Value of color Doppler ultrasound in preoperative typing diagnosis of acute appendicitis

Table 1 Comparison of general characteristics and clinical features between two groups

Variable	Simple (n = 186)	Suppurative (n = 142)	Statistic	P value
Sex			χ2 = 0.18	0.671
Male	104 (55.9)	76 (53.5)
Female	82 (44.1)	66 (46.5)
Age (years)	31.8 ± 13.9	33.4 ± 14.6	t = 0.98	0.328
BMI (kg/m2)	23.6 ± 3.2	24.1 ± 3.5	t = 1.32	0.188
Pain duration (hour)	24.3 ± 12.6	36.8 ± 18.5	t = 6.98	< 0.001
Temperature (°C)	37.5 ± 0.6	38.2 ± 0.8	t = 8.56	< 0.001
WBC (× 109/L)	11.2 ± 2.8	14.8 ± 3.6	t = 9.82	< 0.001
Neutrophil (%)	78.4 ± 7.1	85.6 ± 6.2	t = 9.36	< 0.001
CRP (mg/L)	45.6 ± 18.7	82.5 ± 28.3	t = 13.24	< 0.001

Data was showed as n (%) or mean ± SD. Continuous variables compared using independent sample t-test; categorical variables compared using χ² test. BMI: Body mass index; WBC: White blood cell count; CRP: C-reactive protein.

Table 2 Comparison of preoperative ultrasound parameters between two groups

Parameter	Simple (n = 186)	Suppurative (n = 142)	Statistic	P value
Successful visualization	174 (93.5)	132 (93.0)	χ2 = 0.03	0.862
Max appendiceal diameter (mm)	8.5 ± 1.6	11.8 ± 2.3	t = 14.82	< 0.001
Appendiceal wall thickness (mm)	2.4 ± 0.6	3.8 ± 0.9	t = 15.67	< 0.001
Intraluminal fluid/pus	61 (32.8)	111 (78.2)	χ2 = 62.35	< 0.001
Peri-appendiceal fluid	34 (18.3)	92 (64.8)	χ2 = 68.92	< 0.001
Blood flow grade 0-I	133 (71.5)	37 (26.1)	χ2 = 61.48	< 0.001
Blood flow grade ≥ II	53 (28.5)	105 (73.9)
Lymph node enlargement	47 (25.3)	80 (56.3)	χ2 = 29.87	< 0.001

Data was showed as n (%) or mean ± SD.

Table 3 Multivariate Logistic regression analysis for preoperative prediction of suppurative appendicitis

Variable	β	SE	Wald χ2	P value	OR	95%CI
Max. diameter (≥ 9.8 mm)	1.230	0.229	28.84	< 0.001	3.42	2.18-5.37
Wall thickness (≥ 3.2 mm)	1.061	0.228	21.68	< 0.001	2.89	1.85-4.52
Blood flow (≥ grade II)	0.971	0.217	20.03	< 0.001	2.64	1.72-4.05
Constant	-3.156	0.315	100.32	< 0.001	0.043	-

Forward stepwise method (forward: LR) used for variable selection. Entry criterion P < 0.05, removal criterion P > 0.10. Hosmer-Lemeshow goodness-of-fit test: χ² = 6.82, P = 0.556; overall model prediction accuracy = 89.3%.

Table 4 Comparison of surgical approach and related indicators between two groups

Variable	Simple appendicitis (n = 186)	Suppurative appendicitis (n = 142)	Statistic	P value
Initial operative approach			χ2 = 64.35	< 0.001
Laparoscopic surgery	183 (98.4)	101 (71.1)
Open surgery	3 (1.6)	41 (28.9)
Conversion to open	3/183 (1.6)	22/101 (21.8)	χ2 = 27.85	< 0.001
Final operative approach			χ2 = 98.76	< 0.001
Completed laparoscopic surgery	180 (96.8)	79 (55.6)
Open or converted surgery	6 (3.2)	63 (44.4)
Operative time (minutes)	45.3 ± 12.8	68.5 ± 15.2	t = 14.26	< 0.001
Intra-operative blood loss (mL)	28.4 ± 12.3	52.8 ± 18.6	t = 12.87	< 0.001
Reasons for conversion			χ2 = 2.18	0.336
Dense adhesions	2 (66.7)	13 (59.1)
Unclear anatomy	1 (33.3)	6 (27.3)
Appendiceal abscess	0 (0)	3 (13.6)

Data was showed as n (%) or mean ± SD.

Table 5 Comparison of postoperative recovery and complications between two groups

Variable	Suppurative appendicitis (n = 142)	Simple appendicitis (n = 186)	Statistic	P value
First flatus (hour)	48.6 ± 12.8	28.3 ± 8.5	t = 15.82	< 0.001
Oral intake resumed (hour)	52.4 ± 14.2	32.6 ± 9.8	t = 13.45	< 0.001
Post-operative LOS (day)	5.8 ± 1.4	3.2 ± 0.9	t = 18.74	< 0.001
Overall morbidity	26 (18.3)	9 (4.8)	χ2 = 15.87	< 0.001
Wound infection	8 (5.6)	5 (2.7)
Intra-abdominal abscess	7 (4.9)	2 (1.1)
Ileus	6 (4.2)	2 (1.1)
Wound dehiscence	3 (2.1)	0 (0)
Pneumonia	2 (1.4)	0 (0)

Data was showed as n (%) or mean ± SD.