Effect of hyoscine N-butylbromide on adenoma detection rate: meta-analysis of randomized clinical trials

Provider-reported use of butylscopolamine in gastrointestinal endoscopy in Germany

Introduction The anti-cholinergic agent hyoscine-N-butylbromide (HBB) is used in gastrointestinal (GI) endoscopy to decrease motility and facilitate endoscopic procedures. Data from clinical studies to support this practice is limited especially for therapeutic procedures. Likewise, patterns of use among endoscopist are largely unclear. This study sought to assess usage of HBB among German-speaking endoscopists. Material and Methods We conducted an anonymous online survey among endoscopists in German-speaking countries. Results A total of 207 physicians participated in the survey. The majority (76.9%) were experienced endoscopists and 92.3% of respondents use HBB at least occasionally during procedures. The reported median stated frequency of HBB use varied greatly between different types of procedures and increased with the complexity of the procedure being performed. HBB was rarely used in diagnostic esophagogastroduodenoscopies (EGD) (median stated frequency 1% of procedures), while use frequency was significantly higher in EGD with endoscopic mucosal resection (EMR) (10%; p=0.002) and EGD with endoscopic submucosal dissection (ESD) (20%; p<0.001). Similarly, use frequency during diagnostic colonoscopy was lower (5%) compared to colonoscopy with EMR (20%, p=0.005) or ESD (42.5%, p<0.001). The highest use frequency was reported for ERCP (50%). The most frequently stated reason to use HBB was facilitation of the procedure (80.6%) followed by increasing diagnostic yield (58.3%). Conclusion German-speaking endoscopists commonly use HBB, most frequently to facilitate complex therapeutic procedures. Given there is almost no data supporting HBB use in therapeutic endoscopy, we suggest that more research is needed to evaluate benefits and risks of this practice.

Quality in colonoscopy: time to ensure national standards are implemented?

Background

High-quality colonoscopy is crucial to ensure complete mucosal visualisation and to maximise detection of pathology. Previous audits showing variable quality have prompted national and international colonoscopy improvement programmes, including the development of quality assurance standards and key performance indicators (KPIs). The most widely used marker of mucosal visualisation is the adenoma detection rate (ADR), however, histological confirmation is required to calculate this. We explored the relationship between core colonoscopy KPIs.

Methods

Data were collected from colonoscopists in eight hospitals in North East England over a 6-month period, as part of a quality improvement study. Procedural information was collected including number of colonoscopies, caecal intubation rate (CIR), ADR and polyp detection rate (PDR). Associations between KPIs and colonoscopy performance were analysed.

Results

9265 colonoscopies performed by 118 endoscopists were included. Mean ADR and PDR per endoscopist were 16.6% (range 0-36.3, SD 7.4) and 27.2% (range 0-57.5, SD 9.3), respectively. Mean number of colonoscopies conducted in 6 months was 78.5 (range 4-334, SD 61). Mean CIR was 91.2% (range 55.5-100, SD 6.6). Total number of colonoscopies and ADR>15% were significantly associated (p=0.04). Undertaking fewer colonoscopies and using hyoscine butylbromide less frequently was significantly associated with ADR<15%. CIR, endoscopist grade, % male patients, mean patient age and CIR were not significantly related to ADR<15%. In adjusted analyses, factors which affected ADR were PDR and mean patient age.

Conclusion

Colonoscopists who perform fewer than the nationally stipulated minimum of 100 procedures per year had significantly lower ADRs. This study demonstrates that PDR can be used as a marker of ADR; providing age is also considered.

Detection rates of colorectal neoplasia during colonoscopies and their associated factors in the SCREESCO study

BACKGROUND AND AIM

Colonoscopy quality, including lesion detectability, is variable, and factors influencing lesion detection are not fully understood. This study investigated lesion detection rates during colonoscopies and the associated factors in the SCREEning of Swedish COlons (SCREESCO) study.

METHODS

In this cross-sectional analysis of data from SCREESCO, a large-scale randomized controlled trial of colorectal cancer screening in the Swedish population aged 60 years, we assessed data of first-time colonoscopies performed in both colonoscopy and fecal immunochemical test (FIT) arms.

