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PORTAL HYPERTENSION 437
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FIG. 1 Steps of performing a transjugular intrahepatic portosystemic shunt (TIPS) placement. (A) Access into the right hepatic vein (black arrowhead) is achieved
through the right internal jugular vein (black arrow) to the inferior vena cava (IVC). Once the right hepatic vein is selected (B), a balloon catheter (black arrow) may be used to measure indirect portal pressures. Right portal vein is accessed through the liver parenchyma (C) from the right hepatic vein with a long needle (black arrow). Confirmation of proper portal vein access is obtained with contrast injection (D) via a catheter (black arrow). A wire (arrows) is then advanced deep with its tip (arrowhead) into the portal vein (E). At this point direct portal pressures are obtained. If no portal hypertension is found, the operator must exclude presinusoidal causes (i.e., splenic vein thrombosis, narrowing). If no presinusoidal cause is found, TIPS is aborted. Balloon dilation of the liver tract is performed (F). The traversed liver parenchyma is fibrotic and difficult to cross unless predilated. A small caliber (4- to 6-mm diameter) balloon (white arrow) is used to pre- dilate the liver parenchyma between the right portal and hepatic veins. The TIPS stent (arrow) is partially deployed in the portal vein (G). Its distal 2 cm (black arrowheads) are self-expandable and used to anchor the stent while the operator pulls the stent back for positioning. Once position is satisfactory (H), the rest of the stent is fully extended (arrow). Final pressures are measured and a portal venogram is performed via a catheter (arrowhead) to confirm proper positioning and function. (Color images courtesy Jeni Fairman and Dr. Cory Sandone, Department of Art as Applied to Medicine, Johns Hopkins University.)
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FIG. 2 Transjugular intrahepatic portosystemic shunt (TIPS) with partially occlusive portal vein thrombus and balloon retrograde transvenous obliteration
(BRTO). (A) Portal venogram obtained through tract from the inferior vena cava (IVC), through the right hepatic vein and into the portal vein demon­strates a filling defect in the portal vein (black arrowhead) consistent with thrombus. Large varices visualized in the left upper quadrant of the abdomen (black arrows). Selective catheterization of large varix (B) with para-esophageal varix (black arrow). A large draining vessel is visualized (black arrowhead). Deployment of embolization coils (C) in the previously visualized varix (black arrow). TIPS shunt (D) subsequently deployed into the portal vein. Coils from embolized varix visualized (black arrow). Portal venogram demonstrates a patent proximal portal vein (white arrow).
Shunt Evaluation
Usually a 10-mm diameter stent is used, and initially it is dilated up to 8 mm in diameter. The direct portal pressure is measured again; if it is not satisfactory, a 10-mm balloon is used to open the stent to capacity. The smaller the stent diameter, the lower risk of enceph­alopathy postprocedure. A final portal venogram is performed to document flow and lack of variceal filling.
SPECIAL CASES
Direct Intrahepatic Portosystemic Shunt
DIPS is a recently developed modification to the TIPS procedure. Using intravascular ultrasound guidance, DIPS has been shown to decrease radiation dose and procedural time compared with
TIPS. DIPS uses the caudate lobe as a parenchymal tract to create a side-to-side portocaval shunt, which removes the possibility of hepatic vein stenosis. Portal venous access is then accomplished, and a shunt can be created using a polytetrafluoroethylene-covered stent graft. Creation of specific stent-graft devices have improved patency rates.
In patients with an occluded TIPS, challenging anatomy, calcifica­tion of the portal vein, or portal vein thrombosis due to hepatocellu­lar carcinoma, DIPS is of value. Additionally, the creation of a TIPS in a patient with Budd-Chiari syndrome is especially challenging because the hepatic veins are thrombosed (Fig. 3). This appears as the classic spider vein appearance on a hepatic venogram. Although portal decompression is best accomplished by placing the TIPS from the hepatic to the portal vein, DIPS is often the best option when the hepatic veins are occluded.
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Parallel Transjugular Intrahepatic Portosystemic Shunt
Rarely, despite a previous TIPS, the patient’s symptoms may not be alleviated completely. If revision has already been attempted, a second TIPS may be placed using the other hepatic and portal veins (Fig. 4).
Transumbilical, Transplenic, or Direct Portal Access
When access into the portal vein is challenging due to anatomy or thrombosis of the portal vein, the operator has several other options. First, access into the umbilical vein, which is usually dilated, provides a conduit to the left portal vein. A catheter there allows opacification of the portal venous system, which provides a better target for TIPS.
