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| Journal of the New Zealand Medical Association,
22-August-2008, Vol 121 No 1280
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Post-procedure surveillance in liver biopsy: how long
is long enough?
Rowena Howard, George Karageorge, Kate van Harselaar,
Melanie Bell, Pete Basford, Michael Schultz, Sarah Derrett
Liver biopsy is the current gold standard for assessing
chronic liver disease. It is, however, an invasive and costly procedure
associated with complications. Research into less invasive methods of assessing
liver fibrosis1 is still inconclusive, and
these methods have not yet been routinely implemented.
The most common indications for liver biopsy are viral
hepatitis and abnormal liver function tests.2
Other indications include haemochromatosis, methotrexate monitoring, and
assessment for malignancy.3
Major complications of liver biopsy such as bleeding and
visceral perforation are rare—occurring in less than 1% of
patients—but the procedure is associated with an overall mortality rate of
0.01–0.17%.2,3,4–7 Minor
complications such as pain, vasovagal episode, nausea, and vomiting occur more
frequently in up to 35% of patients.4,8,9
Shorter observation periods after biopsy have been
suggested.10 In a recent American study of more
than 3000 patients, the post-procedure observation was consecutively reduced
from 6 hours to 1 hour over a 9-year period, as the majority of complications
were found to occur within 1 hour of the
procedure.11 Economic advantages of shorter
observation periods have been
reported.10,11
To our knowledge, an ideal observation time before discharge
has not been studied in New Zealand. The situation in New Zealand is unique as
the population being served by secondary and tertiary hospitals is often rural
and many patients do not have ready access to health care providers once
discharged.
This study aims to:
MethodsPercutaneous liver biopsy—At
Dunedin Public Hospital (DPH), a single consultant has been overseeing the liver
biopsies during the observation period. Current blood results (full blood count
and INR) were reviewed and informed consent obtained one day prior to the
procedure. For the procedure, patients were placed in the supine position, and
the ideal location for the liver biopsy on the lateral lower aspect of the right
thorax was established both by percussion as well as immediately prior to the
investigation by means of a 3.5MHz sector ultrasound probe (Sonolayer-LS SAL
5AS, Toshiba Medical Systems Corporation, Japan).
From 2005 onwards following disinfection of the skin
with iodine, pethidine (50 mg iv, Mayne Pharma [NZ] Limited, Wellington, NZ) was
given for pain control. The skin and various layers of the thoracic wall were
then locally anaesthetised with 5–10 ml of 1% lignocaine containing
1:100,000 adrenaline (Astra Zenica, Auckland, NZ). A small incision into the
skin was made using a disposable scalpel (Swann-Morton, Sheffield, UK) before
the biopsy was performed using a modified Menghini biopsy set (17/16 G, TSK
Laboratory, Japan).
After the procedure, patients were placed on their
right-hand-side to rest on a sandbag for 1 hour, followed by 4 hours lying flat
and a final 1 hour sitting. Blood pressure, pulse, and wound site were checked
every 15 minutes for the first hour and thereafter hourly until the time of
discharge. If pain was experienced, based on the severity, either pethidine 50mg
i.v. or paracetamol 1g p.o. was administered. Patients living beyond a 40-minute
driving radius of DPH were asked to stay close to DPH overnight after
discharge.
Study population—Following
ethical approval, a retrospective audit of percutaneous liver biopsies was
undertaken at DPH. DPH is a tertiary teaching hospital with 350 inpatient beds.
For specialised services such as gastroenterology it serves a population of more
than 190,000 people usually resident in Otago
province.12 Otago is the second largest
province of New Zealand and covers approximately 32,000 square kilometres of
land in the lower South Island.
Data collection—Unique patient
identifiers (National Health Index numbers) of patients having a liver biopsy
between 1 January 2001 and 31 December 2006 were extracted from the DPH
Information Services. Medical files were then obtained and analysed. Patients
having CT or ultrasound-guided biopsies organised by other teams, and biopsies
undertaken during abdominal operations, were excluded from analysis.
Data collected included age, sex, indication for
biopsy, and date of biopsy. Also, data was collected from patients’ files
regarding the administration, type, and timing of post-procedural analgesia.
Peri- and post-procedural complications, and the timing of their occurrence,
were recorded for analysis if pain was noted in the patient file, analgesia was
administered, or any other complication was noted.
Statistical methods—Descriptive
statistics were computed for patient characteristics. Chi-squared tests of
proportions were used to compare various outcomes for those who had pre-biopsy
analgesia with those who did not. All statistical analyses were carried out in
SAS v9.1 software.13
Results493 liver biopsies were carried out between 2001 and 2006.
Of these, 447 were included in the study. Reasons for exclusion of biopsies from
the study are presented in Table 1. There were 428 patients included in the
study, of whom 15 patients received more than one biopsy (to a maximum of four
biopsies per patient) during the study period.
Table 1. Reasons for exclusion from
study
Patient characteristics—The majority
of patients were aged between 40 and 60 years (see Table 2), with more men than
women undergoing biopsies. The main indication for percutaneous biopsy was
hepatitis C, followed by abnormal liver function tests and methotrexate
therapy.
