A Liebold

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS)

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.

Comparing microvascular alterations during minimal extracorporeal circulation and conventional cardiopulmonary bypass in coronary artery bypass graft surgery: A prospective, randomized study

OBJECTIVESnMinimal extracorporeal circulation (MECC) has been introduced in coronary artery bypass graft (CABG) surgery, offering clinical benefits owing to reduced hemodilution and no blood-air interface. Yet, the effects of MECC on the intraoperative microvascular perfusion in comparison with conventional extracorporeal circulation (CECC) have not been studied so far.nnnMETHODSnThe current study aimed to analyze alterations in microvascular perfusion at 4 predefined time points (T1-T4) during on-pump CABG using orthogonal polarization spectral imaging. Forty patients were randomized for being operated on with either MECC or CECC. Changes in functional capillary density (FCD), blood flow velocity, and vessel diameter were analyzed by a blinded investigator.nnnRESULTSnAfter start of extracorporeal circulation (ECC) and aortic crossclamping (T2), both groups showed a significant drop of FCD, with a significantly higher FCD in the MECC group (206.8 ± 33.6 cm/cm² in CECC group versus 217.8 ± 35.3 cm/cm² in MECC group; P = .034). In the late phase of the ECC (T3), FCD in the MECC group was already recovered, whereas FCD in the CECC group was still significantly depressed (223.1 ± 35.6 cm/cm² in MECC group; P = .100 vs T1; 211.1 ± 36.9 cm/cm² in CECC group; P = .017 vs T1). After termination of ECC (T4), FCD recovered in both groups to baseline. Blood flow velocity tended to be higher in the MECC group, with a significant intergroup difference after aortic crossclamping (T2).nnnCONCLUSIONSnOrthogonal polarization spectral imaging data reveal an impairment of microvascular perfusion during on-pump CABG. Changes in FCD indicate a faster recovery of the microvascular perfusion in MECC during the reperfusion period. Beneficial recovery of microvascular organ perfusion could partly explain the perioperative advantages reported for MECC.

Anticoagulation management during multivessel coronary artery bypass grafting: a randomized trial comparing individualized heparin management and conventional hemostasis management.

Individualized heparin management (IHM) uses heparin dose–response curves to improve hemostasis management during cardiac surgery as compared with activated clotting time‐based methods.

Isolated Whipple's Endocarditis: An Underestimated Diagnosis That Requires Molecular Analysis of Surgical Material

Tropheryma whipplei is known as the bacterium that causes Whipples disease, a rare systemic illness typically affecting gastrointestinal tract, joints, and central nervous system. In addition, T whipplei infection may present as an isolated endocarditis. Although previously regarded as a rare condition, T whipplei has been recognized as a major cause of culture-negative endocarditis when integrating specific molecular analysis of surgical material into the diagnostic algorithm. Here, we report the case of a 67-year-old man undergoing mitral valve replacement due to T whipplei endocarditis, and discuss diagnostic and therapeutic implications.

Similarity of coagulation and inflammation despite different surgical revascularization strategies – a prospective randomized trial

Background: Supposedly, minimized extracorporeal circulation or off-pump revascularization as alternatives to conventional extracorporeal circulation (ONCAB) reduce inflammation and coagulation disturbances. Methods: One hundred and twenty coronary artery bypass graft (CABG) patients were prospectively randomized for three surgical techniques. Coagulation and inflammation markers were measured up to 72 hours postoperatively. Results: Coagulation factors I, II, V, X, antithrombin III and C-reactive protein did not differ perioperatively between the groups and increased, as did several other markers, 12 to 72 hours postoperatively. Compared to its alternatives, ONCAB showed the most obvious transient increase in thrombin-antithrombin complexes (p<0.0001), D-dimers (p=0.0059), tissue factor pathway inhibitor (p=0.0005), factor VIII (p=0.0041) and tumor necrosis factor α (p=0.0300) during the operation and up to 12 hours postoperatively. Furthermore, ONCAB generated lower leukocyte and platelet counts and higher values of soluble P-selectin and soluble intercellular adhesion molecule 1 at some time points. Conclusions: With similarity in pivot coagulation factors, a specific detrimental influence of ONCAB on common coagulation pathways was excluded. Higher perioperative concentrations of products from the coagulation cascade most likely indicate activation of pericardial blood – recirculated only in ONCAB. Furthermore, with only temporary differences in markers of inflammation, the alternatives to ONCAB altogether were without advantage at 72 hours postoperatively. In the general answer to surgical trauma, the part of modern extracorporeal circulation is possibly overestimated. The study is registered at the German Clinical Trial Registry. Registration number DRKS00007580. URL: https://drks-neu.uniklinik-freiburg.de/drks_web/ URL: http://apps.who.int/trialsearch/

Early prosthetic valve endocarditis caused by Corynebacterium kroppenstedtii

Corynebacterium (C.) kroppenstedtii is a rarely detected agent of bacterial infections in humans. Here, we describe the first case of prosthetic valve endocarditis caused by C. kroppenstedtii. Application of molecular methods using surgically excised valve tissue was a cornerstone for the establishment of the microbiological diagnosis, which is crucial for targeted antimicrobial treatment.

Effects of centrally administered endocannabinoids and opioids on orofacial pain perception in rats

Endocannabinoids and opioids play a vital role in mediating pain‐induced analgesia. The specific effects of these compounds within the orofacial region are largely unknown. In this study, we tried to determine whether an increase in cannabinoid and opioid concentration in the CSF affects impulse transmission between the motor centres localized in the vicinity of the third and fourth cerebral ventricles.

