1

Introduction

Transcatheter aortic valve replacement (T-AVR) is an emerging technology for patients with severe aortic stenosis (AS) considered high risk for open chest surgery due to co-morbid conditions and for patients who are inoperable . A T-AVR procedure using the Edwards SAPIEN transcatheter heart valve (Edwards Lifesciences, Irvine, CA) can be done by a transfemoral or transapical approach. If performing the transapical approach, the thoracotomy and ventricular access require general anesthesia. The transfemoral approach can be done under general anesthesia and intubation or under monitored anesthesia care without intubation. Performing a T-AVR procedure under monitored anesthesia care using a CoreValve prosthesis (CoreValve Inc., Irvine, CA) was reported with trend for shorter procedure time, intensive care unit stay, and overall hospital stay . Transesophageal echocardiography (TEE) may require patient sedation, eventually leading to respiratory depression, a risky condition in severe cardiac disease. As a result, most of the T-AVR procedures performed in the U.S. and worldwide when guided by TEE are done under general anesthesia with intubation. General anesthesia is associated with potential complications, particularly respiratory-related. Patients referred to T-AVR are elderly and many have co-morbidities, including lung disease, which place them at higher risk with general anesthesia.

The present study aimed to examine the feasibility and safety of T-AVR using the Edwards SAPIEN valve guided by TEE under monitored anesthesia care and to compare the procedural data and clinical outcomes of patients who underwent T-AVR with monitored anesthesia care to the outcomes of those patients who underwent T-AVR with general anesthesia.

2

Methods

This prospective cohort study was approved by the Institutional Review Board of the MedStar Health Research Institute. We consecutively enrolled 137 patients from April 2007 to January 2011 who had symptomatic severe AS and who participated in a randomized T-AVR trial [PARTNER (Placement of AoRTic traNscatheER valves)]. All patients were screened and consented for the study.

All patients had angiographic (aortogram, coronary and aorto-iliac angiogram), echocardiographic, and computed tomography (chest without contrast and abdominal with contrast) assessment before the T-AVR procedure. If coronary revascularization was required, this was carried out percutaneously before the T-AVR procedure.

The present analysis included 92 consecutive patients undergoing T-AVR guided by TEE using the Edwards SAPIEN transcatheter heart valve system via transfemoral approach; 43 patients had transapical approach and were excluded and in 2 patients the procedure was aborted due to the inability to advance the dilators beyond the common iliac. This cohort was divided into 2 groups: I, monitored anesthesia care ( n = 70; 76.1%) and II, intubation ( n = 22; 23.9%). The procedure was performed in a hybrid operating room with the capabilities of both a traditional cardiac operating room and an angiographic suite. The decision to provide general anesthesia with intubation or monitored anesthesia care was made by the anesthesiologist. During the initial experience, most of the procedures were done under general anesthesia but in later stages most of the procedures were done under monitored anesthesia care, save for cases of patients with anticipated difficulty in airway access.

Monitored anesthesia care was provided by a cardiac anesthesiologist present and ready with airway equipment and induction agents for rapid incubation if necessary. Sedation was given in 1 of the 2 protocol regimens: Propofol/Ketamine dose mix 1 cc (50 mg) of ketamine with 20 cc of propofol standard concentration 10 mg/cc, dose 10–50 ucg/kg/min or Dexmedetomidine 0.3–0.7 mcg/kg/h. Very low-dose Versed (1 mg/cc) or Fentanyl (50 ucg/cc) was administered as needed.

All patients had TEE monitoring. In cases with general anesthesia, the TEE probe was inserted after endotracheal intubation, and in cases with monitored anesthesia care the TEE probe was inserted after sedation. At the end of the procedure, the probe was removed.

All patients received 1% lidocaine subcutaneously at the arterial and venous access sites. A multi-lumen vascular introducer sheath with a large infusion port was placed in the jugular central vein followed by insertion of a pulmonary artery catheter. A radial artery catheter was placed for dedicated continuous systemic blood pressure monitoring. The femoral artery was accessed percutaneously or by surgical cut down with exposure of the common femoral. In cases using the percutaneous approach, after wire introduction, pre-closure of the artery occurred using a single Prostar XL device (Abbott Vascular Devices, Redwood City, CA) or 2 Perclose ProGlide 6F suture-mediated closure devices (Abbott Vascular Devices, Redwood City, CA). For safer percutaneous closure management, contra-lateral access was obtained as previously described . Heparin (70 unit/kg) was given to maintain an activated clotting time > 250 s when introducing the up-sizing dilators over a stiff wire and exchange for the sheath. After placement of the 22F or 24F delivery sheath, we proceeded to cross the aortic valve, dilate the valve and then deploy the prostheses. In 7 (7.6%) cases the dilators or the large sheath did not reach the common iliac, and we accessed the common iliac retroperitoneally.

After crossing the aortic valve, an Amplatz super stiff ST-1 (1 cm tip) guidewire was used. The native valve was first dilated by balloon valvuloplasty under rapid right ventricular pacing and the crimped valve balloon was advanced with a delivery catheter. The RetroFlex catheter (Edwards Lifesciences, Irvine, CA) was withdrawn into the ascending aorta and the valve was pulled to its optimal position, with 50% of the assembly on the ventricular side of the aliened sinuses.

