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ABSTRACT: La physiologie anorectale fait intervenir trois organes: deux organes réservoir (le côlon et le rectum) et un organe résistif
(le canal anal entouré de l’appareil sphinctérien lisse et strié). L’arrivée des matières dans l’ampoule rectale va être à
l’origine de deux phénomènes: 1) la perception de plénitude rectale; 2) le réflexe d’échantillonnage. À partir de là, et en
fonction des conditions environnementales, le sujet sera capable de différer ou de satisfaire son besoin exonérateur. Lors
de la défécation, la force d’expulsion du bol fécal est engendrée, d’une part, par la contraction de l’ampoule rectale associée
à une fermeture de la charnière rectosigmoïdienne et, d’autre part, par un phénomène propulsif assuré par une augmentation
de la pression intra-abdominale associée à une activité contractile du rectum. De façon concomitante, les sphincters anaux
interne et externe se relâchent assurant ainsi une parfaite synergie rectosphinctérienne.
Anorectal physiology involves three organs. Two of these are reservoirs: the colon and the rectum. The third is an organ of
resistance: the anal canal surrounded by the smooth and striated muscle of the sphincteric apparatus. The arrival of material
in the rectal ampulla initiates two phenomena: the recognition of rectal filling and the sampling reflex. From then on, and
depending on environmental conditions, the subject will be able to satisfy or defer the need to empty his rectum. During defaecation,
the force of expulsion of the faecal mass is generated both by contraction of the rectal ampulla combined with closure of
the rectosigmoid junction and by propulsion resulting from contractile activity of the rectum and an increase in intra-abdominal
pressure. At the same time, the internal and external anal sphincters relax, thus ensuring perfect recto-sphincteric coordination.
Mots clésDéfécation-Appareil anorectal-Continence-Innervation extrinsèque-Innervation intrinsèque
KeywordsDefaecation-Anorectal apparatus-Continence-Extrinsic innervation-Intrinsic innervation
Pelvi-périnéologie 04/2012; 5(3):166-170. · 0.07 Impact Factor
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S Gallas,
F Michot,
J L Faucheron,
G Meurette,
P A Lehur,
X Barth,
H Damon,
F Mion,
E Rullier,
F Zerbib,
I Sielezneff,
M Ouaïssi,
P Orsoni,
V Desfourneaux,
L Siproudhis,
M Mathonnet,
J F Menard,
A M Leroi
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ABSTRACT: Sacral nerve stimulation (SNS) has a place in the treatment algorithm for faecal incontinence (FI). However, after implantation, 15-30% of patients with FI fail to respond for unknown reasons. We investigated the effect of SNS on continence and quality of life (QOL) and tried to identify specific predictive factors of the success of permanent SNS in the treatment of FI.
Two hundred consecutive patients (six men; median age = 60; range 16-81) underwent permanent implantation for FI. The severity of FI was evaluated by the Cleveland Clinic Score. Quality of life was evaluated by the French version of the American Society of Colon and Rectal Surgeons (ASCRS) quality of life questionnaire (FIQL). All patients underwent a preoperative evaluation. After permanent implantation, severity and QOL scores were reevaluated after six and 12 months and then once a year.
The severity scores were significantly reduced during SNS (P = 0.001). QOL improved in all domains. At the 6-month follow-up, the clinical outcome of the permanent implant was not affected by age, gender, duration of symptoms, QOL, main causes of FI, anorectal manometry or endoanal ultrasound results. Only loose stool consistency (P = 0.01), persistent FI even though diarrhoea was controlled by medical treatment (P = 0.004), and low stimulation intensity (P = 0.02) were associated with improved short-term outcomes. Multivariate analysis confirmed that loose stool consistency and low stimulation intensity were related to a favourable outcome.
Stool consistency and low stimulation intensity have been identified as predictive factors for the short-term outcome of SNS.
