1. Introduction
LVAs have long been described at autopsy, but LVA was not recognized to be a consequence of coronary artery disease until 1881 [1]. The angiographic diagnosis of LVA was first made in 1951 [1]. The surgical treatment of ventricular aneurysm was introduced in 1944, when Claude S. Beck reinforced the wall of LVA with fascia lata aponeurosis in order to reduce excessive dilatation and avoid LVArupture. In 1955, Likoff and Bailey performed closed ventriculotomy by placing a large vascular clamp on the beating heart tangentially across the base of LVA followed by resection and suture [2]. In 1958, Cooley and colleaues performed the first postinfarction aneurysm resection and linear repair of left ventriculotomy with the use of cardiopulmonary bypass. The technique offered by Levinsky and colleagues in 1979 supposed the performance of left ventricular reconstruction with a woven Dacron patch after resection of anterior postinfarction aneurysm. In 1985, Jatene and Dor independetly presented a fundamentally new, anatomic left ventricular reconstruction method with endoventricular circular reduction and stiching patch in the formed ventriculotomy orifice [3].
The aim of this paper was to study the management of true LVA following MI in a major Iraqi cardiac surgical centre noting the methods of diagnosis and surgical treatment options and the outcome in view of the relevant literature.
2. Materials and Methods
Twenty-seven patients (20 males and 7 females) with LVA who were admitted to Ibn-Albitar Centre for Cardiac Surgery (IBCCS) over the period from May 1st, 2001 to December 31st, 2011 were retrospectively studied. Patients’ informed consents and approval of the Hospital Ethics Committee were obtained. The case sheets of these patients were obtained. Information like age, sex, place of residency, presenting symptoms and signs, past medical history particularly ischemic heart disease (IHD) were looked for. The diagnostic work-up was reviewed looking for specific investigations like electrocardiography (ECG), chest radiography (CXR), echocardiography, cardiac catheterization and coronary angiography. All patients in this study were initially seen and thoroughly investigated by cardiologists. Thereafter, surgical candidates were referred for surgery.
All patients had repair of aneurysm (mostly linear repair or Dor procedure) together with myocardial revascularization (CABG) except 3 patients who had repair of their aneurysm alone. Four patients with an associated VSD had closure of this defect as well. The operative notes and the perfusionists’ notes were all reviewed to get an idea of the conduct of the operation. Intra-aortic balloon pump (IABP) was used selectively (either before induction of anesthesia or at the end of operation).
Operative procedure: The aneurysmal wall was incised and thrombi removed if present. Repair was done either by the linear method for small aneurysms or Dor procedure for big ones. In the linear method, after excising the aneurysm, the edges of viable myocardium were sutured together by interrupted pledgeted sutures over Teflon felts. While in Dor technique, a purse string (2 zero) Polypropylene suture was used to narrow the defect. The remaining ventriculotomy was closed by a Dacron patch sutured interruptedly by pledgeted Polypropylene sutures over Teflon strips.
The postoperative morbidity and mortality were studied. The follow-up was unfortunately not available apart from the interval between surgery and discharge.
3. Results
The male to female ratio of patients was 2.8:1.
The youngest patient was a 36-year-old male and the oldest one was a 67-year-old lady. The mean age was 54.6 years old. The age and sex distribution of these patients is displayed in Table 1. Most of the patients (96.3%) were above 40.
All patients had history of IHD and therefore; LVA was a complication of MI.
We could obtain ECG recordings from 19 patients only. These were studied carefully. The typical LV aneurysm morphology (ST elevation seen > 2 weeks follow-
Table 1. The age and sex distribution.
ing acute MI, most commonly in the precordial leads, with a concave or convex morphology, associated with well-formed Qor QS-waves and a relatively small amplitude T-waves) was observed in 8 patients (42.1%).
During the period of this study 1136 patients with IHD had CABG operations in IBCCS. Thus the overall rate of LVA repair to CABG operations was 2.4%. Regarding distribution of patients over years of the study, we found that 62% of them were seen in the last three years.
Echocardiography was done in 25 patients. The ejection fraction values are shown in Table 2. The vast majority (84.2%) had subnormal values. Other echocardiographic findings are shown in Table 3.
The sites of aneurysm are displayed in Table 4: apical and antero-apical locations were the commonest.
