Colonoscopy: go small for success?

Colonoscopy using standard adult colonoscopes can be difficult in patients with fixed, angulated sigmoid colons. An earlier study from the same center suggested that in women who have had hysterectomy, successful colonoscopy occurred with greater frequency when initiated with a pediatric colonoscope versus an adult colonoscope. This follow-up study was a nonblinded clinical trial comparing the use of a pediatric colonoscope with an adult colonoscope for routine colonoscopy in women with previous hysterectomy. A total of 100 female patients presenting for an outpatient colonoscopy were randomized to use the pediatric (Olympus PCF-100) or adult (Olympus CF-100L or CF-Q140L) colonoscope.
The primary outcome was the comparative rate of cecal intubation. Secondary outcomes included total procedure time, cecal insertion time, sedative administration, procedural difficulty, and patients' experience. Endoscopists encountering difficult insertion had the opportunity to use the alternate scope. The cecum was reached in 49 of 51 (96.1%) women when using the pediatric colonoscope versus 35 of 49 (71.4%) women when using the adult colonoscope. Of the 14 incomplete examinations initiated with an adult colonoscope, the pediatric colonoscope was used 12 times, and the cecum was reached in nine, adjusting the rate of successful colonoscopy to 44 of 49 (89.8%). There was no statistical difference in total procedure time, cecal insertion time, sedative drug dosages, procedural difficulty, or patient comfort using either scope.
When performing routine colonoscopy in women with previous hysterectomy, the authors recommend either starting with a pediatric colonoscope or having one available in the advent of a fixed, angulated sigmoid colon.     

A randomized controlled trial in a training institution comparing a pediatric variable stiffness colonoscope, a pediatric colonoscope, and an adult colonoscope

BACKGROUND: There are few comparative data on the efficacy of different colonoscopes. This study compared the efficacy of a new pediatric variable stiffness colonoscope with that of standard pediatric and adult colonoscopes in the performance of routine colonoscopy. METHODS: Three hundred sixty-three consecutive patients were randomized to undergo colonoscopy with a pediatric variable stiffness (n = 122), pediatric (n = 114), or adult colonoscope (n = 127). Primary outcomes recorded were minutes to the cecum and completeness of the examination. Secondary outcomes included patient tolerance, use of abdominal compression, and endoscopists' assessment of the difficulty of the procedure. RESULTS: Cecal intubation rates were not statistically different between the groups: variable stiffness (94.3%), pediatric (96.5%), and adult (89.8%) (p = 0.099). There was no significant difference in mean insertion time, patient tolerance, use of abdominal compression, or endoscopists' global assessment or examination difficulty between groups. Overall, the initial completion rate of 93% increased to 97% on switching to a different colonoscope. Colonoscopy was unsuccessful more often and was more time consuming in women who had undergone hysterectomy. CONCLUSION: The variable stiffness colonoscope performs well, but does not appear to offer any distinct advantage over standard pediatric or adult colonoscopes for routine colonoscopy. Further study may identify subgroups of patients that benefit from this new technology.     

