Percutaneous Coronary Intervention for Left Main Stem Restenosis in a Patient with Tetralogy of Fallot after Bovine Pericardium Angioplasty: A Case Report

Owing to the drug-eluting stents, percutaneous coronary intervention has become an increasingly acceptable treatment for patients with left main coronary artery disease. Rare reports of placing a drug-eluting stent in restenosis vassal which is made by bovine pericardium after surgical angioplasty have been described. We report a patient who performed operation due to Fallot, this patient’s left main coronary was injured accidentally during the operation. To rebuild left main coronary, we chose surgical angioplasty and bovine pericardium was chosen as patch. However, postoperative coronary angiography suggested restenosis of artificial left main coronary artery. We placed a drug-eluting stent in this stenosis successfully. Thus, this case demonstrates that placing drug-eluting stents in restenosis vassals which are made by bovine pericardium is feasible.


Introduction
Owing to the dominance of the left coronary circulation, left main coronary artery disease (LMCAD) usually predicts higher prognostic risk [1]. At present, the revascularization of LMCAD mainly includes coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI) and surgical angioplasty of the left main coronary artery (SA-LMCA). Contrasted with the well-documented CABG and PCI, the long-term results of SA-LMCA have rarely been reported [2]. Moreover, case reports concerning placing drug-eluting stents in restenosis vassals after surgical angioplasty are even less. This paper reports a successful case of PCI of a left main coronary bovine pericardial sheet for restenosis after Fallot tetralogy.
her syndrome had worsened in severity, the clinical concern was of failure of radical operation for tetralogy of Fallot.
Transthoracic echocardiography showed a left ventricular ejection fraction of 60%, and mitral valve, tricuspid valve, and pulmonary valve all have moderate to severe regurgitation. Coronary Artery Stenosis (Figure 1a, b). Accordingly, we decided to carry out the PCI in this narrow spot. A 2.5×15mm compliant balloon was used to pre-expand the stenosis, and a 4.0 × 20mm drug-eluting stent was placed ( Figure 2). And a 4.5×20mm NC TREK non-compliant balloon was applied to expand the residual stenosis, and the residual stenosis was <10% (Figure 3a, b). After the PCI, the patient's chest pain was gradually relieved. With Clopidogrel and Aspirin dual antiplatelet the patient's condition gradually stabilized. However, the patient suffered from sudden upper gastrointestinal bleeding. With a series of treatments such as somatostatin, PPI, blood transfusion etc., the patient's condition became stable. However, her family decided to stop treatment and asked for against-advice discharge. Unfortunately, we lost contact with the patient after she was discharged.   biocompatibility, and ease of handling. Also, it has the reliable strength to allow a tight-fitting closure, which yields less suture line bleeding and prevents aneurysmal dilatation [6]. On the other hand, bovine pericardium heralds the possibility of restenosis, even though a study reports a low incidence of restenosis over 12 in patient who underwent CEA with bovine pericardial patch angioplasty [7]. The main cause of restenosis is related with intimal hyperplasia in the area at or near the bovine pericardial patch.
However, the fundamental molecular and cellular mechanisms is still unclear.
As the most widely used method for CAD, PCI has undergone continuous improvement over the past few decades, especially with the advent of drug-eluting stents. Drug-eluting stents can inhibit the formation of vascular neointimal tissues by releasing anti-angiogenic drugs (such as rapamycin), significantly reducing the occurrence of intravascular restenosis (ISR). Owing to the drugeluting stents, PCI becomes an increasingly acceptable treatment for patients with LMCAD. A study indicates that there is no significant difference between PCI and CABG in patients with LMCAD of low or intermediate anatomical complexity [8].
For this patient, the left main coronary artery is accidentally injured, the consideration about graft in the young patient and the intention to restore more physiologic flow steer us away from CABG. Instead, we choose SA-LMCA to rebuild the LM. As for the patch materials, we are unable to resort to the internal mammary artery and autologous pericardium as a patch material because the patient's previous surgery has caused adhesions around the heart. Moreover, considering that the patient's cardiac arrest is too long, choosing saphenous vein as patch would have prolonged the operation time and increased the unnecessary surgical risk.
Consequently, bovine pericardium with good biocompatibility is chosen as the patch. However, the postoperative coronary angiography suggests restenosis of the artificial left main coronary artery. Finally, we place a drug-eluting stent in the stenosis of left main coronary. Chest pain and other symptoms are relieved significantly after PCI, and no malignant events such as ventricular fibrillation occur, which prove that this treatment scheme is effective and worthy of clinical reference.