Table 1. Diagnostic rate and complications of tissue biopsy techniques in the investigation of undiagnosed pleural effusions.

Trial	Technique	Total patients	Diagnostic rate for all causes (%)§	Diagnostic rate for malignancy (%)§	Mortality	Major complication rate#	Minor complication rate
Macha et al., 1993 (37)	LAT	687	–	95	0	4/687	“Very few”
Boutin et al., 1993 (38)	LAT	188	–	98	0	4/188	30/188
Hansen et al., 1998 (39)	LAT	146	–	90.4	0	3/146	2/146
Sakuraba et al., 2006 (40)	LAT	138	–	97.1	0	0/138	“Few”
Blanc et al., 2002 (41)	LAT	149	–	93.3	1/149	10/168*	31/168
Metintaş et al., 1995 (35)	CT-guided	30	–	83.3	0	9/30	Not recorded
Maskell et al., 2003 (21)	CT-guided	25	–	87	0	0	0
Adams et al., 2001 (24)	CT- or US-guided	33	–	91	0	1/21	0
Benamore et al., 2006 (33)	CT- or US-guided	82	–	76	0	4/82	6/82
Chang et al., 1991 (28)	US-guided	25	76	70	0	0	0
Stigt et al., 2012 (42)	US-guided	14	–	80	0	0	1
Hallifax et al., 2014 (43)	US-guided	50	94	–	0	0	0
Medford et al., 2008 (44)	VATS	86	82.3	N/A	0	1/82	6/86

^§, Combined image-guided biopsy diagnostic rate =83% (95% CI, 82-84.1%), combined LAT diagnostic rate =94.8% (95% CI, 94.6-95%); ^#, major complications include pneumonia, empyema, significant haemorrhage, death, pneumothorax and tumour tract seeding; *, 149 patients had diagnostic LAT. The complication rate was reported for 168 patients in total, 19 undergoing LAT for non-diagnostic purposes. LAT, local anaesthetic thoracoscopy; CT, computed tomography; US, ultrasound; VATS, video assisted thoracic surgery; N/A, not available.