Surgery for left ventricular aneurysm

Restoring ventricular restoration: A call to re-evaluate a surgical therapy considered ineffective

The technique of surgical restoration of postischemically dilated left ventricles (SVR) has almost disappeared from operating theaters after the Surgical Treatment of IsChemic Heart failure (STICH) Trial demonstrated no treatment effect in patients with CAD and ejection fraction below 35%. Criticism on the trial was expressed stating that surgical expertise and patient selection (i.e., almost no aneurysm patients included) may have been inadequate to test the procedure s potential. Gaudino and colleagues now propose to conduct an analysis comparing the STICH patient population to a group of comparable SVR patients treated by a center with documented specific expertise for this technique. We here address the background of the trial and the following controversy and suggest a rationale why the suggested analysis has the potential to add valuable information to the field.

Effects of Surgical Ventricular Restoration on Left Ventricular Shape, Size, and Function for Left Ventricular Anterior Aneurysm

Background:

Surgical ventricular restoration (SVR) has been performed to treat left ventricular (LV) aneurysm. However, there is limited analysis of changes in LV shape. This study aimed to evaluate the changes in LV shape induced by SVR and the effects of SVR on LV size and function for LV aneurysm.

Methods:

Between April 2006 and March 2015, 18 patients with dyskinetic (dyskinetic group) and 12 patients with akinetic (akinetic group) postinfarction LV anterior aneurysm receiving SVR with the Dor procedure at Chinese People's Liberation Army General Hospital were enrolled in this study. A retrospective analysis was carried out using data from the echocardiography database. LV shape was analyzed by calculating the apical conicity index (ACI). LV end-diastolic volume index, end-systolic volume index, and ejection fraction (EF) were measured. One-way analysis of variance was used to compare means at different time points within each group.

Results:

Within one week after SVR, LV shape became more conical in the two groups (ACI decreased from 0.84 ± 0.13 to 0.69 ± 0.11 [t = 5.155, P = 0.000] in dyskinetic group and from 0.73 ± 0.07 to 0.60 ± 0.11 [t = 2.701, P = 0.026] in akinetic group; LV volumes were decreased significantly and became closer to normal values and EF was improved significantly in the two groups). On follow-up at least one year, LV shape remained unchanged in dyskinetic group (ACI increased from 0.69 ± 0.11 to 0.74 ± 0.12, t = −1.109, P = 0.294), but became more spherical in akinetic group (ACI significantly increased from 0.60 ± 0.11 to 0.75 ± 0.11, t = −1.880, P = 0.047); LV volumes remained unchanged in dyskinetic group, but increased significantly in akinetic group and EF remained unchanged in the two groups.

Conclusions:

SVR could reshape LV to a more conical shape and a more normal size and improve LV function significantly early after the procedure in patients with dyskinetic or akinetic postinfarction LV anterior aneurysm. However, LV tends to be more spherical and enlarged in the akinetic group on at least 1-year follow-up.

Geometric adaption of biodegradable magnesium alloy scaffolds to stabilise biological myocardial grafts. Part I

Synthetic patch materials currently in use have major limitations, such as high susceptibility to infections and lack of contractility. Biological grafts are a novel approach to overcome these limitations, but do not always offer sufficient mechanical durability in early stages after implantation. Therefore, a stabilising structure based on resorbable magnesium alloys could support the biological graft until its physiologic remodelling. To prevent early breakage in vivo due to stress of non-determined forming, these scaffolds should be preformed according to the geometry of the targeted myocardial region. Thus, the left ventricular geometry of 28 patients was assessed via standard cardiac magnetic resonance imaging (MRI). The resulting data served as a basis for a finite element simulation (FEM). Calculated stresses and strains of flat and preformed scaffolds were evaluated. Afterwards, the structures were manufactured by abrasive waterjet cutting and preformed according to the MRI data. Finally, the mechanical durability of the preformed and flat structures was compared in an in vitro test rig. The FEM predicted higher durability of the preformed scaffolds, which was proven in the in vitro test. In conclusion, preformed scaffolds provide extended durability and will facilitate more widespread use of regenerative biological grafts for surgical left ventricular reconstruction.

