Becky McCall
October 16, 2023
COPENHAGEN, Denmark — A real-time, blood-sensing capsule (PillSense, EnteraSense Ltd) that detects upper gastrointestinal bleeding (UGIB) is safe and effective for patients before undergoing upper endoscopy, according to results from the first US open-label, single-arm comparative clinical trial of a novel bleeding sensor for patients with suspected UGIB. It is also the largest such trial.
This tool is rapidly deployed, safe to use, and easy to interpret, study researchers say. In under 7 minutes, the capsule correctly detected the presence of blood in 26 of 28 patients and its absence in 87 of 96 patients, as confirmed afterward by esophagogastroduodenoscopy (EGD).
“The use of the PillSense system will positively impact patient outcomes by providing early diagnosis, triaging, and directing care for UGIB,” said Karl Akiki, MD, study lead, who is in the Division of Gastroenterology and Hepatology at the Mayo Clinic, Rochester, Minnesota. He presented the results were here at the United European Gastroenterology (UEG) Week 2023.
“Due to its ability to rapidly diagnose UGIB, it helps us, as doctors, expedite accurate clinical decision-makingwhile also optimizing services to ensure the maximum number of patients obtain the best outcome,” he told Medscape Medical News.
“There are some preendoscopic assessment scores, like the Rockell or the Glasgow-Blatchford score, but they have limited clinical utility in predicting and confirming bleeding in suspected patients,” explained Akiki. He highlighted the need for a novel device that is rapid, accurate, and safe to use. He also pointed out that despite being the gold standard for diagnosis, EGD remains challenging in terms of time, personnel, and resources.
“The results of our study show the PillSense is a good diagnostic tool that will aid triage,” he said. He noted that PillSense and EGD supplement each other in patient care.
“It’s not a device to replace the EGD itself,” he explained, but given the results from the capsule, it will act “as a kind of a bridge that helps us to determine which patients should undergo EGD.”
Optical Sensing Technology
The researchers aimed to assess the safety and efficacy of the PillSense system for patients with suspected UGIB. They enrolled 131 patients (mean age, 62 years), 60% of whom were men. The most common presenting symptoms for UGIB were melena (52%), anemia (41%), and hematemesis (15%). Five participants withdrew consent before capsule ingestion, and for two patients, primary endpoint data were missing. This left an intent-to-treat population of 124 patients; 110 completed the study.
Patients were asked to swallow the capsule and to lay on their left side. The PillSense is based on optical sensing technology that uses an optical signature of blood in the gut. The device differentiates blood from any other liquids that may be present. After 5–7 minutes, the device gathers and transmits data wirelessly to an external, handheld receiver that processes binary data and indicates either “blood detected” or “noblood detected” in the upper GI tract, explained Akiki.
Following the capsule reading, patients underwent EGD within 4 hours. This enabled the researchers to compare data between the two modalities. Follow-up visits were conducted on days 7, 14, and 21 to ensure the capsule had passed from the body. Endoscopists were blinded to the capsule result when reading the EGD.
Primary endpoints were the sensitivity and specificity of the device; secondary endpoints were positive predictive value, negative predictive value, successful passage of the capsule, and safety.
Rapid and Accurate
The researchers determined the efficiency of the capsule in correctly detecting a UGIB. The capsule’s positive and negative predictive values were 74.3% and 97.8%, respectively.
“We achieved a sensitivity around of 93% (92.9%; P = 0.024) with the PillSense capsule and a specificity of 91% (90.6%; P < .001]), which were pretty good. We also detected a range from minimal bleeding, so, speckles of blood to large amounts of active bleeding covering the entire stomach,” reported Akiki.
There were no differences in terms of patient demographics, laboratory results, or concomitant use of medications. PillSense recording time was a mean of 6.71 minutes, the time from capsule ingestion to EGD was a mean of 55 minutes, and the time to capsule passage through the GI tract was 3.6 days. Most bleeds were found to be in the stomach (18/30; 60%), followed by the duodenum (5/30; 16.6%).
Various capsules for detecting UGIB are under development or are already available, but unlike some of the others, “[the PillSense] is not a video capsule,” said Akiki. “It does not take pictures at all but is more of a photo sensor capsule that measures the absorption of wavelengths.”
This explains why the PillSense was so rapid ― results were available in around 7 minutes and did not require an interpretation by a physician, he explained. “Trained nonphysician personnel can use it, and this is where it differs from other devices, such as video capsules that require someone highly trained to interpret the output. It’s an easy procedure and process to follow.”
The PillSense has value in improving workflow, Akiki said. “If we had someone come in during the night with a suspected upper GI bleed, we could give them the capsule, determine if they need an EGD or not, and potentially postpone it to a time ― say, the morning, when more resources are available ― freeing up the night for emergency cases. It helps me, as a physician, to determine which patients to send to EGD immediately or which to wait.”
He added that more studies are needed in the postmarketing phase to understand optimal use of the device and to define the exact clinical pathway for optimal implementation.
The device was approved by the US Food and Drug Administration in February of this year. Akiki noted that there were no adverse events or deaths related to the capsule.
Co-moderator, Philip Chiu, MD, gastroenterologist from the Chinese University of Hong Kong, China, said, “It’s an interesting study because sometimes we can’t differentiate by clinical symptoms as to whether this is a problem of continuous bleeding or something else. The capsule might help us in our decision-making in this respect and help determine whether we should scope the patients or just manage conservatively.”
Akiki and Chiu have disclosed no relevant financial relationships.
United European Gastroenterology (UEG) Week 2023: Abstract OP087. Presented October 16, 2023
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