Aspirin exposure and its association with metal stent patency in malignant distal biliary obstruction: a large international multicenter propensity score-matched study

BACKGROUND AND AIMS

Stent dysfunction is common after ERCP with self-expandable metal stent (SEMS) insertion for malignant distal biliary obstruction (MDBO). Chronic aspirin (acetylsalicylic acid; ASA) exposure has been previously shown to potentially decrease this risk. We aim to further ascertain the protective effect of ASA and to identify other predictors of stent dysfunction.

METHODS

This multicenter retrospective cohort study was conducted at 9 sites in Canada and 1 in the United States. Patients with MDBO who underwent ERCP with SEMS placement between January 2014 and December 2019 were included and divided into 2 cohorts: ASA exposed (ASA-E) and ASA unexposed (ASA-U). Propensity-score matching (PSM) was performed to limit selection bias. Matched variables were age, sex, tumor stage, and type of metal stent. The primary outcome was the hazard rate of stent dysfunction. A multivariable Cox proportional hazards model was used to identify independent predictors of stent dysfunction.

RESULTS

Of 1396 patients assessed, after PSM 496 patients were analyzed (248 ASA-E and 248 ASA-U). ERCP with SEMS placement was associated with a high clinical success of 82.2% in ASA-E and 81.2% in ASA-U cohorts (P = .80). One hundred eighty-four patients had stent dysfunction with a mean stent patency time of 229.9 ± 306.2 days and 245.4 ± 241.4 days in ASA-E and ASA-U groups, respectively (P = .52). On multivariable analysis, ASA exposure did not protect against stent dysfunction (hazard ratio [HR], 1.25; 95% confidence interval [CI], .96-1.63). An etiology of pancreatic cancer (HR, 1.36; 95% CI, 1.15-1.61) predicted stent dysfunction, whereas cancer therapy was protective (HR, .73; 95% CI, .55-.96). Chronic ASA use was not associated with an increased risk for adverse events including bleeding, post-ERCP pancreatitis, and perforation.

CONCLUSIONS

In this large, multicenter study using PSM, chronic exposure to ASA did not protect against stent dysfunction in MDBO. Instead, the analysis revealed that the etiology of pancreatic cancer was an independent predictor of stent dysfunction and cancer therapy was protective.

Autonomous Artificial Intelligence vs Artificial Intelligence-Assisted Human Optical Diagnosis of Colorectal Polyps: A Randomized Controlled Trial

BACKGROUND & AIMS

Artificial intelligence (AI)-based optical diagnosis systems (CADx) have been developed to allow pathology prediction of colorectal polyps during colonoscopies. However, CADx systems have not yet been validated for autonomous performance. Therefore, we conducted a trial comparing autonomous AI to AI-assisted human (AI-H) optical diagnosis.

METHODS

We performed a randomized noninferiority trial of patients undergoing elective colonoscopies at 1 academic institution. Patients were randomized into (1) autonomous AI-based CADx optical diagnosis of diminutive polyps without human input or (2) diagnosis by endoscopists who performed optical diagnosis of diminutive polyps after seeing the real-time CADx diagnosis. The primary outcome was accuracy in optical diagnosis in both arms using pathology as the gold standard. Secondary outcomes included agreement with pathology for surveillance intervals.

RESULTS

A total of 467 patients were randomized (238 patients/158 polyps in the autonomous AI group and 229 patients/179 polyps in the AI-H group). Accuracy for optical diagnosis was 77.2% (95% confidence interval [CI], 69.7-84.7) in the autonomous AI group and 72.1% (95% CI, 65.5-78.6) in the AI-H group (P = .86). For high-confidence diagnoses, accuracy for optical diagnosis was 77.2% (95% CI, 69.7-84.7) in the autonomous AI group and 75.5% (95% CI, 67.9-82.0) in the AI-H group. Autonomous AI had statistically significantly higher agreement with pathology-based surveillance intervals compared to AI-H (91.5% [95% CI, 86.9-96.1] vs 82.1% [95% CI, 76.5-87.7]; P = .016).

CONCLUSIONS

Autonomous AI-based optical diagnosis exhibits noninferior accuracy to endoscopist-based diagnosis. Both autonomous AI and AI-H exhibited relatively low accuracy for optical diagnosis; however, autonomous AI achieved higher agreement with pathology-based surveillance intervals. (ClinicalTrials.gov, Number NCT05236790).

Local recurrence rates after resection of large colorectal serrated lesions with or without margin thermal ablation

INTRODUCTION

Serrated lesions (SLs) including traditional serrated adenomas (TSA), large hyperplastic polyps (HP) and sessile serrated lesions (SSLs) are associated with high incomplete resection rates. Margin ablation combined with EMR (EMR-T) has become routine to reduce local recurrence while cold snare polypectomy (CSP) is becoming recognized as equally effective for large SLs. Our aim was to evaluate local recurrence rates (LRR) and the use of margin ablation in preventing recurrence in a retrospective cohort study.

METHODS

Patients undergoing resection of ≥15 mm colorectal SLs from 2010-2022 were identified through a pathology database and electronic medical records search. Hereditary CRC syndromes, first follow-up > 18 months or no follow-up, surgical resection were excluded. Primary outcome was LRRs (either histologic or visual) during the first 18-month follow-up. Secondary outcomes were LRRs according to size, and resection technique.

RESULTS

191 polyps in 170 patients were resected (59.8% women; mean age, 65 years). The mean size of polyps was 22.4 mm, with 107 (56.0%) ≥20 mm. 99 polyps were resected with EMR, 39 with EMR-T, and 26 with CSP. Mean first surveillance was 8.2 mo. Overall LRR was 18.8% (36/191) (16.8% for ≥20 mm, 17.9% for ≥30 mm). LRR was significantly lower after EMR-T when compared with EMR (5.1% vs. 23.2%; p = 0.013) or CSP (5.1% vs. 23.1%; p = 0.031). There was no difference in LRR between EMR without margin ablation and CSP (p = 0.987).

CONCLUSION

The local recurrence rate for SLs ≥15 mm is high with 18.8% overall recurrence. EMR with thermal ablation of the margins is superior to both no ablation and CSP in reducing LRRs.

Incomplete resection of colorectal polyps of 4-20 mm in size when using a cold snare, and its associated factors

BACKGROUND : Cold snare polypectomy (CSP) is increasingly used for polypectomy and is recommended as the first-line modality for small (< 10 mm) polyps. This study aimed to evaluate incomplete resection rates (IRRs) when using CSP for colorectal polyps of 4-20 mm. METHODS : Adults (45-80 years) undergoing screening, surveillance, or diagnostic colonoscopy and CSP by one of nine endoscopists were included. The primary outcome was the IRR for colorectal polyps of 4-20 mm, defined as the presence of polyp tissue in marginal biopsies after resection of serrated polyps or adenomas. Secondary outcomes included the IRR for serrated polyps, ease of resection, and complications. RESULTS:  413 patients were included (mean age 63; 48 % women) and 182 polyps sized 4-20 mm were detected and removed by CSP. CSP required conversion to hot snare resection in < 1 % of polyps of < 10 mm and 44 % of polyps sized 10-20 mm. The IRRs for polyps < 10 mm and ≥ 10 mm were 18 % and 21 %. The IRR was higher for serrated polyps (26 %) compared with adenomas (16 %). The IRR was higher for flat (IIa) polyps (odds ratio [OR] 2.9, 95 %CI 1.1-7.4); and when resection was judged as difficult (OR 4.2, 95 %CI 1.5-12.1), piecemeal resection was performed (OR 6.6, 95 %CI 2.0-22.0), or visible residual polyp was present after the initial resection (OR 5.4, 95 %CI 2.0-14.9). Polyp location, use of a dedicated cold snare, and submucosal injection were not associated with incomplete resection. Intraprocedural bleeding requiring endoscopic intervention occurred in 4.7 %. CONCLUSIONS : CSP for polyps of 4-9 mm is safe and feasible; however, for lesions ≥ 10 mm, CSP failure occurs frequently, and the IRR remains high even after technical success. Incomplete resection was associated with flat polyps, visual residual polyp, piecemeal resection, and difficult polypectomies.

