Impact of anesthetics on pyloric characteristics measured using the EndoFLIP® system in patients with gastroparesis

BACKGROUND

Pyloric distensibility has been reported as a predictive measure in gastroparesis. Measures can be obtained either during endoscopy under anesthesia or in unsedated patients. However, the impact of anesthetic drugs on the results of pyloric characteristics remains unknown. The objective of the present study was to determine the impact of anesthetics on pyloric characteristics measured using EndoFLIP® in patients with gastroparesis.

METHODS

Consecutive patients with gastroparesis from three French tertiary centers were retrospectively analyzed. Patients with a previous history of pyloric intervention were not considered for analysis. Medical records were reviewed for the potential use of anesthetic drugs during EndoFLIP® measurement.

KEY RESULTS

One hundred twenty-five patients were included in the present study [median age: 55.0 years (43.0-66.0)]. Thirty-four patients (27.2%) had pyloric assessment without general anesthesia and 91 patients (72.8%) with general anesthesia. Pyloric pressure at 40 mL of distension was higher in patients with general anesthesia in comparison with patients without general anesthesia [18.7 (13.0-25.6) mmHg vs. 15.4 (11.9-20.7) mmHg; p = 0.044)]. In multivariate analysis, suxamethonium chloride administration was associated with decreased pyloric distensibility (OR: 3.9; 95% CI: 1.3-11.4; p = 0.013) while ephedrine was rather associated with increased pyloric distensibility (OR: 0.3; 95% CI: 0.1-0.9; p = 0.036).

CONCLUSIONS AND INFERENCES

This study is the first to have found an impact of general anesthesia on pyloric measurement using the EndoFLIP®. Therefore, further studies are needed to confirm these findings, if possible, prospective studies.

Delayed gastric emptying as an independent predictor of mortality in gastroparesis

BACKGROUND

Whether gastroparesis is associated with a shortened life expectancy remains uncertain as no systematic study has evaluated the impact of gastroparesis on mortality, based on gastric emptying (GE) tests.

AIM

This study aimed to assess whether delayed GE was predictive of mortality.

METHODS

GE was measured using a 13C-octanoic acid breath test in 1563 consecutive patients. Delayed GE at baseline defined the gastroparesis group. Patients were followed up for a mean of 8.9 years, yielding 13 466 patients per year. Mortality was assessed using the French CepiDc database with data from local civil registries. The cause of death was determined from medical records. Mortality rates were assessed using the Kaplan-Meier method and hazard ratio (HR) was calculated using the Cox regression model.

RESULTS

Age and symptoms severity were not different among patients with normal GE (n = 1179) and with delayed GE (n = 384) while diabetes mellitus was more frequent in the gastroparesis group. Kaplan-Meier analysis showed increased mortality in the gastroparesis group compared to patients with normal GE. Cox regression model identified delayed GE as independently associated with increased mortality (HR = 1.63[1.09-2.42]; P = 0.02). Other independent factors associated with increased mortality included age, male sex, and diabetes. No difference was observed between groups for the cause of death, with cancer and cardiovascular disease being the leading causes.

CONCLUSION

This study has shown that gastroparesis, diagnosed on GE tests, was associated with increased mortality, independently of age, sex, BMI or diabetes status (NCT04918329).

Is it necessary to perform a morphological assessment for an esophageal motility disorder? A retrospective descriptive study

BACKGROUND

Esophageal motility disorders are most often of primary origin but may be secondary to an occult malignancy or another etiology. High-resolution esophageal manometry cannot differentiate between secondary or primary origin. This study aimed at discussing the usefulness of a morphological assessment in the diagnosis of specific esophageal motility disorders, and to establish the predictive factors of a potential secondary origin.

METHODS

In this retrospective study, patients with suspected esophageal motility disorders who underwent an esophageal manometry were included. High-resolution manometry results were interpreted according to the Chicago Classification, 3rd version. The results of endoscopic ultrasound and computed tomography, assessed by a panel of experts, allowed to diagnose a secondary origin.

KEY RESULTS

Out of 2138 patients undergoing manometry, 502 patients had a esophageal motility disorder suspect to be from secondary origin; among them 182 patients underwent tomography or endoscopic ultrasound. According to experts, 16 patients (8.8%) had a secondary esophageal motility disorder: esophagogastric junction outflow obstruction (n = 7), jackhammer disorder (n = 4), achalasia (n = 3) and localized pressurization (n = 2). The etiology was malignant in 8 patients. Predictive factors suggesting potential secondary esophageal motility disorders were smoking, age ≥ 58 years and an Integrated Relaxation Pressure higher than 10 mmHg for water swallows.

CONCLUSION AND INFERENCES

Esophageal motility disorders with organic origin are not uncommon. A morphological assessment using endoscopic ultrasonography and/or computed tomography may be of use to diagnose a secondary origin, especially in the elderly and smokers.

The use of impedance planimetry (Endoscopic Functional Lumen Imaging Probe, EndoFLIP® ) in the gastrointestinal tract: A systematic review

BACKGROUND AND PURPOSE

The EndoFLIP® system is a method of delineating impedance and was first designed to investigate the characteristics of the esophago-gastric junction. In the last decade, its use was widened to investigate other sphincteric and non-sphincteric systems of the gastrointestinal tract. The objective of the present systematic review was to summarize the available data in literature on the use of the EndoFLIP® system in the gastrointestinal tract, including sphincteric and non-sphincteric regions. We performed a systematic review in accordance with recommendations for systematic review using PRISMA guidelines without date restriction, until June 2020, using MEDLINE-PubMed, Cochrane Library, and Google Scholar databases. Only articles written in English were included in the present review. Five hundred and six unique citations were identified from all database combined. Of those, 95 met the inclusion criteria. There was a lack of standardization among studies in terms of anesthetic drugs use, probe placement, and inflation protocol. In most cases, only small cohorts of patients were included. Most studies investigated the EGJ, with a potential use of the EndoFLIP® to identify a subgroup of patients with achalasia and for intraoperative assessment of treatment efficacy in achalasia. However, the use of EndoFLIP® in the esophageal body (esophageal panometry), other esophageal diseases (gastro-esophageal reflux disease, eosinophilic esophagitis), and other sphincter regions (anal canal, pylorus) will need further confirmatory studies. The EndoFLIP® system provides detailed geometric data of the gastrointestinal lumen but further works are needed to determine its use in clinical practice.

[Anorectal disorders in patients with multiple sclerosis: Physiopathology, prevalence, impact, and management]

OBJECTIVE

Neurogenic bowel disorders (NBD) are frequently observed in patients with multiple sclerosis (MS); the prevalence of constipation is estimated to be 35-54 % and fecal incontinence between 29 and 51 % (LE 4). They contribute to the deterioration of patients' quality of life (LE 4). The aim of this article is to review the literature on the physiopathology, prevalence, impact, and management of bowel disorders in patients with MS in order to educate caregivers about their existence and thus help them to optimize therapeutic choices.

MATERIALS AND METHODS

A bibliographic search was conducted between 2000 and 2019 and 31 relevant scientific articles were selected. Relevant references were subsequently added, bringing the total to 50 articles. A level of scientific evidence (LE) was assigned to each article, except for literature reviews.