Successful surgical restoration of a giant immature left ventricular aneurysm with computer assisted ventricle engineering

Background: Although circular ventricle resection techniques are the gold standard of left ventricle restoration, these techniques can lead to suboptimal results. Postoperative systolic resection line can be inadequate, as it must be planned on a heart stopped in diastole. The impaired geometry and contractility may lead to increased short- and long-term mortality. Moreover, postoperative low cardiac output due to insufficient left ventricular volume results in a potentially unstable condition, and cannot be corrected. Our aim was to find a preoperative method to minimize risk and maximize outcome with left ventricle restoration. Methods: We have created a novel method combining surgery with modern imaging techniques to construct a preoperative 3D systolic heart model. The model was utilized to determine resection could be intraoperatively used to create the new left ventricle. Results: The computer assisted ventricle engineering technique is described step by step through a successful aneurysmectomy of a 61-year-old female patient with a complicated giant left ventricle aneurysm. Conclusions: Using this model we are able to find the optimal resection line providing excellent postoperative result, thus minimizing the risk of low cardiac output syndrome. This is the first report of our new combined approach to left ventricle restoration.

Efficacy of aneurysmectomy in patients with severe left ventricular dysfunction: favorable short-and long-term results in ischemic cardiomyopathy

INTRODUCTION

The purpose of this study was to (1) identify the functional results after aneurysm surgery in patients with ischemic cardiomyopathy and (2) identify predictors of favorable outcomes.

METHODS AND MATERIAL

Patients (n = 169) with angiographic left ventricular ejection fraction of 22 ± 5% underwent aneurysm surgery and were prospectively followed for three years. Prior to surgery, 40% and 60% of the patients were in congestive heart failure NYHA class I/II and III/IV, respectively. Concomitant revascularization was performed on 95% of the patients.

RESULTS

Cumulative in-hospital and 36-month mortalities were 7% and 15%, respectively. These respective rates varied according to preoperative parameters: CHF class I-II, 4% and 13%; CHF class III-IV, 8% and 16%; LVEF,20%, 12% and 26%; LVEF 21-30%, 2% and 6%; gated LVEF exercise/rest .5%, ,1% and 4%; and gated LVEF exercise/rest #5%, 17% and 38%. Higher LVEF ex/rest ratio (p = 0.01), male sex (p = 0.05), and a higher number of grafts (p = 0.01) were predictive of improvement in CHF class at follow-up based on the results of a multivariate analysis. After three years of follow-up, 84% of the patients were in class I/II, LVEF was 45 ± 7%, and gated LVEF ex/rest ratio was 13% higher (p,0.01) compared to the beginning of the study.

CONCLUSIONS

These data suggest that aneurysmectomy among patients with severe LV dysfunction result in short and long-term favorable functional outcome and survival. Selection of appropriate surgical candidates may substantially improve survival rates among these patients.

Left ventricular aneurysm in patients with previous cardiac surgery

Left ventricular aneurysm in patients who have undergone previous cardiac surgery is infrequently reported. We reviewed the results in all patients treated for left ventricular aneurysm between 1983 and 1995 at St. Vincent Hospital and Medical Center. Of 109 patients undergoing left ventricular aneurysm surgery, 10 had open heart surgery an average of 8.9 years previously. There was no mortality or significant morbidity in those who had previous operations. Functional status improved significantly after surgery. We concluded that surgical treatment of left ventricular aneurysm in patients who had previous open heart surgery can be performed with acceptable risks and leads to functional improvement.

A clinically relevant large-animal model for evaluation of tissue-engineered cardiac surgical patch materials

Extracellular matrix (ECM) scaffolds may be useful as a tissue engineering approach toward myocardial regeneration in the infarcted heart. An appropriate large-animal model for testing the utility of biologically derived ECM in this application is needed. The purpose of this study was to develop such a model for optimal procedural success during and after patch implantation surgery. Myocardial infarction (MI) was created by embolization of the diagonal artery (DA) branch of the left anterior descending coronary artery with collagen suspension. After 4 to 6 weeks, 14 pigs received patch implant (ECM or expanded polytetrafluoroethylene). Six pigs were infarcted in the first DA and seven pigs in the second DA. Electrophysiology study was performed within 3 days before surgery. During surgery, the size and location of the infarct were measured. Infarcted myocardium (1.5-cm diameter) was transmurally excised under partial cardiopulmonary bypass. Patches (3-cm diameter) were sutured to the endomyocardial defect. Four pigs died postoperatively. After 1 month, 10 pigs were euthanized and the locations of patches were examined. Success rate of patch implant in the second DA (85.7%) was higher than the first DA (50%) group. Infarct size in the second DA was smaller than in the first DA (4.6+/-1.2 vs. 10.8+/-2.4 cm(2), P<.05). The second DA was more anteriorly positioned, which enabled easier access from the midsternal thoracotomy. However, the first DA was more laterally located requiring more manipulation of the heart during surgery. Electrophysiology revealed no ventricular tachyarrhythmia in the second DA but 33.3% in the first DA group (P<.05). At necropsy, the endocardial position of the first DA-infarct patches was anteroapical, whereas the second DA-infarct patches were more basolateral and often involved the anterior papillary muscle. The success rate of patch implant was associated with infarction size and location, and may be related to arrhythmic substrate. Experimental MI created by the second DA embolization is a feasible model for investigation of tissue-engineered cardiac patch implantation. This large-animal model is also suitable for study of cell therapy via endocardial catheter-based approaches or open surgical methods.

