INTRODUCTION
Approximately 70% of liver tumours in childhood are malignant. In Europe and North America, pri- mary malignant liver tumours constitute about 1.1%
of childhood malignancies and are the tenth most common pediatric cancer. Hepatoblastomas are the most common childhood hepatic malignancy com- prising nearly 80% of all primary hepatic cancers and 43–64% of all hepatic neoplasm. Most patients present at younger than 3 years of age. Hepatocellular carcinoma comprises 23% of pediatric liver tumours but is rare in infancy with a bimodal distribution.
The early cases occur before 5 years of age and the second peak occurs between 13 and 15 years of age.
Complete surgical resection is the prerequisite for cure in both tumours. Other primary hepatic malig- nancies for which liver resections may be indicated include rhabdomyosarcoma, embryonal sarcoma, leiomyosarcoma, and angiosarcoma. Benign hepatic tumours account for about one-third of all liver tu- mours in children and occasionally will require liver resection. Theses lesions include vascular malforma- tions or hemangiomas, mesenchymal hamartoma, hepatic adenoma and focal nodular hyperplasia. The liver is a relatively frequent site of metastatic disease in childhood. Non-Hodgkin’s lymphoma, neuroblas- toma, rhabdomyosarcoma, rhabdoid tumours,Wilms tumour, desmoplastic small round cell tumour, ad- renal cortical carcinoma, osteogenic sarcomas and a host of other malignancies may metastasize to the liver. Criteria for surgical removal of hepatic metas- tases include control of the primary site, a solitary or limited number of metastases, good performance status, and a reasonable expectation of prolonged survival or cure.
Children with hepatoblastoma most commonly present with an asymptomatic abdominal mass and the child is usually in good health. Thrombocytosis is common and serum α-fetoprotein is well established as an initial tumour marker in the diagnosis of he- patoblastoma and a means of monitoring the thera- peutic response. The normal level is under 20 ng/ml, but can be elevated more than 20,000 times normal.
Imaging studies often show a large tumour with evi- dence of central necrosis.
In contrast, children and adolescents with hepato- cellular carcinoma frequently present with palpable abdominal masses but many are symptomatic at di- agnosis. Pain, anorexia, malaise, nausea and vomiting and significant weight loss occur with greater fre- quency. Hepatitis B and C infections are correlated with the incidence of hepatocellular carcinoma. The α-fetoprotein is elevated in approximately 85% of pa- tients with most levels more than 1,000 ng/ml, but usually lower than those measured in hepatoblasto- ma patients. Jaundice is rare in either disease. Multi- focality is more common in hepatocellular carcino- ma, and up to 10% may present with tumour rupture and a haemoperitoneum.
Survival in hepatoblastoma is dependent on the complete removal of the primary liver tumour. Multi- ple studies support the effectiveness of systemic chemotherapy combined with complete surgical re- section. Historically, the combination of doxorubicin and cisplatin has been used with great success, but the present day protocol of cisplatin, 5-fluorouracil, and vincristine is equally effective and less toxic.
Very young infants who undergo complete resection may receive a shortened course (three doses) of ad- juvant single agent doxorubicin, which is well toler- ated.
The primary treatment of hepatocellular carcino- ma is also complete surgical resection and long-term survival is unlikely without it. Unfortunately, this is often impossible because of a high incidence of mul- tifocality within the liver, extrahepatic extension to regional lymph nodes, vascular invasion, and distant metastases. Infiltration with thrombosis of portal and hepatic venous branches is common and even the vena cava may be involved. Historically, the same chemotherapy protocols used for hepatoblastoma were also applied to hepatocellular carcinomas in childhood. Cisplatin, in particular, has had activity against hepatocellular carcinoma, but long term sur- vival still approaches zero, and new therapies are the subject of current research.
Imaging studies are crucial in the preoperative
evaluation of liver tumours and in planning major
hepatic resections. Doppler ultrasonography can de-
Wendy T. Su, Michael P. La Quaglia
Figure 44.1
A thorough understanding of the functional surgical anatomy of the liver is essential. The schema of he- patic anatomy most useful for the surgeon is based on the anatomic classification of Couinaud. The liver is divided into the right and left lobe by the main portal fissure containing the middle hepatic vein, marked by the line drawn from the vena cava poste- riorly to the porta hepatis anteriorly. Each lobe is again divided into a paramedian and a lateral sector by the right and left hepatic veins. The left portal fis- sure is identified by the falciform ligament externally but there is no external feature identifying the right
portal fissure dividing the right lobe into anterome- dial and posterolateral sectors. The four sectors are subdivided into anterior and posterior segments.
