Retroperitoneal fibrosis is still underdiagnosed entity with poor prognosis

Intelligent Ureteral Stent Placeable via Standard Procedure for Kidney Pressure Telemetry: An Ex-Vivo Study

This paper reports the first telemetric ureteral stent compatible with common placement procedure, enabling wireless sensing and detection of ureteral obstruction and resultant kidney swelling known as hydronephrosis at an early stage. This sensor-integrated "intelligent" ureteral stent is prototyped via the design and fabrication approaches that raise the practicality of the device and tested in a harvested swine kidney-ureter model ex vivo. Leveraging a polymeric double-J stent and micro-electro-mechanical systems technology, the intelligent stent is built by embedding micro pressure sensors and a radiofrequency antenna, forming a resonant circuit that enables wireless kidney pressure monitoring in an operating frequency of 40-50 MHz. The stent device is entirely packaged with Parylene-C for both biocompatibility and electrical insulation of the device in order to function in the real environment including urine, an electrically conductive liquid. A comparison between the results measured in in-vitro and ex-vivo settings show a good match in the sensitivity to applied pressure. In particular, the ex-vivo test in the kidney-ureter model pressurized with artificial urine in a cycled manner demonstrates wireless pressure tracking with a response of 1.3 kHz/mmHg, over pressures up to 37 mmHg that well covers a range of pressure increase known for chronic obstruction. This testing is enabled by the prototype placement into the ex-vivo model using the standard stenting technique and tools without noticeable functional degradation or failures, showing potential compatibility of the device with today's clinical need as a ureteral stent.

Radical nephrectomy for retroperitoneal fibrosis: Case report

INTRODUCTION AND IMPORTANCE

Retroperitoneal fibrosis is a proliferative disease of fibroblasts with a still unclear appearance and low incidence. The clinical manifestations are nonspecific and appear late, pain is the most common symptom present. Elevated serum IgG4 levels are observed in up to 60 % of the patients and the main goal of treating this condition is to preserve kidney function.

CASE PRESENTATION

We present a case of an asymptomatic 34-year-old man. A poorly defined mass in the pre-aortic, pre-caval and right rim regions with possible malignancy was observed. After 3 biopsies, it was treated as low-grade follicular lymphoma with chemotherapy. With new growth after 1 year, right radical nephrectomy was performed to resect the lesion. Pathology showed that it was advanced retroperitoneal fibrosis with negative IgG4.

CLINICAL DISCUSSION

RPF usually presents as an irregular mass of periaortic tissue that frequently has malignancy as a risk factor and may be associated with high levels of IgG4. Most of the time, the disease is asymptomatic. When the patient presents symptoms, pain is the most common, although late. Its diagnosis is made by imaging and histopathological exams. Treatment varies according to the progression of the disease, but aims to try to preserve renal function.

CONCLUSION

RPF is a disease characterized by the accumulation of fibroblasts in the abdominal region with an etiology that has not yet been fully discovered, which can present in several ways, generally identified by imaging exams and can be treated individually depending on the invasiveness of the disease.

Multiple Myeloma and Retroperitoneal Fibrosis: A Rare Association Report and Literature Review

Multiple myeloma (MM) is a common hematological malignancy. Autologous hematopoietic stem cell transplantation (auto-HSCT) can significantly improve the prognosis of patients with MM, but a variety of complications may occur after transplantation. Retroperitoneal fibrosis (RPF) is a rare cause of obstructive nephropathy. Because there are no specific symptoms at the time of onset and the course of the disease is often insidious, special laboratory and instrumental examination methods are usually needed to confirm the diagnosis. This article describes the clinical case of a 50-year-old female patient diagnosed with multiple myeloma. She developed postoperative acute kidney injury (AKI) more than 20 days after transplantation and was subsequently diagnosed with retroperitoneal fibrosis. After multidisciplinary collaboration, early transurethral vesicoureteral stent placement was performed, the obstruction was relieved, and her renal function returned to normal. Reports of retroperitoneal fibrosis after multiple myeloma transplantation are relatively rare. This case report advances our understanding of these 2 diseases, and the correlation between MM and RPF warrants further exploration.

Open repair of an abdominal aortic and right common iliac artery aneurysm with idiopathic retroperitoneal fibrosis in a 19-month-old infant

An abdominal aortic aneurysm (AAA) in children is a rare clinical condition, with idiopathic AAAs even more atypical. We report a case of a 19-month-old girl with incidental findings of an infrarenal AAA and right common iliac artery aneurysm during workup for heart failure. Extensive genetic testing was unremarkable for connective tissue disorders. An aortic bi-iliac artery bypass with a Dacron graft from the infrarenal aorta to the right external iliac artery and left common iliac artery was performed. The patient achieved complete recovery and only required one oral hypertensive medication at 30 days of follow-up. Wide patency of the graft was observed on the 3-month follow-up computed tomography angiogram.

