Cristina Rodríguez de Miguel

Narrow-band imaging as an alternative to chromoendoscopy for the detection of dysplasia in long-standing inflammatory bowel disease: a prospective, randomized, crossover study

BACKGROUND Narrow-band imaging (NBI) is a novel technique that may represent an alternative method to chromoendoscopy (CE) for the detection of colitis-associated intraepithelial neoplasia (IN) in patients with long-standing inflammatory bowel disease (IBD). OBJECTIVE To compare NBI with CE for the detection of IN. DESIGN Prospective, randomized, crossover study. SETTING Academic hospital. PATIENTS Patients with clinically inactive colonic IBD (≥8 years). INTERVENTION Patients underwent both CE and NBI in randomized order. Targeted biopsy specimens from abnormal areas were obtained. Pathological examination was regarded as the reference standard. MAIN OUTCOME MEASUREMENTS Number of false-positive and true-positive lesions in patients undergoing CE and NBI were compared as well as the proportion of patients with missed IN lesions. RESULTS Eighty patients were screened, of whom 20 were excluded. Mean ± standard deviation withdrawal time for CE was significantly longer than that for NBI (26.87 ± 9.89 minutes vs 15.74 ± 5.62 minutes, P < .01). Thirteen patients had at least 1 IN lesion on 1 of the examinations. In the per-lesion analysis, NBI resulted in a significantly inferior false-positive biopsy rate (P = .001) and a similar true-positive rate. The percentage of missed IN lesions and patients was superior with NBI, albeit without reaching statistical significance. LIMITATIONS Lesions were sampled immediately after detection, which precluded the possibility of paired analysis. CONCLUSIONS NBI appears to be a less time-consuming and equally effective alternative to CE for the detection of IN. However, given the NBI lesion and patient miss rates, it cannot be recommended as the standard technique.

Impact of Wide-Angle, High-Definition Endoscopy in the Diagnosis of Colorectal Neoplasia: A Randomized Controlled Trial

BACKGROUND & AIMS It is essential to optimize standard colonoscopy technique to be able to increase polyp detection. We sought to compare the performance of colonoscopy using a high-definition, wide-angle endoscope (HDE) versus a standard colonoscope (SC) for the detection of colorectal neoplasia. PATIENTS AND METHODS All consecutive consenting adult patients referred from primary care centers were included and randomly assigned at a 1:1 ratio to undergo HDE or SC. Times to reach and withdraw from the cecum were measured. Morphology, size, location, and pathologic diagnosis of each polyp were recorded. Sample size calculation resulted in a total of 682 patients needed. RESULTS A total of 693 consecutive patients fulfilled all inclusion criteria (73 excluded owing to insufficient bowel preparation). Each arm included 310 patients with no baseline characteristic differences. Time to reach the cecum was slightly superior for SC (8.9 +/- 4.8 minutes vs 8.2 +/- 4.5 minutes; P = .055). Pathology examination was feasible in 418 lesions (272 adenomas, 109 hyperplastic polyps, and 37 inflammatory lesions). Both techniques detected a similar number and type of lesions, and there were no differences in the distribution along the colon, in the degree of dysplasia, or morphology of adenomas. The per-patient basis analyses demonstrated that there were no differences between the 2 arms of the study in the detection rates of polyps (SC, 0.84 +/- 1.59; HDE, 0.83 +/- 1.30), adenomas (0.45 +/- 1.07 vs 0.43 +/- 0.87), small adenomas (0.22 +/- 0.71 vs 0.28 +/- 0.78), flat adenomas (0.30 +/- 0.91 vs 0.21 +/- 0.63), or hyperplastic polyps (0.16 +/- 0.50 vs 0.18 +/- 0.54). CONCLUSION HDE did not detect significantly more colorectal neoplasia than SC.

Aberrant gene promoter methylation associated with sporadic multiple colorectal cancer.

