Paraskevas Gkolfakis
National and Kapodistrian University of Athens
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Featured researches published by Paraskevas Gkolfakis.
Endoscopy | 2017
Konstantinos Triantafyllou; Dimitrios Polymeros; Periklis Apostolopoulos; Catarina Brandão; Paraskevas Gkolfakis; Alessandro Repici; Ioannis S. Papanikolaou; Mário Dinis-Ribeiro; George Alexandrakis; Cesare Hassan
Background and study aims The Endocuff (ARC Medical Design, Leeds, UK) is a device that, when mounted on the tip of an endoscope, may assist with inspection of a greater surface of the colonic mucosa by pulling backwards, flattening, and stretching the colonic folds as the endoscope is gradually withdrawn. We aimed to compare the adenoma miss rates of Endocuff-assisted colonoscopy with those of conventional colonoscopy. Patients and methods The included patients underwent same-day, back-to-back, (Endocuff-assisted colonoscopy as the index procedure followed by conventional colonoscopy or vice versa, randomly assigned 1:1) colonoscopies, performed by six endoscopists with documented adenoma detection rates > 35 %, in four tertiary endoscopy facilities. Results We randomized 200 patients (mean age 61.2 years [standard deviation 9.8]; 86.5 % colorectal cancer screening surveillance cases). Overall, there were seven incomplete examinations using Endocuff and one with conventional colonoscopy (P = 0.03). Times for endoscope insertion (5.0 minutes [0.8 - 21.0] vs. 5.0 minutes [1.0 - 16.0]; P = 0.49) and withdrawal (6.0 minutes [3.2 - 29.0] vs. 6.0 minutes [3.1 - 17.0]; P = 0.06) were similar for Endocuff-assisted and conventional colonoscopy. We detected one cancer and 195 adenomas; 84 in the proximal colon. Endocuff-assisted colonoscopy showed significantly lower overall and proximal colon adenoma miss rates compared with conventional colonoscopy (14.7 % [8.0 % - 21.0 %] vs. 38.4 % [28.1 % - 48.6 %] and 10.4 % [1.8 % - 19.1 %] vs. 38.9 % [23.0 % - 54.8 %], respectively). No difference between the two arms was shown regarding advanced adenoma miss rates, either overall or in the proximal colon. There were no serious adverse events related to the procedures. Conclusions In comparison with conventional colonoscopy, Endocuff-assisted colonoscopy has a significantly lower adenoma miss rate when performed by high-detector endoscopists. However, the incomplete colonoscopy rate with Endocuff is higher.ClinicalTrials.gov Identifier: NCT02340065.
World Journal of Gastroenterology | 2017
Paraskevas Gkolfakis; Georgios Tziatzios; George Dimitriadis; Konstantinos Triantafyllou
Colonoscopy is the gold standard for colorectal cancer prevention; however, it is still an imperfect modality. Precancerous lesions can be lost during screening examinations, thus increasing the risk of interval cancer. A variety of factors either patient-, or endoscopist dependent or even the procedure itself may contribute to loss of lesions. Sophisticated modalities including advanced technology endoscopes and add-on devices have been developed in an effort to eliminate colonoscopy’s drawbacks and maximize its ability to detect potentially culprit polyps. Novel colonoscopes aim to widen the field of view. They incorporate more than one cameras enabling simultaneous image transmission. In that way the field of view can expand up to 330°. On the other hand a plethora of add-on devices attachable on the standard colonoscope promise to detect lesions in the proximal aspect of colonic folds either by offering a retrograde view of the lumen or by straightening the haustral folds during withdrawal. In this minireview we discuss how these recent advances affect colonoscopy performance by improving its quality indicators (cecal intubation rate, adenoma detection rate) and other metrics (polyp detection rate, adenomas per colonoscopy, polyp/adenoma miss rate) associated with examination’s outcomes.
