Medical treatment of cardiac cysts can reduce their dissemination during and after surgery. However, it may not prevent cyst rupture or the development of life-threatening complications. Therefore, the treatment of cardiac cysts is primarily surgical, accompanied by pre- and postoperative medical therapy to prevent recurrence.[1]

In this article, we present a rare and unruptured, but potentially life-threatening case of a huge cardiac hydatic cyst.

Transthoracic echocardiography showed that the left ventricle ejection fraction was 60%. Aortic and mitral valve structure and function were normal. Transthoracic echocardiography revealed a well-defined hypoechoic cystic structure, measuring 63x52 mm (Figure 1a), occupying a large portion of the left ventricular cavity, with daughter cysts observed within the anterolateral wall of the left ventricle’s apical segment. Thoracic CT confirmed the presence of a cardiac hydatid cyst (Figure 1b). Thoracic MRI identified a well-demarcated 67x51 mm cystic hyperintense structure with septations and daughter vesicles in the apicolateral region of the left ventricle (Figure 1c, d). To assess the potential dissemination of the cyst, cranial and abdominal MRI scans were also performed, but no pathology indicative of hydatid cysts was detected. Laboratory tests revealed elevated high-sensitivity troponin I (1.96 μg/L), procalcitonin (2.85 ng/mL), and eosinophilia (1.03 K/uL). The hydatid cyst indirect hemagglutination test was positive at 1/640. Albendazole 400 mg twice a day was started five days before the surgical treatment. After discharge, a three-month course of medical therapy and follow-up by the Department of Infectious Diseases and Clinical Microbiology were planned.

Figure 1. Transesophageal echocardiographic appearance and radiological images of cardiac hydatid cyst (a) Intraoperative transesophageal echocardiographic view demonstrating a large mass occupying the left ventricle cavity. Different sized “daughter cysts” may be seen within the larger cyst (red arrow), (b) Hypodense cyst view in the left ventricle on computed tomograph axial section (red arrow), (c) Hyperintense daughter cysts and septation appearance in the left ventricle on axial FIESTA magnetic resonance imaging (red arrow), (d) On magnetic resonance imaging, hydatid cysts appear as a high signal intensity on the coronal T2-weighted images (red arrow).
FIESTA: Fast Imaging Employing Steady-state Acquisition.

Under general anesthesia, a median sternotomy was performed. Aortic arterial and bicaval venous cannulation were established, and a venting cannula was placed in the right upper pulmonary vein. After cross-clamping, the heart was arrested antegradely using a modified cold (10°C) del Nido solution. Cardiopulmonary bypass was performed at a flow rate of 2.2 to 2.4 L/min/m² under mild hypothermia (30 to 32°C). A cyst measuring approximately 6x5 cm was observed in the anterolateral wall of the left ventricle (Figure 2a). Compressors soaked in 1% povidone-iodine and 20% hypertonic saline were used to isolate the cyst from the surgical field. The cyst cavity was sterilized by injecting 20% hypertonic saline (Figure 2b). The pericystic layer was longitudinally opened, and the cyst contents were aspirated and evacuated.

Figure 2. Surgical exploration of the giant left ventricle hydatic cyst. (a) Pericyst capsule of the hydatic cyst (outside view), (b) Intraoperative view of aspiration of cystic fluid and 20% hypertonic saline injected, (c, d) Intraoperative view of the left ventricular cyst showing the multiple daughter cysts and removal of cyst material, (e) Tunnel-shaped defect between the cyst cavity and the left ventricle (red arrow), (f) In the surgical view, repair of the left ventricle defect with the capitonnage similar to ventricular aneurysm repair.

The germinal membrane was excised, revealing numerous daughter cysts of varying sizes (Figure 2c, d). These cysts were meticulously removed without rupture. The cyst cavity was irrigated with both 1% povidone-iodine and 20% hypertonic saline. A tunnel-shaped defect of approximately 5x5 mm was identified connecting the cyst cavity with a blind end through the left ventricular septum (Figure 2e). The defect was repaired primarily with 4/0 polypropylene sutures. The cyst’s free walls were resected down to healthy tissue. The left ventricular wall was closed with continuous Fontan sutures using two 4/0 polypropylene sutures, reinforced bilaterally with Teflon felt and closed linearly, similar to aneurysm repair techniques (Figure 2f). Intraoperative transesophageal echocardiogram (TEE) confirmed that there was no residual cyst structure. Histopathological examination of the excised material confirmed multivesicular hydatid cyst. The postoperative period was uneventful, and the patient was discharged on postoperative Day 7 with albendazole prescribed to prevent recurrence. At one-month of follow-up, TTE showed no cardiac abnormalities. A follow-up MRI was scheduled after three months of medical treatment. A written informed consent was obtained from the patient.

