Wright Estate of v Accident Compensation Corporation

THE DISTRICT COURT AT WELLINGTON [2014] NZACC 348 UNDER The Accident Compensation Act 2001 IN THE MATTER OF an appeal pursuant to section 149 of the Act (Appeal ACR 702/12) BETWEEN ESTATE OF DONALD WRIGHT Appellant AND ACCIDENT COMPENSATION CORPORATION Respondent Hearing: 24 October 2014 Appearances: Ms Larissa Wright (daughter) for appellant Mr J Coates for respondent Judgment: 19 December 2014 RESERVED JUDGMENT OF JUDGE D A ONGLEY [1] Mr Wright had an operation on 4 September 2009. The operation was an anterior bowel resection via a midline laparotomy. It followed a complication of diverticulitis. He had a history of diverticular disease, treated by abscess drainage in November 2006 with ten further admissions for treatment of pancreatitis and diverticular disease up to the time of the bowel operation in 2009. [2] After the laparotomy in 2009, Mr Wright suffered abdominal pain and declining health. He had a further operation in September 201 1 to repair an incisional hernia. He died on 27 February 2013 at the age of 50. [3] ACC did not accept a treatment injury claim for incisional hernia caused by the bowel resection. Mr Wright applied to review the Corporation's decision but the decision was confirmed by a Reviewer on 14 October 2012. This appeal lies from the Reviewer's decision. [4] For the review hearing, Mr Wright provided a statement in which he said that he was a reasonably fit person before his operation. He had been working as a car dismantler and recycler and after that as a firewood merchant. Both jobs demanding fitness and strength. He weighed about 110 kg before the operation and had given up smoking for about three months. [5] Mr Wright understood that the operation wound was stapled rather than stitched, with the result that the staples parted over a period of about 48 hours after the operation. He understood that the wound had been closed by a hospital registrar and that the surgeon, Mr Frank Frizelle, was surprised that it had been stapled. He believed that the stapling, and a lack of surgical matting or mesh were factors that caused post-operative complications. [6] The treatment injury claim was lodged on 6 December 2010. The claim was certified by the appellant's GP. The injury was described as an anterior incisional hernia. Laparotomy surgery [7] Mr Frizelle recorded the laparotomy procedure as "anterior resection of sigmoid and upper rectum with a stapled colo rectal anastomosis. Inflammatory mass in sigmoid - No intra-operative complications". Mr Frizelle on 31 January 201 1 reported: Mr Wright suffers from obesity and is a smoker. He also has had problems with cannabinoids and benzodiazepines and he has psychiatric conditions, possibly bipolar disorder, personality disorder and at times has been recognized as being aggressive and difficult. This seems well supported by the literature in his notes. Mr Wright's surgery was complicated however he continued to have abdominal pain. He has not surprisingly developed a divarication of abdominal wall with a hernia. There is little evidence that this is actually the aetiology of his pain as his ongoing issues of pain have existed for some time now. He has had a number of colonoscopies and scans since then, none of which have revealed any other abnormality. The incisional hernia has developed following his surgery and no doubt a result of the surgery complicated by the effects of his size and smoking habit. [8] On 18 April 2011, colorectal surgeon Mr T W Eglinton wrote to ACC. He recorded that Mr Wright had a history of diverticulitis with previous diverticular disease and abscess formation. In addition he had bipolar disorder, pancreatitis, obesity, chronic abdominal pain and was a previous smoker. After summarising some of the hospital records, he said: In summary a personal injury of incisional hernia did occur in the context of treatment of diverticular disease with anterior resection. The occurrence of a wound infection as documented would increase the likelihood of this occurring. In the context of colorectal surgery where appropriate prophylactic antibiotics have been given such as in the present case the incidence of wound infection should be less than 10%. Development of an incisional hernia is neither a necessary part of or ordinary consequence of the treatment provided. Mr Innes' advice to the Corporation [9] The Corporation sought independent advice from general surgeon Mr D B Innes. On 23 April 2011 Mr Innes advised the Corporation that the hernia was in the umbilical region. That advice was later found to be incorrect. Of relevance to the question of wound infection Mr Innes said: On 4.09.2009 Prof Frizelle performed an anterior resection of the sigmoid and upper rectum with a stapled colorectal anastomosis to restore continuity. Mass closure of the abdominal wall was performed, probably with nylon suture although this is not recorded in the op. note. There is no record of gross contamination of the wound at the operation, the patient was not diabetic at that time, and appropriate antibiotics were given. Although the patient had sepsis at about 8 days after his op., CT scan showed a small juxta anastomotic collection and there was CXR and sputum evidence of significant pneumonia to explain this. There is nothing in the file to suggest a significant wound infection. The first record of a hernia post-operatively is during an admission on 12.06.2010 ... [10] Under "Treatment factors in formation of hernia" Mr Innes stated he could not identify any. He did not identify an incisional hernia and did not provide an opinion whether such a hernia would have been an ordinary consequence. He considered that a paraumbilical hernia (which he thought this was) would not be a consequence of surgery at all. He added a comment that the incidence of incisional hernia after an operation through a long midline incision would be around 5% to 15% and that Mr Wright