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Biomedical subjects

Peter B Cotton

Publications and source records attributed to Peter B Cotton.

At least 19 recordsLinked to original sources
PubMed2006

The MCP-1 -2518 A/G polymorphism is not a susceptibility factor for chronic pancreatitis.

BACKGROUND AND AIMS: Chronic pancreatitis (CP) is an inflammatory process initiated by recurrent acute pancreatitis and characterized by progressive parenchyma destruction and fibrosis. Genetic factors influence susceptibility and modify progression. The monocyte chemotactic protein-1 (MCP-1) -2518 G allele, which modifies the severity of acute pancreatitis, was investigated as a susceptibility factor for CP. METHODS: A genetic association study was performed on 177 CP patients and 116 healthy controls from the NAPS2 Study. The MCP-1 A/G genotype was determined by RFLP and confirmed by DNA sequencing. RESULTS: Compared to the control group the MCP-1 -2518 genotypes were similar: A/A (57% vs. 50%), A/G (34.5% vs. 40%) and G/G (8.5% vs. 10%). These allele frequencies were not statistically different (p = 0.267). CONCLUSIONS: Although the pro-inflammatory chemokine MCP-1 -2518 G allele is a severity factor for AP, it does not significantly alter susceptibility to CP.

Adolescent↗
PubMed2006

Analysis of 59 ERCP lawsuits; mainly about indications.

BACKGROUND: This study reports the analysis of a personal series of 59 cases in which ERCP malpractice was alleged. METHODS: Half of the cases involved pancreatitis; 16 suffered perforation after sphincterotomy (8 of which involved pre-cutting), and 10 had severe biliary infection. There were 2 esophageal perforations. Fifteen of the patients died. The most common allegation (54% of cases) was that the ERCP, or the therapeutic procedure, was not indicated. Most of these patients had pain only, usually after cholecystectomy. Negligent performance was alleged in 19 cases, with corroborating evidence in 8. Inadequate postprocedure care was alleged in 5 cases, including 3 with a delayed diagnosis of perforation. Disputes about the extent of the education and consent process were common. RESULTS: The final outcome was available in 40 cases. Sixteen were withdrawn, and 14 were settled. Of the 10 that came to trial, half were defense verdicts. CONCLUSIONS: The lessons are clear. ERCP should be done for good indications, by trained endoscopists with standard techniques, with good documented patient informed consent and communication before and after the procedure. Speculative ERCP, sphincterotomy, and pre-cuts are high-risk for patients and for practitioners.

Bile Duct Diseases↗
PubMed2006

The endoscopic transilluminator: an endoscopic device for identification of the proximal jejunum for transgastric endoscopic gastrojejunostomy.

BACKGROUND: Localization of the proximal jejunum is important for creation of gastrojejunal anastomosis to palliate gastric outlet obstruction or for treatment of obesity with gastric bypass. OBJECTIVE: To facilitate identification of the proximal jejunum during transgastric endoscopic gastrojejunostomy with the use of an endoscopic transilluminator (ET). DESIGN AND SETTING: Acute experiments in a live porcine model. INTERVENTIONS: The ET is a 3500-mm long, 6F radio-opaque tube with a fiberoptic core that lights up at its distal end. When situated in the intestinal lumen, it transilluminates the bowel wall. With the animal under general anesthesia with endotracheal intubation, a colonoscope was advanced to the proximal jejunum. A plastic tube (3500-mm long, 3.5 mm in diameter) was passed through the biopsy channel and placed into the small bowel. The colonoscope was withdrawn, leaving the tube in place. The ET was introduced into the jejunum through the tube. A gastric wall incision was made and the endoscope was advanced to the peritoneal cavity. The transilluminated loop of the proximal jejunum was identified and gastrojejunal anastomosis was made by use of a previously reported endoscopic technique. MAIN OUTCOME MEASUREMENTS: Identification of the proximal jejunum. RESULTS: Eleven pigs (average weight 55 kg) had ET placement. In all of the pigs, placement of the ET was performed easily to the proximal small bowel, and the proximal jejunum was successfully localized by either direct visualization of the transilluminated loop only or with the aid of fluoroscopy. The tip of the ET was usually located about 50 to 70 cm distal to the ligament of Treitz. There were no complications related to the use of ET. LIMITATIONS: The device has not yet been evaluated in humans. CONCLUSIONS: The ET is a safe instrument and can be used to identify the proximal jejunum to facilitate endoscopic gastrojejunostomy.

