Aortic Valve Bypass Surgery Research Articles

Effect of minimally invasive cardiac surgery on hospital length of stay: A systematic review and meta-analysis

Background: Perioperative management using minimally invasive cardiac surgery (MICS), compared to full sternotomy (FS) cardiac surgery, is considered to improve postoperative recovery, and reduce hospital length of stay (LOS). Methods: A comprehensive systematic search was conducted across MEDLINE/PubMed, Embase, and the Cochrane library to identify RCT comparing MICS to FS approach for aortic valve, mitral valve, and coronary artery bypass surgery. Meta-analysis of extracted data was performed using random effects models. Results: A total of 33 RCTs including 2920 patients were identified. Overall MD (95% CI) for hospital and intensive care unit (ICU) LOS after MICS was significantly shorter compared to FS (-0.88 days (-1.55;-0.20), p<0.013; 2606 patients) and (-0.23 days (-0.41;-0.05), p=0.012; 2242 patients), respectively. Additionally, postoperative blood loss was reduced with the use of MICS, (-192.07 ml (-292.32;-91.82), p=0.002; 718 patients). There was no evidence for differences between both groups in terms of postoperative ventilation times, duration of surgery, reintervention rate, incidence of postoperative atrial fibrillation or stroke, hospital mortality, or 1-year mortality. Conclusion: Within the limitations of a meta-analysis, MICS was found to be effective in promoting faster recovery by reducing postoperative blood loss, ICU, and hospital LOS.

Postoperative cardiac biomarker release is not associated with myocardial mass in computer tomography scans.

Myocardial hypertrophy results in increased levels of cardiac biomarkers in healthy individuals and in patients suffering from acute myocardial infarction. The influence of cardiac mass on postoperative cardiac biomarkers release remains unclear. This study investigated the correlation between myocardial mass and the release of high-sensitivity cardiac Troponin T (hs-cTnT) and creatine kinase-myocardial band (CK-MB) after isolated aortic valve replacement (AVR) or bypass surgery. Myocardial mass of a consecutive retrospective series of patients was measured automatically using preoperative computer tomography scans (636 patients, AVR = 251; bypass surgery = 385). Levels of cardiac biomarkers were measured before and serially after surgery. Spearman and Pearson correlation and a multivariate regression model was performed to measure the degree of association between myocardial mass and the release of hs-cTnT and CK-MB. Patients were divided into 3 tertiles according to their myocardial mass index. Higher biomarker levels were measured preoperatively in the upper tertile of patients undergoing AVR (P = 0.004) or bypass surgery (P < 0.001). Patients with different heart sizes showed no differences in postoperative biomarker release neither after AVR nor bypass surgery. No statistical significant correlation was observed between myocardial mass index and postoperative release of hs-cTnT or CK-MB in any subgroup (ρ maximum 0.106). Postoperative biomarker release is not correlated with myocardial mass. Patient factors leading to increased postoperative biomarker levels need to be elucidated in future studies.

Remote ischaemic preconditioning in isolated aortic valve and coronary artery bypass surgery: a randomized trial†.

This trial was designed and patients were recruited at a time when the benefits of remote ischaemic preconditioning during open-heart surgery were still controversial. We focused on a homogeneous patient population undergoing either isolated aortic valve replacement or coronary artery bypass grafting (CABG) surgery by investigating cardiac injury, metabolic stress and inflammatory response. A 2-centre randomized controlled trial recruited a total of 124 patients between February 2013 and April 2015. Of them, 64 patients underwent CABG and 60 patients underwent aortic valve replacement. Patients were randomized to either sham or preconditioning. Remote ischaemic preconditioning was applied following anaesthesia and before sternotomy. Myocardial injury and inflammatory response were assessed by serially measuring cardiac troponin I, and interleukin-6, 8, 10 and the tumour necrosis factor (TNF-α). Biopsies from the left and the right ventricles were harvested after ischaemic reperfusion injury for nucleotides analysis. Application of remote ischaemic preconditioning did not alter the degree of troponin I release, levels of inflammatory markers and cardiac energetics in both the CABG and the aortic valve replacement groups. Preconditioning did not confer any additional cardioprotection in terms of reducing the levels of troponin I and inflammatory markers and preserving left and right ventricle energy metabolites in patients undergoing isolated CABG or aortic valve surgery. International Standard Randomized Controlled Trial Number (ISRCTN) registry ID 33084113 (doi: 10.1186/ISRCTN33084113) and UK controlled randomized trial number (UKCRN) registry ID 13672.

