BACKGROUND:Although colonoscopy with polypectomy can prevent up to 80% of colorectal cancers, a significant adenoma miss rate still exists, particularly in the right colon. Previous studies ...addressing right colon retroflexion have revealed discordant evidence regarding the benefit of this maneuver on adenoma detection with concomitant concerns about safety and rates of maneuver success. In this meta-analysis, we sought to determine the effect of right colon retroflexion on improving adenoma detection compared with conventional colonoscopy without retroflexion, as well as determine the rates of retroflexion maneuver success and adverse events.
METHODS:Multiple databases including MEDLINE, Embase, and Web of Science were searched for studies on right colon retroflexion and its impact on adenoma detection compared with conventional colonoscopy. Pooled analyses of adenoma detection and retroflexion success were based on mixed-effects and random-effects models with heterogeneity analyses.
RESULTS:Eight studies met the inclusion criteria (N=3660). The primary analysis comparing colonoscopy with right-sided retroflexion versus conventional colonoscopy to determine the per-adenoma miss rate in the right colon was 16.9% (95% confidence interval, 12.5%-22.5%). The overall rate of successful retroflexion was 91.9% (95% confidence interval, 86%-95%) and rate of adverse events was 0.03%.
CONCLUSIONS:Colonoscopy with right-sided retroflexion significantly increases the detection of adenomas in the right colon compared with conventional colonoscopy with a high rate of maneuver success and small risk of adverse events. Thus, reexamination of the right colon in retroflexed view should be strongly considered in future standard of care colonoscopy guidelines for quality improvement in colon cancer prevention.
BACKGROUNDScreening colonoscopy is less effective in preventing proximal colon cancers than distal colon cancers. A repeat examination of the right side of the colon may increase the lesion ...detection. The study aimed to assess the results of a second examination of the right side of the colon with forward-view or retroflexion colonoscopy performed immediately after the initial examination.
MATERIALS AND METHODSWe carried out a meta-analysis of all primary studies that performed a second examination of the right side of the colon with forward-view or retroflexion colonoscopy performed immediately after the initial examination.
RESULTSSix cohorts of five studies with 4155 participants were included in the final study. The adenoma detection rate (ADR) was 28.8% of the combined examinations compared with 24.1% of the single examination (P<0.001), for a pooled odds ratio of 1.34 95% confidence interval (CI)1.13–1.59. For retroflexion assessment, ADR was achieved in 25.4% patients in the combined group, compared with 22.3% in the single examination group (P=0.002), for a pooled odds ratio of 1.19 (95% CI1.06–1.33). For forward-view assessment, ADR was achieved in 46.0% patients in the combined group, compared with 33.5% in the single examination group (P<0.001), for a pooled odds ratio of 1.76 (95% CI1.40–2.22).
CONCLUSIONFor ADR of the right side of the colon, a repeat examination could lead to a modest improvement in the detection of lesions in the proximal colon, irrespective of forward-view or retroflexion assessment.
Little attention has been given to the retroverted dens within the existing medical literature. However, this finding can have a clinical impact, especially in patients with Chiari malformation type ...I (CM1), as it can have consequences for further treatment.
Using standard search engines, we performed a literature review of anatomical, radiologic, and clinical studies as well as pathologic and surgical considerations related to the retroverted dens. Key words for our search included retroverted dens; retroflexed dens; odontoid retroflexion; posterior inclination; and tilted dens.
A retroverted dens is most commonly found in the pediatric population in relation to CM1. Research has demonstrated that high degree of dens angulation can result in significant anterior brain stem compression with the need for both anterior and posterior decompression in patients with symptomatic CM1.
A greater degree of dens angulation can lead to neurologic symptoms secondary to spinomedullary compression. Therefore, correct measurements are essential as such findings can influence presurgical planning.
Introduction
Chiari 1 malformation and hind brain hernia can be associated with skull base and craniocervical anomalies. One of the more recently associated anomalies is a retroverted or retroflexed ...odontoid process or dens. We conducted a retrospective study of our operated symptomatic and conservatively managed asymptomatic Chiari cohort to assess the impact of dens retroflexion on rate of revision or cerebrospinal fluid diversion following primary foramen magnum decompression (FMD).
