Endoscopic ultrasonography.
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Bile Duct Diseases↗
Biomedical subjects
M J Bruno
Publications and source records attributed to M J Bruno.
Mechanisms of biliary stent clogging: confocal laser scanning and scanning electron microscopy.
BACKGROUND AND STUDY AIMS: Endoscopic insertion of plastic biliary endoprostheses is a well-established treatment for obstructive jaundice. The major limitation of this technique is late stent occlusion. In order to compare events involved in biliary stent clogging and identify the distribution of bacteria in unblocked stents, confocal laser scanning (CLS) and scanning electron microscopy (SEM) were carried out on two different stent materials - polyethylene (PE) and hydrophilic polymer-coated polyurethane (HCPC). PATIENTS AND METHODS: Ten consecutive patients with postoperative benign biliary strictures were included in the study. Two 10-Fr stents 9 cm in length, one made of PE and the other of HCPC, were inserted. The stents were electively exchanged after 3 months and examined using CLS and SEM. RESULTS: No differences were seen between the two types of stent. The inner stent surface was covered with a uniform amorphous layer. On top of this layer, a biofilm of living and dead bacteria was found, which in most cases was unstructured. The lumen was filled with free-floating colonies of bacteria and crystals, surrounded by mobile laminar structures of mucus. An open network of large dietary fibers was seen in all of the stents. CONCLUSIONS: The same clogging events occurred in both PE and HCPC stents. The most remarkable observation was the identification of networks of large dietary fibers, resulting from duodenal reflux, acting as a filter. The build-up of this intraluminal framework of dietary fibers appears to be a major factor contributing to the multifactorial process of stent clogging.
Adult↗
Voltage-gated ion channels in nociceptors: modulation by cGMP.
In tissue or nerve injury, proinflammatory mediators are released that can modulate a variety of ion channels found in nociceptors. The changes in channel activity, which primarily occurs through changes in intracellular pathways, may lead to the pathological states of hyperalgesia and allodynia. To understand further the regulatory mechanisms underlying the changes in channel activity, we used whole cell patch-clamp recordings from capsaicin-sensitive nociceptive neurons in rat trigeminal ganglion neurons to examine how the cGMP-dependent pathways may regulate ion channel function. Addition of the 8-(4-chlorophenylthio)-3',5' (CPT)-cGMP, a membrane permeant modulator of ion channels, decreased the number of evoked action potentials by 36% and inhibited the tetrodotoxin-resistant (TTX-R) sodium currents and IA potassium currents by 37 and 32%, respectively. Delayed rectifier potassium (IK) currents were unaffected, suggesting that the effects of CPT-cGMP are unlikely to arise from a nonspecific effect on channel activity as a consequence of the adsorption of amphipathic CPT-cGMP molecules to the membrane's bilayer component. This conclusion was reinforced by the lack of changes in gramicidin A channel function in the presence of CTP-cGMP. In summary, the activation of the cGMP-dependent pathways reduces nociceptor excitability, in part, by decreasing the activity of voltage-gated TTX-R sodium channels. This pathway may be a target for efforts to produce selective analgesics.
8-Bromo Cyclic Adenosine Monophosphate↗
Self-expanding metal stents in benign biliary strictures due to chronic pancreatitis.
BACKGROUND AND STUDY AIMS: In selected patients with chronic pancreatitis in whom conventional plastic stenting fails and in whom surgery is contraindicated or declined, insertion of a biliary self-expanding metal stent (SEMS) may be a valuable treatment option. PATIENTS AND METHODS: Between 1994 and 1999, 13 patients with chronic pancreatitis received SEMS for benign biliary strictures (four women and nine men; mean age 56). The indications for SEMS placement were: contraindication to surgery (n = 10), presumed inoperable pancreatic carcinoma (n = 1), concomitant unresectable lung cancer (n = 1), and declined surgery (n = 1). The success of treatment was defined as adequate biliary drainage due to SEMS therapy. RESULTS: The mean follow-up period was 50 months (range 6 days - 86 months). Nine patients (69 %) were successfully treated with SEMS therapy: a patent first SEMS (n = 5); a patent second SEMS inserted through the first SEMS (n = 3); and one patent SEMS after balloon cleaning. SEMS treatment was not successful in four patients (due to stent migration in one case and occlusion in three ). The mean patency period of the SEMS was 60 months (95 % CI, 43 months - 77 months). At 33 months, the probability of adequate biliary drainage with SEMS therapy was 75 %. CONCLUSIONS: SEMS therapy was safe and provided successful and prolonged biliary drainage in a selected group of patients with benign biliary strictures due to chronic pancreatitis in whom surgical intervention was not possible or desirable.
