[Interaction of somatic findings and psychiatric symptoms in COVID-19. A scoping review]. / Interaktion von körperlichen Veränderungen und psychischen Störungen bei COVID-19. Ein Scoping Review.

An infection with SARS-CoV­2 can affect the central nervous system, leading to neurological as well as psychiatric symptoms. In this respect, mechanisms of inflammation seem to be of much greater importance than the virus itself. This paper deals with the possible contributions of organic changes to psychiatric symptomatology and deals especially with delirium, cognitive symptoms, depression, anxiety, posttraumatic stress disorder and psychosis. Processes of neuroinflammation with infection of capillary endothelial cells and activation of microglia and astrocytes releasing high amounts of cytokines seem to be of key importance in all kinds of disturbances. They can lead to damage in grey and white matter, impairment of cerebral metabolism and loss of connectivity. Such neuroimmunological processes have been described as a organic basis for many psychiatric disorders, as affective disorders, psychoses and dementia. As the activation of the glia cells can persist for a long time after the offending agent has been cleared, this can contribute to long term sequalae of the infection.

THE EFFECT OF THE SARS-COV-2 PANDEMIC ON THE INCIDENCE OF PSYCHIATRIC DISORDERS: AN OVERVIEW.

The SARS-CoV-2 pandemic exerted an unprecedented threat to the population worldwide. This led to a sharp increase in symptoms of depression, anxiety, and PTSD, especially in the early phase of the pandemic. As far as data allowed a comparison with the pre-pandemic era, an increase by odds ratios of up to 3,5 was found. People affected by the virus showed an even greater amount of symptomatology as compared to the general population. Next to psychological stress, direct and indirect effects of the virus on the brain in these persons could be observed. Only on very few occasions, a direct invasion of the virus in the brain could be observed. Yet far more important seems to be the induction of a low-grade inflammation in the brain ("neuroinflammation"). This kind of processes have been observed earlier accompanying many psychiatric and neurologic diseases. In this way, especially cognitive symptoms might persist long after the acute infection has abated.

Unique Device Identification-Based Linkage of Hierarchically Accessible Data Domains in Prospective Surgical Hospital Data Ecosystems: User-Centered Design Approach.

BACKGROUND: The electronic health record (EHR) targets systematized collection of patient-specific, electronically stored health data. The EHR is an evolving concept driven by ongoing developments and open or unclear legal issues concerning medical technologies, cross-domain data integration, and unclear access roles. Consequently, an interdisciplinary discourse based on representative pilot scenarios is required to connect previously unconnected domains. OBJECTIVE: We address cross-domain data integration including access control using the specific example of a unique device identification (UDI)-expanded hip implant. In fact, the integration of technical focus data into the hospital information system (HIS) is considered based on surgically relevant information. Moreover, the acquisition of social focus data based on mobile health (mHealth) is addressed, covering data integration and networking with therapeutic intervention and acute diagnostics data. METHODS: In addition to the additive manufacturing of a hip implant with the integration of a UDI, we built a database that combines database technology and a wrapper layer known from extract, transform, load systems and brings it into a SQL database, WEB application programming interface (API) layer (back end), interface layer (rest API), and front end. It also provides semantic integration through connection mechanisms between data elements. RESULTS: A hip implant is approached by design, production, and verification while linking operation-relevant specifics like implant-bone fit by merging patient-specific image material (computed tomography, magnetic resonance imaging, or a biomodel) and the digital implant twin for well-founded selection pairing. This decision-facilitating linkage, which improves surgical planning, relates to patient-specific postoperative influencing factors during the healing phase. A unique product identification approach is presented, allowing a postoperative read-out with state-of-the-art hospital technology while enabling future access scenarios for patient and implant data. The latter was considered from the manufacturing perspective using the process manufacturing chain for a (patient-specific) implant to identify quality-relevant data for later access. In addition, sensor concepts were identified to use to monitor the patient-implant interaction during the healing phase using wearables, for example. A data aggregation and integration concept for heterogeneous data sources from the considered focus domains is also presented. Finally, a hierarchical data access concept is shown, protecting sensitive patient data from misuse using existing scenarios. CONCLUSIONS: Personalized medicine requires cross-domain linkage of data, which, in turn, require an appropriate data infrastructure and adequate hierarchical data access solutions in a shared and federated data space. The hip implant is used as an example for the usefulness of cross-domain data linkage since it bundles social, medical, and technical aspects of the implantation. It is necessary to open existing databases using interfaces for secure integration of data from end devices and to assure availability through suitable access models while guaranteeing long-term, independent data persistence. A suitable strategy requires the combination of technical solutions from the areas of identity and trust, federated data storage, cryptographic procedures, and software engineering as well as organizational changes.