FIG. 3 Direct intrahepatic portosystemic shunt (DIPS) in a patient with Budd-Chiari. Frontal subtracted hepatic (A) and post-TIPS portal (B) venograms in
a patient with Budd-Chiari. Hepatic venogram (A) shows the “spider-like” appearance (arrow) of multiple small collateral draining veins. The TIPS stent (arrow­heads) allows the venous drainage to bypass the thrombosed hepatic veins (B). Because the hepatic vein is thrombosed, the stent extends directly from the
inferior vena cava (IVC) directly to the right portal vein.
FIG. 4 Parallel TIPS. Frontal subtracted portal venogram (A) via a catheter placed through the middle hepatic vein shows the previously placed right hepat-
ic to right portal vein TIPS (white arrow) to be occluded. Because of this, the patient had recurrent bleeding from gastric varices (white arrowheads). Repeat portal venogram (B) after placement of a parallel TIPS (white arrow) shows antegrade flow into the right atrium and lack of filling of the gastric varices. Previously placed TIPS stent (black arrow) is unchanged and does not contribute to flow.
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Second, access through a naturally occurring portosystemic shunt, such a splenorenal shunt, sometimes can be used to gain access to the portal circulation. Finally, direct access through the spleen into the splenic vein is an option (Fig. 5). When these options are not feasible, direct percutaneous access into the right or left portal vein can allow for contrast opacification and targeting.
Reversal or Revision of Transjugular Intrahepatic Portosystemic Shunt
Occasionally, a TIPS reversal or revision is necessary. This is most commonly in the setting of recurrent bleeding or ascites, in which
case a duplex ultrasound of the stent can determine flow and detect stenosis. This can be addressed by placing a second stent and/or bal­loon angioplasty. Limited liver reserve or overzealous shunting may result in liver failure or intractable encephalopathy. In such cases, the interventional radiologist has the option to decrease the shunting or shut down the TIPS altogether. Several maneuvers exist to reduce shunting, including placing a stent within the TIPS, two stents side­by-side, or even a waisted (hourglass-like) stent (Fig. 6). If these interventions are not possible or inadequate, the entire TIPS can be shut down. TIPS shutdown is a rarely performed and advanced procedure.
FIG. 5 Transsplenic TIPS in patient with complete portal vein occlusion and worsening ascites. The thrombosed portal vein makes splenic vein access
necessary. (A) Splenic venogram via direct percutaneous splenic puncture (black arrowhead). Angiography demonstrates prominent varices and collateral vessels (black arrows). Angioplasty of the splenic vein (B) near the confluence (black arrowhead) through the transsplenic catheter (white arrow). A catheter has been placed in the right internal jugular vein and hepatic vein. A long needle used for creation of the parenchymal tract (black arrowhead) extends par­tially into the hepatic parenchyma. The balloon was used as the target for the TIPS needle. Incidental note is made of a plastic internal common bile duct drain (white arrowhead). After wire access (black arrow) to the portal vein (white arrow) via the right hepatic vein (C) through the portal vein the transgressed hepatic parenchyma is dilated (black arrowheads). After TIPS shunt deployment (D), final portal venogram through the transsplenic catheter (black arrowhead) demonstrates patent flow through the stent placed in the proximal splenic and portal veins (white arrow) and TIPS stent connecting the right portal vein and right hepatic vein (black arrowhead).
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TIPS in the Setting of Portal Vein Thrombus
Originally, portal vein thrombosis was considered a contraindication to TIPS. However, a large recent meta-analysis has shown that portal venous recanalization performed with TIPS is a safe and highly suc­cessful option (recanalization rates >85%) in patients with portal vein thrombus. Because portal vein thrombosis is a relative contraindica­tion to transplant, the treatment of portal vein thrombus with TIPS is now routinely practiced at several large transplant centers in the United States and even in patients with complete portal vein thrombus (see Fig. 5). Either transsplenic or transhepatic access is required to assist with recanalization. Recanalization techniques can be complex, particularly in the setting of tortuous collateral formation. The pri­mary complication of portal vein recanalization is perisplenic bleed­ing; thus, dropping hemoglobin after the procedure should warrant a search for a perisplenic hematoma and potentially embolization. Additionally, portal vein rupture, which is a very rare complication, should be prepared for in the setting of angioplasty and appropriately sized stent grafts should be on hand to treat rupture if necessary.
CLINICAL OUTCOMES
Clinical Response to TIPS
Regardless of whether TIPS is performed as an elective or emergent procedure, admission overnight to the critical care unit is routine. If the postoperative course is uneventful, a patient who underwent an elective TIPS can be discharged the next day. Follow-up of liver func­tion tests (LFTs) and evaluation for encephalopathy are performed during the inpatient stay directly following TIPS placement; a small increase in LFTs is expected postprocedurally.