Adult↗
Endoscopic augmentation of the lower esophageal sphincter for the treatment of gastroesophageal reflux disease: multicenter study of the Gatekeeper Reflux Repair System.
BACKGROUND AND STUDY AIMS: The safety and effectiveness of the Gatekeeper Reflux Repair System (Medtronic Europe, Tolochenaz, Switzerland) in the treatment of gastroesophageal reflux disease (GERD) was evaluated. This new, reversible treatment modality involves the endoscopic introduction of expandable polyacrylonitrile-based hydrogel prostheses into the esophageal submucosa to augment the lower esophageal sphincter (LES). PATIENTS AND METHODS: For this study, data from two prospective, nonrandomized European multicenter trials were pooled. Sixty-nine GERD patients with heartburn and regurgitation and abnormal esophageal acid exposure (24-h pH < 4.0 for > 4 % of the total time) who had responded to proton-pump inhibitor (PPI) therapy were recruited, and 68 were treated with up to six prostheses placed at the gastroesophageal junction. Patients underwent esophageal manometry, endoscopy, 24-h pH-metry, and symptom scoring at intake and 1, 3, and 6 months after the procedure. RESULTS: A total of 77 procedures were performed in 67 patients, and a total of 270 prostheses were placed (mean 4.3 per procedure). At 1 and 6 months, 80.4 % and 70.4 % of the prostheses were retained, respectively. At 6 months, 24-h pH-metry outcomes with pH < 4.0 for > 4.0 % of the time decreased from 9.1 % to 6.1 % (n = 45; P < 0.05). Median LES pressure increased significantly from 8.8 mmHg at baseline to 13.8 mmHg at 6 months (n = 42, P < 0.01). Median GERD heartburn-related quality-of-life scores improved significantly from 24.0 to 5.0 (n = 53, P < 0.01) in patients no longer receiving PPI therapy. Two serious adverse events (3.0 %) occurred. Both patients recovered uneventfully. Prostheses were endoscopically removed from one patient without any adverse events. CONCLUSIONS: The Gatekeeper Reflux Repair System is a safe endoscopic treatment modality that significantly improves GERD symptoms and has objective effects on acid reflux.
Adult↗
A prospective randomized study of hydrophilic polymer-coated polyurethane versus polyethylene stents in distal malignant biliary obstruction.
BACKGROUND AND STUDY AIMS: Hydrophilic polymer-coated polyurethane (HPCP) stents have a low friction coefficient and a hydrophilic layer, which may reduce biofilm formation and increase the period of stent patency. We compared the patency rates with this new stent with the standard Amsterdam-type polyethylene (PE) stent in a prospective randomized trial. PATIENTS AND METHODS: One hundred patients with an unresectable distal malignant bile duct stricture without a previous drainage procedure were randomly assigned to receive either a HPCP stent or a PE stent. The diameter (10 Fr), length (9 cm) and stent design (Amsterdam type) were similar in both stents. Nine patients were excluded. Forty-four patients received an HPCP stent and 47 patients a PE stent. The diagnoses included carcinoma of the pancreas (n = 78), papilla (n = 1), bile duct (n = 10), and metastases (n = 2). RESULTS: Stent insertion was successful in all patients. Stent dysfunction occurred in 27 of the HPCP stents and 20 of the PE stents, with median stent patency periods of 77 days (95 % CI, 53-101 days) for HPCP stents and 105 days (95 % CI, 42-168 days) for PE stents. The patency period was significantly longer for the PE stent (P = 0.04). Early complications occurred in four patients (4%), one in the HPCP group and three in the PE group. CONCLUSION: Hydrophilic polymer-coated polyurethane stents do not prolong the patency period of biliary stents. In fact, the current standard treatment using polyethylene stents in patients with distal malignant biliary obstruction showed a significantly longer patency period.
Aged↗
Endoscopic ultrasonography.
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Clinical Trials as Topic↗
Caerulein induced pancreatitis.
