Validation of a Novel Noninvasive Technology to Estimate Blood Oxygen Saturation Using Green Light: Observational Study.

BACKGROUND: Pulse oximeters work within the red-infrared wavelengths. Therefore, these oximeters produce erratic results in dark-skinned subjects and in subjects with cold extremities. Pulse oximetry is routinely performed in patients with fever; however, an elevation in body temperature decreases the affinity of hemoglobin for oxygen, causing a drop in oxygen saturation or oxyhemoglobin concentrations. OBJECTIVE: We aimed to determine whether our new investigational device, the Shani device or SH1 (US Patent 11191460), detects a drop in oxygen saturation or a decrease in oxyhemoglobin concentrations. METHODS: An observational study (phase 1) was performed in two separate groups to validate measurements of hemoglobin and oxygen concentrations, including 39 participants recruited among current university students and staff aged 20-40 years. All volunteers completed baseline readings using the SH1 device and the commercially available Food and Drug Administration-approved pulse oximeter Masimo. SH1 uses two light-emitting diodes in which the emitted wavelengths match with absorption peaks of oxyhemoglobin (hemoglobin combined with oxygen) and deoxyhemoglobin (hemoglobin without oxygen or reduced hemoglobin). Total hemoglobin was calculated as the sum of oxyhemoglobin and deoxyhemoglobin. Subsequently, 16 subjects completed the "heat jacket study" and the others completed the "blood donation study." Masimo was consistently used on the finger for comparison. The melanin level was accounted for using the von Luschan skin color scale (VLS) and a specifically designed algorithm. We here focus on the results of the heat jacket study, in which the subject wore a double-layered heated jacket and pair of trousers including a network of polythene tubules along with an inlet and outlet. Warm water was circulated to increase the body temperature by 0.5-0.8 °C above the baseline body temperature. We expected a slight drop in oxyhemoglobin concentrations in the heating phase at the tissue level. RESULTS: The mean age of the participants was 24.1 (SD 0.8) years. The skin tone varied from 12 to 36 on the VLS, representing a uniform distribution with one-third of the participants having fair skin, brown skin, and dark skin, respectively. Using a specific algorithm and software, the reflection ratio for oxyhemoglobin was displayed on the screen of the device along with direct hemoglobin values. The SH1 device picked up more minor changes in oxyhemoglobin levels after a change in body temperature compared to the pulse oximeter, with a maximum drop in oxyhemoglobin concentration detected of 6.5% and 2.54%, respectively. CONCLUSIONS: Our new investigational device SH1 measures oxygen saturation at the tissue level by reflectance spectroscopy using green wavelengths. This device fared well regardless of skin color. This device can thus eliminate racial disparity in these key biomarker assessments. Moreover, since the light is shone on the wrist, SH1 can be readily miniaturized into a wearable device.

Developing a novel device based on a new technology for non-invasive measurement of blood biomarkers irrespective of skin color.