Animals↗
PubMed2006

Pilot study of the porcine uterine horn as an in vivo appendicitis model for development of endoscopic transgastric appendectomy.

BACKGROUND: Iatrogenic inflammation of the porcine uterine horn may serve as an in vivo appendicitis model for the development of endoscopic transgastric appendectomy. OBJECTIVE: Five female pigs. STUDY DESIGN: Animal study. SETTINGS: General anesthesia. MAIN OUTCOME MEASUREMENTS: Anatomical appearance and technical feasibility. INTERVENTIONS: Three pigs were used to identify an injectable material that would inflame the uterine horn, and 2 pigs were used for a pilot appendectomy. Three types of materials were individually injected into the bilateral uterine horns, and the ideal material to inflame the uterine horn was injected into the right uterine horn for the last 2 pigs. After 24 hours, the injected uterine horns of the first 3 pigs were assessed and a pilot appendectomy was performed in the last 2 pigs. RESULTS: Ethanolamine oleate (EO) injected uterine horns demonstrated similarities to the inflamed human appendix. Simulations of the appendectomy were successfully performed by using the EO model. LIMITATIONS: Suboptimal existing tools. CONCLUSIONS: This preliminary study demonstrated the technical feasibility to create a model for acute appendicitis by using the porcine uterine horn and transgastric appendectomy.

Animals↗
PubMed2006

Simulators in competence assessment and credentialing: prospects and problems.

Systems that simulate endoscopic procedures have considerable potential in assessing endoscopic competence and assisting credentialing, but there are significant problems. If it can be shown that simulation tests correlate with real performance, the questions will be how to pay for the infrastructure and staff and how to motivate endoscopists to use them.

Clinical Competence↗
PubMed2005

Post-sphincterotomy bleeding after the introduction of microprocessor-controlled electrosurgery: does the new technology make the difference?

BACKGROUND: Bleeding as a complication of endoscopic sphincterotomy is influenced by several factors. The objective of this study was to compare rates of bleeding after sphincterotomy performed with two different electrosurgical current generators (Valleylab SSE2L and ERBE ICC200). METHODS: A total of 6179 consecutive reports of ERCP were analyzed to compare the frequency of endoscopically and clinically evident bleeding after sphincterotomy when using the Valleylab SSE2L generator (from February 1994 to November 1997) and the ERBE ICC200 generator (from December 1997 to September 2000). Relevant risk factors were assessed by univariate analysis and significant predictors were included in a multiple logistic regression model. RESULTS: A total of 2711 sphincterotomies were performed in 2309 patients (1749 biliary, 962 pancreatic). Endoscopically observed bleeding occurred in 68 patients (5.5%) in the ValleyLab group and 13 (1.2%) in the ERBE group. The ValleyLab generator was independently associated with an increase in endoscopically observed bleeding (OR 4.02: 95% CI[2.13, 7.61], p <0.001). There was no significant difference in clinically evident bleeding between the two groups. CONCLUSIONS: Use of the microprocessor-controlled ERBE electrosurgical generator for endoscopic sphincterotomy was associated with a significantly lower frequency of endoscopically observed bleeding but not clinically evident bleeding.

Adult↗
PubMed2005

Peroral transgastric endoscopic ligation of fallopian tubes with long-term survival in a porcine model.

