A prospective study of bowel preparation for colonoscopy with polyethylene glycol-electrolyte solution versus sodium phosphate in Lynch syndrome: a randomized trial

Colonoscopic surveillance in Lynch syndrome: guidelines in perspective

Lynch syndrome predisposes to a high risk of colorectal cancer and colonoscopy remains the primary preventive strategy. The prevention of colorectal cancer through colonoscopy relies on identifying and removing adenomas, the main precursor lesion. Nevertheless, colonoscopy is not an optimal strategy since post-colonoscopy colorectal cancer remains an important issue. In continuation of a 2021 journal review, the present article seeks to offer an updated perspective by examining relevant articles from the past 3 years. We place recent findings in the context of existing guidelines, with a specific focus on colonoscopy surveillance. Key aspects explored include colonoscopy quality standards, timing of initiation, and surveillance intervals. Our review provides a comprehensive analysis of adenoma-related insights in Lynch syndrome, delving into emerging technologies like virtual chromoendoscopy and artificial intelligence-assisted endoscopy. This review aims to contribute valuable insights into the topic of colonoscopy surveillance in Lynch syndrome.

Colorectal cancer screening in Lynch syndrome: Indication, techniques and future perspectives

Lynch syndrome (LS) is an inherited predisposition to colorectal cancer (CRC), responsible for 3-5% of all CRC. This syndrome is characterized by the early occurrence of colorectal neoplastic lesions, with variable incidences depending on the type of pathogenic variants in MMR genes (MLH1, MSH2, MSH6, PMS2 and EPCAM) and demographics factors such as gender, body mass index, tobacco use and physical activity. Similar to sporadic cancers, colorectal screening by colonoscopy is efficient because it is associated with a reduction >50% of both CRC incidence and CRC related mortality. To that end, most guidelines recommend high definition screening colonoscopies in dedicated centers, starting at the age of 20-25 years old, with a surveillance interval of 1-2 years. In this review, we discuss the importance of high definition colonoscopies, including the compliance to specific key performance indicators, as well as the expected benefits of specific imaging modalities including virtual chromoendoscopy and dye-spray chromoendoscopy.

Same-day Versus Split-dose Bowel Preparation Before Colonoscopy: A Meta-analysis

BACKGROUND

Split-dose regimens (SpDs) were recommended as a first choice for bowel preparation, whereas same-day regimens (SaDs) were recommended as an alternative; however, randomized trials compared them with mixed results. The meta-analysis was aimed at clarifying efficacy level between the 2 regimens.

MATERIALS AND METHODS

We used MEDLINE/PubMed, EMBASE, Scopus, CINAHL, Cochrane Library, and Web of Science to identify randomized trials published from 1990 to 2016, comparing SaDs to SpDs in adults. The pooled odds ratios (ORs) were calculated for preparation quality, cecal intubation rate (CIR), adenoma detection rate (ADR), and any other adverse effects.

RESULTS

Fourteen trials were included. The proportion of individuals receiving SaDs and SpDs with adequate preparation in the pooled analysis were 79.4% and 81.7%, respectively, with no significant difference [OR=0.92; 95% confidence interval (CI), 0.62-1.36] in 11 trials. Subgroup analysis revealed that the odds of adequate preparation for SaDs with bisacodyl were 2.45 times that for SpDs without bisacodyl (95% CI, 1.45-4.51, in favor of SaDs with bisacodyl). Subjects received SaDs experienced better sleep.

CONCLUSIONS

SaDs were comparable with SpDs in terms of bowel cleanliness, CIR, and ADR, and could also outperform SpDs in preparation quality with bisacodyl. SaDs also offered better sleep the previous night than SpDs did, which suggests that SaDs might serve as a superior alternative to SpDs. The heterogenous regimens and measurements likely account for the low rates of optimal bowl preparations in both arms. Further studies are needed to validate these results and determine the optimal purgatives and dosages.

