Cath Lab Digest

Case Report
A 34-year-old man presented with a ruptured infrarenal abdominal aortic aneurysm (AAA) (Figure 1). He reported no previous symptoms or illness. His father died at the age of 46 years from a drug overdose. His mother died of AIDS at the age of 44 years. The patient underwent emergency repair of the AAA with a Dacron tube graft and had a smooth postoperative recovery. However, he was readmitted 18 months later with severe abdominal pains. A computed tomography (CT) scan and magnetic resonance angiogram of the aorta indicated a false aneurysm of the distal aortic suture line (Figure 2). He underwent another uneventful repair involving segmental replacement of the original Dacron graft with a Hemashield^® Dacron (Boston Scientific Corp., Natick, Massachusetts) graft soaked in rifampicin.

Nine months later, the patient presented with a large retroperitoneal hematoma and multiple false aneurysms noted again at both proximal and distal suture lines. An urgent repair was done by aortobifemoral graft. All tissue and blood cultures were negative for an infectious etiology. One year later, the patient was admitted again with bilateral groin abscesses, which were drained, and the infection was controlled with broad-spectrum antibiotics. A subsequent CT scan revealed possible erosion of the left limb of the graft into the left colon. He underwent a colostomy, and after adequate nutritional support, underwent removal of the aortofemoral graft. There was no obvious infection noted around the graft at this time and aortic reconstruction was performed using paneled superficial femoral veins. The postoperative period was complicated by suture-line bleeding from the paneled superficial femoral veins within 24 hours, and all attempts to repair the disruptions in the vein graft were unsuccessful. He subsequently underwent replacement of the veins with a bifurcated aortofemoral Gortex^® graft (Gore Medical, Flagstaff, Arizona).

Within the next month, the patient developed suture line dehiscence with bleeding, which necessitated removal of the graft and suture legation of the infrarenal aorta and reconstruction using bilateral axillobifemoral grafts. He had a complicated postoperative course requiring a tracheotomy and stayed in the hospital for 6 weeks. He again presented to the emergency room 14 months later with an occluded right limb of the axillofemoral graft. His right lower extremity was not viable and was complicated with a thigh compartment syndrome with a CPK of 70,000 units and renal failure. He underwent an above-knee amputation, which healed well, and his renal function returned to normal. At present, he is living in a nursing home and is asymptomatic at 1 year of follow up.

Discussion
Aneurysm of the aorta (AA) is relatively rare in young adults. Patients younger than 50 years infrequently require AA surgery.^1,2 AA is less common in men of Afro-Caribbean descent.³ Muluk et al1 found that younger patients with AA have more symptoms at presentation than older patients (46% versus 6.7%, P < 0.001). These authors identified a subgroup of young patients at risk for early aggressive AA disease. Even so, our patient was asymptomatic and had no known medical comorbidities when he presented with a primary ruptured AA. The aggressive pattern of his disease was characterized by successive life-threatening complications through the next 3 years.

Moreover, the infrarenal location of his aortic aneurysm is rare because, usually, in young adults AAA is associated with more proximal aortic involvement than AAA in older patients.¹ To evaluate the patient’s cohort of complications we looked at the definable causes of aortic aneurismal disease, such as developmental or degenerative conditions, infections, familial or congenital factors, and rheumatologic phenomenon. In children and young adults, AA has been reported in association with trauma, infection, and connective tissue disorders, such as Takayasu’s,⁴ Cogan’s, Behcet’s,⁵ Marfan, and Ehlers-Danlos syndromes² or Tuberous sclerosis.⁶ However, isolated AAA, without any of the above risk factors is extremely rare.² Our patient had no evidence of infective or connective tissue disorders, and his index presentation was with the ruptured aneurysm. It also has been suggested that genetic factors are of major importance in the onset of AA.

Sterpetti et al⁷ identified two groups of patients with probable congenital AAA. They defined type I congenital AAA as a generalized disorder of the arterial tissue in which AAA is associated with aneurysms in other areas, whereas, type II congenital AAA is a localized defect of the abdominal aorta. Such a defect may become apparent in adult life.⁸

Taking into consideration that all of our patient’s severe complications, including the multiple suture-line disruptions and the false aneurysms that occurred in the same area of the infrarenal aorta, we speculated that our patient could be described as having type II congenital AAA. The extent, if any, the patient’s family history contributed to the severity of complication cannot be assessed.

Questions also have been raised about the long-term durability of Dacron grafts in young patients.⁸ Overall, graft-related complications are expected to occur in approximately 9.4% of patients after AAA repair.⁹ The morbidity and mortality rates in young patients after AAA repair are similar to elderly patients.^10,11