RESULTS

This study included 16 552 individuals. The adenoma detection rate was 23.9% and 37.8% in colonoscopy and FIT arms, respectively. Regarding colonoscopy procedures, a withdrawal time ≥ 6 min was associated with higher detection rates of advanced adenomas (adjusted odds ratio [AOR] 2.474, 95% confidence interval [CI] 1.295-4.723), adenomas (2.181, 1.515-3.140), and proximal serrated lesions (pSLs) (1.713, 1.007-2.915). Antispasmodic use was associated with higher detection rates of these lesions and sessile serrated lesions (SSLs) (AOR, 95% CI: 1.523, 1.295-1.791; 1.361, 1.217-1.522; 1.450, 1.247-1.687; and 1.810, 1.512-2.167, respectively). Insertion time > 20 min was related to lower detection rates of adenomas, pSLs, and SSLs (AOR, 95% CI: 0.753, 0.639-0.887; 0.640, 0.495-0.828; and 0.704, 0.518-0.955, respectively). The relationship between a recent period and higher detection rates of pSLs and SSLs was also demonstrated.

CONCLUSION

Lesion detectability in SCREESCO was mostly acceptable with room for improvement. In addition to sufficient withdrawal time, antispasmodic use and acquiring skills enabling short insertion time may improve lesion detection.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02078804.

Canadian Association of Gastroenterology (CAG) Position Statement on the Use of Hyoscine-n-butylbromide (Buscopan) During Gastrointestinal Endoscopy

Hyoscine butylbromide, also known as hyoscyamine or scopolamine, and sold under the trade name Buscopan, is an antimuscarinic agent commonly used to induce smooth muscle relaxation and reduce spasmodic activity of the gastrointestinal (GI) tract during endoscopic procedures. However, the balance between desirable and undesirable (adverse) effects is not clear when used during GI endoscopy. The Clinical Affairs Committee of the Canadian Association of Gastroenterology (CAG) conducted systematic reviews and applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to develop recommendations for the use of Buscopan during GI endoscopy. To summarize, we recommend against the use of Buscopan before or during colonoscopy (strong recommendation, high certainty of evidence). We suggest against the use of Buscopan before or during gastroscopy (conditional recommendation, very low certainty of evidence). We suggest the use of Buscopan before or during ERCP (conditional recommendation, very low certainty of evidence). More research is needed to determine whether patients undergoing advanced procedures such as endoscopic mucosal resection or endoscopic submucosal dissection benefit from its use. Buscopan should be used with caution in patients with cardiac comorbidities. According to its product monograph, Buscopan is contraindicated in patients with tachycardia, angina, and cardiac failure. Thus, Buscopan should be used very cautiously in patients with these conditions, and only when the potential benefits of its use outweigh the potential risks in a particular case. Such patients require careful cardiac monitoring in an environment where resuscitation equipment and appropriately trained staff to use it are readily available. According to its product monograph, Buscopan is also contraindicated in patients with prostatic hypertrophy with urinary retention, and therefore, should be used very cautiously in such patients as well, and only when the potential benefits of its use outweigh the potential risks in a particular case. Obtaining a preprocedural history of glaucoma is unlikely to be of value when considering Buscopan use. However, in cases where Buscopan has been used, patients should be counselled postprocedurally and told to present to an emergency facility should they experience eye pain, redness, decreased vision, nausea and vomiting or headache.

L-Menthol for Gastrointestinal Endoscopy: A Systematic Review and Meta-Analysis

In randomized controlled trials, L-menthol inhibits gastrointestinal peristalsis during endoscopy. Our goal was to quantitatively synthesize the available evidence to evaluate the efficacy and safety of L-menthol for gastrointestinal endoscopy.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Standards of diagnostic colonoscopy for early-stage neoplasia: Recommendations by an Asian private group

BACKGROUND AND AIM

In recent years, the incidence of colorectal cancer has been increasing, and it is now becoming the major cause of cancer death in Asian countries. The aim of the present study was to develop Asian expert-based consensus to standardize the preparation, detection and characterization for the diagnosis of early-stage colorectal neoplasia.

