Table 3. Comparisons of perioperative parameters after PSM.

Characteristics	PSM for Tri-VATS and Uni-VATS				PSM for VATS and RATS
	Tri-VATS (n=40)	Uni-VATS (n=40)	P value		VATS group (n=49)	RATS group (n=49)	P value
Duration of operation, mean ± SD, minutes	61.42±23.87	69.47±32.30	0.548		67.91±29.62	76.02±30.91	0.083
Intraoperative blood loss, mean ± SD, mL	15.56±9.77	18.03±16.95	0.816		14.22±5.33	23.16±18.33	0.015
Unplanned thoracotomy, n (%)			0.675				0.041
Conversion to thoracotomy	4 (10.0)	2 (5.0)			4 (8.2)	0 (0.0)
Bleeding	2 (2.5)	0 (0.0)			2 (4.2)	0 (0.0)
Oncologic reasons	1 (5.0)	1 (2.5)			1 (2.0)	0 (0.0)
Pleural adhesions	1 (2.5)	1 (2.5)			1 (2.0)	0 (0.0)
Without thoracotomy	36 (90.0)	38 (95.0)			45 (91.8)	49 (100.0)
Chest tube placement time, mean ± SD, days	2.35±0.86	1.83±1.20	0.013		2.27±0.76	2.20±1.14	0.754
Postoperative pain, n (%)			0.778				0.006
Degree I	0 (0.0)	5 (12.5)			0 (0.0)	15 (30.6)
Degree II	39 (97.5)	30 (75.0)			45 (91.8)	28 (57.2)
Degree III	1 (2.5)	5 (12.5)			2 (4.1)	5 (10.2)
Degree IV	0 (0.0)	0 (0.0)			2 (4.1)	1 (2.0)
Postoperative complication, n (%)			1.000				0.695
Pleural effusion	1 (2.5)	1 (2.5)			1 (2.0)	0 (0.0)
Fever	1 (2.5)	1 (2.5)			2 (4.1)	1 (2.0)
Pulmonary thromboembolism	0 (0.0)	0 (0.0)			1 (2.0)	0 (0.0)
Chylothorax	1 (2.5)	1 (2.5)			0 (0.0)	1 (2.0)
Arrhythmia	0 (0.0)	0 (0.0)			0 (0.0)	1 (2.0)
Hospital length of stay, mean ± SD, days	3.95±2.00	3.23±1.03	0.043		4.02±2.19	3.59±1.22	0.236
Total expense, mean ± SD, USD	3,718.42±771.82	3,502.01±855.39	0.238		3,761.93±726.17	8,995.45±2,189.36	<0.001

mL, milliliter; RATS, robot-assisted thoracic surgery; SD, standard deviation; USD, USA dollar; VATS, video-assisted thoracoscopic.