Hemodynamic assessment of obstructive aortoiliac disease

Angiographic demonstration of obstructive aortoiliac disease is of paramount importance prior to surgery. Obstructive disease in the femoral popliteal system can only be surgically relieved if inflow is adequate. Severely stenotic lesions may be missed by angiography due to the oblique course of the iliac arteries and inability to obtain right angle views. Translumbar downstream catheterization of the abdominal aorta and puncture of both femoral arteries allows simultaneous pressure recordings. The injection of 30 mg of papaverine into the femoral artery assures maximal vasodilatation mimicking conditions under exercise. A minimal gradient at rest may become obvious following the injection of papaverine, indicating hemodynamically significant disease and warranting surgical correction. The technique has proved to be simple and valuable, and there have been no complications.     

CT angiography versus intraarterial digital subtraction angiography for assessment of aortoiliac occlusive disease

OBJECTIVE: The purpose of this study was to evaluate the accuracy of CT angiography (CTA) with a single helical acquisition for assessment of stenoses and occlusions of the iliac arteries. SUBJECTS AND METHODS: In our prospective study, intraarterial digital subtraction angiography and IV CTA were performed from the suprarenal aorta to below the femoral bifurcation in 30 patients with vascular occlusive disease. Maximum-intensity-projection images in multiple views were also obtained. The accuracy of CTA with and without analysis of axial images was determined. RESULTS: Sensitivity and specificity of CTA were 100% for iliac artery occlusions with a confidence interval 85-100% and 97-100%, respectively. When axial scans were interpreted, 14 of 15 high-grade (> 75%) stenoses were recognized. Sensitivity and specificity of CTA were 93% (range, 68-100%) and 99% (range, 97-100%), respectively. When maximum intensity projections alone were analyzed, sensitivity for the diagnosis of 15 high-grade stenoses was only 53% (range, 27-79%) because calcified plaques obscured six stenoses. CONCLUSIONS: CTA accurately reveals iliac artery occlusions. Observers of CT angiograms may overlook short stenoses in rare instances. Calcified plaques limit the use of maximum-intensity-projection images.     

Long-term results after open and semiclosed thrombendarterectomy for aortoiliac occlusive disease

OBJECTIVES: This study reviews the long-term results of 514 aortoiliac thrombendarterectomies (TEA's). DESIGN: A prospective study in a major university hospital in Switzerland. SUBJECTS: 353 male and 62 female patients with aortoiliac occlusive disease. Operative indications: disabling claudication (n=334), rest pain (n=44), and gangrene (n=37). METHODS: Open and semiclosed TEA's were performed on 167 and 347 limbs, respectively. Follow-up was continuous and complete in 97.1 % of patients over a period of more than 15 years. RESULTS: The overall life-table patency rate at 5, 10, and 15 years postoperatively were 93.4 %, 90.4 %, and 84.2 %, respectively. Fifteen years postoperatively, the patency rate of 92.3 % after open TEA was significantly higher (p<0.04) than after semiclosed TEA (79.5 %). However, similar patency rates of 69.5 % and 69.8 % were observed 20 years postoperatively. Further significant prognostic factors on patency were: anatomic localization (p<0.004), preoperative stage of arterial occlusive disease (p<0.008), and gender (p<0.007). Patient's age did not influence the outcome in terms of patency. Hospital mortality rate was 1.2 %. Early obstruction occurred in 2.2 %, leading to subsequent early amputation of 1.4 % and reoperations in 1.2 %. The long-term actuarial survival rates of the patients were 55 %, 36 %, and 18 % after 10, 15, and 20 years postoperatively. CONCLUSION: Both open and semiclosed TEA give highly satisfactory long term results in aortoiliac occlusive disease with a low morbidity and low mortality.     

Selection of surgical approaches in the treatment of aortoiliac arterial occlusive disease

31 patients with aortoiliac occlusive disease with or without infrainguinal occlusion was treated with thromboendarterectomies, aortoiliac or aortofemoral arterial bypasses, extra-anatomic bypasses and sequential arterial bypasses in the past 5 years. The results were satisfactory. The surgical mortality was 3.2%, the primary 5-year patent rate was 84.2%, and the secondary 5-year patent rate was 96.5%. We emphasize the value of ABI to indicate arterial reconstruction.     

Asymptomatic myocardial ischemia before and after surgical revascularization in patients with multivessel occlusive coronary disease