Usefulness of a pediatric colonoscope for colonoscopy in adults

BACKGROUND: There are few published data on how different types of colonoscopes affect success in reaching the cecum and patient comfort. We examined the feasibility of using a pediatric colonoscope for routine colonoscopy in adults and investigated whether there were subgroups of patients in whom use of this instrument was preferable. METHODS: One-hundred fifty adults undergoing outpatient colonoscopy were randomized to colonoscopy with a standard colonoscope (Olympus CF-100L) or with a pediatric colonoscope (Olympus PCF-100). All procedures were performed by a faculty endoscopist and timed by an independent observer. After examinations, the endoscopist graded procedure difficulty and patients were given a questionnaire that assessed their experience. RESULTS: The adult (n = 77) and pediatric (n = 73) colonoscope groups were comparable in all outcomes measured, including success in reaching the cecum (91% vs. 93%, p = 0.61), mean time to reach the cecum (11.4 vs. 9.7 min, p = 0.07), mean total procedure time (21.8 vs. 21.9 min, p = 0.95), mean meperidine dose (55 vs. 52 mg, p = 0.17); median midazolam dose (2.0 mg in both groups, p = 0.10), the endoscopists' perception of procedure difficulty, and patient comfort scales. Of the 7 patients in whom colonoscopy with the adult colonoscope was unsuccessful, the cecum was reached in 4 by switching to a pediatric colonoscope (all women, 3 of whom had prior hysterectomy). In the 5 patients in whom colonoscopy with the pediatric colonoscope was unsuccessful, the cecum was reached in 1 by switching to an adult colonoscope. Including the cases in which the cecum was reached by switching to the alternative colonoscope, the overall frequency of cecal intubation was 143 of 150 (95%). Subgroup analysis disclosed no difference between the 2 groups in outcomes when gender, presence of diverticulosis, and patient size were considered. Colonoscopy with the pediatric colonoscope was more successful than with the adult instrument in reaching the cecum in women with prior hysterectomy (11 of 12 [92%] vs. 15 of 21 [71%]); however, the numbers in each group were relatively small and the difference was not significant (p = 0.22). CONCLUSIONS: The pediatric colonoscope is suitable for routine colonoscopy in adults. It is also useful in patients in whom colonoscopy with the adult colonoscope is unsuccessful in reaching the cecum (particularly in women). Additional study is needed to see if the pediatric colonoscope is actually superior to the adult colonoscopy for routine colonoscopy in women with prior hysterectomy.     

Usefulness of pediatric colonoscopes in adult colonoscopy

Use of small diameter, extraflexible pediatric colonoscopes has proved to be valuable in adult endoscopy practice, not only for passing strictures and stomas but also where either fixation due to diverticular disease or postoperative adhesions, or unavoidably painful looping made passage of adult colonoscopes impossible. In 70 of 78 (92%) of the cases where the adult colonoscope could not be passed through the sigmoid colon by an expert endoscopist, the pediatric colonoscope passed through, often very easily. Fifteen of these patients were considered to have been saved surgery by successful passage. The "failure" rate for all colonoscopy examinations was only 2%; this low failure rate was attributable to the use of pediatric instruments whenever passage through the sigmoid colon proved to be impossible with standard colonoscopes. In our opinion every unit performing frequent colonoscopies should have a pediatric colonoscope available for selected adult patients as well as for use in children.     

Is the variable-stiffness paediatric colonoscope more effective than a standard adult colonoscope for outpatient adult colonoscopy?: A randomised controlled trial

BACKGROUND: Trials with variable-stiffness colonoscopes have yielded conflicting results regarding efficacy and patient tolerance. AIM: We compared a variable-stiffness paediatric colonoscope with a standard adult colonoscope. METHODS: Two hundred and forty consecutive adult outpatients presenting for colonoscopy were randomised to either a variable-stiffness paediatric colonoscope or an adult colonoscope. If there was difficulty in performing colonoscopy with the assigned scope, the endoscopist was given the option of switching to the alternative instrument. In the condition of a severely fixed, angulated sigmoid colon, a final 'salvage' (backup) option was that of switching to an even thinner diameter paediatric colonoscope. RESULTS: The initial frequency of total colonoscopy was similar with the variable-stiffness paediatric colonoscope and adult colonoscope (95.8% versus 96.6%, p=1.0). Factoring in scope changes, the final frequency was 98.3% versus 99.2% (p=1.0). There was no statistical difference between the two groups in terms of insertion time, doses of sedative medications, scales of procedure difficulty, or patient satisfaction. CONCLUSIONS: Adult colonoscope and variable-stiffness paediatric colonoscope are both effective instruments for routine colonoscopy. In cases when the use of the initial scope is unsuccessful, switching to the alternative scope may permit passage to the caecum. There are occasional patients with fixed, angulated sigmoid colons in whom use of an even thinner diameter paediatric colonoscope can be helpful.     

