Pre operative liver functions assessment

1. Pre-operative Liver Function
Assessment
. Dr Mebanshanbor Garod
(MS General Surgery, FMAS,
FEBS Surgical Oncology)
Surgical Oncology Dept.,
NEIGRIHMS, Shillong

2. IMPORTANCE
• Determination of baseline parenchymal
disease (fibrosis, steatosis, cirrhosis),
• The predicted volume of the remnant liver (hepatic
reserve),
• The appropriate extent of resection required &
• Prediction of risk of postoperative hepatic
failure.
Hence, better selection of patients as well as
better selection of operative procedures
(high-risk patients for alternative procedures, such as
staged resection, non-anatomic resection, ablative
procedures or PVE)

3. Concepts of:
1.Hepatic reserve
What is expected of the liver after complicated
injury, invasive procedures, or surgical resection
Demands of regeneration and healing
+
Functional obligations
[aerobic and anaerobic metabolism
protein synthesis and degradation
various detoxification processes]

4. 2.Steatosis
In the absence of frank cirrhosis
Defined as diffuse accumulation
of fat droplets affecting >10%
of hepatocytes
BIOPSY -
Mild 10-30%
Moderate 30-60%
Severe >60% A. Microsteatosis
B. Macrosteatosis

5. McCormack et al, Ann Surg 2007

6. 3. Portal hypertension
Portocaval pressure gradient > 10 mmHg
Presence of oesophageal varices (grade 2, 3)
Surrogate markers:
Low platelet count < 100 000/mL
Splenomegaly
Other features on imaging
In Child A cirrhotics without portal hypertension, a 5-yr
postresection survival of 70% has been reported

7. Critical tool in patient selection for liver
surgery
Requirement
for resection
with adequate
margins
Underlying
hepatic
functional
impairment
Safe liver surgery

8. Preoperative Evaluation can be divided into the
following
Four categories:
1. Clinical scoring systems using standard
assessment and laboratory values,
2. Measurements of hepatic uptake and
excretion,
3. Measurements of hepatic metabolism and
excretion, and
4. Measurements of predicted postoperative
liver volume.

9. The multiple and diverse functions of the liver
preclude easy evaluation.
No individual test, or even a panel of tests,
completely and accurately assesses preoperative
liver function prior to resection.

10. 1. SCORING SYSTEMS
Child-Turcotte-Pugh
Child-Pugh
APACHE
MELD

11. i) “Child” system – original version
Patient survival after portal-systemic shunt
surgery
Inconsistent predictive value when used alone
Independent factors associated with morbidity
after liver resection in cirrhotics
Serum Bilirubin
Ascitis
ICG clearance

12. The Child system and its modifications

13. Child-Pugh scoring system

14. Predictive value of the Child score
Presumed mortality from liver-
related causes:
.
Child status 1-yr mortality
A ≈ 0
B 20%
C 55%
Studies assessing mortality
following liver resection
Child A: 3.7%
Child B,C: 16.7%
Franco et al
No difference
Nagao et al
Nagasue et al
Unacceptable mortality
rates in early cirrhotics
Bismuth et al
Not entirely reliable…

15. Normal Liver :
Segments Volume
5 + 8 30 %
6 + 7 35 %
1 + 4 20 %
2 + 3 15 %
65 % of Right Liver
35 % of Left Liver
Correlation of Child score
with volume –
Child A 50% can be resected
Child B 25% can be resected
Child C transplant only

16. 2. MELD Model for End-Stage Liver Disease
Initially developed to predict mortality in patient
who undergone TIPS.
Now used by UNOS and Eurotransplant for
determining prognosis and prioritizing allocation
of liver transplants.
Has been studied in the setting of resection also
Strong correlation of postoperative morbidity after
hepatectomy

17. MELD Formula*
MELD Score = 0.957 × log (creatinine mg/dL)
+ 0.378 × log (bilirubin mg/dL)
+ 1.120 × log (INR)
+ 0.643
Widely accepted for prioritization for liver
transplantation
Few studies in the setting of resection

18. 2. DYNAMIC TESTS: measurement of
hepatic uptake, metabolism and excretion.
Based on the pharmacokinetics of an exogenous substance

19. Indocyanine green retention
Solely removed by the liver
Retention at 15 minutes (ICG 15)
0.5mg/kg injected
>15% retained
impaired function
Serial
sampling
Pulsed spectrometry

20. Tailoring resection according to ICG Clearance

21. NUCLEAR SCINTIGRAPHY
Galactosyl serum albumin (GSA)
Neogalactosyl albumin
Hepatic aminodiacetic acid (HIDA
Sulfur colloid
Gold
-Volumetric/anatomic information
-Functional assessment of the ability of the liver to clear the
synthetic asialoglycoproteins

22. 99m-Tc-galactosyl-human serum
albumin scintigraphy
Takes advantage of the role of the liver in
metabolizing senescent proteins through an
active transport process facilitated by hepatocyte
membrane receptors ( which are reduced in
cirrhotic liver and absent in HCC)
Approved for use in Japan.
(Nihon Mediphysics, Nishinomiya, Japan)
Bolus inj. 185 MBq 99m-Tc-GSA

23. Dynamic scintigraph obtained with gamma
cameras located over the heart and liver
Correlates with ICG, Child score,
and other indices of liver function
? Provides additional information
Nakajima KK, et al. Ann Nucl Med 1999

24. Nuclear imaging (99 m-Tc-GSA, etc)
Provides volumetric data .
Still relatively preliminary.
Superiority not confirmed

25. 3. Measurement of PREDICTED POST-
OP LIVER VOLUME : CT Volumetry
Automated
Interactive (software-aided)
Manual
Accurate in normal livers or mild disease
TLV = -794.41 + 1267.28 X BSA
Standardized FLR = measured FLR/TLV
FLR volume = (remnant liver volume X 100)/ (total
liver volume – tumour volume)

28. PREOPERATIVE ASSESSMENT OF
HEPATIC RESERVE
Normal liver Impaired liver function
Child score assessment
Portal hypertension assessment
Dynamic tests
Volumetric assessment
for functional reserve
Steatosis/occult
cirrhosis also ruled out
by invasive/non-
invasive diagnostic
techniques
A step-by-step approach…

29. Is the liver function impaired?

30. Why is it impaired?

31. Summary
• Surgical judgment – decision to resect/extent
(Assessment of severity of the underlying liver
disease, the extent of the tumour, and the future
liver remnant)
• Child score remains best assessment tool
especially as a predictor of post-op
complications and liver failure.

32. • Dynamic tests : ICG and Nuclear Scintigraphy
(99mTcGSA) more specific indicators of
hepatic reserve in preparation for resection.
• No single test available
• Tests are required to augment, and not just
correlate with the Child score to improve
surgical outcomes after resection

33. Thank you…