This 1997 study by Sardinha et al compared the productivity of a sheathed flexible sigmoidoscope (EndoSheath® Technology, Vision Sciences, Natick, MA) with that of a conventional sigmoidoscope (Pentax, Orangeburg, NY). All the sheaths used in the trial had air, water, and biopsy/suction channels. The specific goal of the study was to measure sigmoidoscope preparation time (that is, mean total reprocessing time between clinical procedures) with the two instruments. The per-procedure cost associated with each sigmoidoscope was also calculated.
The study took place during a 2-day period, and all sigmoidoscope procedures were performed by the same physician. Ten patients were randomly assigned to undergo examination with the sheathed sigmoidoscope and nine with the conventional device. Reprocessing of the sheathed instrument consisted of removal and replacement of the EndoSheath® Technology and cleaning and disinfection of the control knobs. Reprocessing of the conventional sigmoidoscope included meticulous manual cleaning and use of an automatic washer to achieve high-level disinfection.
The mean reprocessing time for the conventional sigmoidoscope was about 47 minutes (range, 46-50), whereas that for the sheathed sigmoidoscope was 5 minutes (range, 2-6; P < 0.0001), a difference of nearly tenfold. In 1993 dollars, the per-procedure cost at the researchers’ facility was higher with the sheathed sigmoidoscope ($47 versus $33). However, Sardinha et al estimated that a daily increase in revenue of about $1000 would be possible with the sheathed device because of the 42 minutes a day of additional time its use made available.
The authors commented that effective reprocessing of standard flexible sigmoidoscopes is costly and time consuming and that an ideal sterilizing agent has not yet been found. Moreover, the complex design of conventional devices does not permit visualization or confirmation of efficient cleaning of all channels, and this may result in improper or incomplete disinfection. Sardinha et al also noted that exposure to germicides used in high level disinfection can increase the risk of physical damage to standard endoscopes and of glutaraldehyde-induced colitis in patients. The researchers concluded that the sheathed sigmoidoscope offers an improved safety profile compared with standard instruments and appears to be a viable, cost-effective alternative for facilities performing flexible sigmoidoscopy.