In the differential diagnosis of inadequate ultrafiltreation, one of the possible entities is a dialysate leak. The more insidious leak will present with weight gain and decreased drain volumes as the dialysate leaks into different planes/potential spaces and is not available for the peritoneal dialysis (PD) catheter to drain. We discuss some of the more common leaks here.
Authors differentiate leaks in one of two ways, either by time or location. Early leaks typically are those occurring within 30 days of catheter insertion and late leaks after this time. Early leaks are typically related to the catheter placement and are more frequently external while late leaks often represent acquired defect of the peritoneal membrane and are more frequently internal.
Let’s review the different types of leaks below:
1. Exit Site – Typically an earlier complication of PD, exit site leaks are seen as a result of increased abdominal pressure when PD is initiated urgently/before the catheter has time to heal. Should an exit site leak occur, the treatment is typically peritoneal rest. There is a risk of tunnel infection and peritonitis when exit site leak is present, so antibiotic prophylaxis is recommended.
2. Abdominal Wall – Patients presenting with increased abdominal size and decrease in ultrafiltration should be evaluated for the presence of abdominal wall defect and dialysate leak. Prior to or at the time of placement of the PD catheter, any known hernia should be repaired. Asymmetry of edema and pitting abdominal wall edema may be clues to the presence of hernia/leak.
3. Genital – Genital edema is often either due to peritoneal membrane defect along the catheter tract or patent processus vaginalis. Peritoneal scintigraphy can differentiate these two entities. If a patent processus vaginalis is noted during laparoscopic insertion of the peritoneal dialysis catheter, it should be tied off.
4. Pleural – Massive unilateral pleural effusion is the hallmark of this condition, colloquially termed the “Sweet hydrothorax”. Dialysate crosses defects in the diaphragm resulting in pleuro-peritoneal connection. Similar to cirrhosis, this typically occurs on the right side. Pleural studies revealing high glucose concentration is diagnostic and various therapies have been attempted.
The incidence of dialysate leaks reported in literature is variable and possibly related to advances in insertion technique. When suspected clinically (either by direct visualization or by history of edema, weight gain, and poor UF) diagnosis can be obtained by either CT scan with radiocontrast infused dialysate or with non-contrast magnetic resonance imaging as dialysate is hyperintense on T2 imaging.
Post by: Ankur Shah, MD (@NephroShah)
Nephrology, Brown University