Intravascular flow prior to and following angioplasty in peripheral vessels (arteries).

OBJECTIVES: The aim of this study was to assess mean values of velocities in peripheral arterial vessels prior to and following angioplasty in patients with peripheral arterial occlusive disease. Standard values are evaluated with the guidewire positioned proximal to the lesion, inside the lesion and distal to the lesion. METHODS: Twenty-five measurements were taken prior to and following angioplasty in 22 patients with peripheral arterial occlusive disease. The Doppler guidewire was inserted over a 5 French sheath and a Cobra catheter. During measurements, the catheter was totally pulled back and the sheath was placed as proximal as possible. RESULTS: Prior to angioplasty, the velocities in the arteries were 69 +/- 60 cm/second proximal to the lesion, 186 +/- 112 cm/second inside the stenoses and 47 +/- 36 cm/second distal to the lesion. The values increased to 97 +/- 105 cm/second, 89 +/- 89 cm/second and 83 +/- 72 cm/second, respectively. Proximal velocities were lower inside occlusions and increased more markedly compared to stenoses. CONCLUSION: The Doppler guidewire is a practical and valuable tool in assessing technical success after angioplasty of peripheral lesions. In successful angioplasties, no flow acceleration should be observed. Standard values were evaluated.

Intra-arterial Doppler flowmetry in the superficial femoral artery following angioplasty.

The aim of the study was to assess the diagnostic value of an intravascular Doppler guidewire in patients with peripheral percutaneous angioplasty (PTA). The prognostic value was also evaluated. Measurements were done prior and following angioplasty in 22 patients with peripheral arterial occlusive disease. As additional therapy, stent insertion and peripheral (Aa. poplitea Tll/tibial) angioplasty was performed (4 patients per group). For stress testing, adenosinetriphosphate (ATP) was given intra-arterially. Follow-up was performed by angiography, colour-coded duplex ultrasound or judged by unequivocal clinical stage at follow-up to 13 months. Average (APV) and maximal peak velocity (MPV) increased following PTA, after additional treatment (peripheral PTA or stent), and after intra-arterial application of a vasodilator. Patients with peripheral lesions had markedly lower velocities prior treatment and following PTA after vasodilatation. Following peripheral PTA, the values were similar to the patients with PTA alone. Velocities after stenting were markedly increased in the stress condition. Of the 22 patients, 7 had a recurrent disease. The latter patients had higher velocities at rest prior to and following PTA. In stented lesions higher velocities seem to be linked with a worse outcome. The ratio between velocity prior to and after the application of the vasodilator seems to be of diagnostic importance. A ratio of 1.9 or more was of positive prognostic value. The Doppler guidewire is a practical and valuable tool in assessing technical success after angioplasty of peripheral lesions, critical or morphologically worse lesions. In our study the decision for stent application was made on the morphological image; however, increased velocity and changes in phasicity substantiated our decisions. Increased ratios prior to and after vasodilation (flow reserve) are of prognostic value and therefore suitable as indication for stent placement or tibial angioplasty.

[The long-term results after Hydrolyser-supported angioplasty--a prospective study]. / Langzeit-Ergebnisse nach Hydrolyser-unterstützter Angioplastie--eine prospektive studie.

PURPOSE: Data of a three-year follow-up after mechanical thrombolysis with the Hydrolyser catheter were evaluated. Patients have otherwise been treated by local thrombolysis. METHOD: 35 patients were treated by thrombolysis, balloon angioplasty, aspiration, local thrombolysis, and stent placement, if necessary. Morphological results following Hydrolyser treatment and additional treatment were evaluated. RESULTS: Following Hydrolyser treatment a significant reduction of the degree and length of the occlusion was observed. Primary clinical success was 80%. Patency rate after 3 years was 0.5. 23% of all patients died in the follow-up period. CONCLUSION: The Hydrolyser treatment is a relevant alternative to local thrombolysis. This method reduces the time of treatment. The authors favor the lateral opening of the catheter to remove mural thrombus.