Variable stiffness colonoscopes are associated with less pain during colonoscopy in unsedated patients

OBJECTIVES: Application of a new variable stiffness colonoscope (VSC) is expected to control loop formation and to lessen patient discomfort. The aim of this prospective study was to compare the efficacy of VSC with a conventional colonoscope (CC) in unsedated colonoscopy, based on the experience of examiners. METHODS: Four-hundred sixty-seven patients were randomly assigned to undergo colonoscopy with either VSC or CC by an endoscopist, including experienced and less-experienced examiners. The percentages of completed procedure and time to cecal intubation were recorded. Patients were asked to rate pain on a 5-point pain score. RESULTS: The percentages of completed procedure with VSC and CC were 98% and 95%, respectively, by less-experienced hands, and 99% and 98%, respectively, by experienced hands. Time for cecal intubation with VSC and CC was 15.7 and 18.5 min, respectively, by less-experienced hands, and 9.8 and 10.6 min, respectively, by experienced hands. A significantly lower mean pain score was noted in VSC patients compared with CC patients, irrespective of experience of the examiner. The percent of patients rating the procedure as moderately or severely painful was significantly lower with VSC than with CC, both in less-experienced (19% vs 40%; p < 0.01) and experienced hands (15% vs 26%; p < 0.05). CONCLUSIONS: Our results indicated that VSC allows favorable examination compared with CC regarding completeness, time to cecal intubation, and comfort of patients undergoing unsedated colonoscopy, irrespective of the examiner's experience. These features suggest VSC as the preferred colonoscope for patients undergoing unsedated colonoscopy.     

Ultrathin colonoscope with a diameter of 9.8 mm for total colonoscopy

BACKGROUND: The pediatric colonoscope is superior to the standard colonoscope in some patients with a fixed, angulated colon. A colonoscope thinner than the pediatric one is thought to outperform even the pediatric colonoscope in such cases. This study was conducted to assess the efficacy of an ultrathin colonoscope, 9.8 mm in diameter, comparing it with pediatric and standard colonoscopes. METHODS: Three types of colonoscopes were used: ultrathin, pediatric, and standard. A total of 287 consecutive patients were assigned to three groups: ultrathin (n=94), pediatric (n=98), and standard (n=95). First assessment was the ratio of cecal intubation and the reasons for unsuccessful colonoscopy. The second was the time to cecal intubation. RESULTS: Cecal intubation rates were not different among three groups (96% in each). The main reasons for failed colonoscopy were looping in the ultrathin group, and angulation or stricture in the pediatric and standard groups. Mean time to the cecum was slightly longer in the ultrathin group (6.5 minutes) than the pediatric group (5.6 minutes) and standard group (6.1 minutes), but there were no significant differences among three groups. CONCLUSION: Colonoscopy with the ultrathin colonoscope was as successful as with the pediatric and standard colonoscopes. The advantage of the ultrathin colonoscope might be notable in cases with stricture or severe angulation.     

A prospective trial of variable stiffness pediatric vs. standard instrument colonoscopy

BACKGROUND: The pediatric variable stiffness colonoscope is believed to have theoretical advantages over the standard colonoscope, however a systematic evaluation of this instrument in routine clinical practice involving adult patients is lacking. METHODS: Consecutive patients (blinded) undergoing colonoscopy in an outpatient endoscopy center by one of 4 experienced colonoscopists had the procedure performed with a standard colonoscope (n=384) or pediatric variable stiffness colonoscope (n=413). Failure to negotiate the sigmoid colon within 10 minutes was regarded as a failure and, if suitable, the patient was crossed over to colonoscopy with the alternative instrument. RESULTS: Median (95% CI) time to the cecum was significantly faster in the pediatric variable stiffness colonoscope group (odds ratio 5.0: 95% CI[4.7,5.3] minutes) compared with the standard colonoscope group (odds ratio 5.5: 95% CI[5.2,5.8] minutes, p=0.01). There were 22 failures overall (2.8%), 14 in the standard colonoscope group (3.6%) and 8 in the pediatric variable stiffness colonoscope group (1.9%; p=0.1). With regard to the 14 failures in the standard colonoscope group, colonoscopy was attempted with the pediatric variable stiffness colonoscope in 13 and completed successfully in 12 (92%). The pediatric variable stiffness colonoscope was superior in cases of severe stenosing diverticular disease; two of 27 examinations with the pediatric variable stiffness colonoscope were rated as failed vs. 12 of 18 with the standard colonoscope (p<0.001). CONCLUSIONS: Intubation time was faster with the pediatric variable stiffness colonoscope, but use of this instrument was not associated with a superior cecal intubation rate compared with the standard colonoscope. However, in patients with severe stenosing diverticular disease, the intubation rate with the pediatric variable stiffness colonoscope was superior.     