TIPS is the most effective option for treating gastroesophageal
FIG. 6 TIPS stent revision in the setting of persistent encephalopathy. To
reduce flow through the TIPS stent, a second longer stent can be partially opened (white arrow) through the original stent (black arrow). Pressures are sequentially measured as the second stent is gradually deployed to desired effect.
TIPS in Transplanted Livers
TIPS is often used to bridge to liver transplantation in patients with end-stage liver disease. Before transplantation, TIPS is used to man­age complications of portal hypertension and ensure patients can remain as transplant candidates. The same etiologies that resulted in native liver failure in the first place can occur in the transplanted liver, leading to the recurrent portal hypertension. For this reason, indications for TIPS in transplanted livers are the same as those for patients pretransplantation. Studies have shown that TIPS can be effective in addressing early complications such as portal vein thrombosis and delayed graft functions. Understanding of the venous anastomosis of the inferior vena cava is critical to performing a TIPS in a transplanted liver; the piggyback technique to TIPS can be used to address this challenge. In this technique, TIPS placement is performed in the left internal jugular vein rather than in the right.
Fewer shunt stenoses and procedural complications have been recorded in posttransplant patients compared with pretransplant patients. Approximately 10% to 20% of stents in patients with transplants require revision compared with 70% in patients without transplants. However, patients with transplants who undergo TIPS have higher risks of infection, renal failure, and neurologic complica­tions than patients without transplants. Clinical success rate of TIPS in patients without transplants is much higher than in patients with transplants (93% vs. 77%).
variceal bleeding. The rebleeding rate after TIPS placement is 4% per year, the lowest amongst all treatment options, including endoscopic management. TIPS is reserved for use after failure of endoscopic management, only because of the greater risks associated with it, particularly encephalopathy. Cessation of bleeding is evident almost immediately after TIPS creation.
TIPS also has been shown to be effective in treating ascites, as well as reducing the risk of ascites by 50% to 80% over the patient’s life. In addition, TIPS has been shown to improve survival and transplant-free survival compared with other treatment options. Resolution of ascites may take up to 4 weeks after TIPS placement.
In patients with HRS, TIPS can improve renal function in 62% of patients. However, it can occasionally be difficult to distinguish noncirrhotic-related chronic renal insufficiency from HRS.
Complications and Management
The complications related to TIPS are shown in Table 3. The most feared complication is liver failure, which usually results from exces­sive portohepatic venous shunting in a liver with limited baseline reserve. If patients with limited liver reserve are excluded appropri­ately, the risk of liver failure is 2% to 4%.
Encephalopathy can be seen in up to 12% of patients with com­pensated liver disease and up to 50% of patients with decompensated liver disease. Flagyl and lactulose provide significant relief for such patients, but a small percentage (4%) will not respond and may require TIPS reversal.
Death from sepsis is rare (<1%). Bacteremia results in TIPS stent seeding; the stent graft infection can be very challenging or impos­sible to treat. Broad-spectrum antibiotics may clear the bacteremia, but in some cases, it recurs after cessation of treatment, as the seeded stent elutes more bacteria. Active infection is an absolute contraindi­cation to TIPS, and any infection must be cleared before intervention.
The overall post-TIPS 30-day mortality ranges from less than 2% to 30% and is mostly dependent on whether the procedure is performed emergently or electively. Higher mortality rates are seen
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TABLE 3 Complications of TIPS
Complication Predisposing Factor(s) Mitigating Factors
Liver failure Limited reserve
High bilirubin Overshunting
Encephalopathy History of
encephalopathy High ammonia levels Limited reserve
Bleeding Difficult anatomy
Abnormal coagulation
profile
Sepsis Active infection Treat infection
Renal failure Elevated creatinine
Dehydration High contrast load
in patients with poorly compensated liver disease who are having TIPS placed on an emergent basis, usually for life-threatening var­iceal bleeding. For patients with compensated liver disease who are having an elective TIPS created, mortality is less than 5%. It is there­fore important to carefully select patients and refer for TIPS before an emergency. Administration of vasoactive drug therapy, such as somatostatin and octreotide, in patients presenting with acute var­iceal hemorrhage has been shown to reduce the risk of mortality at 7 days, in addition to improving hemostasis and shortening length of stay.
The MELD score, routinely used to predict survival with end­stage liver disease and allocate transplants, was initially developed to predict poor survival in patients after creation of a TIPS. The cut-off score for high-risk short-term mortality (expected survival of less than 3 months after TIPS creation) was 18. Subsequent research using the Na-MELD score that also incorporates serum sodium (Na) has been shown to be a more accurate predictor of risk post-TIPS (≥15). Most versions of the MELD score are more accurate predictors of risk after TIPS than the Child-Pugh score.