First-episode psychotic disorders in the wake of the COVID-19 pandemic: a descriptive review of casereports.

OBJECTIVE: Since the onset of COVID-19 pandemic, many case reports and case series dealt with new-onset psychotic disorders in patients either infected with SARS-CoV-2 or thematically linked to the pandemic, but without an infection. Our aim was to provide a comprehensive collection of these reports to illustrate the nature of these psychoses. METHODS: We conducted a literature search in MEDLINE, Embase, PsycINFO, using search terms regarding first-episode psychotic disorders in the context of corona. RESULTS: 96 case reports or case series covering 146 patients (62 without and 84 with SARS-CoV-2 infection) were found. Compared to patients without infection, patients with infection showed significantly more often visual hallucinations (28.6% vs 8.1%), confusion (36.9% vs 11.3%), an acute onset of illness (88.5% vs 59.6%) and less often depression (13.1% vs 35.5%) and a delusional content related to the pandemic (29.5% vs 78.3%). Both groups had an equally favourable outcome with a duration of psychosis ≤2 weeks in half and full remission in two-thirds of patients. In patients with infection, signs of inflammation were reported in 78.3% and increased CRP in 58.6%. While reports on patients with infection are continuously published, no report about patients without infection was found after July 2020. CONCLUSION: Cases without infection were considered reactive and originated all from the first wave of the corona pandemic. In cases with infection, inflammation was considered as the main pathogenetic factor but was not found in all patients. Diagnosis was impeded by the overlap of psychosis with delirium.

[Neuropsychiatric Aspects of COVID-19 - A Narrative Overview]. / Neuropsychiatrische Aspekte von COVID-19 ­ Eine narrative Übersicht.

The SARS-CoV-2 virus (Severe Acute Respiratory Syndrome Coronavirus Type 2) and COVID-19 (Coronavirus Disease 2019) can affect numerous organ systems. In the present paper we offer an overview of the current state of knowledge about the psychiatric aspects of SARS-CoV-2 infection.Medline, Embase und LIVIVO were searched for relevant literature, the last query dating from March 2nd, 2021. Different stress factors in the context of the pandemic can lead to manifest mental illnesses. In addition, there is a risk of neuropsychological changes due to the biological effects of the virus itself.Our work describes the psychological symptoms of COVID-19 sufferers themselves and the psychological effects of the epidemic and the associated socio-economic and psychosocial stress factors on those who are not sick.The most common psychiatric complication among people with COVID-19 is delirium, while hospitalized patients seem to have an increased incidence of symptoms of anxiety, depression and PTSD. There are many case reports on psychotic disorders. In general, an existing psychiatric illness (especially dementia and psychotic disorders) also increases the risk of infection and of a more severe course of the disease. After recovery from COVID-19 infection, there is also a higher incidence of mental illnesses, in particular "Chronic Post-SARS Syndrome" with its manifestations such as fatigue, anxiety, depression and PTSD. In addition, the course of dementia seems to be negatively influenced by an infection with SARS-CoV-2.The second part deals with the effects of the epidemic as a stressor and the established socio-political measures on the mental health of people with and without previous mental illnesses. The literature currently available shows high symptom values for anxiety and depressive disorders as well as post-traumatic stress disorders, stress, suicidality, sleep disorders etc. Risk factors seem to include female gender, younger age and fewer resources, as well as previous psychiatric or physical illnesses. Extrinsic factors such as high infection rates, large numbers of deaths, long curfews/lockdowns, low trust in the government and ineffective measures against economic and social consequences increase the burden.

Electromechanical Reciprocity Applied to the Sensing Properties of Guided Elastic Wave Transducers.

