Physiology of intra-abdominal and intrathoracic Nissen fundoplications in a porcine model.

BACKGROUND: The physiologic competency of intrathoracic fundoplications remains controversial. This study compared the physiologic qualities of intra-abdominal Nissen fundoplications (IAF) with those of intrathoracic Nissen fundoplications (ITF) in a porcine model. METHODS: The lower esophageal sphincter (LES) length (cm), LES resting pressure (mm Hg), and intragastric pressure (mm Hg) necessary to produce reflux or wrap distribution were manometrically assessed before and after IAF and ITF in 10 pigs. Mean +/- SD were compared using analysis of variance. RESULTS: There was no difference in LES length before and after IAF or ITF, but there was a significant increase in resting LES pressure after eithe

A comparison of common bile duct pressures after botulinum toxin injection into the sphincter of Oddi versus biliary stenting in a canine model.

BACKGROUND: Botulinum toxin A (Botox) functionally paralyzes the sphincter of Oddi in both animals and humans, resulting in reduced pressures. No study, however, has specifically addressed common bile duct (CBD) pressures after Botox injection into the sphincter of Oddi with regard to treating biliary leaks and fistulae. The goals of this present study are to compare, versus biliary stenting, the change in CBD pressures after Botox injection into the sphincter of Oddi, as well as to evaluate the timing of onset and duration of these effects on sphincteric relaxation. METHODS: After midline laparotomy in 20 mongrel dogs, a pediatric umbilical catheter was inserted into the CBD via a small cholecystotomy and attached to a water-perfused pressure transducer. After baseline CBD pressure readings, a lateral duodenotomy was performed. A total of 100 units of Botox was injected with an endoscopic sclerotherapy needle into all four quadrants of the ampulla. The dogs were randomly divided into four groups to undergo repeat laparotomy at either postoperative day 1 (group I), postoperative day 3 (group II), postoperative day 7 (group III), or postoperative day 14 (group IV). At the time of second laparotomy, a pressure-sensing catheter was reinserted into the CBD and pressures recorded. Each dog then underwent transpapillary biliary stenting with a 7 Fr. x 5 cm Cotton-Leung biliary stent and CBD pressures were again recorded. RESULTS: CBD pressures were significantly lower as compared with baseline for all groups after Botox injection and after biliary stenting (P <0.001) In addition, no significant differences in the degree of CBD pressure reduction were identified between groups I through IV after Botox injection. The measured decrease in CBD pressure from baseline after Botox injection as compared with biliary stenting was significantly different for groups I and II (P <0.05) but not for groups III and IV. CONCLUSION: Botox injection into the sphincter of Oddi results in significant CBD pressure reduction within 24 hours and continues for 14 days. Also, after postoperative day 3, there is no significant difference in the reduction of CBD pressure from baseline between Botox injection and biliary stenting. Based on these findings, Botox injection into the sphincter of Oddi may be a beneficial alternative to biliary stenting for the treatment of biliary leaks and fistulae.

Bispectral index monitoring of sedation during endoscopy.

BACKGROUND: No objective measure of the level of sedation is universally accepted. However, bispectral index monitoring is currently used to objectively measure sedation levels in several clinical settings. This study compares the temporal relationship of bispectral index levels versus the Observer's Assessment of Alertness/Sedation (OAA/S) scale for sedation during endoscopy and proposes a functional bispectral index range for endoscopic procedures. METHODS: Fifty consecutive adults undergoing endoscopic retrograde cholangiopancreatography, colonoscopy, or esophagogastroduodenoscopy by a single endoscopist were studied. Intravenous sedation was achieved with diazepam and meperidine. Bispectral index levels (0 to 100) and OAA/S scores (1 to 5) were recorded every 3 minutes by a single trained observer. RESULTS: There were significant temporal correlations between bispectral index levels and OAA/S scores (r = 0.59, p < 0.0001). Bispectral index levels and OAA/S scores corresponded with the need for additional sedation as determined clinically by the endoscopist. An OAA/S score of 3 corresponded to a bispectral index level of 81.49 +/- 9.78. CONCLUSIONS: Bispectral index monitoring temporally correlates with the OAA/S scale and therefore provides an objective measure of sedation during endoscopy. This preliminary, observational study suggests that a bispectral index level near 82 corresponds with sufficient and functional sedation levels for endoscopy.