Radial Artery Tonometry to Monitor Blood Pressure and Hemodynamics in Ambulatory Left Ventricular Assist Device Patients in Comparison With Doppler Ultrasound and Transthoracic Echocardiography: A Pilot Study.

Noninvasive measurements of blood pressure (BP) and cardiac output (CO) are crucial in the follow-up of continuous-flow left ventricular assist device (CF-LVAD) patients. For our pilot study, we sought to compare BP measurements between a tonometry blood pressure pulse analyzer (BPPA) (DMP-Life, DAEYOMEDI Co., Ltd., Gyeonggi-do, South Korea) and Doppler ultrasound in CF-LVAD patients, as well as to compare the BPPA estimated CO to LVAD calculated blood flow and to the patient's intrinsic CO estimated with transthoracic echocardiography (TTE). Ambulatory CF-LVAD patients (6 HeartMate, 26 HeartMate II), were included. According to TTE findings, patients were then subdivided in two groups: patients with an opening aortic valve (OAV) [n = 21] and those with an intermittent opening aortic valve (IOAV) [n = 11]. We found a very good correlation of systolic BP (SBP) measurements between the two methods, BPPA and Doppler ultrasound (r = 0.87, P < 0.0001). Bland-Altman plots for SBP revealed a low bias of -4.6 mm Hg and SD of ±4.7 mm Hg. In CF-LVAD patients with IOAV, the BPPA-CO had a good correlation with the LVAD-flow (r = 0.78, P < 0.0001), but in OAV patients, there was no correlation. After adding the patient's intrinsic CO, estimated from TTE in patients with OAV to the LVAD-flow, we found a very good correlation between the BPPA-CO and LVAD-flow + TTE-CO (r = 0.81, P = 0.002). Our study demonstrated that compared with the standard clinical method, Doppler ultrasound, the BPPA measured BP noninvasively with good accuracy and precision of agreement. In addition, tonometry BPPA provided further valuable information regarding the CF-LVAD patient's intrinsic CO.

Synchronous or Staged Carotid Endarterectomy and Coronary Artery Bypass Grafting? Propensity score matched study.

BACKGROUND: The optimal treatment strategy in patients presenting with hemodynamically significant carotid artery disease who are to undergo cardiac surgery, remains controversial. In this study, we retrospectively analyzed the outcome data of patients receiving synchronous or staged coronary artery bypass graft (CABG) surgery and carotid endarterectomy (CEA). METHODS: Between 2011 and 2016, 3173 patients underwent CABG surgery in our institution, of whom 323 received CABG and CEA either as synchronous (N = 307) or as staged (N = 16) procedures. Patients´ characteristics, peri- and postoperative data were collected from our digital medical database. Propensity score matching was used to match each patient from the staged group to two appropriate patients (1:2 matching) from the synchronous group (synchronousmatched). RESULTS: The overall incidence of ischemic stroke (IS) and transitory ischemic attack (TIA) was 4.9% and 5.6%, respectively. No hemorrhagic stroke was noted in both groups. Incidence of IS did not differ significantly between matched groups (P = 1.000). Significantly higher rates of postoperative neurological complications, such as TIA and delirium, were found in the synchronousmatched group (P = .041 and P = .043, respectively) compared with the staged group. Additionally, there were more postoperative respiratory insufficiencies in the synchronousmatched group (P = .043). Thirty days mortality did not differ significantly between the matched groups. CONCLUSION: In this experience combined with the data given in literature, our findings suggest a possible superiority of the staged CABG/CEA approach. Large, randomized studies are required to verify our findings and to establish applicable guidelines.

Sildenafil Reduces the Risk of Thromboembolic Events in HeartMate II Patients with Low-Level Hemolysis and Significantly Improves the Pulmonary Circulation.

