Can a Medical Negligence claim still succeed without evidence of negligent surgical technique?
The recent decision of Paul v Cooke  NSWCA 2011 considered the interesting concept of whether a patient could succeed in a claim for damages where a known risk of surgery occurred without any allegation of negligence on the part of the surgeon.
In summary, the patient required surgery for an intracranial aneurysm.
It was argued that the aneurysm had been missed on a scan 3 years prior to it ultimately being diagnosed.
The Plaintiff argued that had the aneurysm been diagnosed 3 years earlier that it ultimately was she would have undergone a procedure different to the one she ultimately undertook in 2006.
Both of those procedures came with a a set of risks which were of a similar scope and likelihood.
The procedure that was ultimately performed in 2006 unfortunately lead to a complication which left her significantly incapacitated, however, there was no suggestion that that complication had occurred as a result of surgeon negligence.
The Court of Appeal ultimately decided that the risk which ultimately eventuated had always been present once the Plaintiff had developed her aneurysm and the Defendant did not create the risk which ultimately eventuated. Detailed analysis of the decision is below.
Paul v Cooke  NSWCA 211 and the application of inherent risk
In 2003, Ms Paul underwent a scan to determine whether she had an intracranial aneurysm. Upon conducting the scan, Dr Cooke negligently failed to diagnose an aneurysm that existed in Ms Paul’s brain. In 2006 when undergoing another scan it was successfully diagnosed. Ms Paul underwent a procedure to remove it however, during the procedure it ruptured without any lack of care or skill on behalf of the surgeon, causing her to have astroke and suffer serious injuries.
Ms Paul claimed that if Dr Cooke had diagnosed the aneurysm in 2003 she would have undergone a different procedure then to remove it. However, neither operation carried any more or less risk and the aneurysm remained unchanged in the period between the negligent failure to diagnose and the failed removal of the aneurysm.
One of the primary questions and whether or not s 5I – the materialization of inherent risk provision – applied.
The substantive judgment in this case was delivered by Leeming JA, dealing with the subject of inherent risk from  – .
In his interpretation of s 5I(materialization of inherent risk), his Honour indicated that he disagreed with the application of the trial judge. He engaged in a lengthy statutory interpretation exercise of the definition provided in s 5I(2), ultimately concluding at , that the definition requires a “forward-looking” analysis of the position before the inherent risk materialized. Following this conclusion, his Honour found that the relevant question being asked by the statute is:
Whether the “risk of something occurring”, ie the “risk of intra-operative rupture followed by stroke”, could have been avoided by the exercise of reasonable care and skill. That had to be determined from Ms Pauls position before she underwent surgery .
Accordingly, he concluded that s 5I applied because there was always a small but unavoidable risk of intra-operative rupture followed by stroke. Significantly, this cas was distinguished from that of the class of case exemplified by Mahony v J Kruschich (Demolitions) Pty Ltd, where (at 74):
…the defendant creates the initial injury and also therefore the unavoidable risk of complications in its treatment. In those circumstances, the defendant’s liability may continue even if the treatment is itself undertake negligently. “[T]he first tortfeasor may be liable in negligence for a subsequent injury and its consequences although the act or omission of another tortfeasor is the more immediate cause of that injury… The original injury can be regarded as carrying some risk that medical treatment might be negligently given”: Mahony at 528-529.
This case is quite different in that Ms Paul’s condition was not caused by Dr Cooke’s negligence, and in fact, pre dated negligent diagnosis. His Honour states (at 75):
Dr Cooke did not create the relevant risk – the occasion for Ms Paul to run (if she so chose) the risk of intra-operative rupture. That risk could not be avoided by reasonable care on the part of Dr Cooke; that risk was always present once Ms Paul developed an aneurysm. It could never materialize until it was diagnosed and Ms Paul chose to undergo surgery.
His Honour concludes at  that only where, as here, the risk pre-dates and is neither created or increased by the defendant’s negligence would the section apply.