To revascularize or not before transcatheter aortic valve implantation?

Concomitant coronary artery disease (CAD) and aortic stenosis occur in approximately 60-75% of patients referred for surgical or transcatheter aortic valve replacement (TAVR). Current guidelines support simultaneous surgical aortic valve replacement and bypass surgery with a class IIa recommendation, based on observational, non-randomized data. With the inception of TAVR, this strategy has been challenged, as observational studies have not shown significant outcome differences in patients with and without CAD treated with TAVR. Performing percutaneous coronary intervention (PCI) in patients with aortic stenosis is safe, but the indication and timing remain controversial. Complete revascularization before TAVR with low residual Syntax score (<8) may be considered in selected cases with extensive, proximal, and severe CAD to improve outcomes. PCI before TAVR may require less contrast and reduce the risk of acute kidney injury, but uninterrupted dual antiplatelet therapy may increase the risk of bleeding during TAVR. Combined PCI and TAVR can be considered for unstable patients with simple lesions or ostial lesions, with risk of coronary occlusion after deployment of the transcatheter heart valve. PCI after TAVR may be considered in patients who remain symptomatic with significant residual ischemia despite optimal medical therapy. In the near future, it is expected that randomized clinical trials will further clarify the indications and role of revascularization in patients undergoing TAVR. In this article we provide an extensive review on the management of CAD in TAVR candidates, including additional considerations on technical aspects, device selection, and adjunctive pharmacological therapies.

Aortic valve bypass surgery in severe aortic valve stenosis: Insights from cardiac and brain magnetic resonance imaging

ObjectiveTo investigate and describe the distribution of aortic and cerebral blood flow (CBF) in patients with severe valvular aortic stenosis (AS) before and after aortic valve bypass (AVB) surgery. MethodsWe enrolled 10 consecutive patients who underwent AVB surgery for severe AS. Cardiovascular magnetic resonance imaging (CMR) and brain magnetic resonance imaging were performed as baseline before surgery and twice after surgery. Quantitative flow measurements were obtained using 1.5-T magnetic resonance imaging (MRI) scanner phase-contrast images of the ascending aorta, descending thoracic aorta (3 cm proximally and distally from the conduit-to-aorta anastomosis), and ventricular outflow portion of the conduit. The evaluation of CBF was performed using 3.0-T MRI scanner arterial spin labeling (ASL) through sequences acquired at the gray matter, dorsal default-mode network, and sensorimotor levels. ResultsConduit flow, expressed as the percentage of total antegrade flow through the conduit, was 63.5 ± 8% and 67.8 ± 7% on early and mid-term postoperative CMR, respectively (P < .05). Retrograde perfusion from the level of the conduit insertion in the descending thoracic aorta toward the aortic arch accounted for 6.9% of total cardiac output and 11% of total conduit flow. We did not observe any significant reduction in left ventricular stroke volume at postoperative evaluation compared with preoperative evaluation (P = .435). No differences were observed between preoperative and postoperative CBF at the gray matter, dorsal default-mode network, and sensorimotor levels (P = .394). ConclusionsAfter AVB surgery in patients with severe AS, cardiac output is split between the native left ventricular outflow tract and the apico-aortic bypass, with two-thirds of the total antegrade flow passing through the latter and one-third passing through the former. In our experience, CBF assessment confirms that the flow redistribution does not jeopardize cerebral blood supply.

