Study design and data collection
This is a prospective observational cohort study on patients who underwent esophagectomy for esophageal cancer form August 1, 2017 to March 30, 2020. Diagnosis was made based on clinical presentation, endoscopic evaluation, biopsy, and radiologic study (contrast x-rays and / or CT scan).
All male and female patient’s older than18 years of age who underwent standard esophagectomy were included in the study.
Patients who had exploration only, patients with feeding gastrostomy or jejunostomy tube insertion
without esophagectomy due to unresectable disease, patients with poor pre-operative performance status, patients with cervical esophageal cancer, and patients who had signs indicative of advanced disease state such as hoarseness of voice , malignant ascites …etc. were excluded.
Sample size and sampling technique
The sample size was calculated using statistical software Epinfo with power of 80 and CI of 95%. Consecutive patients were used in sampling technique.
Data collection data collection tool
Data were collected prospectively in a structured and pretested data collection format. Socio-demographics, clinical information on preoperative and intraoperative variables, as well as postoperative morbidity, mortality, and post op stay were documented. Modified Takita’s grading 1 -614 was used for the assessment of dysphagia. American Society of Anesthesiology (ASA) physical status classification system I-IV15 for preoperative anesthesiology evaluation, BMI (Body Mass Index) based on body weight and height (kg/m2),Eastern Cooperative Oncology Group (ECOG) performance classification (0-4)16, serum albumin, serum creatinine, serum electrolytes and liver enzyme tests were recorded. Preoperative ECG, echocardiography and radiologic characteristics from barium swallow and CT studies were also recorded. AJCC 8th edition Esophageal Cancer staging was used for clinical staging17.
As one of frequently used thresholds identified in systematic review done by Bijker et al18, SBP < 90 mmHg, and duration of more than 5 min18,19 was used to define Intra Operative Hypotension (IOH).
Anastomotic leak was defined by clinically diagnosed leak, and prolonged hospital stay was defined as hospital stay more than 7thth post op day.
Intraoperative blood loss, intraoperative events including arrhythmias, need for blood transfusion, need for inotropic and / or vasopressor support were documented.
Trans hiatal esophagectomy was preferred for mid and distal thoracic esophageal cancers and performed in 51.0% (n=26) of cases. McKeown’s esophagectomy was preferred for mid and upper thoracic esophageal cancers which are at T4 stage and performed in 15.7% (n=8) of the cases. Ivor – Lewis procedure was performed for 3.9% (n=2) patients while 29.6% (n=16) patients had Left thoracotomy approach as it was preferred for gastro esophageal junction and proximal gastric cancers. All esophago-gastric anastomosis were done via the anatomical esophageal bed and with hand sewn techniques.
The primary end point was the individual outcome variables or composite outcome of anastomotic leak, mortality of any cause, and prolonged postop hospital stay. Patients were followed for 30 days post operatively.
Data quality assurance
Data completeness was checked by reviewing data collection format and Patient medical records regularly.
An approval from the Institutional ethics review board (Addis Ababa University College of Health Sciences: Protocol Number 084/17/Surg.) was acquired and written consent was obtained from the patients
IBM SSPS 23 software package was used for statistical data analysis. Descriptive statistics was used for describing the data and results are presented in percentage and simple frequency, mean (SD) and median are used for other data. Factors with a possible influence on perioperative morbidity and mortality were calculated using multivariate regression analysis. A p-value of <0.05 was considered statistically significant.