Establishing an Evidence Based Technique for Mucosal Landmarks’ measurement, Ethnic Disparity in Segment Length and Biopsy Technique In Barrett’s Oesophagus and Gastrointestinal Endoscopy

Abstract

Barrett’s Oesophagus (BO) is a metaplastic condition affecting 1-2% of the UK population with propensity to evolve into dysplasia and Adenocarcinoma of Oesophagus (ACO). Early detection of dysplasia by tissue biopsies is dependent on regular surveillance which is reliant on measuring the correct length of BO and microscopic examination of biopsy specimens. The length of BO is dependent on the position of gastroesophageal junction (GOJ) from incisors, which could be measured in both intubation and extubation of endoscope. However, it is not clear if there is any difference in the position when measured during both phases. Furthermore, it is not clear if taking biopsies in a certain way i.e., single (SBB), or double bite (DBB) affects the histological quality of specimens. Moreover, BO is a global disease and in racial terms there are clinical, demographic, and prognostic differences between White British (WBP) and South Asian populations (SAP). One such specific difference is the progression of BO to ACO. It is noteworthy that segment length strongly correlates with ACO progression, yet literature lacks clarity on segment length differences between the populations.

MD Aim
To assess the quality of histological specimens collected through SBB and DBB, comparing size, orientation, crush artefacts and overall effect on histological diagnosis. It is also aimed to identify oesophageal landmarks in relation to BO in both phases of endoscopy as well as to chart and compare the length of BO segment SAP and WBP using statistical approaches. To achieve these aims, the MD was divided into three studies.

Methods
In study I Patients (>18 years) were assigned randomly to SBB or DBB groups and biopsies were collected prospectively. In addition, patients were also prospectively included for the assessment of oesophageal landmarks (Study II) and finally, segments length of the BO was analysed based on ethnicity, and difference was compared statistically (Study III).

Results:
Study I (n=135, 54% males), aged ranged from 20 to 91 (M 54± 15.8) and 144 procedures were performed. The time taken to collect sets of SBB (n=72) was 74 to 286 seconds (M = 180, SD±55.9) and DBB (n=72) ranged from 39 to 149 seconds (M = 88.5, SD±28.5, IQR = 71-111) with significant difference, suggesting SB takes longer time (P<0.001, r = -.009.). No significant difference was seen when analysed as per size, orientation, crush artefacts, tissue loss and overall effect on diagnosis (p>0.05).

Study II I (n=259, 46.7% males) age for the population ranged from 18 to 95 years (M = 58.9, SD±17.2). GOJ on insertion was located distal in comparison to Intubation (M =40 ±2.8, n =259, IQR=38-42) and extubation (Mdn = 40, M =40 ±2.9, n =258, IQR=38-42), z = -3.9, p<.01). The length of HH was compared Intubation (Mdn = 1, M =1.44 ±.92, n =137, IQR=1-2) and extubation (Mdn = 1, M =1.48 ±.87, n =175, IQR=1-2), z = -2.0 p=.03) and found shorter in intubation.

Study III: 249 cases of BO were identified in both sets of data. Landmarks and biopsy data and age ranged from 18 to 95 years (M = 58.2, SD±17.3, IQR = 25-75). SAP has short MBO as compared to WBP, and this was true for SAP males on subgroup analysis. To assess for significance, both segments were compared and significant difference was observed in both MBO (WBP (Median = 2, n = 221, IQR=2-3) and SAP (Median = 2, n = 28, IQR=1-2), U = 2247, z = -2.4, p =0.01)) and CBO (WBP (Median = 1, n = 219, IQR=1-2) and SAP (Median = 1, n = 28, IQR=1-1), U = 2407, z = -2.0, p <0.01))

Discussion and conclusion:
We show here that there is no significant difference between SBB and DBB biopsies in terms of histological quality however when considering time, SB takes significantly longer to complete number of biopsies per cycle. Therefore, we suggest that when taking large number of biopsies DBB technique should be used. In relation to landmarks, there is proximal displacement of GOJ during the extubation and this changes the number of diagnosed HH, hence it is suggested that for the purpose of standardisation all measurements should be taken in the extubation. This research further suggests that there is a significant difference between WBP and SAP in relation to BO segment length nevertheless comprehensive research to assess BO in different ethnicities in holistic fashion is needed. Such a project may form basis for new guidelines where ethnicity may also be a relevant factor in surveillance of BO.