Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Cystic disease of the liver
Introduction
Most hepatic cysts, regardless of type, remain asymptomatic, and hepatic function is not affected. Occasionally cysts are the focus of hemorrhage or infection, or produce hepatic dysfunction by bile duct compression or portal hypertension.
This chapter emphasizes open surgical approaches to cystic disease of the liver.
Diagnosis
Ultrasound
Simple cysts are characterized by acoustic enhancement posterior to the mass. They are solitary, thin-walled without focal thickening or nodularity, and anechoic without debris, and they lack septa. Septa typically are found in cystadenomas ( Fig. 8.1 ); mural or septal nodularity most typically is seen in cystadenocarcinoma ( Fig. 8.2 ). Hydatid cysts are typically hypoechoic and contain concentric peripheral daughter cysts within the larger cyst and may have partial or complete calcification of the cyst wall ( Fig. 8.3 ). Additionally, biliary ductal dilation or intraductal debris may be found within the biliary tree. Layering of blood within cysts may be seen after hemorrhage.
Computed tomography
Computed tomographic features of hepatic cysts are similar to features seen on ultrasound (see Fig. 8.3 ). Cyst hemorrhage and infection are confirmed by intracystic fluid layering or increased density. Vascular enhancement within the cyst wall or mural nodules suggest a cyst-associated malignancy or a cystadenocarcinoma ( Fig. 8.4 ), whereas only septations occur with cystadenoma ( Fig. 8.5 ). Polycystic liver disease (PLD) usually has some component of hepatic venous compression, but ascites usually indicates marked compression of all the major hepatic veins and the retrohepatic inferior vena cava. Computed tomography (CT) can define the extent of the compression of the major hepatic veins and inferior vena cava and help determine the extent of cyst resection or fenestration required to resolve hepatic venous outflow obstruction.
Magnetic resonance imaging (MRI) should be reserved to address specific issues. If CT fails to define hepatic vasculature accurately, MRI can define the vascular anatomy without contrast media, which may be important in patients with PLD and renal failure.
Endoscopic retrograde cholangiopancreatography (ERCP) documents the site and degree of biliary obstruction or often the site of biliary communication in jaundiced patients. Finally, cholangiography is essential to differentiate bile duct cysts from hepatic cysts with biliary communication. Magnetic resonance cholangiopancreatography (MRCP) also can be used for definition of the biliary system.
Simple cysts
Simple cysts may be solitary or multiple, but they are usually unilocular. Simple cysts rarely have true septations but frequently have intrahepatic portal pedicles, which traverse a portion of the cyst periphery, and may mimic septa. Simple cysts do not communicate with the biliary tree. The content of simple cysts is usually serous but can be bile stained, mucoid, bloody, or turbid and thick. The adjacent liver may become compressed and atrophic, and there may be compression of the adjacent portal pedicles.
Symptoms develop insidiously and include abdominal fullness or pressure, satiety, and mild dyspnea from cyst expansion and compression of adjacent organs. Sharp pain may follow intracystic hemorrhage. Cyst infection is associated with fever and rigors. Jaundice may accompany extensive compression of the bile duct confluence or common hepatic duct but is very rare. Liver function is almost always normal.
The indications for treatment of simple cysts are symptoms or associated complications. Simple cysts may be complicated by hemorrhage, infection, rupture into the peritoneal cavity or into the biliary tree or adjacent bowel, jaundice, and, very rarely, portal hypertension. Aspiration should never be used as a sole definitive treatment because cyst recurrence is certain.
Treatment
Currently the choice of treatment for simple cysts includes aspiration and sclerosis, laparoscopic excision or fenestration, and excision or fenestration at laparotomy.
Laparoscopic cyst excision
Generally, laparoscopic management should be considered before open laparotomy. Laparoscopic management is indicated in patients with symptomatic superficial cysts located within the anterior liver segments (III, IV, V, and VI) and in patients who have not had extensive upper abdominal surgery. Cysts in segments VII and VIII of the liver can pose technical problems if approached laparoscopically. The major problem is the abutment of the rim of the cysts to the diaphragm; when the liver returns to its normal position, the apposition of cyst rim to diaphragm prevents intraperitoneal drainage of cyst fluid with subsequent cyst recurrence.
The basic laparoscopic approach has been standardized. The cyst is punctured and the cyst contents aspirated. The cyst wall is grasped and excised widely to its interface with the hepatic parenchyma.
Endovascular staplers can be used for secure closure of larger vasculobiliary structures recognized intraoperatively at the cyst-parenchyma interface. Any thickened bands along the cyst periphery are controlled. After excision of the superficial cyst wall, the concavity of the residual cyst should be inspected. If irregularities are seen, biopsy is indicated. Ablation of the cyst lining by argon beam coagulation or topical sclerosant or omentoplasty may reduce the risk of recurrence.
Management by laparotomy
I do not advocate laparoscopy for very large cysts in segments VII and VIII. Cysts complicated by active hemorrhage or enteric communication are probably also best treated by open laparotomy.
Wide excision is essential, preferably excising more than half the cyst to prevent sealing of the cyst remnant by adjacent viscera or diaphragm or residual cyst wall contraction with cyst recurrence. If less than half of the cyst is excisable, omentoplasty and ablation of the residual cyst epithelium by coagulation or sclerosant should be performed. Alternatively, hepatic resection prevents recurrence totally.
I recommend ablation of the residual cyst wall with the argon beam coagulator followed by omentoplasty.
Cystadenoma and cystadenocarcinoma
Cystadenomas or cystadenocarcinomas are true neoplastic hepatic cysts. They may be serous or mucinous, although the latter are more common.
Cystadenomas are more common in women, and clinical presentation is similar to that of large simple cysts. Prominent intraductal septa and focal wall thickening with or without mural nodularity are the hallmarks of cystadenomas on imaging studies (see Figs. 8.1 and 8.5 ). Although the presence of septations or nodular projections within the cyst on imaging classically differentiates cystadenomas from simple cysts, cystadenomas frequently are unilocular. If cystadenoma is suspected, complete excision is indicated. Mucinous cystadenomas have a malignant potential and require complete excision. Partial hepatectomy ( Chapters 2 to 6 ) is the preferred approach.
Cystadenocarcinomas are exceedingly rare, and few have been reported (see Figs. 8.2 and 8.4 ). If cyst excision is undertaken, any irregularity of the cyst wall requires biopsy to exclude cystadenocarcinoma. If carcinoma is diagnosed, formal hepatic resection is recommended. Hepatic resection may be complicated because of the gross distortion of the intrahepatic ductal anatomy. Despite this intrahepatic ductal distortion, wide excision with adequate tumor-free margins is required. Long-term survival has been obtained only after complete excision.
Polycystic liver disease
In contrast to simple cysts, PLD is inherited as an autosomal dominant trait presenting in adulthood ( ). Most autosomal dominant PLD is associated with renal cysts.
The number and size of cysts increase with age, female sex, and severity of renal cystic disease. Presentation almost always occurs after puberty. Hepatic failure is rare. Even with marked hepatosplenomegaly and portal hypertension, liver function is well preserved. Ascites usually results from hepatic venous outflow obstruction. PLD in adults may also be associated with multiple cysts of the pancreas, spleen, ovaries, and lungs.
Symptoms develop insidiously and late in the natural history of PLD. They are caused by increased liver volume and adjacent visceral compression. The most common complaints are increased abdominal girth, chronic dull abdominal pain, satiety, weight loss, dyspnea, and physical disability. Physical examination reveals a large nodular liver. Liver function tests are usually normal. CT best defines the extent of liver and adjacent organ involvement.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here