Long-term randomized controlled trial of a novel nanopowder hemostatic agent (TC-325) for control of severe arterial upper gastrointestinal bleeding in a porcine model.

BACKGROUND AND STUDY AIM: Endoscopic therapy of brisk upper gastrointestinal bleeding remains challenging. A proprietary nanopowder (TC-325) has been proven to be effective in high pressure bleeding from external wounds. The efficacy and safety of TC-325 were assessed in a survival gastrointestinal bleeding animal model. METHOD: 10 animals were randomized to treatment or sham. All animals received intravenous antibiotics, H2-blockers and heparin (activated clotting time 2 × normal). In a sterile laparotomy the gastroepiploic vessels were dissected, inserted through a 1-cm gastrotomy, and freely exposed in the gastric lumen, and the exposed vessel lacerated by needle knife. The treatment group received TC-325 by a modified delivery catheter while the sham group received no endoscopic treatment. Time to hemostasis, and mortality at 60 minutes, 24 hours, 48 hours, and 7 days were noted. Necropsy was performed in all animals. RESULTS: Spurting arterial bleeding was achieved in all animals. No control animal showed hemostasis within the first hour compared with 100 % (5 / 5) in the treatment arm (mean 13.8 minutes, P < 0.0079). Durable hemostasis was achieved with no evidence of rebleeding after 1 and 24 hours in 80 % (4 / 5) of the treated animals compared with none in the control group ( P < 0.0098). None of the control animals survived more than 6 hours. Necropsy at 1 week in treated animals revealed healed gastrotomy without foreign body granuloma or embolization to the lung or brain. CONCLUSION: TC-325 is safe and highly effective in achieving hemostasis in an anticoagulated severe arterial gastrointestinal bleeding animal model.

Adhesion formation after peritoneoscopy with liver biopsy in a survival porcine model: comparison of laparotomy, laparoscopy, and transgastric natural orifice transluminal endoscopic surgery (NOTES).

BACKGROUND AND STUDY AIMS: Minimizing the invasiveness of operations by using natural orifice transluminal endoscopic surgery (NOTES) may reduce adhesion formation. The aim of the study was to compare rates of adhesion formation after peritoneoscopy with liver biopsy by laparotomy, laparoscopy, and transgastric NOTES. MATERIALS AND METHODS: Experimental comparative survival study, at a university hospital. using 18 female pigs weighing 35 - 40 kg. Peritoneoscopy with liver biopsy was randomized to one of three groups: laparotomy, laparoscopy, and transgastric NOTES. Preoperative, operative, and postoperative care was standardized. Main outcome measures were: (i) survival and complication rates; (ii) assessment of adhesion formation using the Hopkins Adhesion Formation Score at necropsy (day 14). RESULTS: 100 % of pigs with laparotomy and 33.3 % with laparoscopy had adhesions compared with 16.7 % who underwent transgastric NOTES. Documented adhesion bands totals for each group were: transgastric NOTES 1; laparoscopy 4; laparotomy 17. Median adhesion formation scores were: laparotomy 2.5 (range 2 - 4), compared with laparoscopy 0.0 (0 - 2), and transgastric NOTES 0.0 (0 - 1) ( P < 0.001). Spearman coefficient analysis revealed that correlation between adhesion scores assigned by two investigators was excellent (r = 0.99, P < 0.001, 95 % confidence interval [CI] 0.9978 - 0.9996). CONCLUSIONS: Although this was a short-term study, with a low number of animals, it showed that transgastric NOTES and laparoscopy are associated with statistically significantly lower rates of adhesion formation than open surgery when peritoneoscopy with liver biopsy is performed. Incidence and severity of adhesions were lowest with transgastric NOTES.