Outcome of thoracoabdominal aortic operations using deep hypothermia and distal exsanguination.

BACKGROUND: Operation of the descending and thoracoabdominal aorta may be affected by a significant perioperative morbidity, mainly because of ischemic damage of the spinal cord and malperfusion of the abdominal organs. METHODS: A comparative analysis was performed on two consecutive series of patients operated between 1982 and 1998. Group 1 consisted of 90 patients operated with moderate hypothermic left heart bypass. Group 2 included 38 patients operated using deep hypothermic cardiopulmonary bypass and a period of circulatory arrest while performing the proximal anastomosis and distal exsanguination during confection of the distal anastomosis. RESULTS: Main demographic factors and causes of the aortic disease were similar in both groups. Early mortality was significantly higher in the group of patients with aortic cross-clamping (15 of 90, 16%) than in those operated with circulatory arrest (2 of 38, 5.2%), p < 0.001. Paraplegia occurred in 8 patients in the group operated with mild hypothermia (8.8%) but in only 1 patient (2.6%) when deep hypothermia had been used. CONCLUSIONS: In our experience, deep hypothermia combined with distal exsanguination significantly improved the early postoperative outcome after operation of the descending and thoracoabdominal aorta. This technique allowed easy confection of proximal and distal anastomoses, and the duration of the operation was not prolonged significantly through this approach.

Early and late outcome of operated and non-operated acute dissection of the descending aorta.

OBJECTIVE: At present debate continues concerning the optimal mode of treatment for type B dissections. Controversies are mainly due to discordant results regarding survival following medical or surgical treatment. We assessed early and long-term outcome of acute dissection of the descending aorta treated by emergency aortic replacement, medical treatment or delayed surgery. METHODS: Between 1980 and 1995, 225 patients were hospitalized in the medical or surgical department of our institution with the diagnosis of acute type B aortic dissection. A total of 38 patients (16.8%) underwent replacement of the descending aorta within the first week after hospital admission. Primary indications for immediate surgery were: rupturing aneurysm (n = 15), diameter of the descending aorta (n = 13), malperfusion of the thoracoabdominal aorta (n = 8) and pseudocoarctation syndrome with uncontrollable hypertension (n = 2). All other patients (n = 187) underwent primary conservative treatment on the intensive care unit, including appropriate anti-hypertensive medication. In 12 of them, surgery was denied because of age or significant concomitant diseases. RESULTS: Hospital mortality after urgent or emergency surgery was 21% (8/38 patients) for the overall time period. There has been a significant decrease in hospital mortality during the last 5 year-period (12% versus 30% between 1980 and 1994). Causes of death were: cardiac failure in 3, bleeding complications in 2, postoperative mesenteric ischemia in 2 and septicemia in one patient. From the 30 operative survivors, 9 (30%) patients required further surgery on the native aorta after a mean follow-up of 48 +/- 13 months. Hospital mortality during conservative treatment was 17.6% (33/187 patients). Main causes of death were rupture in 14, thoraco-abdominal malperfusion in 13 and cardiac failure in 3 patients, whereas in 3 patients, the cause of death could not be evaluated. In this group, 9 patients had to be shifted to early surgery during the initial hospitalization because of impending rupture (n = 4), rapidly increasing diameter (n = 2) and suspicion of intestinal ischemia (n = 3). After hospital discharge, surgery for chronic dissection was performed in 47 patients, mainly because of expanding descending aortic aneurysm. Hospital mortality was 8% (4/47 patients). Actuarial survival rates after surgery during the first admission were 85 +/- 6% at 5 years and 61 +/- 8% at 10 years, versus 76 +/- 5 and 50 +/- 7% respectively, following conservative treatment (P < 0.001). CONCLUSION: Nowadays, acute type B dissection can be treated surgically with a reasonable perioperative risk. Despite aggressive anti-hypertensive treatment, hospital mortality of primary conservative treatment is still high and a substantial percentage of patients requires surgery during initial hospitalization. Main causes of death in both groups are rupture and abdominal malperfusion: therefore, closed clinical and radiologic assessment of the whole thoraco-abdominal aorta is of utmost importance. Long-term results are satisfying; unlimited radiographic follow-up allows for detection of potential severe complications and for proper planning of elective reoperations when indicated.

[Acute type B aortic dissection: prognosis after initial conservative treatment and predictive factors for a complicated course]. / Akute Aortendissektion Typ B: Prognose nach initial konservativer Behandlung und prädiktive Faktoren für einen komplizierten Verlauf.