Low-level hemolysis (LLH) after left ventricular assist device implantation contributes to thromboembolic events (TE). Free plasma hemoglobin (fHb) scavenges nitric oxide (NO), which causes endothelial dysfunction and activates platelets. fHb also interacts with von Willebrand factor (vWF). We hypothesized that improved hemodynamic and enhanced NO signaling in HeartMate II (HMII) patients with LLH taking the phosphodiesterase-5 inhibitor sildenafil may reduce the risk of TE.From 2011 to 2015, 83 patients underwent HMII implantation. Patients with LLH as defined by elevated lactate dehydrogenase (400 < LDH ≤ 700 U/L) at hospital discharge were identified. Patients were categorized into 4 groups: 1) LLH + sildenafil, 2) LLH no sildenafil, 3) no LLH + sildenafil, and 4) no LLH no sildenafil. Adverse event-free survival was compared between the groups.Thirty-four patients (40.9%) were discharged with LLH and 22 (64.7%) of them took sildenafil. LDH and fHb remained significantly elevated in both LLH groups compared to the no LLH patients (P < 0.0001). Overall incidence of pump thrombosis (PT) was 4.8% and of ischemic stroke (IS) was 8.4%. HMII patients with LLH not on sildenafil had higher risk of TE (hazard ratio (HR): 14.4, 95%-CI: 1.8-117.1, P = 0.001). vWF activity and bleeding incidence did not differ between the LLH and no LLH patients. Mean pulmonary artery pressure and pulmonary vascular resistance decreased significantly in HMII taking sildenafil (P < 0.0001) while cardiac index increased (P < 0.0001).Sildenafil treatment among HMII patients with LLH reduced the risk of thromboembolic events and significantly improved and decompressed the pulmonary circulation during HMII support.

Expression of inflammation in myocardial tissue of rabbits: comparison of two miniaturized heart-lung machines.

The majority of cases involving the surgical treatment of congenital heart disease require implementation of cardiopulmonary bypass (CPB). However, neonates and infants are particularly prone to serious complications associated with CPB as a result of capillary leak due to cardiovascular failure. These complications are related to the transfusion of foreign blood, the disproportionately large area of contact between the patient's blood and foreign material, as well as the systemic inflammatory response induced by hemolysis. To attenuate these risks, we developed a novel, highly integrative, miniaturized heart-lung machine (MiniHLM) with a static priming volume of only 102 mL. This prototype was tested in comparison with a conventional heart-lung machine (static priming volume 213 mL) using a rabbit animal model. The animals were anesthetized, sternotomized, and connected to CBP via the aorta and right atrium. The aorta was cross-clamped for 1 h. Blood samples for examination were taken at regular intervals. Biopsies of the right atrial appendage (RAA) were removed directly after initiation and after cessation of CPB. After gradual reduction of perfusion with the HLM, all rabbits were successfully weaned from CPB, and the sternum was closed. Foreign blood was not administered in all cases. After cryopreservation of the RAA tissue, de novo transcription of inflammatory cytokines was measured by means of real-time polymerase chain reaction using the comparative CT method. No significant differences in the expression of the inflammatory parameters of the myocardial tissue samples were found between the study groups.

Standardized pharmacological management of delirium after on-pump cardiac surgery reduces ICU stay and ventilation in a retrospective pre-post study.

Cardiac surgery patients not only undergo a highly invasive procedure but are at risk for a diversity of postoperative complications. Up to 53% of these patients suffer from postoperative delirium (POD). This severe and common adverse event increases mortality and prolonged mechanical ventilation and extends the intensive care unit stay. The objective of this study was to test the hypothesis that standardized pharmacological management of delirium (SPMD) may reduce the length of stay in the intensive care unit (ICU), duration of postoperative mechanical ventilation, and the incidence of postoperative complications such as pneumonia or bloodstream infections in on-pump cardiac surgery ICU patients. In this retrospective, single-center observational cohort study, 247 patients were examined between May 2018 to June 2020, who underwent on-pump cardiac surgery, suffered from POD, and received pharmacological POD treatment. 125 were treated before and 122 after SPMD implementation in the ICU. The primary endpoint was a composite outcome, including the length of ICU stay, postoperative mechanical ventilation time, and ICU survival rate. The secondary endpoints were complications including postoperative pneumonia and bloodstream infections. Although the ICU survival rate was not significantly different between both groups, the length of ICU stay (control group: 23 ± 27 days; SPMD group: 16 ± 16 days; p = 0.024) and the duration of mechanical ventilation were significantly reduced in the SPMD-cohort (control group: 230 ± 395 h; SPMD group: 128 ± 268 h; p = 0.022). Concordantly, the pneumonic risk was reduced after SPMD introduction (control group: 44.0%; SPMD group: 27.9%; p = 0.012) as well as the incidence for bloodstream infections (control group: 19.2%; SPMD group: 6.6%; p = 0.004). Standardized pharmacological management of postoperative delirium in on-pump cardiac surgery ICU patients reduced the length of ICU stay and duration of mechanical ventilation significantly, leading to a decrease in pneumonic complications and bloodstream infections.

