Discussion
Intramyocardial dissection is rare and mostly secondary to myocardial infarction.In a meta-analysis2 of the literature including 40 cases of Intramyocardial dissection,32 cases after myocardial infarction and in 8 patients following trauma.3-4 In 5 patients, communication between the left and right ventricles was found. In-hospital mortality was 23%. Multivariate analysis showed that the strongest independent predictor of mortality was EF<35%.2 There also were a few reports of intramyocardial dissection secondary to the cardiac echinococcosis.5-6 Intramyocardial dissection following cardiac tumor excision is uncommon,the evidence available is limited to few case reports. This complication is due to destruction of the integrity of the interventricular septum and entry into the ventricular cavities during resection of the tumor. In our patient, only very thin endocardium separated the tumor from the ventricular cavity, entering into the left ventricular cavity when the tumor was dissected.we repaired the septum with a bovine pericardium patch. It may be due to the fragility of the myocardial tissue leading to the suture avulsion, followed by the formation of ventricular septal intramyocardial dissection and residual shunt.
The optimal management of intramyocardial dissection is controversial due to its rarity and lack of supportive evidence. Most of the experience come from studies of intramyocardial dissection after myocardial infarction. Treatment includes surgery, intervention and conservative medical therapy. In a systematic review of patients with postinfarction intramyocardial dissection, the mortality rate was significantly higher in the medical group versus surgical-treated group (85.7% versus 42.3%).7 For our patient, the age was only 3 months, interventional treatment was difficult, and the risk of reoperation was high. Most importantly, the patient was asymptomatic and hemodynamically stable.So we performed conservative strategy. During follow-up, we found that the cystic dissection was slightly reduced and the shunts between the cystic dissection and right ventricle disappeared. We will continue to follow up the patient.
Echocardiography is a noninvasive and simple technique.It has a important role in diagnosing intramyocardial dissection. Echocardiography
can evaluate the size and location of the intramyocardial dissection, detect flow within the cavity,assess heart function, thus assisting in the decisions about treatment strategy.We can learn from our case that when resecting tumors located in the ventricular septum, we should try to ensure the integrity of the ventricular septum and avoid entering the ventricular cavity. After resection, we should carefully check and repair the ventricular septum. For benign cardiac tumors can be partial resection to prevent damage to important structures.8