A rare case of late aortic pseudoaneurysm post double valve replacement

Abstract

Here, we present a case of pseudoaneurysm of the aorta, 2 years after double valve replacement (DVR) in an 18-year-old male patient presented with a pulsatile swelling over the sternum. The pseudoaneurysm of the aorta extending up to the skin 2 years after cardiac surgery is a rare condition. Most cases are asymptomatic and need emergency surgery. Here, we present the case which was successfully managed with surgery.

Introduction

Pseudoaneurysm of the ascending aorta following cardiac surgery is a rare complication. Ṃost patients are asymptomatic. However, if untreated, the pseudoaneurysm may increase in diameter over a short period of time. There are chances of sudden rupture causing catastrophy also. Rarely, a pseudoaneurysm sac may erode the overlying sternum and ṃay present as a pulsatile superficial swelling. It may also compress the surrounding structures. We herein describe successful surgical management of a case of pseudoaneurysm of the ascending aorta in a patient with double valve replacement (DVR) surgery, done 2 years back for rheumatic heart disease.

Case report

An 18-year-old male patient, with a past history of DVR done 2 years back, presented with a pulsatile and expansile swelling over the sternal scar near the suprasternal area for 15 days. There was no history of trauma or high-grade fever. The swelling gradually increased to a size of 4 cm × 3 cm (Fig. 1a, b). Chest X-ray (Fig. 2b), echocardiography and contrast-enhanced computed tomography (CECT) scan (Fig. 2a) showed a swelling originating from the aortic root with features suggestive of a pseudoaneurysm.

Fig. 1.

a, b Showing pulsatile subcutaneous swelling. c Showing post excision of pseudoaneurysm

Fig. 2.

a Contrast-enhanced axial image showing a large pseudoaneurysm arising from the ascending aorta (Asc aorta) with narrow neck (red arrows). There is partial thrombus (yellow outline) surrounding the pseudoaneurysm sac. b Preoperative chest X-ray showing dilated ascending aorta. c Chest X-ray post excision

The patient was taken up for surgery with due consent. Femoro-femoral cardiopulmonary bypass (CPB) was initiated. Cooling was started and patient was cooled up to 25 °C. Sternotomy was started but the sac got ruptured suddenly as it was anticipated before. Total circulatory arrest (TCA) was initiated and sternotomy with retraction of the sternum was completed. Then, the pseudoaneurysm sac was excised (Fig. 3a). A rent was identified approximately of 2 cm² arising from the aortotomy suture line. The distal ascending aorta was dissected and flow was gradually started. Aortic cross clamp was applied after deairing. Cardioplegia was delivered via coronary ostia through the rent. Repair of the rent was done using double patch (Dacron patch on the outside and autologous pericardial patch inside) with pledgeted interrupted prolene suture (Fig. 3b). The double patch was made using the pericardial tissue and Dacron patch. Both were sutured side by side. The patch was used to close the rent and to reinforce the aorta. A Cardioplegia needle was placed in the ascending aorta through which deairing was started. Cross clamp was removed and aortic root vent was applied. Gradually the patient was weaned off from cardiopulmonary bypass. Total circulatory arrest time was 8 min. Postoperative period was uneventful with absence of mediastinal widening in chest X-ray (Fig. 2c) and absence of suprasternal swelling (Fig. 1c). The patient was discharged on the seventh postoperative day.

Fig. 3.

a Intraoperative image showing the rent in ascending aorta over previous aortotomy site with pseudoaneurysm sac dissected below. b Intraopearative image after repair of the rent with a double patch (white arrow)

Discussion

Pseudoaneurysm of the ascending aorta after valve replacement is uncommon [1]. The incidence of pseudoaneurysm in patients with significant aortic dilatation following aortic valve replacement (AVR) is 27%, whereas the overall incidence of acute aortic dissection after AVR is 0.6% [2]. The interval between valve replacement and pseudoaneurysm formation may vary from 2 months to 17 years [3].

Ascending aortic pseudoaneurysms have high morbidity and mortality rates. Most patients die due to dissection or rupture. Untreated cases have a 40–60% mortality risk within 48 h of the rupture. Ascending aortic pseudoaneurysms are mostly asymptomatic. Sometimes, widening of the mediastinum on chest X-ray may be found. Therefore, postoperative imaging at regular interval during follow-up in patients with mildly or moderately dilated aortic root may be helpful for making a diagnosis of aortic aneurysms [4]. In our case, the patient was asymptomatic except for a pulsatile swelling in the suprasternal area. There was widening of the mediastinum in chest X-ray (Fig. 2b). CECT scan demonstrated a large pseudoaneurysm sac of 6.8 cm × 5.2 cm arising near the root of the ascending aorta with a narrow neck (Fig. 2a) and surrounding thrombus. Transthoracic echocardiography demonstrated a hugely dilated ascending aorta with normally functioning aortic and mitral prosthetic valves with left ventricular ejection fraction of 50%.

The predisposing factors for pseudoaneurysm formation reported in the literature [5, 6] are paraprosthetic leakage due to infection and leakage from the suture lines of the aortic valve, aortotomy site or cannulation site. Most of the cases are due to mechanical rupture of aortic sutures as evident in our case. As reported in the previous literatures, postsurgical aortic pseudoaneurysm often occurs after several weeks to a few months from operation. It is rare that this patient was surprisingly presented before us 2 years after the operation.

The management of such a case is always a challenge for the surgeon [7]. The pseudoaneurysm sac extended up to the skin as the manubrium sterni was eroded. It is rarely reported in the literature. Total circulatory arrest (TCA) was planned for sternotomy. Massive haemorrhage was managed accordingly. The approach via median redo sternotomy using circulatory arrest was helpful in this case. The manubrium sterni was already eroded by pseudoaneurysm sac, so the pectoralis muscles were mobilised and the deficient manubrium sterni was covered to protect the aorta.

Conclusion

The pseudoaneurysm following aortic valve surgery is a case of potential fatal complication which demands immediate surgery. Routine follow-up with chest X-ray can be an option for making an early diagnosis. Early diagnosis at the initial stage of progression of the disease makes surgical treatment easier and successful.

The learning message

Ascending aortic pseudoaneurysms following cardiac surgery are mostly asymptomatic. In regular follow-up, we should advice chest X-ray and we should check for if there is any mediastinal widening for early detection and management.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Informed consent

Informed consent was obtained from all individual participants included in the study. Additional informed consent was obtained from all individual participants for whom identifying information is included in this study.

Ethical approval

All procedures performed in the studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standard.