Combining Minimally Invasive Surgery With Ultra-Fast-Track Anesthesia in HeartMate 3 Patients: A Pilot Study.

BACKGROUND: Minimally invasive surgery for left ventricular assist device implantation may have advantages over conventional sternotomy (CS). Additionally, ultra-fast-track anesthesia has been linked to better outcomes after cardiac surgery. This study summarizes our early experience of combining minimally invasive surgery with ultra-fast-track anesthesia (MIFTA) in patients receiving HeartMate 3 devices and compares the outcomes between MIFTA and CS. METHODS: From October 2015 to January 2019, 18 of 49 patients with Interagency Registry for Mechanically Assisted Circulatory Support profiles >1 underwent MIFTA for HeartMate 3 implantation. For bias reduction, propensity scores were calculated and used as a covariate in a regression model to analyze outcomes. Weighted parametric survival analysis was performed. RESULTS: In the MIFTA group, intensive care unit stays were shorter (mean difference, 8 days [95% CI, 4-13]; P<0.001), and the incidences of pneumonia and right heart failure were lower than those in the CS group (odds ratio, 1.36 [95% CI, 1.01-1.75]; P=0.016, respectively). At 6 and 12 hours postoperatively, MIFTA patients had a better hemodynamic performance with lower pulmonary wedge pressure (mean difference, 2.23 mm Hg [95% CI, 0.41-4.06]; P=0.028) and a higher right ventricular stroke work index (mean difference, -1.49 g·m/m2 per beat [95% CI, -2.95 to -0.02]; P=0.031). CS patients had a worse right heart failure-free survival rate (hazard ratio, 2.35 [95% CI, 0.96-5.72]; P<0.01). CONCLUSIONS: Compared with CS, MIFTA is a beneficial approach for non-Interagency Registry for Mechanically Assisted Circulatory Support 1 HeartMate 3 patients with lower adverse event incidences, better hemodynamic performance, and preserved right heart function. Future large multicentric investigations are required to verify MIFTA's effects on outcomes.

Prevention of Sternal Wound Infections in Women Using an External Sternum Fixation Corset.

PURPOSE: Deep sternal wound infection (DSWI) and mediastinitis are devastating complications after median sternotomy. Previous studies demonstrated an effective prevention of sternal wound infection (SWI) using an external sternal corset in high-risk cardiac surgery patients. The aim of this study is to assess the preventive effect of the Stern-E-Fix corset in high-risk poststernotomy female patients. METHODS: A total of 145 high-risk female patients undergoing cardiac surgery through median sternotomy were retrospectively analyzed. Patients were divided into group A (n = 71), who received the Stern-E-Fix corset (Fendel & Keuchen GmbH, Aachen, Germany), and group B (n = 74), who received the elastic thorax bandage (SanThorax) postoperatively for 6 weeks. The mean follow-up period was 12 weeks. RESULTS: Incidence of SWI was 7% in group A vs. 17.6% in group B (p = 0.025). One patient presented with DSWI in group A vs. seven patients in group B (p = 0.063). No patient developed mediastinitis in group A vs. four patients in group B (p = 0.121). In all, 4.2% of group A patients required operative wound therapy vs. 16.2% of group B patients (p = 0.026). The length of hospital stay was significantly longer in group B (p = 0.006). CONCLUSION: Using an external supportive sternal corset (Stern-E-Fix) yields a significantly better and effective prevention against development of sternal dehiscence, DSWI, and mediastinitis in high-risk poststernotomy female patients.

