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Chapter 34 / Interventional Radiology Support of HPB Surgery 421
more than 1,000 papers have been published allowing for the development
of guidelines to dene the role of TIPS in the management of portal
hypertension.
Cirrhosis is common throughout the world and may lead to ascites
formation, variceal bleeding, and hepatic encephalopathy. Of these compli-
cations, variceal bleeding is the most common indication for TIPS. In fact,
the mortality rate within 6 weeks of bleeding is 30%, which can most com-
monly be attributed to uncontrolled or early recurrent bleeding.
e model for end-stage liver disease (MELD) score was developed
specically to predict post-TIPS outcomes. is formula, which takes into
account the creatinine, bilirubin, and international normalized ratio (INR),
is an
accurate predictor of 30-day mortality. If the MELD score is 1 to 10, the
30-day mortality is 3.7%. If the MELD is greater than 24, the 30-day mortality
rises to 60%.
As the name indicates, TIPS is placed via a right internal jugular vein
approach. It may be performed with moderate sedation or general anesthe-
sia. e type of stent that is placed is operator dependent. Current evidence
suggests that a PTFE-covered stent (Viatorr) may have the best long-term
outcomes.
Technical success rates are greater than 95%. Hemodynamic success
rates are greater than 95%. Clinical success rates are measured in terms of
survival, control of bleeding, or ascites. Control of bleeding is achieved in
90%, and improved ascites control is seen in 60% to 85%.
Complications include stent malposition, hemobilia, radiation skin
burn, hepatic infarction, acute TIPS thrombosis, stent stenosis (usually
due to neointimal hyperplasia), liver failure, encephalopathy, heart failure,
recurrent portal hypertension, and recurrent bleeding. Indications and
contraindications to TIPS are shown in Table 34.2.
Indications
1. Secondary prevention of variceal bleeding
2. Refractory acutely bleeding varices
3. Refractory cirrhotic ascites
4. Portal hypertensive gastropathy
5. Gastric antral vascular ectasia
6. Refractory hepatic pleural effusion
7. Hepatorenal syndrome (type 1 or 2)
8. Budd-Chiari syndrome
9. Venoocclusive disease
10. Hepatopulmonary syndrome
Contraindications
Absolute
1. Severe or rapidly progressive liver failure
2. Severe or uncontrolled encephalopathy
3. Heart failure
Relative
1. Severe uncorrectable coagulopathy
2. Uncontrolled sepsis
3. Unrelieved biliary obstruction
4. Extensive primary or metastatic hepatic malignancy
5. Polycystic liver disease
Indications and Contraindications to TIPS
TABLE
34.2
Section IV / Multidisciplinary HPB Care422
Preoperative Evaluation
Contrast-enhanced CT is necessary to evaluate for underlying malignancy,
anatomy, and patency of the hepatic and portal veins. Alternatively, a
Doppler ultrasound of the liver may be performed to evaluate vessel patency.
Appropriate lab work includes liver function tests and alpha-fetoprotein.
Postoperative Care
Admit for 24-hour observation, if the procedure is done electively. When
TIPS is placed emergently, the patient is normally admitted to the ICU. Post-
TIPS ultrasound should be ordered the following day if a bare metal stent
is placed and in 1 to 2 weeks if a Viatorr (PTFE-covered) stent is used. is
test is used as a baseline for future follow-up of the shunt. Changes in blood
ow velocity through the stent predict potential shunt issues.
PREOPERATIVE PORTAL VEIN EMBOLIZATION
Liver resection often times is the only option that may confer long-term sur-
vival in patients with primary and secondary liver malignancies. However,
patients with limited liver remnant volumes are at increased risk of post-
operative liver failure and death. Preoperative PVE has emerged as a use-
ful preoperative technique to stimulate hypertrophy of the future remnant
liver (FRL) to facilitate the possibility of a major hepatectomy.
Rous and Larimore were the rst to demonstrate the regenerative
capacity of the liver following portal vein occlusion in the 1920s. In 1961, the
rst human portal vein ligation was performed during a two-stage hepatec-
tomy. e rst preoperative PVE in humans was performed in 1986. Since
then, PVE has been shown to be safe and eective in inducing FRL hyper-
trophy in preparation for surgical resection.