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Acute Disease↗
Magnification endoscopy, high resolution endoscopy, and chromoscopy; towards a better optical diagnosis.
In the past few years, optical magnification endoscopy and chromoscopy have gained renewed interest in the West as a means for the early detection of minute lesions in patients with Barrett's oesophagus and in patients referred for colonic cancer screening. In Barrett's oesophagus, the vast majority of data on the use of chromoscopy deals with the application of methylene blue. Conventional videoendoscopy in combination with methylene blue staining improves the detection of Barrett's mucosa. A correlation has been shown between variation and intensity of staining and histologically verified stages of dysplasia or cancer. Magnification endoscopy and chromoscopy improve the detection of colonic non-polypoid lesions associated with neoplasia and carcinoma. Pitt pattern analysis enables the distinction of non-neoplastic non-polypoid lesions (type I and II) from neoplastic type non-polypoid lesions (type III-V) with great accuracy. It is certain that "old fashioned" chromoscopy combined with advanced endoscopic technology carry a great diagnostic potential and should be further put to the test for use in daily clinical practice.
Barrett Esophagus↗
Strain rate dependent orthotropic properties of pristine and impulsively loaded porcine temporomandibular joint disk.
The purpose of this study was to characterize the tensile stress-strain behavior of the porcine temporomandibular joint (TMJ) disk with respect to collagen orientation and strain rate dependency. The apparent elastic modulus, ultimate tensile strength, and strain at maximum stress were measured at three elongation rates (0.5, 50, and 500 mm/min) for dumbbell-shaped samples oriented along either anteroposterior or mediolateral axes of the disks. In order to study the effects of impact-induced fissuring on the mechanical behavior, the same properties were measured along each orientation at an elongation rate of 500 mm/min for disks subjected to impulsive loads of 0.5 N. s. The results suggested a strongly orthotropic nature to the healthy pristine disk. The values for the apparent modulus and ultimate strength were 10-fold higher along the anteroposterior axis (p < or = 0.01), which represented the primary orientation of the collagen fibers. Strain rate dependency was evident for loading along the anteroposterior axis but not along the mediolateral axis. No significant differences in any property were noted between pristine and impulsively loaded disks for either orientation (p > 0.05). The results demonstrated the importance of choosing an orthotropic model for the TMJ disk to conduct finite element modeling, to develop failure criteria, and to construct tissue-engineered replacements. Impact-induced fissuring requires further study to determine if the TMJ disk is orthotropic with respect to fatigue.
Animals↗
Is endoscopic balloon dilation for removal of bile duct stones associated with an increased risk for pancreatitis or a higher rate of hyperamylasemia?
BACKGROUND AND STUDY AIMS: We studied the rate of pancreatitis and asymptomatic hyperamylasemia after endoscopic balloon dilation (EBD) and endoscopic sphincterotomy (EST) for removal of bile duct stones. PATIENTS AND METHODS: Patients with bile duct stones of all sizes were randomly allocated to undergo EBD (8-mm dilation balloon) or EST. Pancreatitis was defined as epigastric pain combined with at least a threefold rise in serum amylase at 24 hours after the endoscopic retrograde cholangiopancreatography (ERCP). Asymptomatic hyperamylasemia was defined as a threefold rise in serum amylase without epigastric pain. RESULTS: There were 180 patients (67 men, 113 women; mean age 67, SD 16.2) available for analysis. Complete stone removal after a single ERCP was achieved in 82 (88%) of 93 EBD patients and in 81 (93%) of 87 EST patients (P = 0.38). Mechanical lithotripsy was used more frequently in the EBD group (31% vs. 13%, P = 0.005). Early complications occurred in 16 EBD patients (17%) and in 19 EST patients (22%) (P = 0.46). Pancreatitis was observed in seven patients in each group (8%). Logistic regression identified no significant predictors for the occurrence of pancreatitis. Asymptomatic hyperamylasemia occurred in 21 EBD patients (23%) vs seven EST patients (8%) (P = 0.008). Logistic regression identified EBD as the only significant predictor for asymptomatic hyperamylasemia: odds ratio 2.9 (95% confidence interval (CI) 1.1 to 7.3, R2 = 0.02). CONCLUSIONS: We did not observe a difference in the rate of pancreatitis between EBD and EST. Asymptomatic hyperamylasemia was observed more frequently after EBD. Although asymptomatic hyperamylasemia is not a clinical entity, this finding may indicate that EBD causes more irritation of the pancreas than EST.