A newly developed miniaturized heart-lung machine--expression of inflammation in a small animal model.

Cardiopulmonary bypass may cause severe inflammatory reactions and multiorgan failure, especially in premature and low-weight infants. This is due in part to the large area of contact with extrinsic surfaces and the essential addition of foreign blood. Thus, we developed a new miniaturized heart-lung machine (MiniHLM) with a total static priming volume of 102mL (including arterial and venous lines) and tested it in a small animal model. Seven Chinchilla Bastard rabbits were perfused with the MiniHLM (dynamic priming volume 127mL). Seven animals serving as a control were perfused using Dideco Kids and a Stöckert roller pump (modified dynamic priming volume 149mL). The rabbits were anesthetized and sternotomized, followed by cannulation of the aorta and the right atrium. The aorta was clamped for 1h. Blood for examination of inflammation (TNF-α, IL-1ß, IL-6, IL-8, and IL-10) and blood gas analysis were taken before skin incision, 5min before opening of the aorta, 15min after opening of the aorta, and 4 h after the initiation of cardiopulmonary bypass. The parameters of inflammation were expressed by means of the comparative C(T) method (ΔΔC(T) method). After gradual reduction of perfusion with the HLM, the heart was decannulated, and the sternum was closed. All rabbits were successfully weaned from cardiopulmonary bypass. Blood gas analysis was unremarkable in all cases. Foreign blood was not administered. Although statistical significance was not achieved, there was a reduced expression of inflammatory markers in the MiniHLM group. The newly developed MiniHLM prototype was tested successfully in a small animal model in terms of technical function and expression of inflammation. Upcoming tests with the industrially manufactured MiniHLM may reveal the advantages of the MiniHLM in comparison with the conventional HLM.

The Aachen MiniHLM--a miniaturized heart-lung machine for neonates with an integrated rotary blood pump.

The operation of congenital heart defects in neonates often requires the use of heart-lung machines (HLMs) to provide perfusion and oxygenation. This is prevalently followed by serious complications inter alia caused by hemodilution and extrinsic blood contact surfaces. Thus, one goal of developing a HLM for neonates is the reduction of priming volume and contact surface. The currently available systems offer reasonable priming volumes for oxygenators, reservoirs, etc. However, the necessary tubing system contains the highest volumes within the whole system. This is due to the use of roller pumps; hence, the resulting placement of the complete HLM is between 1 and 2 m away from the operating table due to connective tubing between the components. Therefore, we pursued a novel approach for a miniaturized HLM (MiniHLM) by integrating all major system components in one single device. In particular, the MiniHLM is a HLM with the rotary blood pump centrically integrated into the oxygenator and a heat exchanger integrated into the cardiotomy reservoir which is directly connected to the pump inlet. Thus, tubing is only necessary between the patient and MiniHLM. A total priming volume of 102 mL (including arterial filter and a/v line) could be achieved. To validate the overall concept and the specific design we conducted several in vitro and in vivo test series. All tests confirm the novel concept of the MiniHLM. Its low priming volume and blood contact surface may significantly reduce known complications related to cardiopulmonary bypass in neonates (e.g., inflammatory reaction and capillary leak syndrome).

Evaluation of Left Ventricular Myocardial Work Performance in Patients Undergoing On-Pump and Off-Pump Coronary Artery Bypass Surgery.

