Variable Stiffness Colonoscope Research Articles

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RATIONALE Ectopic varix at the hepaticojejunostomy site is a rare finding. So symptomatic jejunal varices at this site are difficult to manage. PATIENT CONCERN A 37-year-old female presented with bleeding per rectum for 5 months with a history of hepaticojejunostomy done 6 years back for management of postcholecystectomy bile leak. DIAGNOSIS The endoscopic investigation could not identify the source of bleeding. When conservative management could not control her bleeding, she underwent DSA which showed haemorrhage from ectopic varices at the hepaticojejunostomy site. INTERVENTION The patient underwent embolization of ectopic varices to arrest bleeding OUTCOME After embolization, patient bleeding per rectum stopped and improvement in haemoglobin was noted within 3 days of the procedure. ABBREVIATIONS DSA: Digital subtraction angiography, SMA: Superior mesenteric artery, SMV: Superior mesenteric vein, HJ: Hepaticojejunostomy, AVSC: Adult variable stiffness colonoscope, SBE-Single balloon enteroscopy, DBE: Double balloon enteroscopy KEY WORDS Hepaticojejunostomy, Portal Biliopathy, Ectopic Varices, Variceal Embolization.

A pilot study of a novel variable-stiffness stylet for efficient colonoscope insertion with ex-vivo colon model.

Objectives: The variable-stiffness colonoscope is reportedly useful for making colonoscope insertion easier. However, this function is not associated with all colonoscopes. We developed a variable-stiffness stylet that can be inserted into the endoscope instrumentation channel to change the rigidity of the endoscope. Methods: We developed a stylet with adjustable stiffness and investigated its utility in colonoscope insertion using an ex-vivo model. Four endoscopists performed 24 colonoscope insertions, alternating between using the stylet (Stylet method) and the conventional method. We assessed insertion rate, rate of applying abdominal compression, and insertion time between the two groups. Results: In all procedures, the endoscope was inserted up to the cecum. There were significantly fewer external abdominal compressions with the Stylet method (1/12, 8.3%) compared to the conventional method (6/12, 50%). The insertion time was shorter with the Stylet method (140.9 ± 53.7 s) compared to the conventional method (181.3 ± 64.9 s). Conclusions: Using the variable-stiffness stylet, currently under development, resulted in significantly fewer external abdominal compressions and tended to have shorter insertion time.

Gradual stiffness versus magnetic imaging-guided variable stiffness colonoscopes: A randomized noninferiority trial.

Colonoscopes with gradual stiffness have recently been developed to enhance cecal intubation. We aimed to determine if the performance of gradual stiffness colonoscopes is noninferior to that of magnetic endoscopic imaging (MEI)-guided variable stiffness colonoscopes. Consecutive patients were randomized to screening colonoscopy with Fujifilm gradual stiffness or Olympus MEI-guided variable stiffness colonoscopes. The primary endpoint was cecal intubation rate (noninferiority limit 5%). Secondary endpoints included cecal intubation time. We estimated absolute risk differences with 95% confidence intervals (CIs). We enrolled 475 patients: 222 randomized to the gradual stiffness instrument, and 253 to the MEI-guided variable stiffness instrument. Cecal intubation rate was 91.7% in the gradual stiffness group versus 95.6% in the variable stiffness group. The adjusted absolute risk for cecal intubation failure was 4.3% higher in the gradual stiffness group than in the variable stiffness group (upper CI border 8.1%). Median cecal intubation time was 13 minutes in the gradual stiffness group and 10 minutes in the variable stiffness group (p < 0.001). The study is inconclusive with regard to noninferiority because the 95% CI for the difference in cecal intubation rate between the groups crosses the noninferiority margin. (ClinicalTrials.gov identifier: NCT01895504).

Sa1421 Effect of Functional Relaxation on Patients Undergoing Colonoscopy: A Prospective Randomized Controlled Trial

Sa1421 Effect of Functional Relaxation on Patients Undergoing Colonoscopy: A Prospective Randomized Controlled Trial

Does “responsive insertion technology” improve practice of colonoscopy? Results of a randomized study