BACKGROUND: We have previously reported the feasibility and safety of the peroral transgastric endoscopic approach for diagnostic peritoneoscopy, liver biopsy, and gastrojejunostomy with long-term survival in a porcine model. This approach eliminates incisions of the abdominal wall, providing a less invasive alternative to diagnostic and therapeutic laparoscopy. We now report successful performance of peroral endoscopic transgastric ligation of Fallopian tubes with long-term survival in a porcine model. METHODS: Six female 50-kg pigs had general anesthesia and irrigation of the stomach with an antibiotic solution. Gastric puncture was performed with needleknife electrocautery followed by balloon dilatation of the tract with 20-mm TTS dilating balloon (Microvasive). A standard upper endoscope that underwent high-level disinfection and gas sterilzation was advanced into the peritoneal cavity through a sterile overtube. Both Fallopian tubes were identified and one was ligated using Olympus Endoloops. The other patent tube served as a control. Tubal patency was evaluated by hysterosalpingogram before and after ligation. After a follow-up period of 2-3 weeks, the pigs were sacrificed for postmortem examination. RESULTS: The Fallopian tubes were easily accessed, identified and ligated in all 6 pigs. In each pig, fluoroscopy confirmed complete obstruction of the ligated tube with preserved patency of the other tube. All pigs survived well and ate heartily without any ill-effects. Postmortem examination did not reveal any peritonitis or intra-abdominal adhesions. The Endoloops were in place with complete obstruction of the ligated tubes and patency of the controls. Histopathologic examination of the tubes showed chronic inflammatory infiltrates without abscesses. CONCLUSIONS: The peroral endoscopic transgastric approach to ligation of the Fallopian tubes with long-term survival is technically feasible and safe in a porcine model. The endoscopic transgastric approach to the peritoneal cavity has potential for a wide array of diagnostic and therapeutic procedures.

Animals↗
PubMed2005

Predictors of outcome in pancreatic duct disruption managed by endoscopic transpapillary stent placement.

BACKGROUND: The aim of this study was to identify predictors of outcome for pancreatic duct (PD) disruption managed by endoscopic transpapillary stent insertion. METHODS: An endoscopy database was used to identify patients with PD disruption, defined as extravasation of contrast from the PD during ERCP. Data collected included demographic information, the results of imaging studies, management before endoscopic intervention, and outcomes after stent placement. Stents typically were exchanged at intervals of 6 to 8 weeks. Success was defined as clinical and pancreatographic resolution of the PD disruption. RESULTS: Ninety-seven consecutive patients (34 women, 63 men; mean age, 53.7 [12.3] years) with PD disruption seen from 1995 to 2002 were identified. Causes of the disruption were the following: chronic pancreatitis (47), acute pancreatitis (44), operative injury (4), and trauma (2). Transpapillary PD stent insertion was technically successful in 92 (95%) patients; two underwent a combined cystenterostomy. The median duration of stent placement was 58 days (range 4-640 days). The outcome of stent insertion was successful in 52 patients (55%), unsuccessful in 32 (36%), and indeterminate in 8 (9%). On univariate analysis, a partially disrupted PD (p < 0.001), a disruption in the body of the pancreas (p = 0.04), a stent positioned to bridge the disruption (p < 0.001), and a longer duration of stent therapy (p = 0.03) were associated with a successful outcome. On multivariable logistic regression, only a partially disrupted duct and a stent bridging the disruption correlated with a successful outcome. Complications occurred in 6 patients. CONCLUSIONS: Successful resolution of PD disruption by transpapillary stent insertion depends on the type of disruption and the ability to bridge the disrupted duct with a stent.

Adult↗
PubMed2005

The yield and the predictors of esophageal pathology when upper endoscopy is used for the initial evaluation of dysphagia.

BACKGROUND: The utility of EGD when used as an initial test for the evaluation of dysphagia is unclear. The objective was to determine the yield and the predictive factors of significant pathology when EGD is performed as the initial test to evaluate dysphagia. METHODS: This is a retrospective analysis of a computerized database. Data on patients who underwent EGD for dysphagia were retrieved from the endoscopy database of 6 endoscopy units. Patients who had undergone prior esophageal evaluation, failed EGD, or who had a history of prior upper-GI pathology were excluded. Univariate and multivariable logistic regression analyses were performed to evaluate any relation between endoscopic findings and presenting clinical features. RESULTS: A total of 1649 patients with dysphagia (mean age 56.7 years, standard deviation 16.4; M:F 3:2) were analyzed. Abnormal findings at EGD were found in 70% (1150) of the patients, and a major pathology was seen in 54% (898). Male gender (p=0.0001), heartburn (p=0.0007), and odynophagia (p=0.0001) predicted the presence of major pathology. Cancer was found in 4% (70) of patients and was predicted by male gender (p=0.0002), age (p=0.01), and weight loss (p=0.04). The esophagus was normal in 29% (483) of patients and was predicted by female gender (p=0.0001) and the absence of heartburn (p=0.0004) but not age. There was a lack of details on patients' presentation and clinical history and an absence of long-term clinical follow-up. CONCLUSIONS: EGD is an effective and an appropriate tool for the initial evaluation of patients presenting with dysphagia. Early EGD should be considered, particularly, in male patients aged more than 40 years old who concomitantly report heartburn, odynophagia, or weight loss.