PURPOSE: Benefits of off-pump coronary bypass (OPCAB) over on-pump (ONCAB) remain controversial. We aimed to evaluate the early impacts of OPCAB vs ONCAB for varying left ventricular (LV) function baselines by applying the non-invasive myocardial work (MW) analysis, which enables further insights in cardiac mechanics, contractility, and efficacy. METHODS: We retrospectively analyzed 98 patients (55 ONCAB vs 43 OPCAB). Transthoracic echocardiography (TTE) and concurrent arterial blood pressure measurements taken at rest, prior to, and early after surgery were performed. Global myocardial work index (GMWI), global constructive work (GCW), and global work efficiency (GWE), inter alia, were quantified. RESULTS: Preoperatively, OPCAB patients had significantly lower values than ONCAB patients in terms of GMWI (1404.33 ± 585.41 mmHg% vs 1619.07 ± 535.42 mmHg%, p = 0.039), GWE (90% (60%, 96%) vs 93% (74%, 98%), p = 0.028). After surgery, GMWI was reduced in both groups. However, a more significant GMWI impairment occurred early after ONCAB than after OPCAB (-343.14 ± 35.20 mmHg%, p <0.001 vs -224.04 ± 120.91 mmHg%, p = 0.042). CONCLUSION: Despite lower preoperative LV function in OPCAB patients, GMWIs after OPCAB were superior to ONCAB, indicating better preservation of systolic LV function early after OPCAB by means of contractility compared to ONCAB. Further studies should investigate the long-term course of MW response and their clinical impact.

The Aachen miniaturized heart-lung machine--first results in a small animal model.

Congenital heart surgery most often incorporates extracorporeal circulation. Due to foreign surface contact and the administration of foreign blood in many children, inflammatory response and hemolysis are important matters of debate. This is particularly an issue in premature and low birth-weight newborns. Taking these considerations into account, the Aachen miniaturized heart-lung machine (MiniHLM) with a total static priming volume of 102 mL (including tubing) was developed and tested in a small animal model. Fourteen female Chinchilla Bastard rabbits were operated on using two different kinds of circuits. In eight animals, a conventional HLM with Dideco Kids oxygenator and Stöckert roller pump (Sorin group, Milan, Italy) was used, and the Aachen MiniHLM was employed in six animals. Outcome parameters were hemolysis and blood gas analysis including lactate. The rabbits were anesthetized, and a standard median sternotomy was performed. The ascending aorta and the right atrium were cannulated. After initiating cardiopulmonary bypass, the aorta was cross-clamped, and cardiac arrest was induced by blood cardioplegia. Blood samples for hemolysis and blood gas analysis were drawn before, during, and after cardiopulmonary bypass. After 1 h aortic clamp time, all animals were weaned from cardiopulmonary bypass. Blood gas analysis revealed adequate oxygenation and perfusion during cardiopulmonary bypass, irrespective of the employed perfusion system. The use of the Aachen MiniHLM resulted in a statistically significant reduced decrease in fibrinogen during cardiopulmonary bypass. A trend revealing a reduced increase in free hemoglobin during bypass in the MiniHLM group could also be observed. This newly developed Aachen MiniHLM with low priming volume, reduced hemolysis, and excellent gas transfer (O(2) and CO(2)) may reduce circuit-induced complications during heart surgery in neonates.

MR and PET-CT monitoring of tissue-engineered vascular grafts in the ovine carotid artery.

The modification of biomaterials to comply with clinically employed monitoring techniques is a promising strategy to support clinical translation in regenerative medicine. Here, multimodal imaging of tissue-engineered vascular grafts (TEVG) was enabled by functionalizing the textile scaffold with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles. The resulting MR-imageable grafts (iTEVG) were monitored non-invasively throughout their whole life-cycle, from initial quality control to longitudinal functional evaluation in an ovine model for up to 8 weeks. Crucial features such as the complete embedding of the textile mesh in the developing tissue and the grafts' structural stability were assessed in vitro using 1T-, 3T- and 7T-MRI scanners. In vivo, the grafts were imaged by 3T-MRI and PET-CT. Contrary to unlabeled constructs, iTEVG could be delineated from native arteries and precisely localized by MRI. USPIO labeling neither induced calcifications, nor negatively affected their remodeling with respect to tissue-specific extracellular matrix composition and endothelialization. Functionality was confirmed by MR-angiography. 18F-FDG uptake (assessed via PET-CT) indicated only transient post-surgical inflammation. In conclusion, USPIO-labeling enables accurate localization of TEVG and opens up opportunities for multimodal imaging approaches to assess transplant acceptance and function. Thereby, it can support clinical decision-making on the need for further pharmacological or surgical interventions.

