New techniques ease colon cancer procedures for patients

Developing superior screening options is paramount in the treatment of colon cancer, as it has one of the highest cure rates of all cancers when detected early. Scientists are continuing to refine the practice of colorectal screening, evaluating novel methods aimed at increasing patient comfort while improving outcomes and further decreasing the risk of developing the disease. Research presented today at Digestive Disease Week® 2006 (DDW) offers updates in colon screening sedation to improve patient quality of life while accurately assessing colon health. DDW is the largest international gathering of physicians and researchers in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.

Computer-Assisted Colonoscopy (The NeoGuide System): Results of the First Human Clinical Trial [Abstract 719]

While colonoscopy is the most effective procedure to screen for early signs of colon cancer, many people avoid the screening because of the discomfort associated with the process. A novel colonoscope may be able to reduce the pain of the procedure, along with the need for sedation, and help to increase rates of colorectal cancer screening.

The NeoGuide Endoscopy System, a computer-assisted colonoscope, has previously been tested with successful results in animal trials, and now demonstrates similar success in its first human clinical trial. A research team from Stanford University and Klinikum Ludwigshafen in Germany evaluated the function of the colonoscope with the help of five physicians of varying levels of experience and 10 patient volunteers.

The colonoscopy was successfully completed in all patients, with the scope reaching the cecum in the 10 patients and the terminal ileum in nine. Although speed was not an endpoint of the study, the cecum was reached in less than six minutes in three patients. The NeoGuide colonoscope allows for standard therapies to be given during the procedure; this study included biopsies and the removal of multiple polyps. Patients were evaluated after the procedure at discharge, 48 hours and 30 days, with no complications or adverse effects. In fact, all 10 patients were contacted shortly after the procedure and expressed willingness to undergo the same procedure again.

"With the success of colonoscopy to detect cancer early, patient comfort is extremely important to raise the rates of screening," said Jacques Van Dam, M.D., of Stanford University and lead author of the study. "We hope that larger clinical trials will confirm that the technology improves the comfort and success of the procedure."

Pain during colonoscopies is often related to "looping" of the colonoscope, which stretches the colon and the surrounding tissue. The NeoGuide system is designed to avoid looping by following the natural shape of the colon. The system builds a three dimensional map of the colon as the scope is inserted and then directs multiple bendable sections to follow the path taken by the tip.

Randomized Controlled Trial of Sedation for Colonoscopy: Entonox versus Intravenous Sedation [Abstract 645]

Most patients request some sedation when undergoing a colonoscopy to make the process more comfortable. Although intravenous sedation (IV) is the most frequently used type of sedation, it has been associated with cardio-respiratory complications, delayed recovery and prolonged drowsiness. Researchers from the University of Hull in the United Kingdom evaluated the efficacy of entonox, an inhaled sedative using nitrous oxide and oxygen, and found it to be more effective than IV, providing greater patient pain relief and facilitating earlier discharge.

Study authors recruited 120 patients, asking them to complete anxiety and pain questionnaires and a baseline letter-cancellation test. Patients were then administered either entonox or midazolam/fentanyl, a commonly used IV sedation, before undergoing a routine colonoscopy. After the colonoscopy, patients again completed the letter-cancellation test and a marked pain assessment. Finally, patients completed a satisfaction survey at discharge and 24 hours after the procedure.

While patients experienced similar pre-procedure anxiety scores, entonox patients reported significantly less pain post-procedure (mean score of 25 for Entonox patients versus 40 for intravenous sedation patients,) and also reported a higher satisfaction rate (98 versus 80). Entonox patients were typically released within 26 minutes after the procedure while the intravenous group waited an average of 44 minutes.

Patients receiving entonox experienced faster recovery because the medicine is discharged from the body within one to two minutes after patients stop inhaling it, whereas IV sedation effects last for a longer period of time. Entonox causes less sedation and grogginess while providing effective pain relief, so the recovery is faster. The results of the letter test showed that patients with IV sedation were not completely back to normal at discharge whereas those with entonox were fully normal at discharge, meaning that patients who are given entonox can likely drive themselves home immediately after the procedure.

"Entonox shows significant value in improving patient satisfaction after colonoscopy, better accommodating a patient’s lifestyle by enabling them to drive home after the procedure and, perhaps, making them less apprehensive about undergoing the procedure again," said Sushil Maslekar, M.D., University of Hull and lead study author. "Physicians will also benefit from a sedative that is more cost-effective and less time-consuming than current sedation options." A letter cancellation test is a simple test used to assess the psychomotor awareness of the patient, gauging how well the patient has recovered from sedation. The pain assessment and patient satisfaction were determined by simple visual analogue scales — a straight line from 0-100. For pain, 0 equals no pain and 100 equals intolerable pain, and for satisfaction, 0 means no satisfaction or extreme dissatisfaction and 100 means extremely satisfied.