Usefulness of a small-caliber, variable-stiffness colonoscope as a backup in patients with difficult or incomplete colonoscopy

OBJECTIVES: Although variable-stiffness colonoscopes have been developed, difficult or incomplete colonoscopies occasionally occur. The aim of this study was to evaluate the usefulness of a small-caliber, variable-stiffness colonoscope (scVSC) as a backup in patients with difficult or incomplete colonoscopies. METHODS: First, we retrospectively reviewed the cecal intubation rate of colonoscopies in which an adult standard colonoscope (AC) was immediately switched to an scVSC in all patients in whom a colonoscopy with an AC was incomplete. Second, 374 consecutive patients were randomized to undergo colonoscopy with a pediatric variable-stiffness colonoscope (PVSC, n = 123), AC (n = 125), or scVSC (n = 126). The scVSC was used by the same endoscopist to reattempt colonoscopy immediately after colonoscopy with a PVSC or an AC had been assessed as difficult or incomplete. The cecal intubation rate and time and the ancillary maneuvers used were evaluated. RESULTS: Fifty-two (2.5%) of the 2,056 attempted colonoscopies with an AC did not reach the cecum. Fifty-one of the 52 patients (98.1%) had complete colonoscopies after the switch from the AC to the scVSC. The initial intubation rate and time were not statistically different among the groups: PVSC, 95% and 6.8 min; AC, 91% and 7.5 min; and scVSC, 98% and 8.2 min. Cecal intubation was achieved in all five patients (100%) and in 10 out of 11 (91%) patients, respectively, after the PVSC or AC was switched to the scVSC. CONCLUSIONS: The completion rate markedly improved after switching from an AC or PVSC to an scVSC in difficult or incomplete colonoscopies, although the scVSC does not appear to offer any distinct advantage over the AC or PVSC for routine colonoscopies.     

Routine colonoscopy with a standard gastroscope. A randomized comparative trial in a western population

Background and aims Colorectal cancer screening increased the workload of colonoscopic procedures in endoscopic units. Recent developments advocated the use of smaller and more flexible scopes to achieve the goal of a complete examination to the cecum. Therefore, the use of an upper GI scope for colonoscopy can be considered. Materials and methods Six-hundred and fifty consecutive patients (age, 64 ± 20 years, 395 women) undergoing routine colonoscopy were examined with either a standard colonoscope or an upper GI scope in randomized order. In case of an incomplete examination, colonoscopy was repeated with the alternative instrument in the same session. All patients underwent bowel preparation with 4 l of a polyethylene glycol solution, and the examinations were performed under conscious sedation (midazolam and pethidine i.v.) by a single investigator. Results Because of insufficient colonic preparation or refusal to participate, 28 patients had to be excluded. Both groups (colonoscope group, n = 315, upper GI scope group, n = 307) were well comparable with respect to their demographic data, previous abdominal surgery, the presence of diverticulosis, and the number of former colonoscopic examinations, respectively. Successful cecum intubation was achieved in 96% of the cases in the colonoscope group and in 93% of the patients from the upper GI scope group (p = 0.82). However, the time until the cecum was reached was prolonged to 8.7 ± 2.4 min when using the upper GI scope compared with 8.2 ± 2.3 min in the colonoscope group (p = 0.006). In the colonoscope group, a switch to the upper GI scope enables a complete colonoscopy in all but three cases (11/14, 79%) whereas this aim was only achieved vice versa in the upper GI scope group (using a colonoscope) in 7 of 21 patients (33%, p = 0.04). Conclusion Routine colonoscopy can be performed effectively with standard upper GI scopes in a western population if no colonoscope is available.     

