The rationale of opportunistic bilateral salpingectomies (OBS) during benign gynaecological and obstetric surgery: a consensus text of the Flemish Society of Obstetrics and Gynaecology (VVOG).

Ovarian cancer (OC), is a disease difficult to diagnose in an early stage implicating a poor prognosis. The 5-year overall survival in Belgium has not changed in the last 18 years and remains 44 %. There is no effective screening method (secondary prevention) to detect ovarian cancer at an early stage. Primary prevention of ovarian cancer came in the picture through the paradigm shift that the fallopian tube is often the origin of ovarian cancer and not the ovary itself. Opportunistic bilateral salpingectomy (OBS) during benign gynaecological and obstetric surgery might have the potential to reduce the risk of ovarian cancer by as much as 65 %. Bilateral risk-reducing salpingectomy during a benign procedure is feasible, safe, appears to have no impact on the ovarian function and seems to be cost effective. The key question is whether we should wait for a RCT or implement OBS directly in our daily practice. Guidelines regarding OBS within our societies are therefore urgently needed. Our recommendation is to inform all women without a child wish, undergoing a benign gynaecological or obstetrical surgical procedure about the pro's and the con's of OBS and advise a bilateral salpingectomy. Furthermore, there is an urgent need for a prospective registry of OBS. The present article is the consensus text of the Flemish Society of Obstetrics and Gynaecology (VVOG) regarding OBS.

[The false aneurysm of the left ventricle complicating mitral valvular surgery]. / Faux anévrysme du ventricule gauche compliquant un remplacement valvulaire mitral.

The false aneurysm of the left ventricle is a rare complication after a mitral valvular surgery. It results from the rupture of the ventricular wall inside an adhering pericardium, thus constituting a cavity whose wall is devoid of myocardial elements and communicates with the ventricle by a large collar. Its clinical presentation remains not very specific with an insidious spontaneous evolution which is generally done towards rupture with sudden death by tamponade. Various sophisticated modern diagnostic techniques allows a precise diagnosis. The letal nature of this lesion must be recognized and justifies an immediate surgical repair. We report the case of a 68 years old patient who presented herself in consultation of cardiology with a NYHA IIb (New York Heart Association) cardiac failure 4 months after a surgery of mitral valvular replacement. The transthoracic echography showed a voluminous false aneurysm of the left ventricle confirmed by cardiac CT scan. She has benefited from an anevrismectomy with good clinic evolution. This observation illustrates the late and silent character of the development of the false aneurysm of the left ventricle after mitral valvular surgery.

Le faux anévrysme du ventricule gauche est une complication rare après chirurgie valvulaire mitrale1. Il résulte de la rupture de la paroi du ventricule dans le péricarde adhérant, constituant ainsi une cavité dont le mur est dépourvu d'éléments myocardiques et qui communique avec le ventricule par un large collet. Sa présentation clinique reste peu spécifique avec une évolution spontanée insidieuse qui se fait le plus souvent vers la rupture avec mort subite par tamponnade1,2. Diverses techniques diagnostiques modernes permettent un diagnostic précis. La nature potentiellement létale de cette lésion doit être reconnue et justifie une réparation chirurgicale immédiate. Nous rapportons le cas d'une patiente âgée de 68 ans qui s'est présentée en consultation de cardiologie avec un tableau d'insuffisance cardiaque gauche stade IIB selon la New York Heart Association (NYHA) 4 mois après une chirurgie de remplacement valvulaire mitral. L'échographie transthoracique a montré un volumineux faux anévrysme de la paroi inférolatérale du ventricule gauche, confirmé par le scanner cardiaque. Elle a bénéficié d'une anévrysmectomie avec bonne évolution clinique. Cette observation illustre le caractère tardif et parfois silencieux du développement du faux anévrysme du ventricule gauche après chirurgie valvulaire mitrale.

Pyrene-end-functionalized poly(L-lactide) as an efficient carbon nanotube dispersing agent in poly(L-lactide): mechanical performance and biocompatibility study.

