Capsule endoscopy:Do we still need it after 24 years of clinical use?

In this letter,we comment on a recent article published in the World Journal of Gastroenterology by Xiao et al,where the authors aimed to use a deep learning model to automatically detect gastrointestinal lesions during capsule endoscopy(CE).CE was first presented in 2000 and was approved by the Food and Drug Administration in 2001.The indications of CE overlap with those of regular diagnostic endoscopy.However,in clinical practice,CE is usually used to detect lesions in areas inaccessible to standard endoscopies or in cases of bleeding that might be missed during conventional endoscopy.Since the emergence of CE,many physiological and technical challenges have been faced and addressed.In this letter,we summarize the current challenges and briefly mention the proposed methods to overcome these challenges to answer a central question:Do we still need CE?

Clinical and demographic features of patients undergoing videocapsule endoscopy management:A descriptive study

BACKGROUND Video-capsule endoscopy(VCE)is an efficient tool that has proven to be highly useful in approaching several gastrointestinal diseases.VCE was implemented in Colombia in 2003,however current characterization of patients undergoing VCE in Colombia is limited,and mainly comes from two investigations conducted before the SARS-CoV-2 pandemic period.AIM To describe the characteristics of patients undergoing VCEs and establish the main indications,findings,technical limitations,and other outstanding features.METHODS A descriptive study was carried out using data from reports of VCE(PillCam SB3 system)use in a Gastroenterology Unit in Bogotá,Colombia between September 2019 and January 2023.Demographic and clinical variables such as indication for the VCE,gastric and small bowel transit times(GTT,SBTT),endoscopic preparation quality,and limitations were described[n(%),median(IQR)].RESULTS A total of 133 VCE reports were analyzed.Most were in men with a median age of 70 years.The majority had good preparation(96.2%),and there were technical limitations in 15.8%of cases.The main indications were unexplained anemia(91%)or occult bleeding(23.3%).The median GTT and SBTT were 14 and 30 minutes,respectively.The frequencies of bleeding stigma(3.79%)and active bleeding(9.09%)were low,and the most frequent abnormal findings were red spots(28.3%),erosions(17.6%),and vascular ectasias(12.5%).CONCLUSION VCE showed high-level safety.The main indication was unexplained anemia.Active bleeding was the most frequent finding.Combined with artificial intelligence,VCE can improve diagnostic precision and targeted therapeutic interventions.

Capsule endoscopy and panendoscopy:A journey to the future of gastrointestinal endoscopy

In 2000,the small bowel capsule revolutionized the management of patients with small bowel disorders.Currently,the technological development achieved by the new models of double-headed endoscopic capsules,as miniaturized devices to evaluate the small bowel and colon[pan-intestinal capsule endoscopy(PCE)],makes this non-invasive procedure a disruptive concept for the management of patients with digestive disorders.This technology is expected to identify which patients will require conventional invasive endoscopic procedures(colonoscopy or balloon-assisted enteroscopy),based on the lesions detected by the capsule,i.e.,those with an indication for biopsies or endoscopic treatment.The use of PCE in patients with inflammatory bowel diseases,namely Crohn’s disease,as well as in patients with iron deficiency anaemia and/or overt gastrointestinal(GI)bleeding,after a non-diagnostic upper endoscopy(esophagogastroduodenoscopy),enables an effective,safe and comfortable way to identify patients with relevant lesions,who should undergo subsequent invasive endoscopic procedures.The recent development of magnetically controlled capsule endoscopy to evaluate the upper GI tract,is a further step towards the possibility of an entirely non-invasive assessment of all the segments of the digestive tract,from mouth-to-anus,meeting the expectations of the early developers of capsule endoscopy.

