W.E. Waterfall
McMaster University
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Featured researches published by W.E. Waterfall.
The American Journal of Gastroenterology | 1999
Jeff Kolbasnik; W.E. Waterfall; Beth Fachnie; Ying Chen; Gervais Tougas
OBJECTIVE:We sought to examine the long-term efficacy of intrasphincteric Botulinum toxin A injection in a prospective cohort study of 30 patients with achalasia.METHODS:Thirty patients with classical achalasia were treated with intrasphincteric Botulinum toxin A injection. Follow-up consisted of clinical assessment, symptom scoring, and postinjection manometry.RESULTS:Symptomatic improvement for >3 months was seen in 23 of 30 patients (77%). Of the 23 initial responders, seven (30%) experienced a sustained symptomatic response after a single Botulinum toxin injection (mean follow-up, 21 months). The remaining 16 initial responders (70%) eventually relapsed (mean initial response, 11 months). Nine received a 2nd Botulinum toxin injection, and seven experienced an ongoing response (mean duration, 9 months); two patients eventually required a 3rd injection with good effect (mean duration, 22 months). The remaining seven patients who relapsed after Botulinum toxin opted for pneumatic dilation or surgical myotomy. Five of the seven patients who had no initial response received a 2nd injection but again did not respond. A residual lower esophageal sphincter pressure <18 mm Hg after the first Botulinum toxin injection predicted a good response to Botulinum therapy (single or multiple injections, p < 0.002, positive predictive value = 0.71, negative predictive value = 1.0). Neither initial nor sustained response to Botulinum toxin could be predicted based on gender, age, duration of illness, previous pneumatic dilation, or esophageal motility before treatment.CONCLUSIONS:We found that 77% of patients with classical achalasia experienced a good symptomatic response after Botulinum toxin and 30% of initial responders achieve sustained symptomatic relief after a single treatment with Botulinum toxin. The initial responders who relapsed did well with subsequent Botulinum toxin A. Lack of an initial symptomatic response and residual lower esophageal sphincter pressure ≥18 mm Hg after Botulinum toxin are associated with a poor response.
Journal of Behavioral Medicine | 1979
Paul Latimer; Dugal Campbell; Margaret Latimer; S. K. Sarna; Ed Daniel; W.E. Waterfall
This study tested the hypothesis that, in patients with irritable bowel syndrome (IBS), there is a primary hyperalgesia of the colon. Previous work, which examined these patients and normals, has not included subjects who provide a control for relevant psychological characteristics. We compared ratings of pain, following varying degrees of distension of the sigmoid colon, in normals, patients with IBS, and patients who were psychologically disturbed but without bowel symptoms. Psychological characteristics were assessed by a psychiatric interview and psychometric inventories; response to distension was tested by placing a tube in the rectosigmoid colon and successively inflating and deflating a balloon at its tip at 10 cm3 increments up to 50 cm3. Ratings of pain were recorded at each volume. The results indicated that the two patient groups were psychologically similar and both were more disturbed than normals. A linear relation was found between reports of pain and volume of distension in all three groups. There were no significant differences between the proportions of subjects experiencing pain in each group or the average of the ratings. There were no significant associations between the pain ratings and measures of anxiety, depression, neuroticism, and extraversion. The data do not support the hypothesis that colonic hyperalgesia is an important contributory factor in the etiology of the irritable bowel syndrome.
Gut | 1981
W.E. Waterfall; G S Cameron; S. K. Sarna; T D Lewis; E E Daniel
This report presents the findings of investigation of a child with idiopathic intestinal pseudo-obstruction (IIP). Functional abnormalities of the smooth muscle of the gastrointestinal tract were disclosed by electrical recordings from the gut obtained after laparotomy. In vitro analysis of tissue and ultrastructure were undertaken and a possible aetiology of the disorder in this patient based on these findings is presented.
Gastroenterology | 1981
Paul Latimer; S. K. Sarna; Dugal Campbell; Margaret Latimer; W.E. Waterfall; E. E. Daniel
Gastroenterology | 1980
S. K. Sarna; Bardakjian Bl; W.E. Waterfall; Lind Jf
Gastroenterology | 1981
S. K. Sarna; W.E. Waterfall; Bardakjian Bl; Lind Jf
Gastroenterology | 1978
T.D. Lewis; E. E. Daniel; S. K. Sarna; W.E. Waterfall; L. Marzio
Gastroenterology | 1977
S. K. Sarna; E. E. Daniel; W.E. Waterfall
Gastroenterology | 1978
S. K. Sarna; E. E. Daniel; W.E. Waterfall; T.D. Lewis; L. Marzio
Prostaglandins | 1979
E. E. Daniel; S. K. Sarna; W.E. Waterfall; J. Crankshaw