Abstract 17048: Prognostic Implication of Enlarged Left Ventricle in Patients Who Underwent Valve Surgery due to Mitral Valve Prolapse or Flail Mitral Valve: Volume versus Dimension

Introduction: Left ventricular end-systolic dimension (LVESD) has been being used to guide the optimal timing of surgery in patients with mitral valve prolapse (MVP) or flail mitral valve (FMV). We sought to evaluate whether LVES volume (LVESV) measured by echocardiography can provide additive prognostic information. Methods: Of patients who underwent MV surgery due to MVP or FMV from 2000 to 2014, after exclusion of patients whose rhythm was atrial fibrillation or who needed concomitant maze procedure, aortic valve or coronary bypass surgery, a total of 648 patients (age 51±14 years; ejection fraction 64±7%; LVESD 38±6 mm; LVESV 60±26 mL; repair/replacement = 612/36) was selected. Clinical outcomes included cardiovascular (CV) death, admission due to heart failure (HF) and development of LV dysfunction (EF &lt;45% at the last follow-up). Results: During median follow up of 4.2 years (interquartile range, 1.8-6.6 years), 5 patients died of CV death, 36 admitted for HF, and 38 developed LV dysfunction. Increased LVESD (≥45mm) could not predict CV death. But patients with enlarged LVESV index (LVESV/ body surface area ≥50 ml/m 2 , n=64, 10%) showed higher rate of CV death (p=0.04), HF admission (p=0.04) and composite clinical events (p&lt;0.001). In multivariate regression analysis, enlarged LVESV index was the only independent variable associated with composite clinical events (hazard ratio 2.67, 95% confidence interval 1.39-5.13, p=0.003). Conclusions: In the modern era of MV repair surgery for MVP and FMV, LV volume provides more robust prognostic information than LV dimension.

Hemodynamic changes following aortic valve bypass: a mathematical approach.

Aortic valve bypass (AVB) has been shown to be a viable solution for patients with severe aortic stenosis (AS). Under this circumstance, the left ventricle (LV) has a double outlet. The objective was to develop a mathematical model capable of evaluating the hemodynamic performance following the AVB surgery. A mathematical model that captures the interaction between LV, AS, arterial system, and AVB was developed. This model uses a limited number of parameters that all can be non-invasively measured using patient data. The model was validated using in vivo data from the literature. The model was used to determine the effect of different AVB and AS configurations on flow proportion and pressure of the aortic valve and the AVB. Results showed that the AVB leads to a significant reduction in transvalvular pressure gradient. The percentage of flow through the AVB can range from 55.47% to 69.43% following AVB with a severe AS. LV stroke work was also significantly reduced following the AVB surgery and reached a value of around 1.2 J for several AS severities. Findings of this study suggest: 1) the AVB leads to a significant reduction in transvalvular pressure gradients; 2) flow distribution between the AS and the AVB is significantly affected by the conduit valve size; 3) the AVB leads to a significant reduction in LV stroke work; and 4) hemodynamic performance variations can be estimated using the model.

