Insights into the behavioural responses of juvenile thornback ray Raja clavata to alternating and direct current magnetic fields.

As part of energy transition, marine renewable energy devices (MRED) are currently expanding in developed countries inducing the deployment of dense networks of submarine power cables. Concern has thus raised about the cable magnetic emissions (direct or alternating current) because of potential interference with the sensorial environment of magneto-sensitive species, such as sharks and rays. This study sought to assess the short-term behavioural responses of juvenile thornback rays (Raja clavata) (n = 15) to direct and alternating (50 Hz) uniform 450-µT artificial magnetic fields using 1 h focal-sampling design based on a detailed ethogram. Careful control of magnetic fields' temporal and spatial scales was obtained in laboratory conditions through a custom-made Helmholtz coil device. Overall, qualitative or quantitative behavioural responses of juvenile rays did not significantly vary between control vs. exposed individuals over the morning period. Nonetheless, rays under direct current magnetic field increased their activity over the midday period. Synchronisation patterns were also observed for individuals receiving alternating current exposure (chronologic and qualitative similarities) coupled with a high inter-individual variance. Further studies should consider larger batches of juveniles to address the effect of long-term exposure and explore the sensitivity range of rays with dose-response designs.

Effects of anthropogenic magnetic fields on the behavior of a major predator of the intertidal and subtidal zones, the velvet crab Necora puber.

With the progress of the offshore renewable energy sector and electrical interconnection projects, a substantial rise in the number of submarine power cables is expected soon. Such cables emit either alternating or direct current magnetic fields whose impact on marine invertebrates is currently unknown and hardly studied. In this context, this study aimed to assess potential short-term exposure (30 min) effects of both alternating and direct magnetic fields of increasing intensity (72-304 µT) on the behavior of the high-ecological value velvet crab (Necora puber). Three experiments were designed to evaluate whether the strongest magnetic field intensities induce crabs' attraction or repulsion responses, and whether foraging and sheltering behaviors may be modified. We extracted from video analyses several variables as the time budgets crabs spent immobile, moving, feeding, or sheltering as well as total and maximal distance reached in the magnetic field (MF) gradient. The crabs exposed to artificial MF did not exhibit significant behavioral changes compared with those exposed to the "natural" MF. Overall, our results suggest that, at such intensities, artificial magnetic fields do not significantly alter behaviors of N. puber. Nevertheless, future studies should be conducted to examine the effects of longer exposure periods and to detect potential habituation or resilience processes.

The nocturnal life of the great scallops (Pecten maximus, L.): First description of their natural daily valve opening cycle.

Valvometry techniques used to monitor bivalve gaping activity have elucidated numerous relationships with environmental fluctuations, along with biological rhythms ranging from sub-daily to seasonal. Thus, a precise understanding of the natural activity of bivalves (i.e., not exposed to stressful environmental variations) is necessary as a baseline for detecting abnormal behaviors (deviations). This knowledge is also needed to reliably interpret observations of bivalve gaping behavior and associated biological processes (e.g., respiration, nutrition) acquired over time-limited periods. With this in mind, we investigated the natural daily gaping activity of the great scallop (Pecten maximus) by continuously monitoring 35 individuals in several individual tanks and in situ (Bay of Saint-Brieuc, Brittany, France) using fully autonomous Hall effect sensors. Our results revealed a circadian cycle (τ = 24.0h) in scallop gaping activity. Despite significant inter-individual variability in mean opening and cycle amplitude, almost all individuals (87.5%) exhibited nocturnal activity, with valves more open at night than during the day. A shift in light regime in the tanks triggered an instantaneous change in opening pattern, indicating that light levels strongly determine scallop activity. Based on the opening status of scallops, we also identified several gaping behaviors deviating from the regular daily pattern (lack of rhythmicity, high daytime opening), potentially reflecting physiological weakness. While further long-term studies are required to fully understand the natural activity of scallops, these findings pave the way for studies focused on the scallop response to external factors and introduce further research into the detection of abnormal behaviors. Coupling observations of diel valve gaping cycles with other daily variations in organismal and environmental parameters could help explain mechanisms driving the growth patterns of scallops observed in their shell striations. From a technical perspective, our field-based monitoring demonstrates the suitability of autonomous valvometry sensors for studying mobile subtidal bivalve activity in remote offshore environments.

