Abstract
Objective: The study aimed to compare the clinical outcomes of simplified linear
plication and classic patch plasty in patients with left ventricular
aneurysm (LVA).
Methods: We retrospectively reviewed 282 patients undergoing LVA repair between 2006
and 2016. After propensity score matching, 45 pairs of patients receiving
LVA surgery were divided into either a patch group (on-pump endoventricular
patch plasty) or a plication group (off-pump linear plication). Then, their
early surgical outcomes and long-term survival were compared in two matched
groups.
Results: The heart function improvement at discharge was similar in the two matched
groups, while patients in the patch group more commonly suffered from low
cardiac output syndrome (P=0.042) with higher proportion of
intra-aortic balloon pumping assistance (P=0.034) than
patients in the plication group. Compared with patients in the patch group,
the patients in the plication group had shorter recovery times, regarding to
mechanical ventilation, intensive care unit stay, and hospital stay
(P<0.001, P<0.001, and
P=0.001, respectively). No significant difference was
found in the long-term survival (P=0.62).
Conclusions: Off-pump linear plication presented acceptable results in terms of early
outcomes and long-term survival. For high-risk patients, the simplified LVA
repair technique may be an option.
Keywords: Left Ventricular Aneurysm, Patch Plasty, Linear Plication Repair, Outcomes.
Carátula del artículo
Left Ventricular Aneurysm Repair: Off-pump Linear Plication
versus On-pump Patch Plasty
Hua Wei
Capital Medical University, China
Beijing Institute of Heart, Lung, and Blood
Vessel Diseases, China
Shoudong Chai
Clinical School of Taishan Medical
University, China
Changcheng Liu
Capital Medical University, China
Beijing Institute of Heart, Lung, and Blood
Vessel Diseases, China
Xinsheng Huang
Capital Medical University, China
Beijing Institute of Heart, Lung, and Blood
Vessel Diseases, China
Chengxiong Gu
Capital Medical University, China
Beijing Institute of Heart, Lung, and Blood
Vessel Diseases, China
Brazilian Journal of Cardiovascular Surgery, vol. 34, no. 2, pp. 187-193, 2019
Sociedade Brasileira de Cirurgia Cardiovascular
Received: 16 October 2018
Accepted: 17 December 2018
Funding
Funding source: National Natural Science Foundation of China
Contract number: 81370436
Funding statement: This work was supported by the National Natural Science
Foundation of China [grant number 81370436].
Abbreviations,
acronyms & symbols
INTRODUCTION
Left ventricular aneurysm (LVA) secondary to acute myocardial infarction (AMI) can
lead to a poor prognosis. Heart failure[1] is the most common cause of death in patients with LVA duo
to severe left ventricle (LV) remodeling. Surgical repair is still the optimal
therapy for LVA. The Dor procedure (endoventricular circular patch
plasty)[2] has been
advocated as a classic surgical technique with a more physiologic geometric
reconstruction. But this procedure must be performed with ventriculotomy and
cardiopulmonary bypass (CPB) assist. And extensive myocardial incision could cause
additional myocardial damage, possibly impairing the cardiac function and increasing
the operative risk.
Recently, the linear plication of LVA without ventriculotomy and CPB assist has been
accepted as a simplified surgical technique[3,4]. However, the most appropriate LVA repair technique remains a
matter of controversy. In this retrospective study, we compared off-pump linear
plication with on-pump patch plasty regarding to early surgical outcomes and
long-term survival.
METHODS
Patient population
From 2006 to 2016, 316 patients suffering from severe coronary disease and LVA
underwent myocardial revascularization and LVA repair. Thirty-four patients who
also presented mural thrombosis of LV, ventricular arrhythmias, or valve disease
were excluded, remaining the 282 patients who were recruited in the study.
