Biodegradable stent or balloon dilatation for benign oesophageal stricture: Pilot randomised controlled trial

Table 1 Baseline characteristics

	Endoscopic balloon dilatation				Biodegradable Stent				Mean difference	P value1
	mean ± SD	Min	Max	n	mean ± SD	Min	Max	n
Age (yr)	63.8 ± 9.1	54	74	6	62.7 ± 12.5	40	78	9	-1.1	1.000
Age at diagnosis (yr)	61.9 ± 10.5	49	74	6	59.6 ± 13.9	36	77	9	-2.3	0.955
Gender male:female	[5:1]				[8:1]					1.000
Weight (kg)	61.0 ± 10.0	47	71	6	71.7 ± 29.5	45	141	9	10.7	0.864
Height (cm)	168 ± 14	143	181	6	170 ± 10	156	188	9	2.0	1.000
Smoking (never:previously:currently)	(1:2:3)				(4:2:3)					0.660
Time since quitting smoking (yr)	4.3 ± 5.7	0.3	8.3	2	1.8 ± 1.5	0.7	2.8	2	-2.5	1.000
n cigarettes/d (if current)	18.3 ± 2.9	15	20	3	18.3 ± 2.9	15	20	3	0.0	1.000
Current drinker (no:yes)	(3:3)				(4:5)					1.000
Alcohol units/w (if current)	22.3 ± 17.2	10	42	3	15.8 ± 11.0	1	29	5	-6.5	0.786
Number of dilatations (ever)	3.2 ± 2.3	1	6	6	6.2 ± 5.1	1	16	9	3.0	0.224
Number of dilatations (in last 12 m)	1.2 ± 0.8	0	2	6	1.9 ± 1.8	0	5	9	0.7	0.607
Stricture length (cm)2	4.0 ± 1.9	2	6	5	3.5 ± 1.3	2	5	8	-0.5	0.524
Luminal diameter (mm)2	12.3 ± 4.9	9	18	3	23.2 ± 31.8	6	80	5	10.9	1.000
Extent of stricture (from)2	31.0 ± 3.7	25	36	6	34.6 ± 2.5	30	38	8	3.6	0.081
Extent of stricture (to)2	35.8 ± 2.9	32	40	5	38.0 ± 1.9	34	40	8	2.2	0.171
Dysphagia score (baseline)	1.83 ± 0.98	1	3	6	2.00 ± 1.22	0	4	9	0.17	0.776
EQ5D score (baseline)	0.69 ± 0.31	0.26	1	6	0.69 ± 0.24	0.36	1	9	0.00	0.955
EQVAS score (baseline)	73 ± 21	35	95	6	57 ± 22	30	95	9	-16	0.145
Intervention balloon dilatation (mm)	14.5 ± 1.2	12	15	6
Intervention stent length (mm)					96.1 ± 31.5	60	135	9
Intervention fluoroscopy (no:yes)	(4:2)				(0:9)					0.011

¹Continuous measures: independent samples Mann-Whitney U Test (exact significance); count data: Fisher’s exact test;

²At endoscopy prior to intervention.

Table 2 Baseline comorbidities n (%)

	Endoscopic balloon dilatation (n = 6)	Biodegradable stent (n = 9)	P value1
Alcohol dependence	3 (50)	5 (56)	1.000
Alcohol overdose	0 (0)	1 (11)	1.000
Appendicitis	1 (17)	1 (11)	1.000
Barrett's oesophagus	0 (0)	1 (11)	1.000
Biliary colic	0 (0)	1 (11)	1.000
Diarrhoea	0 (0)	1 (11)	1.000
Diverticular disease	2 (33)	1 (11)	0.525
Duodenitis	0 (0)	1 (11)	1.000
Reflux disease/oesophagitis	4 (67)	3 (33)	0.315
Haematemesis	1 (17)	0 (0)	0.400
Helicobacter pylori	1 (17)	0 (0)	0.400
Hiatus hernia	2 (33)	3 (33)	1.000
Inguinal hernia	0 (0)	1 (11)	1.000
Ischaemic sigmoid colon stricture	0 (0)	1 (11)	1.000
Oesophageal perforation	0 (0)	1 (11)	1.000
Perforated duodenal ulcer	1 (17)	0 (0)	0.400
Reversal of ileostomy	0 (0)	1 (11)	1.000
Wernicke's Encephalopathy	0 (0)	1 (11)	1.000

¹Count data: Fisher’s exact test.