EComment. Aortic thrombus after aortic valve bypass surgery

Conventional aortic valve replacement (AVR) carries significant operative risks, especially in the elderly, high-risk patients with severe aortic valve stenosis including porcelain ascending aorta, complex left ventricular outflow tract obstruction, previous cardiac surgery (patent coronary grafts) or prior sternal infection, and previous radiation to the mediastinum. Transcatheter aortic valve implantation (TAVI) is an alternative therapeutic option in these complicated situations. Nevertheless, TAVI has some limitations in patients with severe aorto-iliac disease, small aortic annulus (<18 mm), and previous prosthetic valve. It is associated with an increased incidence of major stroke, an injury to atrioventricular conduction system, and major vascular complications. Due to a higher incidence of complications of TAVI, aortic valve bypass (AVB, apicoaortic conduit) surgery may be a therapeutic means of choice in high-risk patient populations with comorbidities. We read the article by Lund et al. [1] with great interest. The authors have shared with us their Danish experiences regarding AVB. They are to be commended for reminding us of another alternative in the armamentarium for the treatment of severe aortic stenosis. The authors clearly stated the benefits of AVB. However, there is mention of a few serious complications. We would like to add a short comment concerning the complications of AVB. AVB involves the use of a valved conduit to connect the left ventricular apex to the descending aorta, thereby providing an additional outlet for blood flow and relieving the left ventricular pressure overload. Despite these advantages, there are likely concerns about malperfusion, aortic stasis and the potential for complications concerning the conduit. The potential complications of AVB include bleeding, thromboembolic events, porcine valve deterioration, endocarditis, myocardial infarction, arrhythmias, pseudoaneurysm formation of left ventricular apex graft anastomosis, conduit dehiscence from left ventricular apex, ventricular septal defect as reported by the authors, and thrombus formation in the aorta. Aortic thrombus is a rare moribund complication of AVB and needs to be recognized. There have been some case reports of thrombus formation in the ascending aorta possibly caused by stagnation of native antegrade blood flow and fractionation of the cardiac output [2-5]. Parsa et al. [2] reported catastrophic complication of thrombus in the aortic root after AVB in a patient with severely left ventricular dysfunction, which required a left ventricular assist device. On the contrary, Takeda et al. [3] reported unusual thrombus formation in the aortic arch after AVB for severe aortic stenosis with good left ventricular ejection fraction. Kotani et al. [4], by postoperative cine MRI study, reported that 29% of the cardiac output occurred through the native aortic valve but antegrade flow had decreased to 6% of the cardiac output at one year after surgery. Takahashi et al. [5] described that thrombus formation may be due to flow competition after AVB, especially in cases with poor left ventricular function. Despite these undesired complications, we think that AVB still remains a safe and alternative option for a few high-risk complex patients in whom surgical AVR or TAVI is not feasible. Conflict of interest: none declared.

Transcatheter Aortic Valve Replacement as a Treatment for Late Apicoaortic Conduit Obstruction in a Patient With Severe Aortic Stenosis

A 62-year–old man presented with progressive exertional dyspnea and angina. His past medical history is notable for coronary artery disease, for which he underwent a coronary artery bypass graft surgery 8 years earlier. A few years afterward, he underwent aortic valve (AV) bypass (AVB) surgery for severe aortic stenosis (AS) using an apicoaortic conduit to the descending aorta consisting of a 16-mm connector and an 18-mm valved conduit (Hancock valve; Medtronic, Minneapolis, MN; Figures 1 and 2; online-only Data Supplement Movie I). After a period of initial improvement in symptoms, the patient developed progressive dyspnea and angina and was referred for additional cardiac workup. Figure 1. An ECG-gated thin-slice contrast-enhanced cardiac computed tomography scan showing a heavily calcified native aortic valve (AV), hypertrophied left ventricle (LV), and the apical LV insertion site of the apicoaortic valved conduit. Figure 2. A 3-dimensional cardiac computed tomography reconstruction image showing the apicoaortic valved conduit, extending from its apical insertion site into the left ventricle (LV) to its insertion site into the descending aorta. Arrow , Conduit valve. The patient underwent a bicycle ergometer test, which showed a diminished functional capacity and was stopped because of fatigue and a hypotensive response. He underwent a 2-dimensional transthoracic echocardiogram with gradual dobutamine infusion. He was found to have a heavily calcified AV (online-only Data Supplement Movie II) with a rest mean transvalvular gradient of 34 mm Hg and velocity of 3.5 m/s, which increased to 50 mm Hg and 4.8 m/s, respectively, at peak dobutamine dose (Figure 3). This corresponded with a …

Another Use for Transesophageal Echocardiography During Aortic Valve Bypass Surgery

