Endoarch Repair of Ruptured Extra-Anatomic Ascending to Descending Bypass Graft in Hypoplastic Arch With Coarctation

Abstract

Background

Hypoplastic arch and residual coarctation are treated with ascending to descending extra-anatomic bypasses and are challenging to manage.

Case Summary

A 36-year-old woman with several sternotomies had undergone ascending to descending extra-anatomic bypass as a neonate. She experienced blunt force trauma to her chest, and significant delay in diagnosis led to decompensation. A nondisplaced fracture lacerated the aortic graft and led to a contained rupture and bacteremia. She underwent left thoracotomy and complex thoracic endovascular aortic repair. Six weeks of antibiotics and careful conservative management led to a safe outcome.

Discussion

Management of a ruptured extra-anatomic bypass in the setting of bacteremia with thoracic endovascular aortic repair is controversial. Given multiple prior sternotomies, the degree of required tissue debridement, and anticipated lifelong antibiotic suppression, an initial endovascular approach seemed warranted. Unconventional approaches to complex adult congenital heart disease (ACHD) lesions are necessary to increase longevity and mitigate disease.

Take-Home Messages

Patients with ACHD require early recognition with a high index of suspicion. Endovascular repair in ACHD arch pathology should be considered.

Visual Summary

History of Presentation

A 36-year-old high-functioning woman with trisomy 21 initially presented with shortness of breath and chest pain to a rural emergency department after a ground-level fall 2 weeks prior (Figure 1A). No investigations were pursued, although new erythema at the prior sternotomy site was noted. Computed tomography angiography of the chest was notable for severe cardiomegaly, a small pericardial effusion, and scattered bilateral atelectasis. She was hemodynamically stable and was discharged following negative serology. Four weeks later, she was admitted from another outside emergency department with persistent fever, dyspnea on exertion, worsening tachypnea, a pulsatile hematoma, and tachycardia (Figures 1B and 2A) (IRB #00030237).

Figure 1.

Cross-Sectional Imaging

(A) Initial computed tomography angiography (CTA) obtained following ground-level fall. The orange stars show no acute pathology. (B) CTA scan obtained before transfer. The orange stars show significant fluid collections and clinically were the site of a pulsatile hematoma.

Figure 2.

Physical Findings

(A) Initial pulsatile hematoma on presentation. (B) Resolving hematoma day before discharge. (C) Resolved sternal wound a month after the operation. (D) Healed left redo thoracotomy a month after the operation.

Past Medical History

The patient had a history of complex cyanotic heart disease including a large muscular ventricular septal defect (VSD), hypoplastic right aortic arch with coarctation, and persistent left superior vena cava (Video 1). Her neonatal repair included pulmonary artery banding, followed by staged VSD closure and subsequent VSD patch leak revision––all through separate sternotomies. Eventually, a left thoracotomy and combined redo sternotomy were used to place a 26-mm extra-anatomic ascending to descending aortic conduit. At the most recent presentation, she was transferred from the outside hospital with methicillin-susceptible Staphylococcus aureus bacteremia and presumed graft infection (Video 1).

Differential Diagnosis

The differential included pneumonia, blunt traumatic sternal fracture with hematoma, and bacteremia with VSD patch and/or aortic conduit infection.

Investigations

Workup included chest x-ray with right middle lobe opacification and concern for pneumonia, transthoracic echocardiogram demonstrating normal left ventricular ejection fraction and unobstructed flow through the aortic conduit, no residual VSD or vegetations, and laboratory analysis showing elevated procalcitonin and B-type natriuretic peptide. Respiratory panel was negative. Repeat blood cultures were obtained, and she was empirically started on ceftriaxone and azithromycin. Cross-sectional imaging demonstrated concerns for chest wall abscess and conduit infection. Gated computed tomography angiography of the chest demonstrated focal anterior outpouching of the proximal aortic conduit and a rim-enhancing anterior chest wall fluid collection concerning for a contained rupture with communication to an anterior chest wall fluid collection, purportedly because of traumatic laceration and rib fracture (Figure 1B, Video 1).

