Left ventricular restoration

Patients with large left ventricular aneurysms gain symptomatic relief from simple linear aneurysmectomy. So called "ventricular restoration" has recently extended from scarred paradoxical segments to akinetic areas which were not previously thought suitable for surgery.13 The goal of surgical reversal of remodelling is to exclude the infarcted septum and free wall and reshape the left ventricle from globular to elliptical without critically reducing

Table 11.3 Decision making in the surgery of end stage ischaemic heart disease



Reversible ischaemia LVESVI < 60ml/m2 Full thickness scar and left ventricular aneurysm Akinetic/dyskinetic left ventricle LVESVI > 60

ml/m2 Reversible ischaemia Class III/IV mitral regurgitation No reversible ischaemia LVESVI >100 ml/m2 Pulmonary hypertension (PAP > 70 mm Hg) Right ventricular failure

CABG alone

Linear resection ± CABG Surgical remodelling ± CABG

Mitral repair ± CABG

Left ventricular assist device or transplantation (no conservative option)

LVESVI, left lentricular end systolic volume index (normal is < 30 ml/m2); CABG, coronary artery bypass grafting; PAP, pulmonary artery pressure.

Endoventricular _repair_

Figure 11.2. Left ventricular restoration by endoventricular patch repair (the Dor procedure) as opposed to simple linear aneurysmectomy.

Figure 11.3. The Dor procedure restores an elliptical shape from the globular failing left ventricle (courtesy of Dr Vincent Dor).

Figure 11.2. Left ventricular restoration by endoventricular patch repair (the Dor procedure) as opposed to simple linear aneurysmectomy.

cavity volume. This improves global function and arrests progression of left ventricular failure. Ventricular dysrhythmias and mitral regurgitation are addressed during the same procedure.

In the Dor procedure, or the Buckberg modification, the left ventricle is opened through scar and subtotal endocardectomy (fig 11.2), performed over the septum and posterior wall.14 In the event of recurrent ventricular arrhythmias, cryotherapy is applied at the limits of the resection. The boundary between normal endocardium and scar is defined and a circumferential endoventricular (Fontan) circular suture passed between 1-2 cm outside the limit of healthy muscle. This circular constricting suture is tied to reduce the size of the left ventricle around a balloon inflated within the cavity to a diastolic volume of 50-70 ml/m2. The residual apical defect is then closed with a Dacron patch cut according to the circumference of the circular suture after removing the balloon. The technique restores an elliptical shape (fig 11.3) with improved function over the globular failing ventricle. Intraoperative echocardiography has shown a decrease in LVEDV from a mean of 194 ml to 128 ml (p = 0.001) and an improvement in LVEF from a mean of 29% to 41% (p = 0.003).The operation can be performed in patients with very low LVEF (< 20%) and pulmonary hypertension with a hospital mortality of 12-18%. This compares with a 3% mortality for those with ejection fraction > 30%. Most patients improve to NYHA I or II, but 10% of survivors are not improved and about 25% have persistently raised pulmonary artery pressure through impaired diastolic compliance.

Figure 11.3. The Dor procedure restores an elliptical shape from the globular failing left ventricle (courtesy of Dr Vincent Dor).

Linear left ventricular aneurysm resection and the Dor procedure both improve remote myocardial function secondary to a reduction in wall tension. This "LaPlace" concept was expanded by Batista in his partial left ventri-culectomy operation.15 The much hyped procedure was devised to reduce left ventricular volume and wall stress, thereby improving LVEF and symptomatic status.16 It was widely adopted as an alternative to transplantation without adequate guidelines or convincing information on sustainability or survival. The technique itself consists of a wedge resection of posterolateral left ventricular wall either between or including the papillary muscles. The incision begins at the apex of the ventricle and extends to within 2-3 cm of the mitral annulus (fig 11.4). Full thickness myocardial excision proceeds irrespective of the coronary anatomy and usually removes the obtuse marginal branches in the circumflex territory. The cavity is then reconstituted along its long axis with a continuous suture.

There is surprisingly little information on the amount of myocardium excised. The Cleveland Clinic group weighed the resected specimen, which ranged from 30-290 g (mean 96 g).17 The San Paolo group removed a posterolateral segment measuring 10.9 (2) cm x 5 (0.8) cm, equivalent to about 20% of the left ventricular circumference.18 When the resection includes the base of one or both papillary muscles (88% of cases), the valve is either replaced with a prosthesis or the papillary muscles are reimplanted with transfixion sutures at the margins of the ventriculotomy (fig 11.5). If the mitral subvalvar apparatus is preserved, the free margins of the anterior and posterior leaflets are sewn together to produce

• The goal of left ventricular restoration surgery (Dor procedure) is to reshape (from globular to elliptical) and reorganise the ventricle, not to reduce the volume. Reversible ischaemia, mitral regurgitation, and dysrhythmias should be addressed at the same time.

• Left ventricular end systolic volume index (LVESVI) is a strong predictor of death in heart failure (LVESVI > 60 ml/m2 carries a one year mortality of 33%).

• Patients with a good outcome from the Dor operation have an LVESVI > 40 ml/2.

• Coronary bypass alone improves ejection fraction only if the preoperative LVESVI is < 100 ml/m2.

• Linear left ventricular remodelling (the Batista operation) is unpredictable with an unacceptable early failure rate and late mortality.

Figure 11.4. Partial left ventriculectomy (the Batista operation).

a double channelled mitral valve (Alfieri method)19 (fig 11.6). Even published hospital mortality has been prohibitive, ranging from 1.9-27% with an average of 17.4%.20 Low hospital mortality has been achieved only with the aid of long term LVAD support (20% of patients), and cardiac transplantation.

In survivors, there is a significant decrease in both end diastolic and end systolic volume indices. While LVEF initially improves, restudy at 12 months fails to show significant differences between preoperative LVEF (17.7 (4.6)) and late LVEF (23.7 (6)) in matched patients. The suggested mechanism for improvement in LVEF is reduction of systolic wall stress rather than a change in contractility. There is an inverse relation between the decrease of circumferential end systolic stress and increase in LVEF. In McCarthy's series, mean LVEF improved from 13% to 21% and peak oxygen consumption from 11 ml/kg/min to 16 ml/kg/ min at 12 months.17 Twelve month survival at the Cleveland Clinic was 80% though LVADs were required for bridge to transplantation in 16% of patients. However, freedom from heart failure of any cause (relisting for transplant, death or class IV symptoms) was only 50% by 12 months and 38% at two years.

Though the reduced ventricular geometric dimensions may be sustained up to 12 months (fig 11.7), pump function begins to deteriorate after six months. The first sign is a rise in left atrial pressure. The discrepancy between geometry and sustainability of mechanical function is attributed to the fact that mass reduction causes changes in diastolic compliance.

Though late data are scarce, we defined a 16% mortality from all reported series through progressive heart failure (38%), sudden or arrhythmic death (38%), stroke, transplant heart failure, sepsis or hepatic failure.20 The procedure has been abandoned in ischaemic cardiomyopathy through a prohibitive incidence of fatal dysrhythmias caused by stretch-

Figure 11.5. Diagrammatic and echocardiography illustration of the partial left ventriculectomy operation. The mitral subvalvar apparatus is preserved by reimplanting the papillary muscles at the margins of the ventriculotomy.

ing of the scar tissue.21 In reality, most centres who enthusiastically embraced partial left ventriculectomy have now radically cut back operating only on highly selected dilated cardiomyopathy patients. With emerging alternatives the Batista operation is destined to join skeletal muscle cardiomyoplasty in the dustbin of heart failure operations.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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