3.1 Demographic results
In total, ninety-two patients were included in the study. 59 patients received a manually sutured bowel anastomosis, the other 33 patients were stapled robotically.
We did an extensive analysis of potential confounding factors, to make sure both groups were comparable, see Table 1. There were no statistical differences between both groups concerning age, sex, clinical and pathological TNM stages, neo-adjuvant chemotherapy, smoking history as defined in pack years, previous abdominal surgery (including both laparoscopic and open surgery), Charlson comorbidity index (CCI), diabetes mellitus type 2 (DM2), vascular disease (both peripheric and coronary) and chronic kidney disease (CKD). A graphic display of aforementioned parameters can be found in Figure 2. There was a small but statistically significant difference in body mass index (BMI) and American Society of Anesthesiologists (ASA) score. Patients in the stapled anastomosis group tended to have a higher BMI (p=0.0285) and a lower ASA score (p=0.0297).
There were also no statistical differences in main surgical indications between both groups: bladder cancer (BC; 85 patients, 92.4%), invasive prostate cancer (2 patients, 2.2%) or functional complaints (8 patients, 8.7%). Some patients had multiple indications. In total, 30% of patients received an early cystectomy, 58% were for muscle-invasive bladder cancer.
After an extensive analysis of the demographic and comorbidity data, we concluded both groups to be remarkably comparable and decided against a constriction of our patient numbers by creating a propensity score matching cohort.
Table 1. Demographic and descriptive data. Comparison between sutured and stapled bowel anastomosis patient groups. Binary data are listed as number of patients (n) and proportion of patients (%), and p-values were calculated using Chi-square tests. Numerical data are listed as median and interquartile range, and p-values were calculated using non-parametric two-sided Mann-Whitney U tests. For BMI, data represent mean ± standard deviation and the p-value was calculated using a parametric two-sided Student’s t-test. Pathological T-stage as mentioned in the TUR bladder histopathological report, clinical TNM-stage as assessed by the primary surgeon based upon preoperative imaging. MIBC: muscle invasive bladder cancer, BMI: body mass index, SD: standard deviation, ASA: american society of anesthesiology, CCI: Charlson comorbidity score, DM2: diabetes mellitus type 2, CKD: chronic kidney disease, G: grade.
Variable
|
Total
|
Sutured
|
Stapled
|
p-value
|
Patients, n (%)
|
92 (100.00)
|
59 (64.13)
|
33 (35.87)
|
|
Age, median (interquartile range)
|
71 (65.25-77)
|
71 (65-76)
|
70 (65-77)
|
0.8126
|
Sex, n males (%)
|
74 (80.43)
|
48 (81.36)
|
26 (78.79)
|
0.7659
|
Bladder cancer, n (%)
|
85 (92.39)
|
56 (94.92)
|
29 (87.88)
|
0.2221
|
Early, n (%)
|
28 (30.43)
|
21 (35.59)
|
7 (21.21)
|
0.1505
|
MIBC, n (%)
|
53 (57.61)
|
33 (55.93)
|
20 (60.61)
|
0.6635
|
Prostate invasive Cis, n (%)
|
4 (4.35)
|
2 (3.39)
|
2 (6.06)
|
0.5469
|
pT, n (%)
|
|
|
|
|
≤pTis
|
44 (47.83)
|
29 (49.15)
|
15 (45.45)
|
0.7334
|
>pTis
|
48 (52.17)
|
30 (50.85)
|
18 (54.55)
|
|
cT, n (%)
|
|
|
|
|
≤cT2
|
74 (80.43)
|
