A. R. van Erkel
Leiden University
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Featured researches published by A. R. van Erkel.
European Radiology | 1998
A. B. Van Rossum; A. R. van Erkel; E. L. Persijn van Meerten; E. R. Tjin A. Ton; S. A. Rebergen; Peter M. T. Pattynama
Abstract. The aim of this study was to test the influence of observer experience on the accuracy for interpreting helical CT for acute pulmonary embolism (PE) and to identify sources of observer errors. Three observers of different expertise blindly assessed 147 helical CT scans for suspected PE (true status regarding absence or presence of PE known from independent reference studies). These observers were (a) an experienced CT radiologist, (b) a fellow in CT, and (c) a second-year resident without any formal training in CT. None of them had prior experience with CT for PE. Firstly, 70 CT scans were scored without revealing true PE status. Afterwards, feedback was provided and another 77 CT scans were evaluated. The CT scans were scored on a 5-point confidence scale and receiver-operator-characteristic analysis was performed. Different sources of interpretation errors were analyzed. The two observers with CT experience were significantly more accurate than the unexperienced observer. Their performance was not influenced by feedback training. Certain observer errors were identified, but there was no clear difference among the three observers considering the type of errors. There is significant influence of observer experience on accuracy of reading helical CT for PE: A basic working experience with whole-body CT seems to be a prerequisite. These results suggest that with this experience any radiologist should be able to achieve good accuracy; helical CT thus might become a suitable technique for acute PE in routine clinical practice.
Journal of Bone and Joint Surgery-british Volume | 2011
S. P. J. Muijs; A. R. van Erkel; P. D. S. Dijkstra
Vertebral compression fractures are the most prevalent complication of osteoporosis and percutaneous vertebroplasty (PVP) has emerged as a promising addition to the methods of treating the debilitating pain they may cause. Since PVP was first reported in the literature in 1987, more than 600 clinical papers have been published on the subject. Most report excellent improvements in pain relief and quality of life. However, these papers have been based mostly on uncontrolled cohort studies with a wide variety of inclusion and exclusion criteria. In 2009, two high-profile randomised controlled trials were published in the New England Journal of Medicine which led care providers throughout the world to question the value of PVP. After more than two decades a number of important questions about the mechanism and the effectiveness of this procedure remain unanswered.
Journal of Bone and Joint Surgery-british Volume | 2012
M. J. Nieuwenhuijse; A. R. van Erkel; P. D. S. Dijkstra
The optimal timing of percutaneous vertebroplasty as treatment for painful osteoporotic vertebral compression fractures (OVCFs) is still unclear. With the position of vertebroplasty having been challenged by recent placebo-controlled studies, appropriate timing gains importance. We investigated the relationship between the onset of symptoms - the time from fracture - and the efficacy of vertebroplasty in 115 patients with 216 painful subacute or chronic OVCFs (mean time from fracture 6.0 months (sd 2.9)). These patients were followed prospectively in the first post-operative year to assess the level of back pain and by means of health-related quality of life (HRQoL). We also investigated whether greater time from fracture resulted in a higher risk of complications or worse pre-operative condition, increased vertebral deformity or the development of nonunion of the fracture as demonstrated by the presence of an intravertebral cleft. It was found that there was an immediate and sustainable improvement in the level of back pain and HRQoL after vertebroplasty, which was independent of the time from fracture. Greater time from fracture was associated with neither worse pre-operative conditions nor increased vertebral deformity, nor with the presence of an intravertebral cleft. We conclude that vertebroplasty can be safely undertaken at an appropriate moment between two and 12 months following the onset of symptoms of an OVCF.
American Journal of Transplantation | 2016
M. F. Nijhoff; Marten A. Engelse; Jeroen Dubbeld; Andries E. Braat; Jan Ringers; Dave L. Roelen; A. R. van Erkel; H. S. Spijker; H. Bouwsma; P. J. M. van der Boog; J.W. de Fijter; Ton J. Rabelink; E. J. P. de Koning
Pancreatic islet transplantation is performed in a select group of patients with type 1 diabetes mellitus. Immunosuppressive regimens play an important role in long‐term islet function. We aimed to investigate the efficacy of islet transplantation in patients with type 1 diabetes and a previous kidney transplantation using an alemtuzumab‐based induction regimen and triple maintenance immunosuppression. Patients with type 1 diabetes, who had received a kidney transplant previously, were treated with alemtuzumab as induction therapy for their first islet transplantation and basiliximab induction therapy for subsequent islet transplantations. Maintenance immunosuppression consisted of triple immunosuppression (tacrolimus, mycophenolate mofetil, and prednisolone). Thirteen patients (age 50.9 ± 9.2 years, duration of diabetes 35 ± 9 years) received a total of 22 islet transplantations. One‐ and 2‐year insulin independence was 62% and 42%, respectively; graft function was 100% and 92%, respectively. HbA1c dropped from 57.2 ± 13.1 (7.4 ± 1.2%) to 44.5 ± 11.8 mmol/molHb (6.2 ± 0.9%) (p = 0.003) after 2 years. Six of 13 patients suffered from severe hypoglycemia before islet transplantation. After transplantation, severe hypoglycemia was restricted to the only patient who lost graft function. Creatinine clearance was unchanged. Islet‐after‐kidney transplantation in patients with type 1 diabetes using an alemtuzumab‐based induction regimen leads to considerable islet allograft function and improvement in glycemic control.