OBJECTIVE: Today there is still debate concerning the optimal mode of treatment for type B dissection of the aorta. Controversies are mainly due to discordant results regarding survival following medical or surgical treatment. We assessed the early and long-term outcome of acute dissection of the descending aorta after initial conservative treatment. METHODS: Between 1980 and 1995, 225 patients were hospitalized in the medical or surgical department of our institution with the diagnosis of acute type B aortic dissection. 38 patients (16.8%) underwent replacement of the descending aorta within the first week after hospital admission. Primary indications for immediate surgery were rupturing aneurysm in 15 patients, extensive dilatation of the descending aorta in 13, distal malperfusion in 8, and pseudocoarctation syndrome with uncontrollable hypertension in 2. All other patients (n = 187) underwent primary conservative treatment in the intensive care unit, which included appropriate antihypertensive medication. RESULTS: Hospital mortality during and after initial conservative treatment was 17.6% (33/187 patients). Main causes of death were rupture in 14 patients, intestinal malperfusion in 13 and cardiac failure in 3, whereas in 3 patients the cause of death could not be determined. Nine additional patients had to be referred for early surgery during the initial hospitalization because of contained rupture (n = 4), rapidly increasing size of the aorta (n = 2) and suspected intestinal ischemia (n = 3). Hospital mortality after early surgery was 21% (8/38 patients) for the overall time period. After hospital discharge from the initial acute dissection, surgery for chronic dissection was performed in 47 patients, mainly because of expanding descending aortic aneurysm. Hospital mortality was 8% in these patients (4/47). Actuarial survival rates after primary conservative therapy were 76 +/- 5% and 50 +/- 7% after 5 and 8 years respectively. CONCLUSION: Currently, surgery for acute type B dissection is limited to patients with rupturing disease, distal malperfusion or uncontrollable hypertension and pains. Despite aggressive antihypertensive treatment, hospital mortality after primary conservative treatment is still high and a substantial proportion of patients requires surgery during initial hospitalization. Although conservative treatment is recommended in most uncomplicated type B aortic dissections, early surgery should be considered in the following situations: younger patients with 5 cm diameter of the aorta at initial evaluation, as well as those with Marfan syndrome, patients with limited false aneurysm or retrograde dissection into the aortic arch, and those with poor medical compliance or uncontrollable proximal hypertension. Radiographic follow-up for an indefinite period may allow detection of potential late complications and proper planning of elective operations when indicated.

[Family forms in East Germany]. / Formy rodziny w NRD.

PIP: The author reviews family characteristics in East Germany. Although the nuclear family remains the norm, increases in second marriages, divorces, and consensual unions are noted. (SUMMARY IN ENG AND RUS)^ieng

Myoglobin in the heart tissue of fishes lacking hemoglobin.

Myoglobin has been identified in the heart tissue of three species of antarctic icefish, Chaenocephalus aceratus, Pseudochaenichthys georgianus and Chaenodraco wilsoni. Quantitative analysis shows myoglobin concentrations that are substantially lower than other teleost fish. A simple and accurate method for the direct measurement of myoglobin in tissue is described.

Direct Respiration of Lipids During Heat Production in the Inflorescence of Philodendron selloum.

Respiration in the heat-generating, sterile florets of Philodendron selloum was examined by electron microscopy and carbon isotopic analysis of respired carbon dioxide. After the spathe unfolded, the florets switched from carbohydrate oxidation to lipid oxidation, which persisted during heating and for at least 2 days thereafter. The scarcity of glyoxysome-like organelles and the low catalase activity in this tissue indicate that the lipid was respired directly and not after conversion to carbohydrate by the glyoxylate shunt. Thus, lipid metabolism in this heat-generating plant tissue appears to mimic aspects of the biochemistry and physiology of heat production in some animal tissues.

The complete amino acid sequence of both subunits of allophycocyanin, a light harvesting protein-pigment complex from the cyanobacterium Mastigocladus laminosus.

The amino acid sequences of the alpha- and beta-subunit of allophycocyanin, a water-soluble light-harvesting protein-pigment complex from the thermophilic cyanobacterium Mastigocladus laminosus have been determined. The alpha-chain consists of 160 amino acid residues and the beta-chain of 161 amino acid residues. The homology of the alpha- and beta-chains is 37%. A comparison with C-phycocyanin reveals that the second chromophore of the C-phycocyanin beta-subunit is attached to an inserted peptide of 10 amino acid residues at position 151-160.

Properties of allophycocyanin II and its alpha- and beta-subunits from the thermophilic blue--green alga Mastigocladus laminosus.

Purified allophycocyanin II and its subunits have been examined with respect to spectroscopic properties, sedimentation, reconstitution and isoelectric behaviour. In 0.02m-potassium phosphate buffer, pH8.0, and at a concentration of 0.25mg/ml, allophycocyanin II and its alpha- and beta-subunits show visible absorption maxima at 650, 615 and 615nm respectively, whereas the fluorescence emission maxima were determined to be at 662, 640 and 630nm respectively. The absorption difference spectrum (dilution difference) of allophycocyanin II displays maxima at 650 and 590nm with a minimum at 610nm. The c.d. spectrum of allophycocyanin II showed only one positive-ellipticity band at 635nm, and a major negative-ellipticity band at 340nm. Oxidation of allophycocyanin II, low- and high-pH solutions (pH3.0 and 11.0), various ethanol concentrations as well as dialysis against distilled water induce a spectral change leading to phycocyanin-like characteristics. In most cases these shifts are reversible. Allophycocyanin II is thermostable over a period of 60min at temperatures up to 60 degrees C. The isoelectric points of allophycocyanin II and its alpha- and beta-subunits are 4.65, 4.64 and 4.82 respectively. Estimated molecular weights from sedimentation-equilibrium analyses were 102500 for allophycocycanin II, 16000 for the alpha- and 31500 for the beta-subunit. Recombination of alpha- and beta-subunits leads to allophycocyanin II, which is indistinguishable from native allophycocyanin with respect to its spectral form, to its gel-filtration and to its electrophoretic behaviour.