Clinical value of computed tomography-based three-dimensional reconstruction of the pelvis and mesorectum in middle to low rectal carcinoma

Table 1 Normality test analysis for each variable

	W value	P value
Age	0.984	0.243
BMI	0.977	0.078
Surgical time	0.776	0.000a
Intraoperative blood loss	0.648	0.000a
Duration of postoperative hospital stay	0.715	0.000a
Postoperative anal evacuation time	0.765	0.000a
Postoperative resumption of semi-liquid food time	0.941	0.000a
Tumor height	0.923	0.000a
Tumor maximum diameter	0.947	0.000a
Anterior-posterior diameter of pelvic inlet	0.980	0.122
Transverse diameter of pelvic inlet	0.991	0.729
Anterior-posterior diameter of pelvic outlet	0.977	0.070
Interischial spine diameter	0.964	0.008a
Interischial tuberosity diameter	0.981	0.163
Superior-inferior diameter of the pubic symphysis	0.082	0.000a
Sacrococcygeal distance	0.989	0.579
sacrococcygeal-pubic angle	0.131	0.000a
Anterior-posterior diameter of pelvic inlet/sacrococcygeal distance	0.937	0.000a
Rectal mesenteric fat volume at the level of the superior border of the 3rd sacral vertebra	0.948	0.001a
Rectal volume at the level of the superior border of the 3rd sacral vertebra	0.877	0.000a
Rectal mesenteric fat volume at the level of the sciatic spine	0.932	0.000a
Pelvic volume	0.986	0.390
Anorectal angle	0.993	0.853
Rectal mesenteric volume at the level of superior border of the 3rd sacral vertebra	0.944	0.000a
Rectal mesenteric fat volume at the superior border of the 3rd sacral vertebra/pelvic volume	0.981	0.195

^aP < 0.05 indicates significant deviation from normal distribution.

BMI: Body mass index.

Table 2 Clinical and pathological characteristics data of 103 patients in the laparoscopic low anterior resection for rectal cancer

	Range	mean ± SD/median (Q1, Q3)	Number of cases, n (%)
Age (year)	32-89	64.81 ± 11.832
Gender
Male			71 (68.9)
Female			32 (31.1)
BMI (kg/m2)	15.94-33.980	22.63 ± 2.910
Underlying comorbidities			48 (46.6)
Diabetes			14 (13.6)
Hypertension			39 (37.9)
Heart disease			8 (7.8)
Pulmonary disease			3 (2.9)
Stroke			4 (3.9)
Other			4 (3.9)
History of previous abdominal surgery			16 (15.5)
Neoadjuvant therapy			4 (3.9)
Hypoalbuminemia			17 (16.5)
Anemia			73 (70.9)
Blood transfusion			2 (1.9)
Tumor height (cm)	4-10	7 (6, 8)
Tumor maximum diameter (cm)	0.9-10	3.9 (3, 5)
Intraoperative preventive ostomy			36 (35.0)
pT/ypT staging
T0			1 (1.0)
Tis			4 (3.9)
T1			12 (11.7)
T2			13 (12.6)
T3			70 (68.0)
T4a			3 (2.9)
pN/ypN staging
N0			61 (59.2)
N1			26 (25.2)
N2			16 (15.5)
pTNM/ypTNM staging
0			5 (4.9)
I			20 (19.4)
II			36 (35)
III			42 (40.8)
Tumor differentiation grade
N/A			2 (1.9)
Well-differentiated			6 (5.8)
Moderately differentiated to well-differentiated			11 (10.7)
Moderately differentiated			70 (68)
Moderately differentiated to poorly differentiated			11 (10.7)
Poorly differentiated			3 (2.9)
Surgical time (minute)	78-892	222.83 (173, 260)
Intraoperative blood loss (mL)	10-300	50 (20, 50)
Postoperative complications (CD grade)
No complications			77 (74.8)
I			5 (4.9)
II			16 (15.5)
III			4 (3.9)
IV			1 (1.0)
Duration of postoperative hospital stay (days)	6-56	14 (12, 16)
Postoperative anal evacuation time (days)	1-7	2 (2, 3)
Postoperative resumption of semi-liquid food time (days)	3-17	7 (5, 9)

If the data follows a normal distribution: mean ± SD will be used to represent numerical data. The n (%) will be used to represent count and ordinal data. If the data does not follow a normal distribution: Median (Q1, Q3) will be used to represent numerical data. The n (%) will be used to represent count and ordinal data. N/A: Not applicable, BMI: Body mass index; CD: Clavien-Dindo.

