OC-033 SLOWLY RESORBABLE VERSUS PERMANENT SYNTHETIC MESH IN OPEN RETROMUSCULAR VENTRAL HERNIA REPAIR - 3 YEAR RESULTS OF A RANDOMIZED CONTROLLED TRIAL

Introduction

Implantation of synthetic meshes provides long-term hernia repair, but may result in mesh-related complications. The longterm resorbable mesh used in this study maintains more than 50% of its strength for 6 months and is completely resorbed after 3 years.

Methods

This multi-centre, randomized controlled trial compared the use of the TIGR® Matrix Surgical Mesh (Novus Scientific, Sweden) with a large-pore polypropylene mesh (Soft®mesh, BD, UK) in primary ventral and incisional hernia repair. Retromuscular mesh repair was performed. Primary endpoint was hernia recurrence rate after a 3 year follow-up period. Secondary endpoints were hernia recurrence rate at 1 year and 2 years, as well as perioperative morbidity and longterm complications including pain.

Results

Seventy-nine patients were included, but 69 patients received study treatment. Fifty-seven patients (82.6%) completed follow-up of 3 years. One patient (2.9%) developed a seroma after hernia repair with TIGR mesh. Three patients had a reintervention for hematoma (8.6%) in the control group versus two reinterventions (5.9%) after repair with TIGR mesh (p=0.673. One patient underwent late re-operation and mesh removal after hernia repair with TIGR mesh due to chronic wound infection. During three years follow-up, seven (10.1%) patients experienced a hernia recurrence, two (5.7%) in the control group and five (14.7%) after TIGR mesh (p=0.15).

Conclusion

Although not statistically significant, this multicentric RCT showed a higher recurrence rate for longterm degradable mesh patients after 3 years of follow-up. These results call for larger studies with long-term follow-up comparing slowly resorbable mesh materials with permanent mesh products.

Individual differences in behaviour and gut bacteria are associated in collared peccary (Mammalia, Tayassuidae)

AIMS

We tested the hypothesis that the behaviour of an individual is associated with the diversity of its gut bacteria, using the collared peccary (Pecari tajacu) as a model.

METHODS AND RESULTS

In all, 24 adult male collared peccaries received either low- (n = 12) or high-fibre diet (n = 12) to induce contrasting gut fermentation profiles. They were submitted to three short-term challenges, allowing us to rate the animals in a coping-style dimension named 'calmness'. At the end of the experimental period, we collected samples of peccaries' forestomach contents to characterize bacterial diversity. We found a significant positive association between individual 'calmness' z-scores and the bacterial evenness index in gut bacteria (and a similar trend with the Simpson's diversity index), suggesting a more homogeneous bacterial community of calmer individuals. We also found a positive association between fibres digestibility and gut bacterial diversity in the peccaries' forestomach, but no effect of the dietary fibre level.

CONCLUSIONS

Gut bacteria evenness increases with 'calmness' z-scores, suggesting a more homogeneous bacterial community of calmer individuals, compared with the more heterogeneous of the most distressed ones. Our results also suggest associations between the digestibility of ADF with the gut bacterial diversity indices and with the relative abundance of the Actinobacteria phylum.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our data showed that the hosts' individual behavioural differences are potentially aligned with gut bacterial diversity. The behaviour-microbiota link is correlated with host feed efficiency and, ultimately, may have implications for animal health and welfare of farm animals.

Induction of Long-Lasting Changes of Visual Cortex Excitability by Five Daily Sessions of Repetitive Transcranial Magnetic Stimulation (rTMS) in Healthy Volunteers and Migraine Patients

We have shown that in healthy volunteers (HV) one session of 1 Hz repetitive transcranial magnetic stimulation (rTMS) over the visual cortex induces dishabituation of visual evoked potentials (VEPs) on average for 30 min, while in migraineurs one session of 10 Hz rTMS replaces the abnormal VEP potentiation by a normal habituation for 9 min. In the present study, we investigated whether repeated rTMS sessions (1 Hz in eight HV; 10 Hz in eight migraineurs) on 5 consecutive days can modify VEPs for longer periods. In all eight HV, the 1 Hz rTMS-induced dishabituation increased in duration over consecutive sessions and persisted between several hours ( n = 4) and several weeks ( n = 4) after the fifth session. In six out eight migraineurs, the normalization of VEP habituation by 10 Hz rTMS lasted longer after each daily stimulation but did not exceed several hours after the last session, except in two patients, where it persisted for 2 days and 1 week. Daily rTMS can thus induce long-lasting changes in cortical excitability and VEP habituation pattern. Whether this effect may be useful in preventative migraine therapy remains to be determined.

