Intraluminal Bubbles Research Articles

Randomized, double-blinded, placebo-controlled trial evaluating simethicone pretreatment with bowel preparation during colonoscopy.

BACKGROUNDThe presence of small air bubbles and foam are an impediment to a successful colonoscopy. They impair an endoscopist’s view and diminish the diagnostic accuracy of the study. This has been particularly noted to be of concern with the switch to lower volume polyethylene glycol (PEG) and bisacodyl combination preparation.AIMTo evaluate the effect of oral simethicone addition to bowel preparation on intraluminal bubbles reduction during colonoscopy.METHODSDescribed is a prospective, randomized, multi-center, double-blinded, placebo-controlled study to evaluate the use of premixed simethicone formulation with split-regimen, low-volume PEG-bisacodyl combination bowel preparation for 168 outpatients undergoing screening, surveillance, and diagnostic colonoscopies. Primary outcome includes evaluation of bubbles during colonoscopy graded using the Intraluminal Bubbles Scale. Secondary outcomes include evaluation of the Boston Bowel Preparation Scale (BBPS), total number of polyps, polyp size differentiation, polyp laterality, adenoma detection, mass detection, cecal insertion time, withdrawal time, and patient-reported adverse events.RESULTSHigher Intraluminal Bubbles grades III and IV (less than 75% of the mucosa cleared of bubbles/foam requiring intervention with simethicone infused wash) were detected in the placebo group [Simethicone n = 4/84 vs Placebo n = 20/84 (P = 0.007)]. BBPS total score was 7.42 [standard deviation (SD) = ± 1.51] in the simethicone group and 7.28 (SD = ± 1.44) in the placebo group (P = 0.542) from a total of 9. Significantly higher number of adenomas were detected in the simethicone group (P = 0.001).CONCLUSIONThe addition of simethicone to bowel preparation is well advised for its anti-foaming properties. The results of this study suggest that addition of oral simethicone can improve bowel wall visibility.

Simethicone Pre-Treatment With Polyethylene Glycol and Bisacodyl Combination Preparation in an Effort to Improve Bowel Wall Visualization

Introduction: The presence of small air bubbles and foam can lead to impaired endoscopist view and diminish the diagnostic accuracy of a colonoscopy. Few studies have evaluated the efficacy of simethicone as an anti-foaming component with bowel preparations. This has been particularly noted to be of concern with the switch to lower volume polyethylene glycol (PEG) and bisacodyl combination preparations. Methods: We designed a prospective, randomized, multi-center, double blinded study to evaluate the use of simethicone formulation with split regimen, low volume PEG-Bisacodyl combination bowel preparation for outpatients undergoing elective colonoscopies. 124 adults are allocated into the treatment arm consisting of 200 mg of liquid simethicone and 126 adults are allotted to the control arm containing placebo water preparation to be mixed along with the bowel preparation. Intra-luminal bubbles scale is used as a primary endpoint defined by the percentage of the mucosa obscured by bubbles as seen by endoscopists during the procedure and whether intervention with simethicone infused saline wash is required. Secondary outcomes include the evaluations of adequacy of bowel preparation using the validated Boston Bowel Preparation Scale (BBPS), the number and types of polyps/masses detected, cecal insertion time, withdrawal time, and patient reported adverse effects. In an effort to reduce and measure inter-observer variability, 10 gastroenterologists are provided imaging examples of the Bubbles Scale and the Boston Bowel Preparation Scale for reference during rating and intermittently assessed through grading various images of intra-luminal bubbles. Results: The incidence of high levels of bubbles (Grade III and IV, less than 75% of the mucosa cleared of bubbles/foam requiring intervention with simethicone infused saline wash) is 5% and 30% respectively in simethicone vs. placebo group (P=<0.001). BBPS total score is 7.42 (+/- 1.62) simethicone and 7.29 (+/- 1.40) with the placebo group (P=0.474). Polyp detection rate is 1.51 in simethicone group vs. 1.13 in control group (P=0.825). Conclusion: Although recruiting has been completed, the study is in progress and 139 out of 250 participants have undergone endoscopies. Remaining participants are scheduled for the study duration ending in July 2018. Due to the fewer number of existing studies and lack of significant data, simethicone has not been incorporated in most commercially available bowel preparations for its anti-foaming properties.516_A Figure 1. Bubbles Scale516_B Figure 2. Logos