Complications—Table 3 shows
complications and the timing of post-procedure analgesia administration. No
complications were reported for 69% of the biopsies performed. Two patients had
two complications (pain and hypotension) and one patient had pain, hypotension,
and nausea.
There were 139 biopsies (134 patients) where analgesia was
administered at least once post-procedurally; 4 patients were given analgesia
twice post-procedurally; and 1 patient was given analgesia three times. Opiates
were administered 68% of the time post-procedurally.
A greater proportion of females had complications than
males: 47% and 31% respectively (95% CI for the difference: 6% to 25%,
p=0.0009).
Only 11 complications other than pain were recorded. Of
these, the time period of complication occurrence was unreported for 3 patients;
for the remaining 8, complications occurred within 2 hours of biopsy.
Table 2. Patient characteristics and
indications for percutaneous biopsy
*All biopsies shown, including repeats; †e.g.
sarcoidosis, metabolic syndrome, systemic lupus erythmatosis, raised ferritin,
portal hypertension.
Table 3. Complications and the timing of
post-procedural analgesia administration
*One record is missing pre-procedural analgesia; **All
complications are shown.
Effects of pre-procedural
pethidine—Pre-procedural pethidine was given to 130 patients
(29.2%). The proportion of those that experienced complications with and without
pre-procedural pethidine were 34% and 39% respectively (95% CI for the
difference -4% to 15%, p=0.29). The rates of pre-biopsy pethidine was 31% for
females and 28% for males (95% CI for the difference -6% to 11%, p=0.52).
The proportion of those who required analgesia with and
without pre-procedural pethidine were 31% and 32% respectively (95% CI for the
difference -10% to 9%, p=0.92).
Of those who received postoperative analgesia, a smaller
proportion of patients received opiates post-procedure when given pre-procedural
pethidine compared to the group not receiving pre-procedural pethidine, 49% and
77% respectively (95% CI for the difference 10% to 45%, p=0.0014).
DiscussionDespite recent advances in non-invasive tests to determine
the stage of liver fibrosis, percutaneous liver biopsy remains the gold
standard. The invasive nature of this procedure carries the risk of
complications necessitating a period of observation after biopsy. Determining
the ideal length of this observation period has not yet been ascertained,
particularly in countries with a large rural population.
This retrospective study of 493 biopsies demonstrated that
patient characteristics and indications for biopsy are similar in New Zealand
when compared with international studies.2,4 No
major complications were experienced. The use of pre-procedural ultrasound to
identify the ideal location for all biopsies, and the less traumatic low-gauge
Menghini technique in combination with a single consultant overseeing the liver
biopsies at our unit, may contribute to this.14
Minor complications, predominantly pain, were recorded for less than one third
of patients, which is comparable to similar international
studies.4,8,9
Administration of pre-procedural pethidine did not affect
the rate of complications. A smaller proportion of patients receiving
pre-procedural pethidine received post-procedural opiates as compared to those
who did not receive pre-procedural pethidine. Clinically, pethidine is reported
to reduce pre-procedural anxiety. Further research is required to determine the
best use of prophylactic opiates for percutaneous liver biopsy.
The post-procedural observation period is a major factor in
the overall cost of biopsy to the health system; but cost savings need to be
weighed against risks to patients. Our study found that the majority of
complications occurred within two hours of the procedure.
In summary, based on our retrospective findings, we suggest
reducing the post-procedure observation period for percutaneous liver biopsies
to 2 hours warrants consideration. It remains unclear if early discharge and
therefore mobilisation of patients will lead to an increase of pain or other
complications, but the overall practicality of this management is supported by
the finding that no late major complications or early re-admissions occurred
during the study periods.
We did not identify any major complications in our study,
and cannot therefore comment on the timing of such. Nevertheless, in Otago,
because of the rural environment, the current policy of patients from rural
areas remaining within a 40-minute driving radius of the hospital overnight
ought to be maintained.
Competing interests: None known.
Author information: Rowena Howard, George
Karageorge, and Kate van Harselaar: Trainee Interns, Department of Preventive
and Social Medicine, University of Otago, Dunedin; Melanie Bell, Senior
Lecturer, Department of Preventive and Social Medicine, University of Otago,
Dunedin; Pete Basford, Registrar, Department of Gastroenterology, Otago District
Health Board, Dunedin; Michael Schultz, Senior Lecturer and Consultant
Gastroenterologist, Department of Medical and Surgical Sciences, University of
Otago, Dunedin; Sarah Derrett: Senior Research Fellow, Department of Preventive
and Social Medicine, University of Otago, Dunedin
Acknowledgements: We are most grateful to
the other members of the trainee intern group who contributed to the design and
data collection (Ivor Cormack, Lara Colbourne, Michael Hamilton, Victor Kong,
and Ben La Hood) as well as Dr Ralf Lubcke (Gastroenterologist at the Otago
District Health Board) for his helpful comments.
Correspondence: Dr Michael Schultz,
Department of Medical and Surgical Sciences, University of Otago, PO Box 913,
Dunedin, New Zealand. Fax: +64 (0)3 4747724; email: michael.schultz@stonebow.otago.ac.nz
References:
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