The flutter-by effect: a comprehensive study of the fluttering cusps of the Perceval heart valve prosthesis.

OBJECTIVES: Sutureless aortic valve prostheses are gaining popularity due to the substantial reduction in cross-clamp time. In this study, we report our observations on the cusp-fluttering phenomenon of the Perceval bioprosthesis (LivaNova, London, UK) using a combination of technical and medical perspectives. METHODS: Between August 2014 and December 2016, a total of 108 patients (69% women) with a mean age of 78 years had aortic valve replacement using the Perceval bioprosthesis (34 combined procedures). All patients underwent transoesophageal echocardiography (TOE) intraoperatively. TOE was performed postoperatively to detect paravalvular leakage and to measure gradients, acceleration time, Doppler velocity indices (Vmax and LVOT/Vmax AV) and effective orifice area indices. In addition, a TOE examination was performed in 21 patients postoperatively. Data were collected retrospectively from our hospital database. RESULTS: The retrospective evaluation of the intraoperative TOE examinations revealed consistent fluttering in all patients with the Perceval bioprosthesis. The echocardiographic postoperative measurements showed a mean effective orifice area index of 0.91 ± 0.12 cm2/m2. The overall mean pressure and peak pressure gradients were in a higher range (13.5 ± 5.1 mmHg and 25.5 ± 8.6 mmHg, respectively), whereas acceleration time (62.8 ± 16.4 ms) and Doppler velocity indices (0.43 ± 0.11) were within the normal range according to the American Society of Echocardiography or european association of echocardiography (EAE) guidelines. The 2-dimensional TOE in Motion Mode (M-Mode) that was performed in patients with elevated lactate dehydrogenase (LDH) levels revealed remarkable fluttering of the cusps of the Perceval bioprosthesis. CONCLUSIONS: In our study cohort, we observed the fluttering phenomenon in all patients who received the Perceval bioprosthesis, which was correlated with elevated LDH levels and higher pressure gradients.

Are elevated serum haemolysis markers a harbinger of adverse events in HeartMate II patients?

OBJECTIVES: Haemolysis during left ventricular assist device support is associated with thrombosis. In this retrospective study, we analysed whether low-level haemolysis (LLH) as defined by simultaneously elevated lactate dehydrogenase (LDH) and free haemoglobin (fHb) levels had an impact on thromboembolic and bleeding events and on von Willebrand factor levels in HeartMate II patients. METHODS: After exclusion of patients with LDH >700 U/l and fHb >40 mg/dl at hospital discharge, 79 HeartMate II patients were included. LDH and fHb levels were measured at discharge and in 3 months interval. von Willebrand factor activity and antigen activity were measured 3 months postoperatively. Outcomes regarding ischaemic stroke (IS), pump thrombosis (PT) and gastrointestinal bleeding were recorded. Patients with LLH (400 < LDH ≤ 700 U/l and 30 < fHb ≤ 40 mg/dl) at discharge (pre-Hemolyzers) were compared with the rest of the cohort (non-Hemolyzers). Competing risk analysis and Cox regression were applied for the comparison between groups. RESULTS: In all, 20% of the patients were identified as pre-Hemolyzers. Of these, 5 patients had PT and 3 patients had IS compared with 2 PT and 2 IS in the non-Hemolyzers group (P = 0.003 and P = 0.053, respectively). Fifty percent of the pre-Hemolyzers suffered gastrointestinal bleeding compared with 42% of the non-Hemolyzers (P = 0.399). The cumulative risk of thromboembolic events (IS or PT) in the pre-Hemolyzers group was significantly higher compared with the non-Hemolyzers group (hazard ratio 11.8, 95% confidence interval 3.7-37.7; P = 0.005). LLH did not have an impact on von Willebrand factor and the incidence of gastrointestinal bleeding. CONCLUSIONS: LLH as assessed by elevated fHb and LDH values at discharge during HeartMate II support is associated with thromboembolic events.