Measuring the observer (Hawthorne) effect on adenoma detection rates

Background and study aims An independent observer can improve procedural quality. We evaluated the impact of the observer (Hawthorne effect) on important quality metrics during colonoscopies. Patients and Methods In a single-center comparative study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the index group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the reference group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure. Results We included 327 index individuals and 360 referents in the final analyses. The index group had significantly higher PDRs (62.4% vs. 53.1%, P =0.02) and ADRs (39.4% vs. 28.3%, P =0.002) compared with the reference group. The SLDR and AADR were not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (relative risk [RR] 1.51; 95%, CI 1.05-2.17) and more than twofold (RR 2.17; 95%, CI 1.05-4.47) more likely to be higher in the index group than in the reference group. Conclusions The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in practice.

Automated Detection of Anatomical Landmarks During Colonoscopy Using a Deep Learning Model

Background and aims

Identification and photo-documentation of the ileocecal valve (ICV) and appendiceal orifice (AO) confirm completeness of colonoscopy examinations. We aimed to develop and test a deep convolutional neural network (DCNN) model that can automatically identify ICV and AO, and differentiate these landmarks from normal mucosa and colorectal polyps.

Methods

We prospectively collected annotated full-length colonoscopy videos of 318 patients undergoing outpatient colonoscopies. We created three nonoverlapping training, validation, and test data sets with 25,444 unaltered frames extracted from the colonoscopy videos showing four landmarks/image classes (AO, ICV, normal mucosa, and polyps). A DCNN classification model was developed, validated, and tested in separate data sets of images containing the four different landmarks.

Results

After training and validation, the DCNN model could identify both AO and ICV in 18 out of 21 patients (85.7%). The accuracy of the model for differentiating AO from normal mucosa, and ICV from normal mucosa were 86.4% (95% CI 84.1% to 88.5%), and 86.4% (95% CI 84.1% to 88.6%), respectively. Furthermore, the accuracy of the model for differentiating polyps from normal mucosa was 88.6% (95% CI 86.6% to 90.3%).

Conclusion

This model offers a novel tool to assist endoscopists with automated identification of AO and ICV during colonoscopy. The model can reliably distinguish these anatomical landmarks from normal mucosa and colorectal polyps. It can be implemented into automated colonoscopy report generation, photo-documentation, and quality auditing solutions to improve colonoscopy reporting quality.

Inactivation of foodborne viruses by novel organic peroxyacid-based disinfectants

Viruses are responsible for most enteric foodborne illnesses worldwide. The foods most frequently involved are fresh fruits and vegetables since they undergo little or no processing. Washing with a chemical disinfectant is a convenient way of inactivating viruses on foods. Peracetic acid, widely used as a disinfectant in the food industry, has the drawback of leaving a strong odor and is ineffective alone against some foodborne viruses. In this study, four disinfectants, namely per levulinic acid with or without sodium dodecyl sulfate, peracetic acid and a commercial peracetic acid-based disinfectant were tested on murine norovirus 1 (MNV-1), hepatitis A virus (HAV), and hepatitis E virus (HEV). Disinfectant concentrations were 50, 80, 250, 500, and 1000 mg l^-1 and contact times were 0.5, 1, 5, and 10 min. Under these conditions, per levulinic acid supplemented with 1% SDS reduced MNV-1 infectious titer by 3 log cycles vs. 2.24 log cycles by peracetic acid within 0.5 min. On stainless steel at 80 ppm, only peracetic acid produced 3-log reductions within 0.5 min. None of these peroxyacids was able to reduce infectious titers of HAV or HEV by even 2 log cycles at any concentration or time-tested. This study will guide the development of new chemical formulas that will be more effective against major foodborne viruses and will have less impact on food quality and the environment.

Incomplete resection rates of 4- to 20-mm non-pedunculated colorectal polyps when using wide-field cold snare resection with routine submucosal injection

Background and study aims  Incomplete resection of 4- to 20-mm colorectal polyps occur frequently (> 10 %), putting patients at risk for post-colonoscopy colorectal cancer. We hypothesized that routine use of wide-field cold snare resection with submucosal injection (CSP-SI) might reduce incomplete resection rates (IRRs). Patients and methods  Patients aged 45 to 80 years undergoing elective colonoscopies were enrolled in a prospective clinical study. All 4- to 20-mm non-pedunculated polyps were resected using CSP-SI. Post-polypectomy margin biopsies were obtained to determine IRRs through histopathology assessment. The primary outcome was IRR, defined as remnant polyp tissue found on margin biopsies. Secondary outcomes included technical success and complication rates. Results  A total of 429 patients (median age 65 years, 47.1 % female, adenoma detection rate 40 %) with 204 non-pedunculated colorectal polyps 4 to 20 mm removed using CSP-SI were included in the final analysis. CSP-SI was technical successful in 97.5 % (199/204) of cases (5 conversion to hot snare polypectomy). IRR for CSP-SI was 3.8 % (7/183) (95 % confidence interval [CI] 2.7 %-5.5 %). IRR was 1.6 % (2/129), 16 % (4/25), and 3.4 % (1/29) for adenomas, serrated lesions, and hyperplastic polyps respectively. IRR was 2.3 % (2/87), 6.3 % (4/64), 4.0 % (6/151), and 3.1 % (1/32) for polyps 4 to 5 mm, 6 to 9 mm, < 10 mm, and 10 to 20 mm, respectively. There were no CSP-SI-related serious adverse events. Conclusions  Use of CSP-SI results in lower IRRs compared to what has previously been reported in the literature for hot or cold snare polypectomy when not using wide-field cold snare resection with submucosal injection. CSP-SI showed an excellent safety and efficacy profile, however comparative studies to CSP without SI are required to confirm these results.

A25 MEASURING THE OBSERVER (HAWTHORNE) EFFECT ON ADENOMA DETECTION RATES: A CASE-CONTROL RETROSPECTIVE STUDY

Background

The effectiveness of colonoscopy screening to prevent colorectal cancer (CRC) is directly linked to its procedural quality. An independent observer (Hawthorne effect) can improve colonoscopy procedural quality metrics, including adenoma detection rate (ADR). However, the results of studies are limited or controversial.

Purpose

We aimed to evaluate the colonoscopy quality metrics in a group of patients undergoing screening or diagnostic colonoscopies under stringent observer conditions.

Method

In a single-center, case–control study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the case group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the control group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR), the mean number of adenomas detected per patient (MAP), and the mean number of adenomas and serrated lesions detected per patient (MASP) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure.