Most patients in this study had multi-vessel CAD. Review of the coronary angiograms revealed about 46 stenotic or occlusive lesions in 27 patients as shown in Table 5. The most frequently diseased artery was the LAD.
The perfusion charts of 25 patients were reviewed. Almost one third of patients (8) required IABP support mostly at the end of operation.
The operative procedures done to the patients in this study are shown in Table 6. Twenty four patients (88.9%) had CABG. Four patients (14.8%) with an associated VSD had closure of these defects.
The type of repair of LV aneurysms is shown in Table 7. Linear repair and Dor technique were almost used equally. The details of myocardial revascularization are shown in Table 8. Most of the patients had multivessel coronary artery disease and received complete revascularization.
Regarding the outcome of patients with an associated VSD; one patient has died making a mortality of 25%.
In regard to the duration of postoperative hospitalization, most patients (19, 70.4%) stayed for 1 - 2 weeks.
The complications are displayed by Table 9. The commonest was bleeding.
Five out of twenty-seven patients who were managed surgically had died (18.5%). This represents death during the first hospitalization only. The mortality after discharge might be higher as there was no recordable follow up.
4. Discussion
The 27 patients with LVA repair represented 2.4% of the total 1136 patients who underwent CABG operations
Table 3. Other echocardiographic findings.
Table 8. Details of myocardial revascularization.
Table 9. Postoperative complications.
during the period of the study in IBCCS. This figure is close to that reported by Antunes et al. from Portugal (2%) [4].
4.1. Age & Sex Distribution
LVA following MI has a similar age and sex distribution to IHD [4-10].
4.2. Symptoms
With regard to presenting symptoms, absence of angina pectoris and dyspnea as the predominating symptom was associated with early mortality according to a study by Vural et al. [11]. Moreover, lack of angina was an independent predictor for operative mortality [11]. It can be speculated that, preoperative angina, probably but not necessarily, may indicate viable myocardial tissue existence, which is capable of generating power during systole, more compliant during diastole and has less compromising effect on ventricular geometry when compared to a totally fibrotic aneurysmal sac [11].
4.3. Electrocardiography
The typical LV aneurysm morphology in the ECG described earlier in the Results was observed in 8 patients (42.1%) only. This ECG pattern has a sensitivity of 38% and a specificity of 84% for the diagnosis of ventricular aneurysm [7].
4.4. Incidence
62% of patients were seen in the last three years of the study. This could be related to a real increase in the incidence of IHD and its complication like LVA, a concomitant rise in CABG operations, a better diagnosis of LVA, increased awareness of cardiologists about the role of surgery in LVA and thus more referral of cases and a significant increase in the number of efficient young coronary surgeons capable of performing LVA repair with concomitant CABG.
4.5. Diagnosis
Echocardiography has a sensitivity and specificity of 93% and 94%, respectively, for detecting LV aneurysm, representing the most frequent and easily applied test for such an anatomic abnormality. Left ventriculography, however, remains the gold standard for the diagnosis [9].
4.6. Ejection Fraction
The vast majority of our patients (84.2%) had subnormal EF values. Results of many studies have shown that the ejection fraction of the total left ventricle is an important predictor of the outcome of open heart surgery [11,12]. Ventricular ejection fraction improves following aneurysm repair whether linear or patch technique is used [1].
4.7. Other Echocardiographic Findings
In the present study, echocardiography was very useful. This is evident by looking at Table 4 which displayed many studied parameters. Mural thrombi were found in 20% of patients exactly the same as reported by Mangschau et al. [13] and were removed surgically. Four postischemic VSDs were accurately diagnosed and fixed surgically thereafter.
4.8. Location
In this study, anterior (11; 40.7%) and apical aneurysms (10; 37.1%) were the commonest. In clinical reports, LVA is usually located in the anterior wall, whereas infero-posterior or postero-lateral aneurysms are less common. Postinfarction LVA follows pathology of the LADdiagonal system (anterior aneurysm), circumflex branches (posterolateral aneurysm), or right coronary artery (inferoposterior aneurysm) [14]. In our series, a significant LAD lesion was present in 21 patients (77.8%). The prevalence of inferoposterior aneurysms is significantly higher in autopsy series than in clinical reports [14]. This may be due to the extensive infarction necessary for LVA formation. When this occurs in the inferoposterior wall, the result is often acute, severe mitral regurgitation and the patient dies in the acute phase rather than develops LVA [14].
