Marc Hartert

Contemporary spinal cord protection during thoracic and thoracoabdominal aortic surgery and endovascular aortic repair: a position paper of the vascular domain of the European Association for Cardio-Thoracic Surgery

Ischaemic spinal cord injury (SCI) remains the Achilles heel of open and endovascular descending thoracic and thoracoabdominal repair. Neurological outcomes have improved coincidentially with the introduction of neuroprotective measures. However, SCI (paraplegia and paraparesis) remains the most devastating complication. The aim of this position paper is to provide physicians with broad information regarding spinal cord blood supply, to share strategies for shortening intraprocedural spinal cord ischaemia and to increase spinal cord tolerance to transitory ischaemia through detection of ischaemia and augmentation of spinal cord blood perfusion. This study is meant to support physicians caring for patients in need of any kind of thoracic or thoracoabdominal aortic repair in decision-making algorithms in order to understand, prevent or reverse ischaemic SCI. Information has been extracted from focused publications available in the PubMed database, which are cohort studies, experimental research reports, case reports, reviews, short series and meta-analyses. Individual chapters of this position paper were assigned and after delivery harmonized by Christian D. Etz, Ernst Weigang and Martin Czerny. Consequently, further writing assignments were distributed within the group and delivered in August 2014. The final version was submitted to the EJCTS for review in September 2014.

A Follicular Dendritic Cell Sarcoma of the Mediastinum With Immature T Cells and Association With Myasthenia Gravis

Follicular dendritic cell (FDC) sarcoma is a very rare neoplasm showing morphologic and phenotypic features of FDCs. It occurs primarily in lymph nodes but also in extranodal sites. So far, there have been no reports on FDC sarcoma associated with myasthenia gravis. In the following we will present a case of an FDC tumor of the mediastinum associated with paraneoplastic myasthenia gravis in a 39-year-old man. The tumor contained a major proportion of immature T cells, which may be connected to this patients very unusual clinical presentation with autoimmune phenomena. Extranodal FDC sarcomas still seem hardly noticed, and their clinical and pathologic characteristics remain to be better defined.

Value and pitfalls of neurophysiological monitoring in thoracic and thoracoabdominal aortic replacement and endovascular repair.

BACKGROUND The aim of our study was to analyze the neurophysiological monitoring method with regard to its potential problems during thoracic and thoracoabdominal aortic open or endovascular repair. Furthermore, preventive strategies to the main pitfalls with this method were developed. METHODS Between 11/2000 and 05/2007 in 97 cases open surgery or endovascular stentgraft-implantation was performed on the thoracic or thoracoabdominal aorta. Intraoperatively, neurophysiologic motor- and somatosensory-evoked potentials were monitored. RESULTS Our cases were divided into four groups: event-free patients with normal potentials (A, 63 cases), with correlation of modified evoked potentials and neurological outcome (B, 14 cases), false-positive or false-negative results (C, 4 cases), and medication interaction or technical issues (D, 16 cases). We observed a sensitivity of 93 % and a specificity of 96 % for the neurophysiological monitoring. CONCLUSIONS Monitoring spinal cord function during surgical and endovascular interventions on the thoracic and thoracoabdominal aorta is necessary. It can be made more effective by precisely analyzing the interference factors of the neurophysiological monitoring method itself. Successful strategies of immediate troubleshooting could be identified.

Development of a Special Balloon Occlusion Device to Prevent Adverse Events in High-Risk Patients during Open Aortic Surgery

Objective: To prevent clamp injury that may occur during aortic surgery, we aimed to develop a special balloon occlusion (BO) device to lower the thromboembolic risk in patients with severe atherosclerosis during aortic aneurysm repair. Methods: The study comprised two test phases: a laboratory-testing series focussing on flexible artificial aortas, and an experimental series conducted on 10 pigs. Results: The device proved to be effective during the laboratory tests and the experiments on pigs. No complications such as intraoperative balloon rupture, dislocation, or occlusion leaks occurred. No damage to the aortic vessels was observed in further histological examinations. Conclusions: This BO device has the potential to become an alternative to cross-clamping for vascular surgeons in patients with severely atherosclerotic vessels.

Lobar lung resection in elderly patients with non-small cell lung carcinoma: impact of cardiac comorbidity on surgical outcome.

