Current Water Management of Small Lotic Waterbodies in the Context of Nature Conservation in Germany.

Small lotic waterbodies are abundant and species rich habitats, offering refuges and microhabitats to protected species of the European Union Habitats Directive. Highly impacted by water management actions, it is essential to reveal the current status and challenges of water management. The present study aims to identify relevant issues by conducting a survey concerning water management authorities. Authorities were selected according to their involvement in the management of small lotic waterbodies within the actual range of a threatened species, Coenagrion mercuriale (Odonata), which is highly dependent on water management actions and protected by the Habitats Directive. The survey involved three sets of questionnaires, (1) socio-demographic (personal) questions (2) specific questions about water management and (3) questions on the biological background. Out of 181 selected authorities, 75 participated in the survey. The results showed that though nature conservation interests are partially considered, they represented a minor factor in water management decision-making. In addition, knowledge exchange is insufficient between involved stakeholders from policy, management practice and science, which was especially reflected in the case of equipment use and accruing material. The reconciliation of both, water management and nature conservation interests, can contribute to enhance the conservation status of key protected species of small lotic waterbodies under the Habitats Directive.

Impact of preoperative malperfusion on postoperative outcomes in type A aortic dissection - importance of serum lactate estimation in ongoing malperfusion.

INTRODUCTION: Acute type A aortic dissection (ATAAD) is one of the most critical emergencies in cardiovascular surgery. Additional complications such as organ malperfusion can significantly decrease the chances of survival. Despite promptly performed surgical treatment, impaired organ perfusion may persist, thus close postoperative monitoring is recommended. But, is there a surgical consequence due to the existence of a preoperatively known malperfusion and is there a correlation between pre-, peri- and postoperative levels of serum lactate and proven malperfusion? METHODS: Between 2011 and 2018, 200 patients (66% male; median age: 62.5 years; interquartile range: +/-12.4 years) that received surgical treatment at our institution for an acute dissection DeBakey type I were enrolled in this study. The cohort was divided into two groups according to the preoperative existence of malperfusion and non-malperfusion. At least one kind of malperfusion occurred in 74 patients (Group A: 37%), while 126 patients (Group B: 63%) showed no evidence of malperfusion. Furthermore, lactate levels of both cohorts were differentiated into four periods: preoperative, intraoperative, 24 hours after surgery, and 2-4 days after surgery. RESULTS: The patients' status differed significantly prior to surgery. Group A (malperfusion) showed an elevated requirement for mechanical resuscitation (A: 10.8%; B: 5.6%; p: 0.173), were significantly more often admitted in an intubated state (A: 14.9%; B: 2.4%; p: 0.001) and showed higher incidences of stroke (A: 18.9% (n = 149); B: 3.2% (n = 4); p: 0.001). Levels of serum lactate from the preoperative period until days 2-4 were significantly increased in the malperfusion cohort at all times. CONCLUSIONS: Preexisting malperfusion due to ATAAD may significantly increase the chance of early mortality in patients with ATAAD. Serum lactate levels were a reliable marker for inadequate perfusion from admission until day 4 after surgery. Despite this, early intervention survival in this cohort remains limited.

Expanding the Minimally Invasive Approach towards the Ascending Aorta-A Practical Overview of the Currently Available Techniques.

Minimally invasive techniques have gained immense importance in cardiovascular surgery. While minimal access strategies for coronary and mitral valve surgery are already widely accepted and often used as standard approaches, the application of minimally invasive techniques is currently expanded towards more complex operations of the ascending aorta as well. In this new and developing field, various techniques have been established and reported ranging from upper hemisternotomy approaches, which allow even extensive operations of the ascending aorta to be performed through a minimally invasive access to sternal sparing thoracotomy strategies, which completely avoid sternal trauma during ascending aorta replacements. All of these techniques place high demands on patient selection, preoperative planning, and practical surgical implementation. Application of these strategies is currently limited to high-volume centers and highly experienced surgeons. This narrative review gives an overview of the currently available techniques with a special focus on the practical execution as well as the advantages and disadvantages of the currently available techniques. The first results demonstrate the practicability and safety of minimally invasive techniques for replacement of the ascending aorta in a well-selected patient population. With success and complication rates comparable to classic full sternotomy, the proof of concept for minimally invasive replacement of the ascending aorta is now achieved.

