University Hospital St Pierre

Brussels, Belgium

University Hospital St Pierre

Brussels, Belgium

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Piepsz A.,University Hospital St Pierre | Gordon I.,ULC Institute of Child Health
Quarterly Journal of Nuclear Medicine and Molecular Imaging | Year: 2010

The aim of this work is to present to the reader the practical experience of three clinicians having actively participated to the publication of the guidelines on renography in children. The present publication should be considered as a practical guide. We have underlined good practice, obvious errors to avoid, common pitfalls which might be overlooked, some items for which more than one reasonable solution exists and finally a few controversial points, for which there is still no agreement and no solid evidence to resolve these issues. This paper is only focused on the aspects of acquisition and processing and will not cover the clinical aspects, namely the interpretation of the renogram in terms of renal obstruction or, more precisely, in terms of risk of renal deterioration.


Stevens E.,University Hospital St Pierre | Roman A.,University Hospital St Pierre
Vascular | Year: 2014

The classic procedure for aortobifemoral bypass is open surgery. Laparoscopy has been accepted by several authors as a minimal invasive alternative for aortoiliac occlusive disease. The totally retroperitoneal laparoscopic procedure has been described as an alternative to the transperitoneal approach. Whatever the approach, the aortoprosthetic anastomosis is a major difficulty making those techniques unpopular despite obvious advantages for the patients. We report a clampless and sutureless approach for the proximal anastomosis of a totally retroperitoneal laparoscopic aortobifemoral bypass using an EndoVascular REtroperitoneoScopic Technique (EVREST). This approach was proposed to a 56-year-old man with severe aortoiliac occlusive disease. There was no indication for endovascular re-vascularization. The patient was placed in a 30° right lateral decubitus position. The dissection of the retroperitoneal space was performed and the infrarenal aorta was exposed. A bifurcated graft was inserted into the retroperitoneal space. Under videoscopic control the prosthetic limbs were brought to the groins. The main body of the graft was connected on the left side of the aorta by an intra and extra aortic covered stent-graft. This connection was performed without the use of an aortic clamp and without suture. The femoral anastomoses were performed by classic open surgery. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.


Piepsz A.,University Hospital St Pierre | Tondeur M.,University Hospital St Pierre | Nogarede C.,University Hospital St Pierre | Collier F.,Childrens Hospital Queen Fabiola | And 2 more authors.
Nuclear Medicine Communications | Year: 2011

INTRODUCTION: Until recently, renogram, performed in children with pelvi-ureteric junction stenosis detected antenatally, has not been able to predict the probability of function improvement after surgery or the risk of function deterioration in case of conservative attitude. Recently, Schlotmann et al. have suggested that cortical transit might have this predictive role. The aim of this study, focused on those kidneys with severely impaired cortical transit, was to verify this statement. METHODS: All renograms performed in children during a 3-year period (n=729) were retrospectively reviewed and 19 pediatric patients were selected based on an antenatally detected unilateral pelvi-ureteric junction syndrome, the existence of at least two renograms during the follow-up and a severe cortical transit impairment, visually defined. Twenty-six pairs of data could be analyzed and allowed comparing preoperative and postoperative differential renal function (DRF), and the DRF changes during the conservative management. RESULTS: Among the 16 patients who underwent pyeloplasty, 10 showed a significant DRF improvement. Among the 10 patients with conservative follow-up, four showed a significant DRF deterioration. CONCLUSION: Severely impaired cortical transit seems to be a valuable marker of those patients who could benefit from a pyeloplasty, either because of the high probability of postoperative DRF improvement, or because of DRF deterioration in case of an conservative approach. However, a normal cortical transit, as defined in this study, does not exclude the risk of DRF deterioration. Alternatively, the design of this study does not allow excluding the fact that DRF might improve after pyeloplasty despite a normal cortical transit. © 2011 Wolters Kluwer Health | Lippincott Williams &Wilkins.