In cases of surgical cut-down, the access site was closed surgically. In cases using the percutaneous approach, the access site was closed using a protective contra-lateral crossover technique. This technique is performed by utilizing the previously placed wire through the contra-lateral femoral artery, which allows for the crossover placement of an 8–10 mm peripheral balloon as needed. To achieve hemostasis, this peripheral balloon could be inflated to a nominal pressure just below the iliac bifurcation to control bleeding while the access site was sutured.

Continuous variables are presented as mean ± SD and categorical variables are presented as percentages. Procedure duration, intensive care unit and hospital stays are presented as median (25th, 75th percentiles). Differences between continuous variables were assessed by Student’s t test. Paired tests were analyzed by paired Student’s t test. Categorical variables were compared using the χ 2-test or Fisher’s exact test as indicated. Significance was set at p < 0.05.

2

Methods

This prospective cohort study was approved by the Institutional Review Board of the MedStar Health Research Institute. We consecutively enrolled 137 patients from April 2007 to January 2011 who had symptomatic severe AS and who participated in a randomized T-AVR trial [PARTNER (Placement of AoRTic traNscatheER valves)]. All patients were screened and consented for the study.

All patients had angiographic (aortogram, coronary and aorto-iliac angiogram), echocardiographic, and computed tomography (chest without contrast and abdominal with contrast) assessment before the T-AVR procedure. If coronary revascularization was required, this was carried out percutaneously before the T-AVR procedure.

The present analysis included 92 consecutive patients undergoing T-AVR guided by TEE using the Edwards SAPIEN transcatheter heart valve system via transfemoral approach; 43 patients had transapical approach and were excluded and in 2 patients the procedure was aborted due to the inability to advance the dilators beyond the common iliac. This cohort was divided into 2 groups: I, monitored anesthesia care ( n = 70; 76.1%) and II, intubation ( n = 22; 23.9%). The procedure was performed in a hybrid operating room with the capabilities of both a traditional cardiac operating room and an angiographic suite. The decision to provide general anesthesia with intubation or monitored anesthesia care was made by the anesthesiologist. During the initial experience, most of the procedures were done under general anesthesia but in later stages most of the procedures were done under monitored anesthesia care, save for cases of patients with anticipated difficulty in airway access.

Monitored anesthesia care was provided by a cardiac anesthesiologist present and ready with airway equipment and induction agents for rapid incubation if necessary. Sedation was given in 1 of the 2 protocol regimens: Propofol/Ketamine dose mix 1 cc (50 mg) of ketamine with 20 cc of propofol standard concentration 10 mg/cc, dose 10–50 ucg/kg/min or Dexmedetomidine 0.3–0.7 mcg/kg/h. Very low-dose Versed (1 mg/cc) or Fentanyl (50 ucg/cc) was administered as needed.

All patients had TEE monitoring. In cases with general anesthesia, the TEE probe was inserted after endotracheal intubation, and in cases with monitored anesthesia care the TEE probe was inserted after sedation. At the end of the procedure, the probe was removed.

All patients received 1% lidocaine subcutaneously at the arterial and venous access sites. A multi-lumen vascular introducer sheath with a large infusion port was placed in the jugular central vein followed by insertion of a pulmonary artery catheter. A radial artery catheter was placed for dedicated continuous systemic blood pressure monitoring. The femoral artery was accessed percutaneously or by surgical cut down with exposure of the common femoral. In cases using the percutaneous approach, after wire introduction, pre-closure of the artery occurred using a single Prostar XL device (Abbott Vascular Devices, Redwood City, CA) or 2 Perclose ProGlide 6F suture-mediated closure devices (Abbott Vascular Devices, Redwood City, CA). For safer percutaneous closure management, contra-lateral access was obtained as previously described . Heparin (70 unit/kg) was given to maintain an activated clotting time > 250 s when introducing the up-sizing dilators over a stiff wire and exchange for the sheath. After placement of the 22F or 24F delivery sheath, we proceeded to cross the aortic valve, dilate the valve and then deploy the prostheses. In 7 (7.6%) cases the dilators or the large sheath did not reach the common iliac, and we accessed the common iliac retroperitoneally.

After crossing the aortic valve, an Amplatz super stiff ST-1 (1 cm tip) guidewire was used. The native valve was first dilated by balloon valvuloplasty under rapid right ventricular pacing and the crimped valve balloon was advanced with a delivery catheter. The RetroFlex catheter (Edwards Lifesciences, Irvine, CA) was withdrawn into the ascending aorta and the valve was pulled to its optimal position, with 50% of the assembly on the ventricular side of the aliened sinuses.

In cases of surgical cut-down, the access site was closed surgically. In cases using the percutaneous approach, the access site was closed using a protective contra-lateral crossover technique. This technique is performed by utilizing the previously placed wire through the contra-lateral femoral artery, which allows for the crossover placement of an 8–10 mm peripheral balloon as needed. To achieve hemostasis, this peripheral balloon could be inflated to a nominal pressure just below the iliac bifurcation to control bleeding while the access site was sutured.

Continuous variables are presented as mean ± SD and categorical variables are presented as percentages. Procedure duration, intensive care unit and hospital stays are presented as median (25th, 75th percentiles). Differences between continuous variables were assessed by Student’s t test. Paired tests were analyzed by paired Student’s t test. Categorical variables were compared using the χ 2-test or Fisher’s exact test as indicated. Significance was set at p < 0.05.