Result(s)

We included a total of 687 patients (327 cases and 360 controls) in the final analyses. The case group had significantly higher PDRs (62.4% vs. 53.1%) and ADRs (39.4% vs. 28.3%) compared with the control group. The SLDR was also higher in the case group than in the control group, but the difference was not significant (7.3% vs. 4.4%; P = 0.14). The AADR was not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (odds ratio [OR] 1.51; 95%CI 1.05–2.17) and more than twofold (OR 2.17; 95%CI 1.05–4.47) more likely to be higher in the case group than in the control group. The MAP and MASP were significantly increased in the case group compared with the control group (P < 0.001). The regression analyses for both metrics demonstrated the direct and significant association between the Hawthorne effect and elevated MAP/MASP.

Conclusion(s)

The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in routine practice.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

M. Taghiakbari: None Declared, D. Coman: None Declared, M. Takla: None Declared, A. N. Barkun: None Declared, M. Frija-Gruman: None Declared, M. Bouin: None Declared, S. Bouchard: None Declared, E. Deslandres: None Declared, S. Sidani: None Declared, D. von Renteln Grant / Research support from: ERBE, Ventage, Pendopharm, and Pentax, Consultant of: Boston Scientific and Pendopharm

A108 AUTOMATED DETECTION OF ILEOCECAL VALVE, APPENDICEAL ORIFICE, AND POLYP DURING COLONOSCOPY USING A DEEP LEARNING MODEL

Background

Identification and photo-documentation of the ileocecal valve (ICV) and appendiceal orifice (AO) confirm completeness of colonoscopy examinations. We hypothesized that an artificial intelligence (AI)-empowered solution could help us automatically differentiate anatomical landmarks such as AO and ICV from polyps and normal colon mucosa.

Purpose

We aimed to develop and test a deep convolutional neural network (DCNN) model that can automatically identify ICV and AO, and differentiate these landmarks from normal mucosa and colorectal polyps.

Method

We prospectively collected annotated full-length colonoscopy videos of 318 patients undergoing outpatient colonoscopies. We created three non-overlapping training, validation, and test datasets with 25,444 unaltered frames extracted from the colonoscopy videos showing four landmarks/image classes (AO, ICV, normal mucosa, and polyps). For each landmark, we extracted an average of 30 frames for each time of its appearance. All the extracted frames were reviewed and annotated by a team of three clinicians. Using a quality assessment tool, the clinicians examined a total of 86,754 frames (7982 AO, 8374 ICV, 32,971 polyps, and 37,427 normal mucosa) and verified whether or not the frame contained one unique landmark. For this research, all frames were extracted from the white-light colonoscopies, and all narrow-band imaging frames were excluded. A DCNN classification model was developed, validated, and tested in separate datasets of images. The primary outcome was the proportion of patients in whom the AI model could identify both ICV and AO, and differentiate them from polyps and normal mucosa, with an accuracy of detecting both AO and ICV above a threshold of 40% (representing a value in which reliable identification of the landmarks can be assumed without increasing false-positive alerts).

Result(s)

We trained a DCNN AI model on 21,503 unaltered frames extracted from the recorded colonoscopy videos of 272 patients, and validated and tested the model on 1,924 (25 patients) and 2,017 (21 patients) unaltered frames, respectively. We applied a transfer learning technique to fine-tune the model parameters to the endoscopic images using a cross-entropy loss function and back-propagation algorithm. After training and validation, the DCNN model could identify both AO and ICV in 18 out of 21 patients (85.71%), if accuracies were above the threshold of 40%. The accuracy of the model for differentiating AO from normal mucosa, and ICV from normal mucosa were 86.37% (95% CI 84.06% to 88.45%), and 86.44% (95% CI 84.06% to 88.59%), respectively. Furthermore, the accuracy of the model for differentiating polyps from normal mucosa was 88.57% (95% CI 86.60% to 90.33%).

Conclusion(s)

The model can reliably distinguish these anatomical landmarks from normal mucosa and colorectal polyps. It can be implemented into automated colonoscopy report generation, photo-documentation, and quality auditing solutions to improve colonoscopy reporting quality.

Please acknowledge all funding agencies by checking the applicable boxes below

Other

Please indicate your source of funding;

MEDTEQ

Disclosure of Interest

M. Taghiakbari: None Declared, S. Hamidi Ghalehjegh Employee of: Imagia Canexia Health Inc. , E. Jehanno Employee of: Imagia Canexia Health Inc. , T. Berthier Employee of: Imagia Canexia Health Inc. , L. di Jorio Employee of: Imagia Canexia Health Inc. , A. N. Barkun Grant / Research support from: co-awardee in funded research projects with Imagia Canexia Health Inc., Consultant of: Medtronic Inc. and A.I. VALI Inc, E. Deslandres: None Declared, S. Bouchard: None Declared, S. Sidani: None Declared, Y. Bengio: None Declared, D. von Renteln Grant / Research support from: ERBE, Ventage, Pendopharm, and Pentax, Consultant of: Boston Scientific and Pendopharm

EMR combined with hybrid argon plasma coagulation to prevent recurrence of large nonpedunculated colorectal polyps (with videos)

BACKGROUND AND AIMS

EMR is the mainstay of therapy for large colorectal polyps. Local recurrence after EMR is common and can be reduced using margin ablation. Our aim was to evaluate recurrence rates when using hybrid argon plasma coagulation (h-APC) ablation after EMR.

METHODS

Adult patients (aged 18-89 years) undergoing EMR of nonpedunculated colorectal polyps ≥20 mm were enrolled in a prospective multicenter study. h-APC was used to ablate all defect margins and also the resection surface in selected cases. The primary study outcome was recurrence rates found during the first follow-up colonoscopy. Secondary outcomes were technical success and adverse event rates.

RESULTS

EMR with h-APC ablation was used in 101 polyps (84 patients, 46.4% women). EMR with h-APC ablation was technically successful in all cases (median EMR time, 15 minutes; median h-APC ablation time, 4 minutes). Median polyp size was 30 mm (range, 20-60). Resected polyps were either adenomas (68/101 [67.3%]), sessile serrated lesions (27/101 [27%]), or adenocarcinomas (6/101 [6%]). The post-EMR recurrence rate was 2.2% (2/91) (95% confidence interval, .27-7.71). All 6 patients with cancer (intramucosal cancer, 4; T1sm cancer, 2) were found to have complete eradication of the primary tumor after EMR with h-APC, and none had lymph node metastasis. Four serious adverse events occurred in 3 patients (2 delayed bleeding [2.4%], 1 abdominal pain [1.2%], and 1 microperforation [1.2%]. All serious adverse events resolved with either endoscopic or antibiotic treatment only.

CONCLUSIONS

EMR with h-APC showed a high technical success rate, low adverse event rate, and very low post-EMR recurrence rates. (Clinical trial registration number: NCT04015765.).

Non-optical polyp-based resect and discard strategy: A prospective clinical study

BACKGROUND

Post-polypectomy surveillance intervals are currently determined based on pathology results.

AIM

To evaluate a polyp-based resect and discard model that assigns surveillance intervals based solely on polyp number and size.

METHODS

Patients undergoing elective colonoscopies at the Montreal University Medical Center were enrolled prospectively. The polyp-based strategy was used to assign the next surveillance interval using polyp size and number. Surveillance intervals were also assigned using optical diagnosis for small polyps (< 10 mm). The primary outcome was surveillance interval agreement between the polyp-based model, optical diagnosis, and the pathology-based reference standard using the 2020 United States Multi-Society Task Force guidelines. Secondary outcomes included the proportion of reduction in required histopathology evaluations and proportion of immediate post-colonoscopy recommendations provided to patients.