Endoventricular Patch Reconstruction of Ischemic Failing Ventricle. A Single Center with 20 years Experience. Advantages of Magnetic Resonance Imaging Assessment

The left ventricular reconstruction (LVR) with endoventricular circular patch plasty (EVCPP) was reported in 1984 as a surgical method to rebuild left ventricular aneurysm or asynergy after myocardial infarction. Scarred LV wall can be dyskinetic or akinetic according to the type of infarction (transmural or not), and the progressive dilatation of LV (remodeling) depends on the size of the asynergic scar. Assessment of this extension and of LV volume and performances, is easy and reliable by magnetic resonance (CMR). The surgical technique is based on the insertion inside the ventricle on contractile myocardium, of a circular patch restoring curvature and physiological volume, and allowing exclusion of asynergic non resectable regions. The ventricular reconstruction method also has other components that include coronary revascularization (almost always), mitral repair (if needed) and endocardectomy when spontaneous or inducible ventricular tachycardia (VT) are present. The experience of the authors (> 1100 cases) and results obtained by other Centers, allows proposal of this technique as a way to treat the ischemic failing ventricle.

Changes in left ventricular volume and predictors of cardiac events after endoventricular circular patch plasty

OBJECTIVE

The aim of this study was to identify predictors of cardiac events after endoventricular circular patch plasty (Dor operation) by analyzing our experience with Dor operation.

METHODS

Thirty patients with left ventricular aneurysm and/or ischemic cardiomyopathy who underwent Dor operation were included in this study. Hemodynamic and clinical results were analyzed, and the predictors of cardiac events were examined.

RESULTS

Hospital mortality was 3.3%. Postoperative clinical status and left ventricular (LV) function in all survivors significantly improved. The survival rates at 1, 3, and 5 years after operation were 93%, 89% and 89%. The corresponding cardiac event-free rates were 75%, 67% and 49%. Pre- and postoperative LV function and volume did not differ significantly between patients with or without cardiac events. However, the proportion of reduced end-diastolic volume index (EDVI) (preoperative EDVI-postoperative EDVI) to preoperative EDVI was significantly higher in patients with cardiac events than in cardiac event-free patients. Postoperative LV volume re-increased in the cases with cardiac events during follow-up. Cox regression analysis confirmed that preoperative clinical premature ventricular contraction and end-systolic volume index (ESVI), postoperative EDVI, ESVI, and ejection fraction were independent predictors of late cardiac events. There was a significant positive correlation between preoperative ESVI and postoperative EDVI.

CONCLUSION

Though LV function significantly improved after Dor operation, LV reconstruction with excessive reduction can cause restarting LV remodeling and increasing mortality and morbidity. Therefore, LV reconstruction of appropriate sizes and shapes, considering the function of residual myocardium, has a significant effect on prognosis. It is highly reasonable to expect that preoperative ESVI can predict the optimal size of reconstructed left ventricle.

Experience with nifekalant hydrochloride in a patient with ischemic cardiomyopathy and severe ventricular dysfunction after dor operation

A 52-year-old male with ischemic cardiomyopathy and severe ventricular dysfunction underwent coronary artery bypass grafting and left ventricular reconstruction (Dor operation). The patient developed acute onset of incessant ventricular tachycardia in the early postoperative period that was refractory to therapy with class I antiarrhythmic agents, and multiple attempts at electrical cardioversion were required. A combination of intravenous nifekalant hydrochloride and enteral amiodarone was elected as treatment for this recurrent incessant ventricular tachycardia. Nifekalant hydrochloride was administered as a loading dose (0.3 mg/kg/5 min), followed by an intravenous infusion (0.4 mg/kg/hr). Several days after initiating therapy, the patient no longer experienced episodes of ventricular tachycardia, and there was no compromise in hemodynamics. We conclude that nifekalant hydrochloride is a useful agent for suppression of ventricular tachycardia in patients with severe left ventricular dysfunction, especially during the early postoperative period.

