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Christopher J Gostout

Publications and source records attributed to Christopher J Gostout.

17 recordsLinked to original sources
PubMed2003

Understanding endoluminal gastroplications: a histopathologic analysis of intraluminal suture plications.

BACKGROUND: Endoluminal gastroplication is used to treat GERD, with modest results. Little is known of the histologic reaction to endosutures. Thus, the histologic response to intraluminal plications at different penetration depths within the gastric wall was studied in an animal model. METHODS: Intraluminal gastroplications were performed through a laparotomy in 18 New Zealand rabbits. Three sets of everted plications were placed at different penetration depths in each stomach: submucosa (SMpl), muscularis propria (Mpl), and serosa (Spl). Animals were randomized to survival times of 3, 10, or 60 days (respectively, Groups I, II, and III). Plications were compared with a grade scale for each histologic healing phase and gross inspection. RESULTS: Fusion between folds was absent in all groups. Serosa differed from muscularis propria with respect to the proportion of samples with microscopic ischemia (67% vs. 8%; p = 0.015), remaining sutures in Group III (33% vs. 3%; p < 0.05 in a single test of significance, but correction for multiple testing removes this significance), and remaining plications in Group II (96% vs. 54%; p < 0.05 in a single test of significance, but correction for multiple testing removes this significance). All of the total and partial histologic scores for the corresponding healing phase in each group escalated with penetration depth. Overall comparison of the histologic scores showed a significant difference among the plications in the proliferation (Group II, p = 0.004) and maturation (Group II, p = 0.009) phases. Total scores also differed among the plications in Groups II (p < 0.001) and III (p < 0.001). Plications were absent in all of Group III, with Spl resulting only in a flat scar. CONCLUSION: Everted intraluminal gastroplications do not result in fusion between folds irrespective of suture-penetration depth. A flat scar is the final outcome and appears proportional to the amount of ischemia, foreign body reaction, and suture depth.

Anastomosis, Surgical↗
PubMed2003

Hydroxypropyl methylcellulose: A better submucosal fluid cushion for endoscopic mucosal resection.

BACKGROUND: Formation of a submucosal fluid cushion has become integral to endoscopic mucosal and polyp resection. Solutions available for injection into the submucosa of the GI tract create short-lasting submucosal fluid cushions or are costly. The feasibility, durability, and histologic response to submucosal fluid cushions created by injection of hydroxypropyl methylcellulose were studied in the esophagus of pigs. METHODS: Thirty-six esophageal submucosal fluid cushions created with hydroxypropyl methylcellulose were studied in 12 animals divided in 2 groups of 6 animals each. In Group I, 18 submucosal fluid cushions were created by submucosal injection of hydroxypropyl methylcellulose followed by tattooing. In Group II, 18 submucosal fluid cushions were created by submucosal injection of hydroxypropyl methylcellulose, with sites marked by an endoscopically placed suture. In all cases, the duration of the submucosal fluid cushion was measured. After 7 days, submucosal fluid cushion sites were assessed by EGD, necropsy, and histologic evaluation. RESULTS: The mean submucosal fluid cushion duration was 36 minutes (3-45 minutes) and 38 minutes (5-45 minutes) for, respectively, Groups I and II. EGD and necropsy after 1 week showed normal-appearing mucosa at the site of all submucosal fluid cushions in both groups. Some Group I animals additionally had nodules at the tattoo sites. Histologic assessment demonstrated minimal alterations in 33 of 36 (92%) submucosal fluid cushion sites and localized mild inflammatory reaction in 3 of 36 (8%). In Group I, 8 of 18 (44%) tattoo sites exhibited a significant inflammatory reaction, including 3 abscesses. CONCLUSIONS: Hydroxypropyl methylcellulose creates a long-lasting submucosal fluid cushion with minimal tissue reaction and should be considered a low-cost option for creating submucosal fluid cushions. The use of tattooing with carbon black should be carefully considered when histologic study is required to assess potential inflammatory tissue responses to an invasive technique or instillation of foreign material in the GI tract.

