A prospective RCT comparing combined chromoendoscopy with water exchange (CWE) vs water exchange (WE) vs air insufflation (AI) in adenoma detection in screening colonoscopy.

Background: A low adenoma detection rate (ADR) increases risks of interval cancers (ICs). Proximal colon flat polyps, e.g. serrated lesions (SLs), are difficult to find. Missed proximal colon flat lesions likely contribute to IC. Aims: We compared chromoendoscopy with water exchange (CWE), water exchange (WE) and air insufflation (AI) in detecting adenomas in screening colonoscopy. Methods: After split-dose preparation, 480 veterans were randomized to AI, WE and CWE. Results: Primary outcome of proximal ADR (55.6% vs 53.4% vs 52.2%, respectively) were similar in all groups. Adenoma per colonoscopy (APC) and adenoma per positive colonoscopy (APPC) were comparable. Detection rate of proximal colon SLs was significantly higher for CWE and WE than AI (26.3%, 23.6% and 11.3%, respectively, p = 0.002). Limitations: single operator; SLs only surrogate markers of but not IC. Conclusions: When an endoscopist achieves high-quality AI examinations with overall ADR twice (61.6%) the recommended standard (30%), use of WE and CWE does not produce further improvement in proximal or overall ADR. Comparable APC and APPC confirm equivalent withdrawal inspection techniques. WE alone is sufficient to significantly improve detection of proximal SLs. The impact of increased detection of proximal SLs by WE on prevention of IC deserves to be studied. This study is registered at ClinicalTrial.gov (NCT#01607255).

Underwater polypectomy without submucosal injection for colorectal lesions ≤ 20 mm in size-a multicenter retrospective observational study.

BACKGROUND: Underwater polypectomy (UWP) of large (≥ 20 mm) colorectal lesions is well described, but reports of UWP for lesions ≤ 20 mm in size, which account for > 95% of polyps encountered in routine clinical practice, are limited. We assessed the feasibility of UWP in routine practice across various sites for colorectal lesions ≤ 20 mm in size. METHODS: A multicenter retrospective study was performed on pooled data from nine colonoscopists at 3 U.S., 1 Taiwanese and 2 Italian sites. Outcomes related to UWP on lesions ≤ 20 mm in size were analyzed. RESULTS: In 117 patients, UWP netted 169 lesions. Polypectomy by hot (HSP, 54%) or cold (CSP, 41%) snare, and cold forceps (CFP, 5%) were performed successfully without endoscopic evidence of residual neoplasia or immediate clinically significant adverse events. The majority (74.6%) were tubular adenomas; 60.9% were from the proximal colon. Histopathologic margins were positive in 4 and unavailable in 26 CSP and 24 HSP specimens. The remainder had negative resection margins on pathologic reports. CONCLUSION: UWP for colorectal lesions ≤ 20 mm in routine practice across multiple sites confirms the feasibility and acceptability of this technique. Improvement of resection outcomes by UWP in routine practice deserves further evaluation in a randomized controlled trial.

The water method significantly enhances patient-centered outcomes in sedated and unsedated colonoscopy.

Failure of cecal intubation when using air insufflation during scheduled unsedated colonoscopy in veterans prompted a literature search for a less uncomfortable approach. Water-related maneuvers as "adjuncts" to air insufflation were identified as effective in minimizing discomfort, although medication requirement was not reduced and willingness to repeat unsedated colonoscopy was not addressed. These adjunct maneuvers were combined with turning the air pump off to avoid colon elongation during insertion. Warm water infusion in lieu of air insufflation was evaluated in observational studies. Subsequent refinements evolved into the water method - a combination of air exclusion by aspiration of residual air to minimize angulations at flexures and a dynamic process of water exchange to remove feces in order to clear the view and aid insertion. In subsequent randomized controlled trials, the water method significantly reduced medication requirement, increased the proportion of patients in whom complete unsedated colonoscopy could be achieved, reduced patient recovery time burdens (sedation on demand), decreased abdominal discomfort during and after colonoscopy, enhanced cecal intubation, and increased willingness to repeat the procedure (scheduled unsedated). Supervised education of trainees and self-learning by an experienced colonoscopist were feasible. Lessons learned in developing the water method for optimizing patient-centered outcomes are presented. These proof-of-principle observations merit further research assessment in diverse settings.

Laser spectroscopy of NiI: new electronic states and hyperfine structure.

