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Detection of Angioectasias and Haemorrhages Incorporated into a Multi-Class Classification Tool for the GI Tract Anomalies by Using Binary CNNs

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Journal of Biomedical Science and Engineering 2021年第12期14卷 402-414页

作者： Christos Barbagiannis Alexios polydorou Michail Zervakis andreas polydorou Eleftheria Sergaki School of Electrical and Computer Engineering (ECE) School Technical University of Crete Chania Greece Department of Surgery School of Medicine National and Kapodistrian University of Athens Athens Greece

The proposed deep learning algorithm will be integrated as a binary classifier under the umbrella of a multi-class classification tool to facilitate the automated detection of non-healthy deformities, anatomical landmarks, pathological findings, other anomalies and normal cases, by examining medical endoscopic images of GI tract. Each binary classifier is trained to detect one specific non-healthy condition. The algorithm analyzed in the present work expands the ability of detection of this tool by classifying GI tract image snapshots into two classes, depicting haemorrhage and non-haemorrhage state. The proposed algorithm is the result of the collaboration between interdisciplinary specialists on AI and Data Analysis, Computer Vision, Gastroenterologists of four University Gastroenterology Departments of Greek Medical Schools. The data used are 195 videos (177 from non-healthy cases and 18 from healthy cases) videos captured from the PillCam(R) Medronics device, originated from 195 patients, all diagnosed with different forms of angioectasia, haemorrhages and other diseases from different sites of the gastrointestinal (GI), mainly including difficult cases of diagnosis. Our AI algorithm is based on convolutional neural network (CNN) trained on annotated images at image level, using a semantic tag indicating whether the image contains angioectasia and haemorrhage traces or not. At least 22 CNN architectures were created and evaluated some of which pre-trained applying transfer learning on ImageNet data. All the CNN variations were introduced, trained to a prevalence dataset of 50%, and evaluated of unseen data. On test data, the best results were obtained from our CNN architectures which do not utilize backbone of transfer learning. Across a balanced dataset from no-healthy images and healthy images from 39 videos from different patients, identified correct diagnosis with sensitivity 90%, specificity 92%, precision 91.8%, FPR 8%, FNR 10%. Besides, we comp

关键词： Capsule Endoscopy (CE) Small Bowel Bleeding (SBB) Angioectasia Haemorrhage Gatrointestinal (GI) Small Bowel Capsule Endoscopy (SBCE) Convolutional Neural Network (CNN) Computer Aided Diagnosis (CAD) Image Level Annotation Pixel Level Annotation Binary Classification

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Endoscopic retrograde cholangiopancreatography-related perforations: Diagnosis and management

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World Journal of Gastrointestinal Endoscopy 2015年第14期7卷 1135-1141页

作者： Antonios Vezakis Georgios Fragulidis andreas polydorou Academic Department of Surgery and Endoscopy Unit University of Athens Aretaieion Hospital

Endoscopic retrograde cholangiopancreatography(ERCP) has become an important therapeutic modality for biliary and pancreatic disorders. Perforation is one of the most feared complications of ERCP and endoscopic sphincterotomy. A MEDLINE search was performedfrom 2000-2014 using the keywords "perforation", "ERCP" and "endoscopic sphincterotomy". All articles including more than nine cases were reviewed. The incidence of ERCP-related perforations was low(0.39%, 95%CI: 0.34-0.69) with an associated mortality of 7.8%(95%CI: 3.80-13.07). Endoscopic sphincterotomy was responsible for 41% of perforations, insertion and manipulations of the endoscope for 26%, guidewires for 15%, dilation of strictures for 3%, other instruments for 4%, stent insertion or migration for 2% and in 7% of cases the etiology was unknown. The diagnosis was made during ERCP in 73% of cases. The mechanism, site and extent of injury, suggested by clinical and radiographic findings, should guide towards operative or non-operative management. In type I perforations early surgical repair is indicated, unless endoscopic closure can be achieved. Patients with type II perforations should be treated initially non-operatively. Non-operative treatment includes biliary stenting, fasting, intravenous fluid resuscitation, nasogastric drainage, broad spectrum antibiotics, percutaneous drainage of fluid collections. Non-operative treatment was successful in 79% of patients with type II injuries, with an overall mortality of 9.4%. Non-operative treatment was sufficient in all patients with type III injuries. Surgical technique depends on timing, site and size of defect and clinical condition of the patient. In conclusion, diagnosis is based on clinical suspicion and clinical and radiographic findings. Whilst surgery is usually indicated in patients with type I injuries, patients with type II or III injuries should be treated initially non-operatively. A minority of them will finally require surgical intervention.

