Table 1 Epidemiological, oncological, and surgical characteristics

 Age years

63 (54–68)

63 (53–68)

63 (55–68)

0.99

 Sex m/f (%)

331 / 113 (74.5 / 25.5)

165 / 46 (78.2 / 21.8)

166 / 67 (71.2 / 28.8)

0.09

 BMI (kg/m²)

26.9 (24.7–29.6)

27.1 (25.1–29.7)

26.8 (24.3–29.6)

0.21

 Charlson comorbidity score

2 (0–2)

2 (0–2)

2 (0–2)

0.74

 eGFR mL/min/1.73 m^{2 a}

80.0 (65.1–93.1)

82.0 (69.9–94.9)

76.9 (61.5–91.1)

0.004

 Serum creatinine mg/dL

0.97 (0.83–1.14)

0.93 (0.82–1.08)

1.0 (0.85–1.2)

0.03

 eGFR category ^b (%)

0.04

  G1

134 (30.2)

70 (33.2)

64 (27.5)

0.22

  G2

223 (50.2)

111 (52.6)

112 (48.1)

0.41

  G3

73 (16.4)

24 (11.4)

49 (21.0)

0.005

  G4

9 (2.0)

5 (2.4)

4 (1.7)

0.90

  G5

0 (0.0)

0 (0.0)

0 (0.0)

–

  No data

5 (1.1)

1 (0.4)

4 (1.7)

0.22

 Haemoglobin g/dL

14.5 (13.6–15.4)

14.7 (13.8–15.5)

14.4 (13.5–15.3)

0.02

 Blood pressure categories ^c (%)

0.92

  Optimal blood pressure

36 (8.1)

16 (7.6)

20 (8.6)

  Normal blood pressure

84 (18.9)

30 (14.2)

54 (23.2)

  High-normal blood pressure

75 (16.9)

32 (15.2)

43 (18.5)

  Grade 1 hypertension [mild]

132 (29.7)

60 (28.4)

72 (30.9)

  Grade 2 hypertension [moderate]

50 (11.3)

16 (7.6)

34 (14.6)

  Grade 3 hypertension [severe]

10 (2.3)

5 (2.4)

5 (2.1)

  No data

57 (12.8)

52 (24.6)

5 (2.1)

 RCC subtype (%)

0.53

  Clear cell

303 (68.2)

141 (66.8)

162 (69.5)

  Papillary

94 (21.2)

52 (24.6)

42 (18.0)

  Chromophobic

34 (7.7)

14 (6.6)

20 (8.6)

  Others ^d

5 (1.1)

2 (0.9)

3 (1.3)

  No data

8 (1.8)

2 (0.9)

6 (2.6)

 TNM (7th edition UICC 2010) staging (%)

<  0.001

  T1a

315 (70.9)

170 (80.6)

145 (62.2)

<  0.001

  T1b

83 (18.7)

29 (13.7)

54 (23.2)

0.008

  T2a

10 (2.3)

1 (0.5)

9 (3.9)

0.02

  T2b

3 (0.7)

0 (0.0)

3 (1.3)

0.10

  T3a

22 (5.0)

8 (3.8)

14 (6.0)

0.26

  T3b

1 (0.2)

0 (0.0)

1 (0.4)

0.34

  T3c

0 (0.0)

0 (0.0)

0 (0.0)

–

  T4

1 (0.2)

1 (0.5)

0 (0.0)

0.30

  Tx

9 (2.0)

2 (0.9)

7 (3.0)

0.13

 Nodal status (%)

0.17

  N0

45 (10.1)

17 (8.1)

28 (12.0)

  N1

0 (0.0)

0 (0.0)

0 (0.0)

  Nx

399 (89.1)

194 (91.9)

205 (88.0)

  M0

444 (100.0%)

211 (100.0)

233 (100.0)

–

  M1

0 (0.0)

0 (0.0)

0 (0.0)

–

  Mx

0 (0.0)

0 (0.0)

0 (0.0)

–

 Grading (%)

0.20

  G1

77 (17.3)

39 (18.5)

38 (16.3)

  G2

300 (67.6)

150 (71.1)

150 (64.4)

  G3

36 (8.1)

13 (6.2)

23 (9.9)

  G4

2 (0.5)

0 (0.0)

2 (0.9)

  No data

29 (6.5)

9 (4.3)

20 (8.6)

  R0

396 (89.2)

194 (91.9)

202 (86.7)

0.86

  R1

15 (3.4)

7 (3.3)

8 (3.4)

0.14

  R2

0 (0.0)

0 (0.0)

0 (0.0)

–

  Rx

33 (7.4)

10 (4.7)

23 (9.9)

0.04

  R+

16 (3.6)

7 (3.3)

9 (3.9)

0.68

 Tumour diameter cm

3.0 (2.2–4.0)

2.7 (2.0–3.5)