A new variable stiffness colonoscope makes colonoscopy easier: a randomised controlled trial

BACKGROUND: Colonoscopy remains technically difficult in 10-20% of procedures due to variable colonic anatomy and fixation. The ability to vary endoscope shaft flexibility may help insertion to the caecum. METHODS: Consecutive patients attending for day case colonoscopy were randomised to examination with either the conventional Olympus CF200HL (200HL) or a new variable stiffness (VS) colonoscope. Intubation time, use of stiffening function, and patient pain scores were compared. RESULTS: Of 100 cases, 43 were performed with the 200HL and 57 with the VS. Four incomplete examinations occurred with the 200HL (two sigmoid fixations, two benign strictures) and two with the VS (one obstructing cancer, one fixed sigmoid). Changing to the paediatric scope was successful in all but one patient from each group (obstructive lesions). Stiff mode was applied 23 times in 18 patients and was effective in 15 of these. Intubation time was quicker with the VS (median 6 minutes 32 seconds) than with the 200HL (median 10 minutes 35 seconds) (p = 0.0005). Pain scores were less with the VS (median 7) than with the 200HL (median 24) (p = 0.0081). CONCLUSIONS: The variable stiffness colonoscope combines paediatric shaft characteristics with the ability to stiffen when needed. This instrument significantly reduces intubation time and patient discomfort. Further comparisons should be made with the newest colonoscopes which are less stiff.     

Impact of bending section length on insertion and retroflexion properties of pediatric and adult colonoscopes

BACKGROUND: Colonoscopes with short bending sections facilitate retroflexion but their effect on other aspects of colonoscope insertion are unknown. We sought to determine the impact of short bending on cecal insertion, terminal ileal intubation, and proximal colon retroflexion. METHODS: Two studies were performed. In study 1, we randomized 104 adult patients with intact colons to undergo colonoscopy with a standard pediatric colonoscope (Olympus PCF-160), a prototype pediatric colonoscope with short bending in four directions (PCF-AYL), or a prototype pediatric colonoscope with short bending in two directions, and normal bending in two directions (PCF-AY3L). In study 2, we randomized 70 patients with intact colons to undergo colonoscopy with a prototype 170 degrees wide angle colonoscope (CFQ160-WL) with a standard bending section length or to a prototype 170 degrees colonoscope with a short bending section (CFQ160-W2L). RESULTS: In study 1, the cecum was reached in all patients. Using the AYL, the cecal intubation time (4.08 min) was significantly longer when compared to both the PCF-160 (2.62 min; p=0.0001) and the AY3L (3.25 min; p=0.02). The AYL required the application of abdominal pressure (79%) and activation of the variable stiffness device (70%) more frequently when compared to both the PCF-160 (32%; p=0.0001 and 41%; p=0.02, respectively) and the AY3L (34%; p=0.0003 and 41%; p=0.02, respectively). Successful cecal retroflexion was possible less often with the PCF-160 (57%) when compared to either the AYL (94%; p=0.005) or AY3L (91%; p=0.001). The ability to intubate the terminal ileum was similar in all three groups (PCF-160 and AY3L 100%; AYL 94%) as was the time needed to intubate (p=0.73). Depth of ti intubation was deeper for the PCF-160 when compared to the AYL (p=0.0002) or AY3L (p=0.02). There was a trend toward deeper ileal intubation with the AY3L compared to AYL (p=0.09). In study 2, no difference was noted in cecal intubation time (p=0.1) or in frequency of application of abdominal pressure (p=0.28), position change (p=0.15), or activation of the stiffening device (p=0.46). Cecal retroflexion was successful more often when using the W2L when compared to the WL (p=0.00001). CONCLUSION: Short bending sections facilitate proximal colon retroflexion for both pediatric and adult colonoscopes, but can negatively impact cecal insertion and terminal ileal intubation in pediatric colonoscopes. A pediatric colonoscope with short bending in only two directions had good function for both cecal insertion and proximal colon retroflexion.     

Does flexible small-diameter colonoscope reduce insertion pain during colonoscopy?