关键词： Endoscopic retrograde cholangiopancreatography End

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Closure of a persistent sphincterotomy-related duodenal perforation by placement of a covered self-expandable metallic biliary stent

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World Journal of Gastroenterology 2011年第40期17卷 4539-4541页

作者： Antonios Vezakis Georgios Fragulidis Constantinos Nastos Anneza Yallourou andreas polydorou Dionisios Voros 2nd Department of Surgery Endoscopy Unit Aretaieion Hospital University of Athens Athens 11528 Greece

Retroperitoneal duodenal perforation as a result of endoscopic biliary sphincterotomy is a rare complication, but it is associated with a relatively high mortality risk, if left untreated. Recently, several endoscopic techniques have been described to close a variety of perforations. In this case report, we describe the closure of a persistent sphincterotomy-related duodenal perforation by using a covered self-expandable metallic biliary (CEMB) stent. A 61-year-old Greek woman underwent an endoscopic retrograde cholangiopancreatography (ERCP) and sphincterotomy for suspected choledo-cholithiasis, and a retroperitoneal duodenal perforation (sphincterotomy-related) occurred. Despite initial conservative management, the patient underwent a laparotomy and drainage of the retroperitoneal space. After that, a high volume duodenal fistula developed. Six weeks after the initial ERCP, the patient underwent a repeat endoscopy and placement of a CEMB stent with an indwelling nasobiliary drain. The fistula healed completely and the stent was removed two weeks later. We suggest the transient use of CEMB stents for the closure of sphincterotomy-related duodenal perforations. They can be placed either during the initial ERCP or even later if there is radiographic or clinical evidence that the leakage persists.

关键词： Endoscopic sphincterotomy Complications Retroperitoneal perforation Duodenal perforation Metallic stent

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Improving CAD Hemorrhage Detection in Capsule Endoscopy

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Journal of Biomedical Science and Engineering 2021年第3期14卷 103-118页

作者： polydorou Alexios Sergaki Eleftheria polydorou andreas Barbagiannis Christos Vardiambasis Ioannis George Giakos Zervakis Michail School of Electrical and Computer Engineering Technical University of Crete Chania Greece Department of Surgery School of Medicine National and Kapodistrian University of Athens Athens Greece Department of Electronic Engineering Faculty of Engineering Hellenic Mediterranean University Chania Crete Greece School of ECE Manhattan College New York USA

This study explores an automated framework to assist the recognition of hemorrhage traces and bleeding lesions in video streams of small bowel capsule endoscopy (SBCE). The proposed methodology aims to achieve fast image control (<10 minutes), save valuable time of the physicians, and enable high performance diagnosis. A specialized elimination algorithm excludes all identical consecutive frames by utilizing the difference of gray levels in pixel luminance. An image filtering algorithm is proposed based on an experimentally calculated bleeding index and blood-color chart, which inspects all remaining frames of the footage and identifies pixels that reflect active or potential hemorrhage in color. The bleeding index and blood-color chart are estimated of the chromatic thresholds in RGB and HSV color spaces, and have been extracted after experimenting with more than 3200 training images, derived from 99 videos of a pool of 138 patients. The dataset has been provided by a team of expert gastroenterologist surgeons, who have also evaluated the results. The proposed algorithms are tested on a set of more than 1000 selected frame samples from the entire 39 testing videos, to a prevalence of 50% pathologic frames (balanced dataset). The frame elimination of identical and consecutive frames achieved a reduction of 36% of total frames. The best statistical performance for diagnosis of positive pathological frames from a video stream is achieved by utilizing masks in the HSV color model, with sensitivity up to 99%, precision 94.41% to a prevalence of 50%, accuracy up to 96.1%, FNR 1%, FPR 6.8%. The estimated blood-color chart will be clinically validated and used in feature extraction schemes supporting machine learning ML algorithms to improve the localization potential.