A review of the current treatment methods for retroperitoneal fibrosis with obstructive uropathy

Introduction and aims

Retroperitoneal fibrosis (RPF) is a fibroinflammatory disease in which patients may suffer obstructive uropathy (OU). The optimum treatment strategy for RPF with secondary OU is currently unclear, and the aim of this literature review is to assess the methods used to treat this patient cohort.

Methods

Medline, Embase, Cinahl, the Cochrane Library and PubMed were systematically searched to find studies assessing treatment outcomes in this patient cohort. After reviewing the studies' titles, abstracts and full texts, 12 were found that matched our search aims. Data from these publications were analysed and reported.

Results

The demographic and symptomatic features of patients across the 12 studies were representative of the general RPF population. No randomised control trials (RCTs) were found, and just one study formally compared outcomes between patients who underwent different treatment strategies. Many of the studies concluded that using medical and surgical methods in combination led to positive outcomes; whereas, others found positive outcomes following a variety of regimens. Many studies also highlighted, however, that significant minorities required further treatment after initial therapy. Conclusions regarding optimum treatment methods were limited as most publications did not formally compare outcomes following different strategies and had an observational study design.

Conclusion

Although positive outcomes were commonly seen following medical, surgical and a combination of treatments, the literature currently lacks research formally comparing outcomes after assigning specific treatment protocols to groups of RPF patients. More research is therefore required to determine how to best manage RPF leading to secondary OU.

The current landscape of antifibrotic therapy across different organs: A systematic approach

Fibrosis is a common pathological process that can affect virtually all the organs, but there are hardly any effective therapeutic options. This has led to an intense search for antifibrotic therapies over the last decades, with a great number of clinical assays currently underway. We have systematically reviewed all current and recently finished clinical trials involved in the development of new antifibrotic drugs, and the preclinical studies analyzing the relevance of each of these pharmacological strategies in fibrotic processes affecting tissues beyond those being clinically studied. We analyze and discuss this information with the aim of determining the most promising options and the feasibility of extending their therapeutic value as antifibrotic agents to other fibrotic conditions.

Diagnostic Approach to IgG4-Related Retroperitoneal Fibrosis After Colorectal Cancer Surgery in a Patient With Normal IgG4 Levels: A Case Report

An asymptomatic 75-year-old man who underwent transverse colon cancer surgery two years previously presented with retroperitoneal fibrosis (RPF) around the ventral sacral and right external iliac artery and vein on abdominal computed tomography (CT) during a routine surveillance visit. We assumed cancer recurrence or immunoglobulin G4 (IgG4)-related disease (RD), but although generic tumor markers and IgG4 levels were normal, soluble interleukin 2 receptor (sIL-2R) was elevated at 569 U/mL (reference: 122-496 U/mL). No diagnosis was made at this time, and the patient was followed up. He subsequently developed edema of both lower extremities. Abdominal enhanced CT showed an enlarged RPF without invasion of surrounding organs and with a delayed contrast effect, and positron emission tomography-CT showed fluorodeoxyglucose accumulation in the same area but a lower standardized uptake value (SUV) than at the time of transverse colon cancer diagnosis. Although generic tumor markers and IgG4 levels remained within the reference range, sIL-2R was further elevated to 1100 U/mL. An open biopsy and histopathology showed a high IgG4/IgG-positive cell ratio and infiltration of IgG4-positive plasma cells. The patient was finally diagnosed with IgG4-RD RPF. In cases of RPF after colorectal cancer surgery, the combined findings of elevated sIL-2R, lack of infiltration into surrounding organs, and lower SUV values ​​than at the cancer site could provide useful information to aid the diagnosis of IgG4-RD RPF.

Diagnostic value of contrast-enhanced ultrasound in the activity of idiopathic retroperitoneal fibrosis: a retrospective study

OBJECTIVES

To explore the diagnostic value of contrast-enhanced ultrasound (CEUS) in the disease activity of idiopathic retroperitoneal fibrosis (IRPF).

METHODS

This retrospective study included 148 CEUS examinations from 63 patients with IRPF treated in our hospital from April 2016 to September 2021. They were divided into two groups: IRPF active group (69 examinations) and inactive group (79 examinations). Uni- and multivariable analyses were used to identify independent risk factors for IRPF activity. Receiver operating characteristic (ROC) curves were drawn to establish different diagnostic models to evaluate the diagnostic value of IRPF activity. The z test was used to compare the differences of the area under the curves (AUCs). The value of CEUS in evaluating the variation of disease activity over time was also investigated between repeat patient studies.

RESULTS

Univariate and multivariate logistic regression analyses revealed the thickness [odds ratio (OR) = 14.125, 95% confidence interval (CI) = 3.017-66.123] was the most significant independent risk factor for IRPF activity (P < 0.01). The best diagnostic model was model 3, which was established by CEUS score combined with thickness. The AUC was 0.944 (95%CI = 0.912-0.977), and the sensitivity and specificity were 89.86% and 86.08%, respectively. The diagnostic performance was not significantly improved after combining clinical symptom (back pain) and laboratory indicators [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)]. Compared with before treatment, the CEUS score and thickness were significantly decreased after treatment (x2 = 14.580, P < 0.001 and z = 4.708, P < 0.001, respectively).