The Danubian cryptic invader Theodoxus fluviatilis (Gastropoda: Neritidae) in the River Rhine: a potential indicator for metal pollution?

Metal pollution poses a major threat to aquatic systems especially in anthropogenic influenced areas, in as much as metals are persistent in the environment. The freshwater snail Theodoxus fluviatilis has often been used as an indicator species for the ecological status in river monitoring. In the River Rhine, the native Northern-European form of T. fluviatilis is nowadays extinct, whilst the Danubian form is spreading along the river. The aim of our study was to investigate if the cryptic invader is affected by metal exposure present in the River Rhine and to discuss its potential as an indicator for metal pollution. Several environmental abiotic (14 water environmental variables plus five common metal concentrations in water and biofilm) and biotic parameters (biofilm mass) were measured across 23 sites along the River Rhine. Five population and six histopathological parameters were evaluated on snails collected at all 23 sites. Aqueous chromium concentration was positively correlated to the damage of male reproductive organs of T. fluviatilis, and higher ammonium concentration was correlated to a decrease in snail size and an increase in the proportion of juveniles. None of the analysed snail parameters was negatively correlated to concentrations of other metals measured, like copper and zinc. Therefore, based on the parameters evaluated, our results indicate that the Danubian form of T. fluviatilis is only restrictedly suitable as an indicator for metal pollution in the River Rhine system. Further field and laboratory investigations including other stressors are necessary to evaluate the indicator potential of the cryptic invader holistically.

Aortic Valve-Sparing Root Replacement (David I Procedure) in Adolescents: Long-Term Outcome.

INTRODUCTION: Aortic valve-sparing root replacement (David's procedure) is an especially appealing treatment option for young patients. Here, we present the short-, mid, and long-term outcomes of this operation in adolescent patients. METHODS: Between September 1994 and March 2014, 29 patients aged 6 to 21 years underwent the David-I procedure at our center. We conducted a retrospective study with follow-up. RESULTS: The mean age was 16.8 ± 3.4 years and 90% (n = 26) were male. Marfan's syndrome was present in 86% (n = 25) of cases. Ninety-seven percent (n = 28) of cases were performed electively, and one case (3%) was performed emergently for acute aortic dissection type A. There were no early perioperative deaths (0%). Follow-up, which was completed on 100% of patients, comprised a total of 394 patient years and a mean follow-up time of 13.6 ± 5.4 years. The estimates for survival at 1, 5, and 10 years after initial surgery were 100, 97, and 93%, respectively. During follow-up, there were four (14%) late deaths and five (17%) aortic valve-related reoperations. The 1-, 5-, and 10-year estimates for freedom from valve-related reoperation were 100, 86, and 83%, respectively. The perioperative mortality for these five reoperations was 0%. DISCUSSION: Aortic valve-sparing root replacement can be performed in adolescents with a very low perioperative risk. Long-term survival seems to be affected by connective tissue diseases.

Effects of Copper Ions on Non-target Species: A Case Study Using the Grazer Theodoxus fluviatilis (Gastropoda: Neritidae).

The various uses of copper or copper compounds in industrial, biocidal or pesticidal products lead to inputs of the metal into aquatic environments. To assess effects of copper ions on non-target organisms, the freshwater snail Theodoxus fluviatilis was used as test organism for a three-week laboratory experiment. Snails were exposed to four copper concentrations ranging from 4 to 39 µg Cu2+/L, and besides mortality, several sublethal parameters were evaluated. Concerning survival, an aqueous copper concentration of 6 µg/L was determined as NOEC, and 16 (± 0.1) µg/L as LC50. Negative sublethal effects on reproduction, activity and pathological modifications in the snails were detected in the treatment with an aqueous copper concentration of 15 µg/L. Our results using T. fluviatilis as a mere grazer exclusively feeding on biofilms contribute to findings that field relevant copper concentrations have a significant effect on non-target organisms in aquatic environments.

