Direct comparison of multiple computer-aided polyp detection systems.

BACKGROUND AND STUDY AIMS: Artificial intelligence (AI)-based systems for computer-aided detection (CADe) of polyps receive regular updates and occasionally offer customizable detection thresholds, both of which impact their performance, but little is known about these effects. This study aimed to compare the performance of different CADe systems on the same benchmark dataset. METHODS: 101 colonoscopy videos were used as benchmark. Each video frame with a visible polyp was manually annotated with bounding boxes, resulting in 129 705 polyp images. The videos were then analyzed by three different CADe systems, representing five conditions: two versions of GI Genius, Endo-AID with detection Types A and B, and EndoMind, a freely available system. Evaluation included an analysis of sensitivity and false-positive rate, among other metrics. RESULTS: Endo-AID detection Type A, the earlier version of GI Genius, and EndoMind detected all 93 polyps. Both the later version of GI Genius and Endo-AID Type B missed 1 polyp. The mean per-frame sensitivities were 50.63 % and 67.85 %, respectively, for the earlier and later versions of GI Genius, 65.60 % and 52.95 %, respectively, for Endo-AID Types A and B, and 60.22 % for EndoMind. CONCLUSIONS: This study compares the performance of different CADe systems, different updates, and different configuration modes. This might help clinicians to select the most appropriate system for their specific needs.

SERUM FENTANYL CONCENTRATIONS AND BEHAVIOR ASSOCIATED WITH TRANSDERMAL FENTANYL APPLICATION ON HEALTHY CORN SNAKES (PANTHEROPHIS GUTTATUS).

Snakes are common household pets and frequently managed in zoos. Geriatric snakes commonly develop osteoarthritis, leading to a declining quality of life that often results in euthanasia. Anecdotally, the application of transdermal fentanyl patches (TFP) appears to contribute to clinical improvement, including increased activity level, in osteoarthritic snakes presumed to be in pain. This study evaluated serum fentanyl concentrations over time and the effects of TFP on the normal behavior of healthy, captive, adult corn snakes (Pantherophis guttatus) using constant video monitoring. Serum fentanyl concentrations were evaluated over 4 wk during 12.5 µg/h TFP application, and the results demonstrated long-lasting (>4 wk) serum concentrations that were consistent with analgesic efficacy in mammalian species during TFP application. At 4 wk of TFP application, mean serum fentanyl concentrations were 11.5 ± 5.5 ng/ml. Snakes were videotaped for 1 wk prior to and 2 wk after 12.5 µg/h TFP application, and behavior was evaluated by an ethogram. Behavioral changes associated with TFP application included decreased mean time spent active, decreased mean number of climbs, and decreased mean number of water visits; feeding behavior was unchanged. Overall, these results suggest that TFP application may provide safe, clinically effective analgesia in healthy corn snakes for at least 4 wk without inducing deleterious side effects, and may therefore be appropriate analgesia for management of osteoarthritic snakes.

Texture and color enhancement imaging versus high definition white-light endoscopy for detection of colorectal neoplasia: a randomized trial.

BACKGROUND: Texture and color enhancement imaging (TXI) was recently proposed as a substitute for standard high definition white-light imaging (WLI) to increase lesion detection during colonoscopy. This international, multicenter randomized trial assessed the efficacy of TXI in detection of colorectal neoplasia. METHODS: Consecutive patients aged ≥ 40 years undergoing screening, surveillance, or diagnostic colonoscopies at five centers (Italy, Germany, Japan) between September 2021 and May 2022 were enrolled. Patients were randomly assigned (1:1) to TXI or WLI. Primary outcome was adenoma detection rate (ADR). Secondary outcomes were adenomas per colonoscopy (APC) and withdrawal time. Relative risks (RRs) adjusted for age, sex, and colonoscopy indication were calculated. RESULTS: We enrolled 747 patients (mean age 62.3 [SD 9.5] years, 50.2 % male). ADR was significantly higher with TXI (221/375, 58.9 %) vs. WLI (159/372, 42.7 %; adjusted RR 1.38 [95 %CI 1.20-1.59]). This was significant for ≤ 5 mm (RR 1.42 [1.16-1.73]) and 6-9 mm (RR 1.36 [1.01-1.83]) adenomas. A higher proportion of polypoid (151/375 [40.3 %] vs. 104/372 [28.0 %]; RR 1.43 [1.17-1.75]) and nonpolypoid (136/375 [36.3 %] vs. 102/372 [27.4 %]; RR 1.30 [1.05-1.61]) adenomas, and proximal (143/375 [38.1 %] vs. 111/372 [29.8 %]; RR 1.28 [1.05-1.57]) and distal (144/375 [38.4 %] vs. 98/372 [26.3 %]; RR 1.46 [1.18-1.80]) lesions were found with TXI. APC was higher with TXI (1.36 [SD 1.79] vs. 0.89 [SD 1.35]; incident rate ratio 1.53 [1.25-1.88]). CONCLUSIONS: TXI increased ADR and APC among patients undergoing colonoscopy for various indications. TXI increased detection of polyps < 10 mm, both in the proximal and distal colon, and may help to improve colonoscopy quality indicators.

