Meta-analysis in metastatic uveal melanoma to determine progression free and overall survival benchmarks: an international rare cancers initiative (IRCI) ocular melanoma study.

BACKGROUND: Despite the completion of numerous phase II studies, a standard of care treatment has yet to be defined for metastatic uveal melanoma (mUM). To determine benchmarks of progression free survival (PFS) and overall survival (OS), we carried out a meta-analysis using individual patient level trial data. METHODS: Individual patient variables and survival outcomes were requested from 29 trials published from 2000 to 2016. Univariable and multivariable analysis were carried out for prognostic factors. The variability between trial arms and between therapeutic agents on PFS and OS was investigated. RESULTS: OS data were available for 912 patients. The median PFS was 3.3 months (95% CI 2.9-3.6) and 6-month PFS rate was 27% (95% CI 24-30). Univariable analysis showed male sex, elevated (i.e. > versus ≤ upper limit of normal) lactate dehydrogenase (LDH), elevated alkaline phosphatase (ALP) and diameter of the largest liver metastasis (≥3 cm versus <3 cm) to be substantially associated with shorter PFS. Multivariable analysis showed male sex, elevated LDH and elevated ALP were substantially associated with shorter PFS. The most substantial factors associated with 6-month PFS rate, on both univariable and multivariable analysis were elevated LDH and ALP. The median OS was 10.2 months (95% CI 9.5-11.0) and 1 year OS was 43% (95% CI 40-47). The most substantial prognostic factors for shorter OS by univariable and multivariable analysis were elevated LDH and elevated ALP. Patients treated with liver directed treatments had statistically significant longer PFS and OS. CONCLUSION: Benchmarks of 6-month PFS and 1-year OS rates were determined accounting for prognostic factors. These may be used to facilitate future trial design and stratification in mUM.

Adenomyosis and endometriosis. Re-visiting their association and further insights into the mechanisms of auto-traumatisation. An MRI study.

PURPOSE: In a series of publications, we had developed the concept that uterine adenomyosis and pelvic endometriosis as well as endometriotic lesions at distant sites of the body share a common pathophysiology with endometriosis constituting a secondary phenomenon. Uterine auto-traumatization and the initiation of the mechanism of tissue injury and repair (TIAR) were considered the primary events in the disease process. The present MRI study was undertaken (1) to corroborate this concept by re-visiting, in view of discrepant results in the literature, the association of adenomyosis with endometriosis and (2) to extend our views concerning the mechanisms of uterine auto-traumatization. PATIENTS AND METHODS: MRI was performed in 143 women attending our center, in whom, on the basis of transvaginal sonography (TVS) and historical data, such as documented endometriosis and dysmenorrhea of various degrees of severity, the presence of uterine adenomyosis was suspected. In addition to the measurement of the diameter of junctional zone (JZ) of the anterior and posterior walls in the mid-sagittal plane, the diagnosis of adenomyosis was based on visualization, in that all planes were analyzed with scrutiny. By this method of "visualization" all transient enlargement of the JZ, such as peristaltic waves of the archimyometrium and sporadic neometral contractions that might mimic adenomyotic lesions could be excluded. At the same time, this method allowed to lower the limit of detection in terms of thickness of the JZ for assured diagnosis of adenomyosis. Furthermore, the localizations of the individual lesions, their shapes and patterns were described. RESULTS: With the method of 'visualization', the diagnosis of uterine adenomyosis could be verified in 127 of the 143 patients studied. The prevalence of endometriosis in adenomyosis was 80.6% and the prevalence of adenomyosis in endometriosis was 91.1%. As concluded from their localization within the uterine wall, the adenomyotic lesions predominantly developed in the median region of the upper two-thirds of the uterine wall. Cystic cornual angle adenomyosis was a distinct phenomenon that was only observed in patients suffering from extreme primary dysmenorrhea. Aside from this, the majority of the patients complained of primary dysmenorrhea (80%). On the basis of these findings and the fact that particularly extreme primary dysmenorrhea is associated with high intrauterine pressure, menstrual 'archimetral compression by neometral contraction' has to be considered as an important cause of uterine auto-traumatization in addition to uterine peristalsis and hyperperistalsis. Both mechanical functions of the non-pregnant uterus exert their strongest power in the upper region of the uterus, which is compatible with the predominant localization of the adenomyotic lesions. CONCLUSIONS: The data confirm our previous results of a high association of adenomyosis with endometriosis and vice versa. Our view of the mechanism of uterine auto-traumatization by mechanical functions of the non-pregnant uterus has to be extended, in that 'archimetral compression by neometral contractions' could be realized as the predominant cause of mechanical strain to the non-pregnant uterus. The data of this study confirm our concept of the etiology and pathophysiology of adenomyosis and endometriosis in that the process of chronic proliferation and inflammation is induced at the level of the archimetra by chronic uterine auto-traumatization. Furthermore, with respect to the diagnosis of uterine adenomyosis (and consequently endometriosis) this study shows a high degree of accordance between the findings in real-time TVS and MRI.