Reduce or close the
TIPS
Reduce or close the
TIPS
Flagyl or lactulose
Correct coagula-
tion profile
before TIPS
Hydrate Bicarbonate Utilize CO
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Follow-Up
Long-term TIPS follow-up is based mostly on clinical signs and symptoms. Ultrasound surveillance is useful if signs or symptoms of recurrent portal hypertension occur; importantly, TIPS ultrasound should generally be avoided for the first 2 weeks after TIPS creation. This is because the newly placed TIPS has air trapped within it, which limits ultrasound penetration and can simulate the sono­graphic appearance of an occluded TIPS. Recurrent variceal bleeding or ascites is a very specific indicator of TIPS restenosis or occlusion and should prompt a diagnostic venogram or intervention.
SUMMARY
The most important determinant of clinical outcomes after TIPS placement is proper patient selection and preparation. Cirrhotic patients with portal hypertension should be under surveillance and referred for TIPS after conservative management fails but before com­plications of portal hypertension manifest into an emergency. This, along with optimal patient preparation, can help reduce the once high morbidity and mortality related to TIPS. The benefits of TIPS include reduced drop-off rate from the liver transplant list, improved lifestyle quality (i.e., resolution of ascites), and reduction of many portal-hypertension-related complications. Most importantly, TIPS is often a lifesaving procedure for those with variceal hemorrhage.
S U G G E S T E D R E A D I N G S
Carrion AF, Martin P. Keeping Patients with End-Stage Liver Disease Alive
While Awaiting Transplant: Management of Complications of Portal Hypertension. Clin Liver Dis. 2021;25(1):103–120.
Ferral H, Behrens G, Lopera J. Budd-Chiari syndrome. AJR Am J Roentgenol.
2012;199(4):737–745.
Ferral H, Gamboa P, Postoak DW, et al. Survival after elective transjugular
intrahepatic portosystemic shunt creation: prediction with model for end­stage liver disease score. Radiology. 2004;231:231–236.
García-Pagán JC, Caca K, Bureau C, et al. Early TIPS (Transjugular
Intrahepatic Portosystemic Shunt) Cooperative Study Group. Early use of TIPS in patients with cirrhosis and variceal bleeding. N Engl J Med. 2010;362(25):2370–2379.
Kim DJ, Darcy MD, Mani NB, etal. Modified Balloon-Occluded Retrograde
Transvenous Obliteration (BRTO) Techniques for the Treatment of Gastric Varices: Vascular Plug-Assisted Retrograde Transvenous Obliteration (PARTO)/Coil-Assisted Retrograde Transvenous Obliteration (CARTO)/ Balloon-Occluded Antegrade Transvenous Obliteration (BATO). Cardiovasc Intervent Radiol. 2018;41(6):835–847.
Valentin N, Korrapati P, Constantino J, Young A, Weisberg I. The role of tran-
sjugular intrahepatic portosystemic shunt in the management of portal vein thrombosis: a systematic review and meta-analysis. European Journal of Gastroenterology & Hepatology. 2018;30(10):1187–1193.
Management of Refractory Ascites
Justin Brilliant, MD, and James P. Hamilton, MD
INTRODUCTION
Ascites, the abnormal accumulation of fluid in the peritoneal cavity, is one of the major complications of portal hypertension in cirrhosis and portends a poor prognosis. Ascites is the most common com­plication of cirrhosis with approximately 50% of patients developing ascites within 10 years. The initial workup for a cirrhotic patient
with ascites should include evaluation of the ascitic fluid and kidney function because of common complications such as spontaneous bacterial peritonitis (SBP) and hepatorenal syndrome. All patients should restrict their daily sodium intake to 2 grams to minimize fluid retention, consume at least 1 g/kg of their body weight of protein each day to avoid malnourishment, and start diuretics for a goal of
0.5 kg of fluid loss each day. In the meantime, prompt referral for liver transplant should be undertaken as one-half of all cirrhotic patients with ascites die within 5 years.
However, as cirrhosis progresses with worsening ascitic fluid retention, patients have greater difficulty maintaining their effective arterial blood volume leading to impaired renal solute-free water excretion and renal vasoconstriction. This complication is known
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as refractory ascites and is defined as fluid that cannot be mobilized despite a 2-gram sodium-restricted diet and high-dose diuretic treatment (160 mg of furosemide and 400 mg of spironolactone) or that reaccumulates rapidly after therapeutic paracentesis. Signs of diuretic failure include lack of weight loss, inadequate sodium excretion in the urine (<78 mEq/day), and development of com­plications such as progressive azotemia, hepatic encephalopathy, or progressive electrolyte imbalances. Refractory ascites only occurs in 10% of patients with both cirrhosis and ascites. Importantly, detailed assessment of dietary and medicine compliance, abstinence from alcohol and medications that reduce effective arterial blood volume (e.g., nonsteroidal antiinflammatory drugs, angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, etc.), and exclusion of infection should be done before the diagnosis and subsequent management of refractory ascites.
