Evidence Relating to the Times at which the Limitation Periods Commenced
19 In support of its contention that the application was commenced out of time, Getz Bros relies upon:
(a) the allegations in the statement of claim;
(b) Ms Carey-Hazell's account of her medical history;
(c) four letters which Ms Carey-Hazell received before 13 March 1998; and
(d) two letters which Ms Carey-Hazell wrote before 13 March 1998.
The submissions for Getz Bros referred first to a copy of a booklet which was provided to Ms Carey-Hazell in hospital following the implantation of the mitral valve. This booklet is referred to in par 23 of the statement of claim. Getz Bros pointed to a passage from the booklet warning of the need for recipients of the St Jude mitral heart valves to take preventive measures against formation of blood clots on or around the implanted heart valve. The relevant passage of the booklet was in the following terms:
"ANTICOAGULANTS
Your doctor may prescribe an anticoagulant medication to prevent blood clots from forming on or around your St Jude Medical heart valve. The dosage will be closely monitored by blood tests.
To maintain proper levels of anticoagulation, take your medication as prescribed and follow up with blood tests as scheduled. Take only those medications your physician prescribes. Check with your doctor before taking any other medication, including over-the-counter products such as aspirin.
Always inform your dentist and physicians that you are on an anticoagulant medication. Adjustments in your medication may be needed prior to any procedure."
20 The booklet also contained advice about the interaction between diet and anticoagulants and the need to obtain medical advice about dietary habits. The reader of the booklet is also warned to consult a physician in relation to anticoagulants and if any of the following symptoms develop:
· Excessive bruising
· Excessive bleeding
· Blood in your urine
· Bloody or black, tarry bowel movements
· Unusual nosebleeds
· Bleeding gums
21 As appears from Ms Carey-Hazell's affidavit she suffered severe pain on her left side on or about 13 October 1996 and was readmitted to Sir Charles Gairdner Hospital where she remained until 27 October 1996. She was treated by Dr Jeffrey Hamdorf, a general surgeon at the hospital. A Computer Tomography scan showed that she had suffered infarctions in her left kidney and spleen. Dr Kermode, a neurologist, told her that the infarctions had been caused by blood clots forming on the valve, flying off the valve and travelling through her blood stream to her left kidney and spleen where they caused a blockage in a blood vessel within that organ and, in turn, caused the surrounding tissue to die from lack of blood supply. She understood that the process which caused the infarction was called thromboembolism.
22 As the result of a car accident which she had suffered in 1993, Ms Carey-Hazell had engaged Paynes, Barristers and Solicitors to act for her. On or about 6 March 1997, she received from her solicitors copies of medical correspondence, including a letter dated 6 March 1997, from Dr Hamdorf to the solicitors which made reference to the infarctions of her spleen and kidney. In relation to the infarction of the kidney Dr Hamdorf said:
"This is a condition which I elected to treat conservatively. Infarction is caused by embolism and this was thought to be most likely from her artificial mitral valve (replacement was performed in June 1996 by Mr T Nicholls). Following such surgery, anticoagulation using Warfarin is highly recommended if not considered mandatory. At the time of her presentation, her level of anticoagulation was probably not within a satisfactory range therefore whilst under my care I submitted her to frequent clinical observation and re-institution of the anticoagulation therapy.
On presentation, Ms Carey-Hazell's INR level was 2.4 whilst the day before that (14 October 1996) it was 2.0 and three weeks prior to this on 24 September 1996 it was 1.7. This indicates that her level of anticoagulation was not adequate and further to this suggests that there was some trouble stabilising the level of Warfarin required."
After reference to the interaction of Warfarin and other medication which she was taking for back pain following the motor vehicle accident in 1993, the letter went on:
"Because of the presence of a prosthetic mitral valve in the heart, Ms Carey-Hazell is at further risk of embolisation. The risk is increased if Warfarin stabilisation is not perfect and the desired range for her INR is now 3.5 to 4.0. In an effort to optimise the control of this, I strongly recommended that the medications she uses for her back pain be made regular and I took steps to institute this management during her admission and followed this up when I reviewed her on 1 November 1996. Nevertheless, she remains at a moderately high risk given the presence of the prosthetic heart valve. It should be noted that this risk is likely to be life long."
23 Getz Bros submission referred to the strokes suffered by Ms Carey-Hazell on 21 March 1997 and 12 June 1997 as appears from her affidavit evidence and the replacement of her mechanical valve by a natural tissue valve on 26 June 1997. Reference was then made to a letter dated 11 October 1997 from Mr Thompson to Ms Carey-Hazell's solicitors, which included the following statements:
"1.1 Karen had complications from her aortic valve surgery including multiple small strokes as a result of blood clots arising in the region of the valve. Eventually the valve had to be replaced.
…
2.1 The reason for the surgery in 1997 was because Karen developed a most unusual complication from her initial valve replacement. The valve developed a coating of blood clot which resulted in recurrent clotting despite vigorous attempts at anti-coagulation. Fragments of the blood clot were breaking off and landing in various parts of her body including the spleen, kidneys and brain. The blood clots to the spleen and kidney were self limiting. One of the blood clots to the brain caused a stroke with interference with her co-ordination and eyesight.