Each of the eight segments is supplied by a portal triad composed of a branch of the portal vein and he- patic artery and drained by a tributary of the right or left main hepatic ducts. Segment one, the caudate lobe, situated posteriorly between the vena cava and the ligamentum venosus, receives inflow from both the right and left branches of the hepatic artery and portal vein, and drains directly into the inferior vena cava (IVC) via numerous small veins.
Figure 44.2
Nonanatomic wedge resections with a satisfactory margin may be feasible in the uncommon instance of a small peripheral or pedunculated lesion. More fre- quently, a major anatomic resection is required. Ana- tomic resections are associated with less blood loss
segments to be resected has been utilized in adult pa- tients to increase residual hepatic volume with some success.
The major hepatic resections include left lateral lobectomy with removal of segments II and III, left cava, and identify satellite lesions. At present, mag-
netic resonance imaging (MRI) provides the greatest amount of information concerning both the lesion and surrounding veins and bile ducts. Computerized tomography with three-dimensional reconstructed angiogram and cholangiogram has evolved recently to provide an alternative imaging modality. Doppler sonography combined with MRI of the liver gives sufficient information concerning the vascular and biliary anatomy to assess resectability and arterio-
chest and a bone scan are needed to rule out pulmo-
nary and osseous metastases respectively. Cerebral
metastases are rare but have been reported and pa-
tients with neurological symptoms should undergo
cranial MRI. A tissue diagnosis is mandatory. Percut-
aneous needle core or aspiration biopsy is useful for
hepatoblastomas but may not be definitive in the
case of hepatocellular carcinoma. Open or laparos-
copic biopsy is also acceptable.
VIII
V
VI
IV
I
II
III VII
Figure 44.1
V VIII VII
VI
I
IV
III II
Figure 44.2
Pre-operative preparations include a comprehensive laboratory evaluation including a complete blood count, coagulation profile and liver function tests.
Adequate cross-matched blood should be available. If the patient had received doxorubicin as part of the chemotherapy regimen, an echocardiogram evaluat- ing cardiac function should be obtained. Bowel prep is carried out on the day prior to liver resection. A prophylactic antibiotic, usually a first generation cephalosporin is administered pre-operatively.
Gram-negative coverage should also be instituted if the biliary tree has been previously instrumented. An epidural catheter is useful for post-operative pain control unless otherwise contraindicated. A Central venous catheter and arterial line are placed to facili- tate haemodynamic management.
Pre-operative and intra-operative communication with the anaesthesiology team is extremely crucial for any major hepatic resections. The key to success- ful intra-operative patient care is low central venous pressure anaesthesia (LCVP) in conjunction with he- patic inflow and outflow control. LCVP is designed to preclude vena caval distension and facilitate mobil-
ization of the liver, and dissection of retrohepatic ve- na cava and major hepatic veins. LCVP minimizes hepatic venous bleeding during parenchymal tran- section and facilitates control of inadvertent venous injury. The blood loss resulting from a vascular inju- ry is directly proportional to both the pressure gradi- ent across the vessel wall and the fourth power of the radius of the injury as illustrated by Poiseuille’s Law.
In addition to decreasing the pressure component of the equation, LCVP also minimizes the radial com- ponent of flow by reducing vessel distension.
Fluid restriction is an important component of this technique and is continued until the resection is complete. Intravascular hypovolemia is counteracted with the patient in Trendelenburg position to im- prove venous return and preserve haemodynamic stability. The central venous pressure is kept at or be- low 3 mmHg and small fluid boluses maybe given to maintain haemodynamic stability. With this cooper- ative surgical-anaesthetic technique, major hepatic resections can be carried out with minimal blood loss and morbidity.
Figure 44.4a–c
The patient is positioned supine with a roll under the upper abdomen to facilitate exposure. Slight right lateral decubitus position with the right side elevated at a 30º angle may be helpful in right hepatectomies.