Urinary Electrolyte Measurement in Refractory Ascites
Patients who gain weight on maximum diuretics but excrete less than 78 mEq of sodium per day from the urine are refractory to diuretics. To measure urinary sodium excretion, a 24-hour urinary collection is necessary as an inadequate collection can underestimate the true value; however, it can be difficult to obtain an accurate 24-hour urinary collection in a real-life setting. A random urinary sodium/ potassium ratio can quickly estimate urinary sodium excretion. Approximately 90% of patients with a urine sodium/potassium ratio greater than 1 excreted more than 78 mEq/day of sodium in a 24-hour collection. In patients with excretion of more than 78 mEq of sodium per day from the urine, they are identified as being diuret­ic-sensitive, thus ruling out refractory ascites; these patients should theoretically lose weight if adherent to a sodium-restricted diet and diuretics.
SPONTANEOUS BACTERIAL PERITONITIS
Diagnosis
Spontaneous bacterial peritonitis (SBP) is an infection of the ascitic fluid in the absence of an intraabdominal, surgically treatable source. SBP represents the most frequent bacterial infection in patients with cirrhosis with the clinical presentation ranging from no symptoms to mild abdominal pain to sepsis. One-half of the episodes of SBP are present at the time of hospital admission, and therefore, prompt rec­ognition of SBP, ideally within 6 hours, via a diagnostic paracentesis is essential in patients hospitalized with both cirrhosis and ascites. The diagnosis is made in the presence of an elevated polymorpho­nuclear leukocyte (PMN) count of 250 cells/mm ascitic fluid, with or without a positive culture in the ascitic fluid, in the absence of other causes of peritonitis.
Empiric Treatment
When the ascitic fluid PMN count is 250 cells/mm3 or higher, empiric antibiotic therapy is indicated even before cultures grow bacteria to mitigate risks of sepsis, end-organ damage, and mortality. Patients who meet the PMN criterion but have negative ascitic fluid cultures have been labeled with culture-negative neutrocytic ascites. These patients have the same symptoms and mortality as those with SBP and thus require the same treatment as SBP. Patients with fewer than 250 cells/mm bacterial fluid culture, have been labeled with nonneutrocytic bacteras- cites. The positive bacterial fluid culture in this setting may represent a short-lived, reversible colonization that may not warrant antibiotics; it has been reported that 62% to 86% of cases resolve spontaneously. However, if a follow-up paracentesis is performed (48 hours later) and the bacterial fluid culture remains positive, empiric treatment is
3
of PMN in their ascitic fluid, but who have positive
3
or higher in the
recommended, especially if patients develop any convincing signs of infection including sepsis, fever, abdominal pain, and encephalopathy. Finally, the recognition of secondary bacterial peritonitis is critical in patients who have localized abdominal symptoms, polymicrobial growth in ascitic fluid culture, elevated ascitic protein concentration, or worsening symptoms on broad-spectrum antibiotics because dedi­cated imaging with surgical management may be necessary.
Choice of Antibiotics
Broad-spectrum antibiotic therapy is warranted for the treatment of SBP. The treatment of choice is a third-generation cephalosporin including cefotaxime or ceftriaxone because it provides coverage against 95% of the three most common bacterial species that cause SBP. Piperacillin-tazobactam or meropenem may be options in patients with suspected healthcare-associated or nosocomial SBP because of higher incidence of bacteria resistant to third-generation cephalosporins. Furthermore, empiric coverage with carbapenems such as meropenem may have decreased in-house mortality com­pared with third-generation cephalosporins among critically ill patients. However, carbapenem-resistant bacteria have emerged over the past decade necessitating alternative treatment regimens, such as combining β-lactams or carbapenems with β-lactamase inhibitors, that are still currently being investigated. Five days of treatment has been shown to be efficacious, and treatment may be narrowed based on sensitivities of cultured organisms. Oral-based regimens including ofloxacin were as effective as third-generation cephalo­sporins in asymptomatic SBP but is not routinely recommended until additional trials are performed. Patients who had received fluoroquinolones as prophylaxis against SBP should be treated with nonfluoroquinolone-based regimens secondary to risk of microbial resistance to the former regimen.
Intravenous Albumin Infusion
The administration of albumin can theoretically improve the decreased effective arterial blood volume to reduce the risk of renal failure that afflicts 30% to 40% of patients with SBP. In addition to the previously discussed antibiotics, IV albumin 25% (1.5 g/kg within 6 hours on the first day followed by 1 g/kg on day 3) has been shown to decrease mortality in SBP. The beneficial effect of albumin was shown particularly in patients with hepatic decompensation or renal dysfunction (serum bilirubin ≥4 mg/dL, BUN ≥30 mg/dL, and serum creatinine ≥1 mg/dL).