PRINCIPLES The aim of this study was to evaluate the impact of cardiac comorbidity on the perioperative morbidity and mortality after lobar lung resection for lung cancer in patients aged 70 years and older. METHODS The medical records of all 68 patients ≥70 years, who underwent lobar lung resection for non-small cell lung cancer (NSCLC) from 2003 to 2011 at our department, were reviewed retrospectively. Twenty-two patients with a mean age of 76.3 years had cardiac comorbidities (Group A) including previous cardiac operations in 4 patients, previous myocardial infarction in 5 patients, previous coronary stent insertion in 3 patients, medically treated coronary artery disease in 10 patients and medically treated valvular heart disease in 2 patients whereas 46 patients (mean age = 74.5 years) had no previous cardiac history (Group B). RESULTS There were no significant differences in postoperative morbidity (13.6% in Group A vs. 17.4% in Group B) between both groups. No in-hospital mortality was observed in both groups. CONCLUSION In our experience lobar lung resections for NSCLC in elderly patients with cardiac comorbidity seem to be a safe therapy option for this increasing subpopulation. Though, our retrospective data with the small number of study objects require further confirmation in larger prospective trials.

Evozierte Potentiale in der Aortenchirurgie

ZusammenfassungEinleitungDieser Artikel beschreibt das Anlegen von Elektroden, die der Überprüfung der neurophysiologischen Funktionsfähigkeit des Rückenmarks bei Operationen an der thorakalen und thorakoabdominellen Aorta dienen.MethodenDas intraoperative Monitoringverfahren umfasst die Aufzeichnung sowohl somatosensorisch evozierter Potentiale (SSEP) als auch motorisch evozierter Potentiale nach transkranieller elektrischer Stimulation (tcMEP). Für die Messung der tcMEP werden die Stimulationsnadeln mittels subkutaner Elektroden an Position C3 und C4 entsprechend des 10–20–Systems für EEGAufzeichnungen angebracht. Die tcMEP werden von beiden Seiten des M. tibialis anterior sowie M. gastrocnemius abgenommen. Die SSEPElektroden werden lateral und kaudal am Malleolus medialis fixiert, um den N. tibialis zu stimulieren. Der Stimulus wiederum wird durch Elektroden aufgezeichnet, die auf der Kopfhaut innerhalb der Region des sensorischen Kortex befestigt sind.ErgebnisseDas Anlegen der Elektroden kann leicht erlernt und ohne größere Schwierigkeiten durchgeführt werden. Sind die Elektroden einmal angebracht, erlauben sie eine schnelle Beurteilung und Interpretation der aktuellen Rückenmarksfunktion. Externe Störfaktoren (z.B. unzureichende Impedanz, mangelhafte Elektrodenfixierung, Interferenzen mit medizinisch–technischem Gerät) können schnell identifiziert werden und ermöglichen eine Differenzierung zwischen physiologischen und pathologischen neurologischen Potentialantworten.SchlussfolgerungTcMEP und SSEP ermöglichen eine adäquate, direkte und zuverlässige intraoperative Beurteilung der Rückenmarksfunktion. Gleichzeitig versetzen sie einerseits das Neuromonitoring– Team in die Lage, eine drohende Ischämie zu diagnostizieren und erlauben andererseits dem Chirurg, eine adäquate und rechtzeitige Gegenmaßnahme einzuleiten. Die neurophysiologische Monitoring– Messtechnik stellt für das Operationsteam eine Möglichkeit dar, neurologische Aspekte in den Fokus chirurgischer Eingriffe an der thorakalen und thorakoabdominellen Aorta zu integrieren.SummaryBackgroundThe article exemplifies a procedure concerning the intraoperative neurophysiological placement technique of electrodes to control the spinal cord function during thoracoabdominal aortic aneurysm repair.MethodsIntraoperative monitoring is performed by motor–evoked myogenic potentials after transcranial electric stimulation (tcMEP) and somatosensory–evoked potentials (SSEP). In tcMEP, the stimulating percutaneous needle electrodes are placed at C3 and C4 according to the 10–20 system for EEG–recordings. TcMEP are recorded from the anterior tibial and gastrocnemius muscles on both sides. The SSEP electrodes are located laterally and caudally onto the malleolus medialis in order to stimulate the tibial nerve. The stimulus is documented via electrodes attached to the scalp within the sensory cortex region.ResultsThe application method of the electrodes is both easy to understand and without further difficulties to perform. Once attached, the electrodes provide quick assessment and interpretation of spinal cord function. The identification of external sources of disturbance during the monitoring (e.g. insufficient impedance, unfavorable electrode positioning, and technical interferences caused by medical equipment) enables the supervisor to differentiate between normal and abnormal neurological responses.ConclusionTcMEP and SSEP allow an adequate, direct, and reliable intraoperative assessment of spinal cord function, enabling the surgeon to diagnose an impending ischemia and act accordingly. This measurement technique provides the surgical team with a means for integrating neurological aspects in thoracoabdominal aneurysm repair into the surgical focus.