Background: Human hemoglobin is a tetrameric metalloporphyrin. The heme part contains iron radicle and porphyrin. The globin part consists of two pairs of amino-acid chains. The absorption spectrum of hemoglobin spans from 250 nm to as high as 2,500 nm, with high coefficients reported in blue and green color zone. The visible absorption spectrum of deoxyhemoglobin has one, while the visible absorption spectrum of oxyhemoglobin shows two peaks. Objective: (1) To study absorption spectrometry of hemoglobin in 420 to 600 nm range; (2) to conduct preclinical experiments to validate a new device and technology based on green color absorption by hemoglobin; (3) to use this new technology and device for phase 1 study in healthy human volunteers for confirmation. Design material and methods: (1) Checking absorption spectrometry of hemoglobin in venous blood. We measured absorption spectrometry of 25 mother-baby pairs as an observational study. Readings were plotted from 400 nm to 560 nm. These included peaks, flat lines and deeps. Graph tracings of all samples - cord blood and maternal blood - showed similar patterns. (2) Preclinical experiments were set up (a) to correlate the reflection of green light by hemoglobin and concentration of hemoglobin, (b) to correlate concentration of O2 and reflection of green light related to oxyhemoglobin, (c) to correlate concentration of melanin in upper and the hemoglobin in lower layer of tissue phantom and to check the sensitivity of new device with green light for measuring Hb in presence of high levels of melanin, and lastly (d) to check if the new device can measure changes in oxy-hemoglobin and deoxy-hemoglobin, again in presence of high levels of melanin with normal as well as with low levels of hemoglobin. The experiments using bilayer tissue phantom were conducted with horse blood in lower cup as dermal tissue phantom and synthetic melanin in upper layer as epidermal tissue phantom. (3) Phase 1 observational studies following a protocol approved by the institutional review board (IRB) were done in two cohorts. Readings were taken using our device and a commercially available pulse oximeter. In the comparison arm we had Point of Care (POC) Hb test (HemoCu or iSTAT blood test). We had 127 data points of POC Hb test and 170 data points for our device and pulse oximeters. This device uses two wavelengths from the visible spectrum of light and uses reflected light. Light of specific wavelengths is shone on the skin of the individual, and the reflected light is collected as 'optical signal'. This optical signal - after conversion to electrical signal - is processed and finally analysed with a digital display on the screen. Melanin is accounted using Von Luschan's chromatic scale (VLS) and a specially designed algorithm. Results: In this set of various preclinical experiments using different concentrations of hemoglobin and melanin, we indeed demonstrated good sensitivity of our device. It could pick up signals from hemoglobin despite high levels of melanin. Our device is a non-invasive device to measure hemoglobin like a pulse oximeter. Results of our device and pulse oximeter were compared with those by POC Hb test like HemoCu and iSTAT. Our device showed better trending linearity and concordance than a pulse oximeter. Since the absorption spectrum of hemoglobin is the same is new-borns and adults, we could develop one device for all age groups and for people of all colors. Furthermore, the light is shone on the wrist of the individual and is then measured. So, in future this device has the potential of being incorporated in a wearable or smart watch technology.

Use of a solid-state nanopore for profiling the transferrin receptor protein and distinguishing between transferrin receptor and its ligand protein.

A nanopore device is capable of providing single-molecule level information of an analyte as they translocate through the sensing aperture-a nanometer-sized through-hole-under the influence of an applied electric field. In this study, a silicon nitride (Six Ny )-based nanopore was used to characterize the human serum transferrin receptor protein (TfR) under various applied voltages. The presence of dimeric forms of TfR was found to decrease exponentially as the applied electric field increased. Further analysis of monomeric TfR also revealed that its unfolding behaviors were positively dependent on the applied voltage. Furthermore, a comparison between the data of monomeric TfR and its ligand protein, human serum transferrin (hSTf), showed that these two protein populations, despite their nearly identical molecular weights, could be distinguished from each other by means of a solid-state nanopore (SSN). Lastly, the excluded volumes of TfR were experimentally determined at each voltage and were found to be within error of their theoretical values. The results herein demonstrate the successful application of an SSN for accurately classifying monomeric and dimeric molecules while the two populations coexist in a heterogeneous mixture.

Atomic Scale Interactions between RNA and DNA Aptamers with the TNF-α Protein.

Interest in the design and manufacture of RNA and DNA aptamers as apta-biosensors for the early diagnosis of blood infections and other inflammatory conditions has increased considerably in recent years. The practical utility of these aptamers depends on the detailed knowledge about the putative interactions with their target proteins. Therefore, understanding the aptamer-protein interactions at the atomic scale can offer significant insights into the optimal apta-biosensor design. In this study, we consider one RNA and one DNA aptamer that were previously used as apta-biosensors for detecting the infection biomarker protein TNF-α, as an example of a novel computational workflow for selecting the aptamer candidate with the highest binding strength to a target. We combine information from the binding free energy calculations, molecular docking, and molecular dynamics simulations to investigate the interactions of both aptamers with TNF-α. The results reveal that the RNA aptamer has a more stable structure relative to the DNA aptamer. Interaction of aptamers with TNF-α does not have any negative effect on its structure. The results of molecular docking and molecular dynamics simulations suggest that the RNA aptamer has a stronger interaction with the protein. Also, these findings illustrate that basic residues of TNF-α establish more atomic contacts with the aptamers compared to acidic or pH-neutral ones. Furthermore, binding energy calculations show that the interaction of the RNA aptamer with TNF-α is thermodynamically more favorable. In total, the findings of this study indicate that the RNA aptamer is a more suitable candidate for using as an apta-biosensor of TNF-α and, therefore, of greater potential use for the diagnosis of blood infections. Also, this study provides more information about aptamer-protein interactions and increases our understanding of this phenomenon.

