Approaching prosthesis infection environment: Development of an innovative in vitro Staphylococcus aureus biofilm model.

The major role and implication of bacterial biofilms in the case of bone and prosthesis infections have been highlighted and often linked to implant colonization. Management strategies of these difficult-to-treat infections consist in surgeries and antibiotic treatment, but the rate of relapse remains high, especially if Staphylococcus aureus, a high-virulent pathogen, is involved. Therapeutic approaches are not adapted to the specific features of biofilm in bone context whereas infectious environment is known to importantly influence biofilm structure. In the present study, we aim to characterize S. aureus SH1000 (methicillin-sensitive strain, MSSA) and USA300 (methicillin-resistant strain, MRSA) biofilm on different surfaces mimicking the periprosthetic environment. As expected, protein adsorption on titanium enhanced the number of adherent bacteria for both strains. On bone explant, USA300 adhered more than SH1000. The simultaneous presence of two different surfaces was also found to change the bacterial behaviour. Thus, proteins adsorption on titanium and bone samples (from bank or directly recovered after an arthroplasty) were found to be key parameters that influence S. aureus biofilm formation: adhesion, matrix production and biofilm-related gene regulation. These results highlighted the need for new biofilm models, more relevant with the infectious environment by using adapted culture medium and presence of surfaces that are representative of in situ conditions to better evaluate therapeutic strategies against biofilm.

Staphylococcus aureus Behavior on Artificial Surfaces Mimicking Bone Environment.

Infections, which interfere with bone regeneration, may be a critical issue to consider during the development of biomimetic material. Calcium phosphate (CaP) and type I collagen substrates, both suitable for bone-regeneration dedicated scaffolds, may favor bacterial adhesion. Staphylococcus aureus possesses adhesins that allow binding to CaP or collagen. After their adhesion, bacteria may develop structures highly tolerant to immune system attacks or antibiotic treatments: the biofilms. Thus, the choice of material used for scaffolds intended for bone sites is essential to provide devices with the ability to prevent bone and joint infections by limiting bacterial adhesion. In this study, we compared the adhesion of three different S. aureus strains (CIP 53.154, SH1000, and USA300) on collagen- and CaP-coating. Our objective was to evaluate the capacity of bacteria to adhere to these different bone-mimicking coated supports to better control the risk of infection. The three strains were able to adhere to CaP and collagen. The visible matrix components were more important on CaP- than on collagen-coating. However, this difference was not reflected in biofilm gene expression for which no change was observed between the two tested surfaces. Another objective was to evaluate these bone-mimicking coatings for the development of an in vitro model. Thus, CaP, collagen-coatings, and the titanium-mimicking prosthesis were simultaneously tested in the same bacterial culture. No significant differences were found compared to adhesion on surfaces independently tested. In conclusion, these coatings used as bone substitutes can easily be colonized by bacteria, especially CaP-coating, and must be used with an addition of antimicrobial molecules or strategies to avoid bacterial biofilm development.

Adhesions in abdomino-pelvic surgeries: A real economic impact?

STUDY OBJECTIVE: To evaluate the epidemiologic and economic burden related to adhesions and their complications for the French healthcare system. DESIGN: A descriptive and economic retrospective analysis. SETTING: Medicalized information system program (PMSI), national scale of costs. PATIENTS: Female patients operated on to treat adhesions related complications in 2019. INTERVENTIONS: All patients with coded adhesiolysis acts were selected in order to identify the characteristics of Diagnosis related groups (DRG) and compare them with the general DRGs. Then, a sub-analysis on surgery types (laparoscopy or open procedures) was performed to evaluate impact adhesions development and Length of Stay. Lastly, direct costs of adhesions for the healthcare system were quantified based upon adhesiolysis acts coded as main diagnosis. MEASUREMENTS AND MAIN RESULTS: 26.387 adhesiolysis procedures were listed in France in 2019 through 8 adhesiolysis acts regrouping open surgeries and laparoscopic procedures. Adhesiolysis was coded in up to 34% in some DRGs for laparoscopic procedures. 1551 (1461 studied in our study) surgeries have been realized in 2019 with main procedure: adhesiolysis. These surgeries were associated with an expense of €4 million for the healthcare system for rehospitalizations and reoperations only. Social costs such as sick leaves, drugs and other cares haven't been taken in consideration. CONCLUSION: Adhesions related complications represent a massive burden for patients and an expensive problem for society. These difficulties may likely to be reduced by a broader use of antiadhesion barriers, at least in some targeted procedures.