INTRODUCTION: The objective of this study was to examine the occurrence of asymptomatic myocardial ischemia prior to and after myocardial revascularization in patients with multivessel occlusive coronary disease. Asymptomatic ischemia can be described as real ischemia without anginal pain or other ischemic symptoms in patients with coronary disease or coronary artery spasm. Our study examined silent ischemia after myocardial revascularization. Early detection of silent ischemia is important for prevention of cardiac incidents. MATERIAL AND METHODS: We have examined patients with multivessel coronary disease with occurrence of continued preoperative silent ischemia. All patients have undergone ECG examination, exercise stress test and Holter-monitoring prior to and after myocardial revascularization. RESULTS: The investigation comprised 27 patients and their average age was 54.5 years. All patients with silent ischemia had a multivessel occlusive coronary disease and have undergone myocardial revascularization managed with triple or quadruple aortocoronary bypass surgery. Exercise stress test was performed postoperatively in elder patients, as well as ECG and Holter-monitoring. Silent ischemia was established in 21.6% of patients, while in 87.5% untreated diabetes mellitus was diagnosed. Silent ischemia most often occurred in the early morning hours and it was frequently associated with heart rhythm disturbances (VES) whereas these rhythm disturbances depended on the length of the ischemic episode. Intermittent 2nd degree atrioventricular block was found in one patient. CONCLUSION: Silent myocardial ischemia occurred in 21% of patients after myocardial revascularization. It is most often detected in the early morning hours and is associated with ventricular rhythm disorders. Silent ischemia is easily detected by simple examination procedures providing adequate therapy and prevention of cardiac incidents.     

Instrumental and metabolic evaluation of patients affected by peripheral arterial occlusive disease (PAOD) following surgical revascularization surgery

Experiments were performed on eight subjects affected by peripheral arterial occlusive disease (PAOD) of the lower limbs. Each patient was submitted to Ecodoppler, angiography and the "Treadmill test". Two bioptic muscle of these patients. A sample was used for the spectrophotometric and spectrophotofluorimetric determinations of: glycogen, pyruvate, lactate, citrate, alpha-ketoglutarate, malate, aspartate, glutamate, AMP, ADP, ATP and creatine phosphate (CP). The other bioptic sample was used to determine the following enzyme activities: hexokinase, phosphofructokinase, pyruvate kinase, lactate dehydrogenase, citrate synthase, succinate dehydrogenase, malate dehydrogenase, total NADH cytochrome c reductase, cytochrome oxidase, aspartate aminotransferase and alanine aminotransferase. Patients showed an increase in lactate dehydrogenase, total NADH cytochrome c reductase and succinate dehydrogenase activities, a decrease in glycogen, ATP and CP concentrations. Telethermographic data showed patient muscle thermic emission quantitatively different from control group. The telethermographic test can be used as an additional diagnostic tool to determine and monitor the efficiency of a muscle undergoing metabolic failure.     

Detection and assessment of laser-mediated injury in transmyocardial revascularization

When channels are made through the myocardium with a laser, tissue surrounding the channels is injured. Thus, methods of examining and quantifying the histologic changes caused by laser-mediated injury are required both for comparison of different channel making protocols and also to help understand the mechanisms of transmyocardial revascularization. The two principal components of the myocardium, collagen and muscle, are both normally birefringent. This optical property can be exploited with the use of polarized light microscopy to assess tissue structure at the cellular and subcellular levels allowing several different types of injury to be detected. Increases in tissue temperature above 60 degrees C for muscle and 70 degrees C for collagen decrease their birefringence and, hence, result in decreased brightness when viewed with polarized light. Lower temperatures may cause cell membrane injury, calcium overload, and the formation of contraction bands, which appear as areas of increased birefringence. In this way, the extent of thermal injury can be assessed. The same optical properties can be used to measure cell and fiber orientation and, hence, enable assessment of mechanical disruption of the tissue after ablation. Long-term remodeling of the myocardium in the form of scar formation, increased interstitial fibrosis, and muscle disarray can also be quantified. The ability to measure the acute injury and the long-term structural consequences of that injury with the use of polarized light microscopy should prove vital in determining the optimal laser "dose" required and may also reveal information on the mechanism(s) of benefit found with transmyocardial revascularization.     

Hemodynamic effects of transdermal estradiol alone and combined with norethisterone acetate

Of various vital dyes used to assess schistosomula viability, toluidine blue enabled differential counting of the schistosomula on microscope slides but not in culture wells, whereas methylene blue could be added directly to the schistosomula suspension in culture wells of microtiter plates. Toluidine blue uptake by dead parasites was very fast. It mostly also partially stained damaged but not dead organisms. Its main disadvantage was rapid, nonspecific staining of live schistosomula, requiring prompt counting of a preparation and additional reliance on motility for assessment of viability. Methylene blue staining of dead worms was slower, but it did not stain the live worms until about 1 h after dye application, enabling its addition to a series of preparations for consecutive counting. It did not always stain flattened, dead schistosomula or it stained them an uncontrasting pale blue. This dye remarkably induced movement in seemingly inert and probably damaged worms, thus enabling determination of viability even following poor staining or a lack of staining.     

The management of Hodgkin's disease with chemotherapy or combined modality treatment

Systemic polychemotherapy and local radiation are two well-established treatments for Hodgkin's disease. With the use of modern techniques, the great majority of patients with pathologic stage I-II Hodgkin's disease can be cured with irradiation alone. Since the invention of the MOPP and ABVD schemes, polychemotherapy has become indispensable for the treatment of advanced-stage Hodgkin's disease. The role of radiotherapy in combination with chemotherapy is limited to specific indications. ABVD therapy is as effective as MOPP alternating with ABVD, and both are superior to MOPP alone in the treatment of advanced Hodgkin's disease. MOPP/ABVD hybrid chemotherapy was significantly more effective than sequential MOPP-ABVD in 8-year failure-free survival and overall survival. The patients with advanced-stage Hodgkin's disease who did not achieve a complete remission from their initial treatment with combination chemotherapy have a dismal prognosis. Those whose initial remissions had lasted longer than 12 months had a very high probability of obtaining a second complete remission when re-treated with MOPP or ABVD, but those whose remission lasted less than 12 months fared less well with any conventional-dose chemotherapy. High-dose chemotherapy and radiotherapy with autologous hemopoietic stem cell transfusion are superior in the treatment of those whose disease is refractory or resistant to the initial therapy.     