According to the strategy of the LVA reconstruction, 97 patients underwent the
Dor procedure (patch group), and the others underwent off-pump linear plication
repair (plication group). Baseline characteristics, surgical outcomes, and
survival information were collected from medical records and patients' follow-up
visits. The study was carried out in accordance with the Ethical Guideline of
the Committee on Human Experimentation of our institution, and the informed
consent was obtained from the patients about the experimentation.
To reduce the selection bias, the differences in the distribution of baseline
characteristics between the patch group and the plication group were eliminated
by matching on the propensity score. And the propensity score was calculated
using the logistic regression model based on the following variables: age,
gender, hypertension, diabetes mellitus, dyslipidemia, chronic obstructive
pulmonary disease (COPD), prior cerebrovascular disease, renal dysfunction, New
York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF),
number of diseased arteries, LVA location, and left ventricular aneurysm
dimensions (LVAD) (mmxmm) measured by the apical two-chamber view of LV in
transthoracic echocardiogram. Based on the calculated propensity score, matching
between the two groups was achieved through a propensity score matching
algorithm. Finally, 45 pairs of patients were successfully matched in a 1:1
manner (area under the receiver operating characteristic curve = 0.764;
Hosmer-Lemeshow statistic = 0.2).
Surgical Techniques
All patients underwent standard procedural protocol involving median sternotomy
under general anesthesia and harvesting of the left internal mammary artery
(LIMA) and saphenous vein (SV). The decision on the LVA repair technique was
based on the size of the aneurysmal sac during surgery. Dor procedure was
performed in case of a large scar with marked aneurysmal sac, whereas off-pump
linear plication was preferred in case of a small scar.
In the patch group, CPB was established following the routine moderate systemic
hypothermia (esophageal 26°C-32°C). After cross-clamping the aorta, myocardial
protection was achieved by antegrade perfusion and graft perfusion with cold,
blood-infused cardioplegia. After the distal anastomosis of the traditional
coronary artery bypass grafting (CABG), the LVA was repaired using the Dor
procedure (endoventricular scar resection and circular patch plasty). Dor
procedure details refer to a previous study[5]. Once the ventricular repair was completed,
the proximal anastomosis was created on the site of antegrade perfusion.
In the plication group, off-pump CABG was performed firstly. Following, the LVA
and the transitional zone of viable myocardium and thinned scar tissue were
confirmed by visual inspection and palpation. Then, LVA was isolated in the
transitional zone and 2-0 Surgipro843 sutures were passed through one strip of
Teflon felt, the rim of the aneurysm, and the opposite strip of the Teflon felt,
successively, in a horizontal mattress fashion. Plication was designed to remove
as much nonfunctioning thin wall as possible while restoring the ventricular
size and shape using the linear closure (Figure
1).
Fig. 1
Off-pump plication repair technique of left ventricular aneurysm.
(A) Linear plication was performed with Teflon felt successively in
a horizontal mattress fashion. (B) Schematic diagram showed the
linear plication.
LV=left ventricle; RV=right ventricle
Follow-Up
The follow-up was conducted via telephone contact with patients or revisits to
our outpatient department. Primary endpoint was cardiac death. All patients were
followed up until mid-September 2017.
Statistical Analysis
Statistical analysis was performed using an extensively admissive software
program, the SAS software (version 9.4; SAS Institute Inc., Cary, NC, USA). Data
were presented as means ± standard deviation (SD) for continuous
variables and as frequencies and percentages for categorical variables. The
continuous variables were analyzed using Wilcoxon rank-sum analysis. Chi-squared
test and Fisher's exact test were applied for the comparison of categorical
variables. Log-rank (Mantel-Cox) survival curves were made to compare the
long-term survivals of the two surgical interventions. All the
P values < 0.05 were considered statistically
significant.