Total cavopulmonary connection with a new restorative vascular graft: results at 2 years.

BACKGROUND: To present a 2-year follow-up regarding safety and hemodynamic performance of a new restorative vascular graft used as extracardiac cavo-pulmonary connection in patients with univentricular congenital heart malformations. METHODS: The graft was implanted in five patients (aged 4-12 years) as extracardiac connection between the inferior vena cava and the pulmonary artery. The conduit consists of a bioabsorbable polymer-based implant able to generate endogenous tissue restoration leading to a fully functional neo-vessel while the polymer progressively absorbs. All patients have reached more than 24 months following surgery and underwent echocardiography and magnetic resonance imaging. RESULTS: All patients are doing well at 24 months follow-up, with no graft-related serious adverse events. Transthoracic echocardiography demonstrated adequate function of the conduit in all patients while magnetic resonance imaging showed anatomical and functional stability of the restorative grafts. CONCLUSIONS: The new restorative conduit has been successfully used for the second step of the Fontan procedure as extracardiac total cavopulmonary connection. The results are promising because they suggest that complete transformation of a bioabsorbable polymer and replacement through endogenous tissue may represent a major advantage in the treatment of congenital heart disease patients. Further monitoring will allow to evaluate the long-term behavior of this new graft, in terms of clinical and hemodynamic performance, thrombogenicity and ability to grow.

Surgical antegrade transcatheter valve implantation and heavily calcified heart.

It is well known that a heavily calcified mitral valve significantly increases the perioperative and postoperative risks of mitral valve surgery. A 71-year-old woman was referred to our department with severe mitral valve disease. Cardiac imaging revealed extremely severe calcification of the entire left heart. Surgery was performed through a median sternotomy with standard cardiopulmonary bypass. After dilating the mitral orifice with a balloon, we replaced the valve with a transcatheter Edwards Sapiens 3 aortic valve under direct vision. Seven months after the procedure, the patient was doing well and no longer suffered from dyspnea.

Total Anomalous Pulmonary Venous Connection: A 40 years' Experience Analysis.

Background Total anomalous pulmonary venous connection is a rare cardiac malformation associated with significant morbidity and mortality rates. We report a large surgical series study to evaluate mid-term and long-term results of conventional surgical techniques. Methods and Results We performed a retrospective analytic study of all patients operated on for simple total anomalous pulmonary venous connection in the University Hospital of Lyon, France, between January 1973 and June 2014. A total of 180 patients were included (43% supracardiac, 27% intracardiac, 19% infracardiac, and 11% mixed types). Mean cardiopulmonary bypass and aortic cross clamp times were respectively 66 and 39 minutes. Overall mortality was 27.1%, including 38 early deaths (21.1%) and 12 late deaths (6.1%). The percentage of early death greatly decreased over the eras, from 42.1% in the seventies to 7.4% after 2010. Besides the earlier era of intervention (p < 0.0001), significant risk factors for death in multivariate analysis were preoperative pulmonary hypertension, acidosis, and cardiopulmonary bypass time. There were 24 reoperations, including 7 for pulmonary venous obstruction; 6 died. Factors directly and independently associated with late complications were the anatomic type (mixed forms, p = 0.0023), and length of aortic cross clamp time (p = 0.01). Long-term results for survivals are excellent. We report 84.7% of asymptomatic patients with a mean follow-up of 10.8 years. Conclusions The overall prognosis of total anomalous pulmonary venous connection repair with conventional procedures has greatly improved over the years with excellent long-term results. A thorough evaluation of all preoperative characteristics is imperative to achieve the best outcome.

