Hepatosplanchnic Ischemia/Reperfusion is a Major Determinant of Lung Vascular Injury After Aortic Surgery

Objectives

To study risk factors, including the level of cross-clamping and ischemia/reperfusion, for lung vascular injury after aortic surgery.

Design

Single-center prospective observational study.

Patients and Methods

Twenty-seven consecutive and mechanically ventilated patients were included within 3 h after elective aortic surgery, i.e., surgery on the thoracoabdominal aorta supported by left atrial to femoral bypass (n = 3), surgery on the suprarenal aorta (n = 5), surgery on the infrarenal aorta (n = 15), and reconstructions of the celiac and mesenteric arteries (n = 4). The ⁶⁷Gallium (Ga)-transferrin pulmonary leak index (PLI) served as a measure of lung vascular injury.

Results

The PLI was elevated (≥14.1 × 10⁻³/min) in 74% of all patients and more so in patients undergoing suprarenal aortic surgery or reconstruction of celiac and mesenteric arteries than in the patients undergoing the other types of surgery (P = 0.006). Clamping of the celiac and/or mesenteric arteries during surgery (n = 6) resulted in an almost 4 times higher PLI compared with not clamping these arteries (P = 0.001). In general linear models, the elevated PLI was particularly associated with suprarenal and celiac/mesenteric artery surgery, independently of aortic camping time and transfusion of blood products, even though the PLI directly correlated with aortic clamping time and number of red blood cell concentrates transfused (P = 0.031 or less).

Conclusions

This study suggests that hepatosplanchnic rather than lower body/leg ischemia/reperfusion is a major risk factor for pulmonary vascular injury, associated with aortic surgery and independent of clamping time and transfusion of blood products.

Key Words: acute lung injury, pulmonary edema, increased permeability, ischemia/reperfusion injury, left-left bypass pump, transfusion-related acute lung injury