Abdominal Pain↗
PubMed2005

Endoscopic suturing without extracorporeal knots: a laboratory study.

BACKGROUND: To eliminate cumbersome extracorporeal knotting, we designed a new endoscopic suturing device, the Eagle Claw V. The efficacy of the new device was tested on the Erlangen model and was compared with the initial extracorporeal knotting version (Eagle Claw II). METHODS: Segments of porcine splenic arteries were placed on the mucosal surface of the anterior wall of a pig stomach. The two ends of the artery were brought out through the gastric wall and were connected to a two-channel manometer. The Eagle Claw V has a curved needle with a detachable tip. After puncturing the tissue, the needle tip was engaged into a catching cartridge, where the suture had been embedded in a tightening mechanism. The suture could be tightened by simply pulling the end. The Eagle Claw V was used to plicate the splenic arteries mounted on the stomach. Suturing was considered secure if the suture could withstand endoluminal pressure greater than 200 mm Hg that lasted at least 10 seconds. RESULTS: Eleven of 15 stitches (73.3%) gained secure plication of the vessels. The suturing time (mean +/- standard deviation 2.93 +/- 0.80 minutes) was significantly faster than that of the Eagle Claw II (9.38 +/- 1.51 minutes). The device consistently achieved penetration of the muscular layer, and 4 of 15 sutures included the serosa. The 4 failures were because of suture breakage in two, thread entanglement in one, and cartridge dislodgement in one. CONCLUSIONS: The present prototype represents significant improvements in the ease of operation and the security of the suture, bringing the technique closer to clinical use for a variety of applications.

Animals↗
PubMed2005

Eagle Claw II: A novel endosuture device that uses a curved needle for major arterial bleeding: a bench study.

BACKGROUND: Control of bleeding from major arteries in the upper-GI tract remains difficult with currently available endoscopic devices. We designed an endosuture device that uses a curved needle and extracorporeal knotting, and assessed the device in stopping arterial bleeding in a bench model. METHODS: Harvested porcine splenic arteries (2-mm diameter) were tunneled submucosally in pig stomach with the open end protruding into an artificially created mucosal defect. The outer end of the vessel was connected to a pulsatile pump, and red ink was infused at a pressure of about 100 mm Hg. The stomach was installed on an Erlangen endo-training model. The suturing device (Eagle Claw II), mounted outside an endoscope, has an eyed, curved needle that carries a 3-0 nylon thread. After puncture, the thread was retrieved by using a hook. Three-throw square knots were tied at the thread extracorporeally and were pushed into place by using a knotting cap. The criteria of successful plication was defined as hemostasis after knotting, no leakage at pressures of >200 mm Hg, and the vessel was completely encircled by the suture. RESULTS: A total of 25 sutures were made with the mean time of 9.38 minutes (standard deviation 1.51). Control of the bleeding was obtained with 17 sutures (68%). The causes for failure were the following: a suture was too shallow (4), a loose knot (2), incorrect suture position (1), and stomach-wall edema (1). CONCLUSIONS: Control of bleeding from large arteries by using endoscopic suturing is possible. Continued refinements of the device are required.

Animals↗
PubMed2005

Endoscopic gastrojejunostomy with survival in a porcine model.

