Comparison of endoscopic sphincterotomy techniques after Billroth II gastrectomy using a novel mechanical simulator.

BACKGROUND AND AIMS: A postsurgical anatomy renders endoscopic sphincterotomy (EST) more challenging. Although different EST techniques for such a situation exist, comparative studies are lacking. The aim of the study was to compare the efficacy of different EST techniques using a novel mechanical simulator. METHODS: Ten expert endoscopists performed 6 different EST techniques on a novel mechanical Billroth II (BII) simulator in a random sequence. The EST techniques were (1) standard sphincterotome used with a side-viewing endoscope, (2) BII sphincterotome used with a side-viewing endoscope, (3) needle-knife EST guided by biliary endoprosthesis used with a side-viewing endoscope, (4) standard sphincterotome used with a forward-viewing endoscope, (5) BII sphincterotome used with a forward-viewing endoscope, and (6) needle-knife EST guided by biliary endoprosthesis used with a forward-viewing endoscope. The results of videotaped ESTs were evaluated by a blinded expert and duration for each EST modality was calculated. RESULTS: Needle-knife EST guided by endoprosthesis was rated superior to EST using a BII sphincterotome (p = 0.017) or a standard sphincterotome (p < 0.001). EST using the BII sphincterotome was significantly faster than EST with the needle knife (p = 0.004) and the standard sphincterotome (p = 0.005). There were no differences between the use of a forward-viewing endoscope and a side-viewing endoscope. CONCLUSION: In an ex vivo model for EST in B II gastrectomy needle-knife EST guided by endoprosthesis achieved superior ratings in comparison to the use of a BII sphincterotome, although it was more time-consuming. A standard sphincterotome should not be used for such a procedure.

Prospective randomized comparison of short-access mother-baby cholangioscopy versus direct cholangioscopy with ultraslim gastroscopes.

BACKGROUND: Mother-baby technologies, the criterion standard for cholangioscopy, have several limitations. A novel, short-access, mother-baby (SAMBA) system may improve this technique. Direct cholangioscopy (DC) was recently developed as an alternative to mother-baby cholangioscopy. OBJECTIVE: Comparison of success rates with SAMBA and DC. DESIGN: Single-center, randomized, controlled trial. SETTING: Academic tertiary-care referral center. PATIENTS: Sixty patients with suspected cholangiopathies randomized to either SAMBA (n = 30) or DC (n = 30). INTERVENTION: Cholangioscopy under deep sedation. MAIN OUTCOME MEASUREMENTS: Technical success rate of diagnostic or therapeutic procedure. RESULTS: A total of 24 and 21 diagnostic procedures were performed in the SAMBA and DC groups, respectively. There were no significant differences in the overall technical success rates between SAMBA (90.0%) and DC (86.7%) (P = 1.0). There was better correlation between the endoscopic prediction and histologic findings in DC (P = .013). Procedure times were shorter in DC (P < .03). In patients without significant stenoses, SAMBA allowed intrahepatic bile duct exploration in all cases, compared with 10.5% of cases in DC (P < .01). No differences regarding adverse event rates between the groups occurred (10.0% both groups). LIMITATIONS: Small sample size. Heterogeneous indications for cholangioscopy. DC requires advanced skills of the endoscopist. The study is not replicable. CONCLUSION: SAMBA and DC offer high technical success rates for diagnostic and therapeutic interventions. The advantages of DC consist of superior imaging, shorter total procedure time, and a wider working channel for adequate tissue sampling. SAMBA is better than DC with regard to intraductal stability and accessibility of the intrahepatic bile ducts.

Preliminary assessment of two novel mechanical colonoscopic polypectomy simulators: Description, evaluation and validation.

Background and study aims Colonoscopic polypectomy is an essential endoscopic skill. The simulators available for training are limited and based on raw porcine colons. Animal intestines are inconvenient and offer limited advantages for polypectomy training. These limitations are avoided by two novel mechanical simulators - the magnetic system based simulator (MSPS) and the simulator for polypectomy with high frequency current (HFPS) - described here. They are equipped to demonstrate self-repair of polyps after making a cut and hybrid polyps. The aim of this study was to describe and establish face, content, and construct validity of the two simulators and to assess their perceived utility as training and assessment tools. Methods Ten novice, seven intermediate, and 10 advanced endoscopists participated in this study. Each one performed two polypectomies in MSPS and then one polypectomy and polyp retrieval in HFPS. The median times were compared among the three groups to preliminarily assess construct validity as a primary outcome. To establish face validity, the novices and intermediates completed a questionnaire about the credibility of each simulator after finishing the tasks. For content validity, the experts completed a questionnaire grading different aspects of the simulators' realism and their usefulness for training. Results All 27 participants completed the modules. Median times needed to complete the tasks in both simulators differed significantly between the participants with different levels of experience ( P  < 0.05). Both MSPS and HFPS received favorable scores regarding face and content validity. No technical problems were encountered. Conclusion This study provides preliminary validation for MSPS and HFPS as useful training tools in a preclinical setting as well as during colonoscopy training. Moreover, we demonstrated the construct validity of both simulators, which confirms their use as a skill assessment tool during a colonoscopy training program.