Today, percutaneous transhepatic PVE is the technique of choice. PVE
can be performed from an ipsilateral or contralateral approach. e choice
of approach is usually based on the tumor burden within the liver, the need
for segment 4 embolization, and operator preference. Many options for
embolics exist, including Gelfoam, coils, Amplatzer plugs, polyvinyl alcohol
particles, n-butyl cyanoacrylate and Lipiodol, or brin glue.
The technical success rate of PVE is 99%, and the clinical success
rate is 96%. Few patients are unsuitable for hepatic resection because
of inadequate hypertrophy. Regardless of approach, complications rates
range from 9% to 15%. Complications include subcapsular hematoma,
hemobilia, AV fistula, pseudoaneurysm, arterioportal shunt, nontarget
embolization, portal vein thrombosis (of the FRL), portal hypertension,
and sepsis.
Patient Selection
1. Patients with primary or metastatic liver disease, who are otherwise
hepatic resection candidates, except for the following:
a. Cirrhosis and/or advanced brosis and an FLR/total liver volume
(TLV) < 40%
b. Extensive chemotherapy and an FLR/TLV < 30%
c. Normal underlying liver and an FLR/TLV < 20%
2. Patients with diabetes mellitus but without underlying liver disease may
benet from PVE, as the magnitude of postresection liver hypertrophy is
usually less in these patients.
3. Patients undergoing complex hepatectomy with concomitant extrahe-
patic surgery, particularly pancreatectomy. In this group, studies have
shown that hepatic regeneration is inversely proportional to the extent
of pancreatectomy.
Chapter 34 / Interventional Radiology Support of HPB Surgery 423
Preoperative Workup
Volumetric 3D contrast-enhanced CT is essential for planning hepatic
resection and calculating TLV and FLR. ese measurements are easily cal-
culated by dedicated abdominal radiologist (Fig. 34.3).
Postoperative Care
Admit for 24-hour observation. Patients generally do not develop postem-
bolization syndrome as PVE leads to apoptosis as opposed to necrosis.
Hydrate vigorously until the patient tolerates oral hydration. Symptomatic
treatment of pain, fever, and nausea. Repeat CT is typically performed in
3to 4 weeks to evaluate FLR hypertrophy and recalculate volumetrics.
RADIOFREQUENCY ABLATION
Image-guided percutaneous techniques for local tumor ablation oer
eective treatment of select hepatic malignancies including hepatocellu-
lar carcinoma (HCC) and colorectal metastases. Although many ablation
techniques exist, RFA is the primary ablative technique used currently.
Traditionally, ultrasound has been the imaging modality of choice for guid-
ance. However, hepatic lesions are not always visible by this technique.
In cases where lesions are not visible on gray-scale ultrasound, contrast-
enhanced ultrasound, CT, and magnetic resonance can be utilized.
e goal of RFA is to induce thermal injury to the tumor through elec-
tromagnetic energy deposition. In fact, the patient is part of a closed loop
circuit that includes the RF generator, the electrode needle, and a large dis-
persive electrode. An alternating electric eld is created within the target
tumor. is agitates the tissue, which results in frictional heat around the
electrode, and this generated heat is focused and concentrated around the
needle electrode.
FIGURE 34.3 Preoperative volumetric analysis of a patient with right intrahepatic cholan-
giocarcinoma (arrow). Planned operation is right hepatectomy; note FLR outlined in blue.
Section IV / Multidisciplinary HPB Care424
Heating of the target tissue at 50°C to 55°C for 4 to 6 minutes produces
irreversible cellular damage. Temperature between 60°C and 100°C pro-
duces irreversible damage to mitochondrial and cytosolic enzymes of the
cells. At more than 100°C, tissue essentially vaporizes. For adequate tumor
tissue destruction, the ablative objective therapy is maintenance of 50°C to
100°C throughout the target tissue volume for 4 to 6 minutes. Slow thermal
conduction through tissues, however, increases the ablation time to 10 to
20 minutes.
