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.

Everyday discrimination, co-ethnic social support and mood changes in young adult immigrants in Germany-Evidence from an ecological momentary assessment study.

Objective: In the context of international migration flows, Germany is the second largest receiving country of migrants in the world. The aim of this study is to investigate the momentary mood effects of discrimination experiences for young adult immigrants and which social resources can buffer negative effects. A distinction is made between the importance of inter and intra-ethnic interaction partners in processing stressors. Method: Using an ecological momentary assessment design, first-generation migrants in Germany who had recently migrated from Poland, Turkey or Syria were interviewed three times a day over seven days in June 2021 (N individuals = 976; N observations = 11,470). The timing of the short surveys was chosen at random using a signal contingent sampling method. Participants reported their momentary mood and instances of discrimination, along with information on social support perception and interaction partners during the preceding hour in the context of their everyday lives. Hybrid mixed-effects regression models were estimated and the research questions were tested with three-way interactions. Results: The results indicate that perceived social support only moderately buffers the negative effect of everyday discrimination experiences on mood. A positive main effect on mood is observed for situational variations in perceived social support as well as for support from interaction partners. Conclusion: The findings illustrate that being embedded in supportive relationships is important in everyday life, regardless of the occurrence of stressors. Furthermore, the study suggests that the level of perceived support is more important for first-generation migrants than the ethnic origin of the support provider.

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.

Minimally Invasive Approach for Replacement of the Ascending Aorta towards the Proximal Aortic Arch.

Objectives: In recent years, minimally invasive approaches have been used with increasing frequency, even for more complex aortic procedures. However, evidence on the practicability and safety of expanding minimally invasive techniques from isolated operations of the ascending aorta towards more complex operations such as the hemiarch replacement is still scarce to date. Methods: A total of 86 patients undergoing elective surgical replacement of the ascending aorta with (n = 40) or without (n = 46) concomitant proximal aortic arch replacement between 2009 and 2023 were analyzed in a retrospective single-center analysis. Groups were compared regarding operation times, intra- and postoperative complications and long-term survival. Results: Operation times and ventilation times were significantly longer in the hemiarch replacement group. Despite this, no statistically significant differences between the two groups were observed for the duration of the ICU and hospital stay and postoperative complication rates. At ten-year follow-up, overall survival was 82.6% after isolated ascending aorta replacement and 86.3% after hemiarch replacement (p = 0.441). Conclusions: Expanding the indication for minimally invasive aortic surgery towards the proximal aortic arch resulted in comparable postoperative complication rates, length of hospital stay and overall long-term survival compared to the well-established minimally invasive isolated supracommissural ascending aorta replacement.

Valve-sparing aortic root replacement using a straight tube graft (David I procedure).

OBJECTIVES: We present our 25-year experience with valve-sparing aortic root replacement using a straight tube graft (David-I). METHODS: From 1993 to 2019, 677 patients (median age, 56.0 years; range, 42-65) underwent the David-I procedure with a straight tube graft. A total of 24 different surgeons performed these operations. Marfan syndrome was present in 111 patients (16.4%), and bicuspid aortic valve was present in 71 patients (10.5%). Aortic root aneurysm was present in 544 patients (80.4%), and acute dissection was present in 133 patients (19.6%). RESULTS: Ministernotomy was used in 57 patients (8.4%). Additional cusp plasty was performed in 84 patients (12.4%). Concomitant procedures were coronary artery bypass grafting (n = 122, 18.0%), mitral valve surgery (n = 34, 5%), proximal arch replacement (n = 125, 18.4%), subtotal arch replacement (n = 43, 6.4%), and total arch replacement (n = 102, 15.1%). Overall in-hospital mortality was 4.0% (n = 27), and perioperative stroke occurred in 26 patients (3.8%). Postoperative echocardiography showed aortic insufficiency less than I° in 600 of 623 (96.3%). The 1-, 5-, 10-, 15-, and 20-year survivals were 97%, 92%, 79%, 68%, and 50%, respectively. The rates for freedom from aortic valve-related reoperation at 1, 5, 10, 15, and 20 years were 97%, 92%, 87%, 84%, and 80%, respectively. Multivariate Cox regression analysis identified age (odds ratio, 0.974; 95% confidence interval, 0.957-0.992; P = .004), senior surgeon (odds ratio, 0.546; 95% confidence interval, 0.305-0.979; P = .042), and residual postoperative aortic insufficiency (odds ratio, 4.864; 95% confidence interval, 1.124-21.052; P = .034) as independent risk factors for aortic valve-related reoperation. CONCLUSIONS: The aortic valve-sparing David-I procedure can be performed with very low perioperative morbidity and mortality. The short- and long-term results are excellent. The straight tube graft does not lead to increased leaflet erosion. This procedure is reproducible by multiple surgeons.

