Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Zacharias P. Tsiamoulos is active.

Publication


Featured researches published by Zacharias P. Tsiamoulos.


Endoscopy | 2014

Diagnosis and management of iatrogenic endoscopic perforations: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement.

G. Paspatis; Jean-Marc Dumonceau; Marc Barthet; Søren Meisner; Alessandro Repici; Brian P. Saunders; Antonios Vezakis; Jean Michel Gonzalez; Stine Ydegaard Turino; Zacharias P. Tsiamoulos; Paul Fockens; Cesare Hassan

This Position Paper is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). It addresses the diagnosis and management of iatrogenic perforation occurring during diagnostic or therapeutic digestive endoscopic procedures. Main recommendations 1 ESGE recommends that each center implements a written policy regarding the management of iatrogenic perforation, including the definition of procedures that carry a high risk of this complication. This policy should be shared with the radiologists and surgeons at each center. 2 In the case of an endoscopically identified perforation, ESGE recommends that the endoscopist reports: its size and location with a picture; endoscopic treatment that might have been possible; whether carbon dioxide or air was used for insufflation; and the standard report information. 3 ESGE recommends that symptoms or signs suggestive of iatrogenic perforation after an endoscopic procedure should be carefully evaluated and documented, possibly with a computed tomography (CT) scan, in order to prevent any diagnostic delay. 4 ESGE recommends that endoscopic closure should be considered depending on the type of perforation, its size, and the endoscopist expertise available at the center. A switch to carbon dioxide insufflation, the diversion of luminal content, and decompression of tension pneumoperitoneum or tension pneumothorax should also be done. 5 After closure of an iatrogenic perforation using an endoscopic method, ESGE recommends that further management should be based on the estimated success of the endoscopic closure and on the general clinical condition of the patient. In the case of no or failed endoscopic closure of the iatrogenic perforation, and in patients whose clinical condition is deteriorating, hospitalization and surgical consultation are recommended.


Endoscopy | 2009

Argon plasma coagulation has a long-lasting therapeutic effect in patients with chronic radiation proctitis

Georgios Karamanolis; Konstantinos Triantafyllou; Zacharias P. Tsiamoulos; Dimitrios Polymeros; Theodora Kalli; Nikolaos Misailidis; Spiros D. Ladas

BACKGROUND AND STUDY AIMS The optimal treatment of bleeding due to radiation proctitis is still controversial. Although argon plasma coagulation (APC) has been recently reported as an effective treatment, its efficacy in relation to disease severity is unknown. The study aims were to prospectively evaluate (i) the efficacy of APC in endoscopically mild and severe radiation proctitis, and (ii) the recurrence rate following successful treatment. PATIENTS AND METHODS 56 patients (mean age 68.4 years) with radiation proctitis after radiotherapy for prostate cancer were studied. All presented with rectal bleeding, occurring a median 21.5 months after radiotherapy. Using an established scoring system, patients were classified into two groups, with mild or severe disease. We also examined the correlation between endoscopic severity and hemoglobin level as a more objective measure of bleeding activity. Success was defined either as cessation of bleeding or a significant reduction so that further treatment was not required. RESULTS Proctitis was classified as mild in 27 patients (48%) and severe in 29 (52%). Endoscopically judged severity and hemoglobin level showed good correlation (R = 0.58). All patients with mild proctitis and 23/29 (79%) with severe disease were successfully treated (P < 0.05). During a follow-up of a mean of 17.9 months (range 6-33), 34/38 patients (89.5%) remained in clinical remission. Recurrence was higher in those using anticoagulant or aspirin (P = 0.02). CONCLUSIONS APC is highly effective in all patients with mild radiation proctitis and in the majority of those with severe disease, providing long-lasting clinical remission.


Gastrointestinal Endoscopy | 2012

A new accessory, endoscopic cuff, improves colonoscopic access for complex polyp resection and scar assessment in the sigmoid colon (with video)