RESULTS
Baseline Characteristics
Baseline data were showed in Table 1. The
two groups had different demographics and concomitant diseases. Patients in the
patch group suffered from more severe left ventricular remodeling than those in
the plication group (LVEF: 33.50±7.35% versus
38.32±7.86%; LVAD: 51mmx43mm versus 38mmx32mm,
respectively; P<0.01). However, patients in the plication
group were older than those in the patch group (62.32±9.23
versus 59.58±8.26, respectively;
P=0.015). Compared with the patch group, the diabetes mellitus
was more common in the plication group, 40.00% versus 27.83%,
respectively (P=0.043). Furthermore, the plication group had a
higher proportion of high-risk patients with severe concomitant diseases than
the patch group, with respect to peripheral vascular diseases, COPD, and prior
cerebrovascular diseases (24.86% versus 14.43%, 12.97% versus
4.12%, and 16.22% versus 7.22%, respectively;
P<0.05). After the propensity score matching, the
characteristic distribution of any demographics, hemodynamic data, and severe
concomitant diseases in the two groups had a non-significant difference. The
details were showed in Table 2.
Table 1
Baseline characteristics of the two groups.
Table 2
Baseline characteristics of the two matched groups.
Operative Characteristics and Early Prognosis
No significant statistical difference was found between the two matched groups in
terms of number of grafts and LIMA-left anterior descending branch (LAD)
anastomosis. The early mortality at discharge was 4.44% in the patch group, but
there was no early death in the plication group. In addition, patients in patch
group more commonly suffered from low cardiac output syndrome (42.22%
versus 22.22%, P=0.042) with higher
proportion of intra-aortic balloon pumping assistance (37.78%
versus 17.78%, P=0.034) than those in the
plication group. Major postoperative complications including stroke and acute
renal failure were similar between the two matched groups, but patients in the
plication group had shorter recovery time, regarding to mechanical ventilation,
intensive care unit (ICU) stay, and hospital stay (P<0.001,
P<0.001, and P=0.001, respectively)
than those in the patch group. The details were showed in Table 3. Patch plasty and linear plication repairs both
improved cardiac geometry and function remarkably. The echocardiography
indicated that no significant differences between the two surgical techniques
were founded with respect to LVEF, left ventricular end-diastolic volume index
(LVEDVI), and left ventricular end-systolic volume index (LVESVI) (Table 4).
Table 3
Intra- and post-operative outcomes in the two matched groups.
Table 4
Pre- and post-operative 3 months echocardiography parameters in the
two matched groups.
The Long-Term Survival
Follow-up was complete for the two matched groups. The mean duration of follow-up
was 5.5 years (1 year-10.3 years). Patients' overall survival at 1 year, 5
years, and 10 years were 93.33%, 80%, and 64.44%, respectively, in the patch
group versus 91.11%, 75.56%, and 60%, respectively, in the
plication group. The survival curve indicated that cumulative survival rate in
the two matched groups had no significant difference (Figure 2).
Fig. 2
Estimated Mantel-Cox survival curves for two matched
patients.
DISCUSSION
The normal shape of LV is a prolate ellipsoid[6]. In post-infraction LVA, akinetic or dyskinetic
aneurysmal segments distort the LV ellipsoid geometry, which leads to LV dilatation
and spherical remodeling. The main purpose of LVA surgery is to exclude the
infracted region and to revert the ventricular dilatation, spherically remodeling it
to a more ellipsoid geometry. Dor procedure[7] and off-pump linear plication[8] have been proven to ensure
clinical benefits by improving LV geometry and reducing ventricular volume. Our
results with good surgical outcomes were similar to those from previous studies. And
the law of Laplace[9]
also explains the clinical benefits from LVA repair. As noted before, the two
surgical techniques reduced the LV wall tension remarkably by reducing the radius LV
cavity, which benefits the patients with LVA repair in the following aspects:
reducing the consumption of oxygen at the cardiac level; improving ventricular
fibers orientation, and thus the contractile efficiency; and enabling the heart to
do the same amount of work, but with a lower expenditure of energy[10].
