Table 2.
Descriptive statistics of the cohort as segregated according to ureteral canalization (n = 263)
| Ureteral canalization | Lack of canalization | p-value* | |
|---|---|---|---|
| Age (years) | 0.08 | ||
| Median (IQR) | 56 (47–64) | 53 (47–65) | |
| Range | 19–84 | 23–81 | |
| Male gender [no. (%)] | 113 (54.3) | 31 (56.3) | 0.8 |
| BMI (kg/m2) | 0.6 | ||
| Median (IQR) | 24.2 (21.5–28.1) | 25.3 (22.6–26.7) | |
| Range | 17.9–42.2 | 18.7–38.3 | |
| CCI (score) | 0.9 | ||
| Median (IQR) | 0.0 (0.0) | 0.0 (0.0) | |
| Mean (SD) | 0.6 (0.2) | 0.6 (0.2) | |
| Range | 0–8 | 0–6 | |
| CCI ≥ 1 [no. (%)] | 76 (36.5) | 21 (38.1) | 0.4 |
| Laterality [no. (%)] | 0.8 | ||
| Right | 100 (48.1) | 27 (49.1) | |
| Left | 108 (51.9) | 28 (50.9) | |
| Stone volume (cm3) | < 0.01 | ||
| Median (IQR) | 1.8 (0.8–3.8) | 3.1 (1.1–5.6) | |
| Range | 0.5–18.9 | 2.7–23.6 | |
| Multiple stone [no. (%)] | 95 (45.7) | 34 (61.8) | 0.03 |
| Stone in renal pelvis [no. (%)] | 108 (51.9) | 41 (74.5) | < 0.01 |
| Mean stone density (Hounsfield unit) | 0.5 | ||
| Median (IQR) | 825 (574–1080) | 850 (629–1104) | |
| Range | 150–1280 | 372–1983 | |
| Multiple access tracts [no. (%)] | 22 (10.6) | 7 (12.7) | 0.7 |
| Procedure type [no. (%)] | 0.4 | ||
| vamPCNL | 164 (78.8) | 46 (83.6) | |
| vcmPCNL | 44 (21.2) | 9 (16.4) | |
| Operative time (min) | < 0.01 | ||
| Median (IQR) | 90 (73–125) | 105 (75–140) | |
| Range | 30–180 | 50–180 | |
| Hospitalization time (days) | < 0.01 | ||
| Median (IQR) | 4 (3–5) | 6 (4–7) | |
| Range | 3–20 | 3–15 | |
| Postoperative complications [no. (%)] | 0.03 | ||
| (Highest Clavien score) | |||
| Clavien–Dindo I-II | 35 (16.8) | 15 (27.2) | |
| Clavien–Dindo IIIa/b | 15 (7.2) | 7 (12.7) | |
| Stone-free rate [no. (%)] | 178 (85.5) | 47 (85.4) | 0.2 |
Keys: BMI body mass index, CCI Charlson Comorbidity Index, vamPCNL vacuum-assisted mini-percutaneous nephrolithotomy, vcmPCNL vacuum cleaner mini-percutaneous nephrolithotomy
* p-value according to the Mann–Whitney test and Fisher exact test, as indicated