[Pediatric heart surgery in developing countries. Twenty years experience of La Chaine de L'espoir (Chain of Hope)]. / La chirurgie cardiaque pédiatrique dans les pays en voie de développement. Vingt ans d'expérience de la chaîne de l'Espoir.

Because of their high incidence, cardiac disorders in children are now a public health issue. These children require multidisciplinary management, but surgery is sometimes unavoidable. The two most frequent types of cardiac disorder in children are congenital defects and rheumatic valve disease. La Chaine de l'Espoir (Chain of Hope) is present in more than 30 countries in Africa, Asia and the Middle East. Due to the socio-economic context and lack of technical resources, pediatric heart surgery has several particular characteristics in developing countries. Infants rarely undergo cardiac surgery, given the complexity of their management and particularly the need for intensive care. Another specificity is the need to limit treatment to reparatory or conservative methods. Surgery is rarely attempted in terminally ill patients. Costs must be kept to a minimum, and this is why we have optedfor local manufacture of mitral rings, led by Daniel Roux. After 20 years of practice we have found that regional hospitals are the smallest structures that can offer acceptable results in terms of patient care and professional training

A current synthesis on the effects of electric and magnetic fields emitted by submarine power cables on invertebrates.

The goal of clean renewable energy production has promoted the large-scale deployment of marine renewable energy devices, and their associated submarine cable network. Power cables produce both electric and magnetic fields that raise environmental concerns as many marine organisms have magneto and electroreception abilities used for vital purposes. Magnetic and electric fields' intensities decrease with distance away from the cable. Accordingly, the benthic and the sedimentary compartments are exposed to the highest field values. Although marine invertebrate species are the major fauna of these potentially exposed areas, they have so far received little attention. We provide extensive background knowledge on natural and anthropogenic marine sources of magnetic and electric fields. We then compile evidence for magneto- and electro-sensitivity in marine invertebrates and further highlight what is currently known about their interactions with artificial sources of magnetic and electric fields. Finally we discuss the main gaps and future challenges that require further investigation.

Cardiac surgery in low-income settings: 10 years of experience from two countries.

BACKGROUND: Access to cardiac surgery is limited in low-income settings, and data on patient outcomes are scarce. AIMS: To assess characteristics, surgical procedures and outcomes in patients undergoing open-heart surgery in low-income settings. METHODS: This was a cohort study (2001-2011) in two low-income countries, Cambodia and Mozambique, where cardiac surgery had been promoted by visiting non-governmental organizations. RESULTS: In Cambodia and Mozambique, respectively, 1332 and 767 consecutive patients were included; 547 (41.16%) and 385 (50.20%) were men; median age at first surgery was 11 years (interquartile range [IQR] 4-14) and 11 years (IQR 3-18); rheumatic heart disease affected 490 (36.79%) and 268 (34.94%) patients; congenital heart disease (CHD) affected 834 (62.61%) and 390 (50.85%) patients, with increasingly more CHD patients over time (P<0.001); and the number of patients lost to follow-up reached 741 (55.63%) and 112 (14.6%) at 30 days. A total of 249 (32.46%) patients were lost to follow-up in Mozambique, remoteness being the only influencing factor (P<0.001). Among patients with known vital status, the early (<30 days) postoperative mortality rate was 6.10% (n=40) in Mozambique and 3.05% (n=18) in Cambodia. Overall, 109 (8.18%) patients in Cambodia and 94 (12.26%) patients in Mozambique underwent re-do surgery. In Mozambique, a further 50/518 (9.65%) patients died at a median of 23months (IQR 7-43); in Cambodia, a further 34/591 (5.75%) patients died at a median of 11.5months (IQR 6-54.5). CONCLUSIONS: Cardiac surgery is feasible in low-income countries with acceptable in-hospital mortality and proof of capacity building. Patient outcomes after cardiac surgery in low-income countries remain unknown, given the strikingly high numbers of lost to follow-up.

Long-term results of mitral valve repair in active endocarditis.