51 (86.44)
|
23 (69.70)
|
0.0522
|
>cT2
|
18 (19.57)
|
8 (13.56)
|
10 (30.30)
|
|
cN, n (%)
|
|
|
|
|
No
|
81 (88.04)
|
54 (91.53)
|
27 (81.82)
|
0.1687
|
Yes (≥N1)
|
11 (11.96)
|
5 (8.47)
|
6 (18.18)
|
|
cM, n (%)
|
|
|
|
|
No
|
89 (96.74)
|
57 (96.61)
|
32 (96.97)
|
0.9258
|
Yes (≥M1a)
|
3 (3.26)
|
2 (3.39)
|
1 (3.03)
|
|
Neo-adjuvant chemotherapy, n (%)
|
31 (33.70)
|
19 (32.20)
|
12 (36.36)
|
0.6855
|
BMI, mean (± SD)
|
26.73 (± 4.49)
|
25.97 (± 4.20)
|
28.09 (± 4.73)
|
0.0285
|
ASA, median (interquartile range)
|
3 (2-3)
|
3 (2-3)
|
2 (2-3)
|
0.0297
|
Pack years, median (interquartile range)
|
15 (0-40)
|
15 (0-35)
|
11 (0-54)
|
0.6974
|
Previous abdominal surgery, n (%)
|
48 (52.17)
|
30 (50.85)
|
18 (54.55)
|
0.7334
|
CCI (interquartile range)
|
5 (4-7)
|
5 (4-7)
|
5 (4-7.5)
|
0.8978
|
DM2, n (%)
|
18 (19.57)
|
10 (16.95)
|
8 (24.24)
|
0.3977
|
Vascular disease, n (%)
|
27 (29.35)
|
20 (33.90)
|
7 (21.21)
|
0.2000
|
CKD, n (%)
|
|
|
|
|
≤G2
|
69 (75.00)
|
43 (72.88)
|
26 (78.79)
|
0.5303
|
>G2
|
23 (25.00)
|
16 (27.12)
|
7 (21.21)
|
|
3.2 Procedural data
We performed an analysis of all procedures, again, to exclude any significant differences between both groups; see table 2. In total, 83 out of the 92 cystectomy patients received an ileal conduit as diversion, whereas 9 out of 92 cystectomy patients received a neobladder as diversion. An equal proportion of both procedure types were performed with either a stapled or a sutured bowel anastomosis.
There was a slightly larger proportion of the stapled group (6 patients, 19% vs 1 patient, 2%, p=0.0036) undergoing a separate implantation of the ureters on the bowel segment. This could be explained by the fact that in a stapled anastomosis the proximal end of the bowel segment is already stapled shut, making a separate uretero-enteral anastomosis here easier to perform than a Wallace plate.
We performed several additional robot-assisted procedures during the same session as the cystectomy, e.g. two nephro-ureterectomies and a partial nephrectomy (all in the stapled group), 10 female anterior pelvic exenterations (6 in the sutured and 4 in the stapled group), two perineal urethrectomies (one in each group), one proximal urethrectomy (sutured group), one adrenalectomy (sutured group), one unilateral and one bilateral inguinal hernia correction (one in each group) and two ileocaecal resections (one in each group).
There were slightly more patients undergoing a pelvic LND in the sutured group than in the stapled group. In total, LND was performed in 90.13% of patients.
Concerning nerve sparing, blood loss and additional procedures, no statistical differences between both groups were seen. Nerve sparing was always done bilaterally, except in 1 case.
Table 2. Procedural data. Comparison between sutured and stapled bowel anastomosis patient groups. Binary data are listed as number of patients (n) and proportion of patients (%), and p-values were calculated using Chi-square tests. Numerical data are listed as median and interquartile range, and the p-value was calculated using a non-parametric two-sided Mann-Whitney U test. We defined LND patterns to conform to the 2023 EAU MIBC guideline definitions (section 7.3.4) (2). LND: lymph node dissection.