[Diagnosis of and therapy for hepatocellular carcinoma]. / Diagnostik und Therapie des hepatozellulären Karzinoms.

The interdisciplinary guidelines at the S3 level on the diagnosis of and therapy for hepatocellular carcinoma (HCC) constitute an evidence- and consensus-based instrument that is aimed at improving the diagnosis of and therapy for HCC since these are very challenging tasks. The purpose of the guidelines is to offer the patient (with suspected or confirmed HCC) adequate, scientifically based and up-to-date procedures in diagnosis, therapy and rehabilitation. This holds not only for locally limited or focally advanced disease but also for the existence of recurrences or distant metastases. Besides making a contribution to an appropriate health-care service, the guidelines should also provide the foundation for an individually adapted, high-quality therapy. The explanatory background texts should also enable non-specialist but responsible colleagues to give sound advice to their patients concerning specialist procedures, side effects and results. In the medium and long-term this should reduce the morbidity and mortality of patients with HCC and improve their quality of life.

[S3 guidelines for diagnostics and treatment of peripheral arterial occlusive disease]. / S3-Leitlinien zur Diagnostik und Therapie der peripheren arteriellen Verschlusskrankheit.

This report summarizes the most important aspects of the new German S3 guidelines for the diagnostics and treatment of peripheral arterial occlusive disease (PAOD) from March 2009. The guidelines include definitions and epidemiology of peripheral arterial occlusive disease, diagnostic methods including clinical and technical procedures as well as imaging methods, treatment by non-invasive, interventional and surgical methods and patient care during follow-up. In key messages recommendations are given which are graded corresponding to the scientific evidence concluded from the literature.

[C-arm CT for chemo-embolization of liver tumors]. / C-Arm-CT bei der Chemoembolisation von Lebertumoren.

Local efficacy of transarterial chemo-embolization (TACE) is enhanced if selective treatment is performed. Selectivity of TACE mainly depends on vascular anatomy but also on the identification and catheterization of tumor feeding arteries. Correlation of vascular territories and target tumor volume in angiographic projection images is more difficult if tumors are not hypervascularized and contrast of liver parenchyma is inhomogeneous.C-arm CT offers the option of selective perfusion imaging via tumor-feeding arteries. This allows the comparison of perfusion images and baseline cross-sectional imaging to evaluate if tumors are covered completely by local treatment and to change the catheter position if necessary. Furthermore the uptake of embolization material, such as lipiodol can be checked by C-arm CT.In a prospective study of 75 TACE of liver tumors and liver metastases we evaluated the appropriateness of 85 catheter positions ready for delivery by perfusion C-arm CT and compared the diagnostic confidence of angiography and perfusion C-arm CT in terms of judgment of correct catheter position for the planned treatment. Diagnostic confidence was improved by perfusion C-arm CT in 55% of cases and in 11 cases (13%) catheter positions were inappropriate and had to be corrected. The reasons for catheter repositioning were incomplete coverage of the target tumor by perfusion volume (mismatch) in 6 cases, inappropriate perfusion of adjacent liver parenchyma in 2 cases and non-selective tumor perfusion via collateral arteries in 3 cases. C-arm CT allowed sufficient visualization of uptake of lipiodol in all cases evaluated.The diagnostic benefit of C-arm CT increases if tumors are treated more selectively, are not strongly hypervascular, are located centrally and if the enhancement of liver parenchyma is inhomogeneous. C-arm CT causes additional working time and contrast load, which is relatively low compared to angiography. Radiation exposure of 151 microGy per C-arm series necessitates careful and therapy-oriented assessment of indications.

Ablation characteristics of arterial vessel walls irradiated with the pulsed dye laser--an analysis of variance.