RESULTS

The origin of NBD is multifactorial and includes impairment of neurological pathways, polypharmacy, behavioural disorders, and loss of autonomy (LE 4). Patients with MS should be questioned about their bowel habits and, in cases of proven NBD, specific management options should be offered. The first step concerns the dietary and lifestyle rules associated with the use of laxatives, suppositories, and/or enemas (LE 4). In the event of failure, therapies such as abdominal massages (LE 1 and 2), biofeedback and transanal irrigation can be proposed (LE 4). Anterograde colonic irrigation may also be an option (LE 4). The efficacy of stimulating the posterior tibial nerve needs to be proven (LE 4). The implantation of a sacral neuromodulation device is, for the moment, difficult due to the impossibility of performing a spinal magnetic resonance imaging during follow-up. A stoma improves the quality of life of patients and should not be proposed too late.

CONCLUSION

Effective treatment of NBD improves the quality of life of patients and reduces the incidence of bladder disorders (LE 4).

Does Bilateral Deep Brain Stimulation of the Subthalamic Nucleus Modify Ano-Rectal Motility in Parkinson's Disease? Results of a Randomized Cross-Over Study

BACKGROUND

Ano-rectal motility impairment is often observed during Parkinson's disease (PD), generating symptoms as constipation and/or incontinence with impaired quality of life. Subthalamic nuclei (STN) deep brain stimulation (DBS) improves motor symptoms of PD, but its effects on anorectal motility are unknown. This study aimed to assess the effects of STN-DBS on the anorectal motility in PD patients, in a randomized cross-over study.

METHODS

Sixteen PD patients with bilateral STN-DBS for at least 6 months were included. The anal resting pressure, duration and maximal amplitude of squeeze effort, recto-anal inhibitory reflex, maximal tolerable rectal volume, and anal pressure during defecation effort were measured and compared after STN-DBS was switched OFF and then ON for 2 hours, or vice-versa, in a randomized order.

KEY RESULTS

STN-DBS increased maximal amplitude of anal squeezing pressure (OFF: 85.7 ± 14.5 vs ON: 108.4 ± 21.0 cmH₂ O; P = 0.02), with no significant difference in the duration (P = 0.10). No other significant difference was found between stimulation conditions (OFF vs ON) for anal resting pressure (OFF: 72.5 ± 8.6 cmH₂ O vs ON: 71.7 ± 9.0 cmH₂ O; P = 0.24), recto-anal inhibitory reflex, maximal tolerable rectal volume (OFF: 231 ± 24 mL vs ON: 241 ± 26 mL; P = 0.68), or anal pressure during defecation effort with a similar rate of ano-rectal dyssynergia (7/16 and 8/16 with and without STN-DBS, respectively). No order effect (ON-OFF vs OFF-ON) was observed.

CONCLUSION AND INFERENCES

STN-DBS increased anal squeezing pressure, but did not modify anorectal dyssynergia in PD patients, This study demonstrated the involvement of STN in the voluntary control of anorectal motility in PD patients.

Development of a Remote-Controlled Implantable Rat Sacral Nerve Stimulation System

OBJECTIVES

Sacral nerve stimulation (SNS) is a surgical treatment of urinary and fecal incontinence. Despite its clinical efficacy, the mechanisms of action of SNS are still poorly known. This may be related to the use of acute stimulation models. Up to date, no rodent model of chronic SNS implants has been developed. Therefore, the aim of this study was to create a fully implantable and remotely controllable stimulating device to establish an animal model of chronic SNS.

MATERIALS AND METHODS

The stimulating device consisted of an implantable pulse generator linked to a platinum electrode. The communication with the device was made through an inductive link which allowed to adjust the stimulation parameters; that is, to turn the device on and off or check the battery status remotely. Rats underwent two surgical procedures. In the first procedure, we achieved chronic sacral stimulation but the implanted electrode was not fixated. In the second procedure, the electrode was fixated in the sacral foramen using dental resin. In both cases, the correct positioning of the electrode was evaluated by computed tomography (CT) imaging and the presence of tail tremor in response to high intensity stimulation. We only tested the function of implanted electrode with fixation using micturition frequency assessment following bipolar or unipolar SNS for three days after recovery.

RESULTS

CT imaging showed that implantation of the electrode required fixation as we found that the second surgical procedure yielded a more precise placement of the implanted electrode. The correct placement of implanted electrode observed with imaging was always correlated with a successful tail tremor response in rats, therefore we pursued our next experiments with the second surgical procedure and only assessed the tail tremor response. We found that both bipolar and unipolar SNS reduced micturition frequency.

CONCLUSION

This stimulating device provides an efficient method to perform chronic SNS studies in rats.

The diagnostic value of the functional lumen imaging probe versus high-resolution anorectal manometry in patients with fecal incontinence

BACKGROUND

The functional lumen imaging probe (EndoFLIP^® ) is a new technology that measures the distensibility of the anal canal represented by the anal distensibility index. The aims of this study were (i) to compare the anal distensibility index to anal pressure in a cohort of patients with fecal incontinence (FI) and (ii) to compare the diagnostic value of the EndoFLIP^® to that of high-resolution anorectal manometry (HRAM) in the same cohort of patients.

METHODS

Eighty-three consecutive patients with FI who underwent EndoFLIP^® and HRAM assessments were enrolled. The diagnostic value of the EndoFLIP^® was compared to that of HRAM and agreement between EndoFLIP^® and HRAM data was assessed.

KEY RESULTS

More than 70% of the patients diagnosed with anal deficiency at rest and/or during voluntary contractions by HRAM had the same diagnosis using the EndoFLIP^® . Two patients with higher distensibility indexes at rest had normal anal resting pressures. Sixteen patients with a normal EndoFLIP^® index (ie, normal distensibility index at rest and during voluntary contractions) had an abnormal HRAM result. Seven of these 16 patients (44%) had no sphincter lesion or neuropathic disorder that could explain an abnormal anal sphincter function.

CONCLUSIONS & INFERENCES

We demonstrated that the anal distensibility index and HRAM results are largely in agreement. We did, however, identify several discrepancies between the two techniques, indicating that they may be complementary.

Reinnervation of the diaphragm by the inferior laryngeal nerve to the phrenic nerve in ventilator-dependent tetraplegic patients with C3-5 damage

The aim of this study was to evaluate the feasibility of unilateral diaphragmatic reinnervation in humans by the inferior laryngeal nerve. This pilot study included chronically ventilated tetraplegic patients with destruction of phrenic nerve motoneurons. Five patients were included. They all had a high level of tetraplegia, with phrenic nerve motor neuron destruction. They were highly dependent on ventilation, without any possibility of weaning. They did not have other chronic pathologies, especially laryngeal disease. They all had diaphragmatic explorations to diagnose the destruction of the motoneurons of the phrenic nerves and nasoendoscopy to be sure that they did not have laryngeal or pharyngeal disease. Then, surgical anastomosis of the right phrenic nerve was performed with the inferior laryngeal nerve, by a cervical approach. A laryngeal reinnervation was performed at the same time, using the ansa hypoglossi. One patient was excluded because of a functional phrenic nerve and one patient died 6 months after the surgery of a cardiac arrest. The remaining three patients were evaluated after the anastomosis every 6 months. They did not present any swallowing or vocal alterations. In these three patients, the diaphragmatic explorations showed that there was a recovery of the diaphragmatic electromyogram of the right and left hemidiaphragms after 1 year. Two patients had surgical diaphragmatic explorations for diaphragmatic pacing 18-24 months after the reinnervation with excellent results. At 36 months, none of the patients could restore their automatic ventilation. In conclusion, this study demonstrated that diaphragmatic reinnervation by the inferior laryngeal nerve is effective, without any vocal or swallowing complications.