Coronary artery bypass with ventricular restoration is superior to coronary artery bypass alone in patients with ischemic cardiomyopathy

BACKGROUND

Coronary artery bypass is an acceptable therapy in patients with ischemic cardiomyopathy. However, it has been demonstrated that patients with increased left ventricular volume have a worse outcome than patients with normal ventricular volume. Our hypothesis was that ventricular restoration plus coronary artery bypass provides improved outcome compared with coronary artery bypass alone in ischemic cardiomyopathy with ventricular enlargement.

METHODS

A retrospective analysis was performed of patients with ischemic cardiomyopathy (ejection fraction <30%) who underwent operation between 1998 and 2002. Patients with enlarged ventricles (end-diastolic dimension > or =6.0 cm) who underwent either coronary artery bypass alone or coronary artery bypass with ventricular restoration were compared. Preoperative and postoperative ejection fraction, morbidity, mortality, and freedom from heart failure (hospitalization secondary to heart failure) were assessed.

RESULTS

Ninety-five patients were included in the study. Thirty-nine patients had coronary artery bypass alone, whereas 56 patients had ventricular restoration with coronary artery bypass. Both groups demonstrated an improved postoperative ejection fraction; however, the improvement was significantly greater in the ventricular restoration plus coronary artery bypass group (P <.01). There were no hospital deaths in either group; however, late mortality was higher in the coronary artery bypass group. Freedom from heart failure was achieved in all but 2 of the ventricular restoration plus coronary artery bypass patients (2/56, or 3.6%) versus 7 in the coronary artery bypass group (7/39, or 18%). The combined outcomes of freedom from failure and late mortality were significantly improved in the ventricular restoration plus coronary artery bypass group (P <.05).

CONCLUSIONS

Ventricular restoration affords significant improvement in ejection fraction compared with coronary artery bypass alone, without added mortality. Most importantly, left ventricular restoration reduces late morbidity and mortality compared with coronary artery bypass alone in patients with large ventricles.

Efficacy of endoventricular circular patch plasty

OBJECTIVES

We report hemodynamic and clinical results of our series of endoventricular circular patch plasty (Dor operation) and consider some advantages of this procedure for patients with ischemic cardiomyopathy.

METHODS

Between 1996 and 2001, 23 consecutive patients with left ventricular aneurysm and/ or ischemic cardiomyopathy after myocardial infarction who underwent Dor operation were included in this study. Hemodynamic and clinical results of Dor operation were analyzed periodically. Patients were divided into two groups according to the extent of asynergy, more than 60% or not, i.e., an ischemic cardiomyopathy group (ICM group) or a simple left ventricular aneurysm group (sLVA group).

RESULTS

Hospital mortality was 4.4%. Postoperative New York Heart Association functional class was improved in all survivors to class I or II. Postoperative ejection fraction (EF) increased and postoperative left ventricular (LV) volume decreased in all survivors. In both groups, early and 1 year postoperative EF increased significantly. Additionally, end-diastolic and end-systolic volumes decreased significantly in the early postoperative period. Postoperative LV volume had re-enlarged in the cases in which preoperative left ventricular end-systolic volume index was more than 90 mL/m2, though left ventricular ejection fraction was maintained or rather improved at 1 year postoperatively. The survival rates after 3 years of the operation in the sLVA and ICM groups were 85.7% and 81.3%.

CONCLUSION

Though patients with ischemic cardiomyopathy with severe LV dysfunction may benefit the most from Dor operation, postoperative LV re-dilatation may deteriorate late mortality. At operation, whether optimal LV size and shape can be reconstructed and the timing of operation are the important issues because they affect prognoses.

The beating heart approach is not necessary for the dor procedure

BACKGROUND

Ventricular reconstruction using the Dor technique has been demonstrated to improve outcome in patients with dilated left ventricles. It has been suggested that a beating heart approach improves ventricular function by allowing the surgeon to palpate that part of the ventricle to exclude.

