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S1536: Wireless Biosensing of Lower Gastrointestinal Bleeding and Occult Gastrointestinal Bleeding: A Paradigm Shift in Diagnosis and Treatment
Abstracts colonoscopy. Follow up colonoscopies were determined by the British Society of Gastroenterology guidelines. Incidence density of polyp recurrence was calculated in patients undergoing either piecemeal or en-bloc resection and a Poisson distribution was assumed for the purposes of calculation and analysis for incidence rate ratio was adjusted for the site and size of lesion, use of argon plasma coagulation (APC), morphology of the lesion and histology of lesion. Stata version 9.1 was used for the analysis.Results: EMR was performed on 154 polyps more than 10 mm in size in 130 patients. 79 polyps with a mean size of 22.6⫾9 mm were rescted piecemeal and 75 polyps with a mean size of 14.6⫾5.5 mm were resected en-bloc. There were 9 recurrences in the piecemeal group and one recurrence in the en-bloc group. The incidence density (ID) of polyp recurrence in the piecemeal group was 80.2 per 1000 person years of follow up (95% CI 36.7-152.2). The ID of polyp recurrence in the en-bloc group was 10.7 per 1000 person years of follow up (95% CI 0.3-59.6). The adjusted incidence rate ratio (IRR) for recurrence in the en-bloc compared to piecemeal group was 0.42 (95% CI 0.22-0.78). Among patients undergoing piecemeal resection alone, the adjusted IRR for additional use of APC was 0.7 (95% CI 0.38-1.27), for histologically less advanced lesions was 0.3 (95% CI 0.14-0.61) and for sessile but not flat lesions was 0.13 (95% CI 0.19-0.75). Conclusions :The adjusted recurrence rates after en-bloc resection of colonic polyps are 60% less than that after piecemeal resection. The use of APC did not significantly change the recurrence rates after piecemeal resection, but flat lesions and histologically advanced lesions made recurrences more likely.
reached, COL was deemed unsuccessful based on intention to treat (ITT) but COL was continued aiming to reach the cecum. Air was used for withdrawal in all. Performance measures: ITT and final cecal intubation rates, cecal intubation and withdrawal times; need for external pressure and patient position change during COL; additional intra-procedural sedation drug use; colon cleanliness and tolerance for COL; patients with tubular adenomas (TAs) detected; TAs distribution (distal vs proximal) and size (ⱕ5 mm, 6-9 mm and ⱖ 10 mm). Results: In all water method patients, final cecal intubation was 100%. The ADR and cecal intubation rate in the historical cohort with air insufflation was 43% and 98%, respectively. Learning curve group: ADR significantly increased from 36.4% to 65.6% from the initial 33 to the next 32 patients (p⫽0.02) whereas ITT cecal intubation rates also increased from 82% to 88%. For the head-to-head comparison, ITT cecal intubation was 92%. Compared to the air group, the water group had significantly: shorter withdrawal time, less external pressure, and cleaner colon (Table). The number of TAs ⱕ5 mm (both proximal and distal) in the water group was significantly greater than in the air group (51% vs. 27%, respectively; p⫽0.002). This difference was only maintained for those located proximally (p⫽0.01) (Table).Conclusions: During the learning process, ADR increased significantly as ITT cecal intubation rates also improved. Compared to air method, despite significantly shorter withdrawal time, a cleaner colon may account for the numerically higher ADR in the water group. Water method also revealed significantly more proximal diminutive adenomas
S1536 Wireless Biosensing of Lower Gastrointestinal Bleeding and Occult Gastrointestinal Bleeding: A Paradigm Shift in Diagnosis and Treatment Marvin K. Ryou, Alex Nemiroski, Dan E. Azagury, Sohail N. Shaikh, Michele B. Ryan, Keith L. Obstein, Robert M. Westervelt, Christopher C. Thompson
Age Time to cecum (min) Withdrawal time (min) External pressure Excellent prep Patients with TAs Total TAs TAs ⱕ 5mm TAs 6-9 mm TAs ⱖ 10 mm
Introduction: Lower gastrointestinal bleeding (LGIB) and occult gastrointestinal bleeding (OGB) account for approximately 200,000 hospitalizations per year in the U.S., and a definitive etiology remains elusive in 40-88% of patients after initial endoscopy. We have developed an endoscopically implantable wireless biosensor system which detects bleeding and then emits a wireless emergency signal to medical personnel using Bluetooth technology. The biosensors can be implanted singly to detect occurrence of rebleeding, or they can be implanted in series to help with localization of obscure bleeding sources. Aims: To develop and test endoscopically implantable wireless biosensor for detection and localization of lower GI bleeding in ex vivo and in vivo porcine models.Methods: Both ex vivo and acute porcine bleeding experiments were performed. Ex vivo experiments consisted of evaluation of (1) the biosensor’s sensitivity for detecting fresh porcine blood as a function of blood concentration of a fluorescent marker and content of colonic milieu; and (2) the biosensors’s ability to wirelessly transmit a signal through soft tissue while