Добавил:
kiopkiopkiop18@yandex.ru t.me/Prokururor I Вовсе не секретарь, но почту проверяю Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:

Ординатура / Хирургия / @xirurgi_2025 / @xirurgi_2025 - 280 - файл

.pdf
Скачиваний:
0
Добавлен:
28.08.2026
Размер:
66 Мб
Скачать
PORTAL HYPERTENSION 449
https://t.me/medicina_free
Gastrointestinal bleeding is another common precipitant of HE. In addition to overt evidence of bleeding, high blood urea nitro­gen-to-creatinine ratio or history of known varices or portal hyper­tensive gastropathy may be clues. Gastrointestinal bleeding decreases perfusion to key organs in ammonia clearance including the liver and kidneys. In addition, blood also acts as a large protein substrate in the gut, leading to increased production of ammonia.
Patients with cirrhosis are at risk for volume depletion and elec­trolyte imbalance, each of which can precipitate HE. Overdiuresis or misuse of laxatives can both cause and exacerbate volume depletion.
TREATMENT FOR HE IN CHRONIC
LIVER DISEASE
Nonabsorbable Disaccharides
Lactulose is recommended by the American Association for the Study of Liver Diseases (AASLD) and European Association for the Study of the Liver (EASL) guidelines as first-line treatment for overt HE (grade II B) (Table 4). It is a nonabsorbable disaccharide that is thought to acidify the gut environment, making it less favorable to ammonia-producing bacteria. It also increases bowel movement, increasing excretion of nitrogen-containing compounds.
Lactulose is titrated to effect and required dose varies among patients. Initially it should be started at 20 to 30 g every hour until def­ecation occurs. It can then be spaced to 20 to 30 g every 4 to 6 hours
depending on clinical improvement. In patients unable to take oral lactulose, enteral access may be obtained via nasogastric tube for lactulose administration. In some patients, placement of a nasogastric tube may be contraindicated (i.e., esophageal varices or recent band­ing), and lactulose can also be administered rectally by enema.
After an initial episode of HE, lactulose is recommended to pre­vent recurrent episodes of HE and is generally titrated to 2 or 3 bowel movements per day. Recent studies, however, suggest that fewer bowel movements may be as effective. Common side effects include nausea, bloating, and diarrhea. Lactinol is another nonabsorbable disaccharide with comparable effectiveness; however, it is not avail­able in the United States.
Oral Nonabsorbable Antibiotics
Rifaximin is the primary nonabsorbable antibiotic used for the treat­ment of HE. It suppresses intestinal flora and thus decreases their production of ammonia and associated toxins in the gut and has been studied for treatment in HE in several clinical trials. Rifaximin has mainly been studied as an addition to lactulose therapy. There is some evidence that rifaximin monotherapy may be appropriate in those who have HE refractory to lactulose or with lactulose intolerability, though further research is needed. Unfortunately, rifaximin is often not cov­ered by insurance and is expensive as an outpatient therapy. Currently, rifaximin is recommended for use in combination with lactulose for prevention of recurrent HE (grade IA recommendation).
TABLE 4 Medical Treatments for Hepatic Encephalopathy
Drug Dosing Comments
GUIDELINE RECOMMENDED FIRST-LINE THERAPIES
Lactulose Oral: Initial: 20 to 30 g every hour until
defecation. Reduce to 20 g every 4–6 hours until clinical improvement. Maintenance: 20 g every 8–12 hours, titrated to goal 2–3 stools/day
Rectal: Enema. 200 g lactulose in tap water
Repeat every 4–6 hours
Rifaximin Oral: 550 mg twice a day Guideline recommended
ALTERNATIVE THERAPIES
Polyethylene glycol (PEG) Oral: PEG-based electrolyte solution: 4 L admin-
istered over 4 hours or 2 L every 12 hours
PEG powder: 17 g twice daily to three times
daily, titrated to 2-3 bowel movements daily
BCAA No standard dosing Add-on or alternative therapy
LOLA IV: 30 g daily Add-on or alternative to first-line therapy
Probiotics Varies Many different types available commer-
Zinc Varies depending on zinc level Patients should be screened for zinc deficiency;
First-line guideline recommended therapy SE: bloating, nausea, diarrhea Recent studies suggesting increased number of
BMs may not be needed for lactulose to be effective
Add on to lactulose or as alternative if lactu-
lose not tolerated
Can be expensive and may not be covered by
insurance
Second-line therapy May be more effective than lactulose, further
studies needed
IV BCAA not effective
Oral LOLA not effective
Not available in the United States
cially, most effective for HE appear to be Lactobacilli and Bifidobacteria species
empiric supplementation has less evidence
BCAA, Branched-chain amino acids; BM, bowel movement; LOLA, L-ornithine and L-aspartate; SE, side effects.
450 MANAGEMENT OF HEPATIC ENCEPHALOPATHY
https://t.me/medicina_free
Alternative Therapies for HE
Polyethylene glycol (PEG) has been used both as a PEG-based elec­trolyte solution (Golytely, Nulytely) and in powder form (MiraLAX). It has been shown to improve measures of HE as well as outcomes such as hospitalization and survival in patients with HE. Recent studies show that it may be more effective than standard therapy with lactulose. It is not yet recommended in guidelines as a first-line treatment; however, it is a good alternative, especially in patients unable to tolerate lactulose. Other laxatives have been studied, but more research is required to examine their efficacy and safety in HE.
