Left Ventricular Outflow Tract Pseudoaneurysm Formation Following Three Aortic Valve Replacement Surgeries.

We present a case of a pseudoaneurysm arising from the left ventricular outflow tract/aortic root as a complication of aortic valve surgery. A 45-year-old Nigerian female presented to our institution's emergency department with chest discomfort. She had three bioprosthetic aortic valve replacements in the preceding year at an outside institution for aortic regurgitation and wanted a second opinion on remaining surgical options. The learning points relevant to this case are as follows: (1) Recognizing potential complications postmultiple valve surgeries, (2) screening patients for chronic infections and rheumatologic conditions that can contribute to failed valve surgeries.

INTRODUCTION

While aortic valve replacement (AVR) is the treatment of choice for several aortic valve disorders;[1] it is important to recognize some complications post this surgical procedure. Most importantly, these include valve dehiscence, conduction abnormalities, thrombosis, infective endocarditis, fistulas, and left ventricular outflow tract (LVOT) pseudoaneurysms, among others.[123] Current imaging modalities such as echocardiography, computed tomography (CT), and magnetic resonance imaging have allowed us to detect these potential complications during follow-up of postoperative patients. In this case report, we present the case of a patient with three previous surgical bioprosthetic AVRs who presented to our institution for an additional surgical opinion. An LVOT/aortic root pseudoaneurysm was identified by echocardiography and confirmed by CT. Images of this worrisome AVR complication are presented.

CASE REPORT

A 45-year-old Nigerian female was seen in our emergency department complaining of chest pain. Her history was remarkable for having three bioprosthetic AVR procedures in the preceding year at another institution, the most recent being 6 months prior to the presentation. The initial indication for AVR was aortic regurgitation and her previous valve surgeries were noted to be complicated by endocarditis. Her past medical history is remarkable for childhood malarial and typhoid infections; all completely treated.

She had no other significant past medical history. She complained of dyspnea on exertion, chest discomfort, orthopnea, and the need for supplemental oxygen at home; therefore, she requested a second opinion regarding any remaining surgical options to treat her disabling symptoms. During her hospital course, an echocardiogram was obtained that demonstrated the sewing ring to be positioned higher than it normally is above the Sinuses of Valsalva [Figure 1, Videos 3 and 4]. A small mass was also noted on the posterior portion of the sewing ring with a fibrinous strand going to the base of the native aortic annulus [Figure 1]. A mild perivalvular leak was also noted [Figure 2 and Video 5]. More interestingly, there appeared to be a 2 cm perforation in the LVOT and a large clear space in the lateral pericardial wall consistent with a pseudoaneurysm [Figure 3]. Contrast was used to opacify the chambers and the pseudoaneurysm is clearly seen [Figure 4, Videos 1, 2 and 6]. Rheumatology, allergy and immunology, as well as infectious diseases services were consulted to assist with management of this case and determine if there was any underlying process contributing to her bioprosthetic AVR failure and development of the postsurgical pseudoaneurysm. They were unable to demonstrate any underlying systemic process as contributing to her cardiac disease. The patient had a cardiac CT that confirmed echocardiographic findings. The CT demonstrated a large multilobulated pseudoaneurysm arising from the LVOT/aortic root. The volume of the pseudoaneurysm cavity measured 197.9 mL.

Figure 1

Parasternal long view showing the sewing ring to be positioned higher than it normally is above the Sinuses of Valsalva (arrow) and a small mass was also noted on the posterior portion of the sewing ring with a fibrinous strand going to the base of the native aortic annulus. LV = Left ventricle, LA = Left atrium

Figure 2

Parasternal long view showing mild perivalvular leak

Figure 3

Apical 4-chamber showing 2 cm perforation in the left ventricular outflow tract and a large clear space in the lateral pericardial wall consistent with a pseudoaneurysm. RV = Right ventricle, PSA = Pseudoaneurysm

Figure 4

Apical 4-chamber with contrast demonstrating the pseudoaneurysm clearly

DISCUSSION

Aortic valve replacement surgery is associated with multiple complications. Formation of a pseudoaneurysm can occur especially after multiple valve surgeries. The development of the pseudoaneurysm is most times related to suturing technique. The high-velocity blood flow in the LVOT enters the tear formed by the suture and a pseudoaneurysm develops.[45] Barbetseas and colleagues used echocardiography for evaluation of aortic aneurysms after AVR.[6] Even though transthoracic echocardiography clearly documented the presence of the pseudoaneurysm that formed postoperatively in our case; cardiac CT was ordered for confirmatory purposes to reach a final therapeutic decision. In our patient's case, the decision of whether or not to reoperate has not yet been made.