RESULTS

Of 944 patients (mean age 62.6 years, 49.3% male, 933 polyps) were enrolled. The surveillance interval agreement for the polyp-based strategy was 98.0% [95% confidence interval (CI): 0.97-0.99] compared with pathology-based assignment. Optical diagnosis-based intervals achieved 95.8% (95%CI: 0.94-0.97) agreement with pathology. When using the polyp-based strategy and optical diagnosis, the need for pathology assessment was reduced by 87.8% and 70.6%, respectively. The polyp-based strategy provided 93.7% of patients with immediate surveillance interval recommendations vs 76.1% for optical diagnosis.

CONCLUSION

The polyp-based strategy achieved almost perfect surveillance interval agreement compared with pathology-based assignments, significantly reduced the number of required pathology evaluations, and provided most patients with immediate surveillance interval recommendations.

The location-based resect and discard strategy for diminutive colorectal polyps: a prospective clinical study

BACKGROUND

Clinical implementation of the resect-and-discard strategy has been difficult because optical diagnosis is highly operator dependent. This prospective study aimed to evaluate a resect-and-discard strategy that is not operator dependent.

METHODS

The study evaluated a resect-and-discard strategy that uses the anatomical polyp location to classify colonic polyps into non-neoplastic or low risk neoplastic. All rectosigmoid diminutive polyps were considered hyperplastic and all polyps located proximally to the sigmoid colon were considered neoplastic. Surveillance interval assignments based on these a priori assumptions were compared with those based on actual pathology results and on optical diagnosis. The primary outcome was ≥ 90 % agreement with pathology in surveillance interval assignment.

RESULTS

1117 patients undergoing complete colonoscopy were included and 482 (43.1 %) had at least one diminutive polyp. Surveillance interval agreement between the location-based strategy and pathological findings using the 2020 US Multi-Society Task Force guideline was 97.0 % (95 % confidence interval [CI] 0.96-0.98), surpassing the ≥ 90 % benchmark. Optical diagnoses using the NICE and Sano classifications reached 89.1 % and 90.01 % agreement, respectively (P < 0.001), and were inferior to the location-based strategy. The location-based resect-and-discard strategy allowed a 69.7 % (95 %CI 0.67-0.72) reduction in pathology examinations compared with 55.3 % (95 %CI 0.52-0.58; NICE and Sano) and 41.9 % (95 %CI 0.39-0.45; WASP) with optical diagnosis.

CONCLUSION

The location-based resect-and-discard strategy achieved very high surveillance interval agreement with pathology-based surveillance interval assignment, surpassing the ≥ 90 % benchmark and outperforming optical diagnosis in surveillance interval agreement and the number of pathology examinations avoided.

Inactivation of Foodborne Viruses by UV Light: A Review

Viruses on some foods can be inactivated by exposure to ultraviolet (UV) light. This green technology has little impact on product quality and, thus, could be used to increase food safety. While its bactericidal effect has been studied extensively, little is known about the viricidal effect of UV on foods. The mechanism of viral inactivation by UV results mainly from an alteration of the genetic material (DNA or RNA) within the viral capsid and, to a lesser extent, by modifying major and minor viral proteins of the capsid. In this review, we examine the potential of UV treatment as a means of inactivating viruses on food processing surfaces and different foods. The most common foodborne viruses and their laboratory surrogates; further explanation on the inactivation mechanism and its efficacy in water, liquid foods, meat products, fruits, and vegetables; and the prospects for the commercial application of this technology are discussed. Lastly, we describe UV’s limitations and legislation surrounding its use. Based on our review of the literature, viral inactivation in water seems to be particularly effective. While consistent inactivation through turbid liquid food or the entire surface of irregular food matrices is more challenging, some treatments on different food matrices seem promising.

Clinical validation of the SIMPLE classification for optical diagnosis of colorectal polyps

Background and study aims  A novel endoscopic optical diagnosis classification system (SIMPLE) has recently been developed. This study aimed to evaluate the SIMPLE classification in a clinical cohort. Patients and methods  All diminutive and small colorectal polyps found in a cohort of individuals undergoing screening, diagnostic, or surveillance colonoscopies underwent optical diagnosis using image-enhanced endoscopy (IEE) and the SIMPLE classification. The primary outcome was the agreement of surveillance intervals determined by optical diagnosis compared with pathology-based results for diminutive polyps. Secondary outcomes included the negative predictive value (NPV) for rectosigmoid adenomas, the percentage of pathology exams avoided, and the percentage of immediate surveillance interval recommendations. Analysis of optical diagnosis for polyps ≤ 10 mm was also performed. Results  399 patients (median age 62.6 years; 55.6 % female) were enrolled. For patients with at least one polyp ≤ 5 mm undergoing optical diagnosis, agreement with pathology-based surveillance intervals was 93.5 % (95 % confidence interval [CI] 91.4-95.6). The NPV for rectosigmoid adenomas was 86.7 % (95 %CI 77.5-93.2). When using optical diagnosis, pathology analysis could be avoided in 61.5 % (95 %CI 56.9-66.2) of diminutive polyps, and post-colonoscopy surveillance intervals could be given immediately to 70.9 % (95 %CI 66.5-75.4) of patients. For patients with at least one ≤ 10 mm polyp, agreement with pathology-based surveillance intervals was 92.7 % (95 %CI 89.7-95.1). NPV for rectosigmoid adenomas ≤ 10 mm was 85.1 % (95 %CI CI 76.3-91.6). Conclusions  IEE with the SIMPLE classification achieved the quality benchmark for the resect and discard strategy; however, the NPV for rectosigmoid polyps requires improvement.

Virtual reality-based exposure with applied biofeedback for social anxiety disorder

Introduction

Social Anxiety Disorder (SAD) is considered the most prevalent anxiety disorder with the highest disease burden amongst anxiety disorders. Despite available effective treatment with Cognitive Behavioral Therapy, a majority of individuals with SAD do not seek treatment and many drop out when confronted with elements of exposure. Several studies highlight the many advantages virtual reality exposure holds over in vivo exposure. In this study, we investigate the added effect of real-time biofeedback during virtual reality exposure.

Objectives

The current study is part of a large scale study called VR8. The current study aims to develop and evaluate the feasibility of a VR-biofeedback-intervention for adults with mild to severe social anxiety disorder, before continuing randomized controlled trials.

Methods

Data from semi-structured interviews and surveys will be compared to biodata collected during VR exposure. Participants include a minimum of (n=10) patients and (n=10) clinicians from the Mental Health Services in the Region of Southern Denmark. Surveys include questionnaires used for assessment of anxiety symptoms, usability of technology, and presence in the virtual environment. Collected biodata includes heart rate variability and electrodermal activity. Behavioral markers include eye-gaze. The findings will be analyzed and discussed in a mixed methods design.

Results

The study is ongoing. Preliminary results will be available at presentation.

Conclusions

Successful development and implementation of a biofeedback-informed virtual reality exposure intervention may provide increased reach for patients and individuals who would have otherwise not sought- or dropped out of regular treatment, as well as inform the clinician on how to proceed during virtual exposure.