Branched-chain amino acids (BCAA) including valine, leucine, and isoleucine enhance ammonia detoxification to glutamine, par­ticularly in skeletal muscle. BCAA supplementation may also reduce malnutrition and decrease loss of muscle mass common in severe liver disease. Studies in patients with HE showed improvement in outcomes in patients with or without symptoms of muscle wasting. However, BCAAs also carry side effects such as disruption of certain metabolic pathways and altered neurotransmission, and thus further research is needed to evaluate their use in patients with HE.
L-Ornithine and L-aspartate (LOLA) are involved in the urea cycle and help glutaminase convert ammonia and accelerate its elimination from the body. Although LOLA is not widely used, it is a good option, particularly for patients with HE due to portosystemic shunting. LOLA is recommended as an adjuvant treatment, not as a monotherapy, but it is not currently available in the United States.
OTHER THERAPIES REQUIRING
FURTHER RESEARCH
Probiotics are cultures of live microorganisms that help balance the normal flora of the gut. Most commercially available probiotic prod­ucts are derived from food sources, especially milk products. There are many microorganisms that have been studied, with the most efficacious species for HE being Lactobacilli or Bifidobacteria. Some studies have suggested benefit in prevention of recurrent HE. However, more data are needed for a strong recommendation for the treatment or prevention of HE.
Zinc is a cofactor in the urea cycle and may facilitate ammonia clearance. Zinc deficiency should be screened for and repleted in all patients with HE. Clinical trial data regarding empiric zinc supple­mentation is lacking; however, it has few side effects.
Metabolic ammonia scavengers act as urea surrogates and have been used in treatment for inborn errors of the urea cycle. Ornithine phenylacetate and glyceryl phenylbutyrate have been studied for HE; however, further clinical trials are needed for clinical recommendation.
Flumazenil is an antagonist of benzodiazepine receptors. It has been shown in small randomized controlled trials to transiently improve mental status, however, is not commonly used for this indi­cation and is not recommended for routine treatment of HE.
Phenylbutyrate reduces glutamine availability, suppressing ammonia production. It also promotes ammonia detoxification via glutamine synthetase reaction. Studies have shown that use of glycerol phenylbutyrate and sodium phenylbutyrate in patients with recurrent HE resulted in fewer episodes of HE. However, phenylbu­tyrate also causes a decrease in BCAA in the blood.
Other antibiotics: Neomycin was previously used in treat­ment of HE. It is a nonabsorbable antibiotic, a known glutaminase inhibitor and functions similarly to rifaximin. However, it has been shown to have some systemic absorption with ototoxic and nephritic side effects and thus is not recommended for long-term first-line use. Metronidazole has similarly been studied as a short­term therapy, but is also associated with ototoxicity, nephrotoxicity, and neurotoxicity.
Other laxatives: Other laxatives, without the prebiotic prop­erties of disaccharides, may also be beneficial by increasing bowel movement. However, further research is needed before these can be recommended in routine use.
OTHER CONSIDERATIONS
Nutrition
Nutrition plays a crucial role in patients with cirrhosis and especially HE, as they are prone to malnutrition and sarcopenia. Muscle tissue in partic­ular plays a compensatory role in HE through metabolism of ammonia via glutamine synthetase. Protein restriction, previously recommended in this patient population, is no longer routinely advised. Recent studies recommend daily intake of energy of 35 to 40 kcal/kg and 1.2 to 1.5 g pro­tein/kg (grade IA recommendation). Regular caloric ingestion with fre­quent meals or snacks is also recommended (grade IA recommendation), as conversion of amino acids for glucose production in gluconeogenesis depletes tissue protein stores and produces ammonia. Consultation with a nutritionist is often helpful in tailoring an optimal diet.
Hepatic Encephalopathy after Transjugular Intrahepatic Portosystemic Shunt
Transjugular intrahepatic portostytemic shunt (TIPS) is often performed in patients with chronic liver disease for management of bleeding esophageal varcies or refractory ascites. HE is a major complication after TIPS, and patients must be carefully selected before undergoing TIPS. Lactulose and rifaximin are not recom­mended prophylactically after TIPS; however, they can be used if HE develops. Post-TIPS HE may be refractory to conventional management, and in these cases shunt diameter reduction, or higher goal portal pressure, can be helpful.
Portosystemic Shunts
Recurrent HE with relatively preserved hepatic function should lead to investigation for spontaneous portosystemic shunts. Depending on the type of shunt, it may be possible to embolize the shunt, with resolution of HE in many patients.
Liver Transplantation
HE alone is not considered an indication for liver transplantation (LT). However, in some patients with relatively good liver status, HE may be severe and significantly worsen quality of life, and LT may be considered. Although HE should improve after LT, those with large PSSs may have persistent symptoms. Additionally, patients may develop confusion during the postoperative period due to the toxic effect of immunosuppressant drugs.
Acute Liver Failure
ALF is defined as severe liver injury in the absence of prior liver disease with development of coagulopathy (INR >1.5) and HE. In the developing world, acetaminophen toxicity is the most common etiology, while viral hepatitis is the most common in the developing world. Given the potential for rapid deterioration, early transfer to the Intensive Care Unit for monitoring and management is rec­ommended. Patients with grade 3 HE or higher will likely require intubation for airway protection and should have regular neurologic checks to evaluate for signs of elevated intracranial pressure (ICP). Patients with ALF should be transferred to a liver transplant center early in their course for evaluation for LT.