Validation of the X-Vision ERCP Training System and technical challenges during early training of sphincterotomy.

BACKGROUND & AIMS: A new fluoroscopy-free training system for endoscopic retrograde cholangiopancreatography (ERCP) with different model subtypes recently was developed. This study aimed to establish construct validity by investigating whether the X-Vision ERCP Training System could distinguish experienced endoscopists from beginners and to reveal characteristic mistakes during sphincterotomy. METHODS: Six staff gastroenterologists that practice ERCP, 10 trainees that perform esophagogastroduodenoscopy and colonoscopy, and 12 residents without endoscopic experience each sequentially attempted 4 different models, simulating selective cannulation of the pancreatic or bile duct, intubation of differently arranged rubber papillas, stent placement, and sphincterotomy of a biopapilla. Performance parameters were recorded and participants' expectations were compared before and after training to determine whether the simulator was a credible tool for ERCP training. Staff gastroenterologists graded the realism and utility of the simulation. The quality of sphincterotomy was assessed by an expert endoscopist. RESULTS: Participants with ERCP experience had significantly shorter procedure times compared with those with intermediate (P < .001) or no endoscopic experience (P < .001). Total and single credibility scores significantly increased after simulator practice. The faculty found the X-Vision ERCP Training System to be realistic and useful for training. In the less-experienced groups, common mistakes made during sphincterotomy included inadequate positioning of the duodenoscope, traumatic intubation of the papilla, and continued cutting despite insufficient endoscopic view. CONCLUSIONS: The X-Vision ERCP Training System distinguished subjects with different levels of experience and was regarded as realistic and useful for ERCP training. Common mistakes during sphincterotomy could be assessed objectively.

Auditory evoked potentials compared with bispectral index for monitoring of midazolam and propofol sedation during colonoscopy.

OBJECTIVES: The purpose of this study was to evaluate and compare Bispectral index (BIS) and A-line auditory evoked potential index (AAI) for monitoring depth of low-dose midazolam and propofol sedation during colonoscopy. METHODS: A total of 115 consecutive patients (ASA I-IV), receiving low-dose midazolam and propofol sedation for colonoscopy, were evaluated. BIS and AAI levels, Observer's Assessment of Alertness/Sedation (OAA/S) scores, blood pressure, heart rate, oxygen saturation, as well as the presence or absence of eyelash reflex, patient reaction to an external noxious stimulus and to procedure-related pain were recorded every 1-3 min by a single trained observer. RESULTS: There was a positive correlation between BIS and OAA/S scores (correlation coefficient=0.77) and to a lesser extent AAI and OAA/S scores (correlation coefficient=0.47). BIS and AAI showed significant differences between subsequent levels of sedation (P<0.001). The clustered receiver operating characteristic curve estimate of BIS for the detection of deep sedation was significantly better than that of AAI (P<0.001). Regarding the presence or absence of eyelash reflex and patient reaction to an external noxious stimulus and to procedure-related pain, significant different levels were found for BIS as well as AAI, respectively. Only small changes were observed in hemodynamic variables and oxygen saturation. Overall, our data suggest target BIS levels of slightly above 73 for moderate sedation (defined as OAA/S scores 2 and 3). CONCLUSIONS: BIS and AAI correlated with the level of sedation. Hemodynamic variables were poor indicators of the hypnotic-anesthetic status of the patient. BIS discriminated best between moderate and deep sedation and could complement clinical observation for guidance of moderate sedation.

Combined laparoscopic-endoscopic resections of colorectal polyps: 10-year experience and follow-up.