Zacharias P. Tsiamoulos; Brian P. Saunders

BACKGROUND Difficult and unstable endoscopic access to large sessile/flat colon polyps in the sigmoid colon may prevent successful and complete EMR. OBJECTIVE We report our experience with the use of an endoscopic cuff, a new endoscopic accessory, to improve endoscopic access during endoscopic therapy and scar assessment. DESIGN Single-center, retrospective, feasibility case series. SETTING Tertiary referral academic endoscopy unit. PATIENTS Nonconsecutive patients referred for endoscopic resection of large flat/sessile sigmoid colon polyps or surveillance of postpolypectomy scars in the sigmoid colon. INTERVENTIONS When conventional methods to achieve stable access and visualization were unsuccessful, the endoscopic cuff was used to retract sigmoid colon folds. MAIN OUTCOME MEASUREMENTS Safety, procedural success, and complications. RESULTS Five patients (mean age 62 years, 3 male/2 female) underwent endoscopic cuff-assisted EMR polypectomy, and 7 patients (mean age 62 years, 2 male/5 female) underwent post-EMR scar surveillance with an endoscopic cuff-assisted flexible sigmoidoscopy. All sessile/flat polyps (mean size 29 mm) or post-EMR scar sites (mean size 15 mm) were located at acute bends in the sigmoid colon. With the endoscopic cuff placed around the tip of the colonoscope, endoscopic access improved significantly by flattening/depressing colon folds close to the lesion/scar. The entire polyp/scar surface was revealed, facilitating a complete polyp excision and a meticulous scar assessment. No immediate or delayed adverse events were seen. LIMITATIONS Single-center, nonrandomized case series. CONCLUSIONS An endoscopic cuff appears to be a safe and easily used accessory to facilitate colonoscopic access for complex polypectomy and scar assessment in the sigmoid colon.


Gastrointestinal Endoscopy | 2012

Endoscopic mucosal ablation: a new argon plasma coagulation/ injection technique to assist complete resection of recurrent, fibrotic colon polyps (with video)

Zacharias P. Tsiamoulos; Leonidas Bourikas; Brian P. Saunders

BACKGROUND Incomplete piecemeal EMR of large, sessile/flat colon polyps results in polyp recurrence, with massive submucosal scarring making subsequent attempts at endoscopic resection problematic. OBJECTIVE We report our experience with a new endoscopic mucosal ablation (EMA) technique that can be used to complement the eradication of recurrent fibrotic colon polyps. DESIGN Single-center, retrospective case series. SETTING Tertiary-care referral academic endoscopy unit. PATIENTS This study involved consecutive patients referred for endoscopic excision of recurrent benign colon polyps with severe submucosal fibrosis (>30% of the entire lesion). INTERVENTION Application of high-power argon plasma coagulation (APC), preceded by injection of a submucosal fluid cushion (normal saline/diluted adrenaline and/or sodium hyaluronate solution) to protect the muscle layer, was performed to augment further piecemeal EMR and polyp eradication. MAIN OUTCOME MEASUREMENTS Technical safety and success, complication and recurrence rates. RESULTS Fourteen patients (mean age 73 years; 9 men, 5 women) with 15 recurrent colon adenomas (mean polyp size 30 mm, 9 proximal/6 distal) were included. EMA with a mean APC power setting of 55 W was applied. Complete polyp eradication was achieved in 9 of 11 patients (82%) at first or second completed follow-up. One patient needed laparoscopic colectomy because of cancer, and 1 underwent transanal endoscopic microsurgery for benign massive recurrence. The other 3 patients with small, easily treatable recurrence (≤3 mm) were followed by 1-year-surveillance. No perforations and no postpolypectomy syndrome were reported. LIMITATIONS Single-center, nonrandomized case series with short duration follow-up. CONCLUSION EMA appears to be a safe and easily applicable technique to assist the complete eradication of recurrent fibrotic colon polyps.


Journal of Clinical Gastroenterology | 2009

Effect of sleep on excessive belching: a 24-hour impedance-pH study.

George Karamanolis; Konstantinos Triantafyllou; Zacharias P. Tsiamoulos; Dimitrios Polymeros; Theodora Kalli; Nikolaos Misailidis; Theodoros Liakakos; Spiros D. Ladas

In patients with repetitive and troublesome belching an organic cause is seldom found, indicating the presence of an acquired abnormal behavior. The aim of our study was to investigate the incidence and pattern of belching during a 24-hour period. Methods Combined 24-hour pH and intraluminal impedance monitoring was performed in 14 patients (9 female; mean age: 43 y) with excessive belching and 10 patients (6 women, mean age 42 y; range 28 to 56) with noncardiac chest pain. Thereafter, we counted the number of belching events and differentiated the number of supragastric and gastric belches. Results During the 24-hour study, the hourly rate of belching was 38.7±6.0; rate of supragastric belches were significantly higher compared to gastric belches (37.7±6.0 vs 1.0±0.5, P<0.001). Patients with noncardiac chest pain showed a lower average hourly rate of belching (3.1±0.6, P<0.001). Dividing the recording into 2 periods (daily-upright and night-supine), there was a significant decrease in the hourly rate at night (37.8±6.1 vs. 0.9±0.5, respectively, P<0.001); mostly due to decrease in supragastric belches, where as the rate of gastric belches remained unchanged. None of the patients showed pathological acid reflux and none of the supragastric belches was associated with acid or nonacid reflux events. Conclusions Supragastric belch is the prominent belching pattern in patients with excessive belching. Supragastric belches almost ceased at night suggesting the presence of a behavioral disorder. There were no diurnal changes in the rate of gastric belches.


