The effect of using an alternative irrigant between sodium hypochlorite and chlorhexidine to prevent the formation of para-chloroaniline within the root canal system.

AIM: To determine if the formation of para-chloroaniline (PCA) can be avoided by using an alternative irrigant following sodium hypochlorite but before chlorhexidine. METHODOLOGY: Fifty-five single-rooted teeth were decoronated, instrumented to size 40, .06 taper whilst being irrigated with 14% ethylene-diamine-tetra-acetic acid (EDTA) and 6% NaOCl. Samples were then randomly divided into three experimental and two control groups. Group 1 was irrigated with saline followed by 2% chlorhexidine gluconate (CHX). Group 2 was irrigated with 50% citric acid (CA) followed by 2% CHX. Group 3 was irrigated with 14% EDTA followed by 2% CHX. The chemical identity and quantification of the PCA in the formed precipitate was determined using gas chromatography/mass spectrometry (GC/MS). RESULTS: All experimental groups contained PCA. The mean level of PCA for group 1 (sterile saline) was 229 ng mL(-1), group 2 (citric acid) 72 ng mL(-1) and group 3 (EDTA) 400 ng mL(-1), respectively. A significant difference was found between the saline and EDTA groups and the negative control (P < 0.05). Although no statistical significance was found between the negative control and citric acid group, PCA was still present in this experimental group. CONCLUSIONS: Citric acid used as the intermittent irrigant had the least amount of PCA formation in the canal system. Until the threshold required to cause biological damage in humans is determined, the combination of NaOCl and CHX in root canal treatment should be avoided.

Evolution of carotid endarterectomy in two community hospitals: Springfield revisited--seventeen years and 2243 operations later.

PURPOSE: The purpose of this study was to evaluate and update the results of carotid endarterectomy (CEA) in two community hospitals over a 17-year period and to determine whether there had been any reduction in the unacceptably high incidence of complications previously reported from these same two hospitals. METHODS: We retrospectively reviewed the records of 1981 patients who underwent 2243 CEAs from July 1976 to November 1993. RESULTS: There were 36 operative deaths (1.6%) and 120 operative strokes (5.3%), for a combined stroke-mortality rate of 6.3%. The mortality, stroke, and combined stroke-mortality rates all decreased significantly (p < 10(-5)) compared with the rates reported in the original study (6.6%, 14.5%, and 21.1%, respectively). Nonfatal stroke rates decreased significantly for patients diagnosed with asymptomatic carotid artery disease, 18.2% to 2.9% (p = 0.04); transient ischemic attacks, 17.8% to 3.9% (p < 10(-6)); and prior stroke, 15.2% to 8.0% (p = 0.04). Improvement in combined stroke-mortality rates occurred for all operative indications, but was significant only in the transient ischemic (p < 10(-8)) and prior stroke groups (p = 0.00002). Surgical experience varied, with 31 surgeons performing one to 236 CEAs. Although results were not significantly correlated with individual operative activity, 10 surgeons who performed more than 12 CEAs per year had a statistically lower incidence of operative stroke (4.1%) compared with 21 surgeons who performed fewer procedures (7.2%) (p = 0.009). The incidence of stroke (2.7%) and the combined stroke-mortality rate (3.7%) of surgeons with additional vascular training was superior to the stroke rate (6.8%) and combined stroke-mortality rate (7.9%) of surgeons who did not (p = 0.0014 and p = 0.0006); but several surgeons in the latter group had results that were comparable to those of the vascular group. CONCLUSIONS: Although overall operative complication rates in these two community hospitals have declined dramatically compared with previously reported results, they are still not optimal and probably will remain high as long as individual surgeons with high complication rates continue to perform CEAs.

Gastroesophageal physiology after stapled gastroesophagostomy in dogs.

A stapled vertical gastroesophagostomy (VGE) has been proposed for benign esophageal stricture. The VGE involves performing an anastomosis using a linear cutting stapler inserted via a gastrotomy (one limb in the esophagus, the other in the proximal fundus). In phase I of the study, a 50-mm VGE was performed in 13 dogs; 7 received an additional fundoplication. Endoscopy with pinch biopsies, esophageal manometry, and 4-hour ambulatory pH recordings were performed in each dog prior to and 1 month after VGE. The only difference between groups postoperatively was a higher lower esophageal sphincter pressure in the group with the added fundoplication. The incidence of histologic esophagitis was low in both groups. In phase II of the study, a VGE was performed in six dogs using a 75-mm linear cutting stapler, accompanied by fundoplication in each dog. These dogs were then followed for 6 months to more completely assess the long-term risk of developing reflux esophagitis. At necropsy, no gross or histologic evidence of esophagitis was found. The performance of a VGE through the lower esophageal sphincter in normal dogs does not result in significant reflux esophagitis. VGE may be an alternative to resection for esophageal stricture.