BackgroundNeurosurgery performed in the semi-sitting position provides advantages for certain procedures. However, this approach is associated with potential complications, particularly venous air embolism. Due to typically negative venous pressure at the wound site, air can be drawn into the veins. This risk is especially high in patients presenting with an intra- or extracardiac right-to-left-shunt. Transoesophageal echocardiography can be used to detect a patent foramen ovale or other possible pulmonary-systemic shunt before placing the patient in the sitting position.Case presentationIn this report, we present two young patients undergoing scheduled microsurgical vestibular schwannoma removal in a semi-sitting position who were diagnosed with congenital heart defects during routine perioperative assessment to detect possible intracardiac right-to-left shunts, using pre- and intraoperative transesophageal echocardiography (TEE) and additionally conducting an agitated saline bubble study under Valsalva manoeuvre. Patient A was diagnosed with a persistent left superior vena cava and Patient B with an unroofed coronary sinus (UCS). These findings confronted the anesthesiological and surgical teams with difficult individual decisions regarding further perioperative management.ConclusionsPerioperative transesophageal echocardiography is a diagnostic tool to both detect intraoperative position-related air embolisms and to rule out intracardiac right-to-left shunts, e.g. a patent foramen ovale, in order to decide for or against a (semi-)sitting position. Depending on the surgical circumstances a semi-sitting positioning of patients presenting with an intracardiac right-to-left-shunt, e.g. a PFO, can be feasible in individual cases if there is an implemented therapeutic algorithm to immediately terminate significant venous air entry. However, since certain other intra- or extracardiac right-to-left-shunts, such as here presented PLSVC or UCS, are rare, there is no definitive way of estimating the amount of entered air through detected shunts or anomalous vessels. Therefore, it is recommended to avoid a (semi-)sitting position in favour of a lateral or prone position for a patient undergoing intracranial surgery, once the perioperative TEE shows air bubbles in the left atrium or ventricle whose origins cannot be defined solely through TEE for certain in order to ensure patient safety by minimizing the risk of intraoperative paradoxical air embolisms.

Background: Even though mechanical recanalization techniques have dramatically improved acute stroke care since the pivotal trials of decompressive hemicraniectomy for malignant courses of ischemic stroke, decompressive hemicraniectomy remains a mainstay of malignant stroke treatment. However, it is still unclear whether prior thrombectomy, which in most cases is associated with application of antiplatelets and/or anticoagulants, affects the surgical complication rate of decompressive hemicraniectomy and whether conclusions derived from prior trials of decompressive hemicraniectomy are still valid in times of modern stroke care. Methods: A total of 103 consecutive patients who received a decompressive hemicraniectomy for malignant middle cerebral artery infarction were evaluated in this retrospective cohort study. Surgical and functional outcomes of patients who had received mechanical recanalization before surgery (thrombectomy group, n = 49) and of patients who had not received mechanical recanalization (medical group, n = 54) were compared. Results: The baseline characteristics of the two groups did significantly differ regarding preoperative systemic thrombolysis (63.3% in the thrombectomy group vs. 18.5% in the medical group, p < 0.001), the rate of hemorrhagic transformation (44.9% vs. 24.1%, p = 0.04) and the preoperative Glasgow Coma Score (median of 7 in the thrombectomy group vs. 12 in the medical group, p = 0.04) were similar to those of prior randomized controlled trials of decompressive hemicraniectomy. There was no significant difference in the rates of surgical complications (10.2% in the thrombectomy group vs. 11.1% in the medical group), revision surgery within the first 30 days after surgery (4.1% vs. 5.6%, respectively), and functional outcome (median modified Rankin Score of 4 at 5 and 14 months in both groups) between the two groups. Conclusions: A prior mechanical recanalization with possibly associated systemic thrombolysis does not affect the early surgical complication rate and the functional outcome after decompressive hemicraniectomy for malignant ischemic stroke. Patient characteristics have not changed significantly since the introduction of mechanical recanalization; therefore, the results from former large randomized controlled trials are still valid in the modern era of stroke care.