Guided elastic wave (GEW) transducers for structural health monitoring (SHM) can act as transmitters (senders) and receivers (sensors). Their performance in both cases depends on the structure to which they are coupled. Therefore, they must be characterized as system transducer- structure. The characterization of the transducer-structure as transmitter using a Scanning Laser Doppler Vibrometer (SLDV) is straightforward, whereas its characterization as receiver is non-trivial. We propose to exploit electromechanical reciprocity, which is an identity between the transfer functions of electrical-to-mechanical and mechanical-to-electrical conversions. For this purpose, the well-known electromechanical reciprocity theorem was adapted to the following situation: The two reciprocal states are "electrical excitation and detection of the surface velocity at point P" and "mechanical excitation at P and measurement of the electrical quantities". According to the derived formulas, the quantities on the mechanical and electrical sides must be chosen appropriately to ensure reciprocity as well as that the corresponding transfer functions are equal. We demonstrate the reciprocity with experimental data for correctly chosen transfer functions and show the deviation in reciprocity for a different choice. Furthermore, we propose further applications of electromechanical reciprocity.

Effectiveness of an Annular Closure Device to Prevent Recurrent Lumbar Disc Herniation: A Secondary Analysis With 5 Years of Follow-up.

Importance: Patients with large annular defects following lumbar microdiscectomy for disc herniation are at increased risk for symptomatic recurrence and reoperation. Objective: To determine whether a bone-anchored annular closure device in addition to lumbar microdiscectomy resulted in lower reherniation and reoperation rates vs lumbar microdiscectomy alone. Design, Setting, and Participants: This secondary analysis of a multicenter randomized clinical trial reports 5-year follow-up for enrolled patients between December 2010 and October 2014 at 21 clinical sites. Patients in this study had a large annular defect (6-10 mm width) following lumbar microdiscectomy for treatment of lumbar disc herniation. Statistical analysis was performed from November to December 2020. Interventions: Lumbar microdiscectomy with additional bone-anchored annular closure device (device group) or lumbar microdiscectomy only (control group). Main Outcomes and Measures: The incidence of symptomatic reherniation, reoperation, and adverse events as well as changes in leg pain, Oswestry Disability Index, and health-related quality of life when comparing the device and control groups over 5 years of follow-up. Results: Among 554 randomized participants (mean [SD] age: 43 [11] years; 327 [59%] were men), 550 were included in the modified intent-to-treat efficacy population (device group: n = 272; 270 [99%] were White); control group: n = 278; 273 [98%] were White) and 550 were included in the as-treated safety population (device group: n = 267; control group: n = 283). The risk of symptomatic reherniation (18.8% [SE, 2.5%] vs 31.6% [SE, 2.9%]; P < .001) and reoperation (16.0% [SE, 2.3%] vs 22.6% [SE, 2.6%]; P = .03) was lower in the device group. There were 53 reoperations in 40 patients in the device group and 82 reoperations in 58 patients in the control group. Scores for leg pain severity, Oswestry Disability Index, and health-related quality of life significantly improved over 5 years of follow-up with no clinically relevant differences between groups. The frequency of serious adverse events was comparable between the treatment groups. Serious adverse events associated with the device or procedure were less frequent in the device group (12.0% vs 20.5%; difference, -8.5%; 95% CI, -14.6% to -2.3%; P = .008). Conclusions and Relevance: In patients who are at high risk of recurrent herniation following lumbar microdiscectomy owing to a large defect in the annulus fibrosus, this study's findings suggest that annular closure with a bone-anchored implant lowers the risk of symptomatic recurrence and reoperation over 5 years of follow-up. Trial Registration: ClinicalTrials.gov Identifier: NCT01283438.

How does grazing incidence ultrasonic microscopy work? A study based on grain-scale numerical simulations.

Grazing incidence ultrasonic microscopy (GIUM) is an experimental method for visualising the microstructures of polycrystals with local preferential orientations. It has previously been demonstrated on an austenitic stainless steel weld, exposing grains much smaller than the propagating wavelength, but the physical mechanism of the method has only been proposed as a hypothesis. In this paper, we use grain-scale finite element simulations based on the EBSD measurements to verify the principles behind GIUM images further and to assess how deep does the method penetrate the component under examination. The simulations indicate that while lateral contraction of grains contains microstructure signatures, the free surface effect is the crucial factor contributing to the generation of the images. Further, we show that only features up to the depth in the order of the average grain size in that direction can be visualised.