How Much Can Simethicone Do in Colonoscopy

Meta-analyses suggest that adding simethicone to colonoscopy bowel preparation effectively reduces intraluminal bubbles but does not improve bowel

A single-center randomized controlled study of the effect of dyclonine hydrochloride mucilage on bubble removing in bowel preparation

Objective To evaluate the effect of two dosages of the dyclonine hydrochloride mucilage on removing bubbles in bowel preparation before colonoscopy. Methods Data of 774 patients who received colonoscopy from November 2015 to April 2016 in People′s Hospital of Xinjiang Uygur Autonomous Region were randomly divided into groups A, B and C. As the control group, group A only used four boxes of polyethylene glycol (PEG) for bowel preparation and drank 50 mL water after bowel preparation; group B was given 10 mL dyclonine hydrochloride mucilage with 50 mL water after four boxes of PEG for bowel preparation; group C was given 20 mL dyclonine hydrochloride mucilage with 50 mL water after four boxes of PEG. Intestinal cleanliness, intraluminal gas bubbles and satisfaction were graded by endoscopic physicians. Polyps of less than 5 mm were recorded and adverse reactions were observed. Results There were no significant differences in intestinal cleanliness among groups A, B and C (P>0.05). The intraluminal gas bubbles grading, physician satisfaction and detection rate of polyps of less than 5 mm of groups B and C were significantly better than those of group A(P<0.01), and group C was superior to group B in these variables(P<0.01). The proportion of level Ⅰ and Ⅱ in foam evaluation in group C was higher than that in group B(P<0.01). Conclusion Dyclonine hydrochloride mucilage can eliminate the bubbles inside the intestine, and the effect of 20 mL dyclonine hydrochloride mucilage for bowel preparation is superior to 10 mL. Key words: Colonoscopy; Dyclonine hydrochloride mucilage; Polyethylene glycol; Patient satisfaction

