Post-operative Chylothorax in Patients with Repaired Transposition of the Great Arteries

Octreotide improves human lymphatic fluid transport a translational trial

OBJECTIVES

Chylothorax is a complex condition and many different pharmacological agents have been tried as treatment. Octreotide is used off-label to treat chylothorax, but the efficacy of octreotide remains unclear. A decrease in lymph production is suggested as the mechanism. In this cross-over study, we explore the direct effect of octreotide on human lymphatic drainage.

METHODS

Pre-clinical: the effect of octreotide on force generation was assessed during acute and prolonged drug incubation on human lymphatic vessels mounted in a myograph. Clinical: in a double-blinded, randomized, cross-over trial including 16 healthy adults, we administered either octreotide or saline as an intravenous infusion for 2.5 h. Near-infrared fluorescence imaging was used to examine spontaneous lymphatic contractions and lymph pressure in peripheral lymphatic vessels and plethysmography was performed to assess the capillary filtration rate, capillary filtration coefficient and isovolumetric pressures of the lower leg.

RESULTS

Pre-clinical: human thoracic duct (n = 12) contraction rate was concentration-dependently stimulated by octreotide with a maximum effect at 10 and 100 nmol/l in the myograph chamber. Clinical: spontaneous lymphatic contractions and lymph pressure evaluated by near-infrared fluorescence did not differ between octreotide or placebo (P = 0.36). Plethysmography revealed similar capillary filtration coefficients (P = 0.057), but almost a doubling of the isovolumetric pressures (P = 0.005) during octreotide infusion.

CONCLUSIONS

Octreotide stimulated lymphatic contractility in the pre-clinical setup but did not affect the spontaneous lymphatic contractions or lymph pressure in healthy individuals. Plethysmography revealed a doubling in the isovolumetric pressure. These results suggest that octreotide increases lymphatic drainage capacity in situations with high lymphatic afterload.

Understanding the next circulation: lymphatics and what the future holds

PURPOSE OF REVIEW

The lymphatic system was previously considered the forgotten circulation because of an absence of adequate options for imaging and intervention. However, recent advances over the last decade have improved management strategies for patients with lymphatic disease, including chylothorax, plastic bronchitis, ascites, and protein-losing enteropathy.

RECENT FINDINGS

New imaging modalities have enabled detailed visualization of lymphatic vessels to allow for a better understanding of the cause of lymphatic dysfunction in a variety of patient subsets. This sparked the development of multiple transcatheter and surgery-based techniques tailored to each patient based on imaging findings. In addition, the new field of precision lymphology has added medical management options for patients with genetic syndromes, who have global lymphatic dysfunction and typically do not respond as well to the more standard lymphatic interventions.

SUMMARY

Recent developments in lymphatic imaging have given insight into disease processes and changed the way patients are managed. Medical management has been enhanced and new procedures have given patients more options, leading to better long-term results.

Risk factors and early outcomes of chylothorax following congenital cardiac surgery: A single-center experience

Background

This study aims to investigate the incidence and risk factors for chylothorax and to evaluate the effect of chylothorax on the early postoperative outcomes following congenital cardiac surgery.

Methods

A total of 1,053 patients (606 males, 447 females; median age: 12 months; range, 3 days to 48 years) who underwent surgery for congenital heart disease at our institute between January 2018 and December 2019 were retrospectively analyzed. Patients with chylothorax were identified and the data of this cohort was compared with the entire study population. Following the diagnosis of chylothorax, a standardized management protocol was applied to all patients.

Results

Of 1,053 patients operated, 78 (7.4%) were diagnosed with chylothorax. In the univariate analysis, younger age, peritoneal dialysis, preoperative need for mechanical ventilation, surgical complexity, delayed sternal closure, high vasoactive inotrope score in the first 24 h after operation, residual or additional cardiac lesions which required reoperations were found to be the risk factors for chylothorax (p<0.05). In the multivariate analysis, the correlation persisted with only younger age, infections, and peritoneal dialysis requirement (p<0.05). In the chylothorax group, ventilation times were longer, and re-intubation and infection rates were higher (p<0.05). Although the length of intensive care unit and hospital stay was significantly longer in this patient group, there was no significant association between the development of chylothorax and in-hospital mortality (p>0.05).

Conclusion

Chylothorax following congenital cardiac surgery is a significant problem which prolongs the length of hospital stay and increases the infection rates. Complex cardiac pathologies which require surgery at early ages and re-operations are risk factors for chylothorax. Although there is no consensus on the most optimal therapeutic strategy, standardizing the management protocol may improve the results.