Background
Persistent ascites is an uncommon complication after orthotopic liver transplantation (OLT). Data on etiology, treatment and outcome are limited.
Material and Methods
Data on 691 orthotopic liver transplantations in 585 patients were reviewed retrospectively. Patients with persistent ascites (longer than 4 weeks after successful liver transplantation) were selected and for each case two controls (no ascites after 4 weeks) were assigned and matched for age, sex, etiology of liver disease and pre-transplantation Child-Pugh-score/MELD-score.
Results
Persistent ascites for more than 4 weeks after liver transplantation was present in 5.6% (33/585) patients and 4.8% (33/691) cases for a mean of 159±174 days. The most common underlying reason was bacterial or fungal peritonitis (69.7%; 23/33). Other etiologies included renal dysfunction (6%; 2/33), obstruction of the portal vein (3%; 1/33), and obstruction of the liver vein outflow (12%; 4/33); the etiology was unclear in 9% (3/33).
Liver function tests, c-reactive protein levels and parameters of renal function at 4 weeks post liver transplantation did not differ significantly between cases and controls. Patients with persistent ascites had refractory ascites before OLT significantly more often than controls. The 1-year survival rate was 92.3% for controls vs. 75.8% for cases (Kaplan Meier estimate p<0.05).
Treatment (paracentesis; diuretic medical treatment; antibiotic treatment for patients with peritonitis or bacterial infection; radiologic intervention in cases of underlying vascular obstruction) resolved ascites in 72.7% (24/33 patients). Ascites due to infection was treated successfully significantly more often than all other groups (p<0.05).
Conclusions
Persistent ascites after liver transplantation is rare, but is associated with reduced 1-year survival. The underlying mechanisms are diverse, abdominal bacterial infection being the most common cause. The majority of cases can be successfully treated.

Keywords: liver transplantation, ascites, complications after liver transplantation