METHODS

We performed a retrospective analysis of patients who underwent an endoventricular circular patch plasty (Dor procedure) between 1998 and 2001. All patients who received ventricular restoration, with or without revascularization or valve repair, were included in the analysis. Discrete left ventricular aneurysms were excluded. Patients were divided into two groups: group 1 (n = 15) underwent ventricular reconstruction with the beating heart technique, whereas group 2 (n = 38) underwent restoration with the aorta cross-clamped. Clinical and hemodynamic data were collected from medical records and computerized databases and compared between the two groups.

RESULTS

Fifty-three patients underwent endoventricular circular patch plasty. All patients had enlarged ventricles (echocardiogram demonstrating unidimensional end-diastolic diameter >/= 6.0 cm) and echocardiographic evidence of severe left ventricular dysfunction (mean ejection fraction: group 1 = 21.4%; group 2 = 23.4%). No operative mortalities occurred in either group and all patients were discharged home alive (mean postoperative hospital stay 8.3 days [6 to 22 days]). All patients had improvement in left ventricular function with mean postoperative left ventricular ejection fraction of 36.9% (25% to 52%) in group 1 versus 38.1% (31% to 50%) in group 2, p = 0.081. Ventricular arrhythmias occurred in 5 of 15 group 1 patients and in 9 of 38 group 2 patients. Two patients in the entire cohort (1 patient in group 1, and 1 patient in group 2) had at least one readmission within 12 months with evidence of heart failure. The group 1 patient went on to successful transplant 11 months later, whereas the group 2 patient died 10 months later.

CONCLUSIONS

These results demonstrate that the Dor technique of ventricular restoration significantly improves left ventricular function and the beating heart approach provides no additional advantage over continuous aortic cross clamping.

Atrophic degeneration and loss of myocytes of residual left ventricular myocardium after Dor operation for ischemic cardiomyopathy associated with left ventricular remodeling

A 32-year-old male with familial hypercholesterolemia suffered from severe left ventricular dysfunction caused by left ventricular remodeling after myocardial infarction (ischemic cardiomyopathy), and endoventricular circular patch plasty (Dor operation) was performed. The patient's postoperative recovery was favorable. Postoperative left ventricular function was significantly improved and the patient was discharged from our hospital. However, about 5 months later, the patient developed congestive heart failure, which progressed rapidly and irreversibly, with death at postoperative month 6. At autopsy, atrophic degeneration and loss of myocytes of the residual left ventricular myocardium were suggested to be the cause of irreversible heart failure. The postoperative balance between function of the residual myocardium and reduced left ventricular volume should be considered in cases of Dor operation for ischemic cardiomyopathy with left ventricular remodeling.

Ischemic dilatative cardiomyopathy and aneurysms of the left ventricular cavity: transplantation vs alternative surgery

Patients with terminal end-stage heart failure due to severe coronary disease associated with dilatative cardiomyopathy have an annual mortality of 30-50%. Between July 1997 and December 1999, 21 patients at the University Hospital in Frankfurt, and 25 patients from Skopje underwent total circular repair with simultaneous coronary artery bypass.

Surgical ventricular restoration in patients with postinfarction coronary artery disease: effectiveness on spontaneous and inducible ventricular tachycardia

Surgical ventricular reconstruction (SVR) involves resection of scar, septal exclusion, cavity reduction by endoventricular patch, and complete coronary grafting. At the Cardiothoracic Centre of Monaco, ventricular stimulation (PVS) is performed before SVR, unless contraindicated. In patients with spontaneous and/or inducible ventricular arrhythmias, nonguided endocardiectomy and cryosurgery are added. We report clinical and hemodynamic results after SVR in postinfarction patients, to compare management of patients with spontaneous and/or inducible ventricular tachycardia, with those without arrhythmias. The 3 subsets were: Group A, 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia (Spontaneous); Group B, 105 patients without clinical ventricular arrhythmias but with inducible ventricular tachycardia at PVS (Inducible); and Group C, 190 patients without spontaneous arrhythmias and not inducible ventricular tachycardia at PVS (No arrhythmias). Overall surgical mortality rate was 7.6% (29 of 382). Sudden death mortality was only 18.7% of all deaths. Surgical management caused marked reduction of inducible ventricular tachycardia, from 144 of 352 inducible ventricular tachycardia before surgery (41%), to 26 of 307 (8%) at early study, and 14 of 177 (8%) one year later. Cardiac mortality was low at 5 years, and not different among groups; this indicates that the surgical procedure limits the ventricular arrhythmias that normally impair prognosis in postinfarction dilated cardiomyopathy. We believe the favorable electrical success rate and low mortality are not linked to one aspect of the surgical procedure, but to an integrated approach that relieves ischemia (coronary bypass graft), and reduces left ventricular volumes (SVR) to improve pump function, and nonguided endocardiectomy plus cryoablation, to interrupt functional reentry circuits.