AIM:It is well known that colonoscopy can be difficult due to abdominal pain induced during colonoscope insertion, if sedative agents are not given. Recently, an extra-flexible, small-diameter colonoscope (CF-SV, Olympus Inc.Japan) was developed in order to improve safety and comfort. The aim of this study was to access the usefulness of the CF-SV.METHODS:One hundred patients undergoing sigmoidoscopy were recruited and colonoscopy was performed by one experienced colonoscopist. First, a routine type colonoscope (CF-230I) was inserted into the colon without sedation. When the patient complained of abdominal pain (even if mild), the scope was not advanced further and was withdrawn after the anatomic location of its tip was determined fluoroscopically. Then, the CF-SV was inserted until it reached the cecun or the site where abdominal pain occurred. Previous abdominal surgery and abdominal disease were considered as unfavorable factors (UF) and the relationship between abdominal pain and UF, age and gender were investigated.Furthermore, the colonic insertion pressures in 36 patients with abdominal pain were measured with a force gauge.RESULTS:Thirty-four cases (34%) felt no pain with the CF-230I and successful pancolon-oscopies to the cecum were performed. Sixty-six cases (66%) complained of abdominal pain. The procedure was painless for 47% of men and 24% of women, respectively. The CF-230I scope failed to reach the sigmoid-descending colon junctions in 59 (89.4%) of the 66 patients complaining of abdominal pain. However, CF-SV reached proximal area in 94.9% of those who failed with CF-230I. The median pressure for pain-inducing was 700g/cm(2).CONCLUSION:Unsedated patients with UF were prone to complain of pain when the standard type CF-230I scope was used. The newly developed extra-flexible CF-SV is useful for the aged and for those with UF or being prone to suffer from abdominal pain. Sedative agents may be unnecessary if this new type of colonoscope is used.     

A prospective trial of variable stiffness colonoscopes with different tip diameters in unsedated patients

OBJECTIVES: Few data exist comparing the clinical versatility of variable stiffness (VS) colonoscopes with different tip diameters and stiffness ranges. We compared the intubation time and success rate, maneuvering ease, and patient comfort of three colonoscopes: pediatric VS (PVSC), nonmagnifying adult VS (AVSC), and magnifying VS (MVSC).
METHODS: Two hundred sixteen consecutive patients scheduled for routine colonoscopy were randomized to undergo colonoscopy with one of the three different colonoscopes (PVSC N = 72, AVSC N = 72, MVSC N = 72). Outcome measurements included time required for cecal intubation, success rate for cecal intubation, maneuvering ease, and patient comfort.
RESULTS: The overall success rate for cecal intubation was 95.83%. Intubation time was significantly different among the groups (PVSC 12.88 ± 7.11 min, AVSC 9.25 ± 5.16 min, MVSC 9.62 ± 5.55 min; P < 0.01). Intubation time with PVSC required about 3 min more when compared with AVSC or MVSC. Multivariate analyses revealed that colonoscopy with AVSC required 3 min less when compared with PVSC ( P = 0.03). Age greater than 55 yr, waist circumference, prior hysterectomy, and pain experienced by patients were also factors affecting intubation time.
CONCLUSIONS: In this study, a PVSC might not decrease patient discomfort or intubation time. The ideal colonoscope is the AVSC that has a modest diameter and stiffness range and thus is capable of achieving both a short intubation time and an acceptable comfort level. We also should bear in mind that MVSC has an additional function of magnifying observation.     

