Comparison of Right Colon Flat Polyp Detection Rate by Water Exchange Versus Water Immersion-pooled Results of Data File of 3 Published Reports

GOALS

We tested the hypothesis that water exchange (WE) achieved a significantly higher right colon flat polyp detection rate (rFPDR) than water immersion (WI).

BACKGROUND

Current endoscopy methods provide real-time morphology but not histopathology. Flat serrated polyps are difficult to find during colonoscopy. In 2022 2 studies reported that the serrated polyp detection rate (SPDR) significantly inversely predicted the development of interval cancers. In 2021 1 systemic review with meta-analysis showed that WE, but not WI increased SPDR. The relative contributions of WE and WI on rFPDR are unknown.

STUDY

Individual patient data from 3 reports comparing air insufflation, WI, and WE were pooled. Multiple logistic regression analysis was used to assess the factors associated with a higher rFPDR.

RESULTS

The pooled data showed that the rFPDR of air insufflation, WI, and WE were 15.4%, 14.1%, and 19.4% ( P =0.009), respectively. After adjusting for age and withdrawal time, multiple logistic regression analysis revealed that WE, when compared with WI, was significantly associated with a higher rFPDR (adjusted odds ratio[aOR]=1.53, P =0.002). Analysis of data on pathology and size were omitted to avoid duplicating our earlier publications.

CONCLUSIONS

Significantly higher rFPDR was achieved by WE. Water exchange rather than WI merits consideration for use to maximize rFPDR. Removal of flat polyps, and by inference serrated polyps, ensures their optimal management to minimize the occurrence of interval cancers. The potential benefit of WE in maximizing SPDR and minimizing interval cancers deserves evaluation in long-term randomized controlled studies focused on flat polyps detection.

The gut microbiome dysbiosis and regulation by fecal microbiota transplantation: umbrella review

Background

Gut microbiome dysbiosis has been implicated in various gastrointestinal and extra-gastrointestinal diseases, but evidence on the efficacy and safety of fecal microbiota transplantation (FMT) for therapeutic indications remains unclear.

Methods

The gutMDisorder database was used to summarize the associations between gut microbiome dysbiosis and diseases. We performed an umbrella review of published meta-analyses to determine the evidence synthesis on the efficacy and safety of FMT in treating various diseases. Our study was registered in PROSPERO (CRD42022301226).

Results

Gut microbiome dysbiosis was associated with 117 gastrointestinal and extra-gastrointestinal. Colorectal cancer was associated with 92 dysbiosis. Dysbiosis involving Firmicutes (phylum) was associated with 34 diseases. We identified 62 published meta-analyses of FMT. FMT was found to be effective for 13 diseases, with a 95.56% cure rate (95% CI: 93.88-97.05%) for recurrent Chloridoids difficile infection (rCDI). Evidence was high quality for rCDI and moderate to high quality for ulcerative colitis and Crohn's disease but low to very low quality for other diseases.

Conclusion

Gut microbiome dysbiosis may be implicated in numerous diseases. Substantial evidence suggests FMT improves clinical outcomes for certain indications, but evidence quality varies greatly depending on the specific indication, route of administration, frequency of instillation, fecal preparation, and donor type. This variability should inform clinical, policy, and implementation decisions regarding FMT.

Safety of high-carbohydrate fluid diet 2 h versus overnight fasting before non-emergency endoscopic retrograde cholangiopancreatography: A single-blind, multicenter, randomized controlled trial

BACKGROUND

Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography (ERCP), the benefits and safety of high-carbohydrate fluid diet (CFD) intake 2 h before ERCP remain unclear. This study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients' recovery.

METHODS

This prospective, multicenter, randomized controlled trial involved 15 tertiary ERCP centers. A total of 1330 patients were randomized into CFD group (n = 665) and fasting group (n = 665). The CFD group received 400 mL of maltodextrin orally 2 h before ERCP, while the control group abstained from food/water overnight (>6 h) before ERCP. All ERCP procedures were performed using deep sedation with intravenous propofol. The investigators were blinded but not the patients. The primary outcomes included postoperative fatigue and abdominal pain score, and the secondary outcomes included complications and changes in metabolic indicators. The outcomes were analyzed according to a modified intention-to-treat principle.

RESULTS

The post-ERCP fatigue scores were significantly lower at 4 h (4.1 ± 2.6 vs. 4.8 ± 2.8, t = 4.23, P <0.001) and 20 h (2.4 ± 2.1 vs. 3.4 ± 2.4, t = 7.94, P <0.001) in the CFD group, with least-squares mean differences of 0.48 (95% confidence interval [CI]: 0.26-0.71, P <0.001) and 0.76 (95% CI: 0.57-0.95, P <0.001), respectively. The 4-h pain scores (2.1 ± 1.7 vs. 2.2 ± 1.7, t = 2.60, P = 0.009, with a least-squares mean difference of 0.21 [95% CI: 0.05-0.37]) and positive urine ketone levels (7.7% [39/509] vs. 15.4% [82/533], χ2 = 15.13, P <0.001) were lower in the CFD group. The CFD group had significantly less cholangitis (2.1% [13/634] vs. 4.0% [26/658], χ2 = 3.99, P = 0.046) but not pancreatitis (5.5% [35/634] vs. 6.5% [43/658], χ2 = 0.59, P = 0.444). Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla (odds ratio [OR]: 0.61, 95% CI: 0.39-0.95, P = 0.028) in the multivariable models.

CONCLUSION

Ingesting 400 mL of CFD 2 h before ERCP is safe, with a reduction in post-ERCP fatigue, abdominal pain, and cholangitis during recovery.

TRAIL REGISTRATION

ClinicalTrials.gov, No. NCT03075280.

Identification of a novel bile marker clusterin and a public online prediction platform based on deep learning for cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor, and its diagnosis is still a challenge. This study aimed to identify a novel bile marker for CCA diagnosis based on proteomics and establish a diagnostic model with deep learning.

METHODS

A total of 644 subjects (236 CCA and 408 non-CCA) from two independent centers were divided into discovery, cross-validation, and external validation sets for the study. Candidate bile markers were identified by three proteomics data and validated on 635 clinical humoral specimens and 121 tissue specimens. A diagnostic multi-analyte model containing bile and serum biomarkers was established in cross-validation set by deep learning and validated in an independent external cohort.

RESULTS

The results of proteomics analysis and clinical specimen verification showed that bile clusterin (CLU) was significantly higher in CCA body fluids. Based on 376 subjects in the cross-validation set, ROC analysis indicated that bile CLU had a satisfactory diagnostic power (AUC: 0.852, sensitivity: 73.6%, specificity: 90.1%). Building on bile CLU and 63 serum markers, deep learning established a diagnostic model incorporating seven factors (CLU, CA19-9, IBIL, GGT, LDL-C, TG, and TBA), which showed a high diagnostic utility (AUC: 0.947, sensitivity: 90.3%, specificity: 84.9%). External validation in an independent cohort (n = 259) resulted in a similar accuracy for the detection of CCA. Finally, for the convenience of operation, a user-friendly prediction platform was built online for CCA.

