# Impact of Left Atrial Hemodynamics on the Development of Pulmonary Vein Stump Thrombus: Results of Early and Late Postoperative Studies

## TL;DR

This study shows that risky blood flow patterns near the pulmonary vein stump after surgery predict the development of blood clots, both early and late after surgery.

## Contribution

The study demonstrates that hemodynamic risk assessment remains valid for predicting PVST even in the late postoperative period.

## Key findings

- PVST developed only in patients classified as hemodynamically risky.
- Late postoperative hemodynamic assessments help identify high-risk patients for PVST.
- Risky hemodynamics persist beyond the early postoperative period.

## Abstract

Pulmonary vein stump thrombus (PVST) is a relatively common complication after left upper lobectomy that can cause vital organ embolism. We previously found that patients with PVST on postoperative day 7 show risky hemodynamic features around the pulmonary vein stump on 4-dimensional (4D) flow magnetic resonance imaging (MRI), which may contribute to thrombus development. However, it remains unclear whether such hemodynamics persist later.

Eleven patients who underwent left upper lobectomy for lung cancer received 4D flow MRI on postoperative day 7 and again after over 3 months. Hemodynamic parameters were used to classify each case as risky or non-risky for PVST.

According to a total of 24 examinations in 11 patients, 7 were classified as risky and 17 as non-risky. PVST developed in 6 patients during various postoperative phases, and all PVST cases developed under the risky conditions. Furthermore, PVST did not develop under non-risky conditions, suggesting that our risk assessment is valid as a predictive marker for PVST.

Our results suggest that late postoperative hemodynamic assessments, as well as early postoperative assessments, are useful for identifying patients at high risk of PVST. A late postoperative hemodynamic assessment may contribute to determining when to discontinue anticoagulants.