Acute sacral nerve stimulation reduces visceral mechanosensitivity in a cross-organ sensitization model

BACKGROUND

Sacral nerve stimulation (SNS) is a surgical treatment of fecal and urinary incontinence that consists of inserting a stimulating electrode into one of the s3 or s4 sacral holes. In addition to the benefit of SNS in the treatment of incontinence, recent studies showed that SNS is effective in the treatment of irritable bowel syndrome as well as bladder pain syndrome. The aim of this study was to evaluate the effect of SNS on visceral mechanosensitivity in a cross-organ sensitization rat model.

METHODS

Hypersensitive model was obtained by instillation of acetic acid into the bladder of rats during 5 minutes, 30 minutes before the start of the experiments. Visceral sensitivity was assessed by monitoring the change in mean arterial pressure in response to graded isobaric colorectal distension series. To decipher the mechanisms underlying SNS effect, rats were administered intravenously either a nonselective opioid receptor antagonist (naloxone) or a nitric oxide synthesis antagonist (L-NAME). Neuronal activation in the dorsal horn of the sacral spinal cord was measured by counting c-fos immunoreactive cells in response to colorectal distension and NMS.

KEY RESULTS

Intravesical acetic acid instillation increased mean arterial pressure variation in response to colorectal distension when compared to saline group. SNS reduced the variation in arterial pressure. Colorectal distension induced a rise in c-fos immunoreactive cells in the dorsal horn of the spinal cord. This effect was reduced by SNS.

CONCLUSIONS & INFERENCES

SNS reduces visceral mechanosensitivity in a cross-organ sensitization model.

Do endoflip assessments of anal sphincter distensibility provide more information on patients with fecal incontinence than high-resolution anal manometry?

BACKGROUND

Anal manometry is the standard technique for evaluating anal sphincter function. However, the functional lumen imaging probe (EndoFLIP(®) ) can be used to measure sphincter distensibility during volume-controlled distensions. Our aims were (i) to assess anal distensibility in patients with fecal incontinence (FI) and in healthy subjects using the EndoFLIP(®) and (ii) to compare the results with anal pressures measured by 3D high-resolution manometry (3D-HRM) to determine whether the EndoFLIP(®) was more sensitive and specific for diagnosing FI than 3D-HRM.

METHODS

EndoFLIP(®) and 3D-HRM assessments of 34 female FI patients and 40 healthy female subjects were performed. Anal distensibility was measured as the median cross-sectional area at the narrowest point divided by the corresponding intra-bag pressure at rest and during peak voluntary contraction and was expressed in mm(2) /mmHg.

KEY RESULTS

A 40-mL anal distensibility index was selected for further comparisons as it provided the best discrimination between the FI patients and the healthy subjects. The index was significantly higher in the FI patients than in the healthy subjects at rest (p = 1.10(-4) ) and during voluntary contraction (p = 1.10(-4) ). The index at rest and during voluntary contraction appeared to be more appropriate than anal pressures for discriminating between FI patients and healthy subjects.

CONCLUSIONS & INFERENCES

The present study confirmed that FI is associated with an abnormally high distensibility index at rest and during voluntary contraction. The ability of the distensibility index to discriminate between FI patients and healthy subjects was significantly better than anal pressure.

Impact of deep brain stimulation on pharyngo-esophageal motility: a randomized cross-over study

BACKGROUND

Bilateral subthalamic nucleus (STN) stimulation is used to alleviate Parkinson's disease (PD) motor symptoms. Recently, it has been shown that this therapeutic also increased gut cholinergic contractions. We therefore investigated the effect of STN stimulation on esophageal motility in an interventional randomized study.

METHODS

Sixteen humans PD patients (4 women, 12 men; age: 62.4 ± 9.3-years old) who underwent STN stimulation for at least 6 months were randomly evaluated with either stimulator turned OFF then ON, or inversely. Esophageal high resolution manometry was performed at the end of each ON and OFF period, with a 5 min resting period followed by ten swallows of 5 mL.

KEY RESULTS

During the ON, an increase in the distal contractility index was found (OFF: 1750 ± 629 vs ON: 2171 ± 755 mmHg/cm/s; p = 0.03), with no difference in the distal front velocity. A decrease in the integrative relaxation pressure of the lower esophageal sphincter (LES) was noted (OFF: 11.1 ± 1.8 mmHg vs ON: 7.2 ± 1.8 mmHg; p < 0.05) in ON. The LES resting pressure remained unchanged during the two periods. This resulted in a decrease in the intrabolus pressure (p = 0.03). No difference was observed for the upper esophageal sphincter, nor the pharyngeal contraction amplitude and velocity.

CONCLUSIONS & INFERENCES

In conclusion, STN stimulation in PD patients increased esophageal body contractions and enhanced the LES opening. This suggests that the nigrostriatal-striatonigral loop is involved in the control of esophageal motility.

Acute sacral nerve stimulation reduces visceral mechanosensitivity in Rat through spinal opioid pathway

BACKGROUND

Sacral nerve stimulation (SNS) is an alternative surgical treatment of refractory urge incontinence and/or fecal incontinence. Despite its clinical efficacy, the mechanisms of action of SNS remain poorly understood. The aim of this experimental study was to evaluate the effect of SNS on visceral mechanosensitivity in rats.

METHODS

Anesthetized Sprague-Dawley rats were treated with SNS or sham stimulation. SNS was performed by implanting an electrode close to the sacral nerve root S1. Rats were administered either a non-selective opioid receptor antagonist (naloxone) or a nitric oxide synthase inhibitor (L-NAME). Colonic mechanosensitivity was evaluated using the variation of arterial blood pressure as a spino-bulbar reflex in response to graded isobaric colorectal distension (CRD). C-fos immunoreactive neurons were quantified in spinal and supraspinal sites. μ-opioid receptor (MOR) internalization was counted in the sacral spinal cord with sham or effective SNS in response to CRD.

KEY RESULTS

SNS reduced visceral mechanosensitivity in response to CRD. This effect was reversed by intrathecal and intraveinous naloxone administration. In both models, CRD induced increased c-fos immunoreactivity in the dorsal horn neurons of the sacral spinal cord and supraspinal areas. This increase was prevented by SNS. MOR internalization was significantly higher in stimulated group.

CONCLUSIONS & INFERENCES

SNS impacts on visceral mechanosensitivity by decreasing the spino-bulbar reflex in response to CRD. Spinal opioid receptors are likely involved in this effect.

Impaired fasting pyloric compliance in gastroparesis and the therapeutic response to pyloric dilatation

BACKGROUND

Pyloric pressure and compliance have never been investigated in health nor gastroparesis.

AIM

We hypothesised that pyloric pressure and/or compliance may be altered in gastroparesis.

METHODS

Fasting pyloric pressure and compliance were investigated in 21 healthy volunteers (HV), 27 gastroparetic patients (GP) and 5 patients who had undergone oesophagectomy without pyloroplasty as positive controls. Under videofluoroscopic control, pyloric compliance and pressure were measured by the EndoFLIP technique. Gastric emptying half time (T1/2 ) using (13) C-octanoic acid breath test, as well as symptoms and quality of life (GIQLI score) were also monitored.

RESULTS

Mean fasting pyloric compliance was measured at 25.2 ± 2.4 mm²/mmHg in HV, and was lower both in GP (16.9 ± 2.1 mm²/mmHg; P < 0.05) and patients with oesophagectomy (10.9 ± 2.9 mm²/mmHg; P < 0.05). By contrast, fasting pyloric pressure was not different among groups. Fasting pyloric compliance and pressure correlated with T1/2 in GP (R = -0.43; P = 0.04). Fasting pyloric compliance, but not pressure, correlated with symptoms and GIQLI score. Pyloric dilation in 10 GP with low fasting pyloric compliance (<10 mm²/mmHg) increased compliance from 7.4 ± 0.4 to 20.1 ± 4.9 mm²/mmHg (P < 0.01) and improved the GIQLI score from 72.5 ± 5.5 to 89.3 ± 6.1 (P = 0.04).