BACKGROUND: We have previously reported the feasibility and the safety of an endoscopic transgastric approach to the peritoneal cavity in a porcine model. We now report successful performance of endoscopic gastrojejunostomy with survival. METHODS: All procedures were performed on 50-kg pigs, with the pigs under general anesthesia, in aseptic conditions with sterilized endoscopes and accessories. The stomach was irrigated with antibiotic solution, and a gastric incision was performed with a needle-knife and a sphincterotome. A standard upper endoscope was advanced through a sterile overtube into the peritoneal cavity. A loop of jejunum was identified, was retracted into the stomach, and was secured with sutures while using a prototype endoscopic suturing device. An incision was made into the jejunal loop with a needle-knife, and the filet-opened ends of the jejunal wall were secured to the gastric wall with a second line of sutures, completing the gastrojejunostomy. OBSERVATIONS: Two pigs survived for 2 weeks. Endoscopy and a radiographic contrast study performed after gastrojejunostomy revealed a patent anastomosis with normal-appearing gastric and jejunal mucosa. Postmortem examination demonstrated a well-healed anastomosis without infection or adhesions. CONCLUSIONS: The endoscopic transgastric approach to create a gastrojejunostomy is technically feasible and can be performed, with survival, in a porcine model.

Animals↗
PubMed2004

Computed tomographic colonography (virtual colonoscopy): a multicenter comparison with standard colonoscopy for detection of colorectal neoplasia.

CONTEXT: Conventional colonoscopy is the best available method for detection of colorectal cancer; however, it is invasive and not without risk. Computed tomographic colonography (CTC), also known as virtual colonoscopy, has been reported to be reasonably accurate in the diagnosis of colorectal neoplasia in studies performed at expert centers. OBJECTIVE: To assess the accuracy of CTC in a large number of participants across multiple centers. DESIGN, SETTING, AND PARTICIPANTS: A nonrandomized, evaluator-blinded, noninferiority study design of 615 participants aged 50 years or older who were referred for routine, clinically indicated colonoscopy in 9 major hospital centers between April 17, 2000, and October 3, 2001. The CTC was performed by using multislice scanners immediately before standard colonoscopy; findings at colonoscopy were reported before and after segmental unblinding to the CTC results. MAIN OUTCOME MEASURES: The sensitivity and specificity of CTC and conventional colonoscopy in detecting participants with lesions sized at least 6 mm. Secondary outcomes included detection of all lesions, detection of advanced lesions, possible technical confounders, participant preferences, and evidence for increasing accuracy with experience. RESULTS: A total of 827 lesions were detected in 308 of 600 participants who underwent both procedures; 104 participants had lesions sized at least 6 mm. The sensitivity of CTC for detecting participants with 1 or more lesions sized at least 6 mm was 39.0% (95% confidence interval [CI], 29.6%-48.4%) and for lesions sized at least 10 mm, it was 55.0% (95% CI, 39.9%-70.0%). These results were significantly lower than those for conventional colonoscopy, with sensitivities of 99.0% (95% CI, 97.1%->99.9%) and 100%, respectively. A total of 496 participants were without any lesion sized at least 6 mm. The specificity of CTC and conventional colonoscopy for detecting participants without any lesion sized at least 6 mm was 90.5% (95% CI, 87.9%-93.1%) and 100%, respectively, and without lesions sized at least 10 mm, 96.0% (95% CI, 94.3%-97.6%) and 100%, respectively. Computed tomographic colonography missed 2 of 8 cancers. The accuracy of CTC varied considerably between centers and did not improve as the study progressed. Participants expressed no clear preference for either technique. CONCLUSIONS: Computed tomographic colonography by these methods is not yet ready for widespread clinical application. Techniques and training need to be improved.

Colonography, Computed Tomographic↗
PubMed2004

Technical outcomes and complications of ERCP in children.