Table 3 Within-group comparison of pelvic measurements and soft tissue measurements in 20 patients

	mean ± SD/median (Q1, Q3)	mean ± SD/median (Q1, Q3)	r value (correlation coefficient)	P value (correlation coefficient)	P value (mean or median difference)
Anterior-posterior diameter of pelvic inlet (mm)	114.07 ± 12.58	113.74 ± 12.72	0.998	0.000a	0.936
Transverse diameter of pelvic inlet (mm)	120.91 ± 8.22	120.60 ± 8.16	0.998	0.000a	0.905
Anterior-posterior diameter of pelvic outlet (mm)	87.98 ± 12.07	88.12 ± 11.68	0.998	0.000a	0.971
Interischial spine diameter (mm)	91.56 (85.19, 106.16)	91.02 (84.84, 106.15)	0.992	0.000a	0.892
Interischial tuberosity diameter (mm)	97.128 ± 14.21	96.53 ± 14.35	0.998	0.000a	0.896
Superior-inferior diameter of the pubic symphysis (mm)	36.94 (33.34, 40.26)	36.08 (32.99, 39.37)	0.838	0.000a	0.589
Sacrococcygeal distance (mm)	127.09 ± 12.19	126.82 ± 12.35	0.998	0.000a	0.944
sacrococcygeal-pubic angle (°)	55.49 (46.10, 60.55)	54.59 (46.58, 60.59)	0.989	0.000a	0.978
Anterior-posterior diameter of pelvic inlet/sacrococcygeal distance	0.90 (0.82, 0.98)	0.90 (0.81, 0.98)	0.994	0.000a	0.957
Rectal mesenteric fat volume at the level of the superior border of the 3rd sacral vertebra (cm3)	178.91 (137.08, 198.96)	168.68 (135.51, 189.72)	0.92	0.000a	0.534
Rectal mesenteric fat volume at the level of the sciatic spine (cm3)	39.15 (33.12, 56.53)	35.56 (30.62, 53.16)	0.974	0.000a	0.626
Pelvic volume (cm3)	849.37 ± 112.75	836.76 ± 109.53	0.978	0.000a	0.722
Anorectal angle (°)	119.99 ± 14.88	119.67 ± 14.77	0.995	0.000a	0.946
Rectal mesenteric volume at the level of superior border of the 3rd sacral vertebra (cm3)	247.14 (219.43, 301.38)	241.78 (211.90, 297.89)	0.892	0.000a	0.516
Rectal volume at the level of the superior border of the 3rd sacral vertebra (cm3)	78.49 (55.94, 119.31)	68.76 (53.53, 123.11)	0.991	0.000a	0.589
Rectal mesenteric fat volume at the superior border of the 3rd sacral vertebra/pelvic volume	0.32 ± 0.08	0.31 ± 0.07	0.964	0.000a	0.619

^aP < 0.001.

If the data are normally distributed, they are expressed as mean ± SD; if not, they are expressed as median (Q1, Q3).

Table 4 Between-group comparison of pelvic measurements and soft tissue measurements in 20 patients

