Hydatid Cyst of Interventricular Septum

Figure 1: 40x35 mm cystic mass

Introduction

Hydatid disease (cystic echinococcosis) arises from the echinococcus granulosus tapeworm and is endemic in some livestock-raising countries. Cardiac involvement is seen in only 0.2-3% of patients with hydatid disease, and IVS is involved in just 4% of cardiac cases (3). Hydatid disease may present as heart block and VSD (1).

A 35-year-old female presented with a history of fatigue, palpitations, syncopy, and heaviness of chest for the past year. Her symptoms were more pronounced on exertion and relieved on rest. She did not have any other associated problems. She did not have a significant past medical or surgical history. She was afebrile with Hb. of 13.1 g/dl, WBC 10*10^9/L on admission. Her blood type was A+, and HCV and HIV blood tests were negative. Echinococcus granulosus IHA titer was less than 1:16 (negative). On two-dimensional transthoracic echocardiography EF was 65% and there was evidence of LVOT obstruction. A cystic mass measuring 40 × 35 mm within the basal interventricular septum was discovered (Figure 1). Computed tomography of the chest showed a cyst in the interventricular septum and no other cysts were found (Figure 2). MRI showed the brain to be normal.

Figure 2: CT scan of cyst

Case Report

The authors decided to treat the patient surgically, followed by Albendazole. The patient underwent a median sternotomy and was placed on cardiopulmonary bypass (CPB) with aortic arterial and bicaval venous cannulation. The aorta was cross-clamped and heart arrested with cardioplegia. The right atrium was opened and the cyst was aspirated across the tricuspid orifice. Hypertonic saline was injected for scolicidal effects. With this approach, the pseudomembrane of the cyst was opened directly .The entire contents of the cyst and its germinative membrane were removed together (Figure 3). The cavity was washed and obliterated with pledgeted mattress sutures. After adequately irrigating, the RA was closed and the case was finished in standard fashion. No postoperative complications were seen. The patient was discharged on 400 mg of oral Albendazole twice daily to prevent recurrence. Histopathology confirmed a hydatid cyst.

Figure 3: Removal of cyst

Discussion

Echinococcus disease in humans is caused by the larval development of taenia echinococcus, a cestode tapeworm. Dogs are typically the definitive host of taenia echinococcus, but humans can become incidentally infected through contact with dogs via a fecal-oral route. The liver is the organ most frequently involved in echinococcus disease, followed by the lung. Cardiac involvement is seen only in 0.2%–3% of cases, making early diagnosis and treatment important (3). The most affected sites in the heart are the left and right ventricles and the interventricular septum (4). The pericardium and left and right atria are the least affected (4). Depending on the location and the direction of least resistance, primary hydatid cysts of the heart have a marked tendency to rupture either into the lumen of a cardiac chamber or into the pericardial sac (3).

Early surgical removal of a hydatid cyst is the treatment of choice. Off-pump resection of epicardial cysts is advocated by some, but the majority use cardiopulmonary bypass regardless of the cyst’s location. The two main principles of the surgery are to: avoid handling the heart before cross-clamping, and completely excise the germinal layer. As for the residual cavity, some prefer to let it heal by secondary intent to avoid complications. However, this approach risks leaving a potential space behind; therefore, the authors obliterated the cavity with sutures.

Conclusion

Surgical resection of an interventricular septal hydatid cyst and concurrent Albendazole therapy is a safe and recommended approach for this rare problem.

References

1. Hydatid cyst of the interventricular septum causing complete heart block and postoperative ventricular septal defect. Feridoun Sabzi and Reza Faraji.Indian J Crit Care Med. Jul 2014; 18(7): 473–475. doi: 10.4103/0972-5229.136080.PMCID: PMC4118517
2. Hydatid cyst of the cardiac interventricular septum Department of Cardiac Surgery, Tabba Heart Institute, Karachi, Pakistan ,Dow University of Health Sciences, Karachi, Pakistan . Syed Nadir Naeem1,Hira Burhan2,Ghufranullah Khan1
3. Echinococcus Disease of the Heart JORGE DIGHIERO, EDUARDO JOAQUIN CANABAL, CESAR V. AGUIRRE, JACOBO HAZAN, and JOSÉ O. HORJALES. Circulation. 1958;17:127-132, doi:10.1161/01.CIR.17.1.127
4. Cardiac hydatid cysts located in both the left ventricular apex and the intraventricular septum: case report. Heart Vessels 2000; 15: 243–244. Ulgen MS, Alan S, Karadede A, Aydinalp O, Toprak N

Authored by: Azam Jan, Syed Mumtaz Shah, Amir Muhammad, Muhammad Aasim, Syed Shahkar Ahmed Shah, Azam Khan, Kashif Anwar