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Biomedical subjects

Elizabeth Rajan

Publications and source records attributed to Elizabeth Rajan.

42 records · Page 3Linked to original sources

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↗

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↗

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↗