Animals↗
PubMed2003

Development of a swine model for benign stenosis of the bile duct by endoscopic application of intraluminal thermal injury.

BACKGROUND: A simple animal model is desirable for the study of endoscopic therapies used in the management of biliary strictures. The aim of this study was to identify a method for inducing benign biliary stenoses in a porcine model by using endoscopic techniques. METHODS: Endoscopic retrograde cholangiography was performed in 9 swine. Intraluminal injury was applied to the common hepatic duct with graded applications of either a heat probe or a multipolar probe. Cholangiography was repeated at 7-day intervals. If a stricture was not identified by 28 days, injury was created at another site in the common hepatic duct by using a higher energy dose. After a stricture was identified, the animal was killed and bile duct samples were obtained for histopathologic evaluation. RESULTS: Thirteen thermal injuries were created in the 9 animals. Six of 7 heat probe treatments and 1 of 6 multipolar probe treatments resulted in a stricture (p = 0.025, Fisher exact test). Applications of the heat probe at 10 or 15 J produced a stricture in 6 of 6 cases. All strictures were indistinguishable histopathologically from benign strictures in humans. CONCLUSIONS: The application of intraluminal thermal injury with a heat probe results in a reproducible animal model of benign biliary stenosis.

Animals↗
PubMed2003

Prospective controlled assessment of variable stiffness enteroscopy.

BACKGROUND: Push enteroscopy is a well-established technique for evaluation of the small intestine. However, looping of the enteroscope within the stomach limits depth of insertion. Stiffening overtubes that minimize gastric looping are tolerated marginally by patients and disliked by endoscopists. A variable stiffness instrument has the potential to eliminate the need for an overtube while still minimizing gastric looping. The performance of a prototype variable stiffness enteroscope was compared prospectively with that of a conventional push enteroscope with and without use of an overtube. METHODS: Consecutive patients undergoing enteroscopy were randomized to have the procedure with a variable stiffness instrument, a conventional instrument with overtube, or a conventional instrument without overtube. Depth of insertion distal to the ligament of Treitz was determined by plain abdominal radiography. OBSERVATIONS: In total, 67 patients were randomized to variable stiffness enteroscopy (25 patients), enteroscopy with overtube (23 patients), and enteroscopy without overtube (19 patients). Median depth of insertion distal to the ligament of Treitz, respectively, for each group, was 89 cm, 68 cm and 41 cm (p = 0.03). In multivariate analysis, variable stiffness instrument use was predictive of intubation to 65 cm distal to the ligament of Treitz (odds ratio 5.53: 95% CI [1.25, 31.25] vs. no overtube, and odds ratio 2.50: 95% CI [0.63, 11.1] vs. overtube). Procedure duration and overall patient tolerance did not differ significantly among the 3 groups, although more patients in the overtube group required additional sedation than patients in the variable stiffness group (p = 0.03). Both endoscopists' (r = 0.34) and nurses' (r = 0.36) estimates of patient discomfort during the procedure correlated poorly with patient tolerance. CONCLUSIONS: A variable stiffness push enteroscope enhances insertion depth compared with the conventional instrument with or without overtube. Further studies are required to determine whether this improved performance increases diagnostic yield.

Aged↗
PubMed2002

Safety and outcome of endoscopic snare excision of the major duodenal papilla.

