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You are here: BAILII >> Databases >> Scottish Court of Session Decisions >> Farrer (AP) v Lothian Health Board [1999] ScotCS 93 (31 March 1999) URL: http://www.bailii.org/scot/cases/ScotCS/1999/93.html Cite as: [1999] ScotCS 93

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On 25 July 1992 the pursuer, who was then aged 28, gave birth to her first child, a boy named Jordan, at St. John's Hospital at Howden, Livingston. The baby was delivered by Dr Giwa Osagie, an obstetrician and gynaecologist employed by the defenders, and for whose acts and omissions in the course of his employment with them the defenders are liable. For several months following the birth the pursuer experienced faecal incontinence, believing it to be diarrhoea. On investigation it was found inter alia that her external and internal anal sphincters had been ruptured at the time of the birth and that by the time of the investigation they were beyond repair. On 18 May 1993 the pursuer underwent an operation to form a defunctioning colostomy, which has remained in place since then. It is possible that her anal function may be restored to an acceptable level by means of a form of reconstruction called stimulated gracilis muscle transposition, but it is not necessary for the purposes of this Opinion for me to consider whether she is likely to undergo this operation and, if so, how likely it is to be successful. Nor need I consider further the undoubtedly serious problems experienced by the pursuer since the birth. This is because the parties have agreed by Joint Minute inter alia that in the event of Dr Osagie being found negligent and in the event of the pursuer's loss, injury and damage being found to have been caused by said negligence the damages in the case shall be £50,000, comprising £39,000 for solatium, £7,500 for loss of employability, £2,500 for services and £1,000 for other patrimonial losses. The figure for solatium is an indication of the seriousness of the pursuer's problems. No one who heard her evidence about them, or the way in which she gave her evidence, can have failed to feel sympathy for her.

It is an unfortunate consequence of childbirth that the mother often suffers injury. Nearly every primiparous birth results in at least a minor injury to the soft tissues of the vagina, perineum and vulva. Such injuries often take the form of tears or lacerations (the two expressions are synonymous). It is standard practice for the obstetrician attending the delivery to perform an episiotomy, which is an incision into the perineum to enlarge the vaginal opening. This reduces the likelihood of extensive tearing, but nonetheless serious lacerations can occur, in particular by extension of the episiotomy by tearing through the soft tissues of the perineum towards the anus. Lacerations are graded according to their degree of severity. Of relevance for present purposes is what is called a third-degree perineal laceration. In this instance the skin, mucous membrane and perineal body are torn, and the external anal sphincter is ruptured anteriorly with retraction of its severed ends. A tear which extends up the anterior rectal wall to compromise the internal sphincter is sometimes referred to as a fourth-degree laceration, but the medical witnesses were all, as I understood it, agreed on including this degree of injury in the description of a third-degree tear. It is not in dispute that at the time of giving birth the pursuer suffered ruptures of both the external and internal anal sphincters. The pursuer offers to prove that she had suffered a third-degree perineal tear involving the anal sphincters.

Before turning to the pursuer's pleadings in more detail, I propose to mention certain matters of fact which are not in dispute. By the Joint Minute the parties have agreed that all the relevant general practitioner and hospital records relating to the pursuer are true and accurate. This agreement has an obvious bearing on all statements of fact contained in the records, and I shall consider some of these in due course. Secondly, the parties have agreed on a narrative of fact up to the point of delivery, and it is appropriate that I should repeat that narrative at this stage.

On or about 24 July 1992 the pursuer had passed the full term of her pregnancy by six days. She was admitted to St. John's Hospital on account of reduced foetal movements and increased blood pressure. Until then the pregnancy had been uncomplicated. At about 1000 hours on 25 July 1992 a standard induction of labour was carried out with the use of a prostaglandin pessary. The pursuer became distressed with contractions and at about 1645 was transferred to the labour ward. At 1700 an artificial rupture of the foetal membranes was performed revealing clear liquor, and a foetal scalp electrode was applied. The foetal heart rate was noted to be satisfactory with a reactive trace. At 1705 diamorphine 10 mgs and cyclizine were given for pain relief. At 1815 the pursuer was noted to be very distressed with contractions and an epidural was discussed. At 1820 a further vaginal examination revealed the cervix to be fully effaced and 6 cms dilated but with the head still 1 cm above the spines (just engaged) and in the occiput anterior position with a small caput (oedema of the scalp at the most dependent part of the foetal head) present. At 1915 an epidural was set up for pain relief. During this procedure the foetal scalp electrode stopped working and the foetal heart was therefore checked. The epidural was being done with the pursuer in the sitting position and the midwife noted that the foetal heart dropped to 80 beats per minute. The pursuer was put on her side, the foetal heart electrode reapplied and the foetal heart noted to be satisfactory at 130 beats per minute. A further vaginal examination at 2245 disclosed the head to be at the level of the spines in the occiput anterior position with a slight anterior rim of cervix only. Another vaginal examination at 0030 on 26 July 1992 disclosed the cervix to be fully dilated with the head at the level of the spines and the foetal heart still satisfactory. Epidural top-ups were given at 2125 (on 25 July), 0110 and 0130 (on 26 July). At 0300 the pursuer was distressed with contractions and the vertex still only visible "in the distance". The pursuer was very tired and a doctor informed of the slow progress and her condition. The pursuer was seen by Dr Osagie at about 0330 and underwent a further vaginal examination. He found that the head was 1-2 cms below the spines, "in the ROA [right occiput anterior] position with moulding + but no caput". Dr Osagie advised syntocinon augmentation (a synthetic hormone given intravenously to stimulate uterine contractions) and a forceps delivery. A syntocinon infusion was set up and at 0400 the pursuer was prepared for the forceps delivery. At about 0410 she had bilateral pudendal block analgesia. The first stage of labour had lasted approximately 14 hours and about 4 hours of the second stage of labour had passed when Dr Osagie made the decision to perform a forceps delivery. At 0417 the baby was delivered by Dr Osagie using forceps and aided by a right medio-lateral episiotomy, moderate traction and maternal pushing.