Preoperative pericardial hematoma in patients with acute type A aortic dissection (AAAD): Do we need an adjusted treatment?

OBJECTIVE: An acute type A aortic dissection (AAAD) is a critical emergency and remains one of the most challenging diseases in cardiothoracic surgery. The existence of a pericardial hematoma caused by an aortic rupture can dramatically reduce the chances of survival (Jerzewski and Kulik in J Card Surg 29(4):529-530, 2014; Mehta et al. in Circulation 105(2):200-206, 2002; Gilon et al. in Am J Cardiol 103(7):1029-1031, 2009; Isselbacher et al. in Circulation 90(5):2375-2378, 1994). We assessed the surgical outcome of a high-risk group of patients with AAAD and a pericardial hematoma. METHODS: In this study we included 430 Patients (67% male; median age: 64 years) who received surgical treatment between January 2000 and January 2018 at our facility for acute aortic dissection DeBakey type I. We divided the cohort in two groups: Group A consisted of high-risk patients with a pericardial hematoma (n = 162) and Group B of patients without pericardial hematoma (n = 268). RESULTS: Patients with a preoperative pericardial hematoma had a significantly higher requirement for preoperative mechanical resuscitation (A: 21%; B: 1.5%; P: < 0.001) and were relevantly more frequently admitted to the operation theater with an intubated status (A: 19.8%; B: 8.6%; P: < 0.001). The incidence of visceral malperfusion differed significantly between both groups (A. 11.7%, B. 6:0%; P: 0.034). Limited aortic arch repair (proximal aortic arch replacement) was preferred in the high-risk group (A: 51.9%; B: 40.3%; P: 0.020). However, survival time was generally reduced in these patients (A: 7.5 y; B: 9.9 y). CONCLUSION: AAAD patients with preoperative pericardial hematoma present themselves in potentially lethal conditions, with a significantly higher rate of visceral malperfusion. Despite the existence of this risk factor, a limited arch repair was favored. We have proven that cardiac compression is associated with preoperative intubation and mechanical resuscitation. Patients with pericardial hematoma must be further evaluated for preoperative pericardial drainage. In the event of long transfer times to an aortic center a slow drainage should be discussed to prevent early mortality.

Onset of pain to surgery time in acute aortic dissections type A: a mandatory factor for evaluating surgical results?