Objective. During colonoscopy, advancing the endoscope can sometimes be difficult due to the appearance of loops or bends in the insertion tube. Therefore, research continues toward improving colonoscope technology. The aim of this study is to compare the use of colonoscopes equipped with “responsive insertion technology” (RIT) versus regular non-RIT colonoscopes. Materials and methods. Prospective, comparative and randomized trials that included patients submitted to colonoscopy. In group I, RIT colonoscopes were used, while in group II, colonoscopies with variable stiffness but without the other components of the RIT technology were used. Demographic variables and variables related to colonoscopy, as well as the pain perceived by the patient and the difficulty in performing endoscopy were recorded. Results. A total of 122 patients were included in group I and 120 patients in group II. The cecal intubation rate was similar in both groups. The use of the RIT colonoscopes was associated with a lower cecal intubation time (4.4 ± 2.0 vs. 5.4 ± 3.5, p = 0.005) and a lower difficulty in performing examinations for both the endoscopist (19.1 ± 20.0 vs. 27.7 ± 22.2, p = 0.002) and the nursing staff (20.8 ± 17.0 vs. 26.3 ± 19.6, p = 0.04). No significant differences were found between both groups in the need for ancillary maneuvers or in the pain perceived by the patient. Conclusions. RIT colonoscopes allow cecal intubation in a shorter time compared to variable stiffness colonoscopes, and are associated with a greater level of ease of the procedure.

Factors related to the effectiveness of variable stiffness colonoscope: results of a multivariate analysis

Various studies and two meta-analysis have shown that a variable stiffness colonoscope improves cecal intubation rate. However, there are few studies on how this colonoscope should be used. The aim of this study was to identify factors related to the advancement of the colonoscope when the variable stiffness function is activated. Prospective study enrolling consecutive patients referred for colonoscopy. The variable stiffness colonoscope (Olympus CF-H180DI/L®) was used. We performed univariate and multivariate analyses of factors associated with the success of the variable stiffness function. After the data inclusion period, 260 patients were analyzed. The variable stiffness function was used most in the proximal colon segments (ascending and transverse colon 85%; descending/sigmoid colon 15.2%). The body mass index was lower in patients in whom the endoscope advanced after activating the variable stiffness than those in which it could not be advanced (25.9 + or - 4.8 vs. 28.3 + or - 5.4 kg/m2, p = 0.009). The endoscope advanced less frequently when the stiffness function was activated in the ascending colon versus activation in other segments of the colon (25% vs. 64.5% ascending colon vs. other segments; p < 0.05). In the multivariate analysis, only the colon segment in which the variable stiffness was activated was an independent predictor of advancement of the colonoscope. The variable stiffness function is effective, allowing the colonoscope advancement especially when applied in the transverse colon, descending colon and sigmoid. However, when used in the ascending colon it has a lower effectiveness.

Colonoscopy, pain and fears: Is it an indissoluble trinomial?

Colonoscopy is the reference method in the secondary prevention, diagnosis and, in some cases, treatment of colorectal cancer. It can often cause pain associated with embarrassment, anxiety, and physical and emotional discomfort. Pain intensity is influenced by a lot of factors, and there is a strict relationship among pain, pain perception, and mind. Several methods can be used to break the trinomial colonoscopy, pain and fear. Sedoanalgesia is recommended by several guidelines. If no sedation is offered, the patient must accept a higher chance of unacceptable discomfort and the endoscopist a lower chance of completing the procedure because of patient discomfort. Other non-pharmacologic methods such as acupuncture, music, and hydrocolonoscopy can be used as alternatives to pharmacologic sedoanalgesia. Furthermore, new endoscopic technologies such as variable-stiffness colonoscopes and ultrathin colonoscopes, or the use of carbon dioxide instead of air for colon insufflation, can reduce the pain caused by colonoscopy. In the future, technical improvements such as wireless capsules or robotic probes, will probably enable to overcome the present concept of colonoscopy, avoiding the use of traditional endoscopes. However, at present the poor attention paid by endoscopists to the pain and discomfort caused by colonoscopy can not be justified. There are several methods to reduce pain and anxiety and to break the trinomial colonoscopy, pain and fear. We must use them.

Tu1326 Cap-Assisted Upper Endoscope Versus Cap-Assisted Colonoscope for Difficult Sigmoid Colon: a Prospective Randomized Study

