King Edward Memorial Hospital - Departments: Radiology

Radiology

Case of the Month

Case No. :	02
Month :	February
Year :	1999
Contributor :	Dr. Shrinivasa Prasad

Other Cases

Clinical Features | Angiographic findings | Differential diagnosis | Discussion | Management

Clinical Profile:

A twenty four year old man presented with a six months history of dyspnea, bilateral lower limb claudication and occasional blackouts. Clinical examination revealed systemic BP of 160/100 mm of Hg and a radio-femoral delay. Abdominal ultrasound demonstrated normal echo-pattern of the kidneys. There was no adrenal mass lesion. ESR was normal.

Fig. 1

Fig. 2

Fig. 3

An aortogram was performed to evaluate the cause of claudication and hypertension (Fig.1).

Angiographic findings:

The right transfemoral aortogram (Fig.1) demonstrates an approximately 75% circumferential narrowing of a 7 cm segment of the distal descending thoracic aorta at the level of D9 and D11 vertebral bodies. There is post-stenotic dilatation of the suprarenal abdominal aorta. The celiac and the superior mesenteric artery and their branches were normal. The renal arteries were normal in origin and calibre. The mean pressure gradient across this narrowing 30 mm of Hg.

Diagnosis:

The angiographic findings are classical for Non-specific Aorto-arteritis (NSAA).

Endovasular Treatment:

A self-expanding nitinol stent ( 18 mm diameter, 80 mm long), with thermal memory (Memotherm, BARD, Germany) was deployed across the aortic narrowing through the trans-femoral route. The stent was then dilated with a 18mm, 4cm long balloon angioplasty catheter. Post-stenting aortogram (Fig. 2) showed minimal residual narrowing with persistence of post-stenotic dilatation. However, there was 100% reduction in the pressure gradient across the stent.

Follow-up:

There was immediate relief of caludication following the stenting. At the end of six months following stent deployment, the patient was asymptomatic with a systemic blood pressure of 140/84 mm of Hg. The patient had no claudication. Aortogram (Fig.3) performed at this juncture revealed significant remodelling of the aortic calibre.

Discussion:

Non-specific aorto-arteritis is an idiopathic, vaso-obliterative condition affecting the aorta and its major branches. It predominantly affects young people with a striking female preponderance.

The anatomic localization of the disease process, the degree of vascular occlusion and the adequacy of collateral circulation determine the clinical presentation, signs and symptoms. Patients present with non-specific constitutional symptoms like low-grade fever, anorexia and loss of weight during the active phase of the disease. A majority of patients manifest systemic hypertension and its attendant complications. Other clinical manifestations include syncope, stroke, limb claudication, abdominal angina, pulmonary hypertension and right heart failure. Rarely myocardial ischemia/infarction may ensue owing to involvement of the coronary arteries.

NSAA is characterized by panarteritis and extensive periarterial fibrosis/adhesions and mural thickening. Vessel wall calcification may occur. All these changes lead to a tough, non-compliant, rigid vessel wall. Microscopically there is evidence of panarteritis with increase in collagenous tissues and perivascular mononuclear infiltrates.

Media may show granulomatous lesions, coagulation necrosis and various types of giant cells in the early stages of the disease. Subsequently, there is lymphocyte/ plasma cell infiltration and fibrosis. Vasavasorum may show changes of endarteritis and perivascular mononuclear cuffing.

Angiographic findings:

Angiographic findings reflect pathologic changes in the vessel wall. The following angiographic features are seen.

1: Irregularity: This is the earliest change due to intimal fibrosis.
2: Stenosis: This represents an advanced lesion due to circumferential intimal/mural thickening.
3: Complete Occlusion
4: Diffuse dilatation and aneurysm formation.
5: Combination of the above lesions.

Based on the anatomic location of the lesions, the following is the commonly accepted classification system of NSAA.

Modified Nasu classification:

Type I: Aortic arch and its branches only.
Type II: Desending thoracic aorta and its branches only.
Type III: Abdominal aorta and its branches only.
Type IV: Extensive involvement of aorta and its branches.
Type V: Ascending aorta only.
Type VI: Branches of aorta only.

Management:

Vascular reconstructive surgery is the traditional mode of treatment of NSAA. However, endovasular treatment is emerging as the preferred modality of treatment. Angioplasty with or without stent placement is a minimally invasive procedure with low morbidity. The use of self-expandable metallic stents is currently the promising treatment option in patients of NSAA.