Usefulness of a pediatric colonoscope for routine colonoscopy in women who have undergone hysterectomy

BACKGROUND: Colonoscopy can be difficult in some women who have undergone hysterectomy, which can be associated with a fixed, angulated sigmoid colon caused by postoperative pelvic adhesions. Our goal was to determine whether colonoscopy is easier and more comfortable for women after hysterectomy when performed with a pediatric colonoscope, which is thinner in diameter and more flexible than a standard "adult" colonoscope. METHODS: One hundred women with a history of hysterectomy undergoing outpatient colonoscopy were randomized in unblinded fashion to colonoscopy with a standard colonoscope (CF-100L or CF-Q140L, Olympus) or with a pediatric colonoscope (PCF-100, Olympus). All procedures were performed by a faculty endoscopist and timed. After examination, the endoscopist graded procedure difficulty, and patients were given a questionnaire that assessed their experience. RESULTS: The cecum was intubated more frequently in the pediatric colonoscope group than in the standard colonoscope group (96.1% vs. 71.4%, p < 0.001). Success increased in the standard colonoscope group to 89.8% when the pediatric colonoscope was used to complete the examination. There were no differences in the two groups in terms of mean total procedure times (21.4 minutes vs. 22.6 minutes), mean doses of meperidine administered (57 mg both groups), mean doses of midazolam administered (1.5 mg vs. 1.7 mg), scales of procedure difficulty as graded by the endoscopists, and comfort scales as graded by patients. For the cases in which the cecum was intubated, the mean time to reach the cecum (11.7 minutes for the pediatric colonoscope group vs. 12.7 minutes for the adult) was similar. CONCLUSIONS: The pediatric colonoscope is a reasonable choice for colonoscopy in women who have had a hysterectomy. Alternatively, if the endoscopist elects to start the procedure with a standard colonoscope, it is helpful to have a pediatric colonoscope available for use should a fixed, angulated sigmoid colon be encountered that cannot be easily or safely traversed with the standard colonoscope.     

Can optical diagnosis of small colon polyps be accurate? Comparing standard scope without narrow banding to high definition scope with narrow banding

AIM: To study the accuracy of using high definition(HD) scope with narrow band imaging(NBI) vs standard white light colonoscope without NBI(ST), to predict the histology of the colon polyps, particularly those 1 cm.METHODS: A total of 147 African Americans patients who were referred to Howard University Hospital for screening or, diagnostic or follow up colonoscopy, during a 12-mo period in 2012 were prospectively recruited. Some patients had multiple polyps and total number of polyps was 179. Their colonoscopies were performed by 3 experienced endoscopists who determined the size and stated whether the polyps being removed were hyperplastic or adenomatous polyps using standard colonoscopes or high definition colonoscopes with NBI. The histopathologic diagnosis was reported by pathologists as part of routine care. RESULTS: Of participants in the study, 55(37%) were male and median(interquartile range) of age was 56(19-80). Demographic, clinical characteristics, past medical history of patients, and the data obtained by two instruments were not significantly different and two methods detected similar number of polyps. In ST scope 89% of polyps were 1 cm vs 87% in HD scope(P = 0.7). The ST scope had a positive predictive value(PPV) and positive likelihood ratio(PLR) of 86% and 4.0 for adenoma compared to 74% and 2.6 for HD scope. There was a trend of higher sensitivity for HD scope(68%) compare to ST scope(53%) with almost the same specificity. The ST scope had a PPV and PLR of 38% and 1.8 for hyperplastic polyp(HPP) compared to 42% and 2.2 for HD scope. The sensitivity and specificity of two instruments for HPP diagnosis were similar.CONCLUSION: Our results indicated that HD scope was more sensitive in diagnosis of adenoma than ST scope. Clinical diagnosis of HPP with either scope is less accurate compared to adenoma. Colonoscopy diagnosis is not yet fully matched with pathologic diagnosis of colon polyp. However with the advancement of both imaging and training, it may be possible to increase the sensitivity and specificity of the scopes and hence save money for eliminating time and the cost of Immunohistochemistry/pathology.     

Methods of Reducing Discomfort During Colonoscopy

In the United States sedation for colonoscopy is usual practice. Unsedated colonoscopy is limited to a small proportion of unescorted patients and those with a personal preference for no sedation. Over 80% of patients who accept the option of as-needed sedation can complete colonoscopy without sedation. Colonoscopy in these unsedated patients is performed with techniques similar to those used in the sedated patients. Uncontrolled observations indicate willingness to repeat colonoscopy amongst these patients was correlated significantly with low discomfort score during the examination. Methods reported to minimize patient discomfort or enhance cecal intubation during sedated or unsedated colonoscopy included use of pediatric colonoscope, variable stiffness colonoscope, gastroscope, and inhalation of nitrous oxide or insufflation of carbon dioxide, hypnosis, music, audio distraction, or simply allowing the patients to participate in administration of the medication. Research focusing on confirming the efficacy of a simple inexpensive nonmedication dependent method for minimizing discomfort will likely improve the outcome of care and more importantly will ensure compliance with future surveillance in patients accepting the unsedated option.     

