Abstract
Left ventricular diverticulum is an extremely rare anomaly, especially in the absence of other findings, and as such it has been rarely imaged, rarely seen intraoperatively, and has no standardized management algorithm. We report our suggested imaging and management in the context of previous management philosophies.
Keywords
Case Description
A three-year-old, 22-kg female patient was referred to pediatric cardiology for echocardiographic evaluation due to gestation as an infant of diabetic mother. The initial study showed concentric hypertrophic cardiomyopathy, but repeat outpatient follow-up images demonstrated gradual resolution. Echocardiogram six months after referral revealed complete resolution of the cardiomyopathy and a large left ventricular (LV) diverticulum with thick muscular walls and a narrow neck (Figures 1 and 2). A magnetic resonance imaging (MRI) study corroborated these findings (Figures 3 and 4). The patient was completely asymptomatic with electrocardiogram findings of diffuse T wave inversion, perhaps more pronounced in the inferior and lateral leads. All the data were reviewed at multimodality pediatric cardiology/cardiac surgery conference, and the traditionally stated potential for clot formation, systemic stroke, endocarditis, and rupture were discussed. All of the imaging seemed to reveal an adequate left-sided pumping chamber in addition to the diverticulum at the LV apex. There was no contraindication for surgery, and the patient was put forward for repair.
Preoperative transthoracic echocardiography image of large congenital left ventricular diverticulum. Subcostal coronal view: a large communication connects the diverticulum with the left ventricle. LV indicates left ventricle; N, neck; D, diverticulum.
Color flow Doppler from apical four-chamber view. The diverticulum wall is contractile resulting in systolic forward flow from the diverticulum cavity toward the left ventricle body. LVindicates left ventricle; N, neck; D, diverticulum.
Cardiac magnetic resonance imaging (MRI) with a four-chamber view demonstrates a large apical diverticulum with a thick muscular wall. Cine imaging showed systolic contraction of the diverticulum and a flow jet at the neck.
Cardiac magnetic resonance imaging (MRI) with dynamic contrast-enhanced perfusion sequences demonstrates contrast filling of the left ventricle (LV) apical diverticulum. Subsequent images showed LV and apical myocardial enhancement.
Via a median sternotomy, the patient was placed on aorto-right atrial cardiopulmonary bypass (CPB) using a dual stage venous cannula. The heart was fully decompressed but remained beating with a systemic temperature of 32°C. Figure 5 demonstrates the appearance of the intact diverticulum with the heart decompressed on CPB. Certain of no systemic ejection, stay sutures were placed and the diverticulum was opened and inspected to find a thick muscular wall and small fibrous neck (Figure 6). The remainder of the myocardium appeared normal in structure and function, and the combination of inspection and intraoperative transesophageal echocardiogram suggested adequate LV size. The majority of the diverticulum was cut away with a 1-cm rim remaining for reconstruction. In order to ensure more adequate sewing 1 dose of cardiopledgia was used, and both arms of a running 4-0 polypropylene suture were run to form a two-layer closure of this rim, and this was doubly reinforced with interrupted 4-0 polypropylene sutures with felt pledgets (Figure 7). The CBP time was 50 minutes and the cross-clamp time was 17 minutes. The patient was extubated and transferred from the cardiac intensive care unit within 24 hours followed by an uneventful hospital discharge on postoperative day 5.
Intraoperative photograph of the left ventricular diverticulum with the heart decompressed on cardiopulmonary bypass. The diverticulum is grasped with forceps.
Intraoperative photograph of the open left ventricular diverticulum revealing a thick muscular wall and narrow neck connecting the left ventricle proper. A pair of forceps is open within the narrow fibrous neck.
Intraoperative photograph of the repaired left ventrile after resection of the majority of the diverticulum and reconstruction of the defect.
Discussion
A Pubmed search for LV diverticulum reveals only 66 entries since the first report was registered in 1965. 1 Many of these describe only one case or relist previously described cases in review, and some are fetal images with an uncertain outcome such that probably less than 80 to 90 have been reported during this period spanning over 50 years. 2 –10 A good portion of descriptions mention it as part of Cantrell Pentad and/or ectopic cordis 3,5,9 making isolated presentation even rarer. Arrhythmia seems to be a common presenting feature that has led to this diagnosis in the past cases. 2,6 Some descriptions of sur-gical resection and Dor-type operations have been scantly described. 8,9
A recent review stresses that LV aneurysm is most properly defined as a thin, dyskinetic outpouching with a wide connection to the LV chamber, while a diverticulum should have all three heart layers that can often be demonstrated to have intact systolic contraction and a narrow neck connecting to the LV. 7 The figures presented herein thus demonstrate a stereotypical LV diverticulum. This is an important distinction, as it affects the considerations in operative management. We summarize and expound on the recommendations outlined in the previous literature as follows: an otherwise well-functioning and well-sized LV in a minimally symptomatic patient may undergo resection with modification of the LV reconstruction principles outlined by Dor, 10 while poorly functioning ventricles with small remaining chamber size in patients already symptomatic with heart failure may be forced down a transplant pathway. We feel MRI is an excellent imaging modality that adds viability data and precise chamber size measurement data which are important elements in the above decision making. It is important to note that although clot was raised as a concern for patient in preoperative discussion, there is no meaningful natural history data available regarding the true risk of adverse events in children with LV diverticulum.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.