Methods
We undertook a retrospective study of all foramen magnum decompression (FMD) cases for Chiari type 1 malformation performed over a 15-year period in a single tertiary paediatric neurosurgical unit. For comparison, non-operated asymptomatic Chiari cases were considered as reference cohort. Information gathered included: demographics, age, sex, length of cerebellar tonsils below McRae’s line, pB-C2 distance (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C2 body), angle of retroflexion (angle formed between a line drawn through the odontoid synchondrosis and its intersection with a line drawn from the tip of the odontoid process) and angle of retroversion (angle formed between the line drawn from the base of C2 and its intersection with a line drawn from the tip of the odontoid process). Grade of retroflexion was measured using pre-operative mid-sagittal MR images and classified as grade 0 (> 90°), grade 1 (85°–89°); grade 2 (80°–84°) and grade 3 (< 80°). The rates for redo surgery or need for cerebrospinal fluid (CSF) diversion were obtained from clinical records and compared in the operated and non-operated groups.
Results
One hundred twenty-six Chiari 1 patients were included in this study with adequate imaging. Sixty-five patients were in the non-operated asymptomatic cohort with 61 patients in the operated symptomatic cohort. Mean age of non-operated cohort was 10.2 years with M:F ratio (30:35). Mean cerebellar tonsillar length below McRae’s line was 10.3 mm. 7.7% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 76 and 78°, respectively. Retroflexion grades included (9.2% grade 1, 35% grade 2 and 52.3% grade 3). pB-C2 distance was 6.8 mm. Mean age of operated cohort was 11.3 years, with M:F ratio (21:40). Mean cerebellar tonsillar length below McRae’s line was 15 mm. 45.9% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 73 and 74.5°, respectively. Retroflexion grades included (4.9% grade 1, 16.5% grade 2 and 78.6% grade 3). pB-C2 distance was 6.9 mm. No association was identified between retroflexion grade and rate of revision or CSF diversion following primary foramen magnum decompression.
Conclusion
The operated Chiari 1 cohort had more retroflexed dens, longer tonsils and associated syrinx compared to the non-operated asymptomatic cohort.
Complications of cecal retroflexion performed during colonoscopy have not previously been reported to occur. We report a case of contained colonic perforation secondary to using cecal retroflexion ...technique to examine the colon, and review available published reports of complications associated with this technique. We conclude that complications may rarely occur with use of cecal retroflexion, and that the clinical benefit of this technique is uncertain.
Missed polyps during colonoscopy are considered an important factor for interval cancer appearance, especially in the ascending colon (AC). We evaluated the contribution of retroflexion to polyp and ...adenoma detection in the AC.
This prospective observational study included consecutive patients who underwent a complete colonoscopy between 06/2017 and 06/2018. The AC was examined in 2 phases: the first included 2 forward views from the hepatic flexure to the cecum; the second involved a retroflexion in the cecum, inspection up to the hepatic flexure and reinsertion to the cecum.
The study included 655 patients, 628 (95.88%) with successful retroflexion (mean age: 62.5±10.8 years, 332 male). Indications for colonoscopy were screening in 33.28%, follow up in 36.03%, and diagnostic assessment in 30.69%. In total, 286 polyps and 220 adenomas were detected in the AC. Phase 1 identified 119 adenomas, yielding an adenoma detection rate (ADR) in the AC of 14.2% (95% confidence interval CI 11.52-16.84%) while phase 2 identified 86 additional adenomas, improving the ADR in the AC to 22.75% (95%CI 19.54-25.96%; P<0.01). Adenoma miss rate was 39.1% (86/225) and per-patient adenoma miss rate was 11.15% (73/655). Retroflexion proved beneficial mainly in the upper third of the AC (odds ratio OR 4.29, 95%CI 1.84-11.56; P<0.01) and for small (<5 mm) adenomas (OR 1.61, 95%CI 1.02-2.56; P=0.04). Multivariate analysis showed that age >60 years, detection of adenomas in forward views and the indication "follow up" influenced ADR during retroflexion.
Retroflexion is a simple and safe maneuver that increases the ADR in the AC and should complete a second forward view.