β-Blockers
Recent studies have called in to question the previous notion that there was higher mortality in SBP associated with continuation of nonselective β-blockers for prevention of variceal hemorrhage in portal hypertension. Previously, β-blockers in SBP increased the risk for hepatorenal syndrome and acute kidney injury, the time of hospitalization, and reduced transplant-free survival. However, mor­tality seems to be more related to the degree of impaired systemic perfusion. Therefore, nonselective β-blockers may be considered or reintroduced as long as patients have no evidence of circulatory dys­function (e.g., mean arterial pressure <65 mm Hg). Future studies are needed to clarify the optimal duration of nonselective β-blockers and scenarios when the risk of complications outweighs their benefits.
Follow-Up Paracentesis
A repeat paracentesis to document resolution of SBP is generally not necessary. Most cirrhotic patients with SBP and typical ascitic fluid analysis will show clinical response on antibiotic treatment. However, if symptoms persist or worsen, atypical organisms grow in culture, or suspicion of secondary peritonitis arises, then a repeat paracentesis can be performed to evaluate for unresolved infection.
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MEDICAL TREATMENT CONSIDERATIONS IN REFRACTORY ASCITES
β-Blockers
As stated previously, there may be a role for nonselective β-blockers in refractory ascites, but they should be used with extreme caution because patients are predisposed to circulatory collapse. Several recent studies have shown that increased left ventricular systolic function via activation of β-1-receptors serves as a compensatory mechanism due to peripheral vasodilation and decreased effective arterial blood volume. This physiologic state may underlie the association from prior studies between nonselective β-blockers that suppress this cardiac response and poor survival in patients with refractory ascites. However, only when arterial perfusion pressure falls below a certain threshold (blood pressure <90/60 mm Hg) does risk of renal failure, circulatory dysfunction, and mortality increase. Therefore, a therapeutic window exists for nonselective β-blockers, and they should be used with caution in patients with hypotension, hyponatremia, or acute kidney injury. These medications offer a survival benefit in variceal bleeding prophylaxis and should be carefully reintroduced if appropriate; doses greater than 160 mg/ day of propranolol or 80 mg/day of nadolol should be avoided.
Vasoconstrictors and Albumin
Vasoconstrictors have been used in the management of hepatore­nal syndrome and the prevention of hemodynamic instability after large volume paracentesis (LVP), along with albumin. The use of vasoconstrictors with intravenous albumin in patients with cirrhosis can improve sodium excretion, circulatory function, and ascites control as long as kidney function is preserved. When taken for at least 30 days, midodrine, an α-1 receptor agonist, has been shown to be as effective as albumin in reducing morbidity and mortality among patients undergoing an LVP at a significantly lower cost. Midodrine can treat severe hypotension with systolic blood pressures in the 70s or 80s characteristic of patients with refractory ascites and improve sensitivity to diuretics while preserving hemodynamic stability (along with cessation of a β-blocker, if applicable). The addition of midodrine to standard medical therapy for refractory ascites can improve renal perfusion, increase renal sodium excretion, and reduce ascites. Octreotide, a somatostatin analogue, can cause splanchnic vasoconstriction and improve renal perfusion. Parenteral octreotide has been effective with oral midodrine and albumin in reversing type-1 hepatorenal syndrome. In one study analyzing patients with hepatorenal syndrome, therapy with midodrine, oct­reotide, and albumin compared with albumin alone was associated with resolution of kidney injury and decreased mortality. Terlipres­sin, a vasopressin derivative, also induces splanchnic vasoconstric­tion and can be used to control ascites. Although terlipressin is not available in the United States, it has been widely used in Europe and other parts of the world for hepatorenal syndrome. Recently, a large randomized, double-blind, placebo-controlled trial (CONFIRM trial) comparing the safety and efficacy of terlipressin and albumin in patients with hepatorenal syndrome to those treated with placebo and albumin was performed. This trial showed that terlipressin and albumin is associated with a higher likelihood of reversal of hepa­torenal syndrome for at least 30 days and 10-day survival without renal replacement therapy when compared with placebo. However, patients who received terlipressin were more likely to have respira­tory failure within 90 days after the first dose. Terlipressin is not yet approved in the United States for the management of type-1 hepato­renal syndrome until safety concerns are resolved.
INTERVENTIONAL METHODS IN THE TREATMENT OF REFRACTORY ASCITES
Liver Transplantation
Liver transplantation is the definitive therapy for patients with cir­rhosis and refractory ascites. The development of refractory ascites
confers a poor prognosis, with approximately half of patients dying within 1 year without transplantation. Therefore, suitable candidates should be referred to a liver transplant center.
