An 83-year old woman with severe AS was scheduled for TAVI. She had had dyspnea on exertion (NYHA class III) for 10 years, and this had aggravated recently. Her past history included hypertension, pulmonary tuberculosis when younger, and percutaneous coronary stent insertion in the left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA) 5 months ago. She has taken aspirin 100 mg, clopidogrel 75 mg, and diltiazem 90 mg daily, and all of these medications were continued. Transthoracic echocardiography showed severe AS with an aortic valve area (AVA) of 0.8 cm², a mean pressure gradient of 41 mmHg and an aortic annulus diameter of 21 mm. Mild mitral regurgitation (MR) was present and the left ventricular ejection fraction was 62%. Coronary angiography (CAG) showed that all stents were patent. Computed tomography (CT) showed diffuse calcification in the abdominal aorta and no tortuosity in either common iliac artery. The right iliac artery was 13.2 mm and the right femoral artery was 8.9 mm in diameter. The logistic EuroSCORE was 14.3%.

The procedure was performed in the cardiac catheterization laboratory under general anesthesia. A 5-lead electrocardiograph, pulse oximeter, BIS sensor, and two cerebral oxymetry sensors were applied. Anesthesia was induced with etomidate 12 mg, rocuronium 50 mg, and continuous infusion of remifentanil (target effect site concentration 10 ng/ml) and propofol (target effect site concentration 1.0 µg/ml) using a target controlled infusion system (Orchestra®, Fresenius vial, Brezims, France). An intra-arterial catheter was inserted into the left radial artery and endotracheal intubation was performed. A central venous catheter (MAC™ Two-Lumen Central Venous Access set, ARROW®, Reading, PA, USA) with a Swan-Ganz catheter (Swan-Ganz CCOmbo, CCO/SvO₂/CEDV, Edwards lifesciences LLC, Irvine, CA, USA) was inserted into the right internal jugular vein for continuous monitoring of cardiac output and mixed venous oxygen saturation using continuous cardiac output monitoring (Vigilance®, Edwards lifesciences LLC, Irvine, CA, USA). During the procedure, anesthesia was maintained with oxygen (2 L/min), and continuous infusion of remifentanil (target effect site concentration 10-20 ng/ml), propofol (target effect site concentration 1.0-1.5 µg/ml) and rocuronium 0.5 µg/ml/min. Two external defibrillator pads were attached. Transesophageal echocardiography (TEE) (Live 3D TEE, iE33, Philips ultrasound, Bothell, WA, USA) was performed to confirm the aortic annulus diameter and to provide images for correct valve positioning during the procedure. Heparin (1 mg/kg) was given to achieve an activated coagulation time > 250 seconds. The left femoral vein was used for the placement of a pacing wire (Electrophysiology catheter, St. Jude Medical®, St. Paul, MN, USA) in the right ventricular apex and the left femoral artery was used for insertion of a pigtail catheter in the aortic root. Surgical exposure of the right femoral artery was performed and a 12 French introducer was inserted. Balloon valvuloplasty was successfully performed under rapid ventricular pacing (RVP) of 200 beats/min (Dual chamber temporary pacemaker, Medtronic®, Minneapolis, MN, USA) (Fig. 1). The duration of cardiac standstill during RVP was less than 10 seconds. Blood pressure and cardiac rhythm were restored well after RVP. Systolic blood pressure was 110-140 mmHg and diastolic blood pressure was 50-60 mmHg before and after RVP. The 12 French sheath was exchanged with a 24 French introducer sheath. Althought preoperative CT indicated that the right femoral artery was large enough for a 24 French introducer, it was a tight fit during the procedure, and insertion required the cardiologist to exert more force than anticipated. A 23 mm Edward-Sapien valve (Edwards Lifesciences LLC, Irvine, CA, USA) crimped onto a balloon was then advanced into the aortic annulus. The optimal prosthetic valve position was confirmed using TEE and fluoroscopy. The balloon was inflated after RVP. However, the prosthetic valve was ejected into the ascending aorta and moved down to the descending thoracic aorta. TEE was performed immediately and showed that the valve was packed in the descending thoracic aorta. However, there was no flow disturbance around the valve and the vital signs were stable. The cardiologist made a decision to leave the valve in place and insert another valve. The second valve crimped onto a balloon was advanced through the embolized valve. RVP was repeated several times to enable correct positioning and intermittent bolus injections of phenylephrine (100 µg/ml) were used without continuous infusion of a vasopressor. The second trial was successful. TEE showed that the valve was stable and there was no paravalvular leakage. A root aortogram showed patent coronary arteries and no paravalvular leakage or aortic regurgitation (AR) (Fig. 2). After confirmation of valve function, the cardiac surgeon tried to remove the 24 French introducer, but initially found that it would not move in any direction. After approximately 30 minutes of manipulation, the surgeon was able to move the introducer backward. At that time, the mean arterial pressure abruptly decreased to 30 mmHg. Angiography was performed and showed a right external iliac artery rupture. Packed red blood cells and colloid solutions were rapidly infused. The cardiologist inserted the balloon catheter into the descending aorta and inflated the balloon. A vascular surgeon performed an emergecy laparotomy and clamped the proximal side of the right external iliac artery. The patient was then sent to the operating room. The 24 French introducer was removed (Fig. 3) and an emergency femorofemoral bypass was performed. The total infused fluid volume was 14 units of packed red blood cells, 10 units of fresh frozen plasma, 10 units of platelets, 1,500 ml of cell saver blood, 4,400 ml of crystalloid solutions and 1,000 ml of colloid solutions. On post-operative day 1, the patient was mentally alert, had good motor and sensory nerve function, and a normal pulse in her right lower extremity. Echocardiography showed a well-functioning prosthetic aortic valve, a mean pressure gradient of 16 mmHg, mild paravalvular leakage and mild AR. Chest radiography showed no migration of the embolized valve (Fig. 4). The patient was extubated on postoperative day 2 and sent to the general ward. The prosthetic aortic valve was functioning stable, however, the patient had ileus till post-operative day 30.