	mean ± SD/median (Q1, Q3)	mean ± SD/median (Q1, Q3)	r value (correlation coefficient)	P value (correlation coefficient)	P value (mean or median difference)
Transverse diameter of pelvic inlet (mm)	124.44 ± 6.87	123.84 ± 6.93	0.988	0.000a	0.782
Anterior-posterior diameter of pelvic outlet (mm)	87.74 ± 8.45	87.61 ± 8.27	0.983	0.000a	0.962
Interischial spine diameter (mm)	93.02 (86.26, 100.70)	91.98 (86.63, 100.32)	0.991	0.000a	0.925
Interischial tuberosity diameter (mm)	96.90 ± 13.52	96.74 ± 13.33	0.997	0.000a	0.969
Superior-inferior diameter of the pubic symphysis (mm)	38.24 (35.63, 41.85)	37.68 (33.50, 42.26)	0.896	0.000a	0.589
Sacrococcygeal distance (mm)	122.33 ± 9.10	122.12 ± 9.05	0.992	0.000a	0.940
sacrococcygeal-pubic angle (°)	50.56 (45.18, 55.68)	51.35 (44.52, 54.76)	0.956	0.000a	0.620
Anterior-posterior diameter of pelvic inlet/sacrococcygeal distance	0.91 (0.83, 1.02)	0.91 (0.84, 1.01)	0.992	0.000a	0.989
Rectal mesenteric fat volume at the level of the superior border of the 3rd sacral vertebra (cm3)	170.50 (135.04, 213.31)	169.18 (111.89, 235.48)	0.814	0.000a	0.968
Rectal mesenteric fat volume at the level of the sciatic spine (cm3)	31.10 (24.55, 48.92)	30.85 (22.43, 46.44)	0.856	0.000a	0.883
Pelvic volume (cm3)	920.94 ± 110.70	946.28 ± 142.86	0.898	0.000a	0.534
Anorectal angle (°)	104.79 ± 14.39	105.21 ± 14.37	0.996	0.000a	0.926
Rectal mesenteric volume at the level of superior border of the 3rd sacral vertebra (cm3)	258.69 (212.54, 295.30)	249.25 (185.80, 321.64)	0.826	0.000a	0.883
Rectal volume at the level of the superior border of the 3rd sacral vertebra (cm3)	71.82 (58.29, 104.09)	77.43 (59.98, 93.66)	0.892	0.000a	1.000
Rectal mesenteric fat volume at the superior border of the 3rd sacral vertebra/pelvic volume	0.28 ± 0.09	0.28 ± 0.12	0.909	0.000a	0.955

^aP < 0.001.

If the normal distribution is satisfied, it is expressed as mean ± SD; if not, it is expressed as median (Q1, Q3).

Table 5 Gender comparison of pelvic and soft tissue parameters in 103 patients, mean ± SD/median (Q1, Q3)

	Total cases (n = 103)	Male (n = 71)	Female (n = 32)	P value
Anterior-posterior diameter of pelvic inlet (mm)	111.60 ± 12.86	107.21 ± 11.15	121.35 ± 11.01	0.000b
Transverse diameter of pelvic inlet (mm)	122.90 ± 7.51	120.38 ± 6.36	128.50 ± 6.88	0.000b
Anterior-posterior diameter of pelvic outlet (mm)	87.80 ± 8.86	85.837 ± 7.96	93.21 ± 8.47	0.000b
Interischial spine diameter (mm)	92.54 (85.89, 101.40)	88.70 (83, 93.66)	106.35 (98.98, 108.94)	0.000b
Interischial tuberosity diameter (mm)	97.69 ± 12.95	92.88 (86.91, 97.61)	111.28 (101.37, 118.30)	0.000b
Superior-inferior diameter of the pubic symphysis (mm)	39.67 (36.55, 43.26)	39.92 (37.02, 44.22)	38.35 (35.63, 42.49)	0.180
Sacrococcygeal distance (mm)	123.40 ± 11.85	124.74 ± 11.14	120.44 ± 12.97	0.089
sacrococcygeal-pubic angle (°)	51.08 (45.10, 56.65)	54.17 (48.06, 58.46)	45 (40.76, 49.81)	0.000b
Anterior-posterior diameter of pelvic inlet/sacrococcygeal distance	0.89 (0.83, 0.97)	0.85 (0.81, 0.91)	1.01 (0.92, 1.05)	0.000b
Rectal mesenteric fat volume at the level of the superior border of the 3rd sacral vertebra (cm3)	171.25 (136.59, 212.59)	184.47 (146.11, 222.21)	155.94 (119.33, 199.55)	0.047a
Rectal volume at the level of the superior border of the 3rd sacral vertebra (cm3)	66.87 (53.51, 95.88)	66.19 (51.83, 91.02)	69.68 (56.26, 100.46)	0.613
Rectal mesenteric fat volume at the level of the sciatic spine (cm3)	33.59 (24.40, 46.15)	40.42 (26.24, 49.66)	28.16 (21.20, 35.76)	0.001a
Pelvic volume (cm3)	896.54 ± 113.97	876.50 ± 108.21	941.00 ± 115.49	0.007a
Anorectal angle (°)	110.17 ± 16.36	110.11 ± 17.31	110.30 ± 14.29	0.958
Rectal mesenteric volume at the level of superior border of the 3rd sacral vertebra (cm3)	250.79 (205.78, 294.21)	250.79 (215.41, 299.18)	238.86 (194.19, 286.30)	0.197
Rectal mesenteric fat volume at the superior border of the 3rd sacral vertebra/pelvic volume	0.2880 ± 0.079	0.3019 ± 0.078	0.2569 ± 0.073	0.007a

^aP < 0.05.