Cap-Assisted Upper Endoscope Versus Cap-Assisted Colonoscope for Difficult Sigmoid Colon: a Prospective Randomized Study Seon-Young Park*, Ho-Seok Ki, Chunghwan Jun, Chang-Hwan Park, Hyun-Soo Kim, Sung Kyu Choi, Jong-Sun Rew Chonnam National University School, Gwang-Ju, Republic of Korea Background/Aims: Studies have estimated that failure of cecal intubation occurs with conventional colonoscope around 10% of cases. Various methods have been adopted to improve cecal intubation rates, including a transparent cap and special scopes, such as variable-stiffness colonoscope, upper endoscope, pediatric endoscope and enteroscope. The objective of the study is to assess the efficacy of cap-assisted upper endoscope compared with cap-assisted colonoscope for complete examination of the colon in patients with technically difficult sigmoid colon. Methods: One hundred and thirty nine patients with technically difficult sigmoid colon were randomly assigned to receive colonoscopy with either cap-assisted upper endoscope (E-cap, n 69) or capassisted colonoscope (C-cap, n 70). The primary endpoint was cecal intubation rate. Secondary end points included cecal intubation time, self-assessed pain score and endoscopist-assessed pain score. Results: Clinical characteristics were not different between two groups. Cecal intubation rate was significantly higher in the ‘E-cap’ (65/69, 94.2%) than in the ‘C-cap’ (50/70, 71.4%, p 0.0001). No statistically significant difference was found between two groups regarding cecal intubation time and total procedure time. Self-assessed pain (moderate to severe) was more frequently reported in the ‘C-cap’ (14/70, 20.0%) than in the ‘E-cap’ (5/69, 7.2%, p 0.029). Endoscopist-assessed pain (moderate to severe) was more frequently reported in the ‘C-cap’ (13/70, 18.6%) than in the ‘E-cap’ (3/69, 7.2%, p 0.009). Cecal intubation rate was significantly higher in the ‘E-cap’ (37/38, 97.4%) than in the ‘C-cap’ (15/29, 51.7%, p 0.0001) in patients with low body mass index (BMI 22 kg/m). Conclusion: A cap-assisted upper endoscope is more tolerable and effective than a cap-assisted colonoscope for complete examination of the colon in patients with technically difficult sigmoid colon.

Comparative study of a responsive insertion technology (RIT) colonoscope versus a variable-stiffness colonoscope

recently, Olympus developed a new prototype (XCF-Q180AY2L) with responsive insertion technology (RIT), which besides the still known variable stiffness technology, included a passive bending section and a new high force insertion tube. Our objective was to investigate whether the use of this prototype could ease colonoscope insertion, increasing the cecal intubation rate, and/or shortening the cecal intubation time. the study was designed as a prospective observational study in 305 consecutive patients from a colo-rectal cancer screening program. We compared colonoscopies performed with conventional colonoscopes (CFH180AL/CFQ160L) with those performed with the prototype XCF-Q180AY2L. End points were mean cecal and terminal ileal intubation times, cecum intubation rate, and need for specific maneuvers. All colonoscopies were performedunder sedation with intravenous propofol. Finally, 288 patients were included. no complications were observed. Complete cecal intubation rate was 100 % in both groups. The ileum could be reached in 98.95 % of cases. Mean time required to reach the cecum was shorter in the prototype endoscope group (4.31 min, SD 2.63 min) than in the conventional endoscope group (4.66 min, SD 2.52 min) (p < 0.05). Compared with the standard colonoscope group, we observed in the prototype group less subjective sensation of difficultyin the passage of the sigma (p < 0.01), fewer maneuvers when it proved necessary to straighten the scope (p < 0.01), and less frequent need to modify the stiffness of the endoscope (p < 0.05). we concluded that the prototype endoscope (XCFQ180AY2L) facilitated colonoscope insertion, requiring slightly less time to reach the cecum than a standard colonoscope.

Use of a single-balloon enteroscope compared with variable-stiffness colonoscopes for endoscopic retrograde cholangiography in liver transplant patients with Roux-en-Y biliary anastomosis