BACKGROUND AND OBJECTIVE: Since most clinical laser angioplasties require the use of over-the-wire delivery systems, we studied the effects of pulsed dye laser energy (504 nm, 1.4 microseconds on arterial vessel walls in combination with a multifiber catheter system. MATERIAL AND METHODS: Postmortem arterial segments (n = 368) were exposed under blood or saline. Laser pulses (n = 100-800) were transmitted via 9F-multifiber-catheters, at energy densities of 3-16 J/cm2. Ablation characteristics revealed by histologic examination and morphometry were analyzed by multiple analysis of variance. RESULTS: Ablation occurred more frequently in saline compared to blood. Below an energy density of 10 J/cm2 ablation occurred in saline only. Specimens irradiated under blood showed only thermal changes at 10 J/cm2. In saline, 92% of normal, 88% of fibro-fatty and 60% of calcified tissue showed ablation at 13 J/cm2. The average ablation threshold in saline was about 3-4 J/cm2 per pulse for normal tissue, 5 J/cm2 for fatty plaques, and 8-9 J/cm2 for calcified plaques. In blood, the average ablation thresholds did not differ significantly between the different stages of arteriosclerosis (12 J/cm2 for normal tissue, 11 J/cm2 for fatty plaque, and 10 J/cm2 for calcified tissue). Carbonization and vacuolization were seen regularly at energy levels > or = 13.4 J/cm2. CONCLUSIONS: Selective ablation of arteriosclerotic tissue with the pulsed dye laser could not be found. Further investigation is needed before an effective ablation of arteriosclerotic arterial tissue can be expected.

Evaluation of K-space segmented cine sequences for fast functional cardiac imaging.

RATIONALE AND OBJECTIVES: In functional cardiac magnetic resonance imaging, reduction of measuring time is very important for many patients who are not able to rest motionless for long-lasting examinations. In this study, the image quality of sequences with k-space segmented data recording was compared with conventional gradient-echo sequences for cine imaging with flow compensation in applications on patients with normal and reduced ejection fractions. METHODS: Thirty-one subjects (4 volunteers and 27 patients with cardiac diseases) were examined using different techniques for cine imaging of the left and right ventricles. The ejection fraction in the patients was calculated based on images of a conventional two-dimensional gradient-echo technique using a biplane ellipsoid model. The results from k-space segmented methods (3 to 9 Fourier lines per cardiac cycle for each phase image) were compared with the conventional images of the same short-axis view separately for groups of subjects with normal and reduced ejection fraction. The contrast between blood and myocardium at several sites of the heart and the homogeneity of the blood signal in the ventricle were evaluated for several phases of the heart cycle. RESULTS: The segmentation in the acquisition of raw data allows reduction of measuring time to approximately 20% to 40% of the time required for conventional sequences in cine imaging of the heart. In patients with normal or only slightly reduced heart function (ejection fraction > or = 60%) the image quality of k-space segmented sequences was not significantly different from the conventionally recorded images. In contrast, patients with markedly lowered ejection fraction (< 60%) showed degraded results of the k-space segmented sequences compared with the conventional sequence (P < 0.001). The anterolateral border and the right ventricle especially were not sufficiently delineated by the k-space segmented sequences in these patients. CONCLUSION: The k-space segmentation for the reduction of examination time is suitable for measuring heart volumes and functional parameters of patients expected to have a nearly normal ejection fraction, whereas for patients with markedly reduced cardiac function further technical improvements of segmented techniques are necessary.

Expression of hypoxia-inducible genes in tumor cells.

Tumor tissue oxygenation impacts on proliferation of cancer cells and their sensitivity towards radio- and chemotherapy. Under low oxygen, mammalian cells show an adaptive response that leads to the induction of a number of genes with well-defined roles in oxygen supply and energy maintenance, e.g. genes encoding enzymes of the glycolytic pathway. The hypoxia-inducible factor 1 (HIF-1), a transcription factor consisting of the two proteins HIF-1alpha and HIF-1beta, plays a major role in the pleiotropic response observed under low oxygen. We have determined, by Northern analysis, the mRNA levels of HIF-1alpha and of two glycolytic enzymes known to be transcriptionally activated by HIF-1, namely phosphoglycerate kinase 1 (PGK 1) and pyruvate kinase M2 (PKM2), in different hepatoma cell lines and in mouse and human tissues. Hypoxic treatment of various mouse and human hepatoma cell lines led to the expected increase in the amount of PGK1 and PKM2 mRNA, while HIF-1alpha mRNA levels were not significantly elevated. Analysis of mouse liver tumors demonstrated no tumor-specific increases in HIF-1alpha or PGK1 mRNA levels. In five of eight human colorectal cancers investigated, PGK1 and PKM2 mRNA levels were increased in comparison to the corresponding normal tissues, while HIF-1alpha mRNA levels were not significantly changed. The majority of the colorectal cancers demonstrated p53 immunoreactivity, presumably due to mutation of the gene; there was, however, no correlation between the p53 staining pattern and mRNA expression levels of glycolytic enzymes.