[Indications and outcome effectiveness of transpopliteal angioplasty]. / Indikation und Erfolg der retrograden transpoplitealen Angioplastie.

PURPOSE: In this retrospective study, the results following angioplasty by the retrograde transpopliteal approach were evaluated to confirm the indications of this technique. PATIENTS AND METHODS: 34 patients were evaluated. Of these 28 were male and 6 were female. Differences to a normal group of patients planned to have angioplasty are the different location of the puncture and on extremely negative selection. RESULTS: Technical success was observed in 84%. A long-term patency ratio of 0.53 was achieved after 30 month. No complications relevant to the therapy were observed. CONCLUSIONS: The transpopliteal approach is a safe and efficient alternative to femoral puncture if the latter is impossible. Compared to the crossover-technique, mechanical considerations favor this technique.

Immediate sealing of arterial puncture site following femoropopliteal angioplasty: a prospective randomized trial.

PURPOSE: A new hemostatic puncture closure device (HPCD) was evaluated following femoropopliteal angioplasty. Efficacy in hemostasis and complications were compared between manual compression and the new system. METHODS: One hundred patients undergoing percutaneous interventional procedures were randomly assigned to receive either manual compression or HPCD. The time to complete hemostasis (when a compression bandage was applied) was noted as well as complications such as hematoma or arterial stenosis at the puncture site. Follow-up was by clinical examination and color-coded duplex sonography (CCDS). RESULTS: With the HPCD, immediate hemostasis was achieved in 22 patients (44%). Discrete oozing without the necessity of external compression or further consequences was observed in 11 patients. Mean manual compression time was 25 (+/- 20) min including application of the pressure bandage. Eleven patients needed additional manual compression and technical failures were observed in 6 patients (12%). The compression time in these 17 cases was 27 (+/- 12) min. Subcutaneous hematomata with a diameter of more than 5 cm developed in 15 of 48 patients in the HPCD group and in 14 of 48 patients in the manual compression group. No surgical or percutaneous intervention was necessary. The complication rate was comparably low in the experimental and control groups. CONCLUSION: Compared with manual compression HPCD is faster and more accurate for sealing the arterial puncture defect following angioplasty. After an initial learning curve, it is easy to handle and time-saving as well as convenient for the patient. Furthermore, immediate and full anticoagulation is possible and arterial inflow is not compromised. A drawback is the necessity of an 8 Fr sheath. Nevertheless, the complication rate is comparably low for both methods.

[Current problems with delayed reactions to intravascular administration of nonionic contrast media]. / Aktuelle Problematik von Spätreaktionen nach intravasaler Applikation nichtionischer Kontrastmittel.

Administration of X-ray contrast media is essential in many radiologic procedures such as angiography, computed, tomography, and many other diagnostic methods. These substances have become made more tolerable since the introduction of the first water-soluble X-ray media. Adverse drug reactions decreased by the factor 4 with the development of nonionic contrast media compared to the elder ionic substances. At the same time, a shift to more frequent delayed reactions occurred. Currently the dimeric contrast media for intravascular use are suspected of causing frequent delayed side effects, especially with rashes and other cutaneous symptoms. In this paper, the reasons for adverse reactions independent of drug administration, are discussed. Causes related to patients and geographic differences are reviewed. Summing up, it may be said that the new dimeric contrast media are well tolerated drugs. A higher incidence of adverse drug reactions is not evident from scientific studies. A shift to more delayed side effects, especially, reactions is possible. The mechanism is still unclear. Additionally a classification of the time of incidence of side effects is proposed.

[Delayed adverse reactions following the intravascular administration of a nonionic x-ray contrast medium]. / Spätnebenwirkungen nach intravasaler Anwendung nichtionischer Röntgenkontrastmittel.