Colorectal Disease 03/2010; 13(6):689-96. · 2.93 Impact Factor
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ABSTRACT: Our aim was to determine whether ventilation and swallowing tasks can modify oropharyngeal cortical motor organisation. Mylohyoid motor-evoked potentials (MEP) induced by non-focal (NF) and focal (F) magnetic stimulations were recorded in nine healthy volunteers four times, with 1 week between each recording. Baseline values were evaluated and their reproducibility was assessed 1 week later. Thereafter, the subjects were asked to perform swallowing and ventilation tasks in random order 15 min per day for 1 week. The NF MEP amplitudes after the swallowing and ventilation tasks increased after effortful swallows (p<0.001) and ventilation efforts (p<0.001). The F MEP amplitudes obtained after focal cortical stimulations increased after effortful swallows (p<0.01) and ventilation efforts (p<0.05). The cortical magnitude of the oropharyngeal muscle representation increased after swallowing practice (p<0.01). In conclusion, swallowing and ventilation tasks modified the motor cortex of oropharyngeal muscles and should be evaluated for use in rehabilitation strategies.
Respiratory Physiology & Neurobiology 06/2009; 167(2):208-13. · 2.24 Impact Factor
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ABSTRACT: Although sacral nerve root stimulation (SNS) can result in a symptomatic improvement of faecal incontinence, the mechanism of action remains unknown. The aim of this study was to assess whether short-term magnetic SNS can inhibit pharmacologically induced propulsive colonic contractions. Twelve healthy volunteers (median age: 43.5 years old) were studied on two separate occasions and randomized into either active (15 Hz, 100% output intensity for 5 s min(-1) for 30 min) or sham rapid rate lumbosacral magnetic stimulation (rLSMS). Colorectal motility was recorded with a manometric catheter located at the most proximal transducer in the left colon and the most distal, in the rectum. Colonic contractions were provoked by instilling Bisacodyl. The effects of rLSMS on colonic, sigmoid and rectal contractions were monitored and recorded after Bisacodyl instillation. The appearance of high-amplitude contractions propagated or not (HAC/HAPC) provoked by Bisacodyl instillation was significantly delayed during active compared to sham stimulation (P = 0.03). There was no difference in the characteristics of HAC/HAPC (i.e. frequency, amplitude, duration, velocity of propagation) or the motility index with active or sham stimulation. The perception of urgency tended to be decreased with rLSMS following Bisacodyl instillation. The catheter was expulsed within a median of 16.5 min (range 8-39) after Bisacodyl administration during active stimulation compared to 14 min (range 5-40) during sham stimulation (P = 0.03). This study suggests that rLSMS could delay the appearance of the first Bisacodyl-induced colonic contractions.
Neurogastroenterology and Motility 01/2009; 21(4):411-9. · 3.41 Impact Factor
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ABSTRACT: Fecal incontinence (FI) is a debilitating condition that can be socially and personally incapacitating. A broad range of treatment options, often stepwise, are available, depending on severity. This prospective study reports a large single-centered series of patients who have benefited of temperature-controlled radio frequency (Secca) energy delivered to the anal canal.
This investigation was a single-center, nonrandomized, prospective, clinical study of a single patient group with each serving as the control. All patients had experienced FI for at least 3 months and had attempted, but were not satisfied, with the results of medical and/or surgical therapies. The study aims to evaluate changes in FI symptom scores and quality of life between the baseline and follow-up intervals.
Between March 2005 and March 2006, 15 Secca procedures were performed. All 15 patients were alive and in contact with the investigational site at time of 12 months. There were no long term complications. The mean Wexner score improved from 14.07 (+/-4.5) at baseline to 12.33 (+/-4.6) at 1 year (p=0.02). The mean fecal incontinence quality of life of life score was only improved in the depression subscore. There were no changes in endoanal ultrasound and anorectal manometry.
This prospective trial confirmed the safety of the Secca procedure. Although we demonstrated a significant improvement in the Wexner Score, these clinical results have to be mitigated because most patients remained in the moderate incontinences category as defined by the scoring system and did not improved their quality of life excepted in the depression subscore.