BACKGROUND: Large, colorectal polyps or those that are difficult to access may be unamenable to conventional snare polypectomy and may require surgical resection. This study was designed to evaluate the resection of such lesions by the use of combined laparoscopic-endoscopic resections (CLER). METHODS: Patients who had received CLER for colorectal polyps between January 1997 and December 2006 were identified from a prospectively maintained database. Patients with biopsies consistent with invasive cancer were excluded from the combined approach. Baseline characteristics, surgical, pathological, postoperative, and follow-up data of patients and lesions were reviewed. RESULTS: A total of 146 consecutive patients underwent CLER for 154 lesions, and 120 (82%) patients underwent local excision (i.e., laparoscopy-assisted endoscopic resection, endoscopy-assisted wedge resection, and endoscopy-assisted transluminal resection). Twenty-six (18%) patients received endoscopy-assisted segmental colon resection. Conversion rate was 5% and intraoperative complications occurred in two patients (1%). Major postoperative complications occurred in five patients (3%), necessitating surgical reintervention in four of them. Follow-up colonoscopy revealed metachronous adenomas in 33 patients, of which 8 patients showed macroscopic or microscopic characteristics of advanced lesions. One patient, who had been converted to open resection because of incomplete laparoscopic resection of an adenoma, developed relapse of the initial adenoma and was successfully treated with repeat CLER accounting for a local recurrence rate of 0.9%. CONCLUSIONS: Combined laparoscopic-endoscopic resection is an efficient, safe, and minimally invasive alternative to open resection for selected patients with difficult polyps, but it should be restricted to benign disease.

Detection of cholangiocarcinoma in vivo using miniprobe-based confocal fluorescence microscopy.

BACKGROUND & AIMS: The preoperative diagnosis of cholangiocarcinoma is associated with a low sensitivity. To overcome this limitation, a new imaging modality was evaluated to detect neoplasia in vivo in the biliary tract. METHODS: Fourteen patients with biliary strictures were examined. Mucosal imaging was performed with a miniaturized confocal laser scanning miniprobe introduced via the accessory channel of a cholangioscope. Thereafter, targeted biopsy specimens were taken from the same regions. RESULTS: All strictures could be reached. Presence of irregular vessels use confocal laser microscopy enabled prediction of neoplasia with an accuracy rate of 86%, sensitivity of 83%, and specificity of 88%. The respective numbers for standard histopathology were 79%, 50%, and 100%. The mean signal-to-noise-ratio of laser microscopic images acquired from malignant strictures differed significantly from those of benign origin (1.8 +/- 0.8 vs 2.6 +/- 1.0; P = .005). CONCLUSIONS: Miniprobe-based confocal laser scanning microscopy considerably increases sensitivity for the detection of biliary neoplasia and therefore represents a promising diagnostic approach.

Percutaneously assisted endoscopic surgery using a new PEG-minitrocar for advanced endoscopic submucosal dissection (with videos).

BACKGROUND: For endoscopic submucosal dissection (ESD), adequate exposure and visualization of the submucosa for controlled dissection is of eminent importance. OBJECTIVE: To determine the feasibility and safety of percutaneously assisted endoscopic surgery (PA-ES) with a new prototype PEG-minitrocar (PMT) for advanced ESD in a porcine model. INTERVENTIONS: Placement of the PMT was done in all pigs by the use of a modified pull-through technique. After endoscopic incision of the mucosa, traction was provided for ESD by grasping the incisional margins of the mucosa with a rigid forceps introduced through the PMT, enabling stepwise dissection of the exposed submucosa under direct vision. MAIN OUTCOME MEASUREMENTS: Feasibility and safety of the new PMT for PA-ES and en bloc resection of prespecified mucosal areas. RESULTS: The study started with acute experiments in 8 animals, followed by a 10-day survival study in another 8 pigs. A total of 20 mucosal pieces were resected. The sizes of the resected pieces varied up to 7.5 x 4.0 cm ex vivo. All but one could be resected en bloc. Percutaneous assistance resulted in an excellent exposure of the submucosal space and enabled stepwise dissection of the submucosal connective tissue. Neither the PMT nor advanced ESD led to relevant complications. CONCLUSIONS: We demonstrated the feasibility and safety of a new PMT for advanced ESD. With the use of PA-ES, mucosal pieces of various sizes can be resected en bloc in gastric locations that are difficult to access by flexible endoscopy alone.

Midazolam-pain, but one cannot remember it: a survey among Southern German endoscopists.