关键词： Capsule Endoscopy Small Bowel Bleeding Detection Computer Aided Diagnosis (CAD) Color Models Color Feature

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Effects of endoscopic sphincterotomy on biliary epithelium:A case-control study

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World Journal of Gastroenterology 2012年第8期18卷 794-799页

作者： John Kalaitzis Antonios Vezakis George Fragulidis Irene Anagnostopoulou Spyros Rizos Efstathios Papalambros andreas polydorou First Department of Surgery Tzaneio General Hospital of Piraeus Second Department of Surgery and Endoscopic Unit National and Kapodistrian University of Athens Medical School Aretaieion Hospital Department of Cytology Tzaneio General Hospital of Piraeus First Department of Surgery National and Kapodistrian University of Athens Medical School Laiko General Hospital

AIM: To study the long-term effects of endoscopic sphincterotomy on biliary epithelium. METHODS: This is a prospective case-control study. A total of 25 patients with a median age of 71 years (range 49-89 years) and prior endoscopic sphincterotomy (ES) for benign disease formed the fi rst group. The median time from ES was 42 mo (range 8-144 mo). Another 25 patients with a median age of 76 years (range 44-94 mo) and similar characteristics who underwent current endoscopic retrograde cholangio-pancreatography (ERCP) and ES for benign disease formed the second group (control group). Brush cytology of the biliary tree with p53 immunocytology was performed in all patients of both groups. ERCPs and recruitment were conducted at the Endoscopic Unit of Aretaieion University Hospital and Tzaneio Hospital, Athens, from October 2006 to June 2010. RESULTS: No cases were positive or suspicious for malignancy. Epithelial atypia was higher in the first group (32% vs 8% in the second group, P = 0.034). Acute cholangitis and previous biliary operation rates were also higher in the fi rst group (acute cholangitis, 60% vs 24% in the second group, P = 0.01; previous biliary operation, 76% vs 24% in the second group, P = 0.001). Subgroup analysis showed that previous ES was the main causal factor for atypia, which was not related to the time interval from the ES (P = 0.407). Two patients (8%) with atypia in the fi rst group were p53-positive. CONCLUSION: ES causes biliary epithelial atypia that represents mostly reactive/proliferative rather than premalignant changes. The role of p53 immunoreactivity in biliary atypia needs to be further studied.

关键词： Endoscopic sphincterotomy Brush cytolo-gy Atypia Cholangiocarcinoma p53 immunocytology

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Managing injuries of hepatic duct confluence variants after major hepatobiliary surgery:An algorithmic approach

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World Journal of Gastroenterology 2008年第19期14卷 3049-3053页

作者： Georgios Fragulidis Athanasios Marinis andreas polydorou Christos Konstantinidis Georgios Anastasopoulos John Contis Dionysios Voros Vassilios Smyrniotis Second Department of Surgery Areteion University HospitalAthens Medical SchoolUniversity of Athens

AIM:To investigate injuries of anatomy variants of hepatic duct confluence during hepatobiliary surgery and their impact on morbidity and mortality of these procedures. An algorithmic approach for the management of these injuries is proposed. METHODS:During a 6-year period 234 patients who had undergone major hepatobiliary surgery were retrospectively reviewed in order to study postoperative bile leakage. Diagnostic workup included endoscopic and magnetic retrograde cholangiopancreatography (E/MRCP), scintigraphy and fistulography. RESULTS:Thirty (12.8%) patients who developed postoperative bile leaks were identified. Endoscopic stenting and percutaneous drainage were successful in 23 patients with bile leaks from the liver cut surface. In the rest seven patients with injuries of hepatic duct confluence, biliary variations were recognized and a stepwise therapeutic approach was considered. Conservative management was successful only in 2 patients. Volume of the liver remnant and functional liver reserve as well as local sepsis were used as criteria for either resection of the corresponding liver segment or construction of a biliary-enteric anastomosis. Two deaths occurred in this group of patients with hepatic duct confluence variants (mortality rate 28.5%). CONCLUSION:Management of major biliary fistulaethat are disconnected from the mainstream of the biliary tree and related to injury of variants of the hepatic duct confluence is extremely challenging. These patients have a grave prognosis and an early surgical procedure has to be considered.

