[Angioscopy: a new intraoperative diagnostic and interventional tool for thoracic aortic treatment]. / Angioskopie: Neues intraoperatives diagnostisches und interventionelles Verfahren für die Therapie der thorakalen Aortenerkrankung.

In complex thoracic aortic disease endovascular techniques and the use of hybrid stent grafts enables a combination therapy of the aortic arch and the descending aorta through a median sternotomy. This emphasizes the importance of intraoperative visualization of the descending aorta and its pathologies. Intraoperative angioscopy is a new diagnostic method for the assessment of distal aortic disease and assists in therapeutic decision-making and navigation of endovascular techniques in the descending aorta. This study presents the angioscopic results of 62 patients (mean age 60±12 years, 73% male, 54 aortic dissections, eight aortic aneurysms) during surgery of the thoracic aorta. Visualization of the extent of pathology along the downstream aorta was feasible in all patients. The implantation of a hybrid stent graft prosthesis was assisted by angioscopy in 34 patients and endovascular balloon dilatation of the stent graft was navigated by angioscopy in 11 patients. Angioscopy has become an indispensable tool in the intraoperative treatment of complex thoracic aortic disease in our clinic, particularly in the navigation of endovascular interventions in the distal thoracic aorta through the aortic arch.

[Perioperative antocoagulation in patients with prosthetic heart valves: recommendations]. / Perioperatives Gerinnungsmanagement bei Patienten mit Kunstklappen : Empfehlungen.

Lifelong anticoagulation, mainly with oral Vitamin K antagonists, represents the treatment of choice in patients with prosthetic heart valves to prevent thrombembolic complications. As a result, anticoagulant-related complications like excessive bleeding during interventions or surgical procedures will occur. Therefore, timely stopping of vitamin K antagonists prior to elective surgery is mandatory. However, based on the long half-life of all common vitamin K antagonists, interruption of oral anticoagulation will definitively lead to an increase of thrombembolic events. Hence, adequate bridging anticoagulation by temporary substitution of this therapy with heparin is necessary. This article gives a recommendation on the basis of the American College of Chest Physician and European Society of Cardiology current.

The last deglaciation of the southeastern sector of the Scandinavian ice sheet.

The Scandinavian Ice Sheet (SIS) was an important component of the global ice sheet system during the last glaciation, but the timing of its growth to or retreat from its maximum extent remains poorly known. We used 115 cosmogenic beryllium-10 ages and 70 radiocarbon ages to constrain the timing of three substantial ice-margin fluctuations of the SIS between 25,000 and 12,000 years before the present. The age of initial deglaciation indicates that the SIS may have contributed to an abrupt rise in global sea level. Subsequent ice-margin fluctuations identify opposite mass-balance responses to North Atlantic climate change, indicating differing ice-sheet sensitivities to mean climate state.

Heart transplantation and consecutive mitral valve replacement.

A 48-year-old man was diagnosed with progressive mitral insufficiency due to fibrosis of papillary muscles and chordae tendineae, necessitating mitral valve replacement (MVR) 8 months after cardiac transplantation. Donor echocardiography and inspection of the heart at procurement were inconspicuous. The patient is alive, free from valve-related complications and functionally improved six years after MVR. The limited yet successful experiences with left-sided valve repair or replacement in the transplanted heart are reviewed.

Effects of defibrillator implantation testing on myocardial metabolism.

BACKGROUND: The effects of fibrillation/defibrillation episodes (FDEs) during defibrillator implantation on myocardial metabolism were investigated at various defibrillation energies in patients with different cardiac pathologies. METHODS: Myocardial lactate extraction (MLE) was examined during defibrillation threshold (DFT) testing in patients with either coronary artery disease (CAD, n = 20) or non-ischemic cardiomyopathy (CM, n = 10). Defibrillation pulses were released 15 seconds after induced fibrillation. A test cycle of four FDEs separated by 2-minute intervals was applied in each case. RESULTS: Mean MLE decreased significantly from 28 +/- 4% before FDEs to 8 +/- 5% immediately after all episodes in CAD patients, but recovered to 27 +/- 7% within 2 minutes even in patients with reduced left-ventricular function. In patients with CM mean MLE decreased markedly from 29 +/- 3% to -11 +/- 3% immediately after each FDE but increased to baseline (33 +/- 8%) within the recovery period. MLE changes were independent of defibrillation energy in all cases. CONCLUSIONS: Myocardial lactate production, suggesting cardiac ischemia, was observed in patients with CM, but not in patients with CAD. But recovery of myocardial lactate extraction was not faster in CAD patients, indicating that the fixed FDE cycle used was well tolerated by all patients.