CONCLUSION

This prospective study assessed pyloric compliance for the first time, and showed that fasting pyloric compliance is decreased in gastroparetic patients and is associated with T1/2 , symptoms and quality of life. This suggests that pyloric compliance may be a new relevant metric in gastroparetic patients, and may be useful to target patients for pyloric dilation or botulinum toxin injection.

Effect of transcranial magnetic stimulation on rectal sensitivity in irritable bowel syndrome: a randomized, placebo-controlled pilot study

AIM

Repetitive transcranial magnetic stimulation (rTMS) applied to the motor cortex can induce analgesic effects in patients with chronic pain syndromes through its effect on central pain-modulatory systems. Our aim was to evaluate the effect of rTMS on rectal sensitivity in irritable bowel syndrome (IBS) patients.

METHOD

In this randomized, sham-controlled, proof-of concept trial, 21 IBS patients (11 women and 10 men; mean age 44.0 ± 12.6 years) were randomized, using a double-blind crossover protocol, to active or sham rTMS for 5 days of treatment. The primary outcome was the increase in the pressure pain threshold after rTMS. Secondary outcomes were the changes in maximum tolerated rectal volume, rectal compliance and average pain intensity between baseline and the end of the treatments.

RESULTS

There were no statistically significant differences between active and sham rTMS in terms of an increase in the pressure pain threshold, maximum tolerated volume and rectal compliance at the end of the treatments compared with baseline. However, in the subgroup of patients with the most marked rectal hypersensitivity, the volume threshold was significantly improved by active, but not by sham, rTMS (P = 0.03). Patients experienced a significant improvement in pain regardless of the type of stimulation.

CONCLUSION

This pilot study failed to demonstrate any benefit of rTMS on our primary end-point. However, the effect of rTMS on rectal tolerated volume in the most hypersensitive patients was encouraging enough to plan more powered studies.

Evoked pressure curves from the external anal sphincter following transcranial magnetic stimulation in healthy volunteers and patients with faecal incontinence

AIM

The hypothesis was tested that evoked pressure curves (EPCs) after transcranial magnetic stimulation (TMS) would provide additional neuropathophysiological information on the descending pathways to the external anal sphincter (EAS) in patients with faecal incontinence (FI).

METHOD

Twenty-five healthy subjects and 69 patients with FI were investigated. TMS was applied to the vertex, and EPCs were recorded with a probe placed through the EAS. TMS was performed with the EAS at rest and during contraction (facilitated responses). At least three responses were recorded for each modality. Clinical data and anorectal manometric, electrophysiological perineal and transanal ultrasound recordings were compared with respect to the EPC results.

RESULTS

There was no statistically significant difference between the EPCs of healthy subjects and FI patients. Twenty-three per cent of the FI patients had abnormal EPC latencies, with significantly lower voluntary contraction amplitudes (P = 0.03) and significantly higher rectal sensation (P = 0.04) than the other group. We found no significant difference between FI patients with and without abnormal EPC latencies in terms of clinical characteristics and electrophysiological and endoanal ultrasound parameters. There was no difference in the identified causes of the FI between the two groups.

CONCLUSION

As abnormal EPC latencies were found in 23% of FI patients with no known central neurological disease, abnormal EPC latencies might reveal undetected lesions of descending pathways in patients with FI.

Can multichannel intraluminal pH-impedance monitoring be limited to 3 hours? Comparison between ambulatory 24-hour and post-prandial 3-hour recording

Esophageal multichannel intraluminal pH-impedance recording (MII) is now a valid technique for determining the acidic, liquid, gas or mixed nature of gastroesophageal reflux episodes. However, some recordings may stop prematurely due to technical reasons or poor patient tolerance of the probe. Therefore, we questioned whether analysis of post-prandial 3-hour recording could predict the results obtained in ambulatory 24-hour recording. Fifty patients with symptoms of gastroesophageal reflux disease were investigated. For each patient, post-prandial 3-hour MII was recorded after a test meal, then followed by ambulatory 21-hour MII. Correlation between the total number of liquid reflux events in the 3-hour and 24-hour recordings was elevated (R=0.71; P<0.001), with better correlation for acid (R=0.80; P<0.001) and weak acid reflux (R=0.56; P<0.001) than non-acid reflux (R=0.44; P<0.01). Sensitivity and specificity of 3-hour recording in detecting elevated liquid reflux over 24 hours (id>75reflux/24 h) were 49% and 100%, respectively, for 8 or less liquid/mixed reflux events per 3 hours, and 78% and 88%, respectively for 15 or more liquid/mixed reflux events per 3 hours. The sensitivity and specificity of symptom association probability (SAP) calculated over 3 hours were 56% and 91%, respectively. In conclusion, we identified relevant indicators on the 3-hour post-prandial recording likely to give accurate prediction of absence or presence of gastroesophageal reflux disease from 24-hour MII recording.

Influence of gastric emptying on gastro-esophageal reflux: a combined pH-impedance study

BACKGROUND

The involvement of delayed gastric emptying (GE) in the pathophysiology of gastro-esophageal reflux disease (GERD) remains debated and has been to date only assessed using esophageal pH-metry that only detects acidic reflux. We therefore investigated whether delay in GE could impact on liquid, mixed, and gas reflux detected using combined esophageal pH-impedance recording.

PATIENTS AND METHODS

Thirty consecutive patients were explored with GE and esophageal pH-impedance measurement in the workup of typical symptoms of GERD. Gastric emptying was assessed using the (13) C-octanoic acid breath test and an ambulatory esophageal pH-impedance recording was performed off proton pump inhibitors (PPIs) for 24 h.

KEY RESULTS

Gastric emptying was normal in 17 patients and delayed in 13 patients. Delay in GE increased the daily number of liquid/mixed reflux events detected by combined esophageal pH-impedance monitoring, but had no effect of esophageal acid exposure or gas reflux. This translated in increased number of postprandial reflux events, with a longer bolus clearance time and increased esophageal proximal extension. In patient with delayed GE, symptomatic reflux had a higher proximal extension and a longer bolus clearance time compared to symptomatic reflux events from patients with normal GE.

CONCLUSIONS & INFERENCES

Delay in GE increases daily and postprandial liquid/mixed reflux events. Reflux characteristics differently trigger symptoms in patients with normal and delayed GE, and may impact on the therapeutic strategy.

Gastric electrical stimulation decreases gastric distension-induced central nociception response through direct action on primary afferents

Background & Aims

Gastric electrical stimulation (GES) is an effective therapy to treat patients with chronic dyspepsia refractory to medical management. However, its mechanisms of action remain poorly understood.

Methods

Gastric pain was induced by performing gastric distension (GD) in anesthetized rats. Pain response was monitored by measuring the pseudo-affective reflex (e.g., blood pressure variation), while neuronal activation was determined using c-fos immunochemistry in the central nervous system. Involvement of primary afferents was assessed by measuring phosphorylation of ERK1/2 in dorsal root ganglia.

Results

GES decreased blood pressure variation induced by GD, and prevented GD-induced neuronal activation in the dorsal horn of the spinal cord (T9–T10), the nucleus of the solitary tract and in CRF neurons of the hypothalamic paraventricular nucleus. This effect remained unaltered within the spinal cord when sectioning the medulla at the T5 level. Furthermore, GES prevented GD-induced phosphorylation of ERK1/2 in dorsal root ganglia.