Capsule endoscopy in patients refusing conventional endoscopy

Capsule endoscopy is nowadays the diagnostic technique of choice in the study of small bowel pathologies,allowing the non-invasive study of the entire mucosa.This has led,together with new technical advances,to the creation of two new models(PillCam ESO and PillCam Colon)for the study of esophageal and colonic diseases.These two new capsules offer an interesting alternative to conventional endoscopy in the study of the upper and lower digestive tracts,because traditional endoscopy is often unpleasant and uncomfortable for the patient,can be painful,often requires moderate or deep sedation and is not without complications(hemorrhage,perforation,etc.).PillCam Colon is particularly important for its usefulness in the diagnosis of colonic polyps,and is a potentially useful tool in cases of incomplete colonoscopy or in colorectal cancer screening,even more when most patients are reluctant to undergo screening programs due to the said disadvantages of conventional colonoscopy.This article discusses the advantages of capsule endoscopy over conventional endoscopy,its current application possibilities and indications in routine clinical practice.In the various sections of the work,we assess the application of endoscopic capsule in different sections of the digestive tract(esophagus,stomach,and colon)and finally the potential role of panendoscopy with PillCam Colon.

Colon capsule endoscopy: Current status and future directions

Colon capsule endoscopy(CCE; Pill Cam Colon; Given Imaging; Yoqneam, Israel) is a minimally invasive wireless technique for the visualization of the colon. With the recent introduction of the second generation colon capsule the diagnostic accuracy of CCE for polyp detection has significantly improved and preliminary data suggest it may be useful to monitor mucosal inflammation in patients with inflammatory bowel disease. Limitations include the inability to take biopsies and the procedural costs. However, given the potentially higher acceptance within an average risk colorectal cancer(CRC) screening population, its usefulness as a screening tool with regard to CRC prevention should be further evaluated.

Colon capsule endoscopy:Can it contribute to green endoscopy?

Climate change due to sustained carbon dioxide(CO_(2))emissions poses a serious threat to human existence,such as extreme weather events that must be addressed in all sectors of society.Gastrointestinal endoscopy is a healthcare sector that produces high levels of CO_(2) emissions.Colonoscopy(CS)is the gold standard for colorectal cancer(CRC)screening that reduces the number of CRC-related deaths.However,vast amounts of cleaning solutions used to disinfect the colonoscope are disposed of,and multiple nonrenewable wastes are generated in performing CS,which significantly impact the environment.Currently,colon capsule endoscopy(CCE)retains good accuracy and has excellent potential to reduce CO_(2) emission through a simple procedure.However,to date,colon capsules are single-use and lack a clear collection pathway.In addition,there is a lack of specific data regarding the environmental impact of CCE.Further research is needed to prove that CCE is a more environmentally friendly tool than CS.

Understanding deep learning in capsule endoscopy: Can artificial intelligence enhance clinical practice?

Wireless capsule endoscopy(WCE)enables physicians to examine the gastrointestinal tract by transmitting images wirelessly from a disposable capsule to a data recorder.Although WCE is the least invasive endoscopy technique for diagnosing gastrointestinal disorders,interpreting a WCE study requires significant time effort and training.Analysis of images by artificial intelligence,through advances such as machine or deep learning,has been increasingly applied to medical imaging.There has been substantial interest in using deep learning to detect various gastrointestinal disorders based on WCE images.This article discusses basic knowledge of deep learning,applications of deep learning in WCE,and the implementation of deep learning model in a clinical setting.We anticipate continued research investigating the use of deep learning in interpreting WCE studies to generate predictive algorithms and aid in the diagnosis of gastrointestinal disorders.

Wireless capsule endoscopy: Perspectives beyond gastrointestinal bleeding

Wireless capsule endoscopy(CE) is a technology developed for the endoscopic exploration of the small bowel. The first capsule model was approved by the Food and Drug Administration in 2001, and its first and essential indication was occult gastrointestinal(GI) bleeding. Over subsequent years, this technology has been refined to provide superior resolution, increased battery life, and capabilities to view different parts of the GI tract. Indeed, cases for which CE proved useful have increased significantly over the last few years, with new indications for the small bowel and technical improvements that have expanded its use to other parts of the GI tract, including the esophagus and colon. The main challenges in the development of CE are new devices with the ability to provide therapy, air inflation for a better vision of the small bowel, biopsy sampling systems attached to the capsule and the possibility to guide and move the capsule with an external motion control. In this article we review the current and new indications of CE, and the evolving technological changes shaping this technology, which has a promising potential in the coming future of gastroenterology.

