Left Ventricular Outflow Tract Reconstruction Research Articles

Modified composite-graft technique for aortic root replacement.

This report describes a novel modification of a self-assembled composite graft to replace the aortic root and left ventricular outflow tract (LVOT). This technique enables the implantation of a larger valve than conventional ways and simultaneous reconstruction of LVOT. This technique comprises Inspiris Resilia aortic valve and Gelweave Valsalva graft. By placing the valve in the sinus portion of the graft, the bioprosthesis that is 1mm smaller than the graft can be accommodated, providing a proper length of the collar for LVOT reconstruction. This technique is useful for patients who require redo-aortic root replacement and have restricted LVOT.

In Situ Composition of Valved Conduit for Complex Reoperative Aortic Root Replacement

We describe a novel technique, in situ composition of a valved conduit, for complex reoperative aortic root replacement. The absence of a rigid stented aortic valve prosthesis facilitates left ventricular outflow tract (LVOT) reconstruction and coronary reimplantation. First, a Dacron graft, inverted and inserted into the LVOT, is sewn to the LVOT, followed by coronary button reimplantation and then prosthetic valve implantation. For cases that require LVOT reconstruction, the graft below the prosthetic valve serves as a circumferential patch. Our technique requires only surgical materials that are readily available without the need for a specialized skillset.

557 Streptococcus Pneumoniae: A Rare Case of Fulminant Multivalvular Infective Endocarditis Presenting With Septic Arthritis

Streptococcus pneumoniae is an uncommon cause of native valve infective endocarditis in the post-antibiotic era. We present a rare case of disseminated s.pneumoniae infection presenting with septic arthritis, complicated by life-threatening Infective Endocarditis (IE). A 52 year old female presented to the emergency department (ED) with a painful swollen right knee two weeks after a fall. Fracture was excluded and a provisional diagnosis of ruptured Baker’s cyst was made. She re-presented by ambulance to ED two weeks later with fever, confusion and worsening knee swelling. Blood cultures and joint aspirate were positive for S. pneumoniae and joint washout was performed. On day 3 of admission, she deteriorated with hypotension, hypoxia and bilateral chest x-ray infiltrates requiring intubation and noradrenaline infusion. Bedside transthoracic echocardiogram on day 5 demonstrated a 1.5cm aortic valve vegetation with severe aortic regurgitation, aortic root abscess and mitral regurgitation. Transoesophageal echocardiogram confirmed severe endocarditis with aortic, mitral and tricuspid involvement, aortic root abscess and perforation of the interventricular septum and aorto-mitral curtain. She underwent emergency surgery with extensive debridement, ventricular septal defect closure, left ventricular outflow tract reconstruction, mitral and tricuspid valve repair, and mechanical aortic valve replacement. She required a pacemaker for postoperative atrioventricular block and has recovered completely. This report describes an unusual presentation of endocarditis caused by an uncommon and destructive pathogen, S. pneumoniae. It highlights the importance of early investigation for infective endocarditis in cases of bacteraemia with haemodynamic or respiratory compromise, even in pathogens uncommonly causing endocarditis.

P300 Reappraisal of aortic stenosis severity grading inconsistencies using 3D aortic valve area

Abstract Funding Acknowledgements no fundings Background Different 3D imaging modalities have been proposed to overcome the limitations in aortic stenosis (AS) grading derived from underestimation of left ventricular outflow tract (LVOT) area by 2D transthoracic echocardiography (2D-TTE). Transesophageal echocardiography manual and software measurements (3D-TEEm and 3D-TEEs) and multidetector computed tomography (MDCT) have been recently been shown as valuable tools for AS grading using a combined approach incorporating 3D LVOT measurements and 2D Doppler parameters in the continuity equation (CE). This approach results particularly useful in cases of 2D-TTE grading inconsistence. As all these 3D imaging modalities provide larger AVA compared to 2D-TTE, we have recently proposed a 1.2 cm2 AVA cut-off could to define AS severity with 3D-TEE and MDCT. Purpose To compare AVA measurements with 3D-TEEm and 3D-TEEs using MDCT as gold standard in order to assess inconsistencies and evaluate the impact of a 1.2 cm2 AVA cut-off on AS severity grading. Methods 288 patients (80 ± 11 years, 52.4% male) with symptomatic AS underwent 2D-TTE, 3D-TTEm, 3D-TEEs and MDCT within the same hospitalization. 3D-TEE LVOT reconstruction was performed manually and with semi-automated software (EchoPAC version 201). 3D-TEEm, 3D-TEEs and MDCT LVOT areas were combined with 2D-TTE Doppler parameters to calculate AVA by CE. The grading of AS was reassessed in patients with low flow-low gradient AS using a 1.2 cm2 cut-off for severity. Results Patients were classified according to flow state (stroke volume index ≥35 ml/m2 or <35 ml/m2) and mean pressure gradient (MPG ≥40 mmHg or <40 mmHg) into 4 groups: normal flow-high gradient (NF-HG; n 173, 60%), normal flow-low gradient (NF-LG; n 45, 15.5%), low flow-high gradient (LF-HG; n 39, 13.5%), and low flow-low gradient (LF-LG; n 31, 11%) AS. Among patients classified as LF-LG AS, 95%, 55%, 29% and 55% of cases were classified as severe by 2D-TTE, 3D-TEEm, 3D-TEEs and MDCT respectively using a 1.0 cm2 AVA cut-off. When the proposed severity AVA cut-off of 1.2 cm2 was applied using 3D imaging modalities, the proportion of severe AS significantly increased to 84% (p = 0.012) (3D-TEEm), 52% (p = 0.046) (3D-TEEs) and 71% (p < 0.001) (MDCT) respectively. Conclusion The use of a 1.2 cm2 AVA cut-off for 3D-TEE and MDCT significantly reduces the number of cases of inconsistently graded AS, increasing the proportion of patients with severe AS.