In order to improve the mechanical properties of poly(L-lactide) (PLLA) based implants, a study was made of how far well dispersed multi-walled carbon nanotubes (MWCNTs) within a PLLA matrix were able to positively affect these properties. To this end, pyrene-end-functionalized poly(L-lactide) (py-end-PLLA) was evaluated as a dispersing agent. Transmission electron microscopy (TEM) analyses and mechanical tests of MWCNTs-based materials demonstrated an enhancement of MWCNT dispersion in the PLLA matrix and improved Young's modulus (E) when 4 wt% of py-end-PLLA was used as the dispersing agent. Subsequently, the bioacceptance of PLLA/py-end-PLLA/MWCNTs nanocomposites was evaluated using human bone marrow stromal cells (HBMC) in vitro. The inclusion of py-end-PLLA and MWCNTs supported HBMC adhesion and proliferation. The expression levels of the bone-specific markers indicated that the cells kept their potential to undergo osteogenic differentiation. The results of this study indicate that the addition of MWCNT combined with py-end-PLLA in PLLA/py-end-PLLA/MWCNTs nanocomposites may widen the range of applications of PLLA within the field of bone tissue engineering thanks to their mechanical strength and cytocompatibility.

Derivatization of free radicals in an isopropanol plasma polymer film: the first step toward polymer grafting.

Plasma-polymerized films (PPF) synthesized by plasma-enhanced chemical vapor deposition (PECVD) find increasing applications in biomedicine and differ in many ways from conventional polymers. One of the most specific properties of the PPF is the high reactivity of its free-radical-rich surface, arising from the deposition mechanism. Although generally considered as a disadvantage leading to the aging of the PPF, reactivity of the plasma-treated polymers and PPF surfaces can be beneficially employed, for example, for grafting of a specific chemical functionality or short polymer chains. The quantitative evaluation of the surface radical density of the PPF is thus considered as the necessary preparatory step toward any subsequent grafting reaction. In the present study, the surface radical density of an isopropanol-based PPF was quantitatively determined by a combination of NO chemical derivatization and X-ray photoelectron spectroscopy (XPS). Once the derivatization conditions were optimized, the radical density, derived from at % N determined by XPS, was evaluated as a function of the deposition power. It was found out that the surface density of free radicals presents a maximum for the deposition power of 200 W (~2.3 × 10(14) spin/cm(2)) and it stabilizes (~2.1 × 10(14) spin/cm(2)) with further power increase. XPS findings were supported by in situ FTIR measurements that provided additional information about the degree of plasma fragmentation denoting fragmentation saturation for a deposition power of 200 W. By fitting the N1s peak it was possible to identify primary, secondary and ternary radicals and to study their respective evolutions with different deposition conditions. Angle-resolved XPS analysis allowed the in-depth distribution of radicals to be addressed, revealing that on the top surface, primary, and secondary radicals are dominating, whereas more tertiary radicals are present in the subsurface region. Finally, some preliminary chemical grafting experiments have allowed the relevance of derivatization results to be cross-checked.

A pharmaceutical study of doxorubicin-loaded PEGylated nanoparticles for magnetic drug targeting.

One of the new strategies to improve cancer chemotherapy is based on new drug delivery systems, like the polyethylene glycol-coated superparamagnetic iron oxide nanoparticles (PEG-SPION, thereafter called PS). In this study, PS are loaded with doxorubicin (DOX) anticancer drug, using a pre-formed DOX-Fe(2+) complex reversible at lower pH of tumour tissues and cancer cells. The DOX loaded PS (DLPS, 3% w/w DOX/iron oxide) present a hydrodynamic size around 60nm and a zeta potential near zero at physiological pH, both parameters being favourable for increased colloidal stability in biological media and decreased elimination by the immune system. At physiological pH of 7.4, 60% of the loaded drug is gradually released from the DLPS in ∼2h. The intracellular release and distribution of DOX is followed by means of confocal spectral imaging (CSI) of the drug fluorescence. The in vitro cytotoxicity of the DLPS on MCF-7 breast cancer cells is equivalent to that of a DOX solution. The reversible association of DOX to the SPION surface and the role of polymer coating on the drug loading/release are discussed, both being critical for the design of novel stealth magnetic nanovectors for chemotherapy.

Early and late parameters describing the offset of neuromuscular blockade are highly intercorrelated.