Large Volume Paracentesis with Albumin Replacement
LVP with albumin replacement is one of the first-line treatments for refractory ascites while patients are awaiting liver transplantation. This procedure ameliorates the characteristic symptoms of large volume ascites such as early satiety, bloating, abdominal pain, and shortness of breath. Based on the available studies, an infusion of albumin is recommended after a paracentesis that removes 5 liters or more of ascitic fluid; the recommended dose of albumin is 6 to 8 g/L of ascites removed. The use of albumin in patients requiring the removal of at least 5 liters of ascitic fluid reduced electrolyte abnormalities, renal dysfunction, and postparacentesis circulatory dysfunction (PPCD). Although there has traditionally been no set limit on the amount of volume removed, limiting each LVP session to less than 8 liters with additional albumin (9.0 ± 2.5 g/L of ascites removed) in one study may reduce mortality and preserve renal function over a mean period of 2 years despite the onset of PPCD in 40% in this cohort of patients. Furthermore, albumin infusion can be considered in patients who have <5 L of ascites removed and either systolic blood pressure <90 mm Hg, hyponatremia (Na <130 g/dL), or an acute kidney injury. Patients can be scheduled for serial LVPs every 2 weeks as an outpatient, but this treatment is not an ideal long­term solution because repeated LVPs cause protein depletion, leading to worsening malnutrition.
The preferred site for needle entry is 3 cm medial and 3 cm supe­rior to the anterosuperior iliac spine on the left lower quadrant of the abdomen. The right lower quadrant is less desirable because the cecum can become distended in patients who take lactulose. A distended cecum has a higher risk of perforation. The needle should avoid areas with cutaneous infection, abdominal wall hematoma, scars, or visibly engorged subcutaneous areas. Bedside ultrasound is useful in locating a safe site for needle entry away from vascular structures.
The paracentesis needle can be inserted with either the angular technique or the Z-track technique. In the angular technique, the needle is inserted obliquely from the cutaneous site into the perito­neum. In the Z-track technique, cutaneous tissues are pulled down and the needle is inserted straight into the peritoneum. These tech­niques ensure that cutaneous and peritoneal needle entry sites do not directly overlap, thereby minimizing postprocedure ascitic fluid leakage (Fig. 1).
Inferior
ic
artery
FIG. 1 Preferred needle entry site for paracentesis.
(From Drake R, Vogel AW. Gray’s Atlas of Anatomy. Philadelphia: Elsevier; 2007.)
Anterior superior
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Transjugular Intrahepatic Portosystemic Shunt
Transjugular intrahepatic portosystemic shunt (TIPS) is an artificial communication between the portal vein and hepatic vein usually placed by an interventional radiologist (Fig. 2). The direct result of TIPS placement is a significant reduction in portal pressure through the creation of an alternative pathway for portal venous flow. Before and after TIPS placement, the proceduralist can quantify the degree of portal hypertension by measuring the portosystemic gradient. The benefit of TIPS is in reversing portal hypertension, the cause of many complications of cirrhosis. After successful TIPS procedure, ascites may completely resolve along with portosystemic shunts (e.g., esophageal varices) over the span of months.
Under fluoroscopic guidance, the interventional radiologist accesses the liver through the internal jugular vein in the neck. Once venous access is confirmed, the radiologist inserts a guidewire and introducer sheath that enables access to the hepatic veins by passing the superior vena cava and inferior vena cava. Once the catheter enters the hepatic vein, the radiologist injects contrast to locate the portal vein and advances a needle through the liver parenchyma to connect the two veins. An inflated angioplasty balloon creates a
Inferior vena cava
Catheter
(enters body
in neck)
channel for the shunt along the needle tract. Last, the shunt forms by placing a polytetrafluoroethylene-covered stent to maintain the tract. The covered stent has been a standard for many years. It has a higher patency interval compared with the older uncovered stent.
Absolute contraindications for TIPS include heart failure, severe tricuspid regurgitation, and severe pulmonary hypertension. TIPS in the setting of these conditions can lead to severe cardiac volume overload because blood flow is diverted past the liver and into the right heart. Sepsis, biliary obstruction, and severe hepatic enceph­alopathy are other absolute contraindications to TIPS placement. Patient selection and the timing of a TIPS procedure are very import­ant predictors of patient outcome. The Model for End-Stage Liver Disease (MELD) score, now used to prioritize organ allocation in liver transplantation, was initially developed to predict the 3-month mortality after TIPS. Patients with a MELD score of ≥18 have poorer outcomes after TIPS. The use of smaller diameter (8–10 mm) stents has been associated with a lower incidence of hepatic encephalop­athy following TIPS with no reduction in ascites clearance. One study showed that earlier TIPS placement after patients developed ascites improved 1-year transplant survival compared with patients receiving serial LVPs, albumin infusions, and diuretics (93% vs.
