Search PubMed⌕ Search

Biomedical subjects

Charles H Knowles

Publications and source records attributed to Charles H Knowles.

8 recordsLinked to original sources
PubMed2005

Rectal intussusception: characterization of symptomatology.

PURPOSE: Rectal intussusception is a common finding at evacuation proctography; however, its significance has been debated. This study was designed to characterize clinically and physiologically a large group of patients with rectal intussusception and test the hypothesis that certain symptoms are predictive of this finding on evacuation proctography. METHODS: A total of 896 patients underwent evacuation proctography from which three groups were identified: those with isolated rectal intussusception (n = 125), those with isolated rectocele (n = 100), and those with both abnormalities (n = 152). Multivariate analyses were used to identify symptoms predictive of findings by evacuation proctography. RESULTS: The symptoms of anorectal pain and prolapse were highly predictive of the finding of isolated intussusception over rectocele (odds ratio, 3.6, P = 0.006; odds ratio, 4.9, P < 0.001) or combined intussusception and rectocele (odds ratio, 2.9, P = 0.02; odds ratio, 2.4, P = 0.03). The symptom of "toilet revisiting" was associated with the finding of rectoanal intussusception (odds ratio, 3.55, P = 0.04). Although patients with mechanically obstructing intussuscepta evacuated slower and less completely (P < 0.001) than those with nonobstructing intussuscepta, no symptom was predictive of this finding on evacuation proctography. CONCLUSIONS: Although certain symptoms are predictive of the finding of rectal intussusception, there is a wide overlap with symptoms of rectocele, another common cause of evacuatory dysfunction. Furthermore, the observation that "obstruction to evacuation" made on proctography had no impact on the incidence of evacuatory symptoms suggests that beyond simply demonstrating the presence of an intussusception, analysis of proctography and subclassifying intussusception morphology seems of little clinical significance, and selection for surgical intervention on the basis of proctographic findings may be illogical.

Adolescent↗
PubMed2004

Anal sphincter morphology in patients with full-thickness rectal prolapse.

PURPOSE: The aim of this study was to assess the morphologic change of the anal canal in patients with rectal prolapse. METHODS: The endoanal ultrasound scans of 18 patients with rectal prolapse were compared with those of 23 asymptomatic controls. The thickness and area of the internal anal sphincter and submucosa were measured at three levels. RESULTS: Qualitatively, patients with rectal prolapse showed a characteristic elliptical morphology in the anal canal with anterior/posterior submucosal distortion accounting for most of the change. Quantitatively, internal anal sphincter (IAS) and submucosa (SM) thicknesses and area were greater in all quadrants of the anal canal (especially upper) in patients with rectal prolapse compared with controls. There was statistical evidence (in a regression model) of a relationship between increases in all measured variables and the finding of rectal prolapse. CONCLUSIONS: The cause of sphincter distortion in rectal prolapse is unknown but may be a response to increased mechanical stress placed on the sphincter from the prolapse or an abnormal response by the sphincter complex to the prolapse. Patients found to have this feature on endoanal ultrasound should undergo clinical examination and defecography to look for rectal wall abnormalities.

Adult↗
PubMed2004

Intra-operative culture in appendicitis: traditional practice challenged.

INTRODUCTION: Traditionally, microbiological swabs are taken for culture during appendicectomy. However, the pathogens encountered are largely predictable, and sensitive to broad-spectrum antibiotics. Thus, we aimed to examine the clinical value of this practice, by determining the influence of microbiological results on postoperative outcome in patients undergoing appendicectomy. PATIENTS AND METHODS: The study population comprised 721 consecutive patients undergoing appendicectomy for suspected acute appendicitis in a single district general hospital. Microbiological culture results and sensitivities of isolates were recorded in relation to histopathological findings and infective morbidity, to establish whether they influenced postoperative outcome. RESULTS: Swabs were taken during 463 (64%) appendicectomies. Only 113 (24%) yielded positive cultures ('coliforms', anaerobes and Streptococcus milleri were most frequently isolated). Organisms resistant to broad-spectrum antibiotics were encountered in only 11 of 463 patients (2%) where swabs were taken. Overall, 39 patients (5%) developed significant infective complications postoperatively. Neither the presence of a positive intra-operative culture, nor the isolation of resistant organisms were significant in predicting infective complications (P = 0.11 and 0.17, respectively). CONCLUSIONS: In the population studied, the results of intra-operative culture did not influence clinical outcome in patients undergoing appendicectomy. The practice of taking routine microbiological swabs for culture must be seriously questioned.

Adolescent↗
PubMed2003

A systematic analysis of polyglucosan bodies in the human gastrointestinal tract in health and disease.

Polyglucosan inclusion bodies have been described in smooth muscle of the gastrointestinal tract of aged dogs, and rarely in association with enteric dysmotility in humans. We have systematically examined the human small and large bowel for the presence of such inclusions in health and motility disorders. Systematic, blinded, dual observer analysis of colonic and ileal tissue from patients (n=80, age 20-92 years) undergoing large bowel resections for non-dysmotile conditions, principally neoplasia was performed, as well as retrospective review of all intestinal tissues referred for specialist histochemistry from patients undergoing surgery for motility disorders. All sections were stained with haematoxylin and eosin and periodic acid-Schiff stains. No polyglucosan bodies were identified in any specimen without dysmotility, regardless of age, but were a feature of 4/104 patients with diverse severe gastrointestinal motility disorders. In contrast to dogs, polyglucosan bodies are not a feature of normal ageing in human gastrointestinal smooth muscle but, in accord with previous suggestions, are seen in rare cases of human gut dysmotility. The significance of this difference is unclear.

Adult↗
PubMed2003

Rectal heat thresholds: a novel test of the sensory afferent pathway.

PURPOSE: Currently, rectal sensation may be measured by balloon distention or mucosal electrostimulation. This study investigated the application of a graded heat stimulus to the rectum using a novel thermal probe as a further method of evaluating rectal sensory afferent mechanisms. METHODS: A thermal probe specially designed in our institution was used to test rectal heat sensitivity in 31 healthy subjects. This was compared with all other standard anorectal physiologic measurements. Repeatability studies were also performed. RESULTS: Heat stimulation of the mid rectum elicited sensory responses in all subjects. The most common reported response was not heat but a sharp or prickling sensation. The median rectal heat threshold was similar in males (median, 47 degrees C; range, 44-50 degrees C) compared with females (median, 45 degrees C; range, 43-50 degrees C; P > 0.05). There was a high degree of repeatability with rectal heat and balloon distention thresholds, but not electrostimulation thresholds. A strong correlation was found between rectal heat thresholds and defecatory desire (r = 0.71; P < 0.001) and maximum tolerable volumes (r = 0.8; P < 0.001) measured with balloon distention. CONCLUSION: This is the first demonstration of a repeatable sensory response to heat stimulation in the rectum of normal subjects. Strong correlation between heat thresholds and balloon distention to maximum tolerable volumes and defecatory desire suggest common sensory afferent pathway excitation. Heat stimulation is a simple technique that has a high degree of repeatability and may be an objective assessment of polymodal nociceptor function in the rectum.

Adolescent↗