BACKGROUND: Neuromuscular blocking agents have always shown wide inter-individual variability when it comes to their duration of action. This prevents clinicians from anticipating the evolution of the neuromuscular block for any given patient. With this study, we aimed to assess the nature of the relationships existing between different time course parameters used to describe paralysis onset and offset. METHODS: Sixty American Society of Anesthesiologists (ASA) score III-IV anaesthetised patients were randomised to receive a single equipotent dose (2ED95) of either rocuronium, mivacurium or atracurium. We used acceleromyography to monitor neuromuscular transmission. We described the relationships between the time-interval measurements of: onset, the first response (T1) reappearance, T1 25% of control, train-of-four ratio 0.25 and 0.75. Pearson correlation coefficients were calculated. RESULTS: We found no significant relationships between onset and any of the four parameters used to describe the offset. On the other hand, we showed strong and highly significant linear relationships between all the parameters describing the offset for each of the muscle relaxants studied (correlation coefficients ranging from 0.850 to 0.992). CONCLUSIONS: We evidenced strong linear correlations between the four offset time course parameters of spontaneous recovery after a single neuromuscular blocking agents (NMBAs) bolus. Such relationships open up new clinical perspectives concerning quantitative neuromuscular transmission monitoring: the scope of individual valuable anticipation of the patient's recovery.

Novel method of doxorubicin-SPION reversible association for magnetic drug targeting.

A new method of reversible association of doxorubicin (DOX) to superparamagnetic iron oxide nanoparticles (SPION) is developed for magnetically targeted chemotherapy. The efficacy of this approach is evaluated in terms of drug loading, delivery kinetics and cytotoxicity in vitro. Aqueous suspensions of SPION (ferrofluids) were prepared by coprecipitation of ferric and ferrous chlorides in alkaline medium followed by surface oxidation by ferric nitrate and surface treatment with citrate ions. The ferrofluids were loaded with DOX using a pre-formed DOX-Fe(2+) complex. The resulting drug loading was as high as 14% (w/w). This value exceeds the maximal loading known from literature up today. The release of DOX from the nanoparticles is strongly pH-dependent: at pH 7.4 the amount of drug released attains a plateau of approximately 85% after 1h, whereas at pH 4.0 the release is almost immediate. At both pH, the released drug is iron-free. The in vitro cytotoxicity of the DOX-loaded SPION on the MCF-7 breast cancer cell line is similar to that of DOX in solution or even higher, at low-drug concentrations. The present study demonstrates the potential of the novel method of pH-sensitive DOX-SPION association to design novel magnetic nanovectors for chemotherapy.

Physico-chemical and hygienic property modifications of stainless steel surfaces induced by conditioning with food and detergent.

The effect of repeated conditioning procedures (25 runs), consisting of soiling (milk and meat products) and cleaning steps, on the hygienic status, physico-chemical properties and surface chemical composition of stainless steel (SS) surfaces, was investigated. Five SSs differing in grade and finish were used. Both soiling and surface cleaning/conditioning procedures resulted in a similar increase in the surface contamination with carbon, while the changes in the basic component of the surface free energy depended on the conditioning procedure. The passive film was also affected, the Fe/Cr ratio in particular. The hygienic status was also changed, especially with milk as shown by monitoring the number of residual adhering Bacillus cereus spores after contaminating the surface with spores followed by cleaning. The results show that in food environments, the presence and the nature of conditioning molecules play a major role in the hygienic status of SS surfaces.

[A teaching medical simulator: phacoemulsification in virtual reality]. / Simulateur pédagogique médical: la phacoémulsification en réalité virtuelle.

INTRODUCTION: Improvements in computer technology have made it possible to design a cataract surgery teaching simulator in real time. MATERIAL AND METHODS: A computed representation of the lens was made with a mechanical model simulating the behavior of the lens, to which we added texture. The different models use mesh to make a section, which allowed us to make a section in real time using element removal or separation. Different models were used: a mass-spring mesh, a rigid model and a deformable model created using the finite element method. The contact with the lens is simulated by a collision sphere, which provides the interaction between the surgical instruments and the virtual environment. The surgical instruments viewed on the screen are controlled by a stylus with 6 degrees of freedom. DISCUSSION: We obtained the first step of phacoemulsification in real time with a good visual aspect. The surgeon views the procedure and can modify his movements instantaneously. This simulator provides the opportunity for students to safely learn phacoemulsification and improve their technique with an infinite number of procedures. CONCLUSION: The realism offered by this tool provides a rigorous teaching tool that might reduce the learning curve for phacoemulsification.

Interventional therapy procedures assisted by medical imaging and simulation. The experience of U 703 Inserm (Lille France).

