Discussion
Our experience highlights the reliability of radical thrombectomy in massive PE cases. Thrombectomy for peripheral PE remains a challenge. Thrombectomy in acute PE surgery has often been performed in beating hearts, as we have previously reported4. The concern regarding beating surgery for PE cases is the possibility of residual peripheral PA thrombi. The advantages of pulmonary embolectomy are reduction of PA pressure immediately after surgery5and improvement of right ventricular function after surgery6, which requires more reliable thrombus removal. Some researchers have recommended gentle thrombectomy with a Fogarty catheter if the thrombus is torn off during thrombectomy to avoid PA injury and the associated pulmonary hemorrhage7. However, this approach for peripheral PE is imperfect and can lead to right ventricular failure and/or chronic thromboembolic pulmonary hypertension (CTEPH)8. To address this concern, we recently applied the CTEPH technique to treat acute PE. CTEPH surgery aims to reduce postoperative right ventricular pressure by involving a secure endarterectomy of the peripheral PA under circulatory arrest9,10. Obtaining a clear view of the right PA is also challenging in acute PE surgery; mobilizing the SVC and compressing the aorta, as described above, can facilitate the task. Furthermore, the right thrombus of the right PA is more prone to tearing than the left PA, owing to anatomical angulation issues. Even if the thrombus breaks off, as explained above, the present method allows for the removal of the thrombus from the peripheral PA. The difference with surgery for CTEPH is that the present procedure does not require circulatory arrest as a fresh thrombus is not strongly adherent to the PA wall. We believe that the cardiac arrest procedure does not adversely affect postoperative cardiac function. All patients without preoperative ECMO support were successfully weaned off CPB. Although one preoperative ECMO case was lost, both preoperative ECMO cases were successfully weaned from ECMO postoperatively. The postoperative course and computed tomography findings indicated that our procedure could accomplish radical thrombectomy of peripheral PE, resulting in low right ventricular pressure and stable hemodynamics postoperatively. Several studies have compared surgical and nonsurgical approaches5,11, but few have compared the clinical outcomes of each surgical approach. We believe that our technique can be useful for treating severe PE, and more experience should be accumulated.
Author contributions: Concept/design: HS, RK, MM. Article drafting: HS. Critical revision of the article: RK. Approval of the article: all authors.