Postoperative Respiratory Complications and Clinical Outcome among Patients Undergoing Upper Gastrointestinal Tumor Surgery: A Systematic Review and Meta-analysis

Background: Cancer’s incidence has been increasing world-wide and has become the leading cause of death in
many countries. Upper Gastrointestinal cancer is highly prevalent and associated with a high mortality rate. For
Upper GIT carcinomas, the mainstay of therapy is always surgery as it usually promises higher rates of survival
than other treatment options. Although surgery is considered the mainstay of therapy but it may be associated with
some complications and adverse events.
Objective: To evaluate the post-operative respiratory complications following upper gastrointestinal tumour
surgery according to timing, severity, type, incidence and possible measures for prophylaxis and management.
Patients and Methods: Fifteen trials included postoperative respiratory complications and clinical outcomes among
patients undergoing upper gastrointestinal tumor surgery. Outcomes of this study included pneumonia, ARDS,
atelectasis, ventilator dependency, hospital mortality and chylothorax.
Results: Regarding pneumonia was assessed in fifteen included studies there was no significant heterogeneity
among trials (P 0.001, I2 = 97.86%), OR 0.206, 95% CI (0.157, 0.256). While ARDS was assessed in 8 included
studies there was no significant heterogeneity among trials (P 0.001, I2 = 91.87%), OR 0.042, 95% CI (0.024,
0.061). Regarding Atelectasis was assessed in 4 included studies. There was no significant heterogeneity among
trials (P 0.001, I2 = 99.59%), OR 0.236, 95% CI (0.018, 0.454). Regarding ventilator dependency, it was evaluated
in 6 included studies there was no significant heterogeneity among trials (P 0.001, I2 = 96.17%), OR 0.099, 95%
CI (0.064, 0.133). Regarding Hospital mortality due to respiratory complications it was assessed in five included
studies, there was no significant heterogeneity among trials (P 0.001, I2 = 88.88%), OR 0.045, 95% CI (0.015,
0.075). Regarding chylothorax was assessed in 4 included studies, there was no significant heterogeneity among
trials (P 0.004, I2 = 77.44%), OR 0.039, 95% CI (0.019, 0.059).
Data Sources: Medline databases (PubMed, Medscape, and Science Direct. EMF-Portal) and all materials available
in the internet till 2021.
Conclusion: Our meta-analysis is done on 15 studies including 18,817 patients. Pneumonia, ARDS, ventilator
dependency, atelectasis and chylothorax are statistically significant post-operative complications and are significant
causes that lead to hospital mortality. Those complications are found more in patients with increase in tumor size,
T4 staging, bad general condition and patients with co-morbidities. In addition, prevention of those complications
by early intervention, early ambulation and well preparation of the patients pre-operatively are significant cause in
decreasing the pulmonary complications post-operative.