would fit into the upper end of this range because he was significantly over weight and a smoker. [1 1] Mr Innes did not give a direct answer to the question whether the hernia was an ordinary consequence of treatment. He did not know that it was an incisional hernia. He wrote: Without examining the patient I cannot be sure whether he has an umbilical or incisional hernia. This might be considered academic and irrelevant but In my opinion a true paraumbilical hernia is not a consequence of surgery and hence not a Treatment Injury. Mr Innes did not offer an opinion as to whether Mr Wright's incisional hernia was an ordinary consequence of treatment. His opinion was obtained before the nature of the hernia was identified at subsequent surgery by Mr Ward. Mr Innes was not asked to consider his opinion in the light of Mr Ward's findings. Dr Welch's advice to the Corporation [12] Dr Lorraine Welch is a general practitioner with specialist interest in obstetrics and gynaecology, and engaged as a medical advisor to the Corporation. She furnished a treatment injury report to the Corporation on 11 May 2011. At that time she was unable to establish that Mr Wright had a new physical injury by way of an incisional hernia. She explained that an incisional hernia is the result of surgical incision and its subsequent scar tissue failing to attain adequate tensile strength in a timely manner, leaving a gap or weak spot in the abdominal wall through which structures normally confined to the abdominal cavity can protrude. [13] On the information then available to her, Dr Welch considered that the hernia was pre-existing and was not an incisional hernia, even though her report noted that Mr Eglinton and Mr Frizelle both described the hernia as an incisional hernia. She adopted the uncertainty expressed by Mr Innes because the imaging reports and other records did not describe a new hernia. [14] Dr Welch's opinion resulted in a decision by ACC on 16 May 2011 declining the claim. The decision letter explaining the reason for refusal was not produced, but the accompanying Treatment Injury Report was produced. That report traversed the question of identifying the hernia as incisional or paraumbilical, and concluded that the hernia was probably pre-existing. The report concluded: ACC is unable to grant cover for this claim on the basis that the hernia existed prior to surgery on 4 September 2009 and so therefore is not caused by treatment; accordingly this claim is declined for cover. Mr Ward's repair of the hernia [15] The fact that the hernia was incisional was identified when, on 27 September 2011, Mr Malcolm Ward performed surgery after Mr Wright had presented with a two day history of abdominal pain and vomiting with associated severe constipation. The operation was described as "Sublay mesh repair midline incisional hernia". Mr Ward describe the hernia as a "longstanding incisional hernia complicating a left sided bowel resection for diverticular disease in 2009". [16] Mr Frizelle advised in a letter on 24 May 2012 that that the imaging taken before Mr Ward's operation showed quite clearly that the umbilical hernia had been repaired, and the new hernia repaired by Mr Ward was at a distinct site away from the umbilical hernia. Mr Eglinton also confirmed that the umbilical hernia was separate from the (later) incisional hernia. [17] Dr Welch furnished a second Treatment Injury Centre Medical Advice Response dated 31 May 2012. Dr Welch referred to Mr Frizelle's letter of 24 May stating that the new hernia was at a distinct site away from the earlier hernia repair. Dr Welch referred to the radiology which confirmed that Mr Wright had a pre- existing umbilical hernia before his surgery on 4 September 2009. She said that it was not at all clear whether the opinions were discussing the same hernia. She noted that the claim related to the first hernia, not any later diagnosed new or recurrent hernia. She thought that it remained unclear whether he had only a pre- existing primary ventral abdominal wall umbilical hernia, that has maybe increased in size over time, or whether, as suggested by Mr Frizelle, there was also a second new hernia which is incisional and unrelated to Mr Wright's pre-existing para umbilical tissue defect. [18] Dr Welch's opinion catalogued various studies that showed the incidence of incisional hernia. She began by referring to the radiology and treatment records, but she was unable to accurately date a CT scan which suggested that there was still a paraumbilical hernia. She wrote: ... it is possible that the original paraumbilical hernia may have been repaired and now recurred. Having read Professor Frizelle's letter and considered the images it is no longer clear to me that Professor Frizelle, Mr Innes, and myself are all discussing the same hernia - the paraumbilical hernia diagnosed by imaging on 16/10/2008. However I note that this claim appears to have been lodged for the first hernia not any later diagnosed new / recurrent hernia. Professor Frizelle's letter of 24 April 2012 and the images raise the possibility that ACC may be missing some relevant medical information. It would assist please if Professor Frizelle could clarify the following: [19] Mr Frizelle answered some of those question in a letter of 5 July 2012 in which he said: 4. The most recent images suggest that Mr Wright's original para-umbilical hernia had been repaired and he has a hernia elsewhere. That was and still is my opinion and is what I have said previously. I have provided such documentation to Mr Wright's lawyers saying this as well. That is what I told his lawyer. My opinion has not changed. This has been reviewed both at our Multi-Disciplinary Meeting and also by Mr Malcolm Ward and Mr Tim Eglinton, (both surgeons) both of whom agree with this 5. You have asked what is the most likely substantial cause for the incisional hernia in Mr Wright's case. The most likely cause is that he has had previous