Aged↗
A randomized trial of endoscopic balloon dilation and endoscopic sphincterotomy for removal of bile duct stones in patients with a prior Billroth II gastrectomy.
BACKGROUND: A prior Billroth II gastrectomy renders endoscopic sphincterotomy (EST) more difficult in patients with bile duct stones. Endoscopic balloon dilation (EBD) is a relatively easy procedure that potentially reduces the risk of bleeding and perforation. METHODS: Thirty-four patients with bile duct stones and a previous Billroth II gastrectomy were randomized to EST or EBD. Complications were graded in a blinded fashion. Results were compared with those for a group of 180 patients with normal anatomy from a previously reported randomized trial of EBD versus EST. RESULTS: All stones were removed in 1 endoscopic retrograde cholangiopancreatography in 14 of 16 patients who underwent EBD versus 14 of 18 who had EST (p = 1.00). Mechanical lithotripsy was used in 3 EBD procedures versus 4 EST procedures (p = 1.00). Early complications occurred in 3 patients who had EBD versus 7 who underwent EST (p = 0.27). Three patients had bleeding after EST; 1 patient had mild pancreatitis after EBD. The median time required for stone removal was 30 minutes in both groups. Compared with patients with a normal anatomy, patients with a previous Billroth II gastrectomy had a significantly increased risk of bleeding after EST (17% vs. 2%, relative risk = 7.25, p < 0.05). CONCLUSIONS: A prior Billroth II gastrectomy renders EST more difficult and increases the risk of a complication. EBD in these patients is easy to perform and is not associated with an increased need for mechanical lithotripsy or a longer procedure time. The risk of bleeding is virtually absent after EBD and the risk of pancreatitis after EBD seems not significantly increased in these patients.
Adult↗
Long-term follow-up after biliary stent placement for postoperative bile duct stenosis.
BACKGROUND: The outcome of temporary biliary stent placement for postoperative bile duct stenosis was retrospectively evaluated with the main aim of assessing long-term complications after stent removal. METHODS: ERCP was performed between 1981 and 1991 in 74 patients with postoperative bile duct stenoses. Two 10F stents were inserted for a maximum of 12 months with stent exchange every 3 months to avoid cholangitis caused by clogging. RESULTS: Stent insertion failed in 11 patients with complete and 4 patients with incomplete biliary obstruction. Early complications occurred in 14 patients (19%) including 2 deaths. Therefore 57 patients were included in the stent phase of the study. In 10 patients the referring physician did not adhere to the treatment protocol, and nonelective stent exchange for jaundice and/or cholangitis was necessary in 7 (70%). Of the 47 patients treated according to protocol, complications developed in 40% during the period with stents in situ. Stents were eventually removed in 44 patients who were subsequently followed for a median of 9.1 years. Late complications developed in 15 patients (34%) including recurrent stenosis in 9 (20%). All cases of recurrent stenosis occurred within 2 years of stent removal. CONCLUSIONS: Endoscopic treatment is feasible in 80% of patients who undergo an ERCP for postoperative bile duct stenosis. After stent insertion and during the time with stents in situ, complications occur at a significant rate but are usually mild or reflect the patient's underlying condition. After stent removal, recurrent stenosis develops in 20% of patients within 2 years of stent removal. Endoscopic treatment should be the initial management of choice for postoperative bile duct stenosis.
Adult↗
Current insights into the pathogenesis of acute and chronic pancreatitis.
For a long time the pathogenesis of pancreatitis has remained enigmatic. Recent developments in cellular and molecular biology, however, have provided a tremendous research impetus and some of its mysteries are finally being disclosed. This review discusses the implications of the discovery of the disease gene in hereditary pancreatitis and outlines recent advances in our understanding of the mechanism and site of trypsinogen activation and the role of immunocytes and cytokines in acute pancreatitis. With respect to chronic pancreatitis, this review focuses on its association with mutations in the cystic fibrosis conductance regulator gene and the mechanisms of pancreatic fibrosis. These advances in our knowledge of the pathogenesis of the disease, together with emerging biotechnological techniques, will boost the development of future therapies aimed at strategically targeting key pathophysiological processes involved in acute and chronic pancreatitis.