Outcomes After Left Ventricular Outflow Tract Reconstruction With a Tube Graft for Annular Erosion

Aortic annular erosion is a serious complication of aortic valve endocarditis or previous aortic valve replacement. This study examined the outcomes of a technique for left ventricular outflow tract reconstruction using a polyester tube graft, followed by translocation of the aortic valve and coronary arteries. A total of 23 patients with extensive annular erosion resulting from endocarditis or previous aortic valve replacement with or without pseudoaneurysm formation, or occurring after excision of the native valve, underwent suture of a polyester tube graft in the left ventricular outflow tract below the annulus, replacement of the aortic valve and proximal ascending aorta with a composite graft, and reimplantation of the coronary arteries with the use of interposition polyester grafts. The mean age of the patients was 50 years, and 57% were men. There were no hospital deaths. The mean duration of follow-up was 6.5 years and extended to 16 years. Actuarial survival at 1, 5, and 10 years was 86.7%, 82.2%, and 62.6%, respectively. Two patients required reoperation for a graft-graft pseudoaneurysm and for degeneration of a porcine bioprosthesis. Echocardiograms obtained at a mean of 75 months postoperatively in 15 of the 23 patients demonstrated normal left ventricular outflow tract dimensions and velocities and a mean effective valve orifice area of 1.07 cm2/m2. All coronary artery grafts were patent on angiography a mean of 40 months postoperatively in 13 patients. Extended experience with this technique confirms its safety and effectiveness for patients withextensive destruction of the aortic annulus. It represents a suitable alternative to other currently used techniques.

Pre-procedural multi-slice computed tomography (MSCT) in aortic valve replacement. Important measurements

PurposeTo describe the preoperative role of MSCT in aortic valve lesions regarding detection of valve morphological changes and important measurements needed for valve replacement. Subjects and methodsThis was a prospective study included 24 patients their mean age 53.4years, with known aortic valve stenosis (AS) or regurgitation (AR) over a study period 1year. All patients underwent CT angiography using 128 MSCT. The coronary angiography was done by means of a bolus tracking technique. Measurements were conventionally made from an “optimized” sagittal oblique left ventricular outflow tract (LVOT) reconstruction. ResultsThe most common cause for aortic valve lesion was degenerative (63%). Echocardiography (ECHO) and MSCT had highly statistically significant kappa agreement in differentiating AS and AR. The mean aortic valve area (AVA) in AS and AR were (1.2±0.5 and 3.8±0.3cm2) with p value (0.000∗∗). Aortic valve dimension at sinus of valsalva were (3.5±0.2 & 4.6±0.7cm) in AS and AR respectively. At the sino-tubular junction (STJ) were (3.1±0.2 & 4.4±1.4) in AS and AR respectively. The mean aortic annulus area was (5.7±1.3cm2) in AS and (6.6±0.8cm2) in AR. MSCT was more significant than ECHO in detection and grading of calcification (p value<0.01). The distance from the aortic annulus to the ostia of the left and the right coronary arteries were (1.8±0.3cm) and (1.6±0.3cm) respectively. Concomitant coronary atherosclerosis and >50% attenuated lumen was detected in (25% &12.5%) of our patients respectively. ConclusionThe familiarity with the MSCT features of aortic valve and using various measurements are considered to be helpful for the accurate diagnosis and proper pre-operative valve replacement preparation.