Objective: An acute aortic dissection type A (AADA) is a rare but life-threatening event. The mortality rate ranges between 18% to 28% and mortality is often within the first 24 h and up to 1%-2% per hour. Although the onset of pain to surgery time has not been a relevant factor in terms of research in the field of AADA, we hypothesize that a patient's preoperative conditions depend on the length of this time. Methods: Between January 2000 and January 2018, 430 patients received surgical treatment for acute aortic dissection DeBakey type I at our tertiary referral hospital. In 11 patients, the exact time point of initial onset of pain was retrospectively not detectable. Accordingly, a total of 419 patients were included in the study. The cohort was categorized into two groups: Group A with an onset of pain to surgery time < 6 h (n = 211) and Group B > 6 h (n = 208), respectively. Results: Median age was 63.5 years (y) ((IQR: 53.3-71.4 y); (67.5% male)). Preoperative conditions differed significantly between the cohorts. Differences were detected in terms of malperfusion (A: 39.3%; B: 23.6%; P: 0.001), neurological symptoms (A: 24.2%; B: 15.4%; P: 0.024), and the dissection of supra-aortic arteries (A: 25.1%; B: 16.8%; P: 0.037). In particular, cerebral malperfusion (A 15.2%: B: 8.2%; P: 0.026) and limb malperfusion (A: 18%, B: 10.1%; P: 0.020) were significantly increased in Group A. Furthermore, Group A showed a decreased median survival time (A: 1,359.0 d; B: 2,247.5 d; P: 0.001), extended ventilation time (A: 53.0 h; B: 44.0 h; P: 0.249) and higher 30-day mortality rate (A: 25.1%; B: 17.3%; P: 0.051). Conclusions: Patients with a short onset of pain to surgery time in cases of AADA present themselves not only with more severe preoperative symptoms but are also the more compromised cohort. Despite early presentation and emergency aortic repair, these patients show increased chances of early mortality. The "onset of pain to surgery time" should become a mandatory factor when making comparable surgical evaluations in the field of AADA.

Is aortic valve-sparing root reimplantation (David-I) justified in cardiac redo surgery?

OBJECTIVES: Aortic valve-sparing root reimplantation (AVSRR) is a complex procedure, which offers the benefit of preserving the native aortic valve. Cardiac redo surgery is complex and time-consuming, and it is not known if David procedure is safe or beneficial in this context. METHODS: Between 1993 and 2019, we performed a total of 544 elective AVSRR operations at our centre. Patients were assigned to either group A (n = 30, redo) or group B (n = 514, first-time sternotomy). RESULTS: Aortic cross-clamp time was higher in the redo group (173[62] vs 125[31], P < 0.001). Cardiopulmonary bypass time was higher in the redo group as well (250[78] vs 179[51], P < 0.001). There were significantly more concomitant total arch replacements in the redo group (43.3% vs 5.8%, P < 0.001) using the 'beating heart' technique (20.0% vs 1.9%, P < 0.001). In-hospital mortality was comparable in both groups (3.3% vs 1.8%, P = 0.44). The rates for perioperative complications in terms of permanent neurological deficit and rethoracotomy were comparable between the 2 groups, too. Follow-up was complete for 99.6% of all patients and comprised a total of 584 patient-years. The 1-, 5-, 10- and 15-year survival rates were 90%, 81%, 60% and 55%, in group A (redo) and 96%, 90%, 78% and 67% in group B (native, P = 0.16), respectively. The rates for freedom from valve-related reoperation at 1, 5, 10 and 15 years after initial surgery were 96%, 92%, 92% and 92% in group A (redo) and 97%, 92%, 87% and 84% in group B (native, P = 0.52), respectively. CONCLUSIONS: Despite significantly more concomitant total arch replacements in the redo group, early mortality was comparable in both groups. We conclude that AVSRR can be performed in redo cardiac surgery without compromising the early postoperative outcome. Careful patient assessment and selection are mandatory when evaluating patients with a history of previous cardiac surgery for David procedure.

Single-center experience with thoracoabdominal aortic replacement in patients with Marfan syndrome.