Incomplete colonoscopy: Maximizing completion rates of gastroenterologists

BACKGROUND

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.

OBJECTIVES:

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.

METHODS:

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.

RESULTS:

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).

CONCLUSION:

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.     

Comparison of Glucagon and Scopolamine Butylbromide as Premedication for Colonoscopy in Unsedated Patients

Purpose Premedication with glucagon or hyoscyamine is reported to be effective in reducing colonic spasm. However, these drugs can be associated with unfavorable events. This prospective study was designed to compare the effects of premedication with glucagon with those of scopolamine butylbromide on cardiopulmonary parameters, intubation time, and patient discomfort in unsedated patients undergoing diagnostic colonoscopy. Methods One hundred consecutive adult patients (65 males) undergoing colonoscopy without sedation were randomized toreceive 1 mg of glucagon (n = 50) or 20 mg of scopolamine butylbromide (n = 50), intramuscularly. Physiologic changes, including systolic blood pressure, heart rate, and oxygen saturation, were monitored before colonoscope insertion and at three-minute intervals during colonoscopy. The percentages of completed procedure and time to cecal intubation were recorded. Patients were asked to rate pain by using a five-point pain score (0 = no pain; 4 = severe pain). Results The percentages of completed procedure (96 vs. 98 percent), time to cecal intubation (16.3 vs. 14.5 minutes), and pain score (1.7 vs. 1.5) did not differ significantly between two groups. An increase in heart rate of more than ten beats per minute from baseline during colonoscopy occurred significantly more often in scopolamine group (44 percent of 50 patients) than in the glucagon group (12 percent of 50 patients; P = 0.0004). There were no significant differences between the two study groups with regard to changes in systolic blood pressure and decrease in oxygen saturation during colonoscopy. Conclusions Premedication with 1 mg of glucagon facilitates favorable examination with respect to physiologic changes compared with 20 mg of scopolamine. These features favor glucagon as the preferred premedication for patients undergoing colonoscopy. Presented at the meeting of Digestive Disease Week, New Orleans, Louisiana, May 15 to 20, 2004.     

Preoperative colonoscopy through the colonic stent in patients with colorectal cancer obstruction

AIM:To evaluate the feasibility of a preoperative colonoscopy through a self-expendable metallic stent(SEMS)and to identify the factors that affect complete colonoscopy.METHODS:A total of 48 patients who had SEMS placement because of acute malignant colonic obstruction underwent preoperative colonoscopy.After effective SEMS placement,patients who showed complete resolution of radiological findings and clinical signs of acute colon obstruction underwent a standard bowel preparation.Preoperative colonoscopy was then performed using a standard colonoscope.If the passage of colonoscope was not feasible gastroscope was used.After colonoscopy,cecal intubation time,grade of bowel preparation,tumor location,stent location,presence of synchronous polyps or cancer,damage to colonoscopy and bleeding,and stent migration after colonoscopy were recorded.RESULTS:Complete evaluation with colonoscope was possible in 30 patients(62.5%).In this group,adenoma was detected in 13 patients(43.3%).The factors that affected complete colonoscopy were also analyzed:Tumor location at an angle;stent placement at an angle;and stent expansion diameter,which affected complete colonoscopy significantly.However in multivariate analysis,stent expansion diameter was the only significant factor that affected complete colonoscopy.Complete evaluation using additional gastroscope was feasible in 42 patients(87.5%).CONCLUSION:Preoperative colonoscopy through the colonic stent using only conventional colonoscope was unfavorable.The narrow expansion diameter of the stent may predict unfavorable outcome.In such a case,using small caliber scope should be considered and may expect successful outcome.