Background Several methods have been proposed to measure cerebrovascular autoregulation (CA) in traumatic brain injury (TBI), but the lack of a gold standard and the absence of prospective clinical data on risks, impact on care and outcomes of implementation of CA-guided management lead to uncertainty. Aim To formulate statements using a Delphi consensus approach employing a group of expert clinicians, that reflect current knowledge of CA, aspects that can be implemented in TBI management and CA research priorities. Methods A group of 25 international academic experts with clinical expertise in the management of adult severe TBI patients participated in this consensus process. Seventy-seven statements and multiple-choice questions were submitted to the group in two online surveys, followed by a face-to-face meeting and a third online survey. Participants received feedback on average scores and the rationale for resubmission or rephrasing of statements. Consensus on a statement was defined as agreement of more than 75% of participants. Results Consensus amongst participants was achieved on the importance of CA status in adult severe TBI pathophysiology, the dynamic non-binary nature of CA impairment, its association with outcome and the inadvisability of employing universal and absolute cerebral perfusion pressure targets. Consensus could not be reached on the accuracy, reliability and validation of any current CA assessment method. There was also no consensus on how to implement CA information in clinical management protocols, reflecting insufficient clinical evidence. Conclusion The Delphi process resulted in 25 consensus statements addressing the pathophysiology of impaired CA, and its impact on cerebral perfusion pressure targets and outcome. A research agenda was proposed emphasizing the need for better validated CA assessment methods as well as the focused investigation of the application of CA-guided management in clinical care using prospective safety, feasibility and efficacy studies.

Patient-specific management methodology is crucial for outcomes of patients with traumatic brain injury (TBI). The clinical outcomes depend on cerebrovascular autoregulation (CA) impairments which can also be affected by patients’ age, brain injury grade or pharmacological influences. Here we compare the effectiveness of optimal cerebral perfusion pressure (CPPopt) targeted therapy in younger (<45 years-old) and elderly (≥45 years-old) TBI patients. Multimodal invasive ABP(t), ICP(t), CPP(t), and CPPopt(t) monitoring was performed on 81 severe TBI patients in Republic Vilnius University Hospital (Lithuania). ICM+ software was used for continuous CPPopt(t) assessment by identification of Pressure Reactivity Index (PRx(t)). The analysis of associations between the patients' outcome and complex of monitored physiological parameters was performed by creating multifactorial model of TBI patient’s outcome prediction. The most significant prognostic factors were age, GCS, serum glucose, Helsinki CT score and duration of Longest CA Impairment event (LCAI) when PRx(t) > 0.5 within 24 h after admission. The modeled accuracies for mortality and unfavorable outcome prediction were 82% and 86%, respectively. Age > 45 years was associated with unfavorable outcome. CPP values close to CPPopt were associated with a better outcome in younger patients. Mean ΔCPPopt < −5.0 mmHg, mean PRx > 0.36, and LCAI > 100 min were significantly associated with mortality for the younger patients. The critical values of averaged PRx > 0.26 and LCAI > 61 min were significantly associated with mortality for the elderly group. Autoregulation guided treatment was more effective for individual TBI management in younger patients. A phase III study is needed to prove an effectiveness of CPPopt targeted therapy for elderly patient.

Background and objective: Stereotactical procedures require exact trajectory planning to avoid blood vessels in the trajectory path. Innovation in imaging and image recognition techniques have facilitated the automatic detection of blood vessels during the planning process and may improve patient safety in the future. To assess the feasibility of a vessel detection and warning system using currently available imaging and vessel segmentation techniques. Methods: Image data were acquired from post-contrast, isovolumetric T1-weighted sequences (T1CE) and time.-of-flight MR angiography at 3T or 7T from a total of nine subjects. Vessel segmentation by a combination of a vessel-enhancement filter with subsequent level-set segmentation was evaluated using three different methods (Vesselness, FastMarching and LevelSet) in 45 stereotactic trajectories. Segmentation results were compared to a gold-standard of manual segmentation performed jointly by two human experts. Results: The LevelSet method performed best with a mean interclass correlation coefficient (ICC) of 0.76 [0.73, 0.81] compared to the FastMarching method with ICC 0.70 [0.67, 0.73] respectively. The Vesselness algorithm achieved clearly inferior overall performance with a mean ICC of 0.56 [0.53, 0.59]. The differences in mean ICC between all segmentation methods were statistically significant (p < 0.001 with post-hoc p < 0.026). The LevelSet method performed likewise good in MPRAGE and 3T-TOF images and excellent in 7T-TOF image data. The negative predictive value (NPV) was very high (>97%) for all methods and modalities. Positive predictive values (PPV) were found in the overall range of 65-90% likewise depending on algorithm and modality. This pattern reflects the disposition of all segmentation methods - in case of misclassification - to produce preferentially false-positive than false-negative results. In a clinical setting, two to three potential collision warnings would be given per trajectory on average with a PPV of around 50%. Conclusions: It is feasible to integrate a clinically meaningful vessel detection and collision warning system into stereotactical planning software. Both, T1CE and MRA sequences are suitable as image data for such an application. (C) 2019 Elsevier B.V. All rights reserved.