In order to achieve low rates of local tumor recurrence, the
i
nterventional radiologist aims to produce a 360-degree, 0.5- to 1.0-cm-
thick tumor-free margin around each tumor. Hence, the diameter of the
ablation must be 1 to 2cm larger than the diameter of the target tumor.
Incidence of early major complications is 2% to 3% and includes
intraperitoneal bleeding, liver abscess, intestinal perforation, pneumotho-
rax, hemothorax, and bile duct stenosis. Late major complications include
seeding of the needle tract (0.5%). e incidence of minor complications
is 5% to 9% and includes pain, fever, pleural eusion, and asymptomatic
self-limiting intraperitoneal bleeding. e mortality rate is 0.1% to 0.5% and
commonly due to sepsis, hepatic failure, colon perforation, and portal vein
thrombosis.
Indications
1. HCC: A single tumor smaller than 5cm or as many as three nodules
smaller than 3cm each without evidence of vascular invasion or extra-
hepatic spread. A good performance status and Child-Pugh class A or B.
2. Secondary liver metastasis: Nonsurgical patients with metastases iso-
lated to the liver. In limited instances, a patient with extrahepatic metas-
tasis may be a candidate for percutaneous treatment, for example, if the
extrahepatic disease is deemed curable.
Contraindications
1. Tumor located less than 1cm to a main bile duct secondary to increased
risk of stenosis of the central biliary system
2. Intrahepatic biliary dilation
3. Anterior exophytic location of the tumor, due to risk of tumor seeding
4. Untreatable coagulopathy
Relative Contradictions
1. Bilioenteric anastomosis; increased risk of hepatic abscess
2. Supercial lesions; increased rate of complications (e.g., lesions adjacent
to any part of the GI tract as there is an increased risk of thermal injury)
3. Tumors located adjacent to the gallbladder; increased risk of chole cystitis
4. Pacemaker/debrillators. Can deactivate prior to procedure
Preoperative Workup
Pretreatment imaging must dene lesion(s) location relative to surround-
ing structures and organs. Positron emission tomography (PET) may be
indicated to exclude extrahepatic metastatic disease.
Preoperative labs include alpha-fetoprotein (HCC) and carcinoem-
bryonic antigen (colorectal cancer [CRC]), coagulation panel, and CBC.
Antiplatelet therapy should be discontinued for 5 to 10 days prior to
ablation and may be restarted 48 hours postprocedure. Warfarin should be
discontinued 5 days prior and may be restarted 24 hours postprocedure.
Chapter 34 / Interventional Radiology Support of HPB Surgery 425
Postoperative Care
Patients are generally kept at bed rest for 2 hours and admitted for 23-hour
observation.
Repeat imaging evaluation is performed 4 to 8 weeks postproce-
dure (Fig. 34.4). Successful tumor ablation will show nonenhancing abla-
tion region with or without peripheral rim enhancement on CT and MR.
Standard follow-up imaging and evaluation should be performed as recom-
mended for the specic malignancy treated.
FIGURE 34.4 Pre- (A) and post- (B) procedural imaging of a patient undergoing percutane-
ous RFA to treat metastatic colorectal adenocarcinoma (arrow, A). Note a large, nonenhanc-
ing pattern in postablation images (circle, B).
Section IV / Multidisciplinary HPB Care426
TRANSARTERIAL THERAPY
Over the past 20 years, interventional radiologists have been exploring
novel ways to treat cancer via the transcatheter endovascular approach. In
the last 10 years, these therapies have been studied and rened such that a
new branch of IR has emerged, inter ventional oncology. Transcath eter ther-
apy provides clinical benets that are distinct from the traditional medical,
surgical, and radiation oncologic treatments.
Transarterial therapy includes bland embolization, chemoemboliza-
tion, or radioembolization, techniques that selectively treat primary and
metastatic hepatic malignancies via its nutrient arterial supply.
Bland embolization refers to the infusion of embolic particles
via the nutrient artery to cause occlusion of the tumor arterioles.
