, ACDA was the most cost-effective technique, with an incremental cost effectiveness ratio ranging from $2.900/QALY to $98.475/QALY. There was great heterogeneity between the costs of due to different in- and exclusion criteria of costs and charges, cost perspective, baseline characteristics, and calculation methods. The methodological quality of the included studies was moderate. CONCLUSION: The majority of studies report ACDA to be a more cost-effective technique in comparison with ACDF. The lack of uniform literature impedes any solid conclusions to be drawn. There is a need for high-quality cost-effectiveness research and uniformity in the conduct, design and reporting of economic evaluations concerning the treatment of CDDD. TRIAL REGISTRATION: PROSPERO Registration: CRD42020207553 (04.10.2020).

A randomized controlled TRIal of cognitive BEhavioral therapy for high Catastrophizing in patients undergoing lumbar fusion surgery: the TRIBECA study.

BACKGROUND: Around 20% of patients undergoing spinal fusion surgery have persistent back or leg pain despite surgery. Pain catastrophizing is the strongest psychological predictor for chronic postsurgical pain. Psychological variables are modifiable and could be target for intervention. However, randomized controlled trials evaluating the effectiveness of psychological interventions to reduce chronic pain and disability after spinal fusion in a population of patients with high preoperative pain catastrophizing scores are missing. The aim of our study is to examine whether an intervention targeting pain catastrophizing mitigates the risk of chronic postsurgical pain and disability. Our primary hypothesis is that targeted perioperative cognitive behavioral therapy decreases the risk of chronic postsurgical pain and disability after spinal fusion surgery in high catastrophizing patients. METHODS: We will perform a two-center prospective, single-blind, randomized, controlled study comparing lumbar spinal fusion surgery outcome between 2 cohorts. Adult patients selected for lumbar spinal fusion with decompression surgery and a minimum score of 24 on the pain catastrophizing scale will be randomized with 1:1 allocation for either perioperative cognitive behavioral therapy (intervention group) or a perioperative education plus progressive exercise program (control group). Patients randomized to the intervention group will receive six individual sessions of cognitive behavioral therapy, two sessions before the operation and four after. Primary outcome is the Core Outcome Measures Index at 12 months. Secondary outcomes include pain, disability, depression and quality of life. DISCUSSION: This is the first trial that evaluates the effectiveness of cognitive behavioral therapy as a perioperative tool to improve pain and disability after spinal fusion surgery in comparison with an educational/exercise control intervention, in patients with high levels of pain catastrophizing. If perioperative cognitive behavioral therapy proves to be effective, this might have important clinical implications, reducing the incidence of chronic postsurgical pain and improving outcome after spinal fusion surgery. TRIAL REGISTRATION: Clinicaltrials ( NCT03969602 ). Registered 31 May 2019.

Unexpected death after occipital condylar fracture.

We present a rare fatal complication of an occipital condylar fracture. The patient was initially neurologically intact, but showed secondary clinical deterioration. Imaging revealed extensive extra-axial hemorrhage at the craniocervical junction and an acute obstructive hydrocephalus. MR imaging demonstrated a T2 hyperintens signal in both the lower brainstem and upper cervical spinal cord, likely caused by the extra-axial hemorrhage. As prognosis was estimated infaust, supportive treatment was discontinued and the patient died soon thereafter. This case report illustrates a rare, delayed complication and unexpected death in a patient having sustained an occipital condylar fracture.

Implementation of a mobile 0.15-T intraoperative MR system in pediatric neuro-oncological surgery: feasibility and correlation with early postoperative high-field strength MRI.