Another Use for Transesophageal Echocardiography During Aortic Valve Bypass Surgery

Hemodynamic characterization of Aortic Valve Bypass Surgery (AVBS) using patient-specific computational models based on MRA and PCMR

Background AVBS is an option for patients who suffer from both aortic valve stenosis and severe ascending aortic calcification. In AVBS, a conduit containing a prosthetic valve is introduced into the LV transapically and attached to the descending thoracic aorta (Fig 1). However, AVBS patients tend to suffer from a higher number of cerebral events, and intra-aortic thrombus has been reported (Kotani et al, ICVTS, 2009). The objective of this study is to use Magnetic Resonance Angiography (MRA), Phase Contrast Magnetic Resonance (PCMR), and Computational Fluid Dynamics (CFD) to understand the hemodynamics of AVBS in order to correlate how flow patterns may relate to post-surgical complications.

Post-surgical hemodynamics in aortic valve bypass (AVB) patients evaluated with phase contrast magnetic resonance (PCMR)

Background Many high-risk patients with severe aortic stenosis cannot undergo valve replacement surgery due to calcification of the ascending aorta. Aortic valve bypass (AVB) surgery uses a conduit and prosthetic valve placed transapically into the left ventricle to divert flow from the apex of the heart through the conduit and prosthetic valve to the descending thoracic aorta to improve cardiac output, Fig 1. The hemodynamics resulting from AVB are not well understood. Specifically, there appears to be significant patient-to-patient variability in the amount of retrograde blood flow in the descending thoracic aorta (location 3, flow from conduit to arch vessels). The objective of this study is to use phase contrast magnetic resonance (PCMR) to examine the hemodynamics in AVB patients and determine the relationship between pre-surgery native aortic valve pressure gradient and post-surgery retrograde blood flow in the thoracic aorta.

Management of Aortic Valve Bypass Surgery

The 3 leading causes of aortic stenosis (AS) in adults are calcific degeneration of a normal trileaflet aortic valve (AV), calcific degeneration of a congenital bicuspid AV, and rheumatic AS. Therapeutic options in patients with severe AS include aortic valve replacement (AVR), transcatheter aortic valve implantation (TAVI), or aortic valve bypass (AVB). An AVB involves the placement of a valved conduit between the apex of the left ventricle and the descending thoracic aorta. AVB serves as a useful alternative to treat severe AS in patients deemed high risk for conventional AVR (ie, porcelain aorta, previous cardiac surgery) or TAVI (ie, severe aorto-iliac disease, limited experience, lack of hybrid operating room). Advantages of on-pump AVB include the avoidance of aortic cannulation, cross-clamping, and cardioplegic cardiac arrest. The procedure can also be performed without cardiopulmonary bypass. In this article, the authors review the circulatory physiology, perioperative anesthetic management, the role of intraoperative transesophageal echocardiography, and surgical considerations of AVB surgery through 3 cases.