Conclusions

GES decreases GD-induced pain and/or discomfort likely through a direct modulation of gastric spinal afferents reducing central processing of visceral nociception.

Transcutaneous electrical tibial nerve stimulation in the treatment of fecal incontinence: a randomized trial (CONSORT 1a)

OBJECTIVES

The objective of this study was to show that although transcutaneous electrical tibial nerve stimulation (TENS) is being increasingly used to treat fecal incontinence (FI), its efficacy has never been proved using controlled trials.

METHODS

In this randomized, double-blind, sham-controlled trial, 144 patients aged 30-82 years from nine centers were randomly assigned to receive either active or sham stimulations for 3 months. The primary end point was the response to treatment based on the number of incontinence and urgency episodes. Secondary end points were severity scores, quality of life scores, delay to postpone defecation, patient self-assessment of treatment efficacy, physician assessment of TENS efficacy, anorectal manometry, and adverse events.

RESULTS

No statistically significant difference was seen between active and sham TENS in terms of an improvement in the median number of FI/urgency episodes per week. Thirty-four patients (47%) who received the active TENS treatment exhibited a >30% decrease in the FI severity score compared with 19 patients (27%) who received the sham treatment (odds ratio 2.4, 95% confidence interval 1.1-5.1, P=0.02). No differences in delay to postpone defecation, patient self-assessment of treatment efficacy, or anorectal manometry were seen between the two groups. The evaluating physicians rated the active stimulations as more effective than the sham stimulations (P=0.01). One minor therapy-related adverse event was observed (1.5%) (see Supplementary Consort 1b).

CONCLUSIONS

We failed to demonstrate any benefit of TENS on our primary end-point.

Long term efficacy of gastric electrical stimulation in intractable nausea and vomiting

BACKGROUND

Although the efficacy of gastric electrical stimulation has been reported in short-term studies, there is a lack of data on the long-term improvement of nausea and vomiting by gastric electrical stimulation in patients with delayed or normal gastric emptying.

METHODS

Thirty-one patients were implanted at our centre for medically refractory severe and chronic nausea and/or vomiting. Patients were evaluated at baseline, 6 months then 5 years after implantation (mean follow-up 80±4 months) using a symptomatic and quality of life scores.

KEY RESULTS

Amongst the 31 patients, 4 were lost to follow-up, 6 explanted due to lack of improvement, and 1 patient died. Out of the 20 patients evaluated over 5 years, the quality of life score showed 27% improvement (p<0.01), including nausea (62%; p<0.01), vomiting (111%; p=0.03), satiety (158%; p<0.01), bloating (67%; p<0.01) and epigastric pain (43%; p=0.03). Over 5 years, 15/20 patients reported a 50% improvement with a global satisfaction rated at 64±6%. Therefore, 15/27 patients (56%) were improved by gastric electrical stimulation over 5 years in intention to treat. Improvement of nausea 6 months after implantation was predictive of 5-year success of gastric electrical stimulation (p=0.04). Finally, patients with delayed gastric emptying or with normal gastric emptying rate before surgery were similarly improved over 5 years (60% versus 50% respectively).

CONCLUSION

Gastric electrical stimulation is safe and effective in the long term in patients with medically refractory nausea and vomiting, with an efficacy over 50% beyond 5 years in intention to treat. Gastric emptying measured before implantation did not influence the response rate over 5 years.

Management of neurogenic bowel dysfunction

There are several modalities for treating neurogenic bowel dysfunction (NBD), including conservative treatments (diet, medications, biofeedback, transanal irrigation, massage, electrical stimulation, anal plug). When conservative treatments fail, clinicians can choose from a variety of therapeutic options, including colostomies, Malone anterograde continence enemas, sacral anterior root stimulator implantations, graciloplasties, and artificial bowel sphincters. We reviewed the various treatments for constipation and/or fecal incontinence in patients with NBD and propose over-reaching stepwise algorithms for the management of NBD. Our review included English language articles, randomized controlled studies, cohort studies, case-control studies, and retrospective studies (if necessary) that assessed the management of NBD. Our literature search identified 577 articles, of which 79 met our inclusion criteria. There is little evidence for the success of conservative but non-pharmacological treatments. There is strong evidence for the success of pharmacological interventions (i.e., prokinetic agents) in the treatment of chronic constipation. While surgical interventions may be considered, there is little evidence of their effectiveness. Bowel management programs for patients with neurologic diseases require a multi-faceted approach. While a range of medical and surgical treatments are available, there is little evidence for their effectiveness, with the exception of pharmacological interventions.

Effect of unilateral subthalamic deep brain stimulation on rat digestive motor activity

A significant proportion of patients with Parkinson's disease suffers from digestive symptoms. Bilateral deep brain stimulation of the subthalamic nucleus has become a reliable therapeutic option for parkinsonian patients, but its effects on digestive motility remain poorly investigated. The aim of our study was to assess whether subthalamic stimulation could induce changes in gastric, colonic, and rectal motility and modulate brain centers involved in gut motility.

METHODS

In anesthetized rats, unilateral subthalamic nucleus stereotactic implantation was performed while intra-gastric, -colonic, and -rectal pressures were recorded during the ON and OFF periods of the stimulation. c-Fos protein expression was quantified by immunostaining in the nucleus of the solitary tract, the dorsal motor nucleus of the vagus nerve, the locus coeruleus, and the Barrington's nucleus.

RESULTS

Compared to baseline, sham stimulation did not change phasic gastric, colonic or rectal motor activity. Unilateral subthalamic stimulation increased colonic phasic motility (P<0.05) compared to baseline and the OFF period with no change in gastric and rectal motility. Pre-treatment with atropine, or specific D1 and D2 receptors antagonists prevented the rise in colonic motor activity. An increase in c-Fos protein-positive cells within all the studied nuclei was observed in the stimulated group compared to the sham group.

CONCLUSIONS

Unilateral subthalamic stimulation impacts on gut motility in anesthetized rats with a significant increase in colonic motility probably via the modulation of several brain centers. These findings warrant further confirmation in parkinsonian rat models before being transposed to clinical conditions.

How sacral nerve stimulation works in patients with faecal incontinence

AIM

Sacral nerve stimulation (SNS) reduces incontinence episodes and improves the quality of life of patients treated for faecal incontinence. However, the exact mechanism of action of this technique remains unclear. The present article reviews the pertinent neuroanatomy and neurophysiology related to SNS and provides explanations for potential mechanisms of action.

METHOD

A systematic review of the literature was performed for studies of the potential mechanisms of action of SNS, using MEDLINE, PubMed, Embase and the Cochrane Library. Articles dealing with the technique, adverse events and economic evaluations of SNS, as well as literature reviews, were excluded, except for reviews dealing with the mechanisms of action of SNS. The following inclusion criteria were used to select articles: (i) articles in English, (ii) randomized, double-blinded, sham-controlled studies, and (iii) cohort studies. Case-control studies or retrospective studies were cited only when randomized or cohort studies could not be found.

RESULTS

We propose three hypotheses to explain the mechanism of action of SNS: (i) a somato-visceral reflex, (ii) a modulation of the perception of afferent information, and (iii) an increase in external anal sphincter activity.

CONCLUSION

The mechanism of action of SNS in patients with faecal incontinence almost certainly depends on the modulation of spinal and/or supraspinal afferent inputs. Further research on humans and animals will be required to gain a better understanding of the mechanisms of action of SNS.

Rumination syndrome: when the lower oesophageal sphincter rises

BACKGROUND

Rumination syndrome is an uncommon condition characterised by the self-induced regurgitation from the stomach to the mouth of recently ingested meal that is chewed and reswallowed. Rumination is caused by a voluntary rise in intra-abdominal and intra-gastric pressure leading to the reflux of the gastric content into the oesophagus. However, the precise mechanisms preventing reflux at the gastro-oesophageal junction during the rise in intra-gastric pressure remains unknown.