Oral ENT-01 Targets Enteric Neurons to Treat Constipation in Parkinson Disease : A Randomized Controlled Trial.

BACKGROUND: Parkinson disease (PD) is associated with α-synuclein (αS) aggregation within enteric neurons. ENT-01 inhibits the formation of αS aggregates and improved constipation in an open-label study in patients with PD. OBJECTIVE: To evaluate the safety and efficacy of oral ENT-01 for constipation and neurologic symptoms in patients with PD and constipation. DESIGN: Randomized, placebo-controlled phase 2b study. (ClinicalTrials.gov: NCT03781791). SETTING: Outpatient. PATIENTS: 150 patients with PD and constipation. INTERVENTION: ENT-01 or placebo daily for up to 25 days. After baseline assessment of constipation severity, daily dosing was escalated to the prokinetic dose, the maximum dose (250 mg), or the tolerability limit, followed by a washout period. MEASUREMENTS: The primary efficacy end point was the number of complete spontaneous bowel movements (CSBMs) per week. Neurologic end points included dementia (assessed using the Mini-Mental State Examination [MMSE]) and psychosis (assessed using the Scale for the Assessment of Positive Symptoms adapted for PD [SAPS-PD]). RESULTS: The weekly CSBM rate increased from 0.7 to 3.2 in the ENT-01 group versus 0.7 to 1.2 in the placebo group (P < 0.001). Improvement in secondary end points included SBMs (P = 0.002), stool consistency (P < 0.001), ease of passage (P = 0.006), and laxative use (P = 0.041). In patients with dementia, MMSE scores improved by 3.4 points 6 weeks after treatment in the ENT-01 group (n = 14) versus 2.0 points in the placebo group (n = 14). Among patients with psychosis, SAPS-PD scores improved from 6.5 to 1.7 six weeks after treatment in the ENT-01 group (n = 5) and from 6.3 to 4.4 in the placebo group (n = 6). ENT-01 was well tolerated, with no deaths or drug-related serious adverse events. Adverse events were predominantly gastrointestinal, including nausea (34.4% [ENT-01] vs. 5.3% [placebo]; P < 0.001) and diarrhea (19.4% [ENT-01] vs. 5.3% [placebo]; P = 0.016). LIMITATION: Longer treatment periods need to be investigated in future studies. CONCLUSION: ENT-01 was safe and significantly improved constipation. PRIMARY FUNDING SOURCE: Enterin, Inc.

Evaluation of a questionnaire to assess the indication for screening colonoscopy for asymptomatic patients.