In contrast to chronic liver disease, arterial ammonia levels have been shown to correlate with severity of HE in ALF. Ammonia levels >200 have been associated with increased risk of cerebral edema and intracranial hypertension. Conventional treatments for HE, lactulose and rifaximin, have not been shown to be beneficial in ALF. Contin­uous renal replacement therapy (CRRT) is an effective method of rapid and clinically meaningful ammonia clearance.
CT scans should be carefully considered in these patients, as moving patients with severe HE can lead to surges of ICP. Furthermore, CT scans may be insensitive to small changes in ICP, though they are helpful in
PORTAL HYPERTENSION 451
https://t.me/medicina_free
the diagnosis of intracranial hemorrhage and cerebral herniation. Other neuroprotective interventions include elevation of the head to 30 degrees, avoiding fever, and maintaining euglycemia. It is also recommended to maintain serum sodium between 140 and 145 mmol/L with use of hyper­tonic saline when needed. Development of clinical signs of increased ICP should be treated with hypertonic saline (200 mL, 2.7% or 20 mL, 30%) or intravenous mannitol (150 mL, 20%) given over 20 minutes. Hyperventilation to reduce arterial PaCO be beneficial in the acute setting to promote cerebral vasoconstriction.
The use of invasive ICP monitoring devices is controversial, espe­cially given high risk of bleeding in patients with ALF. In patients with monitored ICP, the goal pressure is below 20 to 25 mm Hg, and the cerebral perfusion pressure should be above 50 mm Hg. Noninva­sive techniques such as transcranial Doppler ultrasound and jugular venous oximetry may be helpful as another tool for risk stratification.
to 25 to 30 mm Hg may also
2
Extracorporeal Liver Support Devices
Extracorporeal liver support (ELS) is an invasive option in patients with ALF, with limited data showing benefit in HE but no clear mor­tality benefit. The Molecular Adsorbent Recirculating System (MARS) dialyzes blood across an albumin-impermeable membrane, with protein-bound and water-soluble toxins removed through a second­ary circuit. Randomized trials have not shown overall benefit effect of MARS on morality in patients with ALF or acute on chronic liver failure, though some nonrandomized trials have suggested benefit in HE symptoms or in need of transplantation. The fractionated plasma separation, adsorption, and dialysis technology of the Prometheus sys­tem separates patients’ albumin and plasma from blood and then uses two columns of absorbents and a high-flux dialyzer to clear toxins. One study showed safety and efficacy in patients with ALF, though it did not improve survival of patients with acute on chronic liver failure. Single pass albumin dialysis (SPAD) uses a specialized high-flux albu­min impermeable membrane and addition of HSA to a standard dialy­sis setup. In the few studies thus far, it has not shown to have an impact
on survival or referral to transplantation. High volume therapeutic plasma exchange (HVP) is based on removal of toxins and harmful inflammatory mediators, as well as replacement of beneficial plasma proteins (such as coagulation factors) and in small studies has been shown to have a survival benefit, though further research is needed.
ELS is used at some centers in patients with ALF as a bridging option to either transplant or recovery of liver function, though studies for these indications are still needed. In addition, ELS has been used in cases of secondary liver failure, for example, in hypoxic hepatitis or in conjunction with extracorporeal life support (i.e., extracorporeal membrane oxygenation [ECMO]). Studies have shown improvement in HE and a trend toward decrease in mortality; however, there is still no clear data showing a benefit in mortality and morbidity in specific patient populations, for example, as a bridge to transplant or in concurrence with ECMO.
S U G G E S T E D R E A D I N G S
Bajaj JS. The role of microbiota in hepatic encephalopathy. Gut Microbes.
2014;5(3):397–403. Campion D, Giovo I, Ponzo P, Saracco GM, Balzola F, Alessandria C. Dietary
approach and gut microbiota modulation for chronic hepatic encephalop-
athy in cirrhosis. World J Hepatol. 2019;11(6):489–512. Rahimi RS, Singal AG, Cuthbert JA, Rockey DC. Lactulose vs. Polyethylene
Glycol 3350-Electrolyte Solution for Treatment of Overt Hepatic
Encephalopathy: The HELP Randomized Clinical Trial. JAMA Intern
Med. 2014;174(11):1727. Vilstrup H, Amodio P, Bajaj J, etal. Hepatic encephalopathy in chronic liver
disease: 2014 Practice Guideline by the American Association for the
Study of Liver Diseases and the European Association for the Study of the
Liver: Vilstrup etal. Hepatology. 2014;60(2):715–735. Wendon J, Cordoba J, Dhawan A, et al. EASL Clinical practical guide-
lines on the management of acute (fulminant) liver failure. J Hepatol.
2017;66(5):1047–1081. Wiesmann T, Hoenl D, Wulf H, Irqsusi M. Extracorporeal liver support:
trending epidemiology and mortality - a nationwide database analysis
2007–2015. BMC Gastroenterol. 2019;19(1):160.
Management of Budd-Chiari Syndrome
Joseph DiNorcia, MD, and Ronald W. Busuttil, MD, PhD
INTRODUCTION
Budd-Chiari syndrome (BCS) is a rare disorder that results from the obstruction of hepatic venous outflow, leading to progressive liver damage and portal hypertension. In 1845, George Budd, a British internist, first described the clinical syndrome as a triad of abdominal pain, hepatomegaly, and ascites. In 1899, Hans Chiari, an Austrian pathologist, described the pathologic features of BCS as occlusion of the hepatic veins. This venous occlusion can be due to various causes. Primary BCS results from intrinsic thrombosis of the hepatic veins secondary to prothrombotic, hypercoagulable states or a congenital venous web. Secondary BCS results from thrombosis due to extrinsic compression or invasion of the hepatic veins, for exam­ple, due to a tumor, granuloma, cyst, or abscess (Box 1).