Management

Multidisciplinary discussion among adult congenital heart disease (ACHD) Cardiology, congenital cardiac surgery, vascular surgery, intensive care unit, and cardiac anesthesia was completed. Complex endovascular exclusion with a direct aortic approach was conceived. There was significant tortuosity of the distal thoracic aorta and a prior aortic bypass graft, which precluded graft delivery via femoral access. Following comprehensive informed and contingency consents, the patient underwent bilateral femoral access and redo left anterolateral thoracotomy. Given dense adhesions, a short segment of rib resection above the aortic conduit was necessary (Figure 3A); single-lung isolation was confirmed, and the prior aortic graft was partially dissected free. The graft was directly accessed, following placement of pledgeted purse-string sutures. Combinations of fluoroscopy, aortography, and Seldinger’s technique were used to dilate a 4-F micropuncture access through the purse string to a 5-F sheath, and eventually a 33-cm, 22-F Gore DrySeal Introducer Sheath (W.L. Gore & Associates, Inc) was advanced into the distal aortic graft (Figure 3B). A Gore TAG (W.L. Gore & Associates, Inc) conformable thoracic stent graft, 26 mm × 100 mm was advanced over a stiff supportive wire and deployed following biplanar confirmation at the proximal anastomosis site of the aortic graft at the ascending aorta (Figure 4, Video 2). The aortic rupture had $\approx$3-cm proximal and $\approx$5-cm distal seal zones. Completion angiography was satisfactory (Video 3). Transesophageal echocardiography confirmed no change from baseline, and the patient had palpable pulses in all extremities.

Figure 3.

Intraoperative Images

(A) Intraoperative resected rib margins and exposed anterior aortic graft. (B) Intraoperative muscle-sparing entry and direct access surgical site setup.

Figure 4.

Procedural Angiography

(A) Access angiogram demonstrative of a diminutive distal aorta. (B) Radio-opaque pig tail marker in the aortic conduit, the orange star demonstrates the operative field exposure. (C) Aortogram that demonstrates significant tortuosity of the extra-anatomic bypass graft and the orange star shows the suspicious site of the rupture. (D) Aortogram that redemonstrates the tortuosity, and the delayed contrast that is “hung up” and extravasating from the extra-anatomic bypass graft at the orange star.

Outcome and Follow-Up

Following hemodynamic management and optimization, the patient was extubated on postoperative day 2 with no change in sternal hematoma size and was discharged home on hospital day 8 with 6 weeks of cefazolin and subsequent lifelong oral suppressive antibiotics (Figure 2B). Eventually, there was complete resolution of the hematoma (Figures 2C and 2D), no evidence of bacteremia, a normal echocardiogram, and axial imaging demonstrating no extra-anatomic fluid collections, fat stranding, or concerns of endoleak (Video 4, Video 5, Video 6). Approximately 18 months later, the patient has shown no evidence of recurrent infection through radiographic, microbiologic, and clinical surveillance. Cross-sectional imaging obtained 14 months after the operation suggested complete resolution of the hematoma (Figure 5).

Visual Summary.

Timeline of the Case Events

The flow sequence diagram demonstrates how the patient interacted with health care system(s). CTA = computed tomography angiography; ER = emergency room; IV = intravenous; POD = postoperative day.

Figure 5.

Cross-Sectional Scan Obtained 14 months After Operation Where the Orange Stars Show Complete Resolution of the Hematoma

Discussion

Extra-anatomic bypass with a Dacron conduit is a well-established and effective technique for bypass of aortic coarctation, particularly in complex anatomy, a hypoplastic native aorta, or recurrent disease. Long-term morbidity, especially from early-generation grafts, remains significant and includes peri-graft fluid collections from poor adherence, obstructing pseudointima, porosity, aneurysm formation from fiber degeneration, and thrombogenicity.¹ These risks are amplified by anastomotic suture line leaks, altered nonlaminar flow dynamics and pseudoaneurysm, lifelong exposure to systemic loss of aortic compliance and, in some cases, chronic anticoagulation.2, 3, 4 These conduits are usually connected in the distal ascending aorta and tunneled to the descending thoracic aorta. They are simpler to install in a neonate and become onerous to manage in an adult. We are the first to report rupture the management of an extra-anatomic bypass conduit with thoracic endovascular aortic repair (TEVAR) through thoracotomy and direct graft access (Figure 3).

The role of advanced cardiac imaging––echocardiography and cross-sectional tomography––cannot be overstated given the complex hypoplastic aorta and arch, prior VSD repair, and clockwise rotation of the coronaries. The proximity of the conduit to the pulmonary artery and the risk of tamponade in this case are significant and provide credence to advanced testing. The independent roles of cardiac critical care and ACHD cardiology for periprocedural and longitudinal care are essential to a successful outcome (Figure 5, Video 4, Video 5, Video 6).

Although underappreciated, increased left ventricle afterload, decreased subendothelial blood supply during diastole, and reduced coronary flow reserve––collectively called the Windkessel effect––are important events after TEVAR.⁵ Hence, preoperative echocardiography of the native aortic valves and coronary flow is crucial given the impact on both periprocedural and longitudinal care. Lastly, from a structural perspective, our patient is likely to require an aortic valve intervention in her lifetime, and understanding access for transcatheter intervention predicated on lifetime management of her valves is imperative. Taken together, the complexity of this case is germane to cardiovascular disease experts and requires active engagement in a multidisciplinary fashion.

