256 research outputs found
Regarding “Graft patency is not the only clinical predictor of success after exclusion and bypass of popliteal artery aneurysms”
A Case Report: Is the Lack of Sufficient Radial Force Unfreezing the “Frozen Elephant Trunk”?
The “frozen elephant trunk” is a hybrid technique to treat aortic arch and proximal descending aortic pathologies in a single step. Despite its encouraging early and long-term results, some stent-graft-related adverse events have been reported. Here, we describe a possible treatment option to "re-freeze" the FET in case of loss of landing zone. We report a patient who developed significant kinking of the FET over the course of the first 2 postoperative years. The 1-year follow-up computed tomography angiography (CTA) showed significant kinking and proximal migration of the endograft portion of the FET, resulting in new thrombus formation. Due to kinking and thrombus progression in subsequent CTA follow-ups (2 years and 2½ years) with risk for peripheral embolization, a secondary endovascular repair was indicated. Transfemoral relining of the stent component with a thoracic aortic endovascular repair (Zenith®TX2®30142) stent-graft was performed. In the context of postoperative aneurysm sac shrinkage, the low radial force and lack of longitudinal stiffness of the hybrid graft may lead to proximal migration, thus secondary kinking, emphasizing the importance of an adequate degree of oversizing of the primary graft and an appropriate follow-up. Selection of a suitable graft for a particular pathology concerning the radial force and longitudinal stiffness is furthermore important
Concomitant cardiac and cerebral leiomyosarcoma: A challenge for surgical and adjuvant therapy
The Cosmic Ray Muon Flux at WIPP
In this work a measurement of the muon intensity at the Waste Isolation Pilot
Plant (WIPP) near Carlsbad, NM, USA is presented. WIPP is a salt mine with a
depth of 655 m. The vertical muon flux was measured with a two panels
scintillator coincidence setup to
Phi_{vert}=3.10(+0.05/-0.07)*10^(-7)s^(-1)cm^(-2)sr^(-1).Comment: 18 pages, p figure
Morphology Of Current Of Injury Does Not Predict Long Term Active Fixation ICD Lead Performance
Background: Currents of injury (COI) have been associated with improved lead performance during perioperative measurements in pacemaker and ICD implants. Their relevance on long term lead stability remains unclear.Methods: Unipolar signals were recorded immediately after active fixation ICD lead positioning, blinded to the implanting surgeon. Signals were assigned to prespecified COI types by two independent investigators. Sensing, pacing as well as changes requiring surgical intervention were prospectively investigated for 3 months.Results: 105 consecutive ICD lead implants were studied. All could be assigned to a particular COI with 48 type 1, 43 type 2 and 14 type 3 signals. Pacing impedance at implant was 703.8±151.6 Ohm with a significant COI independent drop within the first week. Sensing was 10.6mV± 3.7mV and pacing threshold at implant was 0.8±0.3mV at 0.5ms at implant. There was no significant difference between COI groups at implant and during a 3 months follow up regarding sensing, pacing nor surgical revisions.Conclusions: Three distinct patterns of unipolar endocardial potentials were observed in active fixation ICD lead implant, but COI morphology did not predict lead performance after 3 months
Intraoperative Changes in Cerebrospinal Fluid Gas Tensions Reflect Paraplegia During Thoracoabdominal Aortic Surgery
Background:
In this study, gas tensions in cerebrospinal fluid (CSF) were prospectively evaluated as intraoperative markers for the detection of neurological deficits.
Methods:
Spinal fluid, serum, and heart lung machine (HLM) perfusate were monitored for gas tensions (po2/pCo2) and related parameters (pH, lactate, and glucose) during thoracoabdominal aortic repair and correlated with perioperative neurological examination and electrophysiological testing.
Results:
Forty-seven patients were assessed for the study, and 40 consecutive patients were finally included. The patients were divided into 3 groups: group A (23 patients, 57.5%): no clinical or laboratory signs of neurological damage; group B (14 patients, 35%) who developed subclinical deficits; and group C (3 patients, 7.5%) who had paraplegia. Significant intraoperative changes in CSF gas tensions were observed with postoperative paraplegia. Glucose ratio between serum and CSF showed higher variability in group C, confirming a damage of the blood–brain barrier (BBB).