CONCLUSIONS

This is the largest and most comprehensive study combining bile and serum biomarkers to differentiate CCA. This diagnostic model may potentially be used to detect CCA.

Saline irrigation for reducing the recurrence of common bile duct stones after lithotripsy: a randomized controlled trial

Background

Mechanical lithotripsy produces stone fragments that are not easily detected by cholangiography and is a potential cause of recurrence of common bile duct stones (CBDS). This study aims to clarify whether 100 ml saline irrigation after mechanical lithotripsy reduces the recurrent rate of CBDS.

Methods

In this randomized controlled trial performed at the Surgical Endoscopy Center, the First Hospital of Lanzhou University between May 10, 2019, and Dec 31, 2020, patients undergoing endoscopic mechanical lithotripsy were randomly assigned to receive saline irrigation (study group) or no irrigation (control group). The saline irrigation was given 100 ml saline pulse irrigation after cholangiography showed no residual stones. Patients were followed up for at least 24 months after endoscopic stone removal to assess the recurrence of CBDS. This study was registered with ClinicalTrials.gov (NCT03937037).

Findings

During the median follow-up period of 35.6 months (interquartile range, 26.0-40.7), 43 of the 180 patients had stone recurrence (24%). The frequency of recurrence of CBD stones was 12.22% in the saline irrigation group and 35.56% in the control group, with a difference of 23.33% between the two groups (95% confidence interval [CI], 11.35%-35.32%, p < 0.001). Multivariable Cox proportional hazards analyses showed that constipation (hazard risk [HR] 2.42; 95% CI, 1.22-4.80, p = 0.012), periampullary diverticulum (PAD) (HR 3.06; 95% CI, 1.62-5.79, p < 0.001), and total to direct bilirubin ratio (HR 1.48; 95% CI, 1.21-1.81, p < 0.001) were independent risk factors for the recurrence of CBDS. Saline irrigation was the only preventive factor for the recurrence of CBDS (HR 0.22; 95% CI, 0.11-0.44, p < 0.001).

Interpretation

For patients with CBDS requiring mechanical lithotripsy, 100 ml saline irrigation effectively reduces the recurrent rate of CBDS after endoscopic stone removal.

Funding

This work was supported by National Natural Science Foundation of China (32160255); Natural Science Foundation of Gansu Province (22JR5RA898, 20JR10RA676); Science and Technology Planning Project of Chengguan District in Lanzhou (2020JSCX0043).

A survey of colonoscopists with and without in-depth knowledge of water-aided colonoscopy

BACKGROUND AND AIM

Endoscopy featured water-aided colonoscopy (WAC) as novel in the Innovation Forum in 2011. Gastrointestinal Endoscopy published a modified Delphi consensus review (MDCR) that supports WAC for clinical practice in 2021. We tested the hypothesis that experience was an important predictor of WAC use, either as water immersion (WI), water exchange (WE), or a combination of WI and WE.

METHODS

A questionnaire was sent by email to the MDCR authors with an in-depth knowledge of WAC. They responded and also invited colleagues and trainees without in-depth knowledge to respond. Logistic regression analysis was used with the reasons for WAC use treated as the primary outcome. Reports related to WAC post MDCR were identified.

RESULTS

Of 100 respondents, > 80% indicated willingness to adopt and modify practice to accommodate WAC. Higher adenoma detection rate (ADR) incentivized WE use. Procedure time slots ≤ 30 and > 30 min significantly predicted WI and WE use, respectively. Co-authors of the MDCR were significantly more likely to perform WAC (odds ratio [OR] = 7.5, P = 0.037). Unfamiliarity with (OR = 0.11, P = 0.02) and absence of good experience (OR = 0.019, P = 0.002) were associated with colonoscopists less likely to perform WAC. Reports related to WAC post MDCR revealed overall and right colon WE outcomes continued to improve. Network meta-analyses showed that WE was superior to Cap and Endocuff. On-demand sedation with WE shortened nursing recovery time.

CONCLUSIONS

An important predictor of WAC use was experience. Superior outcomes continued to be reported with WE.

Safety and effectiveness of underwater cold snare resection without submucosal injection of large non-pedunculated colorectal lesions

Background and study aims  Adverse events are uncommon with cold snaring, but cold techniques are generally reserved for lesions ≤ 9 mm out of concern for incomplete resection or inability to mechanically resect larger lesions. In a non-distended, water-filled lumen, colorectal lesions are not stretched, enabling capture and en bloc resection of large lesions. We assessed the effectiveness and safety of underwater cold snare resection (UCSR) without submucosal injection (SI) of ≥ 10 mm non-pedunculated, non-bulky (≤ 5 mm elevation) lesions with small, thin wire snares. Patients and methods  Retrospective analysis of an observational cohort of lesions removed by UCSR during colonoscopy. A single endoscopist performed procedures using a small thin wire (9-mm diameter) cold or (10-mm diameter) hybrid snare. Results  Fifty-three lesions (mean 15.8 mm [SD 6.9]; range 10-35 mm) were removed by UCSR from 44 patients. Compared to a historical cohort, significantly more lesions were resected en bloc by UCSR (84.9 % [45/53]; P  = 0.04) compared to conventional endoscopic mucosal resection (EMR) (64.0 % [32/50]). Results were driven by high en bloc resection rates for 10- to 19-mm lesions (97.3 % [36/37]; P  = 0.01). Multiple logistic regression analysis adjusted for potential confounders showed en bloc resection was significantly associated with UCSR compared to conventional EMR (OR 3.47, P  = 0.027). Omission of SI and forgoing prophylactic clipping of post-resection sites did not result in adverse outcomes. Conclusions  UCSR of ≥ 10 mm non-pedunculated, non-bulky colorectal lesions is feasible with high en bloc resection rates without adverse outcomes. Omission of SI and prophylactic clipping decreased resource utilization with economic benefits. UCSR deserves further evaluation in a prospective comparative study.

A novel machine learning model and a public online prediction platform for prediction of post-ERCP-cholecystitis (PEC)

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) is an established treatment for common bile duct (CBD) stones. Post- ERCP cholecystitis (PEC) is a known complication of such procedure and there are no effective models and clinical applicable tools for PEC prediction.

METHODS

A random forest (RF) machine learning model was developed to predict PEC. Eligible patients at The First Hospital of Lanzhou University in China with common bile duct (CBD) stones and gallbladders in-situ were enrolled from 2010 to 2019. Logistic regression analysis was used to compare the predictive discrimination and accuracy values based on receiver operation characteristics (ROC) curve and decision and clinical impact curve. The RF model was further validated by another 117 patients. This study was registered with ClinicalTrials.gov, NCT04234126.