Combination of sildenafil and bosentan for pulmonary hypertension in a human ex vivo model.

PurposeBoth sildenafil and bosentan have been used clinically to treat pulmonary arterial hypertension. As these substances target different pathways to modulate vasoconstriction, we investigated the combined effects of both drug classes in isolated human pulmonary vessels.MethodsSegments of pulmonary arteries (PA) and veins (PV) were harvested from 51 patients undergoing lobectomy. Contractile force was determined isometrically in an organ bath. Vessels were constricted with norepinephrine (NE) to determine effects of sildenafil. They were constricted with ET-1 to assess effects of bosentan, and with NE and ET-1 to evaluate the combination of both substances.ResultsSildenafil (1E-5 M) significantly reduced maximum constriction by NE of both PA (13.0u2009±u200911.1 vs. 34.9u2009±u20097.6xa0% relative to KCl induced constriction; nu2009=u20096; pu2009<u20090.001) and PV (81.2u2009±u200934.2 vs 121.6u2009±u200920.8xa0%; nu2009=u20096; pu2009<u20090.01) but did not affect basal tones. Bosentan (1E-5 M) significantly reduced maximum constriction of PV (56.6u2009±u200921.5 vs. 172.1u2009±u200930.0xa0%; nu2009=u20096; pu2009<u20090.01) by ET-1 and led to a small but insignificant decrease of basal tone (pu2009=u20090.07). Bosentan almost completely abolished constriction of PA (1.0u2009±u20090.9 vs. 74.7u2009±u200925.7xa0%; nu2009=u20096; pu2009<u20090.001) by ET-1, but did not affect basal tone. Bosentan (1E-7 M) significantly attenuated combined ET-1/NE dose–response curves in PA (93.1u2009±u200947.4 vs. 125.3u2009±u200941.0xa0%; nu2009=u200912; pu2009<u20090.001) whereas the effect of sildenafil (1E-5 M) was less pronounced (103.6u2009±u200920.2xa0%; pu2009<u20090.05). Simultaneous administration of both substances showed a significantly greater reduction of maximum constriction in PA compared to individual administration (64.6u2009±u200926.3xa0%; pu2009<u20090.001).ConclusionsSildenafil only at its highest concentration was effective in suppressing NE induced pulmonary vessel contraction. Bosentan was able to completely suppress ET-1 induced contraction of PA and strongly attenuated contraction of PV. The present data suggest a benefit of sildenafil/bosentan combination therapy as they affect different pathways and may allow lower dosages.

Contact-free monitoring of vessel graft stiffness – proof of concept as a tool for vascular tissue engineering

Tissue‐engineered vessel grafts have to mimic the biomechanical properties of native blood vessels. Manufacturing processes often condition grafts to adapt them to the target flow conditions. Graft stiffness is influenced by material properties and dimensions and determines graft compliance. This proof‐of‐concept study evaluated a contact‐free method to monitor biomechanical properties without compromising sterility. Forced vibration response analysis was performed on human umbilical vein (HUV) segments mounted in a buffer‐filled tubing system. A linear motor and a dynamic signal analyser were used to excite the fluid by white noise (0–200 Hz). Vein responses were read out by laser triangulation and analysed by fast Fourier transformation. Modal analysis was performed by monitoring multiple positions of the vessel surface. As an inverse model of graft stiffening during conditioning, HUV were digested proteolytically, and the course of natural frequencies (NFs) was monitored over 120 min. Human umbilical vein showed up to five modes with NFs in the range of 5–100 Hz. The first natural frequencies of HUV did not alter over time while incubated in buffer (p = 0.555), whereas both collagenase (−35%, p = 0.0061) and elastase (−45%, p < 0.001) treatments caused significant decreases of NF within 120 min. Decellularized HUV showed similar results, indicating that changes of the extracellular matrix were responsible for the observed shift in NF. Performing vibration response analysis on vessel grafts is feasible without compromising sterility or integrity of the samples. This technique allows direct measurement of stiffness as an important biomechanical property, obviating the need to monitor surrogate parameters. Copyright

On-Pump Nonrobotic Total Endoscopic Coronary Artery Bypass Grafting: An Animal Study

BACKGROUNDnu2003Total endoscopic coronary artery bypass grafting (TECAB) is currently performed exclusively with the help of a telemanipulator. After extensive practice in a biomechanical model, the operation was performed as a nonrobotic approach in an animal study.nnnMETHODSnu2003Six large domestic pigs were anesthetized and intubated. Port access and endoscopic vision were used exclusively during the intrathoracic procedure. In five animals, an internal mammary artery was harvested, extracorporeal circulation was established via peripheral vessel access, and the ascending aorta occluded with an intraluminal balloon. In cardioplegic arrest, an anastomosis of internal mammary artery and left anterior descending coronary artery was performed with shortened 7-0 monofil thread running suture. As a terminal study, the animals were humanely killed and the quality of the anastomoses was checked.nnnRESULTSnu2003After a steady learning curve, the fifth animal was operated on successfully and a satisfactory anastomosis was documented.nnnCONCLUSIONnu2003Despite demanding differences to humans as shape of thoracic cavity and size of peripheral access vessels, the viability of the nonrobotic TECAB concept was documented in a living animal model.