INTRODUCTION: Colorectal cancer is the second most common cause of cancer death worldwide. Screening colonoscopy is a very effective measure to prevent colorectal cancer and can reduce mortality at the population level. However, the participation rates of screening programs are low.To provide easily accessible information on screening colonoscopy and to increase the participation rates of screening programs, we developed a questionnaire for asymptomatic patients based on the German guidelines to assess the indication for screening colonoscopy. We evaluated the questionnaire with reference to the indications given by specialists in gastroenterology. METHODS: Patients who visited a specialist in gastroenterology in an outpatient clinic of a tertiary hospital for other reasons than a colonoscopy were eligible for the study. A maximum of seven questions to assess the indication for screening colonoscopy were answered by the patients. Afterward, the indication for screening colonoscopy was given or not by a specialist in gastroenterology. The accuracy of the questionnaire was measured in terms of sensitivity, specificity, and predictive values. RESULTS: In total, 335 patients were included in the analyses, of whom 50 and 285 patients were given and were not given an indication for screening colonoscopy by the specialists, respectively. In 0/50 patients, the questionnaire was false negative and in 8/285 patients false positive. Thus, the questionnaire had a sensitivity of 100% (95% confidence interval: 93-100%), a specificity of 97% (95-99%), a negative predictive value of 100% (99-100%), and a positive predictive value of 86% (75-94%).A subgroup analysis including patients who had never had a colonoscopy (n=109) showed comparable results: sensitivity of 100% (92-100%), specificity of 92% (83-97%), negative predictive value of 100% (94-100%), and positive predictive value of 90% (87-97%). CONCLUSION: The self-assessment questionnaire for asymptomatic individuals to assess the recommendation for screening colonoscopy is very sensitive and specific compared to a specialist in gastroenterology.The questionnaire can be found at: https://www.interdisziplinaere-endoskopie.mri.tum.de/de/infos-patienten/index.php.

Over-the-scope-clips versus standard treatment in high-risk patients with acute non-variceal upper gastrointestinal bleeding: a randomised controlled trial (STING-2).

OBJECTIVE: Acute non-variceal upper gastrointestinal bleeding (NVUGIB) is managed by standard endoscopic combination therapy, but a few cases remain difficult and carry a high risk of persistent or recurrent bleeding. The aim of our study was to compare first-line over-the-scope-clips (OTSC) therapy with standard endoscopic treatment in these selected patients. DESIGN: We conducted a prospective, randomised, controlled, multicentre study (NCT03331224). Patients with endoscopic evidence of acute NVUGIB and high risk of rebleeding (defined as complete Rockall Score ≥7) were included. Primary endpoint was clinical success defined as successful endoscopic haemostasis without evidence of recurrent bleeding. RESULTS: 246 patients were screened and 100 patients were finally randomised (mean of 5 cases/centre and year; 70% male, 30% female, mean age 78 years; OTSC group n=48, standard group n=52). All but one case in the standard group were treated with conventional clips. Clinical success was 91.7% (n=44) in the OTSC group compared with 73.1% (n=38) in the ST group (p=0.019), with persistent bleeding occurring in 0 vs 6 in the OTSC versus standard group (p=0.027), all of the latter being successfully managed by rescue therapy with OTSC. Recurrent bleeding was observed in four patients (8.3%) in the OTSC group and in eight patients (15.4%) in the standard group (p=0.362). CONCLUSION: OTSC therapy appears to be superior to standard treatment with clips when used by trained physicians for selected cases of primary therapy of NVUGIB with high risk of rebleeding. Further studies are necessary with regards to patient selection to identify subgroups benefiting most from OTSC haemostasis. TRIAL REGISTRATION NUMBER: NCT03331224.

Short bends using curved mirrors in silicon waveguides for terahertz waves.

Dielectric waveguides are capable of confining and guiding terahertz waves along sub-wavelength sized structures. A small feature size allows for a denser integration of different photonic components such as modulators, beam-splitters, wavelength (de)multiplexers and more. The integration of components on a small scale requires bending of the waveguides. In this paper we demonstrate a very short silicon 90°-bend, based on total internal reflection on an elliptically curved outer facet and a rounding of the inner corner joining two waveguides, with an average loss of 0.14 dB per bend in the 600-750 GHz range.

Over-wavelength pitch sized diffraction gratings for augmented reality applications.

Waveguide based optical combiners for augmented reality (AR) glasses are integrating several surface relief gratings (SRG) whose pitch sizes can be as small as 200 nm for the blue wavelength. All SRG components exploit the first diffraction order to couple in and out or to deviate the light. We present SRG using higher diffraction orders featuring over-wavelength pitch sizes. Our gratings use the edge wave (EW) diffraction phenomenon to steer light in the preferred far field direction.

Magnetic Resonance Elastography of Intervertebral Discs: Spin-Echo Echo-Planar Imaging Sequence Validation.