FINDINGS

A total of 1117 patients were enrolled (90 PEC, 8.06%) to build the predictive model for PEC. The RF method identified white blood cell (WBC) count, endoscopic papillary balloon dilatation (EPBD), increase in WBC, residual CBD stones after ERCP, serum amylase levels, and mechanical lithotripsy as the top six predictive factors and has a sensitivity of 0.822, specificity of 0.853 and accuracy of 0.855, with the area under curve (AUC) value of 0.890. A separate logistic regression prediction model was built with sensitivity, specificity, and AUC of 0.811, 0.791, and 0.864, respectively. An additional 117 patients (11 PEC, 9.40%) were used to validate the RF model, with an AUC of 0.889 compared to an AUC of 0.884 with the logistic regression model.

INTERPRETATION

The results suggest that the proposed RF model based on the top six PEC risk factors could be a promising tool to predict the occurrence of PEC.

Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations

BACKGROUND AND AIMS

Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR.

METHODS

Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements.

RESULTS

In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11).

CONCLUSIONS

The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.

Could saline irrigation clear all residual common bile duct stones after lithotripsy? A self-controlled prospective cohort study

BACKGROUND

A previous study showed that irrigation with 100 mL saline reduced residual common bile duct (CBD) stones, which potentially cause recurrent stones after endoscopic retrograde cholangiopancreatography.

AIM

To determine whether saline irrigation can improve CBD clearance after lithotripsy.

METHODS

This prospective self-controlled study enrolled patients receiving mechanical lithotripsy for large (> 1.2 cm) CBD stones. After occlusion cholangiography confirmed CBD stone clearance, peroral cholangioscopy (POC) was performed to determine clearance scores based on the number of residual stones. The amounts of residual stones spotted via POC were graded on a 5-point scale (score 1, worst; score 5, best). Scores were documented after only stone removal (control) and after irrigation with 50 mL and 100 mL saline, respectively. The stone composition was analyzed using infrared spectroscopy.

RESULTS

Between October 2018 and January 2020, 47 patients had CBD clearance scores of 2.4 ± 1.1 without saline irrigation, 3.5 ± 0.7 with 50 mL irrigation, and 4.6 ± 0.6 with 100 mL irrigation (P < 0.001). Multivariate analysis showed that CBD diameter > 15 mm [odds ratio (OR) = 0.08, 95% confidence interval (CI): 0.01-0.49; P = 0.007] and periampullary diverticula (PAD) (OR = 6.51, 95%CI: 1.08-39.21; P = 0.041) were independent risk factors for residual stones. Bilirubin pigment stones constituted the main residual stones found in patients with PAD (P = 0.004).

CONCLUSION

Irrigation with 100 mL of saline may not clear all residual CBD stones after lithotripsy, especially in patients with PAD and/or a dilated (> 15 mm) CBD. Pigment residual stones are soft and commonly found in patients with PAD. Additional saline irrigation may be required to remove retained stones.

The evaluation of ENGBD versus PTGBD in high-risk acute cholecystitis: A single-center prospective randomized controlled trial

BACKGROUND

Gallbladder drainage plays a key role in the management of acute cholecystitis (AC) patients. Percutaneous transhepatic gallbladder drainage (PTGBD) is commonly used while endoscopic naso-gallbladder drainage (ENGBD) serves as an alternative.

METHODS

A single center, prospective randomized controlled trial was performed. Eligible AC patients were randomly assigned to ENGBD or PTGBD group. Randomization was a computer-generated list with 1:1 allocation. All patients received cholecystectomy 2-3 months after drainage. The primary endpoint was abdominal pain score, and the intention-to-treat population was analyzed. (ClinicalTrials.gov: NCT03701464).

FINDINGS

Between Oct 1, 2018 and Feb 29, 2020, 22 out of 61 consecutive AC patients were enrolled in the final analysis. The mean abdominal pain scores before drainage, and at 24, 48, and 72 h after drainage in ENGBD were 6.9 ± 1.1, 4.3 ± 1.2, 2.2 ± 0.8 and 1.5 ± 0.5, respectively, while those of PTGBD were 7.4 ± 1.2, 6.2 ± 1.2, 5.3 ± 1.0 and 3.7 ± 0.9; and the mean gallbladder area tenderness scores were 8.4 ± 1.2, 5.7 ± 0.9, 3.5 ± 0.7, 2.5 ± 0.5 for ENGBD and 8.6 ± 0.9, 7.3 ± 1.0, 7.4 ± 0.5, 4.8 ± 0.9 for PTGBD. The mean abdominal pain and gallbladder area tenderness scores of the ENGBD significantly decreased than the PTGBD (group × time interaction P<0.001, respectively). ENGBD group presented lower post-operative hemorrhage and abdominal drainage tube placement rates (median (IQR) 15[5-20] vs 40[20-70]ml, 3vs9, P = 0.03), and pathological grade and lymphocyte count were observed (P = 0.004) between groups. No adverse events were observed in 3 months follow-up.

INTERPRETATION

Compared to PTGBD, ENGBD group presented less pain, better gallbladder pathological grades and less surgical difficulties during cholecystectomy procedures.

FUNDING

National Natural Science Foundation of China (82060551).

Underwater versus conventional endoscopic resection of nondiminutive nonpedunculated colorectal lesions: a prospective randomized controlled trial (with video)

BACKGROUND AND AIMS

Incomplete resection of colorectal neoplasia decreases the efficacy of colonoscopy. Conventional resection (CR) of polyps, performed in a gas-distended colon, is the current standard, but incomplete resection rates of approximately 2% to 30% for nondiminutive (>5 mm), nonpedunculated lesions are reported. Underwater resection (UR) is a novel technique. The aim of this study was to determine the incomplete resection rates of colorectal lesions removed by UR versus CR.

METHODS

In a randomized controlled trial, patients with small (6-9 mm) and large (≥10 mm) nonpedunculated lesions were assigned to CR (gas-distended lumen) or UR (water-filled, gas-excluded lumen). Small lesions in both arms were removed with a dedicated cold snare. For CR, large lesions were removed with a hot snare after submucosal injection. For UR, large lesions were removed with a hot snare without submucosal injection. Four-quadrant biopsy samples around the resection sites were used to evaluate for incomplete resection.

RESULTS

Four hundred sixty-two eligible polyps (248 UR vs 214 CR) from 255 patients were removed. Incomplete resection rates for UR and CR were low and did not differ (2% vs 1.9%, P = .91). UR was performed significantly faster for lesions ≥10 mm in size (10-19 mm, 2.9 minutes vs 5.6 minutes, P < .0001); ≥20 mm, 7.3 minutes vs 9.5 minutes, P = .015).