INTRODUCTION: We analyze our preliminary experience using the PoleStar N20 mobile intraoperative MR (iMR) system as an adjunct for pediatric brain tumor resection. METHODS: We analyzed 11 resections in nine children between 1 month and 17 years old. After resection, we acquired iMR scans to detect residual tumor and update neuronavigation. We compared final iMR interpretation by the neurosurgeon with early postoperative MR interpretation by a neuroradiologist. RESULTS: Patient positioning was straightforward, and image quality (T1 7-min 4-mm sequences) sufficient in all cases. In five cases, contrast enhancement suspect for residual tumor was noted on initial postresection iMR images. In one case, a slight discrepancy with postoperative imaging after 3 months was no longer visible after 1 year. No serious perioperative adverse events related to the PoleStar N20 were encountered, except for transient shoulder pain in two. CONCLUSIONS: Using the PoleStar N20 iMR system is technically feasible and safe for both supra- and infratentorial tumor resections in children of all ages. Their small head and shoulders favor positioning in the magnet bore and allow the field of view to cover more than the area of primary interest, e.g., the ventricles in an infratentorial case. Standard surgical equipment may be used without significant limitations. In this series, the use of iMR leads to an increased extent of tumor resection in 45 % of cases. Correlation between iMR and early postoperative MR is excellent, provided image quality is optimal and interpretation is carefully done by someone sufficiently familiar with the system.

An evidence-based mobile decision support system for subaxial cervical spine injury treatment.

Bringing evidence to practice is a key issue in modern medicine. The key barrier to information searching is time. Clinical decision support systems (CDSS) can improve guideline adherence. Mounting evidence exists that mobile CDSS on handheld computers support physicians in delivering appropriate care to their patients. Subaxial cervical spine injuries account for almost half of spine injuries, and a majority of spinal cord injuries. A valid and reliable classification exists, including evidence-based treatment algorithms. A mobile CDSS on this topic was not yet available. We developed and tested an iPhone application based on the Subaxial Injury Classification (SLIC) and 5 evidence-based treatment algorithms for the surgical approach to subaxial cervical spine injuries. The application can be downloaded for free. Users are cordially invited to provide feedback in order to direct further development and evaluation of CDSS for traumatic lesions of the spinal column.

Predictive value of clinical characteristics in patients with suspected cauda equina syndrome.

BACKGROUND AND PURPOSE: Overlooking a potential diagnosis of cauda equina syndrome (CES) can result in severe long-term neurologic deficits. There is a growing trend to order urgent magnetic resonance imaging (MRI) scans of the lumbar spine in any patient presenting with signs suspicious for CES. A substantial number of these MRI scans do not show cauda compression. The purpose of this study is to assess whether clinical characteristics can predict MRI-confirmed cauda compression. METHODS: We retrospectively studied 58 consecutive cases of suspected CES who presented at our hospital's emergency room. RESULTS: Eight of 58 patients had cauda compression on MRI. When measured, MRI + CES patients (6) had more than 500 ml urinary retention. Moreover, when these patients had at least two of the following characteristics: bilateral sciatica, subjective urinary retention or rectal incontinence symptoms, MRI was more probable to demonstrate cauda compression with an OR of 48.00, 95% (CI 3.30-697.21), which was also significant (P of 0.04). The presence of other symptoms or signs alone was not significantly different between both groups. CONCLUSION: In our series, urinary retention of more than 500 ml alone or in combination with two or more specific clinical characteristics were the most important predictors of MRI confirmed cauda compressions.

[Intraoperative MRI in brain surgery]. / Intraoperatieve MRI bij hersenchirurgie.

Neuronavigation is a frequently used method in the planning of intracranial neurosurgical procedures. During surgery however, due to anatomical changes such as loss of cerebrospinal fluid, tumour resection and oedema, preoperative data become inaccurate. Updated data acquisition during the procedure using intraoperative MRI (iMRI) overcomes this problem, as it enables maximum tumour resection or accurate tumour biopsy, whilst minimizing the risk of damaging healthy brain tissue. The choice between low field and high field strength systems depends on the desired image quality and integration into the regular workflow. In spite of its high costs, iMRI surgery seems to be cost-effective, due to reduced length of hospital stay, reduced repeat resection, and reduced hospital charges. In the future, intraoperative imaging combined with virtual planning stations, is expected to play an important role in implementing robotization into neurosurgery.

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

CO2 reactivity and brain oxygen pressure monitoring in severe head injury.

