Threshold Volume (threshold + volume)

Distribution by Scientific Domains


Selected Abstracts


Differences in ano-neorectal physiology of ileoanal and coloanal reconstructions for restorative proctectomy

COLORECTAL DISEASE, Issue 4 2010
A. D. Rink
Abstract Objective, Restorative proctectomy with straight coloanal anastomosis (CAA) and restorative proctocolectomy with ilealpouch-anal anastomosis (IPAA) are options for maintaining bowel integrity after rectal resection. The aim of this study was to compare clinical function and anorectal physiology in patients treated with CAA and IPAA. Method, Three-dimensional vector-manometry and neorectal volumetry were performed in straight CAA [53 patients (34 male)] and IPAA [61 patients (39 male)] for ulcerative colitis. Function was assessed using a 14 day incontinence diary. Results, Function was similar in both groups, but neorectal compliance and threshold volumes for sensation, urge and maximum tolerated volume (MTV) were significantly higher after IPAA than after CAA. Mean pressure, vector volume and sphincter symmetry at rest were significant determinants of continence in both groups but squeeze pressure did not correlate significantly with function in either group. Threshold volume, MTV, and compliance were significantly correlated with frequency of defecation in patients with IPAA but not with CAA. Conclusion, A strong consistent resting anal sphincter pressure is one determinant of continence after both IPAA and CAA. Squeeze pressures do not influence the functional result. In IPAA but not CAA, the neorectum has a reservoir function which correlates with the postoperative frequency of defaecation. [source]


External urethral sphincter activity in diabetic rats

NEUROUROLOGY AND URODYNAMICS, Issue 5 2008
Guiming Liu
Abstract Aim To examine the temporal effects of diabetes on the bladder and the external urethral sphincter (EUS) activity in rats. Methods Female Sprague-Dawley rats (n,=,24) were divided into two groups: streptozotocin-induced diabetic rats and age-matched controls. Cystometrograms (CMGs) were taken under urethane anesthesia and electromyograms (EMG) of the EUS were evaluated in all rats at 6 and 20 weeks after diabetes induction. After EMG assessment, the tissues of the urethra were harvested for morphological examination. Results Diabetes caused reduction of body weight, but an increase in bladder weight. CMG measurements showed diabetes increased threshold volume, contraction duration, high-frequency oscillations (HFO), and residual volume. Peak contraction amplitude increased in 6-week but not 20-week diabetic rats. EUS-EMG measurements showed increased frequency of EUS-EMG bursting discharge during voiding in 6-week diabetic rats (8.1,±,0.2 vs. 6.9,±,0.6/sec) but not in 20-week (5.8,±,0.3 vs. 6.0,±,0.2/sec) diabetic rats compared with controls. EUS-EMG bursting periods were also increased in both 6-week and 20-week diabetic rats compared with controls. EUS-EMG silent periods were reduced in 6-week diabetic rats, but were not changed in 20-week diabetic rats compared with controls. Active periods did not change in 20-week diabetic rats, but increased in 6-week diabetic rats compared with controls. Morphometric analysis showed atrophy of the EUS after 20 week but not 6 weeks of DM induction. Conclusions Our data indicates diabetes causes functional and anatomical abnormalities of the EUS. These abnormalities may contribute to the time-dependent bladder dysfunction in diabetic rats. Neurourol. Urodynam. 27:429,434, 2008. © 2008 Wiley-Liss, Inc. [source]


Deterioration of the Pharyngo-UES Contractile Reflex in the Elderly ,

THE LARYNGOSCOPE, Issue 9 2000
Junlong Ren MD
Abstract Objectives/Hypothesis Deterioration of aerodigestive tract reflexes such as the esophagoglottal and pharyngoglottal closure reflexes and pharyngeal swallow has been documented in the elderly. However, the effect of aging on the contractile response of the upper esophageal sphincter (UES) to pharyngeal water stimulation has not been studied. The aim of this study was to characterize the pharyngo-UES reflex in the healthy elderly. Methods We studied nine healthy elderly (77 ± 1 y [SD]; four men, five women) and nine healthy young volunteers (26 ± 2 y [SD]; four men, five women). A UES sleeve sensor was used to measure the pressure. We tested pharyngeal stimulation induced by rapid pulse and slow continuous injection of water. Results The volume of water required to stimulate the pharyngo-UES contractile reflex by rapid pulse injection in the elderly (0.5 ± 34 0.1 mL) was significantly higher than that in the young (0.1 ± 0.02 mL) (P < .05). In contrast to young subjects, there was no pressure increase in resting UES pressure observed in the elderly for continuous pharyngeal water infusion. In both young and elderly, the threshold volume for the pharyngo-UES contractile reflex was significantly lower than that for pharyngeal swallows. Conclusions The pharyngo-UES contractile reflex deteriorates with aging. This deterioration is primarily due to abnormalities of the afferent limb of the reflex. [source]


Contribution of the pudendal nerve to sensation of the distal rectum

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 7 2005
C. L. H. Chan
Background: Anal and rectal sensory mechanisms and pudendal nerve function are important in the control of faecal continence. The contribution of the pudendal nerve to sensation of the distal rectum was investigated. Methods: Heat thresholds in the anal canal, distal and mid rectum were measured using a specially designed thermoprobe. Rectal sensory threshold volumes were measured using the balloon distension method. Needle electrodes were inserted into the external anal sphincter. Pudendal nerve block was performed through a perineal approach, and completeness assessed by loss of electromyographic activity. Heat and rectal volume thresholds were measured again following unilateral and bilateral pudendal nerve block. Results: The technique was successful in four of six volunteers. Bilateral pudendal nerve block produced complete anaesthesia to heat in the anal canal (P = 0·029), but had no effect on heat thresholds in the distal or mid rectum. Rectal sensory threshold volumes were also unaffected by pudendal nerve anaesthesia. Conclusion: Anal canal sensation is subserved by the pudendal nerve, but this nerve is not essential to nociceptive sensory mechanisms in the distal or mid rectum. The transition between visceral control mechanisms in the lower rectum and somatic mechanisms in the anal canal may have functional importance in the initiation of defaecation and the maintenance of continence. Copyright © 2005 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]


Differences in ano-neorectal physiology of ileoanal and coloanal reconstructions for restorative proctectomy

COLORECTAL DISEASE, Issue 4 2010
A. D. Rink
Abstract Objective, Restorative proctectomy with straight coloanal anastomosis (CAA) and restorative proctocolectomy with ilealpouch-anal anastomosis (IPAA) are options for maintaining bowel integrity after rectal resection. The aim of this study was to compare clinical function and anorectal physiology in patients treated with CAA and IPAA. Method, Three-dimensional vector-manometry and neorectal volumetry were performed in straight CAA [53 patients (34 male)] and IPAA [61 patients (39 male)] for ulcerative colitis. Function was assessed using a 14 day incontinence diary. Results, Function was similar in both groups, but neorectal compliance and threshold volumes for sensation, urge and maximum tolerated volume (MTV) were significantly higher after IPAA than after CAA. Mean pressure, vector volume and sphincter symmetry at rest were significant determinants of continence in both groups but squeeze pressure did not correlate significantly with function in either group. Threshold volume, MTV, and compliance were significantly correlated with frequency of defecation in patients with IPAA but not with CAA. Conclusion, A strong consistent resting anal sphincter pressure is one determinant of continence after both IPAA and CAA. Squeeze pressures do not influence the functional result. In IPAA but not CAA, the neorectum has a reservoir function which correlates with the postoperative frequency of defaecation. [source]