From stent to stability: Conservative management of post-stenting aortic dissection in coarctation of the aorta

ABSTRACT

Coarctation of the aorta (CoA) is characterized by congenital narrowing of the aortic isthmus. Primary treatment modalities include balloon dilatation, stenting, and surgical repair. Here, we present the case of a 37-year-old male with refractory hypertension who underwent successful stenting of a severe postductal CoA, achieving complete resolution of the trans-coarctation gradient. Twenty-four hours later, he developed severe inter-scapular pain, and computed tomography aortography revealed an extensive Stanford type B aortic dissection extending from the distal stent margin to beyond the aortic bifurcation. As there were no signs of end-organ malperfusion, conservative management was pursued with close monitoring and blood pressure control. The dissection stabilized and the patient responded favorably, with sustained stability on the follow-up.

INTRODUCTION

Coarctation of the aorta (CoA) accounts for 5%–8% of all congenital heart diseases.[1] It can present from infancy to adulthood with the symptoms of congestive heart failure, hypertension, stroke, and epistaxis. The treatment modalities include balloon/stent coarctoplasty or corrective surgery, depending on the age of diagnosis and the anatomical suitability.[2]

CASE REPORT

A 37-year-old male presented with refractory hypertension and an intractable headache. On physical examination, a discrepancy was noted between his upper and lower limb blood pressures (BP), with readings of 220/130 mmHg in the right brachial artery and 170/100 mmHg in the right popliteal artery, accompanied by a significant radio-femoral delay.

Cardiac examination revealed a sustained apical impulse and a loud aortic component of the second heart sound (A2). A soft, continuous murmur was audible in the interscapular region. No significant past history was noted.

An electrocardiogram showed sinus rhythm with left ventricular hypertrophy (LVH) [Figure 1a]. A chest radiogram revealed a characteristic bilateral rib notching involving the inferior borders of the 4^th–8^th ribs with characteristic indentation on the aortic knuckle (“3” sign) [Figure 1b].

Figure 1.

(a) Twelve lead electrocardiogram showing sinus rhythm and left ventricular Hypertrophy, (b) A chest radiogram anteroposterior (AP) view showing the indentation of the aortic arch-the “3” sign (2 arrows) and characteristic rib notching involving the inferior borders of the 4^th to 8^th ribs (3 arrows)

Transthoracic echocardiography showed concentric LVH, Sievers’ type I normally functioning bicuspid aortic valve without significant dilatation of the aortic root. Suprasternal view revealed severe CoA beyond the left subclavian artery [Figure 2a], with peak gradients of 61 mmHg and characteristic diastolic tailing [Figure 2b]. A computed tomography (CT) aortogram confirmed severe postductal coarctation of the descending thoracic aorta, 8 mm distal to the origin of the left subclavian artery. The narrowest segment had a diameter of 6 mm, the immediate precoarctation segment had a diameter of 22 mm, and the aorta at the level of the diaphragm measured 25 mm. Given the hemodynamically significant coarctation, with severe hypertension, it was decided to proceed with transcatheter intervention using a covered stent.

Figure 2.

(a) Suprasternal 2D echo and color Doppler image of the aortic arch demonstrating flow turbulence at the site of maximum narrowing (yellow arrow), (b) Continuous-wave Doppler at the coarctation segment in panel demonstrating a peak systolic gradient of 61 mmHg with diastolic tailing consistent with a diagnosis of severe coarctation

Management and intervention

The procedure was performed under general anesthesia, with a right femoral 7 Fr primary access for the stent deployment and right radial 6 Fr secondary access for pressure monitoring and aortography. Baseline peak-to-peak pressure gradient of 62 mmHg was noted [Figure 3b].

Figure 3.