Intraoperative findings, complications, and short-term results after lumbar microdiscectomy with or without implantation of annular closure device.

BACKGROUND: Standard microscopic lumbar discectomy (MLD) is a short operation with minimal blood loss, and a low rate of peri- and intraoperative complications. The objective of this study was to evaluate intraoperative findings, complications, and early postoperative neurological outcome (< 105 days) in patients undergoing MLD with or without implantation of an annular closure device (ACD). METHODS: This study is based on data analysis of a post-marketing, prospective, multicenter RCT in Europe including patients undergoing standard MLD with or without implantation of an ACD (Barricaid®, Intrinsic Therapeutics, Inc., Woburn, MA). Enrollment of 554 patients in 21 centers in Europe (Germany, Switzerland, Austria, Belgium, The Netherlands, and France) started in 2010 and was completed in October 2014, with 276 patients randomized to the ACD group and 278 to the control group. RESULTS: Mean operation time was 70 min in the ACD group and 52 min in the control group (p < 0.0001). Intraoperative fluoroscopy time was 24 s in the ACD group and 7 s in the control group (p < 0.0001). Average blood loss was 94.2 ml in the ACD group and 64.7 ml in the control group (p = 0.0001). Serious device- or procedure-related adverse events occurred in 3.7% (10/272) of the ACD group and 7.9% (22/278) of the control group. Dural injuries occurred in 13 (4.8%) patients in the ACD group and 7 (2.5%) in the control group. There was one device-related nerve root injury resulting in a nerve root amputation. Surgical complications included 3 hematomas in the ACD group and 4 in the control group; 3 infections occurred in both groups. Device migrations were documented in 3 patients in the ACD group. Patients in the ACD group (n = 7, 2.6%) underwent fewer reoperations compared with that in the control group (n = 16, 5.8%, OR = 2.3 (0.9-5.7)). Mean VAS leg pain at 3 months was 11.9 in the ACD and 15.1 in the control group, respectively. CONCLUSION: Short-term outcome after MLD with or without implantation of ACD was similar in both groups. Patients included in the ACD group underwent fewer reoperations in the first 3 months after surgery. Nevertheless, longer operation time, higher amount of blood loss, and risk of nerve root lesion during device implantation should be considered additional risks in patients undergoing ACD implantation after MLD.

Serotonin 1A receptor density measured by F18-Mefway PET/CT in mesiotemporal cortex and raphe does not discriminate therapeutic response in patients with major depressive episode.

BACKGROUND: More than 50% of patients with major depressive episode (MDE) fail to respond to initial treatment with first line pharmacological therapy. Altered receptor and serotonin transporter function are considered to be associated with mental disorders. Our investigation aimed on the density of the HT1A receptor in mesiotemporal cortex (MTC) and raphe measured by F18-Mefway in patients with MDD. METHODS: Patients with untreated clinically suspected major depressive episode were recruited from June 2012 to May 2014. 49 patients were included into the study: 36 patients (73%) were identified as responders, whereas 13 (27%) were non-responders. Gender distribution was 26 men (56%) and 23 women (44%). For treatment, only a standard medication of a selective serotonin reuptake inhibitor (SSRI) with escitalopram in a range of 10-20 mg/day was permitted. Responders were defined by improvement of the MADRS>50%. Visually MTC had the highest uptake of F18-Mefway among all brain regions, an asymmetry could not be observed in any patient. An elliptical region was drawn over the amygdala and hippocampus area and a small circular region was drawn over the raphe nuclei. All data were calculated related to (unspecific) cerebellar uptake. RESULTS: The quotient of the right MTC was 5.00 [4.33; 5.50] in all patients, in responders 5.00 [4.00; 5.75] and in non-responders 5.00 [4.50; 5.50] (P=0.56). The quotient of the left MTC presented with a median level of 4.50 [4.50; 5.50] in all persons. The responders had 4.50 [4.50; 5.75] which was not statistically significant to the data of the non-responders with 5.00 [4.50; 5.50] at P=0.64. The raphe had a median quotient of 2.50 [2.00; 3.00] in all and the cohort of responders, whereas non-responders had 2.50 [2.00; 2.50] (P=0.61). Also the absolute values of SUV in the three brain regions were not statistically different between the cohorts. Additionally, we did not find any sex-related differences in our patient group. CONCLUSIONS: Serotonin 1A receptor density can be assessed efficiently by F18-Mefway and PET-CT in patients with MDE. The method can be estimated as a possible tool for clinical and academic investigation, marked tracer uptake can constantly be observed at MTC and the raphe. Anyhow, under conditions of real life in patient care, it is not possible to distinguish patients with a good prognosis who will respond to standard SSRI therapy from non-responders who would benefit from a different therapeutic approach starting earlier.