Reoperative double ventricular outflow tract reconstruction in grown-up congenital heart disease patients with conotruncal anomalies.

Surgical experiences of the reoperative double ventricular outflow tract reconstruction long after the successful repair of conotruncal anomalies were reviewed. Ten adult patients with conotruncal anomalies (6 females, 22.9 ± 5.5 years old) underwent the reoperative double ventricular outflow tract reconstruction. Primary diagnosis was pulmonary atresia with ventricular septal defect in 6 patients, truncus arteriosus in 3, and double-outlet right ventricle in 1. The indication for the left ventricular outflow tract reconstruction was the left ventricular dilatation and dysfunction derived from moderate or greater systemic semilunar valve insufficiency. The indication for the right ventricular outflow tract reconstruction was severe pulmonary insufficiency in all patients, and concomitant right ventricular outflow tract obstruction in 7. The systemic semilunar valve replacement was performed in all patients. The right ventricular outflow tract patching was performed in 4 patients, and the revision of extra-cardiac conduit in 6. Within a mean follow-up of 9.0 ± 7.0 years, there was no mortality. The left ventricular end-diastolic volume index improved from 147 ± 37 to 108 ± 19 ml/m(2) (p = 0.005), and the peak pressure gradient across right ventricular outflow tract improved from 43 ± 17 mmHg to 9 ± 2 at 1 year after (p = 0.02). The plasma brain natriuretic peptide level improved from 83 ± 57 to 34 ± 32 pg/ml (p = 0.03). Reoperative double ventricular outflow tract reconstruction long after the repair of conotruncal anomalies was safely performed, and provided the ventricular reverse remodeling and improvement of serum BNP level.

Left ventricular pseudoaneurysm following aortic valve prosthesis endocarditis

A 63-year-old man underwent aortic valve replacement and an early reoperation for recurrent endocarditis. Sixteen months later he presented with persistent fever and a 64-slice computed tomography (CT) scan revealed a subannular left ventricular pseudoaneurysm. He underwent successful left ventricular outflow tract reconstruction and aortic valve prosthesis, partial root and ascending aorta replacement.

Reoperative Techniques for Complications After Arterial Switch

The purpose of this study is to review our experience with late reoperations after the arterial switch operation (ASO) and to introduce reparative solutions adapted from previous techniques. A retrospective study was performed on 23 patients who underwent late reoperations after ASO between 1983 and 2010. Eighteen patients were from our concomitantly reported cohort of 258 ASO patients and 5 came from distant referrals. Twenty-seven reoperations on 23 patients were performed for lesions relating to coronary arteries (9 procedures, 7 patients), the neoaortic root (12 procedures, 10 patients), and the right ventricular outflow tract (6 procedures, 6 patients). Four patients died: 1 from an exsanguinating gastric ulcer 4 years after prosthetic valve replacement; 1 from coronary occlusion one month postoperatively from an unroofed intramural left main coronary artery; and 2 after supravalvar pulmonary artery stenosis repair complicated by coexisting left ventricular dysfunction from the original ASO. The ASO remains the treatment of choice for transposition of the great arteries and its variants. While the incidence of late reintervention is low, a subset of patients will require operations that extend the principles of myocardial revascularization, left ventricular outflow tract reconstruction, and relief of pulmonary stenosis.

Left ventricular outflow tract reconstruction and translocation of the aortic valve for annular erosion: Early and midterm outcomes

Aortic annular erosion is a serious complication of aortic valve endocarditis or previous aortic valve replacement without endocarditis, and its surgical management is challenging. We present the early and midterm results of a technique for left ventricular outflow tract and aortic root reconstruction with a polyester tube graft and translocation of the aortic valve and coronary arteries. A polyester tube graft is placed into the left ventricle and sutured to the left ventricular outflow tract below the area of erosion. The graft is then everted and sutured to a composite graft. Interposition polyester grafts from the coronary arteries are attached to the composite graft above the valve. This technique has been used in 12 cases. All but 1 patient had previously undergone aortic root or aortic valve replacement, and 4had endocarditis of prosthetic (n=2) or aortic allograft (n=2) valves. There were no in-hospital deaths. There was 1 early death from pulmonary embolism at 1 postoperative month and 2 late deaths at 15 and 64 postoperative months, both resulting from heart failure. The remaining 9patients are alive at 3 to 132 postoperative months. Actuarial 5-year survival is 75%. Left ventricular outflow tract reconstruction with translocation of the aortic valve and coronary arteries for annular erosion is a useful technique that safely excludes the area of annular erosion and eliminates left ventricular outflow tract obstruction. The procedure can be safely performed with satisfactory early outcomes and 5-year survival.

