Peritoneovenous shunts
Peritoneovenous shunts are medical devices surgically implanted to manage intractable ascites, a condition marked by fluid accumulation in the abdominal cavity typically resulting from chronic liver disease or certain cancers. The procedure involves inserting a flexible tube that drains excess fluid from the abdomen into the jugular vein, allowing it to enter the systemic circulation. This intervention is often considered for patients with advanced cancers, such as ovarian, colorectal, and liver cancer, when other treatments like diuretics or chemotherapy fail to alleviate discomfort associated with ascites, such as nausea and shortness of breath.
Before surgery, patients undergo various assessments, including blood tests and imaging studies to ensure the safety and effectiveness of the procedure. The surgery itself is performed under sedation, and careful monitoring follows to manage potential complications, which can range from shunt malfunctions to infections. Although advancements in shunt design and technique have improved outcomes, the procedure carries inherent risks, including an operative mortality rate of 10-20%. Due to these risks and the emergence of alternative therapies, the use of peritoneovenous shunts is declining, despite their role in providing relief for patients experiencing severe ascites.
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Peritoneovenous shunts
ALSO KNOWN AS: Peritoneovenous ascites shunts
DEFINITION: Peritoneovenous shunts are surgically implanted devices to relieve intractable ascites cases. This condition, characterized by excess buildup of fluids in the peritoneal (abdominal) cavity, generally results from chronic liver disease but may also occur due to malignancy. The shunt, a plastic or silicone rubber tube, drains fluid from the abdominal cavity into the jugular vein in the neck.
Cancers treated: Any advanced cancer that causes ascites; cancers most commonly associated with ascites include: ovarian, uterine, cervical, colorectal, stomach, pancreatic, breast, and liver
Why performed: Tumor-induced ascites is a challenging condition to manage and are usually a manifestation of late-stage cancer. The condition causes abdominal swelling, nausea, loss of appetite, and shortness of breath due to fluid accumulation in the chest cavity. Peritoneovenous shunting carries potential risks but may be recommended to ease discomfort when medical therapy consisting of salt restriction, diuretics, repeated fluid aspirations, chemotherapy, or immunotherapy fails to reduce ascites.
Patient preparation: Before surgery, the patient undergoes routine laboratory tests, including a coagulation profile and liver panel, and imaging tests, such as computed tomography (CT) scan and ultrasonography, to assess the extent of ascites and the condition of the veins selected for shunting. The operation is contraindicated if an additional test shows that the ascitic fluid is infected.
Steps of the procedure: The patient is given a sedative and undergoes either local or general anesthesia at the hospital. The surgeon makes a small and inserts a shunting tube under the skin of the chest that will run from the abdominal cavity to the jugular vein. The tube is then passed down to the superior vena cava, a large vein that returns blood to the heart. With a pump chamber and a one-way valve that prevents backflow, the shunt drains ascitic fluid into the systemic circulation.
After the procedure: After surgery, the patient’s vital signs are monitored by nursing staff, and the shunt is checked to ensure proper function. Antibiotics and pain medication are prescribed as needed. Patients are instructed to pump the shunt daily to remove fluid from the abdomen, take their prescribed medication, and restrict sodium intake.
Risks: Complications are common and include shunt malfunction, infection, blood clots, edema, leakage of ascitic fluid, and heart failure. The operative mortality risk is 10–20 percent.
Results: The procedure is deemed successful when fluid in the abdomen gradually ceases to accumulate after surgery, but frequently, a blood clot or scar tissue forms around the shunt and blocks the valve or tube. Evolution in shunt design and placement techniques, as well as a better understanding of patient outcomes, have improved peritoneovenous shunts and their related procedures. However, due to complications and the advent of alternative treatments, peritoneovenous shunts are used with decreasing frequency to control ascites and related conditions.
Bibliography
Binda, Anna. "Peritoneovenous Shunts." Salem Health: Cancer. Edited by Wendy White-Ryan, Laurie Jackson-Grusby, and Jeffrey A. Knight. Pasadena: Salem, 2009.
Hanks, Geoffrey, et al. "Peritoneovenous Shunting." Oxford Textbook of Palliative Medicine. 4th ed., New York: Oxford UP, 2011, pp. 876–7.
Khatri, Vijay P. Atlas of Advanced Operative Surgery. Philadelphia: Saunders, 2013.
Malik, Talia. “Peritoneovenous Shunt - StatPearls.” NCBI, 31 July 2023, www.ncbi.nlm.nih.gov/books/NBK562160. Accessed 28 June 2024.
Martin, Louis G. “Percutaneous Placement and Management of the Denver Shunt for Portal Hypertensive Ascites.” AJR. American journal of Roentgenology, vol. 199.4, 2012, pp. W449-53, doi:10.2214/AJR.12.9203.
Niederhuber, John E., et al. "Peritoneovenous Shunting." Abeloff's Clinical Oncology. 5th ed., Saunders, 2014, pp. 797–8.
Sooriakumaran, P, et al. "Peritoneovenous Shunting Is an Effective Treatment for Intractable Ascites." Postgraduate Medical Journal, vol. 81, no. 954, 2005, pp. 259-261, doi.org/10.1136/pgmj.2004.023663. Accessed 28 June 2024.