New insights into the natural course and clinical relevance of Modic changes over 2 years following lumbar limited discectomy: analysis of prospective collected data.

PURPOSE: Few retrospective studies have addressed Modic changes (MC) following lumbar spine surgery, though it is usually assumed that MC increase in grade and incidence. To test this conventional wisdom, we investigated the natural course of MC following primary lumbar limited discectomy with two-year follow-up. In addition, a possible clinical relevance to those changes was assessed. METHODS: The data of the control group (278 subjects) of a prospective randomized, controlled trial (RCT) were evaluated retrospectively. RESULTS: We did not observe a simple increase in MC with regard to grade. There is variable activity observed in Type 2 (at 12 months) and in Type 1 (at 24 months). Conversion from one grade to another may occur and may be upward or downward. The incidence of MC increased slightly over time, as after surgery a decreasing percentage of the study group remained without MC over two years (1 year: 34% (85/250); 2 years: 30% (72/237)). Radiological parameters (rotation, translation, and spondylolisthesis) had no significant correlation to MC or MC subtypes. Lastly, we found that neither the different MC types nor their changes were correlated with clinical parameters (VAS back, VAS leg, ODI score) preoperatively or during follow-up. CONCLUSION: The pattern of Modic changes following lumbar limited discectomy is complex, not simply increasing. There is variable activity in MC Types 1 and 2 at the different time points of follow-up, and conversion from a higher grader to a lower one or vice versa is possible. These slides can be retrieved under Electronic Supplementary Material.

Challenges in the Analysis of Longitudinal Pain Data: Practical Lessons from a Randomized Trial of Annular Closure in Lumbar Disc Surgery.

Purpose. To analyze leg pain severity data from a randomized controlled trial (RCT) of lumbar disc surgery using integrated approaches that adjust pain scores collected at scheduled follow-up visits for confounding clinical events occurring between visits. Methods. Data were derived from an RCT of a bone-anchored annular closure device (ACD) following lumbar discectomy versus lumbar discectomy alone (Control) in patients with large postsurgical annular defects. Leg pain was recorded on a 0 to 100 scale at 6 weeks, 3 months, 6 months, 1 year, and 2 years of follow-up. Patients with pain reduction ≥20 points relative to baseline were considered responders. Unadjusted analyses utilized pain scores reported at follow-up visits. Since symptomatic reherniation signifies clinical failure of lumbar discectomy, integrated analyses adjusted pain scores following a symptomatic reherniation by baseline observation carried forward for continuous data or classification as nonresponders for categorical data. Results. Among 550 patients (272 ACD, 278 Control), symptomatic reherniation occurred in 10.3% of ACD patients and in 21.9% of controls (p < 0.001) through 2 years. There was no difference in leg pain scores at the 2-year visit between ACD and controls (12 versus 14; p = 0.33) in unadjusted analyses, but statistically significant differences favoring ACD (19 versus 29; p < 0.001) in integrated analyses. Unadjusted nonresponder rates were 6.0% with ACD and 6.7% with controls (p = 0.89), but 15.7% and 27.8% (p = 0.001) in integrated analyses. The probability of nonresponse was 16.4% with ACD and 18.3% with controls (p = 0.51) in unadjusted analysis, and 23.7% and 31.2% (p = 0.04) in integrated analyses. Conclusion. In an RCT of lumbar disc surgery, an integrated analysis of pain severity that adjusted for the confounding effects of clinical failures occurring between follow-up visits resulted in different conclusions compared to an unadjusted analysis of pain scores reported at follow-up visits only.