Background
Colonoscopy is the gold standard investigation for the detection of colorectal cancer, but the right colon is more difficult to examine than the left colon. A second examination of the ...proximal colon has the potential to reduce rates of missed pathology.
Objective
To determine whether proximal retroflexion improves the adenoma detection rate or other outcomes in the right colon compared with the forward view.
Methods
We performed a multicentre randomized controlled trial of patients from the colorectal cancer screening programme with a positive faecal immunochemical test. Patients were randomized to a second right colon examination using proximal retroflexion or forward view.
Results
A total of 692 patients were included. A second examination of the right colon, with an average additional procedure time of 1.62 min, increased the adenoma detection rate by 11%, regardless of the method used (9% proximal retroflexion vs. 12% second forward view, p = 0.21). The adenoma miss rate was 19% (17% proximal retroflexion vs. 20% forward view, p = 0.28) The success rate of retroflexion was 83%, without secondary complications. In the 15.6% of patients in whom lesions were detected during the second pass, endoscopic follow-up was modified by reducing the time of the next colonoscopy.
Conclusions
A second examination of the right colon, either from retroflexion or second forward view, can increase adenoma detection rate and shorten surveillance intervals in patients undergoing screening colonoscopy. This should be emphasized during colonoscopy training and integrated into diagnostic colonoscopy practice.
Abstract
Background
As right colon polyps are challenging to detect, a retroflexed view of right colon (RV) may be useful. However, cecal retroflexion (CR) without a RV to the hepatic flexure (HF) is ...inadequate. We aimed to determine the frequency of CR and quality of the RV in routine practice.
Methods
This prospective observational study performed at an academic medical center assessed colonoscopy inspection technique of endoscopists who had performed ≥ 100 annual screening colonoscopies. We video recorded ≥ 28 screening/surveillance colonoscopies per endoscopist and randomly evaluated 7 videos per endoscopist. Six gastroenterologists blindly reviewed the videos to determine if CR was performed and HF withdrawal time (cecum to HF time, excluding ileal/polypectomy time).
Results
Reviewers assessed 119 colonoscopies performed by 17 endoscopists. The median HF withdrawal time was 3 min and 46 s. CR was performed in 31% of colonoscopies. CR frequency varied between endoscopists with 9 never performing CR and 2 performing CR in all colonoscopies. When performed, nearly half (43%) of RVs did not extend to the HF with median RV duration of 16 s (IQR 9–30 s). Three polyps were identified in the RV (polyp detection rate of 8.1%), all identified prior to a forward view.
Conclusions
CR is performed infrequently in routine practice. When CR is performed, the RV is of low quality with a very short inspection duration and insufficient ascending colon examination. Further education is required to educate endoscopists in optimal technique to improve overall colonoscopy quality.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
The effect of retroflexed view (RV) for the reexamination of the right colon after forward view (FV) examination has not been fully understood.
Methods
We searched multiple databases ...including PubMed, Embase, and the Cochrane Library for prospective studies exploring the role of RV for reexamination of the right colon. A meta‐analysis was performed on outcomes including lesion detection rates, lesion miss rates, and withdrawal time.
Results
Four randomized controlled trials aimed to compare the impact of the second withdrawal from the right colon in RV vs. FV following a standard colonoscopy. Both the additional adenoma detection rate (AADR) and additional polyp detection rate (APDR) of the right colon were lower in the RV group compared with the FV group (risk ratio RR 0.73 for AADR; RR 0.76 for APDR); similar results were noted in comparisons of the adenoma miss rate and polyp miss rate. Six prospective cohort studies aimed to describe the effect of the RV examination of the right colon after one or two rounds of FV examination. Both the adenoma detection rate (ADR) and polyp detection rate (PDR) of the right colon were slightly higher in combined examinations with RV examination than single FV examination (RR 1.11 for ADR; RR 1.16 for PDR) or two FV examinations (RR 1.21 for ADR; RR 1.22 for PDR).
Conclusions
FV may detect more adenomas and polyps than RV during the second withdrawal from the right colon. RV may detect additional adenomas and polyps in the right colon after two FV examinations.
PDF