surgery in the presence of sepsis. If he has not had the surgery he would not have a hernia. There is no one cause for these, there s a combination of causes that align and cause this problem. No one element in itself will be the underlying cause. This is too simplest a view (though often attempted to be used by lawyers). The etiological factor however relates to the fact that he had surgery in the first place for diverticular disease, secondly that he has sepsis, thirdly that he has chronic cough and fourthly that he is overweight. I could go on but you must understand what I am saying by now. [20] In this letter Mr Frizelle confirmed that the umbilical hernia had been repaired at the time of the laparotomy that he had performed in 2009. He pointed out that "it is impossible to undertake a full length abdominal incision in the midline and close the abdomen without closing the hernia". This was confirmed by Mr Ward on 9 July 2012. Mr Ward wrote "I have no doubt that the problem I was dealing with was an incisional hernia resultant on previous laparotomy, and not related to his previous umbilical hernia." He explained his reasons for that finding. [21] Finally, in a Treatment Injury Report on 23 July 2012, radiologist Dr Michael Nowitz advised that after repair of the paraumbilical hernia an epigastric hernia developed progressively from a midline defect under the surgical incision wound over a period from 15 September 2009 to 27 September 2011. This midline defect was first seen in the post-operative scan on 15 September 2009. It then increased in size with the development of an epigastric hernia containing small bowel and mesenteric vessels. By September 2011 contained a portion of the transverse colon and had increased in size to 7.5 cm by 13.5 cm. [22] It is now clear from the evidence overall that the hernia that caused such trouble to Mr Wright after his laparotomy in 2009 was an incisional hernia and it was a consequence of the operation performed by Mr Frizelle. The incisional hernia was caused by the operation and by Mr Wright's underlying health factors, including his weight, his history of smoking and his medical background. [23] Mr Wright was represented at that stage by Mr Bell who wrote to Mr Frizelle asking for a further opinion. Mr Frizelle replied: Unfortunately I am not willing to have anything further to do with this patient, or any further questions regarding him, because of his threatened physical actions towards myself and my colleagues. Treatment injury [24] Treatment injury is defined in s 32 of the Act as follows: 32 Treatment injury (1) Treatment injury means personal injury that is - (a) Suffered by a person (i) Seeking treatment from 1 or more registered health professionals; or ii) Receiving treatment from, or at the direction of, 1 or more registered health professionals; or (ifi) (not applicable) (b) Caused by treatment; and (c) Not a necessary part or ordinary consequence of the treatment, taking into account all the circumstances of treatment, including (i) The person's underlying health condition at the time of the treatment; and (ii) The clinical knowledge at the time of the treatment. (2) Treatment injury does not include the following kinds of personal injury (a) Personal injury that is wholly or substantially caused by a person's underlying health condition: (b) Personal injury that is solely attributable to a resource allocation decision: (c) Personal injury that is a result of a person unreasonably withholding or delaying their consent to undergo treatment. (3) The fact that treatment did not achieve a desired result does not, of itself, constitute a treatment injury. . .. [25] A personal injury is not a treatment injury if the personal injury was a necessary part or ordinary consequence of treatment (section 32(1)(c)). The question in this appeal is whether the hernia was an ordinary consequence. That is to say an anticipated kind of outcome for this particular patient. [26] Mr Wright had a complex medical background. He had a greater risk of developing an incisional hernia than the average risk for a person of his age. It was recorded that his medical background pre-surgery included chronic non-specific abdominal pain, diverticulitis, bipolar affective disorder, appendectomy, use of cannabis and tobacco, obesity, dysuria, and obstructive respiratory disease. Before his laparotomy, a left inguinal hernia had been found on 9 January 2007 and an umbilical hernia on 12 December 2008. The incisional hernia which is the subject of this claim was at a different site from the umbilical hernia. Mr Wright's belief [27] The appeal case was presented by Mr Wright's daughter Larissa Wright. She repeated a concern that her father had always had about inadequate closure of the laparotomy wound. In her written submission she stated: After the operation there was no surgical matting which contributed to the staples tearing and causing an incisional hernia. It was left for so long that the bell adhesives itself to the bladder then perforated between the bell and the bladder so the content of the bell and bladder fluids mixed together causing sepses. I remember my sisters having a debate with the nurses in regards to my father's treatment as this was brought to their attention long before the problem was fixed to my knowledge it was not the surgeon that did not put the matting in he left the last of the procedure to his register as I believe he may not have been fully qualified or experienced enough to do so. [28] That echoed evidence that Mr Wright had given at the review hearing, when he said [ required the 2009 operation because I suffered from diverticulitis which was left so it became chronic. That caused polyps to burst leading to a fistula in the section between the bowel and the bladder. I became infected and sepsis set in. On 4 September 2009 I was operated on by Professor Frank Frizelle. I had to undergo an anterior resection for my diverticulitis. I