Primary choriocarcinoma of the pulmonary artery mimicking pulmonary embolism.

Due to their rarity, primary tumours of the pulmonary arteries are often incorrectly diagnosed as more common diseases such as pulmonary thromboembolism and are seldom diagnosed during a patient's lifetime. Surgery or potentially curative chemotherapy may therefore be withheld. We report a patient with a primary choriocarcinoma of the left pulmonary artery, which was first suspected on a CT scan. The neoplastic nature of the obstruction of the pulmonary arteries was confirmed by positron emission tomography.

Posttransplant renal artery stenosis--outpatient intraarterial DSA versus color aided duplex Doppler sonography.

A prospective trial was conducted to assess the accuracy of color aided duplex Doppler (CADD) sonography to rule out transplant renal artery stenosis (TRAS) and to determine feasibility and safety of intraarterial digital subtraction angiography (DSA) in hypertensive renal allograft recipients on an outpatient basis. All patients were hypertensive (n = 18, mean age: 42 +/- 11 years) and underwent CADD and an i.a. DSA with 4F catheters. There was a 4 hour rest post DSA. Duplex Doppler measurements of maximum velocity were obtained. Absolute values of > or = 100 cm/s were considered indicative to suspect TRAS. DSA revealed severe TRAS in 4 patients (22%). The stenoses were located near the iliorenal anastomosis (n = 2) and at the bifurcation of the renal artery (n = 2). Duplex Doppler classified twelve (67%) renal artery pedicles normal (maximum velocity: 79 +/- 23 cm/s). TRAS was suspected in 6 patients with a maximum velocity of 159 +/- 48 cm/s (P < 0.01). False positive CADD diagnoses were due to tortuous graft vessels and a postbiopsy arteriovenous fistula. Sensitivity of CADD was 100%, specificity 86%. There were no DSA related complications. No impairment of graft function occurred. CADD allows renal angiography to be reserved to clarify an inconclusive ultrasound study and for definite diagnosis of angiomorphology and lesion classification. Intraarterial DSA of renal grafts in outpatients may be performed without an increased risk of procedure-related complications.

[MRI-guided percutaneous radiofrequency ablation of hepatic neoplasms--first technical and clinical experiences]. / MRT-gestützte perkutane Radiofrequenzablation hepatischer Neoplasien--Erste technische und klinische Erfahrungen.

PURPOSE: To evaluate the safety and efficacy of MR-guided radiofrequency ablation (RFA) of hepatic neoplasms. MATERIAL AND METHODS: 16 hepatic neoplasms (1.3-3.0 cm in diameter) in 11 patients were treated by 22 percutaneous RFA sessions during a prospective study. 16 G, MR-compatible cooled-tip electrodes with active lengths of 2 cm and 3 cm, respectively, were placed under MR-guidance in an open 0.2 Tesla MR system (Magnetom Open, Siemens, Erlangen) using fast T1-weighted sequences. Pretreatment studies, evaluation of tumor necrosis (one week after last RFA), and further follow-up studies every 3 months were performed using 1.5 Tesla MR systems. RESULTS: The mean procedure time was 2.8 (1.5-3.3) h. Complications related to percutaneous treatment were not encountered. 14 of 16 neoplasms (87%) showed no CM enhancement during MRI after the last RFA and were judged to be completely necrotic. In 11 tumors one treatment session was necessary, in 4 tumors two and in one tumor three. Follow-up studies revealed persistent complete necrosis in 13 of 14 (93%) tumors during a period of 3-18 (median: 11.8) months. In 5 patients new intrahepatic tumors developed that were not suitable for further RFA treatment because of their number, size and location. CONCLUSION: MR-guided RFA using single cooled tip electrodes is safe and technically effective for treatment of hepatic neoplasms up to 3 cm in size, however further improvements are necessary.

[Spiral CT and CT angiography after coronary bypass surgery]. / Spiral-CT und CT-Angiographie nach koronarer Bypassoperation.

