Palliation of malignant extrahepatic biliary obstruction with plastic versus expandable metal stents: An evidence-based approach.
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Biliary Tract Neoplasms↗
Biomedical subjects
Christopher J Gostout
Publications and source records attributed to Christopher J Gostout.
Postpolypectomy lower gastrointestinal bleeding: potential role of aspirin.
INTRODUCTION: Limited data exist on the role of aspirin in increasing the risk of clinically significant postpolypectomy bleeding (PPB), which is defined as lower gastrointestinal (GI) hemorrhage following colonoscopic polyp removal requiring transfusion, hospitalization, endoscopic intervention, angiography, or surgery. OBJECTIVES: To determine if aspirin use prior to colonoscopy increases the risk of clinically significant PPB. METHODS: A case-control study of patients with clinically significant PPB at Mayo Clinic Scottsdale and Rochester was performed. Information collected included age, gender, recent use of aspirin or NSAIDs (within three days of colonoscopy), polyp characteristics, and polypectomy technique. The control group consisted of patients matched for age (+/-3 yr), gender, and cardiovascular morbidity who had undergone polypectomy without any complications. The populations were compared to determine the odds ratio (OR) of PPB with aspirin use. RESULTS: During the study period, 20,636 patients underwent colonoscopy with polypectomy at the two institutions and 101 patients presented with clinically significant PPB. Twenty patients were excluded from analysis because of prior anticoagulant use. The remaining 81 patients were matched to 81 patients who had undergone colonoscopy without complications. The two groups were comparable in terms of polyp size (97%< or = 10 mm, bleeding group; 95%< or = 10 mm, control group). Aspirin use prior to polypectomy was 40% in the bleeding group and 33% in the control group (OR 1.41; 95% C.I. 0.68 to 3.04). CONCLUSION: Postpolypectomy bleeding is an uncommon but important complication of endoscopic polypectomy. There was no statistically relevant difference in prior aspirin use before polypectomy in the bleeding group and the matched controls.
Age Distribution↗
Pulmonary embolization of 2-octyl cyanoacrylate after endoscopic injection therapy for gastric variceal bleeding.
N-butyl-2-cyanoacrylate, a tissue adhesive that polymerizes on contact with weak bases such as blood, is being used widely outside the United States to obliterate gastric varices. Embolization of this material can occur via portosystemic shunts. We report a case of pulmonary embolization of 2-octyl cyanoacrylate (an analogue of N-butyl-2-cyanoacrylate) that occurred after endoscopic injection therapy for gastric variceal bleeding. Cyanoacrylate embolism is difficult to diagnose with computed tomographic angiography because radiopaque emboli are masked by the contrast material. It is important to distinguish these emboli from conventional thromboemboli because "glue emboli" require only symptomatic treatment. Clinicians should have a high index of suspicion for embolism in the setting of tachycardia, chest pain, or hypoxia after a patient undergoes endoscopic injection therapy with cyanoacrylate glue for gastric variceal bleeding. The radiologist should be alerted so that the appropriate radiographic settings are used to make the diagnosis.
Cyanoacrylates↗
Cost analysis of endoscopic antireflux procedures: endoluminal plication vs. radiofrequency coagulation vs. treatment with a proton pump inhibitor.
BACKGROUND: Both endoluminal gastroplication and radiofrequency coagulation of the lower esophageal sphincter and gastroesophageal junction (Stretta procedure) represent emerging endoscopic therapies for GERD. The economic impact of endotherapy for GERD has not been described. The aim of this study was to apply a decision analysis model to compare the costs of endoluminal gastroplication vs. the Stretta procedures vs. a proton pump inhibitor for treatment of GERD. A cost minimization approach was used. METHODS: Model entry criteria were GERD responsive to daily or twice daily administration of a proton pump inhibitor. Performance characteristics of endotherapy were determined from published data. The baseline probabilities for annual endotherapy failure rates (20%), partial failure rates (10%), and complication rates (1%) were varied through a plausible range by using sensitivity analysis. Cost data for endotherapy were calculated from per case instrumentation costs plus professional fees plus facility fees for ambulatory patient classification codes; cost of treatment with a proton pump inhibitor was based on national average wholesale price. The endpoint was sustained resolution of GERD symptoms. RESULTS: In patients requiring twice daily use of a proton pump inhibitor for symptom relief, endotherapy proves to be the most economical strategy after 17 months. If uniform endotherapy failure rates over time are assumed, medication regains superiority after 29 months. Sensitivity analysis revealed that a proton pump inhibitor remains the most economical option beyond 3 years, provided annual endotherapy failure rates remain greater than 20% (endoluminal gastroplication) or 19% (Stretta). Pharmacotherapy is the least costly approach, irrespective of time, if the daily cost of a proton pump inhibitor is less than $140 a month or endotherapy costs more than $3400. For patients in whom symptoms are relieved with once daily dosing with a proton pump inhibitor, medication remains the most economical option regardless of endotherapy failure rate. CONCLUSION: Endotherapy appears to offer an economical treatment option for patients requiring a proton pump inhibitor twice daily, with its cost superiority enduring for 2.5 years. More long-term follow-up data are required to determine the durability of the endotherapy benefit over time.
Catheter Ablation↗
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↗
Future opportunities and developments for endoscopic gastroesophageal reflux disease therapy.