Myocardial lactate extraction during repeated fibrillation/defibrillation episodes in defibrillator implantation testing.

Intraoperative testing with several fibrillation/defibrillation episodes (FDEs) is routinely performed during defibrillator implantation. Testing is considered safe even in patients with severe cardiac impairment, provided the recovery timespans and number of FDEs are adapted to the individual patient. Myocardial lactate extraction (MLE) was examined in two testing protocols. In 30 patients with coronary artery disease defibrillator implantations were performed under intravenous anesthesia. A percutaneous catheter was positioned into the coronary sinus (CS) underfluoroscopy. Two groups were randomly formed: group A (n = 20, mean number of FDEs: 4.2/patient) with 2 minutes waiting time between FDEs, and group B (n = 10, mean number of FDEs 4.1/patients) with 10 minutes between FDEs. Defibrillation pulses were released 15 seconds after T wave shock induced fibrillation. To estimate MLE, arterial and CS blood samples were collected before and after each FDE. After the last FDE, samples were obtained after 5, 10, and up to 20 minutes. In group A, MLE fell from a baseline value of 29.6% +/- 3.6% before the FDEs to 7.8% +/- 5.4% immediately after the episodes. MLE recovered to 27.2% +/- 6.5% within 1 minute and overshot to 35.6% +/- 5.8% within 5 minutes. In group B, MLE decreased from 37.6% +/- 7.5% to 15.1% +/- 8.1% immediately after each FDE and rose to its original value (33.6 +/- 7.8) within the 5-minute recovery period. MLE decreased immediately after each FDE, and recovered within 1 minute even in poor left ventricular function. For full MLE recovery a 2-minute wait between episodes is sufficient, if the total number of FDEs does not exceed four.

Intravascular ultrasound (IVUS) examination reverses therapeutic decision from percutaneous intervention to a surgical approach in patients with alterations of the left main stem.

Intravascular ultrasound (IVUS) represents a new method to assess vessel lumen and wall morphology. To prospectively evaluate the usefulness of IVUS for further therapeutic decisions in left main stem (LM) lesions with unclear angiographic definition, this study was launched. We studied 56 patients with significant stenosis of the LAD and/or LCX arteries and questionable LM morphology. 30-MHz IVUS catheters with 2.9 or 3.2 F outer diameters were used. A significant luminal reduction of the left main stem was defined as an area stenosis greater than 50% or a minimal luminal diameter smaller than 3 mm as determined by IVUS. 36 of 56 patients (61%) fulfilled these criteria. Additionally, 12 patients showed a ruptured plaque within the LM. 30 of these 36 patients were originally thought to be candidates for angioplasty. After positive IVUS 34 of these 36 patients were sent to surgery. No perioperative ischemic complications occurred. In angiographically unclear left main stem findings. IVUS establishes a definitive diagnosis. After IVUS confirmation of significant left main stem pathology operative management should be the preferred approach as compared to transluminal coronary interventions. However, prospective randomized studies are needed to define the most efficient approach.

Single-lung transplantation in a patient with cystic fibrosis and an asymmetric thorax.

We report metachronous single-lung transplantation for cystic fibrosis after contralateral pneumonectomy. Kyphoscoliosis and mediastinal shift required careful donor-lung sizing with computed tomography and was not dependent on typical parameters. Severe reperfusion injury was treated with nitric oxide, C1-esterase inhibitor, and continuous venovenous hemodialysis. The patient was extubated on the fifth postoperative day and is alive and well. We conclude that single-lung transplantation after contralateral pneumonectomy for patients with cystic fibrosis and an asymmetric chest and evident lung volume mismatch may be an acceptable functional therapeutic option.