Aortopexy offers surgical options for a variety of pathological tracheal conditions in paediatric patients.

OBJECTIVES: Aortopexy is widely used; however, many surgeons still regard it with suspicion. To date, there are only a few large series and minimal long-term data. Against this background, our goal was to report our experience, particularly with regard to the recent expansion of indications and modification of diagnostic routine and surgical strategy. METHODS: Between 1994 and 2012, 53 patients (mean age: 1.1 years; 5 weeks-10.2 years) were operated on. Tracheomalacia after the operation for oesophageal atresia was the main indication for aortopexy (74%), followed by tracheal compression by the innominate artery (17%) and other selected indications (9%). Computed tomography angiography has emerged in recent years as the method of choice for preoperative diagnosis. Median sternotomy has replaced lateral thoracotomy, and intraoperative bronchoscopy has become the standard. RESULTS: In contrast to magnetic resonance imaging, computed tomography angiography resulted in perfect visualization of the condition. Median sternotomy and simultaneous bronchoscopy led to immediate readjustment of the aortopexy sutures in 6 patients. There were no surgical deaths or serious morbidities. The mean follow-up was 4.9 (0.3-14.9) years. Two patients with additional complex diseases died during the follow-up period. In all survivors, symptoms improved markedly or disappeared. However, we observed an increased susceptibility to lower respiratory tract infections over the long-term (32%). CONCLUSIONS: Aortopexy is effective for treating tracheomalacia of different origins and other pathological conditions as well. Preoperative computed tomography angiography offers excellent visualization of the condition. Median sternotomy and intraoperative bronchoscopy provide a combination for reliable operative and long-term results. However, many patients still have an increased susceptibility to lower respiratory tract infections.

Comparison between radial artery tonometry pulse analyzer and pulsed-Doppler echocardiography derived hemodynamic parameters in cardiac surgery patients: a pilot study.

BACKGROUND: Bedside non-invasive techniques, such as radial artery tonometry, to estimate hemodynamic parameters have gained increased relevance as an attractive alternative and efficient method to measure hemodynamics in outpatient departments. For our pilot study, we sought to compare cardiac output (CO), and stroke volume (SV) estimated from a radial artery tonometry blood pressure pulse analyzer (BPPA) (DMP-Life, DAEYOMEDI Co., Gyeonggi-do, South Korea) to pulsed-wave Doppler (PWD) echocardiography derived parameters. METHODS: From January 2015 to December 2016, all patients scheduled for coronary artery bypass (CABG) surgery at our department were screened. Exclusion criteria were, inter alia, moderate to severe aortic- or Mitral valve disease and peripheral arterial disease (PAD) > stage II. One hundred and seven patients were included (mean age 66.1 ± 9.9, 15 females, mean BMI 27.2 ± 4.1 kg/m2). All patients had pre-operative transthoracic echocardiography (TTE). We measured the hemodynamic parameters with the BPPA from the radial artery, randomly before or after TTE. For the comparison between the measurement methods we used the Bland-Altman test and Pearson correlation. RESULTS: Mean TTE-CO was 5.1 ± 0.96 L/min, and the mean BPPA-CO was 5.2 ± 0.85 L/min. The Bland-Altman analysis for CO revealed a bias of -0.13 L/min and SD of 0.90 L/min with upper and lower limits of agreement of -1.91 and +1.64 L/min. The correlation of CO measurements between DMP-life and TTE was poor (r = 0.501, p < 0.0001). The mean TTE-SV was 71.3 ± 16.2 mL and the mean BPPA-SV was 73.8 ± 19.2 mL. SV measurements correlated very well between the two methods (r = 0.900, p < 0.0001). The Bland-Altman analysis for SV revealed a bias of -2.54 mL and SD of ±8.42 mL and upper and lower limits of agreement of -19.05 and +13.96 mL, respectively. CONCLUSION: Our study shows for the first time that the DMP-life tonometry device measures SV and CO with reasonable accuracy and precision of agreement compared with TTE in preoperative cardiothoracic surgery patients. Tonometry BPPA are relatively quick and simple measuring devices, which facilitate the collection of cardiac and hemodynamic information. Further studies with a larger number of patients and with repeated measurements are in progress to test the reliability and repeatability of DMP-Life system.