PATHOGENESIS
Hepatic venous outflow obstruction causes increased pressure in the hepatic sinusoids, leading to venous congestion and decreased intrahe­patic portal venous perfusion within the liver. The congestion induces
hepatic fibrosis that progresses over time to cirrhosis with resultant portal hypertension, collateral venous flow, and ascites. The decreased intrahepatic portal venous perfusion further contributes to ischemia, hepatocyte necrosis, and fibrosis that causes hepatic dysfunction. Gross pathologic examination of livers with BCS commonly demonstrates large regenerative nodules. Acute histologic features include marked sinusoidal dilatation with centrilobular congestion, edema, and hem­orrhage, which progresses in the chronic setting to hepatocyte necrosis, fibrosis, and cirrhosis. Central venous thrombi may be seen as well.
PRESENTATION
The clinical presentation of BCS depends on the onset, severity, and duration of the disease and can be categorized as acute liver failure (life-threatening symptoms of acute liver injury), acute (rapid symptom onset without acute liver failure), subacute (insidious symptom onset before cirrhosis), and chronic (late symptom onset after the development of cirrhosis). Acute liver failure secondary to BCS is rare and results from massive liver necrosis causing coma, severe coagulopathy, and hypogly­cemia. The chronic form of BCS is more common, presenting with stig­mata of end-stage liver disease such as fatigue, hepatic encephalopathy, jaundice, gastrointestinal bleeding, abdominal distension due to ascites, renal dysfunction, sarcopenia, and lower extremity edema. Right upper quadrant abdominal pain, hepatosplenomegaly, and an enlarged caudate lobe, which can be felt as a mass in the epigastrium, are additional signs and symptoms. About 10% of patients may be asymptomatic.
452 MANAGEMENT OF BUDD-CHIARI SYNDROME
https://t.me/medicina_free
BOX 1 Etiologies of Budd-Chiari Syndrome
Myeloproliferative disorders
Essential thrombocythemia Polycythemia vera JAK2 mutation Idiopathic myelofibrosis
Hypercoagulable disorders
Hyperhomocysteinemia Factor V Leiden mutation Prothrombin gene mutation G20210A MTHFR C677T mutation Protein C deficiency Protein S deficiency Antithrombin deficiency Antiphospholipid syndrome Paroxysmal nocturnal hemoglobinuria Thalassemia
Malignancy
Cholangiocarcinoma Hepatocellular carcinoma
Benign hepatic lesions
Adenoma Cyst Cystadenoma Polycystic liver disease
Infection
Hepatic abscess Invasive aspergillosis Mucormycosis Mycotic aortic aneurysm
Syphilitic gumma Oral contraceptives Pregnancy Alpha-1 antitrypsin deficiency Behçet syndrome Systemic lupus erythematosus Hypereosinophilic syndrome Idiopathic granulomatous venulitis Inflammatory bowel disease Protein-losing enteropathy Minimal change nephrotic syndrome Mixed connective tissue disease Neurofibromatosis Sarcoidosis Sjögren’s syndrome Trauma Torsion of the liver Membranous web Venoocclusive disease Idiopathic
FIG. 1 CT scan of a patient with chronic Budd-Chiari syndrome shows
a heterogeneous appearance of the liver with regenerative nodules (arrowhead) and caudate lobe hypertrophy (white arrows). Black arrow points to an occluded transjugular intrahepatic portosystemic shunt (TIPS).
FIG. 2 Direct hepatic venography demonstrates the classic “spiderweb”
morphology of intrahepatic venous collaterals. Percutaneous access via the right internal jugular vein allowed the catheter to traverse the occluded hepatic veins (arrow).
DIAGNOSIS
The diagnosis of BCS should be considered in any patient with acute or chronic liver disease. Routine laboratory tests reflect hepatocyte injury and dysfunction. Elevated transaminases, alkaline phospha­tase, bilirubin, and prothrombin time are common, and the albumin level may be low depending on the degree of liver dysfunction and protein loss in ascites. When present, the ascites is characterized by a high serum–ascites albumin gradient (>1.1 g/dL).
The initial diagnostic imaging to assess the hepatic venous outflow is Doppler ultrasound. Secondary studies include con­trast-enhanced cross-sectional imaging, either CT or MRI, to image the inferior vena cava (IVC), hepatic veins, and consequent venous
collaterals from the obstruction. Historically, invasive hepatic venog­raphy played a major role in the diagnosis of BCS, but advances in noninvasive imaging have made it less important in the diagnosis. Now, direct hepatic venography is performed at the time of endo­vascular intervention. Classic imaging findings include an enlarged caudate lobe and “spiderweb” appearance of intrahepatic venous collaterals (Figs. 1 and 2). Additional diagnostic studies for patients with BCS include upper endoscopy to assess varices and workup for hypercoagulable disorders.
MEDICAL MANAGEMENT
The management of patients with BCS involves prevention of thrombus propagation, restoration of hepatic venous outflow to
PORTAL HYPERTENSION 453
https://t.me/medicina_free
decompress the liver, and prevention and treatment of complications of portal hypertension. Initial management involves prompt identi­fication and treatment of the underlying cause of the venous outflow obstruction. Early initiation of anticoagulation is essential to treat any hypercoagulable state and prevent propagation of thrombus. When patients have signs and symptoms of portal hypertension, prophylaxis against variceal bleeding with beta-blockade, endoscopy for surveillance and banding of varices, and control of ascites with sodium restriction, diuretics, or paracentesis become very important management tools.