When in Trouble Think of the Bubble: Paradoxical Cerebral Arterial Gas Embolism after Endoscopic Retrograde Cholangiopancreatography.

Air embolism (a result of direct communication with the vasculature and an external pressure gradient from the gastrointestinal or the biliary tract), although rare, is a potentially devastating adverse event seen in endoscopic retrograde cholangiopancreatography (ERCP) procedures. Whether venous, arterial, or paradoxical, the clinical presentation ranges from asymptomatic patients to cardiorespiratory arrest. This is of particular importance because it makes the diagnosis of air embolism even more difficult in an already sedated patient. Since early recognition increases the chances of patients' survival, endoscopists should be highly motivated and trained to recognize this complication as early as possible. With only 60 cases of air embolism reported (and even fewer related to paradoxical air embolism), we aimed to report a case of paradoxical cerebral air embolism in a patient undergoing ERCP due to a common bile duct stricture and to provide a mini-review of this clinical entity that can serve as a bedside quick reference guide for endoscopists worldwide.

10-Day Versus 14-Day Quadruple Concomitant Nonbismuth Therapy for the Treatment of Helicobacter pylori Infection: Results From a Randomized Prospective Study in a High Clarithromycin Resistance Country.

GOALS: The aim of this study was to investigate the implementation of a 14-day quadruple nonbismuth concomitant regimen, as proposed by recent Guidelines and Consensus Statements. BACKGROUND: In Greece, a region with >20% clarithromycin resistance where bismuth is unavailable, the 10-day quadruple concomitant scheme has already been adopted as the accepted first-line Helicobacter pylori eradication treatment. STUDY: Our prospective randomized study included 364 patients with newly diagnosed H. pylori infection, randomized to receive a 10-day or a 14-day nonbismuth quadruple concomitant scheme. Treatment outcome was assessed by C-urea breath test and/or histology at least 4 weeks after therapy. Intention to treat and per protocol analyses of the eradication rates were performed. Secondary endpoints included patient adherence, safety, and the impact of prior antibiotic exposure in treatment efficacy. RESULTS: The overall eradication rates of the 2 treatments were 87.9% versus 87.4% in the intention to treat analysis, P=1.000, and 93% versus 94.1%, P=0.859, in the per protocol analysis for the 10-day and the 14-day treatment group, respectively. Both groups displayed excellent compliance rates (99.5% for the 10-day vs. 96.2% for the 14-day treatment duration, P=0.067). As regards treatment safety, serious adverse events that led to the discontinuation of both regimens were few, with no statistical difference between the 2 groups (0.5% in the 10-day group and 2.2% in the 14-day group, P>0.05). Previous antibiotic exposure was not significant with regard to treatment efficacy. CONCLUSION: In Greece, the 10-day concomitant nonbismuth quadruple regimen for first-line treatment remains the most efficient strategy for H. pylori eradication.

Size does matter: when a large plastic biliary stent ends up in the root of the mesentery.

Duodenal perforations due to biliary stenting migration, although rare, can occur. We report a unique case of duodenal perforation due to a large in length plastic stent with no (or marginal) migration, which ended up in the root of the mesentery, explaining the normal laboratory values and minimal imaging findings observed. Any clinical symptom during the postprocedural period should raise the suspicion of a major complication and prompt quick management decisions.

Cortical activity in fine-motor tasks in children with Developmental Coordination Disorder: A preliminary fNIRS study.