Intermediate survival and predictors of death after surgical ventricular restoration

This study examined the effects of Dor procedure on long-term survival in patients with previous transmural anterior myocardial infarction who were referred to a single experienced center for left ventricular reconstruction by endoventricular patch-plasty repair. Our aim was to evaluate the impact of this procedure on long-term survival and to assess the ability of preoperative, perioperative, and postoperative variables to predict late survival. Major indications for surgery were left ventricular dysfunction, angina, ventricular arrhythmias, or a combination of the three; 20 patients underwent urgent cardiac surgery. The total group was 245 patients, with 8.1% hospital mortality, and 19 patients lost to follow-up [corrected]. The study group comprised 207 patients. Many pre- and postoperative clinical, hemodynamic, and functional variables, as well as operative parameters, were studied by univariate analysis. During a mean follow-up period of 39+/-19 months, 30 end points were observed, including 27 deaths and 3 heart transplants. Event-free survival was 98%+/-1% at 1 year, 95.8%+/-1.4% at 2 years, and 82.1%+/-3.3% at 5 years. Cox regression analysis showed preoperative New York Heart Association functional class, ejection fraction, end systolic volume index, and remote asynergy as independent predictors of mortality. The procedure has a favorable impact on 5-year survival. Independent predictors of late survival are the preoperative functional status and the left ventricular systolic function.

Effects of the Dor procedure on left ventricular dimension and shape and geometric correlates of mitral regurgitation one year after surgery

OBJECTIVES

In the present study we retrospectively analyzed ventriculographic data from symptomatic patients after myocardial infarction who underwent the Dor procedure (endoventricular circular patch plasty repair) to evaluate left ventricular shape 1 year after the operation and to analyze the geometric correlates of late mitral regurgitation.

METHODS

Forty-four patients with previous transmural anterior myocardial infarction comprised the study group. Left ventricular volumes, global left ventricular systolic and diastolic sphericity, the extent of wall motion abnormalities, and the presence and degree of mitral regurgitation were analyzed before and 1 year after operation.

RESULTS

Comparing preoperative diastole to systole within the cardiac cycle, left ventricular shape becomes more elliptical in systole than it was in diastole (eccentricity index closer to 1). The intervention leads to an increased diastolic sphericity, but for each cardiac cycle, the systolic shape is more elliptical relative to its diastolic counterpart in respect to basal conditions. Mitral regurgitation was detected after operations in 17 patients; 14 of them did not have mitral regurgitation before operations. Patients with late mitral regurgitation had greater preoperative volumes and more spherical chamber than did patients without late mitral regurgitation.

CONCLUSIONS

Despite a more spherical postoperative left ventricular chamber, systolic pump function improves after the Dor procedure, mainly for the improvement in inferior wall shortening. The presence of late mitral regurgitation is relatively frequent in this series of patients, and this emphasizes the importance of a more accurate quantitative evaluation of preoperative functional mitral regurgitation to repair the valve when appropriate. Geometric correlates of late mitral regurgitation appeared to be greater chamber sphericity and larger ventricular volumes preoperatively.

Akinetic versus dyskinetic postinfarction scar: relation to surgical outcome in patients undergoing endoventricular circular patch plasty repair

OBJECTIVES

This retrospective study attempted to relate surgical outcome with the extent and type of preoperative wall motion asynergy in patients with postinfarction myocardial scar who underwent endoventricular circular patch plasty repair and associated coronary grafting.

BACKGROUND

Left ventricular (LV) pump function improvement is difficult to predict after aneurysmectomy, for either akinetic or dyskinetic scar, and previous studies have reported that the absence of paradoxic systolic motion correlates with higher operative mortality and no improvement in pump function.

METHODS

Two hundred forty-five patients who underwent endoventricular circular patch plasty repair and associated coronary grafting were retrospectively selected if they had technically adequate right and left anterior LV angiograms before the operation. All had right and left cardiac catheterization. The centerline method was applied to preoperative right anterior oblique LV angiography to assess the absolute motion of the chords and the percent length of the perimeter showing a fractional shortening <2 SD from the normal mean value (extent of asynergy ([A%]).