If medicine is coming close to its limits conflicts sometimes occur. Most conflicts in the intensive care unit (ICU) involve the medical team and patients' relatives. In particular decisions about withholding and withdrawing life-sustaining therapy lead to conflicts. Decisions about limiting life-sustaining treatment are burdened by conflicts and put an enormous strain particularly on relatives.Illustration of currently available studies and existing recommendations on how to manage potentially conflict-laden decision-finding discussions on the ICU are presented.This article is based on a selective literature research in the PubMed database.Studies have been carried out to evaluate posttraumatic stress disorders in relatives who were involved in life-limiting treatment decisions. Conflicts on the ICU put an emotional strain on relatives. Evidence-based recommendations are available regarding physicians' attitudes during discussions about therapy decisions, communication style and other contextual factors. Study results show that the emotional stress level relatives have to endure can be reduced if conversations between patients' families and the clinical personnel were conducted according to these recommendations. The involvement of a clinical ethics committee can prevent conflicts and has been shown to have no impact on the mortality rate but does decrease the time life-sustaining measures were unsuccessfully pursued.To prevent conflicts between the medical personnel and patients' relatives on the ICU, a timely, congruent and empathic conversation style in an appropriate, quiet environment is essential. Consultation with clinical ethics committees is recommended to de-escalate disputes.

BACKGROUND AND PURPOSE:MR imaging in neuro-oncology is challenging due to inherent ambiguities in proton signal behavior. Sodium-MR imaging may substantially contribute to the characterization of tumors because it reflects the functional status of the sodium-potassium pump and sodium channels. MATERIALS AND METHODS:Sodium-MR imaging data of patients with treatment-naïve glioma WHO grades I-IV (n = 34; mean age, 51.29 ± 17.77 years) were acquired by using a 7T MR system. For acquisition of sodium-MR images, we applied density-adapted 3D radial projection reconstruction pulse sequences. Proton-MR imaging data were acquired by using a 3T whole-body system. RESULTS:We demonstrated that the initial sodium signal of a treatment-naïve brain tumor is a significant predictor of isocitrate dehydrogenase (IDH) mutation status (P < .001). Moreover, independent of this correlation, the Cox proportional hazards model confirmed the sodium signal of treatment-naïve brain tumors as a predictor of progression (P = .003). Compared with the molecular signature of IDH mutation status, information criteria of model comparison revealed that the sodium signal is even superior to IDH in progression prediction. In addition, sodium-MR imaging provides a new approach to noninvasive tumor classification. The sodium signal of contrast-enhancing tumor portions facilitates differentiation among most glioma types (P < .001). CONCLUSIONS:The information of sodium-MR imaging may help to classify neoplasias at an early stage, to reduce invasive tissue characterization such as stereotactic biopsy specimens, and overall to promote improved and individualized patient management in neuro-oncology by novel imaging signatures of brain tumors.

Wenn man an medizinische Grenzen stößt, sind Konflikte manchmal unvermeidbar. Die häufigsten Konflikte auf der Intensivstation treten zwischen dem medizinischen Team und den Angehörigen auf. Dabei sind insbesondere Therapieentscheidungen am Lebensende konfliktbeladen und stellen v. a. für Angehörige eine große Belastung dar.

Fig. 2: a) Na MRI of a healthy human brain (Hamming filter). b) Before the calculation of the Cl/Na ratio maps, the Na MRI data was reconstructed with a Gaussian filter (b) to achieve the similar actual spatial resolution than in Cl MRI (c). d) Calculated Cl/Na ratio maps of the healthy human brain. Fig. 3: Glioblastoma patient. a) Contrastenhanced T1-weighted MPRAGE image (B0=3T). b) Cl /Na ratio maps; c) Cl MRI; d) Na MRI. In the area affected by the glioblastoma, the measured C/Na ratio is reduced compared to healthy brain tissue and cerebrospinal fluid. 3631 Combined Imaging of Cl and Na at 7 Tesla: First Results in Brain Tumors Armin M. Nagel, Reiner Umathum, Marc-André Weber, Jan-Oliver Neumann, and Armin Biller Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Germany, Radiology, German Cancer Research Center (DKFZ), Germany, Dpt. of Neurosurgery, University Hospital of Heidelberg, Heidelberg, Germany, Dpt. of Neuroradiology, German Cancer Research Center (DKFZ), Heidelberg, Germany