also submerged. Subsequently, laparotomies were performed on 4 Yorkshire pigs to create acute LGIB models by transmural fixation of a mesenteric vessel or iliac artery across a random segment of colonic wall. A series of 3 to 5 biosensors were endoscopically placed over 60cm of colon, followed by needle knife laceration of the surgicallyimplanted vessel. The sequence of biosensor activation was recorded. Estimated blood loss leading to sensor activation was recorded.Results: Benchtop results showed maximal sensor sensitivity at a fluorophore concentration of 0.05 mg/mL and a 10:1 signal-to-noise ratio despite the presence of food, stool, and food dyes. A porcine LGIB model was successfully created. Biosensors functioned successfully in 4/4 cases. Sequential activation of biosensors in series correctly localized the culprit segment of colonic bleeding in 4/4 cases. Biosensors were able to wirelessly transmit an emergency signal to a cell phone in all cases. Estimated blood loss leading to biosensor activation was 30 cc (10-75 cc). Conclusions: An endoscopically implantable wireless biosensor to detect LGIB and occult GIB succeeded in a porcine bleeding model. Biosensors in series were able to localize bleeding source through sequential activation. Endoscopic placement of a series of wireless biosensors could potentially complement angiography, tagged RBC scans, and video capsule with localization of difficult LGIB or small bowel bleeding sources.
S1537 Adenoma Detection Rate (ADR) of Water Infusion Technique At Screening Colonoscopy (COL): A Head-to-Head Comparison With Air Insufflation Francisco C. Ramirez, Felix W. Leung Water infusion in lieu of air insufflation has promising features. Aim: to assess ADR and other performance measures during screening COL in: 1) a group used to learn the water technique and a historical cohort with air insufflation, 2) a head-to-head comparison group of water vs. air methods. Methods: Water method COL started without air insufflation and water infused through the colonoscope using a pedal pump. If air had to be used and cecum had not been
AB188 GASTROINTESTINAL ENDOSCOPY
Volume 71, No. 5 : 2010
Air (nⴝ62)
Water (nⴝ83)
p
58.7⫾0.8 6.0⫾0.4 15.1⫾1.0 24 (38.7%) 21 (33.9%) 30 (48.4%) 63 17 (27%) 27 (43.5%) 19 (30.2%)
59.9⫾0.7 7.1⫾0.4 13.1⫾0.5 12 (14.5%) 45 (54.2%) 49 (59%) 110 56 (50.9%) 31 (28.2%) 23 (20.9%)
0.25 0.06 0.04 0.001 0.02 0.2 0.002 0.06 0.2
S1538 Colonoscopic Evaluation After Acute Diverticulitis: Is There an Association With Colonic Malignancy? Mohsen M. Elramah, Jonathan P. Horwitz, Michael M. Einstein, Jamal Qureshi, Julia Leo, Mohamed Omballi, Aboud Affi, Nimish B. Vakil Aim: Despite a lack of evidence-based guidelines, the current standard of care recommends colonoscopy 4 to 6 weeks after an episode of acute diverticulitis due to the risk of an underlying malignancy. Our aim was to determine whether diverticulitis is associated with colonic malignancy or advanced adenoma at a rate greater than the general population.Methods: All patients diagnosed with diverticulitis at 3 community hospitals over a 9-year period were included. Using ICD9 coding for diverticulitis, 188 patients were identified. Of these, 58 did not meet inclusion criteria (CT evidence of diverticulitis and a follow-up colonoscopy within 6 months of the acute attack). The remaining 130 patients were included for evaluation. Patients were divided into 4 groups based on CT scan findings: diverticulitis alone, diverticulitis with mass-like lesion, diverticulitis with abscess, and diverticulitis with perforation.Results: The average age of our cohort was 63.7 years, 79% were Caucasian, 62% were female. One hundred and fifteen patients (88%) were noted to have diverticulitis alone on CT scan. Of those, 105 patients were managed medically. One cancer was identified in this group; however it did not correlate with the radiographic location of diverticulitis. The remaining 10 patients required surgery and none had malignancy. Of the 7 patients whose CT scan demonstrated a mass-like lesion, 6 were managed medically. At follow-up colonoscopy, 2 patients (28.5 %, p-value 0.03) were found to have colon cancer (Stage IIA cecal adenocarcinoma and Stage IV sigmoid adenocarcinoma) that corresponded in location to the CT scan findings. The remaining patient was diagnosed with Stage IV sigmoid adenocarcinoma at surgery rather than by follow-up colonoscopy. Three patients had diverticulitis with abscess, all required surgery and no malignancy was identified. Five patients had diverticulitis with perforation, all required surgery and no cancer was found. Of note, of the 130 patients who received a follow-up colonoscopy, 2 patients had a single tubular adenoma, neither of which was greater than 1 cm.Conclusion: 1. Colon cancer corresponding to the location of diverticulitis was found in 2.3% of patients with acute diverticulitis, which is substantially higher than in the general population. 2. Patients with a mass effect on computed tomography are at greatest risk for an underlying neoplasm and need careful follow-up. 3. Although prospective studies are needed, our data support current guidelines for colonoscopy after acute diverticulitis.