Demeester R.P.,Institute of Tropical Medicine | Demeester R.P.,University of Antwerp | Demeester R.P.,University Hospital St Pierre | Bottieau E.,Institute of Tropical Medicine | And 7 more authors.
Journal of Travel Medicine | Year: 2011

Background. KABISA TRAVEL is a clinical decision support system developed by the Institute of Tropical Medicine of Antwerp, Belgium, for the diagnosis of febrile illnesses after a stay in the tropics. This study aimed to compare the diagnostic accuracy of KABISA TRAVEL with that of expert travel physicians. Methods. From December 2007 to April 2009, travelers with fever after a stay in the tropics were included in a multicenter trial conducted in travel referral centers in the Netherlands, Italy, Spain, and Belgium. Physicians were asked (1) to rank their first assessment diagnoses, (2) to enter in KABISA TRAVEL clinical and laboratory data available within 36 hours, and (3) to interact with the tutor until its final diagnostic ranking. Both physicians and KABISA TRAVEL rankings were then compared with the final diagnosis confirmed by reference methods. The clinical utility was also surveyed. Results. A total of 205 cases with confirmed diagnosis were evaluated (male/female ratio: 1.85; mean age: 35 y). Most patients were western travelers or expatriates (60%) and were returning from sub-Saharan Africa (58%). Travel physicians and KABISA TRAVEL ranked the correct diagnosis in the first place for 70 and 72% of the cases, respectively, and within the top five both for 88% of them. Travel physicians reported having been suggested useful further investigations in 16% of the cases, and having been helped for obtaining the diagnosis in 24%. This was reported more frequently when they had initially missed the diagnosis (suggestion: 48% in missed vs 12% in found diagnoses, p < 0.001; helpful: 48% in missed vs 21% in found diagnoses, p = 0.005). Conclusions. KABISA TRAVEL performed as well as expert travel physicians in diagnosing febrile illnesses occurring after a tropical stay. Clinicians perceived the system as more helpful when they had not immediately considered the correct diagnosis. © 2011 International Society of Travel Medicine.


Tondeur M.,University Hospital St Pierre | Nogarede C.,University Hospital St Pierre | Donoso G.,Hospital San Juan Of Dios | Piepsz A.,University Hospital St Pierre
Scandinavian Journal of Clinical and Laboratory Investigation | Year: 2013

Purpose. To evaluate inter-and intra-observer reproducibility of renographic quantitative parameters of input and output in children. Methods. 100 children with unilateral or bilateral uropathy were selected, aiming to cover the entire range of ages, overall glomerular filtration rate (GFR), differential renal function (DRF) and quality of drainage. Renograms were acquired and processed according to the EANM guidelines, using a non-commercial software. Following parameters were tested: DRF using integral and Patlak methods, normalized residual activity (NORA) and output efficiency (OE) at 20 min and on the late post-erect post-micturition acquisition. Three observers from the same department and one from Santiago (Chile) processed independently the 100 renograms using the same renal software. Two observers reprocessed the 100 renograms again two months later in order to evaluate the intra-observer reproducibility. Results and conclusion. No significant difference was observed between the four observers, whatever the considered parameter of input function or output. For left DRF (Integral and Patlak methods), 95% of the individual differences were between-5% and +5 %. They were between-0.5 and +0.5 units for both NORA 20 and NORA PM, and between-10% and +10% for OE 20 and OE PM. Inter-and intra-observer reproducibility were comparable. Outliers tended to be more frequent for Patlak than for Integral. Very low GFR (< 20 mL/min/1.73 m2), very young age (first days of life), huge megaureters, NORA values higher than 2.0, OE values below 60% and bladder in the renal background area (ectopic kidney) were the main characteristics of extreme differences. © 2013 Informa Healthcare.


