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Dive into the research topics where Lars Kamper is active.

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Featured researches published by Lars Kamper.


Urologia Internationalis | 2014

Tamoxifen Monotherapy in the Treatment of Retroperitoneal Fibrosis

A.S. Brandt; Lars Kamper; Sonja Kukuk; Patrick Haage; Stephan Roth

Objective: To evaluate the therapeutic effect of tamoxifen monotherapy in patients with retroperitoneal fibrosis (RPF). Patients and Methods: From 2007 on, 31 patients with idiopathic RPF were treated with tamoxifen monotherapy. Follow-up investigations included magnetic resonance imaging, laboratory measurements, registration of side effects and changes or removal of ureteral stents. Data were stored in the Else Kröner-Fresenius Registry of Retroperitoneal Fibrosis. Results: 25 men and 6 women with a mean age of 56.6 years were treated with tamoxifen monotherapy. Mean duration of treatment was 13.3 months, mean follow-up 26.8 months. A total of 44 renal units were affected by hydronephrosis and covered by DJ stents. Radiological regression of fibrosis was detected in 22 cases (71.0%); removal of ureteral stents was possible in 27/44 renal units (61.4%) and 17/29 patients (58.6%), respectively. Most patients showed only mild or no side effects of therapy. In 7 cases (22.3%) tamoxifen therapy had to be abandoned because of severe side effects, progression of fibrosis or persistent intolerance. Conclusions: Tamoxifen is an alternative in the medical treatment of RPF, especially if patients want to avoid glucocorticoids. The potential of regression of fibrosis seems to be slightly inferior and the relapse rate is higher compared to steroids, but the rate of successful DJ removals is comparable.


Journal of Vascular Access | 2008

Radiological central vein treatment in vascular access

Mansour M; Lars Kamper; Altenburg A; Patrick Haage

In the last decades, the percutaneous interventional approach for the treatment of central venous obstructions (CVO) has become increasingly popular as the treatment of first choice because of its minimal invasiveness and reported success rates. CVOs are caused by a diverse spectrum of diseases which can be broadly categorized into two principal eliciting genera, either benign or malignant obstructions. The large group of benign venous obstructions includes the increasing number of end-stage renal disease patients with vascular access related complications. Due to the invasiveness and complexity of thoracic surgery for benign CVOs, the less invasive percutaneous interventional therapy can generally be considered the preferred treatment option. Initially, the radiological intervention consisted of balloon angioplasty alone, subsequently additional stent placement was applied. This was advocated as either primary placement or secondary in cases of elastic recoil or residual stenosis after percutaneous transluminal angioplasty (PTA). The efficacy of angioplasty of CVO in patients with vascular accesses, either with or without stenting, has been addressed by various studies. Overall, reports indicate an initial technical and clinical success rate above 95% and satisfactory patency rates. However, systematic follow-up and frequent re-interventions are necessary to maintain vascular patency to achieve long-term success.


Journal of Clinical Medicine Research | 2013

An Aid to Decision-Making in Therapy of Retroperitoneal Fibrosis: Dynamic Enhancement Analysis of Gadolinium MRI

A.S. Brandt; Lars Kamper; Sonja Kukuk; Werner Piroth; Patrick Haage; Stephan Roth

Background Idiopathic retroperitoneal fibrosis (IRF) as an uncommon cause of obstructive uropathy is often primarily treated medically by the attending urologist. We evaluated dynamic enhancement analysis (DEA) as a possible predictor of response to medical treatment and for treatment monitoring. Methods From 2007, 24 patients with fibrosis were assessed by magnetic resonance imaging (MRI) with DEA. The dynamic enhancement quotient (DEQ) was measured before therapy with prednisone (n = 12) or tamoxifen (n = 12) and in follow-up investigations after 3 and 6 months. Response to medical treatment was recorded by changes in the retroperitoneal mass on MRI and possible relief of ureteral obstruction, which was monitored by intravenous pyelogram and/or MAG3 scan after removal of DJ stents. Results Treatment groups did not differ significantly as to age, gender, or laboratory values, and response to medical treatment showed no significant difference between agents. Overall there were no cases of progression, 2 cases of stable disease, 11 cases of mild fibrotic regression, and 11 of significant or complete regression. DJ stents could successfully be removed in 21 of 35 renal units (60.0%). In a total of 61 DEAs the DEQ was significantly higher (P < 0.001) in patients with a good response (DEQ = 4.02) than in those with an average response (3.11) or none (2.14). Conclusions DEA was able to distinguish between patients with different response rates to medical treatment of IRF and may be useful to individualize therapeutic decision-making.