Although the Dor procedure has been accepted as a classic and effective technique for
LVA repair, the limitations of the technique should be considered. Firstly, the
endocardial patch plasty excluded an akinetic or dyskinetic region and replaced it
with an akinetic patch, which may be counterproductive to reconstruct the LV.
Secondly, the circular patch maybe affects the realignment of non-diseased
myocardial fibers[11].
Thirdly, on-pump extensive resection of endocardial scar maybe affects postoperative
recovery duo to extra myocardial damage and inherently negative effects of CPB. Our
results showed that the mean time of mechanical ventilation, ICU stay, and hospital
stay were longer in the patch group than in the plication group.
Comparing with on-pump patch plasty, off-pump linear plication may be a less invasive
repair strategy. Off-pump linear plication maintains the integrity of the
ventricular wall and avoids ventriculotomy, and thus possible myocardial damage.
Also, it is performed on beating hearts in order to facilitate visual identification
of noncontractile zones of LVA, which ensures to absolutely isolate the akinetic or
dyskinetic region from the viable myocardium. But the more challenging aspects of
off-pump linear plication are intraventricular thrombi, the non-removal of scarred
septum, and concomitant ischemic mitral regurgitation. Fortunately, large-sized LVA
combining with mural thrombosis or valve diseases are much less prevalent now than
in the past. The probable reason is the use of timely and aggressive postischemic
treatments, including thrombolysis, acute percutaneous coronary intervention, as
well as other medical anti-thrombosis and anti-heart failure therapies. So, off-pump
linear plication, as a relatively simple and less invasive technique, may be
promising for LVA with small dimensions, not combining mural thrombi and valve
diseases.
Furthermore, CABG is generally considered as an important part of LVA surgical
treatments, irrespective of repair techniques. CABG not only improves ischemia,
probably enhancing global contraction of LV, but also prevents angina pectoris and
ventricular arrhythmias. And the clinical outcomes might be more likely to be
achieved with total revascularization and LIMA to the LAD[12]. In recent years, off-pump CABG,
an effective surgical technique, has been demonstrated to benefit particularly the
high-risk population, because this technique avoids the manipulation of the CPB and
eliminates complications secondary to CPB[13,14].
Off-pump linear plication combined with off-pump CABG may be an acceptable strategy
for patients with postinfraction LVA. And Huang et al[3] demonstrated that patients with
LVA could benefit from the combined intervention (off-pump CABG and linear
plication) with acceptable symptomatic relief and long-term survival.
Limitations
This study has some limitations. The study was susceptible to inherent bias from
retrospective nature. But propensity score matching on baseline characteristics
resulted in equivalent risk profiles between the two groups. The cohort was
small because the subjects belonged to a highly selected subgroup. And patients
with LVA concomitant with valve diseases and mural thrombosis did not meet the
study criteria.
CONCLUSION
LVA repair concomitant with surgical revascularization can be performed with
relatively low operative mortality while markedly improving the clinical status of
the patients. Off-pump linear plication obtained the acceptable results in terms of
early outcomes and long-term survival. For high-risk patients, the simple LVA repair
technique may be an option.
Authors' roles & responsibilities
ACKNOWLEDGMENTS
We thank all the participating colleagues, nurses, and imaging and laboratory
technicians.
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Notes
Notes
This study was carried out at the Department of Cardiac Surgery, Beijing Anzhen
Hospital, Capital Medical University, Beijing, China.
Financial Support
This work was supported by the National Natural Science Foundation of China
[grant number 81370436].
Conflict of interest declaration
No conflict of interest.
Author notes
Correspondence Address: Chengxiong Gu,
http://orcid.org/0000-0002-5847-1839, Department of Cardiac Surgery, Beijing
Anzhen Hospital, Beijing Institute of Heart, Lung, and Blood Vessel Diseases,
Capital Medical University, Anzhen Street No. 2 - Chaoyang District, Beijing,
China - Zip code: 100029. E-mail: anzhengu@sina.com