Conflict of interest

Prof. Stephané Bouchard is consultant to and own equity in Cliniques et Développement In Virtuo, which develops virtual environments, and conflicts of interests are managed according to UQO’s conflict of interests policy; however, Cliniques et Développeme

A119 THE LOCATION-BASED RESECT AND DISCARD STRATEGY FOR DIMINUTIVE COLORECTAL POLYPS: A PROSPECTIVE CLINICAL STUDY

Background

Replacing histopathology evaluation of diminutive polyps with optical polyp diagnosis is considered a cost-effective approach. However, the widespread use of optical diagnosis is limited due to concerns about making incorrect optical diagnoses and the requirements of training, credentialing and auditing of performance.

Aims

This prospective study aimed to evaluate a simplified resect and discard strategy that is not operator dependent.

Methods

The study evaluated a resect and discard strategy that uses anatomical polyp location to classify colon polyps into non-neoplastic or low-risk neoplastic. All rectosigmoid diminutive polyps were considered hyperplastic and all polyps located proximally to the sigmoid colon were considered neoplastic. Surveillance interval assignments based on these a priori assumptions were compared with those based on actual pathology results and optical diagnosis, respectively. The primary outcome was ≥90% agreement with pathology in surveillance interval assignment.

Results

Overall, 1117 patients undergoing complete colonoscopy were included and 482 (43.1%) had at least one diminutive polyp. Surveillance interval agreement between the location-based resect and discard strategy and pathological findings using the 2020 US Multi-Society Task Force guideline was 97.0% (95% CI = 0.96 - 0.98), surpassing the ≥90% benchmark. Optical diagnoses using NICE and Sano classifications reached 89.1% and 90.01% agreement, respectively (p &lt;0.0001), and were inferior to the location-based strategy. The location-based resect and discard strategy allowed a 69.7% (95% CI = 0.67 - 0.72) reduction in pathology examinations compared with 55.3% (95% CI = 0.52 - 0.58) (NICE and Sano) and 41.9% (95% CI = 0.39 - 0.45) (WASP) with optical diagnosis.

Conclusions

The location-based resect and discard strategy achieved very high surveillance interval agreement with pathology-based surveillance interval assignment, surpassing the ≥90% quality benchmark and outperforming optical diagnosis in surveillance interval agreement and the number of pathology examinations avoided.

Funding Agencies

None

Optical diagnosis of colorectal polyps: a randomized controlled trial comparing endoscopic image-enhancing modalities

BACKGROUND AND AIMS

Optical polyp diagnosis using image-enhanced endoscopy (IEE) allows for real-time histology prediction of colorectal polyps. The aim of this study was to evaluate a recently introduced IEE modality (Optivista [OV]; Pentax Medical, Tokyo, Japan) in a randomized controlled trial.

METHODS

In a prospective cohort of subjects (ages 45-80 years) undergoing elective screening, surveillance, or diagnostic colonoscopy, all colorectal polyps between 1 and 5 mm underwent IEE assessment. Study subjects were randomized before their colonoscopy procedure to undergo optical polyp diagnosis using either OV IEE or iScan (IS) IEE. A validated IEE scale (NBI International Colorectal Endoscopic classification) was used for optical polyp diagnosis. The primary outcome was the agreement of surveillance intervals determined when using OV IEE compared with IS IEE in reference with pathology-based surveillance intervals. Secondary outcomes were the percentage of surveillance intervals that could be given on the same day as the procedure, percentage of pathology tests avoided, diagnostic performance, and negative predictive value (NPV) of optical diagnosis for rectosigmoid adenomas.

RESULTS

Four hundred ten patients were enrolled in the trial. The polyp detection rate was 58.6%, and the adenoma detection rate was 38.8%. The proportion of correct surveillance interval assignment when using OV or IS IEE was 96.5% versus 96.0% (P = .75). A total of 65.1% of patients could be given same-day surveillance intervals when using OV IEE versus 73.1% for IS IEE (P = .07). The NPV for rectosigmoid adenomas (including sessile serrated adenomas) was 97.5% when using OV IEE and 88.2% when using IS IEE. Using high-confidence optical diagnosis instead of pathology would have resulted in a 44.3% elimination of required pathology examinations for OV IEE versus 52.8% for IS IEE (P = .34).

CONCLUSIONS

Optical diagnosis using OV and IS IEE both surpassed the 90% benchmark of surveillance interval assignment, and no significant difference with regard to correct surveillance interval assignment was found. OV IEE surpassed the ≥90% NPV for rectosigmoid adenomas, whereas IS IEE did not. (Clinical trial registration number: NCT03515343.).

Adherence to post-polypectomy surveillance guidelines: a systematic review and meta-analysis

BACKGROUND

Colorectal cancer (CRC) is a major worldwide cause of cancer-related mortality. Colonoscopy programs based on guideline-recommended surveillance intervals have been put in place to reduce the morbidity and mortality associated with CRC. We were interested to evaluate clinical practice adherence to guideline-recommended surveillance intervals, the potential extent of early repeat colonoscopies, and causes of nonadherence to guideline recommendations.

METHODS

We performed a literature search for articles reporting on guideline adherence for surveillance colonoscopies. Exclusion criteria included inflammatory bowel disease and hereditary CRC syndrome cohorts. Primary outcome was correct interval assignment in patients undergoing surveillance colonoscopy. Groups were assessed for adherence according to their respective guideline recommendations (North American or European).

RESULTS

16 studies were included in the analysis. The mean colonoscopy surveillance interval adherence rate was 48.8 % (95 % confidence interval [CI] 37.3 - 60.4). For North American guidelines, surveillance interval assignments were adherent to guideline recommendations in 44.7 % (95 %CI 24.2 - 66.3) of patients after detection of low risk lesions and in 54.6 % (95 %CI 41.4 - 67.4) after detection of high risk lesions. For European guidelines, surveillance interval assignments were adherent to recommendations in 24.4 % (95 %CI 1.1 - 63.4) of patients after detection of low risk lesions and in 73.6 % (95 %CI 35.5 - 98.8) after detection of high risk lesions.

CONCLUSIONS

The worldwide adherence to surveillance colonoscopy guidelines was low, with more than 50 % of patients undergoing repeat colonoscopies either too early or too late. Early repeat colonoscopies occurred with the highest frequency for patients in whom only hyperplastic polyps or low risk adenomas were found.

Diagnosis and management of pancreatic exocrine insufficiency (PEI) in primary care: consensus guidance of a Canadian expert panel

BACKGROUND

Pancreatic exocrine insufficiency (PEI) results in maldigestion due to inadequate activity of pancreatic enzymes in the small bowel. PEI can arise from a variety of medical conditions that reduce enzyme synthesis within the pancreatic parenchyma or from secondary factors that may occur despite optimal parenchymal function, such as pancreatic duct obstruction or impaired or poorly synchronized enzyme release.

PURPOSE

To provide practical guidance for primary care physicians managing patients who are at risk of PEI or who present with symptoms of PEI.

METHODS

For each of six key clinical questions identified by the authors, PubMed searches were conducted to identify key English-language papers up to April 2017. Forward and backward searches on key articles were conducted using Web of Science. Clinical recommendations proposed by the co-chairs (P.D. and C.T.) were vetted and approved based on the authors?

FINDINGS

The most characteristic symptom of PEI is steatorrhea ? voluminous, lipid-rich stools; other common signs and symptoms include unexplained weight loss and deficiencies of fat-soluble vitamins and other micronutrients. Pancreatic enzyme replacement therapy (PERT) can relieve symptoms and long-term sequelae of PEI. Diagnosis of PEI and initiation of PERT are usually the responsibility of gastroenterology specialists. However, primary care physicians (PCPs) are well positioned to identify potential cases of PEI and to participate in the collaborative, long-term management of patients already seen by a specialist.

