Robotic-assisted laparoscopic partial nephrectomy: A comparison of approaches to the posterior renal mass

Table 1 Patient characteristics

	RP (n = 54)	TP (n = 37)	P
Age at time of surgery, mean (SD)	56.5 (13)	57.2 (11.6)	0.801
BMI (SD)	31.1 (5.8)	32.1 (7.0)	0.511
Race
Asian	1 (1.9%)	0	0.452
Black	3 (5.6%)	3 (8.1%)
Hispanic	7 (13.0%)	2 (5.4%)
Other	0	1 (2.7%)
White	43 (79.6%)	31 (83.8%)
Sex
Female	17 (31.5%)	17 (46.0%)	0.163
Male	37 (68.5%)	20 (54.1%)
Preoperative creatinine, mean (SD)	0.95 (0.21) n = 53	0.90 (0.17) n = 36	0.271

P = Significance based on:

¹Independent samples t-test;

²Fisher exact test;

³Pearson χ² test. RP: Retroperitoneal; TP: Transperitoneal; BMI: Body mass index; SD: Standard deviation.

Table 2 Tumor characteristics

	RP (n = 54)	TP (n = 37)	P
Renal location
Left	20 (37.0%)	22 (59.5%)	0.043
Right	34 (63.0%)	15 (40.5%)
Pathologic tumor size (cm), mean (SD)	3.1 (1.6) n = 53	2.9 (1.2) n = 36	0.541
Surgical margin
Negative	50 (98.0%)	32 (91.4%)	0.302
Positive	1 (2.0%)	3 (8.6%)
RENAL score, mean (SD)	6.5 (1.9)	6.6 (1.8)	0.711
Radius
1	42 (77.8%)	33 (89.2%)	0.412
2	10 (18.5%)	4 (10.8%)
3	2 (3.7%)	0
Exophytic
1	29 (53.7%)	15 (40.5%)	0.412
2	20 (37.0%)	19 (51.4%)
3	5 (9.3%)	3 (8.1%)
Nearness
1	23 (42.6%)	15 (40.5%)	0.943
2	8 (14.8%)	5 (13.5%)
3	23 (42.6%)	17 (46.0%)
Location relative to polar line
1	30 (55.6%)	19 (51.4%)	0.513
2	12 (22.2%)	6 (16.2%)
3	12 (22.2%)	12 (32.4%)

P = Significance based on:

¹Independent samples t-test;

²Fisher exact test;

³Pearson χ² test. RP: Retroperitoneal; TP: Transperitoneal; SD: Standard deviation; RENAL: Radius of the tumor, exophytic/endophytic properties of the tumor, nearness of tumor to the collecting system, anterior/posterior position, location relative to the polar line.

Table 3 Operative factors

	RP (n = 54)	TP (n = 37)	P
Total operative time (SD)	180.7 (62.3)	227.8 (59.0)	< 0.0011
Robot console time, mean (SD)	126.9 (40.0)	164.3 (51.3)	< 0.0011
WIT, median (IQR)4	28.0 (20-31)	27.0 (21-31)	0.963
	n = 23	n = 28
Conversion
No	52 (96.3%)	32 (86.5%)	0.122
Yes	2 (3.7%)	5 (13.5%)
EBL, median (IQR)	32.5 (20-100)	150.0 (50-250)	< 0.0013

P = Significance based on:

¹Independent samples t-test;

²Fisher exact test;

³Wilcoxon-Rank Sum test;

⁴Excludes patients with WIT = 0. RP: Retroperitoneal; TP: Transperitoneal; SD: Standard deviation; IQR: Interquartile range; WIT: Warm ischemia time; EBL: Estimated blood loss.

Table 4 Renal function

	RP (n = 54)	TP (n = 37)	P
Preoperative creatinine, mean (SD)	0.95 (0.21)	0.90 (0.17)	0.271
	n = 53	n = 36
Postop creatinine, mean (SD)	1.0 (0.21)	1.0 (0.18)	0.671
	n = 46	n = 28

P = Significance based on:

¹Independent samples t-test. RP: Retroperitoneal; TP: Transperitoneal; SD: Standard deviation.