Piepsz A.,University Hospital St Pierre
Seminars in Nuclear Medicine | Year: 2011

Although renography has been used for half a century to evaluate the function of the infant kidney, there are still important disagreements among the specialists involved in this particular pathology. Each department of nuclear medicine has his own way to acquire and process a renogram; to interpret the obtained images, curves, and quantitative parameters; and to make recommendations for the referring physician. The urologist has his or her part of responsibilities because the decision for operating or not operating varies from one center to another and is generally determined by a series of unproven assumptions. The aim of the present work is to focus on the main controversies involving both the nuclear medicine physician and the urologist. Concerning the technique of renography. The bladder catheter, systematically recommended in different centers, can best be replaced in most of the cases by a much less-invasive procedure, namely the acquisition and processing of late postmicturition (PM) posterect images. The change of patient's position contributes strongly to the renal washout. Intravenous hydration is used to standardize the level of hydration. However, the patients, in most of the cases, are in good health, and adequate oral hydration is sufficient. Even if hydration was not ideal when the procedure began, the administration of furosemide and the late PM images will result in a very good drainage of a normal kidney. Any renal tracer with high extraction rate is adequate, but diethylene triamine pentaacetic acid (99mTc-DTPA) does not allow a precise estimation of differential function in children younger than 6 months. The moment of furosemide injection (F0, F+20, F-15) does not influence the quality of the final renal washout, and the F0 procedure is recommended in cases of known hydronephrosis because it shortens the time of acquisition on the gamma camera and allows the simultaneous injection of both the tracer and the diuretic. Background correction remains controversial among nuclear medicine physicians. Including in the background area some liver and spleen activity, which are responsible for an important part of the extrarenal activity within the renal area, will improve the quality of the renogram curve, suppressing almost completely the initial vascular phase. The supporters of the Rutland-Patlak (R-P) fit for calculating differential function state that the vascular component is eliminated better than with use of the classical integral method. However, this method is based on a slope, with counting statistics being rather poor in infants with immature function. In most of the cases, the integral method will provide robust results. Determination of the same differential function by the use of both methods increases the level of confidence of the final results. It is generally admitted that the first renogram in children with antenatally detected hydronephrosis should be performed at approximately 1 month of age. However, there is a tendency to start earlier, and even in the first days of life, in case of huge hydronephrosis. The renogram should be repeated in case of significant hydronephrosis, significant increase of dilation, poor response to furosemide, or low initial differential function. Moderate dilation associated with normal differential function can probably be monitored by ultrasound alone. T of the diuretic curve is an empiric parameter that does not take into account the bladder emptying and the change of patient's position. Output efficiency (OE) and normalized residual activity (NORA), measured on the late PM and posterect images, represent physiological parameters not dependent on the input function of the considered kidney and can be used whatever the moment of furosemide injection. There is presently no way to quantitatively measure cortical transit in antenatally detected pelviureteric junction syndrome; all methods are limited by the slight kidney motion related to respiratory movements and by the almost-complete superimposition between cortical area and collecting system. The best approach probably is a visual estimation. Concerning the position of the urologist. The main controversy is related to the definition of obstruction and the indication for surgery. Neither the degree of hydronephrosis nor the impairment of differential function and/or the quality of the response to furosemide can define which kidney is in danger of further deterioration. Alternatively, these parameters are unable to predict for which kidneys an improvement of differential function can be expected because of a pyeloplasty. It has not been excluded, according to recent published work, that cortical transit could be a better predictive factor of the risk of a conservative attitude or the benefits of a surgical procedure, but this procedure has still to be confirmed. © 2011 Elsevier Inc. All rights reserved.


Piepsz A.,University Hospital St Pierre | Nogarede C.,University Hospital St Pierre | Tondeur M.,University Hospital St Pierre
Nuclear Medicine Communications | Year: 2011

BACKGROUND: Output efficiency (OE) and normalized residual activity (NORA) are two parameters that allow quantifying the renal drainage at any moment of renographic acquisition. Although OE is theoretically more accurate than NORA in case of a decreased overall renal function, both parameters present some weaknesses. OBJECTIVES: To compare both parameters and to evaluate whether the clinical information provided by both parameters is identical. METHODS: From a large database of Tc-99m mercaptoacetyltriglycine 3 renographic studies, 450 kidneys were selected covering a large range of ages, overall function, split function, and quality of drainage. NORA and OE were calculated at the end of the 20-min renogram, as well as on the late post erect postmicturition (PM) views. RESULTS: An inverse correlation was observed between NORA 20 and OE 20 (r=-0.926), as well as between NORA PM and OE PM (r=-0.936). Discrepancies were noted in approximately 10% of the kidneys, but main discrepancies, which would result in a different estimation of the quality of drainage, were only observed in 2% of the kidneys. There was no bias in the discordances; OE could reveal a better as well as a worse quality of drainage than NORA. It is likely therefore that imperfections of both parameters might be the cause of the divergences. The stratification of the kidneys according to age, overall renal function, split function, or quality of drainage did not modify the results. CONCLUSION: NORA, being much easier to program, can replace the output efficiency in the evaluation of renal drainage. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.