Variable
|
Total
|
Sutured
|
Stapled
|
p-value
|
Operation type, n (%)
|
|
|
|
|
Bricker
|
83 (90.22)
|
53 (89.83)
|
30 (90.91)
|
0.8674
|
Neobladder
|
9 (9.78)
|
6 (10.17)
|
3 (9.09)
|
|
LND, n (%)
|
|
|
|
|
No
|
10 (10.87)
|
3 (5.08)
|
7 (21.21)
|
0.0171
|
Limited
|
16 (17.39)
|
11 (18.64)
|
5 (15.15)
|
0.6716
|
Normal
|
4 (4.35)
|
0 (0.00)
|
4 (12.12)
|
0.0063
|
Extended
|
60 (65.22)
|
44 (74.58)
|
16 (48.48)
|
0.0117
|
Superextended
|
2 (2.17)
|
1 (1.69)
|
1 (3.03)
|
0.6736
|
Nerve sparing, n (%)
|
34 (36.96)
|
21 (35.59)
|
13 (40.63)
|
0.6357
|
Ureter anastomosis, n (%)
|
|
|
|
|
Wallace plate
|
84 (92.31)
|
58 (98.31)
|
26 (81.25)
|
0.0036
|
Separate
|
7 (7.69)
|
1 (1.69)
|
6 (18.75)
|
|
Blood loss, median (interquartile range)
|
250 (150-350)
|
250 (150-350)
|
225 (150-475)
|
0.6072
|
Additional operation, n (%)
|
25 (27.47)
|
15 (25.42)
|
10 (31.25)
|
0.5522
|
3.3 Primary outcome parameters
Table 3. Primary outcome parameters. Comparison between sutured and stapled bowel anastomosis patients. Binary data are listed as number of patients (n) and proportion of patients (%). p-values were calculated using Fisher’s exact tests. Numerical data are listed as median and interquartile range, and the p-value was calculated using a non-parametric two-sided Mann-Whitney U test. Both in-hospital and post-hospitalization data up to 3 months after discharge were included. GI: gastro-intestinal, GT: gastric tube. TPN: Total parenteral nutrition.
Variable
|
Total
|
Sutured
|
Stapled
|
p-value
|
GI complications, n (%)
|
23 (25.00)
|
16 (27.12)
|
7 (21.21)
|
0.6206
|
Complication type, n (%)
|
|
|
|
|
Peritonitis
|
1 (1.09)
|
1 (1.69)
|
0 (0.00)
|
>0.9999
|
Mechanic ileus
|
5 (5.43)
|
3 (5.08)
|
2 (6.06)
|
>0.9999
|
Paralytic ileus
|
16 (17.39)
|
11 (18.64)
|
5 (15.15)
|
0.7793
|
Dehiscence
|
1 (1.09)
|
1 (1.69)
|
0 (0.00)
|
>0.9999
|
Total blowout
|
1 (1.09)
|
1 (1.69)
|
0 (0.00)
|
>0.9999
|
Bleeding at anastomosis
|
1 (1.09)
|
1 (1.69)
|
0 (0.00)
|
>0.9999
|
GI treatments, n (%)
|
22 (23.91)
|
15 (25.42)
|
7 (21.21)
|
0.8001
|
GI treatment type
|
|
|
|
|
Gastric tube, n (%)
|
15 (16.30)
|
9 (15.25)
|
6 (18.18)
|
0.7724
|
GT reinsertion duration in days, median (interquartile range)
|
3 (1-4.25)
|
3 (1.25-4.75)
|
3 (0-6.5)
|
0.7862
|
Medication, n (%)
|
12 (13)
|
9 (15.25)
|
3 (9.09)
|
0.5268
|
Explorative laparotomy, n (%)
|
1 (1.09)
|
1 (1.69)
|
0 (0.00)
|
>0.9999
|
TPN, n (%)
|
3 (3.26)
|
3 (5.08)
|
0 (0.00)
|
0.5504
|
As projected in Table 3 and Figure 3, gastrointestinal (GI) complications were seen in 25% of patients. Most of those had a paralytic ileus (17% of patients), usually treated conservatively or by (re-)insertion of a gastric tube, on average for about 3 days. 5 patients were radiologically diagnosed with a mechanical ileus, for which only 1 explorative laparotomy had to be performed. This particular instance involved a patient with a manually sutured bowel anastomosis, who, following a standard postoperative recovery and discharge on day 5, returned on day 8 with a blowout of the bowel anastomosis. Subsequent interventions were necessitated, including an open reconstruction of the bowel anastomosis, which unfortunately resulted in a second bowel dehiscence. Notably, this case occurred early in the adoption of sutured bowel anastomosis procedures and was an isolated occurrence, suggesting a potential learning curve challenge.
All four other cases of mechanical ileus were managed conservatively.
We found no statistically significant differences between both surgical techniques in any of the mentioned GI complications or their treatments.
3.4 Secondary outcome parameters
Secondary outcome parameters are listed in Table 4 and graphically presented in Figure 4.
Operation duration was 300 min per procedure on average. Although not statistically significant (p=0.12), stapled procedures were about 13 minutes longer than sutured procedures. This shows that manually suturing the bowel back together does not necessarily prolong the procedure and can even shorten it, when performed by experienced hands.
