Successful Reintroduction of Peritoneal Dialysis After Peritoneal-Pericardial Fistula in a Child: A Case Report.

Editor: Pericardial effusion secondary to peritoneal-pericardial fistula is a rare but serious complication of peritoneal dialysis (PD). A recent survey of the European Pediatric Dialysis Working Group reported a prevalence of 0.13% (1). While the pathophysiology of peritoneal-pericardial fistula creation remains unclear, congenital or traumatic peritoneal membrane damage and dialysate-related intra-abdominal pressure changes are likely contributing factors (2). Identified risk factors include previous peritonitis, cardiac and/or abdominal surgery, excessive and/or rapid increase in fill volume, and malnutrition (1,3,4). Suggested management of pericardial effusion includes switch to hemodialysis (HD) and surgical closure of the peritoneal defect. Although previous reports have described spontaneous resolution of peritoneal-pleural fistulae and other late dialysate leaks, the natural history of peritonealpericardial f istulae remains unclear (1,2,5,6). Here, we describe a 9-year-old girl chronically managed with PD and relapsed post-renal transplantation, who presented with pericardial effusion due to peritoneal-pericardial fistula. The patient had a 3.5-year history of biopsy-proven focal segmental glomerulosclerosis (FSGS). She presented with hypertension, hyperlipidemia, nephrotic range-proteinuria, and edema. Renal biopsy was performed after 2 months of steroid-resistant nephrotic syndrome, confirming FSGS. Her post-biopsy course was complicated by bacterial peritonitis and posterior reversible encephalopathy. A gastrostomy tube was endoscopically placed 1 year post-diagnosis to assist with nutrition and growth. Nephrotic syndrome remained refractory to therapy with cyclosporine, mycophenolate mofetil (MMF), rituximab, tacrolimus, and plasmapheresis. Her renal disease progressed to chronic kidney disease stage 5 over the next 2 years. She commenced PD 2.5 years after diagnosis. Following 1 year of PD with a dwell volume of 1,000 mL/m2, she received a living, unrelated-donor kidney transplant. Post-transplant immunosuppression was maintained with thymoglobulin, rituximab, tacrolimus, MMF, and prednisone. She received intravenous immunoglobulin (CytoGam, CSL Behring, Berne, Switzerland) every 2 weeks. Recurrent nephrotic syndrome developed within 48 hours of transplantation, with subsequent oligo-anuria secondary to recurrent FSGS in the allograft. Ultrasound and surgical exploration did not identify a thrombus. She required plasmapheresis and resumed HD on post-operative days 3 – 8 for volume control. She was then transitioned back to PD and continued plasmapheresis 3 times per week. Renal biopsy 1 month post-transplant demonstrated mild tubular injury and glomerular sclerosis without signs of rejection. Two months following kidney transplantation, she pre sented with fever and cough. Chest X ray revealed cardiomegaly. Echocardiography showed a large (2.2-cm posterior, 1.7-cm left lateral) circumferential pericardial effusion. She was mildly tachycardic and normotensive. Laboratory investigations revealed mild leukopenia, anemia, hypogammaglobulinemia, and uremia. She had negative blood, urine, and peritoneal fluid cultures. The differential diagnoses considered included infectious pericarditis, inflammatory pericarditis, and uremic pericarditis. Immunosuppression was maintained with MMF, prednisolone, and tacrolimus. She continued PD for the next 7 days with a 50% reduced fill volume. She remained hemodynamically stable. Repeat echocardiogram demonstrated increasing volume of the pericardial effusion without obvious tamponade. Peritoneal scintigraphy was completed due to the possibility of a peritoneal-pericardial connection. Dynamic images of the abdomen and thorax were obtained for 1 hour following injection of 74MBq Tc-99m sulfur colloid through the PD catheter. Multiple static images of the thorax were obtained up to 24 hours post-radiotracer administration. This demonstrated tracer accumulation in the mediastinum, suggestive of a peritoneal-pericardial communication, as illustrated by SPECT/CT fused images (Figure 1). No intraperitoneal pressure measurements were recorded. Risk factors for fistula formation in this patient include recurrent intra-abdominal surgery, prolonged immunosuppression, and previous malnutrition. As PD was causative, she was transitioned to HD. Serial echocardiograms demonstrated resolution of the pericardial effusion over the next 1.5 months without need for drainage. She was maintained on 6 times weekly HD. Repeat peritoneal scintigraphy, after 3 and 6 months, of HD demonstrated a persistent peritoneal-pericardial communication. Nine months after conversion to HD, a thoracic-abdomen computed tomography (CT) scan was completed in preparation for surgical repair; 300 mL of dilute radiographic contrast were instilled through the PD catheter. Images were acquired at 30 and 90 minutes post injection. Repeat scintigraphy was performed 1 week later. Neither contrast nor tracer accumulation was identified in the mediastinum. She resumed PD without recurrence of the pericardial effusion or any other complications (currently 4 months of follow-up).