Robotic nephron-sparing surgery is traditionally performed via a transperitoneal (TP) approach. However, the retroperitoneal (RP) approach has gained popularity, particularly for posterolateral renal masses. The RP approach is associated with shorter operative time, less blood loss, and shorter length of stay, while preserving oncologic outcomes in selected masses. Here, we aim to assess the feasibility of the RP approach in excising anterior renal masses. Patients ≥ 18 years of age who underwent robotic nephron-sparing surgery for anterior renal masses were retrospectively identified (2008–2022). Baseline demographics, tumor characteristics, and perioperative data were collected and characterized based on TP vs RP approaches. Wilcoxon rank sum test and Pearson’s Chi-squared test were used to compare continuous and categorical variables, respectively. Two hundred and sixteen patients were included—178 (82.4%) underwent TP approach and 38 (17.6%) underwent RP approach. Baseline demographics, preoperative tumor size, and renal nephrometry scores were similar. The RP approach was associated with shorter operative (150 vs 203 min, p < 0.001) and warm ischemia time (12 vs 21 min, p < 0.001), and less blood loss (20 vs 100 cc, p = 0.002) (Table 1). The RP approach was associated with shorter length of stay (1 vs 2 days, p < 0.001) and less total complications (5.3% vs 19.1%, p = 0.038). Major complication (Clavien–Dindo Grade > 3) rates were similar. There was no difference in positive surgical margin rates or pathologic characteristics. Robotic RP approach for nephron-sparing surgery is feasible for eligible anterior tumors and is associated with favorable perioperative outcomes with preserved negative surgical margin rates.
Table 1 Patient baseline demographics
Overall
Transperitoneal
Retroperitoneal
p value
Median/N
IQR/%
Median/N
IQR/%
Median/N
IQR/%
N
216
178
82.4%
38
17.6%
Age (years)
60.5
(52.1–67.7)
60.4
(52.8–67.7)
61.6
(49.1–69.2)
0.393
Sex
Male
126
58.3%
100
56.2%
26
68.4%
Female
90
41.7%
78
43.8%
12
31.6%
0.165
Race
White
162
75.0%
137
77.0%
25
65.8%
Asian
4
1.9%
2
1.1%
2
5.3%
Black
21
9.7%
18
10.1%
3
7.9%
Hispanic
26
12.0%
18
10.1%
8
21.1%
Other
2
0.9%
2
1.1%
0
0.0%
0.197
Body mass index (kg/m2)
< 25
32
14.8%
25
14.0%
7
18.4%
25–30
68
31.5%
55
30.9%
13
34.2%
30–35
60
27.8%
50
28.1%
10
26.3%
35 +
56
25.9%
48
27.0%
8
21.1%
0.808
Prior abdominal surgery
Yes
118
54.6%
104
58.4%
14
36.8%
No
98
45.4%
74
41.6%
24
63.2%
0.015
Prior kidney surgery
Yes
10
4.6%
9
5.1%
1
2.6%
No
206
95.4%
169
94.9%
37
97.4%
0.518
Chronic kidney disease stage ≥ 3
Yes
45
20.8%
38
21.3%
7
18.4%
No
171
79.2%
140
78.7%
31
81.6%
0.687
Charlson comorbidity index
0
138
63.9%
116
65.2%
22
57.9%
1
46
21.3%
38
21.4%
8
21.1%
2
19
8.8%
13
7.3%
6
15.8%
≥ 3
13
6.0%
11
6.2%
2
5.3%
0.412
Tumor size (cm)
2.7
(2–3.6)
2.8
(2–3.5)
2.55
(2–3.7)
0.796
Tumor laterality
Left
100
46.3%
78
43.8%
22
57.9%
Right
116
53.7%
100
56.2%
16
42.1%
0.114
Clinical T stage
cT1a
186
86.1%
152
85.4%
34
89.5%
cT1b
30
13.9%
26
14.6%
4
10.5%
0.509
RENAL Nephrometry score
Low (4 to 6)
94
43.5%
76
42.7%
18
47.4%
Intermediate (7 to 9)
112
51.9%
94
52.8%
18
47.4%
High (≥ 10)
19
4.6%
8
4.5%
2
5.3%
0.829
TE tumor enucleation, SPN standard margin partial nephrectomy, IQR interquartile range
