The matched pair analysis was performed at the Department of General, Visceral and Transplantation Surgery, University Hospital of the RWTH Aachen, Germany. The study was conducted in accordance with the study protocol, the Declaration of Helsinki and applicable regulatory requirements. The study was approved by the ethics committee of the faculty of medicine of the RWTH University of Aachen. The approval number is EK 105/11.
Between June 2009 and June 2010 36 consecutive patients received an esophageal resection due to esophageal cancer in our department. All patients underwent Ivor Lewis subtotal esophagectomy with two-field lymph node dissection. In brief, all resections were performed by initial abdominal exploration through an upper midline laparotomy. The stomach was mobilized on the right gastric and gastroepiploic arteries. The left gastric artery was divided at its origin, and all lymph nodes along the celiac axis and its three branches along the left aspect of the portal vein, in front of the inferior vena cava, along the diaphragmatic pillars were resected. A pyloromyotomy was not performed routinely. With a right anterolateral thoracotomy, the chest was entered through the fifth intercostal space. The azygos vein arch was divided, and the esophagus was dissected from esophagogastric junction to the apex of the chest. Complete lymph node dissection of the dorsal mediastinum including subcarinal lymph nodes was performed. A resection of the thoracic duct was not performed routinely. Denudation of the lesser curvature was usually performed in the pleural cavity. After resection of the specimen, an end-to-side anastomosis was constructed between the esophagus and the stomach. The anastomosis was located in the apex of the chest and was delivered by a circular stapler device. None of the patients were excluded.
For each patient in the intrathoracic group, patients who received a cervical anastomosis in the time between January 2007 and May 2009 were selected from our database of patients (n = 60) in the same institution who matched the following criteria: age and tumor stage.
Among patients with cervical anastomosis in case of adenocarcinoma a transhiatal resection of the esophagus with left-sided cervical hand sutured end-to-end esophagogastric anastomosis was carried out, whereas in case of squamous cell carcinoma abdomino-right-sided-thoracic resection with two-field lymphadenectomy and left-sided cervical hand sutured end-to-end esophagogastric anastomosis was performed. Mobilisation of the gastric tube and lymph node dissection was equal to the technique described above. All patients with thoracotomy received a right-sided chest tube insertion.
Prospectively collected data from these patients were reviewed retrospectively. The observation period was the initial hospital stay. We analyzed the following clinical markers representing the early perioperative outcome: resected lymph nodes, operation time, intensive care stay (ICU), re-ICU-stay, overall hospital stay, In-hospital mortality, blood substitution intra- and postoperatively, postoperative bleeding, pneumonia, need of postoperative CPAP (non-invasive continuous positive airway pressure), re-intubation, anastomotic leakage, revision operation, wound infection, thrombemboli and chylothorax. In case of postoperative dysphony a larnygoscopy was performed to document potential laryngeal nerve palsy.
All patients were discussed at a weekly multidisciplinary meeting, and treatment strategies were developed and tailored for individual patients. In general, patients with squamous cell carcinoma were offered neoadjuvant radiochemotherapy in case of tumor stage II and III. Since 2007 patients with adenocarcinoma (stage II and III) received neoadjuvant chemotherapy according to the MAGIC Trial .
Preoperatively, all patients received a thoracic peridural catheter. After surgery, all patients returned to the intensive care unit and were extubated on the same day. All patients received a restrictive volume regime. All patients received a nasojejunal feeding tube during surgery which was removed on day 5 after surgery. Oral feeding started on day 5 after surgery. Before return to solid food a gastrografin swallowing (50 to 100 ml) examination was performed in all patients. In case of radiographically or clinically suspected anastomotic leakage endoscopy was performed. In cases of obvious leakage among patients with cervical anastomosis a nutrition tube was inserted into the duodenum endoscopically for enteral nutrition until spontaneous closure of the defect occurred. In cases of leakage of thoracic anastomosis a double-layered self-expandable stent was inserted with patient under sedation. Each stent was individually adapted in diameter and length dependent on the leakage size, and subjected to the distance between defect and upper esophageal sphincter. The location of the stent was visualized and controlled radiographically during the implantation.
Means and standard deviations (notation: mean ± SD) as well as frequencies and percentage were given to describe the data. In case of not normal distribution data is represented as median and range. According to the matched pairs study design, we used paired t-tests to compare means between the intrathoracic and cervical anastomosis groups, e.g. the mean ICU stay. Further the Cochrane Mantel Haenszel test stratified by pairs was used to compare proportions between the intrathoracic and cervical anastomosis groups, e.g. proportion of anastomotic leakage. Statistically significance was assessed if the p-value of the corresponding test fell below the significance level of 0.05. Due to the small sample size our statistical analysis was limited to bivariate statistical analysis. Thus no stratified (multivariate) analysis could be conducted because of lack of model fit. We used SAS® V9 under Windows XP for computations.