4.9. Linear vs. Patch Repair
In the present series, linear and Dor repair were almost equally used (11 patients, 40.7% in each group), whereas the method of repair was not clear in 4 patients (14.8%). The basis on which patients were offered either type of repair is not known. Generally, the choice of repair technique should not be made randomly, but depending on factors such as size and extension of scar tissue [11].
Although aneurysmectomy has been performed for almost five decades, the most appropriate surgical approach to a patient with a dyskinetic LVA is still controversial [4]. Antunes et al. believed that the technique of repair of postinfarction dyskinetic LVAs should be adapted in each patient to the cavity size and shape, and the dimension of the scar [4]. Unduly wide excision of the scar area and linear closure of the LV defect might lead to deformation of the LV chamber and a reduction in LV diastolic volume [15].
4.10. Impact of Coronary Revascularization
CABG is one of the important components of LVA surgery, and the revascularization rate varies in the literature from 68% to 100% [3] Twenty four patients in this study (88.9%) had CABG; which goes with the international standard. Most of the patients had multi-vessel coronary artery disease and received complete revascularization as shown in Table 9. Although the surgical risk is increased, patients with low LVEF and multi-vessel disease have a particular survival benefit after CABG [14]. The biological basis for this is recruitment of hibernating myocardium [14].
4.11. When CABG Is Not Added!
Three patients in this study had LVA repair without CABG. Two patients survived while the third (having total occlusion of RCA) died. It is noteworthy that RCA disease is associated with low cardiac output (CO) on multivariate analysis [3] which probably was the cause of death in this patient. In a study on 303 patients with LVA from Sweden, Stahle et al. reported an early mortality of 23% in patients who underwent aneurysm resection alone and 8.1% in cases of aneurysm resection with CABG [6]. This emphasizes the importance of concomitant CABG with LVA repair. Vural et al. in a retrospective analysis of 248 patients also found that concomitant CABG reduced the incidence of low CO state [11].
4.12. LVA + VSD
This is an important complication of MI that has been commonly associated with progression to death [16]. Surgery is routinely performed in patients with acute VSD during MI [16]. Schlichter et al. reported a 3% incidence of VSD in a series of 102 patients with LVA [17]. Acquired VSD was first surgically repaired by Cooley et al. (1957) using CPB and hypothermia [17]. In 1962, Collis et al. described the repair of a VSD and LVA in a man of 59 [17]. When LVA coexists with a VSD, there is an obvious route for access to the septum since the left ventricular myocardium is already damaged [17]. The approach from the left which is thus afforded is ideal, first in that the septum on this side is smoother and the defect thus is more easily defined, and secondly the left ventricular pressure keeps the patch in contact with the septum, whereas a patch applied from the right side may be forced away from the septum [17]. Lazopoulos et al. described a case of giant LVA and VSD following a silent MI managed by an endoventricular circular plasty (Dor procedure), interrupted suturing of ventricular septum and CABG [18].
In the present series, 4 patients had LVA + VASD (14.8%). One patient died (25% mortality). This is higher than what was reported by Olearchyk et al. (20%) [19].
4.13. Morbidity
The commonest postoperative complication was bleeding. In other studies [3,4] low CO was on the top of the list.
4.14. Overall Mortality
5 out of 27 patients who were managed surgically had died (18.5%). In a collection of 3439 operations for LVA performed between 1972 and 1987, hospital mortality was 9.9% and ranged from 2% to 19% [1] and it has recently fallen to 3% to 7% in the last decade [1]. In view of these figures, our mortality is obviously high. The most likely reason is the small number of patients and the limited experience in the management of this condition. In regard to the possible causes of death, postoperative bleeding was blamed in 2, low CO in 1 while it remained unknown in 2 patients. Low CO accounted for 34% of early mortality in Vural et al. series [11]. Mukkadirov et al. also believes that severe low CO is one of the main causes of early mortality after aneurysmectomy [3].
4.15. Perfusion Time and IABP
The mean perfusion time in this study was 100 minutes, higher than that reported by Antunes et al. (82.7 minutes) [4]. Long periods of aortic-cross clamping have detrimental effects during weaning from CPB [20].
IABP was used in 8 patients (32%) in this study, whereas Eid used it in 26.7% of his patients [20]. IABP has become a prerequisite for surgical repair of LVA [20] especially in patients with compromised LV function [20].
NOTES