Ascites Complicating Unilateral Nephrectomy and Peritoneal Dialysis Catheter Implantation in a Patient with Massive Polycystic Kidney and Liver Disease

Abstract

Peritoneal dialysis (PD) is a well-established therapeutic option for patients with polycystic kidney disease. However, in patients with massive polycystic kidney and liver disease, subclinical hepatic venous outflow obstruction may elicit the appearance of ascites after implantation of a peritoneal catheter. The case of a patient who developed ascites after implantation of a PD catheter and further lowering of abdominal pressure after unilateral nephrectomy is discussed.

• ADPKD
• ascites
• peritoneal dialysis
• HVOO obstruction
• portal hypertension

INTRODUCTION

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary diseases in adults. Liver involvement with cysts is common and their prevalence was higher than 90% when liver MRI was used as a diagnostic test.¹ Although liver tests remain well preserved until late stages of the disease, compression of the biliary tract by cysts is responsible for the elevation of alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase (γGT) commonly observed in these patients.² Obstruction of the liver venous outflow, caused by cyst compression of the inferior vena cava or supra-hepatic veins, is even rarer in patients with ADPKD. A case of hepatic venous outflow obstruction (HVOO) manifested soon after a unilateral nephrectomy for preparation of renal transplantation in a patient who simultaneously implanted a peritoneal dialysis (PD) catheter is discussed.

CASE REPORT

A 51-year-old Caucasian male with polycystic kidney and liver disease was referred to our institution to initiate PD. The patient had a family history of ADPKD and suffered of hypertension, abdominal distention, and progressive chronic renal failure. In the last months he experienced increasing fullness and early satiety. Light alcohol consumption was mentioned. On physical examination the patient appeared mildly malnourished, with huge abdominal masses occupying the abdomen, consistent with polycystic liver and kidney disease. On admission his serum creatinine was 4.5 mg/dL, with an estimated glomerular filtration rate of 14 mL/min/1.73 m² [Modification of Diet in Renal Disease (MDRD) formula]. He presented mild elevation of γGT (114 U/L; normal value <38 U/L) and ALP (192 U/L; normal value 45–129 U/L) while other liver function tests remained normal [aspartate aminotransferase (AST) 29 U/L; alanine aminotransferase (ALT) 25 U/L; prothrombin time 12.4/11.6 s; total bilirubin 0.21 mg/dL; albumin 4.1 g/dL]. Tests for hepatitis B antigen and for hepatitis C antibody were negative. A CT scan showed massive polycystic kidney and liver disease with no other clinical significant findings. A left nephrectomy was proposed after surgical consult, in order to create space for PD and renal transplant. Nephrectomy was performed and a 6.820 kg kidney, with longitudinal length of 38 cm and a volume of 7.080 L, was removed (Figure 1). The post-surgery follow-up was complicated by a deterioration of renal function and hemodialysis was started through a central venous catheter. Kidney function eventually recovered and dialysis was interrupted. The patient was discharged on the sixth day post-surgery. Training for PD started and in the first use of the Tenckhoff catheter 2500 mL of a peritoneal fluid was drained without any previous infusion of PD solution. On the following days drainages of the abdominal cavity were performed, always with removal of large amounts of fluid. The fluid presented a serum-ascites albumin gradient >1.1 g/dL, suggesting portal hypertension as the cause of the ascites. Bacteriological tests of the ascitic fluid were negative and no neoplastic cells were found. Abdominal CT scan was repeated and disclosed large polycystic liver and right kidney, as well as moderate ascites without any other significant findings (Figure 2). A Doppler evaluation of the hepatic veins confirmed the patency of the portal and supra-hepatic veins. An upper gastrointestinal endoscopy showed grade 1 esophageal varices, consistent with portal hypertension. As renal function worsened, continuous ambulatory peritoneal dialysis was started and the patient was referred to a transplant center for combined hepatic and renal transplantation. For the next 3 months of follow-up the patient was well adapted to PD, tolerating the necessary volumes of PD solution required for appropriate treatment, with good results both on solute removal (Kt/V 2.29, creatinine clearance 103.13 mL/min) and volume control (always normotensive and with progressive resolution of lower limb edema). With PD dwells some of the ascitic fluid could be removed, keeping the patient asymptomatic. Nutritional state improved gradually as albumin levels rose (from 2.6 g/dL when ascites developed to 3.2 g/dL 3 months later).

Figure 1.  Nephrectomy specimen of the left polycystic kidney (axial length: approximately 38 cm; weight 6.820 kg).

Figure 2.  CT scan of the pelvis performed after the appearance of ascites; note the massive right kidney pulling the gut to the left and the peritoneal dialysis catheter in the upper right.

DISCUSSION

Prevalence of hepatic cysts in ADPKD patient is almost universal.³ In the CRISP study, 94% of patients were affected at the age of 46 years.¹ Liver involvement is clinically silent in most patients because it does not result in hepatic failure, leading Grünfeld to state that “patients with a polycystic liver have a huge, silent and durable liver.”⁴ However, complications of liver involvement by cysts other than liver failure are well described and range from cyst infection and rupture to hemorrhage, HVOO, and Budd–Chiary syndrome.⁵ In an ADPKD patient with hepatic cysts, ascites can occur for different reasons⁵: first, hepatic fibrosis or cirrhosis, which cannot be excluded in this case because liver biopsy was not performed; however, alcohol consumption was low and hepatitis B and C were excluded. Second, in massive liver involvement, compression of the venous outflow is the most probable cause of ascites, leading to a condition termed HVOO. In the case we presented, portal hypertension is demonstrated by the occurrence of esophageal varices and the characteristics of the ascitic fluid. However, the massive abdominal masses increased abdominal pressure, hiding subclinical portal hypertension and blocking ascites formation before surgery. Nephrectomy alleviated the abdominal pressure that counteracted portal hypertension, and ascites developed. The PD catheter further contributed to lower abdominal pressure and triggered ascites formation. The occurrence of ascites after nephrectomy of a polycystic kidney is a rare condition. Torres⁶ presented four cases of HVOO and reviewed another six published in the literature, in three of which bilateral nephrectomy has been performed previously. In our own experience of 46 nephrectomies in ADPKD patients as a preparation for renal transplant (unpublished) this is the first case of ascites.

Polycystic kidney disease is not a contraindication for PD, although abdominal volume may limit the ability to infuse large volumes into the peritoneum. Furthermore, PD has been advocated to treat ascites in patients with ADPKD who develop HVOO.⁷ Pre-transplant nephrectomy is promoted for ADPKD patients with a medical history of cyst infection and rupture, in order to prevent complications under immunosuppressive therapy or to create space for the allograft.

CONCLUSION

Even though it is a rare occurrence, it is important to be aware that ascites may develop after nephrectomy in patients with massive polycystic kidney and liver disease with HVOO.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.