Endoscopic retrograde cholangiography (ERC) is technically challenging in liver transplant patients with Roux-en-Y biliary anastomosis. The optimal endoscope for such cases remains unknown. Compare efficacy and safety of performing ERC in liver transplant patients with Roux-en-Y biliary anastomosis by using an adult colonoscope (AC), a pediatric colonoscope (PC), and a single-balloon enteroscope (SBE). Retrospective chart review. Tertiary-care referral center. Liver transplant patients with Roux-en-Y biliary anastomoses. ERC with AC, PC, and SBE. Rates of reaching the afferent limb and biliary anastomosis; rates of cannulation; rates of diagnostic, therapeutic, and procedural success; and number of adverse events. Ninety patients underwent 199 ERCs from 2002 to 2012; 86 with an AC, 55 with a PC, and 58 with an SBE. Biliary cannulation and diagnostic, therapeutic, and procedural success rates were all significantly higher with an SBE than with a PC. Among patients undergoing the initial ERC, no statistical difference was found among SBE, the PC, and an AC. However, the rate of procedural success with SBE during initial ERC over the last 4 years has increased. Of 25 total failures with ACs, exchange for SBEs resulted in procedural success in 4 of 4 attempts. Of 22 failures with a PC, exchange for an SBE resulted in success in 3 of 4 cases. Of 4 failures with SBE exchange in 6 cases (4 to AC, 2 to PC), SBE resulted in success in only 1. No adverse events occurred directly related to type of endoscope. Retrospective study, single center, lack of standardized approach to selection of endoscopes, uncontrolled variables (general anesthesia, learning curve). In liver transplant patients with Roux-en-Y anatomy, rates of biliary cannulation, therapeutic success, and procedural success are higher with use of an SBE than with a PC and tend to be higher compared with use of an AC among the overall cohort. Use of an SBE and procedural success rates with SBEs have increased over the last 4 years. Failed cases with either an AC or PC can be completed if exchanged for an SBE.

Application value of variable stiffness colonoscope in colonoscopy in elderly patients

Application value of variable stiffness colonoscope in colonoscopy in elderly patients

Does the variable-stiffness colonoscope makes colonoscopy easier? A meta-analysis of the efficacy of the variable stiffness colonoscope compared with the standard adult colonoscope

BackgroundThe variable-stiffness colonoscope (VSC) appears to have advantages over the standard adult colonoscope (SAC), although data are conflicting. To provide a comprehensive up-to-date review, we conducted a meta-analysis to compare the efficacies of the VSC and SAC.MethodsElectronic databases, including PubMed, EMBASE, the Cochrane library and the Science Citation Index, were searched to retrieve relevant trials. In addition, meeting abstracts and the reference lists of retrieved articles were reviewed for further relevant studies.ResultsEight randomized controlled trials (RCTs), enrolling a total of 2033 patients, were included in the meta-analysis. There was no significant heterogeneity among these studies. The cecal intubation rate was higher with the use of VSC (RR = 1.03, 95% CI 1.01 to 1.06, 8 RCTs). The VSC was also associated with fewer position changes made during colonoscopy. Time to cecal intubation was similar with VSC and SAC (WMD −0.54, 95% CI −1.40 to 0.32) but shorter in subgroup analysis with the use of VSC (WMD = −1.36, 95% CI −2.29 to −0.43). Sedation dose used with the two types of instruments showed no evidence of differences either. For all trials, only patients were blinded because of the nature of the interventions.ConclusionUse of the VSC significantly improved the cecal intubation rate and reduced ancillary maneuvers made during the procedure. Cecal intubation time was similar for the two colonoscope types over all trials, whereas a shortened time with the use of the adult VSC was seen in subgroup analysis.

Single- Versus Double-Balloon-Assisted Colonoscopy After Previous Incomplete Standard Colonoscopy