Arterial switch operation using aortic homograft for transposition of the great arteries with pulmonary regurgitation

We report a case of a 15 month-old boy who underwent the arterial switch operation using cryopreserved aortic homograft for transposition of the great arteries with pulmonary regurgitation, with coexisting right ventricular outflow tract obstruction precluding atrial switch operation. Follow-up echocardiography at 6 months showed trivial neoaortic valve regurgitation, no significant systemic outflow obstruction, with good cardiac function. In small children, the choice of material for left ventricular outflow tract reconstruction is one of the most crucial issues. Cryopreserved homograft has been one of the primary options for the aortic valve replacement in small children because of the ease of suturing and excellent hemostasis.

Pulmonary homografts: current status.

Pulmonary homografts are used more frequently in cardiac surgery. They are used primarily for reconstruction of the right ventricular outflow tract, both in children with complex congenital disease and in adults undergoing the Ross procedure for aortic valve replacement. They have been used for left ventricular outflow tract reconstruction, but they are less,durable in this high-pressure position. They have excellent hemodynamic characteristics, require no anticoagulation, and are free from problems of thromboembolism. However, there is concern that over time pulmonary homografts may develop stenosis secondary to low-grade immune reactions. Even as they become more popular, a shortage of available grafts may limit their use.

Aortic allografts for left ventricular outflow tract replacement in children.

Aortic allografts provide many advantages in children requiring left ventricular outflow tract (LVOT) reconstruction. The low risk of thromboembolic events and freedom from the requirement for anticoagulation are primary benefits. Additionally, excellent hemodynamic results are possible even in the presence of multilevel obstruction. The pulmonary autograft has become the favored approach in most pediatric centers, as the limited longevity of the aortic allograft has now become apparent. However, some children are not candidates for the pulmonary autograft. Thus, the aortic allograft remains a useful aortic valve substitute in children. Using standard aortic root replacement (ARR) or extended aortic root replacement (EARR) techniques, aortic allografts can be used in any circumstance. Young age and small size are predictive of shortened valve longevity and higher operative mortality compared with older children. Reoperation to replace a degenerated aortic allograft can be accomplished safely. Copyright 2000 by W.B. Saunders Company

Intraoperative Transgastric Echo Assessment During Left Ventricular Outflow Tract Surgery: A Reliable Predictor of Residual Obstruction.

Standard transesophageal echocardiography (TEE) views of the left ventricular outflow tract (LVOT) are limited by poor Doppler beam alignment with the peak velocity of flow. Transgastric imaging allows well-aligned continuous-wave Doppler interrogation of the LVOT and was attempted during intraoperative TEE in all children undergoing LVOT surgery at Children's Hospital of Wisconsin. Thirty-eight patients, ranging in age from 2 days to 18 years (median, 5.2 years) and in weight from 2.9 to 100 kg (median, 16.7 kg), had TEE during surgery to resect membranous or fibromuscular subaortic obstruction (20 patients), valvuloplasty for aortic stenosis/insufficiency (13 patients), aortoplasty for supravalvar stenosis (one patient), or repair/replacement for aortic insufficiency (four patients). In four patients, transgastric images of the LVOT could not be obtained. Intraoperative Doppler gradients identified severe residual obstruction (mean, 67 +/- 13.5 mmHg) after surgery in seven patients; six of these patients underwent immediate repeat operation with subsequent adequate relief, and one patient required later aortoventriculoplasty for persistent annular/valvar obstruction. All other patients had successful LVOT reconstruction with intraoperative Doppler gradients ranging from 0 to 46 mmHg, and none required early repeat operation. Good correlation was found between the intraoperative transgastric gradient (mean, 25.8 +/- 17.7 mmHg) and the early postoperative transthoracic echo gradient (mean, 21.8 +/- 21.4 mmHg). In addition, there was consistent agreement in the assessment of aortic insufficiency between the transesophageal and transthoracic studies. We conclude that transgastric Doppler assessment of the LVOT is a critical component of intraoperative monitoring during LVOT surgery and is a reliable predictor of residual obstruction.