was operated on in the presence of sepsis. After the operation it turned out that my stomach had been stapled together, rather than stitched. I was left with a very large and long scar and the staples started failing and tearing apart from between 24 and 48 hours after the operation. Risk factors [29] There is evidence concerning the incidence of incisional hernia following midline incision. Mr Innes advised that the incidence of incisional hernia after an operation through long midline incision would be around 5% to 15%. He said that Mr Wright would fit into the upper end because he was overweight and a smoker. But Mr Innes did not examine or interview Mr Wright and he did not know that the hernia was incisional. It was believed at that time that it was a paraumbilical hernia. [30] Mr Eglinton advised that the occurrence of a wound infection would increase the chance of an incisional hernia occurring. The incidence of wound infection should be less than 10% in colorectal surgery with appropriate prophylactic antibiotics. Whether wound infection was a cause of this hernia is not clear from the material presented. Mr Eglinton considered that development of an incisional hernia is neither a necessary part of nor an ordinary consequence of the treatment provided to Mr Wright. That opinion provides the main support for the appellant's case. Neither Mr Ward nor Mr Frizelle offered an opinion whether the hernia was an ordinary consequence of the laparotomy having regard to Mr Wright's underlying health condition. [31] In her review decision, the Reviewer summarised Dr Welch's references to the risk of incisional hernia. Dr Welch said incisional hernias were a "relatively frequent secondary surgical event" and that medical literature suggested personal factors played a part in the development of such hernias. She referred to various studies, mentioned in the Reviewer's decision: . Laparotomy wound failure is "closer to 11%" (Franz): . Incisional hernias complicate approximately 10-15% of abdominal incisional closures (Veljkovic, 2010): . For midline laparotomy wounds such as Mr Wright's, primary incisional hernias occurred in 11-20% of patients (Luijendijk): . For vertical midline incisions, incisional hernias were reported in between 5% and 15% of patients (O'Dwyer). Post-operative care [32] Prof Frizelle had summarised the causes of the incisional hernia, as being related to the fact that Mr Wright had surgery in the first place for diverticular disease, secondly that he had sepsis, thirdly that he had chronic cough and fourthly that he was overweight. [33] At the appeal hearing, Ms Wright referred to the fact that her father had stopped smoking three months before surgery and was a fit man. The family understood that the laparotomy wound had been stapled rather than sutured, and that the closing had been done by a Registrar without colorectal surgical experience. The Court is not in a position to find whether such failings occurred or whether there was a treatment failure relevant to the occurrence of the hernia. Adequacy of post-operative care was not mentioned by the medical professionals whose opinions were introduced in evidence at the review. There is no medical comment that stopping smoking three months before the operation would have reduced the risk factor for incisional hernia, even if it may have reduced other risk factors. [34] Failure of proper care resulting in an unanticipated outcome was not a focus of the Corporation's investigation of treatment injury. The expert evidence is mainly directed to inherent risk factors, or the incidence of incisional hernia following midline laparotomy. The Court cannot reach conclusions on the ground that the wound was not properly closed without medical evidence to that effect. The medical narrative does refer to the wound being stapled, but there is no medical comment that stapling was the wrong procedure. [35] Dr Welch explained that medical research has not identified treatment factors that can be applied or modified in order to avoid incisional hernias. She stated: In Mr Wright's case, from the records viewed, I have been unable to identify any technical aspect of his surgery that has likely largely caused any incisional hernia. [36] Failure of proper care is not a ground in itself for treatment injury cover within the wording of section 32, but it is a basis in appropriate cases for assessment of an adverse consequence as being not an ordinary consequence of treatment. Although the family is concerned that there were deficiencies in treatment there has been no medical evidence that would require the Corporation cause an investigation on the basis that an untoward consequence of treatment was caused by medical error rather than inherent risk. Therefore in this case, there is no support for an untoward consequence caused by medical error. Personal risk factors [37] Dr Welch wrote a further treatment injury advice on 31 May 2012 before the review hearing. She set out relevant conclusions from the literature (italicised) and said: Because incisional hernias are not uncommon for many decades medical science has endeavoured to identify potentially modifiable treatment factors which are likely causally implicated in their development. Despite lengthy and ongoing evaluation of surgical technical matters (e.g. suture selection, type of fascia) closure, ratio of suture to incision length, postoperative interventions such as symptomatic control of vomiting and cough) it has not been possible to consistently attribute the weakness in a surgical incision to treatment factors other than deep surgical site wound infection and a few medications. Medical research indicates that adjusting technical factors such as suture material, suture tension, wound suture length ratios has had little impact on the rate of hernia formation over the last 40 years. In Mr Wright's case, from the records viewed, I have been unable to identify any technical