BACKGROUND: Magnetic resonance elastography (MRE) is an imaging technique that can noninvasively assess the shear properties of the intervertebral disc (IVD). Unlike the standard gradient recalled echo (GRE) MRE technique, a spin-echo echo-planar imaging (SE-EPI) sequence has the potential to improve imaging efficiency and patient compliance. PURPOSE: To validate the use of an SE-EPI sequence for MRE of the IVD compared against the standard GRE sequence. STUDY TYPE: Cross-over. SUBJECTS: Twenty-eight healthy volunteers (15 males and 13 females, age range: 19-55). FIELD STRENGTH/SEQUENCE: 3 T; GRE, SE-EPI with breath holds (SE-EPI-BH) and SE-EPI with free breathing (SE-EPI-FB) MRE sequences. ASSESSMENT: MRE-derived shear stiffnesses were calculated via principal frequency analysis. SE-EPI derived shear stiffness and octahedral shear strain signal-to-noise ratios (OSS-SNR) were compared against those derived using the GRE sequence. The reproducibility and repeatability of SE-EPI stiffness measurements were determined. Shear stiffness was evaluated in the nucleus pulposus (NP) and annulus fibrosus (AF) regions of the disc. Scan times between sequences were compared. STATISTICAL TESTS: Linear mixed models, Bland-Altman plots, and Lin's concordance correlation coefficients (CCCs) were used with P < 0.05 considered statistically significant. RESULTS: Good correlation was observed between shear stiffnesses derived from the SE-EPI sequences with those derived from the GRE sequence with CCC values greater than 0.73 and 0.78 for the NP and AF regions, respectively. OSS-SNR was not significantly different between GRE and SE-EPI sequences (P > 0.05). SE-EPI sequences generated highly reproducible and repeatable stiffness measurements with CCC values greater than 0.97 in the NP and AF regions and reduced scan time by at least 51% compared to GRE. SE-EPI-BH and SE-EPI-FB stiffness measurements were similar with CCC values greater than 0.98 for both regions. DATA CONCLUSION: SE-EPI-based MRE-derived stiffnesses were highly reproducible and repeatable and correlated with current standard GRE MRE-derived stiffness estimates while reducing scan times. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.

Frame-by-Frame Analysis of a Commercially Available Artificial Intelligence Polyp Detection System in Full-Length Colonoscopies.

INTRODUCTION: Computer-aided detection (CADe) helps increase colonoscopic polyp detection. However, little is known about other performance metrics like the number and duration of false-positive (FP) activations or how stable the detection of a polyp is. METHODS: 111 colonoscopy videos with total 1,793,371 frames were analyzed on a frame-by-frame basis using a commercially available CADe system (GI-Genius, Medtronic Inc.). Primary endpoint was the number and duration of FP activations per colonoscopy. Additionally, we analyzed other CADe performance parameters, including per-polyp sensitivity, per-frame sensitivity, and first detection time of a polyp. We additionally investigated whether a threshold for withholding CADe activations can be set to suppress short FP activations and how this threshold alters the CADe performance parameters. RESULTS: A mean of 101 ± 88 FPs per colonoscopy were found. Most of the FPs consisted of less than three frames with a maximal 66-ms duration. The CADe system detected all 118 polyps and achieved a mean per-frame sensitivity of 46.6 ± 26.6%, with the lowest value for flat polyps (37.6 ± 24.8%). Withholding CADe detections up to 6 frames length would reduce the number of FPs by 87.97% (p < 0.001) without a significant impact on CADe performance metrics. CONCLUSIONS: The CADe system works reliable but generates many FPs as a side effect. Since most FPs are very short, withholding short-term CADe activations could substantially reduce the number of FPs without impact on other performance metrics. Clinical practice would benefit from the implementation of customizable CADe thresholds.

Mobile Apps for the Management of Gastrointestinal Diseases: Systematic Search and Evaluation Within App Stores.

BACKGROUND: Gastrointestinal diseases are associated with substantial cost in health care. In times of the COVID-19 pandemic and further digitalization of gastrointestinal tract health care, mobile health apps could complement routine health care. Many gastrointestinal health care apps are already available in the app stores, but the quality, data protection, and reliability often remain unclear. OBJECTIVE: This systematic review aimed to evaluate the quality characteristics as well as the privacy and security measures of mobile health apps for the management of gastrointestinal diseases. METHODS: A web crawler systematically searched for mobile health apps with a focus on gastrointestinal diseases. The identified mobile health apps were evaluated using the Mobile Application Rating Scale (MARS). Furthermore, app characteristics, data protection, and security measures were collected. Classic user star rating was correlated with overall mobile health app quality. RESULTS: The overall quality of the mobile health apps (N=109) was moderate (mean 2.90, SD 0.52; on a scale ranging from 1 to 5). The quality of the subscales ranged from low (mean 1.89, SD 0.66) to good (mean 4.08, SD 0.57). The security of data transfer was ensured only by 11 (10.1%) mobile health apps. None of the mobile health apps had an evidence base. The user star rating did not correlate with the MARS overall score or with the individual subdimensions of the MARS (all P>.05). CONCLUSIONS: Mobile health apps might have a positive impact on diagnosis, therapy, and patient guidance in gastroenterology in the future. We conclude that, to date, data security and proof of efficacy are not yet given in currently available mobile health apps.