Using stereoscopic visualizations as templates to construct a spatial hands-on representation-is there a novelty effect?

Sculpting representations of human organs out of modeling clay is an acknowledged method of teaching anatomical structures. Because of its potential to provide detailed spatial information, stereoscopic imagery can be understood to function as a suitable template for such sculpting tasks. Currently, it is unknown whether the advantages of stereoscopic images for modeling structures result from enhanced depth impression alone, or whether task performance is impacted by factors such as situational intrinsic motivation and perceived competence while sculpting a human organ using stereoscopic imagery as template. To clarify these queries, 35 eighth-grade students constructed a representation of the nasal cavity consisting of modeling clay. After the working phase, their situational intrinsic motivation and their perceived competence were assessed by a paper-and-pencil test and then analyzed, as was the elaboration of the sculpted representations. A control group with 38 students working with nonstereoscopic visualizations functioned as a counterpart. Stereoscopic imagery outperformed nonstereoscopic imagery concerning the accuracy in elaborating structures within the representations. However, there was no difference between situational intrinsic motivation and perceived competence in the context of using the digital template for forming the representations. Within the cohort working with nonstereoscopic imagery, situational intrinsic motivation was correlated with task performance. In contrast, within the cohort working with stereoscopic imagery, there was no relation concerning this. The findings show that depth impression due to stereoscopic imagery can be utilized to construct template-close representations, independently of situational feelings. This independence from situational sensitivities indicates that low situational intrinsic motivation will not condemn students to poor task performance.

Multimodal Imaging for In Vivo Evaluation of Induced Pluripotent Stem Cells in a Murine Model of Heart Failure.

Myocardial stem cell therapy in heart failure is strongly dependent on successful cellular transfer, engraftment, and survival. Moreover, massive cell loss directly after intramyocardial injection is commonly observed, generating the need for efficient longitudinal monitoring of transplanted cells in order to develop more efficient transplantation techniques. Therefore, the aim of the present study was to assess viability and cardiac retention of induced pluripotent stem cells after intramyocardial delivery using in vivo bioluminescence analysis (BLI) and magnetic resonance imaging (MRI). Murine induced pluripotent stem cells (iPSCs) were transfected for luciferase reporter gene expression and labeled intracellularly with supraparamagnetic iron oxide particles. Consequently, 5 × 105 cells were transplanted intramyocardially following left anterior descending coronary artery ligation in mice. Cardiac iPSCs were detected using BLI and serial T2* sequences by MRI in a 14-day follow-up. Additionally, infarct extension and left ventricular (LV) function were assessed by MRI. Controls received the same surgical procedure without cell injection. MRI sequences showed a strong MRI signal of labeled iPSCs correlating with myocardial late enhancement, demonstrating engraftment in the infarcted area. Mean iPSC volumes were 4.2 ± 0.4 mm3 at Day 0; 3.1 ± 0.4 mm3 at Day 7; and 5.1 ± 0.8 mm3 after 2 weeks. Thoracic BLI radiance decreased directly after injection from 1.0 × 106 ± 4.2 × 104 (p/s/cm2 /sr) to 1.0 × 105 ± 4.9 × 103 (p/s/cm2 /sr) on Day 1. Afterward, BLI radiance increased to 1.1 × 106 ± 4.2 × 104 (p/s/cm2 /sr) 2 weeks after injection. Cardiac graft localization was confirmed by ex vivo BLI analysis and histology. Left ventricular ejection fraction was higher in the iPSC group (30.9 ± 0.9%) compared to infarct controls (24.0 ± 2.1%; P < 0.05). The combination of MRI and BLI assesses stem cell fate in vivo, enabling cardiac graft localization with evaluation of LV function in myocardial infarction.

In Vitro Evaluation of Inflow Cannula Fixation Techniques in Left Ventricular Assist Device Surgery.