Objectives: Patients with Marfan syndrome are usually not suitable for endovascular repair of the thoracoabdominal aorta. This study was designed to analyze our center's experience with open surgical thoracoabdominal aortic replacement in Marfan patients. Methods: This was a retrospective study with prospective follow-up. Between January 1995 and September 2021, a total of 648 patients underwent thoracoabdominal aortic replacement at our center. Of these, 60 had Marfan syndrome and were included in this study. Results: The mean age was 39.5 ± 10.7 years, and 36 (60%) were male. Ten (17%) had aortic aneurysm, 4 (7%) acute/subacute dissection, and 46 (77%) chronic dissection. Patients presented with the following extent of aortic disease according to the Crawford classification: I-17 (28%), II-18 (30%), III-22 (37%), IV-2 (3%), and V-1 (2%). The mean cardiopulmonary bypass time was 173.9 ± 84.7 minutes. Four (7%) patients required stent graft extraction. Postoperatively, 5 (8%) patients required rethoracotomy and 6 (10%) tracheostomy. One (1.7%) patient had permanent paraplegia and 2 (3%) permanent paraparesis. Two (3%) patients had stroke. One (1.7%) patient was discharged with dialysis. The 30-day mortality was 3% (n = 2). Median follow-up time was 21.5 (range, 9.4-33.6) years. The 1-, 5-, and 10-year survival rate was 87%, 80%, and 68%, respectively. There were 16 aortic reinterventions in 9 patients during follow-up. Conclusions: Thoracoabdominal aortic replacement remains a complex procedure but can be done extremely safely in Marfan patients. Perioperative mortality rates are very low, and the long-term outcomes are enduring. Because endovascular aortic repair is not recommended for patients with connective tissue disease, open surgery remains an important cornerstone of therapy.

Valve-sparing David procedure via minimally invasive access does not compromise outcome.

Objectives: Aortic valve sparing-aortic root replacement (David procedure) has not been routinely performed via minimally invasive access due to its complexity. We compared our results of elective David procedure via minimally invasive access to those via a full sternotomy. Methods: Between 1993 and 2019, a total of 732 patients underwent a valve sparing root replacement (David) procedure. Out of these, 220 patients underwent elective David-I procedure (isolated) without any other concomitant procedures at our center. Patients were assigned to either group A (n = 42, mini-access) or group B (n = 178, full sternotomy). Results: Cardiopulmonary bypass time were 188.5 ± 35.4 min in group A and 149.0 (135.5-167.5) in group B (p < 0.001). Aortic cross-clamp time were 126.2 ± 27.2 min in group A and 110.0 (97.0-126.0) in group B (p < 0.001). Post-operative echocardiography showed aortic insufficiency ≤ I° in 41 (100%) patients of group A and 155 (95%) of group B. In-hospital mortality was 2.4% (n = 1) in group A and 0% (n = 0) in group B (p = 0.191). Perioperative stroke occurred in 1 (2.4%) patient of group A and 2 (1.1%) patients of group B (p = 0.483). Reexploration for bleeding was necessary in 4 (9.5%) patients of group A and 7 (3.9%) of group B (p = 0.232). Follow-up was complete for 98% of all patients. The 1-, 2-, 4-, and 6-year survival rates were: 97, 97, 97, and 97%, in group A (mini-access) and 99, 96, 95, and 92% in group B (full sternotomy), respectively. The rates for freedom from valve-related re-operation at 1, 2, 4, and 6 years after initial surgery were: 97, 95, 95, and 84% in group A and 97, 95, 91, and 90% in group B, respectively. Conclusion: Early post-operative results after David procedure via minimally invasive access are comparable to conventional full sternotomy. Meticulous attention to hemostasis is a critical factor during minimally access David procedures. Long-term outcome including the durability of the reimplanted aortic valve seems to be comparable, too.

Light control of the peptide-loading complex synchronizes antigen translocation and MHC I trafficking.

Antigen presentation via major histocompatibility complex class I (MHC I) molecules is essential to mount an adaptive immune response against pathogens and cancerous cells. To this end, the transporter associated with antigen processing (TAP) delivers snippets of the cellular proteome, resulting from proteasomal degradation, into the ER lumen. After peptide loading and editing by the peptide-loading complex (PLC), stable peptide-MHC I complexes are released for cell surface presentation. Since the process of MHC I trafficking is poorly defined, we established an approach to control antigen presentation by introduction of a photo-caged amino acid in the catalytic ATP-binding site of TAP. By optical control, we initiate TAP-dependent antigen translocation, thus providing new insights into TAP function within the PLC and MHC I trafficking in living cells. Moreover, this versatile approach has the potential to be applied in the study of other cellular pathways controlled by P-loop ATP/GTPases.

