Leaving no stone unturned: Impact of appendicolith and characteristics on long-term recurrence after non-operative appendicitis

Table 1 Patient demographics and clinical presentation by appendicolith presence, n (%)

Variable		Total (n = 797)	No appendicolith (non-AG) (n = 729)	Appendicolith (AG) (n = 68)	P value
Gender	Female	362 (45.4)	333 (45.8)	29 (42.7)	0.62
	Male	434 (54.6)	395 (54.3)	39 (57.3)
Age (years) mean ± SD		25.4 ± 14.4	25.5 ± 14.4	25.3 ± 14.4	0.94
Length of pain prior to admission (hours), mean ± SD		39.3 ± 61.5	38.8 ± 62.3	44.2 ± 52.3	0.94
Fever at home		85 (10.6)	79 (10.9)	6 (8.8)	0.75
Temperature at admission (celsius), mean ± SD		36.7 ± 0.6	36.7 ± 0.6	36.8 ± 0.7	0.94
Heart rate on admission, mean ± SD		89.0 ± 19.5	89.1 ± 19.5	87.9 ± 18.8	0.62
White blood count (× 109/L), mean ± SD		11.4 ± 3.9	11.4 ± 3.9	11.8 ± 4.5	0.62
C-reactive protein (mg/dL), mean ± SD		3.3 ± 5.4	3.2 ± 5.2	3.7 ± 6.9	0.62
Ultrasound performed		462 (58.0)	422 (58.1)	40 (58.8)	0.88
Computed tomography performed		460 (57.7)	419 (57.6)	41 (60.3)	0.65
Radiological findings	Largest appendix diameter (mm), mean ± SD	8.7 ± 2.4	8.5 ± 2.2	10.2 ± 1.4	0.001
	Free fluid on imaging	229 (28.7)	203 (27.9)	26 (38.2)	0.08
Length of stay, median (IQR), day		2.6 (2-3)	2.6 (2-3)	2.8 (1-3)	0.43
Recurrence of appendicitis		158 (19.8)	139 (19.1)	18 (26.5)	0.14
Time to recurrence (months), mean ± SD		5.7 ± 8.3	5.9 ± 8.1	3.9 ± 10.4	0.04
Pathology at readmission	Normal appendix	11 (1.4)	10 (1.4)	1 (1.5)	0.01
	Inflamed	126 (15.8)	117 (16.1)	9 (13.2)
	Perforated	10 (1.3)	6 (0.8)	4 (5.9)
	Neoplasia	5 (0.6)	4 (0.5)	1 (1.5)
Follow up, median (IQR), months		44.2 (31.9-63.1)	46.2 (32.1-65.0)	35.8 (24.0-53.4)	0.001

AG: Appendicolith group; IQRs: Interquartile ranges.

Table 2 Focused analysis of appendicolith characteristics on recurrence vs non-recurrence, n (%)

Variable		Total (n = 68)	Non-recurrence (n = 50)	Recurrence (n = 18)	P value
Number of appendicolith	1	53 (77.9)	41 (82)	12 (66.7)	0.18
	2	14 (20.6)	8 (16)	6 (33.3)
	3	1 (1.5)	1 (2)	0 (0)
Appendicolith location	Proximal third	22 (32.4)	18 (36)	4 (22.2)	0.69
	Mid third	16 (23.5)	10 (20)	6 (33.3)
	Distal third	25 (36.9)	18 (36)	7 (38.9)
Second appendicolith location	Proximal	4 (5.9)	3 (6)	1 (5.6)	0.80
	Mid	5 (7.4)	2 (4)	3 (16.7)
	Distal	5 (7.4)	3 (6)	2 (11.1)
Appendicolith size (mm)	Length	7.1 ± 3.7	7.3 ± 3.9	6.6 ± 3.1	0.68
	Width	4.2 ± 2.4	4.3 ± 2.7	3.7 ± 1.2	0.93
	Length to size ratio	1.8 ± 0.4	1.8 ± 0.6	1.8 ± 0.8	0.52
Second appendicolith size length (mm)		4.7 ± 1.8	5.5 ± 1.7	3.6 ± 1.4	0.02
Second sppendicolith size wide (mm)		2.8 ± 0.9	3.1 ± 1	2.4 ± 0.8	0.36
Largest diameter of appendix on imaging modality (mm)		10.2 ± 1.4	10.2 ± 1.2	10.3 ± 1.5	0.64

Table 3 Comparison of recurrence vs non-recurrence after non-operative management, n (%)

Variable		Total (n = 797)	No recurrence (n = 640)	Recurrence (n = 157)	P value
Gender	Female	362 (45.4)	290 (45.4)	72 (45.6)	0.91
	Male	434 (54.5)	349 (54.6)	85 (53.8)
Age (years) mean ± SD		25.4 ± 14.4	25.5 ± 13.7	25.4 ± 14.6	0.96
Length of pain prior to admission (hours), mean ± SD		39.3 ± 61.5	38.8 ± 59.0	41 ± 70.6	0.70
Fever at home		79 (9.9)	68 (10.6)	11 (7.0)	0.17
Temperature at admission (Celsius), mean ± SD		36.7 ± 0.6	36.7 ± 0.6	36.7 ± 0.5	0.77
Heart rate on admission, mean ± SD		89.0 ± 19.5	88.2 ± 18.0	89.2 ± 19.8	0.59
White blood count (× 109/L), mean ± SD		11.4 ± 3.9	11.3 ± 3.9	11.8 ± 4.0	0.14
C-reactive protein (mg/dL), mean ± SD		3.3 ± 5.3	3.2 ± 5.3	3.5 ± 5.7	0.60
Ultrasound performed		462 (58.0)	379 (59.3)	83 (52.5)	0.12
Computed tomography performed		460 (57.7)	367 (57.4)	93 (59.0)	0.75
Appendicolith		68 (8.5)	50 (7.8)	18 (11.5)	0.08
Radiological findings	Largest appendix diameter (mm), mean ± SD	8.7 ± 2.4	8.6 ± 2.4	9.1 ± 2.6	0.03
	Free fluid on imaging	229 (28.7)	178 (27.9)	51 (32.3)	0.32
Length of stay, median (interquartile ranges) (day)		2.6 (2-3)	2.6 (2-3)	2.7 (2-3)	0.53