Colonoscopy is the principle screening tool used for the detection of colorectal cancer and removal of colorectal adenomatous polyps [1, 2]. Recently, a large clinical study showed that colonoscopic removal of adenomatous polyps reduced mortality from colorectal cancer by 53 % [3]. While complete colonic evaluation is essential for screening colonoscopy, the rate of incomplete colonoscopy using a conventional standard colonoscope has been reported to be 5–10 % [4–6]. A study conducted in Ontario found that 43,483 (13.1 %) of 331,608 screening colonoscopies failed to evaluate the entire colon [7]. In this population-based cohort study, the factors associated with incomplete colonoscopy were increased patient age, female sex, a history of prior abdominal or pelvic surgery, and having the procedure done in a private office. Other predictors of incomplete colonoscopy include decreased functional status of the patient [8] and anatomic factors such as colonic elongation, tortuosity, and severe diverticulosis [9]. Malignant and pre-malignant lesions may go undetected in patients that are not completely evaluated by screening colonoscopy. In a population-based cohort study, 4.3 % of advanced colonic neoplasms were missed by incomplete colonoscopy [10]. Since 33–50 % of advanced neoplasms are found only in the proximal colon [11–13], additional efforts should be made to adequately visualize the remaining colon after an incomplete colonoscopy. An alternative diagnostic modality such as computed tomographic colonography has been utilized in these cases, however, its usefulness is limited by low sensitivity for small polyps, radiation exposure, and the inability to perform histologic biopsy and therapeutic procedures including polypectomy [14, 15]. As a result, endoscopic approaches are still favored after incomplete standard colonoscopy. Additional endoscopic techniques using gastroscope, variable stiffness colonoscope, pediatric or cap-pitted colonoscope have been tried, but failed to achieve an adequate cecal intubation rate. More recently, a balloon-assisted technique, which was originally introduced to investigate the small bowel, has been applied in patients with previous failed or incomplete colonoscopy. For a balloon-assisted colonoscopy, two types of balloon enteroscopes are available; the double-balloon enteroscope developed by Yamamoto et al. [16], and the single-balloon enteroscope developed by Tsujikawa et al. [17]. The reported success rates of single(SBC) or doubleballoon-assisted colonoscopy (DBC) in patients with previous incomplete conventional colonoscopy range from 88 to 100 % [18–23]. In the current issue of Digestive Diseases and Sciences, Dzeletovic et al. [24] compared the performance outcomes of SBC and DBC in patients with previous incomplete conventional colonoscopy. In this study, the authors retrospectively reviewed 26 cases of SBC and 27 cases of DBC in patients whom underwent failed conventional colonoscopy. The current study showed that cecal intubation was successful in 96 % of patients using either SBC or DBC (100 % with SBC vs. 93 % with DBC, p = 0.049). The median cecal intubation time and total procedure time using SBC and DBC were 17 min vs. 20 min (p = 0.37) and 43.5 min vs. 46.0 min (p = 0.32), respectively. While SBC required less time than DBC, the difference was not statistically significant. Balloon-assisted colonoscopy revealed additional colonic polyps in 35 % of patients in the SBC group and 30 % of patients in the DBC group. Despite the J. U. Lim J. M. Cha (&) Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, 149 Sangil-dong, Gangdong-gu, Seoul 134-727, Korea e-mail: drcha@khu.ac.kr

PMO-003 Effect of MRI and variable stiffness colonoscopes on caecal intubation rates by experienced endoscopists

IntroductionMagnetic endoscopic imager (MEI) and variable stiffness colonoscopes (VSC) have been shown to improve caecal intubation rates in trainees. Many trained endoscopists in our department prefer to perform colonoscopies with...

370 Use of Variable Stiffness Colonoscopes Compared to the Single Balloon Enteroscope for Endoscopic Retrograde Cholangiography in Liver Transplant Patients With Roux-en-Y Anatomy

Endoscopic retrograde cholangiography (ERC) is technically challenging in patients with postsurgical anatomy such as Roux-en-Y. The optimal endoscope for such cases remains unknown. We compared the efficacy and safety of an adult colonoscope, pediatric colonoscope, and the more recently employed single balloon enteroscope for performing ERC in orthotopic liver transplantation (OLT) patients with Roux-en-Y biliary anatomy.

Incomplete Colonoscopy: Maximizing Completion Rates of Gastroenterologists

Cecal intubation is one of the goals of a quality colonoscopy; however, many factors increasing the risk of incomplete colonoscopy have been implicated. The implications of missed pathology and the demand on health care resources for return colonoscopies pose a conundrum to many physicians. The optimal course of action after incomplete colonoscopy is unclear. To assess endoscopic completion rates of previously incomplete colonoscopies, the methods used to complete them and the factors that led to the previous incomplete procedure. All patients who previously underwent incomplete colonoscopy (2005 to 2010) and were referred to St Paul's Hospital (Vancouver, British Columbia) were evaluated. Colonoscopies were re-attempted by a single endoscopist. Patient charts were reviewed retrospectively. A total of 90 patients (29 males) with a mean (± SD) age of 58 ± 13.2 years were included in the analysis. Thirty patients (33%) had their initial colonoscopy performed by a gastroenterologist. Indications for initial colonoscopy included surveillance or screening (23%), abdominal pain (15%), gastrointestinal bleeding (29%), change in bowel habits or constitutional symptoms (18%), anemia (7%) and chronic diarrhea (8%). Reasons for incomplete colonoscopy included poor preparation (11%), pain or inadequate sedation (16%), tortuous colon (30%), diverticular disease (6%), obstructing mass (6%) and stricturing disease (10%). Reasons for incomplete procedures in the remaining 21% of patients were not reported by the referring physician. Eighty-seven (97%) colonoscopies were subsequently completed in a single attempt at the institution. Seventy-six (84%) colonoscopies were performed using routine manoeuvres, patient positioning and a variable-stiffness colonoscope (either standard or pediatric). A standard 160 or 180 series Olympus gastroscope (Olympus, Japan) was used in five patients (6%) to navigate through sigmoid diverticular disease; a pediatric colonoscope was used in six patients (7%) for similar reasons. Repeat colonoscopy on the remaining three patients (3%) failed: all three required surgery for strictures (two had obstructing malignant masses and one had a severe benign obstructing sigmoid diverticular stricture). Most patients with previous incomplete colonoscopy can undergo a successful repeat colonoscopy at a tertiary care centre with instruments that are readily available to most gastroenterologists. Other modalities for evaluation of the colon should be deferred until a second attempt is made at an expert centre.

