Feasibility, Safety and Utility of Endomicroscopy to Study the Intestines of Unsedated Infants at University of Virginia (UVa)
Phase: NA
Conditions: Healthy
Sponsor: Massachusetts General Hospital

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
Page 1 of 15 
Version: 02-03-2023 
 
PROTOCOL 
Background 
1. Provide the scientific background, rationale and relevance of this project.   
 
The Tearney Laboratory at Massachusetts General Hospital invents and translates new noninvasive, high-
resolution optical imaging modalities that enable disease diagnosis from living patients without excising tissues 
from the body. Led by Guillermo (Gary) Tearney, MD, PhD, the lab’s large multidisciplinary team invents, validates 
and translates novel devices that use light to conduct microscopy in living patients. Light is uniquely well suited 
for noninvasively interrogating the microscopic structure, molecular composition and biomechanical properties of 
biological tissues. The goal of the laboratory’s research is to improve understanding and diagnosis of disease by 
imaging the human body at the highest possible level of detail in vivo.  
 
The Tearney lab has a long-standing partnership with the Bill and Melinda Gates Foundation for harnessing the 
ability of Optical Coherence Tomography (OCT) technology to collect detailed information about the gut to obtain 
more information about diseases like Environmental Enteric Dysfunction EED, which are underserved. This study, 
funded by the Bill and Melinda Gates foundation seeks to demonstrate the safety and feasibility of using the Trans 
Nasal Endomicroscopy (TNE) and associated accessory tools to evaluate the intestines of unsedated infants. The 
goal of this trial is to demonstrate a safe and minimally invasive means for obtaining detailed information on 
infantile intestinal tissue that is needed for the development of effective environmental enteropathy (EE) 
dysfunction interventions.  
 
Briefly, this procedure will involve trans-nasal deployment of the device into the intestine of the infant subjects, 
through a procedure identical to clinical naso-gastric tube placement. Once the device is in place, then intestinal 
sampling will proceed through the device. Sampling may consist of either microbiome brushings or measurement 
of the electrical potential differences in the intestine, or both. Once the sampling is complete, the devices will be 
removed from the subject.  
Environmental Enteric Dysfunction (EED) 
Environmental Enteric Dysfunction (EED) is a poorly understood condition characterized by villous inflammation and 
loss and disruption of microscopic intestinal architecture, resulting in decreased intestinal permeability(1). EED is 
prevalent in regions of the world with inadequate sanitation and hygiene. Bacterial overgrowth and chronic exposure to 
fecal pathogens is hypothesized to cause inflammation and structural changes in the small bowel, which ultimately result in 
functional changes(2). As a result, EED is suspected to be the driving factor for carbohydrate malabsorption, 
malnourishment, poor growth and stunting, poor neurological development, oral vaccine failure and infection affecting 
25% of all children globally and causing over a million deaths each year(1–4) 
 
Growth faltering with the resulting poor neurocognitive development and stunting caused by EED in children is largely 
irreversible after 2 years of life(1). Progress towards understanding EED and developing effective interventions has been 
hampered by an inability to evaluate the intestinal mucosa of populations in impoverished regions of the world where 
this condition is endemic. Currently, the only means for directly evaluating the intestine is endoscopy with mucosal 
biopsy(1). Unfortunately, endoscopy is untenable for the study of EED because of the invasiveness of the method, 
limited resources and the high cost(4). As a result, there is a clear, unmet need for a less invasive tool that can be used 
in low- and middle-income countries (LMICs) to evaluate the intestine  

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
Page 3 of 15 
Version: 3-25-22 
AKUH Infant Imaging:   
The TNE device has been used to image 9 infants between the ages of 6 and 18 months at AKUH, Pakistan. 
 
 
 
 All infants tolerated the procedure well with no 
adverse events or complications. 
Trans Nasal Endomicroscopy [TNE] Catheter 
The Trans Nasal Endomicroscopy (TNE) catheter is comprised of a trans nasal introduction tube and an optical probe. 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
 
Page 4 of 15 
Version: 3-25-22 
 
 
 
 
  
 
Microbiome Brush 
There have been theories proposed that increased microorganism load and/or dysbiosis or an imbalance in the 
composition of gut microorganisms in the intestine may be important in the establishment and/or maintenance of EED. 
Development of EED has also been associated closely with the transition of infants from breast feeding to weaning foods. 
While there is definite association of increased/abnormal microbial load with EED, there have been few papers published 
which examine this association in detail (10).  
 
