Right atrial fat emboli detection and changes in D-dimer values in reverse shoulder arthroplasty: a comparison with total hip arthroplasty

Introduction
The underlying pathophysiology of venous thromboembolism (VTE) in upper limb surgery has been scarcely reported. This prompted us to investigate, using transoesophageal echocardiography (TEE) intraoperatively, the impact on haemodynamics in reverse shoulder arthroplasty (RSA) as compared with total hip arthroplasty (THA).

Material and methods
The subjects comprised five shoulders undergoing RSA (RSA group) in our department. In all cases TEE was performed intraoperatively, with the haemodynamic state of the right atrium and superior vena cava monitored throughout the intraoperative period. As investigated items, blood D-dimer values were measured and compared intraoperatively, on postoperative day 1, day 4, week 1, and week 2. As a control group, five cases undergoing THA under the same conditions were compared with the RSA group.

Results
Intraoperatively, in both RSA and THA groups, echogenic emboli were identified in the right atrium on TEE during bone reaming and artificial joint insertion. No significant differences were found between the two groups with respect to intraoperative or postoperative D-dimer changes. Also, in neither group was deep vein thrombosis (DVT) or pulmonary embolism (PE) detected either by lower limb venous ultrasonography or lung ventilation-perfusion scintigraphy.

Conclusions
Fat emboli occur as frequently in upper limb surgery as in lower limb surgery, and the possibility of fat embolism syndrome as a postoperative complication needs to be kept in mind. Measurement of D-dimer values is useful in the early detection of DVT in upper limb surgery.