Polymer degradation induced drug precipitation in PLGA implants - Why less is sometimes more.

Nifedipine and nicardipine loaded PLGA extrudates have a great potential to prevent cerebral vasospasms after subarachnoid hemorrhage or surgical clipping of aneurysm. A constant release over approx. two weeks is desired. Although in vivo studies on humans have been reported, there is limited knowledge about the release kinetics and the underlying mechanisms. Therefore, nifedipine and nicardipine loaded PLGA implants with different drug loads were manufactured by extrusion and investigated. In addition to the measurements of the release kinetics, GPC, DSC, X-ray diffraction and light microscopic investigations were performed for a detailed characterization. The water uptake and polymer erosion studies showed an initial lag phase of 5-7 days and an acceleration of both processes thereafter. With 5% loaded implants a higher drug release compared to 10% drug loaded polymers could be achieved and not only the relative amount of drug release (% of loaded drug), but surprisingly also the absolute amount of the released drug increased. The drugs were initially in an amorphous state. For nifedipine, formation of drug crystals with time has been observed by light microscopy and X-ray diffraction. The analysis of the drug content in the degrading polymer showed a very large increase from 10% to about 20% (nifedipine) and over 50% (nicardipine). In contrast, no or only a moderate increase of the drug content occurred for initially 5% loaded polymer implants. We postulate that water penetration and polymer degradation induced changes of the microenvironment lead to supersaturated systems. A supersaturated state is faster reached for polymers with higher drug load and therefore, drug precipitation takes place at earlier time points. As a result, drug release might be incomplete for poorly soluble drugs and paradoxically, the total amount of drug release might be higher for systems with a lower drug load. Drug release is initially controlled by the PLGA matrix, but later by the dissolution kinetics of the precipitated drug which are very slow for poorly soluble drugs according to the Noyes-Whitney equation.

Annular closure in lumbar microdiscectomy for prevention of reherniation: a randomized clinical trial.

BACKGROUND CONTEXT: Patients with large annular defects after lumbar discectomy for disc herniation are at high risk of symptomatic recurrence and reoperation. PURPOSE: The present study aimed to determine whether a bone-anchored annular closure device, in addition to lumbar microdiscectomy, resulted in lower reherniation and reoperation rates plus increased overall success compared with lumbar microdiscectomy alone. DESIGN: This is a multicenter, randomized superiority study. PATIENT SAMPLE: Patients with symptoms of lumbar disc herniation for at least 6 weeks with a large annular defect (6-10 mm width) after lumbar microdiscectomy were included in the study. OUTCOME MEASURES: The co-primary end points determined a priori were recurrent herniation and a composite end point consisting of patient-reported, radiographic, and clinical outcomes. Study success required superiority of annular closure on both end points at 2-year follow-up. METHODS: Patients received lumbar microdiscectomy with additional bone-anchored annular closure device (n=276 participants) or lumbar microdiscectomy only (control; n=278 participants). This research was supported by Intrinsic Therapeutics. Two authors received study-specific support morethan $10,000 per year, 8 authors received study-specific support less than $10,000 per year, and 11 authors received no study-specific support. RESULTS: Among 554 randomized participants, 550 (annular closure device: n=272; control: n=278) were included in the modified intent-to-treat efficacy analysis and 550 (annular closure device: n=267; control: n=283) were included in the as-treated safety analysis. Both co-primary end points of the study were met, with recurrent herniation (50% vs. 70%, P<.001) and composite end point success (27% vs. 18%, P=.02) favoring annular closure device. The frequency of symptomatic reherniation was lower with annular closure device (12% vs. 25%, P<.001). There were 29 reoperations in 24 patients in the annular closure device group and 61 reoperations in 45 control patients. The frequency of reoperations to address recurrent herniation was 5% with annular closure device and 13% in controls (P=.001). End plate changes were more prevalent in the annular closure device group (84% vs. 30%, P<.001). Scores for back pain, leg pain, Oswestry Disability Index, and health-related quality of life at regular visits were comparable between groups over 2-year follow-up. CONCLUSIONS: In patients at high risk of herniation recurrence after lumbar microdiscectomy, annular closure with a bone-anchored implant lowers the risk of symptomatic recurrence and reoperation. Additional study to determine outcomes beyond 2 years with a bone-anchored annular closure device is warranted.

