Hydrostatic pressure of the renal pelvis as a radiation-free alternative to fluoroscopic nephrostogram following percutaneous nephrolithotomy.

BACKGROUND: We evaluated the hydrostatic pressure of the renal pelvis (RPP) as a radiation-free alternative to fluoroscopic nephrostogram to assess ureteral patency after percutaneous nephrolithotomy (PCNL). METHODS: Retrospective non-inferiority study analyzing 248 PCNL-patients (86 female (35%) and 162 males (65%)) between 2007 and 2015. Postoperatively, RPP was measured using a central venous pressure manometer in cmH2O. The primary endpoint was to assess RPP depending on the patency of the ureter and the nephrostomy tube removal. Secondary, the upper limit of normal RPP of [Formula: see text] 20 cmH2O was assessed as an indicator of an unobstructed patency. RESULTS: The median procedure duration was 141 min (112-171.5) with a stone free rate of 82% (n = 202). RPP was significantly higher in patients with obstructive nephrostogram with 25.0 mmH2O (21.0-32.0) versus 20.0 mmH2O (16.0-24.0; p < 0.001). The pressure was lower in successful nephrostomy removal with 18 cmH2O (15-21) versus 23 cmH2O (20-29) in the leakage group (p < 0.001). The analysis of a cut-off of [Formula: see text] 20 cmH2O showed a sensitivity of 76.9% (95% CI [60.7%; 88.9%]) and a specificity of 61.5% (95% CI [54.6%; 68.2%]). The negative predictive value was 93.4% (95% CI: [87.9%; 97.0%]) and the positive predictive value 27.3% (95% CI [19.2%; 36.6%]). The accuracy of the model showed an AUC = 0.795 (95% CI [0.668; 0.862]). CONCLUSION: The hydrostatic RPP seems to allow a bedside evaluation of ureteral patency after PCNL.

The "Guidewire-Coil"-Technique to prevent retrograde stone migration of ureteric calculi during intracorporeal lithothripsy.

BACKGROUND: Stone retropulsion represents a challenge for intracorporeal lithotripsy of ureteral calculi. The consequences are an increased duration and cost of surgery as well as decreased stone-free rates. The use of additional tools to prevent proximal stone migration entails further costs and risks for ureteral injuries. We present the simple technique of using a coil of the routinely used guidewire to prevent stone retropulsion. METHODS: We retrospectively evaluated all patients with mid-to-proximal ureteral stones in 2014, which were treated by ureteroscopic lithotripsy (Ho: YAG and/or pneumatic lithotripsy). The preoperative stone burden was routinely assessed using low dose CT scan (if available) and/or intravenous pyelogram. RESULTS: The study population consisted of 55 patients with 61 mid-to-proximal calculi. Twentyseven patients underwent semirigid ureterorenoscopy using the "Guidewire-Coil-Technique", the second group (n = 28) served as control group using the guidewire as usual. There has been a statistically significant reduction of accidental stone retropulsion (2/27 vs. 8/28, p < 0.05) as well as a decreased use of auxiliary procedures (p < 0.05) compared to the control group. No difference was observed in operative time. One ureteral injury in the control group required a prolonged ureteral stenting. CONCLUSION: The "Guidewire-Coil-Technique" is a simple and safe procedure that may help to prevent proximal calculus migration and therefore may increase stone-free rates without causing additional costs.

(18)F-FDG PET/MRI evaluation of retroperitoneal fibrosis: a simultaneous multiparametric approach for diagnosing active disease.

PURPOSE: The aim of this study was to evaluate integrated (18)F-FDG PET/MRI as a one-stop diagnostic procedure in the assessment of (active) idiopathic retroperitoneal fibrosis (RPF) METHODS: A total of 22 examinations comprising a PET/CT scan followed by a PET/MRI scan in 17 patients (13 men, 4 women, age 58 ± 11 years) with histopathologically confirmed RPF at diagnosis or during follow-up under steroid therapy were analysed in correlation with laboratory inflammation markers (ESR, CRP). The patient cohort was subdivided into two groups: 6 examinations in untreated and 16 in treated patients. Tissue formations in typically periaortic localization suggestive of RPF were visually and quantitatively evaluated. The PET analysis included the assessment of SUVmax and a qualitative score for FDG uptake in RPF tissue in relation to the uptake in the liver. MRI analysis included evaluation of the T2-weighted image signal intensity, contrast enhancement and diffusion restriction (ADC values). Mean values were compared using the Mann-Whitney U test. ADC, SUVmax and ESR values were correlated using Pearson's correlation. RESULTS: MRI analysis revealed restricted diffusion in 100 % and 56 %, hyperintense T2 signal in 100 % and 31 %, and contrast enhancement in the periaortic tissue formation suggestive of RPF in 100 % and 62.5 % in the untreated and treated patients, respectively. In the qualitative and quantitative PET analysis, statistically significant differences were found for mean FDG uptake scores (2.5 ± 0.8 in untreated patients and 1.1 ± 0.9 in treated patients) and mean SUVmax (7.8 ± 3.5 and 4.1 ± 2.2, respectively). A strong correlation was found between the ADC values and SUVmax (Pearson r -0.65, P = 0.0019), and between ESR and CRP values and SUVmax (both r = 0.45, P = 0.061). CONCLUSION: Integrated (18)F-FDG PET/MRI shows high diagnostic potential as a one-stop diagnostic procedure for the assessment of (active) RPF providing multiparametric supportive information.

