The effect of pindolol on experimental myocardial infarction was studied in a pig model. Intravenous application of 0.05 mg pindolol per kg body weight was initiated one hour after coronary ligation and repeated at 12-hour intervals for five days. No significant difference in infarct size could be found between pindolol-treated animals (20.4 +/- 0.6% SEM of whole ventricular mass, n = 6) and untreated controls (20.5 +/- 1.2% SEM, n = 9). Hemodynamic data did not change significantly throughout the experiment. These results differ in part from those reported by other investigators: The disagreement may be due to the specific pharmacological properties of the applied drug, to variations in the dosages of beta blockers, as well as to differences in the study design.

Animals↗

PubMed1986

[Risk of reoperations and acute interventions in valvular surgery].

Reoperations in valvular surgery can be subdivided into procedures following reconstructive measures (group A) and interventions following implantation of a valve prosthesis (group B). In group A (valve replacement after conservative mitral surgery, 41 cases from 1976 to 1984 in our institution), operative mortality does not significantly differ from patients undergoing primary isolated mitral valve replacement (7.3% v. 4.4%). In group B, however, the risk of prosthetic valve reoperation mainly depends on the morphological alterations implying the surgical intervention. Among these conditions, prosthetic valve endocarditis has the poorest prognosis (operative mortality 25% in our own experience), especially if an emergency intervention is mandatory as a result of severe heart failure. In contrast to this high risk group, patients being reoperated on an elective basis due to paraprosthetic leakage or recurrent arterial embolism, do not show a higher risk when compared to first procedures. The risk of emergency surgery on native heart valves is discussed under the consideration of patients suffering from acute infective endocarditis (AIE). As in reoperations, the preoperative cardiac functional status and the urgency of the surgical intervention are the principal determinants for the operative risk. Both for reoperations and emergency procedures surgical timing is of great importance in the management of valvular patients; when ever possible, surgery should be carried out before the development of advanced ventricular failure necessitates an intervention under emergency conditions.

Aortic Valve↗

PubMed1985

[Radiologic follow-up of the replacement of the ascending aorta with a composite graft. Comparison of angiography and computed tomography].

Only a few long-term results after replacement of the ascending aorta with a composite graft are available. Twelve patients were therefore evaluated clinically, by computer tomography (CT) and angiography 8-102 months postoperatively. 7 patients had a type I dissecting aneurysm, 1 patient a type II and 4 patients a true aneurysm. Clinically there were no signs of valvular dysfunction or symptoms of lower limb ischemia. All patients were in functional class I or II. On CT all patients with a type I aneurysm showed a chronic dissection with a perfused false lumen extending into the descending aorta. Opacification of the coronary ostia was possible in 4 patients. In 1 patient a false aneurysm at the distal suture line was visualized. Angiography confirmed all CT findings. Coronary angiography demonstrated widely patent coronary ostia. No false aneurysm around the implants was found. Thus, functional results after composite graft operation are good despite the persistence of massive chronic dissection in all patients with a type I aneurysm. CT is an ideal method of evaluating the extent of this dissection. Angiography is necessary to visualize the anatomy of the aortic root and of the coronary ostia.

Adult↗

PubMed1984

[Thoracic aortic aneurysms].