Randomized Controlled Trials in Hereditary Cancer Syndromes

Conducting randomized controlled trials (RCTs) in patients with germline mutations in genes that predispose to adult-onset cancer is hampered by the rarity of these mutations, barriers to their identification, and challenges inherent to randomizing high-risk individuals as part of a clinical trial. Most of the clinically relevant RCTs have been conducted in 3 syndromes in only some of the high-risk genes for which clinical testing is currently available. This article reviews the surgical, screening, and chemoprevention RCTs in each of the syndromes in clinically relevant studies conducted in the past 10 years.

The use of mechanical bowel preparation in laparoscopic gynecologic surgery: a decision analysis

OBJECTIVE

The use of mechanical bowel preparation prior to laparoscopy is common in gynecology, but its use may affect the rates of perioperative events and complications. Our objective was to compare different mechanical bowel preparations using decision analysis techniques to determine the optimal preparation prior to laparoscopic gynecological surgery.

STUDY DESIGN

A decision analysis was constructed modeling perioperative outcomes with the following mechanical bowel preparations: magnesium citrate, sodium phosphate, polyethylene glycol, enema, and no bowel preparation. Comparisons were made using published utility values. Secondary analyses included the percentages that had 1 or more preoperative events and 1 or more intra- or postoperative complications.

RESULTS

Overall, the highest utility values were for no bowel preparation (0.98) and magnesium citrate (0.97), whereas the other values were as follows: enema (0.95), sodium phosphate (0.94), and polyethylene glycol (0.91). The difference between no bowel preparation and magnesium citrate was less than the published minimally important differences for utilities, so there is likely no real difference between these strategies. The probability of having at least 1 preoperative event was lowest for no bowel preparation (1%), whereas the probability of having at least 1 intra- or postoperative complication was lowest with magnesium citrate (8%).

CONCLUSION

The highest utilities were seen with no bowel preparation, but the absolute difference between no bowel preparation and magnesium citrate was less than the minimally important difference. With similar overall utilities, our model raises questions as to whether mechanical bowel preparation is a necessary step prior to laparoscopic gynecological surgery. However, if a surgeon prefers a bowel preparation, magnesium citrate is the preferred option.

Neostigmine Administered With MoviPrep Improves Bowel Preparation for Elective Colonoscopy in Patients With Spinal Cord Injury: A Randomized Study

BACKGROUND

Poor preparation for elective colonoscopy is exceedingly common in persons with spinal cord injury (SCI). This unsatisfactory outcome is likely due to long-standing difficulty with evacuation and decreased colonic motility, which may result in inadequate responses to conventional bowel preparation regimens. We determined whether the addition of neostigmine to MoviPrep before elective colonoscopy produced a higher percentage of acceptable bowel preparations in patients with SCI.

METHODS

Twenty-seven SCI subjects were prospectively randomized to 1 of 2 arms: low-volume polyethylene glycol-electrolyte lavage with ascorbic acid (MoviPrep) or MoviPrep plus neostigmine methylsulfate and glycopyrrolate (MoviPrep+NG); 28 able-bodied subjects received MoviPrep alone. The quality of the cleansing preparation for colonoscopy was determined by gastroenterologists "calibrated" to use the Ottawa Scoring System, with an acceptable Ottawa Score (OS) considered to be ≤3.

RESULTS

The administration of MoviPrep alone resulted in suboptimal bowel cleansing in the SCI group compared with the able-bodied group (50% vs. 89% of subjects had an acceptable OS; χ=7.94, P=0.05). However, when NG was added to MoviPrep in the SCI group, it markedly improved the quality of the bowel preparation, with 85% of patients then having an acceptable OS. The use of NG resulted in minimal bloating and distention before bowel evacuation (P=0.0005), and eye and muscle twitching; these were resolved within 1 hour after NG administration. No significant differences were noted among the preparation groups for adenoma detection rate (P=0.41).

CONCLUSIONS

The combination of MoviPrep+NG was safe, well tolerated, and an effective approach to prepare the bowel for elective colonoscopy in patients with SCI. The side effects of this preparation were significant compared with the other treatment groups but were considered mild and anticipated.

[Bowel preparation for colonoscopy. Any significant progress on the horizon?]