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reached, COL was deemed unsuccessful based on intention to treat (ITT) but COL was continued aiming to reach the cecum. Air was used for withdrawal in all. Performance measures: ITT and final cecal intubation rates, cecal intubation and withdrawal times; need for external pressure and patient position change during COL; additional intra-procedural sedation drug use; colon cleanliness and tolerance for COL; patients with tubular adenomas (TAs) detected; TAs distribution (distal vs proximal) and size (ⱕ5 mm, 6-9 mm and ⱖ 10 mm). Results: In all water method patients, final cecal intubation was 100%. The ADR and cecal intubation rate in the historical cohort with air insufflation was 43% and 98%, respectively. Learning curve group: ADR significantly increased from 36.4% to 65.6% from the initial 33 to the next 32 patients (p⫽0.02) whereas ITT cecal intubation rates also increased from 82% to 88%. For the head-to-head comparison, ITT cecal intubation was 92%. Compared to the air group, the water group had significantly: shorter withdrawal time, less external pressure, and cleaner colon (Table). The number of TAs ⱕ5 mm (both proximal and distal) in the water group was significantly greater than in the air group (51% vs. 27%, respectively; p⫽0.002). This difference was only maintained for those located proximally (p⫽0.01) (Table).Conclusions: During the learning process, ADR increased significantly as ITT cecal intubation rates also improved. Compared to air method, despite significantly shorter withdrawal time, a cleaner colon may account for the numerically higher ADR in the water group. Water method also revealed significantly more proximal diminutive adenomas
S1536 Wireless Biosensing of Lower Gastrointestinal Bleeding and Occult Gastrointestinal Bleeding: A Paradigm Shift in Diagnosis and Treatment Marvin K. Ryou, Alex Nemiroski, Dan E. Azagury, Sohail N. Shaikh, Michele B. Ryan, Keith L. Obstein, Robert M. Westervelt, Christopher C. Thompson
Age Time to cecum (min) Withdrawal time (min) External pressure Excellent prep Patients with TAs Total TAs TAs ⱕ 5mm TAs 6-9 mm TAs ⱖ 10 mm
Introduction: Lower gastrointestinal bleeding (LGIB) and occult gastrointestinal bleeding (OGB) account for approximately 200,000 hospitalizations per year in the U.S., and a definitive etiology remains elusive in 40-88% of patients after initial endoscopy. We have developed an endoscopically implantable wireless biosensor system which detects bleeding and then emits a wireless emergency signal to medical personnel using Bluetooth technology. The biosensors can be implanted singly to detect occurrence of rebleeding, or they can be implanted in series to help with localization of obscure bleeding sources. Aims: To develop and test endoscopically implantable wireless biosensor for detection and localization of lower GI bleeding in ex vivo and in vivo porcine models.Methods: Both ex vivo and acute porcine bleeding experiments were performed. Ex vivo experiments consisted of evaluation of (1) the biosensor’s sensitivity for detecting fresh porcine blood as a function of blood concentration of a fluorescent marker and content of colonic milieu; and (2) the biosensors’s ability to wirelessly transmit a signal through soft tissue while also submerged. Subsequently, laparotomies were performed on 4 Yorkshire pigs to create acute LGIB models by transmural fixation of a mesenteric vessel or iliac artery across a random segment of colonic wall. A series of 3 to 5 biosensors were endoscopically placed over 60cm of colon, followed by needle knife laceration of the surgicallyimplanted vessel. The sequence of biosensor activation was recorded. Estimated blood loss leading to sensor activation was recorded.Results: Benchtop results showed maximal sensor sensitivity at a fluorophore concentration of 0.05 mg/mL and a 10:1 signal-to-noise ratio despite the presence of food, stool, and food dyes. A porcine LGIB model was successfully created. Biosensors functioned successfully in 4/4 cases. Sequential activation of biosensors in series correctly localized the culprit segment of colonic bleeding in 4/4 cases. Biosensors were able to wirelessly transmit an emergency signal to a cell phone in all cases. Estimated blood loss leading to biosensor activation was 30 cc (10-75 cc). Conclusions: An endoscopically implantable wireless biosensor to detect LGIB and occult GIB succeeded in a porcine bleeding model. Biosensors in series were able to localize bleeding source through sequential activation. Endoscopic placement of a series of wireless biosensors could potentially complement angiography, tagged RBC scans, and video capsule with localization of difficult LGIB or small bowel bleeding sources.