aspect of his surgery that has likely largely caused any incisional hernia. There was no post operative surgical site infection involving the site which later developed the hernia. Increasingly medical knowledge indicates that pervasive connective tissue co-morbidity has a significant influence on the development of primary and recurrent herniation in adults. We know pervasive connective tissue co-morbidity, related to acquired and heritable factors, has a significant influence on the development of primary and recurrent herniation in the adult (Read 2007) Collagen deposition, maturation, and subsequent remodelling are essential to the wound's functional integrity. A defective connective tissue metabolism resulting in reduced quality and amount of collagen is an important factor for hernia formation (in Nyphus & Condon's Hernia) It is the pathological changes in collagen that set the stage for the development of a hernia. (Bendavid 2004) Collagen is the main structural component of the abdominal wall, accounting for more than 80% of the abdominal fascia. Imbalance in collagen synthesis and breakdown is thought to weaken tissues and predispose to hernia formation. Mr Wright's pre-2009 inguinal and umbilical hernias raises the possibility that he has an innate personal pre-disposition to hernias Another possibility also exists in his case as the contemporaneous medical records confirm that at the time of his 2009 surgery Mr Wright was heavy cigarette and marijuana smoker. Smoking, as a potent activator of collagenase activity, stimulates collagen breakdown in the rectus sheath and transversalis fascia increasing hernia formation up to three-fold Heniford) Any incisional hernia Mr Wright may have has likely developed because his surgical incision has failed to heal I attain adequate tensile strength leaving a weak spot or gap in his abdominal wall through which structures normally confined to the abdominal cavity could protrude. In Mr Wright's case, from the information available, I am unable to identify any treatment factors which are likely implicated in the development of an incisional hernia. Currently there is no evidence available indicating that his healing response was adversely influenced by any specific aspects of his treatment. However his smoking habit is very likely to be very relevant. [38] In answer to the question whether the development, of the hernia should be considered an ordinary consequence of the treatment taking into account patient related factors, Dr Welch wrote: Overall incisional hernias are a relatively frequent secondary surgical event. The frequency with which they are identified following surgery varies with the length of follow-up and the modality used for diagnosis Prospective studies find that the true rate of laparotomy wound failure is closer to 1 1% ... (Franz) Incisional hernias remain a frequent secondary surgical event, complicating approximately 10% to 15% of abdominal incisional closures (Veljkovic, 2010) With respect to midline laparotomy wounds such as Mr Wright's Incisional hernia is a frequent complication of abdominal surgery. In prospective studies with sufficient follow-up, primary incisional hernia occurred in 11 to 20 percent of patients who had undergone laparotomy (Luijendijk) Incisional hernia is a frequent complication of abdominal wall closure with a reported incidence of between 5% and 15% following vertical midline incisions at one-year follow-up. (O'Dwyer) The above percentages are general and pertain to groups/populations. However current medical knowledge indicates a hernia in Mr Wright's particular circumstances [is] something [that] could have reasonably been expected to occur because 1. At the time of his 04/09/2009 bowel resection Mr Wright was a current heavy, daily tobacco and marijuana user. Smoking is a potent activator of collagenase activity and stimulates collagen breakdown in the rectus sheath and transversalis fascia (abdominal wall) increasing the likelihood of hernia formation 2. BMI at time of surgery - while this is not explicitly documented in Mr Wright's case his weight was recorded as 110 kg and he described as 'morbidly obese" in the operation record. "Obese" is generally defined as a BMI > 30. The term morbidly obese equates to a BMI that is even higher than 30. A BMI over 30 at the time of surgery is associated with an increased likelihood of a later incisional hernia (Park, Veljkovic). 3. History of antecedent inguinal (January 2007) and umbilical (November 2008) hernias before surgery 04/09/2009 4. The (necessary) anatomical placement of his surgical incision ~ the abdominal midline is a naturally occurring area of anatomical weakness. Incisional hernias of the ventral abdominal wall following a midline laparotomy incision are common. In Mr Wright's case the particular personal factors listed above mean that he was more likely than most to develop an incisional hernia following his 04/09/2009 bowel excision. [39] Dr Welch was mistaken about Mr Wright's smoking at the time of surgery. He had reduced his heavy smoking three months before the operation. He described himself before that as a chain smoker. He continued to smoke cannabis, but not tobacco. It might seem unlikely that the health consequences of Mr Wright's heavy smoking would have changed much in three months, however there is no expert evidence on that point. Section 32 considerations 40] Section 32 refers to a "necessary part or ordinary consequence" of treatment. In this case the incisional hernia was not a necessary part of the surgery. The question is whether it was an ordinary consequence. The Act does not further define what is not an ordinary consequence. [41] The leading authority is McEnteer v ACC [2010] NZCA 126. That case concerned a question whether the ordinary consequence of treatment was to be considered at a point before surgery began or at a later point when the nature of a patient's condition became apparent during the