Hepatic resection is usually performed through a bi- lateral subcostal incision (chevron). Frequently, this must be extended vertically in the midline to allow visualization of the IVC at the confluence of the he- patic veins. Raising a small skin flap in the midline and incising just the midline fascia can sometimes be done. This avoids the upper skin extension and al- lows a more cosmetic closure. A right subcostal inci- sion with vertical midline extension up to the base of xiphoid cartilage (hockey stick) can also be used for
patients with narrow costal margins. This approach
provides similar exposure to a bilateral subcostal in-
cision with vertical midline extension, and results in
better healing. A right thoracoabdominal incision
may be required in patients with large lesions that
arise high in the right lobe with or without diaphrag-
matic invasion. This is a good approach as well if ca-
val resection is planned because it facilitates control
of the supradiaphragmatic vena cava and access to
the right atrium. A left thoracoabdominal incision is
rarely required. The exposure is maintained with a
self-retaining retractor attached to the operating ta-
ble.
CVP
CVP
Figure 44.4a–c
a b c
The falciform ligament is identified and the ligamen- tum teres (round ligament) is ligated and divided as the abdomen is entered. The falciform ligament should be divided close to the anterior abdominal wall in order to preserve for possible future use. The ligamentum teres is used later as a landmark for the umbilical fissure.
The liver is widely mobilized by sharply dividing the right triangular and coronary ligaments to the falciform ligament anteriorly and the IVC posterior- ly. The left triangular ligament is also separated from
the diaphragm with care not to injure the left phren- ic vein. The suprahepatic vena cava and the hepatic veins are visualized. Thorough palpation of the en- tire liver should be carried out to identify multifocal disease and congenital anomalies. Intra-operative ultrasound, if available, maybe performed at this stage to look for satellite lesions, and to further delin- eate vascular and ductal anatomy. Tumour proximity or invasion into vascular or ductal structure can be identified to better plan resection and reconstruc- tion.
Figure 44.6
Once resectability is confirmed, the hepatoduodenal ligament is identified and surrounded with a looped vascular tape to expedite a subsequent Pringle ma- noeuvre. A Rumel tourniquet may also be used.
The key principle in all major hepatic resection is
the control of vascular structures prior to parenchy-
mal division. This can be achieved with extrahepatic
vascular control or hepatic pedicle ligation.
Figure 44.5
Figure 44.6
쐽 Extended Right (1) – Right Lobe Inflow Control.
Right hepatic resections are the most frequently per- formed major liver resections (60%). Segments V, VI, VII, and VIII are removed in right hepatic lobectomy.
An extended right hepatectomy or right trisegmen- tectomy additionally removes segment IV, and seg- ment I may be included as well.
After mobilizing the liver and obtaining control of the hepatoduodenal ligament, the cystic duct and ar- tery should be ligated and divided. The gallbladder infundibulum can be dissected free from the liver and retracted superiorly to expose the hilar plate.
The first step in vascular control of segments V–- VIII is the exposure of the right hepatic artery and the right branch of the portal vein by lowering the hi- lar plate. The hilar plate is divided and lowered using sharp dissection to expose the bifurcation of the he- patic artery and portal vein, as well as the confluence of the hepatic ducts.
The right hepatic artery arises from the main he- patic trunk and usually passes posterior to the com- mon bile duct. With the common bile duct gently re- tracted to the left, the right hepatic artery is isolated and divided. The right branch of the portal vein is then dissected free and then divided between vascu- lar clamps or ligated in continuity. The proximal stump is oversewn with fine Prolene sutures.Alterna- tively, a vascular stapler can be used.
To minimize injury to the biliary tree, the extrahe- patic biliary dissection can be withheld and the right hepatic duct controlled and divided intrahepatically later during parenchymal transection. If the right he- patic duct is divided at the hilum, it must be made certain that the confluence of the common bile duct and the left hepatic duct is well preserved.
Figure 44.8
Alternatively, a right pedicle ligation technique can be employed. Hepatotomies are made at the base of the gallbladder fossa and the caudate lobe. The right pedicle is isolated intraparenchymally through the hepatotomies and divided with a vascular stapler.
The advantage of this manoeuvre is that the left ped-
icle is well protected. However, if the tumour is close
to the hilum, extrahepatic inflow control will be nec-
essary to achieve tumour clearance.