METHODS

A professional group was formed by 36 experts of the Asian Novel Bio-Imaging and Intervention Group (ANBI² G) members. Representatives from 12 Asia-Pacific countries participated in the meeting. The group organized three consensus meetings focusing on diagnostic endoscopy for gastrointestinal neoplasia. The Delphi method was used to develop the consensus statements.

RESULTS

Through the three consensus meetings with debating, reviewing the literature and regional data, a consensus was reached at third meeting in 2016. The consensus was reached on a total of 10 statements. Summary of statements is as follows: (i) Adequate bowel preparation for high-quality colonoscopy; (ii) Antispasmodic agents for lesion detection; (iii) Image-enhanced endoscopy (IEE) for polyp detection; (iv) Adenoma detection rate for quality indicators; (v) Good documentation of colonoscopy findings; (vi) Complication rates; (vii) Cecal intubation rate; (viii) Cap-assisted colonoscopy (CAC) for polyp detection; (ix) Macroscopic classification using indigocarmine spray for characterization of colorectal lesions; and (x) IEE and/or magnifying endoscopy for prediction of histology.

CONCLUSION

This consensus provides guidance for carrying out endoscopic diagnosis and characterization for early-stage colorectal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early-stage colorectal neoplasia.

Targeting M3 Muscarinic Receptors for Colon Cancer Therapy

BACKGROUND

Expression and activation of subtype-3 muscarinic receptors (M3R) plays an important role in the progression of colorectal neoplasia.

METHOD

Herein, we describe the role of muscarinic receptors in colon cancer, focusing specifically on M3R, illustrate how M3R over-expression and activation of post-receptor signaling pathways potentiates tumor progression, and explore the efficacy and safety of a variety of therapeutic approaches that can target the molecules involved.

RESULTS

Colon cancers overexpress M3R mRNA (CHRM3) and protein, and post-M3R signaling stimulates cell proliferation. Post-M3R signal transduction is complex, involving interplay between epidermal growth factor receptors (EGFR)/ERK and protein kinase C (PKC)/p38 mitogen-activated protein (MAP) kinase signaling pathways. In particular, the development of an invasive and metastatic phenotype requires that these signaling interactions augment cellular release of a key collagenase, matrix metalloproteinase-1 (MMP1). Blocking either M3R activation or post-M3R signaling attenuates MMP1 release and colon cancer invasiveness.

CONCLUSION

Parsing the complexities of these signaling interactions is important, not only to understand these mechanisms of cancer initiation and progression, but also to develop novel treatment modalities. Since the vast majority of persons with colon cancer die from disseminated disease, preventing or reversing metastatic spread of cancer cells by targeting M3R, post-M3R signaling, or MMP1 has therapeutic potential.

Does Hyoscine improve polyp detection rate during colonoscopy? Systematic Review & meta-analysis of randomized clinical trials

BACKGROUND/OBJECTIVE

Published studies have shown conflicting results regarding the benefit of Hyoscine Butylbrmoide use during colonoscopy in polyp and adenoma detection rates. This meta-analysis was conducted with the aim to summarize all available evidence.

METHODS

A literature search was carried out using PubMed, Ovid MEDLINE and the Cochrane Library database from inception to December 2017. Studies that compared the use of Hyoscine Butylbrmoide compared to placebo during colonoscopy were included. Pooled odds ratio and 95% confidence interval were calculated using Mantel-Haenszel fixed-effects model when there was no heterogeneity identified.

RESULTS

Of the 423 retrieved studies, eight met the eligibility criteria and were included in the analysis. There was no significant difference between the groups in terms of polyp and adenoma detection rates.There was no significant difference between the Hyoscine and placebo groups in polyp detection rate (49.3% vs 48%, OR = 1.06, 95% CI: 0.90-1.23, P = 0.50). Adenoma detection rate was also not significantly different between the 2 groups 33.7% vs, 31%; OR = 1.13; 95%CI: 0.95-1.35; P = 0.16). No heterogeneity was observed (P = 0.65, I² = 0%).

CONCLUSION

This meta-analysis found no significant impact of Hyoscine on polyp and adenoma detection when used during colonoscopy.