Journal of Crohns & Colitis | 2011

Peculiar antibody reactivity to human connexin 37 and its microbial mimics in patients with Crohn's disease

Andreas Koutsoumpas; Dimitrios Polymeros; Zacharias P. Tsiamoulos; Daniel S. Smyk; George Karamanolis; Konstantinos Triantafyllou; Eirini I. Rigopoulou; Alastair Forbes; Diego Vergani; Dimitrios P. Bogdanos; Spiros D. Ladas

BACKGROUND/AIMS We found that pooled Crohns disease (CD) sera strongly react with a human gap-junction connexin 37 (Cx37) peptide and tested for anti-Cx37 antibody reactivity in sera from CD patients and controls. We also investigated whether peptide-recognition is due to Cx37/microbial molecular mimicry. METHODS The PSI-BLAST program was used for Cx37(121-135)/microbial alignment. Reactivity to biotinylated human Cx37(121-135) and its microbial mimics was determined by ELISA using sera from 44 CD, 30 ulcerative colitis and 28 healthy individuals. RESULTS Anti-Cx37(121-135) reactivity (1/200 dilution) was present in 30/44 (68%) CD cases and persisted at 1/1000 dilution. Database search shows that Cx37(121-135) contains the -ALTAV- motif which is cross-recognized by diabetes-specific phogrin and enteroviral immunity. Testing of 9 Cx37(121-135)-microbial mimics revealed 57-68% reactivity against human enterovirus C, Lactococcus lactis, coxsackie virus A24 and B4. Anti-Cx37(121-135) was inhibited by itself or the microbial mimics. No reactivity was found against the poliovirus, rubella, and Mycobacterium tuberculosis mimics, or the beta cell phogrin autoantigen. Microbial/Cx37 reactivity was not able to differentiate CD patients from UC or healthy controls, in terms of overall prevalence and antibody titres, but microbial mimics were unable to inhibit reactivity to human Cx37 in the majority of the controls. CONCLUSIONS Sera from CD patients react with connexin 37 and cross-react with specific Cx37-mimicking enteroviral peptides. Microbial/self reactivity can be seen in UC and healthy controls. The lack of responses to other Cx37(121-135) microbial mimics and the inability of the reactive microbes to inhibit reactivity to self is intriguing and warrants further investigation.


Gut | 2018

Improved adenoma detection with Endocuff Vision: the ADENOMA randomised controlled trial

Wee Sing Ngu; Roisin Bevan; Zacharias P. Tsiamoulos; Paul Bassett; Zoe Hoare; Matthew D Rutter; Gayle M. Clifford; Nicola Totton; T J W Lee; Arvind Ramadas; John Silcock; John Painter; Laura J Neilson; Brian P. Saunders; Colin Rees

Objective Low adenoma detection rates (ADR) are linked to increased postcolonoscopy colorectal cancer rates and reduced cancer survival. Devices to enhance mucosal visualisation such as Endocuff Vision (EV) may improve ADR. This multicentre randomised controlled trial compared ADR between EV-assisted colonoscopy (EAC) and standard colonoscopy (SC). Design Patients referred because of symptoms, surveillance or following a positive faecal occult blood test (FOBt) as part of the Bowel Cancer Screening Programme were recruited from seven hospitals. ADR, mean adenomas per procedure, size and location of adenomas, sessile serrated polyps, EV removal rate, caecal intubation rate, procedural time, patient experience, effect of EV on workload and adverse events were measured. Results 1772 patients (57% male, mean age 62 years) were recruited over 16 months with 45% recruited through screening. EAC increased ADR globally from 36.2% to 40.9% (P=0.02). The increase was driven by a 10.8% increase in FOBt-positive screening patients (50.9% SC vs 61.7% EAC, P<0.001). EV patients had higher detection of mean adenomas per procedure, sessile serrated polyps, left-sided, diminutive, small adenomas and cancers (cancer 4.1% vs 2.3%, P=0.02). EV removal rate was 4.1%. Median intubation was a minute quicker with EAC (P=0.001), with no difference in caecal intubation rate or withdrawal time. EAC was well tolerated but caused a minor increase in discomfort on anal intubation in patients undergoing colonoscopy with no or minimal sedation. There were no significant EV adverse events. Conclusion EV significantly improved ADR in bowel cancer screening patients and should be used to improve colonoscopic detection. Trial registration number NCT02552017, Results; ISRCTN11821044, Results.