The therapy of terminal heart failure with left ventricular assist devices has become a standard in cardiac surgery. Yet the surgical implantation technique is not standardized and differs from center to center. Complications associated with left ventricular assist device (LVAD) inflow cannula placement are thrombosis, suction events, and flow disturbances. Within this in vitro study we aimed to investigate if the fixation technique of the sewing ring has an impact on the position of the inflow cannula. For this in vitro study the HeartMate III LVAD (Thoratec Corporation, Pleasanton, CA, USA) was used. In five sessions, two approaches were considered for coring of the ventricle for LVAD inflow cannula insertion: "sew-then-core" and "core-then-sew." In the "sew-then-core" technique, the sewing cuff is first affixed to the heart, usually with 8-16 interrupted pledgeted mattress sutures. Subsequently, a cylindrical knife is used to resect a cylindrical core of myocardium to permit cannula insertion. In the "core-then-sew" technique, the sequence is reversed such that the knife is used before the suture ring is affixed. When the "sew-then-core" technique is used, the mattress sutures may be placed with full-thickness bites that penetrate the endocardium (i.e., transmural stitching) or partial-thickness bites that do not penetrate the endocardium (i.e., epicardial stitching). When the "core-then-sew" technique is used, the suture is passed fully into the ventricular lumen and fed back through the cored hole, at which point the needle may be reinserted into the freshly cored myocardium such that it exits the epicardium (i.e., transmural stitching with back stitch) or not (i.e., transmural stitching without back stitch). These four different sewing ring fixation suturing techniques were tested by experienced surgeons to affix the sewing ring: transmural stitching, epicardial stitching, transmural stitching with back stitch, and transmural stitching without back stitch. The sewing ring was sewed onto a silicone dummy designed to simulate the left ventricle with standard 2-0 Ethibond sutures (Ethicon, Somerville, NY, USA). Afterward, the dummies were measured and documented via photography. In addition, porcine hearts were used to simulate the suturing techniques in a physiological setting. The setting of the inflow cannula is substantially influenced by the fixation method of the sewing ring. Epicardial stitching showed the best results with stable cannula fixation, minimal gap around the cannula and no contact between the sutures and sewing ring with blood. The method of transmural stitching without back stitch showed the worst results by creating the biggest epithelial gap between inflow cannula and tissue as well as proving the biggest surface for blood contact between sewing ring and sutures. In general, both "sew-then-core" techniques resulted in a greater degree of apposition between the cuff and epicardial tissue. Within the study we revealed that the surgical fixation of the sewing ring has a significant impact on the inflow cannula stability, position, and tissue apposition in LVAD implantation surgery. Epicardial stitching of the sewing ring provides the best results in order to prevent suction events as well as thrombosis formation.

The Unplanned Postoperative Coronary Angiogram after CABG: Identifying the Patients at Risk.

Objectives Coronary artery bypass grafting (CABG) is the "gold standard" for patients with multiple vessel coronary artery disease (CAD). However, there is no "gold standard" to control bypass patency immediately postoperatively. "Post-completion" control angiogram (CA) is not routinely performed. We retrospectively analyzed the data of all patients undergoing urgent coronary angiogram post-CABG at our center. Methods Between January 2005 and June 2011, a total of 6,025 patients underwent CABG (isolated or combined) for CAD in our hospital. In patients who underwent urgent postoperative CA, high serum cardiac enzymes (>100 CK-MB), severe new ECG changes, or unexpected low left ventricular function were present. Results A total of 106 patients (1.8%) underwent post-CABG urgent coronary angiogram. Overall 30-day mortality in this cohort was 8.5%. The average time between the cardiac operation and the coronary angiogram in these patients was 3.41 ± 5.68 days. The rates for an urgent coronary angiogram were 1.3% (n = 25), 2% (n = 65), and 1.8% (n = 16) for total arterial, combined arterial, and venous and solely venous CABG, respectively. Twenty-four percent of patients underwent CABG bypass revision, while 32% of the patients underwent PTCA, stenting, or both. Younger patients, female patients, smaller patients, and patients receiving a combined arterial and venous revascularization were at a higher risk for an unplanned postoperative CA in the multivariate risk analysis. Conclusion This study shows that the necessity for urgent post-CABG coronary angiogram is low (1.8%). However, more than half of the patients undergoing postoperative coronary angiogram needed reintervention, and, in spite of it, had high mortality. "Completion" control angiogram is not always feasible, patients at higher risk (e.g., female patients) should be identified and post-CABG coronary angiogram performed as soon as possible without undue delay, or a primary hybrid approach with an intraoperative CA should be applied.

