Optimizing ventricular shape in anterior restoration

Giant lateral left ventricular wall aneurysm sparing the submitral apparatus

Left ventricular aneurysms are a frequent and serious complication following acute transmural myocardial infarction and are most commonly located at the ventricular apex. The majority of these patients presents with severe mitral insufficiency, congestive heart failure, systemic embolism and sudden cardiac death. Giant aneurysms occurring in a submitral position between anterior and posterior papillary muscles on the lateral ventricular wall constitute a minor entity and those leaving the mitral apparatus intact are extremely rare.

Herein, we report the case of a 57 y/o Caucasian male patient with a past medical history of coronary artery disease and myocardial infarction with a giant left ventricular aneurysm measuring 15x10x8 cm in diameter. Despite the size of the aneurysm and its close topographical relation to the posterior mitral annulus the mitral apparatus was intact with a competent valve and normal left atrial size. He underwent successful surgical ventricular restoration.

Left ventricular pseudoaneurysm associated with septal ventricular rupture following myocardial infarction

We report a case of anterior left ventricular pseudoaneurysm and associated interventricular septal defect, following myocardial infarction. This report shows an unusual clinical presentation, successful echocardiographic management and surgical findings. Echocardiography appeared to be a useful technique, safe and specific for the diagnosis of a rare complication of myocardial infarction. Early recognition of this rare complication has therapeutic importance because immediate surgical correction is life saving.

Left Ventricular Reconstruction by Modified Linear Technique with Absorbable Suture

BACKGROUND

Linear and endoventricular techniques of left ventricular (LV) reconstruction often utilise prosthetic material for epicardial reinforcement or endocardial patch. We report a technique of LV aneurysm repair using absorbable suture without prosthetic material.

METHODS

Between November 1999 and August 2004, 55 patients underwent linear LV reconstruction, for ischaemic cardiomyopathy, using only continuous 3/0 polydioxanone suture. Survival, functional class and echocardiographic outcomes are reported.

RESULTS

Fifty-two patients (mean age 64+/-10 years) were studied. There was no perioperative mortality and the Kaplan-Meier survival at five years was 81%. Fifty-one patients underwent postoperative follow up (mean 28 months) with echocardiography (mean 20 months). There were no recurrent aneurysms. The postoperative LV eccentricity index (EI) was 0.72 (CI 0.48-0.9). Mean LV ejection fraction increased from 0.33+/-0.09 preoperatively to 0.41+/-0.15 at late follow up (mean within patient change 0.08+/-0.15, p=0.003). Mean symptom class improved from 3.3+/-0.8 to 1.6+/-0.7 (mean within patient improvement 1.6+/-1.0, p<0.001). Mitral regurgitation of grade 2/4 was identified in six patients and grade 3/4 in one patient.

CONCLUSION

Linear repair with absorbable suture material and without prosthetic material may be safely undertaken with good early and mid-term results.

Cardiac remodeling and failure: from molecules to man (Part III)

Given the lack of a unified theory of heart failure, future research efforts will be required to unify and synthesize our current understanding of the multiple mechanisms that control remodeling in the failing heart. Matrix remodeling and the associated activation of inflammatory cytokines and MMPs have emerged as key pathways in the development of heart failure. As such, attempts to understand the integrated control of ECM homeostasis with the bioactivation of inflammatory cytokines may be of particular relevance to the development of effective anti-remodeling approaches. Notably, the implantation of isolated populations of cells in failing myocardium has a profound and consistent anti-remodeling effect that limits the progression to CHF. These observations were consistently identified in numerous studies using diverse experimental animal models and varied cell types. Accordingly, multicenter clinical trials are underway, and the preliminary data in patients with CHF are encouraging. Despite the enormous promise of cell transplantation to restore and regenerate failing myocardium, the mechanisms underlying these profound biological effects are not understood. An improved understanding of the myocardial response to cell implantation, particularly on parameters of matrix remodeling, may help unify our current understanding of the progression of heart failure and optimize the development of this technique for its evolving therapeutic use. The following review outlines recent advances in medical and surgical approaches to control the remodeling process that underlies the progression of heart failure.

Factors affecting late survival after surgical remodeling of left ventricular aneurysms

OBJECTIVES

Surgical remodeling of the left ventricle has involved various techniques of volume reduction. This study evaluates factors that influence long-term survival results with 3 operative methods.

METHODS

From 1979 to 2000, 157 patients (134 men, mean age 61 years) underwent operations for class III or IV congestive heart failure, angina, ventricular tachyarrhythmia, and sudden death after anteroseptal myocardial infarction. The preoperative ejection fraction was 28% +/- 0.9% (mean +/- standard error), and the pulmonary artery occlusive pressure was 15 +/- 0.07 mm Hg. Cardiogenic shock was present in 26 patients (16%), and an intra-aortic balloon pump was used in 48 patients (30%). The type of procedure depended on the extent of endocardial disease and was aimed at maintaining the ellipsoid shape of the left ventricle cavity. In group I patients (n = 65), radical aneurysm resection and linear closure were performed. In group II patients (n = 70), septal dyskinesis was reinforced with a patch (septoplasty). In group III patients (n = 22), ventriculotomy closure was performed with an intracavitary oval patch.

RESULTS

Hospital mortality was 16% (25/157) and was similar among the groups. Actuarial survival up to 18 years was better with a preoperative ejection fraction of 26% or greater (P =.004) and a pulmonary artery occlusive pressure of 17 mm Hg or less (P =.05). Survival was worse in patients who had intra-aortic balloon pump support (P =.03). Five-year survival for all patients in group III was higher than for patients in group II (67% vs 47%, P =.04).

CONCLUSIONS

Factors that improved long-term survival after left ventricular surgical remodeling were intraventricular patch repair, preoperative ejection fraction of 26% or greater, and pulmonary artery occlusive pressure of 17 mm Hg or less without the need for balloon pump assist.

Restoration and regeneration of failing myocardium with cell transplantation and tissue engineering

Cell transplantation and the creation of bioengineered cardiovascular tissues are novel biologic approaches to restore and regenerate failing myocardium. These rapidly evolving therapies may complement and enhance other mechanical and surgical interventions for patients with congestive heart failure, providing cardiac surgeons with a wider range of treatments for patients at risk of congestive heart failure. Proof-of-concept studies have been performed in several experimental animal models of human cardiovascular disease, such as myocardial infarction and dilated cardiomyopathy. Although the exact mechanisms are unclear, cell transplantation restores cardiac function and limits ventricular dilatation. Clinical cell transplantation has been performed in a limited number of patients with encouraging preliminary results. In contrast, bioengineered muscle grafting is largely experimental but offers the promise of myocardial regeneration by replacing irreversibly damaged myocardium with healthy autologous tissue to facilitate more extensive ventricular remodeling surgery.

Left ventricular remodeling and functional mitral regurgitation: mechanisms and therapy

Myocardial damage that results in dysfunction and remodeling changes left ventricular shape and size. Mitral competence requires the functional integrity of all components of the mitral apparatus. Progressive remodeling ultimately leads to geometric distortion of multiple elements of the mitral apparatus, resulting in functional mitral regurgitation (MR). In this article, we examine the mechanisms of functional MR in the remodeled ventricle. Surgical treatment should aim to correct all abnormalities of the mitral apparatus. These include (1) revascularization of viable myocardium, (2) reduction of ventricular volume and restoration of shape, (3) realignment of papillary muscles, and (4) reduction of annular orifice size.