Development Of A Prototype Of Video Synchronisation For Relocalization Of Biopsy Sites During Endoscopic Evaluation Of Barrett's Oesophagus: Preliminary Experimental And Clinical Study

International audienceINTRODUCTION: The prevalence of Barrett's oesophagus (BE) is 5 to 6% in the general population, with a progression from dysplasia to adenocarcinoma 0.6 to 0.7 patient-years. Hence, endoscopic surveillance is justified to detect early lesions accessible to endoscopic treatment. However, the relocalisation of lesions detected by biopsies may be difficult during follow-up endoscopies. The purpose of this study was to evaluate the prototype of a magnetic probe for accurate location of the position of the endoscope, allowing the relocalisation of this position in a subsequent endoscopy. We report the results of a feasibility study in pigs and the use of this device in two patients with BE. AIMS & METHODS: The system consists of an electromagnetic (EM) field transmitter and an EM probe constituting the electromagnetic tracking system (EMS) (NDI, Aurora). The EM probe is inserted through the operating channel of a double channel gastroscope. The EM field generator is positionned on the patient chest wall. The system also includes a new software developed at IHU/IRCAD, which performs simultaneous recording of the video from the endoscope alongwith its corresponding position, as measured by the EMS. During a second endoscopy, this software allows automatic synchronization of the recorded video to provide relocalisation of the endoscope in front of previous biopsy sites in the oesophagus. The system was tested in 5 anesthetized pigs. During the first endoscopy, ten markings were performed by argon plasma electrocoagulation (ERBE Tübingen, Germany) in the distal esophagus. The position of each marking was recorded by the system. A second operator to then performed a blind endoscopy on the same pigs and was asked to follow the system implicitly as a guide to relocate the markings. In 2 patients with BE, the system was then tested to facilitate relocalization of the biopsy sites. RESULTS: Ten markings were made in the distal oeosphagus of 5. After withdrawal of the endoscope the second operator found 48 of the 50 markings (96%) using the guidance provided by the system. The positioning of the endoscope provided by the EMS system was within a 2mm range from the initial positionning. In the evaluation of BE patients, the system relocalized the biospy sites within a range of 3mm. CONCLUSION: This preliminary study shows the feasibility of the EMS prototype to relocalize the endoscope in the oesophagus within an acceptable range. The clinical usefulness of this system should be evaluated further during the follow-up of patients with BE

Video Synchronization: An Approach to Biopsy Site Re-localization

International audienceBarrett’s esophagus (Barrett’s esophagus) is the pre-malignant lesion for the majority of patients with esophageal adenocarcinoma. The sequence of events from Barrett’s esophagus to adenocarcinoma has several steps, encompassing low grade intra-epithelial Neoplasia (LGIN), and high grade intra-epithelial neoplasia (HGIN). As it seems that this evolution spans many years, endoscopic surveillance for patients with Barrett’s esophagus has been advocated, to detect neoplasia at early and curable stages. In recent years endoscopic imaging techniques have improved greatly. However, even using sophisticated imaging techniques, the standard approach of comprehensive endoscopic biopsy protocol includes direct sampling from suspicious areas in combination with systematic random four quadrant biopsies (4QBs) every 1±2 cm along the length of the Barrett’s segment, according to the Seattle protocol, is recommended as the gold standard for surveillance. The approach is labor-intensive but iscurrently considered to be the state of the art. However, the primary problem is the inter-operative re-localization of these biopsy sites to guide the treatment. Often re-localization is performed using the markings made on the endoscope which are highly unreliable and prevent targeted treatments

Inter-Operative Biopsy Site Relocalization in Endoluminal Surgery

International audienceBarrett's oesophagus, a pre-malignant condition of the oesophagus has been on a rise in the recent years. The standard diagnostic protocol for Barrett's involves obtaining biopsies at suspicious regions along the oesophagus. The localization and tracking of these biopsy sites " inter-operatively " poses a significant challenge for providing targeted treatments and tracking disease progression. This paper proposes an approach to provide guided navigation and relocalization of the biopsy sites using an electromagnetic tracking system. The characteristic of our approach over existing ones is the integration of an EM sensor at the flexible endoscope tip, so that the endoscopic camera depth inside the oesophagus can be computed in real-time, allowing to retrieve and display an image from a previous exploration at the same depth. We firstly describe our system setup and methodology for inter-operative registration. We then propose three incremental experiments of our approach. First, on synthetic data with realistic noise model to analyze the error bounds of our system. The second on in-vivo pig data using an optical tracking system to provide a pseudo ground-truth. Accuracy results obtained were consistent with the synthetic experiments despite uncertainty introduced due to breathing motion, and remain inside acceptable error margin according to medical experts. Finally, a third experiment designed using data from pigs to simulate a real task of biopsy site relocalization, and evaluated by 10 GI experts. It clearly demonstrated the benefit of our system towards assisted guidance by improving the biopsy site retrieval rate from 47.5% to 94%

