Infective Endocarditis-Related Pseudoaneurysms After Bentall Surgery: The Role of 3D Printing in Pre-Surgical Planning and Management: Case Report

Abstract

We present a case report of a male patient who underwent modified Bentall surgery with a mechanical valved conduit due to severe aortic regurgitation and ascending aortic aneurysm. Four years later, the patient developed a cascade of events as acute stoke, infective endocarditis due to Brucella abortus complicated by pseudoaneurysms of aortic graft with left ventricular outflow tract communication. A multi-modality approach, included a three-dimensional printing, facilitated the diagnosis and surgical planning. During surgery, the team opted for a salvage approach, and the patient showed continued improvement during follow-up. This case highlights the importance of careful monitoring and detection of potential complications after Bentall surgery, as well as the value of 3D printing in pre-operative planning.

1. Introduction

Bentall surgery, which involves replacing the aortic root and/or prosthetic aortic valve (AV) with a mechanical or bioprosthetic valve, was developed in the 1960s [1]. However, the surgery has a high rate of complications and reintervention, which can be classified into four categories: AV prosthesis, aortic graft, native aorta, or coronary arteries related [2]. Additionally, all cardiac prostheses and devices are vulnerable to endocarditis (IE), with prosthetic valve endocarditis accounting for 20% of all cases of IE and with prevalence of 6% for those with valve prostheses [3]. In our case-report, we present a case involving IE-related pseudoaneurysms after Bentall surgery, emphasizing the importance of a multidisciplinary, multi-modality approach and the use of three-dimensional (3D) printing as an adjunct tool to accurately identify the anatomical lesion and guide the appropriate surgical and medical management plan by providing a realistic and accurate representation of the patient’s anatomy. Moreover, 3D printing may allow a better visualization, preoperative manipulation and planning, and intraoperative guidance. Furthermore, its ability to identify complex lesions such as IE-related pseudoaneurysms emphasizes the importance of incorporating this technology into clinical practice.

2. Case presentation

A male patient, 39 years of age, had undergone modified Bentall surgery with size 27 mm mechanical valved conduit master HP series from St. Jude medical. The indication of surgery was bicuspid AV, severe aortic regurgitation, ascending aortic aneurysm of 7 cm in diameter, coarctation of the descending aorta, and severe left ventricular (LV) systolic dysfunction and dilatation (Fig. 1). Over the course of the four years following this procedure, his annual transthoracic echocardiography (TTE) studies were unremarkable, and there was a progressive improvement in LV dimension and function. However, four years later, the patient presented with acute neurological symptoms and was found to have acute thrombosis of the basilar artery by brain computed tomography angiography (CTA). Thrombolytic therapy (tPA) was done with improvement of the neurological deficit. During hospitalization the patient developed fever and blood cultures were positive for Brucella abortus, most likely contracted as a result of regular consumption of unpasteurized dairy products. Antimicrobial therapy in the form of gentamycin and rifampicin was initiated, and the patient underwent transesophageal echocardiography (TEE) to exclude infective endocarditis (IE). TEE revealed a posterior aortic root pseudoaneurysm measuring 18 mm in diameter with left ventricular outflow tract (LVOT) communication. Successively, the patient was transferred to our hospital. Upon arrival, the patient was alert, oriented, and afebrile, but did experience mild weakness on his right side. Septic workup continued to indicate B. abortus, but inflammatory markers, liver function, and kidney function all remained within acceptable parameters. TTE was repeated and confirmed the presence of an aortic pseudoaneurysm at the anterior and right side of the aorta extending from 9 O’clock to 1 O’clock in the short axis view, communicating with LVOT anteriorly. TEE revealed a circumferential pseudoaneurysm communicating with LVOT (Fig. 2). A cardiac CT scan revealed the presence of stable pseudoaneurysms arising from the anterior and posterior subvalvular LVOT, as well as a well-seated prosthetic AV (Fig. 3). Due to the intricacy of the case, a heart-team discussion was held, and the decision was made to proceed with cardiac surgery after repeated negative blood cultures along with long term antimicrobial therapy. Using 3D printing from reconstructed CT images, the anatomy was better understood and pre-operative planning was greatly facilitated (Figs. 4 and 5). The software used to process and analyze CT data is Materialise, while 3D System D2P is used to create 3D images from CT data. Finally, the 3D printer NexDent was used to produce the final 3D replica. Upon examining the 3D replica, the pseudoaneurysms were small but in direct contact with coronary arteries. Considering the high-risk nature of the surgery per se, the coronary reimplantation and potential high recurrence rate of the pseudoaneurysms, conservative approach was considered. The aortic prosthesis was properly placed, and a small pseudoaneurysm was present. Irrigation and debridement of periaortic area, aortic sub-valvular pannus resection and closure of the left atrial appendage were done. The patient’s recovery after the operation did not have any significant events. Co-trimoxazole and doxycycline were continued after being discharged. The patient showed continued clinical improvement during follow-up and regained full functional capacity. Four and 6-month follow-up indicated a stable pseudoaneurysm and well-seated aortic prosthesis. Brucella serology remained low while receiving extended suppressive antibiotic therapy.