Side effects experienced by patients up to 7 days after intravasal administration of nonionic contrast media were recorded with the help of questionnaires. These were completed by the patients themselves and compared with data recorded in patients examined without the use of contrast media. Of the 1000 questionnaires distributed, 499 were returned (271 in the contrast media group, 228 in the other group). A statistically significant difference between the two groups was found with regard to local pain at the injection site. The reactions correlated with the time of intervention. Another significant side effect was found in increased diuresis, which did not lessen during the 7 days of our survey. Increasing side effects were noted with higher contrast medium dosage and advancing age.

[What is the contribution of PET in tumor diagnosis today?]. / Welche Bedeutung hat die PET heute in der Tumordiagnostik?

Positron emission tomography (PET) permits qualitative and quantitative measurements of tumor metabolism in the patient. In the clinical setting, the present studies suggest that tumors with a potential for proliferation can be differentiated from scar tissue, soft tissue and benign lesions. Accumulation of tracer by lymph nodes identifies them as metastatic. On the basis of a quantification of the accumulation of tracer and its metabolites, information can be provided about the biological activity of a tumor, and presumably also about the prognosis. The response of a tumor to treatment can be monitored, in particular in combination with CT. Possible selection of resistant parts of the tumor can be determined, so that modification of treatment is possible. Modes of application can also be individualized by identifying pre-treatment advantages of intraarterial or systemic administration; recurrent tumors can be detected with a high degree of accuracy. However, to date, only limited numbers of cases are available, so that, in view of the very promising aspects of this modality, more widespread application followed by the evaluation of larger numbers of patients is needed.

[Contrast medium clearance as a measure of kidney function in patients with renal artery stenoses]. / Kontrastmittel-Clearance als Mass der Nierenfunktion bei Patienten mit Nierenarterienstenosen (NAST).

The quantitative estimation of the characteristic radiation from 127I following external stimulation by 241americium photons makes it possible to estimate iodine concentration. The plasma concentration of non-ionic contrast media handled by glomerular filtration was measured in 16 patients with renal artery stenosis. This was done during diagnostic angiography or percutaneous dilatation, either at an early stage (one to two hours) or at a late stage (five to eight hours). Assuming an exponential excretory function, a clearance value could be calculated. The results were compared with the clearance values of a tubular excreted radiopharmaceutical (99m technetium-MAG3). Despite the different excretory mechanisms, there was a statistically significant correlation between the scintigraphic and contrast clearances at the later time (r = 0.85, p is less than 0.001). At the earlier stage, there was no signification correlation (r = 0.46, p is greater than 0.05). The correlation between the later values and the serum creatinin level was moderately significant (r = 0.55, p less than 0.05).

[The place of computed tomography in the diagnosis of recurrences in patients with bronchogenic carcinoma]. / Der Stellenwert der Computertomographie für die Erkennung von Rezidiven bei Patienten mit Bronchialkarzinomen.

Thirty-five patients with strongly suspected recurrent tumor of the lung and a definitely positive CT scan were reviewed. The patients had undergone surgery (group A, n = 17) or radiation therapy (group B, n = 18). TNM staging of lung cancer in both groups revealed similar results. Small-cell carcinoma (p less than 0.05), central tumors (p less than 0.003) and elder patients (p less than 0.05) were more often found in group B. The disease-free interval was longer in patients with tumor resection (45.5 vs 11.7 months, p less than 0.007) and depended on the T-stage in irradiated cases (p less than 0.05). Local recurrence with or without mediastinal lymph node involvement occurred in all irradiated patients: 3 out of 17 surgical patients showed isolated mediastinal lymph node enlargement without tumor relapse (not seen by plain chest roentgenographs). Plain films failed to detect nearly 20% of space-occupying lesions, which could easily be identified by CT. In one patient the suspected tumor recurrence turned out to be a tuberculous infiltration. A second lung cancer--no tumor recurrence--was pathohistologically assumed in 3 of the resected cases with an interval of from 10 to 181 months after surgery. On the basis of these findings, CT monitoring can be recommended when the patient is resected for cure. Some patients will benefit by an early diagnosis of local regional tumor recurrence when the time until the necessary secondary treatment can be shortened. Long-term-survival may be achieved in a small part of these patients.