Axillary temperature measurement: a less stressful alternative for hospitalised cats?

Rectal temperature measurement (RTM) can promote stress and defensive behaviour in hospitalised cats. The aim of this study was to assess if axillary temperature measurement (ATM) could be a reliable and less stressful alternative for these animals. In this prospective study, paired rectal and axillary temperatures were measured in 42 cats, either by a veterinarian or a student. To assess the impact of these procedures on the cat's stress state, their heart rate was checked and a cat stress score (CSS) was defined and graded from 1 (relaxed) to 5 (terrified). A moderate correlation was found between RTM and ATM (r=0.52; P<0.0001). RTM was on average 0.9 °C (1.6 °F) higher than ATM (P<0.0001), although a wide variation was found in the difference between these two measurements (-2.1 °C to 3.6 °C (-3.8 °F to 6.5 °F)). ATM failed to identify hypothermia in 25 per cent of the cases and hyperthermia in 19 per cent of the cases but may be considered less stressful than RTM. Indeed, RTM induced a mildly greater increase in heart rate (+6 bpm; P=0.01) and in CSS (+0.2; P=0.001) than ATM. The results were not affected by operator type. In conclusion, RTM should remain the standard method to obtain accurate temperatures in cats.

Animal health and welfare: equivalent or complementary?

The concepts of 'health' and 'welfare', whether applied to humans or animals, are increasingly becoming linked. But are they really indissociable, or even synonymous? Although human health is generally defined as a complete state of physical, mental and social well-being, animal health is still considered as simply the absence of disease. However, recent advances in scientific knowledge are forcing us to revise our ideas about the mental complexity of animals and to recognise their ability to feel emotions and to have needs and a degree of consciousness. The precise objective of animal welfare science is to study their mental states and their ability to adapt to domestication. Pending a global application of this concept of health, including mental health, to animals as well as to humans, the idea of welfare remains an important element in addition to traditional health concerns. More generally, this linkage fuels the ethical debate about the ways in which people use animals, prompting society to change its stance on some aspects of the issue.

Almotriptan and Its Combination with Aceclofenac For Migraine Attacks: A Study of Efficacy and The Influence of Auto-Evaluated Brush Allodynia

Early treatment and combining a triptan with a non-steroidal anti-inflammatory drug (NSAID) are thought to improve outcome during migraine attacks, possibly by counteracting the negative influence of cutaneous allodynia. The aim of this multicentre, double-blind pilot study was to evaluate the prevalence of brush allodynia and its relative influence on the efficacy of a triptan-NSAID combination compared with headache intensity at the time of treatment. In a randomized, cross-over design, 112 migraineurs treated two moderate or severe attacks with almotriptan 12.5 mg combined with either aceclofenac 100 mg or placebo. Patients used a 2-cm brush to assess cutaneous allodynia. Allodynia was reported in 34.4± of attacks. The almotriptan-aceclofenac combination was numerically superior to triptan-placebo on 2-24-h sustained pain-free ( P = 0.07), 2-h pain-free ( P = 0.07) and headache recurrence ( P = 0.05) rates, but not on 1-h headache relief. Allodynia numerically reduced treatment success overall, but this effect was not significant for the primary outcome measures. Headache intensity had a significant negative influence on 1-h relief in both attacks ( P = 0.0001 and 0.0008, X2) and on 2-24-h sustained pain-free rates in triptanplacebo-treated attacks ( P = 0.013). Multivariate logistic regression analysis confirmed that headache intensity at treatment intake, rather than allodynia, significantly influenced most outcome measures, predominantly so in attacks treated with almotriptan and aceclofenac. In the latter, severe compared with moderate headache intensity reduced the likelihood of achieving the primary efficacy end-points [odds ratios (OR) 0.12 and 0.33], whereas allodynia was not a significant explanatory variable (OR 0.76 and 0.65). The results apply to the protocol used here and need to be confirmed in larger studies using quantitative sensory testing.