Standard Operating Procedures (SOPs), auch standardisierte Protokolle oder Algorithmen genannt, sind Maßnahmenpakete, die in bestimmten Situationen von unterschiedlichen Anwendern einheitlich durchgeführt werden. Seit Jahrzehnten in Bereichen wie Flug- und Raumfahrt bestens etabliert, haben SOPs auch in die Intensivmedizin Einzug gehalten und sind auf vielen Stationen verbreitet. Manche dieser Protokolle haben sich in randomisiert kontrollierten Studien schon vor über 10 Jahren als vorteilhaft bezüglich klinischem Verlauf und Outcome erwiesen, wie z. B. SOPs zur lungenprotektiven Beatmung [1] [2], zum Weaning [3] [4] [5] oder zur Analgosedierung [6] [7].

Background and Purpose— Optimal timing of tracheostomy in ventilated patients with severe stroke is unclear. We aimed to investigate feasibility, safety, and potential advantages of early tracheostomy in these intensive care unit (ICU) patients. Methods— This prospective, randomized, parallel-group, controlled, open, and outcome-masked pilot trial was conducted in neurological/neurosurgical ICUs of a university hospital. Patients with severe ischemic or hemorrhagic stroke and an estimated need for at least 2 weeks of ventilation were randomized to either early tracheostomy (within day 1–3 from intubation; early) or to standard tracheostomy (between day 7–14 from intubation if extubation could not be achieved or was not feasible; standard). The primary outcome was length of stay in the ICU; secondary outcomes were diverse aspects of the ICU course. Results— Sixty patients were randomized and analyzed. No differences were observed with regard to the primary outcome length of stay in the ICU (median 18 [interquartile range 16–28] versus 17 [interquartile range 13–22] days, median difference: 1 [−2 to 6]; P =0.38) or to most secondary outcomes, including adverse effects. Instead, use of sedatives (62% versus 42% of ICU stay, median difference 17.5 [3.3–29.2]; P =0.02), ICU mortality (ICU deaths 3 [10%] versus 14 [47%]; P <0.01) and 6-month mortality (deaths 8 [27%] versus 18 [60%]; P =0.02) were lower in the early group than in the standard group, respectively. Conclusions— Early tracheostomy in ventilated intensive care stroke patients is feasible, and safe, and presumably reduces sedation need. Whether the suggested benefits in mortality and outcome truly exist has to be determined by a larger multicenter trial. Clinical Trial Registration— http://www.clinicaltrials.gov . Unique identifier: NCT01261091.

A newly-born infant with a congenital dural and bony defect and an associated short-segmented duplication of the superior sagittal sinus suffered from herniation and infarction of parietal brain tissue secondary to vacuum extraction. This ultimately led to the formation of a subgaleal cerebrospinal fluid (CSF) collection. Initial operative closure of the encephalocele was performed by attaching a galeal flap to the periostium surrounding the congenital defect. As the bony defect developed characteristics of a growing fracture later on, dural repair, transplantation of a split-bone flap and, finally, the insertion of a ventriculoperitoneal shunt became necessary. This case affirms that stringent indication and cautious usage of vacuum-assisted delivery is strongly recommended, especially in view of the possibility that undetected congenital cranial, vascular and/or cerebral alterations may be present.

To assess the use of hyperventilation and the adherence to Brain Trauma Foundation-Guidelines (BTF-G) after traumatic brain injury (TBI).

SummaryThe increasing complexity of hepato‐biliary surgery, including major hepatic resections and living donor liver transplantation (LDLT), has lead to an increasing demand for sophisticated imaging modalities. Standard operation planning for hepatic resections and preoperative donor and recipient work‐up for LDLT is based on two‐dimensional computed tomography (CT) images and magnetic resonance imaging. However, even modern multidetector CT scanners are not able to perform routinely three‐dimensional (3D) visualization needed for operation planning in liver surgery or LDLT. As a consequence, special‐purpose computer‐based operation planning systems have been developed that leverage the possibilities of modern image processing to improve surgical planning. The advances in technology enable surgeons to analyse and to visualize the anatomy of the human liver including the vascular structures within the human liver and define the exact volumetric data of the liver tissue to be resected or preserved. Furthermore, 3D visualization of the vessel architecture within the human liver allows a reliable estimation of the amount of liver tissue that could be at risk after resection because of inadequate hepatovenous drainage. Because of its clinical usefulness and real‐time visualization capabilities we already use an operation planning system in selected patients prior to liver resection and before donor hepatectomy for LDLT as a standard.