Developmental Coordination Disorder (DCD) is as a neurodevelopmental condition characterized by poor motor proficiency, which impacts academic performance and activities of daily living. Several studies have determined that children with DCD activate different regions of the brain when performing motor skills in comparison to typically developing (TD) children. However, none have used Functional Near-Infrared Spectroscopy (fNIRS) to explore cortical activation in this population. With that, the goal of this preliminary study was to investigate cortical activation using fNIRS in six children with DCD and six TD children between ages of 8 and 12 years. Three fine-motor tasks were performed: Finger Tapping (FT), Curve Tracing (CT), and Paragraph Writing (PW). Tasks were presented in counterbalanced order and had a baseline of 30s. Cortical activity elicited during performance of the FT, CT, and PW tasks was measured by fNIRS, and activation areas within each group were statistically compared. Results indicated that participant groups used different focal activation areas as well as different neural networks to perform the tasks. These distinct patterns were also task-specific, with differences in the right Pre-Motor Cortex (Pre-MC) and Supplementary Motor Area (SMA) for CT, and the right Dorsolateral Prefrontal Cortex (DLPFC) and the right Pre-MC for the PW task. These results add to the body of research exploring neurological alterations in children with DCD, and establish the feasibility of using fNIRS technology with this population.

Lower adenoma miss rate with FUSE vs. conventional colonoscopy with proximal retroflexion: a randomized back-to-back trial.

Background and study aims Full-spectrum colonoscopy (FSC) promises to increase adenoma detection by providing a wider field of view. The aim of this study was to compare adenoma miss rates of FSC with those of conventional colonoscopy complemented by right-colon re-examination using scope retroflexion (CC/R). Patients and methods At two tertiary endoscopy facilities, patients who were scheduled for colonoscopy for the assessment of symptoms or for colorectal cancer screening/surveillance were randomized (1:1) to undergo same-day, back-to-back colonoscopies (FSC or CC/R first), performed by one of five endoscopists who had documented adenoma detection rates > 35 %. Per-protocol data were analyzed. Results We randomized 220 patients. There were five FSC technical failures (three air pump and two left screen); therefore, 107 and 108 cases were analyzed in the FSC and CC/R index procedure arms, respectively. Withdrawal times were similar for FSC and CC/R (7.7 minutes vs. 7.6 minutes). Overall, we detected 3 cancers and 153 adenomas (FSC = 92; CC/R = 61); 81 were detected in the proximal colon, 3 of which were detected by retroflexed examination. By per-lesion analysis, FSC showed a significantly lower adenoma miss rate compared with CC/R overall (10.9 % [95 % confidence interval (CI) 3.8 to 18.1] vs. 33.7 % [95 %CI 23.4 to 44.1]) and in the proximal colon (13.9 % [95 %CI 2.6 to 25.2] vs. 42.2 % [95 %CI 27.8 to 56.7]). The advanced adenoma miss rate was lower with FSC overall (4.3 % [95 %CI - 4.0 to 12.7] vs. 25.9 % [95 %CI 9.4 to 42.5]). There were no adverse events. Conclusions FSC outperformed conventional colonoscopy with right-colon scope retroflexion in the detection of missed adenomas, both overall and in the proximal colon, even when performed by experienced endoscopists.Trial registered at ClinicalTrials.gov (NCT02117674).

Results of a prospective multicenter neuroendocrine tumor registry reporting on clinicopathologic characteristics of Greek patients.

BACKGROUND: The rare incidence of neuroendocrine neoplasms (NENs) has contributed to a paucity of large epidemiologic studies of patients with this condition. We investigated the occurrence and clinicopathologic features of NENs in Greece. METHODS: Between October 2010 and November 2012 we collected data on 246 newly diagnosed patients from a broad-based multi-institutional registry that comprises eight academic and hospital sites in Greece. The WHO 2010 pathologic classification and the 7th AJCC Staging system was applied in all cases. RESULTS: Of all patients 94 % had a sporadic and 6 % a multiple endocrine neoplasia tumor; 63.4 % were gastroenteropancreatic-(GEP)-NENs, 17.9 % Head & Neck NENs, 9.8 % NENs of Unknown Primary, 6.5 % Lung NENs and 2.4 % Pheochromocytomas. Gastric and pancreatic NENs were the most common primary sites. Poorly differentiated neuroendocrine carcinomas (NEC) were 9.3 %, all sporadic. Fifteen percent of patients were asymptomatic at presentation, 24 % had a first symptom of the disease related to endocrine syndrome and 61 % had symptoms related to locally advanced or metastatic disease. Metastatic disease was established in 25 % of tumors most frequently in the GEP NEN group. Findings are presented according to Ki-67 distribution. MRI had a higher diagnostic positive yield than Octreoscan. Somatostatin analogs, lanreotide and octreotide acetate, were prescribed at 38.5 & 61.5 % of NEN patients respectively and were found to be equally effective at providing symptomatic relief. CONCLUSIONS: This is to our knowledge the first study of a Greek tumor registry and one of the few European Registries providing information regarding clinicopathologic characteristics and therapies in patients with neuroendocrine tumors of various origin sites, beyond GEP NENs.