AIM: Evaluation of spiral-CT and CT-angiography for imaging of venous and arterial coronary bypass grafts during the early postoperative period. PATIENTS AND METHODS: In 198 patients suffering from coronary heart disease, 583 aortocoronary venous grafts (ACVG), 70 arterial grafts and 24 jumped grafts were investigated 9-15 days following coronary surgery. In 57 patients the results were compared to arterial DSA and reconstructive CT-angiography. RESULTS: At arterial DSA 93% of ACVG and 100% of arterial grafts were patent. Spiral-CT demonstrated 104 of 105 ACVG (99%) and 20 of 29 arterial grafts (69%) correct patent. All occluded ACVG (n = 8) were detected. 90% of ACVG but only 32% of arterial grafts were visualised completely over long segments. Imaging of jumped grafts was insufficient. In CT-angiography artificial vessel stenoses impaired correct visualisation of graft morphology. CONCLUSIONS: Spiral-CT allows sufficient differentiation of patent and obstructed ACVG during the early postoperative period. Diagnostic of arterial grafts is of lower accuracy. For CT angiography of venous and arterial coronary grafts further improvements are necessary.

[Interventional treatment of hemobilia]. / Interventionelle Behandlung der Hämobilie.

PURPOSE: Aim of the study was to assess the use of embolisation in cases of iatrogenic haemobilia. METHOD: In 18 patients with severe haemobilia after percutaneous biliary system drainage or stent implantation, an embolisation with minicoils (17 x) or gelfoam particles, was performed. To achieve a sufficient vascular obstruction, Histoacryl (4 x) or Ethibloc (1 x) were additionally used in five cases. A transarterial approach was used in 17 cases. In one patient, an approach through the biliary system was possible. RESULTS: In all cases, the bleeding source was identified (5 false aneurysms, three biliary leaks, 9 irregularities at the junction of the artery and drainage catheter, 1 multiple collaterals at the proximal end of the stent). In 17 out of 18 cases, haemorrhage ceased definitely. In one case of a patient with pancreas carcinoma and obstruction of the portal vein as well as a simultaneous high grade stenosis of the hepatic artery propria, it was only possible to embolise small collaterals to avoid liver necrosis. This resulted in an incomplete bleeding of control. An infected haematoma was the only complication. It was treated by drainage over 10 days. During an observation period ranging approximately 7.6 months, 10 of the patients died due to their basic illness. CONCLUSION: Embolisation is an effective procedure in the treatment of haemobilia, with a low complication rate.

[The adjuvant use of the monoclonal antibody c7E3 Fab in peripheral arterial thrombolysis]. / Adjuvanter Einsatz des monoklonalen Antikörpers c7E3 Fab bei peripherer arterieller Thrombolyse.

Thrombolysis of arterial occlusions has limitations, e.g. it requires extensive time for thrombolysis, occlusions may be resistant to lysis, and the rate of reocclusions may be high. c7E3 Fab inhibits platelet aggregation by binding to the GPIIb/IIIa receptor on platelets. Experimentally, this monoclonal antibody has been shown to decrease, the time required for lysis, and to prevent reocclusion. This is the first report on the adjunctive use of c7E3 Fab in peripheral arterial occlusions in humans. Three patients with occlusion of the iliac or femoropopliteal artery were treated with c7E3 Fab (bolus injection of 0.25 mg/kg KG + i.v.-application 12 micrograms/min for 12 h). In addition, the patients received urokinase (100,000 IU bolus + 100,000 IU/h). Heparin (5,000 IU bolus + 1,000 IU/h) and acetylsalicylate (100 mg/day/p.o.). Occlusion length ranged between 6-40 cm. Therapy was successful in all patients. During the follow-up period (4-6 months) no reocclusion occurred. There were no serious side effects like major bleeding or thrombocytopenia. We conclude that the applied doses appear safe. Even the time required for thrombolysis was short, a conclusion in respect of a significant reduction of the time required for lysis can be drawn only after further controlled studies.

[Radiofrequency ablation of the liver in vitro: increasing the efficacy by perfusion probes]. / Radiofrequenzablation der Leber in vitro: Effektivitätserhöhung mittels perfundierter Sonden.