Table 3 Outcomes

	Endoscopic balloon dilatation				Biodegradable stent				Mean difference	95%CI	P value1	P value2
	mean ± SD	Min	Max	n	mean ± SD	Min	Max	n
Primary endpoint
Dysphagia Score (Average 3 and 6 m)	0.00 ± 0.00	0.00	0.00	5	1.17 ± 0.90	0.00	3.00	9	1.17	0.63-1.78	0.029	0.004
Secondary endpoints
Dysphagia Score (AUC 0-6 m)	0.25 ± 0.13	0.13	0.38	5	0.71 ± 0.46	0.25	1.50	9	0.46	0.16-0.78	0.045	0.042
Dysphagia Score (Average 3, 6 and 12 m)	0.00 ± 0.00	0.00	0.00	4	1.21 ± 1.08	0.00	3.33	8	1.21	0.56-2.00	0.052	0.016
Dysphagia Score (AUC 0-12 m)	0.22 ± 0.12	0.13	0.38	4	1.28 ± 1.01	0.25	3.25	8	1.06	0.43-1.81	0.066	0.008
QALY (EQ5D 0-6 m)	0.34 ± 0.16	0.18	0.50	5	0.35 ± 0.10	0.22	0.48	9	0.00	-0.15-0.15	0.995	1.000
QALY (EQ5D 0-12 m)	0.64 ± 0.42	0.14	1.00	4	0.66 ± 0.23	0.38	0.98	7	0.01	-0.38-0.47	0.949	0.927
QALY (EQVAS 0-6 m)	0.36 ± 0.09	0.24	0.46	5	0.32 ± 0.09	0.22	0.45	9	-0.04	-0.14-0.05	0.385	0.364
QALY (EQVAS 0-12 m)	0.73 ± 0.20	0.49	0.92	4	0.67 ± 0.21	0.42	0.94	7	-0.07	-0.29-0.18	0.602	0.648
Number of additional procedures (0-6 m)	0.80 ± 1.10	0.00	2.00	5	3.22 ± 2.91	0.00	8.00	9	2.42		0.127
Number of endoscopic procedures (0-6 m)	0.00 ± 0.00	0.00	0.00	5	0.33 ± 0.71	0.00	2.00	9	0.33		0.505
Number of balloon procedures (0-6 m)	0.40 ± 0.55	0.00	1.00	5	1.22 ± 1.39	0.00	4.00	9	0.82		0.275
Number of endoscopies (0-6 m)	0.40 ± 0.55	0.00	1.00	5	1.67 ± 1.50	0.00	4.00	9	1.27		0.107
Number of additional procedures (0-12 m)	1.20 ± 0.84	0.00	2.00	5	4.13 ± 3.87	0.00	10.0	8	2.93		0.165
Number of endoscopic procedures (0-12 m)	0.00 ± 0.00	0.00	0.00	5	0.63 ± 1.06	0.00	3.00	8	0.63		0.417
Number of balloon procedures (0-12 m)	0.40 ± 0.55	0.00	1.00	5	1.38 ± 1.77	0.00	5.00	8	0.98		0.385
Number of endoscopies (0-12 m)	0.80 ± 0.45	0.00	1.00	5	2.13 ± 1.89	0.00	5.00	8	1.33		0.203

¹Continuous measures: bootstrap estimation, 10000 replications; count data: Fisher’s exact test for trend;

²Continuous measures: independent samples Mann-Whitney U Test (exact significance).

Table 4 Sensitivity analyses

	Mean difference	95%CI	P value1	P value2
Repeated measures ANOVA
Dysphagia score (3, 6 m)	1.17	(0.21-2.13)	0.022
Dysphagia score (3, 6, 12 m)	1.10	(-0.11-2.31)	0.070
Repeated measures ANOVA (imputed)
Dysphagia score (3, 6 m)	1.13	(-0.05-2.32)	0.058
Dysphagia score (3, 6, 12 m)	1.01	(-0.30-2.32)	0.113
Dysphagia score (imputed)
Dysphagia score (Average 3 and 6 m)	0.94	(0.18-1.70)	0.015	0.021
Dysphagia score (Average 3, 6 and 12 m)	0.93	(0.06-1.79)	0.036	0.025
Dysphagia score (AUC 0-6 m)	0.38	(0.03-0.73)	0.032	0.075
Dysphagia score (AUC 0-12 m)	0.83	(0.07-1.58)	0.033	0.024

¹Imputed values (pooled imputed value of Z scores);

²Independent samples Mann-Whitney U Test (pooled asymptotic value).

Table 5 Number of patients with adverse events

Adverse event1	Endoscopic balloon dilatation (n = 9)		Biodegradable stent (n = 6)
	Unrelated	Related	Unrelated	Related
Abdominal pain			2	1 (1)
Acute exacerbation of chronic bronchitis		1
Acute pancreatitis				1
Alcohol withdrawal syndrome			1 (1)
Atrial fibrillation			1
Chronic obstructive pulmonary disease			1
Constipation			1
Cough				1
Diverticulosis				1
Dry mouth				1
Dysphagia	1	1	6 (1)	1 (1)
Dyspnoea	1
Eye infection - Left eye			1
Foul taste in mouth			1
Fractured rib			1 (1)
Gastro-oesophageal reflux			1
Haematemesis			2	1
Hiccups			1
Hyperglycemia			1 (1)	1
Hypertension	1
Hypotension			1 (1)
Insomnia				1
Oesophageal candidiasis				1
Oesophageal spasm	1
Pain			2 (1)	1
Positive Faecal occult blood test				1
Pruritus - Lower legs (right and left)			1 (1)
Retrosternal pain			1
Vitamin B deficiency			1
Vomiting			1

¹Related adverse events assessed as possibly, probably or definitely related; figures in brackets are events rated as severe.

Table 6 Number of patients receiving concomitant medication

	Endoscopic balloon dilatation (n = 9)	Biodegradable stent (n = 6)
Bowel management
Loperamide	1	0
Constipation
Laxative	1	2
Haematemesis
Metoclopramide	0	1
Heartburn
Alginate	0	1
Nausea/vomiting	1	4
Cyclizine	0	3
Domperidone	0	2
Metoclopramide	1	4
Nutritional deficit
Nutritional Supplement	1	4
Oesophageal candidiasis
Antifungal	0	1
Symptoms of BOS/reflux disease	6	9
Proton pump inhibitor	5	9
H2-receptor antagonist	1	2
Sucralfate	0	1