…
5. Karen's life expectancy has been reduced as a result of her mitral valve disease which preceded the mitral valve replacement. The unfortunate and rare complications from the mitral valve replacement, particularly the small strokes which resulted from the blood clots around the valve, may contribute to a shortening of her life expectancy."
The same letter said that Ms Carey-Hazell would require careful long term cardio-vascular monitoring. She required, at the time, potent anticoagulant treatment to prevent any further blood clots on the new natural tissue valve. Inevitably she would be at risk of some complications although her current condition was stabilising and very encouraging.
24 A report on the explanted valve prepared by St Jude Medical was sent to Ms Carey-Hazell on 24 November 1997 by Mr Mark Newman, the Head of the Department of Cardiothoracic Surgery at Sir Charles Gairdner Hospital. In his letter covering that report, which itself was dated September 18, 1997, he said:
"I was sorry to hear that you had not heard the results of your valve tests. I contacted Mr Nicholls who felt that you had been sent a copy of the report. I have retrieved the report from him and include this for your information. Basically I think it states that the valve was basically normal apart from the thrombus that was on it. This amount of thrombus, despite anticoagulation, is quite rare, but has been described before with mechanical valves…."
25 It is to be noted that the St Jude Medical letter forwarded by Mr Newman relied upon examination by Dr Jack L Titus, "an independent pathologist at the St Paul Heart & Lung Centre". According to the letter, fibrinous deposits were observed on the surfaces of both leaflets of the valve and large amounts detected in the recessed pivot areas. Whitish tissue observed on the sewing cuff was normal fibrous tissue indicative of a healing reaction, most of which had been previously removed. Dr Titus concluded that the restriction of leaflet motion was most likely due to deposits of acute fibrin thrombus in the recessed pivot areas. The valve was then cleaned and visually examined under 10x magnification for anomalies on the surfaces of the leaflets and orifices which were found to be unremarkable. It was disassembled for performance testing, including pneumatic functional leakage testing and hydrodynamic functional testing, both of which were said to yield values within specifications and guidelines for normal operation of the heart valve respectively. The St Jude Medical letter went on to say:
"The results of our investigation indicated the mitral insufficiency the patient experienced was due to deposits of acute fibrin thrombus in the recessed pivot areas, which then caused restricted motion of both leaflets. This is supported by the examination performed by Dr Titus. The restriction of the leaflets was not due to an intrinsic valve defect, as supported by testing performed at St Jude Medical Heart Valve Division. The cause of thrombosis remains unknown."
26 Ms Carey-Hazell wrote to Getz Bros on 12 December 1997 expressing concerns about the St Jude Medical letter. In a passage relied upon by Getz Bros, she said:
"I have serious concerns regarding three aspects of the report. The first is that it is my understanding, from both the medical team at the hospital and written reports from my own cardiologist, that the reason the valve was explanted was that it had developed a blood clotting tendency and was causing me to have multiple infarctions and multiple strokes. Specifically the TOE showed that there were three significant blood clots formed and sitting on the valve that could fly off at any time and cause a major stroke. The report by St Jude indicates that the reason the valve was explanted was due to mitral insufficiency. Accordingly it appears that the main body of testing conducted on the valve related to failure of the leaflet to close properly due to the thrombus on the valve, rather than the cause for the valve developing the thrombus and blood clotting tendency.
Secondly, after the valve was removed one of the doctors told myself and my husband that the valve had been almost totally covered with a velvet or grass like growth which was the cause of the clots forming.…"
27 The letter of 12 December 1997, in passages not relied on by Getz Bros, went on to say that one of Ms Carey-Hazell's doctors told her that a possible cause of the growth was that the coating on the valve may have been faulty with tiny holes or dents that provided a hold for platelets which in turn allowed the growth and blood clots to form. He had told her that a fault in the valve was likely because she was still having strokes despite a high level of anticoagulation. She had been cleared of having any blood disorder that would cause a blood clotting tendency. When she had requested the return of the valve her solicitor was told that it had been sent to St Jude Medical and that special equipment would be used to scan the surface of the valve, which equipment was not available in Australia. When her solicitor had requested that the valve be returned to her after the testing was completed he was advised that the valve would be destroyed in the testing process. Ms Carey-Hazell also complained in her letter of the limitation of the surface examination to a 10x magnification. Her pathologist had indicated that to view a single platelet required a magnification of 400x. Given that the problem was the aggregation of platelets it seemed to Ms Carey-Hazell to have been grossly inadequate to have limited the examination to a 10x magnification. It brought into serious question why the valve had to be sent to St Jude Medical at all and why the valve was destroyed when the level of testing necessary could have been done locally with no damage to the valve.