BACKGROUND: The optimal management of adenoma of the major duodenal papilla is not established. Options include surgical excision, endoscopic ablative techniques, snare excision, and observation with periodic biopsies. The aims of this retrospective study were to determine the safety and outcome of snare excision of the papilla. METHODS: Twenty-eight snare excisions of the papilla were performed in 26 patients. Sixteen had familial adenomatous polyposis. In 22 procedures, a minisnare was used, and in 6 cases a prototype snare was designed for excision of the papilla. Pancreatic stents were placed as a prophylactic measure at the discretion of the endoscopist (n = 10). RESULTS: Histopathologically, resected tissue included 25 adenomas, 1 inflammatory polyp, 1 invasive malignancy, and 1 normal papilla. Immediate complications were minor bleeding (n = 2), mild pancreatitis (n = 4) and a duodenal perforation (n = 1). The presence (n = 10) or absence (n = 18) of a pancreatic stent did not correlate with subsequent pancreatitis (2 in each group, p = NS). Follow-up was available for 21 patients (median, 9 months; range, 2-32 months). Pancreatic duct stenosis at the papillectomy site resulted in pancreatitis in 2 patients (17%) at, respectively, 4 months and 24 months. Follow-up endoscopy revealed recurrent/residual adenomatous tissue in 2 (10%). CONCLUSIONS: Snare excision of the major duodenal papilla was well tolerated. Most complications were mild except for a small duodenal perforation. Stenosis of the pancreatic duct orifice with pancreatitis may be a late complication.

Adenomatous Polyposis Coli↗
PubMed2002

Percutaneous transgastric placement of jejunal feeding tubes with an ultrathin endoscope.

BACKGROUND: Placement of jejunal feeding tubes in patients with PEG tubes by conventional techniques is often difficult. This is a description of a simple method for placement of jejunal tubes by using an ultrathin endoscope. This method does not always require conscious sedation. METHODS: An ultrathin endoscope is passed through a mature gastrostomy tract to the proximal jejunum. A guidewire passed through the endoscope and placed beyond the ligament of Treitz is then used under fluoroscopy to place a transgastric jejunal feeding tube. OBSERVATIONS: Sixteen jejunal feeding tube placements were performed in 13 patients over a period of 20 months. Six patients required conscious sedation. Jejunal tubes had feeding channels of 10 to 12F. There were no complications. Feedings began on the day of placement. CONCLUSIONS: Ultrathin endoscopes can be used to place jejunal feeding tubes by means of the transgastric route. The procedure is simple, quick, and safe. In some patients, the use of conscious sedation can be avoided.

Adult↗
PubMed2002

2-Octyl-cyanoacrylate (Dermabond), a new glue for variceal injection therapy: results of a preliminary animal study.

BACKGROUND: Endotherapy of bleeding gastric varices is problematic. The aim of this descriptive study in an animal model was to compare 2-octyl-cyanoacrylate (Dermabond), a Food and Drug Administration-approved agent for superficial wound closure, to N-butyl-2-cyanoacrylate (Histoacryl), an agent available outside of the United States for the endoscopic treatment of bleeding gastric varices. METHODS: Eight New Zealand white rabbits were randomly assigned to either the study agent Dermabond or the control agent, Histoacryl. Both active agents were equally mixed with ethiodized poppy seed oil (Ethiodol) and injected into the auricular vein. The animals were euthanized at various time intervals after injection. A 2 cm strip of tissue on either side of the injection site along with the adjacent perivascular tissues were resected for histologic evaluation. RESULTS: The use of 0.5 mL of Dermabond effectively induced vascular occlusion compared with 0.2 mL of Histoacryl. The histologic changes acutely and at 1 week were similar with each mixture. CONCLUSION: Dermabond may be useful in the treatment of gastric variceal bleeding, but further studies are necessary to determine dose response rates in animals and humans.

Animals↗
PubMed2002

In vivo characterization of colonic thermal injury caused by argon plasma coagulation.