METHODS

In 5 patients, rumination episodes were monitored using combined multiple intra-luminal impedance monitoring, high resolution manometry, and video-fluoroscopic recording.

RESULTS

We showed that the gastro-oesophageal junction moved from the abdominal cavity into the thorax creating a "pseudo-hernia". This occurred at a range of 1.4 ± 0.3 s before the rise in intra-oesophageal pressure and the gastro-oesophageal reflux.

CONCLUSION

This displacement of the gastro-oesophageal junction into thorax, rather than a lower oesophageal sphincter opening, explains the mechanism of voluntary regurgitations occurring during rumination syndrome.

Predictive factors for successful sacral nerve stimulation in the treatment of faecal incontinence: results of trial stimulation in 200 patients

AIM

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.

METHOD

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.

RESULTS

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.

CONCLUSION

Stool consistency and low stimulation intensity have been identified as predictive factors for the short-term outcome of SNS.

The role of sacral neuromodulation in double incontinence

AIM

Urinary and faecal incontinence are common conditions that are frequently associated. When conservative treatments fail, sacral nerve modulation (SNM) is considered to be a first-line treatment for patients with urge urinary incontinence and for patients with faecal incontinence. This article aims to determine the effect of SNM on the treatment of double incontinence (i.e. urinary and faecal incontinence).

METHOD

We searched for relevant articles in MEDLINE, PubMed and Embase, and for reviews in the Cochrane database. Articles were restricted to the English language.

RESULTS

Only a few studies have studied the efficacy of SNM for double incontinence and in a limited number of patients. Between 30% and 100% of patients with double incontinence experience improvement in urinary and faecal incontinence at medium-term follow up.

CONCLUSION

Further prospective trials are needed to determine which patients with combined problems will benefit from SNM at a long-term follow up.

Surgical management of deep infiltrating endometriosis of the rectum: pleading for a symptom-guided approach

Two surgical approaches are usually employed in the treatment of deep infiltrating endometriosis of the rectum (DIER): colorectal resection removing the rectal segment affected by the disease, and nodule excision either without opening the rectum (shaving) or by removing the nodule along with the surrounding rectal wall (full thickness or disc excision). Although the present available data are from retrospective series reported by surgeons who generally perform only one technique, there is no evidence to support the risk of recurrences as a valid argument in favour of colorectal resection over rectal nodule excision. The advantage of a lower morbidity associated with nodule excision is not necessarily at the cost of an increased rate of pain recurrences, especially in women benefiting from post-operative medical treatment. The symptom-guided surgical approach in DIER primarily focuses on the relief of digestive symptoms and pelvic pains, rather than on mandatory 'carcinologic' resection of lesions. In addition, the risk of new post-operative unpleasant symptoms as a result of a compulsory and systematic excision of all endometriotic foci may be avoided. In a majority of cases, pelvic anatomy and digestive function can be restored by shaving or disc excision, as well as by colorectal resection; thus digestive complaints can be resolved even when the rectum is conserved. The most accurate evaluation of the results of DIER surgery should be provided by post-operative evolution in digestive function. Even though quality of life is improved for the majority of patients managed by colorectal resection, the question is whether or not a greater health improvement can be achieved by performing nodule excision, which avoids various post-operative and functional digestive complications. In addition, continuous medical treatment leads to a decrease in endometriotic nodules and prevents post-operative pain recurrences. Instead of choosing between medical and surgical management in the treatment of DIER, it is most likely that the two therapies should be associated.

Delayed functional outcomes associated with surgical management of deep rectovaginal endometriosis with rectal involvement: giving patients an informed choice

BACKGROUND

The aim of this study was to compare delayed functional digestive and urinary outcomes following two different surgical procedures used in the management of rectal endometriosis.

METHODS

Women who had undergone surgical management of rectal endometriosis with at least 1 year of post-operative follow-up were included in a retrospective study. Post-operative symptoms were evaluated using specific questionnaires which focused on pelvic pain and functional outcomes.

RESULTS

There were 41 women who underwent surgical treatment of symptomatic rectal endometriosis. Post-operative follow-up was completed over 26 +/- 13 months (range 12-53). Colorectal segmental resection was performed in 25 women (61%) and nodule excision in 16 (39%). An increase in the number of daily stools > or =3 was observed in 13 (52%) and 3 (19%) patients managed, respectively, by segmental resection and nodule excision (P = 0.02). Severe constipation (<1 stool/5 days) was recorded in three women having undergone segmental resection. The probabilities of being free of dysmenorrhea, dyspareunia and non-cyclic pain at 24 months in women managed by segmental resection and nodule excision were, respectively, 80% (95% CI: 55-92%), 65% (95% CI: 42-81%), 43% (95% CI: 23-62%) and 62% (95% CI: 34-81%), 81% (95% CI: 52-94), 69% (95% CI: 40-86%). When pain recurrences occurred, a significantly lower post-operative score for pain was observed in both groups. No significant difference in pain improvement was found between surgical procedures.

CONCLUSION

Colorectal segmental resection appears to be associated with several unpleasant functional symptoms when compared with nodule excision. Information about functional outcomes should be provided to patients managed for rectal endometriosis, and should be considered when deciding on the most appropriate treatment of this disease.

Conservative and behavioural management of constipation

This article deals with psychological contributions, such as stool withholding or responses to abuse experiences, to the aetiology of evacuation disorders (with a focus on dyssynergic defecation), and with education and behavioural approaches to treatment.

Sacral nerve stimulation in faecal incontinence: position statement based on a collective experience

OBJECTIVE

Since the first paper published by Matzel et al., in 1995, on the efficacy of sacral nerve stimulation (SNS) in patients with faecal incontinence, the indications, the contraindications, the stimulation technique and follow up of implanted patients have changed. The aim of this article was to provide a consensus opinion on the management of patients with faecal incontinence treated with SNS.

METHOD

Recommendations were based on a critical review of the literature when available and on expert opinions in areas with insufficient evidence.

RESULTS

We have reviewed the indications and contraindications, proposed an algorithm for patient management showing the place of SNS. The temporary test technique, the implantation technique, the patient follow up and the approach in case of treatment failure were discussed.

CONCLUSION

We hope not only to provide a guide on patient management to clinical practitioners interested in SNS but also to harmonize our practices.

Impact of swallowing and ventilation on oropharyngeal cortical representation

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.

Gastric electrical stimulation modulates hypothalamic corticotropin-releasing factor-producing neurons during post-operative ileus in rat

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.

Gastric electrical stimulation in medically refractory nausea and vomiting

INTRODUCTION

High-frequency gastric electrical stimulation is a new therapeutic option to improve refractory nausea and vomiting, in gastroparetic patients. Its effects on gastric emptying are, however, inconstant and limited. Therefore, we have hypothesized that high-frequency gastric electrical stimulation could be also effective in patients suffering from refractory vomiting and nausea with normal gastric emptying, and we have compared the symptomatic efficacy of high-frequency gastric electrical stimulation between patients with delayed and normal gastric emptying.

PATIENTS AND METHODS

Fifteen patients with chronic, severe and medically resistant nausea and vomiting were included in the study. Gastric emptying was delayed in eight patients (Group 1) and normal in seven patients (Group 2). At inclusion and at 6 months after the start of the stimulation, symptoms (nausea and vomiting, bloating, regurgitations, abdominal pain and appetite) and quality of life were prospectively evaluated using the Gastrointestinal Quality of Life Index score whereas gastric emptying was assessed by scintigraphy and/or octanoic acid breath test.