Right-Sided Heart Failure and Extracorporeal Life Support in Patients Undergoing Pericardiectomy for Constrictive Pericarditis: A Risk Factor Analysis for Adverse Outcome.

Background Right ventricular failure is a life-threatening postoperative complication after pericardiectomy. We conducted a retrospective study with a special emphasis on right ventricular failure. Methods Between June 1997 and September 2011, 69 patients underwent surgical pericardiectomy at our center. Mean age was 59 ( ± 15.5) years, and 49 (71%) patients were male. Causes of constrictive pericarditis included idiopathic (52%, n = 36), tuberculosis (9%, n = 6), postcardiotomy (12%, n = 8), radiation (4%, n = 3), renal insufficiency (12%, n = 8), and autoimmune disease (12%, n = 8). Concomitant cardiac surgery was performed in 33 (48%) patients. Results In-hospital mortality rate was 14% (10/69 patients). Extracorporeal membrane oxygenation (ECMO) was necessary in 8 (12%) cases because of right (n = 7) or biventricular (n = 1) failure. Statistical analysis showed a significant correlation between early mortality and the following preoperative variables: postcardiotomy (p = 0.049), radiation (p = 0.009), pleural effusion (p = 0.012), ascites (p = 0.039), hepatic congestion (p = 0.023), absence of calcification on X-ray (p = 0.041), tricuspid valve insufficiency (TI, p < 0.001), and low cardiac index (p = 0.003). Diuretic usage (p = 0.044), peripheral edema (p = 0.050), low voltage (p = 0.027), dip-plateau sign (p = 0.027), elevated GGT (p < 0.001), and decreased serum protein (p < 0.001) correlated with ECMO implantation. Binary logistic regression identified pleural effusion (OR = 16.2, 95% CI = 1.4-191.5), moderate/severe TI (OR = 28.8, 95% CI = 2.7-306.8) and low cardiac index (OR = 25.3, 95% CI = 2.0-315.6) as preoperative independent risk factors for early mortality, whereas elevated GGT (OR = 28.3, 95% CI = 2.4-329.2) and decreased protein (OR = 24.7, 95% CI = 1.8-343.7) could predict right ventricular failure with the need for ECMO. Conclusion We recommend nondelayed ECMO support in case of significant postoperative right-sided heart failure. High-risk patients might benefit from elective pre- or intraoperative ECMO implantation.

Surgical treatment of coronary artery aneurysms.

INTRODUCTION: Coronary artery aneurysms (CAA) are rare. We present our experience with the surgical treatment of patients with CAAs. METHODS: Between March 2000 and October 2016, 15 patients with CAA underwent surgery. RESULTS: Mean age of patients was 60 ± 16 years and 47% (n = 7) were male. Kawasaki syndrome was present in two (13%) patients and 7% (n = 1) patients had Marfan syndrome. Isolated CAAs were found in 73% (n = 11) and involvement of multiple vessels was present in 27% (n = 4) of patients. Coronary arteries (CA) affected by aneurysms were: 19% (n = 4) left main stem, 33% (n = 7) left anterior descending, 14% (n = 3) left circumflex, and 33% (n = 7) right coronary artery. The majority of patients (93%, n = 14) were operated on pump with a mean cross-clamp time of 51 ± 23 min. 53% (n = 8) of patients received total arterial CA bypass grafting, while the remaining patients (47%, n = 7) received venous ± internal thoracic artery grafts. Resection/ligation of CAA was performed in 27% (n = 4) of patients. In-hospital mortality was 0% (n = 0). Follow-up was complete for 100% of patients and comprised a total of 80 patient-years. During follow-up, only one patient (7%) required re-intervention. CONCLUSION: Surgical treatment of CAA has good short- and long-term results.

Total Arterial Revascularization with Radial Artery T-grafts in Patients with Significant Left Main Stem Stenosis Is Not Associated with Higher Perioperative Risk.