course of the treatment. The patient underwent neurosurgery for a subarachnoid haemorrhage caused by an aneurism. In the course of the surgery, the aneurism was found to be adhering to another artery raising a serious risk of rupture, which in fact occurred during dissection of the aneurism. As a consequence of the rupture and proper steps taken to control it, the patient suffered a degree of cognitive impairment. The Court of Appeal said: [13] Mr Gorringe for the appellant argued for a prospective approach. He submitted that the assessment of what constitutes a necessary part or ordinary consequence of treatment is to be made in terms of what is anticipated to happen in the course of the treatment (ie before it actually begins). In the present case, the surgeon knew that certain steps would have to be taken in the course of treatment, including the temporary clipping of arteries. Cover for injuries arising out of those steps would be excluded. But it was not known that the aneurysm would rupture and that that occurrence would necessitate longer clipping that would normally be required. It was this unanticipated development in the course of treatment that caused the appellant's injuries, so that there was cover. [42] The Court held that there was no legislative reason to require the underlying health of the patient to be assessed at a point before treatment. Therefore an ordinary consequence of treatment is to be assessed in light of the underlying health of the patient, even if the health problem is discovered during the course of the treatment. Concerning the alternative of a prospective assessment of likely consequences, and noting comments made by Dobson J in the High Court, the judgment continued: [18] It is artificial because it requires that an attempt be made to assess what medical professionals might reasonably anticipate to be a necessary part or ordinary consequence of particular treatment in the abstract rather than on the basis of what actually emerges during the course of treatment. Dobson J recorded that Mr Radich argued in the High Court that Mr Gorringe's approach required an "abstracted expectation of the 'average outcome' or 'norm' for the medical procedures of that type". Dobson J accepted that there was nothing in the provisions to suggest such an abstracted consideration. We agree with that. In the present case, before he operation began and the precise nature and location of the aneurysm was known, the surgeon could not predict with assurance the exact reatment required or the most likely outcome. Rather, he was faced with performing surgery with a range of possible risks attached to it depending upon what he found in the course of performing it. ... [20] We consider that s 32(1)(c) requires an analysis that is rooted in the facts of the particular case - what was the injury suffered? Was it suffered in the course of the treatment undertaken? Was that injury a necessary part or ordinary consequence of that treatment? The third question in particular requires expert opinion, but not expert opinion in the abstract; rather, it requires expert opinion reflecting what actually occurred. [43] There is an absence in this case of expert opinion reflecting what actually occurred. The decision in McEnteer guards against deciding the question of ordinary consequence on the basis of general outcomes of treatment, although in this case there is little else to go on. In light of McEnteer, the Corporation's investigation should have more actively sought opinions from treating specialists about what actually happened. The investigation was to some extent derailed by the debate about whether this was an incisional hernia and not a paraumbilical hernia. Once that was established the enquiry was not adequately directed to obtaining expert opinion whether Mr Wright's hernia was an ordinary consequence of his surgery. [44] In Porter [2010] NZACC 104, Judge Barber considered the need for an analysis rooted in the facts of the case. He said: [42] It is put for ACC that, first, the words "ordinary consequence" are not used in the Act in such a way as to be interchangeable with "regular" or "usual" as in a "regular consequence" or "usual consequence". I can accept that distinction. Second, concentration on the words alone, without reference to the rest of the subsection, deflects attention from the need to link the interpretation of the words, and the requirement that all of the circumstances of the treatment be taken into account, with specific emphasis on a person's underlying health condition and the state of clinical knowledge at the time of the treatment. That seems a valid approach. [43] I can accept that comparing the words of s 32(1)(c) in the way the Reviewer did might suggest a kind of probability analysis where consequence X is more or less likely from treatment Y. However, a percentage assessment is not required, nor is it appropriate to make a probability assessment of the kind which applied under the previous medical misadventure/medical mishap provisions. [44] I agree with Mr Hunt that the necessary evaluation is whether the injury is an ordinary consequence having regard to all of the circumstances of his treatment, i.e. any relevant circumstance can be taken into account. Mandatory consideration is to be given to the person's underlying health condition and the state of clinical knowledge at the time of treatment. [45] On this basis, the question is not whether there is evidence to show that hernias of this type are an ordinary, regular, or usual outcome for people with Crohn's disease. The question is whether hernias were an ordinary consequence of the treatment the Respondent had, taking into account all the circumstances of his treatment, his underlying health condition, and the state of clinical knowledge at that time. [45] In White [2013] NZACC 189 Judge Spiller allowed an appeal and decided that an incisional hernia following laparotomy was not an ordinary