Concomitant versus sequential therapy for the treatment of Helicobacter pylori infection: a Greek randomized prospective study.

OBJECTIVE: The objective of this study is to compare, in Greece, a region with >20% local resistance to clarithromycin, the efficacy rates of the concomitant versus the sequential H. pylori eradication therapy. MATERIALS AND METHODS: Our prospective randomized study included 364 patients with newly diagnosed H. pylori infection, randomized to receive a 10-day concomitant or 10-day sequential therapy. Treatment outcome was assessed by C(13)-urea breath test at least 4 weeks after therapy. Intention to treat (ITT) and per protocol (PP) analysis of the eradication rates were performed. Secondary end points included patient compliance and safety. RESULTS: The concomitant therapy group achieved statistically significant higher eradication rates when compared with the sequential treatment group, both in the ITT and in the PP analysis (84.6% versus 70.9%, p = 0.002, and 90.6% versus 78.1%, p = 0.001, respectively), after adjusting for age, gender, smoking status, and the presence or not of ulcer and/or non-ulcer dyspepsia. Both groups displayed excellent compliance rates (99.5% for the concomitant therapy group and 96.2% for the sequential therapy group, p = 0.067). Regarding treatment safety, major adverse events that led to the discontinuation of both regimens were few, with no statistical difference between the two groups (7.0% for the concomitant therapy group and 2.9% for the sequential therapy group). CONCLUSIONS: Concomitant therapy led to statistically significant higher eradication rates over sequential therapy. Both therapies showed excellent compliance and an acceptable safety profile. The 10-day quadruple concomitant scheme should be the adopted for first-line H. pylori eradication in Greece.

Small bowel ulcerative lesions are common in elderly NSAIDs users with peptic ulcer bleeding.

AIM: To determine the frequency of small bowel ulcerative lesions in patients with peptic ulcer and define the significance of those lesions. METHODS: In our prospective study, 60 consecutive elderly patients with upper gastrointestinal bleeding from a peptic ulceration (cases) and 60 matched patients with a non-bleeding peptic ulcer (controls) underwent small bowel capsule endoscopy, after a negative colonoscopy (compulsory in our institution). Controls were evaluated for non-bleeding indications. Known or suspected chronic inflammatory conditions and medication that could harm the gut were excluded. During capsule endoscopy, small bowel ulcerative lesions were counted thoroughly and classified according to Graham classification. Other small bowel lesions were also recorded. Peptic ulcer bleeding was controlled endoscopically, when adequate, proton pump inhibitors were started in both cases and controls, and Helicobacter pylori eradicated whenever present. Both cases and controls were followed up for a year. In case of bleeding recurrence upper gastrointestinal endoscopy was repeated and whenever it remained unexplained it was followed by repeat colonoscopy and capsule endoscopy. RESULTS: Forty (67%) cases and 18 (30%) controls presented small bowel erosions (P = 0.0001), while 22 (37%) cases and 4 (8%) controls presented small bowel ulcers (P < 0.0001). Among non-steroidal anti-inflammatory drug (NSAID) consumers, 39 (95%) cases and 17 (33%) controls presented small bowel erosions (P < 0.0001), while 22 (55%) cases and 4 (10%) controls presented small bowel ulcers (P < 0.0001). Small bowel ulcerative lesions were infrequent among patients not consuming NSAIDs. Mean entry hemoglobin was 9.3 (SD = 1.4) g/dL in cases with small bowel ulcerative lesions and 10.5 (SD = 1.3) g/dL in those without (P = 0.002). Cases with small bowel ulcers necessitate more units of packed red blood cells. During their hospitalization, 6 (27%) cases with small bowel ulcers presented bleeding recurrence most possibly attributed to small bowel ulcers, nevertheless 30-d mortality was zero. Presence of chronic obstructive lung disease and diabetes was related with unexplained recurrence of hemorrhage in logistic regression analysis, while absence of small bowel ulcers was protective (relative risk 0.13, P = 0.05). CONCLUSION: Among NSAID consumers, more bleeders than non-bleeders with peptic ulcers present small bowel ulcers; lesions related to more severe bleeding and unexplained episodes of bleeding recurrence.

