Intramyocardial hydatic cyst in a young man – successful excision with cardiopulmonary bypass: case report

Introduction

Cardiac hydatid cyst is a rare disease. ¹ The left ventricle is where it is most commonly located. Symptoms occur when they arise in the left and right ventricles, interventricular septum, atrium and pulmonary arteries. In this article, we present the surgical treatment under cardiopulmonary bypass of a 17-year-old young man who had an intra-myocardial hydatid cyst.

Case Report

A 17-year-old young man was referred to our clinic because of palpations, fever and weakness lasting 1 month. Seeing T and ST wave changes on the electrocardiogram, a transthoracic echocardiogram was performed. In the apicolateral part of the left ventricle, an 8 × 8 cm thick-walled cystic mass, described as a ‘lotus flower’ with heterogeneous density and linear markings, was detected (Figure 1a). Computed tomography (CT) imaging also showed multiple cystic lesions localised in the liver. ELISA results were positive for echinococcus granulosus. Cardiac magnetic resonance imaging (MRI) showed that the cyst had invaded the pericardium and myocardium of the left ventricle. OPEN IN VIEWER

Cardiopulmonary bypass with median sternotomy and left longitudinal ventriculotomy was performed. The pericardium was completely adherent to the ventricle. Cystectomy was performed and the germinative membrane was removed intact (Figure 1b). The cyst extended the length of the pericardium, extending to the myocardium. The cavity was irrigated with 20% hypertonic saline solution, and was obliterated by applying capitonnage, which is the obliteration of a cavity by suturing together the walls of the cavity. The ventriculotomy was closed with a patch of Teflon felt. There were no postoperative complications. Oral treatment with albendazole was continued for 2 months. Regular follow-up by echocardiographic monitoring was performed. At the end of 2 years, we found an ejection fraction of 50% by transthoracic echocardiography, with no evidence of recurrence of hydatid disease.

Discussion

Transthoracic and peri-oesophageal echocardiography is of proven value in the evaluation of cardiac hydatid cyst, itself a rarity. Similarly, CT and MRI give more information about the existence of intrathoracic and extrathoracic cysts. ³ For subepicardial cysts, surgery without cardiopulmonary bypass has been reported. ² However, where a large cyst is found within the myocardium, or is invading both ventricles, rupture of the cyst may result in anaphylactic shock, embolism and sudden death. Furthermore, spread in the pericardial area resulting in pericardial tamponade may complicate matters. ⁴ Owing to these risks, we prefer cardiopulmonary bypass when hydatid disease has invaded the left ventricular myocardium.

For the cysts in the left heart, extracorporeal circulation and aortic cross-clamping protect the patient from systemic embolisation; the cyst and ventricular cavity can also thus be better seen. For cysts in the right heart, clamping of the pulmonary artery protects the patient from the risk of pulmonary embolism in a similar way.

It is a general rule that the heart should not be manipulated before cross-clamp placing in case it may cause embolism. Removing the cyst with its germinative membrane intact and washing the cavity hypertonic saline as a scolicide is important. Capitonnage should be performed after the daughter vesicles have been completely removed. Damage to the coronary arteries may be avoided by performing linear ventriculotomy, and in this way the risk of ventricular arrhythmia is reduced to a minimum. The cyst can be treated medically or surgically. Currently there is no standard treatment for hydatid cyst and it may be medical, surgical or a combination of both. ⁵

Although there is no consensus on the duration of drug treatment postoperatively, we advise treatment with albendazole for 2 months because of the risk of recurrence and the risk of seeding in multiple organs. In our case there was no evidence of recurrence in the ensuing 3 years.