Aneurysm of the Pulmonary Artery, a Systematic Review and Critical Analysis of Current Literature.

Background: Pulmonary artery (PA) aneurysms are rare and their related complications like dissection or rupture have been so far reported in a few reports, and a systematic description of the disease is lacking. To identify patients with PA aneurysm, at high-risk for complications, is critical. We performed a systematic review of the literature to determine characteristics that could identify high-risk patients.

Method: A systematic search strategy was established and executed in Pubmed, Embase, Cochrane Central Register of Controlled Trials and Google scholar. Case reports were included if a minimal set of data were described.

Results: After executing the search strategy and exclusion of non-relevant or duplicate articles, 38 original articles, reviews and 169 case reports could be included. Articles were classified in high and low-pressure PA aneurysms and subdivided in six groups on basis of the causative mechanisms. PA dilatation was most common in association with pulmonary hypertension, but only one dissection was reported in 6 original articles containing 153 patients. Analysis of the case reports suggests that predictors of high-risk patients are: pulmonary hypertension in congenital heart disease, fast PA diameter growth (>2 mm/year), tissue weakness due to infection and possibly pregnancy especially in combination. Except for 2 cases, PA dissection did not occur, when the PA diameter was <75 mm and the PA pressure <50 mmHg.

Conclusion: High-risk PA aneurysms maybe identified by evaluating: the causative mechanism(s) for PA dilatation, absolute PA diameter and growth rate and by evaluating the PA systolic pressure.