Capsule endoscopy findings in patients with occult or overt bleeding older than 80 years.

BACKGROUND: Overt and occult bleeding are the main indications for a wireless capsule endoscopy (WCE) study of the small bowel. Most published studies omit patients aged over 80. AIM: To determine whether WCE is feasible in patients with overt or occult bleeding over age 80 and to define the spectrum of small bowel pathologies in this age group. PATIENTS AND METHODS: In a retrospective non-randomized tertiary care study, 60 patients at least 80 years or older (aged group) and 120 matched patients aged <80 years (younger group) with overt or occult bleeding (including iron deficiency anaemia) and no significant gastroscopic or colonoscopic findings underwent WCE. RESULTS: Of the 180 patients, 46 (77%) patients in the aged group and 97 (81%) in the younger group successfully completed small bowel study (P = 0.51). There was no difference in gastric transit time and small bowel passing time between the two groups. More patients in the aged group (48 cases, 80%) than the younger group (56 cases, 47%) presented with small bowel angiodysplasias (P < 0.0001). Nevertheless, there was no difference between the two groups concerning ulcerative and neoplastic lesions. No patient presented with capsule impaction, but more patients in the aged group (35 cases, 58%) than in the younger group (10 cases, 8%) found the study difficult and tiresome (P < 0.001). Preparation validation was poor in 34% of small bowel lumen in the aged group and 19% in the younger group (P = 0.03). CONCLUSION: WCE is feasible, although rather tiresome, in patients over the age of 80. Though the vast majority of patients older than 80 presented with angiodysplasias, there were no differences between the aged and younger groups in the presence of ulcerative lesions and polyps or tumors.

Endoscopic submucosal dissection for the diagnosis and treatment of a gastric submucosal tumor: initial experience in Greece.

Gastric submucosal tumors (GSMTs) are frequently found incidentally on routine upper endoscopy. Definitive diagnosis based on histological confirmation is relatively difficult. Even without accurate diagnosis before treatment, open or laparoscopic surgery is considered the standard of care for most GSMTs. Alternatively, endoscopic resection of GSMTs using different techniques has been reported in a limited number of papers. We describe a case of an antral submucosal tumor, more specifically a leiomyoma of muscularis mucosa origin, in a 78-year-old woman, that was completely resected en bloc using an endoscopic submucosal technique with a TT-knife. It is suggested that ESD is a feasible option for the diagnosis and treatment of GSTMs.

Endoscopic esophagitis is more severe in gastroesophageal reflux patients with a positive family history.