European Journal of Gastroenterology & Hepatology | 2017
Konstantinos Triantafyllou; Paraskevas Gkolfakis; Nikos Viazis; Panagiotis Tsibouris; Athanasios Tsigaridas; Periklis Apostolopoulos; John Anastasiou; Eleni Hounda; Ioannis Skianis; Konstantina Katopodi; Xhoela Ndini; George Alexandrakis; Demetrios G. Karamanolis
Introduction Since its introduction, small bowel video capsule endoscopy (VCE) use has evolved considerably. Aim Evaluation of the temporal changes of small bowel VCE utilization in three tertiary centers in Greece in Era 1 (2002–2009) and Era 2 (2010–2014) and the development a forecast model for future VCE use during 2015–2017. Materials and methods Data from all small bowel VCE examinations were retrieved and analyzed in terms of the annual number of the performed examinations, their indications and the significance of their findings. Results Overall, we evaluated 3724 VCE examinations. The number of studies peaked in 2009 (n=595) and then decreased to reach 225 in 2014. Overall, more (53.8 vs. 51.4%) patients with iron-deficiency anemia and obscure gastrointestinal bleeding (IDA/OGIB) and fewer (10.7 vs. 14%) patients with chronic diarrhea were evaluated in Era 2 compared with Era 1 (P=0.046). In Era 2, there were more nondiagnostic examinations (39.5 vs. 29.3%, P<0.001), whereas the rate of cases with relevant findings decreased from 47.8 to 40.9%. According to the time trend analysis, we developed a forecast model with two scenarios: the pessimistic and the optimistic. Validation of the model with 2015 data showed that reality was close to the pessimistic scenario: the number of exams further decreased to 190, studies carried out for IDA/OGIB increased to 67%, and there were more negative than positive exams (40.7 vs. 39.2%). Conclusion The number of VCE studies carried out after the emergence of the financial crisis decreased significantly and VCE indications were optimized. Our forecast model predicts lower numbers of VCE studies, with IDA/OGIB being the dominant indication. However, the predicted increase of negative exams requires further evaluation.
Scandinavian Journal of Gastroenterology | 2016
Georgios Tziatzios; Dimitrios Polymeros; Aris Spathis; Maria Triantafyllou; Paraskevas Gkolfakis; Petros Karakitsos; George Dimitriadis; Konstantinos Triantafyllou
Abstract Objective: Platelet activation is a consistent feature in inflammatory bowel disease. However, the role of circulating platelet derived microparticles (PDMPs) and the effects of disease activity and treatment on their levels has not been clarified yet in this disorder. Material and methods: Using flow cytometry, we measured platelet derived microparticles and platelet derived microparticles expressing Annexin V in platelet rich plasma from 47 Crohn’s disease and 43 ulcerative colitis patients and 24 healthy controls. Results: Crohn’s disease patients have greater PDMPs (0.31% ± 0.07% versus 0.14% ± 0.04%, p = 0.02) and PDMPs expressing Annexin V (27% ± 2.6% versus 14.6% ± 2.7%, p = 0.002) levels in comparison with healthy controls; however, both microparticles levels are not related with disease activity. Crohn’s disease patients on 5-ASA therapy show lower levels of PDMPs in comparison with those on no 5-ASA (0.30% ± 0.07% versus 0.32% ± 0.09%, p = 0.048). Ulcerative colitis patients have similar PDMPs and PDMPs expressing Annexin V levels, compared to healthy controls (p = 0.06 and p = 0.2, respectively) and there is no correlation of both microparticles expression with disease activity. 5-ASA has no effect on both microparticles levels in ulcerative colitis patients. Anti-TNF-α treatment has no effect on study’s microparticles expression in Crohn’s and ulcerative colitis patients. Conclusions: Circulating levels of platelet derived microparticles are increased only in Crohn’s patients, but they do not correlate with disease activity. 5-ASA treatment is associated with lower levels of PDMPs only in Crohn’s, while anti-TNF-α treatment does not influence expression of microparticles in inflammatory bowel disease patients.