Since the early 1990s, minimally invasive techniques have been increasingly used in ever more and diversified fields of application. These techniques have some shared characteristics (predominant role of medical imaging, intensive use of new communication technologies, a multidisciplinary medical and scientific framework, etc.) but also shared specific problems (high-tech tools unfamiliar to the medical users, a major and long period of time for technological development, unavailability of training systems, difficulties in obtaining regulatory approval). For a long time, our Laboratory of Medical Physics (U 703 Inserm) has developed an innovative research activity in biomedical engineering in the field of assisted therapy, medical imaging and medical simulation. This paper presents the general context of interventional therapy procedures assisted by image and simulation and describes our scientific activities based on realistic objectives close to medical practice.

[Tissue resistance: what about tension-free?]. / Maintien tissulaire par friction ("frixation"): qu'attendre du tension-free?

OBJECTIVES: The purpose is to quantify objective tissue resistances before healing of prostheses used in pelvic floor surgery. PATIENTS AND METHODS: We measured tissue resistances offered to five types of meshes by four classical surgical routes. We also tested the incidence of the modification of the width of meshes on tissue resistance. This study was realized on frozen cadavers, by pull on prostheses just after implantation. Tests are realized with a dynamometer and results obtained in Newton. RESULTS: In the Retzius space, TVT offers a better resistance than IVS or LIFT meshes. We did not bring to the fore a significant difference between four routes for 1 cm wide prosthesis. The increase of width of Prolene meshes improves their resistance in tissues and thus quality of their fixation. We underscore a better resistance of the trans sacrospinous route with regard to the trans muscular one. DISCUSSION AND CONCLUSION: The increase of resistance is bound to the increase of the contact area between the prosthesis and the tissues. This increase of resistance should be taken into account in prolapse surgery: constraints are stronger than for stress incontinence. The posterior arms of meshes have to measure more than 1 cm wide and be set up through the sacrospinous ligament rather than through the elevator muscles. The type of knitting of prostheses is important and influences the resistance in tissues in the immediate postoperative time. Manufacturers should be interested in conceiving specific meshes for the tension-free fixation, with special and adapted mechanical properties.

Ultrasound image registration for patient setup in conformal radiotherapy of prostate cancer.

The goal of 3D conformal radiotherapy (CRT) is to conform the high dose region to the target volume while sparing surrounding normal tissue. Knowledge about the mobility of organs relative to the bony anatomy and to the reference position is of great importance when daily positioning patient. In this work we present a method to monitor patient setup during CRT of prostate cancer. The method is based on ultrasound tracking and matching with planning modality.

What can the operator actually feel when performing a laparoscopy?

The designing of a laparoscopic simulator, particularly the parameterizing of a force feedback system, has drawn attention to the question of characterizing laparoscopic gestures and effecting quantitative measurement of the various interactions between the organs and the instruments used to operate in the case of animals. These measurements use an instrument previously developed by the authors' team. Laparoscopic gestures are characterized by a visual component and a haptic component. The visual component cannot, of course, be disregarded. The amplitude of the forces generated by interaction between organ and instrument in relation to that of the forces linked with other mechanical phenomena interfering with somesthesic information, such as friction of the operative instrument in the trocar or resistance of the abdominal wall to tilting movement, has led to a discussion about the extent of haptic components involved in the performance of laparoscopic gestures. After describing the measurement's device and the different forces applied on the surgical instrument, the authors describe the measurement of the rubbing strengths caused by the slippage of the instrument in the trocar and one of the elastic torques induced by the abdominal wall when the trocar in slanted. Comparison of values with those obtained during interactions with various organs shows that during some delicate surgical gestures, the influence of the instrument can disturb the haptic sensation. Interference of haptic sensation is greatest at maximal tilting angles and at maximal velocity of insertion and removal movement.

[Effect of laparoscopic trocar model on the quality of the movement: experimental study of friction]. / Influence du type des trocarts utilisés en coelioscopie sur la qualité du mouvement: étude expérimentale du frottement.

OBJECTIVE: To keep the pneumoperitoneum and the tightness of the abdominal and pelvic cavity during a laparoscopy, the sheaths of trocar are provided with a device (valvule, membranes etc.) inducing a friction during the handling of the instrument. The objective of this article is to analyse friction from different types of trocar's port. MATERIALS AND METHODS: We present here the experimental results obtained during a testing bench of three different trocar sheaths. The mechanism of tightness of the first trocar sheath is made of a fine membrane associated to a valve, of a thick membrane for the second trocar sheath, whereas the third trocar sheath is made of two membranes, a fine and a thick, associated to a valve. After reporting the experimental device and the analytic model adopted to describe the relationship between the measured physical parameters, we lay out our results. The identification of parameters of this model makes it possible to objectively compare the three trocars. RESULTS: Our results revealed that, under experimental conditions, the amplitude of friction was significantly lower with trocar's port provided with a valve and a fine membrane than with both other ports (fivefold weaker). DISCUSSION AND CONCLUSION: We evoke the importance of the possible disruption brought by these frictions while referring these values to those of other measurements concerning interactions between instrument and organs. These different behaviours of the material could have some consequences in choosing the tools for the performance of precise gestures.