Oral purgative and simethicone before small bowel capsule endoscopy

To evaluate small bowel cleansing quality, diagnostic yield and transit time, comparing three cleansing protocols prior to capsule endoscopy. Sixty patients were prospectively enrolled and randomized to one of the following cleansing protocols: patients in Group A underwent a 24 h liquid diet and overnight fasting; patients in Group B followed protocol A and subsequently were administered 2 L of polyethylene glycol (PEG) the evening before the procedure; patients in Group C followed protocol B and were additionally administered 100 mg of simethicone 30 min prior to capsule ingestion. Small bowel cleansing was independently assessed by two experienced endoscopists and classified as poor, fair, good or excellent according to the proportion of small bowel mucosa under perfect conditions for visualization. When there was no agreement between the two endoscopists, the images were reviewed and discussed until a consensus was reached. The preparation was considered acceptable if > 50% or adequate if > 75% of the mucosa was in perfect cleansing condition. The amount of bubbles was assessed independently and it was considered significant if it prevented a correct interpretation of the images. Positive endoscopic findings, gastric emptying time (GET) and small bowel transit time (SBTT) were recorded for each examination. There was a trend favoring Group B in achieving an acceptable (including fair, good or excellent) level of cleansing (Group A: 65%; Group B: 83.3%; Group C: 68.4%) [P = not significant (NS)] and favoring Group C in attaining an excellent level of cleansing (Group A: 10%; Group B: 16.7%; Group C: 21.1%) (P = NS). The number of patients with an adequate cleansing of the small bowel, corresponding to an excellent or good classification, was 5 (25%) in Group A, 5 (27.8%) in Group B and 4 (21.1%) in Group C (P = 0.892). Conversely, 7 patients (35%) in Group A, 3 patients (16.7%) in Group B and 6 patients (31.6%) in Group C were considered to have poor small bowel cleansing (P = 0.417), with significant fluid or debris such that the examination was unreliable. The proportion of patients with a significant amount of bubbles was 50% in Group A, 27.8% in Group B and 15.8% in Group C (P = 0.065). This was significantly lower in Group C when compared to Group A (P = 0.026). The mean GET was 27.8 min for Group A, 27.2 min for Group B and 40.7 min for Group C (P = 0.381). The mean SBTT was 256.4 min for Group A, 256.1 min for Group B and 258.1 min for Group C (P = 0.998). Regarding to the rate of complete examinations, the capsule reached the cecum in 20 patients (100%) in Group A, 16 patients (88.9%) in Group B and 17 patients (89.5%) in Group C (P = 0.312). A definite diagnosis based on relevant small bowel endoscopic lesions was established in 60% of the patients in Group A (12 patients), 44.4% in Group B (8 patients) and 57.8% in Group C (11 patients) (P = 0.587). Preparation with 2 L of PEG before small bowel capsule endoscopy (SBCE) may improve small bowel cleansing and the quality of visualization. Simethicone may further reduce intraluminal bubbles. No significant differences were found regarding GET, SBTT and the proportion of complete exploration or diagnostic yield among the three different cleansing protocols.

Usefulness of polyethylene glycol solution with dimethylpolysiloxanes for bowel preparation before capsule endoscopy

Capsule endoscopy (CE) is widely used for diagnosing small intestinal diseases. In some cases, however, observation of target sites is very poor during CE because of residues etc. Herein we report the usefulness of a preparation comprised of polyethylene glycol solution (PEG) for CE. This was a prospective, randomized, and single-blind study. Forty subjects, fasted for 12 h before CE, were randomized into two groups: 20 subjects in Group A were fasted only, whereas 20 in Group B received 1 liter (L) PEG with 200 mg dimethylpolysiloxane 3 h before CE. For evaluation, the observation period of the small intestine was divided into first and second halves. Subsequently, four investigators, blinded as to which group received the preparation, assessed the condition of the intestine using four rating scales in terms of 'residue' and 'intraluminal gas bubbles'. The effects of the preparation were statistically compared. CE images were better in Group B than in Group A with respect to 'intraluminal gas bubbles' (P = 0.0038) in the first half of the observation period, as well as residue (P = 0.0087) and intraluminal gas bubbles (P = 0.0011) in the second half. Bowel preparation using 1 L PEG with dimethylpolysiloxane 3 h before CE significantly reduced residue and intraluminal gas bubbles, and was considered to be a useful method for CE.

Dimethicone powder in bowel preparation before capsule endoscopy

Objective To evaluate the effect of the dimethicone powder in bowel preparation before capsule endoscopy （CE） and to observe its possible adverse effects. Methods A total of 60 patients receiving CE were prospectively randomized into 2 groups according to bowel preparation method. In dimethicone powder group, patients were arranged to take dimethicone powder 30 min before the examination on basis of macrogol electrolytes powder and in control group, patients had macrogol electrolytes powder only. Images of small intestine were equally divided into segments A, B and C according to intestinal transit time, and reviewed by 2 experienced physicians independently. Intraluminal gas bubbles were graded and any possible adverse effects were monitored. Results Interobserver agreement was excellent （P 〈 0. 05 ）. In segments A and C, images from dimethicone powder group were less interfered by gas bubble than those from control group （ P 〈 0. 05 ） , but in segment B there was no difference between 2 groups （ P 〉 0.05 ）. No adverse effects were observed. Conclusion The dimethicone powder administration before capsule endoscopy improves the visualization of the intestinal mucosa. Key words: Capsule endoscopes; Dimethicone powder

