Clinical Analysis Of The Causes Of Ascites And The Significance Of Peritoneal Fluid Parameters In The Differential Diagnosis Of Ascites

Objective:The clinical manifestation of ascites is not dependent upon the peritoneal fluid volume as the onset and course of the disease, whether acute or chronic are different. Local and foreign litteratures show that cancer is a common cause of ascites, and also ascites is more common wherever hepatic cirrhosis is implicated, but Bud-Chiari syndrome, peritoneal mesothelioma, hepatic venular occlusive disease, and other factors are uncommon causes of ascites. The treatment and prognosis of ascites are different because of their variable etiologies. Clinical suspicion is essential when dealing with ascites. The most important task for the physicians is to choose an appropriate method to accurately diagnose it. Laboratory and instrumental tests commonly ordered to determine the causes of ascites are routine peritoneal fluid analysis, biochemistry, and tumor marker test, exfoliative cytology, endoscopy, roentgenography, and pathological report, laparoscopy and others. The specificity of peritoneal fluid cytology in the diagnosis of malignant ascites, is nearly 100%, but due to lack of specificity concerning the number of malignant cells in the peritoneal fluid, degree of destruction of tumor cells, complex cellular components, the repetition of peritoneal fluid cytology, morphology of the atypical exfoliative cells and other factors, its accuracy can be low. Our purpose is to look for highly sensitive and specific indicators. This cohort is set to analyze the clinical features of benign and malignant ascites, the peritoneal fluid tumor markers and biochemistry in search of a more specific and sensitive diagnostic method, which can not only be readily used by phyisicians as a diagnostic tool but also as a source of reference.Methods:In a retrospective study conducted from January 2010 to September 2014 in the department of Gastroenterology of the First Affiliated Hospital of Dalian Medical University,155 patients were screened for "ascites of unknown origin". Parameters measured were gender, age distribution of patients, etiology and clinical features. Using statistical methods, the measured parameters were assessed and compared so as to aid in the differential diagnosis of benign and malignant ascites and also to reveal its significance.Results:155 patients were selected in this cohort. The three most common causes were:liver cirrhosis (39%), cancer(35%), tuberculous peritonitis(14%). The average age of onset of tuberculous peritonitis was lower. Gastrointestinal tumor is the most common cause of malignant ascites (37%). Tuberculous ascites ADA was significantly high, and when compared to non-tuberculous ascites, there was a significant difference. A value exceeding 33.5U/L is optimum for the diagnosis of tuberculous ascites. Peritoneal fluid LDH, total protein, AFP, CEA, CA19-9 in malignant is significantly higher than those of benign ascites and the difference is significant. The followings are the optimum values of peritoneal fluid parameters, above which a diagnosis of malignant ascites can be boldly assigned:LDH 78.5U/L, total protein 23.15g/L, AFP 9.62IU/ml, CEA5.28ug/L, CA19-912.75U/ml. Ascites CA125 assay could not be used to differentiate benign from malignant ascites since the difference was insignificant.Conclusion:1. The three most common causes of ascites are:liver cirrhosis, malignant ascites, abdominal tuberculosis. Tumor of digestive system accounts for most of the malignant ascites.2. Male patients predominate among patients with liver cirrhosis type of ascites, while women predominate among patients with malignant ascites.3. The mean age of patients with tuberculous ascites is lower than those of malignant and liver cirrhosis type of ascites.4. Diarrhea is the most common symptom among patients with liver cirrhosis type of ascites, while fever and abdominal pain predominate among patients with tuberculous ascites, and weight loss among patients with malignant ascites.5. Peritoneal fluid ADA is of high diagnostic value for tuberculous ascites. Peritoneal fluid LDH, total protein, tumor markers AFP, CEA and CA19-9 are essential for the differential diagnosis ofbenign and malignant ascites. Peritoneal fluid tumor marker CA125 holds no significance for the diagnosis of malignant ascites.