Chylothorax as a Risk Factor for Thrombosis in Adults: A Proof-of-Concept Study

Incidence, risk factors, and outcomes of chylothorax after cardiac procedure in the United States

Background

To examine the epidemiology and risk factors of chylothorax after cardiac procedure in the United States using a contemporary nationally representative database.

Methods

We identified postoperative chylothorax events through National Inpatient Sample database (2016-2019) and compared baseline demographics, comorbidities, and in-hospital outcomes between hospitalizations with and without postoperative chylothorax. The Cochrane-Armitage test was used to analyze trends in incidence rates. Multivariable Poisson regression models were used to identify potential risk factors for postoperative chylothorax after cardiac procedure.

Results

A total of 819 (0.24%) admissions were associated with postoperative chylothorax. The crude and standardized incidence rates of chylothorax were 23.7 (95%CI, 22.1-25.4) and 61.5 per 10,000 cardiac procedure-related admissions, respectively, with no significant temporal change in incidence rate over the study period (Ptrend = 0.5249). Infants [adjusted rate ratio (aRR), 117.3, 95% confidence interval (CI), 94.5-145.5] and children (aRR, 60.2, 95%CI, 48.0-75.5) were more likely to develop chylothorax compared to adults. Heart and great vessel procedures (aRR, 4.36, 95%CI, 3.61-5.26), septal repair (aRR, 1.91, 95%CI, 1.58-2.29), heart transplant (aRR, 5.68, 95%CI, 4.55-7.10) and pericardial procedures (aRR, 4.04, 95%CI, 3.32-4.91) were associated with elevated risk for chylothorax. Admissions with chylothorax were associated with higher inpatient mortality (4.9% vs. 3.0%, p<0.0001), longer inpatient stay, higher costs and greater perioperative complication burden.

Conclusions

Following cardiac procedures, chylothorax is an uncommon but serious complication that affects the prognosis. The analysis reveals varying incidence rates across age groups and specific surgical procedures, with infants at elevated risk.

Association between underweight status and chylothorax after esophagectomy for esophageal cancer: A propensity score-matched analysis

Objective

To use a nationwide database of hospitalizations to investigate underweight status as a risk factor for postesophagectomy complications.

Methods

We identified all patients who underwent esophagectomy with a diagnosis of esophageal cancer and known body mass index in the 2018-2020 Nationwide Readmissions Database. All hospital visits for esophagectomy and within 30 days of initial discharge were analyzed for postoperative complications, including chylothorax. Patients who were underweight were propensity score matched with patients who were not. Multivariable logistic regression was performed to identify complications that were significantly associated with underweight status.

Results

There were 1877 patients with esophageal cancer meeting inclusion criteria. Following propensity score matching, 433 patients who were underweight were matched to 433 patients who were not. In the multivariable model of the matched sample, which adjusted for age, sex, Charlson Comorbidity Index, history of chemotherapy or radiation therapy, and preoperative surgical feeding access, patients who were underweight were estimated to have 2.06 times the odds for chylothorax (95% confidence interval [CI], 1.07-4.25, P = .035). Underweight status was also significantly associated with acute bleed (odds ratio [OR], 1.52; 95% CI, 1.12-2.05, P = .007), pneumothorax (OR, 2.33; 95% CI, 1.19-4.85; P = .017), pneumonia (OR, 2.30; 95% CI, 1.53-3.50, P < .001), and in-hospital mortality (OR, 2.42; 95% CI, 1.31-4.69, P = .006).

Conclusions

Underweight status was found to be a risk factor for chylothorax after esophagectomy, which may have implications for perioperative care of esophageal cancer patients. Future studies should assess whether using feeding tubes or total parenteral nutrition preoperatively or thoracic duct ligation intraoperatively decreases risk of chylothorax among patients who were underweight.

Association between low-fat enteral nutrition after esophagectomy and a lower incidence of chyle leakage: A call for more and better evidence

Objective

Reliable methods to prevent chyle leakage after esophagectomy are needed. This retrospective study was performed to evaluate the correlation between low-fat nutrition and the incidence of chyle leakage after esophagectomy.

Methods

This multicenter retrospective case–control study involved patients who underwent Ivor Lewis esophagectomy from December 2012 to August 2017. Tube feeding was started on postoperative day 1 with a normal fat-containing formula (control group, 203 patients) or low fat-containing formula (241 patients).

Results

The patients in the control group and low-fat group had a similar incidence of chyle leakage (7 [3.4%] vs. 19 [9.4%], respectively) and anastomotic leakage (4 [2.0%] vs. 11 [5.4%], respectively). The multivariate logistic regression indicated that high-volume surgeon experience (performance of ≥100 esophagectomies per year) was correlated with a lower incidence of chyle leakage (odds ratio, 0.280; 95% confidence interval, 0.110–0.712), whereas low-fat nutrition was correlated with an increased risk of anastomotic leakage (odds ratio, 5.995; 95% confidence interval, 1.201–29.925).

Conclusion

Prophylactic low-fat enteral nutrition following esophagectomy might not decrease the risk of chyle leakage. More and better evidence is needed.