Two new electronic transition systems, namely, the [14.0](2)Phi(7/2)-Chi (2)Delta(5/2) and the [15.7](2)Phi(5/2)-Chi (2)Delta(5/2) transitions were observed and analyzed using laser vaporization/reaction supersonic free jet expansion and high resolution laser induced fluorescence spectroscopy. In addition, the (v, 0) bands with v=6-10 of the [14.6](2)Delta(5/2)-Chi (2)Delta(5/2) transition were found to be perturbed by the [15.7](2)Phi(5/2) state. The interaction between the [14.6](2)Delta(5/2) and the [15.7](2)Phi(5/2) states is evident in the progressive increase in hyperfine width of rotational lines of the [14.6](2)Delta(5/2)-X (2)Delta(5/2) transition as the vibrational quantum number increases. Deperturbation procedures were successfully applied to analyze the interaction between these two states. All observed spectra show partially resolved hyperfine structure, and the hyperfine width decreases rapidly as J increases suggested that the hyperfine structure conforms to the Hund's case a(beta) coupling scheme. Accurate molecular and hyperfine constants for the [14.0](2)Phi(7/2), the [14.6](2)Delta(5/2) and the [15.7](2)Phi(5/2) states were obtained and analyzed.

Comparison of accessory performance using a novel ERCP mechanical simulator.

BACKGROUND AND STUDY AIMS: There is a paucity of in vitro methods for evaluating ERCP accessories. We hypothesize that the time taken to perform a simulated single stent or multiple stents placement is different for stenting systems with or without the capability of intraductal ductal release (IDR) of the guide wire. PATIENTS AND METHODS: We conducted an un-blinded in vitro comparison of ERCP accessories using a mechanical simulator during hands-on ERCP practice workshops. A total of 21 U.S. participants and 20 Chinese participants with various level of ERCP experience took part in the different practice workshops. Accessories with and without the capability of intraductal release of guide wire were compared. Total time required for completing a simulated stenting procedure with single or multiple stents and the respective simulated fluoroscopy time were recorded. RESULTS: There was no significant difference in the time taken for placement of a single stent using either stenting systems. Stenting system capable of intraductal release of the guide wire required significantly shorter time to complete placement of three stents. CONCLUSIONS: Using time required to complete a specific task, i. e. biliary stenting, the mechanical simulator permits the performance of different accessories by the same group of operators to be evaluated objectively.

Laser spectroscopy of iridium monoboride.

High resolution laser induced fluorescence spectrum of IrB in the spectral region between 545 and 610 nm has been recorded and analyzed. Reacting laser-ablated iridium atoms with 1% B(2)H(6) seeded in argon produced the IrB molecule. This is the first experimental observation of the IrB molecule. Four vibronic transition bands, (v,0) with v=0-3 of an electronic transition system, have been observed. Spectra of all four isotopic molecules, (191)Ir(10)B, (193)Ir(10)B, (191)Ir(11)B, and (193)Ir(11)B, were recorded. Isotopic relationships confirmed the carrier of the spectra and the vibrational quantum number assignment. Preliminary analysis of rotational lines showed that these vibronic bands are with Omega' = 2 and Omega" = 3. The electronic transition identified is assigned as the [16.5](3)Pi(2)-X(3)Delta(3) system. Partially resolved hyperfine structure which conforms to the Hund's case a(beta) coupling scheme has been observed and analyzed. The bond length r(0) of the lower X(3)Delta(3) state of IrB was determined to be 1.7675 A.

Options for screening colonoscopy without sedation: a pilot study in United States veterans.

BACKGROUND: The direct and indirect costs of sedation limit access to screening colonoscopy amongst United States veterans. AIM: To determine if offering the option of sedation on-demand reduces the need for sedation. Design A retrospective review of prospectively collected performance improvement data in an open access screening colonoscopy programme. SETTING: Performance improvement programme to minimize the burden of sedation at a single VA Medical Center. Subjects 44 consecutive veterans who accepted the option of sedation on-demand. They could choose to have premedications before the start of colonoscopy, or to begin colonoscopy without premedications and receive the medications upon their request during the examination. METHOD: Two experienced endoscopists assisted by experienced nurse assistants performed all of the examinations. Insertion of the colonoscope was aided by infusion of warm water through the colonoscope without air insufflation. Medications were administered at the veterans' request. RESULTS: Offering the option of sedation on-demand to 44 consecutive veterans permitted 52% (N = 23) of the veterans to complete screening colonoscopy without any sedation. CONCLUSIONS: This novel approach of sedation on-demand and water infusion for screening colonoscopy deserves to be further evaluated in a randomized-controlled study amongst patients undergoing colorectal cancer screening.