Chemoembolization refers to selective infusion of chemoth erapeutic agents
via the nutrient arterial supply, followed by injection of embolic particles to
increase chemotherapy concentration by preventing chemotherapy wash-
out. An adaptation of chemoembolization with drug-eluting beads (DEBs)
has subsequently been developed. e concept includes loading the che-
motherapeutic agent on a biocompatible, nonresorbable bead that is then
administered via selective catheterization of the tumor’s nutrient arterial
supply. DEBs deliver higher and more sustained chemotherapy doses to the
tumor with reduced systemic exposure.
Radioembolization refers to selective intra-arterial delivery of glass or
resin microspheres loaded with the radioisotope yttrium-90. is delivery
method allows for safe administration of doses that may exceed 150Gy,
whereas the likelihood of developing severe radiation-induced liver disease
may exceed 50% for external beam radiation doses greater than 40Gy. In
fact, even higher doses can be attained when a “radiation segmentectomy”
is performed. With this technique, high doses of radiation are delivered to
one or two hepatic segments to maximize tumor irradiation and minimize
exposure of normal liver parenchyma. Calculated segmental radiation do ses
in excess of 500Gy and calculated tumoral doses greater than 1,200Gy have
been reported, all with very low incidence of biochemical toxicities.
Transarterial Therapy and Hepatocellular Carcinoma
e Barcelona Clinic Liver Cancer (BCLC) staging system for HCC is widely
accepted in clinical practice.
Conventional transarterial chemoembolization (emulsied che-
motherapeutic agent and Lipiodol followed by embolization) is the rec-
ommended rst-line therapy in BCLC stage B disease without vascular
invasion, cancer-related symptoms, or extrahepatic spread. Doxorubicin-
loaded DEBs have similar results to conventional chemoembolization in
this population, but with signicantly higher administer doses of doxorubi-
cin and signicantly reduced serious liver toxicity and doxorubicin-related
adverse events.
An alternative treatment option for HCC patients with BCLC stage B
disease is radioembolization, which has been shown to be safe and eca-
cious specically in patients with portal vein invasion.
To date, no head-to-head randomized controlled trials have compared
radioembolization versus chemoembolization in HCC patients. However,
a comparative eective analysis of more than 200 HCC patients treated
with radioembolization and chemoembolization suggested similar survival
times, with a signicantly reduced toxicity prole for radioembolization.
Transarterial Therapy of Hepatic Metastatic Colorectal Cancer
Both chemoembolization and radioembolization have been used to treat
patients with unresectable metastatic CRC. Radioembolization is used
Chapter 34 / Interventional Radiology Support of HPB Surgery 427
currently for the treatment of chemotherapy-resistant or refractory disease.
Treatment of these patients should be considered in the context of the mul-
tidisciplinary group evaluation.
Transarterial Therapy of Neuroendocrine Tumors
Bland embolization, chemoembolization, or radioembolization can be
used in patients with symptomatic but unresectable disease, clinically sig-
nicant tumor burden, or clinically signicant progressive disease.
Bland embolization and chemoembolization of neuroendocrine
hepatic metastases provide signicant symptomatic improvement and
radiologic responses in the majority of treated patients, with encouraging
progression-free survival.
Radioembolization may provide a complete response in as many as
18% of hepatic neuroendocrine tumor patients, although survival times do
not dier signicantly from bland embolization or chemoembolization.
Transarterial Therapy and Intrahepatic Cholangiocarcinoma
Although radioembolization and conventional chemoembolization have
both been shown to be safe and eective in small series of patients with
unresectable cholangiocarcinoma, no randomized control trial has been
performed to date.
Preprocedure Workup
1. Tissue diagnosis or convincing clinical diagnosis
2. CT or MRI of the abdomen and pelvis
3. Exclusion of extrahepatic disease (PET-CT, bone scan, etc.)
4. Lab test: CBC, INR, creatinine, liver function tests, and tumor markers
5. Arteriography shunt study (radioembolization)
Postoperative Care
1. Twenty-three–hour observation in hospital (chemoembolization, DEBs).
2. Outpatient procedure (radioembolization)
3. Aggressive hydration.
4. Symptomatic treatment of postembolization syndrome.
5. Once the patient is tolerating oral intake and pain is controlled, the
patient is discharged to home.