BACKGROUND: The aim of this study was to compare the success and complications of diagnostic and therapeutic ERCP in children (age <18 years) and adult patients. METHODS: A retrospective case-controlled study was conducted in which all children undergoing ERCP at two centers (1994-2002) were identified from endoscopy databases and were matched with adult patients for all variables (e.g., indication, procedure complexity) except age. Outcomes with regard to technical success and complications were compared between the adult and the pediatric cohorts. Grade of procedure complexity and procedure-related complications were defined by using established criteria. RESULTS: A total of 116 children (mean age 9.3 years, range 1 month to 17 years; median age 8.1 years) and 116 matched adult patients (mean age 56.3 years, range 20-83 years; median age 49.7 years) underwent 163 and 173 ERCP procedures, respectively. According to procedure complexity grade, each group included the same number of patients, grade I, 72 patients; grade II, 12 patients; and grade III, 32 patients. Procedure success rate was 97.5% in children vs. 98% in the adult cohort (p= not significant). The complication rate was not significantly different between children and adult patients (3.4% vs. 2.5%). Most complications were of mild severity and encountered only in patients who underwent grade III procedures, with the exception of a single adult in whom moderate post-sphincterotomy bleeding developed after extraction of a large bile duct stone (grade II complexity). CONCLUSIONS: When ERCP is performed in children by expert endoscopists, the success rate is high and the complication rate is low, both being comparable with those for ERCP in adult patients.

Adolescent↗
PubMed2004

Widespread EMR: a new technique for removal of large areas of mucosa.

BACKGROUND: Widespread EMR is a novel technique for resection of large areas of mucosa as a single bloc. Large lesion size (>2 cm) is a recognized limitation of current EMR techniques. This study assessed the technical feasibility, efficacy, and safety of widespread EMR in a porcine model. METHODS: Widespread EMR was performed in 6 pigs. A submucosal fluid cushion was created in the distal esophagus by using a 0.83% solution of hydroxypropyl methylcellulose. A mucosal strip 5 cm in length and including at least 50% of the luminal circumference was marginated by using a prototype cutting device. The proximal end of the mucosa was stripped from the submucosa by using a grasping forceps. The distal end was snare resected. Resected tissue was assessed histologically. Endoscopy was repeated at weeks 1 and 6. At week 6, a second widespread EMR of the mucosa on the wall opposite the initial resection was attempted to create a full circumferential resection. RESULTS: Widespread EMR was completed in all animals. The esophagus was denuded of mucosa in 5-cm lengths that included 50% of the circumference of the lumen. No procedure-related complication was observed. Histologic assessment demonstrated that the resection specimen included mucosa and submucosa but not muscularis propria. Endoscopy at 1 week revealed mucosal regrowth in two animals and ulceration in 4. At week 6, regrowth of mucosa was noted in all animals. The second wide EMR proved to be technically difficult and was associated with perforation, peri-esophageal abscess, and stricture formation. CONCLUSIONS: Wide EMR appears to be technically feasible for removal of large areas of mucosa. Mucosal strips 5 cm long that included over 50% of the luminal circumference were resected safely. Resection was followed by complete regrowth of the mucosa. However, a second wide EMR to create a circumferential resection proved to be technically difficult and unsafe.

Animals↗
PubMed2004

Efficacy of the Za self-expandable metal stent for palliation of malignant biliary obstruction.

BACKGROUND: The efficacy and safety of the uncoated self-expandable Za metal stent for palliation of malignant distal biliary obstruction was prospectively analyzed. METHODS: Twenty-one patients with unresectable malignant tumors involving mid to distal common bile duct who presented with obstructive jaundice underwent endoscopic implantation of an uncoated self-expandable metal stent. Technical success with stent placement, adverse events, patient survival, duration of stent patency, and device performance were analyzed. RESULTS: Endoscopic biliary stenting was successful in all patients. No adverse events were encountered. The mean follow-up period of the 21 patients was 128 days (range, 3-263): 14 died of progressive disease at mean of 81 days (range, 3-210), 3 remain alive (at days 239, 250, and 263), and 4 were lost to follow-up (at days 90, 91, 92, and 116). The mean duration of stent patency was 249 days. Tumor ingrowth was observed in one patient (5%). Minor technical problems were encountered in 3 patients: 1 proximal deployment, 1 distal deployment, and difficulty associated with the delivery system in 1. CONCLUSIONS: The Za-metal stent provided effective palliation for patients with inoperable malignant biliary tumors. Although minor technical problems were encountered with stent deployment, the overall stent patency, efficacy, and safety profile appear satisfactory.

Aged↗