Translational surgical research on patients with chylous ascites: effectiveness of the application of a peritoneo-venous shunt

Introduction. Chylous reflux is mainly related to lymphatic valvular insufficiency due to chyle-lymphangectasia and dysplasia. The etiology of chylous ascites (also called chyloperitoneum) includes primary abnormalities of lymphatic or chyliferous vessels development or secondary causes, such as trauma, surgery or tumors. Conservative approach is the main treatment and it includes medical and nutritional therapy. In the event of failure of conservative therapy, endovascular procedures and surgical therapy can be used. However, there are cases, especially due to primary dysplastic nature, that do not respond to the combined treatment reported above and require the implantation of a peritoneum-venous shunt (PVS) (such as Denver® Shunts, traditionally used in the eighties for palliation of refractory malignant ascites) or other drainage devices. Objective. The aim of this study is to evaluate the effectiveness in chylous ascites of the application of a device for the peritoneum-venous shunt, in order to achieve the drainage of chylous ascites in a central vein, for the recovery of immunological and nutritional components (such as proteins, albumin, lymphocytes) into the blood circulation. Where peritoneum-venous shunts were not successful, also other drainage devices were evaluated, to temporarily drain the fluids from the abdomen. Materials and methods. The research focused on 3 patients (17- and 47-years old female and 57 years old male) with recurrent spontaneous chyloperitoneum that were studied and treated under local anesthesia with the insertion of a Denver-type peritoneum-jugular shunt. The venous end was inserted into a jugular vein via a subcutaneous tunnel that was created and the peritoneal end of the shunt was placed at the most caudal part of the pelvis. The Denver shunt has a unidirectional pump that was placed in a subcutaneous pocket over the lower ribs and allowed daily manual compressions and movement of fluid. Complications related to the implant of the valve led us to replace it with an external percutaneous drainage device (Relief® system). Results and conclusions. All PVS implants were successfully performed. Follow-up period was 27-32 months (clinical, laboratory and echo-graphic assessment). Significant symptomatic relief was obtained in all patients. All patients initially showed a reduction in abdominal circumferences and body weight. Serum albumin, lymphocytes and immunoglobulins levels increased significantly following PVS placement. Postoperative complications included thrombosis of the jugular vein, treated with low weight heparin subcutaneously. In one patient there was a temporary recurrence of the ascites, spontaneously solved, following a proper low-fat diet. In the first period, all the patients had a significant improvement of the clinical conditions with an acceptable control of chylous ascites and with an improvement of quality of life for more than one year. Then, permanent and unsolvable occlusion of the PVS and venous thrombosis occurred so all PVS were removed and in 2 patients a Relief ®system was implanted to drain the remaining ascites. The idea of deriving ascites in a jugular vein did not lead to satisfactory long-term results in patients with chylous ascites, so it was necessary to switch to the use of other devices. The main problem is the density of the chylous fluid and the presence of coagulation factors that promote thrombosis. In the future it will be necessary to evaluate other technical solutions and special materials that can allow us to overcome the limits of the proposed method.