A novel digital rectoscope for the triage of lower gastrointestinal symptoms in primary care: a prospective multicentre feasibility study

James Lewis; Alan Askari; Arihant Mehta; Yasmin Razak; Prash Patel; Ravi Misra; Henry Tilney; Tanveer Ahmed; Mooyad Ahmed; Adnan Syeed; John Camilleri-Brennan; Ralph John Nicholls; James Macalister Kinross

doi:10.3399/BJGPO.2022.0036

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Figure 1. The LumenEye system
A - The LumenEye® device without its disposable plastic sleeve. The disposable plastic sleeve is graduated to 15cm and includes a 3mm working channel to accommodate endoscopic instruments. The handle contains an air insufflator bellows (blue) allowing single handed use.
B - The LumenEye® dock with the CHiP software. A typical view during a live specialist ‘proctoring’ examination with webcam displays of both the examining clinician and proctor projected over the view from the rectoscope.
C - The LumenEye® in a typical deployment in a GP practice with remote secondary care review via CHiP.
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Figure 2. Flow diagram demonstrating the outcome of patients in the trial. Follow-up data are available for 110 of 114 patients. Three patients were unable to tolerate the procedure and one patient was lost to follow-up despite numerous efforts to contact him. CTVC = computed tomography virtual colonoscopy.

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Table 1. Demographics and presenting symptoms of participants (N = 110)

Category	Variable	n	%
Sex	Female	46	41.8
Sex	Male	64	58.2
Diagnosis of IBD	Yes	4	3.6
Diagnosis of IBD	No	106	96.4
Rectal bleeding	Yes	72	65.5
Rectal bleeding	No	38	34.5
Change in bowel habit	Yes	59	53.6
Change in bowel habit	No	51	46.4
Mucus discharge	Yes	19	17.3
Mucus discharge	No	91	82.7
Proctalgia	Yes	30	27.3
Proctalgia	No	80	72.7
Pruritus ani	Yes	10	9.1
Pruritus ani	No	100	90.9
Haemorrhoids	Yes	25	22.7
Haemorrhoids	No	85	77.3
Mass or prolapse	Yes	7	6.4
Mass or prolapse	No	103	93.6
Family history of bowel cancer	Yes	13	11.8
Family history of bowel cancer	No	97	88.2

IBD = irritable bowel disease.

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Table 2. Significant abnormality, defined as polyps, inflammation, or cancer, identified by the primary care physician at the time of the LumenEye examination (N = 110 patients), compared with the findings of follow-up investigation or expert review, and sensitivity, specificity, positive predictive value, and negative predictive value of the LumenEye in the identification of pathology compared with subsequent colonoscopy, flexible sigmoidoscopy, or CTVC findings

Pathology recorded, n		Cancer	Polyp	Inflammation
Identified in primary care		2	6	16
Identified after formal investigation or expert review of recorded images		2	11	15
All patients	Any pathology	Cancer	Polyp	Inflammation
TP, n	9	2	5	4
TN, n	32	46	45	41
FP, n	4	0	1	3
FN, n	1	0	1	0
Sensitivity = TP/TP + FN, %	90.0	100	83.3	100
Specificity = TN/TN + FP, %	88.9	100	97.8	93.2
PPV = TP/(TP + FP), %	69.2	100	83.3	57.1
NPV = TN/(TN + FN), %	97.0	100	97.8	100
Patients presenting with rectal bleeding ( n = 28)	Any pathology	Cancer	Polyp	Inflammation
TP, n	8	2	3	4
TN, n	15	25	24	21
FP, n	4	0	1	3
FN, n	1	0	1	0
Sensitivity = TP/TP + FN, %	88.9	100	75.0	100
Specificity = TN/TN + FP, %	78.9	100	96.0	87.5
PPV = TP/TP + FP, %	66.7	100	75.0	57.1
NPV = TN/(TN + FN), %	93.8	100	96.0	100

CTVC = computed tomography virtual colonoscopy. FN = false negative. FP = false positive. NPV = negative predictive value. PPV = positive predictive value. TN = true negative. TP = true positive.

Supplementary Data

K_10.3399BJGPO.2022.0036_supp.pdf -
Supplementary material is not copyedited or typeset, and is published as supplied by the author(s). The author(s) retain(s) responsibility for its accuracy.