Reimplantation of left coronary artery from pulmonary artery in a 65-year-old.

Anomalous left coronary artery to the pulmonary artery is a rare pathology with a mortality rate of 90% in the first year of life, directly related to left ventricular function and coronary perfusion, although several adult cases have been reported. Surgical correction consists of ligation of the anomalous left coronary artery associated with coronary artery bypass grafting. We describe the exceptional case of a 65-year-old woman who underwent reimplantation of the left coronary artery in the anatomical position without bridging.

Late complication after repair of aortic coarctation.

BACKGROUND: Coarctation of the aorta is a congenital malformation that has long been considered completely correctable with appropriate surgery in childhood. However, with the aging of these patients, many late complications have been reported, and this notion must be reevaluated. METHODS: We retrospectively reviewed all patients who underwent reoperation between 1992 and 2012 in our adult cardiac surgery department following surgical correction of coarctation in childhood; 18 patients over 15-years old were included in the study. RESULTS: The median time from coarctation repair to reoperation was 25 years. Patients were reoperated on for several late complications: aortic valve disease secondary to bicuspid aortic valve, ascending aortic aneurysm, recoarctation, aortic arch hypoplasia, pseudoaneurysm, associated recoarctation and pseudoaneurysm, subvalvular aortic obstruction, and descending thoracic aortic aneurysm. One patient died due to an intraoperative complication. In the other cases, the surgical results were satisfactory at the 6-month follow-up. According to literature data, age at coarctation repair and surgical technique appear to be essential factors in late complications: older age and surgical repair with prosthesis interposition are associated with a higher rate of reintervention. CONCLUSION: Patients who have undergone repair of aortic coarctation frequently remain asymptomatic for a long time. Late complications can be appropriately treated when diagnosed early. Consequently, all coarctation patients need careful lifelong follow-up, especially those with congenital aortic valve disease or surgery in childhood with interposition of prosthetic material.

Giant-cell aortitis: an unusual case of Bentall operation.

Noninfectious ascending aortitis is a very rare cause of ascending aortic aneurysm. We report a case of the truly fortuitous finding of this rare condition in a 67-year-old man operated on for an ascending aortic aneurysm associated with dystrophic aortic valve regurgitation. Intraoperative inspection revealed dissection of the aorta just above the left main coronary artery. A modified Bentall operation was performed. The pathological diagnosis was giant cell arteritis.

Could anterior papillary muscle partial necrosis explain early mitral valve repair failure?

Standardized techniques of mitral valve repair (MVR) have recently witnessed the introduction of a 'respect rather than resect' concept, the strategy of which involves the use of artificial chordae. MVR displays several advantages over mitral valve replacement in degenerative mitral regurgitation (MR), but the risk of reoperation for MVR failure must be taken into account. Different mechanisms could be advocated as the leading cause of MVR failure; procedure-related mechanisms are usually involved in early MVR failure, while valve-related mechanisms are common in late failure. Here, the case is reported of an early failure of MVR using artificial chordae that could be explained by an unusual procedure-related mechanism, namely anterior papillary muscle necrosis. MVR failure is a well-known complication after surgical repair of degenerative MR, but anterior papillary muscle partial necrosis might also be considered a possible mechanism of procedure-related MVR failure, especially when considering the increasing use of artificial chordae. Owing to the encouraging results obtained, mitral valve re-repair might be considered a viable solution, but must be selected after only a meticulous evaluation of the underlying mechanism of MVR failure.

Corpus callosum hemorrhage during left ventricular-assist device support.

Patients supported by left ventricular-assist devices are at high risk of bleeding, but among the numerous hemorrhagic complications, those involving the corpus callosum are very uncommon. We report the case of a 35-year-old woman who suddenly experienced neurological symptoms 4 months after HeartMate II implantation. Cranial computed tomography showed a voluminous hematoma involving the corpus callosum.