Detachable string magnetically controlled capsule endoscopy for the noninvasive diagnosis of esophageal diseases:A prospective,blind clinical study

BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being applied for the detection of stomach and small intestinal diseases,but its application in treating esophageal diseases is not widespread.AIM To evaluate the safety and efficacy of detachable string MCE(ds-MCE)for the diagnosis of esophageal diseases.METHODS Fifty patients who had been diagnosed with esophageal diseases were pros-pectively recruited for this clinical study and underwent ds-MCE and conven-tional EGD.The primary endpoints included the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for patients with esophageal diseases.The secondary endpoints consisted of visualizing the esophageal and dentate lines,as well as the subjects'tolerance of the procedure.RESULTS Using EGD as the gold standard,the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for esophageal disease detection were 85.71%,86.21%,81.82%,89.29%,and 86%,respectively.ds-MCE was more comfortable and convenient than EGD was,with 80%of patients feeling that ds-MCE examination was very comfortable or comfortable and 50%of patients believing that detachable string v examination was very convenient.CONCLUSION This study revealed that ds-MCE has the same diagnostic effects as traditional EGD for esophageal diseases and is more comfortable and convenient than EGD,providing a novel noninvasive method for treating esophageal diseases.

Colon capsule endoscopy polyp detection rate vs colonoscopy polyp detection rate:Systematic review and meta-analysis

BACKGROUND Colon capsule endoscopy(CCE)is a modern,non-invasive method for large bowel visualization,offering a less invasive alternative to traditional colonoscopy(TC).While TC remains the gold standard for comprehensive large bowel assessment,including the detection and treatment of various conditions,the effectiveness of CCE in detecting polyps is less established.AIM To systematically review and compare the polyp detection rates(PDR)of CCE and TC.METHODS A systematic literature search was conducted using four scientific databases:CINAHL,MEDLINE via EBSCO,Cochrane Library,and MEDLINE/PubMed.A standardized search command was utilized to ensure consistency.Full papers were retrieved if they compared PDR between CCE and TC and involved patients over 18 years old.A meta-analysis was then conducted using the meta package in R software.RESULTS Initially,339 articles were identified,with 128 duplicates and 15 non-English articles excluded,leaving 196 for screening.After further exclusions,9 articles were included in the review.The meta-analysis revealed minimal differences in PDR between CCE and TC.The pooled PDR for TC was 0.61(95%CI:0.48–0.72),and for CCE,it was 0.61(95%CI:0.48–0.73).The overall comparison of the pooled PDR of both methods was 0.96(95%CI:0.90–1.02),indicating that CCE is noninferior to TC.CONCLUSION CCE has emerged as a modern and safe diagnostic alternative to TC for polyp detection,demonstrating noninferiority when compared to the conventional method.

Factors associated with incomplete small bowel capsule endoscopy studies

AIM:To identify patient risk factors associated with incomplete small bowel capsule endoscopy(CE) studies.METHODS:Data from all CE procedures performed at St.Paul's Hospital in Vancouver,British Columbia,Canada,between December 2001 and June 2008 were collected and analyzed on a retrospective basis.Data collection for complete and incomplete CE study groups included patient demographics as well as a number of potential risk factors for incomplete CE including indication for the procedure,hospitalization,diabetes mellitus with or without end organ damage,limitations in mobility,renal insufficiency,past history of bowel obstruction,abdominal surgery,abdominal radiation therapy and opiate use.Risk factors were analyzed using a univariable and multivariable logistic regression model.RESULTS:From a total of 535 CE procedures performed,158 were incomplete(29.5%).The univariable analysis showed that CE procedures performed for overt gastrointestinal bleeding(P = 0.002),and for patients with a prior history of abdominal surgery(P = 0.023) or bowel obstruction(P = 0.023) were significantly associated with incomplete CE studies.Patients on opiate medications(P = 0.094) as well as hospitalized patients(P = 0.054) were not statistically significant,but did show a trend towards incomplete CE.The multivariable analysis showed that independent risk factors for an incomplete CE procedure include prior history of bowel obstruction [odds ratios(OR) 2.77,P = 0.02,95% confidence intervals(CI):1.17-6.56] and procedures performed for gastrointestinal bleeding(Occult OR 2.04,P = 0.037,95% CI:1.04-4.02 and Overt OR 2.69,P = 0.002,95% CI:1.44-5.05).Patients with a prior history of abdominal surgery(OR 1.46,P = 0.068,95% CI:0.97-2.19),those taking opiate medications(OR 1.54,P = 0.15,95% CI:0.86-2.76) and hospitalized patients(OR 1.82,P = 0.124,95% CI:0.85-3.93) showed a trend towards statistical significance.CONCLUSION:We have identified a number of risk factors for incomplete CE procedures that can be used to risk-stratify patients and guide interventions to improve completion rates.