PubMed | University Hospital St Pierre
Type: Journal Article | Journal: Scandinavian journal of clinical and laboratory investigation | Year: 2013

To evaluate inter- and intra-observer reproducibility of renographic quantitative parameters of input and output in children.100 children with unilateral or bilateral uropathy were selected, aiming to cover the entire range of ages, overall glomerular filtration rate (GFR), differential renal function (DRF) and quality of drainage. Renograms were acquired and processed according to the EANM guidelines, using a non-commercial software. Following parameters were tested: DRF using integral and Patlak methods, normalized residual activity (NORA) and output efficiency (OE) at 20 min and on the late post-erect post-micturition acquisition. Three observers from the same department and one from Santiago (Chile) processed independently the 100 renograms using the same renal software. Two observers reprocessed the 100 renograms again two months later in order to evaluate the intra-observer reproducibility.No significant difference was observed between the four observers, whatever the considered parameter of input function or output. For left DRF (Integral and Patlak methods), 95% of the individual differences were between -5% and +5 %. They were between -0.5 and +0.5 units for both NORA 20 and NORA PM, and between -10% and +10% for OE 20 and OE PM. Inter-and intra- observer reproducibility were comparable. Outliers tended to be more frequent for Patlak than for Integral. Very low GFR (< 20 mL/min/1.73 m(2)), very young age (first days of life), huge megaureters, NORA values higher than 2.0, OE values below 60% and bladder in the renal background area (ectopic kidney) were the main characteristics of extreme differences.


PubMed | University Hospital St Pierre
Type: Journal Article | Journal: The quarterly journal of nuclear medicine and molecular imaging : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of... | Year: 2010

The aim of this work is to present to the reader the practical experience of three clinicians having actively participated to the publication of the guidelines on renography in children. The present publication should be considered as a practical guide. We have underlined good practice, obvious errors to avoid, common pitfalls which might be overlooked, some items for which more than one reasonable solution exists and finally a few controversial points, for which there is still no agreement and no solid evidence to resolve these issues. This paper is only focused on the aspects of acquisition and processing and will not cover the clinical aspects, namely the interpretation of the renogram in terms of renal obstruction or, more precisely, in terms of risk of renal deterioration.


PubMed | University Hospital St Pierre
Type: Journal Article | Journal: Nuclear medicine communications | Year: 2011

Until recently, renogram, performed in children with pelvi-ureteric junction stenosis detected antenatally, has not been able to predict the probability of function improvement after surgery or the risk of function deterioration in case of conservative attitude. Recently, Schlotmann et al. have suggested that cortical transit might have this predictive role. The aim of this study, focused on those kidneys with severely impaired cortical transit, was to verify this statement.All renograms performed in children during a 3-year period (n=729) were retrospectively reviewed and 19 pediatric patients were selected based on an antenatally detected unilateral pelvi-ureteric junction syndrome, the existence of at least two renograms during the follow-up and a severe cortical transit impairment, visually defined. Twenty-six pairs of data could be analyzed and allowed comparing preoperative and postoperative differential renal function (DRF), and the DRF changes during the conservative management.Among the 16 patients who underwent pyeloplasty, 10 showed a significant DRF improvement. Among the 10 patients with conservative follow-up, four showed a significant DRF deterioration.Severely impaired cortical transit seems to be a valuable marker of those patients who could benefit from a pyeloplasty, either because of the high probability of postoperative DRF improvement, or because of DRF deterioration in case of an conservative approach. However, a normal cortical transit, as defined in this study, does not exclude the risk of DRF deterioration. Alternatively, the design of this study does not allow excluding the fact that DRF might improve after pyeloplasty despite a normal cortical transit.

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