Hypothalamic stimulation in chronic cluster headache: a pilot study of efficacy and mode of action

We enrolled six patients suffering from refractory chronic cluster headache in a pilot trial of neurostimulation of the ipsilateral ventroposterior hypothalamus using the stereotactic coordinates published previously. After the varying durations needed to determine optimal stimulation parameters and a mean follow-up of 14.5 months, the clinical outcome is excellent in three patients (two are pain-free; one has fewer than three attacks per month), but unsatisfactory in one patient, who only has had transient remissions. Mean voltage is 3.28 V, diplopia being the major factor limiting its increase. When the stimulator was switched off in one pain-free patient, attacks resumed after 3 months until it was turned on again. In one patient the implantation procedure had to be interrupted because of a panic attack with autonomic disturbances. Another patient died from an intracerebral haemorrhage that developed along the lead tract several hours after surgery; there were no other vascular changes on post-mortem examination. After 1 month, the hypothalamic stimulation induced resistance against the attack-triggering agent nitroglycerin and tended to increase pain thresholds at extracephalic, but not at cephalic, sites. It had no detectable effect on neurohypophyseal hormones or melatonin excretion. We conclude that hypothalamic stimulation has remarkable efficacy in most, but not all, patients with treatment-resistant chronic cluster headache. Its efficacy is not due to a simple analgesic effect or to hormonal changes. Intracerebral haemorrhage cannot be neglected in the risk evaluation of the procedure. Whether it might be more prevalent than in deep-brain stimulation for movement disorders remains to be determined.

Excitability of visual V1-V2 and motor cortices to single transcranial magnetic stimuli in migraine: a reappraisal using a figure-of-eight coil

We used transcranial magnetic stimulation (TMS) with a figure-of-eight coil to excite motor and visual V1-V2 cortices in patients suffering from migraine without (MO) (n = 24) or with aura (MA) (n = 13) and in healthy volunteers (HV) (n = 33). Patients who had a migraine attack within 3 days before or after the recordings were excluded. All females were recorded at mid-cycle. Single TMS pulses over the occipital cortex elicited phosphenes in 64% of HV, 63% of MO and 69% of MA patients. Compared with HV, the phosphene threshold was significantly increased in MO (P = 0.001) and in MA (P = 0.007), but there was no difference between the two groups of migraineurs. The motor threshold tended to be higher in both migraine groups than in HV, but the differences were not significant. In conclusion, this study shows that two-thirds (64.86%) of patients affected by either migraine type present an increased phosphene threshold in the interictal period, which suggests that their visual cortex is hypoexcitable.

Motor and phosphene thresholds to transcranial magnetic stimuli: a reproducibility study

OBJECTIVES

As repetitive transcranial magnetic stimulation (rTMS) is often applied on different days, it is of interest to know whether motor (MT) and phosphene (PT) thresholds are reproducible across time and whether the intensity determined on the first day can be used in subsequent sessions.

METHODS

We studied MT and PT over 5 separate recordings in 10 healthy volunteers using a focal coil and a Magstim(Rapid stimulator. After the initial recording (session 1), the others (2 to 5) were performed respectively after 1 day, 7 days, 1 month and 4 months.

RESULTS

Mean MT at rest were 65.30 +/- 5.54%, 65.7 +/- 7.18%, 60.4 +/- 4.27%, 61.8 +/- 4.34%, and 63 +/- 9.1% at sessions 1 to 5. Mean PT were 71.43 +/- 6.68%, 66.29 +/- 10.67%, 60.71 +/- 8.64%, 60.57 +/- 8.08%, and 68.71 +/- 15.48% at sessions 1 to 5. MT and PT were reproducible (ANOVA analysis), however, as shown by coefficients of variation, variability between the first 3 sessions exceeded 10% for MT in 3 subjects and in 4 subjects for PT.

CONCLUSIONS

It seems preferable to determine thresholds and adapt output intensity of the stimulator at each rTMS session.

Central mechanisms in tension-type headaches

Although tension-type headache is the most frequent primary headache, little is known about its pathophysiology. It is a matter of debate if the pain in tension-type headache originates from myofascial tissues or from central mechanisms in the brain. This article presents a summary of available data on the pathophysiology of tension-type headache and proposes a pathogenic model. From experimental research and clinical studies, it appears that myofascial nociception is important in episodic tension-type headache; however, central mechanisms (ie, central sensitization) are preponderant in the pathophysiology of the chronic form. Understanding the mechanisms of this central sensitization could allow for more efficient prophylactic treatments to emerge.