Balloon inflated to dilate tract
Catheter
Guidewire
Portal vein
Right hepatic vein
Balloon inflated to expand wall stent
Stent
x-ray
Varices
Balloon
FIG. 2 Transjugular intrahepatic portosystemic shunt
placement. (Courtesy Johns Hopkins Medical Institutions.)
446 MANAGEMENT OF REFRACTORY ASCITES
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53%, respectively). With additional studies, the optimal timing of TIPS with appropriate selection criteria can be investigated for safe and expedited stent placement to improve mortality before liver transplant.
Peritoneovenous Shunts
Peritoneovenous shunts drain ascitic fluid from the peritoneal cav­ity into systemic veins, such as the superior vena cava. The Denver shunt, popular in the 1970s, is the only peritoneovenous shunt still manufactured today. Although historically requiring an invasive approach, today it is placed percutaneously in a minimally invasive procedure through an internal jugular or subclavian route. The shunt is made of soft tubing connected to a pump chamber that lies subcutaneously over the lower ribs. Ascitic fluid flows spontaneously from the peritoneum to the superior vena cava, but manual pumping helps avoid buildup of proteinaceous material in the shunt. None­theless, because of poor long-term patency and complications such as obstructions, coagulopathy, superior vena cava thrombosis, and sepsis, peritoneovenous shunts are infrequently used today.
Peritoneal Catheters
A peritoneal catheter (PleurX) inserted into the peritoneum can be an option for ascites removal in patients with the goal of palliation. Given the risk of introducing infection into the peritoneum, this option is typically reserved for patients who are near the end of life. The catheter can be placed with minimal discomfort using a small incision. It is then sutured in place to the skin and connected to a catheter bag. Patients may open the catheter to the bag at their con­venience, allowing patients who may be less mobile to avoid traveling to medical facilities for repeated paracenteses.
EXPERIMENTAL OPTIONS
Clonidine and Midodrine
Clonidine is an α-2-adrenergic receptor agonist that suppresses the renin-aldosterone system, which is activated in patients with refractory ascites. Clonidine has shown promise when used in com­bination with furosemide and spironolactone in refractory ascites with one study showing a 60% diuretic-response rate after 3 months. The combination of clonidine with midodrine, an oral α-1-receptor agonist, and standard medical therapy (sodium restriction, use of diuretics, and serial LVPs as needed) was investigated in one trial. The effect of combination therapy on systemic hemodynamics, renal function, and control of ascites was not greater than clonidine or midodrine by themselves when used with standard medical therapy.
Sodium-Glucose Cotransporter 2 Inhibitors
Sodium-glucose cotransporter 2 (SGLT2) inhibitors are medications that are now used in type 2 diabetes mellitus for treating hypergly­cemia. These medications block a major transport protein, SGLT2, in the proximal tubules of the kidney to block nearly 90% of the kidney’s glucose reabsorption. SGLT2 inhibitors have been shown to exhibit protective effects on the liver, heart, and kidney through
natriuresis, deactivation of the renin-angiotensin-aldosterone sys­tem, and antiinflammatory effects. In three patients who had cirrho­sis due to nonalcoholic steatohepatitis and diabetes along with fluid retention, SGLT2 inhibitors were associated with reduction in ascites and peripheral edema. Serum sodium levels improved as well. Clin­ical trials are needed to investigate the safety and efficacy of SGLT2 inhibitors in refractory ascites.
Low-Flow Ascites Pump (ALFApump)
European surgeons and radiologists have collaborated to develop a pump (ALFApump) that moves ascitic fluid from the peritoneal cavity into the urinary bladder. Previous studies showed a decrease in the need for large-volume paracentesis in those with refractory asci­tes, with most patients not requiring paracentesis after implantation of the pump system. In a multicenter randomized controlled trial including 60 patients with refractory ascites, the median time to first LVP was not reached after 6 months in patients with an ALFApump compared with 15 days for the standard-of-care group. Improved quality of life was also seen in the ALFApump group. However, the frequency of severe adverse events, including acute kidney injury and reintervention for pump-related issues, was significant in the ALFApump group but did not impact survival. Commonly observed complications in low-flow ascites pumps include blockage of the peritoneal catheter, infections, and bleeding. Careful discussion on the risks and benefits of these devices need to be undertaken with close longitudinal follow-up. Currently, the ALFApump is not avail­able in North America but is currently under clinical investigation in the United States and Canada.
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