The various pathological types of aneurysm are reviewed and their natural history discussed in relation to morphology, etiology and site of the aneurysm. For diagnostic purposes, computed tomography is a reliable method in the detection of aortic aneurysm; for evaluation of the ascending segment, ultrasonography may also be considered a useful procedure. The two non-invasive methods are particularly valuable in monitoring patients with thoracic aneurysms not (yet) suitable for surgery. In the light of the literature and our own experience, practical guidelines for adequate treatment of non-dissecting aneurysms of the thoracic aorta are elaborated with respect to aneurysm site. In patients with anulo-aortic ectasia, surgical treatment is clearly indicated in the presence of typical Marfan syndrome and in cases showing a demonstrable increase of aneurysm dilatation and/or of aortic regurgitation (hospital mortality 5% in our experience); irrespective of these criteria, surgery should be considered if the echocardiographic root diameter is greater than 6 cm. Replacement of the aortic arch carries a high surgical risk and is suggested for patients suffering from symptoms such as pain or compression of adjacent tissues; in asymptomatic patients, arch resection is scarcely advisable unless the aneurysm is of luetic origin. For aneurysms of the descending aorta, the operative indication will also be related to clinical symptoms as well as to aneurysm expansion and growth; in asymptomatic subjects, surgery is recommended in the presence of a circumscribed posttraumatic false aneurysm, the operative risk being very low in this patient group. In cases with suspected aortic dissection, computed tomography is considered to be the primary diagnostic procedure. Angiography may be mandatory only for those few presurgical candidates who require accurate assessment of aortic valvular regurgitation and determination of peripheral organ perfusion. The extremely unfavourable natural history of acute aortic dissection (50% survival after 48 hours following onset of symptoms) clearly calls for immediate operative treatment in high-risk patients, that is in subjects with acute ascending aortic dissection (hospital mortality 28% in our series). The better prognosis of descending aortic dissection suggests that in these cases conservative hypotensive therapy is the treatment of choice; surgical intervention in type B acute dissection is indicated only if occlusion of a major aortic branch occurs or if impending rupture of the dissecting hematoma becomes evident.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗

PubMed1984

Early phlebographic results after iliofemoral venous thrombectomy.

The results of conventional venous thrombectomy performed in 37 patients with acute iliofemoral thrombosis were evaluated with special reference to early postoperative phlebography. In all patients thrombosis was verified preoperatively by angiography. No mortality was encountered, but the leg of one patient with phlegmasia coerulea dolens and advanced venous gangrene had to be amputated at the above-knee level. Four patients had pulmonary embolism in relation to surgery. Based upon postoperative phlebography, complete clearance of all obstructed segments was achieved in 5 patients only (13.5%), and subtotal or partial restoration resulted in 9 patients (24%). In 16 cases (43%) postoperative phlebograms appeared equivalent to the preoperative study, and in 7 cases (20%) additional vein segments were occluded. Despite the relatively high incidence of recurrent thrombosis, prompt relief of symptoms occurred in the great majority of patients. The more favorable angiographic results were obtained in the ilio-femoral segment; in contrast, new occlusions were predominantly found in the popliteal-crural segments. Restoration of a venous passage was not correlated with the duration of symptoms; in most instances, the removed clots appeared organized and adherent to the vein intima, even in patients with a short clinical history. With regard to probable etiological factors, somewhat better results were achieved for patients exposed to previous surgery or trauma and for patients with severe medical illness. In our view indications for venous thrombectomy should be rather restrictive; successful clearance and long-term patency can be expected mainly in patients with clots lying in the ilio-femoral segment surrounded by contrast medium in the distal portion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1983

[Surgical treatment of coronary circulation disorders].

The objectives of aorto-coronary bypass surgery are threefold: relief of angina pectoris, increase in exercise performance and prolongation of life. The effect of surgery on ischemic pain and exercise tolerance is widely accepted, but the influence of bypass grafting on life expectancy is still controversial. Recent results of prospective randomized trials, however, have shown significantly better survival for surgically treated patients with specific anatomic characteristics such as left main disease and three-vessel disease. Among the operative risks, hospital mortality (1% in our experience) and incidence of perioperative myocardial infarction (around 5%, usually asymptomatic clinical course) have decreased with growing surgical practice and application of cold cardioplegia. Postoperative angiographic studies reveal 85% to 90% graft patency rate at one year; later the mean annual occlusion rate is reported to be less than 3%. The aorto-coronary bypass operation is indicated mainly for the following two groups of patients: 1. those in whom angina or drug therapy results in a restriction of working capacity or an undesirable change in lifestyle despite appropriate medical treatment; 2. the two subsets of patients being exposed to a particularly high risk of myocardial infarction or sudden death: patients with left main disease and patients with three-vessel disease. The benefits of coronary bypass surgery depend on several conditions: major determinants are completeness of revascularization, suitability of distal coronary segments for bypass grafting, and degree of ventricular impairment.

Angina Pectoris↗

PubMed1983

Factors determining the patency of femoropopliteal bypass grafts: an analysis of 350 procedures.