BACKGROUND: Benzodiazepines, especially midazolam, are the most frequently used agents for gastrointestinal endoscopy worldwide. Among other parameters the quality of sedation is determined by patients' satisfaction assessed after endoscopy. This approach is misleading as the potent amnestic effect of midazolam conceals pain actually suffered during the endoscopic procedure involving distraction of the endoscopists from their actual tasks by audible reactions and defense movements. In this study, we eliminated the influence of patients' amnesia on the assessment of the quality of sedation and rather interviewed endoscopists and their assistant personnel about their experience with midazolam sedation. We replaced the mostly vague term 'compliance' by terms which unequivocally describe the reactions of the patient during an unpleasant endoscopy. METHODS: A short survey consisting of 12 questions was developed. The questionnaires were distributed to the participants - 115 endoscopists and their assistants - of a tutorial about sedation for gastrointestinal endoscopy in three major Southern German cities. The questionnaire retrieved the endoscopists' experience regarding patients' discomfort or pain under sedation with midazolam, their wish for better sedative agents, their preferred sedative regimens, their medical specialty and their professional experience. RESULTS: Participants were highly experienced with the majority having more than 10,000 procedures and a median of 18 years of endoscopic experience; 77% of endoscopists utilized midazolam for sedation. Ninety-eight percent of the questioned physicians felt that patients have pain during endoscopy with midazolam+/-opioid, but do not remember later. Ninety-two percent reported that it happens that patients moan aloud because of pain and almost half of the endoscopists (48%) reported of screaming. The majority of the endoscopists (91%) reported fierce defense movements with midazolam or the need to hold the patient down on the examination couch because of fierce movements, respectively (75%). Seventy percent of the endoscopists wished to have the rooms for endoscopy preferably soundproof away from the waiting room and 93% wished for better sedative agents. CONCLUSIONS: Midazolam was rated as insufficient for sedation by both endoscopists and their assistant personnel. A wish for better sedative drugs exists.

A novel mechanical simulator for cannulation and sphincterotomy after Billroth II or Roux-en-Y reconstruction.

INTRODUCTION: In patients with Billroth II (B II) or Roux-en-Y anatomy, endoscopic retrograde cholangiopancreatography (ERCP) is demanding. Here, we describe a novel simulator with simulated fluoroscopy for cannulation and sphincterotomy training in such situations. METHODS: A custom-made simulation system was built based upon a common chassis of a series of previously described ERCP simulators. The papilla is made out of organic material and can be cut by high frequency current. The advancement of guidewires and other instruments within transparent mock bile ducts can be viewed in the window of the simulator without the need for fluoroscopy. The ERCP B II/Roux-en-Y simulation system was first evaluated during an ERCP course. RESULTS: There were no technical problems related to the novel simulator during the course. After sphincterotomy, the organic papillae could easily be exchanged within a few seconds. Overall, the novel B II/Roux-en-Y simulator achieved favorable results by trainees and expert endoscopists in all categories assessed. CONCLUSIONS: The new B II/Roux-en-Y mechanical simulator is simple and practicable. A first evaluation during an ERCP course showed promising results.

A new peroral mother-baby endoscope system for biliary tract disorders.

AIM: To investigate a new mother-baby system, consisting of a peroral cholangioscope and a duodenoscope in patients regarding its feasibility. METHODS: In the study period from January 2007 to February 2010, 76 consecutive patients (33 men, 43 women; mean age 63 years old) were included in this pilot series. Endoluminal images and biopsies were obtained from 55 patients with indeterminate strictures, while 21 patients had fixed filling defects. The diagnostic accuracy of peroral cholangioscopy (POCS) in the visualization of strictures and tissue sampling was evaluated, and therapeutic success was monitored. Follow-up was performed over at least 9 mo. RESULTS: A total of 55 patients had indeterminate strictures. Using the criteria "circular stenosis" and "irregular surface or margins", POCS correctly described 27 out of 28 malignant biliary strictures and 25 out of 27 benign lesions (sensitivity, 96.4%; specificity, 92.6%, diagnostic accuracy 94.5%). Visually targeted forceps biopsies were performed in 55 patients. Tissue sampling during POCS revealed malignancy in 18 of 28 cases (sensitivity: 64.3%). In 21 patients with fixed filling defects, 10 patients with bile duct stones were successfully treated with conventional stone removal. Nine patients with difficult stones (5 giant stones and 4 intrahepatic stones) were treated with visually guided laser lithotripsy. Two patients in the group with unclear fixed filling defects had bile duct adenoma or papillary tumors and were surgically treated. CONCLUSION: The new 95 cm POCS allows for accurate discrimination of strictures and fixed filling defects in the biliary tree, provides improved sensitivity of endoscopically guided biopsies and permits therapeutic approaches for difficult intrahepatic stones.

A new experimental model to allow use of clinical-scale endoscopes in small-animal tumor models.

