Risk factors of early and late complications in patients undergoing endovascular aneurysm repair.

OBJECTIVES: to identify pre-operative factors that could predict complications following from transluminal repair of abdominal aortic aneurysms (AAA). METHODS: during a 5-year period, 96 consecutive patients underwent elective endovascular treatment of a AAA. In all patients, helical CT and/or Magnetic Resonance Imaging (MRI), and plain abdominal roentgenogram were performed at 1, 3, 6, 12, 18, and 24 months and yearly thereafter. Angiography was performed systematically 1 year after the stent-graft implantation, or earlier if helical CT or MRI diagnosed an increase in the maximal transverse diameter or a high flow endoleak. RESULTS: early (<30 days) morbidity (12%) was significantly increased by pre-operative renal insufficiency (p < 0.01). Early mortality (2%) correlated with ASA score (p = 0.01). Median follow-up was 27 months (range 3-66). Mortality (12%) during follow-up was correlated to the pre-operative coronary status (p = 0.01). A type I endoleak was diagnosed in 18 patients (19%). Common iliac artery diameter was correlated with the presence of type I endoleak (p < 0.001). A type II endoleak was diagnosed in 47 (49%) patients. The diagnostic of type II endoleak was significantly increased (p = 0.001) in patients with pre-operative patent IMA associated with more than four patent lumbar arteries. The anatomic characteristics of the aneurysm were correlated to the additional endovascular procedures during stentgraft implantation (p = 0.01), and to the implantation of a complementary iliac limb extension during follow-up (p = 0.01). CONCLUSIONS: the risk factors determined by this statistical analysis could help surgeons to select more accurately patients suitable for endovascular treatment.

Prospective evaluation of magnetic resonance imaging after endovascular treatment of infrarenal aortic aneurysms.

OBJECTIVES: to evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) in the detection of type II endoleaks during follow-up after endovascular treatment of intra-renal aortic aneurysms. DESIGN: prospective study. MATERIAL AND METHODS: between March 1996 and November 1999, 31 patients with infra-renal aortic aneurysms who underwent stentgraft implantation were followed with helical CT and MRI, including magnetic resonance angiography (MRA), at 1 and 6 months after the procedure. Arteriography was performed between 6 and 12 months after intervention. The parameters studied included the change in the maximum anteroposterior and transverse diameters, the nature of the signal on T1 and T2 weighted sequences (homogeneous vs heterogeneous), the presence or absence of Gadolinium uptake on MRI or of contrast uptake on helical CT (early and late phases) in the sac of the aneurysm. On MRA, stentgraft patency and endoleak detection were studied. RESULTS: arteriography demonstrated an endoleak in 19 patients (18 type II, and 1 type I endoleak). MRI at 6 months detected 18/19 endoleaks on T1 weighted sequences after injection of Gadoliniumj; there were 2 false positives. MRA sequences confirmed stentgraft patency in all patients, but did not diagnose type II endoleaks. Helical CT (late phase) at 6 months detected 10/19 endoleaks; there was 1 false positive. The sensitivity of MRI after injection of Gadolinium and of helical CT for the detection of type II endoleaks were 94% and 50% (p=0.003) respectively. The mean maximal anteroposterior and transverse diameters were similar on MRI and on helical CT at 1 month and at 6 months. CONCLUSION: MRI after injection of Gadolinium is more sensitive than helical CT in the detection of type II endoleaks after stentgraft implantation. Its more widespread use may permit earlier intervention in such patients.