Diagnostic and interventional radiology | 2014

Diffusion-weighted MRI findings of treated and untreated retroperitoneal fibrosis

Lars Kamper; A.S. Brandt; Hendrik Ekamp; Nadine Abanador-Kamper; Werner Piroth; Stephan Roth; Patrick Haage

PURPOSE We aimed to evaluate diffusion-weighted imaging (DWI) findings in patients with treated and untreated retroperitoneal fibrosis (RPF). METHODS We analyzed magnetic resonance imaging examinations of 44 RPF patients (36 male, 8 female), of which 15 were untreated and 29 were under therapy. Qualitative DWI and T1 postcontrast signal intensities and the largest perivascular extent of RPF were compared between treated and untreated groups and correlated to erythrocyte sedimentation rate and C-reactive protein values. Quantitative DWI signal intensities and apparent-diffusion-coefficients were calculated in regions-of-interest, together with a relative index between signal intensities of RPF and psoas muscle in 15 untreated patients and 14 patients under treatment with remaining perivascular fibrosis of more than 5 mm. RESULTS The extent of RPF in untreated patients was significantly larger compared with the extent of RPF in treated patients (P <0.0001). DWI signal intensities were significantly higher in untreated patients than in patients under therapy (mean, 27 s/mm2 vs. 20 s/mm2; P = 0.009). The calculated DWI-index was significantly higher in untreated patients than in patients under therapy (P = 0.003). CONCLUSION Our data show significant differences in the DWI findings (b800 signal intensities and relative DWI-index) of patients with treated and untreated RPF. DWI is a promising technique in the assessment of disease activity and the selection of patients suitable for medical therapy.


Journal of Vascular Access | 2010

Endovascular treatment of dysfunctional hemodialysis catheters

Lars Kamper; Werner Piroth; Patrick Haage

Hemodialysis-catheter dysfunction is a common clinical condition in nephrology. Like other central venous devices, hemodialysis-catheters show a disposition for partial or complete thrombotic obstruction and fibrin sleeve formation. Thrombolytic infusion is recommended as therapy of first choice. Alternative interventional strategies include over-the-wire catheter exchange, mechanical fibrin sleeve stripping with a snare and angioplastic sleeve disruption. Those approaches show extremely variable results with mediocre long-term patency rates. Therefore, catheter-avoiding strategies should be considered in detail and AV-fistula creation preferred.


Journal of Vascular Access | 2014

Radiological assessment of vascular access in haemodialysis patients.

Lars Kamper; Michael Frahnert; Scott-Oliver Grebe; Patrick Haage

Clinical examination is still the most important diagnostic tool and duplex ultrasonography is the imaging method of first choice. Radiological assessment of vascular access for haemodialysis includes preoperative analysis of vessel anatomy and postoperative surveillance for access maturation as well as diagnosis in vascular access insufficiency. Compared to ultrasonography digital subtraction angiography is superior for the evaluation of the central veins and allows diagnosis and treatment in one session. Computed tomography should only be used in patients with inconclusive ultrasonography results, for example, for the assessment of the central veins and visualization of the vascular tree. Gadolinium-enhanced magnetic resonance imaging is no longer recommended in dialysis patients, because it may trigger nephrogenic systemic fibrosis. In patients with a history of previous central venous catheters additional preoperative imaging of the central veins should be performed. In this article we review the different radiological imaging methods for preoperative assessment and suspected vascular access dysfunction.


Clinical Research in Cardiology | 2012

Influence of algorithm-based analgesia and sedation in patients after sudden cardiac arrest

Nadine Abanador-Kamper; Lars Kamper; Judith Wolfertz; Wilfried Dinh; Petra Thürmann; Melchior Seyfarth

PurposeThe aim of this study was to analyse the effect of an algorithm-based analgesic-sedative management on mechanical ventilation time and length of stay in a cardiological ICU with critical ill patients after sudden cardiac arrest.MethodsWe examined 100 patients after successful resuscitation in a retrospective-prospective single-centre trial by introducing an algorithm-based sedation management. Demographic data, severity of illness classified by APACHE II score (Acute Physiology and Chronic Health Evaluation II), neurological outcome and data for mechanical ventilation time and length of stay were acquired for both groups.ResultsWe found a shorter ventilation time for young patients without severe illness, whereby significant longer ventilation time was observed for patients with higher APACHE II score. Between both groups, we found no significant differences in mechanical ventilation time and length of stay.ConclusionsOur results demonstrate a tendency towards a reduction of mechanical ventilation time for patients without severe illness after sudden cardiac arrest achieved by implementation of a new sedation management, whereby significant longer ventilation time was observed for severe ill patients. Because of lack of statistical significance of our present study, a randomized study with sufficient power is necessary to demonstrate positive effects of a standardized sedation management and its influence on severity of illness.