Annals of Gastroenterology | 2016
Konstantinos Triantafyllou; Paraskevas Gkolfakis; Maria Triantafyllou; Xhoela Ndini; Anastasia Melissaratou; Giannis-Aimant Moustafa; Eleni Xanthopoulou; Georgios Tziatzios; Georgia Vlachonikolou; Vasilios Papadopoulos; Evdoxos Pantelakis; Chrysoula Malli; George Dimitriadis
Background We prospectively assessed patient satisfaction in a Greek Academic endoscopy facility. Methods Consecutive outpatients filled a satisfaction questionnaire right after their endoscopy (D1), 3 days (D3) and 3 months (M3) later. Overall patient satisfaction was measured by their willingness to repeat endoscopy in our facility and to further recommend it. Participant satisfaction regarding pre-procedural, procedural and post-procedural issues was measured using a five-step Likert scale in 19 items with 4 and 5 scores indicating favorable responses. Pareto analysis was used to determine service issues requiring improvement. Late adverse events were recorded at D3 and M3 assessments. Results Over six months, 501 patients participated (89.4% and 87.8% response rate at D3 and M3 assessments, respectively). More than 97% of the participants would repeat the procedure in our facility and would recommend our endoscopy service, at all three assessments. Pareto analysis identified waiting time until the appointment and on the day of the examination, discomfort during and after the endoscopy, time to obtain the pathology report and overall management of the patient problems as the issues requiring improvement. No predictor of high satisfaction score has been identified. No serious late adverse events were reported. Conclusion Despite the overall high levels of patient satisfaction, management of patient discomfort and organizational issues need improvement.
Digestive and Liver Disease | 2018
Georgios Tziatzios; Paraskevas Gkolfakis; Cesare Hassan; Ervin Toth; Angelo Zullo; Anastasios Koulaouzidis; George Dimitriadis; Konstantinos Triantafyllou
BACKGROUND & AIMS Video capsule endoscopy (VCE) is the first-line diagnostic procedure for investigating obscure gastrointestinal bleeding (OGIB). Different re-bleeding rates following index VCE have been reported among Western and Eastern studies. METHODS We conducted a comprehensive literature search to identify studies examining re-bleeding rates after VCE for OGIB. Meta-analysis assessed the pooled proportion of re-bleeding events after VCE for OGIB according to studys origin (Western vs. Eastern) and according to the length of follow-up (≥24 months vs. <24 months). We also calculated the re-bleeding odds ratios (OR; 95% CI) after positive vs. negative index VCE, overt vs. occult initial presentation of bleeding and after interventional treatment for positive index cases, according to the studys origin. RESULTS We included 46 (30 Western and 16 Eastern) studies with 5796 patients. Significant heterogeneity was detected among meta-analyzed studies. Overall, the pooled re-bleeding rate was similar between Western (29%; 95% CI: 23-34) and Eastern (21%; 95% CI: 15-27) populations, irrespective of the length of follow-up. The odds of re-bleeding was significantly higher after positive as compared to negative index VCE in Eastern studies (OR: 1.77; 95% CI: 1.07-2.94). Application of specific treatment after positive index VCE was associated with lower re-bleeding odds in both Western (OR: 0.37; 95% CI: 0.16-0.87) and Eastern (OR: 0.39; 95% CI: 0.21-0.72) populations. CONCLUSIONS Patients undergoing VCE for OGIB have similar re-bleeding rates in the East and the West, regardless of the length of follow-up. However, increased re-bleeding odds after positive index VCE is observed in Eastern studies.