BACKGROUND: The role of genetic factors in the etiology of gastroesophageal reflux disease (GERD) is still uncertain. AIM: To define whether the presence of reflux symptoms in first-degree relatives can affect the severity of the endoscopic picture of patients with GERD and disease evolution during follow-up. PATIENTS/METHODS: A total of 1930 consecutive patients with GERD were referred for endoscopy from Trikala prefecture, had an entry endoscopy and a follow-up if needed. Before endoscopic evaluation, all patients and their first-degree relatives completed Reflux Symptom Questionnaire. Patients were followed up for 4 years with Reflux Symptom Questionnaire every 6 months. RESULTS: A total of 258 (62.9%) patients with positive and 724 (47.6%) with negative family history of GERD had esophagitis (P<0.0001). Seventy-six (74.5%) patients with more than 1 family member with GERD had esophagitis (P<0.0001). During follow-up endoscopic picture was aggravated in 101 (25%) patients with positive and 46 (3%) with negative family history. A total of 359 (24%) of GERD patients with negative and 24 (10%) with positive family history managed to stop proton pump inhibitors during follow-up (P<0.0001). In logistic regression analysis: age, male sex, presence of hiatal hernia, family history of GERD, tranquilizer use, frequency, and duration of reflux symptoms were independently associated with presence of esophagitis. CONCLUSIONS: Although we cannot overlook the importance of confounding factors such as body weight and/or psychological factors, we found that endoscopic picture is more severe among GERD patients with at least 1 first-degree relative with GERD. During follow-up, patients with negative family history had more chances to wean off proton pump inhibitors after life-style modifications.

Evaluation of capsule endoscopy in active, mild-to-moderate, overt, obscure GI bleeding.

BACKGROUND: The role of capsule endoscopy (CE) in the diagnosis of active mild-to-moderate GI bleeding (GIB) immediately after a negative EGD and ileocolonoscopy has not been prospectively evaluated. OBJECTIVE: To estimate the diagnostic yield and clinical significance of CE in patients with acute, obscure, overt, mild-to-moderate GIB. DESIGN: A single-center prospective study. PATIENTS: During a 3-year period, 573 patients admitted to the hospital with acute mild-to-moderate GIB were included in this study. Among them, 37 patients (6.5%) with negative endoscopic findings, after urgent upper- and lower-GI endoscopies, underwent CE within the first 48 hours to identify the source of bleeding. RESULTS: CE revealed active bleeding in 34 patients and a diagnostic yield of 91.9%, including angiodysplasias in 18 patients, ulcers in 3 patients, and tumors in 2 patients. In the remaining 11 patients (32%), CE revealed the site of bleeding: distal duodenum in 1 case (9%), jejunum in 6 cases (54%), ileum in 2 cases (18%), and cecum in 2 cases (18%). From the 37 bleeders, 16 were managed conservatively, 14 endoscopically, and 7 surgically. During a 12-month follow-up period, bleeding recurrence was observed in 5 of 32 (15.6%). LIMITATIONS: This study had a limited number of patients. CONCLUSIONS: CE appeared to have a high diagnostic yield in patients with acute, mild-to-moderate, active hemorrhage of obscure origin when performed in the hospital after a negative standard endoscopic evaluation and has important clinical value in guiding medical management.

Is endosonography an effective method for detection and local staging of the ampullary carcinoma? A prospective study.

BACKGROUND: The relatively rare carcinoma of the ampulla of Vater is a neoplasia with a good prognosis compared to pancreatic cancer. Preoperative staging is important in planning the most suitable surgical intervention. AIM: To prospectively evaluate the diagnostic accuracy of Endoscopic Ultrasonography (EUS) in comparison with conventional US and CT scan, in staging of patients with ampullary carcinoma. PATIENTS AND METHODS: 20 patients (7 women and 13 men) with histologically proven carcinoma of the ampulla of Vater were assessed by EUS, CT scan and US. Results were compared to surgical findings. RESULTS: Endoscopic biopsies were diagnostic in 76% of the patients. Detection of ampullary cancer with US and CT scan was 15% and 20% respectively. Only indirect signs of the disease were identified in the majority of cases using these methods. Overall accuracy of EUS in detection of ampullary tumours was 100%. The EUS was significantly (p < 0.001) superior than US and CT scan in ampullary carcinoma detection. Tumour size, tumour extension and the existence of metastatic lymph nodes were also identified and EUS proved to be very useful for the preoperative classification both for the T and the N components of the TNM staging of this neoplasia. The diagnostic accuracy for tumour extension (T) was 82% and for detection of metastatic lymph nodes (N) was 71%. CONCLUSION: EUS is more accurate in detecting ampullary cancer than US and CT scan. Tumor extension and locally metastatic lymph nodes are more accurately assessed by means of EUS than with other imaging methods.