Has Anatomic Complexity of Abdominal Aortic Aneurysms Undergoing Open Surgical Repair Changed after the Introduction of Endovascular Treatment? Systematic Review and Meta-analysis of Comparative Studies.

BACKGROUND: At a time when endovascular aneurysm repair (EVAR) is increasingly used to treat abdominal aortic aneurysms (AAAs), lesions undergoing open surgical repair (OSR) may present significant differences compared with those treated before wide EVAR availability. We aim to record discrepancies in AAAs surgically treated before and after the introduction of EVAR.

METHODS: We conducted a systematic review of the literature and meta-analysis of comparative studies. The MEDLINE, CENTRAL, and OpenGrey databases were searched up to October 2017. Outcome measures were anatomic complexity, procedural details, and postoperative outcomes. The random-effects model was used to calculate combined overall effect sizes. Data are presented as odds ratio (OR) or mean difference (MD) with 95% confidence intervals (CIs).

RESULTS: Five observational studies were included. These involved 1,091 patients treated in the pre-EVAR era and 802 in the post-EVAR era. In general, patients undergoing OSR during the first period presented more comorbidities. Increased anatomic complexity was found among patients in the second group as demonstrated by the increased rate of suprarenal clamping (10.5% vs. 22.3%; OR, 0.34; 95% CI, 0.24-0.50), left renal vein division (10.3% vs. 18.8%; OR, 0.46; 95% CI, 0.25-0.88), iliac aneurysm (28.3% vs. 44.9%; OR, 0.48; 95% CI, 0.37-0.64), and iliac occlusive disease (13.1% vs. 20.2%; OR, 0.59; 95% CI, 0.39-0.88). Intraoperative use of blood products was greater during the latter period, but this difference did not reach statistical significance. Procedural duration was slightly increased in the same group. Morbidity and mortality were similar among the groups.

CONCLUSIONS: After the wide availability of endoluminal grafting, more compromised patients tend to be managed with EVAR, leaving a fitter patient population to undergo OSR. At the same time, anatomic complexity of AAAs undergoing open surgery has considerably increased, requiring advanced proximal aortic surgical expertise to deal with these complex aortic pathologies Overall, morbidity and mortality remained unchanged, possibly due to the counterbalancing effects of these factors.