Impact of Hyoscine Bromide Use on Polyp Detection Rate During Colonoscopy: A Systematic Review and Meta-Analysis

Background

Colorectal cancer (CRC) is a leading cause of death worldwide. Polyp detection rate (PDR) and adenoma detection rate (ADR) are key focus in endoscopic research for CRC screening and prevention. Use of anti-spasmodic agents during colonoscopy to help identify adenomas and polyps has remained a controversial topic. Hyoscine butyl bromide (HBB) is the most commonly used anti-spasmodic agent in patients undergoing colonoscopy. Some randomized controlled trials (RCTs) have questioned the clinical efficacy and safety of routine use of HBB for polyp and adenoma detection rates.

Methods

We conducted a systematic search in PubMed and MEDLINE from inception until February 10, 2018, for studies which compared HBB with placebo. We used RevMan version 5.3 for analysis. Procedural end-points were polyps, adenomas, and advanced adenoma detection rates, mean number of polyps detected and cecal intubation time.

Results

We included seven RCTs with 2,588 patients in our analysis. A total of 1,301 patients were randomized to HBB arm and 1,287 to the placebo arm. There was no significant difference in the primary outcome of polyp detection rate, 654 in HBB group vs. 616 in the placebo group, (odds ratio (OR) = 1.11, confidence interval (CI) = 0.93 - 1.34, P = 0.25). There was no difference in secondary outcomes of adenoma detection rate, 430 in HBB group vs. 396 in the placebo group, (OR = 1.06, CI = 0.89 - 1.26, P = 0.51), advanced adenoma detection rate, 92 in HBB vs. 95 in placebo group (OR = 0.95, CI = 0.70 - 1.30, P = 0.76), mean number of polyps detected (point estimate = 0.12, CI = 0.00 - 0.23, P = 0.05), adenomatous polyps (OR = 0.84, CI = 0.39 - 1.81, P = 0.65) and cecal intubation time (point estimate = 0.73, CI = -1.98 - 0.52, P = 0.25) between the two groups.

Conclusions

The use of HBB in patients undergoing colonoscopy does not appear to improve polyp or adenoma detection rates. It showed a non-significant trend of increased mean number of polyps detected with HBB.

Choi C, Kim SJ, Nam HS, Ryu DG, Hong JB, Kim DJ. Cimetropium bromide does not improve polyp and adenoma detection during colonoscope withdrawal: A randomized, double-blind, placebo-controlled study

BACKGROUND

Endoscopic inspection of colonic mucosa is disturbed by colonic folds and peristalsis, which may result in missed polyps. Cimetropium bromide, an antispasmodic agent, inhibits peristalsis and colonic spasms, which may improve polyp detection. The purpose of this randomized, double-blind, placebo-controlled study was to investigate whether cimetropium bromide could improve polyp and adenoma detection in the colorectum and right colon.

METHODS

Patients undergoing screening or diagnostic colonoscopy were randomized to receive intravenous cimetropium bromide (5 mg) or placebo after cecal intubation. The primary outcomes were the number of polyps per patient (PPP) and adenomas per patient (APP); secondary outcomes were the polyp detection rate (PDR), adenoma detection rate (ADR), and advanced neoplasm detection rate (ANDR).

RESULTS

A total of 181 patients were analyzed; 91 patients received cimetropium bromide and 90 patients received placebo. Cimetropium bromide and placebo groups did not significantly differ in the PPP and APP for the colorectum (1.38 ± 1.58 vs 1.69 ± 2.28, P = .298; 0.96 ± 1.27 vs 1.11 ± 1.89, P = .517, respectively) and right colon (0.70 ± 0.95 vs 0.78 ± 1.21, P = .645; 0.47 ± 0.81 vs 0.51 ± 0.81, P = .757, respectively). Two groups also did not significantly differ in the PDR, ADR, and ANDR for the colorectum and right colon. Furthermore, there were no difference between groups in the PPP, APP, PDR, ADR, and ADNR in a sub-analysis of expert and non-expert endoscopists.

CONCLUSIONS

Cimetropium bromide did not improve polyp and adenoma detection in the colorectum and right colon during colonoscope withdrawal, regardless of the expertness of the endoscopist. However, its use may be helpful in patients with active peristalsis or for beginning endoscopists during standard colonoscopy without a transparent cap.

