208 T . Takeichi et al .: J Extra Corpor Technol 2024 , 56 , 207 – 210
Figure
1 . ( a ) Preoperative 3D CT images . ( b – d ), preoperative contrast-enhanced CT images from the abdominal aorta extending to the iliac arteries . CT : Computed Tomography .
tomography ( CT ) demonstrated the SVG traversing the right atrium , raising concerns about the feasibility of retrograde cardioplegia ( Figure 1a ). Additionally , contrast-enhanced CT scans revealed calcification extending from the abdominal aorta to the iliac arteries ( Figures 1b – 1d ). The patient exhibited a low left ventricular ejection fraction ( 30 %), chronic kidney disease ( estimated glomerular filtration rate : 21 mL / min / 1.73m 2 ; creatinine : 2.42 mg / dL ), and a predicted mortality rate of 20 %. The surgical strategy entailed a totally endoscopic redo-MVR .
Upon induction of general anesthesia , the patient underwent redo-MVR via a right mini-thoracotomy without rib spreading . CPB was initiated with a 23 / 25Fr venous cannula ( MICS Cannulae ; LivaNova , Tokyo , Japan ) in the right femoral vein and an 18Fr arterial cannula ( PCKC-A , MERA , Tokyo , Japan ) in the right femoral artery . The pump flow rate was maintained at 2.0 L / min / m 2 , with mean arterial pressure stabilized at 70 mmHg . To mitigate postoperative oliguria due to impaired renal function , continuous administration of furosemide ( 45mL of 20 % mannitol + 50 mg of furosemide ) at 10 mL / h was planned alongside intraoperative hemodialysis via gravity drainage hemodiafiltration ( GHDF ) using a saline solution as dialysate ( Figure 2 ). Although the target temperature was initially set at 30.0 ° C , it was adjusted to 28.0 ° C due to anticipated difficulties with ACC and the patient ’ s mild aortic regurgitation . Cold blood cardioplegia was administered via the aortic root after cross-clamping the ascending aorta , resulting in prompt cardiac arrest .
Figure 2 . Gravity drainage hemodiafiltration method .
The left atrium was opened , the artificial valve was removed , and antegrade cardioplegia was re-administered after repositioning the retractor holding the left atrium . However , aortic root pressure remained low at 20 mmHg despite multiple attempts at re-cross-clamping . Efforts to switch to retrograde cardioplegia were thwarted by significant adhesions of the inferior vena cava ( IVC ) and the bypass graft ( SVG-4PD ),