BACKGROUND: Total arterial revascularization (TAR) has become a standard procedure for the treatment of coronary multivessel disease, due to the superior long-term patency rates of arterial grafts as compared with saphenous vein graft material. Controversies about the use of TAR in patients with left main coronary artery disease exist. Hence, we ought to determine whether left main coronary artery disease is a risk factor for early postoperative mortality and morbidity after TAR using the in situ left internal thoracic artery (LITA) and radial artery as composite T-graft. METHODS: A total of 904 consecutive patients were included in this retrospective study. They underwent first-time coronary artery bypass grafting surgery in our institution, receiving TAR using the in situ LITA and RA T-graft. Of these patients, 247 (27%) had left main coronary artery disease (Group LMSS) and 657 (73%) had no significant left main coronary artery stenosis (Group nLMSS). RESULTS: Results were comparable. Mortality and perioperative myocardial infarction rates were 0.4% LMSS versus 0.3% nLMSS, p = 1, and 2% LMSS versus 2% nLMSS, p = 0.81, respectively. Stroke rate, acute renal failure rate, and reoperation rates were 2% LMSS versus 1% nLMSS, p = 0.36, 7% LMSS versus 8% nLMSS, p = 0.41, and 2% LMSS versus 3% nLMSS, p = 0.5, respectively. Postoperative stay was shorter in the LMSS group (8.1 ± 4.3 days vs. 8.9 ± 6.1 days nLMSS, p = 0.048). CONCLUSION: Our perioperative results indicate that TAR in patients with left main stenosis is safe and feasible. Long-term results will have to be awaited to further evaluate prognostic outcome.

Is Bentall Procedure Still the Gold Standard for Acute Aortic Dissection with Aortic Root Involvement?

INTRODUCTION: The "ideal" treatment of acute aortic dissection type A (AADA) with dissected and dilated root is controversial. We compared the outcome of classical Bentall procedure (biological and mechanical) with valve-sparing David procedure. METHODS: Between January 2002 and July 2011, 119 patients with AADA and aortic root involvement underwent surgery at our center. Thirty-one patients (group 1) received biological conduits, 41 (group 2) received mechanical conduits, and 47 (group 3) underwent David procedures. RESULTS: Cross-clamp, cardiopulmonary bypass, and circulatory arrest times were 151 ± 52, 232 ± 84, and 36 ± 30 minutes (group 1); 148 ± 44, 237 ± 91, and 45 ± 29 minutes (group 2); and 160 ± 46, 231 ± 63, and 35 ± 17 minutes (group 3), respectively. The 30-day mortality rates were 32.3% (group 1), 22% (group 2), and 12.8% (group 3). The 1-year rates for freedom from valve-related reoperation were 100% (group 1), 92.5% (group 2), and 95.2% (group 3) (p = 0.172). The 1-year survival rates were 61% (group 1), 61% (group 2), and 84.1% (group 3) (p = 0.008). CONCLUSION: Even in AADA patients with root involvement, David procedure has acceptable results. David procedure (if possible) or a Bio-Bentall (for pathological valves) seems to be the optimal technique.

Substantial early loss of induced pluripotent stem cells following transplantation in myocardial infarction.

The limited success of cardiac stem cell therapy has lately generated discussion regarding its effectiveness. We hypothesized that immediate cell loss after intramyocardial injection significantly obscures the regenerative potential of stem cell therapy. Therefore, our aim was to assess the distribution and quantity of induced pluripotent stem cells after intramyocardial delivery using in vivo bioluminescence analysis. In this context, we wanted to investigate if the injection of different cell concentrations would exert influence on cardiac cell retention. Murine-induced pluripotent stem cells were transfected for luciferase reporter gene expression and transplanted into infarcted myocardium in mice after left anterior descending coronary artery ligation. Cells were delivered constantly in aqueous media (15 µL) in different cell concentrations (group A, n = 10, 5.0 × 10(5) cells; group B, n = 10, 1.0 × 10(6) cells). Grafts were detected using bioluminescence imaging. Organ explants were imaged 10 min after injection to quantify early cardiac retention and cell biodistribution. Bioluminescence imaging showed a massive early displacement from the injection site to the pulmonary circulation, leading to lung accumulation. Mean cell counts of explanted organs in group A were 7.51 × 10(4) ± 4.09 × 10(3) (heart), 6.44 × 10(4) ± 2.48 × 10(3) (left lung), and 8.06 × 10(5) ± 3.61 × 10(3) (right lung). Respective cell counts in group B explants were 1.69 × 10(5) ± 7.69 × 10(4) (heart), 2.11 × 10(5) ± 4.58 × 10(3) (left lung), and 3.25 × 10(5) ± 9.35 × 10(3) (right lung). Applying bioluminescence imaging, we could unveil and quantify massive early cardiac stem cell loss and pulmonary cell accumulation following intramyocardial injection. Increased injection concentrations led to much higher intracardiac cell counts; however, pulmonary biodistribution of transplanted cells still persisted. Therefore, we recommend applying tissue engineering techniques for cardiac stem cell transplantations in order to improve cardiac retention and limit biodistribution.