Prevention of postoperative pericardial adhesions with TachoSil.

BACKGROUND: The prevention of the pericardial adhesions largely accountable for the technical difficulty and risk of injury inherent to resternotomy continues to gain in importance with the increasing frequency of reoperations. The hemostatic sponge TachoSil (Nycomed Austria GmbH, Linz, Austria), has shown promising results in adhesion prevention in several regions of the body. This study was designed to evaluate its effectiveness in the prevention of pericardial adhesions in comparison with the Gore-Tex (W. L. Gore and Assoc, Flagstaff, AZ) surgical membrane and a control. METHODS: Twenty-four rabbits were distributed into 3 groups: TachoSil, Gore-Tex, or no barrier agent (control). After median sternotomy and pericardiotomy, the cardial surface was exposed to the aggravating effects of room air, irrigation, and gauze abrasion for one hour. A pericardial defect was created and repaired with one of the barrier agents, or left uncovered (control). Resternotomy was performed after 6 months for the evaluation of adhesion formation. RESULTS: Significantly fewer macroscopic adhesions were observed with TachoSil than Gore-Tex in all regions (p < 0.05) excluding the coronary arteries, where the difference in favor of TachoSil did not achieve significance (0.05< p-value <0.10). TachoSil also demonstrated significantly fewer retrosternal adhesions than the control, as well as a universal non-significant trend of fewer adhesions in all regions. The limited lesions present in the TachoSil group were filmy in nature and removed with blunt dissection relatively easily. No significant differences were found between Gore-Tex and the control. Microscopically, the least pronounced fibrosis formation and inflammatory reaction was detected with TachoSil. CONCLUSIONS: TachoSil is effective in the prevention of pericardial adhesions.

Development of a rabbit animal model for miniaturized heart-lung machines.

The utilization of a heart-lung machine (HLM) for the correction of congenital heart defects can lead to various complications, which can culminate in multiorgan failure and death. To reduce the considerable risk of complications, we developed a miniaturized, highly integrated HLM (MiniHLM) for use in infants and children. For the purpose of testing the MiniHLM, we developed a new rabbit animal model. In all, surgery was performed on 32 rabbits. In the first series, 13 New Zealand white rabbits were placed on cardiopulmonary bypass (CPB) for 1 hour with the use of an initial version of the MiniHLM. In the second series, we operated on 19 Chinchilla Bastard rabbits using the further developed MiniHLM 02 or the Dideco Kids D100 system. While several adjustments had to be made to the operating protocol in the first series in order to lower the mortality rate, 15 of the 19 rabbits were successfully weaned from the HLM in the second series. Blood tests pertaining to hemolysis and the expression of inflammation were performed. In addition, tissue samples were taken from the right atrial auricle for the purpose of investigating the expression of inflammatory parameters. The newly developed MiniHLM prototype was tested successfully in an animal model in terms of technical function, hemolysis, and the expression of inflammation. On account of the comparability of their blood values, as well as their anatomy, Chinchilla Bastard rabbits serve as excellent models for the testing of CPB and support systems for infants and children that do not require the administration of foreign blood.

Direct right atrial insertion of a Hickman catheter in an 11-year-old girl.

Central venous lines are of particular importance in seriously ill children that require parenteral nutrition, chemotherapy, or other medications. The jugular or subclavian veins are ordinarily used for primary access. Alternatives include the femoral veins, the intercostal veins, and transhepatic approaches. If the use of these standard sites of placement is made impossible, due, for example, to chronic thrombosis, an alternative approach has to be found. The following report presents the case of an 11-year-old girl with short-bowel syndrome and a desperate need for parenteral nutrition. Over the course of her treatment, she developed chronic thrombosis of the jugular, subclavian, and femoral veins, as well as thrombosis of the inferior vena cava. As an alternative route for central venous access, we describe a successful direct placement of a tunnelled catheter into the right atrium via a right anterolateral thoracotomy.