Obtaining biopsy samples from the gut remains challenging and requires either an endoscopy or a colonoscopy depending 
on the region of the gut targeted (11). Duodenal aspiration during esophagogastroduodenoscopy (EGD) is currently used 
as gold standard for standard of care to collect targeted microbiome. However, the microbiome yield from this procedure 
is low and the procedure requires an EGD, which is a fairly invasive procedure, and carries all of the risks associated with 
an EGD.  Moreover, EGD is expensive and not easily practicable in LMIC’s.(12,13)   
 
The Tearney Lab (MGH) has developed a brush that can collect microbiota samples from the small intestine, in the 
unsedated subject in a non-invasive manner. 
 
 
 
 
 
  
 
 
 
 
 
Intestinal Potential Difference (IPD) Probe:  
Increased gastrointestinal (GI) permeability is associated with several GI conditions that affect millions of people 
worldwide. Leaky gut is a key feature in celiac disease, Crohn’s disease, inflammatory bowel disease (IBD), and 
environmental enteropathy. It has also been associated with systemic diseases including type 1 diabetes, autoimmune 
hepatitis, and systemic lupus erythematosus (SLE)(14,15). An alternative approach for measuring mucosal permeability is 
through measuring the voltage across the intestinal wall (Intestinal potential difference; IPD) that changes with intestinal 
permeability (16). The Tearney lab has developed an IPD measuring device (IPD probe) that can be deployed trans-nasally 
through the TNIT to measure the intestinal potential difference in real time at selected locations of the gut. 
 
 The probe has been used to 
measure IPD in adult subjects at MGH without any adverse events or complications.  
 
OCT Compact Imaging System 
The TNE catheter is designed to be compatible with an MGH OCT Compact Imaging System (CIS). 
 
  
 
 

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
 
Page 8 of 15 
Version: 3-25-22 
 
 
 
7(c).  When combining the data from multiple sites to assess the study results, is the effect of the treatment to be 
tested (or the association to be tested) assumed to be the same across sites or vary among sites? What is the 
modelling strategy?  
 
7(d). Is there a common protocol used in all sites?  
 
IF NO, how will differences among sites, such as those related to the implementation, inclusion 
criteria, patient characteristics, or other sites characteristics, be considered to assess the study 
results?  
 
Study Procedures-Biomedical Research 
 
1. What will be done in this protocol?    
Overview  
 
Briefly, the procedure will be conducted as follows: 
1. The TNIT (with optical probe inside) is inserted, confirmation of placement within the esophagus is confirmed via 
OCT image and the TNIT is advanced down the esophagus 
2. Once in the gut, the balloon(s) may be inflated.  
3. Once at a location of interest, the optical probe is removed while the TNIT stays in position. 
4. The appropriate accessory device can then be inserted for microbiome brushing/aspiration, and/or IPD 
measurement.  
The infant may receive any or all of the evaluation methods that are detailed in this protocol - intestinal potential 
difference measurement (IPD) and microbiome sample collection. When both evaluation methods are performed, IPD 
will be completed first.  
The research procedure can be stopped at any time. If at any point the family, clinical staff, study staff, or physician feels 
that the subject will not be able to tolerate the TNIT procedure, the procedure will be terminated and the device 
removed from the subject. The procedure is described in detail below.  
Preprocedure  
The PI and other pediatric GI physicians will identify potential subjects aged 6-48 months and contact the CRC with the 
potential patient’s contact information and/or ask the parents of the potential subjects if they’d like a CRC to come 
speak to them in the clinic.  The CRC will verify possible enrollment of this infant with the Pediatric Gastroenterologist 
and contact the family of the patient to gauge their interest.  The CRC will offer trial information to the infant’s family 
(ie: informed consent). The CRC will then inform the UVA and MGH teams about the interested family. The  study team 
will coordinate the timing and logistics of the research and clinical procedures.  Subjects will need to follow this study’s 
guidelines for fasting. Children over 12 months will be asked to fast after midnight the day of the procedure. Formula 
fed infants under 12 months may be given formula up to 6 hours prior to the procedure. Breastfed infants under 12 
months may feed up to 4 hours before the procedure. 