CONCLUSIONS

Low incomplete resection rates are achievable with UR and CR. UR is effective and safe with the advantage of faster resection and potential cost savings for removal of larger (≥10 mm) lesions by avoiding submucosal injection. As an added approach, UR has potential to improve the cost-effectiveness of colonoscopy by increasing efficiency and reducing cost while maintaining quality. (Clinical trial registration number: NCT02889679.).

Percutaneous transhepatic biliary drainage may be the preferred preoperative drainage method in hilar cholangiocarcinoma

Background and study aims  Preoperative biliary drainage of hilar cholangiocarcinoma (HC) is controversial. The goal of this study was to compare the clinical outcome and associated complications for types II, III, and IV HC managed by percutaneous transhepatic biliary drainage (PTBD) and endoscopic retrograde cholangiopancreatography (ERCP). Patients and methods  Between January 2011 and June 2017, a total of 180 patients with II, III, and IV HC were enrolled in this retrospective cohort study. According to the drainage method, patients were divided into two groups: PTBD (n = 81) and ERCP (n = 99). This study was registered with ClinicalTrials.gov, NCT03104582, and was completed. Results  Compared with the PTBD group, the ERCP group had a higher incidence of post-procedural cholangitis (37 [37.37 %] vs. 18 [22.22 %], P  = 0.028) and pancreatitis (17 [17.17 %] vs. 2 [2.47 %], P  = 0.001); required more salvaged biliary drainage (18 [18.18 %] vs. 5 [6.17 %], P  = 0.029), and incurred a higher cost ( P  < 0.05). Patients with type III and IV HC in the ERCP group had more cholangitis than those in the PTBD group (26 [36.62 %] vs. 11 [18.03 %], P  = 0.018). The rate of cholangitis in patients who received endoscopic bilateral biliary stents insertion was higher than patients with unilateral stenting (23 [50.00 %] vs. 9 [26.47 %], P  = 0.034), and underwent PTBD internal-external drainage had a higher incidence of cholangitis than those with only external drainage (11 [34.36 %] vs. 7 [14.29 %], P  = 0.034). No significant difference in the rate of cholangitis was observed between the endoscopic unilateral stenting group and the endoscopic nasobiliary drainage group (9 [26.47 %] vs. 5 [26.32 %], P  = 0.990). Conclusion  Compared to ERCP, PTBD reduced the rate of cholangitis, pancreatitis, salvage biliary drainage, and decreased hospitalization costs in patients with types II, III, and IV HC. Risk of cholangitis for patients with types III and IV was significantly lower in the PTBD group.

Underwater polypectomy without submucosal injection for colorectal lesions ≤ 20 mm in size-a multicenter retrospective observational study

BACKGROUND

Underwater polypectomy (UWP) of large (≥ 20 mm) colorectal lesions is well described, but reports of UWP for lesions ≤ 20 mm in size, which account for > 95% of polyps encountered in routine clinical practice, are limited. We assessed the feasibility of UWP in routine practice across various sites for colorectal lesions ≤ 20 mm in size.

METHODS

A multicenter retrospective study was performed on pooled data from nine colonoscopists at 3 U.S., 1 Taiwanese and 2 Italian sites. Outcomes related to UWP on lesions ≤ 20 mm in size were analyzed.

RESULTS

In 117 patients, UWP netted 169 lesions. Polypectomy by hot (HSP, 54%) or cold (CSP, 41%) snare, and cold forceps (CFP, 5%) were performed successfully without endoscopic evidence of residual neoplasia or immediate clinically significant adverse events. The majority (74.6%) were tubular adenomas; 60.9% were from the proximal colon. Histopathologic margins were positive in 4 and unavailable in 26 CSP and 24 HSP specimens. The remainder had negative resection margins on pathologic reports.

CONCLUSION

UWP for colorectal lesions ≤ 20 mm in routine practice across multiple sites confirms the feasibility and acceptability of this technique. Improvement of resection outcomes by UWP in routine practice deserves further evaluation in a randomized controlled trial.

Optimal dilation time for combined small endoscopic sphincterotomy and balloon dilation for common bile duct stones: a multicentre, single-blinded, randomised controlled trial

BACKGROUND

Endoscopic sphincterotomy is the established treatment for common bile duct stones. Balloon dilation offers an alternative. Prolonged dilation (300 s) with a 10 mm diameter balloon decreases the occurrence of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). We aimed to determine the optimal duration of dilation for combined endoscopic sphincterotomy and balloon dilation for the removal of common bile duct stones.

METHODS

We did a multicentre, single-blinded, randomised controlled trial at 15 tertiary surgical centres in China. Eligible patients (≥18 years) with native papilla and common bile duct stones (≤1·5 cm in size and <2 cm in diameter) undergoing ERCP were randomly assigned (1:1:1:1:1) to receive balloon dilation for 0, 30, 60, 180, or 300 s after deep bile duct cannulation. Randomisation was done by an independent statistician using a computer-generated randomisation list with a block size of ten, stratified by centre. Patients and outcome assessors, but not endoscopists and investigators, were masked to treatment allocation. Balloon dilation was done with controlled radial expansion balloons according to common bile duct stone size. Stones were removed using stone retrieval balloons or baskets. The primary endpoint was overall frequency of post-ERCP pancreatitis. The primary efficacy analysis and safety analyses were done in the modified intention-to-treat population, which included all randomly assigned patients with successful cannulation, but excluded those who withdrew consent after randomisation. This study was registered with ClinicalTrials.gov, number NCT02510495, and is complete.

FINDINGS

Between July 29, 2015, and Dec 1, 2017, 3721 consecutive patients with common bile duct stones were recruited, 1718 of whom were excluded. The remaining 2003 patients underwent a small (3-5 mm) endoscopic sphincterotomy. 83 patients withdrew consent after the ERCP procedure, thus 1920 patients were included in the modified intention-to-treat analysis (0 s [n=371], 30 s [n=384], 60 s [n=388], 180 s [n=390], and 300 s [n=387]). Overall, post-ERCP pancreatitis occurred in 199 (10%) of 1920 patients (44 [12%] patients in the 0 s group, 28 [7%] in the 30 s group, 32 [8%] in the 60 s group, 36 [9%] in the 180 s group, and 59 [15%] in the 300 s group). Prolonged dilation (300 s) significantly increased the occurrence of post-ERCP pancreatitis compared with shorter balloon dilation (p=0·002). The frequency of post-ERCP pancreatitis was significantly lower in the 30, 60, and 180 s groups than in the 300 s group (relative risk [RR] 0·48, 95% CI 0·31-0·73; p=0·0005 vs the 30 s group; 0·54, 0·36-0·81; p=0·003 vs the 60 s group; 0·61, 0·41-0·89; p=0·01 vs the 180 s group). The frequency of post-ERCP pancreatitis was significantly higher in the 0 s group than the 30 s group (RR 1·62, 1·04-2·56; p=0·03). No difference in stone extraction (all ≥90%) was observed between groups. Following ERCP, 90 (5%) of 1920 patients had acute cholangitis, 14 (<1%) had acute cholecystitis, and five (<1%) had gastrointestinal bleeding, with no significant differences between groups. One (<1%) patient had Stapfer II perforation, which resolved spontaneously with conservative treatment.

