[Rare diagnostics of infective endocarditis after kidney transplantation]. / Raritná diagnostika infekcnej endokarditídy po transplantácii oblicky.

INTRODUCTION: Infective endocarditis in a patient after kidney transplantation is a serious infective complication which increases the risk of loss of the graft and also the mortality of patients. The most important predisposing factor is the immunosuppressive therapy - mainly induction immunosuppression.Material and case description: 250 patients underwent kidney transplantation throughout the period of 12 years in the Transplant Center Martin. This set of patients included 5 patients (2 %) after heart valve replacement. We present the case of a patient after kidney transplantation with development of endocarditis of the bioprosthesis of the aortic valve one month after successful kidney transplantation. Diagnostics of endocarditis by standard procedures (examination by transthoracic echocardiogram, transesophageal echocardiography, hemocultures) was unsuccessful. We rarely diagnosed endocarditis only by PET-CT examination with a consequent change of the antibiotic treatment and successful managing of this post-transplant complication. CONCLUSION: Endocarditis after kidney transplantation is a serious complication which significantly worsens the mortality of patients. The risk of development of infective endocarditis after transplantation is also increased by induction, mainly by antithymocyte globulin. Diagnostics only by PET-CT examination is rare; however, in this case it fundamentally changed the approach to the patient and led to a successful treatment.

Anterior mitral basal 'stay' chords are essential for left ventricular geometry and function.

BACKGROUND AND AIM OF THE STUDY: Among the anterior mitral basal chords, two particularly strong and thick stay chords (SC) remain under tension during the entire cardiac cycle. Collagen fibers of the anterior mitral leaflet (AML) are oriented from insertion of the SC on the AML to the fibrous trigones (FT), suggesting that local stress is directed from the papillary muscles (PM) over the SC and AML to the FT, maintaining left ventricular (LV) geometry. METHODS: Sonomicrometry crystals were implanted in sheep at the LV apex (A), the anterior (AW) and septal (SW) LV wall, the PM tips (M1 and M2), the SC insertion into the AML (S1 and S2), the posterior (PMA) and lateral (P1 and P2) mitral annulus, the FT (T1 and T2), the tips of the anterior (AL) and posterior (PL) mitral leaflets, and the base of the aortic right coronary sinus (RCS). Changes in distances, areas, and volume were time-related to aortic flow and LV and ascending aorta pressures. Recordings were taken at baseline and after transection of the SC. RESULTS: After transection of the SC, the systolic distance from M1-T1 increased by +0.96 +/- 0.41 mm (p < 0.05) and from M2-T2 by +0.97 +/- 0.42 mm (p < 0.05). The LV length increased at T1-A by +1.14 +/- 0.60 mm (p < 0.05) and at T2-A by +0.97 +/- 0.37 mm (p < 0.05). The aortomitral angle narrowed at end-systole by -3.26 +/- 0.85 degrees (p < 0.05). Transection of the SC reduced dP/dt by -11.20 +/- 5.29% (p < 0.05), maximum aortic flow by -16.89 +/- 7.86% (p < 0.05), and maximum pressure-volume ratio by -10.83 +/- 3.36% (p < 0.05). CONCLUSION: Transection of the anterior mitral SC did not result in mitral regurgitation but induced significant changes in LV geometry, including narrowing of the aortomitral angle and subsequent deterioration of LV function. The SC are essential for maintaining normal LV geometry and function.

Improving the results of small-bore vascular graft testing in rabbits: a technical primer.

Appropriate models to evaluate the in vivo behavior of small-diameter grafts are varied. To evaluate the behavior of small-diameter, bovine-derived grafts in the arterial circulation, we chose the rabbit abdominal aorta model. In the development of our procedure, we evaluated several models published in the literature, with unsatisfactory results. The high incidence of postoperative mortality and morbidity led us to modify published methods to incorporate cautious surgical technique and mild systemic hypothermia with cross-clamp times shorter than 30 min, as well as perioperative administration of agents with metabolic, rheologic, and neuroprotective properties. These modifications enabled us to achieve 100% operative survival with a very low incidence of postoperative paralysis. The presented model will be used for further evaluation of small-diameter grafts in our laboratory.

Anterior mitral leaflet mobility is limited by the basal stay chords.

BACKGROUND: We hypothesize that 2 tendon-like anterior basal stay chords, which remain taut during the entire cardiac cycle, limit the motion of the anterior mitral leaflet. METHODS AND RESULTS: Sonomicrometric crystals were implanted in 6 sheep at the insertion of stay chords at anterior mitral leaflet (S1 and S2), papillary muscle tips, fibrous trigones, mitral annulus, and the tip of the anterior leaflet (AL). Distances between crystals were recorded before and after section of stay chords. During the cardiac cycle, the angle alpha between mitral annulus and AL changed by +54.2+/-12.4 degrees; the angles between mitral annulus and S1 (beta1) changed by +25.7+/-14.6 degrees, and between mitral annulus and S2 (beta2) by +20.4+/-7.8 degrees. During diastole, AL twice crossed the virtual plane formed by the stay chords: during E-wave by a maximum of 6.5 mm (mean, 2.5+/-2.2 mm) and during A-wave by a maximum of 3.2 mm (mean, 1.7+/-0.9 mm). After section of both stay chords, total anterior mitral leaflet motion increased as follows: AL, +6.9+/-3.4 degrees; S1, +13.1+/-4.4 degrees; and S2, +30.9+/-11.7 degrees (P<0.05). CONCLUSIONS: Although the lateral movement of anterior mitral leaflet is limited by stay chords, the midportion moves unimpaired toward the septum, like a sail, between the 2 stay chords during diastole. A diastolic left ventricular-inflow and systolic left ventricular-outflow funnel mechanism is created. Stay chord section increased lateral anterior mitral leaflet movement.

Techniques for ensuring the correct length of new mitral chords.

Repair of degenerative mitral insufficiency has extensively been shown to be superior to replacement. In the majority of cases, the culprit lesion is limited to the posterior mitral leaflet (PML), which is treated with quadrangular resection of the prolapsing PML, annular plication of the corresponding segment of the annulus, and prosthetic annuloplasty. Anterior mitral leaflet (AML) prolapse is less common and is not always considered an indication for repair despite availability of a variety of surgical maneuvers specifically designed for its treatment. Although reliable if properly performed, chordal shortening at the papillary muscle level is technically demanding. Chordal transfer from the PML with the 'flip-over' technique is highly reproducible, but limited by the very frequent presence of an abnormal PML. Although feasible, transfer of an anterior basal chord to the prolapsing free edge assumes that the basal chords can be sectioned with impunity. More recently, chord replacement with expanded polytetrafluoroethylene (PTFE) sutures has become increasingly popular because of its availability, theoretical simplicity, and demonstrated long-term durability. Although papillary and leaflet anchoring of the neo-chord has not been shown to be a problem, the determination of its appropriate length remains intuitive and based on personal experience. Here, simple surgical maneuvers designed to ensure safe and reproducible results of single or multiple chord replacement with PTFE sutures are described.