CONCLUSIONS

In this document, a panel of Canadian gastroenterologists has conducted a critical review of the literature on PEI and PERT and has developed practical diagnostic and treatment recommendations for PCPs. These recommendations provide guidance on identifying patients at risk of PEI, the triggers for PEI testing and referral, and best practices for co-managing patients with confirmed PEI.

Trans-fistulary endoscopic drainage for post-bariatric abdominal collections communicating with the upper gastrointestinal tract

BACKGROUND AND STUDY AIMS

Diverse endoscopic methods, such as placement of temporary self-expandable stents, have proven effective for the treatment of post-bariatric surgery leaks. However, some patients do not respond to the usual endoscopic treatment. This study tested the efficacy of an alternative treatment strategy based on trans-fistulary drainage with double-pigtail plastic stents.

PATIENTS AND METHODS

We performed a retrospective analysis of patients with abdominal collections following bariatric surgery who were treated by trans-fistulary stenting between May 2007 and February 2015. Clinical success was defined as a sustained (> 4 months) clinical resolution (patient discharged from the hospital without antibiotics and able to resume a normal diet) and radiological response. Patient records, radiological images, and the hospital endoscopy database were reviewed.

RESULTS

A total of 33 patients (26 women/7 men, mean age 42 years [SD 11.2]) were included. Collections occurred after sleeve gastrectomy (n = 28) or after gastric bypass (n = 5). Fourteen patients were treated by trans-fistulary stenting as primary treatment, and 19 patients had undergone previous unsuccessful endoscopic treatment. No serious complication occurred during the drainage procedure. Clinical success was achieved in 26 patients (78.8 %). In two successfully treated patients, stents are still in place. Spontaneous stent migration occurred in 12 patients. In 12 patients, the stents were removed, either electively (n = 5) or because of complications (ulcerations n = 3, upper gastrointestinal symptoms n = 3, splenic hematoma n = 1).

CONCLUSIONS

Trans-fistulary drainage of post-bariatric abdominal collections is safe and associated with high success rates. This technique can be considered in previously untreated patients, when a collection is not properly drained percutaneously, or after failure of other endoscopic treatments.

Video capsule endoscopy: Perspectives of a revolutionary technique

Video capsule endoscopy (VCE) was launched in 2000 and has revolutionized direct endoscopic imaging of the gut. VCE is now a first-line procedure for exploring the small bowel in cases of obscure digestive bleeding and is also indicated in some patients with Crohn’s disease, celiac disease, and polyposis syndrome. A video capsule has also been designed for visualizing the esophagus in order to detect Barrett’s esophagus or esophageal varices. Different capsules are now available and differ with regard to dimensions, image acquisition rate, battery life, field of view, and possible optical enhancements. More recently, the use of VCE has been extended to exploring the colon. Within the last 5 years, tremendous developments have been made toward increasing the capabilities of the colon capsule. Although colon capsule cannot be proposed as a first-line colorectal cancer screening procedure, colon capsule may be used in patients with incomplete colonoscopy or in patients who are unwilling to undergo colonoscopy. In the near future, new technological developments will improve the diagnostic yield of VCE and broaden its therapeutic capabilities.

IgG4-Related Esophageal Disease Presenting as Esophagitis Dissecans Superficialis With Chronic Strictures

IgG4-related disease is a recently recognized autoimmune systemic disorder that has been described in various organs. The disease is characterized histologically by a dense lymphoplasmocytic infiltrate of IgG4-positive cells, storiform fibrosis and can be associated with tumefactive lesions. IgG4-related disease involving the upper gastrointestinal tract is rare and only two previous case reports have reported IgG4-related esophageal disease. We report the case of a 63-year-old female patient with a long-standing history of severe dysphagia and odynophagia with an initial diagnosis of reflux esophagitis. Symptoms persisted despite anti-acid therapy and control esophagogastroduodenoscopy (EGD) revealed endoscopic images consistent with esophagitis dissecans superficialis (sloughing esophagitis). An underlying autoimmune process was suspected and immunosuppressant agents were tried to control her disease. The patient eventually developed disabling dysphagia secondary to multiple chronic esophageal strictures. A diagnosis of IgG4-related disease was eventually made after reviewing esophageal biopsies and performing an immunohistochemical study with an anti-IgG4 antibody. Treatment attempts with corticosteroids and rituximab was not associated with a significant improvement of the symptoms of dysphagia and odynophagia, possibly because of the chronic nature of the disease associated with a high fibrotic component. Our case report describes this unique case of IgG4-related esophageal disease presenting as chronic esophagitis dissecans with strictures. We also briefly review the main histopathological features and treatment options in IgG4-related disease.

Endoscopic treatment for complex biliary and pancreatic duct injuries

Severe injuries of biliary or pancreatic ducts are associated with significant morbidity and mortality. Severe bile duct injuries such as major biliary leaks, complete transection, or complete occlusion of bile ducts can be grouped under the term complex bile duct injuries (CBDI). In the spectrum of pancreatic duct injuries, disconnected pancreatic duct syndrome (DPDS) represents the most severe form and most often occurs after a severe episode of acute pancreatitis. Treatment of these complex injuries is quite challenging and for many years surgical management has been considered the treatment of choice. However, in the past few years, some studies have reported the successful management of CBDI or DPDS using endoscopic procedures alone or in combination with a percutaneous approach. In this review, we detail the endoscopic or combined endoscopic/percutaneous treatment possibilities for CBDI and DPDS.

Virtual Reality Therapy Versus Cognitive Behavior Therapy for Social Phobia: A Preliminary Controlled Study

Social phobia is one of the most frequent mental disorders and is accessible to two forms of scientifically validated treatments: anti-depressant drugs and cognitive behavior therapies (CBT). In this last case, graded exposure to feared social situations is one of the fundamental therapeutic ingredients. Virtual reality technologies are an interesting alternative to the standard exposure in social phobia, especially since studies have shown its usefulness for the fear of public speaking. This paper reports a preliminary study in which a virtual reality therapy (VRT), based on exposure to virtual environments, was used to treat social phobia. The sample consisted of 36 participants diagnosed with social phobia assigned to either VRT or a group-CBT (control condition). The virtual environments used in the treatment recreate four situations dealing with social anxiety: performance, intimacy, scrutiny, and assertiveness. With the help of the therapist, the patient learns adapted cognitions and behaviors in order to reduce anxiety in the corresponding real situations. Both treatments lasted 12 weeks, and sessions were delivered according to a treatment manual. Results showed statistically and clinically significant improvement in both conditions. The effect-sizes comparing the efficacy of VRT to the control traditional group-CBT revealed that the differences between the two treatments are trivial.

Experiential cognitive therapy in the treatment of panic disorders with agoraphobia: a controlled study

The use of a multicomponent cognitive-behavioral treatment strategy for panic disorder with agoraphobia is actually one of the preferred therapeutic approaches for this disturbance. This method involves a mixture of cognitive and behavioral techniques that are intended to help patients identify and modify their dysfunctional anxiety-related thoughts, beliefs and behavior. The paper presents a new treatment protocol for Panic Disorder and Agoraphobia, named Experiential-Cognitive Therapy (ECT) that integrates the use of virtual reality (VR) in a multicomponent cognitive-behavioral treatment strategy. The VR software used for the trial is freely downloadable: www.cyberpsychology.info/try.htm. Moreover, the paper presents the result of a controlled study involving 12 consecutive patients aged 35-53. The selected subjects were randomly divided in three groups: ECT group, that experienced the Cognitive Behavioral Therapy-Virtual Reality assisted treatment (eight sessions), a CBT group that experienced the traditional Cognitive Behavioral approach (12 sessions) and a waiting list control group. The data showed that both CBT and ECT could significantly reduce the number of panic attacks, the level of depression and both state and trait anxiety. However, ECT procured these results using 33% fewer sessions than CBT. This datum suggests that ECT could be better than CBT in relation to the "cost of administration," justifying the added use of VR equipment in the treatment of panic disorders.