Aortic valve-sparing root replacement with Tirone E. David's reimplantation technique: single-centre 25-year experience.

OBJECTIVES: Tirone E. David described aortic valve-sparing root reimplantion (AVSRR) almost 30 years ago. At our centre, we adopted this operation in 1993, and since then, we have performed >700 operations over a time period of >25 years. In this report, we present our single-centre experience. METHODS: Between 1993 and 2019, a total of 732 patients underwent AVSRR at our centre. The mean age was 53 ± 15 and 522 (71%) were male. Marfan syndrome was present in 117 (16%) patients and bicuspid aortic valve in 81 (11%). The indication for surgery was aortic root aneurysm in 588 (80%) patients and acute aortic dissection in 144 (20%) patients. RESULTS: Mini-sternotomy was performed in 74 (10%) patients. A straight tube graft (David I) was used in 677 (92%) and a Valsalva-graft in 55 (8%) patients. Cusp plasty was done in 83 (11%) patients. Concomitant cardiac procedures were performed in 438 (60%) patients. Overall in-hospital mortality was 3.8% (n = 29) and 1.9% (n = 11) in elective cases. Postoperative echocardiography was available for 671 patients and showed aortic insufficiency (AI) ≤I° in 647 (96%) patients. The mean follow-up time was 10 ± 6.7 years and comprised a total of 7307 patient-years. The 1-, 5-, 10- and 15-year survival rates were: 93%, 88%, 77% and 65%, respectively. The rates for freedom from valve-related reoperation at 1, 5, 10 and 15 years after initial surgery were 97%, 93%, 88% and 85%, respectively. Cox regression analysis identified age [odds ratio (OR) = 0.975, 95% confidence interval (CI) = 0.955-0.995, P = 0.016], hyperlipidaemia (OR = 1.980, 95% CI = 1.175-3.335, P = 0.010), preoperative level of left ventricular ejection function (OR = 1.749, 95% CI = 1.024-2.987, P = 0.041) and postoperative degree of AI (OR = 1.880, 95% CI = 1.532-2.308, P ≤ 0.001) as risk factors for the future AI or reoperation. CONCLUSIONS: David procedure can be performed extremely safely, with low risks for perioperative morbidity and mortality, both in elective situations via minimally invasive access and in emergent settings for acute aortic type A dissection. Regarding long-term outcome, David's AVSRR seems to provide excellent clinical results and sustainable function of the aortic valve in the majority of patients almost 3 decades after its introduction.

Native and prosthetic graft infections of the thoracic aorta: surgical management.

OBJECTIVES: Infection of the native aorta or after previous open or endovascular repair of the thoracic aorta is associated with high risks for morbidity and mortality. We analysed the outcome after surgical management of a native mycotic aneurysm or of prosthetic graft infection of the descending aorta. METHODS: From June 2000 to May 2019, a total of 39 patients underwent surgery in our centre for infection of the native descending aorta (n = 19 [49%], group A) or a prosthetic descending aorta [n = 20 (51%), group B]. In the 20 patients in group B, a total of 8 patients had prior open aortic repair with a prosthesis and 12 patients had a previous endovascular graft repair. RESULTS: The cohort patients had a mean age of 57 ± 14; 62% were men (n = 24). The most common symptoms at the time of presentation included fever, thoracic or abdominal pain and active bleeding. Emergency surgery was performed in 11 patients (28%); 3 patients had emergency endovascular stent grafts implanted during thoracic endovascular aortic repair for aortic rupture before further open repair. The 30-day mortality was 42% in group A and 35% in group B. The 90-day mortality was 47% in group A and 45% in group B. Pathogens could be identified in approximately half of the patients (46%). The most commonly identified pathogens were Staphylococcus aureus in 6 patients (15%) and Staphylococcus epidermidis in 4 patients (10%). Survival of the entire group (including patients with both native and prosthetic graft infections) was 44 ± 8%, 39 ± 8% and 39 ± 8% at 1, 2 and 3 years after surgery. The percentage of patients who survived the initial perioperative period was 81 ± 9%, 71 ± 9% and 71 ± 10% at 1, 2 and 3 years after surgery. CONCLUSIONS: Patients with infection of the descending aorta, either native or prosthetic, are associated with both high morbidity and mortality. However, patients who survive the initial perioperative period have an acceptable long-term prognosis. In emergency situations, thoracic endovascular aortic repair may help to stabilize patients and serve as bridge to open repair.

