Safety of Transbronchial Biopsies in Patients with Pulmonary Hypertension: Systematic Review and Meta-Analysis.

Our results show that the patients with PH do not have a significantly elevated risk of bleeding with TBLB as compared to the controls. We hypothesize that significant post-biopsy bleeding might be preferentially originating from bronchial artery circulation as opposed to pulmonary artery circulation, much like episodes of massive spontaneous hemoptysis. This hypothesis can explain our results as in this scenario, elevated pulmonary artery pressure wouldn't be expected to have a bearing on the risk of post-TBLB bleeding. Most of the studies in our analysis included patients with mild to moderate PH and it's not clear if our results can be extrapolated to patients with severe PH. We noted that the patients with PH were at a higher risk of developing hypoxia and needing a longer duration of mechanical ventilation with TBLB, as compared to the controls. Further studies are needed to better understand the origin and pathophysiology of post-TBLB bleeding.