Surgical management of left ventricular outflow tract obstruction in a specialized hypertrophic obstructive cardiomyopathy center

ObjectivesThis study evaluates operative approach and contemporary surgical outcomes in the management of left ventricular outflow tract obstruction by a single surgeon at a high-volume, specialized hypertrophic cardiomyopathy center.MethodsThis is a retrospective review of 1559 consecutive operations for left ventricular outflow tract obstruction from 2005 to 2015. Demographic profiles, echocardiogram-derived ventricular morphology and hemodynamics, operative data, and in-hospital outcomes were analyzed.ResultsOf the 1559 operations, 586 were isolated septal myectomies, 522 were myectomies with mitral valve or subvalvular apparatus intervention, 422 were myectomies with another concomitant procedure, and 29 were isolated mitral valve interventions without myectomy. Common mitral valve interventions included anterior leaflet shortening (16%), chordae tendineae resection (9.8%), papillary muscle resection (7.2%), and papillary muscle reorientation (7.5%). Ninety-two patients underwent mitral valve replacement, 42 for left ventricular outflow tract obstruction and 50 for intrinsic mitral valve pathology. Patients undergoing mitral interventions had thinner septums (18 ± 0.4 mm vs 22 ± 0.5 mm, P < .001) and less myocardium removed (6.2 ± 3.5 g vs 8.8 ± 3.8 g, P < .001) than patients without a mitral intervention. Prevalence of in-hospital permanent pacemaker insertion was 4.2% (n = 1334) for complete heart block and 1.1% (n = 464) for isolated septal myectomy with normal preoperative conduction. Overall, there were 2 postoperative ventricular septal defects (0.13%) and none for isolated myectomies. Operative mortality was 0.38%.ConclusionsSeptal myectomy can be performed safely with excellent outcomes when the procedure is performed by a highly experienced surgeon in a high-volume, specialized center. A mitral valve intervention is a useful adjunct in patients with moderate hypertrophy.     

Recurrence of left ventricular outflow tract obstruction after left anterior descending coronary artery revascularization in a patient with hypertrophic obstructive cardiomyopathy

A patient with known hypertrophic obstructive cardiomyopathy presented with an anteroseptal myocardial infarction which resulted in the disappearance of his subaortic pressure gradient. Surgical revascularization of his left anterior descending coronary artery after the viability of his myocardium had been documented led to the recurrence of his left ventricular outflow tract obstruction and subaortic pressure gradient.     

Fixed left ventricular outflow tract obstruction in presumed hypertrophic obstructive cardiomyopathy: implications for therapy.

BACKGROUND: A subset of patients presenting with a presumed diagnosis of hypertrophic obstructive cardiomyopathy (HOCM) have a fixed left ventricular outflow tract (LVOT) obstruction. Recognition of this pathophysiologic abnormality is important in choosing therapy. METHODS: Of patients referred for treatment of HOCM, 4 had fixed LVOT obstruction. Clinical and echocardiographic data and surgical findings were reviewed. RESULTS: In the 4 patients with clinical features consistent with HOCM or HOCM-like conditions, echocardiography showed fixed LVOT obstruction with an early-peaking LVOT Doppler signal or absence of severe systolic anterior motion of the mitral valve. The causes of fixed obstruction included accessory mitral tissue with associated fibrous ring (1 patient), fixed subaortic tunnel stenosis (2 patients), and a discreet subaortic ridge (1 patient). After surgical relief of the fixed LVOT obstruction, all patients had relief of the ventricular outflow tract gradient. CONCLUSIONS: Not all patients with a presumed diagnosis of HOCM have isolated dynamic LVOT obstruction but may have isolated or additional fixed obstruction. Careful two-dimensional and Doppler echocardiography are needed to identify this subset of patients who are best treated surgically.     

Left ventricular outflow tract obstruction

Left ventricular outflow tract obstruction can occur at the supravalvar, valvar, or subvalvar level. Each level of obstruction is associated with distinct symptomatology, natural history, and operative approach. Reconstructive techniques can usually be used with low operative risk and excellent immediate and longer-term outcomes. Valve replacement for valvar obstruction is advised when reconstruction is not possible. The Ross procedure has greatly improved the results of valve replacement in children.     

Reoperation for persistent outflow obstruction in hypertrophic cardiomyopathy

This study compares results of a second left ventricular myotomy and myectomy (M + M) with those of mitral valve replacement (MVR) as reoperative procedures for persistent left ventricular outflow obstruction after M + M in hypertrophic cardiomyopathy. Comparison of the second M + M group (n = 12) with the MVR group (n = 11) disclosed significant difference (p less than 0.05) in mean age at the initial operation (29 +/- 11 years versus 40 +/- 8 years), interval between operations (46 +/- 57 months versus 18 +/- 13 months), and age at reoperation (33 +/- 10 years versus 42 +/- 8 years); and insignificant differences in mean preoperative functional class, cardiac index, left ventricular outflow gradients at rest or with provocation, and hospital mortality at reoperation (2/12 versus 1/11). At 6 months after reoperation, comparison of results of a second M + M with MVR showed that mean functional class, cardiac index, and left ventricular outflow gradient at rest were similarly improved, but the outflow gradient with provocation was significantly higher in the second M + M group (57 +/- 44 mm Hg versus 14 +/- 9 mm Hg, p less than 0.05). Total follow-up was 108 patient-years (100% complete) with an average of 5.9 years per patient in the second M + M group and 3.4 years per patient in the MVR group. Actuarial survival, including hospital mortality, at 3 and 5 years was 83% and 76%, respectively, after the second M + M, which was similar to 92% and 77% after MVR.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular outflow obstruction in Taussig-Bing malformation.