Lumen-apposing metal stent through the meshes of duodenal metal stents for palliation of malignant jaundice

Background and study aims Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard procedure for malignant jaundice palliation; however, it can be challenging when a duodenal self-expandable metal stent (SEMS) is already in place. Patients and methods The primary aim of our study was to evaluate the technical feasibility of the placement of a lumen apposing metal stent (LAMS) through the mesh (TTM) of duodenal stents. The secondary aims were to evaluate clinical outcomes and adverse events (AEs) related to the procedures. Results Data from 23 patients (11 F and 12 M; mean age: 69.5 ± 11 years old) were collected. In 17 patients (73.9 %) TTM LAMS placement was performed as first intention, while in six patients (26.1 %) it was performed after a failed ERCP. Thirteen patients (56.5 %) underwent the procedure due to advanced pancreatic head neoplasia. One technical failure was experienced (4.3 %). The TTM LAMS placement led to a significant decrease in the serum levels of bilirubin, ALP, GGT, WBC and CRP. No cases of duodenal SEMS occlusion occurred and no other AEs were observed during the follow-up. Conclusions Concomitant malignant duodenal and biliary obstruction is a challenging condition. Palliation of jaundice using TTM LAMS in patients already treated with duodenal stent is associated to promising technical and clinical outcomes

Is EUS-guided drainage a suitable alternative technique in case of proximal biliary obstruction?

Background: Results of endoscopic ultrasound-guided biliary drainage (EUBD) are unknown in case of proximal stricture. The aim is to assess clinical outcomes of EUBD in patients with malignant hilar obstruction. Methods: Patients undergoing EUBD with hilar strictures were prospectively included. Primary outcome was clinical success at 7 and 30 days (defined by 50% bilirubin decrease). Secondary outcomes were technical success, procedure-related complications, length of hospital stay, reintervention rate, survival and chemotherapy administration. Results: Eighteen patients with a mean age of 68.8 years were included. On 15 classable stenosis, 7 (47%) were noted Bismuth I–II, 7 (47%) Bismuth III, and 1 (6.7%) Bismuth IV. Reasons for EUBD were surgically modified anatomy in 10 patients (55.6%), impassable stricture at ERCP in 7 (38.9%) and duodenal obstruction in 1 (5.6%). Only hepaticogastrostomy was performed. Clinical success was at day 7 and 30 respectively 72.2% and 68.8%. Technical success was 94%. Complications occurred in 3 (16.7%) patients. Median (range) length of hospital stay was 10 (6–35) days. Reintervention rate was 16.7%. Median (range) survival was 79 (5–390) days. Chemotherapy was possible in 10 (55.6%) patients. Conclusions: EUBD is feasible for hilar obstruction for surgically altered anatomy or after ERCP failure. Clinical outcome is satisfactory when considering underlying advanced disease, allowing chemotherapy

Endoscopic ultrasound-guided hepaticogastrostomy percutaneous transhepatic drainage for malignant biliary obstruction after failed endoscopic retrograde cholangiopancreatography: a retrospective expertise-based study from two centers

Background: Percutaneous transhepatic biliary drainage (PTBD) is widely performed as a salvage procedure in patients with unresectable malignant obstruction of the common bile duct (CBD) after failed endoscopic retrograde cholangiopancreatography (ERCP) or in case of surgically altered anatomy. Endoscopic ultrasound-guided hepaticogastrostomy (EU-HGS) is a more recently introduced alternative to relieve malignant obstructive jaundice. The aim of this prospective observational study was to compare the outcome, efficacy and adverse events of EU-HGS and PTBD. Methods: From April 2012 to August 2015, consecutive patients with malignant CBD obstruction who underwent EU-HGS or PTBD in two tertiary-care referral centers were included. The primary endpoint was the clinical success rate. Secondary endpoints were technical success, overall survival, procedure-related adverse events, incidence of adverse events, and reintervention rate. Results: A total of 51 patients (EU-HGS, n = 31; PTBD, n = 20) were included. Median survival was 71 days (range 25–75th percentile; 30–95) for the EU-HGS group and 78 days (range 25–75th percentile; 42–108) for the PTBD group ( p = 0.99). Technical success was achieved in all patients in both groups. Clinical success was achieved in 25 (86%) of 31 patients in the EU-HGS group and in 15 (83%) of 20 patients in the PTBD group ( p = 0.88). There was no difference in adverse events rates between the two groups (EU-HGS: 16%; PTBD: 10%) ( p = 0.69). Four deaths within 1 month (two hemorrhagic and two septic) were considered procedure related (two in the EU-HGS group and two in the PTBD group). Overall reintervention rate was significantly lower after EU-HGS ( n = 2) than after PTBD ( n = 21) ( p = 0.0001). Length of hospital stay was shorter after EU-HGS (8 days versus 15 days; p = 0.002). Conclusions: EU-HGS can be an effective and safe mini invasive-procedure alternative to PTBD, with similar success and adverse-event rates, but with lower rates of reintervention and length of hospitalization