Red blood cell transfusion probability and associated costs in neurosurgical procedures.

BACKGROUND: The extent of red blood cell units (RBC) needed for different neurosurgical procedures and the time point of their administration are widely unknown, which results in generously cross-matching prior to surgery. However, RBC are increasingly requested in the aging western populations, and blood donations are significantly reduced. Therefore, the knowledge of the extent and time point of administration of RBC is of major importance. METHODS: This is a retrospective single center analysis. The incidence of RBC transfusion during surgery or within 48 h after surgery was analyzed for all neurosurgical patients within 3 years. Costs for cross-matched and transfused RBC were calculated and risk factors for RBC transfusion analyzed. RESULTS: The risk of intraoperative RBC administration was low for spinal and intracranial tumor resections (1.87%) and exceeded 10% only in spinal fusion procedures. This was dependent on the number of fused segments with an intraoperative transfusion risk of > 12.5% with fusion of more than three levels. Multiple logistic regression analysis showed a significantly increased risk for RBC transfusion for female gender (p = 0.006; OR 1.655), higher age (N = 4812; p < 0.0001; OR 1.028), and number of fused segments (N = 737; p < 0.0001; OR 1.433). Annual costs for cross-matching were 783,820.88 USD and for intraoperative RBC administration 121,322.13 USD. CONCLUSIONS: Neurosurgical procedures are associated with a low number of RBC needed intraoperatively. Only elective spine fusion procedures with ≥ 3 levels involved and AVM resections seem to require cross-matching of RBC. The present data may allow changing the preoperative algorithm of RBC cross-matching in neurosurgical procedures and help to save resources and costs.

Morphology and Clinical Relevance of Vertebral Endplate Changes Following Limited Lumbar Discectomy With or Without Bone-anchored Annular Closure.

STUDY DESIGN: Post hoc analysis of a randomized controlled trial. OBJECTIVE: To characterize the morphology and clinical relevance of vertebral endplate changes (VEPC) following limited lumbar discectomy with or without implantation of a bone-anchored annular closure device (ACD). SUMMARY OF BACKGROUND DATA: Implantation of an ACD following limited lumbar discectomy has shown promise in reducing the risk of recurrent herniation in patients with large annular defects. However, the interaction between the ACD and the lumbar endplate over time is not well understood. METHODS: Patients undergoing limited lumbar discectomy with large postsurgical annular defects were randomized intraoperatively to receive additional ACD implantation or limited lumbar discectomy only (Controls). VEPC morphology, area, and volume were assessed with low-dose computed tomography preoperatively and at 1 and 2 years follow-up. RESULTS: Of 554 randomized patients, the as-treated population consisted of 550 patients (267 ACD, 283 Controls). VEPC were preoperatively identified in 18% of patients in the ACD group and in 15% of Controls. At 2 years, VEPC frequency increased to 85% with ACD and 33% in Controls. Device- or procedure-related serious adverse event (8% vs. 17%, P = 0.001) and secondary surgical intervention (5% vs. 13%, P < 0.001) favored the ACD group over Controls. In the ACD group, clinical outcomes were comparable in patients with and without VEPC at 2 years follow-up. In the Control group, patients with VEPC at 2 years had higher risk of symptomatic reherniation versus patients without VEPC (35% vs. 19%, P < 0.01) CONCLUSION.: In patients with large annular defects following limited lumbar discectomy, additional implantation with a bone-anchored ACD reduces risk of postoperative complications despite a greater frequency of VEPC. VEPC were associated with higher risk of symptomatic reherniation in patients treated with limited lumbar discectomy, but not in those who received additional ACD implantation. LEVEL OF EVIDENCE: 2.

Endplate changes after lumbar discectomy with and without implantation of an annular closure device.