28 Getz Bros also relies on a letter which Ms Carey-Hazell wrote to St Jude Medical, which was exhibited to her affidavit, and which she says was sent on 2 March 1998 although the date does not appear on the exhibit. In that letter she responded to information from St Jude Medical that Dr Titus, who had examined the device, was "only available to answer my questions at your request and then only if you deem the questions to be appropriate". Ms Carey-Hazell raised a question about the independence of Dr Titus given the conditions placed by St Jude Medical on her access to him. She went on:
"Further, I am getting very angry at the treatment I have received from your organisation with regard to this matter. Despite that (sic) fact that clotting problems with the valve have been acknowledged, your organisation provides no warning in your patient literature and once aware of the major clotting problems that I have had your organisation has taken no steps to investigate the cause, save to have provided a second hand report, about which serious questions have arisen. I believe that ensuring patient safety is a much more important issue than legal liability and I think it would be shortsighted to sacrifice all patience (sic) safety in return for limiting your legal liability by failing to investigate fully when an incident occurs."
29 On 11 March 1998, Ms Carey-Hazell was sent a letter from the Medical Devices Section of the Therapeutic Goods Administration. She had written to the Authority about her experience with the artificial heart valve. In the letter, which was apparently received on 18 March 1998 although par 36 of the affidavit refers to 25 March 1998, it was said that because the Therapeutic Goods Administration did not have the opportunity to evaluate the valve which had been removed from Ms Carey-Hazell her correspondence was passed to Professor Cliff Hughes, Chairman of the Therapeutic Devices Evaluation Committee and who was also Head of the Department of Cardio-thoracic Surgery at Royal Prince Alfred Hospital in Sydney.
30 In his letter to the Therapeutic Goods Administration, which was dated 13 February 1998, Professor Hughes said, inter alia:
"Thrombo-embolism is a recognised and not infrequent complication of any mechanical prosthesis used for valve replacement. It is generally accepted that approximately 2 to 5% of patients will have a recognised thrombo-embolic complication each year after cardiac surgery despite optimal anti-coagulation. Such an incidence does not reflect a manufacturing fault on any particular valve type or, indeed, of any particular individual valve. Rather it is a response of blood coming in to contact with artificial substances in the blood stream. The majority of thrombo-emboli in fact come from the sewing ring but a significant number will come from the valve leaflets (or ball) from the hinge mechanisms or from supporting struts.
Warfarin is routinely used as an anti-coagulant in this situation but, despite optimal management of the INR, we still see patients in whom this complication occurs without warning and without reason.
It is not necessary to have pannus or vegetations on the valve for thrombosis to occur. Thrombosis does not necessarily stay adherent to the valve and, in fact, it is for this very reason that the episodes described in Ms Carey-Hazell's letter occurred. Namely small pieces of thrombus broke off from wherever they had formed and lodged in distal organs. Of course, if a patient does develop an infection and then develops vegetations on the valve, these are more likely to produce thrombo-emboli complications. Valve infection is also a recognised complication of any prosthesis, mechanical or biological, placed with the heart. It does not represent a failure of the valve or a fault in its manufacture.
It is also reasonable to expect that a detailed analysis of the valve could fail to show any faults at all and yet thrombosis could occur on any part of the valve.
Of course, once thrombus or fibrin begins to deposit on the valve, it may impinge mobility of the leaflet and cause the valve to leak (regurgitation). The fact that fibrin etc was found in the "recess pivot areas" is not unusual as thrombus tends to occur in areas where there is stasis or turbulent flow such as in recess pivot areas.
In summary, from the information available, I recognise this unfortunate but recognised complication of mechanical prostheses as an accepted, recognised and published complication of any mechanical valve. There is extensive literature on the management of mechanical prostheses, optimal anticoagulation levels and the management of these problems."
31 According to Ms Carey-Hazell's affidavit she was not aware prior to the receipt of that letter on 18 March 1998, nor was she told by any of her doctors, that thromboembolism was a recognised and not infrequent complication of any medical prosthesis used for valve replacement. Nor was she aware or told that it was generally accepted that despite optimal anticoagulation, 2 to 5% of patients each year would have a recognised thromboembolic complication after cardiac surgery. Before that date, she said that she did not know or confidently believe that the St Jude's mechanical heart valve which was used to replace her natural heart valve on 27 June 1996 was defective or not fit for the purpose of replacing her natural mitral valve and providing a permanent, effective, safe and functioning mitral heart valve. She accepted in her evidence that she knew prior to 18 March that she had suffered from thromboembolism as a result of the implantation of the device but did not know that it was caused by the device being defective or not fit for its purpose.
32 Getz Bros contends, however, that the fact that the thromboembolism was a complication of the implantation of the mechanical valve it was made clear in the letters from Doctors Handorf, Thompson and Newman. It was to avoid the symptoms resulting from the complication that Ms Carey-Hazell underwent further surgery to replace the valve. Dr Thompson described the complication as rare and unusual. Professor Hughes' quantification of the complication rate as between 2 to 5% of patients was said to be consistent with that characterisation. His description of the process by which the complication occurs was said to be virtually identical with that which Ms Carey-Hazell gave in her letter of 12 December 1997. There was said to be nothing in the letter she received on 18 March which was new to her.
33 In the circumstances, according to Getz Bros, it was submitted that the action should fail because it was brought outside the three year limitation period set by ss 74J and 75AO of the Act. On that basis, it was said, the appropriate course would be to dismiss her claim as against Getz Bros.