RESULTS

Age, sex, symptoms and quality of life were not different at baseline between the two groups. At 6 months, Gastrointestinal Quality of Life Index and nausea/vomiting scores had significantly improved in both groups. Other symptoms (bloating, regurgitations, abdominal pain and appetite) had improved at 6 months in Group 1 but not in Group 2. Six months after the start of stimulation, gastric emptying was normal in 4/8 Group 1 patients and 5/7 Group 2 patients but was not significantly different from that calculated before the implantation of the stimulator.

CONCLUSION

Our results suggest that high-frequency gastric electrical stimulation could be an effective therapy for treating chronic, severe vomiting and nausea whether gastric emptying is delayed or not.

Results of 24-h manometric recording of colonic motor activity with endoluminal instillation of bisacodyl in patients with severe chronic slow transit constipation

The aims of this study were to assess the prevalence of manometric colonic abnormalities and to evaluate the motor effect of intraluminal bisacodyl in a cohort of refractory constipated patients. Twenty-four hour colonic motility recordings were performed in 40 patients referred for a severe intractable chronic constipation. At the end of each recording session the motor effects of the endoluminal instillation of 10 mg bisacodyl were assessed. These patients were compared with 20 healthy subjects. The number of high-amplitude propagating contractions (HAPC) was significantly decreased in patients with slow transit constipation (12 +/- 11.6 vs 1 +/- 8.6, P < 0.001). Based on manometric patterns four groups of patients were isolated. Ten patients had no spontaneous HAPC, no food-induced colonic motor response and significantly lower colonic activity in transverse colon (374 +/- 1220 vs 3249 +/- 3458, P < 0.05). Five patients had significantly increased sigmoid segmental motility (20298 +/- 6364 vs 88780 +/- 3643, P < 0.001) and eight patients had significantly lower number of HAPC without other manometric abnormalities while 17 patients had normal colonic motility recordings. Endoluminal bisacodyl was able to induce HAPCs in all groups of patients. Patients with severe slow transit refractory constipation represented a heterogeneous group and endoluminal bisacodyl was able to promote a propagated motor activity in a majority of patients even in those suspected of having an inert colon.

Endosonography in the evaluation of anal function after primary repair of a third-degree obstetric tear

BACKGROUND

Disruption of the anal sphincter occurs in 0.6%-6% of women during delivery and almost half have persistent defecatory symptoms despite primary repair. Our aim was to prospectively analyse anal endosonography and rectoanal manometry after primary repair of a third-degree obstetric tear in order to compare the findings with the clinical outcome.

METHODS

Twenty-one women aged 27-41 (mean 31.5 years) who had undergone primary suture of a third-degree disruption of the anal sphincter were interviewed on their pelvic floor function and explored by manometry and endosonography 4 months after delivery.

RESULTS

Twelve women had anal incontinence. External sphincter defect was identified on endosonography in 22% continent and in 91% incontinent women (P < 0.01). The presence of an external sphincter defect was associated with anal incontinence in 91.7%. Surgical repair was identified on endosonography in 88% continent women and in 25% incontinent women (P < 0.03). The combination of a visible surgical repair and absence of defect was highly associated with normal continence (91.7%). Squeezing pressures were higher in continent women (87 +/- 23 cm H2O) than in incontinent women (48 +/- 36 cm H2O; P = 0.04), but no anal pressure threshold could achieve better results than endosonography in predicting the clinical outcome.

CONCLUSION

After primary repair of a third-degree obstetric tear, endosonographic pattern of the anal sphincter correlates with the continence status.

ALES: cell lineage analysis and mapping of developmental events

MOTIVATION

Animals build their bodies by altering the fates of cells. The way in which they do so is reflected in the topology of cell lineages and the fates of terminal cells. Cell lineages should, therefore, contain information about the molecular events that determined them. Here we introduce new tools for visualizing, manipulating, and extracting the information contained in cell lineages. Our tools enable us to analyze very large cell lineages, where previously analyses have only been carried out on cell lineages no larger than a few dozen cells.

RESULTS

Ales (A Lineage Evaluation System) allows the display, evaluation and comparison of cell lineages with the aim of identifying molecular and cellular events underlying development. Ales introduces a series of algorithms that locate putative developmental events. The distribution of these predicted events can then be compared to gene expression patterns or other cellular characteristics. In addition, artificial lineages can be generated, or existing lineages modified, according to a range of models, in order to test hypotheses about lineage evolution.

AVAILABILITY

The program can run on any operating system with a compliant Java 2 environment. Ales is free for academic use and can be downloaded from http://mbi.dkfz-heidelberg.de/mbi/research/cellsim/ales.

Does water-perfused catheter overdiagnose anismus compared to balloon probe?

BACKGROUND

The purpose of this study was to compare the manometric assessment of straining effort as if to defecate and rectoanal inhibitory reflex obtained with a rectosphincteric balloon probe and with a water-perfused catheter in the same subject.

METHODS

Twelve healthy volunteers underwent two manometric assessments of anal sphincter function and electromyographic (EMG) surface recordings. one with a rectosphincteric balloon and one with a water-perfused catheter, 7 days apart in random order.

RESULTS

Increased EMG activity in the external anal sphincter in the midst of the rectoanal inhibitory reflex (P < 0.001) and during straining for defecation (P < 0.001) was more frequently observed with the perfused system than with the balloon probe. There was a discrepancy between the EMG activity of the external anal sphincter and the anal pressures during straining recorded with the perfused system. Duration of the reflex elicited by rectal distension with 10 and 20 ml of air was significantly greater with the rectosphincteric balloon than with the perfused catheter (P = 0.02 and P = 0.05, respectively).

CONCLUSION

Water instilled in the anal canal by the perfused system induces artifacts in EMG recording and active anal contractions. These artifacts and induced contractions could lead to an erroneous diagnosis of anismus, particularly if pelvic floor EMG is only taken into account for the diagnosis of anismus.

Testing life-history pleiotropy in Caenorhabditis elegans

Much life-history theory assumes that alleles segregating in natural populations pleiotropically affect life-history traits. This assumption, while plausible, has rarely been tested directly. Here we investigate the genetic relationship between two traits often suggested to be connected by pleiotropy: maternal body size and fertility. We carry out a quantitative trait locus (QTL) analysis on two isolates of the free-living nematode Caenorhabditis elegans, and identify two body size and three fertility QTLs. We find that one of the fertility QTLs colocalizes with the two body size QTLs on Chromosome IV. Further analysis, however, shows that these QTLs are genetically separable. Thus, none of the five body size or fertility QTLs identified here shows detectable pleiotropy for the assayed traits. The evolutionary origin of these QTLs, possible candidate loci, and the significance for life-history evolution are discussed.

Effect of sacral nerve stimulation in patients with fecal and urinary incontinence

PURPOSE

Preliminary studies have shown improvement in fecal incontinence in several patients who received temporary or permanent stimulation. The purpose of this study was to report our experience in sacral nerve stimulation in the treatment of fecal incontinence and to target patients who would benefit most from stimulation.

METHODS

Patients with fecal incontinence were studied clinically and manometrically before, during, and after temporary nerve stimulation. If temporary nerve stimulation was clinically successful, the patient was implanted and followed up for six months.