BACKGROUND: The implantation of a bone-anchored annular closure device (ACD) might be associated with the developed new endplate changes (EPC) after surgery. METHODS: A post hoc analysis has been done in patients from a prospective randomized multicenter study. All patients underwent limited lumbar discectomy with intraoperative randomization into the groups limited lumbar discectomy alone or additional ACD implantation. Low-dose lumbar computed tomography (CT) and clinical investigations were performed preoperatively and 12 months after the operation. RESULTS: A total of 554 patients were randomized. After exclusion of dropouts, the per-protocol population included 493 patients (251 in the control group and 242 in the ACD group); the follow-up rate was ≥ 90%. The number of patients showing EPC at baseline was similar in both groups. The number of patients showing EPC and the total EPC lesion area significantly increased in both groups over time, but significantly increased more in the EPC group for the superior and inferior endplate (all P < 0.0001). There was no association of pre-existing number and size of EPC with sex, age, or smoking habits. Correlation of clinical variables showed no relation with number, size, and increase of EPC area after surgery. CONCLUSIONS: Patients with primary lumbar disc herniation show EPC in the corresponding segments. There is a significant increase of lesion number and size within 12 months after discectomy. This increase is significantly more pronounced in the ACD group. Presence and growth of EPC is not correlated with low-back pain or ODI.

Reliability and scientific use of a surgical planning software for anterior cervical discectomy and fusion (ACDF).

PURPOSE: Software-based planning of a spinal implant inheres in the promise of precision and superior results. The purpose of the study was to analyze the measurement reliability, prognostic value, and scientific use of a surgical planning software in patients receiving anterior cervical discectomy and fusion (ACDF). METHODS: Lateral neutral, flexion, and extension radiographs of patients receiving tailored cages as suggested by the planning software were available for analysis. Differences of vertebral wedging angles and segmental height of all cervical segments were determined at different timepoints using intraclass correlation coefficients (ICC). Cervical lordosis (C2/C7), segmental heights, global, and segmental range of motion (ROM) were determined at different timepoints. Clinical and radiological variables were correlated 12 months after surgery. RESULTS: 282 radiographs of 35 patients with a mean age of 53.1 ± 12.0 years were analyzed. Measurement of segmental height was highly accurate with an ICC near to 1, but angle measurements showed low ICC values. Likewise, the ICCs of the prognosticated values were low. Postoperatively, there was a significant decrease of segmental height (p < 0.0001) and loss of C2/C7 ROM (p = 0.036). ROM of unfused segments also significantly decreased (p = 0.016). High NDI was associated with low subsidence rates. CONCLUSIONS: The surgical planning software showed high accuracy in the measurement of height differences and lower accuracy values with angle measurements. Both the prognosticated height and angle values were arbitrary. Global ROM, ROM of the fused and intact segments, is restricted after ACDF.

Occurrence of discal and non-discal changes after sequestrectomy alone versus sequestrectomy and implantation of an anulus closure device.

Sequestrectomy alone represents a procedure for the treatment of lumbar disc herniation. For selected cases, an anulus closure device (ACD) can be implanted which may result in lower reoperation rates. However, comparative magnetic resonance imaging (MRI) changes and their clinical relevance of both procedures are unclear and have not been reported so far. Clinical and MRI data of patients after limited discectomy with ACD implantation (group ACD; N=45) and patients after sequestrectomy alone (group S; N=40) with primary lumbar disc herniation were compared retrospectively. Pain intensity on the visual analogue pain scale (VAS), oswestry disability index (ODI) or the patient satisfaction index (PSI) were collected. Disc signal intensity, Modic type changes, endplate reactions, anular tears and reherniations were investigated using MRI before and <18months postoperative. Morphologic changes were correlated with clinical outcome. There was no difference in VAS back, VAS leg or ODI/PSI after the operation although group S showed significantly more reherniations in MRI. The overall rate of repeated surgery at the same level was similar with a trend in favour of the ACD group (P=0.729). Significantly more patients of the ACD group experienced endplate erosions after surgery (P<0.001). Both groups experienced progression of disc signal intensity, Modic type changes, and anular tears with most MRI signs being without clinical relevance. ACD implantation is associated with a significantly lower reherniation rate in MRI but showed a significantly higher rate of endplate erosions. The structural changes do not appear to be clinically relevant.