Imaging Work-Up for Peritoneal Access Care and Peritoneal Dialysis Complications

Late Peritoneal Dialysis Exit-Site Leak: A Case Report

Peritoneal dialysis (PD) pericatheter exit-site leaks most commonly occur early, within 30 days of catheter insertion. Late exit-site leaks are rare. The distinction between early and late exit-site leaks is important because the causes and subsequent management strategies may be different. Early leaks can often be first treated by delaying or holding PD therapy, allowing the prolongation of the healing time because fibrous tissue continues to form around the deep cuff. Late leaks are less likely to heal with cessation of PD alone and often require PD catheter replacement. In this case report, we provide an overview of the diagnosis and management of PD catheter exit-site leaks while highlighting a case of a late presenting exit-site leak resulting from a unique cause of PD catheter trauma.

Compatibility and stability of non-ionic iodinated contrast media in peritoneal dialysis solution and safe practice considerations for CT peritoneography

BACKGROUND

Computerised tomographic (CT) peritoneography is performed on peritoneal dialysis (PD) patients to identify peritoneal boundary defects, dialysate maldistributions and loculated fluid collections. Iodinated contrast media are added to dialysate and infused through the dialysis catheter, and CT images are obtained. Chemical compatibility of contrast media with dialysis solutions has not been studied. In some institutions, pharmacists charged with oversight of compounded sterile preparations have placed a moratorium on the use of contrast media-dialysate mixtures until compatibility data become available. This study was undertaken to examine the compatibility of non-ionic iodinated contrast agents added to PD solution for the performance of CT peritoneography.

METHODS

100 mL of three non-ionic iodinated contrast agents, iopamidol 370 mgI/mL, iohexol 300 mgI/mL and iodixanol 320 mgI/mL, were mixed with 2 L 1.5% dextrose PD solution and stored at 2-8°C, 25°C and 40°C. Observations at predefined intervals were made over 5 days for visual appearance, turbidity, pH, drug concentration and chemical degradation.

RESULTS

Iopamidol, iohexol and iodixanol were stable for 5 days under study conditions. The contrast-dialysate mixture remained clear and colourless, no turbidity changes observed, pH and drug concentrations were stable and no increase in existing impurities or new impurities were detected.

CONCLUSIONS

The addition of commonly used non-ionic iodinated contrast agents to 1.5% dextrose dialysis solution is chemically stable, meeting the criteria set forth in the standards and guidelines of the US Pharmacopeia and the Institute of Safe Medication Practices. A protocol for performing CT peritoneography is recommended herein to facilitate patient safety and diagnostic reliability of the imaging study.

Contrast-enhanced ultrasound in peritoneal dialysis: when and how to perform it

In the field of peritoneal dialysis contrast enhanced ultrasound (CEUS) is a new add-on examination to B-mode ultrasound, but until recently it has never been systematically studied. Based on the experience of the Project Group "Integrated Imaging and Interventional Nephrology" of the Italian Society of Nephrology, CEUS is helpful for evaluating catheter malfunction, peritoneal-pleural communication, leakage, and herniation, and in particular it facilitates dynamic functional imaging of the catheter and its complications. The use of CEUS in peritoneal dialysis is simple, repeatable, safe, radiation-free, and appears to be less time-consuming and more cost-effective than other radiological imaging techniques such as peritoneography, computed tomography, magnetic resonance or peritoneal scintigraphy.

Imaging of Peritoneal Dialysis Complications in Children

Worldwide, peritoneal dialysis (PD) is the preferred renal replacement therapy option for children with end-stage renal disease who are awaiting transplantation. PD involves the instillation of a specifically formulated solution into the peritoneal cavity via a PD catheter, with two-way exchange of solutes and waste products along a concentration gradient. This exchange occurs across the peritoneal membrane. The PD catheter has intraperitoneal, abdominal wall, and external components. Enormous efforts have been directed to augment the efficiency and longevity of the peritoneum as a dialysis system by preventing PD-related infectious and noninfectious complications, which may otherwise result in technique failure and a subsequent temporary or permanent switch to hemodialysis. Imaging has an instrumental role in prompt diagnosis of PD complications and in guiding the management of these complications. The main imaging techniques used in the setting of PD complications-namely, conventional radiography, US, CT, MRI, and peritoneal scintigraphy-as well as the benefits and limitations of these modalities are reviewed. The authors also describe the frequently encountered radiologic findings of each complication. Familiarity with these features enables the radiologist to play a crucial role in early diagnosis of PD complications and aids the pediatric nephrologist in tailoring or discontinuing PD and transitioning to hemodialysis if necessary. Online supplemental material is available for this article. ^©RSNA, 2022.