Higher frequencies of BCRP+ cardiac resident cells in ischaemic human myocardium.

AIMS: Several cardiac resident progenitor cell types have been reported for the adult mammalian heart. Here we characterize their frequencies and distribution pattern in non-ischaemic human myocardial tissue and after ischaemic events. METHODS AND RESULTS: We obtained 55 biopsy samples from human atria and ventricles and used immunohistological analysis to investigate two cardiac cell types, characterized by the expression of breast cancer resistance protein (BCRP)/ABCG2 [for side population (SP) cells] or c-kit. Highest frequencies of BCRP+ cells were detected in the ischaemic right atria with a median of 5.40% (range: 2.48-11.1%) vs. 4.40% (1.79-7.75%) in the non-ischaemic right atria (P = 0.47). Significantly higher amounts were identified in ischaemic compared with non-ischaemic ventricles, viz. 5.44% (3.24-9.30%) vs. 0.74% (0-5.23%) (P = 0.016). Few numbers of BCRP+ cells co-expressed the cardiac markers titin, sarcomeric α-actinin, or Nkx2.5; no co-expression of BCRP and progenitor cell marker Sca-1 or pluripotency markers Oct-3/4, SSEA-3, and SSEA-4 was detected. C-kit+ cells displayed higher frequencies in ischaemic (ratio: 1:25 000 ± 2500 of cell counts) vs. non-ischaemic myocardium (1:105 000 ± 43 000). Breast cancer resistance protein+/c-kit+ cells were not identified. Following in vitro differentiation, BCRP+ cells isolated from human heart biopsy samples (n = 6) showed expression of cardiac troponin T and α-myosin heavy-chain, but no full differentiation into functional beating cardiomyocytes was observed. CONCLUSION: We were able to demonstrate that BCRP+/CD31- cells are more abundant in the heart than their c-kit+ counterparts. In the non-ischaemic hearts, they are preferentially located in the atria. Following ischaemia, their numbers are elevated significantly. Our data might provide a valuable snapshot at potential progenitor cells after acute ischaemia in vivo, and mapping of these easily accessible cells may influence future cell therapeutic strategies.

Should we operate on patients with acute type A aortic dissection who present with cardiopulmonary resuscitation?