consequence of treatment. Medical evidence in that case put the risk factor as high as 15-20% or "very high" in the case of BMI of 40 with a predominant abdominal obesity. The treatment and consequent injury were remarkably similar to the present case, but in that case there was expert medical opinion that the incisional hernia was not an ordinary consequence of treatment. There is no such expert evidence in the present case, despite enquiries having been made by the Corporation. [46] There is an onus on the appellant, in the sense that it has to be shown on the basis of expert evidence that the injury was not an ordinary consequence of treatment. The Corporation has a primary obligation to conduct a proper investigation, but once it has done so, the claim depends on evidence obtained in the investigation or evidence that the appellant is otherwise able to provide. The facts of this case invite consideration of whether the Corporation properly discharged its obligation to properly investigate the treatment injury claim. Submissions [47] Mr Coates submitted that both Mr Frizelle and Mr Innes agreed with Dr Welch's assessment that Mr Wright's underlying health conditions increased the likelihood that he would suffer from a hernia. He submitted that the only expert who has expressly concluded that this was not an ordinary consequence of treatment was Mr Eglington, but that Mr Eglinton neither specified the likelihood of a hernia developing in the general population nor commented at all on the factors personal to Mr Wright. Mr Coates submitted that the weight of evidence is that Mr Wright's hernia was an ordinary consequence of his treatment, having regard to all the circumstances of the treatment including his underlying health condition at the time of treatment. [48] The weight of evidence is that the incisional hernia may have had multiple causes but a substantial and effective cause was the midline incision in the laparotomy treatment. The incision was a necessary part of the laparotomy. The injury itself was clearly not a necessary part of treatment. The question therefore is whether it was an ordinary consequence of the treatment that Mr Wright received, that is to say both the laparotomy and the post-operative care. [49] A troubling aspect of this appeal is that Mr Wright claimed that there was inadequate closing of the wound, or inadequate post-operative treatment, but the Corporation's investigation did not address that question. Its enquiry was taken up with the question of causation and incidence of post-operative hernias. Although there is no medical opinion to support inadequate wound closing, the medical information is largely silent, referring only incidentally to the post-operative infection. [50] The appellant's case is that Mr Wright was reasonably healthy, had stopped smoking three months before his surgery and was overweight but not excessively overweight. Therefore, the appellant says that the ordinary consequence of his laparotomy would have been a healing wound without developing an incisional hernia. Mr Wright at the review hearing gave his own explanation of sepsis exacerbated by medical failure in closing the wound, but that was not supported by medical evidence. [51] The family has consistently maintained that the wound closure or care of the wound post-surgery was inadequate and that there were medical failures that were not a necessary part of treatment. The question of medical error is not supported by any of the medical opinions, but that may be because the question has not been asked directly. There are some incidental comments concerning closure of the wound and the occurrence of post-operative infection. Mr Eglinton referred to "wound infection as documented" but Mr Innes stated that the "patient had sepsis at about 8 days after his op" but that there was "nothing in the file to suggest a significant wound infection". Whether wound infection (if it occurred) was relevant to the site at which the incisional hernia occurred was not explained. Underlying health condition [52] Dr Welch referred to smoking as a potent activator of collagenase activity and to medical literature that associates reduced collagen with wound failure and herniation. She considered that Mr Wright's earlier hernias "raised the possibility" that he had an innate personal pre-disposition to hernia formation. Dr Welch was in error in stating that Mr Wright was a current heavy, daily tobacco user at the time of surgery. However he had been so until three months before and was still smoking cannabis. [53] Relevant features of Mr Wright's known health condition were sepsis, obesity and his medical history. Unproved but likely health conditions were the collagenase effect of heavy smoking of tobacco and cannabis and possible innate pre-disposition to hernia. [54] Underlying health condition is relevant as a matter to be taken into account under s 32(1)(c) and in relation to the exclusion under s 32(2)(a) of personal injury that is wholly or substantially caused by a person's underlying health condition. The "wholly or substantially" test has been the subject of numerous judgments in the context of s 26(2) of the Act which excludes cover for injury caused wholly or substantially by a gradual process, disease, or infection. That is a causation test, whereas s 32(2)(a) addresses the expectation of consequences rather than causation. [55] In the present case, I find that there is insufficient evidence that Mr Wright's underlying health condition was substantially the cause of his incisional hernia which was caused by the laparotomy in 2009. The question is whether the hernia was not an ordinary consequence of treatment taking account of his underlying health conditions. Risk factors [56] Unfortunately, much of the earlier investigation was directed to the question whether the hernia was incisional or umbilical. The main risk factors that were identified were smoking and excess weight described