关键词： Biliary aberrations Bile duct injury Postope-rative bile leakage Hepatic duct confluence Hepatectomy

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An ongoing dispute in the management of severe pancreatic fistula:Pancreatospleenectomy or not?

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World Journal of Gastrointestinal Surgery 2010年第11期2卷 381-384页

作者： Dionysios Dellaportas Aliki Tympa Constantinos Nastos Vasiliki Psychogiou andreas Karakatsanis andreas polydorou George Fragulidis Ioannis Vassiliou Vassilios Smyrniotis Second Department of Surgery Athens Medical SchoolAretaieion Hospital76 Vassilisis Sofias Avenue11528 AthensGreece Fifth Department of Surgery Athens Medical SchoolAretaieion Hospital76 Vassilisis Sofias Avenue11528 AthensGreece

The aim of this manuscript is to review controversies in managing severe pancreatic fistula after pancreatic *** progress in surgical technique and perioperative care has reduced the mortality rate of pancreatic ***,leakage of the pancreatic stump still accounts for the majority of surgical complications after pancreatic *** strategies have been employed in order to manage pancreatic *** high grade pancreatic fistula evokes controversy in relation to the choice of treatment.A Medline search was performed,with regard to conservative treatment options versus completion pancreatectomy for the management of pancreatic fistula grade *** fistula rates remain unchanged with an incidence ranging from 5%-20% and this is considered as the most important cause of postoperative *** authors claim that completion pancreatectomy has probably lost its role in favour of interventional radiology procedures,while others believe that completion pancreatectomy continues to have a place in the management of patients with severe clinical deterioration after pancreatic fistula who do not respond to non-surgical *** is no agreement on the best clinical management of severe pancreatic fistula after pancreatic *** pancreatectomy is reserved for patients not improving with conventional measures.

关键词： Pancreatic fistula Pancreatoduodenectomy Pancreatospleenectomy Completion pancreatectomy Percutaneous drainage

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Surgical approaches of resectable synchronous colorectal liver metastases:Timing considerations

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World Journal of Gastroenterology 2007年第9期13卷 1431-1434页

作者： Ioannis Vassiliou Nick Arkadopoulos Theodosios Theodosopoulos Georgios Fragulidis Athanasios Marinis Agathi Kondi-Paphiti Lazaros Samanides andreas polydorou Constantinos Gennatas Dionysios Voros Vassilios Smyrniotis 2nd Department of Surgery Aretaieion HospitalUniversity of AthensSchool of Medicine AthensGreece Department of Pathology Aretaieion Hospital University of Athens School of Medicine Athens Greece Department of Oncology Aretaieion Hospital University of Athens School of Medicine AthensGreece

AIM: To compare the safety and efficacy of simultaneous versus two stage resection of primary colorectal tumors and liver metastases. METHODS: From January 1996 to May 2004, 103 colorectal tumor patients presented with synchronous liver metastases. Twenty five underwent simultaneous colorectal and liver surgery and 78 underwent liver surgery 1-3 mo after primary colorectal tumor resection. Data were retrospectively analyzed to assess and compare the morbidity and mortality between the surgical strategies. The two groups were comparable regarding the age and sex distribution, the types of liver resection and stage of primary tumors, as well as the number and size of liver metastases. RESULTS: In two-stage procedures more transfusions were required (4 ± 1.5 vs 2 ± 1.8, pRBCs, P < 0.05). Chest infection was increased after the two-stage approach (26% vs 17%, P < 0.05). The two-stage procedure was also associated with longer hospitalization (20 ± 8 vs 12 ± 6 d, P < 0.05). Five year survival in both groups was similar (28% vs 31%). No hospital mortality occurred in our series. CONCLUSION: Synchronous colorectal liver metastases can be safely treated simultaneously with the primary tumor. Liver resection should be prioritized over colon resection. It is advisable that complex liver resections with marginal liver residual volume should be dealt with at a later stage.

关键词： Synchronous colorectal liver metastases Colon resections Liver resections

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