International Journal of Colorectal Disease 08/2008; 23(10):993-7. · 2.38 Impact Factor
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ABSTRACT: High-frequency/low-energy gastric electrical stimulation (GES) is an efficient therapy to treat gastric emptying-related disorders but its mechanism of action remains poorly understood. We aimed to assess the effects of high-frequency/low-energy GES on corticotropin-releasing factor (CRF)-producing neurons in the paraventricular nucleus of the hypothalamus (PVN), which are involved in gastric ileus induced by laparotomy. Two electrodes were implanted in the rat gastric antrum during laparotomy, then stimulation (amplitude: 2 mA; pulse duration 330 micros; frequency: 2 Hz; 1 min ON/2 min OFF) or sham stimulation (control group) were applied. Using immunohistochemistry, the number of c-Fos protein-expressing neurons (c-Fos protein-immunoreactive cells, Fos-IR) was quantified in the PVN after 1 h of stimulation. The number of neurons expressing simultaneously c-Fos protein and CRF mRNA was measured by means of immunocytochemistry combined with in situ hybridization. Finally, c-Fos and CRF mRNA levels in the hypothalamus were determined by in situ hybridization or quantitative reverse transcriptase-polymerase chain reaction. Fos-IR in the PVN was significantly decreased 1 h after GES (P<0.05) but was not affected by sub-diaphragmatic vagotomy. The number of neurons containing c-Fos protein and CRF mRNA was lower in the GES group compared with the control group (P<0.05). In addition, c-Fos and CRF mRNA levels in the PVN were significantly decreased by GES (P<or=0.05). It is concluded that acute GES reduces the number of CRF-producing neurons and decreases CRF expression in the PVN during post-operative gastric ileus.
Neuroscience 09/2007; 148(3):775-81. · 3.38 Impact Factor
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ABSTRACT: This work aimed to study mylohyoid motor-evoked potentials (MHMEPs) and examined if it is related to chronic stroke dysphagia. Conduction time (CT) and amplitudes of the right and left MHMEPs in response to focal cortical magnetic stimulations over affected and unaffected hemispheres were recorded in 16 stroke patients with aspiration (n = 9) or residue (n = 7) and compared with eight control patients. In control group, MHMEPs were present on ipsilateral and contralateral sides after stimulation of both hemispheres and permitted to determine a dominant hemisphere. In stroke patients, after stimulation of the affected hemisphere, ipsilateral MEPs had a longer CT and lower amplitudes in patients with aspiration compared with patients with residue or control patients (P < 0.05). Contralateral CT was not different between the three groups, but amplitudes were lower in patients with residue and aspiration than in control patients (P < 0.01). In the unaffected hemisphere, MHMEPs were present, and not different between the three groups for the ipsilateral side and amplitudes were decreased in contralateral side in patients with residue. In conclusion, MHMEP alterations of the affected hemisphere related to chronic stroke dysphagia severity and were closed to normal in the unaffected hemisphere.
Neurogastroenterology and Motility 06/2007; 19(6):453-8. · 3.41 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Our aim was to determine whether ventilation and swallowing tasks can modify oropharyngeal cortical motor organisation. Mylohyoid motor-evoked potentials (MEP) induced by non-focal (NF) and focal (F) magnetic stimulations were recorded in nine healthy volunteers four times, with 1 week between each recording. Baseline values were evaluated and their reproducibility was assessed 1 week later. Thereafter, the subjects were asked to perform swallowing and ventilation tasks in random order 15 min per day for 1 week. The NF MEP amplitudes after the swallowing and ventilation tasks increased after effortful swallows (p < 0.001) and ventilation efforts (p < 0.001). The F MEP amplitudes obtained after focal cortical stimulations increased after effortful swallows (p < 0.01) and ventilation efforts (p < 0.05). The cortical magnitude of the oropharyngeal muscle representation increased after swallowing practice (p < 0.01). In conclusion, swallowing and ventilation tasks modified the motor cortex of oropharyngeal muscles and should be evaluated for use in rehabilitation strategies.
Respiratory Physiology & Neurobiology.
