Study design and data collection
This is a prospective observational cohort study on patients who underwent esophagectomy for esophageal cancer from August 1, 2017, to March 30, 2020. Diagnosis was based on clinical presentation; endoscopic evaluation, biopsy, and radiologic study (contrast x-rays and/or CT scan).
All male and female patients older than18 years of age who underwent standard esophagectomy were included in the study. Standard esophagectomy is defined as a subtotal resection of the esophagus which is reconstructed using one of the following conduits Stomach, Colon, or Jejunum with one of the following four surgical approaches: Trans Hiatal, Transthoracic (Ivor- Lewis), McKeown's Esophagectomy or Left Thoracotomy.
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 a power of 80 and a CI of 95%. Consecutive patients used in sampling technique.
Data collection and data collection tool
Data 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 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 the frequently used thresholds identified in a 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 a clinically diagnosed leak, and prolonged hospital stay was defined as hospital stay more than 7th 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% (n=26) of cases. McKeown’s esophagectomy was preferred for mid and upper thoracic esophageal cancers which are at T4 stage and performed in 16% (n=8) of the cases. Ivor – Lewis procedure was performed for 4% (n=2) patients while 30 % (n=16) patients had Left thoracotomy approach as it was preferred for gastroesophageal junction and proximal gastric cancers. All esophagogastric anastomosis (stomach was used as a conduit in all cases) was done via the anatomical esophageal bed and with hand-sewn techniques.
Data quality assurance
Data completeness 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 used for statistical data analysis. Descriptive statistics used for describing the data, results are presented in percentage, and simple frequency, mean (SD), and median were 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.