Aortic valve-sparing root replacement in patients with bicuspid aortic valve: long-term outcome with the David I procedure over 20 years.

OBJECTIVES: Aortic valve-sparing root replacement is an excellent treatment option for patients with intact tricuspid aortic valves. However, the durability in patients with bicuspid aortic valves is still a matter of debate. The aim of this study was to analyse the short- and long-term outcomes in patients with bicuspid aortic valves. METHODS: Between July 1993 and October 2015, a total of 582 patients underwent the David I procedure, 50 of whom had a bicuspid aortic valve. In these patients, the mean age was 46 ± 13 years, and 80% (n = 40) were men. Follow-up was complete for 100% of patients and comprised a total of 552 patient-years with a mean follow-up time of 11 ± 5.2 years. RESULTS: In addition to the David procedure, cusp plication was performed in 34% (n = 17) of patients and commissure repair in 8% (n = 4) of patients. There were no in-hospital deaths, and 1 patient (2%) had a perioperative stroke. The 1-, 5-, 10- and 20-year survival rates of patients after discharge were 98%, 94%, 88% and 84%, respectively. The rates for freedom from valve-related reoperation at 1, 5, 10 and 20 years after initial surgery were 98%, 88%, 79% and 74%, respectively. Long-term freedom from reoperation was comparable to that of patients with tricuspid aortic valves (P = 0.2). CONCLUSIONS: The David procedure has excellent short-term results in patients with a bicuspid aortic valve. In this study, the long-term durability of reimplanted bicuspid aortic valves was comparable to that of tricuspid valves. However, careful patient selection might have contributed to this, and further studies might be needed to definitely clarify this issue.

Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus).

In three experiments, adult male Djungarian hamsters (Phodopus sungorus) were exposed 24 hr/day for 60 days to radio frequency electromagnetic fields (RF-EMF) at 383, 900, and 1800 MHz, modulated according to the TETRA (383 MHz) and GSM standards (900 and 1800 MHz), respectively. A radial waveguide system ensured a well defined and uniform exposure at whole-body averaged specific absorption rates of 80 mW/kg, which is equal to the upper limit of whole-body exposure of the general population in Germany and other countries. For each experiment, using two identical waveguides, hamsters were exposed (n = 120) and sham-exposed (n = 120) in a blind fashion. In all experiments, pineal and serum melatonin levels as well as the weights of testes, brain, kidneys, and liver were not affected. At 383 MHz, exposure resulted in a significant transient increase in body weight up to 4%, while at 900 MHz this body weight increase was more pronounced (up to 6%) and not transient. At 1800 MHz, no effect on body weight was seen. The results corroborate earlier findings which have shown no effects of RF-EMF on melatonin levels in vivo and in vitro. The data are in accordance with the hypothesis that absorbed RF energy may result in metabolic changes which eventually cause body weight increases in exposed animals. The data support the notion that metabolic effects of RF-EMFs need to be investigated in more detail in future studies.

Total aortic arch replacement with the elephant trunk technique: single-centre 30-year results.