Digitizing a Therapeutic: Development of an Augmented Reality Dual-Task Training Platform for Parkinson's Disease.

Augmented reality (AR) may be a useful tool for the delivery of dual-task training. This manuscript details the development of the Dual-task Augmented Reality Treatment (DART) platform for individuals with Parkinson's disease (PD) and reports initial feasibility, usability, and efficacy of the DART platform in provoking dual-task interference in individuals with PD. The DART platform utilizes the head-mounted Microsoft HoloLens2 AR device to deliver concurrent motor and cognitive tasks. Biomechanical metrics of gait and cognitive responses are automatically computed and provided to the supervising clinician. To assess feasibility, individuals with PD (N = 48) completed a bout of single-task and dual-task walking using the DART platform. Usability was assessed by the System Usability Scale (SUS). Dual-task interference was assessed by comparing single-task walking and walking during an obstacle course while performing a cognitive task. Average gait velocity decreased from 1.06 to 0.82 m/s from single- to dual-task conditions. Mean SUS scores were 81.3 (11.3), which placed the DART in the "good" to "excellent" category. To our knowledge, the DART platform is the first to use a head-mounted AR system to deliver a dual-task paradigm and simultaneously provide biomechanical data that characterize cognitive and motor performance. Individuals with PD were able to successfully use the DART platform with satisfaction, and dual-task interference was provoked. The DART platform should be investigated as a platform to treat dual-task declines associated with PD.

Directional Stimulation in Parkinson's Disease and Essential Tremor: The Cleveland Clinic Experience.

OBJECTIVE: To assess use of directional stimulation in Parkinson's disease and essential tremor patients programmed in routine clinical care. MATERIALS AND METHODS: Patients with Parkinson's disease or essential tremor implanted at Cleveland Clinic with a directional deep brain stimulation (DBS) system from November 2017 to October 2019 were included in this retrospective case series. Omnidirectional was compared against directional stimulation using therapeutic current strength, therapeutic window percentage, and total electrical energy delivered as outcome variables. RESULTS: Fifty-seven Parkinson's disease patients (36 males) were implanted in the subthalamic nucleus (105 leads) and 33 essential tremor patients (19 males) were implanted in the ventral intermediate nucleus of the thalamus (52 leads). Seventy-four percent of patients with subthalamic stimulation (65% of leads) and 79% of patients with thalamic stimulation (79% of leads) were programmed with directional stimulation for their stable settings. Forty-six percent of subthalamic leads and 69% of thalamic leads were programmed on single segment activation. There was no correlation between the length of microelectrode trajectory through the STN and use of directional stimulation. CONCLUSIONS: Directional programming was more common than omnidirectional programming. Substantial gains in therapeutic current strength, therapeutic window, and total electrical energy were found in subthalamic and thalamic leads programmed on directional stimulation.

Smartphone Application to Reinforce Education Increases High-Quality Preparation for Colorectal Cancer Screening Colonoscopies in a Randomized Trial.