Right hepatic artery Right hepatic duct
Cystic duct Common bile duct
Right portal vein
Right pedicle
Figure 44.8
쐽 Extended Right (2) – Inflow Control of Segment I.
Following inflow control to the right lobe, the next important step is to define the umbilical fissure. The left portal triad enters the liver at the base of the um- bilical fissure. The umbilical fissure is exposed and opened by retracting the ligamentum teres superior- ly and the left portal vein, left hepatic artery and left hepatic duct are visualized. The segmental portal
triads to segment IV can be controlled during paren- chymal transection to avoid injury to the vascular supply or biliary drainage of the left lateral segment and the caudate lobe if it is to be preserved. Howev- er, if the tumour encroaches upon the umbilical fis- sure, these segmental IV branches can be isolated and divided within the umbilical fissure.
Figure 44.10
쐽 Extended Right (3) – Outflow Control. Control of the hepatic vein is the most delicate manoeuvre of any hepatic resection. Attempts at early control of the hepatic vein before hilar vascular control can result in hepatic vein injury and haemorrhage. Placing the patient in Trendelenburg position with 15º head down reduces pressure in the IVC and hepatic veins and minimizes the risk of air embolus.
The division of the right hilar structures will re- duce blood flow through the right hepatic vein and facilitate its dissection. The right lobe is rolled to- ward the patient’s left and the retrohepatic vena cava is exposed. The IVC ligament is a fibrous band of tis-
the caudate lobe are ligated or clipped and divided individually in an inferior to superior fashion. For large right-sided tumours, a large unnamed hepatic vein is usually found before the main right hepatic vein. After this is divided, the junction of the right hepatic vein and the retrohepatic vena cava is care- fully exposed and right hepatic vein is encircled with a vessel loop. The right hepatic vein is then suture li- gated or oversewn or divided with vascular stapler.
The middle hepatic vein is taken in extended right
hepatectomy. The middle hepatic vein usually joins
the left hepatic vein but may enter the vena cava sep-
arately on occasion. Extrahepatic isolation of the
Figure 44.9
Figure 44.10
쐽 Extended Right (4) – Parenchymal Transection.
After a vascular isolation of segments IV–VIII is complete, the line of ischaemic demarcation be- comes apparent. The liver capsule (Glisson capsule) is scored with electrocautery along the line of devas- cularization. The hilar vessels are occluded with the Pringle manoeuvre intermittently for intervals not exceeding 15 minutes at a time. This manoeuvre en- sures minimal blood loss during parenchymal tran- section. The hepatic substance is divided slowly and carefully after fracture with a Kelly clamp. Vascular and biliary radicals are meticulously secured with haemoclips or suture ligatures. Cavitron ultrasonic aspirator, water jet dissector, laser, or harmonic scal- pel may also be used for parenchymal division in dif- ficult cases or based on personal preference.
If the recurrent branches to segment IV are still intact, parenchymal dissection is carried out anteri-
orly down to the base of the umbilical fissure and the arterial and portal vessels to segment IV are identi- fied and divided. This is continued posteriorly to- ward the vena cava and along the plane just to the right of the falciform ligament. The middle hepatic vein is encountered and controlled by suture ligation or division with the vascular stapler. The left hepatic vein is carefully preserved.
After the specimen is removed and the Pringle manoeuvre is released, the raw cut surface is ob- served for haemostasis. The argon beam coagulator is useful in controlling the oozing from the cut sur- face. Major sources of haemorrhage should be suture ligated. A Valsalva manoeuvre will increase the he- patic venous pressure and is helpful in identifying additional bleeding. Topical agents such as thrombin, fibrin glue, or Gelfoam may also be applied.
Figure 44.12
쐽 Extended Right (5) – Biliary Reconstruction. Oc- casionally a large tumour in the base of segment IV may encroach upon the left hepatic duct as it enters the umbilical fissure. If this is the case, mobilizing the left hepatic duct at the hilar area can be difficult and a portion of the left hepatic duct may be resect- ed. The biliary drainage can be re-established by a Roux-en-Y hepaticojejunostomy.
At the conclusion of an extended right hepatecto- my, segments I, II and III are left intact. The remain- ing liver parenchyma is then inspected to ensure vi- ability. The operative field is copiously irrigated.