EComment. Extra-anatomic aortic valve bypass

We have read with interest the report by Domoto and colleagues [1]. Extra-anatomic aortic valve bypass (or apico-aortic conduit) has been adapted to selected high risk patients as an alternative to conventional aortic valve replacement and is based on the experimental work of Alexis Carrel [1–3]. In May 1910, Alexis Carrel (1873–1944) presented his work on experimental surgery of the thoracic aorta and the heart to the American Surgical Association [3]. Notably, at this time, cardiac surgery was limited to the treatment of penetrating wounds of the heart [3]. The poor results of thoracic surgery in the laboratory and in the theatre motivated Carrel to begin experiments with the hope of improving, or finding new surgical methods for the treatment of vascular and valvular diseases of the heart and aneurysms of the thoracic aorta [3]. In an attempt to develop a technique of diverting the blood, whilst avoiding neurological complications, for the treatment of aneurysms of the thoracic aorta, he described both central and lateral diversion of the blood. Lateral diversion consisted of an anastomosis between the left ventricle and the descending aorta through a paraffined rubber tube or a jugular vein (preserved in cold storage) [3]. These experiments were carried out at the Rockefeller Institute for Medical Research, in New York, and he was awarded the Nobel Prize in Medicine in 1912 (the first one of its kind in USA). In 1955, Sarnoff et al. developed the apico-aortic conduit concept further and were able to direct the entire cardiac output from the left ventricle to the thoracic aorta (in animals), using a Hufnagel valve in a lucite tube and permanently occluding the ascending aorta [4]. In 1975, Cooley reported on the 1962–1963 experience of Templeton who implanted Sarnoff's prosthesis in five patients with one 10 year long-term survivor, and Cooley further popularised the apico-aortic conduit procedure [5]. Indications for aortic valve bypass surgery, apart from those reported by Domoto et al., include patients with previous complex cardiac operations (Cabrol and homograft/root replacements) that preclude a safe re-sternotomy, sternal wound infection, regional radiotherapy, failed aortic annular augmentation procedures and patients with complex congenital LV outflow obstruction [1,2]. Specific complications include bleeding, thrombus formation in the aorta, hence the need for anticoagulation or antiplatelet treatment, as well as formation of pseudo-aneurysm or dehiscence from the LV apex in a number of patients [1,2]. Today, with the advent of transcatheter aortic valve implantation (TAVI), the need for the more invasive apico-aortic conduit approach has significantly diminished, but still remains an option for a few complex patients in whom TAVI is not an option. Conflict of interest: none declared.

Automated Coring and Apical Connector Insertion Device for Aortic Valve Bypass Surgery

The technical difficulty of performing the left ventricular apical anastomosis has limited the adoption of aortic valve bypass surgery for the treatment of aortic stenosis. We report the successful use of an automated coring and apical connector device to perform aortic valve bypass surgery. A 74-year-old man, with a history of prior coronary bypass surgery with patent grafts and a porcelain ascending aorta, presented with symptomatic critical aortic stenosis. Through a left anterolateral thoracotomy, a valved conduit was anastomosed to the descending thoracic aorta. The automated coring and apical connector insertion device was used to core a plug of apical myocardium and simultaneously insert an 18-mm apical connector into the left ventricular apex. There were no procedural complications, cardiopulmonary bypass was not used, and estimated blood loss was minimal. The patient was discharged on postoperative day 5, and at 3-month follow-up demonstrated significant clinical and hemodynamic improvement. The automated coring and apical connector insertion device facilitated the safe and effective performance of aortic valve bypass surgery.

Preoperative Levosimendan Infusion in Combined Aortic Valve and Coronary Artery Bypass Surgery

Leppikangas, H.*; Järvelä, K.†; Sisto, T.†; Maaranen, P.†; Virtanen, M.†; Lehto, P.†; Karlsson, S.‡; Kööbi, T.§; Lindgren, L.* Author Information

Robotic-Assisted Aortic Valve Bypass (Apicoaortic Conduit) for Aortic Stenosis

Aortic valve bypass (AVB [apicoaortic conduit]) surgery consists of the construction of a valved conduit between the left ventricular apex and the descending thoracic aorta. In our institution, AVB is routinely performed without cardiopulmonary bypass or manipulation of the ascending aorta or native aortic valve. We report the case of an 83-year-old man with severe symptomatic bioprosthetic aortic stenosis, chronic thrombocytopenia, and a patent bypass graft who underwent robotically assisted beating-heart AVB through an anterior minithoracotomy. The distal anastomosis was constructed entirely using robotic telemanipulation. Robotic assistance enables the performance of beating-heart AVB through a small incision.