Diagnostic and interventional radiology | 2013

The potential role of modern US in the follow-up of patients with retroperitoneal fibrosis.

Lars Kamper; A.S. Brandt; Hendrik Ekamp; Matthias Hofer; Stephan Roth; Patrick Haage; Werner Piroth

PURPOSE We aimed to evaluate a standardized ultrasonography (US) algorithm for the visualization of pathologic para-aortic tissue in retroperitoneal fibrosis (RPF). MATERIALS AND METHODS Thirty-five patients with lumbar RPF of typical extent, as determined by abdominal magnetic resonance imaging, were included. Examinations were conducted using standardized abdominal US with axial sections obtained at the levels of the renal arteries, aortic bifurcation, and both common iliac arteries. Imaging of each section was acquired with fundamental B-mode (US) and tissue harmonic imaging, respectively. In addition, we examined RPF visualized using extended field-of-view US. RESULTS Tissue harmonic imaging adequately visualized RPF of typical extent in 33 patients (94.2%). Excellent and good visualization with mild artifacts were achieved in 25 (71.4%) and six (17.1%) patients, respectively. When RPF spread along the iliac arteries, excellent visualization was achieved in 38.7% for the left side and 34.5% for the right side. There were significantly fewer diagnostic examinations for the right iliac (27.6%) than for the left one (9.7%) (P = 0.016). Overall, harmonic imaging achieved significantly better visualization than fundamental B-Mode (P < 0.001). CONCLUSION We described the first systematic evaluation of RPF visualization by modern US techniques. The best imaging quality was found in the typical RPF location, at the level of the aortic bifurcation. These results advocate for the presented US algorithm as an efficient follow-up alternative to cross-sectional imaging in RPF patients.


Medizinische Klinik | 2010

Bildgebung der Retroperitonealfibrose

Lars Kamper; A.S. Brandt; Sven B. Winkler; Hendrik Ekamp; Werner Piroth; Stephan Roth; Patrick Haage

D retroperitoneale Fibrose (RPF) ist eine seltene fibrosierende Erkrankung des hinteren Bauchraums mit einer Prävalenz von 1–2/200 000 [1]. Die primäre oder idiopathische RPF (Morbus Ormond) wird von einer sekundären Form mit einer erkennbaren Ursache unterschieden. Bei etwa zwei Drittel der Fälle liegt eine idiopathische RPF vor. Inzwischen werden die idiopathische RPF und das inflammatorische Bauchaortenaneurysma zum Formenkreis der chronischen Periaortitis gerechnet [2].


CardioVascular and Interventional Radiology | 2009

Time Management in Acute Vertebrobasilar Occlusion

Lars Kamper; Konrad Rybacki; Michael Mansour; Sven B. Winkler; Udo Kempkes; Patrick Haage

Acute vertebrobasilar occlusion (VBO) is associated with a high risk of stroke and death. Although local thrombolysis may achieve recanalization and improve outcome, mortality is still between 35% and 75%. However, without recanalization the chance of a good outcome is extremely poor, with mortality rates of 80–90%. Early treatment is a fundamental factor, but detailed studies of the exact time management of the diagnostic and interventional workflow are still lacking. Data on 18 patients were retrospectively evaluated. Time periods between symptom onset, admission to hospital, time of diagnosis, and beginning of intervention were correlated with postinterventional neurological status. The Glasgow Coma Scale and National Institute of Health Stroke Scale (NIHSS) were used to examine patients before and after local thrombolysis. Additionally, multivariate statistics were applied to reveal similarities between patients with neurological improvement. Primary recanalization was achieved in 77% of patients. The overall mortality was 55%. Major complications were intracranial hemorrhage and peripheral embolism. The time period from symptom onset to intervention showed a strong correlation with the postinterventional NIHSS as well as the patient’s age, with the best results in a 4-h interval. Multivariate statistics revealed similarities among the patients. Evaluation of time management in acute VBO by multivariate statistics is a helpful tool for definition of similarities in this patient group. Similarly to the door-to-balloon time for acute coronary interventions, the chances for a good outcome depend on a short time interval between symptom onset and intervention. While the only manipulable time period starts with hospital admission, our results emphasize the necessity of efficient intrahospital workflow.

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Stephan Roth

Witten/Herdecke University

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Melchior Seyfarth

Witten/Herdecke University

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Judith Wolfertz

Witten/Herdecke University

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Patrick Haage

Witten/Herdecke University

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Vasiliki Karamani

Witten/Herdecke University

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D.A. Lazica

Witten/Herdecke University

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Daniel Goedde

Witten/Herdecke University

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Petra Thürmann

Witten/Herdecke University

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