Degeneration of aortic valve allografts in young recipients

Aortic allograft fibrocalcification and valvular insufficiency have been observed in patients less than 3 years of age at initial replacement of the left ventricular outflow tract. From June 1985 through May 1992, 47 children have undergone aortic root replacement with cryopreserved aortic valve allografts. Thirty-three children were 3 years of age or older and 14 were less than 3 years of age at operation. In the older patient group, there were three (9%) hospital deaths and one child underwent cardiac transplantation 30 hours after aortic root replacement because of left ventricular failure. Clinical follow-up of the 29 surviving older children is from 4 months to 6.6 years (mean 3.0 years). One patient was lost to follow-up. Two children (7%) have required reoperation, but primary allograft degeneration was not observed. In the younger patient group, there were three (21%) hospital deaths. Follow-up ranged from 2.5 months to 4.7 years (mean 2.3 years). Among 11 operative survivors, one late death resulted from a pulmonary embolus. Seven of 10 (70%) remaining allograft recipients had progressive allograft calcification or insufficiency. Six of them have required reoperation to explant the allograft, and one child is currently receiving cyclosporine therapy with the original valve allograft. The cause of allograft failure is possibly immunologic. The prevalence of early aortic valve allograft degeneration has prompted the consideration of nonviable allografts or xenografts, pulmonary autografts, or minimal immunosuppression as alternatives when left ventricular outflow tract reconstruction is necessary in children less than 3 years of age.

Shone's anomaly: Operative results and late outcome

Shone's anomaly, a congenital cardiac malformation, consists of multiple levels of left heart obstruction including supravalvar mitral ring, parachute mitral valve, subaortic stenosis, and coarctation. The prognosis for patients with Shone's anomaly is poor. To assess operative results and late outcome, we reviewed the records of 30 consecutive patients seen with Shone's anomaly at our institution between 1966 and 1989. Anatomical diagnoses in these patients were supravalvar mitral ring (22 patients), mitral valve abnormalities including parachute mitral valve, fused chordae, or single papillary muscle (26 patients), subaortic gradients (26 patients), and coarctation (29 patients). Nineteen patients had all four lesions. Other common defects were bicuspid aortic valve (19 patients) and ventricular septal defect (20). Two patients were treated medically. The other 28 patients required 84 operative procedures with 18 patients undergoing more than one procedure. Operations included coarctation repair (28 patients), mitral valve repair or replacement (11), ventricular septal defect closure (8), subaortic resection (8), and complex left ventricular outflow tract reconstruction or bypass (4). Age at first operition ranged from 7 days to 7 years (median age, 3 months). There were no operative deaths at the first operation. However, mortality rose to 24% (4/17) after the second operation. All operative deaths were secondary to severe mitral valve disease. The survivors have been followed from 1 to 16 years (mean follow-up, 6 ± 1 years). There were no late or sudden deaths. Morbidity has included stroke (1), gastrointestinal bleeding (2), permanent heart block (1), and persistent congestive heart failure (6). We conclude that although patients with Shone's anomaly are seen with a wide spectrum of major anatomical and hemodynamic abnormalities, a satisfactory long-term outcome is possible for most. Operative mortality is adversely affected by the severity of mitral valve disease and the need for multiple operative procedures.

Clinical and hemodynamic follow-up of left ventricular to aortic conduits in patients with aortic stenosis

To assess the long-term results of left ventricular outflow tract reconstruction utilizing an apical left ventricular to aortic valved (porcine) conduit the clinical and hemodynamic data were reviewed from 24 patients who had placement of an apico-aortic conduit. Eighteen of the patients are asymptomatic and taking no cardiac medications. Three patients were reoperated on, one patient 1.5 years after his original operation for subacute bacterial endocarditis and two patients 3 to 4 years after their original operation for severe conduit valve insufficiency. None of the patients is taking anticoagulants and no thromboembolic events have occurred. Postoperative catheterization has been performed 1 to 1.5 years (mean 1.2) after repair in 15 of 21 patients. The rest left ventricular outflow tract gradient has decreased from 102.5 +/- 20 mm Hg preoperatively to 14.8 +/- 9.9 mm Hg postoperatively (probability [p] less than 0.001). Some degree of conduit obstruction was demonstrated by catheter passage in 11 of the 15 patients. In these 11 patients, the obstruction occurred at three distant sites: at the egress of the left ventricle in 9, at the porcine valve in 5 and at the aortic to conduit junction in 1. Isometric exercise in five and supine bicycle exercise in six patients increased the left ventricular outflow tract gradient by 2.5 +/- 1.1 and 20.8 +/- 11.8 mm Hg, respectively, despite an increase in cardiac index of 1 +/- 0.3 and 3.7 +/- 0.4 liters/min per m2, respectively. The data suggest that a left ventricular to aortic conduit is an effective form of therapy for severe left ventricular outflow tract obstruction.