Anticoagulation can mitigate the disease, but once the hepatic venous outflow is significantly compromised, interventions will be needed to try to restore venous drainage of the liver. Percutaneous transluminal angioplasty (PTA) with or without thrombolysis or stent can be effective, particularly in patients with short-length occlusion of the hepatic vein. The interventional radiologists can use transjugular, transfemoral, or, rarely, transhepatic routes for percuta­neous access to the hepatic venous system. They can use transsplenic, transparaumbilical vein, or transhepatic routes to access the portal venous system for direct portography.
A graded approach is used, beginning with direct hepatic venography and pressure measurements as a diagnostic step. Venography can help define the anatomy and degree of occlusion while pressure measurements can assess for portal hypertension, defined as an hepatic venous pressure gradient (HVPG) of >10 mm Hg. Thrombolysis may be needed initially to enable the traverse of the area of obstruction. Balloon venoplasty then can be used to open the outflow. Additional thrombolysis may be added to remove thrombus, using both tissue plasminogen activator (tPA) infusion and mechanical thrombectomy with suction. Finally, a stent may need to be placed to treat the area of obstruction if it is recalcitrant to thrombolysis and balloon venoplasty alone. Postintervention venography and HVPG measurements can assess the response to treatment.
If recanalization of the hepatic veins is not possible or if portal hypertension persists despite attempts at treatment, transjugular intrahepatic portosystemic shunt (TIPS) may be effective in reducing pressure in the portal venous system and decompressing the con­gested liver (Fig. 3). TIPS thus can treat the complications of portal hypertension, often relieving variceal hemorrhage and ascites. In
FIG. 3 A transjugular intrahepatic portosystemic shunt (TIPS) extends
from the right portal vein into the right atrium, traversing the diseased hepatic venous outflow tract of a patient with Budd-Chiari syndrome.
cases where the hepatic veins are completely obliterated, interven­tional radiologists can create a shunt directly between the IVC and the portal vein, a direct intrahepatic portosystemic shunt (DIPS) or direct extrahepatic portosystemic shunt (DEPS), depending on which portion of the portal vein is shunted. These technical modifi­cations of TIPS also have been effective in relieving portal hyperten­sion in patients with BCS.
SURGICAL MANAGEMENT
Surgery may be needed when minimally invasive, endovascular interventions fail to restore hepatic venous outflow. Options include surgical shunts and liver transplantation. With advances in interven­tional radiology techniques, surgical shunts are rarely performed, reserved for highly select patients with preserved hepatic function and favorable anatomy. Surgical shunts can have excellent long-term outcomes when performed early before the development of irrevers­ible liver damage. However, once the liver damage has progressed to fibrosis and cirrhosis, liver transplantation is the only option to treat BCS definitively. It is important to note that any intervention for BCS should be performed at an experienced center in collaboration with the liver transplantation team because of the real risks of hepatic decompensation and procedural complications.
Surgical Shunts
The goal of a surgical shunt is to drain the portomesenteric venous system into the systemic venous system. Portocaval, mesocaval, and splenorenal shunts can be considered if the IVC is patent and without a significant pressure gradient between the infrahepatic and supra­hepatic sections of the IVC. If the IVC is obstructed, mesoatrial or cavoatrial shunts are options to bypass the compromised portion of the IVC, the latter performed in conjunction with a porto- or meso­caval shunt to decompress the port-mesenteric system.
Careful study of cross-sectional imaging is essential for operative planning to decide which is the optimal shunt for the individual patient. The surgeon can evaluate the anatomy and patency of the portomesenteric veins and IVC as well as the extent of caudate lobe hypertrophy. Attention to the caudate lobe is important because its hypertrophy, particularly the paracaval portion, may render a por­tocaval shunt impossible. Doppler ultrasonography to demonstrate size and patency of saphenous or internal jugular veins is a useful preoperative adjunct when considering an autologous vein graft for creation of the shunt. It also is important for the surgeon to review the available biologic and synthetic graft lengths and diameters in case the autologous vein is insufficient in size or quality. Finally, the surgeon can make a biologic graft by paneling or tubularizing patches of decellularized bovine pericardium or acellular collagen scaffolding, when available.
First and foremost, the creation of any surgical shunt requires proximal and distal control of the involved vasculature. Dissection of the vasculature in the presence of portal hypertension can be challenging because of venous collaterals and requires planning, patience, and purposeful attention to tissue planes. The surgical shunts can be created directly between veins or via grafts in a side-to-side or end-to-side fashion depending on the anatomy and degree of shunting needed. Grafts that can be used include autolo­gous vein grafts (e.g., internal jugular vein or saphenous vein), bio­logic grafts (e.g., cryopreserved saphenous vein or various acellular matrices), or synthetic grafts (e.g., Gore-Tex or polytetrafluoroeth­ylene [PTFE]).