OBJECTIVE: To investigate the effect of hyperventilation on cerebral oxygenation after severe head injury. DESIGN: A prospective, observational study. SETTING: Neurointensive care unit at a university hospital. PATIENTS: A total of 90 patients with severe head injury (Glasgow Coma Scale score < or =8), in whom continuous monitoring of brain tissue oxygen pressure (PbrO2) was performed as a measure of cerebral oxygenation. INTERVENTIONS: Arterial PCO2 was decreased each day over a 5-day period for 15 mins by increasing 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 PbrO2, was performed in all patients. Absolute and relative PbrO2/PaCO2 reactivity was calculated. Outcome at 6 months was evaluated according to the Glasgow Outcome Scale. MEASUREMENTS AND MAIN RESULTS: Effective hyperventilation, defined by a decrease of PaCO2 > or =2 torr (0.27 kPa), was obtained in 218 (84%) of 272 tests performed. Baseline PaCO2 averaged 32.3 +/- 4.5 torr (4.31 +/- 0.60 kPa). Average reduction in PaCO2 was 3.8 +/- 1.7 torr (0.51 +/- 0.23 kPa). PbrO2 decreased by 2.8 +/- 3.7 torr (0.37 +/- 0.49 kPa; p < .001) from a baseline value of 26.5 +/- 11.6 torr (3.53 +/- 1.55 kPa). PbrO2/PaCO2 reactivity was low on day 1 (0.8 +/- 2.3 torr [0.11 +/- 0.31 kPa]), increasing on subsequent days to 6.1 +/- 4.4 torr (0.81 +/- 0.59 kPa) on day 5. PbrO2/PaCO2 reactivity on days 1 and 2 was not related to outcome. In later phases in patients with unfavorable outcome, relative reactivity was increased more markedly, reaching statistical significance on day 5. CONCLUSIONS: Increased hyperventilation causes a significant reduction in PbrO2, providing further evidence for possible increased risk of secondary ischemic damage during hyperventilation. The low PbrO2/PaCO2 reactivity on day 1 indicates the decreased responsiveness of cerebral microvascular vessels to PaCO2 changes, caused by generalized vascular narrowing. The increasing PbrO2/PaCO2 reactivity from days 2 to 5 suggests that the risk of compromising cerebral oxygenation by hyperventilation may increase over time.

Brain oxygen tension in severe head injury.

OBJECTIVE: Ensuring adequate cerebral oxygenation and perfusion is of fundamental importance in the treatment of patients with acute cerebral disorders. Online continuous monitoring of brain oxygenation is possible with a parenchymal microelectrode that measures local brain oxygen tension. The ultimate question is whether therapeutic approaches can be targeted on the basis of such monitoring. Before this question can be addressed, the technique requires validation in the clinical setting. The frequency of occurrence of low values and its relation to outcome need to be established. METHODS: One hundred one comatose head-injured patients (Glasgow Coma Scale score < or = 8) were studied. Local brain oxygen tension probes were inserted in an undamaged part of the frontal region. Patients were treated in conformance with the European Brain Injury Consortium guidelines. Outcome at 6 months was determined by Glasgow Outcome Scale score. RESULTS: Early brain tissue hypoxia was frequently observed, despite aggressive treatment for intracranial pressure and cerebral perfusion pressure. Values lower than 15 mm Hg, for a duration longer than 30 minutes, were observed in 57 patients. Values lower than 10 mm Hg in 42 patients, and lower than 5 mm Hg in 22 patients, were observed during the first 24 hours. Depth and duration of tissue hypoxia were related to outcome and proved to be an independent predictor of unfavorable outcome and death. CONCLUSION: Monitoring the partial oxygen pressure of local brain tissue is a safe and reliable method for regulating cerebral oxygenation. Because brain tissue hypoxia occurs frequently and is significantly related to poor outcome, future efforts should be aimed at the treatment of brain tissue hypoxia. The effects of such brain hypoxia-targeted treatment need to be established in a multicenter study.

Monitoring brain oxygen tension in severe head injury: the Rotterdam experience.

