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Introduction
Nephron-sparing surgery has become the standard of care of small renal masses with laparoscopic partial nephrectomy (LPN) being a favorable approach over open surgery with comparable long-term outcomes. Robotic partial nephrectomy (RPN) has become a rising technique which may offer similar advantages. We evaluated the perioperative outcomes and complications of LPN versus RPN.
Methods
All patients who underwent LPN and RPN by a single surgeon were retrospectively reviewed from February 2009 to January 2012. The surgeon almost exclusively performed LPN from 2009 to January 2011 and performed RPN from January 2011 to January 2012. Three RPN were performed prior to 2011. Patient demographics, tumor characteristics, perioperative outcomes, short-term renal functional data, and complications were reviewed between the two groups.
Results
See Table 1 for results. There were no significant differences in perioperative outcomes, short-term renal functional data, or complications between the two groups except for warm ischemia time which was less in the LPN group (20.4 minutes vs. 24.9 minutes in the RPN group, p=0.006). Although not significant, RPN trends toward GREATER operative time and reduced estimated blood loss.
Conclusions
Although warm ischemia time may be decreased in patients who undergo LPN compared to RPN, short-term renal functional outcomes remain similar as well as other perioperative outcomes and complications. RPN may be a comparable minimally invasive approach to small renal masses as LPN.

Table 1. Results
	LPN (n=39)	RPN (n=30)	P-value
Patient demographics
Mean age (years)	57±11	59±11	0.49
Males/females	29/10	18/12	0.21
Caucasian race	34 (87%)	25 (83%)	0.66
Mean BMI (kg/m2)	29±5	30±7	0.85
Mean ASA score	2	2	0.99
Tumor characteristics
Mean Size (cm)	3.1±1.2	3.2±1.2	0.73
Left/right kidney	24/15	16/14	0.50
Location
Upper pole	13 (33%)	6 (20%)	0.23
Mid pole	20 (51%)	15 (50%)	0.92
Lower pole	6 (15%)	9 (30%)	0.15
Exophytic	3 (8%)	4 (13%)	0.45
Mesophytic	22 (56%)	13 (43%)	0.29
Endophytic	14 (36%)	13 (43%)	0.54
Mean distance to collecting system (mm)	5.0±5.0	3.9±5.2	0.41
Pathology
T1a	23 (59%)	18 (60%)	0.93
T1b	9 (23%)	8 (27%)	0.74
T2 or greater	4 (10%)	1 (3%)	0.28
Benign	3 (8%)	3 (10%)	0.74
Histology
Clear cell	25 (64%)	21 (70%)	0.61
Papillary	7 (18%)	5 (17%)	0.83
Chromophobe	3 (8%)	1 (3%)	0.45
Oncocytoma	2 (5%)	1 (3%)	0.72
Neuroectoderm	1 (3%)	0 (0%)	0.38
Other	1 (3%)	2 (7%)	0.41
Fuhrman Grade
1-2	20 (57%)	22 (81%)	0.04
3-4	15 (43%)	5 (19%)	0.04
Positive margins	4 (11%)	2 (7%)	0.61
Outcomes
Mean estimated blood loss (mL)	235±278	152±189	0.19
Mean warm ischemia time (min)	20.4±6.1	24.9±6.7	0.006
Mean operative room time (min)	119.7±34.1	135.5±36.4	0.08
Mean length of hospital stay (days)	2.7	2.7	0.99
No. of patients with preoperative eGFR <60	2 (5%)	4 (13%)	0.24
No. of patients with postoperative eGFR <60	10 (26%)	7 (23%)	0.83
Average decrease in eGFR	10.1±6.5	7.0±3.3	0.30
Average decrease in serum creatinine	0.4±0.2	0.2±0.2	0.09
Complications
Conversion to radical nephrectomy	2 (5%)	0 (0%)	0.21
Postoperative urinary leak	0 (0%)	0 (0%)	0.99
Postoperative transfusion	2 (5%)	1 (3%)	0.72
Postoperative embolization due to hemorrhage	1 (3%)	0 (0%)	0.38
Postoperative dialysis	0 (0%)	1 (3%)	0.26
Follow-up (months)	6.7±10.2	1.1±1.9	0.009
± = standard deviation; BMI = body mass index; ASA = American Society of Anesthesiologists; eGFR = estimated glomerular filtration rate