Acute Disease↗
[Gastro-intestinal surgery and gastroenterology. V. Chronic pancreatitis: gastroenterologic aspects].
Chronic pancreatitis causes irreversible damage to the pancreatic parenchyma and ultimately leads to exo- and endocrine insufficiency. In the Western world, alcohol is the main cause of chronic pancreatitis; part of the patients with idiopathic or alcoholic pancreatitis conceivably have a raised sensitivity to the toxic effects of alcohol because of a certain genetic predisposition. The most striking symptom, severe recurrent or persistent pain is often difficult to manage. Various forms of imaging examination provide complementary information on lesions of the pancreatic parenchyma, the pancreatic duct, the bile ducts and adjacent structures; ultrasonoscopy is the technique of first choice in case of suspicion of a pancreatic disorder. Endoscopic therapies are booming: sphincterotomy, calculus extraction, insertion of an endoprosthesis in the pancreatic duct and drainage of pseudocysts (transpapillary or through the jejunum or stomach).
Alcoholism↗
[Diagnosis and treatment of cholelithiasis].
Most patients with gallbladder stones are asymptomatic and do not require treatment. Biliary colics are the main indication for laparoscopic cholecystectomy: the treatment of choice for gallbladder stones. Dyspepsia is not an indication for treatment of gallstones. The indications for bile salt therapy and extracorporeal lithotripsy are limited. Acute cholecystitis should be treated with cholecystectomy à chaud whereas longstanding cholecystitis is preferably treated with cholecystectomy à froid. Bile duct stones are mainly treated endoscopically during endoscopic retrograde cholangiopancreatography (ERCP): pancreatitis, bleeding and perforation are the main complications. Prior to cholecystectomy, an ERCP is indicated in case of cholangitis, severe pancreatitis, persisting jaundice, bile duct stones on ultrasonography, or the combination of dilated ducts and abnormal liver function tests. After endoscopic stone removal, a cholecystectomy is indicated for patients < 50 years but a 'wait and see' policy is justified in elderly patients.
Acute Disease↗
Palliation of patients with esophagogastric neoplasms by insertion of a covered expandable modified Gianturco-Z endoprosthesis: experiences in 153 patients.
BACKGROUND: We aimed to evaluate the short- and long-term outcomes of treatment by insertion of a covered expandable modified Gianturco-Z endoprosthesis (Song stent) in patients with esophagogastric malignancies. METHODS: Consecutive patients with esophagogastric malignancies in whom a Song stent was inserted were included. Data were retrieved retrospectively. Dysphagia before and after stent placement was scored on a 5-point scale. Early (less than 30 days) and late complications (more than 30 days) were scored. RESULTS: Analysis included 164 stents in 153 patients. Indications for stent placement were dysphagia and/or fistulas/perforations. The dysphagia score improved from a mean of 3.7 to 2.2 after stent placement (p < 0.0001). Fistulas/perforations sealed in 87% of cases. Early complications after stent placement occurred in 29.9% of cases. These included stent migration (4.3%), stent obstruction (6. 1%), aspiration pneumonia (4.9%), bleeding (4.3%), perforation (1. 8%), and pain (15.9%). Late complications occurred in 27.8% of cases. These included stent migration (2.6%), stent obstruction (9.6%), aspiration pneumonia (2.6%), bleeding (7.0%), perforation (0.9%), and pain (12.2%). The 30-day mortality was 26%. Death related to stent placement occurred in 3.3%. CONCLUSION: Insertion of a Song expandable endoprosthesis in patients with esophagogastric malignancies significantly improves dysphagia, is successful in sealing fistulas/perforations, and is associated with acceptable morbidity and mortality rates.
Aged↗
Black esophagus: a view in the dark.
A 73-year-old man had a low anterior resection for a villous adenoma in the rectosigmoid. On the 4th day after surgery, he suddenly developed severe interscapular pain. Aortic dissection was ruled out, but endoscopy showed black mucosa of the entire esophagus. With conservative treatment, including proton pump inhibition, he recovered completely. We hypothesize that a transient gastric outlet obstruction and massive gastroesophageal reflux played a significant role in the etiology of this rare and alarming, but, in this case, completely reversible, syndrome.
Acute Disease↗