Tamoxifen monotherapy in the treatment of retroperitoneal fibrosis.

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.

[Infrarenal aortic ectasia in retroperitoneal fibrosis (RPF)]. / Aufweitungen der infrarenalen Aorta bei retroperitonealer Fibrose (RPF).

We analysed the infrarenal aortic morphology by abdominal MR-examinations of 47 RPF patients compared to a control group. A significant larger aortic calibre and higher rates of infrarenal dilatation in male RPF patients were observed. The larger aortic diameter in male RPF patients may be due to periaortic inflammation with resulting aortic ectasia and supports the classification of RPF into the spectrum of chronic periaortitis.

Impact of CYP2D6 Polymorphisms on Tamoxifen Treatment in Patients With Retroperitoneal Fibrosis: A First Step Towards Tailored Therapy?

OBJECTIVE: To investigate the influence of CYP2D6 polymorphisms on outcomes and health-related quality of life of patients with retroperitoneal fibrosis (RPF) receiving tamoxifen (TMX). TMX is an effective alternative to corticosteroids for patients with RPF. Conversion of TMX to more potent endoxifen is dependent on enzyme activity of CYP2D6. MATERIALS AND METHODS: CYP2D6 genotyping and phenotype prediction of all patients treated with TMX between 02/2007 and 01/2018 was assessed using multiplex polymerase chain reaction (PCR). Groups were classified by phenotype: extensive (EM) vs poor and intermediate (PM + IM) vs ultrarapid metabolizer (UM). Retrospective evaluation of outcome (including magnetic resonance imaging and positron emission tomography-computed tomography) and health-related quality of life using the SF-36 was performed. RESULTS: A total of 63/194 patients received TMX, 40/63 with complete follow-up were sequenced: Twenty-nine patients with EM phenotype, 8 PM + IM and 3 UM. The median therapy duration was 364.5 days with a mean follow-up of 62.9 months. Seven therapy terminations occurred due to lack of response (17.5%), including all UM patients (P <.001). Magnetic resonance imagings showed a regression of fibrosis for EM and PM + IM in 69% and 62.5% of cases and a progression for UM in 100% (P = .004). In positron emission tomography-computed tomography, glucose utilization of RPF decreased significantly for EM and PM + IM. The physical sum-score of SF-36 improved for EM and PM + IM and decreased for UM (P <.05). The removal of DJ-stents was successful for EM, PM + IM, and UM in 48.3%, 75%, and 0% of cases (P = .0581). CONCLUSION: Contrary to expectations, UM showed the lowest success rate, which concludes that genotyping of RPF-patients may be useful in the sense of a tailored-therapy.

Diffusion-weighted MRI findings of treated and untreated retroperitoneal fibrosis.

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.

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

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.

An aid to decision-making in therapy of retroperitoneal fibrosis: dynamic enhancement analysis of gadolinium MRI.

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.

[Ureteral realignment with the rendezvous procedure in complex ureteral injuries - aspects of technique and our experience]. / Ureter-Realignment mittels Rendez-Vous-Technik bei komplexen Harnleiterverletzungen - Methodik und eigene Erfahrungen.

PURPOSE: The rendezvous procedure for re-establishing ureteral continuity after complex ureteral injuries is introduced and we present our experience with this technique. MATERIAL AND METHODS: Aspects of the technique are described in a detailed step-by-step instruction using intraoperative radiographs. We evaluated our patient data from 1998 until 2009 for cases in which the rendezvous procedure was attempted. RESULTS: The rendezvous procedure was used in a total of 11 patients. Realignment was successful in 10 cases (90.9 %) and the initial nephrostomy could be removed. In 3 of 7 cases postoperative removal of the JJ ureteric stent was successful. In 7 patients the final surgical ureter reconstruction was performed after a medium period of 7 months. 5 cases of ureteroneocystostomy and 2 cases of reconstruction of the ureter either with colon or ileum segments were accomplished. In 1 patient a permanent maintenance of the DJ ureteral stent was necessary. CONCLUSION: Ureteral realignment with the rendezvous procedure enables disposition of the ureteral stent in many cases, exclusively antegrade or retrograde procedures failed. By this means nephrostomy could be spared as a temporary or permanent solution and a better chance of restitutio ad integrum could be realised.