OBJECTIVES: The combined disease of the aortic arch and the descending aorta (aneurysms and dissection) remains a surgical challenge. Various approaches have been used to treat this complex pathology. In the two-stage operation, at the first-stage operation, the aortic arch is replaced through a median sternotomy. Later, at the second-stage operation, the descending thoracic aorta is replaced through a lateral thoracotomy. The elephant trunk (ET) technique was introduced by H.G. Borst at our centre in March 1982, greatly simplifying the second-phase operation. We present our 30-year experience. METHODS: From March 1982 to March 2012, 179 patients (112 males, age 56.4±12.6 years) received an ET procedure for the combined disease of the aortic arch and the descending aorta (91 aneurysms, 88 dissections (47 acute)). Fifty-six of these patients had undergone previous cardiac operations. Concomitant procedures were performed if necessary. The cerebral protection was done either by deep (till 1999) or moderate hypothermic circulatory arrest and selective antegrade cerebral perfusion (SACP, after 1999). RESULTS: Cardiopulmonary bypass (CPB) and X-clamp times were 208.5±76.5 min and 123.7±54.8 min, respectively. The intraoperative mortality and 30-day mortality during the first-stage operation were 1.7% (3/179) and 17.3% (31/179, 15 with AADA), respectively. Perioperative stroke was 7.9% (n=14/176). Postoperative recurrent nerve palsy was present in 18.2% (32/176) and paraplegia in 5.6% (10/176). The second-stage completion operation was performed as early as possible. Fifty-seven second-stage completion procedures were performed, either surgically (n=50) or through interventional techniques (n=7). The intraoperative and 30-day mortality after the second-stage completion procedures were 5.2% (3/57) and 7.0% (4/57), respectively. The stroke, recurrent nerve palsy and paraplegia rates were 0, 0 and 7% (4/54), respectively. CONCLUSIONS: The ET technique has greatly facilitated the two-stage approach to the surgical treatment of combined diseases of the aortic arch and descending aorta. The initial learning curve, acute dissections, re-do and concomitant procedures partially explain the higher mortality rate. Despite the development of new hybrid techniques, there is still a role for the classical ET in selected patients, particularly in the context of proven long-term results and cost effectiveness.

Enhancing activities of daily living of chronic stroke patients in primary health care by modified constraint-induced movement therapy (HOMECIMT): study protocol for a cluster randomized controlled trial.

BACKGROUND: Stroke leads to constant rehabilitation needs even at the chronic stage. However, although many stroke patients receive physical or occupational therapy in primary health care, treatment prescriptions do not generally specify therapeutic goals; in particular, participation is not established as an explicit therapeutic goal in the ambulatory setting. The primary aim of this study is to evaluate the efficacy of a therapy regimen for chronic stroke patients (modified 'constraint-induced movement therapy (CIMT) at home') with impaired hand or arm function with regard to the prerequisites of participation in everyday activities: a sufficient arm and hand function. 'CIMT at home' will be compared with conventional physical and occupational therapy ('therapy as usual'). METHODS/DESIGN: The study is a parallel cluster randomized controlled trial with therapy practices as clusters (n = 48). After written consent from the patients (n = 144), the therapists will be randomly assigned to treat either the intervention or the control group. Blinded external assessors will evaluate the patients using standardized outcome measures before and after the intervention, and six months later. The two coprimary endpoint assessments of arm and hand function as prerequisites for participation (defined as equal involvement in activities of daily living) are the motor activity log (quality of arm and hand use) and the Wolf motor function test (arm and hand function). These assessments are made four weeks post-treatment and relativized to baseline performance. Changes in primary outcomes will be analyzed with mixed models, which consider the hierarchical structure of the data and will be adjusted to the baseline measurements and sex. The primary analysis will be the comparison of the two randomized groups, with respect to the adjusted averages for each of the two coprimary endpoints. To keep an overall significance level of 5%, the two endpoints will be tested at the significance level of 5% each in hierarchical order. DISCUSSION: A modification of the CIMT, feasible in the patients' homes (CIMT at home), appears to be a promising therapeutic approach in the ambulatory care of chronic stroke patients. With proven efficacy and practicality, a participation-oriented, stroke-specific treatment would be available in primary care. TRIAL REGISTRATION: ClinicalTrials.gov NCT01343602.