3.5 (2.5–4.5)

<  0.001

  ≤ 4 cm

357 (80.4)

185 (87.7)

172 (73.8)

<  0.001

  >  4 - < 7 cm

74 (16.7)

25 (11.8)

49 (21.0)

0.01

  ≥ 7 – <  10 cm

10 (2.3)

1 (0.5)

9 (3.9)

0.02

  ≥ 10 cm (%)

3 (0.7)

0 (0.0)

3 (1.3)

0.10

 Side (%)

0.81

  Right

233 (52.5)

112 (53.1)

121 (51.9)

  Left

211 (47.5)

99 (46.9)

112 (48.1)

  Bilateral

0 (0.0)

0 (0.0)

0 (0.0)

 Quantity (%)

0.50

  Unilocally

430 (96.8)

206 (97.6)

224 (96.1)

  Multilocally

13 (2.9)

5 (2.4)

8 (3.4)

  No data

1 (0.2)

0 (0.0)

1 (0.4)

  Located in upper renal section

119 (26.8)

59 (28.0)

60 (25.8)

0.61

  Located in middle renal section

168 (37.8)

86 (40.8)

82 (35.2)

0.24

  Located in lower renal section

159 (35.8)

65 (30.8)

94 (40.3)

0.03

  No data

5 (1.1)

2 (0.9)

3 (1.3)

0.74

 Horizontal locus (%)

<  0.001

  Centrally located

122 (27.5)

41 (19.4)

81 (34.8)

<  0.001

  Peripherically located

313 (70.5)

164 (77.7)

149 (63.9)

<  0.001

  No data

9 (2.0)

6 (2.8)

3 (1.3)

0.25

 Operative time min

185.0 (145.0–230.0)

205.0 (160.0–245.0)

160.0 (130.0–207.0)

<  0.001

 Vessel clamping (%)

<  0.001

  Ischaemia

343 (77.3)

185 (87.7)

158 (67.8)

<  0.001

  No Ischaemia

57 (12.8)

9 (4.3)

48 (20.6)

<  0.001

  No data

44 (9.9)

17 (8.1)

27 (11.6)

0.21

 Ischaemia time min

24 (18–32)

25 (19–34)

23 (17–30)

0.04

 Ischaemia time < 15 min / ≥ 15 min (%)

41 / 302 (9.2 / 68.0)

19 / 166 (9.0 / 78.7)

22 / 136 (9.4 / 58.4)

0.30

 Ischaemia time < 20 min / ≥ 20 min (%)

99 / 244 (22.3 / 55.0)

51 / 134 (24.2 / 63.5)

48 / 110 (20.6 / 47.2)

0.57

 Ischaemia time < 25 min / ≥ 25 min (%)

174 /169 (39.2 /38.1)

84 / 101 (39.8 / 47.9)

90 / 68 (38.6 / 29.2)

0.03

 Ischaemia time < 30 min / ≥ 30 min (%)

231 /112 (52.0 /25.2)

118 / 67 (55.9 / 31.8)

113 / 45 (48.5 / 19.3)

0.13

 Ischaemia time < 35 min / ≥ 35 min (%)

269 / 74 (60.6 /16.7)

141 / 44 (66.8 / 20.9)

128 / 30 (54.9 /12.9)

0.28

 Lymphadenctomy (%)

45 (10.1)

17 (8.1)

28 (12.0)

0.17

 Adrenalectomy (%)

7 (1.6)

3 (1.4)

4 (1.7)

0.92

 Intraoperative transfusion rate (%)

25 (5.6)

4 (1.9)

21 (9.0)

<  0.001

 Transfusion bags

2 (1–2)

1 (1–1.75)

2 (1–2)

0.12

 Estimated intraoperative blood loss mL

200 (100–500) n = 88

150 (50–425) n = 49

400 (200–800) n = 39

<  0.001

 Surgical approach (%)

<  0.001

  Retroperitoneal

162 (36.5)

0 (0.0)

162 (69.5)

<  0.001

  Transperitoneal

275 (61.9)

211 (100.0)

64 (27.5)

<  0.001

  No data

7 (1.6)

0 (0.0)

7 (3.0)

0.01

 Preoperative prophylactic ureteric stent implantation (%)

72 (16.2)

54 (25.6)

18 (7.7)

<  0.001

 Postoperative ureteric stent implantation (%)

14 (3.2)

5 (2.4)

9 (3.9)

0.37

 Intraoperative complications (%)

64 (14.4)

34 (16.1)

30 (12.9)

0.33

 Postoperative complications ^e (%)

140 (31.5)

49 (23.2)

91 (39.1)

<  0.001

 Clavien-Dindo score ≥ 3 (%)

40 (9.0)

16 (7.6)

24 (10.3)

0.32

 Hospitalization d

7 (5–9)

6 (5–8)

8 (6–10)

<  0.001