Table 2.

Descriptive analysis of observational studies.

Authors	Year	Study	Patients	Background	Pleural fluid studies	Bilopleural fistulation
Amir-Jahed et al. [110]	1972	Retrospective cohort	10	Hepatic echinococcosis and amebiasis	n/a	Yes
Andrade-Alegre and Ruiz-Valdes[111]	2013	Retrospective cohort	5	Traumatic chest injury	Bilirubin = 16.24 (average)	Yes
Austin et al. [1]	2015	Case series	5	Upper GI malignancies	PB/SB ≥ 1	n/a
Clark et al. [112]	1981	Retrospective cohort	1 of 42	PTBD	n/a	n/a
Carter [113]	1987	Retrospective	1 of 51	Traumatic chest injury	n/a	n/a
Ciriaco et al. [114]	2006	Case series	3	Traumatic chest injury	n/a	Yes
Demers et al. [115]	2013	Case series	1 of 4	Percutaneous thermal ablation of liver cancer	n/a	Yes
Feld et al. [116]	1997	Case series	2 of 3	Gunshot injury to the thorax	Bilirubin = 24.9 (only 1 patient reported)	Yes
Gil et al. [117]	2008	Retrospective	1 of 38	Balloon dilation of papilla for clearance of CBD stone	n/a (biliary pleural effusion)	No
Ivatury et al. [118]	1984	Case series	3	Traumatic chest injury	n/a	Yes
Najjar et al. [119]	2018	Retrospective	36	n/a	n/a	n/a
Sano and Yotsumoto [120]	2016	Case series	2	PTBD	Bilirubin = 57.78, other n/a	n/a
Sastre et al. [121]	2021	Retrospective study	7	Penetrating trauma of the thoracic and abdominal wall	Presence of bilirubin in the pleural fluid	Yes
Singh et al. [122]	2002	Retrospective study	3 of 8	Abdominal trauma and percutaneous transhepatic cholangiography	Bilious effusion	Yes
Sood et al. [123]	2021	Retrospective study	1 of 10	Bile leak following gunshot injury	Bilious pleural effusion	n/a
Sokouti et al. [92]	2010	Case series	1 of 2	Hydatid cyst of the liver	Bilious effusion	Yes
Strange et al. [95]	1998	Case series	2	Percutaneous biliary drainage	Bilious effusion	No
Wu et al. [104]	2020	Case series	2	Microwave ablation of liver cancer	Bilious effusion	Yes

GI = gastrointestinal; PTBD = percutaneous transhepatic biliary drainage; PB/SB = pleural bilirubin/serum bilirubin; n/a = not available.