BACKGROUND & AIMS: Sufficient bowel preparation is crucial for successful screening and surveillance colonoscopy. However, rates of inadequate preparation are still high. We investigated the effects of reinforced patient education using a smartphone application software (APP) for colonoscopy preparation in participants in a CRC screening program. METHODS: We performed a prospective, endoscopist-blinded study of 500 patients undergoing split-dose bowel preparation for CRC screening or surveillance colonoscopies at multiple centers in Germany, from November 2017 through January 2019. Participants (n = 500) were given oral and written instructions during their initial appointment and then randomly assigned (1:1) to groups that received reinforced education starting 3 days before the colonoscopy (APP group) or no further education (controls). The primary outcome was quality of bowel preparation according to the Boston bowel preparation scale. Secondary outcomes included polyp and adenoma detection rates, compliance with low-fiber diet, split-dose laxative intake, perceived discomfort from the preparation procedure. RESULTS: The mean Boston bowel preparation scale score was significantly higher in the APP-group (7.6 ± 0.1) than in the control group (6.7 ± 0.1) (P < .0001). The percentage of patients with insufficient bowel preparation was significantly lower in the APP group (8%) than in the control group (17%) (P = .0023). The adenoma detection rate was significantly higher in the APP group (35% vs 27% in controls) (P = .0324). Use of the APP was accompanied by a lower level of non-compliance with correct laxative intake (P =.0080) and diet instructions (P = .0089). The APP group reported a lower level of discomfort during preparation (P < .0001). CONCLUSIONS: In a randomized trial, reinforcing patient education with a smartphone application optimized bowel preparation in the 3 days before colonoscopy, increasing bowel cleanliness, adenoma detection, and compliance in patients undergoing CRC screening or surveillance. ClinicalTrials.gov no: NCT03290157.

Risk of appendicitis after endoscopic full-thickness resection of lesions involving the appendiceal orifice: a retrospective analysis.

BACKGROUND: Conventional endoscopic resection of lesions affecting the appendiceal orifice is difficult. Endoscopic full-thickness resection (EFTR) is a novel technique in interventional endoscopy. As EFTR near the appendiceal orifice is associated with a subtotal appendectomy, it remains unclear whether the risk of developing appendicitis is increased. We conducted a retrospective analysis of lesions involving the appendiceal orifice treated by EFTR. METHODS: This was a multicenter retrospective analysis of patients (n = 50) treated with EFTR for lesions involving the appendiceal orifice between 2014 and 2019. The objective was to evaluate the occurrence of appendicitis. RESULTS: Acute appendicitis occurred in seven patients (14 %) during follow-up. Conservative treatment was sufficient in four cases, and three patients underwent appendectomy. CONCLUSIONS: EFTR of lesions involving the appendiceal orifice may be associated with an imminent risk of developing appendicitis and a consecutive need for appendectomy. Patients should be informed about this specific risk prior to resection. It is unclear why some patients develop appendicitis while the majority remains asymptomatic.

Colon diverticulosis is not a risk factor for the detection of adenomatous polyps - results of a prospective study.

BACKGROUND AND AIMS: Colon diverticula (CD) and adenomatous polyps are frequently found during colonoscopy. Data from the literature contains inconsistent information about whether patients with CD have a higher risk for colon adenomas. A positive correlation might influence the current guidelines for screening colonoscopies. The aim of this study was to examine whether presence of CD is associated with endoscopic adenoma detection. MATERIALS AND METHODS: This was a prospective study at 2 centers in Germany. Patients with an indication for colonoscopy were included. The number and localization of diverticula were recorded. Detected polyps were resected, and histopathological results were captured. Logistic regression models were fitted to the data to evaluate the association between CD and adenoma detection. RESULTS: A total of 938 colonoscopies was included. CD occurred in 49.1 % of the colonoscopies. The polyp and adenoma detection rates (PDR, ADR) were 50.3 % and 32.3 %. In 37.5 % of the patients with diverticula, at least 1 adenoma was detected, whereas this was the case in 27.3 % in the absence of diverticula. The presence of diverticula was positively correlated with the detection of adenomas in univariate analysis (p = 0.001), but no significant association could be found in multivariable analysis (p = 0.775). Increasing age (p < 0.001), male sex (p = 0.005), and longer withdrawal time (p < 0.001) were significant predictors for adenoma detection in the multivariable analysis. Similar results were also observed for both the distal and the proximal colon. DISCUSSION: Diverticula and adenomas are frequently found during colonoscopies. However, diverticula disease was not significantly associated with adenoma detection after adjustment for relevant prognostic factors. Older age, male sex, and duration of withdrawal time are predictors for the detection of adenomatous polyps.

Grounded procedures of connection are not created equal.

Lee and Schwarz propose that grounded procedures can also be related to connection rather than separation. Drawing on consumer behavior research, we point to different grounded procedures of connection - in terms of the motor actions involved, their salient properties, and their motivational conditions - and discuss how procedures of separation may be affected by the procedures of connection that precede them.