Hepatobiliary & Pancreatic Diseases International | 2016
Georgios Tziatzios; Paraskevas Gkolfakis; Ioannis S. Papanikolaou; George Dimitriadis; Konstantinos Triantafyllou
Despite the effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) for the treatment of choledocholithiasis, various complications have been described. We herein report the first case of prolonged post-ERCP jaundice due to toxicity of the contrast agent Iobitridol (®XENETIX, Guerbet, Roissy CdG Cedex, France) in a patient who underwent ERCP with sphincterectomy and common bile duct stone removal. While clinical improvement and normalization of aminotransferases and cholestatic enzymes after the procedure, an unexplained increase of direct bilirubin was noticed. A second ERCP was performed one week later, excluding possible remaining choledocholithiasis. Nevertheless, serum direct bilirubin increased further up to 15 mg/dL. Other potential causes of direct hyperbilirubinemia were ruled out and patients liver biopsy was compatible with drug-induced liver toxicity. Additionally, the cause-result time connection between the use of Iobitridol and bilirubin increase indicated the possibility of a toxic effect related to the repeated use of the particular contrast agent. Iobitridol, a contrast agent, can induce prolonged direct hyperbilirubinemia.
World Journal of Gastroenterology | 2018
Paraskevas Gkolfakis; Georgios Tziatzios; Eleftherios Spartalis; Ioannis S. Papanikolaou; Konstantinos Triantafyllou
Although colonoscopy has been proven effective in reducing the incidence of colorectal cancer through the detection and removal of precancerous lesions, it remains an imperfect examination, as it can fail in detecting up to almost one fourth of existing adenomas. Among reasons accounting for such failures, is the inability to meticulously visualize the colonic mucosa located either proximal to haustral folds or anatomic curves, including the hepatic and splenic flexures. In order to overcome these limitations, various colonoscope attachments aiming to improve mucosal visualization have been developed. All of them - transparent cap, Endocuff, Endocuff Vision and Endorings - are simply mounted onto the distal tip of the scope. In this review article, we introduce the rationale of their development, present their mode of action and discuss in detail the effect of their implementation in the detection of lesions during colonoscopy.
Probiotics and Antimicrobial Proteins | 2018
Konstantinos Leventogiannis; Paraskevas Gkolfakis; Georgios Spithakis; Aikaterini Tsatali; Aikaterini Pistiki; Athanasios D. Sioulas; Evangelos J. Giamarellos-Bourboulis; Konstantinos Triantafyllou
The original version of this article contained mistakes, and the authors would like to correct them. The correct details are given below.
Gastrointestinal Endoscopy | 2018
Konstantinos Triantafyllou; Georgios Tziatzios; Paraskevas Gkolfakis
preparation, to preparation with only water, and to mucosal cleansingwithwater flushes during endoscopy. The recently published position statement document of the British Society of Gastroenterology and the Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland about quality standards in upperGI endoscopy recommended that “adequate mucosal visualisation should be achieved by a combination of adequate air insufflation, aspiration and the use of mucosal cleansing techniques,” which include simethicone and N-acetylcysteine or Pronase. In consideration of the concerns about simethicone, an alternative would be to use a mucolytic agent (Pronase, Millipore Sigma, Burlington, Mass; or N-acetylcysteine) alone. Although no evidence is available about a difference in lesion detection, the mucosal visibility obtained with simethicone was superior to that obtained with Pronase or N-acetylcysteine in a meta-analysis. For colonoscopy, simethicone given with bowel preparation seems to reduce the amount of bubbles, although with no evidence of superior cleansing, the implications of the bubble reduction are unclear. The European Society of Gastrointestinal Endoscopy does suggest adding simethicone to standard bowel preparation, whereas the American Society for Gastrointestinal Endoscopy leaves it to the discretion of the prescribing physician. Let’s hope that the potential risks of simethicone use during endoscopy do not increase the already significant resistance among Western endoscopists to implementing the premedication drink before upper GI endoscopy. In countries like Chile, where gastric cancer represents a major health problem and activities to improve the endoscopic detection of early stage lesions are being developed, any restraint in the efforts to improve mucosal cleansing could have devastating effects. In summary, we agree that further investigations are needed to understand the effects of simethicone use on the endoscopes, and the possible risks of infection, but this word of caution should not stop us from using all the tools available in achieving an immaculate mucosa during upper GI endoscopy.