Effects of repetitive transcranial magnetic stimulation on visual evoked potentials in migraine

Between attacks, migraine patients are characterized by potentiation instead of habituation of stimulation-evoked cortical responses. It is debated whether this is due to increased or decreased cortical excitability. We have studied the changes in visual cortex excitability by recording pattern-reversal visual evoked potentials (PR-VEP) after low- and high-frequency repetitive transcranial magnetic stimulation (rTMS), known respectively for their inhibitory and excitatory effect on the cortex. In 30 patients (20 migraine without, 10 with aura) and 24 healthy volunteers, rTMS of the occipital cortex was performed with a focal figure-of-eight magnetic coil (Magstim). Nine hundred pulses were delivered randomly at 1 or 10 Hz in two separate sessions. Stimulus intensity was set to the phosphene threshold or to 110% of the motor threshold if no phosphenes were elicited. Before and after rTMS, PR-VEP were averaged sequentially in six blocks of 100zztieresponses during uninterrupted 3.1 Hz stimulation. In healthy volunteers, PR-VEP amplitude was significantly decreased in the first block after 1 Hz rTMS and the habituation normally found in successive blocks after sustained stimulation was significantly attenuated. In migraine patients, 10 Hz rTMS was followed by a significant increase of first block PR-VEP amplitude and by a reversal to normal habituation of the potentiation (or dishabituation) characteristic of the disorder. This effect was similar in both forms of migraine and lasted for at least 9 min. There were no significant changes of PR-VEP amplitudes after 1 Hz rTMS in migraineurs and after 10 Hz rTMS in healthy volunteers, nor after sham stimulation. The recovery of a normal PR-VEP habituation pattern after high-frequency rTMS is probably due to activation of the visual cortex and the dishabituation in healthy volunteers to cortical inhibition. We conclude, therefore, that the deficient interictal PR-VEP habituation in migraine is due to a reduced, and not to an increased, pre-activation excitability level of the visual cortex.

Mother-young relationships in Belgian Blue cattle after a Caesarean section: characterisation and effects of parity

The systematic use of Caesarean section in "double muscled" Belgian Blue cattle can induce ethical concerns. The aims of the following study was to characterise mother-young relationships in such a situation and to assess the effect of parity. Fifteen heifers and 15 cows of the Belgian Blue breed were observed using video recording when isolated with their calf during the 3 days following Caesarean, a rapid surgery with rare occurrence of aggressive behaviour and no sign of cows' discomfort or weakness. All calves were bottle-fed mother's colostrum once before first suckling occurred. Heifers' calves received a supplementary number of three such artificial meals, while cows' calves needed only one. The overall median time to first licking of the calf by the mother was 3.3min without any effect of parity. The mean licking frequency was 29.2+/-15.8 per 24h: heifers licked their calf less frequently than cows, respectively 23.4+/-15.3 per 24h versus 35.1+/-14.5 per 24h (P<0.05). The mean total licking duration was 42.2+/-25.9min per 24h: there was no significant difference between heifers and cows. The overall median time to first suckling was 6.1h, without any effect of parity. The mean suckling frequency was 8.4+/-4.8 per 24h: for half of these suckling bouts, the calf was situated on the left side of the mother, i.e. the side of the scar. The suckling frequency was negatively correlated with the number of artificial meals (r(s)=-0.45,P<0.05). Heifers suckled their calf less often than cows, respectively 6.1+/-3.1 per 24h versus 10.7+/-5.2 per 24h (P<0.01), but the left side proportion was not significantly different. The mean suckling total duration was 35.3+/-21.0min per 24h. The calf was on the left side of the mother during half of this time. Heifers suckled their calf during a shorter time than cows, respectively 26.9+/-20.0min per 24h versus 43.8+/-19.1min per 24h (P<0.05), and the left side proportion was not significantly different. Licking frequency and suckling duration were positively correlated (r=0.43,P<0.05). Only 10% of the mothers (one heifer and two cows) butted their calf and kicking was never observed. Despite the difficult comparison with results of the literature according to various methodologies, mother-young relationships were considered as similar to those reported after natural calving. In our study, cows can be considered as better mothers than heifers.