Enhanced Kidney Stone Fragmentation by Short Delay Tandem Conventional and Modified Lithotriptor Shock Waves: A Numerical Analysis

We evaluated the effectiveness of modified lithotriptor shock waves using computer models. Finite element models were used to simulate the propagation of lithotriptor shock waves in human renal calculi in vivo. Kidney stones were assumed to be spherical, homogeneous, isotropic and linearly elastic, and immersed in a continuum fluid. Single and tandem shock wave pulses modified to intensify the collapse of cavitation bubbles near the stone surface to increase fragmentation efficiency and suppress the expansion of intraluminal bubbles for decreased vascular injury were analyzed. The effectiveness of the modified shock waves was assessed by comparing the states of loading in the renal calculi induced by these shock waves to those produced by conventional shock waves. Our numerical simulations revealed that modified shock waves produced marginally lower stresses in spherical renal calculi than those produced by conventional shock waves. Tandem pulses of conventional or modified shock waves produced peak stresses in the front and back halves of the renal calculi. However, the single shock wave pulses generated significant peak stresses in only the back halves of the renal calculi. Our numerical simulations suggest that for direct stress wave induced fragmentation modified shock waves should be as effective as conventional shock waves for fragmenting kidney stones. Also, with a small interval of 20 microseconds between the pulses tandem pulse lithotripsy using modified or conventional shock waves could be considerably more effective than single pulse lithotripsy for fragmenting kidney stones.

Computed Tomographic Features of Appendiceal Serositis in Pelvic Inflammatory Disease

The purpose of this study was to describe the computed tomographic (CT) features of the appendiceal serositis in women with pelvic inflammatory disease and to compare these with the pathological findings. Appendiceal serositis was pathologically evaluated in patients with pelvic inflammatory disease who underwent surgery within 3 days of computed tomography. On retrospective review of CT findings, each appendix was evaluated for the following characteristics: location relative to the cecum, maximal diameter, morphology of wall thickening, contrast enhancement, and presence of appendicolith and cecal wall thickening. The presence of fatty infiltration of the periappendiceal fat, mesentery, and omentum was evaluated. The presence of pelvic abscess or ascites, lymph nodes, and paralytic ileus was noted. On pathological review, 10 patients were shown to have appendiceal serositis: mild serositis in 3 patients, moderate in 4, and severe in 3. The maximal appendiceal diameter ranged from 5.4 to 8.9 mm (mean diameter, 7.1 +/- 0.9 mm). Diffuse wall thickening with collapsed lumen was detected in 6 patients. Focal wall thickening with intraluminal gas bubbles or an air-fluid level was detected in 4 cases. Peripheral rim enhancement of the appendix was detected in 3 patients with focal wall-thickened appendix. There was no association between the feature of appendiceal wall thickening and the pathological severity of serositis. Mesenteric fatty infiltration was detected in 5 patients and omental fatty infiltration in 3 patients. Fatty infiltration of the mesentery and omentum was more commonly presented in patients with severe serositis. Pelvic abscesses, including pyosalpinx, were detected in 7 patients; a small amount of free fluid was seen in 8 patients. The CT findings of appendiceal serositis are diffuse or focal wall thickening without severe distension, common association with mesenteric fatty infiltration, and pelvic abscesses.