(a) Aortogram in the left anterior oblique (LAO) view demonstrating postsubclavian severe CoA (yellow arrow), (b) Pullback gradient from the descending thoracic aorta (DTA) to arch of aorta demonstrating a pressure gradient of 62 mmHg, (c) Fluoroscopic image in the LAO cranial view demonstrating stent deployment (white arrow) with relief of the balloon waist at the site of tightest stenosis, (d) Aortogram in LAO cranial view poststent deployment showing no visualized residual stenosis with a well-expanded stent and no evidence of dissection or leak, (e) Postprocedure pressure tracings in the DTA and arch of aorta showing an equalization of pressure between the arch of aorta and the femoral artery causing overlap of the pressure tracings demonstrating a successful procedure

An aortography performed in LAO view with caudal angulation revealed severe coarctation distal to the origin of the left subclavian artery [Figure 3a]. After crossing the coarctation segment with a JR catheter and an angled Terumo guidewire, the femoral access was upsized with a 16 Fr long (70 cm) delivery sheath (Cook), which was advanced over an Amplatzer super stiff wire. A 39-mm premounted covered Cheatham Platinum (CP) stent mounted over a 22 cm × 4 cm balloon (Z Med, NuMed) was successfully deployed across the coarctation site at nominal pressure [Figure 3c] followed by two serial dilatations at 2 atm. Aortography demonstrated excellent stent expansion and a widely patent aortic lumen, with no evidence of aortic dissection or pseudoaneurysm, [Figure 3d] and complete resolution of the pressure gradient [Figure 3e].

After 24 h of uneventful postprocedure period, the patient developed acute interscapular pain. The distal pulses were well palpable, with blood pressures of 132/85 mmHg in both the upper and lower limbs. The echocardiography showed normal biventricular function, no pericardial effusion, and no significant gradient across the coarctation site. A CT aortogram revealed a long Stanford type B aortic dissection extending from the distal stent edge, down across the aortic bifurcation, involving the bilateral common iliac and common femoral arteries [Figure 4a]. However, the celiac, superior mesenteric, and renal arteries all originated from the true lumen, with no radiographic signs of organ hypoperfusion [Figure 4b]. After a multidisciplinary Heart Team discussion, it was decided to manage the patient conservatively.

Figure 4.

(a) A coronal view of the computed tomography aortogram demonstrating the true lumen (yellow arrow) and false lumen (white arrow) separated by the dissection flap, (b) 3D reconstructed computed tomography image of the aortogram demonstrating the stent and true lumen (blue arrow) and false lumen (yellow arrow) with preserved flow in all the vital branches

The patient was closely monitored in the ICU for vital signs and for gut, renal, or lower limb ischemia. The BP was maintained around 110/70 mm Hg with IV beta-blockers and ACE inhibitors. In addition, he was advised strict bed rest and analgesics for pain relief. Over the following days, his backache reduced in intensity, and all the peripheral pulses remained palpable with no abdominal bruit. The patient was discharged after 1 week. A repeat CT aortogram at a 1-month follow-up showed stable stent position and complete thrombosis of the false lumen [Figure 5].

Figure 5.

(a) 3D computed tomography (CT) reconstruction showing the point of dissection entry (yellow arrow) and the false lumen (white arrow), (b) 3D CT reconstruction showing the thrombosed, false lumen without any major vascular compromise

DISCUSSION

Over the last two decades, stent coarctoplasty has become the standard of care while treating CoA. Majority of the studies prefer stenting as it prevents transluminal tears and splints smaller tears against the aortic wall, preventing aneurysm formation.[2] Covered stents are preferred as the risk of aortic dissection is low, between 0% and 3%.[3] However, in patients older than 40 years, due to reduced vessel wall compliance,[4] this complication cannot entirely be prevented.[5] Red herrings alerting the operator toward complications are back pain, renal or mesenteric ischemia manifested by reduced urine output, abdominal distension, paralytic ileus, abdominal bruit, and reduced pulse volume in lower limbs.

The management of poststenting aortic dissection includes covered endovascular stent, graft implantation, or surgical intervention. This requires careful clinical and hemodynamic assessment of the patient, vital organ perfusion, and the location and extent of dissection. Surgical intervention has a high-operative mortality of around 22%.[6] In a meta-analysis by Fattori et al.,[7] the management of patients with native Stanford Type B uncomplicated aortic dissection consisted of conservative management with adequate blood pressure control. The pooled early mortality rate in first 2 weeks was 6.9% with medical management, 10.2% with TEVAR, and 17.5% with open surgery.[7] However, the management of poststenting aortic dissection majorly consisted of surgical repair or second stent deployment as per our review of the literature.[8,9]

Hence, this adoption of conservative management due to hemodynamic stability and absence of organ hypoperfusion in our patient is a deviant from the usual management of complications.

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.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.