[Explosive "thunderclap" headaches: should they be taken seriously?]

"Thunderclap" headaches are explosive, extremely intense and sometimes associated with neurological signs or symptoms. As illustrated by the 3 case histories presented here, they are a heterogenous group as far as etiology and prognosis are concerned. They may be symptomatic of an intracranial disorder (subarachnoïd hemorrhage, cerebral venous thrombosis, pituitary apoplexia) or idiopathic without any known cause and with a benign, though occasionally recurring, course. They can be spontaneous or triggered by Valsalva maneuvers (cough, exertion, coïtus, ...). In certain cases of so-called "idiopathic" thunderclap headache, diffuse, multifocal segmental and reversible vasospasm of cerebral arteries has been found on neuroimaging. As headache characteristics are similar in symptomatic and benign cases, angio-MRI is recommended when CT-scan and CSF examination are normal.

[Clinical case of the month. Multiple pulmonary nodules. Epithelioid hemangioendothelioma]

The epithelioid hemangioendothelioma of the lung is generally detected incidentally by a routine chest radiograph, usually in young asymptomatic woman. This tumor pursues a clinical course intermediate between that of hemangioma and angiosarcoma. Survival over 20 years have already been described in the literature. We report the case of a pulmonary epithelioid hemangioendothelioma diagnosed 16 years ago, with hepatic metastases and a radiologic follow-up that highlights the slow evolution of the pulmonary and hepatic lesions.

Effects of an enriched environment of subsequent fear reactions of lambs and ewes

The effects of an enriched environment (EE, permanent presence of a humanlike model plus colored mobile objects) during the rearing period (from birth to weaning at 3 months) were assessed on subsequent fear reactions of lambs and their mothers. Behavioral tests involved isolation, surprise effect, and the presence of a human. Fear reactions of dam-reared (DR) lambs from the EE did not differ from controls. By contrast, their mothers showed a long-lasting reduction in fear reaction as compared with controls. Artificially reared lambs (AR, in the absence of the mother) placed in the same EE were proved to be less fearful than controls. Finally, no effect of the same EE was found in cyclic ewes. In conclusion, differences between results obtained in AR and DR lambs may be due to the strong mother-young bond which would minimize the impact of the environment. In ewes, there might exist some kind of "sensitive period" between parturition and weaning during which the female may be more sensitive to her physical environment.

Long-term effects of androgen treatment on fear reactions in ewes

We have previously demonstrated that testosterone treatment reduces fear reactions of ewes subjected to daily injections of testosterone propionate (10 mg/day) for 56 days. The long-term effects of this treatment were studied in the same ewes and using the same battery of fear-eliciting tests (isolation from conspecifics, surprise, and presence of a human) 4 and 8 months after the injections were terminated. Twenty-six behavioral items related to fear were recorded. A number of differences in the behavior of treated vs control animals indicate that the former are still less fearful, especially in the surprise and human tests. Overall fearfulness scores of treated and control ewes (the higher the score, the more fearful the animals) were 7.3 +/- 1.7 vs 9.7 +/- 1.9, (P < 0.05) for the surprise test, and 7.0 +/- 1.4 vs 10.0 +/- 2.0 (P < 0.01) for the human test at 4 months, and 6.8 +/- 1.4 vs 8.2 +/- 1.1 (P < 0.05) for the human test at 8 months. Thus, not only does testosterone treatment reduce fear reactions in ewes but it also has a long lasting effect on such reactions.

Effect of androgen treatment on fear reactions in ewes

The effects of prolonged androgen treatment (testosterone propionate, 10 mg/day for 56 days) on fear reactions in ewes were studied using a battery of tests previously designed and validated. These tests involved situations classically reported to induce fear in sheep: isolation from conspecifics, surprise, and presence of a human. Testosterone-treated ewes differed from controls in a number of behavioral characteristics which indicate that they are less fearful in the various test situations. Their overall scores were respectively 9.5 vs 11.5 (P < 0.05) in the isolation test, 7.9 vs 13.1 (P < 0.001) in the surprise test, and 7.8 vs 13.2 (P < 0.001) in the human test. Testosterone treatment thus clearly reduces fear reactions in ewes subjected to nonsocial situations that are typically fear-eliciting.