BACKGROUND: Several investigators have reported the feasibility of mitral valve repair in active endocarditis, but the long-term results are still unknown. METHODS AND RESULTS: We reviewed 37 consecutive patients who underwent mitral valve repair with the Carpentier technique for active endocarditis in our center between 1989 and 1994. This repair involved prosthetic annuloplasty in 31 patients (84%), valve resection in 31 (84%), chordal shortening or transposition in 19 (51%), pericardial patch in 16 (43%), and direct suture of leaflet perforation in 4 (11%). Associated procedures were primarily aortic valve repair or replacement in 11 (30%) and tricuspid repair in 2 (6%). Early complications included 1 operative death (3%; 95% CI, 0 to 15.5) and 1 reoperation for pericardial patch dehiscence. Recurrence of endocarditis was observed in 1 patient (3%; 95% CI, 0 to 16). The 10-year survival rate and freedom from mitral valve reoperation were 80% (95% CI, 66 to 94) and 91% (95% CI, 81 to 100), respectively. At 10 years, most patients (96%) were in good functional status (NYHA class I to II) with no or trivial mitral regurgitation (92%) on echocardiography. CONCLUSIONS: Mitral valve repair using Carpentier's techniques in patients with active endocarditis offers very good long-term results with a low rate of recurrence or reoperation.

Management of commissural lesions in native mitral valve endocarditis: long-term results of valve repair and partial homograft replacement.

BACKGROUND AND AIM OF THE STUDY: Commissural lesions in the context of native mitral valve endocarditis are a technically challenging condition for conservative surgery. Herein are reported the authors' 10-year results for mitral valve repair (MVRep) or partial homograft replacement (PHR) performed in this setting. METHODS: Data were reviewed from 19 consecutive patients who underwent MVRep using either Carpentier's technique (n = 14) or PHR (n = 5) for endocarditis at the authors' institution between 1989 and 1994. RESULTS: There was one operative death (5%; 95% CI 0-15.5%). Two reoperations were performed in each subgroup for recurrence of endocarditis (n = 2) and mitral valve failure (n = 2). The 10-year survival rate and freedom from mitral valve reoperation were 95% (95% CI 84-100%) and 78% (95% CI 59-97%), respectively. At 10 years, 13 (93%) surviving and non-reoperated patients were in good functional status (NYHA class I-II), and 14 (100%) were in sinus rhythm. Although echocardiographic results were excellent in the MVRep group, all PHR patients had moderate or severe mitral valve dysfunction. CONCLUSION: Commissural reconstruction using Carpentier's techniques demonstrated excellent long-term results in patients with native mitral valve endocarditis. In contrast, the results for PHR were rather disappointing.

Aortic cusp extension valvuloplasty for rheumatic aortic valve disease: midterm results.

BACKGROUND: The surgical management of rheumatic aortic insufficiency in the young remains problematic owing to the drawbacks of prosthetic valve replacement at this age. In young foreign patients, for whom long-term anticoagulation therapy is unavailable, we have used a glutaraldehyde preserved autologous pericardium cusp extension technique to repair rheumatic aortic valve insufficiencies resulting from cusp retractions. METHODS: From September 1992 to December 2000, 89 consecutive patients with a mean age of 16 +/- 5 years underwent triple pericardial aortic cusp extension valvuloplasty. Eighty patients had pure aortic insufficiency, 9 had mixed aortic disease. Twenty-nine patients (33%) had isolated aortic valve disease and 60 patients (69%) had combined aortic and mitral valve disease with significant tricuspid valve disease in 21 (24%). Aortic repair consisted of free edge aortic cusp extension using three rectangular strips of glutaraldehyde stabilized autologous pericardium. Twenty-nine patients (33%) underwent an isolated aortic repair, 39 patients (44%) underwent combined aortic and mitral procedures (34 mitral repairs, 3 mitral homografts, and 2 prosthesis replacements), and 21 patients (23%) underwent a triple valve repair. RESULTS: The hospital mortality was 2.2%. Primary failure of the aortic repair requiring immediate reoperation occurred in 2 patients. During follow-up (mean of 62 +/- 22 months) 1 patient died and 7 underwent redo valvular surgery. At 5 years the actuarial survival rate was 96.4%, and 92.1% of the patients were free from redo valvular surgery. At 7 years 90% of the patients were free from valve-related complications. Among the 76 patients free from redo valvular surgery at follow-up, 6 had deterioration of the repair resulting in grade II aortic and mitral insufficiencies. CONCLUSIONS: Our midterm results of glutaraldehyde stabilized autologous pericardial aortic cusp extension are encouraging and suggest that this technique should be considered as a viable alternative palliative procedure in a young rheumatic population, allowing for growth of the annulus and delaying to a less critical period the need for the lifelong anticoagulation therapy required for a prosthetic mechanical valve.