OBJECTIVES: Acute aortic dissection type A (AADA) is a life-threatening medical emergency. Emergent surgical repair is the gold standard but mortality remains high. Mortality is even higher in patients who arrive at the hospital in poor condition, especially after cardiopulmonary resuscitation (CPR). This study was designed to analyse the outcome of patients who underwent surgery for AADA and who require preoperative CPR. METHODS: Between 2000 and 2023, 810 patients underwent emergent surgery for AADA at our centre. Of these, 63 had preoperative CPR. We performed a retrospective analysis with follow-up. RESULTS: Mean age was 64 ± 13 years and 37 (59%) patients were male. Further, 50 (79%) patients had preoperative intubation, and 54 (86%) had pericardial effusion. Twenty-four (38%) patients had out-of-hospital CPR, 19 (30%) required CPR in hospital and 20 (32%) needed CPR in the operating room. Successful CPR with return of spontaneous circulation was achieved in 41 (65%) patients, and 22 (35%) underwent emergent surgery under ongoing CPR. The median time of CPR was 10 (interquartile range 12) min, and the median time from onset of symptoms to start of the operation was 5.5 (interquartile range 4.8) h. The majority of patients underwent ascending aortic replacement with hemiarch repair (n = 37, 59%). Further, 26 (41%) patients underwent full root replacement. Another 15 (24%) patients underwent total arch repair with or without (frozen) elephant trunk repair. Postoperative stroke was present in 8 (13%) patients. The 30-day mortality was 29 (46%). The 30-day mortality of patients with preoperative intubation was not significantly higher (n = 15/28, 54%, P = 0.446). The 1-, 5- and 10-year survival rates of the entire group were 42, 39 and 36%. CONCLUSIONS: Early mortality for patients undergoing surgery for AADA with preoperative CPR is extremely high (almost 50%). However, this means that also ∼50% of patients benefit from surgery despite poor preoperative prognosis. Patients with preoperative intubation after CPR and unknown neurological condition should also undergo surgery. Patients who survive the initial operation for AADA have acceptable long-term survival. Emergent surgery should be offered for all patients with AADA regardless of the preoperative condition, even after CPR.

Impact of Intercostal Artery Reinsertion on Neurological Outcome after Thoracoabdominal Aortic Replacement: A 25-Year Single-Center Experience.

BACKGROUND: Intercostal artery reinsertion (ICAR) during thoracoabdominal aortic replacement remains controversial. While some groups recommend the reinsertion of as many arteries as possible, others consider the sacrifice of multiple intercostals practicable. This study investigates the impact of intercostal artery reinsertion or sacrifice on neurological outcomes and long-term survival after thoracoabdominal aortic repair. METHODS: A total of 349 consecutive patients undergoing thoracoabdominal aortic replacement at our institution between 1996 and 2021 were analyzed in a retrospective single-center study. ICAR was performed in 213 patients, while all intercostal arteries were ligated and sacrificed in the remaining cases. The neurological outcome was analyzed regarding temporary and permanent paraplegia or paraparesis. RESULTS: No statistically significant differences were observed between the ICAR and non ICAR groups regarding the cumulative endpoint of transient and permanent spinal cord-related complications (12.2% vs. 11.8%, p = 0.9). Operation, bypass, and cross-clamp times were significantly longer in the ICAR group. Likewise, prolonged mechanical ventilation was more often necessary in the ICAR group (26.4% vs. 16.9%, p = 0.03). Overall long-term survival was similar in both groups in the Kaplan-Meier analysis. CONCLUSION: Omitting ICAR during thoracoabdominal aortic replacement may reduce operation and cross-clamp times and thus minimize the duration of intraoperative spinal cord hypoperfusion.

Risk factors, prevention, and therapy of intraluminal stent thrombosis in frozen elephant trunk prostheses-what we know so far.

Intraluminal thrombus formation (ILT) is a recently discovered and highly clinically relevant complication after frozen elephant trunk implantation in cardiovascular surgery. In this phenomenon, a thrombus forms within the lumen of the stent graft component of the frozen elephant trunk prosthesis and puts the patient at risk for downstream embolization with visceral or lower limb ischemia. Incidence of ILT reported in the currently available studies ranges from 6% to 17% of patients after frozen elephant trunk implantation. Adverse thromboembolic events include acute occlusion of the celiac and superior mesenteric arteries, both renal arteries as well as acute lower limb ischemia due to iliac or femoral artery embolization that not infrequently require interventional or open embolectomy. Therefore, the presence of ILT is associated with increased short-term mortality and morbidity. Currently proposed strategies to avoid ILT formation include a more aggressive anticoagulation management, minimization of postoperative coagulation factor application, and even technical optimizations of the stent graft portion itself. If ILT is manifested, the therapeutic strategies tested to date are long-term escalation of anticoagulation and early endovascular extension of the FET stent graft with overstenting of the intraluminal thrombus. The long-term efficiency of these prophylactic and therapeutic measures has yet to be proven. Nonetheless, all surgeons performing the frozen elephant trunk procedure must be aware of the risk of ILT formation to facilitate a timely diagnosis and therapy.