RESULTS

Nine patients (6 female) with a mean age of 50.7 +/- 12.3 years underwent temporary nerve stimulation. Temporary nerve stimulation was successful in eight patients, six of whom were implanted. Of the patients who could be evaluated, three of five had improved at the six-month follow-up visit, particularly in relation to the number of urgency episodes and delay in postponing defecation. All implanted patients had urinary symptoms. Urinary urgency was also improved by stimulation. During temporary nerve stimulation, the maximal squeeze pressure amplitude increased. After implantation, only the duration of maximal squeeze pressure seemed to improve.

CONCLUSION

Sacral nerve stimulation can be used in the management of fecal incontinence, particularly in cases of urge fecal incontinence associated with urinary urgency. This study seems to confirm the effect of sacral nerve stimulation on striated sphincter function.

Effects of polyethylene glycol 4000 on 24-h manometric recordings of left colonic motor activity

BACKGROUND

It has been shown that low doses of polyethylene glycol (PEG) 4000 are effective in the treatment of chronic constipation. The aim of this study was to describe the effects on colonic motility of oral PEG 4000 treatment and intraluminal instillation of PEG 4000.

METHODS

Left colonic and rectosigmoid manometric recordings were performed for 27 h in six constipated patients and in six healthy volunteers. At the end of the recording, bisacodyl and PEG 4000 were instilled into the lumen of the colon. To assess the effects of oral administration of PEG 4000 on colonic motility, manometric recordings were also performed in constipated patients after 4 weeks of treatment with PEG 4000.

RESULTS

All patients had significantly more stools during than before PEG treatment. There was no significant difference between the number and the characteristics of high-amplitude propagating contractions (HAPC) or the area under the curve (AUC) before or during treatment with PEG 4000. Intraluminal instillation of PEG induced HAPC in only one patient and in no controls.

CONCLUSION

This study shows that PEG 4000 has no effect on left colonic and rectosigmoid motor activity during oral treatment, despite its clinical effectiveness, or after local instillation.

A power law for cells

Darwin observed that multiple, lowly organized, rudimentary, or exaggerated structures show increased relative variability. However, the cellular basis for these laws has never been investigated. Some animals, such as the nematode Caenorhabditis elegans, are famous for having organs that possess the same number of cells in all individuals, a property known as eutely. But for most multicellular creatures, the extent of cell number variability is unknown. Here we estimate variability in organ cell number for a variety of animals, plants, slime moulds, and volvocine algae. We find that the mean and variance in cell number obey a power law with an exponent of 2, comparable to Taylor's law in ecological processes. Relative cell number variability, as measured by the coefficient of variation, differs widely across taxa and tissues, but is generally independent of mean cell number among homologous tissues of closely related species. We show that the power law for cell number variability can be explained by stochastic branching process models based on the properties of cell lineages. We also identify taxa in which the precision of developmental control appears to have evolved. We propose that the scale independence of relative cell number variability is maintained by natural selection.

[Evoked mechanical and electrical anal sphincter responses after cortical and lumbar magnetic stimulation]

In 13 healthy volunteers we recorded electrical and mechanical anal sphincter (AS) evoked responses. Electrical responses were obtained with surface electrodes, and mechanical responses by anal manometry; all responses were compared with those of anterior tibialis. Mechanical evoked responses' latency and amplitude were calculated. The mean total conduction time of the electrical responses was 26.07 ms at rest and 23.31 ms with mild contraction (p < 0.003). After lumbar magnetic stimulations, because of stimulation artefact, electrical responses couldn't be correctly measured. The mean central conduction time calculated with mechanical responses was 21.44 ms at rest and 18.81 ms with mild contraction (p < 0.003). The mean central conduction time to the anterior tibialis was shorter (14.38 ms; p < 0.003). Evoked mechanical responses', amplitudes were respectively 128.2 cm H2O (cortical stimulations at rest), 138.8 cm H2O (cortical stimulations with mild contraction) and 133.1 cm H2O (lumbar stimulations at rest) (NS). Evoked mechanical responses amplitudes were correlated with the AS maximal voluntary contraction amplitude (p < 10(-4)). Mechanical motor evoked responses after cortical and lumbar magnetic stimulations can be recorded and quantified. In anorectal disorders, this technique could be of major interest for the diagnosis of neurologic lesions versus behavioural problems.

Results of sphincteroplasty in 86 patients with anal incontinence

PURPOSE

This study was designed to analyze critically the short-term and long-term outcome of sphincteroplasty and to identify high-risk factors.

METHODS

Eighty-six patients with fecal incontinence associated with an ultrasound defect of the external anal sphincter were treated by anal sphincteroplasty. Clinical and physiologic assessment was made before surgery, and clinical evaluation was made three months and an average of 40 months after surgery.

RESULTS

The evaluation of 86 patients three months after surgery showed that 42 patients were totally continent (49 percent), 28 were incontinent for gas (33 percent), and 16 still had fecal incontinence (19 percent). Seventy-four patients (86 percent) were contacted 40 months after surgery. Twenty-one patients (28 percent) were totally continent, 17 were incontinent to gas (23 percent), and 36 were incontinent to feces (49 percent). Forty-six percent of patients felt they were clearly improved after surgery. Poor results were associated with an internal anal sphincter defect.

CONCLUSIONS

Our study suggests that in the long term, one-third of patients are totally continent after sphincteroplasty. One-half of patients are satisfied, but only if their incontinence to feces has totally disappeared. Results of sphincteroplasty deteriorate with time. One factor in poor prognosis is the presence of an associated defect of the internal anal sphincter.

Somatic polyploidization and cellular proliferation drive body size evolution in nematodes

Most of the hypodermis of a rhabditid nematode such as Caenorhabditis elegans is a single syncytium. The size of this syncytium (as measured by body size) has evolved repeatedly in the rhabditid nematodes. Two cellular mechanisms are important in the evolution of body size: changes in the numbers of cells that fuse with the syncytium, and the extent of its acellular growth. Thus nematodes differ from mammals and other invertebrates in which body size evolution is caused by changes in cell number alone. The evolution of acellular syncytial growth in nematodes is also associated with changes in the ploidy of hypodermal nuclei. These nuclei are polyploid as a consequence of iterative rounds of endoreduplication, and this endocycle has evolved repeatedly. The association between acellular growth and endoreduplication is also seen in C. elegans mutations that interrupt transforming growth factor-beta signaling and that result in dwarfism and deficiencies in hypodermal ploidy. The transforming growth factor-beta pathway is a candidate for being involved in nematode body size evolution.

Manometric assessment of an artificial bowel sphincter

BACKGROUND

This study investigated the relationship between functional clinical results after artificial bowel sphincter implantation and manometric assessment in 12 consecutive patients.

METHODS

A postoperative manometric study was performed in 12 patients, including measurement of resting and squeeze pressures, opening characteristics and pressure during straining. The relationship between postoperative findings, clinical outcome and preoperative manometric data was investigated. Anal pressure after rectal distension with a closed cuff was studied in seven patients. Results were expressed as mean(s.d.).

RESULTS

Continence for solid stool was achieved in all 12 patients. Five patients remained incontinent for gas. Anal resting pressure was 108(22) cmH2O; there was no difference between continent and incontinent patients. Rectal distension induced anal relaxation in six of seven patients. Total duration of cuff opening was 113(8) s with an amplitude of 60(22) per cent; residual pressure was correlated with the preoperative resting pressure. The total duration of the opening phase in patients with defaecation difficulties (47(24) (range 0-65) s) was shorter than that in patients without defaecation difficulties (178(78) (range 100-320) s) (P = 0.0022).

CONCLUSION

Postoperative defaecation difficulties after implantation of an artificial bowel sphincter are related to a short duration of opening of the cuff. The anal sphincter played a role in postoperative resting anal pressures and allowed relaxation even if the cuff was closed.