Construction of a nomogram model to predict technical difficulty in performing laparoscopic sphincter-preserving radical resection for rectal cancer

Table 4 Clinical and pathological characteristics data of 162 patients undergoing laparoscopic radical sphincter-preserving surgery for rectal cancer

	Range	mean ± SD	No. of cases [n (%)]
Age (yr)	(32.00, 89.00)	65 (59, 72)
Gender
Male			105 (64.81)
Female			57 (35.19)
BMI (kg/m2)	(15.94, 31.25)	22.75 ± 3.25
Underlying comorbidities			72 (44.44)
Diabetes			26 (16.05)
Hypertension			58 (35.8)
Heart disease			8 (4.94)
Pulmonary disease			3 (1.85)
Stroke			5 (3.09)
Other			1 (0.62)
ASA grade
I			18 (11.11)
II			137 (84.57)
III			7 (4.32)
History of previous abdominal surgery			15 (9.26)
Preoperative total protein (g/L)	(53.8, 81)	65.45 (62.4, 68.83)
Preoperative albumin (g/L)	(29, 48.5)	38.64 ± 3.32
Preoperative albumin to globulin ratio	(0.9, 2.1)	1.4 (1.3, 1.6)
Preoperative hemoglobin (g/L)	(89, 166)	134.5 (119, 143.75)
PNI	(35, 58)	47.23 ± 5.02
Preoperative CEA (ug/L)	(0.4, 49.9)	2.9 (1.9, 5.18)
Preoperative CA199 (kU/L)	(0.6, 128.1)	8.55 (5.18, 17.98)
Tumor height (cm)	(2, 15)	8 (6.25, 10)
Tumor Location
Upper rectum (10 cm < distance ≤ 15 cm)			30 (18.52)
Midrectum (5 cm < distance ≤ 10 cm)			103 (63.58)
Lower rectum (distance ≤ 5 cm)			29 (17.9)
Maximum tumor diameter (cm)	(0.8, 10)	3.8 (3, 4.88)
Surgical approach
L-AR			20 (12.35)
L-LAR			135 (83.33)
L-ISR			7 (4.32)
Intraoperative preventive ostomy			39
L-AR + preventive ostomy			0
L-LAR + preventive ostomy			32 (82.05)
L-ISR + preventive ostomy			7 (17.95)
pT staging
Tis			4 (2.47)
T1			19 (11.73)
T2			26 (16.05)
T3			109 (67.28)
T4a			4 (2.47)
pN staging
N0			94 (58.02)
N1			36 (22.22)
N2			32 (19.75)
pTNM staging
0			4 (2.47)
I			38 (23.46)
II			52 (32.1)
III			68 (41.98)
Tumor differentiation grade
Well-differentiated			9 (5.56)
Moderately-differentiated to well-differentiated			20 (12.35)
Moderately differentiated			112 (69.14)
Moderately differentiated to poorly differentiated			17 (10.49)
Poorly-differentiated			4 (2.47)
Tumor nodules			16 (9.88)
Vascular tumor emboli			47 (29.01)
Neural invasion			40 (24.69)
Number of lymph nodes removed	(3, 36)	15 (13, 18)
Surgical duration (min)	(78, 465)	216.5 (179.25, 260)
Intraoperative blood loss (ml)	(10, 300)	50 (20, 100)
Postoperative complications (CD grade)
No complications			125 (77.16)
Grade I			7 (4.32)
Grade II			21 (12.96)
Grade III			8(4.94)
Grade IV			1(0.62)
Postoperative anastomotic fistula grading
No anastomotic fistula			152 (93.83)
Grade A			0
Grade B			6 (3.7)
Grade C			4 (2.47)
Duration of postoperative hospital stay (d)	(6, 56)	14 (12, 16)
Intraoperative use of transanal approach (n)			7 (4.32)
Conversion to open surgery			1 (0.62)
Postoperative anal evacuation time (d)	(1, 7)	2 (2, 3)
Postoperative resumption of semi-liquid food time (d)	(3, 25)	8 (5, 9)
Anastomosis method
Manual anastomosis (Hand-sewn anastomosis)			7 (4.32)
Stapler anastomosis			155 (95.68)
Number of staple nail cartridges used in surgery (n)
L-AR	(1, 2)	2 (1, 2)
L-LAR	(1, 4)	2 (1, 2)
L-ISR	0	0
Length of stapler cartridge used in surgery (mm)
L-AR	(45, 120)	90 (56.25, 90)
L-LAR	(45, 180)	90 (60, 90)
L-ISR	0	0

If the data follows a normal distribution: mean ± SD will be used to represent numerical data. Examples (%) 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. Examples (%) will be used to represent count and ordinal data. BMI: Body mass index; ASA: American Society of Anesthesiologists; CD: Clavien-Dindo; PNI: Prognostic nutritional index; L-AR: Laparoscopic anterior resection; L-LAR: Laparoscopic low or ultralow anterior resection; L-ISR: Laparoscopic intersphincteric resection.