Table 2.

Perioperative and surgical characteristics

	RNSM (n = 40)	CNSM (n = 41)	P value
Anesthesia time, min	331 ± 74	241 ± 43	<0.001*
Operation time, min	279 ± 63	207 ± 46	<0.001*
Blood loss			0.057
≤100 mL	34 (85%)	40 (98%)
>100 mL	6 (15%)	1 (2%)
Administered remifentanil (µg/kg/hr)	0.047 ± 0.010	0.047 ± 0.010	0.998
Fentanyl amounts mixed in PCA (µg/kg)	15.0 ± 1.8	14.6 ± 1.6	0.221
Incision length, cm	4.4 ± 0.7	8.8 ± 2.2	<0.001*
Specimen weight, g	388.7 ± 169.5	421.4 ± 176.0	0.400
Location			0.144
Right	25 (63%)	19 (46%)
Left	15 (38%)	22 (54%)
Type of reconstruction			0.195
Direct-to-implant	32 (80%)	37 (90%)
Tissue expander insertion	8 (20%)	4 (10%)
Volume of reconstruction implant, mL	366 ± 111	357 ± 110	0.718
Adjuvant treatment
Radiation therapy	5 (13%)	8 (20%)	0.390
Chemotherapy	10 (25%)	12 (29%)	0.666
Endocrine therapy	32 (80%)	26 (67%)	0.180

Notes: Data are presented as mean ± standard deviation or number of patients (proportion). *P <0.05.

Abbreviation: RNSM, robotic nipple-sparing mastectomy; CNSM, conventional nipple-sparing mastectomy; PCA, patient-controlled analgesia.