The role of simeticone in small-bowel preparation for capsule endoscopy

Capsule endoscopy is a new diagnostic method allowing painless visualization of the entire small bowel. However, there is as yet no standardized protocol for bowel preparation before the examination. The aim of this study was to assess the effectiveness of simeticone in reducing bowel gas bubbles in patients undergoing capsule endoscopy. A randomized, prospective, and controlled study was conducted, including 56 patients, from March to October 2004. The patients were randomly allocated to groups receiving either simeticone or no simeticone, on the basis of a computer-generated random number table. Patients in the simeticone group (n = 28) received 300 mg simeticone for bowel preparation 20 min before capsule endoscopy, while patients in the non-simeticone group (n = 28) received no medication for bowel preparation. Two experienced endoscopists assessed and graded the visibility of the mucosa and intraluminal gas bubbles in a single-blinded fashion. The visibility of the mucosa in the proximal small bowel in patients who received preparation with simeticone was considered to be better, with fewer intraluminal bubbles, than in those without bowel preparation ( P < 0.025). Interobserver agreement was excellent ( R > or = 0.8, P < 0.05). No adverse effects of simeticone were observed. Simeticone administration before capsule endoscopy improves the visualization of the mucosa in the proximal small intestine.

Simethicone for small bowel preparation for capsule endoscopy: a systematic, single-blinded, controlled study

Background Capsule endoscopy is a new imaging method for visualization of the entire small bowel. However, no standardized protocol for bowel preparation for capsule endoscopy has been evaluated. Methods Capsule endoscopy was performed in 36 consecutive patients, all of whom fasted for 12 hours before ingestion of the capsule. Before capsule endoscopy, 18 patients received 80 mg simethicone and 18 had no supplemental medication for bowel preparation. Two observers, both experienced endoscopists, independently reviewed the examinations in a single-blinded and randomly assigned fashion. Mucosal visibility and intraluminal gas bubbles were assessed and graded by both observers. Results Bowel preparation with simethicone resulted in significantly better visibility because of fewer intraluminal bubbles ( p<0.01). Interobserver agreement was excellent (r≥0.8; k 0.78: 95% CI[0.57, 0.98] ). No adverse effect of simethicone was observed. Conclusions Simethicone may be added to the routine preparation for capsule endoscopy to improve the visibility of small bowel mucosa.

CT Diagnosis of Afferent Loop Syndrome

OBJECTIVE: To report the computed tomography (CT) features of afferent loop syndrome which is often clinically unsuspected. MATERIALS AND METHODS: The CT studies of five patients with afferent loop syndrome were reviewed. These patients had undergone gastroenterostomy and other surgical procedures, for malignant neoplasms in four and for peptic ulcer in one. Patients presented between 4 months and 15 years (average 5.5 years) after surgery. Symptoms were acute in all patients, the most common symptom being abdominal pain. In addition three of the patients had chronic symptoms including recurrent episodes of abdominal pain, recurrent ascending cholangitis, jaundice and bilious vomiting. RESULTS: The obstructed afferent loop appeared on CT as a fluid-filled tubular mass with an average diameter of 5.3cm. Valvulae conniventes were identified in all, and small intraluminal air bubbles in four. The dilated afferent loop was opacified with oral contrast material in only one patient. The loop was located in the subhepatic area in three patients and crossed the midline between the aorta and the superior mesenteric vessels in the other two. Additional findings included biliary dilatation in all five patients and signs of pancreatitis in one. Treatment was surgical in four patients (delayed for four months in one) and conservative in one. CONCLUSION: A fluid-filled tubular structure containing small air bubbles in the right upper quadrant or crossing the midline on CT in symptomatic patients after gastroenterostomy is characteristic of a dilated, possibly obstructed, afferent loop. The diagnosis is often not suspected clinically since patients may present many years after the initial surgery. Recognition of the characteristic CT findings will avoid both inappropriate procedures such as aspiration or drainage of an obstructed afferent loop and delay in treatment. Gayer, G. etal. (2002). Clinical Radiology57, 835–839.