Computer-assisted stereology: point fraction of lung parenchyma and alveolar surface density in fetal and newborn sheep

The aim of this study was to determine the accuracy of a new computer-assisted stereological technique in obtaining structural information of the lung. We compared the point fraction of lung parenchyma (Pp) and alveolar surface density (Sv) obtained by established manual point/intercept counting methods and compared them with those obtained using a computer-assisted method. Lung tissues obtained from normally grown fetal sheep (n = 6) and from newborn lambs with severe lung hypoplasia (n = 5) were inflation fixed via the trachea and processed for light microscopy. In verification-of-technique experiments, Pp and Sv correlated well with known values. There was a significant linear correlation between manual and computer-assisted stereological measurements for values of Pp (r2 = 0.92) and Sv (r2 = 0.98). Our data lead us to believe that the computer-assisted stereological technique described in this study provides accurate estimates of Pp and Sv and hence may be a valuable tool for evaluating the effects of factors upon structural development of the lung.

Virtual reality assisted cognitive behavioral therapy for the treatment of Panic Disorders with Agoraphobia

The chapter describes the characteristics of the Experiential-Cognitive Therapy (ECT) protocol for Panic Disorder and Agoraphobia. The goal of ECT is to decondition fear reactions, to modify misinterpretational cognition related to panic symptoms and to reduce anxiety symptoms. This is possible in an average of eight sessions of treatment plus an assessment phase and booster sessions, through the integration of Virtual Experience and traditional cognitive-behavioral techniques. We decided to employ the techniques included in the cognitive-behavioral approach because they showed high levels of efficacy. Through virtual environments we can gradually expose the patient to feared situation: virtual reality consent to re-create in our clinical office a real experiential world. The patient faces the feared stimuli in a context that is nearer to reality than imagination. For ECT we developed the Virtual Environments for Panic Disorders--VEPD--virtual reality system. VEPD is a 4-zone virtual environment developed using the Superscape VRT 5.6 toolkit. The four zones reproduce different potentially fearful situations--an elevator, a supermarket, a subway ride, and large square. In each zone the characteristics of the anxiety-related experience are defined by the therapist through a setup menu.

Estimation and application of EMG amplitude during dynamic contractions

The sections above have described an EMG amplitude estimator and an initial application of this estimator to the EMG-torque problem. The amplitude estimator consists of six stages. In the first stage, motion artifact and power-line interference are attenuated. Motion artifact is typically removed with a highpass filter. Elimination of power-line noise is more difficult. Commercial systems tend to use notch filters, accepting the concomitant loss of "true" signal power in exchange for simplicity and robustness. Adaptive methods may be preferable, however, to preserve more "true" signal power. In stage two, the signal is whitened. One fixed whitening technique and two adaptive whitening methods were described. For low-amplitude levels, the adaptive whitening technique that includes adaptive noise cancellation may be necessary. In stage three, multiple EMG channels (all overlying the same muscle) are combined. For most applications, simple gain normalization is all that is required. Stage four rectifies the signal and then applies the power law required to demodulate the signal. In stage six, the inverse of the power law is applied to relinearize the signal. Direct comparison of MAV (first power) to RMS (second power) processing demonstrates little difference between the two. Therefore, unless there is reason to believe that the EMG density departs strongly from that found in the existing studies, RMS and MAV processing are essentially identical. In stage five, the demodulated samples are averaged across all channels and then smoothed (time averaged) to reduce the variance of the amplitude estimate, but at the expense of increasing the bias. For best performance, the window length that best trades off variance and bias error is selected. The advanced EMG processing was next applied to dynamic EMG-torque estimation about the elbow joint. Results showed that improved EMG amplitude estimates led to improved EMG-torque estimates. An initial comparison of different system-identification techniques and model orders was reported. It is expected that these advanced processing and identification algorithms will also improve performance in other EMG applications, including myoelectrically controlled prostheses, biofeedback, and ergonomic assessment.

Expression of neuropeptides in normal and abnormal appendices

BACKGROUND/PURPOSE

Increased neuroproliferation in the appendix associated with an increase in substance P (SP), vasoactive intestinal polypeptide (VIP), and growth-associated protein-43 (GAP-43) has been documented in appendices of adults with acute right lower quadrant (RLQ) abdominal pain and absence of gross or histologic signs of appendiceal inflammation. The authors tested whether these findings were present in children with RLQ pain and a normal appendix.

METHODS

Immunohistochemistry staining of paraffin-embedded appendices was performed with GAP-43, VIP, and SP. The positive control group included appendices with acute inflammation (group I, n = 5); the negative control group included appendices removed incidentally (group II, n = 5); and the experimental group included appendices from children suspected to have acute appendicitis without histologic signs of inflammation (group III, n = 9).

RESULTS

Group I: VIP was strongly expressed in the nerve plexuses. The lamina propria and muscularis showed absent or minimal VIP expression. SP staining was strong in all plexuses and was moderate to strong in the muscularis. SP expression in the epithelium and lamina propria was difficult to quantify secondary to inflammation. Group II: VIP expression was essentially undetectable in the epithelium, lamina propria, and muscularis, and was moderate in the nerve plexuses. Mild SP staining was detected in the nerve plexuses of most specimens, and absent to mild staining was found in the epithelium and muscularis. However, one specimen strongly expressed SP in all layers. Group III: VIP expression was moderate to strong in the lamina propria and muscularis of nearly all specimens, and strong expression was found in all nerve plexuses. All but one specimen strongly expressed SP in plexuses. There was moderate to strong expression of SP in the epithelium, lamina propria, and muscularis in over 50% of specimens. The immunostaining for GAP-43 was very weak and nonspecific and did not help discriminate between the 3 study groups.

CONCLUSIONS

Increased neuroproliferation in the lamina propria and muscularis was evident in patients with abdominal pain and normal appendices compared with appendices removed incidentally. The VIP and SP expression in these patients was similar or higher than that observed in patients with acute inflammation on histology.

Pulmonary lymphangiectasia revisited

PURPOSE

Pulmonary lymphangiectasia (PL) is a rare, poorly documented disease characterized by abnormal pulmonary lymphatics. Although case reports are published, little is known about survivors past the neonatal period.

METHODS

This is a retrospective review of histologically proven PL in fetuses, infants, and long term survivors since 1965.

RESULTS

Eleven children (8 boys, 3 girls) and 8 aborted fetuses (7 male, 1 female) were identified. The fetuses weighed 463.4 g (177 to 681 g). Six were aborted between 19 to 24 weeks of gestation for multiple malformations or anencephaly, and 2 spontaneously aborted: one with PL only, the other with twin-twin transfusion syndrome. Clinical PL was diagnosed between 0 and 11 months of age. Six children died (2 neonatal, 4 within 10 days), 5 survived. Two deaths occurred after cardiac surgery. Among survivors, the symptomatology and frequency of admissions diminished over time. Symptoms included progressive respiratory distress, chronic cough, recurrent pneumonia, bronchial asthma, and choking. One child with bilateral chylothorax was later diagnosed with Noonan syndrome; 2 patients had minor cardiac malformations. Rapid deterioration occurred with mild respiratory infections with only supportive treatment available. Chest x-ray showed marked hyperinflation with interstitial infiltrate.