In a patient recently undergoing total intracardiac repair of the Taussing-Bing malformation the immediate cause of death appeared to be an obstruction to left ventricular outflow. Examination of this and other specimens of Taussig-Bing malformations revealed that the obstruction appeared to be a portion of the pulmonary conus. This area may be overlooked in the preoperative evaluation and is so located that the obstructive nature of this muscle mass may not be appreciated at the time of surgical repair. The obstructive part of the pulmonary conus can be excised and this appears to be a more common component of the Taussig-Bing anomaly than has previously been appreciated.     

Grafting and concomitant left ventricular myotomy-myectomy in a patient with coronary artery disease associated with hypertrophic obstructive cardiomyopathy

A 44-year-old man complained of chest oppression and systolic murmur. Echocardiography showed subaortic stenosis with outflow gradient of 135 mmHg, interventricular septal thickness of 21 mm, left ventricular posterior wall thickness of 11 mm, and 2/4 mitral regurgitation. Selective coronary angiography demonstrated 75% stenosis in left anterior desending branch. Coronary artery revasculization comcomitant with left ventricular myotomy-myectomy was performed. He had a good recovery from operation, and was discharged in 19th days in NYHA class I. Echocardiography one month after operation showed mild outflow pressure gradient, light systolic anterior motion of mitral anterior leaflet, and 1/4 mitral regurgitation. Careful operative management, including myocardial protection, avoiding perporation of ventricular septum, and postoperative medical care are mandatory to this group of patients. The use of cathecholamine and Ca-blocker will be attentioned because of the increasing the left ventricular pressure gradient.     

Left ventricular outflow tract obstruction with mitral valve replacement in small ventricular cavities

The inference that mitral valve replacement (MVR) may produce left ventricular outflow tract (LVOT) obstruction has been made, but no comparative hemodynamic studies with various types of prostheses have been done. The purpose of the present study was to compare the gradients created across the LVOT with MVR in young sheep with small left ventricular cavities. Mitral valve replacement was accomplished using cardiopulmonary bypass and hypothermic cardioplegic arrest. Five animals were used for each of the following valves studied: 25-mm Ionescu-Shiley bovine pericardial valve, 25-mm Hancock porcine aortic valve, 2M-6120 28-mm Starr-Edwards ball-valve prosthesis, 25-mm Bj?rk-Shiley 60-degree flat tilting-disc prosthesis, and 25-mm St. Jude Medical hemidisc valve. Gradients across the LVOT were measured after MVR and then during infusion of isoproterenol hydrochloride (0.05 micrograms/kg/min). Following MVR, only the Starr-Edwards valve produced an LVOT gradient (32 +/- 23 mm Hg). Substantial gradients after MVR were seen, however, with isoproterenol administration with the Ionescu-Shiley (47 +/- 4 mm Hg), Hancock (13 +/- 8 mm Hg), and Starr-Edwards (65 +/- 30 mm Hg) valves but not with the low-profile valves (Bj?rk-Shiley and St. Jude Medical). The results of the present study demonstrate that MVR can produce LVOT obstruction. The greatest degree of obstruction was with the high-profile mechanical and bioprosthetic valves.     

Left ventricular outflow tract obstruction with mitral mechanical prosthesis.

Left ventricular outflow tract obstruction after mitral valve replacement may occur when the native mitral apparatus is preserved intact. Although it has usually been reported using bioprostheses, we present one case using a low-profile mechanical prosthesis. The reduction of left ventricular dimensions and valvular redundancy contributed to this complication. We obtained definitive relief of left ventricular outflow tract obstruction by transaortic exposure and partial resection of the obstructing tissue with the help of video-assisted cardioscopy.     

Use of Alfieri stitch technique in a patient with hypertrophic obstructive cardiomyopathy

Systolic anterior motion of the anterior mitral leaflet plays an important role in the dynamic outflow tract obstruction encountered in patients with hypertrophic obstructive cardiomyopathy. Here we present a 58-year-old male patient who was successfully treated with a myectomy procedure applied along with the edge-to-edge Alfieri stitch technique. The use of the Alfieri technique provides satisfactory short-term results and can be considered as an alternative adjunct to abolish systolic anterior motion.     

Left ventricular outflow tract obstruction due to valve myxoma

A life-threatening left ventricular outflow tract obstruction developed in a 26-year-old man because of a very uncommon myxoma emerging from the ventricular side of the mitral valve. Immediate surgical treatment was indicated because of high-risk factors reported herein. After transaortic resection of a single myxoma, the progress of this patient has been excellent, especially as a familial myxoma could be excluded.     

Left ventricular assist device implantation in a patient who had previously undergone apical myectomy for hypertrophic cardiomyopathy

Apical hypertrophy is a rare variant of hypertropic cardiomyopathy. These patients may present with end-stage congestive heart failure subsequent to long standing diastolic dysfunction. We report the technique for left ventricular assist device insertion in a patient with previous apical myectomy for hypertrophic cardiomyopathy.     

Septoplasty and right ventriculoplasty in a pediatric patient with diffuse hypertrophic obstructive cardiomyopathy.

Our successful trans-right ventricular septal myectomy with septoplasty and patch reconstruction of the right ventricular outflow tract in a pediatric patient with diffuse hypertrophic obstructive cardiomyopathy indicates the usefulness of this procedure in such patients.