Thoracotomy

The Norwegian Air Ambulance Service is a nationwide system served by helicopter and fixed wing aircraft bases.5 The Royal Norwegian Air Force's anaesthesiologist-manned 330 Squadron is a dedicated search and rescue (SAR) helicopter service and also contributes regularly to the national Air Ambulance system. We reviewed all missions completed by the SAR base at Banak, Northern Norway, during the period 1 January 1999 to 31 December 2009. We included all patients that had been treated by the service and assessed using the NACA score. Pre-hospital data (patient ID, date of mission, diagnosis, NACA score, pre-hospital interventions and the institution to which the patient was admitted) were collected from the service's electronic patient record.
The hospitals in Hammerfest, Kirkenes and Tromsø receive patients from the service. Relevant in-hospital data from the hospital records of the patients were recorded. Ventilatory support was defined as the institution or continuation of any form of positive pressure ventilation either via endotracheal intubation or non-invasive ventilatory support during the first 24 h after admission. Haemostatic emergency surgery was assessed at two levels of definitions: (1) defined as haemostatic packing of the abdomen or pelvis, or thoracotomy exceeding tube thoracostomy, and (2) the earlier definition plus tube thoracostomy and/or emergency orthopaedic procedures performed within 24 h.
Thirty-day mortality was assessed using the hospitals' medical records based on The National Population Register. Norwegian patients from the catchment area of the hospitals discharged before 30 days after admission have their medical records updated with survival data from The National Population Register, while persons living outside the region were lost to follow-up with regards to mortality. Patients without information on 30-day mortality were considered as survivors if they were discharged to their home directly, even if a follow-up consultation was planned.
Data collection was performed by two experienced consultant anaesthesiologists, with more than 4 years of experience in pre-hospital emergency medicine. The relationship between the NACA score and the outcome measures was assessed using receiver operating characteristic (ROC) curves. With this test, the true positive rate (sensitivity) is plotted against the false-positive rate (1 – specificity) to receive a graphic estimate of the test or scoring system performance as the area under the curve (AUC).6 (link)–9 (link) We regarded an AUC of more than 0.8 as a good and an AUC of more than 0.95 as excellent predictor of outcome.

Surgical preparation was performed as described previously [18 (link)]. In brief, rats were anesthetized by intraperitoneal injection of pentobarbital (90 mg/kg). After thoracotomy hearts were excised and mounted on a Langendorff system. Perfusion of the hearts was performed at constant pressure (80 mmHg) with a Krebs-Henseleit solution, containing (in mM): 116 NaCl, 4.7 KCl, 1.1 MgSO₄, 1.17 KH₂PO₄, 24.9 NaHCO₃, 2.52 CaCl₂, 8.3 glucose, and 2.2 pyruvate at 37°C. The perfusate was bubbled with a mix of 95% O₂ and 5% CO₂, resulting in a pO₂ of 540–620 mmHg, a pCO₂ of 35–38 mmHg, and a pH of 7.38–7.43, respectively.
A fluid filled balloon was inserted into the left ventricle and end-diastolic pressure was set at 1–4 mmHg. All hearts underwent an equilibration period of 20 minutes. Thereafter, heart rate, the rate pressure product (RPP, calculated as heart rate x (maximal left ventricular pressure—minimal left ventricular pressure)), left ventricular end-diastolic pressure (LVEDP), and coronary flow were measured continuously and digitized using an analogue to digital converter (PowerLab/8SP, ADInstruments Pty Ltd, Castle Hill, Australia) at a sampling rate of 500 Hz. The data were continuously recorded on a personal computer using Chart for Windows v5.0 (ADInstruments Pty Ltd, Castle Hill, Australia). Maximal contracture and time to maximal contracture were detected by checking the course of contracture development during index ischemia and selecting the time point when contracture reached its highest level in each experiment. Arrhythmic intervals were not used for data analysis.

All patients with a malignant tumour of the oesophagus or the oesophagogastric junction considered to be resectable with curative intent via oesophagectomy by means of an abdominal and right thoracic approach (Ivor-Lewis procedure) irrespective of neoadjuvant therapy are eligible for the study. All subjects must be suitable for the MIN-E and for the HYBRID-E procedure. Only adult patients (≥18 years of age) with the ability to understand character and individual consequences of the clinical trial will be included. All subjects must provide a written informed consent.
The preoperative exclusion criteria are defined as the presence of distant metastases, tumour localization above the azygos vein, history of right thoracotomy within the last 3 years, American Society of Anesthesiologists (ASA) grade >3 and advanced hepatic cirrhosis (Child B/C). Patients who participate in another intervention trial with interference of the intervention and/or primary outcome of the MICkey trial will be excluded as well as patients with an expected lack of compliance or language problems. Furthermore, two intraoperative exclusion criteria are defined: (a) intraoperative diagnosis of previously occult metastases that prohibit surgical resection according to current S3 guidelines [19 (link)] and (b) the tumour resection is technically impossible. For further handling of these cases (i.e., intraoperative exclusion of previously randomized patients), please refer to the section “Criteria for discontinuing or modifying allocated interventions {11b}”.