Nature Reviews Gastroenterology & Hepatology | 2016

Endoscopic mucosal resection and endoscopic submucosal dissection of large colonic polyps

Brian P. Saunders; Zacharias P. Tsiamoulos

Almost all large and complex colorectal polyps can now be resected endoscopically. Piecemeal endoscopic mucosal resection (PEMR) is an established technique with fairly low complication risk and good short-term and medium-term outcomes. Several modifications to the basic injection and snare technique have been developed contributing to safer and more complete resections. Delayed bleeding requiring reintervention is the most troublesome complication in 2–7% of patients, particularly in those with comorbidities and large, right-sided polyps. Endoscopic submucosal dissection (ESD) has become popular in Japan and has theoretical advantages over PEMR in providing a complete, en bloc excision for accurate histological staging and reduced local recurrence. These advantages come at the cost of a more complex, expensive and time-consuming procedure with a higher risk of perforation, particularly early in the procedure learning curve. These factors have contributed to the slow adoption of ESD in the West and the challenge to develop new devices and endoscopic platforms that will make ESD easier and safer. Currently, ESD indications are limited to large rectal lesions, in which procedural complications are easily managed, and for colorectal polyps with a high risk of containing tiny foci of early submucosally invasive cancer, whereby ESD may be curative compared with PEMR.


Endoscopy International Open | 2015

The ADENOMA Study. Accuracy of Detection using Endocuff Vision™ Optimization of Mucosal Abnormalities: study protocol for randomized controlled trial

Roisin Bevan; Wee Sing Ngu; Brian P. Saunders; Zacharias P. Tsiamoulos; Paul Bassett; Zoe Hoare; Colin Rees

Background: Colonoscopy is the gold standard investigation for the diagnosis of bowel pathology and colorectal cancer screening. Adenoma detection rate is a marker of high quality colonoscopy and a high adenoma detection rate is associated with a lower incidence of interval cancers. Several technological advancements have been explored to improve adenoma detection rate. A new device called Endocuff Vision™ has been shown to improve adenoma detection rate in pilot studies. Methods/Design: This is a prospective, multicenter, randomized controlled trial comparing the adenoma detection rate in patients undergoing Endocuff Vision™-assisted colonoscopy with standard colonoscopy. All patients above 18 years of age referred for screening, surveillance, or diagnostic colonoscopy who are able to consent are invited to the study. Patients with absolute contraindications to colonoscopy, large bowel obstruction or pseudo-obstruction, colon cancer or polyposis syndromes, colonic strictures, severe diverticular segments, active colitis, anticoagulant therapy, or pregnancy are excluded. Patients are randomized according to site, age, sex, and bowel cancer screening status to receive Endocuff Vision™-assisted colonoscopy or standard colonoscopy on the day of procedure. Baseline data, colonoscopy, and polyp data including histology are collected. Nurse assessment of patient comfort and patient comfort questionnaires are completed post procedure. Patients are followed up at 21 days and complete a patient experience questionnaire. This study will take place across seven NHS Hospital Trusts: one in London and six within the Northern Region Endoscopy Group. A maximum of 10 colonoscopists per site will recruit a total of 1772 patients, with a maximum of four bowel screening colonoscopists permitted per site. Discussion: This is the first trial to evaluate the adenoma detection rate of Endocuff Vision™ in all screening, surveillance, and diagnostic patient groups. This timely study will guide clinicians as to the role of Endocuff Vision™ in routine colonoscopy. Study registration: ISRCTN11821044.


World Journal of Gastrointestinal Endoscopy | 2013

How we can measure quality in colonoscopy

Leonidas Bourikas; Zacharias P. Tsiamoulos; Adam Haycock; Siwan Thomas-Gibson; Brian P. Saunders

Measuring quality is a current need of medical services either to assess their cost-effectiveness or to identify discrepancies requiring refinement. With the advent of bowel cancer screening and increasing patient awareness of bowel symptoms, there has been an unprecedented increase in demand for colonoscopy. Consequently, there is an expanding open-discussion on missed rates of cancer or precancerous polyps during diagnostic/screening colonoscopy and on the rate of adverse events related to therapeutic colonoscopy. Delivering a quality colonoscopy service is therefore a healthcare priority. Colonoscopy is a multi-step process and therefore assessment of all aspects of the procedure must be addressed. Quality in colonoscopy refers to a combination of many patient-centered technical and non-technical skills and knowledge aiming to patients safety and satisfaction through a continuous effort for improvement. The benefits of this endless process are hiding behind small details which can eventually make the difference in colonoscopy. Identifying specific quality metrics help to define and shape an optimal service and forms a secure basis of improvement. Τhis paper does not aim to give technical details on how to perform colonoscopy but to summarize what to measure and when, in accordance with the current identified quality indicators and standards for colonoscopy.

Collaboration


Dive into the Zacharias P. Tsiamoulos's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Paul Bassett

University College London

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Dimitrios Polymeros

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Konstantinos Triantafyllou

National and Kapodistrian University of Athens

View shared research outputs
Researchain Logo
Decentralizing Knowledge