Colonoscopy is the method of choice for colorectal cancer screening. To be effective, screening colonoscopy must have high quality standards. The key element is the quality of the preparation. However, up to 20% of patients are inadequately prepared and, at present, anterograde washing is the least tolerated part of the procedure. In the choice of preparation, safety is a prerequisite and efficacy is a priority. Tolerance is a secondary but nevertheless influential factor in the quality of preparation and has consequently been the primary focus of many recent studies. In the last few years, a rapidly increasing number of studies have evaluated new drugs, dosages and adjuvant therapies to improve efficacy and tolerability. These studies have collaterally shown that inadequate preparation and lack of adherence to the prescribed regimen can be partially predicted, making it essential to identify this patient subgroup and invest the necessary effort in their instruction. New individualized and flexible approaches are expected for the different clinical scenarios. The search for the ideal colonoscopy preparation, which would be tolerable, safe and above all effective, remains open.

Comparison of the efficacy and safety of sodium phosphate tablets and polyethylene glycol solution for bowel cleansing in healthy Korean adults

PURPOSE

Bowel cleansing is generally regarded as time-consuming and unpleasant among patients. Patients commonly state that bowel preparation provokes more discomfort than the actual colonoscopic examination. The purpose of this study was to compare two regimens of sodium phosphate (NaP) tablets versus polyethylene glycol (PEG) solution for bowel preparation in healthy Korean adults.

MATERIALS AND METHODS

This was a single center, prospective, open-label, investigator-blinded, randomized, controlled-pilot study. A total of 62 healthy Korean subjects were randomly assigned to two groups (NaP vs. PEG). Efficacy, safety, and patient-related outcomes, as well as procedural parameters, were evaluated.

RESULTS

Although there were no significant differences in total Ottawa bowel quality score, fluid scores and the rate of adequate bowel preparation were significantly better in the NaP group than the PEG group. Additionally, the NaP group showed better results regarding patient tolerance, satisfaction, preference, and rate of adverse events than the PEG group. Significant fluctuations in specific serum electrolytes were common and of a greater magnitude in the NaP group than the PEG group. However, these abnormalities were transient and did not result in serious complications and side effects.

CONCLUSION

In this study, NaP tablets were shown to be an effective, well-tolerated, and acceptable regimen for bowel preparation. Also, our study suggests that NaP tablets may be safe and can be used as a bowel cleansing agent in healthy adults undergoing elective colonoscopy. Further multicenter, large scale studies are needed to confirm these findings.

Quality colonoscopy and risk of interval cancer in Lynch syndrome

PURPOSE

Despite colonoscopic surveillance, Lynch syndrome patients develop colorectal cancer (CRC). Identification of modifiable factors has the potential to improve outcome of surveillance. The aims of this study were to determine (1) characteristics of patients with CRC, (2) endoscopic and histological features of these cancers, and (3) quality of the previous colonoscopy.

METHODS

Approximately 2,200 medical reports from proven and obligate mutation carriers identified at the Dutch Lynch Syndrome Registry and two large hospitals were retrospectively analyzed for the presence of an interval cancer defined as CRC diagnosed within 24 months of previous colonoscopy.

RESULTS

Thirty-one interval cancers were detected in 29 patients (median age of 52 [range 35-73]), after a median time of 17 months. All were MLH1 or MSH2 mutation carriers, and 39 % had a previous CRC. In patients without previous surgery for CRC, 84 % was proximally located. Of all interval cancers, 77 % were at local stage (T1-3N0Mx). In three patients (9 %) with an incomplete previous colonoscopy, CRC was located in the unexamined colon. In six of the nine patients with an adenoma during previous colonoscopy, the cancer was detected in the same colonic segment as the previously removed adenoma.

CONCLUSIONS

Interval cancers were detected in MLH1 and MSH2 mutation carriers, especially in those with a history of previous CRC and between 40 and 60 years. Interval cancer could be related to incompleteness of previous endoscopy and possibly residual adenomatous tissue. Further reduction of the interval cancer risk may be achieved by optimizing endoscopy quality and individualization of surveillance guidelines.