Archive | 1990
A.P.G. van Gils; T. H. M. Falke; A. R. van Erkel; C.J.H. van de Velde; E. K. J. Pauwels
Functioning paragangliomas are catecholamine-secreting tumours originating from the autonomic nervous system. They may be situated anywhere from the neck to the bladder and, although rare in the general population (estimated incidence: 0.001%–0.002%) (Beard et al. 1983), carry a considerable risk to those affected. In these patients there is a marked tendency for multiple functioning paragangliomas occurring simultaneously or consecutively over an extended period (Karasov et al. 1982; Revak et al. 1971; Bogdasarian and Lotz 1979).
Ejso | 2010
S.T.P. Kouwenhoven; Gerrit-Jan Liefers; A. R. van Erkel
AIMS The purpose of this study was to determine if Computed Tomography Arterial Portography (CTAP) has additional value to Contrast Enhanced helical CT (CE-CT) in selecting patients for hepatic surgery or Isolated Hepatic Perfusion/systemic chemotherapy. MATERIALS AND METHODS Forty-one patients were included. All CTs were performed in the normal pre-operative work-up of patients with liver metastases in our regular clinical setting and reviewed blinded by a radiologist. For CE-CT and CTAP the number, size (largest diameter) and location of all suspected malignant liver lesions were recorded. The favourable treatment option was determined based on the results of CE-CT and CTAP independently. The therapeutic decision based on CE-CT and CTAP was compared with the definite treatment. For all patients with recorded findings during surgery, consisting of intra-operative ultrasound, liver palpation and histology a standard of reference for lesion detection was available. For these patients detection rates and the fraction of false positive lesions were calculated. RESULTS Twenty-seven patients were treated with hepatic resection and/or RFA. Fourteen patients were treated with chemotherapy, 4 with Isolated Hepatic Perfusion (IHP) and 10 with systemic therapy. Based on the findings on CE-CT 31 patients were classified as surgical candidates and 10 as non-surgical patients. Based on the findings on CTAP, surgery should be the treatment of choice in 29 patients and 12 patients were classified non-surgical. CE-CT and CTAP disagreed in two cases (4.9%). Seventy-four metastases were identified at surgery and pathologically proved. CE-CT and CTAP showed 53 (.72) and 66 (.89) metastases, respectively. CONCLUSION Despite a significantly higher detection rate for hepatic metastases, CTAP has no added value in the therapeutic stratification in candidates for resection of hepatic metastases of colorectal cancer.
American Journal of Transplantation | 2018
M. F. Nijhoff; Jeroen Dubbeld; A. R. van Erkel; P. J. M. van der Boog; Ton J. Rabelink; Marten A. Engelse; E. J. P. de Koning
Simultaneous pancreas–kidney (SPK) transplantation is an important treatment option for patients with type 1 diabetes (T1D) and end‐stage renal disease (ESRD). Due to complications, in up to 10% of patients, allograft pancreatectomy is necessary shortly after transplantation. Usually the donor pancreas is discarded. Here, we report on a novel procedure to rescue endocrine tissue after allograft pancreatectomy. A 39‐year‐old woman with T1D and ESRD who had undergone SPK transplantation required emergency allograft pancreatectomy due to bleeding at the vascular anastomosis. Islets were isolated from the removed pancreas allograft, and almost 480 000 islet equivalents were infused into the portal vein. The patient recovered fully. After 3 months, near‐normal mixed meal test (fasting glucose 7.0 mmol/L, 2‐hour glucose 7.5 mmol/L, maximal stimulated C‐peptide 3.25 nmol/L, without insulin use in the preceding 36 hours) was achieved. Glycated hemoglobin while taking a low dose of long‐acting insulin was 32.7 mmol/mol hemoglobin (5.3%). When a donor pancreas is lost after transplantation, rescue β cell therapy by islet alloautotransplantation enables optimal use of scarce donor pancreata to optimize glycemic control without additional HLA alloantigen exposure.
Radiology | 1996
A. R. van Erkel; A. B. Van Rossum; Johan L. Bloem; Job Kievit; Peter M.T. Pattynama
Radiology | 1996
V. P. M. Van Der Hulst; J.M. van Baalen; Leo J. Schultze Kool; J.H. van Bockel; A. R. van Erkel; J. Ilgun; Peter M.T. Pattynama
ASCO Meeting Abstracts | 2006
Hans Gelderblom; J. Verweij; Neeltje Steeghs; A. R. van Erkel; L. van Doorn; Jan Ouwerkerk; Prabhu Rajagopalan; A. Matthys; D. Voliotis; F. Eskens