INTERPRETATION

A balloon dilation time of 30 s for combined endoscopic sphincterotomy and balloon dilation reduced the frequency of post-ERCP pancreatitis and was determined to be the optimum dilation time for the removal of common bile duct stones.

FUNDING

National Natural Science Foundation of China, Gansu Competitive Foundation Projects for Technology Development and Innovation.

A prospective RCT comparing combined chromoendoscopy with water exchange (CWE) vs water exchange (WE) vs air insufflation (AI) in adenoma detection in screening colonoscopy

Background

A low adenoma detection rate (ADR) increases risks of interval cancers (ICs). Proximal colon flat polyps, e.g. serrated lesions (SLs), are difficult to find. Missed proximal colon flat lesions likely contribute to IC.

Aims

We compared chromoendoscopy with water exchange (CWE), water exchange (WE) and air insufflation (AI) in detecting adenomas in screening colonoscopy.

Methods

After split-dose preparation, 480 veterans were randomized to AI, WE and CWE.

Results

Primary outcome of proximal ADR (55.6% vs 53.4% vs 52.2%, respectively) were similar in all groups. Adenoma per colonoscopy (APC) and adenoma per positive colonoscopy (APPC) were comparable. Detection rate of proximal colon SLs was significantly higher for CWE and WE than AI (26.3%, 23.6% and 11.3%, respectively, p = 0.002). Limitations: single operator; SLs only surrogate markers of but not IC.

Conclusions

When an endoscopist achieves high-quality AI examinations with overall ADR twice (61.6%) the recommended standard (30%), use of WE and CWE does not produce further improvement in proximal or overall ADR. Comparable APC and APPC confirm equivalent withdrawal inspection techniques. WE alone is sufficient to significantly improve detection of proximal SLs. The impact of increased detection of proximal SLs by WE on prevention of IC deserves to be studied. This study is registered at ClinicalTrial.gov (NCT#01607255).

Discovery of specific targeting ligands as the biomarkers for colorectal cancer

Aim: Targeted diagnosis and therapy for colorectal cancer (CRC) is limited by the lack of specific biomarkers. Our aim was to discover CRC-specific targeting ligands using a one-bead one-compound (OBOC) combinatorial library. Method: Samples of OBOC peptide libraries were color coded, mixed and incubated with commercially available human CRC cells (HT-29 and DLD-1). Libraries with compound beads that bound to CRC cells were selected for further screening. Compound beads that bound to both CRC cells were screened with human colonic epithelial cells to select beads that bound only to CRC cells but not to human colonic epithelial cells. Chemical structures of the positive peptides were determined by Edman chemistry. CRC-targeted imaging agents were developed by conjugation of CRC binding peptide with biotin through a hydrophilic linker and then complexed with streptavidin–Cy5.5. Immunohistochemistry studies were used to evaluate CRC detection efficacy. Targeting specificity was further tested with subcutaneous CRC xenografts in nude mice. Results: Two cyclic peptides, CRC-6 and CRC-9, composed of natural and unnatural amino acids, bind specifically to CRC cells with moderately high affinity and specificity. CRC-9 is able to detect CRC cells grown on chamber slides at the concentration of 1 µM after 30 min incubation. Tail vein injection of 1.8 nmol biotinylated peptide CRC-9, complexed with streptavidin–Cy5.5 (SA–Cy5.5), is able to target the subcutaneous CRC xenograft implants in nude mice. None of the two peptides showed cytotoxic effect on human blood cells, up to the concentration of 500 µM. Conclusion: CRC-9 has the potential to be developed as an effective biomarker for improving the management of CRC patients by enhancing the efficiency of detection and efficacy of targeting treatment.

Comparable Long-term Outcomes of 1-Minute vs 5-Minute Endoscopic Papillary Balloon Dilation for Bile Duct Stones

BACKGROUND & AIMS

Endoscopic papillary balloon dilation (EPBD) is an alternative to endoscopic sphincterotomy for choledocholithiasis. Unlike endoscopic sphincterotomy, EPBD preserves biliary sphincter function, reducing long-term risk of recurrent choledocholithiasis by 50%. Guidelines recommend that duration of EPBD exceeds 2 minutes, to adequately loosen the sphincter and reduce risks of failed stone extraction and post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis. However, it is unclear whether this long duration of EPBD impairs sphincter function and negates the long-term benefit of EPBD. We performed a randomized controlled trial to determine whether long-duration (>1 minute) EPBD increases the risk of subsequent choledocholithiasis and hepatobiliary complications compared with short-duration EPBD (<1 minute).

METHODS

We performed a prospective study of 170 adult patients who underwent ERCP for suspected choledocholithiasis from April 2007 through October 2008 at 2 centers in Taiwan. Patients were randomly assigned to groups that underwent 1-minute (n = 86) or 5-minute (n = 84) EPBD for choledocholithiasis; patients were followed through June 2015. One month after the initial ERCP, patients were examined and liver function tests and abdominal sonographies were performed. Patients were then examined every 3-6 months over a median follow-up period of approximately 7 years. The primary outcome was recurrent choledocholithiasis or acute cholangitis and the secondary outcome was overall hepatobiliary complications. We assessed the effects of EPBD duration by Cox regression.

RESULTS

Thirteen patients (15.1%) developed recurrent choledocholithiasis or acute cholangitis after 1-minute EPBD, and 10 patients (11.9%) developed recurrent choledocholithiasis or acute cholangitis after 5-minute EPBD (P = .352). There was no significant difference between groups in number of hepatobiliary complications (P = .154). Compared with 1-minute EPBD, 5-minute EPBD did not increase risk of the primary outcome (adjusted hazard ratio, 0.76; 95% confidence interval, 0.32-1.82) or the secondary outcome (adjusted hazard ratio, 0.65; 95% confidence interval, 0.31-1.40). Mechanical lithotripsy, performed for failed stone extraction with EPBD at initial ERCP, was a risk factor for primary and secondary outcomes.

CONCLUSIONS

In a randomized controlled trial, we found that the risk of recurrent choledocholithiasis and hepatobiliary complications did not increase with long-duration EPBD (>1 minute), but was increased with mechanical lithotripsy.

