Figure 1.

Surgical procedure and pressure determination at the constriction site. The constriction site (CS) was at the descending aorta segment (A). During the surgery, volatile anesthetic with isoflurane was used for the maintenance of general anesthesia (B). After pre-operative skin preparation (C), an incision was made and a combination of electrosurgical and blunt dissection techniques was used to separate muscle layers (D). The descending segment of the aorta located under the fourth to fifth intercostal space was exposed (E,F). After determining the constriction site, two pressure sensors were placed on the segment proximal to the heart (S1) and after (on the segment distal to the heart, S2) the constriction site (G). The pressures at S1 and S2 were displayed over the ECG monitor (H). When the pressure at S1 (PS1) reached 120% of that at S2 (PS2), the sutures were then secured with surgical knots (I). The aorta (a), accessory hemiazygos vein (b), and lung (c) were shown in (E–G,I).