This is an age-old repair technique, successfully performed since the 1950s. In the US, an estimated 40,000 AAA repairs are carried out annually. This repair entails general anaesthesia. Through a midline incision in the abdomen, the aorta is exposed and controlled. The aneurysm is then clamped at both ends to prevent blood from getting into the aneurysm. A synthetic graft is then implanted, sutured to the healthy portion of aorta. The aneurysmal wall is then used to wrap around the graft. This repair is generally safe with a mortality rate of less than 5%. Extensive pre-operative assessment of the heart and lungs are usually carried out before the operation. The patient is usually nursed in the Intensive Care Unit for a day. The total length of hospital stay is about a week to 10 days.
Endovascular repair (EVAR)
This is a newer form of repair where a pre-fabricated graft is inserted into the aneurysm through the femoral arteries. Two small incisions are made in the groin to expose the femoral arteries and the graft treaded carefully into the aneurysm under fluoroscopic (Cine X-Ray) guidance. This technique was introduced in the 1980s by Dr Parodi. This promised to be a less invasive procedure whereby a long abdominal incision was avoided and could reduce the operative mortality.
The initial enthusiasm of this minimally invasive device has decreased with time. With more widespread usage of this device, new problems emerged. There have been no long-term studies of this modality of therapy and the device is being constantly modified and some have been withdrawn from the market. The main complications that have emerged include endoleaks (leakage of blood through a collateral branch) and stent migration (the stent slipped out of position).
More studies are being conducted to have these problems rectified. Due to the uncertainty of its long-term results and the potential complications, patients need to be monitored with periodic CT scans, initially at one month post implantation of graft, then at six months and then at yearly intervals.
It costs about two-and-a-half to three times the cost of an open repair. Coupled with the need for periodic scans, its cost-effectiveness has been questioned. Recent studies in Europe like the EVAR and DREAM trials have shown that it has decreased perioperative mortality by about 3% in follow-up of patients up to four years. However, judging from its costs and complications, and the lack of long-term follow up data, this procedure is recommended only to high-risk patients.