Flexible transgastric endoscopic liver cyst fenestration: A feasibility study in humans (with video)

There is no clinical report on the use of natural orifice transluminal endoscopic surgery (NOTES) for the management of patients with large liver cysts.This study aims to evaluate the feasibility and safety of NOTES for liver cyst fenestration in humans using a currently available technique.From February 2009 to June 2010, 4 cases of transgastric endoscopic liver cyst fenestration were performed; in which 3 cases received NOTES only, while 1 case received additional laparoscopic assistance.Mean time to endoscopically locate the liver cyst was 16 minutes (5-22 minutes). Cysts that were present in the left lobe or on the liver surface were easier to locate endoscopically. Transgastric endoscopic liver cyst fenestration was successful in all patients. The use of an occlusion balloon helped in the endoscopic clipping of the gastrotomy incision. Mean operative time was 101.3 minutes (range, 90-112 minutes), and there were no intra- or postoperative complications including infections. All patients recovered well after the surgery, with only minor postoperative throat pain. There was no recurrence at a mean follow-up of 12 months (range, 6-48 months).Small sample size.It may be technically feasible and safe to perform transgastric endoscopic liver cyst fenestration in humans with no recurrence at follow up.

Comparison of sequential pancreatic duct guidewire placement technique and needle knife precut sphincterotomy for difficult biliary cannulation

OBJECTIVE

Pancreatic duct guidewire placement (PDGP) includes double guidewire technique (DGT) and transpancreatic sphincterotomy (TPS). DGT can be switched to TPS with ease due to the existing guidewire in the pancreatic duct. In this study, we aimed to combine DGT and TPS as a single technique, named sequential PDGP, and to compare its performance with needle knife precut sphincterotomy (NKPS) in treating difficult biliary cannulation (BC).

METHODS

A total of 83 patients with difficult BC were enrolled in this study. Of these, 63 underwent sequential PDGP and 20 underwent NKPS. Cannulation success rate, cannulation time and endoscopic retrograde cholangiopancreatography (ERCP)-related complications were prospectively recorded and compared between the two groups.

RESULTS

Successful BC was achieved in 88.9% (56/63) of the patients in the sequential PDGP group compared with 70.0% (14/20) in the NKPS group (P = 0.095). Cannulation time was 7.49 ± 5.03 min in the sequential PDGP group and 10.60 ± 7.24 min in the NKPS group (P = 0.086). Post-ERCP pancreatitis occurred in 12.7% of patients in the sequential PDGP group and 10.0% in the NKPS group (P = 1.000). There was no significant difference in the rates of other complications (bleeding, perforation and cholangitis) between the two groups.

CONCLUSIONS

Sequential PDGP is a safe and effective alternative method to NKPS in cases of difficult BC. In those with failed standard cannulation, sequential PDGP can be considered when the guidewire is inadvertently inserted into the pancreatic duct or can be placed in the pancreatic duct without difficulty.

Management of benign biliary strictures with a novel retrievable self-expandable metal stent

OBJECTIVE

Endoscopic placement of covered self-expandable metal stent (SEMS) has gained popularity in the management of benign biliary strictures (BBS). The existing SEMS has been designed primarily to palliate malignant biliary obstruction and has a high frequency of stent migration, difficulty in retrieval and stricture recurrence after stent removal. This study aimed to design a novel retrievable SEMS dedicated to the treatment of extrahepatic BBS and evaluate its clinical efficacy and safety.

METHODS

A short fully covered SEMS (FCSEMS) with a retrieval lasso was designed for the specific treatment of BBS. A total of 45 patients with segmental extrahepatic BBS were included in this study. The stent was placed entirely inside the bile duct with only the retrieval lasso extending from the papilla. The stents were recommended to be in situ for 6 to 12 months before removal.

RESULTS

The FCSEMS was successfully placed in all 45 patients. In all, 33 patients had their FCSEMS successfully removed after a mean period of 8.6 ± 3.7 (range 2-15.5) months. Stent migration occurred in 9.1% of the patients. During a mean follow-up of 18.9 months after stent removal, recurrent stricture was found in 2 (6.1%) patients and was successfully treated with a second FCSEMS. Overall, the strictures resolved in 30/33 (90.9%) patients.

CONCLUSIONS

Intraductal placement of a short FCSEMS is suitable for the treatment of segmental extrahepatic BBS. This new removable design offered prolonged stenting and drainage for BBS for up to one year with minimal complications.

Impact of water exchange colonoscopy on serum sodium and potassium levels: an observational study

BACKGROUND

Concerns over the hypothetical adverse effects of water absorption and the disturbance of serum sodium and potassium levels prompted a quality assurance evaluation of water exchange (WE) colonoscopy.

AIM

The purpose of this study was to evaluate the balance of water infused and suctioned in WE colonoscopy, and to quantify the acute impact on serum levels of sodium and potassium.

METHODS

Prospectively collected quality monitoring data of patients undergoing screening and surveillance colonoscopy at the Sacramento Veterans Affairs Medical Center were analyzed. Measurements were made of volume infused and suctioned during, and blood samples drawn 10 min before the start of and 10 min after completion of WE colonoscopy. Outcome measures included volume of water infused and suctioned, and serum levels of sodium and potassium.

RESULTS

A total of 140 patients (134M:6F), mean age of 59, underwent WE colonoscopy. Mean total volume of water infused was 1,839 mL. A negative balance of an average of 22 mL was documented. The mean (standard deviation) values (in meq/L) of serum levels of sodium 139.33 (2.27) and 139.28 (2.32), and potassium 3.86 (0.36) and 3.91 (0.39), before and after colonoscopy, respectively, showed no significant change.

CONCLUSION

The WE method allowed most of the water infused during colonoscopy to be recovered by suction at the completion of colonoscopy. Serum sodium and potassium levels did not change significantly within 10 min after completion. The WE method appears to be safe with minimal water retention and is devoid of acute fluctuations in serum levels of sodium and potassium.

Abstract P2-01-01: Impact of California breast density notification law SB 1538 on California women and their health care providers

Purpose: To describe the impact of California Breast Density Notification law (SB 1538) on policy development, policy implementation and supplemental screening strategies within California medical facilities. SB 1538 mandates that breast density information be given to patients but provides no funding for supplemental screening, no guidance on how to triage women for supplemental screening nor which imaging modalities to use.

Methods:

As a result of the law, the California Breast Density Information Group (CBDIG) formed from academic and private practice radiologists and risk assessment experts, reviewing scientific literature and nationally recognized guidelines to provide evidence-based recommendations regarding supplemental screening in women with dense breast tissue. A survey was sent to 6 academic and 3 large private practices in California to record their experience in implementing the law.

Results: CBDIG created a public, institution-neutral, evidence-based website, “breastdensity.info”, that includes information and recommendations regarding supplemental breast screening, with triage for supplemental MRI or US based on breast cancer risk assessment using genetic or family history risk models. CBDIG facilities worked with referring health care providers to inform them of the new law, educated their staff and technologists on implementing policy, and developed notification strategies to comply with legislation.