Surgical excision is the primary treatment option for cardiac echinococcosis, even in asymptomatic and unruptured cases, due to potential complications. Median sternotomy is preferred for optimal visualization, although anterolateral thoracotomy can be performed in select cases.[4] Cardiopulmonary bypass and cross-clamping of the aorta is the most preferred method for excision of myocardial cysts and the most reliable method for prevention of systemic embolization. In excision of cysts located in the right heart, clamping of the pulmonary arteries is also recommended to prevent dissemination via the pulmonary artery.[5] Resection of epicardial cysts can be performed without the necessity of cardiopulmonary bypass. To prevent direct regional dissemination in the surgical field, site control should be performed with gauzes impregnated with scolicidal solutions such as 20% NaCl solution and hydrogen peroxide.[4]

Surgical techniques include cyst puncture, aspiration of its contents, resection of the germinal membrane, and cystectomy. Following excision, the cavity is irrigated with scolicidal solutions and either closed via capitonnage or left open for secondary healing, depending on its location.[4] Various complications may occur after surgery depending on the surgical techniques used. Some of these complications include atrioventricular block leading to the need for permanent pacemaker, myocardial rupture and ventricular arrhythmias due to ventricular scar which may lead to sudden death.[1] Albendazole therapy should continue postoperatively to reduce recurrence risk, as hydatid cysts have a 10% recurrence rate.[6]

In conclusion, cardiac hydatid cysts are quite rare. As demonstrated in this case presentation, cardiac hydatid cysts should be considered in the differential diagnosis of patients with unexplained cardiac symptoms. Surgery is the definitive treatment and should not be delayed, as medical treatment alone does not guarantee against life-threatening complications in the event of cyst rupture or, as in our case, even without cyst rupture. Combined surgical and medical therapy is essential to reduce recurrence and dissemination risk.

Data Sharing Statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Author Contributions: Conception and design of the study: İ.K., U.A.; Literature review: U.A., K.G.; Writing the article: İ.K., S.S., U.A; Control/supervision: İ.K., F.T. All authors participated in drafting and revising the manuscript critically for important intellectual content.

Conflict of Interest: The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Funding: The authors received no financial support for the research and/or authorship of this article.

1) Tuncer E, Tas SG, Mataraci I, Tuncer A, Donmez AA, Aksut M, et al. Surgical treatment of cardiac hydatid disease in 13 patients. Tex Heart Inst J 2010;37:189-93.

2) Akpınar MB, Şahin V, Seçici S, Uyar IS, Ateş M. An asymptomatic huge calcified intramyocardial hydatid cyst: A case report. Cardiovasc Surg Int 2015;2:30-2. doi:

10) 5606/e-cvsi.2015.299

3) Kaplan M, Demirtas M, Cimen S, Ozler A. Cardiac hydatid cysts with intracavitary expansion. Ann Thorac Surg 2001;71:1587-90. doi: 10.1016/s0003-4975(01)02443-2.

4) Jamli M, Cherif T, Ajmi N, Besbes T, Mgarrech I, Jerbi S, et al. Surgical management and outcomes of cardiac and great vessels echinococcosis: A 16-year experience. Ann Thorac Surg 2020;110:1333-8. doi: 10.1016/j.athoracsur.2020.01.065.

5) Orhan G, Ozay B, Tartan Z, Kurc E, Ketenci B, Sargin M, et al. Surgery of cardiac hydatid cysts. Experience of 39 years. Ann Cardiol Angeiol (Paris) 2008;57:58-61. doi: 10.1016/j. ancard.2007.05.003.

6) Yılmaz M, Aydın A, Kumbasar U, Özer N, Paşaoğlu İ. Komplet kalp blok\'u ile seyreden kardiyak kist hidatik olgusu. Turk Gogus Kalp Dama 2013;21:176-8. doi: 10.5606/ tgkdc.dergisi.2013.037.