Triple valve repair for young rheumatic patients.

BACKGROUND: Facing young foreign polyvalvular rheumatic patients, for which long-term anticoagulation is not available, we have chosen to attempt triple valve repair procedures in order to avoid prosthetic implantation in this particular population suffering from triple valve disease. METHODS: Twenty-one young rheumatic patients (mean age:11+/-4 years) underwent triple valve repair procedures including cusp extension on the aortic valve aortic between September, 1992 and December, 2000. Valvular pathology characteristics according to Carpentier's classification included mitral insufficiency type III post+II ant (n=10), type III post (n=4), type II ant (n=2), mitral stenosis (n=5), type III aortic insufficiency (n=21), type I (n=13) and type III (n=8) tricuspid insufficiency. RESULTS: Firstly, the mitral valve disease were corrected using Carpentier's techniques of repair: prosthetic ring annuloplasty (n=16), commissurotomy (n=12), chord transposition (n=11) or shortening (n=4), papillary muscle sliding plasty (n=4) and pericardial patch leaflet enlargement (n=6). Secondly, aortic lesions were corrected using glutaraldehyde stabilized autologous pericardium triple cusps extension technique (n=21). Lastly, tricuspid repairs were always performed on beating hearts using commissurotomy (n=8), prosthetic ring (n=12) or other techniques (n=9) of annuloplasty. The operative mortality was 4.7% (one patient died). Echocardiograms before discharge showed grade I mitral insufficiency in seven patients and grade I aortic insufficiency in five patients. There was no late death during a mean follow-up of 51+/-31 months. Two patients underwent valvular redo surgery because of aortic and mitral plasty deterioration due to rheumatic disease progress. After 5 years, 90% of the patients were free from redo valvular surgery. CONCLUSIONS: In rheumatic patients, autologous pericardial patch extension of the aortic valve permitted widespread use of reconstructive surgery even in patients suffering from triple valve disease. Triple valve repair, in this particular challenging setting of patients, has provided satisfactory initial and mid-term results and could be considered as an interesting palliative surgical approach.

Mitral valve reconstruction in Barlow disease: long-term echographic results and implications for surgical management.

OBJECTIVE: Owing to the complexity of the underlying lesions, Barlow disease remains a challenge for surgeons performing mitral valve repair. We aimed to assess whether our most recent results involving several surgeons were comparable with those of a previous experience in which mitral valve repair was performed by a more limited group of surgeons. METHODS: From September 2000 to January 2007, 200 patients with Barlow disease (135 men and 65 women; mean age, 56 ± 13 years) were referred to our institution for surgical treatment of their mitral regurgitation. We retrospectively analysed the mitral lesions characteristics, the surgical techniques used, and clinical outcomes. Follow-up echocardiograms were biannually reviewed. RESULTS: Lesions comprised annular dilatation, excess tissue, and leaflet prolapse in all cases. The most frequent prolapsed segments were P2 (88.5%; n = 177) and A2 (55.5%; n = 111). Annular calcifications and restrictive valvular motion were associated in 20% (n = 40). Repair was feasible in 94.7% (n = 179/189) of non-redo interventions. Immediate postoperative echocardiography showed residual mitral regurgitation greater than 1+ in 6 cases; these patients were all reoperated on within the next months. Operative mortality was 1.5% (n = 3). Mean follow-up was 77.5 ± 25.6 months. At 8 years postoperatively, overall survival was 88.6% ± 3.1%, freedom from reintervention was 95.3% ± 1.7%, and freedom from late recurrent moderate mitral regurgitation (>2+) was 90.2% ± 3.1% CONCLUSIONS: Provided that the fundamental principles of mitral valve reconstruction are respected, the surgical techniques are highly reproducible with good long-term results, similar to those published during the pioneering phase of this surgery.