6. Follow-up in IR clinic in 4 to 6 weeks with imaging.
POSTOPERATIVE INTRA-ABDOMINAL FLUID DRAINAGE
Percutaneous drainage of postoperative abdominal uid collections is one
of the most commonly performed IR procedures. Furthermore, it is a well-
established management option in patients who do not have another indi-
cation for immediate surgery.
Abdominal CT with or without contrast is needed to evaluate for
an appropriate percutaneous window and collection size and to select
the desired approach, that is, transabdominal, transgluteal, and tran-
srectal. Patients with a limited window or small collections can be
approached using CT guidance. More superficial or large collections can
generally be accessed easily under ultrasound and fluoroscopic guid-
ance. The collections are accessed with an 18-gauge trocar needle, and
a stiff guidewire is placed. The drain is then placed through this access,
sutured to the skin, and placed to an external drainage bag. The drain
size depends on the contents of the collection to be drained. To deter-
mine content, a small volume is aspirated through the trocar needle.
Generally, simple pus-filled collections require 8- to 12-Fr drains. A more
Section IV / Multidisciplinary HPB Care428
complicated collection, such as a peripancreatic collection, may require
14- to 20-Fr drain.
Overall, complication rates are less than 15%, and a 30-day mortal-
ity ranges from 1% to 6% depending largely on the patient’s underlying
medical condition. Major complications include bleeding, septic shock,
enteric fistula, peritonitis, and hemopneumothorax. Minor complica-
tions include pain, infection, pericatheter leak, catheter kinking, and
dislodgement.
Indications
1. Fluid characterization
a. Distinguish purulent uid, bile, blood, urine, lymph, and pancreatic
secretions.
b. Determine if collection is infected or sterile.
2. Treatment of sepsis
a. Can be curative in patients with simple abscesses
b. Can be curative or temporizing in patients with complex abscesses
3. Relief of symptoms
a. Alleviate pressure and pain due to size or location of collection.
b. Obliterate recurring cysts or collections with sclerosing agents.
Contraindications
Absolute
1. Lack of safe pathway to the collection due to interposed vessels or viscera
Relative
1. Sterile collections: Prolonged catheter drainage may increase risk of sec-
ondary infection.
2. Hematoma: Increased risk of infection and poor drainage.
3. Percutaneous route requires transgression of pleura as this increases the
risk of pneumothorax, empyema, and pleural eusion.
4. Tumor abscess may require lifelong catheter drainage.
5. Echinococcal cyst may elicit anaphylactic reaction if contents leak.
Preoperative Workup
CT scan to evaluate uid collection for appropriateness. Coagulation stud-
ies. Prophylactic antibiotics (preprocedure antibiotics generally do not
aect cultures)
Postoperative Care (Drain Management)
Strict record of input and output. Flush catheter twice daily with 10 mL
saline to keep catheter free of complex debris. Daily dressing changes. If
patient to be discharged with the drain, proper drain education should be
performed.
If there is high output from the drain (>50mL/day) beyond 4 days,
the possibility of stula to the bowel, pancreatic duct, or biliary system
should be considered, and uoroscopic-guided catheter injection may be
considered.
If uid collection persists with poor drainage, tissue plasminogen acti-
vator (tPA) or injection drain upsize may be benecial. Typically, 6mg of
tPA is diluted in 50mL of normal saline; up to 50 mL is injected into the
drain twice daily for 3 days. e drain is clamped for 30 minutes after each
injection. is technique can successfully restore drainage in up to 90%
Chapter 34 / Interventional Radiology Support of HPB Surgery 429
of cases, with failure more likely in peripancreatic collections and enteric
stula.
PSEUDOANEURYSMS
False arterial aneurysms, or pseudoaneurysms (PSAs), are injuries to the
arterial wall, which typically bleed into a saccular hematoma that is con-
tained by the surrounding soft tissues. e name can be a source of confu-
sion: PSAs are not aneurysms, but a manifestation of a vessel injury.
e prevalence of PSAs has increased over time due to increasing
surgical and endovascular procedural volume. Surgery can induce PSA
formation through direct trauma to an artery or through introduction of
infection. Figure 34.5 shows superior mesenteric artery PSA after pancre-
atoduodenectomy. Arterial wall erosion from an adjacent tumor or inam-
mation (pancreatitis) can cause PSA.