Cerebral ischemia is considered the central mechanism leading to secondary brain damage in patients with severe head injury. We investigated the technique of continuous monitoring of local brain tissue oxygen tension as parameter for cerebral oxygenation. Eighty-two patients with non penetrating severe head injury were studied. No complications of the monitoring technique were seen. Postmeasurement calibration of the catheters showed a very low zero drift and acceptable sensitivity drift. Low PbrO2 values were seen within the first 12 to 24 hours of injury. Early occurrence of values below 10 mm Hg indicated a poor prognosis. Comparative measurements between two catheters performed in six patients showed differences in absolute values measured, but a good correlation of relative changes was observed. We conclude that continuous monitoring of PbrO2 is reliable, clinically applicable and provides the clinician with a better insight in cerebral oxygenation and hopefully should help in targeting therapy towards improved cerebral oxygenation.

Continuous monitoring of partial pressure of brain tissue oxygen in patients with severe head injury.

Ischemia is one of the major factors causing secondary brain damage after severe head injury. We have investigated the value of continuous partial pressure of brain tissue oxygen (PbrO2) monitoring as a parameter for cerebral oxygenation in 22 patients with severe head injury (Glasgow Coma Scale score, < or = 8). Jugular bulb oxygenation, intracranial pressure, and cerebral perfusion pressure were simultaneously recorded. O2 and CO2 reactivity tests were performed daily to evaluate oxygen autoregulatory mechanisms. PbrO2 monitoring was started an average of 7.0 hours after trauma with a mean duration of 74.3 hours. No complications were seen, and the calibration of the catheters after measurement showed a zero drift of 1.2 +/- 0.8 mm Hg and a sensitivity drift of 9.7 +/- 5.3%. In 86% of patients, PbrO2 was < 20 mm Hg in the acute phase. Mean PbrO2 significantly increased during the first 24 hours after injury. Two distinct patterns of change of PbrO2 over time were noted. The first pattern was characterized by normal stable levels after 24 hours, and the second was characterized by transiently elevated levels of PbrO2 during the second and third days. PbrO2 values < or = 5 mm Hg within 24 hours after trauma negatively correlated with outcome. O2 reactivity was significantly lower in patients with good outcomes. CO2 reactivity showed no constant pattern of change over time and was not correlated with outcome. Increased hyperventilation was shown to decrease PbrO2 in some patients. Accurate detection of the moment of cerebral death was possible on the basis of the PbrO2 measurements. The correlation between PbrO2 and other parameters, such as intracranial pressure and cerebral perfusion pressure, was weak. We conclude that PbrO2 monitoring is a safe and clinically applicable method in patients with severe head injury. The early occurrence of ischemia after head injury can be monitored on a continuous basis. Deficiency of oxygen autoregulatory mechanisms can be demonstrated, and their occurrence is inversely related to outcome. For practical clinical use, the method seemed to be superior to jugular oximetry.

Monitoring cerebral oxygenation: experimental studies and preliminary clinical results of continuous monitoring of cerebrospinal fluid and brain tissue oxygen tension.

Cerebral ischaemia is considered to be the central mechanism leading to secondary brain damage in patients with severe head injury. It would therefore seem appropriate to monitor cerebral oxygenation in these patients. The possibilities of continuous monitoring of brain tissue and CSF oxygen tension as parameters for cerebral oxygenation were evaluated. In experimental studies the influence of changed oxygen offer and decreased cerebral perfusion pressure on CSF and brain tissue pO2 were investigated. Fast changes in CSF pO2 were observed in response to decreasing oxygen offer. Slower changes were noted in response to hypo- and hyperventilation. An autoregulatory mechanism regulating CSF pO2 is postulated. Reducing cerebral perfusion pressure decreased both brain tissue and CSF pO2, but in the reperfusion phase after complete ischaemia a dissociation occurred between brain tissue and CSF pO2, CSF pO2 being restored, but brain tissue pO2 remaining low or even decreasing further. From these studies it is concluded that both CSF pO2 and brain tissue pO2 reflect changes in cerebral oxygenation caused by changes in oxygen offer as well as by changes in cerebral blood flow. Brain tissue pO2 is also sensitive to oxygen demand from the tissue. Preliminary studies of continuous monitoring of brain tissue pO2 in patients with severe head injury are reported.