A portocaval shunt connects the portal vein and the IVC, meso- caval the superior mesenteric vein and the IVC, and splenorenal the splenic vein and the left renal vein. A mesoatrial shunt connects the superior mesenteric vein to the right atrium, and a cavoatrial shunt connects the IVC with the right atrium, both via a conduit. If no large portosystemic collateral veins have formed during the progression of BCS, a cavoatrial shunt to bypass the obstructed section of the IVC
454 MANAGEMENT OF BUDD-CHIARI SYNDROME
https://t.me/medicina_free
will be performed in conjunction with a portocaval or mesocaval shunt to ensure adequate drainage of the portomesenteric venous system. A meso-cavo-atrial shunt also is an option, where the supe­rior mesenteric vein is shunted directly into the cavoatrial graft. Sys­temic heparin administration (50 units per kg) should be discussed with anesthesiology before applying the vascular clamps to the target veins. The anastomoses are created using fine polypropylene sutures with appropriate venting maneuvers to de-air any grafts and to evac­uate any thrombus that may build up behind the clamps. Doppler ultrasound (US) can be used to document patency of the shunts postoperatively, and patients should be anticoagulated indefinitely.
Liver Transplantation
For the patients with BCS who fail anticoagulation, PTA, or endo­vascular or surgical shunt creation, liver transplantation is the only treatment with excellent patient survival in large series. Liver trans­plantation for BCS can be the most technically challenging of liver operations and should be approached with the utmost caution and care.
Liver transplantation for BCS involves multidisciplinary evalua­tion to assess the primary cause of the hepatic venous occlusion, the degree of liver dysfunction, and the medical, surgical, and psychoso­cial fitness of the patient to undergo liver transplantation. If deemed an appropriate candidate, the patient will be waitlisted and ranked by Model for End-Stage Liver Disease (MELD) score (ages ≥12) or Pediatric End-Stage Liver Disease (PELD) score (ages <12), which estimate the 3-month mortality risk without liver transplantation. Decompensated liver disease should be reflected in the score, but if the score does not adequately capture the severity of disease in a par­ticular patient, the transplant center can appeal to the National Liver Review Board for additional exception points for BCS. The appeal should document failure of standard medical management, etiology of hypercoagulable state (when present), specific contraindications to TIPS or reasons for TIPS failure, manifestations of decompensated portal hypertension (e.g., hepatic hydrothorax requiring thoracen­tesis for more than 1 L per week), and the absence of extrahepatic malignancy.
Preoperative planning is essential, particularly for patients with prior endovascular or surgical portosystemic shunts. For example, the proximal and distal extent of TIPS should be determined by cross-sectional imaging to plan the dissection needed for proximal (i.e., portal vein) and distal (i.e., suprahepatic IVC) clamping. Sim­ilarly, the trajectory of DIPS or DEPS should be studied to ensure complete removal of the portions of portal vein and IVC that the stent penetrates. Any portal vein thrombosis should be noted, and thromboendovenectomy or mesenteric venous conduit should be planned.
The hepatectomy in BCS can be very challenging. The congested liver and enlarged caudate lobe can make mobilization of the liver difficult. Large venous collaterals often develop in the perihepatic ligaments, which need to be ligated and divided securely. Thrombo­sis of the hepatic veins often leads to dense, inflammatory adhesions between the liver, diaphragm, and IVC, therefore extra care must be taken when dissecting and clamping the suprahepatic IVC. Depend­ing on the extent of thrombosis, the suprahepatic IVC may need to be dissected completely from the diaphragm up to the right atrium to ensure complete removal of the entire diseased hepatic venous outflow. Occasionally, dividing the diaphragm from the abdominal incision or median sternotomy may be needed for adequate control of the suprahepatic IVC within the pericardium. The cardiac surgery team should be notified and cardiopulmonary bypass should be available in cases where the most distal control of hepatic venous outflow will involve clamping of the right atrium, such as extensive thrombosis or prior atrial shunts. Equal attention also should be paid to the infrahepatic IVC, which also may have thrombus. Sim­ple thrombus can be thrombectomized, though chronic, extensive thrombosis that extends below the renal veins often can be left alone
as venous collaterals provide adequate drainage. In such rare cases, only a suprahepatic IVC anastomosis will be needed for reconstruc­tion of the hepatic venous outflow.
In cases of liver transplant for acute BCS, complete clamping of the IVC can cause hemodynamic instability, and portosystemic venovenous bypass may be needed to preserve venous return and provide drainage of the splanchnic vasculature (Fig. 4). In cases of chronic, advanced BCS, complete clamping of the IVC usually is well tolerated because portosystemic venous collaterals have formed and provide venous return to the heart. With the widespread use of TIPS, fewer patients with BCS have had a prior surgical portosystemic shunt, but when present, shunts must be dissected and ligated to ensure adequate portal inflow to the new liver. It is best to ligate these shunts after reperfusion of the new liver, if possible, to avoid acutely worsening portal hypertension during the hepatectomy (Fig. 5).
Because the obliterated hepatic veins and diseased IVC need to be removed completely with the explanted liver, the IVC will need to be replaced. A deceased donor liver, whether a whole or trisection split allograft, will include the donor IVC, and reconstruction of the venous outflow involves suprahepatic and infrahepatic IVC anas­tomoses with polypropylene sutures. A living donor liver allograft will not have the IVC but rather hepatic veins for outflow, the exact hepatic vein depending on the type of graft procured (e.g., right lobe with or without middle hepatic vein or left lobe with middle and left hepatic veins). The use of a living donor liver allograft in a patient with BCS will require reconstruction of the IVC with either a biologic or synthetic interposition graft. The hepatic vein or veins of the living donor allograft then can be sewn into the side of the interposition graft with polypropylene sutures, taking care to ensure an adequate orifice for excellent hepatic venous outflow.
Subclavian vein
Portal vein
Biopump
External iliac vein
Saphenous vein
FIG. 4 Venovenous bypass. Immediately before completion of the hepatec-
tomy, the axillary, saphenous, and portal veins are cannulated. A centrifugal pump returns systemic and portal venous blood to the heart via the axil­lary vein while the patient is anhepatic.