TEVAR offers several advantages over open repair, and the decision to deviate from a conventional strategy of redo sternotomy, take down of the extra-anatomic bypass, need for circulatory arrest, risking conduit entry, and possible revision of the VSD patch through a 2-incision approach for conduit replacement, along with arch reconstruction, were all part of the consent process. Sternotomy-based entry risked hemorrhagic shock during mobilization with limited cannulation options for cardiopulmonary bypass. The groin access was hostile because of small-caliber femoral vessels, and the overall aortic course was challenged by tortuosity and multiple retro-hairpin bends (Figures 4C and 4D). Alternative access, including transiliac, transapical, and direct transaortic approaches in unsuitable peripheral anatomy, is well known,⁶ but direct approaches are infrequently considered.

TEVAR approach was controversial given the diminutive native abdominal aorta. Although using a graft off the common femoral arteries, iliac arteries, or abdominal aorta for access has been described, the need for a near-right-angle turn in the distal descending thoracic aorta to deliver the sheath and the device was impractical (Figures 4B to 4D). The need to cross the aortic valve with a stiff supportive wire in this case was not necessary. Based on these anatomic features, a direct approach became appealing. Prior reports of direct aortic access for TEVAR have involved right thoracotomy and median sternotomy to access the native descending thoracic aorta.^6,7 Left thoracotomy with direct access to the extra-anatomic aortic conduit allowed us safe delivery of a large-caliber sheath and stent graft deployment. Counterintuitively, other factors that facilitated decision-making were proximity to the chest wall and the need for muscle-sparing focal rib resection, ensuring safe and clear access. The aortic conduit was fused to the ribs, and developing a plane in a muscle-sparing fashion was important for successful closure.

The methicillin-susceptible Staphylococcus aureus bacteremia was an important confounder in management. Given the lack of florid graft infection, wall thickening, or fat stranding and cross-sectional imaging suggestive of conduit disruption with an overlying chest wall fluid collection, with emergent presentation, a less invasive and expedient solution was preferred. That said, there is more than a nontrivial risk of potential future infection with significant implications for a very complex redo operation and possibly >40% mortality and/or >60% morbidity. As such, lifelong oral suppressive antibiotic prophylaxis, albeit unconventional, was necessary in this case when weighed against the risk of reoperation.

Endovascular repair has emerged as a safe and effective treatment option for late aneurysm and pseudoaneurysm formation following prior aortic coarctation repair.^8,9 However, in patients with ACHD, use of endovascular therapies is uncommon. Pediatric congenital cardiac training does not include exposure to transcatheter techniques, and hence collaborations with ACHD and multiple other cardiology subspecialties, cardiac anesthetists, surgeons comfortable with aortic management in patients with ACHD, and vascular surgeons become apropos. This multidisciplinary approach to management is important for successful patient outcomes.

Conclusions

Our case demonstrates that in carefully selected patients, hybrid strategies can provide effective treatment of late-conduit complications while minimizing morbidity and mortality associated with open reintervention. Pseudoaneurysm and contained leak or rupture pathologies in extra-anatomic aortic conduits can be safely treated with alternative approaches and direct aortic access in patients with ACHD.

Take-Home Messages

• •Adult patients with congenital heart diseases are living longer and are being seen with residual or unique clinical presentations.
• •Their care requires early recognition, high index of suspicion, multidisciplinary approach, and occasionally out-of-the-box solutions to improve their longevity and mitigate symptoms.

Funding Support and Author Disclosures

Dr Bhamidipati is a consultant for WL Gore and Associates, Inc. and has served on the clinical events committee for Artivion, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Appendix

Video 1

Preoperative Axial Images From Computed Tomography Angiography (CTA) Obtained Before Transfer

Video 2

Predeployment Angiogram Demonstrating Aortic Valve, Residual Coarctation, Aortic Tortuosity, Delayed Contrast That is “Hung Up” and Extravasating From the Extra-Anatomic Bypass Graft

Video 3

Deployment of the Endograft and Completion Angiogram Demonstrating No Periprocedural Endoleak

Video 4

Postprocedure Axial Images From Gated Computed Tomography Angiography (CTA) of the Chest Before Discharge

Video 5

Postprocedure Coronal Images From Gated Computed Tomography Angiography (CTA) of the Chest Before Discharge

Video 6

Postprocedure Sagittal Images From Gated Computed Tomography Angiography (CTA) of the Chest Before Discharge