Entwicklung eines neuen Ballonokklusions-Device alternativ zur Gefäßklemme bei offenen Eingriffen an der Aorta

ZusammenfassungHintergrundSchwere atherosklerotische Veränderungen der Aorta und anderer großer Gefäße stellen eine besondere Herausforderung für den Gefäßchirurgen dar. Das Abklemmen eines Gefäßes mittels einer herkömmlichen Gefäßklemme kann Schäden am Gefäß verursachen und atheromatöse Plaques aufbrechen, die wiederum zu arteriellen Embolien in der peripheren Strombahn führen können. Um dies zu vermeiden, haben wir ein neues Ballonokklusions (BO-)Device als Alternative zur Gefäßklemme entwickelt.MethodenDie vorliegende Studie umfasste zwei Testphasen. In der In-vitro-Phase wurde an künstlichen, flexiblen Aortenbogenmodellen, das ideale Cuffvolumen des BO-Device bestimmt. In der In-vivo-Phase wurden Untersuchungen unter physiologischen Bedingungen mit dem BO-Device an zehn Hausschweinen durchgeführt. Abschließende histologische Untersuchungen, der mit dem BO-Device geblockten Aortenwände, vervollständigten die Untersuchungen.ErgebnisseDas BO-Device absolvierte die experimentelle In-vitro-Phase problemlos und konnte kontinuierlich weiterentwickelt werden, so dass wir nach kurzer Zeit in der Lage waren, die Aorten im Tierversuch effektiv zu okkludieren. Es traten keine Komplikationen, wie intraoperative Ballonruptur, Dislokation oder Undichtigkeiten, auf. Desweiteren fanden sich keine Dissektionen oder andere Gefäßschäden bei den postoperativen histologischen Nachuntersuchungen.SchlussfolgerungDas BO-Device hat in der experimentellen In-vitro- und In-vivo-Testphase alle Anforderungen erfüllt und gezeigt, dass es dazu beitragen kann Gefäßschäden zu minimieren. Das BO-Device ist jetzt soweit um im klinischen Alltag erprobt zu werden und hat das Potential eine Alternative zur konventionellen Gefäßklemme, bei Patienten mit schwer atherosklerotisch veränderten Gefäßen, zu werden.SummaryBackgroundSevere atherosclerosis of the aorta and the great vessels presents a huge challenge for vascular surgeons. Cross-clamping may cause vessel damage and result in atheromatous degeneration, which can lead to arterial embolism in the terminal vessels. In order to prevent these complications, we developed a new balloon occlusion (BO) device as an alternative to aortic cross-clamping.MethodsThis study comprised two test phases. In the in vitro phase, which focused on flexible artificial aortas, the ideal occlusion volume of the BO device was determined. During in vivo phase the BO device was tested under physiological conditions on ten pigs. Subsequent histological tests of the aortic walls, which were occluded by the BO device, completed the study.ResultsThe BO device met the laboratory test requirements relating to experimental application and material properties and was enhanced successfully, which allowed us in the aftermath to occlude the aortas effectively during the animal experiments. No complications such as intraoperative balloon rupture, dislocation or occlusion leaks occurred. In none of the histological examinations were dissections or other damage to the aortic vessels observed.ConclusionsThe BO device not only meets in vitro and in vivo requirements, it also helps to prevent vessel damage. This BO device is ready to be proved during operations and has the potential to become an operative alternative to conventional vessel clamps on patients with severe atherosclerotic vessels.