PORTAL HYPERTENSION 455
https://t.me/medicina_free
not bleeding. Anticoagulation will need to be continued indefinitely. Recurrent posttransplant BCS can be treated with interventional techniques as discussed earlier. Retransplantation is reserved for highly select patients with favorable anatomy who fail less invasive management.
CONCLUSION
BCS is a rare disease with varied clinical presentation depending on the acuity of onset and degree of liver dysfunction. Treatment
Caudate lobe hypertrophy
Porto-caval shunt
Portal vein
IVC
A
Caudate
lobe
requires multidisciplinary care; input from hematology, hepatology, interventional radiology, and transplant surgery are particularly important. Management first involves anticoagulation to treat the underlying prothrombotic disorder followed by the prevention and treatment of sequelae of portal hypertension. In patients with pre­served liver function, percutaneous endovascular interventions aim to restore hepatic venous outflow. Minimally invasive shunts have essentially replaced surgical portosystemic shunts. When these inter­ventions fail or in cases of irreversible liver damage, liver transplanta­tion becomes the only treatment. The operation is very challenging, and the surgeon should be prepared to control the intrapericardial IVC when needed to remove the entire diseased hepatic venous out­flow tract. Both whole and partial liver allografts can be used, though the latter will require reconstruction of the IVC with an interposition graft. Thoughtful preoperative planning and meticulous execution are essential to ensure excellent outcomes after liver transplantation for patients with BCS.
Side-to-side
portocaval
anastomosis
B
FIG. 5 (A) At the time of liver transplant for Budd-Chiari syndrome, a
prior surgical portocaval shunt. Note the caudate lobe hypertrophy. (B) A side-to-side portocaval shunt. IVC; Inferior vena cava. (Courtesy Corinne
Sandone, Johns Hopkins University.)
Recurrent hepatic venous outflow obstruction is a concern post­transplant for BCS. Anticoagulation needs to be initiated postoper­atively as soon as the liver function has recovered and the patient is
S U G G E S T E D R E A D I N G S
Mentha G, Giostra E, Majno PE, Bechstein WO, Neuhaus P, O’Grady J,
Praseedom RK, Burroughs AK, Le Treut YP, Kirkegaard P, Rogiers X, Ericzon BG, Hockerstedt K, Adam R, Klempnauer J. Liver transplantation for Budd-Chiari syndrome: a European study on 248 patients from 51 centres. J Hepatol. 2006;44(3):520–528.
Narayanan Menon KV, Shah V, Kamath PS. The Budd-Chiari Syndrome. N
Engl J Med. 2004;350:578–585.
Segev DL, Nguyen GC, Locke JE, Simpkins CE, Montgomery RA, Maley
WR, Thuluvath PJ. Twenty years of liver transplantation for Budd-Chiari syndrome: a national registry analysis. Liver Transpl. 2007;13:1285–1294.
Shin N, Kim YH, Xu H, etal. Redefining Budd-Chiari syndrome: a systematic
review. World J Hepatol. 2016;8(16):691–702.
Yoon YI, Lee SG, Moon DB, etal. Surgical techniques and long-term out-
comes of living-donor liver transplantation with inferior vena cava replacement using atriocaval synthetic interposition graft for Budd­Chiari syndrome. Ann Surg. 2019;269(4):e43–e46.
https://t.me/medicina_free
G  B T
https://t.me/medicina_free
Management of Asymptomatic (Silent) Gallstones
Theodore N. Pappas, MD, and Christopher R. Reed, MD
NATURAL HISTORY OF CHOLELITHIASIS
The first description of incidental gallstones probably dates back to the 14th century, a relatively recent observation in the grand scheme of pathologic observations. This has been attributed to the relative rarity of gallstone formation before modern diets. These postmortem findings preceded the first descriptions of symptomatic gallstones by about 200 years, perhaps a testament to their frequently asymptom­atic nature. Without the benefits of modern ultrasonography, open cholecystectomy became the preferred treatment modality for symp­tomatic gallstone disease throughout the early 1900s, and it was not until the 1980s that incidental, asymptomatic cholelithiasis became a very common clinical problem.
The decreased morbidity of laparoscopic cholecystectomy intro­duced considerable interest in surgery for the treatment of asymp­tomatic gallstones. With increasing availability of and expertise with laparoscopic cholecystectomy throughout the 1990s, the sur­gical approach to asymptomatic gallstones became increasingly heterogeneous. This ultimately resulted in the National Institutes of Health convening of a Consensus Development group that set forth now-familiar guidelines recommending cholecystectomy only for symptomatic or otherwise complicated cholelithiasis in 1992. This guidance is the basis of the prevailing expectant approach to patients with silent gallstones for the past 30 years.
Since that time, both the natural history of gallstones and the outcomes associated with laparoscopic cholecystectomy have been better described (Fig. 1). Asymptomatic cholelithiasis is quite com­mon. In a large, prospective, cross-sectional study of 11,229 asymp­tomatic gallbladders with ultrasonography, Festi and colleagues demonstrated an incidental cholelithiasis rate of 7.1% among Italian adults. This probably underestimates the incidence in the United States, where smaller cross-sectional studies show an incidence closer to 15%. In certain ethnic groups and geographic locations in the United States, the rate exceeds 20%, implicating a familiar myriad of demographic and environmental factors in formation of gallstones (estrogen, age, obesity, Hispanic, and Native American). Regardless of their exact incidence, asymptomatic gallstones remain a common dilemma for referring physicians and surgeons alike, and the sur­gical management of asymptomatic cholelithiasis should ultimately be individualized based on the risk of progression to symptomatic disease and the estimated morbidity associated with expectant
management. To thoughtfully approach this predicament, a general understanding of the relative risks of expectant management versus cholecystectomy is crucial.