BACKGROUND: Argon plasma coagulation has been rapidly accepted for endoscopic obliteration of vascular lesions and superficial tumors. Depth of injury is thought to be limited through preferential discharge of energy to nondesiccated tissue. However, argon plasma coagulation-induced injury has not been well characterized. The aim of this study was to characterize argon plasma coagulation-induced colonic injury by using a porcine model. METHODS: Laparotomy was performed in 6 female swine and the colon exteriorized with the subjects under general anesthesia. Lesions were made with an argon plasma coagulation probe held perpendicular and 2 mm from the mucosa. Variables studied were as follows: power (45 W, 60 W, and 75 W) and duration (1, 2, or 3 seconds; n = 11 for each power/duration combination). Injury was graded as either superficial or deep, involving the muscularis propria. RESULTS: Circular muscle layer injury correlated closely with power (p = 0.02), duration (p = 0.001), and total energy delivered (r = 0.977). Longitudinal muscle damage was associated with duration of burn (p = 0.001) and total energy delivered (r = 0.855), but correlated poorly with power (p = 0.40). No perforations occurred. Submucosal injection of saline solution had a protective effect with reductions in circular (90% to 10%, p = 0.002) and longitudinal muscle injury (50% to 0%, p = 0.1). CONCLUSIONS: Injury to the muscularis propria occurs at recommended settings for argon plasma coagulation. Injury correlates with power setting, duration of burn, and total energy delivery. Protective arcing to nondesiccated tissue does not appear to be significant in vivo. Submucosal injection of saline solution protects against deep injury.

Animals↗
PubMed2002

High-resolution chromoendoscopy for classifying colonic polyps: a multicenter study.

BACKGROUND: Chromoendoscopy may reliably separate adenomatous from nonadenomatous polyps. The aim of this multicenter trial was to determine the accuracy of high-resolution chromoendoscopy for the determination of colonic polyp histology. METHODS: This multicenter trial included 4 academic centers and a primary care practice. In 299 patients referred for routine colonoscopy or sigmoidoscopy, 520 polyps 10 mm in size were sprayed with indigo carmine dye. Using a high-resolution endoscope, the endoscopist predicted the histology of each polyp based on its surface characteristics. Hyperplastic polyps had a "pitted" surface pattern of orderly arranged "dots" that resembled surrounding normal mucosa. Adenomatous polyps had at least one surface "groove" or "sulcus." Each polyp was subsequently resected for histopathologic evaluation. RESULTS: The resected polyps were comprised by 193 adenomas (37%), 225 hyperplastic polyps (43%), and 102 "other" types (20%). Forty polyps (7.7%) could not be classified by high resolution chromoendoscopy with indigo carmine dye. For the remaining polyps, the sensitivity, specificity, and negative predictive value of indigo carmine dye staining for adenomatous polyps were, respectively, 82%, 82%, and 88%. The results were consistent among the academic centers and the primary care practice. CONCLUSIONS: High-resolution chromoendoscopy with indigo carmine dye demonstrates morphologic detail of diminutive colorectal polyps that can reliably be used to separate adenomatous from nonadenomatous polyps.

Adenoma↗
PubMed2002

First endoluminal system for transmural resection of colorectal tissue with a prototype full-thickness resection device in a porcine model.

BACKGROUND: Endoluminal transmural resection of colorectal lesions is a pivotal advance in endoscopic technology. A full-thickness resection device has been developed that functions through a combination of tissue grasping, stapling, and cutting under endoscopic guidance. This preclinical study evaluated the performance, safety, and effectiveness of the full-thickness resection device in a porcine model. METHODS: The full-thickness resection device consists of an operative handle, flexible shaft, and a resection chamber head. Eight pigs were randomized to 2 survival groups (4 each) of 14 and 28 days. The mucosa was marked electrosurgically to delineate target areas in the distal colon. A gastroscope inserted through the channel of the full-thickness resection device was advanced together with the device to the target. Targeted tissue was pulled into the resection chamber with a forceps, staples were deployed, and the isolated specimen was resected with a cutting blade. Histologic and radiographic evaluations were performed. RESULTS: All resections were transmural. Mean resected tissue diameter was 3.6 cm (1.4-5.2 cm). Mean procedure time was 30.2 (15) minutes. Minor mechanical problems required the use of replacement devices to complete 3 procedures. Resection sites were identified endoscopically and radiographically at sacrifice. In one animal, local adhesions were present. Histology evaluation disclosed resection line mucosal ulceration in 4 animals with fibroinflammatory changes consistent with healing. CONCLUSIONS: The full-thickness resection device can be used for endoluminal transmural localized resection of colorectal tissue in an animal model.