A PSA may be asymptomatic or can cause local symptoms secondary
to mass eect or adjacent tissue ischemia. e most feared complication is
rupture, which can result in life-threatening hemorrhage. PSAs can com-
municate with and rupture into dierent anatomic spaces, including the
pancreatic duct system, biliary tree, and gut lumen.
Clinically, a PSA can present due to its local or systemic signs and
symptoms (i.e., pain) or can be detected on physical exam with signs
such as a pulsatile mass, an audible bruit, or a palpable thrill. ey can
FIGURE 34.5 Angiography demonstrating large superior mesenteric
artery pseudoaneurysm (arrow) sustained after pancreatoduodenectomy.
Section IV / Multidisciplinary HPB Care430
potentially manifest with a “sentinel bleed,” such as bleeding into a drain or
as a GI bleed (e.g., hematemesis, melena). e diagnosis of PSA is secured
with imaging.
PSAs can be evaluated with computed tomography angiography (CTA)
and magnetic resonance angiography (MRA). Both modalities can demon-
strate deeper arterial structures and can be used for planning intervention.
Contrast-enhanced CTA or MRA can demonstrate a contrast-opacied,
saccular structure communicating with a blood vessel, with unopacied
areas in the sac representing thrombus. CTA is fast and not operator depen-
dent; however, it requires the use of iodinated contrast media, which can be
nephrotoxic, as well as ionizing radiation. MRA lacks ionizing radiation but
is time consuming and limited by motion and other artifacts, which makes
it a suboptimal modality for PSA detection.
Another modality for imaging of PSAs is percutaneous, catheter-
directed arteriography, which involves real-time, dynamic imaging of arte-
rial ow and also allows denitive endoluminal therapeutic intervention.
Catheter-directed arteriography however is invasive and also involves
ionizing radiation and iodinated contrast media. Potential complications,
while rare, include arterial vessel damage, including new PSA formation,
dissection, rupture, thrombosis, and hematoma.
Management of PSAs has classically been surgical; however, with
advances in image-guided percutaneous management, today, virtually all
visceral PSAs are successfully managed with IR techniques.
e purpose of endoluminal management is PSA exclusion from the
circulation. e specic endoluminal treatment depends on whether or not
the blood vessel supplying the PSA is expendable or not and whether or
not collateral circulation exists. If the vessel is not expendable, a covered
stent can be placed across the neck of the PSA. If the vessel is expendable
and is an end artery without collateral supply, the artery feeding the PSA
can be coil embolized. If the vessel is expendable but has collateral circula-
tion, the PSA must be “bracket” embolized, with coils placed in the artery
central and peripheral to the PSA. Complications of endoluminal manage-
ment include “nontarget” embolization, or coils migrating to unintended
locations, as well as blood vessel rupture. Embolized PSAs and feeding
vessels can also occasionally recanalize. Stent graft placement is relatively
contraindicated with mycotic aneurysms due to risk of stent graft infec-
tion. Larger arteries have a lower risk of in-stent thrombosis than smaller
arteries. A small risk of rebleeding exists after IR treatment of visceral PSA;
patients should be counseled accordingly.
CONCLUSION
A diverse array of IR techniques supports HPB surgery today. Close collabo-
ration between HPB surgeon and interventional radiologist is necessary to
optimize diagnosis and treatment of complex HPB pathology.
Suggested Readings
Boyer TD, Haskal ZJ. AASLD practice guidelines: the role of transjugular intrahe-
patic portosystemic shunt (TIPS) in the management of portal hypertension.
Hepatology 2010;51:306.
Cirocchi R, Trastulli S, Boselli C, et al. Radiofrequency ablation in the treatment of liver
metastases from colorectal cancer. Cochrane Database Syst Rev 2012;6:CD006314.
doi: 10/1002/14651858.CD006317.pub3
Mahnken AH, Pereira PL, de Baere T. Interventional oncologic approaches to liver
metastases. Radiology 2013;266(2):407–430. doi 10.1148/radiol.12112544. PMID:
23362094 (Pub Med-indexed for MEDLINE)