The effect of premedication with peppermint oil capsules (Colpermin) prior to colonoscopy: A double blind randomized placebo-controlled trial

BACKGROUND AND STUDY AIMS

Colonoscopy is the cornerstone of diagnosing colonic diseases. Investigators have evaluated the effectiveness of antispasmodic agents in colonoscopy with conflicting evidence. The aim of this study is to determine the efficacy of enteric coated peppermint oil capsules (Colpermin®), an antispasmodic agent, on outcomes during colonoscopy.

PATIENTS AND METHODS

A total of 80 patients undergoing elective colonoscopy were recruited and randomized in a double blinded fashion to receive either placebo or peppermint oil capsules administered 4 h prior to the procedure.

RESULTS

Peppermint oil capsules did not affect caecal intubation time when compared with placebo. Patients' tolerance, endoscopist's satisfaction and demand on sedation were also not affected.

CONCLUSION

This randomized controlled trial does not support the routine use of peppermint oil capsules prior to colonoscopy as a tool for procedure optimization, and patients' and endoscopist's satisfaction.

Antispasmodic drugs in colonoscopy: a review of their pharmacology, safety and efficacy in improving polyp detection and related outcomes

Antispasmodic drugs are cheap, effective and generally safe. They may improve outcomes in colonoscopy, however their use has not been consistent or widespread. This manuscript reviews the three most commonly used antispasmodics in colonoscopy, namely, hyoscine butylbromide (and related ammonium compounds), glucagon and peppermint oil. The pharmacology, action and safety of the agents, as well as the evidence for them improving colonoscopic outcomes will be discussed. In addition to polyp detection, other colonoscopic outcome endpoints of interest include cecal and ileal intubation, and patient comfort. The drugs studied were all found to be effective gastrointestinal antispasmodics with good safety profiles. There is insufficient evidence to conclude whether antispasmodics improve cecal intubation rate, predominantly because the baseline rates are already high. Antispasmodics probably have efficacy in reducing cecal intubation time especially in those with marked colonic spasm. Antispasmodics do not offer significant benefit in polyp detection or improving patient comfort during colonoscopy. Future studies should focus on inexperienced colonoscopists as well as those with marked colonic spasm, in whom the greatest benefit seems to lie.

Technical interventions to increase adenoma detection rate in colonoscopy

Adenoma detection rate (ADR) is the most robust colonoscopy quality metric and clinical studies have adopted it as the ideal method to assess the impact of technical interventions. Areas covered: We reviewed papers focusing on the impact of colonoscopy technical issues on ADR, including withdrawal time and technique, second evaluation of the right colon, patient positional changes, gastrointestinal assistant participation during colonoscopy, water-aided technique, optimization of bowel preparation and antispasmodic administration. Expert commentary: Overall, technical interventions are inexpensive, available worldwide and easy to implement. Some of them, such as the adoption of split dose regimen and slow scope withdrawal to allow a careful inspection, have been demonstrated to significantly improve ADR. Emerging data support the use of water-exchange colonoscopy. According to published studies, other technical interventions seem to provide only marginal benefit to ADR. Unfortunately, the available evidence has methodological limitations, such as small sample sizes, the inclusion of expert endoscopists only and the evaluation of single technical interventions. Additionally, larger studies are needed to clarify whether these interventions might have a higher benefit on low adenoma detectors and whether the implementation of a bundle of them, instead of a single technical maneuver, might have a greater impact on ADR.

Expert opinions and scientific evidence for colonoscopy key performance indicators

Colonoscopy is a widely performed procedure with procedural volumes increasing annually throughout the world. Many procedures are now performed as part of colorectal cancer screening programmes. Colonoscopy should be of high quality and measures of this quality should be evidence based. New UK key performance indicators and quality assurance standards have been developed by a working group with consensus agreement on each standard reached. This paper reviews the scientific basis for each of the quality measures published in the UK standards.

What Can We Do to Optimize Colonoscopy and How Effective Can We Be?