An 84-year old woman with severe AS was scheduled for TAVI. Her past history included hypertension, pulmonary tuberculosis when younger, and intermediate stenosis of LAD and LCX. She has taken aspirin 100 mg, isosorbide dinitrate 40 mg, and atenolol 50 mg daily, and all of these medications were continued. Transthoracic echocardiography showed severe AS with an AVA of 0.8 cm², a mean pressure gradient of 40 mmHg and an aortic annulus diameter of 21.5 mm. Mild AR and mild MR were present. The left ventricular ejection fraction was 66% and mild to moderate atherosclerosis was present in the descending thoracic aorta and aortic arch. CAG showed 70-80% stenosis at the distal LAD and distal LCX. CT showed patent non-tortuous iliac and femoral arteries (the right iliac artery was 8.5 mm and right femoral artery was 7.3 mm in diameter). The logistic EuroSCORE was 6.14%.

The anesthetic preparation was identical as that for case 1. Isosorbide dinitrate 1.0 µg/kg/min was continuously infused after induction. Heparin (1 µg/kg) was given to achieve an activated coagulation time > 250 seconds. Balloon valvuloplasty was successfully performed under RVP. Blood pressure and cardiac rhythm were restored well after RVP. Systolic blood pressure was 90-120 mmHg and diastolic blood pressure was 50-60 mmHg before and after RVP. However, ST segment elevation was observed in lead II and V, and worsened after repeated RVP. The infusion rate of isosorbide dinitrate was therefore increased and intermittent bolus injections of phenylephrine (100 µg/ml) were used. Prosthetic aortic valve implantation was successfully performed and ST segment elevation improved to the normal range. TEE showed a stable valve position and no paravalvular leakage (Fig. 5). A root aortogram showed patent coronary arteries and trace AR. After confirmation of valve function, a new-onset left bundle branch block was observed. The 24 French introducer was easily removed. The procedure took a total of 105 minutes. The patient was extubated uneventfully and sent to the ICU. Although she occasionally complained of chest discomfort without pain, electrocardiography and cardiac enzymes findings remained normal, and the symptoms resolved within 3 hours. The isosorbide dinitrate infusion was ceased, and she continued on her pre-operative oral medications with the addition of clopidogrel 75 mg. The patient was sent to the general ward on post-operative day 1, and showed no signs of complications. Echocardiography showed a satisfactorily functioning prosthetic aortic valve, a mean pressure gradient of 21 mmHg and mild AR. The patient was well at 30-day follow-up.