Conclusion:
Major neurological damage is reflected by early changes in CSF gas tensions and glucose variability, suggesting damage of the BBB in these patients
On the experimental search for neutron -- mirror neutron oscillations
Fast neutron-mirror neutron (n-n') oscillations were proposed recently as the
explanation of the GZK puzzle. We discuss possible laboratory experiments to
search for such oscillaions and to improve the present very weak constraints on
the value of the n-n' oscillation probability.Comment: 11 pages, 0 figures, 1 tabl
Immediate surgical coronary revascularisation in patients presenting with acute myocardial infarction
Background: The number of patients presenting with acute myocardial infarction (AMI) and being untreatable by interventional cardiologists increased during the last years. Previous experience in emergency coronary artery bypass grafting (CABG) in these patients spurred us towards a more liberal acceptance for surgery. Following a prospective protocol, patients were operated on and further analysed. Methods: Within a two year interval, 127 patients (38 female, age 68 +/- 12 years, EuroScore (ES) II 6.7 +/- 7.2\%) presenting with AMI (86 non-ST-elevated myocardial infarction (NSTEMI), 41 STEMI) were immediately accepted for emergency CABG and operated on within six hours after cardiac catheterisation (77\% three-vessel-disease, 47\% left main stem stenosis, 11\% cardiogenic shock, 21\% preoperative intraaortic balloon pump (IABP), left ventricular ejection fraction 48 +/- 15\%). Results: 30-day-mortality was 6\% (8 patients, 2 NSTEMI (2\%) 6 STEMI (15\%), p=0.014). Complete revascularisation could be achieved in 80\% of the patients using 2 +/- 1 grafts and 3 +/- 1 distal anastomoses. In total, 66\% were supported by IABP, extracorporal life support (ECLS) systems were implanted in two patients. Logistic regression analysis revealed the ES II as an independent risk factor for mortality (p<0.001, HR 1.216, 95\%-CI-Intervall 1.082-1.366). Conclusions: Quo ad vitam, results of emergency CABG for patients presenting with NSTEMI can be compared with those of elective revascularisation. Complete revascularisation obviously offers a clear benefit for the patients. Mortality in patients presenting with STEMI and cardiogenic shock is substantially high. For these patients, other concepts regarding timing of surgical revascularisation and bridging until surgery need to be taken into consideration
Total aortic arch replacement with a novel four-branched frozen elephant trunk graft: first-in-man results â€
Abstract OBJECTIVES: The combined disease of the aortic arch and the proximal descending aorta remains a surgical challenge. With the 'frozen elephant technique', the ascending aorta, along with the aortic arch, is replaced conventionally and an endovascular stent graft is placed into the descending aorta in the antegrade manner through the open aortic arch, thereby potentially allowing for a 'singlestage' operation. The purpose of this study was to assess the feasibility of a novel four-branched hybrid graft (Vascutek, Scotland). METHODS: From April 2010 to August 2011, 34 patients (25 males, age 60 ± 14 years) were operated on [14 aneurysms, 20 dissections (18 acute)]. Ten of these patients had undergone previous cardiac operations. The collapsed endoprosthesis was deployed in the descending aorta through the opened aortic arch. A sewing collar between the graft segments simplified the 'distal' anastomosis. The fourbranched graft segment allowed the replacement of the aortic arch and supra-aortic vessels individually. Concomitant procedures were performed if necessary. RESULTS: There were three deaths within the 30 postoperative days. All of them were of AADA patients. The mean cardiopulmonary bypass time was 254 ± 53 min, aortic cross clamp time was 148 ± 48 min and circulatory arrest time was 48 ± 22 min. Aortic valvesparing root surgery was performed in 12 patients, Bentall procedure in four, CABG in three and mitral valve repair in two. In one patient, a secondary endovascular extension of the stent graft was necessary to reach the landing zone. In all others, postoperative CT-Scans confirmed the desired results. CONCLUSIONS: The graft adds to the 'frozen elephant trunk' concept for treating the arch and proximal descending aorta. Early experience demonstrates an excellent 30-day survival. Combining the frozen elephant with a four-branched arch graft increases the armament of the surgeon in the treatment of complex and diverse aortic arch pathology
Early use of methylene blue in vasoplegic syndrome: a 10-year propensity score-matched cohort study
Background: Vasoplegic syndrome is associated with increased morbidity and mortality in patients undergoing cardiac surgery. This retrospective, single-center study aimed to evaluate the effect of early use of methylene blue (MB) on hemodynamics after an intraoperative diagnosis of vasoplegic syndrome (VS). Methods: Over a 10-year period, all patients diagnosed with intraoperative VS (hypotension despite treatment with norepinephrine ≥0.3 μg/kg/min and vasopressin ≥1 IE/h) while undergoing heart surgery and cardiopulmonary bypass were identified, and their data were examined. The intervention group received MB (2 mg/kg intravenous) within 15 min after the diagnosis of vasoplegia, while the control group received standard therapy. The two groups were matched using propensity scores. Results: Of the 1022 patients identified with VS, 221 received MB intraoperatively, and among them, 60 patients received MB within 15 min after the diagnosis of VS. After early MB application, mean arterial pressure was significantly higher, and vasopressor support was significantly lower within the first hour (p = 0.015) after the diagnosis of vasoplegia, resulting in a lower cumulative amount of norepinephrine (p = 0.018) and vasopressin (p = 0.003). The intraoperative need of fresh frozen plasma in the intervention group was lower compared to the control group (p = 0.015). Additionally, the intervention group had higher creatinine values in the first three postoperative days (p = 0.036) without changes in dialysis incidence. The 90-day survival did not differ significantly (p = 0.270). Conclusion: Our results indicate the additive effects of MB use during VS compared to standard vasopressor therapy only. Early MB administration for VS may significantly improve the patients’ hemodynamics with minor side effects
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