Background Colorectal cancer (CRC) multiplicity has been mainly related to polyposis and non-polyposis hereditary syndromes. In sporadic CRC, aberrant gene promoter methylation has been shown to play a key role in carcinogenesis, although little is known about its involvement in multiplicity. To assess the effect of methylation in tumor multiplicity in sporadic CRC, hypermethylation of key tumor suppressor genes was evaluated in patients with both multiple and solitary tumors, as a proof-of-concept of an underlying epigenetic defect. Methodology/Principal Findings We examined a total of 47 synchronous/metachronous primary CRC from 41 patients, and 41 gender, age (5-year intervals) and tumor location-paired patients with solitary tumors. Exclusion criteria were polyposis syndromes, Lynch syndrome and inflammatory bowel disease. DNA methylation at the promoter region of the MGMT, CDKN2A, SFRP1, TMEFF2, HS3ST2 (3OST2), RASSF1A and GATA4 genes was evaluated by quantitative methylation specific PCR in both tumor and corresponding normal appearing colorectal mucosa samples. Overall, patients with multiple lesions exhibited a higher degree of methylation in tumor samples than those with solitary tumors regarding all evaluated genes. After adjusting for age and gender, binomial logistic regression analysis identified methylation of MGMT2 (OR, 1.48; 95% CI, 1.10 to 1.97; p = 0.008) and RASSF1A (OR, 2.04; 95% CI, 1.01 to 4.13; p = 0.047) as variables independently associated with tumor multiplicity, being the risk related to methylation of any of these two genes 4.57 (95% CI, 1.53 to 13.61; p = 0.006). Moreover, in six patients in whom both tumors were available, we found a correlation in the methylation levels of MGMT2 (r = 0.64, p = 0.17), SFRP1 (r = 0.83, 0.06), HPP1 (r = 0.64, p = 0.17), 3OST2 (r = 0.83, p = 0.06) and GATA4 (r = 0.6, p = 0.24). Methylation in normal appearing colorectal mucosa from patients with multiple and solitary CRC showed no relevant difference in any evaluated gene. Conclusions These results provide a proof-of-concept that gene promoter methylation is associated with tumor multiplicity. This underlying epigenetic defect may have noteworthy implications in the prevention of patients with sporadic CRC.

Accuracy of Advanced Endoscopy and Fecal Calprotectin for Prediction of Relapse in Ulcerative Colitis: A Prospective Study

Background:The aim of this study was to determine the accuracy of advanced endoscopy for prediction of relapse in ulcerative colitis, in comparison with serum and fecal biomarkers. Methods:Patients with ulcerative colitis with sustained clinical remission defined as absence of blood in stool for a minimum of 3 months and Mayo endoscopic subscore of 0 were included. High-resolution rectosigmoidoscopy was performed at baseline and at the end of study (week 52 or relapse), assessing mucosal pit pattern by chromoendoscopy and narrow band imaging as well as vascular pattern by narrow band imaging. Histology was evaluated at baseline and at the end of the study. Follow-up for 1 year or until relapse with clinical evaluations and serum and fecal biomarkers every 3 months was established. Relapse was defined as presence of blood in stool and a Mayo endoscopic subscore ≥1 with histologic confirmation. Results:Seventeen out of 64 patients (27%) relapsed during the follow-up period. Baseline clinical characteristics in patients who relapsed and those who did not were similar. Neither pit or vascular pattern nor histology was significantly different between relapsers and nonrelapsers. Among serum biomarkers, high platelet count was significantly associated with higher relapse rates. Fecal calprotectin was predictor of relapse within 3- and 12-month period with high specificity but low sensitivity. Conclusions:Advanced endoscopy and histology do not predict relapse over 1-year period in patients with ulcerative colitis. Fecal calprotectin can predict relapse in 3- and 12-month period with low accuracy.

Yes, we can: reliable colonic closure with the Padlock-G clip in a survival porcine study (with video).

BACKGROUND Secure closure of the colonic access site is one of the most important issues for the development of natural orifice transluminal endoscopic surgery. OBJECTIVE To evaluate the feasibility, reproducibility, and efficacy of a new over-the-scope clip. DESIGN Descriptive study, in vivo porcine colon. INTERVENTION In 10 female Yorkshire pigs weighing 30 to 35 kg, a 10-mm colotomy was performed by using a needle-knife and advancing the endoscope to the peritoneal cavity. Colonic closure was performed by using the Padlock-G clip (Aponos Medical, Kingston, NH) delivered with the Lock-It system (Aponos). MAIN OUTCOME MEASUREMENTS Animals were monitored daily for signs of peritonitis and sepsis over a period of 14 days. During necropsy, the peritoneal cavity was examined, and the colon segment containing the incision was excised for pathological study. RESULTS Closure was achieved in all cases. Nine of 10 pigs survived 14 days without complications, but 1 pig was killed immediately after the procedure because of severe bleeding during the colonic incision. The median closure time was 8 minutes (range 1-30 minutes). At necropsy, adhesions were observed in 5 cases. The incision was hardly visible at the serosa side in 3 cases and was not identified in 6 cases. In 6 cases, the clip was still slightly attached to the mucosa, and it was not found in 3 cases. The pathological study revealed a complete remodeling of the colonic wall in all cases. LIMITATIONS Animal model, noncomparative study. CONCLUSION The Padlock-G clip procedure is feasible, reproducible, effective, and easy to perform, and it provides a reliable colonic closure.