In an attempt to define preoperatively assessed factors that might provide prognostic indications of early graft failure, a series of 350 consecutive femoropopliteal bypass operations have been analyzed with regard to various parameters. Data regarding sex, presence of diabetes and coronary heart disease, severity of symptoms, angiographic assessment of outflow vessels, hemodynamic investigations (ankle systolic pressure index and pulse volume recording), graft material and the site of the distal anastomosis were entered into a computer to study the influence of these factors alone and in combination on early patency rates. Among these factors only the ankle systolic pressure index (ASPI) and pulse volume recording (PVR) significantly affected patency and turned out to be of predictive value in graft prognosis. In particular, when these parameters were severely depressed (ASPI less than 0.40 and PVR less than 2) they became a valuable indicator of early graft thrombosis. By combining different variables we were not able to identify a specific pattern of characteristics for the patient whose graft would probably be doomed to occlusion. Considering the scarcity of accurate prognostic indicators in screening subjects from unsuccessful femoropopliteal reconstruction, we believe that a patient should not be a priori excluded from being considered for surgery if his hemodynamic features (ASPI and PVR) are not greatly reduced.

Adult↗

PubMed1983

Postoperative evaluation of composite aortic grafts: comparison of angiography and CT.

Postoperative angiography and computerised tomography were performed in 10 patients 8 to 57 months after surgical repair (nine composite, one distal graft) of aneurysms of the thoracic aorta (six dissecting, four true aneurysms). Angiography and angio-CT showed chronic dissection of the distal aorta in five of six patients with dissecting aneurysms and detected a pseudoaneurysm originating from the distal suture line in another patient. CT may serve as an initial procedure for postoperative examinations after surgery of aortic aneurysms to demonstrate the state of the false lumen and the formation of pseudoaneurysms. The coronary arteries and aortic valve function have to be evaluated by angiography.

Adult↗

PubMed1983

[Transgenicular amputation: an alternative to thigh amputation?].

Since 1976 we attempted to avoid an above-knee (AK) amputation in favor of a knee disarticulation. From 1976 to 1979 83 patients with an average age of 72 years could be amputated through the knee and 55 patients with average age of 73 years had to be submitted to an AK-amputation. As compared to the AK-amputation the transgenicular (TG) resection has the following advantages: 1) Lower postoperative mortality (TG 10%, AK 33%). --2) Higher prosthetic fitting rate (TG 77%, AK 61%). --3) Significantly improved rehabilitation of the patient (walking with artificial limb: TG 67%, AK 20%). --The results of a TG-amputation may be impaired by disturbances of wound healing with subsequent necrosis and/or infection. Among our patients every forth amputation stump following TG-resection had to be reamputated at above-knee level.

Aged↗

PubMed1982

Management of profound accidental hypothermia with cardiorespiratory arrest.

Complete recovery following rapid rewarming is described in three tourists who were admitted in a state of profound hypothermia with total cardiorespiratory arrest (rectal temperature ranging from 19 to 24 C). In all three patients, respiration and circulation had ceased during the rescue operation. Rapid core rewarming was achieved by thoracotomy and continuous irrigation of the pericardial cavity with warm fluids in one patient, whereas in the other two patients rewarming was accomplished with extracorporeal circulation using femoro-femoral bypass. In the first patient, the heart could not be defibrillated earlier than 90 minutes following thoracotomy; in the other patients rewarming was attained very rapidly, and within half an hour after institution of bypass, resuscitation of the heart was successful. The patients fully recovered their intellectual and physical abilities, despite the prolonged periods of circulatory arrest lasting from 2 1/2 to 4 hours. We conclude that rapid core rewarming is the adequate therapy for profound accidental hypothermia with circulatory arrest or low cardiac output. If feasible extracorporeal circulation represents the method of choice because it combines the advantage of immediate central rewarming with the benefit of efficient circulatory support, the heart is rewarmed before the shell, thus preventing the "rewarming shock" due to peripheral vasodilatation. Resuscitative efforts should be promptly initiated and vigorously pursued, even in the state of clinical death; in profound hypothermia neurologic examination is inconclusive regarding prognosis.