CONCLUSION

CEUS has good diagnostic value for IRPF disease activity. Key points • Thickness and contrast-enhanced ultrasound score were significantly higher in the active group than those in inactive group (P < 0.001). • With thickness of 4 mm and contrast-enhanced ultrasound 2 score as optimal cut-off values, the sensitivity and specificity were 89.86%, 81.01% and 52.17%, 100.00%, respectively. • During follow-up, when the disease progressed, the change of CEUS score was earlier than the change of thickness.

A Review on The Role of Environmental Exposures in IgG4-Related Diseases

PURPOSE OF REVIEW

Immunoglobulin G4-related diseases (IgG4-RDs) are immune-mediated fibroinflammatory multisystemic conditions identified by the presence of tumefactive lesions with a rich infiltrate of IgG4-positive plasma cells, and often by a high IgG4 serum concentration. IgG-RDs have a prevalence of at least 1 case every 100,000 persons, and they are mostly diagnosed after age 50, with a male to female ratio of about 3:1. IgG4-RD pathophysiology is still uncertain: it has been proposed that both genetic predisposition and chronic environmental exposures may play a role by triggering abnormal immune activation that perpetuates the disease. The purpose of this review is to summarize the evidences supporting the hypothesis that certain environmental/occupational exposures can trigger IgG4-RDs, focusing on the possible role of asbestos in an emerging IgG4-RD called idiopathic retroperitoneal fibrosis (IRF).

RECENT FINDINGS

Although some studies suggested a relationship between tobacco smoking and IgG4-RD risk, occupational exposures seem to have the most interesting effects. Positive history of blue-collar work increases the risk of developing an IgG4-RD, and mineral dusts and asbestos were the most strongly associated industrial compounds. Asbestos has been found to be a risk factor for IRF years before its classification as IgG4-RD, and later in two large case-control studies. In the most recent one, conducted on 90 patients and 270 controls, asbestos exposure conferred an increased IRF risk, quantified by odds ratios from 2.46 to 7.07. Further structured studies including serum IgG4 evaluation should be conducted to clarify the effect of asbestos on patients with confirmed diagnosis of IgG4-related IRF. Environmental exposures, especially of occupational origin, appear to play a role in the development of different types of IgG-RDs. In particular, although first suggested very recently, the relationship between asbestos and IRF deserves to be explored in more structured studies, especially because of the biological plausibility of the role of asbestos in IRF pathogenesis.

A role of FDG PET/CT for Response Assessment in Large Vessel Disease?

Currently, a large amount of evidence-based data clearly demonstrates the usefulness of [¹⁸F]FDG PET/CT in the diagnosis of several infectious and inflammatory diseases, including those related to the large vessels. The aim of this article is to clarify whether, beyond initial diagnosis, [¹⁸F]FDG PET/CT may have a role in treatment response assessment in inflammatory or infectious diseases of the large vessels, including large vessel vasculitis, vascular graft infection, retroperitoneal fibrosis/chronic periaortitis and infective native aortic aneurysms. Rapidly accumulating data suggest that [¹⁸F]FDG PET/CT could be a valuable imaging method for therapy monitoring in some infectious and inflammatory diseases of large vessels. The available data, albeit preliminary, indicate that [¹⁸F]FDG PET/CT could even play a pivotal role in the management of these diseases, leading to better drug dosage, confirmation of the usefulness of the treatment, and early modification of the therapeutic strategy. However, to date, the role of [¹⁸F]FDG PET/CT for treatment assessment in large vessel diseases, in particular large vessel vasculitis, is not clearly defined and well-designed prospective studies are needed to confirm its possible role in treatment monitoring and treatment guidance.

Retroperitoneal fibrosis, a rare entity with urorenal and vascular subtypes - preliminary data

Introduction

Retroperitoneal fibrosis (RPF) is a rare disease associated with the formation of hard inflammatory and fibrous tissue in the retroperitoneum. Taking into consideration the fact that RPF is a rare disease with different subtypes, we compared the basal clinical and biochemical characteristics of the vascular and urorenal subtypes.

Patients and methods

From January 2005 until December 2021, 27 patients were identified as vascular subtype (18 males) and 11 as urorenal subtype (9 males).

Results

Patients with a primary urorenal origin had significantly worse kidney function as reflected by serum creatinine and eGFR (both p < 0.001); they also had higher serum cholesterol (p < 0.01). Hypertension, diabetes, hyperlipidemia and nicotinism were significantly more prevalent in vascular subtype (all p < 0.001).

Conclusion

Vascular subtype is more prevalent in our study with more cardiovascular risk factor present. Due to the diversity of symptoms, diagnosis of RPF becomes a challenge for specialists as well as therapy.