Fig. 1. Transthoracic echocardiography pre-Bentall surgery.

Panel (A) parasternal long-axis view PLAX, panel (B) short-axis view showing the ascending aorta aneurysm of 7 cm. Panel (C) Doppler single showing severe aortic regurgitation. Panel (D) Apical long axis view showing ascending aorta aneurysm compressing the left atrium. Panel (E) and (F) showing severe aortic regurgitation with vena contracta of 8 mm in apical three-chamber and five-chamber, respectively.

Fig. 2. Echocardiography.

Panel (A) Long axis view of TEE showed the posterior pseudoaneurysm (yellow arrow) with color doppler in the adjacent image showed communication between the pseudoaneurysm and LVOT. Panel (B) Short axis view of TEE showing the posterior pseudoaneurysm (yellow arrow) and mechanical aortic valve with adjacent image color doppler showed no paravalvular leak. Panel (C) color doppler imaging along with M-mode showing systolic expansion of pseudoaneurysm. Panel (D) CW-doppler showing systolic-flow from LVOT to posterior pseudoaneurysm. TEE: Transesophageal echocardiography, LVOT: left ventricular outflow tract, LA: left atrium, AV: aortic valve prothesis, RV: right ventricle.

Fig. 3. Cardiac computed tomography.

Panel (A), (B), (C): axial, sagittal, coronal multiplanar views, respectively, from reconstructed CT images showing the anterior (arrow head) and posterior (arrow) pseudoaneurysms. Panel (D): 3D reconstructed CT images showing the anterior (arrow head) and posterior (arrow) pseudoaneurysms. Ao: aortic graft, LVOT: left ventricle outflow tract, LA: left atrium.

Fig. 4. Three-dimensional (3D) replica.

3D replica (printing) showing pseudoaneurysms (arrows) communication with LVOT (thin red arrow). LV: left ventricular, LA: left atrium, PV: pulmonary vein, AVTG aortic valve graft tube.

Fig. 5. The process of separation and preparation before 3D printing.

Showing 3D process involving the separation of the area of interest before printing from complete model on the left side of the figure, to the area of interest in the right side. Arrows indicated the pseudoaneurysms. LV: left ventricle, AVTG aortic valve graft tube.

3. Discussion

Bentall surgery is a high-risk surgery with short-and long-term complications occurring at a rate of 2% annually, reoperation at a rate of 0.5% annually, and a 5-year mortality of 5% [4,5]. Pseudoaneurysms are a potential complication following Bentall surgery that can occur early or late after the procedure. To improve early detection of pseudoaneurysms, routine CT scans have been proposed as a screening tool for patients who underwent Bentall surgery [6]. In one case-series, the prevalence of pseudoaneurysms was as high as 54% in a group of patients with infected aortic graft, with or without aortic valve prosthesis involvement, following Bentall surgery. However, the prevalence of IE-related pseudoaneurysms post Bentall surgery is currently unknown [7]. The gold standard treatment of infected aortic graft and/or AV prosthesis is surgical redo. However, given the complexity and high mortality rate associated with this procedure, graft salvage (debridement and irrigation) along with medical treatment (antimicrobial therapy) has been proposed for cases in which surgical risk is high [7,8]. The integration of echocardiography, CT, and MRI is essential for the evaluation of pseudoaneurysms and other complications related to infective endocarditis [9]. 3D printing has emerged as a novel tool that allows the creation of a 3D replica using reconstructed images, typically from CT or MRI. The improvements in imaging acquisition and 3D reconstruction techniques have led to an exceptional anatomical reconstruction, which can separate the area of interest from surrounding structures, yielding high-quality images. In this case, 3D printing included the extension and the relation of the pseudoaneurysms with the origin of the coronary arteries and its connection and extension with LVOT which was an additional tool for pre-surgical planning. Furthermore, the ability to manipulate the model facilitated better pre-operative planning [10].

4. Conclusion

In conclusion, Bentall surgery is a high-risk procedure with potential complications, including pseudoaneurysms, which can be difficult to detect and manage. The case presented in this article highlights the importance of a multidisciplinary, multi-imaging approach to accurately identify and manage such complications. The integration of 3D printing technology provides an additional tool for pre-operative planning and intraoperative guidance, leading to improved surgical outcomes and reduced rates of complications and reoperations. Further studies should explore the potential of 3D printing in improving the management of pseudoaneurysms and other complications related to cardiac surgeries.

Abbreviations

3D

Three-dimensions

AV

Aortic valve

CTA

Computed tomography angiography

FDG-PET

Fluorodeoxyglucose-positron emission tomography

IE

Infective endocarditis

LV

Left ventricle

LVOT

Left ventricular outflow tract

MRI

Magnetic resonance imaging

PVE

Prosthetic valve endocarditis

TEE

Transesophageal echocardiography

TTE

Transthoracic echocardiography