Influence of surface chemistry on the hygienic status of industrial stainless steel.

Coupons of fourteen different stainless steels were investigated in terms of surface chemistry and ease of cleaning. Steel surfaces were exposed to Bacillus cereus spores in static saline solution for 2 h. Surfaces were rinsed and then covered with whole milk and allowed to dry. Surfaces were then cleaned in an experimental flow system that mimics an industrial application. After cleaning, remaining spores were released by sonication, spores cultured and colony forming units determined. Surfaces with higher levels of Fe in the outer surface of the passive film cleaned more easily. There was a relation between the polar component and ease of cleaning. The higher the polar component the more easily the surface cleaned. The cleaning mechanism involves dissolution of Fe enriched hydroxide films on the surface.

Effects of acute decrease in systemic afterload on accuracy of Doppler-derived left ventricular rate of pressure rise measurement in anesthetized patients.

OBJECTIVES: This study was designed to describe exactly the effects of acute decrease in systemic afterload on the accuracy of Doppler-derived left ventricular rate of pressure rise (LV DeltaP/Delta(t)) measurements compared with other routinely used indices of systolic function. METHODS: Twelve patients scheduled for coronary artery bypass grafting were studied. After induction of anesthesia (T0), afterload was modified by incremental administrations of nicardipine (T1-4). At each step of the procedure, thermodilution-derived cardiac index, left ventricular (LV) fractional area change, and LV DeltaP/Delta(t) were measured, and systemic vascular resistances were calculated. RESULTS: During the procedure, the systemic vascular resistances decrease averaged 13.4%. Systemic vascular resistances were correlated with LV DeltaP/Delta(t) (r = 0.843, P =.003) but inversely correlated with cardiac index (r = -0.782, P =.005) and LV fractional area change (r = -0.887, P =.003). CONCLUSION: In conclusion, and inversely to cardiac index or LV fractional area change, LV DeltaP/Delta(t) does not overestimate LV contractility in the presence of an acute decrease in systemic afterload.

[Right ventricular migration of a stent after endovascular treatment of a superior vena cava syndrome]. / Migration ventriculaire droite d'un stent après traitement endovasculaire d'un syndrome cave supérieur.

The authors report a case of migration of a Palmaz stent used for treatment of a patient with a malignant superior vena caval syndrome. Transoesophageal echocardiography showed the metallic device in the tricuspid subvalvular apparatus. Several attempts to recover the stent percutaneously failed. This case illustrates a rare but serious complication of endovascular stenting: migration of the material. Although it is often possible to reposition the stent by radiological interventional techniques, when the stent is located in the right ventricle, the procedure is more difficult and usually fails. Transoesophageal echocardiography enables accurate localisation of the material with respect to the surrounding cardiac structures, especially the tricuspid valve.

Mimicking a conformational B cell epitope of the heat shock protein PfHsp70-1 antigen of Plasmodium falciparum using a multiple antigenic peptide.

The Pf72/Hsp70-1 antigen is a major target in the naturally acquired immunity against Plasmodium falciparum malaria. We carried out an extensive analysis of the responses to several epitopes on the least conserved C-terminal domain, according to the mode of sensitization: malaria infection or immunization with different immunogens. We found significant differences in the panel of B-cell epitopes recognized by animal models including primates, and by humans sensitized by natural infection. We focused the analysis on one epitope that is unique to Plasmodium species. It is specifically recognized by a monoclonal antibody that mediates the killing of infected hepatocytes in vitro. We produced a polymeric multiple antigenic peptide (MAP) form of this sequence, which enabled us to identify a new B-cell epitope not detected by ELISA with linear peptides. The polymer was strongly recognized by sera from monkeys or humans sensitized by natural infection, whereas the monomer was not. We modelled the three-dimensional structure of the Pf72/Hsp70-1 sequence, using known Escherischia coli DnaK structures as a template. This predicted that the corresponding region would form a loop in the native antigen. The results presented here suggest that the MAP strategy is also particularly useful as a means of obtaining suitable synthetic models for conformation-dependent epitopes.