The survey showed that all 9 facilities recommended supplemental screening based on family history models or genetic testing. 3/9 calculated breast cancer risk in the breast imaging clinic, and 2/9 emailed a risk survey to the patient. 3/9 reported risk in the radiology report, and 1/9 reported risk only if the patient was high risk. Risk assessments were performed by technologists and risk assessment health practitioners. 8/9 facilities estimated breast density by visual methods, and 1/9 by computer. All facilities performed screening breast MRI, 4/9 performed handheld screening US, and 2/9 tomosynthesis. 1/9 obtained tomosynthesis in anticipation of the law, 2/9 are trying to obtain automated whole breast US, and 3/9 are trying to obtain tomosynthesis. Facilities expressed concerns about additional false-positive biopsies produced by supplemental screenings, out-of-pocket expenses for women, and disparities (low income) in notified populations.

Conclusion: SB 1538 resulted in the formation of the CBDIG and the website, “breastdensity.info”. Our survey showed variations in imaging modalities available and policy implementation at each facility. Given that several states currently have breast density laws or have laws that will become effective in the near future, it is important for breast imagers and clinicians to be informed of the current literature, realize the variation in equipment and policies at various facilities, and develop recommendation strategies to guide patients seeking supplemental screening. We plan to follow up this survey with a larger survey of the Society of Breast Imagers at a later date.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-01-01.

Coached practice using ERCP mechanical simulator improves trainees' ERCP performance: a randomized controlled trial

BACKGROUND AND STUDY AIMS

Preliminary data suggested that simulation practice using an endoscopic retrograde cholangiopancreatography (ERCP) mechanical simulator (EMS) improved trainees' skill. The aims of the current study were to confirm the impact of coached EMS practice at the beginning of ERCP training and to investigate whether subsequent uncoached EMS practice provides additional benefit.

METHODS

Trainees entering ERCP training in 2008 (n = 8) and 2009 (n = 8) at two referral medical centers were randomized to receive a coached EMS practice either with (2009) or without (2008) subsequent uncoached practices or only routine training (controls). The outcome measures were successful deep biliary cannulation by the trainee and overall performance score as rated by blinded trainers, during the subsequent 3 months of clinical practice.

RESULTS

Trainees undergoing single and multiple EMS practices were more likely than controls to achieve successful biliary cannulation (single: adjusted odds ratio [aOR] 2.89, 95 % confidence interval [CI] 2.21 - 3.80 [P < 0.001]; multiple: 3.09, 95 %CI 1.13 - 8.46 [P = 0.028]) and to have superior overall performance scores (aOR 3.29, 95 %CI 1.37 - 7.91 [P = 0.008] and 6.92, 95 %CI 3.77 - 12.69 [P < 0.001], respectively). The benefit of single and multiple EMS practices on overall performance score remained significant after adjustment for success or failure of deep biliary cannulation (aOR 2.98, 95 %CI 1.38 - 6.43 [P = 0.005] and 6.09, 95 %CI 2.40 - 15.45 [P < 0.001], respectively). The benefits of single vs. multiple EMS practices were not statistically different.

CONCLUSIONS

Coached simulation using EMS improved novice trainees' success of biliary cannulation and overall ERCP performance. Additional uncoached practices did not appear to provide further benefit. Trainees should undergo a coached EMS practice at the beginning of ERCP training.

A novel method with significant impact on adenoma detection: combined water-exchange and cap-assisted colonoscopy

BACKGROUND

Water exchange provides salvage cleansing and improves adenoma detection, but drawbacks include prolonged procedure time. Cap-assisted colonoscopy decreases cecal intubation time but is limited by impaired views when feces lodge in the cap.

OBJECTIVE

To investigate the impact of combined water-exchange and cap-assisted colonoscopy (WCC) on detection of adenomas and proximal colon serrated polyps.

DESIGN

Retrospective, single-center, single-colonoscopist, consecutive group observational study.

SETTING

Veterans Affairs outpatient endoscopy suite.

PATIENTS

Outpatients undergoing screening or surveillance colonoscopy.

INTERVENTION

WCC data collected from 100 consecutive patients were compared to a control group of 101 consecutive patients examined with conventional air insufflation colonoscopy during the prior 4-month period.

MAIN OUTCOME MEASUREMENTS

Adenoma detection rate (ADR), adenomas detected per colonoscopy, proximal colon serrated polyp detection rate, and proximal colon serrated polyps per colonoscopy rate.

RESULTS

Compared with controls, the WCC group had a higher polyp detection rate (93.0% vs 84.2%; P = .07), ADR (75.0% vs 59.4%; P = .02), proximal colon ADR (61.0% vs 47.5%; P = .07), proximal colon serrated polyp detection rate (24.0% vs 9.9%; P = .009), number of adenomas per colonoscopy (2.70 vs 1.50; P = .002), and mean number of proximal colon serrated polyps per colonoscopy (0.38 vs 0.12; P = .004).

LIMITATIONS

Retrospective study; single, unblinded endoscopist.

CONCLUSION

ADR and adenomas per colonoscopy are both sensitive indicators of colonoscopy quality. WCC merges two simple methods to improve the performance of screening and surveillance colonoscopy. The data suggest that larger, prospective studies are necessary to determine if there are differences between water-exchange combined with cap-assisted maneuvers and the individual components used alone in lesion detection in screening and surveillance colonoscopy.

Balloon dilation with adequate duration is safer than sphincterotomy for extracting bile duct stones: a systematic review and meta-analyses

BACKGROUND & AIMS

Endoscopic sphincterotomy (EST) is the standard treatment for choledocholithiasis. Endoscopic papillary balloon dilation (EPBD) has a lower risk for bleeding than EST, but EPBD is reserved for patients with bleeding diathesis because some studies reported that it increases the risk for pancreatitis. A short dilation time (≤1 minute) is therefore recommended to reduce pancreatitis. However, there is evidence for an inverse relationship between EPBD duration and pancreatitis, prompting reevaluation of the optimal duration and relative safety of EPBD vs EST.

METHODS

We systematically reviewed randomized controlled trials to compare long EPBD (>1 minute), short EPBD (≤1 minute), and EST regarding pancreatitis and overall complications. In addition to pairwise meta-analyses, Bayesian network meta-analysis was undertaken to compare the 3 procedures together. Relation between duration and outcome was also analyzed by meta-regression.

RESULTS

Compared with EST, short EPBD had a higher risk for pancreatitis (odds ratio [OR] by traditional analysis, 3.87; 95% confidence interval, 1.08-13.84 and OR by network meta-analysis, 4.14; 95% credible interval, 1.58-12.56), but long EPBD did not pose a higher risk than EST (1.14, 0.56-2.35 and 1.07, 0.38-2.76). Long EPBD had a lower overall rate of complications than EST (0.61, 0.36-1.04 and 0.54, 0.20-1.36). In network meta-analysis, probabilities of being the safest treatment for long EPBD/short EPBD/EST regarding pancreatitis and overall complications were 43.9%/0.2%/55.9% and 90.3%/1.3%/8.4%, respectively.

