This study by Bretthauer et al, conducted during an ongoing population-based screening trial (total of 21,000 men and women ages 50-64), was designed to assess the feasibility of using a disposable sheath system for flexible sigmoidoscopy in decentralized colorectal cancer screening. In many countries there is an increasing demand for colorectal cancer screening by endoscopy. Decentralized screening is difficult because the design of endoscopy equipment towers and cleaning apparatus does not favor mobility. Flexible sigmoidoscopy is recommended for the average-risk population; reusable endoscopes are commonly used for this purpose. The authors point out that cleaning and disinfection of these devices have been a subject of concern, as transmission of infectious material cannot be completely excluded from the working channel; in addition, reprocessing of endoscopes is time-consuming and expensive. An endoscope with disposable sheaths (EndoSheath® Technology) which does not require conventional reprocessing and which is possibly transportable was introduced and selected for use in the study. Bretthauer et al note that according to the colorectal cancer screening committee of OMED (Organisation Mondiale d’Endoscopie Digestive), use of a disposable sheath is generally desirable. Emphasis on the prevention of transmission of infectious agents and reduction of instrument reprocessing time has resulted in promoting the use of disposable sheath systems as opposed to conventionally reprocessed endoscopes for flexible sigmoidoscopy.
For this screening trial, participants were randomly allocated to have fl exible sigmoidoscopy performed with either a 60 cm fiberoptic sigmoidoscope (SS-F32/S-F100 EndoSheath® Technology, Vision-Sciences, Natick, MA) covered with a disposable sheath (EndoSheath® Technology group) or a 140 cm conventional video colonoscope (Olympus 140/VI, Hamburg, Germany) (standard colonoscope group). All examinations were performed at a temporary screening center; three screening centers were used, one of which was located in a remote, rural area. With the exception of the control knobs attached to the control handle, the reusable core of the sheathed endoscope was covered by a disposable barrier to protect working surfaces from contamination. Air, water and biopsy channels are incorporated in the sheath, not the endoscope. The sheath was discarded after each examination to provide every patient with a sterile endoscope. Three experienced endoscopists performed all examinations. No sedation was used. To adjust for the different lengths of the endoscopes, patients in the standard colonoscope group with examinations beyond 60 cm were excluded from analysis. According to the protocol, tissue samples for histological evaluation were taken from all detected polyps, using a disposable biopsy forceps.
Results from examinations of 113 patients in the EndoSheath® Technology group and 87 patients in the standard colonoscope group were analyzed. The patients’ experience was documented using a questionnaire relating to overall satisfaction with the procedure and discomfort during the examination, and the feasibility of running temporary screening units was evaluated. Among the respondents who completed the questionnaire after the examination, 94% were generally satisfied, and 98% would recommend the procedure to others, with no differences between the groups. The vast majority of all patients reported no discomfort: 76% in the EndoSheath® Technology group, and 75% in the standard colonoscope group. Only slight discomfort was reported by 17% in the EndoSheath® Technology group and 18% in the standard group. Seven patients in the EndoSheath® Technology group reported moderate discomfort, compared with six patients in the standard group. None of the individuals examined reported severe discomfort during the examination. No differences were observed between the groups regarding age and gender; mean age was 58.5 years in both groups and the proportions of women were 53% (EndoSheath® Technology group) and 56% (standard colonoscope group).
The researchers found that when the sheathed system was used, all the devices needed could be satisfactorily transported. A screening center could be set up within a few hours. The EndoSheath® system worked adequately during the trial; the investigators noted that for passage and subsequent withdrawal of the forceps, the tip of the endoscope had to be straightened. They also determined an advantage of the EndoSheath® Technology is its stronger suction pump, allowing greater improvement on any suboptimal bowel cleansing, when compared with the standard system.
Bretthauer et al noted that the safety of the procedure, high examination quality, and acceptable cost-effectiveness are important requirements in population-based fl exible sigmoidoscopy colorectal cancer screening. Despite meticulous cleaning, following recommended guidelines, the transmission of infectious material cannot be completely excluded when conventional endoscopes are used. The authors found that the use of disposable sheath systems minimizes the risk of cross-contamination. Additionally, the time and cost-intensive high level reprocessing, which is mandatory when using conventional reusable endoscopes, is not necessarily needed with a disposable sheath system. Mid-level reprocessing is recommended with the EndoSheath® Technology which includes removal and disposal of the sheath, a wash of the endoscope with an enzymatic detergent, rinse, and a wipe down with a 70% alcohol wipe. Several trials have reported a significant decrease in reprocessing time, favoring the EndoSheath® Technology.
Perhaps the most important advantage of the disposable sheath system in this study was its transportability. The researchers were able to easily establish a temporary satellite screening unit, since the system does not require any large cleaning facilities and all the equipment needed could be easily transported in a medium-sized car. By using the EndoSheath® Technology, it was possible to move a completely self supported flexible sigmoidoscopy screening unit by car from one location to another, with two employees, and be operational the same day. The authors noted it would have been more than a 2 hour drive for people living in the remote parts of the screening area to get to the nearest main screening center. By establishing the satellite unit, they were able to maintain a high compliance rate in those areas as well. The investigators suggest the use of easily transportable disposable sheath systems, set up in temporary screening centers, may contribute to high attendance rates for colorectal cancer screening in outlying areas. In rural countries in particular where endoscopy facilities are very distant, the use of the disposable sheath system may be crucial for the success of future colorectal cancer screening programs.