Prospective Evaluation of Single-Operator Peroral Cholangioscopy in Liver Transplant Recipients Requiring an Evaluation of the Biliary Tract

In this descriptive study, we examined the role of single‐operator cholangioscopy (SOC) in the evaluation of biliary complications after liver transplantation (LT). We prospectively included adult recipients of deceased donor LT who were referred for endoscopic retrograde cholangiopancreatography between June 2009 and July 2011. All patients underwent SOC with biopsy of the biliary anastomosis. Sixteen patients were included: 12 with biliary anastomotic strictures (ASs), 2 with common bile duct stones, 1 with a bile leak, and 1 with sphincter of Oddi dysfunction. Patients with ASs displayed 1 of 2 patterns: (A) mild erythema (n = 9) or (B) edema, ulceration, and sloughing (n = 3). Those without ASs displayed a pale mucosa with mild edema at the anastomosis. Patients with ASs and pattern B required a longer period of stenting than patients with pattern A (457 versus 167 days, P = 0.01). In addition, patients with pattern A had a better response and better resolution of their strictures with endoscopic therapy than those with pattern B (88.9% versus 33.4%, P = 0.13). Histological examinations of ASs showed nonspecific intraepithelial inflammation in patients with patterns A and B. Biopsy samples from patients without ASs showed normal columnar epithelial bile duct cells. The total cholangioscopy time for all procedures was 26.8 ± 10.1 minutes. In conclusion, SOC in LT recipients is feasible and allows adequate visualization and tissue sampling of ASs and bile ducts. Two distinct visual patterns that are easily identified with SOC may help to predict the outcomes of endoscopic therapy in patients with biliary complications after LT. Liver Transpl 19:199‐206, 2013.

Infection during Natural Orifice Transluminal Endoscopic Surgery Peritoneoscopy: A Randomized Comparative Study in a Survival Porcine Model

BACKGROUND Infection in natural orifice transluminal endoscopic surgery (NOTES) remains controversial. OBJECTIVE To estimate the frequency of infection during NOTES peritoneoscopy with different routes of access and to compare with laparoscopy. DESIGN Prospective randomized controlled study (Canadian Classification type I). METHODS Forty female pigs were randomly assigned to 3 NOTES (transgastric, transrectal, and transvaginal) and laparoscopic groups. Antiseptic technique was used for NOTES, whereas laparoscopy was performed in a sterile environment. Preoperative and postoperative intravenous antibiotics were administered. Closure of the transluminal access site was performed in all animals. Peritoneal fluid was collected for culture at the end of surgery and at necropsy at day 14. RESULTS Thirty-nine peritoneoscopies were successfully completed. Necropsy confirmed complete healing of NOTES incisions, but 2 animals in the laparoscopy group had small abscesses in the abdominal incisions. There were no statistical differences in the presence of peritoneal adhesions. Positive culture results were seen in all groups at the end of the procedure and in all animals at necropsy, but this did not lead to clinical signs of gross infection. The most common organisms that colonized the peritoneum were gram-positive cocci and gram-negative bacilli from the normal swine gastrointestinal flora. LIMITATIONS Animal model and small sample size. CONCLUSIONS In these small series of animals and with the careful lavage and preparation used, NOTES appeared to be comparable to laparoscopy in terms of peritoneal contamination and clinical infection. Despite the adherence to a strict antiseptic protocol, peritoneal contamination occurs but does not lead to septic complications in the swine.

Exploring the clinical potential of an automatic colonic polyp detection method based on the creation of energy maps.