Laser spectroscopy of NiBr: new electronic states and hyperfine structure.

Laser induced fluorescence spectrum of NiBr in the visible region between 604 and 666 nm has been recorded and analyzed. Fourteen bands belonging to three electronic transition systems, namely, [15.1] (2)Delta(52)-X (2)Pi(32), [15.1] (2)Pi(32)-X (2)Pi(32), and [14.0] (2)Delta(52)-X (2)Pi(32) have been observed. Spectra of isotopic molecules were also observed and analyzed. Detailed analysis of the recorded spectra indicated that the two electronic states [15.1] (2)Pi(32) and [15.1] (2)Delta(52) lie about 1 cm(-1) apart from each other and J-dependent perturbation due to spin-uncoupling interaction has been observed. Least squares fitting procedures involving deperturbation matrix elements were used to fit the observed line positions, which yielded accurate molecular constants for the [15.1] (2)Pi(32) and [15.1] (2)Delta(52) states. In addition, the (1,0) band of the [15.1] (2)Delta(52)-X (2)Pi(32) transition shows partially resolved hyperfine structure that was caused by the interaction of unpaired electron with the magnetic moment of the Br nucleus (nuclear spin of I=32) in the excited state. The rapid decrease in hyperfine width as J increases suggests that the hyperfine coupling in the excited state conforms to Hund's case (a(beta)) coupling scheme.

Papillotomy Performance Scoring Scale--a pilot validation study focused on the cut axis.

BACKGROUND: No published Papillotomy Performance Scoring Scale exists. AIMS: To develop such a scale and to apply it to stratify the quality of performance of recorded papillotomies. METHODS: Expert biliary endoscopists were polled regarding their opinion of a 'perfect' biliary papillotomy and experience with complications in relation to the cut axis. Based on these responses a scoring scale encompassing two components - wire alignment and cut orientation, was proposed. This scoring scale was presented to experienced and trainee endoscopists, who scored recording of five biliary papillotomies. The mean final combined score was used for stratification. RESULTS: The experts' opinion of a 'perfect' biliary papillotomy is one cut along the axis of the distal bile duct and papilla. Their reported experience with complications occurring outside of the perfect axis validated their consensus. Application of the scoring scale stratified recorded papillotomies based on the mean final combined scores. CONCLUSIONS: These pilot data support the hypothesis that a scoring scale focused on the cut axis can be constructed based on expert opinion, experience and consensus. The possibility of stratification of mean final combined scores that are significantly different validates application of the scoring scale for assessment of papillotomy performance.

Extended flexible sigmoidoscopy performed by colonoscopists for colorectal cancer screening: a pilot study.

BACKGROUND: Caecal intubation can be achieved by extended flexible sigmoidoscopy in 32% of patients. AIM: To assess the feasibility of extended flexible sigmoidoscopy performed by colonoscopists for colorectal cancer screening. METHODS: We enrolled 41 patients referred for screening flexible sigmoidoscopy. After purging, examination was performed with a colonoscope. All patients completed sigmoidoscopy (success in meeting referral goal); 93% and 71% had examination to the transverse or ascending colon, and caecum, respectively. Overall yield and right-sided polyps was 56% and 27%, respectively. Caecal intubation and complete examination with polypectomy took 6.0 +/- 2.5 and 18.3 +/- 5.1 min, respectively; with no complications. Twelve patients requested colonoscope withdrawal because of discomfort. Although 46% reported moderate to severe discomfort, 39% and 36%, respectively, were definitely or probably willing to repeat flexible sigmoidoscopy. RESULTS: Unsedated colonoscopy introduced as extended flexible sigmoidoscopy emphasizes the benefits of added yield rather than the negative image of withholding of discomfort relief. The patient can choose to accept the equivalent of an unsedated colonoscopy or reject the option based on perceived discomfort during extended flexible sigmoidoscopy performed by the colonoscopist. CONCLUSION: Extended flexible sigmoidoscopy is a feasible option in carefully selected patients, fully prepared and by an experienced colonoscopist.

Pathogenesis of esophageal rings in eosinophilic esophagitis.