as morbid obesity. In the literature, these factors are associated with the incidence of adverse outcomes in numbers of laparotomies. Statistics of wound infection or incisional hernias do not indicate what factors actually caused the poor outcomes. In the present case it is not possible to say that the hernia was an ordinary consequence because of degradation of collagen from heavy smoking or from the combination of smoking and obesity. All that can be said is that patients with those features have shown a higher incidence of incisional hernia. [57] The Court of Appeal in McEnteer emphasised the need for expert opinion reflecting what actually occurred, rather than expert opinion in the abstract. McEnteer was a case in which a chain of events that occurred during surgery caused brain damage. The Court of Appeal decided that the time at which to consider ordinary consequence was the time when untoward events occurred during the necessary part of treatment. The Court directed the enquiry to expert opinion reflecting what actually occurred, an analysis rooted in the facts of the particular case. This case is of course quite different in that there was no untoward occurrence during the surgery, but the principle in McEnteer applies. The treatment consisted of the surgical procedure and post-operative care, of which there is little mention in the evidence, although Mr Wright had been vocal in his criticism of post-operative care. [58] The Corporation's investigation was never really completed. In Dr Welch's second report to the Corporation on 31 May 2012, she remained uncertain whether the injury was an incisional hernia. That was before the very clear advice by Mr Ward and Dr Nowitz that the hernia was an incisional hernia. Dr Welch recommended some further questions to be put to Mr Frizelle, but his answers in his letter of 5 July 2012 did not provide any really helpful information. There was no further report from Dr Welch. In the result, the opinions of Mr Innes and Dr Welch were given without either doctor accepting that Mr Wright suffered an incisional hernia. [59] Dr Welch's statistical information is fairly comprehensive. Interestingly it is very similar to information provided by Dr Moughan referred to by Judge Spiller in the White judgment. In that case it was thought to be outweighed by the views of the medical specialists who had examined Mr White. In this present case there is no cogent information of that kind. Mr Ward did not provide an opinion about ordinary consequence of treatment, and Mr Frizelle declined to assist further after he had given his opinion concerning causation. He did not address the "ordinary consequence" question. [60] Under s 32 there is no objective yardstick to measure ordinary or not ordinary consequences. Bearing in mind the observations of the Court of Appeal in McEnteer, an opinion that is based entirely on broad risk factors is likely to be inadequate to address the questions that the Reviewer or the Court must decide. Reliable information concerning the incidence of incisional hernias following laparotomy in the case of other patients with Mr Wright's negative health factors is of course relevant, but the information needs to be evaluated by a suitably qualified practitioner or specialist with knowledge of the full circumstances of the treatment and outcomes. Given that the exercise is not likely to be straightforward, an expert opinion needs to be carefully explained. [61] In this case, the investigation was wound up before such an opinion could be obtained. Dr Welch provided an opinion based on medical literature, and without being sure that the appellant had an incisional hernia. Mr Innes did not know that Mr Wright had an incisional hernia. Both opinions therefore have to be regarded as theoretical. Mr Ward, who treated the incisional hernia, was not asked for an opinion as to whether it was an ordinary consequence of the appellant's laparotomy. Mr Frizelle elected not to provide any further opinion. Mr Eglinton thought that the hernia was not an ordinary consequence of treatment, but did not embark on an explanation. [62] Furthermore, the Corporation's decision was not based on a conclusion of ordinary consequences of treatment, but on the now discredited view that the hernia was not caused by treatment. The grounds for the Corporation's decision have been shown to be wrong and the argument at review stage was based on different grounds, that do not address the question of what actually happened. [63] Mr Wright, and now his family, pursued the question of post-operative care on the basis that the incisional hernia was not an ordinary consequence, but was one that occurred because of failures. While the Corporation has relied on grounds that were not part of its decision in May 2011, it seems to have rather ignored the appellant's grounds and has not directed any enquiry into the claim of failure of post-operative care. [64] For the foregoing reason this appeal is allowed. The result is that the Corporation will be required to make a further decision with a focus on what actually happened, rather than on the general incidence of incisional hernias following laparotomy, although that may well be an aspect of formulating an opinion. The enquiry will have to consider the appellant's claim that there was a failure of proper wound closure or adequate post-operative care. Those are matters that will probably have to be derived from the treatment records, but with particular reference to the appellant's claims mentioned in paragraphs [27] and [28] above. [65] The appellant is now the estate of the deceased. The appellant was not professionally represented at the hearing of the appellant and is not entitled to costs, but is entitled to payment of expenses of conducting the appeal. That may be agreed between the parties, failing which they may file memoranda for the matter to be determined by the Court. Judge D A Ongley District Court Judge