CT Diagnosis of Afferent Loop Syndrome

OBJECTIVE: To report the computed tomography (CT) features of afferent loop syndrome which is often clinically unsuspected. MATERIALS AND METHODS: The CT studies of five patients with afferent loop syndrome were reviewed. These patients had undergone gastroenterostomy and other surgical procedures, for malignant neoplasms in four and for peptic ulcer in one. Patients presented between 4 months and 15 years (average 5.5 years) after surgery. Symptoms were acute in all patients, the most common symptom being abdominal pain. In addition three of the patients had chronic symptoms including recurrent episodes of abdominal pain, recurrent ascending cholangitis, jaundice and bilious vomiting. RESULTS: The obstructed afferent loop appeared on CT as a fluid-filled tubular mass with an average diameter of 5.3cm. Valvulae conniventes were identified in all, and small intraluminal air bubbles in four. The dilated afferent loop was opacified with oral contrast material in only one patient. The loop was located in the subhepatic area in three patients and crossed the midline between the aorta and the superior mesenteric vessels in the other two. Additional findings included biliary dilatation in all five patients and signs of pancreatitis in one. Treatment was surgical in four patients (delayed for four months in one) and conservative in one. CONCLUSION: A fluid-filled tubular structure containing small air bubbles in the right upper quadrant or crossing the midline on CT in symptomatic patients after gastroenterostomy is characteristic of a dilated, possibly obstructed, afferent loop. The diagnosis is often not suspected clinically since patients may present many years after the initial surgery. Recognition of the characteristic CT findings will avoid both inappropriate procedures such as aspiration or drainage of an obstructed afferent loop and delay in treatment. Gayer, G. etal. (2002). Clinical Radiology57, 835–839.

Suppression of large intraluminal bubble expansion in SWL

Large, rapid expansion of intraluminal bubbles has recently been demonstrated as a potential mechanism for the rupture of capillaries and small blood vessels in shock wave lithotripsy (SWL). To reduce vascular injury without compromising the fragmentation capability of a lithotripter, we developed a strategy to modify the ellipsoidal reflector of an HM-3 lithotripter so that following each spark discharge a weak compressive pulse is generated to superimpose onto the tensile component of a lithotripter shock wave. This modified waveform was found to significantly suppress bubble expansion; and the propensity of vascular injury, as assessed by the rupture of a cellulose vessel phantom, is reduced by an order of magnitude both at 20 and 24 kV. At 24 kV, stone fragmentation is reduced by about 30% using the modified reflector, which, however, is comparable to that produced by the standard reflector at 20 kV. These results suggest that the modified reflector may be used to produce sufficient stone comminution with much reduced potential for vascular injury in SWL. [Work supported by NIH.]

Appendiceal and peri-appendiceal air at CT: Prevalence, appearance and clinical significance

Aim: Appendiceal air has been reported as both a sign of appendicitis and of a normal appendix both at plain radiography and computed tomography (CT). It is the aim of this investigation to determine the prevalence, range of appearances, and significance of appendiceal and peri-appendiceal air at CT. Patients and Methods: Appendiceal CT scans of 100 patients with proven appendicitis and 100 patients with a normal appendix were reviewed for the presence of appendiceal and peri-appendiceal air. All cases were correlated with surgical and pathological findings or clinical follow-up. Results: In 100 CT cases of appendicitis, appendiceal and/or peri-appendiceal air was present in one or more forms in 31% of cases. When present, it appeared as intraluminal air bubbles (38.7%) or air-fluid levels (22.6%), appendolith air (41.9%), intramural air (16.1%), peri-appendiceal air bubbles (12.9%), or extraluminal air-fluid level(s) (29.0%). Intramural and extraluminal air correlated with perforation in 60% and 100%, respectively. In 100 CT cases of a normal appendix, air was present in 57%. It was always intraluminal and appeared as small bubbles of air (52.6%), a tubular-shaped air collection (43.9%), or as an air-fluid level (3.5%). The appendiceal lumen was either airless (43%), or minimally (32%), moderately (18%), or completely filled with air (7%). Conclusion: Air is a common finding at appendiceal CT in both the normal and inflamed appendix. Intraluminal air is seen in both appendicitis and normal appendices, and cannot be presumed to indicate a patent lumen and thus a normal appendix. Appendolith, intramural and peri-appendiceal air appear diagnostic of appendicitis.