Eosinophilic esophagitis and eosinophilic gastroenteritis is being recognized more frequently among the adult patients. The disease is characterized by massive infiltration of the wall of gastrointestinal tract by sheets of eosinophils. The clinical features depend upon the site of involvement. They include dyspepsia, dysphagia, nausea, vomiting, chest pain, diarrhea and protein-losing enteropathy. Eosinophilic esophagitis may present as chest pain, dysphagia or dyspepsia. The characteristic endoscopic feature of eosinophilic esophagitis is the formation of fine concentric mucosal rings (corrugated esophagus). Regarding the pathogenesis of these mucosal rings our hypothesis is that mast cells in the esophageal wall in response to allergens release histamine, eosinophilic chemotactic factor and platelet activating factor, etc. which activate eosinophils to release toxic cationic proteins. Activation of acetyl choline by histamine may cause contraction of the muscle fibers in the muscularis mucosae resulting in the formation of esophageal rings. This hypothesis can be tested by demonstrating the contraction of muscle layers of muscularis mucosae with the use of high frequency endoscopic ultrasonic probe introduced via the biopsy channel of an endoscope.

Colonic preparation correlates with fasting breath hydrogen in patients undergoing colonoscopy.

BACKGROUND/AIMS: Fasting breath hydrogen has been reported to be low after fasting and polyethylene glycol ingestion. However, the relationship between fasting breath hydrogen and colonic preparation for colonoscopy has not been studied before. We evaluated fasting breath hydrogen in patients undergoing colonoscopy and correlated it with the quality of colonic preparation. METHODOLOGY: One day before colonoscopy, the patients ingested clear liquid diet and starting in the afternoon the day before colonoscopy they drank polyethylene glycol 8oz every 10 minutes for 3 hours. They fasted overnight. Fasting breath hydrogen was measured using an EC 60 gastrolyzer. Colonic preparation was rated as excellent, fair or poor. The colonoscopic findings were noted. RESULTS: There were 69 male patients. 89% had excellent or fair colonic preparation (Group A) 11% had poor preparation (Group B). Fasting breath hydrogen in Group B patients 14.5 +/- 1.5 ppm was significantly higher compared to that in Group A patients 2.2 +/- 0.2 ppm (p < 0.005 t-test). In other respects the two groups were similar. CONCLUSIONS: Patients undergoing colonoscopy after polyethylene glycol ingestion who have poor colonic preparation have higher fasting breath hydrogen compared to those who have excellent/fair colonic preparation. The clinical implication of this observation is discussed.

Circadian variation in portal pressure: appropriate use of non-selective beta blockers in the prevention of variceal bleed.

The circadian variation in some biologic functions may have clinical, fiscal and therapeutic implications. The authors discuss circadian variation in portal pressure in cirrhotic patients and nocturnal occurrence of bleeding from varices in these patients. The pathogenesis of the diurnal variation in portal pressure is presented. The authors submit the hypothesis that an optimal dosing regimen for non-selective beta blocker therapy in the prevention of variceal bleed must include an evening dose of beta blocker medication. In studies reporting comparative efficacy of beta blocker therapy with other modalities in the prevention of variceal bleeding, the optimal dosing schedule for beta blocker therapy must be emphasized.

Bacteriologic analyses of bile and brown pigment stones in patients with acute cholangitis.

BACKGROUND: Bacteria play an important role in the formation of brown pigment stones through adherence and biofilm formation. Scanning electron microscopy of cross sections of these stones reveals a laminated appearance and various bacteria in the different layers. Our postulation was that different bacteria might be involved at different stages of stone formation. METHODS: By using standard bacteriologic cultures, the composition, morphology, and antibiotic sensitivity patterns of bacteria isolated from paired stone were compared with bile samples from 70 patients with acute cholangitis. A further comparison was made between bacteria isolated from the periphery and center of 3 randomly selected brown pigment stones. RESULTS: Ninety-one percent of bile and 99% of stone samples yielded positive cultures, with a total of 151 and 149 bacteria isolated from bile and stones, respectively. In 22 patients (33%), the bacteria isolated from the paired bile and stone samples were totally different. The mean percentage similarity of bacteria isolated from bile and stones was 39% (range 0%-100%). Of the 59 pairs of similar bacteria isolated, the antibiotic sensitivity patterns were different in 24 (41%) cases. Of the 3 brown stones studied, either different bacterial species or the same bacteria but different strains with different antibiotic sensitivities were isolated from the center and periphery of the stones. CONCLUSIONS: Bacteria present in the different layers of brown pigment stones may represent the bacterial flora in bile at different times. Simple bile culture may not identify bacteria trapped inside the stone.

Expression of bacterial beta-glucuronidase in human bile: an in vitro study.