Meckel's diverticulum diagnosis by video capsule endoscopy: A case report and review of literature

BACKGROUND Meckel’s diverticulum （MD） occurs predominantly in chil-dren and adolescents. It is rarely diagnosed in adults. Preoperative diagnosis is diffcult due to low sensitivity of the radiological imaging studies. The role of video capsule endoscopy （VCE） in the diagnosis of MD is unknown, and the endoscopic patterns are not defned. We will describe four of our cases of MD evaluated with VCE and make a review of the literature focusing on the endoscopic characteristics.CASE SUMMARYWe present four cases of MD confirmed by surgery. They were all adult males with ages going from 18 to 50 years, referred to our service from 2004 to 2018, due to obscure gastrointestinal bleeding （OGIB）. TheyGarcía-Compeán D et al . Merckel’s diverticulum diagnosis by VCEhad a history of 1 mo to 10 years of overt and occult bleeding episodes. Laboratory blood test showed an iron-deficiency anemia from 4 to 9 g/dL of hemoglo-bin that required multiple hospitalizations and blood transfusions in all cases. Repeated upper digestive endoscopies and colonoscopies were negative. Small bowel was examined with VCE, which revealed double lumen images in all cases, one with polyps and three with circumferential ulcers in the diverticulum. However, based on VCE findings, preoperative diagnosis of MD was suggested only in two patients. Capsule was retain-ed in one patient, which was recovered with surgery. The anatomopathological report revealed ulcerated ectopic gastric mucosa in all cases.CONCLUSIONVCE is useful for the diagnosis of MD. However, endo-scopic characteristics must be recognized in order to establish preoperative diagnosis.

Virtual chromoendoscopy in small bowel capsule endoscopy: New light or a cast of shadow?

AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single center study. One hundred lesions selected from forty-nine consecutive conventional white light SBCE(SBCE-WL) examinations were included. Lesions were reviewed at three Flexible Spectral Imaging Color Enhancement(FICE) settings and Blue Filter(BF) by two gastroenterologists with ex-perience in SBCE, blinded to each other's findings, whoranked the quality of delineation as better, equivalent or worse than conventional SBCE-WL. Inter-observer percentage of agreement was determined and analyzed with Fleiss Kappa(k) coefficient. Lesions selected for the study included angioectasias(n = 39), ulcers/ero-sions(n = 49) and villous edema/atrophy(n = 12). RESULTS: Overall, the delineation of lesions was im-proved in 77% of cases with FICE 1, 74% with FICE 2, 41% with FICE 3 and 39% with the BF, with a percent-age of agreement between investigators of 89%(k = 0.833), 85%(k = 0.764), 66%(k = 0.486) and 79%(k = 0.593), respectively. FICE 1 improved the delineation of 97.4% of angioectasias, 63.3% of ulcers/erosions and 66.7% of villous edema/atrophy with a percentage of agreement of 97.4%(k = 0.910), 81.6%(k = 0.714) and 91.7%(k = 0.815), respectively. FICE 2 improved the delineation of 97.4% of angioectasias, 57.1% of ulcers/erosions and 66.7% of villous edema/atrophy, with a percentage of agreement of 89.7%(k = 0.802), 79,6%(k = 0.703) and 91.7%(k = 0.815), respectively. FICE 3 improved the delineation of 46.2% of angioecta-sias, 24.5% of ulcers/erosions and none of the cases of villous edema/atrophy, with a percentage of agreement of 53.8% [k = not available(NA)], 75.5%(k = NA) and 66.7%(k = 0.304), respectively. The BF improved the delineation of 15.4% of angioectasias, 61.2% of ulcers/erosions and 25% of villous edema/atrophy, with a per-centage of agreement of 76.9%(k = 0.558), 81.6%(k = 0.570) and 25.0%(k = NA), respectively.CONCLUSION: Virtual chromoendoscopy can improve the delineation of angioectasias, ulcers/erosions and villous edema/atrophy detected by SBCE, with almost perfect interobserver agreement for FICE 1.