Length of stay was, as could be expected, similar for both techniques (p=0.38).
There were more readmissions in the sutured anastomosis group (p=0.02), of whom most were caused by non-GI complications such as leakage of the ileo-ureteric anastomosis (3 out of 17 cases) and infectious complications (11 out of 17 cases). Remarkably, 3 patients presented with an urosepsis due to an obstructive urolithiasis (all in the sutured group).
Most complications were Clavien Dindo grade ≤2 (55%). Most grade 3 complications were due to dislocation of either the catheter or one of the ureteric stents - or due to paralytic ileus necessitating the reinsertion of a gastric tube.
The one patient with a grade 4b complication was hospitalized in the ICU because of a urosepsis with multi-organ failure due to an obstructive urolithiasis (sutured group). The one patient with a grade 4a complication had a cerebrovascular accident (CVA) at home and died afterwards (sutured group).
We reported a 3-month mortality of 3.26% (3 cases). None of the deaths were due to a GI complication and all occurred outside of the hospital. 1 Patient (stapled group) died of respiratory septic shock with an underlying COPD stage Gold 4 and another (stapled group) of dyspnea, no invasive measures were undertaken because of rapidly progressive liver metastasis and pleural metastasis respectively. The reason for the death of the third patient (sutured group) is not documented, but occurred after a CVA at home as mentioned before.
There were no statistically significant differences in time to intake, time to extraction of the drainage, time to flatus or time to defecation.
Table 4. Secondary outcome parameters. Comparison of secondary outcome parameters between sutured and stapled bowel anastomosis groups. Binary data are listed as number of patients (n) and proportion of patients (%). p-values were calculated using Fisher’s exact tests. Numerical data are listed as median and interquartile range, and p-values were calculated using non-parametric two-sided Mann-Whitney U tests. ICU: intensive care unit.
Variable
|
Total
|
Sutured
|
Stapled
|
p-value
|
Operation duration in min, median (interquartile range)
|
300 (240-330)
|
300 (240-315)
|
313 (247.5-373.8)
|
0.1243
|
Length of stay in days, median (interquartile range)
|
8 (6-10.75)
|
7 (6-10)
|
8 (5.5-13)
|
0.3842
|
ICU stay in days, median (interquartile range)
|
1 (0-1)
|
0 (0-1)
|
1 (0-1)
|
0.0508
|
Readmission, n (%)
|
17 (18.48)
|
15 (25.42)
|
2 (6.06)
|
0.0254
|
Readmission stay in days, median (interquartile range)
|
7 (2.5-8)
|
7 (2-8)
|
7.5 (7-8)
|
0.6544
|
Maximum Clavien Dindo grade, median (interquartile range)
|
2 (0-3a)
|
2 (0-3a)
|
2 (0-2)
|
0.2172
|
Clavien Dindo grade, n (%)
|
|
|
|
|
0
|
29 (31.52)
|
17 (28.81)
|
12 (36.36)
|
0.4892
|
1
|
8 (8.70)
|
4 (6.78)
|
4 (12.12)
|
0.4510
|
2
|
27 (29.35)
|
17 (28.81)
|
10 (30.30)
|
>0.9999
|
3a
|
19 (20.65)
|
15 (25.42)
|
4 (12.12)
|
0.1812
|
3b
|
4 (4.35)
|
3 (5.08)
|
1 (3.03)
|
>0.9999
|
4a
|
1 (1.09)
|
1 (1.69)
|
0 (0.00)
|
>0.9999
|
4b
|
1 (1.09)
|
1 (1.69)
|
0 (0.00)
|
>0.9999
|
5
|
3 (3.26)
|
1 (1.69)
|
2 (6.06)
|
0.2915
|
Time to intake in days, median (interquartile range)
|
1 (1-1)
|
1 (1-2)
|
1 (1-1)
|
0.5064
|
Time to flatus in days, median (interquartile range)
|
3 (2-4)
|
3 (2-4)
|
3 (2-4)
|
0.5496
|
Time to defecation in days, median (interquartile range)
|
5 (4-6)
|
5 (4-6)
|
5 (4-7)
|
0.8978
|
Time to drain ex in days, median (interquartile range)
|
4.5 (3-6)
|
4 (3-6)
|
5 (3.25-7.75)
|
0.3496
|