ABC | Volume 113, Nº5, November 2019

Case Report A Rare Cause of Angina After Coronary Bypass Grafting; Left İnternal Mammary Artery to Pulmonary Artery Fistula and Successful Treatment with Transcatheter Coil Embolization Ali Nazmi Calik, 1 C an Yücel Karabay, 1 Evliya Akdeniz, 1 Yiğit Çanga, 1 Baris Gungor, 1 Omer Kozan 1 Doktor Siyami Ersek Gogus Kalp ve Damar Cerrahisi Egitim ve Arastirma Hastanesi, 1 Istanbul – Turkey Mailing Address: Ali Nazmi Calik • Doktor Siyami Ersek Gogus Kalp ve Damar Cerrahisi Egitim ve Arastirma Hastanesi – Cardiology, 34664, Istanbul – Turkey E-mail: calik_nazmi@hotmail.com Manuscript received July 03, 2019, revised manuscript November 14,2019, accepted November 14, 2018 Keywords Mammary Arteries/surgery; Pulmonary Artery; Arterio-Arterial Fistula; Embolization, Therapeutic; Cardiac Catheterization; Drug-Eluting Stents; Self Expandable Metallic Stents. DOI: 10.5935/abc.20190196 Abstract Fistula from left internal mammary artery (LIMA) to pulmonary artery (PA) is rarely encountered in daily practice. In recent years, endovascular therapy options have emerged for the treatment of fistula formations and replaced with surgery. A 53-year-old man admitted to our outpatient clinic with symptoms of typical angina and shortness of breath despite optimal medical therapy. In his relevant history, he had a coronary artery bypass graft (CABG) operation in 2009 in which his LIMA was anastomosed to left anterior descending (LAD) and ramus artery sequentially. Coronary angiography including selective imaging of LIMA demonstrated a fistula formation originating from the proximal portion of the LIMA and draining to PA. After successful closure of fistula with transcatheter coil embolization, the patient was discharged without any complication and symptom. In conclusion, although LIMA to PA fistula is an infrequent clinical condition, it should be considered as a potential cause of persistent angina after CABG operation. Treatment options include conservative medical therapy, surgical ligation and endovascular interventions. The best therapy should be individualised for each patient in respect to patient’s symptoms, surgical compatibility and anatomy of fistula. Introduction Left internal mammary artery (LIMA) is the most commonly used vessel as a bypass graft conduit to the left anterior descending artery (LAD) because of its long term patency. Although fistula between LIMA and pulmonary artery (PA) is a rare clinical condition, coronary artery bypass grafting (CABG) operation is a common cause of the acquired LIMA to PA fistulas. This clinical situation is important with regard to recurrent angina despite optimal medical therapy after CABG. Nowadays, endovascular interventions have been successfully applied for the treatment of fistula formations and are considered as the first line therapy options. In this paper, we report a LIMA to PA fistula and successfull treatment with transcatheter coil embolization. Case Report Fifty-three years oldmale patient who has a history of 2-vessel CABG in 2009 in which his LIMA was anastomosed to LAD and ramus artery sequentially admitted to our outpatient clinic with symptoms of typical angina and shortness of breath despite optimal medical therapy. Coronary angiography demonstrated 60% stenosis of proximal right coronary artery (RCA) with an FFR value 0.87, 90% stenosis of native ramus artery and a fistula formation from LIMA to PA before anastomosing to LAD and ramus artery (Figure 1). Computed tomography (CT) angiogram of coronary arteries and bypass grafts confirmed the diagnosis of fistula and its course. After consulting the patient with the Heart Team including cardiothoracic surgeons and anesthesiologists in sense of treatment strategy, we decided to completely revascularize the patient with stenting native Ramus artery and closing the fistula with transcatheter coil embolization in the same procedure. Our rationale for treating native ramus artery in the same procedure was aiming to block the sequential flow coming from LIMA by competing with it, which will result in augmentation of LIMA to LAD flow. After stenting ramus artery with a 3.0 x 15 mm drug-eluting stent, we carefully engaged the ostium of LIMA with an 8 French internal mammary artery (IMA) guiding catheter and advanced a 0.014’’ PT 2 guidewire to the distal part of fistula. Next, 2.8 French CANTATA microcatheter (Cook Medical, Bloomington, IN, USA) was advanced to the midportion of fistula over the PT 2 guidewire. Since the fistula was draining to PA with two major side branches whichwere dividing tomultiple collaterals into their distal portions, our initial strategy was occluding the twomajor branches of fistula individually. However, the first coil ( 11-2-2 HL spiral, Detach Coil System, Cook Medical, Bloomington, IN, USA) was distally embolized inadvertently and the other two coils ( 11‑3‑4 HL spiral and 18-4-6 HL spiral) for each side branch could not completely occlude the fistula (Figure 2). Hence, we changed our strategy and deployed an additional three larger coils ( 18S-5-7 HL spiral , 18S-6-8 HL spiral, 18S-6-15 HL spiral) to the main branch of fistula. After waiting for a few minutes, control angiography of LIMA demonstrated total occlusion of the fistula without any complication (Figure 3). The patient tolerated the procedure well and was discharged without any complication and symptom. Discussion Fistula formation from LIMA to PA is an uncommon clinical entity. The first LIMA to PA fistula case was presented by 1002