Capsule endoscopy:the road ahead

Since its introduction into clinical practice 15 years ago,capsule endoscopy(CE)has become the first-line investigation procedure in some small bowel pathologies,and more recently,dedicated esophageal and colon CE have expanded the fields of application to include the upper and lower gastrointestinal disorders.During this time,CE has become increasingly popular among gastroenterologists,with more than 2 million capsule examinations performed worldwide,and nearly 3000Pub Med-listed studies on its different aspects published.This huge interest in CE may be explained by its noninvasive nature,patient comfort,safety,and access to anatomical regions unattainable via conventional endoscopy.However,CE has several limitations which impede its wider clinical applications,including the lack of therapeutic capabilities,inability to obtain biopsies and control its locomotion.Several research groups are currently working to overcome these limitations,while novel devices able to control capsule movement,obtain high quality images,insufflate the gut lumen,perform chromoendoscopy,biopsy of suspect lesions,or even deliver targeted drugs directly to specific sites are under development.Overlooking current limitations,especially as some of them have already been successfully surmounted,and based on the tremendous progress in technology,it is expected that,by the end of next 15years,CE able to perform both diagnostic and therapeutic procedures will remain the major form of digestive endoscopy.This review summarizes the literature that prognosticates about the future developments of CE.

Capsule endoscopy:Current status in obscure gastrointestinal bleeding

Capsule endoscopy (CE) is a safe, non invasive diagnostic modality for the evaluation of small bowel lesions. Obscure gastrointestinal bleeding (OGIB) is one of the most important indications of capsule endoscopy. Capsule endoscopy has a very high diagnostic yield especially if the bleeding is ongoing. This technique appears to be superior to other techniques for the detection of suspected lesions and the source of bleeding. Capsule endoscopy has been shown to change the outcome in patients with obscure gastrointestinal (GI) bleed.

Capsule endoscopy in pediatrics: A 10-years journey

Video capsule endoscopy (CE) for evaluation the esophagus (ECE), small bowel (SBCE) and the colon (CCE) is particularly useful in pediatrics, because this imaging modality does not require ionizing radiation, deep sedation or general anesthesia. The risk of capsule retention appears to be dependent on indication rather than age and parallels the adult experience by indication, making SBCE a relatively safe procedure with a significant diagnostic yield. The newest indication, assessment of mucosal change, greatly enhances and expands its potential benefit. The diagnostic role of CE extends beyond the SB. The use of ECE also may enhance our knowledge of esophageal disease and assist patient care. Colon CCE is a novel minimally invasive and painless endoscopic technique allowing exploration of the colon without need for sedation, rectal intubation and gas insufflation. The limited data on ECE and CCE in pediatrics does not yet allow the same conclusions regarding efficacy; however, both appear to provide safe methods to assess and monitor mucosal change in their respective areas with little discomfort. Moreover, although experience has been limited, the patency capsule may help lessen the potential of capsule retention; and newly researched protocols for bowel cleaning may further enhance CE’s diagnostic yield. However, further research is needed to optimize the use of the various CE procedures in pediatric populations.

Role of capsule endoscopy in inflammatory bowel disease:Anything new?