Experience with the posterior leaflet extension technique for correction of rheumatic mitral insufficiency in children.

OBJECTIVE: To describe the experience with the technique of posterior leaflet extension in children suffering of rheumatic mitral regurgitation. METHODS: Between April 2002, and October 2007, 30 children, mean age 11.3 years, underwent correction of mitral insufficiency with the technique of posterior leaflet extension with a pericardial patch. Eight also received a Carpentier ring. Six children had aortic valve disease and were submitted to Ross operation (five cases) or valve replacement with an aortic homograft. All were in functional class III or IV (NYHA classification). RESULTS: There was one death. One child presented severe hemolysis in the postoperative period and was submitted to mitral valve replacement. Clinical evolution in the remaining patients was good. CONCLUSIONS: Posterior leaflet extension of the mitral valve seems to be an effective surgical technique for correction of rheumatic mitral insufficiency in children.

Ebstein's anomaly: the Broussais approach.

Ebstein's anomaly is rare, but it is the most frequent cause of congenital tricuspid valve anomaly. For many years valve replacement was performed. Conservative techniques are now preferred due to improvement of the results. The goals of surgery are to restore a normal tricuspid valve function, to preserve the right ventricular contractility and to decrease the risk of rhythm disturbances. Basically, the technique is based on mobilization of the anterior leaflet and longitudinal plication of the right ventricle. A bidirectional cavo pulmonary shunt is used in severe cases. Results are correlated with the severity of the disease, the expertise of the surgical team and also with the perioperative management.

Posterior leaflet extension with an autologous pericardial patch in rheumatic mitral insufficiency.

We describe our technique of posterior leaflet extension with an autologous pericardial patch in patients suffering from rheumatic mitral regurgitation. Several simple rules have allowed us to achieve satisfying long-term results.

Congenital mitral valve surgery: techniques and results.

PURPOSE OF REVIEW: Congenital lesions of the mitral valve are rare. Conservative surgery is recognized as the best option. In complex anatomy, however, replacement is the only solution to achieve an acceptable result. This review aims to study the long-term follow-up of classical treatments, conservative or replacement, and to examine new technical advances. RECENT FINDINGS: The long-term results of conservative surgery are confirmed with a low incidence of reoperation except in mitral valve stenosis. The Ross II operation using a pulmonary autograft is a difficult technique that may be useful in the youngest patient group when prosthetic devices cannot be used. SUMMARY: In the last few years, surgery of congenital mitral valve lesions has gained from echocardiography, which shows the exact function and anatomy of the mitral valve. The tendency is to avoid multistage operations. Valve replacement by biologic material (Ross II) is still under clinical evaluation.

Ventricular volumes in Ebstein's anomaly: x-ray multislice computed tomography before and after repair.

BACKGROUND: This study was performed to measure right and left ventricular volumes in Ebstein's anomaly before and after operation. METHODS: Twenty-six consecutive patients were operated on with tricuspid valve repair and plication of the atrialized right ventricle, associated with a bidirectional cavopulmonary shunt in 15 patients. Right ventricular (RV) and left ventricular end-diastolic and end-systolic volume indexes were measured by x-ray computerized tomography before and after surgical repair. Left ventricular stroke index and ejection fraction were calculated. RESULTS: Before surgery, the mean stroke index of the atrialized RV was 36 +/- 33 mL/m2, with severe reduction in 9 patients and aneurysmal aspect in 2 patients. After surgery, the atrialized RV was no longer identifiable. Both RV end-diastolic volume index and stroke index of the remaining effective RV were reduced. Bidirectional cavopulmonary shunt was a determinant factor of decrease in the effective RV end-diastolic volume index after repair. Conversely, left ventricular ejection fraction and stroke index increased significantly after surgery. CONCLUSIONS: The atrialized RV with dyskinesia seems a good indication for a plication. RV end-diastolic volume index of the effective RV decreased after surgery. In severe cases, bidirectional cavopulmonary shunt was useful by decreasing RV end-diastolic volume, thus preventing further RV dilation. In all cases left ventricular ejection fraction and stroke volume index increased after surgery.