Elective and uncomplicated hepatic resections do not usually need drainage
The midline portion of the incision is closed with
interrupted absorbable monofilament sutures. The
subcostal incision is then closed by re-approximating
the peritoneum and transversus abdominus. The
internal oblique and the posterior sheath are closed
next followed by the external oblique and anterior
rectus sheath. The subcutaneous space is irrigated
again and the Scarpa’s fascia is closed to eliminate
dead space. Finally, the skin is closed in a subcuticu-
lar fashion.
Figure 44.11
Figure 44.12
쐽 Extended Left Hepatectomy. Extended left hepa- tectomy is necessary when a large tumour arising from the left lobe of the liver crosses the portal fis- sure into segments V and VIII. It may also be carried out to clear multifocal disease. The left lobe and the right anterior sector, which consist of segments II, III, IV, V and VIII, are removed en mass and segment I (caudate lobe) may also be included in the resec- tion.
The liver is completely mobilized by dividing both the right and left ligamentous attachments. Inflow control is obtained by the ligation and division of the left hepatic artery at the base of the umbilical fissure.
The left portal vein is exposed along the umbilical fissure and the branches to the caudate lobe are iden- tified. The portal vein is divided distal to the take-off of the caudate branches. If the caudate lobe is to be removed, the left hepatic artery and portal vein can be controlled at the hilus. The left hepatic duct is then identified and ligated and divided.
The suprahepatic vena cava is fully exposed in the bare area of the liver. The middle and left hepatic veins are controlled next. The middle hepatic vein usually joins the left hepatic vein but may enter the vena cava separately on occasion. The liver is rotated
toward the right and the ligamentum venosum is ex- posed and divided. This opens up a space allowing the middle and left hepatic veins to be encircled and divided. The can be accomplished by oversewing the stump or using the vascular stapler. If the caudate lobe is also to be removed, it is carefully mobilized from the vena cava by serially ligating the short ret- rohepatic veins with sutures or clips.
Inflow control to segments V and VIII is accom- plished via the right anterior sectoral pedicle. Hilar dissection is carried out along the right portal vein and right hepatic artery until they branch into ante- rior and posterior pedicles. Partial parenchymal di- vision may be required for the dissection. The fissure of Gans is a reliable indicator of the course of the posterior pedicle and is used for orientation. Once the anterior pedicle is identified and encircled, it can be suture ligated or divided with vascular stapler.
This will result in a clear ischaemic demarcation
on the surface of the liver indicating the plane of pa-
renchymal transection. This plane lies horizontally,
lateral to the gallbladder fossa, parallel and just ante-
rior to the right hepatic vein. The parenchymal tran-
section is then carried out as described previously.
Figure 44.13
Ligamentum venosum
Figure 44.14
Central hepatic resection removes segments IV, V and VIII. This procedure is indicated for centrally lo- cated hepatic lesions. It avoids the use of extended hepatectomy. The major advantage is the preserva- tion of normal hepatic parenchyma and may lower the risk of late complications such as biliary tract stricture.
The liver is mobilized and the porta hepatis is iso- lated and surrounded with a vascular tape. The hilar plate is lowered and the confluence of the right and left hepatic arteries and portal veins are exposed as described earlier. The recurrent branches of the left portal vein to segment IV are divided in the umbili- cal fissure, taking care to preserve the branches to the left lateral segment and the caudate lobe.
Figure 44.16
The middle hepatic vein is ligated as dissection ap- proaches the vena cava. The left hepatic vein should be carefully preserved.
Control of the arterial and portal inflow to seg- ments V and VIII is accomplished by ligation of the right anterior sectoral pedicle. This will lead to a clear demarcation of segments V and VIII anterior to the right hepatic vein used as the plane of parenchy- mal transection. Segments IV,V, and VIII are now de-
vascularized and isolated from the rest of the liver. A
Pringle manoeuvre is performed and the remaining
hepatic substance posteriorly and inferiorly is divid-
ed with gentle crushing technique with meticulous
haemoclip ligation of vascular and biliary radicals.At
the completion of central hepatic resection, the mid-
dle hepatic vein has been ligated and the right and
left hepatic veins are left intact.
R. posterior sectoral pedical R. anterior sectoral pedical
Middle hepatic vein
R. anterior sectoral pedicle