Capsule endoscopy(CE)is a recently developed diagnostic method for diseases of the small bowel that is non-invasive,safe,and highly tolerable.Its role in patients with inflammatory bowel disease has been widely validated in suspected and established Crohn’s disease(CD)due to its ability to assess superficial lesions not detected by cross-sectional imaging and proximal lesions of the small bowel not evaluable by ileocolonoscopy.Because CE is a highly sensitive but less specific technique,differential diagnoses that can simulate CD must be considered,and its interpretation should be supported by other clinical and laboratory indicators.The use of validated scoring systems to characterize and estimate lesion severity(Lewis score,Capsule Endoscopy Crohn’s Disease Activity Index),as well as the standardization of the language used to define the lesions(Delphi Consensus),have reduced the interobserver variability in CE reading observed in clinical practice,allowing for the optimization of diagnoses and clinical management strategies.The appearance of the panenteric CE,the incorporation of artificial intelligence,magnetically-guided capsules,and tissue biopsies are elements that contribute to CE being a promising,unique diagnostic tool in digestive tract diseases.

Role of wireless capsule endoscopy in the follow-up of inflammatory bowel disease

The introduction of wireless capsule endoscopy in 2000 has revolutionized our ability to visualize parts of the small bowel mucosa classically unreached by the conventional endoscope, and since the recent introduction of colon capsule endoscopy, a promising alternative method has been available for the evaluation of large bowel mucosa. The advantages of wireless capsule endoscopy include its non-invasive character and its ability to visualize proximal and distal parts of the intestine, while important disadvantages include the procedure's inability of tissue sampling and significant incompletion rate. Its greatest limitation is the prohibited use in cases of known or suspected stenosis of the intestinal lumen due to high risk of retention. Wireless capsule endoscopy plays an important role in the early recognition of recurrence, on Crohn's disease patients who have undergone ileocolonic resection for the treatment of Crohn's disease complications, and in patients' management and therapeutic strategy planning, before obvious clinical and laboratory relapse. Although capsule endoscopy cannot replace traditional endoscopy, it offers valuable information on the evaluation of intestinal disease and has a significant impact on disease reclassification of patients with a previous diagnosis of ulcerative colitis or inflammatory bowel disease unclassified/indeterminate colitis. Moreover, it may serve as an effective alternative where colonoscopy is contraindicated and in cases with incomplete colonoscopy studies. The use of patency capsule maximizes safety and is advocated in cases of suspected small or large bowel stenosis.

Diagnostic effect of capsule endoscopy in 31 cases of subacute small bowel obstruction

AIM： TO evaluate the effectiveness and safety of capsule endoscopy （CE） in patients with recurrent subacute small bowel obstruction.METHODS： The study was a retrospective analysis of 31 patients referred to hospital from January 2003 to August 2008 for the investigation of subacute small bowel obstruction, who underwent CE. The patients were aged 9-81 years, and all of them had undergone gastroscopy and colonoscopy previously. Some of them received abdominal computed tomography or small bowel follow-through.RESULTS： CE made a definitive diagnosis in 12 （38.7%） of 31 cases： four Crohn＇s disease （CD）, two carcinomas, one intestinal tuberculosis, one ischemic enteritis, one abdominal cocoon, one duplication of the intestine,one diverticulum and one ileal polypoid tumor. Capsule retention occurred in three （9.7%） of 31 patients, and was caused by CD （2） or tumor （1）. Two with retained capsules were retrieved at surgery, and the other one of the capsules was spontaneously passed the stricture by medical treatment in 6 too. No case had an acute small bowel obstruction caused by performance of CE.CONCLUSION： CE provided safe and effective visualization to identify the etiology of a subacute small bowel obstruction, especially in patients with suspected intestinal tumors or CD, which are not identified by routine examinations.

Expanding role of capsule endoscopy in inflammatory bowel disease

Capsule endoscopy has been shown to detect small bowel inflammatory changes better than any other imaging modality. Selection criteria have been optimized to increase the yield of capsule endoscopy in patients suspected to have Crohn's disease. Capsule endoscopy allows for earlier diagnosis of Crohn's disease of the small bowel and improved diagnosis of colitis in patients where it is unclear if they suffer from Crohn's or ulcerative colitis. A test capsule is available to assess for small bowel strictures and thus avoid capsule retention. A common language has been developed and a new scoring index will be added to capsule software. It is envisioned that the manner in which we treat Crohn's disease in the future will change, based on earlier diagnosis and treatment aimed at mucosal healing rather than symptom improvement.