Angioplasty↗
PubMed2002

Efficacy of colonic submucosal saline solution injection for the reduction of iatrogenic thermal injury.

BACKGROUND: Submucosal saline solution injection may limit the depth of thermal injury to the gut wall by acting as a heat-sink and by increasing the distance between burn and serosa. The aim of this study was to determine the effect of submucosal saline solution injection on depth of colonic thermal injury produced by commonly used endoscopic thermal modalities. METHODS: Longitudinal colotomy incisions were made on the antimesenteric colonic border of anesthetized swine. Lesions were made by using a bipolar device (20 W, 2 seconds), heat probe (30 J); monopolar contact with hot biopsy forceps (20 W, 2 seconds), and monopolar noncontact with argon plasma coagulation (45 W, 3 seconds). Ten or more lesions were created with each device. Lesions were made with or without prior submucosal injection of 2 mL of normal saline solution. After 24 hours the lesions were excised for histologic analysis. Injury was assessed in relation to the severity of damage to the deep (longitudinal) muscle layer. RESULTS: The proportions of control lesions (without submucosal saline solution injection) in which deep injury was evident were as follows: argon plasma coagulation, 86%; hot biopsy forceps, 64%; heat probe, 50%; bipolar device, 18%. Submucosal saline solution injection significantly reduced the proportions of lesions with deep injury for argon plasma coagulation (p = 0.009) and heat probe (p = 0.03), but not hot biopsy forceps or bipolar device (argon plasma coagulation, 86% to 21%; heat probe, 50% to 0%; hot biopsy forceps, 64% to 50%; bipolar device, 18% to 9%). CONCLUSIONS: At equivalent energy outputs, the bipolar device results in less deep injury than the monopolar or heat probe. Submucosal saline solution injection reduced injury to the muscularis propria caused by both heat probe and argon plasma coagulation, but not hot biopsy forceps. Despite submucosal saline solution injection, caution should be exercised when using prolonged monopolar cautery.

Animals↗
PubMed2002

Recurrent bleeding from peptic ulcer associated with adherent clot: a randomized study comparing endoscopic treatment with medical therapy.

BACKGROUND: Endoscopic therapy reduces the recurrence of bleeding from actively bleeding peptic ulcers and those with visible vessels. However, the use of endoscopic therapy for ulcers with adherent clots remains controversial. The purpose of this study was to determine whether removal of clot from an ulcer and endoscopic therapy reduces the frequency of recurrent bleeding. METHODS: Patients with acute upper GI bleeding from peptic ulcers with adherent clots and no active bleeding were enrolled in a multicenter study. At each center patients were stratified for age, use of nonsteroidal anti-inflammatory drugs, and ulcer location, and were randomized to endoscopic or medical management. Endoscopic therapy consisted of injection of the base of the adherent clot with a solution of epinephrine and mechanical removal of the clot. The base of the ulcer and any stigmata of bleeding were then coagulated until cavitation and adequate coagulation were obtained. Patients in both groups received standard medical therapy for peptic ulcer. Patients were evaluated for recurrence of bleeding for 1 month. RESULTS: Fifty-six patients were enrolled. Rates of recurrent bleeding were 34.3% (12/35) in the medical treatment arm versus 4.8% (1/21) in the endoscopic treatment arm (p < 0.02). CONCLUSIONS: In patients with GI bleeding caused by gastric or duodenal ulcers with an adherent clot found on endoscopy, endoscopic therapy with injection of the base of the clot, clot removal, and heat probe coagulation significantly reduces the rate of recurrent bleeding compared with medical therapy alone.

Blood Coagulation↗
PubMed2002

Comparative performance in the porcine esophagus of different solutions used for submucosal injection.

