SS–19 Conservative Management of Dunning Class III Aortocoronary Dissection Introduction and Aim

Abstract

Introduction and Aim: Iatrogenic left main coronary artery (LMCA) dissection with retrograde extension into the ascending aorta is a rare but potentially catastrophic complication of coronary angiography and percutaneous coronary intervention (PCI). According to the Dunning classification, Class III dissections (>40 mm extension into the ascending aorta) are generally considered the most severe form and have traditionally been associated with emergency surgical repair. However, recent evidence suggests that conservative management may be feasible in carefully selected hemodynamically stable patients after successful sealing of the coronary entry site. We present a rare case of Dunning Class III iatrogenic aortocoronary dissection that was successfully managed with PCI followed by conservative medical therapy.

Case Report: A 68-year-old man with a history of anterior myocardial infarction one month earlier was admitted for elective PCI of the left circumflex artery (LCx). The left coronary system was engaged with an EBU guiding catheter, and baseline angiographic images were obtained. Following predilatation of the target LCx lesion, angiography unexpectedly demonstrated an iatrogenic LMCA dissection extending to the aorto-ostial region. The left anterior descending artery (LAD) was immediately wired, and a stent was implanted from the LMCA to the LAD, completely covering the LMCA ostium and successfully sealing the entry point of the dissection. Control angiography demonstrated disappearance of contrast staining extending into the aortic root. However, a residual dissection flap remained confined between the LCx ostium and the previously implanted LCx stent. The LCx was rewired and a two-stent bifurcation strategy using the TAP (T-stenting and Small Protrusion) technique was successfully performed, resulting in complete stenting of the LMCA bifurcation without residual dissection or angiographic complications. The patient was admitted to the coronary intensive care unit for close monitoring. Transthoracic echocardiography showed a left ventricular ejection fraction of 45–50% without pericardial effusion. During follow-up the patient developed back pain, prompting computed tomography (CT) aortography, which demonstrated an extensive peri-aortic hematoma extending from the coronary ostium to the aortic arch and proximal left subclavian artery, consistent with Dunning Class III aortocoronary dissection. Cardiovascular surgery consultation recommended conservative management because the patient remained hemodynamically stable without ongoing ischemia. Strict blood pressure and heart rate control were achieved and laxative therapy was added to minimize Valsalva-related increases in intrathoracic pressure. No electrocardiographic changes, hemodynamic deterioration, electrical instability or pericardial effusion developed during hospitalization. Follow-up CT aortography on Day 4 demonstrated regression of the peri-aortic hematoma, while repeat imaging on Day 20 confirmed complete resolution. The patient was discharged uneventfully on hospital Day 21 with outpatient follow-up.

Conclusion: This case demonstrates that even Dunning Class III iatrogenic aortocoronary dissection can be successfully managed without surgery when the coronary entry site is promptly sealed with PCI and the patient remains clinically stable. Careful patient selection, multidisciplinary decision-making, strict anti-impulse medical therapy and serial CT imaging may provide a safe alternative to surgical intervention in selected cases. This rare case contributes to the limitedliterature supporting conservative management of extensive iatrogenic aortocoronary dissections.