Accidents↗

PubMed1981

[Surgical indications of deep venous thrombosis and pulmonary embolism (author's transl)].

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Humans↗

PubMed1981

Preliminary experience with expanded polytetrafluoroethylene grafts inserted for chronic occlusive disease of the femoro-popliteal artery segment.

In a prospective study the early clinical experience at our clinic with expanded polytetrafluoroethylene grafts was evaluated with special respect to the preoperative angiographic assessment, ankle arm systolic pressure index and pulse volume recording. A total of 94 PTFE grafts were inserted consecutively to by-pass a femoro-popliteal artery segment occluded by chronic occlusive disease. Polytetrafluoroethylene (PTFE) was used when no suitable autogenous vein was available. Seventy-one grafts were inserted for limb salvage (stage III or IV). Within the follow-up period of 6 months for all patients patency rate amounted to 68%. Best results were obtained in patients with a high ASPI and a good peripheral run-off, and in patients with the distal anastomosis placed above knee.

Aged↗

PubMed1980

Monooxygenase, epoxide hydrolase, and glutathione-S-transferase activities in human lung. Variation between groups of bronchogenic carcinoma and non-cancer patients and interindividual differences.

Activities of microsomal monooxygenases (MO) and epoxide hydrolase (EH) and cytoplasmic glutathione-S-transferases (GST) will contribute to controlling the pool of reactive intermediates, enzymatically derived from polynuclear aromatic hydrocarbons (PAH) within the cells of target organs such as the human lung. Therefore, we studied what interindividual differences exist in these enzyme activities and whether there is a correlation between the activities of these epoxide forming and metabolizing enzymes in preparations from peripheral lung samples and the occurrence of bronchogenic carcinomas in smokers and non-smokers. 57 samples obtained from surgery were studied. Among them were 12 samples from non-smoking patients without cancer as a control group. It is not known whether this control group behaves, with respect to the investigated parameters, identically to fully healthy people, since in all cases indications existed which justified the removal of lung biopsies. Using very sensitive standard assays with benzo[a]pyrene, biphenyl, 7-ethoxyresorufin and 7-ethoxycoumarin as substrates, MO activity could only be determined as O-deethylation of 7-ethoxycoumarin and only after modification of the assay method. Evidence was obtained for the presence of a diffusible, but not dialysible, MO inhibitor in human lung microsomes. The MO activity (substrate: 7-ethoxycoumarin) in this fraction was extremely low in human (100-fold lower than in rat lung preparations), whereas EH (substrate: benzo[a]pyrene 4,5-oxide) was slightly (about 2-fold) higher in human and GST (substrate: 2,4-dinitrochlorobenzene) had similar activities in both species. Interindividual variations of enzyme activities in human lung were considerable: MO, 40-fold: EH, 5-fold; GST 10-fold. Compared to the control group (non-smokers without cancer) MO activities were slightly but significantly higher in lungs from bronchogenic carcinoma patients whether they were smokers (170% of controls, p < 0.0005) or non-smokers (320% of controls p < 0.025). MO activities of smokers without cancer were only very slightly elevated (140%) of controls, p < 0.05). Specific EH activities compared to the control group were slightly but significantly increased in smokers without cancer (160% of controls, p < 0.0125) and in bronchogenic carcinoma patients whether they used tobacco products (130% of controls, p < 0.005) or not (140% of controls, p < 0.05). Specific GST activities showed no significant differences (p > 0.1) between the various groups studied. The substrate specificity of human lung EH, which was studied using five K-region epoxides of various PAH as substrates, corresponded to that in human and rat liver and in human, mouse and rat skin and to the pure enzyme isolated from rat liver. In contrast to rat liver hepatoma preparations, where EH had been shown to be increased in the tumor tissue and had been identified as a preneoplastic antigen, EH activity in lung microsomal preparations from samples of peripheral squamous cell carcinomas of two subjects had in the tumor tissue only one third of the activity of non-diseased areas of the same lung.

7-Alkoxycoumarin O-Dealkylase↗

PubMed1979

[The role of surgery in the treatment and prevention of pulmonary embolism (author's transl)].

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Adult↗