Indications and techniques for lower intestinal endoscopy

Robotic Colonoscopy and Beyond: Insights into Modern Lower Gastrointestinal Endoscopy

Lower gastrointestinal endoscopy is considered the gold standard for the diagnosis and removal of colonic polyps. Delays in colonoscopy following a positive fecal immunochemical test increase the likelihood of advanced adenomas and colorectal cancer (CRC) occurrence. However, patients may refuse to undergo conventional colonoscopy (CC) due to fear of possible risks and pain or discomfort. In this regard, patients undergoing CC frequently require sedation to better tolerate the procedure, increasing the risk of deep sedation or other complications related to sedation. Accordingly, the use of CC as a first-line screening strategy for CRC is hampered by patients' reluctance due to its invasiveness and anxiety about possible discomfort. To overcome the limitations of CC and improve patients' compliance, several studies have investigated the use of robotic colonoscopy (RC) both in experimental models and in vivo. Self-propelling robotic colonoscopes have proven to be promising thanks to their peculiar dexterity and adaptability to the shape of the lower gastrointestinal tract, allowing a virtually painless examination of the colon. In some instances, when alternatives to CC and RC are required, barium enema (BE), computed tomographic colonography (CTC), and colon capsule endoscopy (CCE) may be options. However, BE and CTC are limited by the need for subsequent investigations whenever suspicious lesions are found. In this narrative review, we discussed the current clinical applications of RC, CTC, and CCE, as well as the advantages and disadvantages of different endoscopic procedures, with a particular focus on RC.

A histopathologic scoring system as a tool for standardized reporting of chronic (ileo)colitis and independent risk assessment for inflammatory bowel disease

Pathologists regularly evaluate for the presence of chronic (ileo)colitis in lower gastrointestinal mucosal biopsies, for which a major differential diagnosis is inflammatory bowel disease. Although the histologic features of chronic (ileo)colitis are clearly defined, there is no standard, experimentally derived and validated terminology to document these findings in pathology reports and to convey the likelihood of inflammatory bowel disease in a compact, consistent style. This study had 2 retrospective and 1 prospective phases. In phase 1, we developed a histopathologic scoring system for chronic (ileo)colitis and measured the agreement in scoring between pathologists. In phase 2, we emulated the surgical pathology practice by scoring mucosal biopsies of 164 patients who had undergone lower gastrointestinal endoscopies for clinical suspicion of (ileo)colitis. The cases were matched to 6 different groups based on clinical diagnoses. In phase 3, we prospectively assessed accuracy and ease of application of the scoring system in our practice. The scoring system showed low interobserver variability (correlation coefficient, 0.94-0.96) and distinguished chronic (ileo)colitis from negative cases. In addition, it enabled us to provide probabilistic diagnostic statements based on total scores and their positive predictive values, conveying the likelihood of inflammatory bowel disease as low (<20%), intermediate (∼50%), and high (∼90%). In conclusion, this histopathologic scoring system might be a useful approach to report the findings of lower gastrointestinal mucosal biopsies and to provide measured opinion regarding chronic (ileo)colitis independent of available clinical information. In addition, a defined set of diagnostic statements with regard to likelihood of inflammatory bowel disease would reduce interpretive variability.

No effect of perianal application of topical anaesthetic on patient comfort during nonsedated flexible sigmoidoscopy: a randomized, placebo-controlled clinical trial

AIM

A literature review revealed no data on the effects of topical anaesthetic on patient comfort during flexible sigmoidoscopy. We therefore aimed to evaluate this in a randomized manner.

METHOD

One hundred and forty-six patients who underwent flexible sigmoidoscopy were randomly allocated to one of three groups. Vaseline (n = 49), 2% lidocaine gel (n = 51) or a cream of 2.5% lidocaine plus 2.5% prilocaine (n = 46) were applied to the patients 30 min before the procedure. Demographic data and haemodynamic monitoring during procedures were recorded. Pain was assessed by visual analogue scale (VAS) and anxiety levels by the State-Trait Anxiety Inventory (STAI-I and STA-II).

RESULTS

Median pre-procedural STAI-I scores were 45, 46 and 40.5 and median post-procedural STAI-I scores were 35, 34 and 33.5 for the vaseline, lidocaine, and lidocaine/prilocaine treatments, respectively. There was no statistical difference among the groups in terms of STAI-I and II scores. However, post-procedural STAI-I scores were significantly lower than pre-procedural values in each group (P < 0.001). There was no significant difference in VAS scores among the groups. In all groups there were statistically higher VAS scores during the procedure compared with the pre- and post-procedural scores (P < 0.001).

CONCLUSION

Perianal application of topical anaesthetic does not influence patient comfort during sigmoidoscopy.

Endotics system vs colonoscopy for the detection of polyps

AIM

To compare the endotics system (ES), a set of new medical equipment for diagnostic colonoscopy, with video-colonoscopy in the detection of polyps.

METHODS

Patients with clinical or familial risk of colonic polyps/carcinomas were eligible for this study. After a standard colonic cleaning, detection of polyps by the ES and by video-colonoscopy was performed in each patient on the same day. In each single patient, the assessment of the presence of polyps was performed by two independent endoscopists, who were randomly assigned to evaluate, in a blind fashion, the presence of polyps either by ES or by standard colonoscopy. The frequency of successful procedures (i.e. reaching to the cecum), the time for endoscopy, and the need for sedation were recorded. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the ES were also calculated.

RESULTS

A total of 71 patients (40 men, mean age 51.9 ± 12.0 years) were enrolled. The cecum was reached in 81.6% of ES examinations and in 94.3% of colonoscopies (P = 0.03). The average time of endoscopy was 45.1 ± 18.5 and 23.7 ± 7.2 min for the ES and traditional colonoscopy, respectively (P < 0.0001). No patient required sedation during ES examination, compared with 19.7% of patients undergoing colonoscopy (P < 0.0001). The sensitivity and specificity of ES for detecting polyps were 93.3% (95% CI: 68-98) and 100% (95% CI: 76.8-100), respectively. PPV was 100% (95% CI: 76.8-100) and NPV was 97.7% (95% CI: 88-99.9).

CONCLUSION

The ES allows the visualization of the entire colonic mucosa in most patients, with good sensitivity/specificity for the detection of lesions and without requiring sedation.

Drug development in oncology assisted by noninvasive optical imaging

Early and accurate detection of tumors, like the development of targeted treatments, is a major field of research in oncology. The generation of specific vectors, capable of transporting a drug or a contrast agent to the primary tumor site as well as to the remote (micro-) metastasis would be an asset for early diagnosis and cancer therapy. Our goal was to develop new treatments based on the use of tumor-targeted delivery of large biomolecules (DNA, siRNA, peptides, or nanoparticles), able to induce apoptosis while dodging the specific mechanisms developed by tumor cells to resist this programmed cell death. Nonetheless, the insufficient effectiveness of the vectorization systems is still a crucial issue. In this context, we generated new targeting vectors for drug and biomolecules delivery and developed several optical imaging systems for the follow-up and evaluation of these vectorization systems in live mice. Based on our recent work, we present a brief overview of how noninvasive optical imaging in small animals can accelerate the development of targeted therapeutics in oncology.