Full right hepatic grafts are most frequently used for adult-to-adult living donor liver transplantation (LDLT). One of the major problems is venous drainage of segments 5 and 8. Thus, this study was designed to provide information on venous drainage of right liver lobes for operation-planning. Fifty-six CT data sets from routine clinical imaging were evaluated retrospectively using a liver operation-planning system. We defined and analyzed venous drainage segments and the impact of anatomic variations of the middle hepatic vein (MHV) on venous outflow from segments 5 and 8. MHV variations led to significant shifts of segment 5 drainage between the middle and right hepatic vein. In cases with the most frequent MHV branching pattern (n = 33), a virtual hepatectomy closely right to the MHV intersected drainage vessels that provided drainage for 30% of the potential graft, not taking into account potential veno-venous shunts. In individuals with inferior MHV branches that extend far into segments 5 and 6 (n = 10), the overall graft volume at risk of impaired venous drainage increased by 5% (p < 0.001). If this is confirmed in clinical trials and correlated with intraoperative findings, the use of liver operation-planning systems would be beneficial to improve overall outcome after right lobe LDLT.

Die exakte Definition von Lebervenensegmenten und deren Lagebeziehung zu den klassischen Couinaud-Segmenten spielt vor dem Hintergrund der Leberlebendspende eine zunehmende Bedeutung im klinischen Alltag. Unter Zuhilfenahme des vom DKFZ entwickelten Operationsplanungsprogramm LENA werteten wir die CT-Daten von 64 Patienten aus, bei denen in Vorbereitung auf eine Leberresektion routinemäßig eine CT-Untersuchung durchgeführt wurde. Das Drainagegebiet der rechten Lebervene umfasst mit 47,1% das größte Volumen. Die mittlere Lebervene drainiert 32,5% und die linke Lebervene 20,4%. Innerhalb dieser venösen Segmente nehmen die Couinaud- und portalen Segmente 2, 3, 5, 7 und 8 identische räumliche Positionen ein. Das Drainagengebiet der venösen Subsegmente reicht von 79,3 ml bis zu 337 ml. Es besteht keine Lageübereinstimmung zwischen venösen Subsegmenten und Couinaud/portalen Segmenten (kappa<0,6). Im Gegensatz dazu zeigen venöse Segmente/Subsegmente, die den linken/rechten Leberlappen oder die linke/rechte Leberhälfte charakterisieren, identische Volumen-, Form- und Positionsverhältnisse mit den entsprechenden Couinaud/portalen Segmenten (kappa >0,8).

Purpose: To investigate and describe the volume, position and shape of venous segments within the human liver and define their spatial correlation to the Couinaud segments (CS) and to the portal vein segments (PVS). Material and methods: This study was based on 64 routinely acquired CT scans of patients undergoing hepatic surgery. The final analysis included 19 patients. All 19 CT data sets were transformed into 3D liver models. Three venous segments were postulated reflecting the left, middle, and right hepatic vein. Each venous segment was furthermore divided in two venous subsegments. Volume, position and shape of these venous segments/subsegments were calculated and, finally, compared with the volume, position and shape of the Couinaud segments and the portal vein segments. Results: The right hepatic vein covers with 539.8 +/- 119.5 ml (47.1 %) the largest part of total liver volume followed by the middle hepatic vein 372.7 +/- 151.1 ml (32.5%) and the left hepatic vein 248 +/- 75.9 ml (20.4%). The Couinaud liver segments and portal vein segments 2, 3, 5, 7, and 8 have consistent positional assignments within the three venous segments. Only the CS 4a, 4b, and 6 showed significantly different positions compared to the PVS 4a, 4b, and 6 (P < 0.03). The venous subsegments have a broad volumetric distribution reaching from 79 to 337 ml. There is no positional correlation of venous subsegments compared to Couinaud segments or portal vein segments at all (kappa < 0.75). In contrast, the venous segments/subsegments which can be assigned to either liver halve and either liver lobe have an identical volume, shape and position compared to the corresponding Courinaud liver segments (kappa > 0.75). Conclusion: The venous segments distinguish liver areas divided by the left and middle hepatic vein in exactly the same pattern as Couinaud segments and portal vein segments do. However, the comparison of shape and position of venous subsegments showed no correlation with both liver segmental approaches. (C) 2004 Elsevier Ireland Ltd. All rights reserved.