CONCLUSIONS

Duration of EPBD is inversely associated with pancreatitis risk. Currently recommended ≤1-minute dilation actually increases pancreatitis. EPBD with adequate duration may be preferred over EST because of comparable pancreatitis but lower overall complication rates.

Water-aided colonoscopy: a systematic review

BACKGROUND

Water-aided methods for colonoscopy are distinguished by the timing of removal of infused water, predominantly during withdrawal (water immersion) or during insertion (water exchange).

OBJECTIVE

To discuss the impact of these approaches on colonoscopy pain and adenoma detection rate (ADR).

DESIGN

Systematic review.

SETTING

Randomized, controlled trial (RCT) that compared water-aided methods and air insufflation during colonoscope insertion.

PATIENTS

Patients undergoing colonoscopy.

INTERVENTION

Medline, PubMed, and Google searches (January 2008-December 2011) and personal communications of manuscripts in press were considered to identify appropriate RCTs.

MAIN OUTCOME MEASUREMENTS

Pain during colonoscopy and ADR. RCTs were grouped according to whether water immersion or water exchange was used. Reported pain scores and ADR were tabulated based on group assignment.

RESULTS

Pain during colonoscopy is significantly reduced by both water immersion and water exchange compared with traditional air insufflation. The reduction in pain scores was qualitatively greater with water exchange as compared with water immersion. A mixed pattern of increases and decreases in ADR was observed with water immersion. A higher ADR, especially proximal to the splenic flexure, was obtained when water exchange was implemented.

LIMITATIONS

Differences in the reports limit application of meta-analysis. The inability to blind the colonoscopists exposed the observations to uncertain bias.

CONCLUSION

Compared with air insufflation, both water immersion and water exchange significantly reduce colonoscopy pain. Water exchange may be superior to water immersion in minimizing colonoscopy discomfort and in increasing ADR. A head-to-head comparison of these 3 approaches is required.

A new method for screening and surveillance colonoscopy: Combined water-exchange and cap-assisted colonoscopy

BACKGROUND & AIMS

Colonoscopy plays an important and central role in current colorectal cancer screening and prevention programs, but it is an imperfect tool. Adjunct techniques may help improve the performance of colonoscopy to increase the detection of polyps with neoplastic potential. This study investigates the novel approach of combined water-exchange and cap-assisted colonoscopy (WCC) and its impact on adenoma detection.

METHODS

A single-center single-colonoscopist consecutive group observational study to compare WCC with conventional air insufflation colonoscopy was performed. Data were collected from 50 consecutive patients undergoing outpatient colorectal cancer screening or polyp surveillance with WCC. Adenoma detection rates (ADR) and adenomas detected per colonoscopy (APC) were compared to a control group of 101 consecutive patients examined with conventional air colonoscopy during the immediate prior period.

RESULTS

Cecal intubation was achieved in all patients. As an emerging and alternative quality metric for colonoscopy, APC was significantly higher in the WCC group (3.08 vs. 1.50, p=0.0021). The conventional quality metric, overall ADR, was higher in the WCC group compared to the air colonoscopy group (70.0% vs. 59.4%, p=0.22). This difference was not statistically significant, likely due to a type II error.

CONCLUSION

The observational data suggest APC is a more sensitive indicator of quality colonoscopy than ADR. WCC shows promise as a novel technique that merges two simple adjunct methods to help improve the performance of colonoscopy. The data suggest larger, prospective studies are necessary to determine the true impact of water-exchange combined with cap-assisted maneuvers.

Magnetic endoscope imaging (ScopeGuide) elucidates the mechanism of action of the pain-alleviating impact of water exchange colonoscopy - attenuation of loop formation

BACKGROUND

The explanation why water exchange colonoscopy produces a significant reduction of pain during colonoscopy is unknown. A recent editorial recommended use of magnetic endoscope imaging (MEI) to elucidate the explanation.

OBJECTIVE

In unselected patients to show that MEI documents less frequent loop formation when water exchange is used.

DESIGN

Observational, performance improvement.

SETTING

Veterans Affairs outpatient endoscopy.

PATIENTS

Routine colonoscopy cases.

INTERVENTIONS

Colonoscopy using air or water exchange method was performed as previously described. The MEI equipment (ScopeGuide, Olympus) with built-in magnetic sensors displays the configuration of the colonoscope inside the patient. During sedated colonoscopy the endoscopist was blinded to the ScopeGuide images which were recorded and subsequently reviewed.

MAIN OUTCOME MEASURES

Loop formation based on a visual guide provided by Olympus.

RESULTS

There were 41 and 32 cases in the water exchange and air group, respectively. The sigmoid N loop was most common, followed by the sigmoid alpha loop, and exaggeration of scope curvature at the splenic flexure/transverse colon. Of these, 20/32 vs. 9/41 patients (p=0.0007) had sigmoid looping, and 17/32 vs. 9/41 patients (p=0.0007) had sigmoid/splenic looping when the scope tip was in the transverse colon, in the air and water exchange group, respectively.

LIMITATIONS

Colonoscopy method was not blinded and non randomized.

CONCLUSION

MEI data objectively demonstrated significantly fewer loops during water exchange colonoscopy, elucidating its mechanism of pain alleviation - attenuation of loop formation. Since MEI feedback enhances cecal intubation by trainees, the role of MEI combined water exchange in speeding up trainee learning curves deserves further evaluations.

Interim report of a randomized cross-over study comparing clinical performance of novice trainee endoscopists using conventional air insufflation versus warm water infusion colonoscopy

BACKGROUND

The applicability of water method colonoscopy in trainee education is not known.

AIM

To compare the water method vs. usual air method in teaching novice trainee colonoscopy.

METHOD

An IRB approved prospective randomized cross-over study (NCT01482546) in a university setting with diverse patient population.

DESIGN

Three first year GI fellows consented to participate in the study. Trainees were randomized to learn with either usual air method or the water method in performing colonoscopy with a dedicated endoscopy attending during their weekly outpatient endoscopy clinics for the initial six months of training and then cross-over to the other method for the remaining six months.

PATIENTS

Patients undergoing screening, surveillance or diagnostic colonoscopy.

RESULTS

The interim data revealed no significant difference in age, gender, and body mass index (BMI). Trainees rated the water method colonoscopy as significantly easier to learn compared to the air method (p=0.007).

CONCLUSIONS

The interim data demonstrate positive effects of using the water method in training novice endoscopists who reported a significant ease of learning colonoscopy using this method. Training programs could consider joining us in evaluating the use of warm water infusion in colonoscopy education.