PURPOSE: Percutaneous radiofrequency interstitial thermal ablation is a new method in local tumour therapy. The aim of this study was to define the relations between the variable parameters and local efficacy in vitro and to evaluate optimal parameter combinations for this system. Furthermore, we studied the feasibility of increasing the volume of destroyed tissue using perfusion electrodes. MATERIAL AND METHODS: Thermal lesions were produced with radiofrequency in ex vivo pig livers. In separate experiments the parameters wattage (5-30 watts), exposure time (1-15 minutes) and tip exposure were varied. The resulting areas of tissue necrosis coagulation were measured; in 30 of 90 cases the macroscopic findings were compared to the histological findings. RESULTS: Lesion size correlated with tip exposure, wattage and procedure duration up to 10 minutes. For a tip exposure of 2 cm (3 cm) the maximal lesion volume was 18.8 cm3 (33.2 cm3) at a wattage of 20 watts (30 watts) and a procedure duration of 10 minutes. The maximal cross- (length-) diameter of these lesions was 3 cm (4 cm) for 2 cm tip exposure and 3.6 cm (4.9 cm) for 3 cm tip exposure. CONCLUSION: The parameters wattage, procedure duration and tip exposure affect the size of lesions created with radiofrequency under ex vivo conditions. Perfusion electrodes make it possible to produce larger lesions than described for non-perfused electrodes. The ablation of hepatic neoplasms up to a size of 3 cm seems to be possible with a single electrode.

[Precise MR-guided preoperative marking of breast lesions with an embolization coil using a standard MR coil]. / Präzise MR-gestützte präoperative Markierung von Mammaläsionen mit einer Embolisationsspirale unter Verwendung einer Standard-MR-Spule.

PURPOSE: To develop and test a new technique for MR-guided localisation of breast lesions. MATERIALS AND METHODS: The examinations were performed on a 1.0 T imager in prone position, using a sagittally oriented oval spine coil. The localization device consisted of a perforated lateral plate which can be angulated. The plate contained an "M" shaped tube filled with oil. This enabled exact localization of the lesion in relation to the bore holes on the MR images. After needle placement through a sterile bushing, the 5 mm marking coil was placed through the needle adjacent to the lesion. Then a suspension of charcoal, Gd-DTPA, and water was injected. Suspicious lesions that could be visualised only by MR were localised preoperatively and marked in 6 patients. RESULTS: The lesion size ranged from 0.5 to 3.5 cm (median 1.2 cm). Three benign lesions (intraductal hyperplasia twice, radial scar once) and three malignant lesions (ductal invasive cancer twice, DCIS once) were found. Angulation of the plate was beneficial in three cases. CONCLUSION: With the new marking technique, exact MR-guided localization of breast lesions using an add-on device is feasible. Construction of an additional MR coil is not necessary. Excision of the lesion is proven by the concomitant excision of the marking coil.

[Excimer laser angioplasty. I. The tissue effects of a ring catheter system on peripheral arterial vessels]. / Excimer-Laser-Angioplastie. Teil 1: Gewebeeffekte eines Ringkathetersystems an peripheren arteriellen Gefässen.

We have carried out an experimental study using a new laser catheter on 28 cadaver femoral arteries in 14 subjects and on six aortas. This ring catheter system consists of 12 circular quartz fibres with a central lumen and allows the application of energies up to 20 mJ through a 7F flexible catheter in vivo. The laser emits ultraviolet light of a wave-length of 308 nm, in pulses of 60 ns and a frequency of 2-40 Hz. The energy within a single fibre is 5 J/cm2 and exceeds the intensity required to ablate calcifications. Histologically it has been shown that, depending on the type of tissue, 1 to 2.4 microns of tissue per pulse is removed. Experimentally, rate of progress in a calcified occlusive lesion in the femoral artery, using 20 Hz and energy transmission of 20 mJ, was 3 to 5 mm per minute. Perforation of vessel wall if the catheter tip was at right angles to it depended on the degree of atherosclerosis and was between nine and 116 seconds. Marginally, there was only minimal thermal damage.

[Excimer laser angioplasty. II: Initial clinical experience with peripheral arterial occlusive diseases]. / Excimer-Laser-Angioplastie. Teil II: Erste klinische Erfahrungen bei peripherer arterieller Verschlusskrankheit.

First clinical experiences in the treatment of chronically occluded arteries with 7F-multi-fiber catheter systems transmitting pulsed laser light are presented. 16 patients (7 stadium IIb, 4 stadium III, 5 stadium IVa Fontain) underwent the procedure. 14 of 16 lesions (distance: 0.5-10 cm), most of them with visible calcification, could be recanalized successfully. After the catheter had passed lesions several times, remaining stenoses of 48% (mean value) could be reduced by balloon angioplasty. By moving the catheter with less speed than the experimentally determined speed of laser light ablation and by guiding it over a safety wire, perforation and embolization could be avoided. In one case, occlusion material was pressed into collateral vessels and in two cases groin hematomas had to be observed.