Preoperative levosimendan infusion in combined aortic valve and coronary bypass surgery

BackgroundCardiopulmonary bypass may have detrimental effects on intestinal function and decrease the concentrations of the active, long-acting metabolites of levosimendan, an inodilator used to improve cardiac function. The aim of this study was to evaluate the haemodynamic effects of preoperative levosimendan in patients undergoing high-risk cardiac surgery. MethodsTwenty-four patients were randomized to receive levosimendan (12 µg bolus followed by an infusion of 0.2 µg kg−1 min−1) or a placebo 24 h before surgery. The inclusion criteria were left ventricular ejection fraction (LVEF) <50% or LV hypertrophy indicated by a wall thickness of >12 mm. Haemodynamics were recorded every hour for 24 h (pulmonary artery catheter) and daily until postoperative day 4 (whole-body impedance cardiography). Doppler echocardiography with tissue Doppler imaging was used to assess systolic and diastolic cardiac function. ResultsThe cardiac index (CI) and stroke volume index (SI) were higher in the levosimendan group (LG) for the 4 day postoperative period (P<0.05); on the fourth postoperative day, the CI was 3.0 litre m−2 min−1 in the LG compared with 2.4 litre m−2 min−1 in the control group (CG) and the SI was 30 vs 25 ml m−2, respectively. The LVEF measured at baseline and on the fourth postoperative morning decreased in the CG, but was maintained in the LG. ConclusionsLevosimendan improved haemodynamics compared with a placebo in patients undergoing high-risk cardiac surgery. The concentrations of levosimendan’s metabolites were higher compared with earlier studies using perioperative dosing.URL: https://register.clinicaltrials.govClinicalTrials.gov Identifier: NCT01210976

Outcomes of Off-Pump Aortic Valve Bypass Surgery for the Relief of Aortic Stenosis in Adults

Elderly patients with aortic stenosis presenting for an aortic valve replacement with a hostile ascending aorta remain a challenging patient cohort. The purpose of this study was to assess outcomes after the use of an aortic valve bypass performed without cardiopulmonary bypass. A retrospective review was performed on 21 high-risk patients who underwent primary, isolated aortic valve bypass from September 2004 to June 2009 at Emory Healthcare Hospitals. Aortic valve bypass was used for a porcelain aorta alone in 6 (28.6%) patients, previous coronary artery bypass grafting in 4 (19.0%), or both in 10 (47.6%). One patient (4.8%) was thought not to be a candidate for cardiopulmonary bypass secondary to a severe cirrhosis. Mean age was 73.9±7.0 years (median, 75.0 years), and 15 patients (71.4%) were male. Mean New York Heart Association classification was 3.0±1.0 (median, 3.0), and preoperative ejection fraction was 0.460±0.163 (median, 0.500). Preoperative comorbidities included peripheral vascular disease (n=10; 47.6%), chronic lung disease (n=16; 76.2%), diabetes mellitus (n=10; 47.6%), and dialysis-dependence (n=2; 9.5%). Either an 18-mm (n=11; 52.4%) or 20-mm (n=10; 47.6%) conduit was used, with an interposed Freestyle 21 porcine root in all patients. All operations were performed without cardiopulmonary bypass. There were no intraoperative mortalities. The mean intensive care unit stay was 133.7±161.3 hours (median, 80.2 hours), and overall postoperative length of stay was 12.9±10.8 days (median, 9.0 days). In-hospital mortality occurred in 3 patients (14.3%). Mid-term follow-up shows an additional 4 patients died at a median follow-up of 1.3 years. Aortic valve bypass without cardiopulmonary bypass is a feasible alternative for the treatment of severe aortic stenosis with acceptable short-term morbidity and minimal mortality in this extremely high-risk surgical population.

Inducible left ventricular obstruction after apical-conduit aortic valve bypass surgery

In recent years, apical-aortic bypass surgery has been used for patients with a heavily calcified or ‘‘porcelain’’ ascending aorta or hostile mediastinum because these patients would be at high risk for cerebrovascular events during crossclamping of the calcified ascending aorta. In this case, we describe a previously unreported complication of apical aortic bypass and illustrate the role of cardiac catheterization and ventriculography in the hemodynamic evaluation of this patient.