Diagnostic capability of ultrasound in peritoneal catheter malfunction compared to videolaparoscopy

BACKGROUND

The approach to peritoneal catheter malfunction consists usually in a diagnostic and therapeutic sequence of laxative prescription, abdominal radiography, brushing of the catheter, guide-wire manipulation or fluoroscopy and in the end of a videolaparoscopy (VLS) rescue intervention. Ultrasound (US) is able to find out major causes of peritoneal catheter malfunction, however without a clearly defined diagnostic value. The aim of the study was to validate the diagnostic capability of US in catheter malfunction compared to the diagnostic reference of VLS.

METHODS

US scans of the subcutaneous and intraperitoneal segment of the catheter were performed prior to a VLS intervention in 40 adult patients presenting persistent catheter malfunction within a prospective multicentre study. Laxative prescription and brushing of the catheter lumen were undertaken prior to US scan. US diagnosis was compared to the corresponding at VLS, kappa coefficient calculated and the causes of mismatch analysed.

RESULTS

In US, causes of persistent malfunction were catheter dislocation combined with omental wrapping in 21 cases, omental wrapping without dislocation in 11 cases, dislocation only in 4 cases, adherences to non-omental structures in 3 cases and entrapment in the lateral inguinal fossa in 1 case. The US diagnosis corresponded to the respective at VLS in 36 of 40 cases, resulting in a kappa coefficient of 0.89 (95% CI: 0.78-1.00). The discrepancies were due to improper visualization of the catheter between omentum and intestinal loops, resulting in an erroneous US diagnosis of omental wrapping.

CONCLUSIONS

This study suggests that US might have a pivotal role in the diagnostic approach to peritoneal catheter dysfunction.

The ideal position of the peritoneal dialysis catheter is not always ideal

PURPOSE

Peritoneal catheter dysfunction is a frequent complication of peritoneal dialysis (PD). Traditionally, dysfunction has been attributed to catheter malposition, but whether the location of the catheter tip in the small pelvis really determines proper function is unclear.

METHODS

We reviewed 900 abdominal X-ray images of PD patients from a 7-year period in two PD units that use different catheter types (straight and Swan Neck Curled).

RESULTS

In 52% of the images, the dialysis catheter tip was located in the ideal position in the small pelvis and in 48% in other sites. Peritoneal catheter function was normal at the time of imaging in 87% of those with ideal catheter tip position, and in 74% of those with other than ideal position. The tip was located in small pelvis in 35% of images performed during catheter dysfunction and in 56% of those performed during normal catheter function. There were no differences between two catheter types. The positive predictive value of abdominal X-ray images to predict catheter function was 26%, and the negative predictive value 87%. We also found a significant positive correlation between polycystic kidney disease and normal catheter function. In contrast, obese patients were more likely to have catheter malfunction. Previous abdominal surgery was not associated with catheter dysfunction.

CONCLUSION

Our data showed a higher probability of normal function of peritoneal catheters whose tips were located in the small pelvis. However, also malpositioned catheters generally functioned well, and malpositioning of the PD catheter did not in itself explain its malfunction.

Serial changes of computed tomographic peritoneogram in patients with symptomatic ultrafiltration failure complicating continuous ambulatory peritoneal dialysis

INTRODUCTION

It is well-known that continuous ambulatory peritoneal dialysis (CAPD) is associated with complications. And some of these complications are well-demonstrated as abnormalities on computed tomographic peritoneogram (CTP). The objective of our study is to document the serial changes of these complications.

METHODS

We retrospectively reviewed 125 patients treated with CAPD for end staged renal failure (ESRF) who had CTP conducted in our hospital between December 2006 and August 2015. A total of 164 (n = 164) CTPs were performed. Patients with only one CTP performed were excluded from our study. A retrospective review of 68 serial CTPs studies on 28 patients during the 9-year period was undertaken. We looked into the serial changes on CTP.

RESULTS

Among the 28 patients who had serial imaging, 46.43% of patients were found to have retroperitoneal leakage; 92.31% of them showed resolution in subsequent serial CTP. 21.43% of patients had anterior abdominal wall leakage; none of them resolved in subsequent CTP. 14.29% of patients were found to have inguinal hernias; 75% of them showed interval progression in subsequent serial CTPs.

CONCLUSION

Retroperitoneal leakage is a common complication in patients on CAPD and tends to resolve whereas other complications including anterior abdominal wall leakage and hernias are unlikely to resolve and may progress further.