Colonic Ischemia Following AAA Repair In The Era Of EVAR

Jean P Becquemin, Jean Marzelle, Pascal Desganges, Eric Allaire, Hischam Kobeiter.
Henri Mondor Hospital, Creteil, France.

OBJECTIVES: Colonic ischemia is a major adverse event following AAA open repair.
The current study was undertaken to assess, in the era of EVAR, the rate and overall mortality of colonic ischemia and predictive factors of occurrence

METHODS: Between 1995 and 2005 1138 patients with infra renal AAA were treated either by open surgery (n= 623) or by EVAR (n=515). Pre-operative risk factors, anatomical features, intra-operative data and early postoperative outcomes were assessed prospectively and stored in a computerized data base. All patients in whom colonic ischemia was suspected from clinical signs (abdominal pain, early diarrhea, rectorrhagia, unexplained hemodynamic disturbances, elevated lactate enzymes) underwent a colonoscopy. For the purpose of the study, Grade II, III or IV colonic ischemia were considered as validating events and correlated to all identified variables.

RESULTS: Colonic ischemia occurred in 39 out of 1138 patients (3.4%), leading to death in 17/39 patients (43%).
The associated factors of occurrence of colonic ischemia were: type of operation [Open group = 30/623 (4.8%) vs EVAR = 9/515 (1.7%) (p=0.001)], emergent operation [15/156 (9.6%) vs 24/975 (2.4%), p = 0.001], pre-operative renal insufficiency [4/19 (21%) vs 35/1103 (3.1%), p=0.001] and pre-operative respiratory insufficiency [9/ 97 (9.2 %) vs 30/ 970 (3.1 %), p=0.007 ] . When comparing the types of treatment, the incidence of associated factors was not statistically different. The mortality due to colonic ischemia was not statistically different between open surgery 13/30 (43%) and EVAR 4/9 (44%). When looking at technical details, predictive factors of colonic ischemia were hypogastric embolization in the EVAR group [ 5/115 ( 4,3 % ) vs 4/400 ( 1 %) p = 0.046 ], and the site of the distal graft anastomosis in the open repair group [ distal aorta = 10/218 ( 4.5%) , iliac artery = 14/362 ( 3.8%), femoral artery = 6/27 (22% ) p= 0.001 ].

CONCLUSIONS: Colonic ischemia remains a serious complication following AAA repair. EVAR was associated with a lower rate of colonic ischemia. However within the two treatment modalities, the mortality rate remained identical. Preservation of hypogastric arteries appears to be a key issue with both treatments.