1211 柔軟ラバーデバイスを用いた可変剛性型大腸内視鏡の開発 : 最適駆動パターンに関する実験的検討(次世代アクチュエータ,一般講演)

1211 柔軟ラバーデバイスを用いた可変剛性型大腸内視鏡の開発 : 最適駆動パターンに関する実験的検討(次世代アクチュエータ,一般講演)

OVERVIEW OF UPCOMING ADVANCES IN COLONOSCOPY

Although colonoscopy is a very commonly carried out procedure, it is not without its problems, including a risk of perforation and significant patient discomfort, especially associated with looping formation. Furthermore, looping formation may prevent a complete colonoscopy from being carried out in certain patients. The conventional colonoscope has not changed very much since its original introduction. We review promising technologies that are being promoted as a way to address the problems with current colonoscopy. There are some methods to prevent looping formation, including overtube, variable stiffness, computer-guided scopes, Aer-O-Scope, magnetic endoscopic imaging and the capsule endoscope. In recent years, with the progress of microelectromechanical and microelectronic technologies, many biomedical and robotic researchers are developing autonomous endoscopes with miniaturization of size and integration functionality that represent state of the art of the micro-robotic endoscope. The initial results by using aforementioned methods seem promising; however, there are some conflicting reports of clinical trials with the overtube colonoscope, the computer-guided scope and the variable stiffness colonoscope. There are also some limitations in the use of the Aer-o-scope and the capsule endoscope. The autonomous endoscope is based on a self-propelling property that is able to avoid looping completely. This novel technology could potentially become the next generation endoscope; however, there are still critical techniques to be approached in order to develop the effective and efficient novel endoscope.

Development of Variable Stiffness Colonoscope Consisting of Pneumatic Drive Devices

Colonoscopy is important and effective medical procedure to detect colonic disorder including cancer of the colon. However, because the large intestine is soft and complex shape, insertion of conventional colonoscopes into the large intestine is difficult, and it depends on doctors’ skill strongly. In many cases, patients feel strong pain. In this research, we aim at development of a novel colonoscope which can change own stiffness partially and realize safe insertion without special techniques. The colonoscope consists of variable stiffness devices. The device is made from silicone rubber and can change its stiffness by pneumatic pressure. In this report, two kinds of variable stiffness devices made from different silicone rubber materials have been developed by molding, and stiffness change characteristics of them are shown experimentally. By applying not only positive pneumatic pressure but also negative pressure, widely stiffness change range is realized. Additionally colonoscopes have been fabricated using them and FMA (Flexible Microactuator). From insertion experiments into the large intestine phantom, advantages and effectiveness have been recognized.

Does the use of a variable stiffness colonoscope offer advantages during colonoscopy under deep sedation? Results of a randomized trial

Variable stiffness colonoscope may be useful in performing colonoscopies in nonsedated patients or under endoscopist-controlled sedation. The objective of this study is to evaluate whether this instrument facilitates colonoscopy in patients under deep sedation monitored by an anaesthesiologist. Prospective and randomized study enroling consecutive patients referred for colonoscopy under deep sedation monitored by an anaesthesiologist. In group I, a variable stiffness colonoscope was used, whereas in group II, a standard colonoscope was used. The main variable was the need to change the position of the patient during the endoscopy. Fifty-six patients were included in group I (variable stiffness colonoscope) and 54 in group II (standard colonoscope). The caecum was reached in 92.9% of patients in group I and in 90.7% of group II (P=0.7). The time required to reach the caecum was significantly less in group I (6.14±3.5 vs. 7.7±3.8; P=0.035). The variable stiffness colonoscope was effective in 66.7% of cases. Changing the position of the patient was necessary in 12.5% of cases in group I compared with 33.3% of cases in group II (P=0.01). The variable stiffness colonoscope avoids the need to change the patient's position and reduces caecal intubation time in patients undergoing colonoscopy under deep sedation controlled by an anaesthesiologist.