CONCLUSIONS

This is the first long-term study of primary PL and will help counsel parents. Although fatal in the neonatal period, survival is possible if diagnosed past the neonatal period and improvement is expected.

Pleuropulmonary blastoma: a rare pathology with an even rarer presentation

BACKGROUND

Pleuropulmonary blastoma is among the rarest tumors of childhood. Three types have been described: cystic, solid, and mixed. To date, bilateral disease has not been documented.

METHODS AND RESULTS

A 5-week-old girl presented with a history of fever. Chest x-ray showed bilateral diffuse cystic lesions. Bowel obstruction developed that required laparotomy. Multiple small bowel polyps were resected. The patient was readmitted 4 months later with deteriorating respiratory status. She underwent sequential thoracotomies for resection of multiple bullae under high-frequency oscillatory ventilation. Small bowel polypectomies were again required because of obstruction. Lung lesions were compatible with pulmonary blastoma but could not be correlated with intestinal polyposis. Bilateral cystic renal lesions were seen on ultrasound scan. Her disease progressed, despite chemotherapy, with the appearance of metastatic iris lesions. She again underwent laparotomies for multiple recurrent generalized small bowel polyps that were causing obstruction. Expanding renal cysts affected kidney function, and she died at 14 months of age.

CONCLUSIONS

The rare association between pleuropulmonary blastoma and Wilms' tumor or nephroblastomatosis is known but rarely reported. Lacking pathological evidence, we can only speculate that this was the case. We have been unable to demonstrate any histological association between the renopulmonary and digestive lesions. Despite many unanswered questions, we are likely dealing with a "syndrome" of sorts with a dire outcome, despite aggressive treatments.

The otolaryngologic manifestations of gastroesophageal reflux: when is a pH study indicated?

PURPOSE

The aim of this study was to evaluate the pertinence of pH studies for persistent ear, nose, and throat (ENT) symptoms and their eventual relationship to gastroesophageal reflux (GER).

METHODS

Retrospective analysis was performed of age, reason for referral, pH study, treatment, and follow-up of patients with ENT symptoms suspected to have GER.

RESULTS

Of 3,000 esophageal pH studies performed over 16 years, 105 children were referred for ENT symptoms by an otorhinolaryngologist to rule out GER. Mean age was 33 months; 65% were boys. Reasons for referral included (number and mean age): stridor (n = 31, 8 months), laryngomalacia (n = 18, 13 months), recurrent otitis (n = 12, 42 months), laryngitis (n = 16, 50 months), dysphonia (n = 14, 59 months), laryngeal papillomatosis (n = 8, 62 months), sinusitis (n = 5, 56 months), and dysphagia (n = 1). Overall, 41% of study results were positive: stridor (58%), laryngomalacia (61%), laryngitis (56%) and sinusitis (40%). Patients with otitis, dysphonia and laryngeal papillomatosis had GER in 1%, 14%, and 25%, respectively. Follow-up in the three larger groups of patients showed resolution of the ENT symptoms after medical treatment of the reflux in 83% of patients with stridor and reflux, 86% with laryngitis and reflux, and 80% with laryngomalacia and reflux. Four fundoplications were performed: one neurologically impaired patient, and four nonresponders.

CONCLUSIONS

The authors recommend that a pH study be performed in children with stridor, laryngomalacia, laryngitis, and sinusitis when faced with failure of the usual treatment. However, a pH study does not seem as beneficial for recurrent otitis, dysphonia, or laryngeal papillomatosis.

Falls from heights among children: a retrospective review

BACKGROUND

Falls are a major cause of emergency room visits and admissions in pediatric hospitals.

METHODS

To better understand the epidemiology of falls from height and develop prevention strategies, the authors reviewed all admissions after a fall at a single institution from 1994 to 1997. Inclusion criteria are falls from a minimum height of 10 feet.

RESULTS

Of 1,410 patients admitted after a fall, 64 patients including 45 boys and 19 girls with a mean age of 7.4 years (range, 1 to 18) are included in this study. Fifty (78%) children fell from 20 feet or less (two stories) and 14 (22%) from height greater than 20 feet. Patients mainly fell from balconies (n = 15), windows (n = 13), trees (n = 9), roofs (n = 6), stairs (n = 6), diving board (n = 3) and miscellaneous (n = 12). Over 60% of falls occurred in private houses and during the summer months. Fifty-five patients (86%) sustained only one system injury, two patients had no significant injury, and seven patients had multisystem injury. Major injuries included head trauma (39%), musculoskeletal (34%), abdominal (12%), maxillofacial (8%), and spine (6%). A surgical intervention was required for 43% of intracranial trauma, 39% of musculoskeletal injuries, 60% of facial trauma, and 50% of spine fractures. Mean length of stay in hospital varied according to the injured system. The overall survival rate is 98% with only one death after a fall greater than 50 feet.

CONCLUSIONS

Although rarely mortal, falls from height carry a significant morbidity and are costly to the health care system. To decrease the occurrence of injuries caused by falls, strategies should include awareness campaigns, parent's education about the mechanisms of falls, increase parenteral supervision during playing activities, and legislative measures to ensure the safety of windows and balconies before the onset of summer.

Perineal hemangioma, anorectal malformation, and genital anomaly: a new association?

Two patients presented as full-term baby girls with anorectal and genital malformations with extensive perineal hemangiomas. The first patient had a vestibular anus with a perineal hemangioma involving the bladder, rectal, and vaginal walls. Skin ulcerations required a transverse loop colostomy for wound care. The vulva, urethral opening, and clitoris were deviated to the left, labia minora were absent, and the labia majora were abnormal. The second patient had an anus displaced anteriorly and deviated to the right. The external anal sphincter was hypertrophic on the left and atrophic on the right. Rectal examination showed agenesis of the right levator ani and a dentate line located at the skin level. She had a large perineal, sacral, vaginal, pararectal and retroperitoneal hemangioma and developed extensive skin ulcerations. She had only a hemiclitoris located to the left of the midline, near absence of labia minora, and hypertrophied labia majora. The urethra was displaced to the left and opened in the vestibule. Both patients had a spinal malformation (one with tethered cord and one with spina bifida) and a normal karyotype. Steroids and interferon allowed near-complete resolution of hemangiomas in both patients. The authors were impressed by the similarity of these two cases and could not find any previous description of this association.

Cyclic traction machine for long-term culture of fibroblast-populated collagen gels

Our research group has been investigating the effect of cyclic deformations on the evolution of fibroblast populated collagen gels (FPCG). Since existing traction machines are not designed for such an application, we had to design a cyclic traction machine adapted to tissue culture inside an incubator over an extended period of time. Biocompatible materials were used for fabrication to allow for easy sterilization and to prevent any adverse reaction from the tissue. The traction machine is based on a computer-controlled stepping motor system for easy adjustment of the deformation amplitude and frequency. The maximum stretching speed achieved is around 1 mm/s. The traction machine can measure FPCG mechanical properties and perform rupture tests to determine its ultimate strength. Several FPCGs have been successfully cultured with the machine for up to four weeks without any adverse reaction.