One-year experience with the Edwards stentless "Prima" aortic bioprosthesis.

The aortic stentless bioprothesis are expected to have an improved hemodynamic function because of their lack of a sewing ring and stents. From April 1993 to March 1994 we implanted aortic Edwards "Prima" stentless bioprotheses in 21 patients suffering from aortic valve disease. In some patients additional cardiac procedures (CABG, MVR, tricuspid valve anuloplasty) were performed. The patients' age ranged from 56 to 78 years. The size of the bioprothesis ranged from 23 mm to 29 mm in diameter. We used either the subcoronary or the "mini-root" continuous suture technique. Aortic cross-clamp time ranged from 52 min to 128 min. There was no operative mortality. The intraoperative measurements showed that the pressure gradient across the aortic valve was very low or even undetectable. The echocardiographic control after 1 year revealed very good valve function. Our initial experience with this new valve shows a very good short-term result with an only slightly longer cross-clamp time. Since the valve has not been available for a long line, long-term results could not yet be observed.

Autologous bone transplant after sternal resection.

Two patients underwent subtotal sternal resection for tumors of the sternum. Anatomical and functional reconstruction was performed with bone fragments harvested from the internal lamina of both iliac wings. There were no infections and no instabilities. Late postoperative follow-up included CT-scan of the thorax and pulmonary function testing, which was not compromised. We conclude that this surgical approach is very efficient in regard to function and chest wall stability.

Age-dependent changes in the beta-adrenoceptor-G-protein(s)-adenylyl cyclase system in human right atrium.

With increasing age, cardiac beta-adrenoceptor function decreases. To study possible mechanisms underlying this process, we assessed in right atrial appendages from 52 patients of different ages (group A, < 20 years, mean age 3.7 +/- 1.0 years, n = 20; group B, 20-50 years, mean age, 37.9 +/- 2.3 years, n = 9; group C, > 50 years, mean age 66.1 +/- 1.5 years, n = 23) without apparent heart failure who were undergoing open heart surgery beta-adrenoceptor number and subtype distribution (by (-)-[125I]-iodocyanopindolol [ICYP] binding), adenylyl cyclase activity, and Gs- and Gi-protein alpha-subunits (by quantitative Western blotting). beta-Adrenoceptor number in the three groups was not significantly different; in contrast, basal, 10 microM GTP-, 100 microM isoprenaline (ISO), 10 mM NaF-, 100 microM forskolin-, and 10 mM Mn(2+)-stimulated adenylyl cyclase activity was significantly higher in group A than in group B and was further decreased in group C. Similarly, 100 microM terbutaline-, 100 microM histamine-, and 100 microM 5-HT-stimulated adenylyl cyclase activity significantly decreased from group A to group C. Moreover, all these adenylyl cyclase parameters were significantly negatively correlated with the age of the patients. Although Gs alpha was not altered, Gi alpha in group C was significantly higher than in group A; moreover, there was a weak but significant positive correlation between Gi alpha and the age of the patients. We conclude that an impairment of the activity of the catalytic unit of adenylyl cyclase is involved in the decrease in cardiac beta-adrenoceptor function with age; an increase in Gi alpha might contribute further to the reduced beta-adrenoceptor function.

Results of mitral valve reconstruction in mitral valve insufficiency.

In the last three years forty mitral valve reconstruction (MR) procedures were performed in case of mitral insufficiency (MI). In three cases, anatomical changes made reconstruction impossible for us. One patient had to be re-operated because of unsatisfactory valve function. There was no operative mortality. In twelve of the patients, mitral insufficiency was the only problem, while in twenty eight others additional cardiac procedures (CABG, AVR) were performed. The patients' age ranged from 17 to 77 years. The aortic cross-clamping time for mitral reconstruction without additional cardiac procedures ranged from 35 to 134 minutes. With one exception, the post-operative TEE indicated no, or very little, insufficiency. We concluded that the mitral valve insufficiency can be corrected with very good results and with a very low rate of complications. Such corrections ought therefore be taken into consideration before valve replacement.