Dacron Tube Graft-Covered Stenting of Recoarctation of the Aorta.

We report a case with recoarctation within a tubed graft. Covered stent placed inside the tube graft safely and effectively treated the recoarctation of the aorta.

INTRODUCTION

Coarctation of the aorta (CoA) accounts for 4%–7% of all congenital heart defects.[1] The available treatment modalities are surgery, balloon angioplasty, and endovascular stenting. Stenting of native and recurrent CoA with covered stents has become an important therapeutic approach. We report an adult patient with severe recurrent CoA after surgical repair with a Dacron tube graft, who underwent successful percutaneous-covered stent implantation within the Dacron tube graft.

CASE PRESENTATION

A 56-year-old male patient with coronary artery disease (CAD) and hypertension was referred with exertional dyspnea (NYHA II). Past medical history revealed that he had coarctation which was surgically corrected with a 16 mm x 20 mm Dacron tube graft at 21 years of age. On examination, his right upper limb blood pressure was 180/90 mmHg. The femoral pulses were faint. Radial femoral delay was apparent and blood pressure gradient of 30 mmHg was noted between upper and lower extremities. Chest X-ray revealed rib notching. Echocardiography showed a significant narrowing in the descending aorta just distal to subclavian artery inside the tube graft with peak gradient of 38 mmHg and mean gradient of 16 mmHg with diastolic spillage. There was concentric left ventricular hypertrophy with good systolic function. Contrast-enhanced computed tomography revealed severe stenosis at the proximal and distal anastomosis of the Dacron tube graft [Figures 1 and 2].

Figure 1

Computed tomography with severe stenosis at the proximal and distal anastomosis of the Dacron tube (arrow)

Figure 2

Computed tomography with severe stenosis at the proximal and distal

A decision was made to proceed with staged coronary angiography and later CoA stenting. Coronary angiogram revealed mid left anterior descending artery and diagonal disease which were stented. Two weeks later, the patient went for CoA stenting.

Under general anesthesia, a 7F sheath was placed in the left femoral artery and a 6F sheath in the right radial artery. The coarctation site was crossed with 0.035 cm × 150 cm Terumo guidewire and 6F multipurpose catheter. Simultaneous recording from the ascending aorta and descending aorta revealed a peak-to-peak gradient of 54 mmHg.

Ascending aorta angiogram [Figure 3] showed severe coarctation at the sites of proximal and distal anastomosis (6 mm each) of the tubed conduit and normal head and neck branches. The conduit length was 20 mm and diameter 14 mm. A 0.035 cm × 260 cm Amplatz super stiff wire was placed in the right subclavian artery for stability and a 14F Check Flo–Cook long sheath was placed over the wire. A 39-mm Cheatham platinum (CP)-covered stent (NuMed Inc., Hopkinton, New York, USA) was mounted to 14 mm × 40 mm BIB balloon to BIB catheter. Stent position was confirmed using aortic arch angiogram through the right radial artery approach. The stent was deployed inside the Dacron graft with right ventricular pacing at 170 bpm.

Figure 3

Ascending aorta angiogram with severe coarctation at the sites of proximal and distal anastomosis (arrows, 6 mm each) of the tubed conduit and normal head and neck branches

Poststent implantation, the gradient dropped to 11 mmHg. The covered stent was postdilated with a 16 mm × 45 mm BIB balloon twice with good flaring of the proximal and distal ends of stent. Postballoon, dilatation revealed still further drop in gradient to 8 mmHg. Final angiogram [Figure 4] confirmed the good stent position and absence of any extravasation or tear. The measurements at proximal and distal coarctation sites were 14 mm each. The patient had uneventful recovery and discharged home the next day. Currently, the patient is asymptomatic and weaning off all antihypertensive medications.

Figure 4

Final angiogram showing the good stent position and absence of any extravasation or tear

DISCUSSION

CoA should be diagnosed and corrected early in life. The complications of untreated CoA include hypertension, premature coronary artery disease, sudden cardiac death, heart failure, stroke, endocarditis, rupture, dissection and aneurysm formation.[2] Therapeutic goals are symptomatic improvement, hypertension control with an intervention which is suitable for the individual patient. Transcatheter balloon angioplasty was introduced in the 1980s as an alternative approach to treat recurrent coarctation following surgical therapy. Both these strategies have major drawbacks, including recoarctation, residual hypertension, aortic wall injury causing dissection, and aneurysm formation.

To overcome these limitations, intravascular balloon-expandable stent therapy was introduced in the 1990s. The complications of bare metal stenting are aneurysm formation, stent malposition, and stent fracture. In 1999, the first covered stent was used to treat coexistent CoA and aneurysm of the aorta in a young man.[3] Since then, the use of covered stents has expanded for native and recurrent CoA.[24]

A review literature has shown the benefits of transcatheter stenting techniques [Table 1]. The overall long-term complication rates in stent placement were 12.5% as compared to 43.8% for balloon interventions.[4] Multicenter reports from the CCISC registry by Forbes et al.[5] demonstrated procedural success in 97.9% (defined as reduction in gradient <20 mmHg, increase in poststent coarctation to descending aorta ratio of >0.8).

Table 1

Follow-up data of patients with trans catheter intervention for coarctation of the aorta

The CoA Stent Trial (COAST)[6] reported on patients who underwent implantation of a bare-metal CP stent for native or recurrent coarctation through 19 centers in the United States (US) [Table 1]. There were no procedural deaths, adverse events, or surgical intervention. At follow-up, six aortic aneurysms were identified. Five were successfully treated with a covered stent placement, and one resolved without intervention.

The immediate outcome of covered stent placement from patients enrolled from 19 cardiac centers in the US, COAST II study [Table 1] revealed that there were no acute aortic wall injury, repeat interventions, or deaths. The use of covered CP stents can prevent or deal with the complications of aneurysm formation and open stent fractures by “sealing” the stenotic dilated area, the aneurysm or the stent fracture. They can also be successfully used in tortuous lesions and fracture of a covered stent or a stent graft.

Literature review about the behavior of polyester patch grafts in patients with repaired CoA showed increased incidence of aneurysm formation rather than stenosis.[8] In our patient, Dacron tube graft was used for CoA repair 35 years ago. He presented with recoarctation within a tube graft which is very rare. We used the covered CP stent to reduce the possibility of recurrence.

CONCLUSION

Covered CP stent can be used inside a Dacron tube graft to safely and effectively treat and potentially prevent aortic wall injury associated with re-CoA within a tubed graft.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.