I am deeply concerned about the rising
incidence of so called ‘superbug’ infections associated with prostate
biopsy. These bacteria are resistant to
the great majority of antibiotics we have available for use and the only ones
that work generally have to be given through the veins. These bacteria have become particularly
prevalent in Asia where the indiscriminant use of antibiotics in agriculture
has lead to the breeding of antibiotic resistant bacteria in the
community. When you are well, they are
of no risk and they live harmoniously within your body. Should you be placed in circumstances where your
own bacteria turn against you and you happen to have the ‘superbug’, this can
lead to serious infection as conventional antibiotics are not effective. For those who wish to get technical, with the
term ‘superbug’, I am referring to the so called extended spectrum beta
lactamase producing bacteria (ESBL).
With increasing travel to Asia, growing numbers of Australians will carry these
bacteria within their intestines. Any
procedure that carries ANY risk of infection, which happens to include prostate
biopsies, will carry a risk of serious infection.
The article published in the The Age today
is entitled “Prostate
biopsy blamed for preventable superbug deaths”. This headline will understandably place fear
in every man who is about to be scheduled to undergo a prostate biopsy should
they read this piece. However, there
needs to be some perspective on the calls for urgent rectification of the
problem of superbugs by having all public hospitals purchase the equipment that
will enable the risk of any prostate biopsy related infection to be
eliminated. The typical cost of such
equipment is $150,000 and multiply this by the number of public hospitals, it
poses a massive infrastructure cost and represents monies that have to be taken
from somewhere else in the health budget.
Transperineal prostate biopsy (TPB) creates
significant burdens on resource utilization. TPB require a general anaesthetic
and day surgery admission to hospital as well as utilization of precious
operating theatre time. Almost all
Transrectal ultrasound prostate biopsies (TRUSPB) are performed in an
outpatient setting and typically take 15 to 30 minutes including turnover
time. A TPB can typically utilize as
much as 45 to 60 minutes of operating time including turnover time. More than 20,000 prostate biopsies are
performed in Australia each year and if every one of these were to be
immediately pushed into the hospital system, urological surgical resources
would be pressed to cope. Waiting lists
would likely significantly increase and it is highly unlikely that there would
be increased allocations of operating theatre sessions for urological
procedures.
Figure 1. Transperineal biopsies performed in the operating theatre setting
Even if a reliable mechanism was found to
perform the procedure under local anaesthetic, the procedure would still need
to be performed in the hospital setting as appropriate infrastructure such as
physical floor space and the operating table which enables coupling to the
transperineal biopsy equipment is simply not readily available in the
outpatient setting.
The majority of men would need to take the
day off for the procedure and often the following day given that they have had
a general anaesthetic. If the procedure
is performed as a TRUSPB under local anaesthesia, most are able to return to
normal activities either the same or following day.
There are certainly issues with infections
associated with TRUSPB. These men can
become very sick and a small number of cases may require admission to Intensive
Care Units. Men should however, be
reassured that their risk of dying from a prostate biopsy infection is extremely
small. The Victorian data
demonstrates a reported incidence of 2 deaths over the past five years. With
over 7000 biopsies being performed in Victoria each year, this equates to an
incidence of 2 out of over 35,000 prostate biopsy procedures (<0.006%) and
in the article published in the Age today, these are attributed to the
‘superbugs’. When we look at the
mortality rates associated with infections, a recent paper found that the
incidence of community
acquired ESBL sepsis was around 10%. In a mix of patients with healthcare related and
community acquired ESBL sepsis, the mortality rate was as high as 20%. The patients most likely to die were elderly
or had significant medical co-morbidity and exactly the type of patient who
perhaps prostate biopsy ought not be undertaken.
There are relatively few invasive
procedures that do not carry a risk of infection although transperineal
prostate biopsy is one where the risk is negligible if not zero. This data has been repeatedly confirmed and
provide a compelling argument to switch completely from TRUSPB to TPB. But are there any medical reasons why we
should reflect on this assertion? A
recent Australian study
published this year, the risk of acute urinary retention was 4.2% whereas
following TRUSPB, it is a very rare event.
Rather than see panic stations with public
outcry and a call for all hospitals to be immediately armed with the expensive
equipment, other processes should be enter into practice with a greater level
of urgency. We have to be pragmatic and
recognize that hospitals are not about to be funded for this equipment in the
immediate future and other strategies need to be sought in the meantime.
With the recognition that too many men
diagnosed with prostate cancer die with the disease rather than from it, we
need to better select the men in whom prostate biopsies are recommended. We also need better risk assess which men are
more likely to carry the ESBL ‘superbug’ and a history of recent travel to Asia
should be explored. We also need to get
smarter about either using or searching for simple strategies to minimize the
risk of ESBL infection such as performing rectal microbial swabs in advance of
the prostate biopsy, use of antiseptics such as betadine suppositories in the
rectum or dipping the biopsy needle in chemicals such as formaldehyde before
each pass. These strategies need more
work but represent that the profession recognizes more needs to be done. With
growth in the use of MRI scans prior to prostate biopsy, it is also possible
that fewer biopsies will need to be taken and there is the potential that fewer
numbers of biopsies taken may ultimately be proven to be associated with less
risk of infection. We can also
potentially improve the recovery from infection by having men appropriately
counseled to attend for assistance immediately with the onset of infection
rather than ‘sitting on it overnight and attending in the morning’ – when
bacteria are capable of double in numbers as fast as 20 minutes for some, early
presentation can make a huge difference to recovery.
In conclusion, ‘superbug’ infections are a
serious problem and we need to do more to minimize the risk to our patients on
many fronts. I believe that
transperineal prostate biopsies are one way forward, but the practicalities and
priority needs to be considered in the context of other health priorities.
Disclosure - A/Prof Henry Woo has access to TPB equipment at his hospital and does perform this procedure in selected men. The vast majority of his patients undergo TRUSPB under a local anaesthetic prostate block in an ambulatory outpatient setting.