Efficacy and Safety of Endoscopic Full-Thickness Resection in the Colorectum: Results From the German Colonic FTRD Registry.

INTRODUCTION: Endoscopic full-thickness resection (EFTR) is a powerful option for resection of colorectal lesions not amenable to conventional endoscopic resection. The full-thickness resection device (FTRD) allows clip-assisted EFTR with a single-step technique. We report on results of a large nationwide FTRD registry. METHODS: The "German colonic FTRD registry" was created to further assess efficacy and safety of the FTRD System after approval in Europe. Data were analyzed retrospectively. RESULTS: Sixty-five centers contributed 1,178 colorectal FTRD procedures. Indications for EFTR were difficult adenomas (67.1%), early carcinomas (18.4%), subepithelial tumors (6.8%), and diagnostic EFTR (1.3%). Mean lesion size was 15 × 15 mm and most lesions were pretreated endoscopically (54.1%). Technical success was 88.2% and R0 resection was achieved in 80.0%. R0 resection was significantly higher for subepithelial tumor compared with that for other lesions. No difference in R0 resection was found for smaller vs larger lesions or for colonic vs rectal procedures. Adverse events occurred in 12.1% (3.1% major events and 2.0% required surgical treatment). Endoscopic follow-up was available in 58.0% and showed residual/recurrent lesions in 13.5%, which could be managed endoscopically in most cases (77.2%). DISCUSSION: To date, this is the largest study of colorectal EFTR using the FTRD System. The study demonstrated favorable efficacy and safety for "difficult-to-resect" colorectal lesions and confirms results of previous studies in a large "real-world" setting. Further studies are needed to compare EFTR with other advanced resection techniques and evaluate long-term outcome.

Proposal for an integrated silicon-photonics terahertz gas detector using photoacoustics.

A design and multiphysical model is presented for an on-chip gas sensor that transduces terahertz gas absorption through sound generation into a mechanical motion that can be read out externally. The signal is triply enhanced by designing a structure that functions simultaneously as an optical, an acoustical and a mechanical resonator. The structure is made in high-resistivity silicon and can be fabricated using CMOS and MEMS fabrication technologies. The sensor is a purely passive element, so an external THz source and read-out are required. The chip has a footprint of 3 mm2. A detection limit of 234 ppb of methanol for a source power of 1 mW and an integration time of 1 ms is predicted.

Endoscopic full-thickness resection of gastric subepithelial tumors with the gFTRD-system: a prospective pilot study (RESET trial).

BACKGROUND: Gastric subepithelial tumors (SET) are rare and usually benign. However, up to 13% are malignant. Histology after conventional biopsy often is inconclusive. Surveillance endoscopies are the consequence in the majority of gastric SET cases. For SET arising from deeper layers endoscopic resection (ER) with the standard techniques is difficult and associated with the risk of perforation. The RESET trial further evaluates feasibility, efficacy and safety of clip-assisted endoscopic full-thickness resection (EFTR) for gastric SET using the novel gastric full-thickness-resection device (gFTRD). MATERIALS AND METHODS: The RESET trial was initiated in March 2017 (NCT03096236) and designed as prospective observational multicenter pilot trial. Gastric SET up to 15 mm were included. Primary endpoint was technical success (complete enbloc resection). Secondary endpoints were R0 resection, full-thickness resection, adverse events and recurrency at 3-months follow-up. For resection we used the gFTRD (Ovesco Endoscopy, Tübingen, Germany). RESULTS: 29 patients underwent gastric EFTR. Histology prior EFTR after conventional biopsy could define histological tumor type in only 31.2%. Primary endpoint was reached in 89.7%. Histology of the full-thickness-resection specimen could define histological tumor type in 100%. 76% of all SET could be resected histologically complete (R0) and a full-thickness-resection specimen could be obtained in 65.5%. In 31% periprocedural minor bleeding was observed and managed endoscopically. Follow-up was available in 79.3% (OTSC detachment in 78.3%, OTSC in position in 21.7%). No signs of residual or recurrent tumors were observed after 3 months. CONCLUSION: EFTR of gastric SET with gFTRD is feasible and safe. EFTR allows a definite histological diagnosis (including sufficient risk stratification in case of GIST or NET) in contrast to conventional biopsy. R0-resection is possible in most cases and might obviate the need for further surveillance endoscopies for selected patients.