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
 
Page 10 of 15 
Version: 3-25-22 
 
 
 
Once the TNE is inside the GI tract, as confirmed by the OCT images, the balloon(s) may be inflated with air or a biocompatible 
liquid (such as Galinstan, sugar water, saline) to add weight (Fig:3b) to facilitate its motion towards the pylorus and into the 
duodenum (Fig: 3c). Once the balloons are inflated, the team may wait for the device to pass into the duodenum/region of 
interest by peristalsis. The operator may assist in the placement of the TNE device by gently maneuvering the device. The study 
team may have the subjects change their body position or sip water during the procedure to facilitate placement or movement 
of the device and improve imaging, as required. During the device transit from insertion to duodenum, images will be 
periodically acquired to determine and confirm the TNE’s position in the GI tract.     
It is estimated that the catheter will enter the duodenum in anywhere from a few minutes to up to 1 hour from the time 
it is introduced, based on the range of previous gastric emptying times demonstrated in TNE studies in infants and children 
at AKUH. The entire research procedure (insertion, IPD, brush, removal) will not exceed 90 minutes. If the device does not 
pass into the desired region at the end of the IRB allotted procedure time, the device will be removed from the subject.  
Once the catheter has passed through the pyloric sphincter, images of the duodenum and potentially jejunum will be 
continuously acquired as it is propelled down the small intestine via peristalsis. The distance from the nose will be 
measured via marks on the outer sheath of the tether. OCT images of the small intestine will be obtained as the catheter 
descends the small intestine via peristalsis. During the procedure, air, water, and/or saline may be used to flush the lumen 
of the TNIT to allow for easier insertion of the probes and improve image quality. This will be done at the discretion of the 
pediatric gastroenterologist performing the procedure. The optical probe may be removed and reintroduced or replaced 
while the TNIT is in situ inside the subject. Once the TNIT has been placed into the region of interest, as confirmed by OCT 
images, any or all of the following procedures may be performed while the TNIT is in situ. When both evaluation methods 
are performed, IPD will be completed first.  
a. Microbiome brushings and aspiration:  
Once the target site has been identified, the optical probe will be removed while the TNIT remains in place. The operator 
will then introduce the microbiome brush through the accessory port of the TNIT until the tip of the microbiome brush is 
in contact with the mucosa, 
 The brush will then be manipulated back and forth over 
the mucosa, 
, a couple of times and then will be removed completely out of the 
working channel of the TNIT tube. Additionally, a small amount of suction throughout the duration of brushing may also 
be applied via the outer sheath of the brush using a syringe in order to collect a small amount of aspirate for processing.  
A small tube may also be threaded down the TNIT before or after the brush to collect aspirations. Similar to the brush, 
suction will be applied for no more than 30 seconds. 
 
 
 
In order to improve tissue contact, either while imaging or collecting samples, we may apply a small amount of suction 
 
 
This specimen collection procedure may be repeated up to a total of 5 times, with a new brush, tube, and syringe each 
time to ensure adequate specimen collection. We may collect up to a total of 5 brush samples and/or 5 aspirate samples. 
The tip of the TNIT may be moved slightly (by approximately a couple of centimeters) to avoid brushing/aspirating the 
same region multiple times. This will improve the quality of the specimen and avoid excessive mucosal abrasion. Each 
brushing will not last longer than 30 seconds.  
If Microbiome and aspirate samples are collected, then, the tip of the brush and any aspirate collected then, the tip of 
the brush and any aspirate collected, will be stored in appropriately labelled and sealed container with DNA/RNA agent. 

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
 
Page 11 of 15 
Version: 3-25-22 
 
 
 
The samples will be anonymized and sent to a Mass General Brigham (MGB) approved vendor for processing, as per 
institutional policies for transport of biological/other research materials for microbiological processing including culture 
and genomic sequencing.  
b. IPD Measurement  
Once a preferable location for IPD measurements is confirmed via OCT imaging, the optical probe will be removed from 
the TNIT. 
 
 
   
To create a reference potential for IPD measurements, the study team will apply a small skin patch taped to abraded skin. 
The site chosen for the skin patch will be wiped with an alcohol swab. Next, the most superficial epidermal layer will be 
removed using a dermabrasion device (similar to a nail file), or by rubbing dry, unwoven gauze on the site. Once the dermal 
layer has been removed, the skin patch or sponge will be applied (23).  
 