RESULTS

The overall perioperative mortality rate was 6%; 120 patients had akinetic and 125 had dyskinetic scar, and no differences were found among the groups in terms of all the clinical and hemodynamic variables collected in the study. Patients with a large scar (A% >60), either akinetic or dyskinetic, had a higher perioperative mortality rate (12%) than patients with a small scar (2.2%). After the operation, the ejection fraction (EF) increased from 36 +/- 13% to 50 +/- 13% (mean +/- SD), and pulmonary pressures significantly decreased. End-diastolic volume decreased from 199 +/- 75 to 89 +/- 36 ml/m2. Patients with a large akinetic scar had the most severely impaired preoperative function (largest ventricular volumes and highest pulmonary mean pressure); nevertheless, they had an impressive improvement in function (EF from 25 +/- 9% to 41 +/- 12%), not different from that observed with large dyskinetic scarring (EF from 26 +/- 7% to 46 +/- 11%).

CONCLUSIONS

Surgical outcome of endoventricular circular patch plasty repair for postinfarction myocardial scar relates to the extent of LV asynergy rather than to the presence or absence of dyskinesia. Patients with a large akinetic scar and severely depressed pump function benefit from a relatively simple surgical procedure previously reserved only for dyskinetic aneurysm. The reduction of wall tension and oxygen demand, owing to the marked decrease of volumes, and the increase in oxygen supply, owing to revascularization, may play a major role in improving pump function.

Technical advances in the treatment of left ventricular aneurysm

The resulting abnormal geometry after surgical treatment of left ventricular aneurysm has concerned a number of surgeons since the first successful repair in 1958, but little attention was placed on the altered geometry until attempts were made to effect a more physiologic aneurysmorrhaphy in 1973. Substantial attention was focused on a concept of geometric reconstruction from within the left ventricle in 1985. A prosthetic patch was employed with the concept to redirect normal muscle bundles to their original orientation and position. Further refinements include use of improved materials for the repair, preservation and bypass of the left anterior descending coronary artery, ablation of ventricular arrhythmias when indicated, and the absence of prosthetic material used in contact with the pericardial surface. Our experience with repair of 61 left ventricular aneurysms at West Jefferson Medical Center over a 4 1/2-year period with a 3.3% mortality rate has prompted a change from the standard linear repair to routine use of a modified endoventricular repair. Currently, the low surgical risk due to advances in left ventricular aneurysmorrhaphy combined with the knowledge that contractile areas will progressively deteriorate in ventricles stressed by poor hemodynamics and with data showing improved left ventricular function postoperatively have led to more liberal recommendations for early left ventricular aneurysm repair.

Surgery for chronic left ventricular aneurysm. Benefits and side effects

Seventy patients who underwent elective resection of symptomatic postinfarction apico-anterior left ventricular (LV) aneurysm with or without coronary revascularization are reviewed. The early (< or = 30 day) mortality was 5.7%. Mural thrombosis occurred in 29 cases (41.4%), unrelated to the degree of preoperative LV impairment and predictable from preoperative LV angiography in only seven cases. The response to surgery comprised significant overall improvement of global LV ejection fraction (LVEF) during rest and of all variables in stress testing. This LVEF recovery correlated significantly with that of peak ejections rate, a variable of myocardial contractility. Contrastingly, right ventricular ejection fraction (RVEF) at rest decreased slightly but significantly without correlation to preoperative RVEF or LVEF. In comparisons between patients with congestive heart failure or angina at rest as dominant symptom, the former group showed greater depression of preoperative watt and LVEF but better postoperative recovery of these variables, while right ventricular deterioration was significant only in the latter. Postoperative recovery was best in patients with poor preoperative LV function (LVEF < or = 20%), even when surgery comprised only aneurysmectomy in isolated but ungraftable LAD disease (5 cases). The observed RV deterioration may be 'nonspecific', but it must be kept in mind as a side effect of the operation, as it detracts unpredictably from postoperative ventricular recovery. Patients with well preserved preoperative LVEF, small LV aneurysm and marginal expected post-aneurysmectomy changes according to LaPlace's law are probably at risk, and surgery should then instead be directed towards preserving the remaining viable myocardium by direct revascularization.