BACKGROUND: Before endoscopic mucosal resection and polypectomy of sessile lesions, injection of fluid into the submucosa cushions and isolates the tissue and thereby reduces thermal injury and the risk for perforation and hemorrhage. This study investigated the performance of 5 different solutions when used to form submucosal fluid cushions in the porcine esophagus. METHODS: Five groups of 5 pigs were studied. In each pig, 6 separate submucosal injections of 5 mL of a single test solution were performed within the distal third of the esophagus. The time required for the submucosal bleb to flatten completely was recorded after each injection. The solutions used were as follows: normal saline solution, normal saline plus epinephrine solution, 50% dextrose, 10% glycerine/5% fructose in normal saline solution, and 1% rooster comb hyaluronic acid. RESULTS: The normal saline solution and normal saline plus epinephrine solutions had the shortest disappearance times (respectively, median 2.4 and 3.0 minutes), which were significantly shorter compared with the other test solutions. The mean disappearance times for 50% dextrose and 10% glycerine were, respectively, 4.7 and 4.2 minutes. The mean disappearance time for hyaluronic acid was 22.1 minutes. CONCLUSIONS: A solution of hyaluronic acid appears to be ideal for producing a lasting submucosal cushion for prolonged procedures. Dextrose 50% is superior to normal saline solution and may serve as an alternative to hyaluronic acid in terms of availability and cost.

Adjuvants, Immunologic↗
PubMed2002

Endoscopic identification and quantification of aberrant crypt foci in the human colon.

BACKGROUND: Aberrant crypt foci may be precancerous lesions in the human colon. The occurrence of aberrant crypt foci was compared in patients with an endoscopically normal colon, known adenomatous polyps, and known colorectal cancer. METHODS: In 90 patients (30 colonoscopically normal, 30 with adenomatous polyps, 30 with colorectal cancers) magnification chromoscopy was performed to identify aberrant crypt foci in the distal 10 cm of the rectum. Representative biopsy specimens were obtained for histopathologic assessment. RESULTS: Aberrant crypt foci were readily identified. Median and (mean) numbers of aberrant crypt foci were as follows: endoscopically normal colon, 3.5 (5.0); adenomatous polyp(s), 4.0 (6.9); and colorectal cancer, 7.5 (9.9). The number of aberrant crypt foci detected was significantly associated (p = 0.02) with an increased odds that a patient would be in the group with known colorectal cancer (odds ratio = 1.11; 95% CI [1.02, 1.21]), but not in any other group. CONCLUSIONS: Despite a stepwise increase in the number of aberrant crypt foci across the 3 groups, aberrant crypt foci was significantly associated only with comorbid colorectal cancer. Aberrant crypt foci was not associated with adenomatous polyp(s) or normal colon. Additional studies are needed to further elucidate the role of aberrant crypt foci in the development of colorectal neoplasia in humans.

Adenoma↗
PubMed2002

Evaluation of indeterminate bile duct strictures by intraductal US.

BACKGROUND: Cholangiography and tissue sampling (brush cytology, biopsy) are the standard nonsurgical techniques for determining whether a bile duct stricture is benign or malignant. The aim of this study was to determine whether intraductal US is of assistance in distinguishing benign from malignant biliary strictures. METHODS: A retrospective review was undertaken of 30 patients with indeterminate bile duct strictures who underwent ERCP and tissue sampling from September 1999 to November 2000. A 20 MHz over-the-guidewire intraductal US catheter probe was used during ERCP for further examination of the strictures. Final diagnoses of malignant strictures (18 patients) were confirmed histopathologically; confirmation of benign stricture (12 patients) was based on negative tissue sampling plus extended clinical follow-up. RESULTS: Based on retrospective blinded review, the diagnosis by ERCP was correct in 67% of patients, by tissue sampling in 68%, by combined ERCP/tissue sampling in 67%, and by intraductal US in 90% (p = 0.04 vs. ERCP/tissue sampling) of cases. No complication of intraductal US or ERCP was recorded. CONCLUSIONS: Intraductal US is safe and can improve on the ability at ERCP to distinguish benign from malignant biliary strictures.

Adolescent↗