Biodegradation of chlorpyrifos by either single or combined cultures of some soilborne plant pathogenic fungi

Biodegradation of chlorpyrifos was studied in liquid culture media amended with either single or combined eight different plant pathogenic fungi isolated from the continuous cropping wheat fields. The average recovery of chlorpyrifos from the liquid media was found to be 86.1%. The detection limit of chlorpyrifos by the analytical method used was 19 ppb. Data showed that the growth of mixed fungi at concentrations up to 200 ppm of chlorpyrifos was higher than in the control treatment. Chlorpyrifos concentrations declined in the medium of combined fungi more than it did in the medium of any single fungus with increase in the incubation period. The amount of chlorpyrifos recovered was 79.8 ppm (39.9%) in the combined fungal cultures after 21 days. However, those recovered from the media of Fusarium graminearum, F. oxysporum, Rhizoctonia solani, Cladosporium cladosporiodes, Cephalosporium sp., Trichoderma viridi, Alternaria alternata, and Cladorrhinum brunnescens, ranged from 48.0 to 74.8%. The half-life value (T1/2) for chlorpyrifos was 15.8 day in the medium amended with mixed fungi. However, for the single cultures it ranged from 19.3 to 33.0 day.     

单相控制用变压器功率选择及保护

阐述了控制变压器功率选择、校验、保护及二次短路电流的计算方法。     

Tibial and peroneal bypass in severe occlusive disease of the lower extremities

Symptomatic arteriosclerotic occlusive disease involving the femoral and proximal popliteal arteries is currently best treated by reversed autogenous saphenous vein bypass graft. Severe occlusive disease frequently includes the popliteal and/or origin of the trifurcation vessels with reconstitution of one or more of the vessels in the lower leg. We have used distal bypass 97 times in 90 patients during the past decade. There was only one postoperative death in the series in spite of the advanced age and concurrent disease in the majority of the patients. Our indications for operation continue to be relief of pain or salvage of an extremity. We rely on high quality preoperative angiograms for selection of vessels to receive the bypass. The posterior tibial artery was used in 63 of the cases, while the anterior tibial and peroneal were used in 24 and 10 cases, respectively. There were 11 immediate inhospital failures in this series of 97 cases requiring amputation in five. Three additional patients had amputations during the ensuing several months. Of the 85 grafts functioning at the time of discharge from the hospital, 16 or (18.8%) failed during the first years. Grafts that remained patent for one year have a high incidence of long term patency which is in keeping with other reported series.     

The processing of negative or incongruent perceptual and combined perceptual/linguistic stimuli

A psychological model of mediational processes based on the derivation of the meaning of perceptual or linguistic signs predicts increased processing times for signs that have negative affective meaning and conjoined signs with incongruent affective meanings. The procedure used in the experiments enables identical responses for positive and negative signs. The postulated effects are shown to be valid for perceptual as well as conjoined perceptual and linguistic cognitions, using schematic drawings of facial expressions and quotations attributed to persons with the expressions. The findings suggest that perceptual and linguistic cognitions share the same semantic systems, although the latter are more specific.     

Combination endovascular and open treatment of peripheral arterial occlusive disease performed by surgeons

The endovascular treatment of peripheral arterial occlusive disease has historically been performed by interventional radiologists and cardiologists. With additional training in endovascular techniques, surgeons become uniquely suited to manage arterial lesions with both endovascular and conventional surgical techniques. Over a 14-month period, 13 patients underwent combination endovascular and open reconstruction on limbs with peripheral arterial occlusive disease. There were 10 males and 3 females. The mean age was 66 years. All procedures were performed in the operating room by surgery residents under the direct supervision of vascular surgeons. After intraoperative angiography, 26 arterial lesions underwent percutaneous transluminal angioplasty (aorta, 1; common iliac, 14; external iliac, 10; superficial femoral, 1). Twenty-five of 26 lesions were further treated with intraluminal stent placement, the lone exception being a case of superficial femoral artery angioplasty. Concomitant open reconstruction was performed on all limbs, 14 as outflow and 1 as inflow. There were two cases of procedural morbidity and one perioperative death secondary to myocardial infarction. There were no wound-related complications. The mean ankle-brachial index of the affected lower extremity improved from 0.41 (+/- 0.15) to 0.74 (+/- 0.14) at 30 days. Mean follow-up was 8 months (range, 2-14). Based on our early experience, simultaneous combination endovascular and open reconstruction of multisegment arterial occlusive disease can be performed safely and efficiently by surgeons.