In the USA, colorectal cancer is the third most common cancer and third leading cause of cancer death among both men and women. Declining rates of colon cancer in the past decade have been attributed in part to screening and removal of precancerous polyps via colonoscopy. Recent emphasis has been placed on measures to increase the quality and effectiveness of colonoscopy. These have been divided into pre-procedure quality metrics (bowel preparation), procedural quality metrics (cecal intubation, withdrawal time, and adenoma detection rate), post-procedure metrics (surveillance interval), and other quality metrics (patient satisfaction and willingness to repeat the procedure). The purpose of this article is to review the data and controversies surrounding each of these and identify ways to optimize the performance of colonoscopy.

The role of routinely given hyoscine-N-butylbromide in colonoscopy: a double-blind, randomized, placebo-controlled, clinical trial

OBJECTIVE

Hyoscine-N-butylbromide (HBB) has been proposed to ease colonoscopy and improve mucosal visualization, yet the results from previous studies are conflicting. In our prospective, double-blind, placebo-controlled, randomized study we aimed at evaluating whether routine administration of HBB, before and during colonoscopy, ease the procedure or increase the detection rate for polyps.

MATERIAL AND METHODS

One hundred fifty outpatients scheduled for an elective colonoscopy were randomized to receive intravenous injections of either 10 mg hyoscine-N-butylbromide or saline before insertion and at cecum. Patient tolerance and technical ease of colonoscopy were evaluated by visual analogue scale (VAS). Procedure times were recorded. Number of detected polyps per patient was evaluated as well. Heart rate was monitored with a pulse oximetry.

RESULTS

HBB did not improve patient tolerance or technically ease the procedure as evaluated by VAS. However, HBB led to faster ileal intubation (1.5 vs 2.0 min, p < 0.001) and shorter total procedure time (22.0 vs 24.0 min, p = 0.03). Patients who received HBB also needed less often external abdominal pressure (48.6 vs 66.7%, p = 0.03). HBB did not improve polyp detection rate (0.89 vs 0.91, p = 0.90). HBB induced a significant rise in heart rate (p < 0.001) and more often tachycardia (17.6 vs 0%, p < 0.001).

CONCLUSIONS

Routine administration of HBB before and during colonoscopy yields only limited improvement in the technical performance of the examination compromised by high incidence of tachycardia.

Seeing better - Evidence based recommendations on optimizing colonoscopy adenoma detection rate

Colorectal cancer is one of the three most frequent causes of cancer deaths in men and women in Europe and North America. Diagnosis and resection of adenomas has convincingly demonstrated its utility in diminishing colorectal cancer incidence. Therefore, colonoscopy is now the gold standard for colorectal cancer screening. But it is also known that colonoscopy effectiveness varies among endoscopists. Among different quality indicators, the most used is the adenoma detection rate (ADR) which is the percentage of average-risk patients for colorectal cancer who are found to have at least one adenoma or adenocarcinoma during a screening colonoscopy. There is compelling evidence supporting an inverse correlation between ADR and interval colorectal cancer (cancer found after a screening colonoscopy). Many factors such as quality of precolonoscopy preparation, additional observers, manoeuvres with the endoscope (second view, retroflexion, water inflation rather than air), time spent during withdrawal, changes in patient position, fold-flattener devices, new imaging or endoscopic modalities and use of intravenous or through the scope sprayed drugs, have been studied and developed with the aim of increasing the ADR. This reviews discusses these factors, and the current evidence, to “see better” in the colon and optimize ADR.

Improving the utility of colonoscopy: Recent advances in practice

Colonoscopy is a frequently performed diagnostic and therapeutic test and the primary screening tool in several nationalized bowel cancer screening programs. There has been a considerable focus on maximizing the utility of colonoscopy. This has occurred in four key areas: Optimizing patient selection to reduce unnecessary or low yield colonoscopy has offered cost-benefit improvements in population screening. Improving quality assurance, through the development of widely accepted quality metrics for use in individual practice and the research setting, has offered measurable improvements in colonoscopic yield. Significant improvements have been demonstrated in colonoscopic technique, from the administration of preparation to the techniques employed during withdrawal of the colonoscope. Improved techniques to avoid post-procedural complications have also been developed-further maximizing the utility of colonoscopy. The aim of this review is to summarize the recent evidence-based advances in colonoscopic practice that contribute to the optimal practice of colonoscopy.