Scrotal edema secondary to fluid imbalance in patients on continuous peritoneal dialysis.

In addition to local causes--for example, leak of dialysate into an inguinal hernia sac or into the anterior abdominal wall through the track of the catheter for continuous peritoneal dialysis (CPD)--scrotal edema in CPD patients may result from generalized volume retention. We present 2 CPD patients with scrotal edema, illustrating the diagnosis and management of the mechanisms of volume retention. A man with hypertensive nephrosclerosis developed isolated scrotal edema 14 months after an uneventful course of continuous ambulatory peritoneal dialysis (CAPD). After repair of a ventral hernia and of a communicating hydrocele, he started continuous cycling peritoneal dialysis (CCPD), plus 2 daytime CAPD exchanges. After 4 months, he again developed isolated scrotal edema, which decreased at night. Peritoneal scintigraphy showed no dialysate leaks, and peritoneal equilibration test (PET) revealed high-average transport with a residual volume above, and an ultrafiltration volume below, the expected range. Abdominal radiography revealed migration of the CPD catheter. Malposition of the CPD catheter with positional retention of dialysate was diagnosed. The patient was treated with nightly peritoneal dialysis and no daytime exchanges. On this regimen, ultrafiltration improved and the scrotal edema disappeared with no recurrence for 5 months, at which point the patient underwent kidney transplantation. A man with diabetic nephropathy developed poor dialysate return, volume gain, and pronounced edema of the scrotum, penis, and both legs soon after starting CAPD. Peritoneal scintigraphy was negative, and abdominal radiography confirmed the appropriate position of the CPD catheter tip in the right lower abdominal quadrant. PET revealed high peritoneal solute transport, appropriate residual volume, and appropriate for the transport category, but relatively low (0.1 L), ultrafiltration volume. He was treated with a change in the CPD procedure to CCPD, plus 1 daytime icodextrin exchange and instruction to reduce salt intake. This patient has remained free of scrotal edema for 6 months. In men on CPD, scrotal edema can develop from generalized volume gain secondary to either CPD catheter malfunction or imbalance between total fluid removal and salt and water intake. Proper interpretation of PET findings is critical in the evaluation of scrotal edema not resulting from internal dialysate leaks in CPD.