BACKGROUND AND AIMS Polyp miss-rate is a drawback of colonoscopy that increases significantly for small polyps. We explored the efficacy of an automatic computer-vision method for polyp detection. METHODS Our method relies on a model that defines polyp boundaries as valleys of image intensity. Valley information is integrated into energy maps that represent the likelihood of the presence of a polyp. RESULTS In 24 videos containing polyps from routine colonoscopies, all polyps were detected in at least one frame. The mean of the maximum values on the energy map was higher for frames with polyps than without (P < 0.001). Performance improved in high quality frames (AUC = 0.79 [95 %CI 0.70 - 0.87] vs. 0.75 [95 %CI 0.66 - 0.83]). With 3.75 set as the maximum threshold value, sensitivity and specificity for the detection of polyps were 70.4 % (95 %CI 60.3 % - 80.8 %) and 72.4 % (95 %CI 61.6 % - 84.6 %), respectively. CONCLUSION Energy maps performed well for colonic polyp detection, indicating their potential applicability in clinical practice.

On-demand endoscopic CO2 insufflation with feedback pressure regulation during natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy induces minimal hemodynamic and respiratory changes

BACKGROUND Endoscopic insufflation has been associated with marked increase in intra-abdominal pressure (IAP) and hemodynamic and respiratory changes during transgastric surgery. OBJECTIVE To investigate the hemodynamic and respiratory effects during intraperitoneal cavity exploration through 3 different natural orifice transluminal endoscopic surgery (NOTES) access locations compared with laparoscopy. DESIGN AND SETTING Survival experiments using 40 female pigs randomized to transgastric, transcolonic, transvaginal, and laparoscopic peritoneoscopy. INTERVENTIONS On-demand endoscopic insufflation of CO(2) with feedback pressure regulation was used in NOTES with a maximum pressure of 14 mm Hg. In the laparoscopy group, the IAP was maintained at 14 mm Hg. NOTES procedures were performed by an endoscopist (with the assistance of a gynecologist in the transvaginal group and a second endoscopist in the transgastric and transrectal groups) and laparoscopy by 2 surgeons. MAIN OUTCOME MEASUREMENTS Invasive hemodynamic and respiratory data. Blood samples were drawn for gas analyses. RESULTS All experiments except one in the transrectal group were completed. The IAP was significantly lower in all NOTES groups compared with the laparoscopy group. A significant increase in mean systemic arterial blood pressure was observed in the laparoscopy group at 15 and 30 minutes of intraperitoneal cavity exploration, but it remained unchanged during all NOTES procedures. An increase in airway pressures was observed at 15 and 30 minutes of peritoneoscopy in the animals undergoing laparoscopy, whereas those parameters remained unchanged in the NOTES groups. The laparoscopy group showed a significant impairment in pulmonary gas exchange (decrease in Pao(2), increase in Paco(2), and decrease in arterial pH) after 30 minutes of peritoneoscopy, whereas only a slight increase in Paco(2) was observed in the transrectal and transvaginal groups. LIMITATIONS Healthy animal model. CONCLUSION On-demand endoscopic insufflation of CO(2) with feedback pressure regulation can minimize the risk of hemodynamic and respiratory compromise caused by acute changes in IAP.

Gastrotomy closure with a new tissue anchoring device: A porcine survival study

AIM To evaluate the feasibility, reproducibility and efficacy of a new tissue anchoring device in a porcine survival model. METHODS Gastrotomies were performed using a needle-knife and balloon dilator in 10 female Yorkshire pigs weighing 30-35 kg. Gastric closure was attempted using a new tissue anchoring device. The tightness of the closure was confirmed by means of air insufflation and the ability to maintain gastric distension with stability in peritoneal pressure measured with a Veress needle. All animals were monitored daily for signs of peritonitis and sepsis over 14 d. During necropsy, the peritoneal cavity and the gastric access site were examined. RESULTS Transgastric access, closure and 14 d survival was achieved in all pigs. The mean closure time was 18.1 ± 19.2 min and a mean of 2.1 ± 1 devices were used. Supplementary clips were necessary in 2 cases. The closure time was progressively reduced (24.8 ± 13.9 min in the first 5 pigs vs 11.4 ± 5.9 min in the last 5, P = NS). At necropsy, the gastric access site was correctly closed in all cases with all brace-bars present. One device was misplaced in the mesocolon. Minimal adhesions were observed in 3 pigs and signs of mild peritonitis and adhesions in one. CONCLUSIONS The use of this new tissue anchoring device in porcine stomachs is feasible, reproducible and effective and requires a short learning curve.