Endoscopic treatments for gastroesophageal reflux disease are directed at specific targets at the gastroesophageal junction. We explore the limitations and challenges of the anatomy, how current methods alter the anatomy and then speculate on the direction of future therapies.
Esophagogastric Junction↗
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↗
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↗
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↗
Is early colonoscopy after admission for acute diverticular bleeding needed?
OBJECTIVES: Urgent colonoscopy has been proposed for the diagnosis and management of acute colonic diverticular bleeding. Identification of active bleeding and nonbleeding stigmata facilitates diagnosis and endoscopic therapy, but it is unclear whether urgent colonoscopy after presentation increases the diagnostic yield. This study evaluated the association between timing of colonoscopy and diagnostic yield in patients admitted with acute colonic diverticular bleeding. METHODS: Patients admitted for hematochezia and receiving a diagnosis of diverticular hemorrhage were identified using the Mayo Clinic GI Bleeding Team and Emergency Room Admissions Databases for the years 1998-2000. Timing of colonoscopy was determined from the time of admission. Logistic regression analysis was used to assess whether the timing of colonoscopy was associated with an endoscopic finding of active bleeding or nonbleeding stigmata (or both). RESULTS: A diagnosis of definitive or presumptive diverticular bleeding was made in 78 patients (39 men and 39 women, mean age 78 yr, range 49-96 yr). Twelve patients (15%) had active bleeding or stigmata. Colonoscopies were performed a mean of 18 +/- 11 h after admission. The association between a definitive diagnosis of acute diverticular bleeding and the timing of colonoscopy was not significant (p > 0.46). CONCLUSIONS: No significant association is apparent between the timing of colonoscopy after admission and encountering active bleeding or nonbleeding stigmata. Based on these observations, urgent colonoscopy for these patients does not seem advantageous.
Acute Disease↗
An assessment of the management of acute bleeding varices: a multicenter prospective member-based study.
OBJECTIVE: Bleeding from esophagogastric varices is a major complication of portal hypertension. Despite recent practice guidelines for the management of bleeding esophageal or gastric varices, the widespread application of these measures by gastroenterologists has not been evaluated. The purpose of this study was to continue the concept of membership-based research within diverse practice settings by expanding the American College of Gastroenterology (ACG) GI Bleeding Registry to assess the management and outcome of acute variceal bleeding. METHODS: All ACG members (domestic and foreign) were invited to participate during the 1997 Annual Fall meeting and by mail. Data were collected over 12 months. Information obtained included physician training, practice demographics, patient demographics, disease etiology and severity, clinical presentation, medications, transfusion needs, therapy, complications, and rebleeding within 2 wk. RESULTS: A total of 93 physicians/centers (79.6% domestic, 26.9% university and affiliated, 3.2% Veterans Affairs) participated. Complete demographic data were available for 725 of the 741 patients enrolled with index bleeding. The median age of these 725 patients was 52 yr and 73.3% were male. The most common single etiology for portal hypertension was cirrhosis (94.3%). The most common causes of cirrhosis were alcohol (56.7%), hepatitis C virus (30.3%), and hepatitis B virus (10.0%). Hemodynamic instability was noted in 60.7% of the patients (22.3% tachycardic, 9.7% orthostatic, 28.7% hypotensive). Index interventions included banding (40.8%; median five bands), sclerotherapy (36.3%), combination banding/sclerotherapy (6.2%), octreotide (52.6%; median 3 days), balloon tamponade (5.5%), transjugular intrahepatic portosystemic shunt (TIPS) (6.6%), liver transplantation (1.1%), surgical shunt (0.7%), and embolization (0.1%). Transfusion of packed red blood cells, fresh frozen plasma, and platelets was given in 83.4%, 44.7%, and 24.6% of the patients with index bleeding, respectively. Median transfusion was four units of packed red blood cells, three units of fresh frozen plasma, and 1.5 units of platelets. Rebleeding occurred in 92 of the 741 patients (12.6%) at a median of 7 days (mean 11 days) and was treated by banding (18.5%; median six bands), sclerotherapy (30.4%), octreotide (63%; median 2 days), balloon tamponade (17.4%), TIPS (15.2%), and surgical shunt (3.3%). Complications from the index bleeding and rebleeding within 2 wk included ulceration (2.6%, 2.2%), aspiration (2.4%, 3.3%), medication side effects (0.8%, 0%), dysphagia (2.3%, 0%), odynophagia (2.2%,0%), encephalopathy (13%,17.4%), and hepatorenal syndrome (2.4%, 2.2%), respectively. After the index bleeding, 46.2% of patients were treated with beta-blockers and 8.2% with nitrates. The majority of patients with index bleeding had Child's B cirrhosis (61.5%). Patients presenting with recurrent bleeding had mostly Child's B (46.7%) or Child's C cirrhosis (44.6%). The overall short-term mortality after index bleeding was 12.9%. CONCLUSIONS: Acute variceal hemorrhage occurs more often in patients with Child's B and C cirrhosis. Endoscopic banding is the most common single endoscopic intervention. Adjunctive pharmacotherapy is prevalent acutely and after stabilization. Both morbidity and mortality may be lower than reported in previous studies.
Acute Disease↗
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↗
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↗
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↗
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↗
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↗
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↗
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↗