RISK OF PROGRESSION TO SYMPTOMATIC CHOLELITHIASIS
Gallstone disease is generally thought of as a sequence from asymp­tomatic to symptomatic cholelithiasis (i.e., stone formation initially with subsequent development of pain, infection, pancreatitis, or cancer), although the time between development of stones and symptoms is not currently estimable. Through a combination of cross-sectional and longitudinal studies, it has been demonstrated that only a minority of patients with asymptomatic gallstones will ultimately develop symptoms. In their large, longitudinal investiga­tion of 673 European subjects with asymptomatic cholelithiasis and a median follow-up of nearly 20 years, Shabanzadeh and colleagues found that only 20% of gallstones were ultimately found to cause any disease, which has been reiterated by smaller studies. The majority of disease was uncomplicated (i.e., biliary pain without acute cholecys­titis, choledocholithiasis, or pancreatitis).
There are some demographic and ultrasonographic characteris­tics that are associated with increased risk of symptoms, especially with complicated presentation. Female sex, immobility of stones, numerous stones, and large (>10 mm) or small (<5 mm) stones all are independently associated with increased incidence of symptoms and complicated presentation (Fig. 2).
Over about 20 years’ follow-up, Shabanzadeh and colleagues found that about 8% of their subjects with asymptomatic gallstones ultimately presented with acute cholecystitis, choledocholithiasis, or gallstone pancreatitis. None of the patients developed carcinoma of the gallbladder or cholangiocarcinoma during the study period. Festi et al. found a single case of gallbladder carcinoma in follow-up of their 856 patients with asymptomatic gallstones (0.12%).
These longitudinal studies may reflect some inherent bias toward identification of patients who will not develop symptoms, as only patients who were asymptomatic at the time of ultrasound were included, and the duration of cholelithiasis at the time of diagnosis was not known. Regardless, both studies clearly demonstrate that only a minority of patients with asymptomatic gallstones will have complicated gallbladder disease during their lifetime and therefore would have benefited from cholecystectomy at the time of asymp­tomatic gallstone identification.
MORBIDITY ASSOCIATED WITH
LAPAROSCOPIC CHOLECYSTECTOMY
VERSUS EXPECTANT MANAGEMENT
A modern discussion of the management of asymptomatic gallstones should include a modern appraisal of the risks associated with lap­aroscopic cholecystectomy in comparison to potential benefits. It
457
458 MANAGEMENT OF ASYMPTOMATIC (SILENT) GALLSTONES
80% asymptomatic
https://t.me/medicina_free
General
Population
n = 1,000
85% no gallstones
15% Incidental “Silent”
Gallstones
n = 150
20% Symptomatic
Cholelithiasis
n = 30
FIG. 1 Flowchart demonstrating the incidence of silent
gallstones, symptomatic cholelithiasis, and complicated gallstone disease in an illustrative group of 1000 adults representative of the general population. (Based on data from Festi D, Reggiani
ML, Attili AF, etal. J Gastro Hep. 2010; 25:719–724; Shabanzadeh DM, Sørensen LT, Jørgensen T, etal. Gastroenterology. 2016;150: 156-167.e1.)
60% Uncomplicated
Symptomatic
n = 18
60% Choledocholithiasis
and/or Pancreatitis
n = 7
40% Complicated
Symptomatic
n = 12
40% Acute
Cholecystitis
n = 5
is worthwhile to note that consensus guidelines that recommend reserving cholecystectomy only for symptomatic or complicated gallstone disease originate from an early era of laparoscopy, which may consider additional morbidity due to the early learning curve in adopting the procedure. The overall mortality and bile duct injury rates for modern laparoscopic cholecystectomy are less than 0.1% and 0.3%, respectively. Overall significant morbidity of laparoscopic cholecystectomy is about 5%, including hernia formation, bowel obstruction, and both deep and superficial surgical site infections. In the absence of acute inflammation, the morbidity associated with elective laparoscopic cholecystectomy performed for asymptomatic gallstones may be even lower, although there are no large, controlled studies addressing the question since cholecystectomy is so rarely performed prophylactically. Conversely, the ready availability of and low morbidity associated with procedures to treat the potential com­plications of cholelithiasis (endoscopic retrograde cholangiopancrea­tography [ERCP] for choledocholithiasis, for example) mean that complications of contemporary expectant management may also be less morbid.
FIG. 2 Large gallstones are associated with increased risk of symptom development.
Given that the rate of any symptom development after identi­fication of incidental gallstones is about 20%, complicated disease development is about 8%, and major morbidity of laparoscopic cholecystectomy is roughly 5%; decisions regarding the approach to asymptomatic gallstones should be individualized to the patient, with careful consideration of the potential consequences of complicated gallbladder disease versus operative morbidity and fitness at the time of diagnosis.
SPECIFIC PATIENT POPULATIONS
Cancer Risk Reduction
Although gallbladder cancer is very uncommon in the United States (about 1 in 100,000 US adults) and only one patient in the two largest longitudinal studies of asymptomatic cholelithiasis developed this malignancy, there is undeniably a connection between gallstones and cancer. Between 75% and 90% of patients with gallbladder can­cer have cholelithiasis, and many of the risk factors for gallbladder