S1537 Adenoma Detection Rate (ADR) of Water Infusion Technique At Screening Colonoscopy (COL): A Head-to-Head Comparison With Air Insufflation Francisco C. Ramirez, Felix W. Leung Water infusion in lieu of air insufflation has promising features. Aim: to assess ADR and other performance measures during screening COL in: 1) a group used to learn the water technique and a historical cohort with air insufflation, 2) a head-to-head comparison group of water vs. air methods. Methods: Water method COL started without air insufflation and water infused through the colonoscope using a pedal pump. If air had to be used and cecum had not been
AB188 GASTROINTESTINAL ENDOSCOPY
Volume 71, No. 5 : 2010
Air (nⴝ62)
Water (nⴝ83)
p
58.7⫾0.8 6.0⫾0.4 15.1⫾1.0 24 (38.7%) 21 (33.9%) 30 (48.4%) 63 17 (27%) 27 (43.5%) 19 (30.2%)
59.9⫾0.7 7.1⫾0.4 13.1⫾0.5 12 (14.5%) 45 (54.2%) 49 (59%) 110 56 (50.9%) 31 (28.2%) 23 (20.9%)
0.25 0.06 0.04 0.001 0.02 0.2 0.002 0.06 0.2
S1538 Colonoscopic Evaluation After Acute Diverticulitis: Is There an Association With Colonic Malignancy? Mohsen M. Elramah, Jonathan P. Horwitz, Michael M. Einstein, Jamal Qureshi, Julia Leo, Mohamed Omballi, Aboud Affi, Nimish B. Vakil Aim: Despite a lack of evidence-based guidelines, the current standard of care recommends colonoscopy 4 to 6 weeks after an episode of acute diverticulitis due to the risk of an underlying malignancy. Our aim was to determine whether diverticulitis is associated with colonic malignancy or advanced adenoma at a rate greater than the general population.Methods: All patients diagnosed with diverticulitis at 3 community hospitals over a 9-year period were included. Using ICD9 coding for diverticulitis, 188 patients were identified. Of these, 58 did not meet inclusion criteria (CT evidence of diverticulitis and a follow-up colonoscopy within 6 months of the acute attack). The remaining 130 patients were included for evaluation. Patients were divided into 4 groups based on CT scan findings: diverticulitis alone, diverticulitis with mass-like lesion, diverticulitis with abscess, and diverticulitis with perforation.Results: The average age of our cohort was 63.7 years, 79% were Caucasian, 62% were female. One hundred and fifteen patients (88%) were noted to have diverticulitis alone on CT scan. Of those, 105 patients were managed medically. One cancer was identified in this group; however it did not correlate with the radiographic location of diverticulitis. The remaining 10 patients required surgery and none had malignancy. Of the 7 patients whose CT scan demonstrated a mass-like lesion, 6 were managed medically. At follow-up colonoscopy, 2 patients (28.5 %, p-value 0.03) were found to have colon cancer (Stage IIA cecal adenocarcinoma and Stage IV sigmoid adenocarcinoma) that corresponded in location to the CT scan findings. The remaining patient was diagnosed with Stage IV sigmoid adenocarcinoma at surgery rather than by follow-up colonoscopy. Three patients had diverticulitis with abscess, all required surgery and no malignancy was identified. Five patients had diverticulitis with perforation, all required surgery and no cancer was found. Of note, of the 130 patients who received a follow-up colonoscopy, 2 patients had a single tubular adenoma, neither of which was greater than 1 cm.Conclusion: 1. Colon cancer corresponding to the location of diverticulitis was found in 2.3% of patients with acute diverticulitis, which is substantially higher than in the general population. 2. Patients with a mass effect on computed tomography are at greatest risk for an underlying neoplasm and need careful follow-up. 3. Although prospective studies are needed, our data support current guidelines for colonoscopy after acute diverticulitis.
www.giejournal.org