BACKGROUND: Bacterial beta-glucuronidase causes deconjugation of bilirubin diglucuronide resulting in the precipitation of calcium bilirubinate, which contributes to biliary sludge and stone formation. This process is attributed to enzyme activity produced by the aerobic enterobacteriaceae such as Escherichia coli and Klebsiella sp. The presence of Clostridium sp. was detected in 48 of 56 intrahepatic stones by using polymerase chain reaction techniques and cultured Clostridium perfringens from 14 of 18 unblocked biliary stents. Such bacteria are reported to produce beta-glucuronidase activity. The aim of this study was to determine the proportion of biliary bacteria isolated from pigment stones and stents that produce beta-glucuronidase and to compare the enzyme activity expressed by the different bacteria in human bile. METHODS: A total of 202 bacteria were isolated from blocked and unblocked biliary stents and pigment ductal stones recovered from patients. Of these, 61 bacteria expressed beta-glucuronidase activity in brain heart infusion broth. These 61 bacteria were subsequently grown in human bile under aerobic or anaerobic conditions to the early stationary phase and assayed for beta-glucuronidase activity by using rho-nitrophenyl beta-D glucuronide as substrate. Results were normalized and reported as units of enzyme activity per milligram protein of the bacteria. RESULTS: C. perfringens produced beta-glucuronidase enzyme activity that was 34-fold higher than that for E coli, Staphylococcus, Corynebacterium sp., Bacillus sp., Enterococcus sp., Acinetobacter sp., Streptococcus sp., and Klebsiella sp. CONCLUSION: C. perfringens with its higher enzyme activity is more important in the deconjugation of bilirubin diglucuronide than E coli and Klebsiella sp.

Percutaneous imaging-guided core breast biopsy: 5 years' experience in a community hospital.

OBJECTIVE: This study reports the results of a percutaneous imaging-guided core breast biopsy program in a community hospital. MATERIALS AND METHODS: We reviewed the prospectively collected results of our imaging-guided core biopsy program during its first 5 years (1994-1998). A total of 1333 lesions (94% of which were Breast Imaging Reporting and Data System (BI-RADS) assessment category 4) were sampled in 1183 patients. Patients with BI-RADS assessment category 5 lesions were referred to surgeons. Stereotactic guidance was used for the core biopsy of 506 lesions, and sonography was used to guide the predominantly 16-gauge needle core biopsy of 827 solid masses. RESULTS: One hundred forty-seven cancers were diagnosed in 1333 biopsies, resulting in a positive yield of 11%. Of 1020 patients with benign, concordant core biopsy results, 981 (96%) had at least one follow-up imaging examination within 36 months of the biopsy. Nineteen (2%) of these 1020 patients had a suspicious change at follow-up; 18 of these patients underwent surgical excision with benign findings. No cancers were found at imaging follow-up or by tumor registry linkage. All malignant core biopsy results were confirmed as malignant at surgical excision (positive predictive value 100%). Twenty-two patients with atypical ductal hyperplasia at core biopsy had subsequent surgery, and 12 (55%) of them were found to have cancer at surgery. CONCLUSION: An imaging-guided core biopsy program, developed and implemented by a small group of radiologists in a community hospital, can achieve successful results and provide an important service to patients and a cost-effective alternative to surgical biopsy. Our program emphasized sonographic guidance and achieved high follow-up compliance.

Stimulation of intestinal mucosal afferent nerves increases superior mesenteric artery and decreases mesenteric adipose tissue blood flow.

We tested the hypothesis that stimulation of intestinal mucosal afferent nerves produces an increase in superior mesenteric artery (SMA) but a decrease in mesenteric adipose tissue (MAT) blood flow. In anesthetized rats, blood flow in the SMA (pulsed Doppler flowmetry) and MAT (hydrogen gas clearance) was measured simultaneously before and after administration of 0.9% saline, 640 microM capsaicin, or 5% dextrose into the intestinal lumen. The changes in the SMA were 3.8 +/- 3.0, 15.9 +/- 4.0, and 18.8 +/- 7.6%; and those in the MAT, 4.7 +/- 4.0, -11.5 +/- 3.4, and -0.07 +/- 3.4% of baseline, respectively. The data indicate that exposure of the intestinal lumen to an afferent nerve stimulant or nutrient induced a dichotomous pattern of blood flow changes, an increase in the SMA and a reduction in MAT. The capsaicin-sensitive afferent nerves may be instrumental in mediating these energy responses.