Evaluation of recurrent bronchogenic carcinoma by computed tomography.

Thirty-five patients with strongly suspected recurrent tumor of the lung and definitely positive computed tomography (CT) scan were reviewed. The patients had undergone surgery (group A, n = 17) or radiation therapy (group B, n = 18). TNM-staging of lung cancer in both groups revealed similar results. Small cell carcinoma (P less than 0.05), central tumors (P less than 0.003), and elderly patients (P less than 0.05) were more often found in group B. Disease-free interval was longer in patients with tumor resection (45.5 v 11.7 months, P less than 0.007) and depended on T-stage in irradiated cases (P less than 0.05). Local recurrence with or without mediastinal lymph node involvement occurred in all irradiated patients; 3 of 16 surgical patients showed isolated mediastinal lymph node enlargement without tumor relapse (not seen by plain chest roentgenographs). Plain films failed to detect nearly 20% of the space-occupying lesions, which could easily be identified by CT. In one patient the suspected tumor recurrence turned out to be a tuberculous infiltration. A second lung cancer (no tumor recurrence) was pathohistologically assumed in three of the resected cases with an interval from 10-181 mo after surgery. On the basis of these findings, CT-monitoring can be recommended when the patient is resected for cure. Some patients will benefit by an early diagnosis of a local-regional tumor recurrence when the time until the necessary secondary treatment may be shortened. Long-term survival may be achieved in a small group of these patients.

[Computerized tomography findings in rare malignant processes of the thorax]. / Computertomographische Befunde bei seltenen malignen Prozessen des Thorax.

The CT findings in 21 patients with rare malignant space-occupying growths in the thorax were evaluated retrospectively under morphological aspects. The possibility of rare malignant thoracic space-occupying growths should be considered mainly 1) in patients who are either very young or of very old age, 2) if risk factors are absent, especially abuse of nicotine, 3) if there are large inhomogeneous growths, possibly with calcareous areas or necrotic zones and sharp marginal delineation in the node status, 4) if the tumour localisation is atypical of bronchial carcinoma.

[Size and density determination by thin-layer CT in relation to structural diameter and the contrast of the surrounding tissue]. / Grössen- und Dichtebestimmung mit der Dünnschicht-CT in Abhängigkeit von Strukturdurchmesser und Umgebungskontrast.

The reliability of CT size and density measurements has been examined by using phantom measurements with constant examination and reconstruction parameters (Somatom DRH/Siemens). Ten plexiglass rods with diameters from 2 to 15 mm. were measured singly in (1) air, (2) isodense (146 Hu) and (3) hyperdense medium (985 Hu) using 2 mm. sections. In the isodense medium there was only small variation in density measurements (124 to 131 Hu). Measurements of size showed a maximum error up to -35%. Density measurements in the hyperdense medium produced raised values (197 +/- 17 Hu at 15 mm.). There was an even greater increase for rods smaller than 5 mm. Measurement of size was correct, as it was in air (maximum deviation 8%). Density measurements in air for diameters less than 6 mm. were significantly reduced.

[CT morphology and clinical diagnosis of thoracic space-occupying lesions in patients under 40 years of age]. / CT-Morphologie und klinische Diagnose thorakaler Raumforderungen bei unter 40jährigen Patienten.

83 patients with thoracic masses and aged under 40 years, who had been seen in a chest clinic, were examined by CT. They were classified according to their diagnosis and typical CT findings were analysed. Bronchial carcinomas showed predominantly radial extensions and air trapping. Malignant lymphomas and benign tumours usually showed smooth outlines and evidence of some fat content. Malignant mediastinal or neurogenic tumours frequently contained liquid portions and calcification. The CT diagnosis of lymphomas (seven cases), metastases (28 cases) and benign tumours (13 cases) presented no problems in view of the typical appearance and position of the tumours; classification of malignant mediastinal or neurogenic tumours (seven cases) was difficult. Inflammatory masses (14 cases) and bronchial carcinomas (14 cases) showed similar CT appearances.