 
 
 
 
 
 
 
 
  
When IPD and skin probe have been calibrated, te
 
 The operator will then introduce the IPD probe 
 
  
 
 
  
 
 
 
 
 
  
During the IPD measuring period, the IPD probe may be moved within the TNIT or the whole TNIT itself may be moved to 
find different tissue contact sites within the GI tract for more data points. Once the IPD measurements are complete, the 
IPD probe will be removed.  
The same or a different imaging probe may then be reintroduced to reimage the gut. The imaging probe(s) may also be 
introduced at any point between the 2 gut evaluation procedures to reimage the gut as well. Once the transnasal 
procedure is complete, the balloon (s) will be deflated, and the introduction tube will be removed. The entire procedure, 

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
 
Page 14 of 15 
Version: 3-25-22 
 
 
 
Microbiome Brushings Attempted 
$400 
TNE Device Inserted 
OCT Imaging Performed AND 
IPD Measurements Attempted OR Microbiome Brushings Attempted
$200  
Subject consents for study but the team is unable to successfully 
insert the TNE, for any reason 
 
 
2. If this protocol involves study treatment, explain how a subject will be transitioned from study treatment when 
they have completed their participation in the study.     N/A 
 
 
Subject Compliance with Study Procedures 
1. Explain how the study team will monitor the subject for compliance with the study procedures. (e.g. study team 
will administer study drug/ study interventions, study drug inventory of dispensed and returned drug, diary etc.) 
 
The procedure is performed on the consented subject. Subject compliance is not a factor.  
 
If, at any point, the physician/endoscopist or study staff feels that the subject will not be able to tolerate the 
procedure, the study procedure will be terminated. 
 
2.  Describe criteria for when a subject is considered to be non-compliant with study procedures.   
(e.g. subject returns more than 20% of the study drug, subject misses 20% of study visits) 
 
N/A 
Bibliography 
1. Jones VR, Rivera EM, Walton RE. Comparison of carbon dioxide versus refrigerant spray to determine pulpal 
responsiveness. J Endod. 2002 Jul;28(7):531–3.  
2. Bango-Álvarez A, Ariza-Prota M, Torres-Rivas H, Fernández-Fernández L, Prieto A, Sánchez I, et al. Transbronchial 
cryobiopsy in interstitial lung disease: experience in 106 cases – how to do it. ERJ Open Res [Internet]. 2017 Mar 
22;3(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5360885/ 
3. Policy Manager - MCN Healthcare [Internet]. [cited 2017 Jun 15]. Available from: 
https://hospitalpolicies.ellucid.com/documents/view/1029 
4. Evans N, Farrow LJ, Harding A, Stewart JS. New techniques for speeding small intestinal biopsy. Gut. 
1970 Jan;11(1):88–9. 
5. Shiotani A, Opekun AR, Graham DY. Visualization of the small intestine using capsule endoscopy in healthy 
subjects. Dig Dis Sci. 2007 Apr;52(4):1019–25. 
 
6. Levine DS1, Blount PL, Rudolph RE, Reid BJ. Safety of a systematic endoscopic biopsy     protocol in patients with 
Barrett's esophagus. Am J Gastroenterol. 2000 May;95(5):1152-7. 

HSR210428: Feasibility, safety, and utility of endomicroscopy to study the intestines of unsedated infants 
 
Page 15 of 15 
Version: 3-25-22 
 
 
 
7. Babiak A, Hetzel J, Krishna G, Fritz P, Moeller P, Balli T, et al. Transbronchial cryobiopsy: a new tool for lung biopsies. 
Respir Int Rev Thorac Dis. 2009;78(2):203–8.  
8. Merchea A, Cullinane DC, Sawyer MD, Iqbal CW, Baron TH, Wigle D, et al. Esophagogastroduodenoscopy-associated 
gastrointestinal perforations: A single-center experience. Surgery. 2010 Oct 1;148(4):876–82.  
9. Chu KM, Yuen ST, Wong WM, Wong KW, Lai KC, Hu WHC, et al. A Prospective Comparison of Performance of Biopsy 
Forceps Used in Single Passage with Multiple Bites During Upper Endoscopy. Endoscopy. 2003 Apr;35(04):338–42.  
10. Geratherm Medical A. Galinstan Safety Datasheet [Internet]. 2011 [cited 2017 May 2]. Available from: 
http://www.rgmd.com/msds/msds.pdf 
 
11. Greene, H. L., et al. “Biopsy of the Small Intestine with the Crosby-Kugler Capsule.” The American Journal of 
Digestive Diseases, vol. 19, no. 3, Mar. 1974, pp. 189–198. 
 
12. Ishida, Y. et al, A case of acute pancreatitis following endoscopic biopsy of the ampulla of vater, Kurume Medical 
Journal 60, 67-70, 2013 
 
13. Michopoulus, S. et al, Acute pancreatitis following endoscopic ampullary biopsies without attempted cannulation of 
the ampulla of vater, Clin. Endosc. 49, 575-578, 2016. 
 
14. Jeong W. J., Acute pancreatitis after endoscopic biopsy of the minor duodenal papilla in an individual with pancreas 
divisum, Endoscopy 48(Supp 1), E238- E239, 2016.