BACKGROUND: The evaluation of novel endoscopes may require testing in experimental tumor models, particularly when employing new biomarkers. Tumor models, however, exist almost exclusively in small animals. Therefore, we aimed to develop an experimental setting that allows the use of clinical-scale endoscopes in small animals. METHODS: In our approach, the proximal large bowel with intact blood supply is exposed on a movable and height-adjustable table. The endoscope's tip may be inserted into the bowel; the dark environment of the bowel lumen in vivo is simulated by mounting a light-tight curtain around the endoscope. Proof-of-principle experiments were done in Wag/Rij rats following cecal injection of the cell line R1H. RESULTS: Using high-definition television white-light endoscopy, narrow-band and autofluorescence imaging, and miniprobe-based confocal laser microscopy (CLM) marked differences were observed between normal mucosa and tumors. Depending on the techniques, mean examination times ranged from 3 to 10 minutes. Even after 90 minutes the colon displayed an intact blood supply, imaged by Evans blue injection and by CLM. CONCLUSION: These experiments demonstrate that our model allows in vivo examination of small-animals by clinical-scale endoscopes. Therefore, it may be useful for evaluation, at various stages of GI carcinogenesis, of both new biomarkers and endoscopic technologies.

Submucosal endoscopy: a novel approach to en bloc endoscopic mucosal resection (with videos).

BACKGROUND: The submucosal layer is of eminent importance for endoscopic mucosal resection (EMR) in the GI tract. OBJECTIVE: Development of submucosal endoscopy, which allows diagnostic and therapeutic endoscopy of the submucosal space (SS) in the esophagus. DESIGN: Acute experiments in a live porcine model. INTERVENTIONS: An area in the esophagus was marked with a diathermic probe to define a mucosal piece for resection. After local infiltration, a 1- to 2-cm transverse incision was performed 1 to 2 cm proximal and distal of these margins. We entered the SS with a flexible small-caliber videoendoscope through the proximal incision and dissected the fibrous submucosal connective tissue in a longitudinal direction with a blunt forceps. For EMR, the lifted mucosa was subsequently separated by use of an insulated-tip hook needle-knife. MAIN OUTCOME MEASUREMENTS: En bloc resection of prespecified mucosal areas. RESULTS: A total of 15 mucosal pieces were resected in 4 pigs. The size of the resected pieces varied from 1.6 cm x 0.9 cm to 7.4 cm x 1.7 cm ex vivo. In a fifth pig, 2 circular mucosectomies (lengths 3.0 cm and 1.6 cm) were done. All mucosal pieces could be completely resected en bloc. The endoscopic view in the SS was excellent. There were no procedure-related complications. LIMITATIONS: The method has not yet been evaluated in humans. CONCLUSIONS: Entering the SS for submucosal endoscopy is a novel, innovative, and practicable method for the dissection of mucosal neoplastic lesions. We demonstrated that mucosal areas of various sizes could be resected en bloc without complications.

ERCP or EUS for tissue diagnosis of biliary strictures? A prospective comparative study.

BACKGROUND: The accuracy of ERCP-based brush cytology or forceps biopsy for tissue diagnosis is relatively low (usually not exceeding 70%). By contrast, reported accuracy rates for EUS-guided FNA of pancreatobiliary masses are over 80%. This prospective study compared these two modalities for the first time in the diagnosis of indeterminate biliary strictures and pancreatic tumors. METHODS: Fifty consecutive patients (29 men, 21 women; mean age 62.1 years) with obstructive jaundice in whom a tissue diagnosis was required were included. During ERCP, intraductal specimens were obtained with a forceps and with two different types of brush (conventional and spiral suction) in random order. During EUS, only visible mass lesions or localized bile duct wall thickening were aspirated (22-gauge needle), with at least two passes yielding material sufficient for assessment. A cytopathologist was not present in the procedure room to evaluate specimen adequacy. The reference methods were surgery, other biopsy results, follow-up until death, or the conclusion of the study (mean follow-up 20 months). RESULTS: The final diagnoses were malignancy, 28 (16 pancreatic, 12 biliary), and benign biliary stricture, 22. Sensitivity and specificity for ERCP-guided biopsy were 36% and 100%, respectively; for ERCP-guided cytology (when using conventional and spiral suction brushes), 46% and 100%, respectively; and for EUS-guided FNA, 43% and 100%, respectively. If the punctured lesions are considered (n=28) alone, the sensitivity of EUS-guided FNA was 75%. In general, sensitivity was better for ERCP-based techniques in the subgroup biliary tumor (ERCP 75% vs. EUS 25%), whereas EUS-guided biopsy was superior for pancreatic mass (EUS 60% vs. ERCP 38%). CONCLUSIONS: For biliary strictures, combined ERCP- and EUS-guided tissue acquisition seems to be the best approach to tissue diagnosis. From a clinical standpoint, it appears reasonable, when a tissue diagnosis is required, to start with ERCP if biliary malignancy is suspected and with EUS when a pancreatic tumor is thought to be the cause of a biliary stricture.