Type II Minimal-Invasive Extracorporeal Circuit for Aortic Valve Replacement: A Randomized Controlled Trial

Extracorporeal circulation triggers systemic inflammatory response and coagulation disorders which may lead to unfavorable clinical outcome. A type II minimally-invasive extracorporeal circuit (MiECC) is a closed system with markedly reduced artificial surface as compared to conventional extracorporeal circuits (CECC). The aim of this study was to investigate and compare inflammatory responses, complement activation and selected clinical end-points in isolated surgical aortic valve replacement (SAVR) performed with a type II MiECC circuit or a CECC. Fifty patients were prospectively randomized to MiECC or CECC perfusion regimen. Complement activation (sC5b-9), inflammation (IL-6, TNF-α, sCD40-ligand) and activation of the coagulation system (D-dimer, TAT-complex) were determined before operation, at 2 hours and 24 hours after surgery. Clinical end-points included perfusion time, transfusion of allogeneic blood products, postoperative bleeding, sepsis, new onset of atrial fibrillation, stroke and in-hospital mortality. Patient characteristics and baseline plasma markers were similar in both groups. Levels for sC5b-9, TNF-α, sCD40 ligand, TAT-complex and D-dimers were not significantly different between MiECC and CECC at 2 hours and 24 hours after surgery. The IL-6 plasma concentration was lower in the CECC group at 24 hours (P = 0.026, vs. MiECC). Comparisons of the baseline level to values at 2 hours and 24 hours, adjusted for the type of oxygenator and hemoglobin, showed a significantly lower sC5b-9 in MiECC at 2 hours (P = 0.013), but no difference at 24 hours (P=0.990). Compared with CECC, MiECC patients had a shorter perfusion time (P = 0.037) and less transfusion requirements (P = 0.04). In this selected cohort of SAVR patients, the type II MiECC was not inferior to CECC in terms of inflammatory response and complement activation. Thus, MiECC might be an alternative perfusion strategy to conventional.

Type II Minimal-Invasive Extracorporeal Circuit for Aortic Valve Replacement: A Randomized Controlled Trial

Extracorporeal circulation triggers systemic inflammatory response and coagulation disorders which may lead to unfavorable clinical outcome. A type II minimally-invasive extracorporeal circuit (MiECC) is a closed system with markedly reduced artificial surface as compared to conventional extracorporeal circuits (CECC). The aim of this study was to investigate and compare inflammatory responses, complement activation and selected clinical end-points in isolated surgical aortic valve replacement (SAVR) performed with a type II MiECC circuit or a CECC. Fifty patients were prospectively randomized to MiECC or CECC perfusion regimen. Complement activation (sC5b-9), inflammation (IL-6, TNF-α, sCD40-ligand) and activation of the coagulation system (D-dimer, TAT-complex) were determined before operation, at 2 hours and 24 hours after surgery. Clinical end-points included perfusion time, transfusion of allogeneic blood products, postoperative bleeding, sepsis, new onset of atrial fibrillation, stroke and in-hospital mortality. Patient characteristics and baseline plasma markers were similar in both groups. Levels for sC5b-9, TNF-α, sCD40 ligand, TAT-complex and D-dimers were not significantly different between MiECC and CECC at 2 hours and 24 hours after surgery. The IL-6 plasma concentration was lower in the CECC group at 24 hours (P = 0.026, vs. MiECC). Comparisons of the baseline level to values at 2 hours and 24 hours, adjusted for the type of oxygenator and hemoglobin, showed a significantly lower sC5b-9 in MiECC at 2 hours (P = 0.013), but no difference at 24 hours (P=0.990). Compared with CECC, MiECC patients had a shorter perfusion time (P = 0.037) and less transfusion requirements (P = 0.04). In this selected cohort of SAVR patients, the type II MiECC was not inferior to CECC in terms of inflammatory response and complement activation. Thus, MiECC might be an alternative perfusion strategy to conventional.

Inflammation and Its Consequences After Surgical Versus Transcatheter Aortic Valve Replacement

Symptomatic aortic stenosis can be treated by surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR), the latter of which is regarded as a minimally invasive procedure. Differences between these procedures regarding immune responses or changes in coagulation and neurocognitive function have thus far been evaluated only sparsely. We carried out a prospective, single-center, nonrandomized explorative study with 38 patients. Thirteen patients were subjected to either SAVR or transfemoral (TF-) TAVR, and 12 patients underwent transapical (TA-) TAVR. Plasma cytokines (IL-6, -8, -18, presepsin) and acute-phase proteins (C-reactive protein, procalcitonin), markers of coagulation and platelet function, and neurocognitive function (via various standard tests) were assessed before and at five-time points during a 72-h follow-up after surgery. SAVR and TA-TAVR patients responded similarly to the procedure in terms of C-reactive protein, leukocyte numbers, and IL-6, whereas these responses were substantially lower in TF-TAVR patients. Only SAVR patients showed measurable IL-10 levels. SAVR patients without prior anticoagulation experienced a robust and transient restoration of platelet function after surgery, with no hypercoagulation observable in functional coagulation assays. None of the procedures led to an immediate improvement of hand and leg coordination, but patients after TA-TAVR had decreased neurocognitive function. Patients after SAVR or TA-TAVR exhibit a robust pro-inflammatory response, which is-on the cytokine level-counterbalanced only in SAVR patients. Our results point toward a greater impact of TA-TAVR on neurocognitive function and indicate a potentially detrimental activation of platelets in some patients after SAVR.

In Vitro Dialysis of Cytokine-Rich Plasma With High and Medium Cut-Off Membranes Reduces Its Procalcific Activity

Recently developed high-flux (HF) dialysis membranes with extended permeability provide better clearance of middle-sized molecules such as interleukins (ILs). Whether this modulation of inflammation influences the procalcific effects of septic plasma on vascular smooth muscle cells (VSMCs) is not known. To assess the effects of high cut-off (HCO) and medium cut-off (MCO) membranes on microinflammation and in vitro vascular calcification we developed a miniature dialysis model. Plasma samples from lipopolysaccharide-spiked blood were dialyzed with HF, HCO, and MCO membranes in an in vitro miniature dialysis model. Afterwards, IL-6 concentrations were determined in dialysate and plasma. Calcifying VSMCs were incubated with dialyzed plasma samples and vascular calcification was assessed. Osteopontin (OPN) and matrix Gla protein (MGP) were measured in VSMC supernatants. IL-6 plasma concentrations were markedly lower with HCO and MCO dialysis. VSMC calcification was significantly lower after incubation with MCO- and HCO-serum compared to HF plasma. MGP and OPN levels in supernatants were significantly lower in the MCO but not in the HCO group compared to HF. In vitro dialysis of cytokine-enriched plasma samples with MCO and HCO membranes reduces IL-6 levels. The induction of vascular calcification by cytokine-enriched plasma is reduced after HCO and MCO dialysis.