^bP < 0.001.

If the normal distribution is satisfied, it is expressed as mean ± SD; if not, it is expressed as median (Q1, Q3).

Table 6 Comparison of clinicopathological data in both genders and short-term operative outcome in 103 patients with middle and lower rectal carcinoma

	Male (n = 71)	Female (n = 32)	P value
Age (years)	66 ± 11.98	62.16 ± 11.23	0.128
BMI (kg/m2)	22.56 ± 3.08	22.76 ± 2.54	0.748
Underlying comorbidities	39 (54.9)	9 (28.1)	0.012
Diabetes	9 (12.7)	5 (15.6)	0.926
Hypertension	31 (43.7)	8 (25)	0.071
Heart disease	8 (11.3)	0	0.114
Pulmonary disease	3 (4.2)	0	0.550
Stroke	2 (2.8)	2 (6.3)	0.777
Other	2 (2.8)	2 (6.3)	0.777
History of previous abdominal surgery	7 (9.9)	9 (28.1)	0.038a
Neoadjuvant therapy	3 (4.2)	1 (3.1)	1.000
Hypoalbuminemia	14 (19.7)	3 (9.4)	0.191
Anemia	52 (73.2)	21 (65.6)	0.431
Blood transfusion	2 (2.8)	0	1.000
Tumor height (cm)	7 (6, 8)	8 (6.25, 10)	0.063
Tumor maximum diameter (cm)	4 (3, 5)	3.5 (3, 5)	0.134
Intraoperative preventive ostomy	28 (39.4)	8 (25)	0.155
pT/ypT staging			0.420
T0	0	1
Tis	3 (4.2)	1 (3.1)
T1	8 (11.3)	4 (12.5)
T2	6 (8.5)	7 (21.9)
T3	52 (73.2)	18 (56.3)
T4a	2 (2.8)	1 (3.1)
pN/ypN staging			0.481
N0	41 (57.7)	20 (62.5)
N1	17 (23.9)	9 (28.1)
N2	13 (18.3)	3 (9.4)
pTNM/ypTNM staging			0.143
0	3 (4.2)	2 (6.3)
I	9 (12.7)	11 (34.4)
II	29 (40.8)	7 (21.9)
III	30 (42.3)	12 (37.5)
Tumor differentiation grade			0.094
N/A	1 (1.4)	1 (3.1)
Well-differentiated	4 (5.6)	2 (6.3)
Moderately differentiated to well-differentiated	7 (9.9)	4 (12.5)
Moderately differentiated	45 (63.4)	25 (78.1)
Moderately differentiated to poorly differentiated	11 (15.5)	0
Poorly differentiated	3 (4.2)	0
Surgical time (minutes)	222 (178, 265)	195 (154.5, 239.25)	0.216
Intraoperative blood loss (mL)	50 (30, 50)	30 (20, 50)	0.034a
Postoperative complications (CD grade)			0.230
No complications	51 (71.8)	26 (81.3)
I	3 (4.2)	2 (6.3)
II	12 (16.9)	4 (12.5)
III	4 (5.6)	0
IV	1 (1.4)	0
Duration of postoperative hospital stay (day)	14 (11, 16)	13.5 (12, 16.75)	0.983
Postoperative anal evacuation time (day)	2 (2, 2)	2 (2, 3)	0.156
Postoperative resumption of semi-liquid food time (day)	7 (4, 9)	8 (5, 9)	0.755

^aP < 0.05.

In the case of normal distribution, the data are presented as mean ± SD. For non-normal distribution, median (Q1, Q3) is used. Count and ordinal data are represented as n (%). N/A: Not applicable, BMI: Body mass index; CD: Clavien-Dindo.