In addition to their agreement on this narrative in the Joint Minute, the parties are agreed on record that following the delivery Dr Osagie repaired the episiotomy. The pleadings on behalf of the pursuer then proceed with the following averments:

Counsel for the pursuer said that the pursuer's case was accordingly that there was a patent wound, capable of being visualised on examination; he described it at one point as "a glaring wound".

There was no dispute that if these averments were proved, Dr Osagie was negligent, as that term was defined in the case of a doctor in Hunter v Hanley 1955 SC 200. Indeed, counsel for the defenders proceeded on the basis that to fail to discover and repair a third-degree perineal tear would be a clear case of negligence. It is important, however, to bear in mind that by definition a third-degree perineal tear involves the skin and other tissues on the surface, and is accordingly patent rather than occult, and that the concession on behalf of the defenders related only to an injury in the form of a laceration such as I have described. I shall return to the question of occult injuries in due course.

At the proof evidence was led on behalf of the pursuer from the pursuer herself and from two expert witnesses, Dr Michael House, a retired obstetrician and gynaecologist, and Mr David Galloway, a consultant surgeon in general and colorectal surgery. Evidence on behalf of the defenders was led from Dr Osagie and from two expert witnesses, Dr John Mills, a consultant obstetrician and gynaecologist, and Mr Ian Finlay, a consultant colorectal surgeon.

Apart from the agreed narrative which I have quoted and the agreed hospital records, the evidence about the delivery came from the pursuer and Dr Osagie. I propose at this stage to discuss the evidence of Dr Osagie. He qualified in medicine in Nigeria and thereafter pursued a career in that country as an obstetrician and gynaecologist. This included a period of several years in a teaching hospital, where he progressed from senior house officer to registrar and then senior registrar. He came to the United Kingdom in January 1998 and worked as a registrar in a hospital in Falkirk before moving in about August 1988 to St. John's Hospital where he worked as a registrar until about February 1993 before moving to his present post in Inverness. At the teaching hospital in Nigeria there was a policy that elective episiotomies were performed on all primiparous patients and on all patients with assisted deliveries, among others. By 1992 he had repaired well over 1,000 episiotomies. In Nigeria he was trained by his superiors in repairing episiotomies and lacerations to the point where he could repair third-degree perineal tears, and as he progressed it fell to him to train his juniors. At the time of the delivery in 1992 it was his practice to perform an elective episiotomy on a primiparous patient where the delivery was to be assisted by forceps. He said that his practice, after delivery, was to examine, firstly, the cervix for any tear. He then inserted a tampon in the vagina to stop any flow of blood from the uterus. He then examined the episiotomy to see how far it had extended up the vagina. He then looked at the vaginal wall to see if there were any lacerations or other damage. He then looked down the episiotomy to the lower end of the vaginal opening, to see whether there had been any extension by tearing of the episiotomy. He looked in particular to the right side of the episiotomy: by this he meant the right side from his point of view. The episiotomy was performed in a position of about 8 o'clock to the vaginal opening, i.e. on the patient's right side, so to look at the right side of the wound from his point of view enabled him to see whether there had been any involvement of the anal sphincters or the rectum. He also performed a digital examination of the rectum. There had been occasions when he had found lacerations involving the anal sphincters or even the rectum. If he saw any such damage, he repaired it with sutures. He said that it was quite easy to see whether an episiotomy had extended to involve the anal sphincters. There was no challenge to or criticism of Dr Osagie's evidence, as I have so far summarised it, so my consideration of the remainder of his evidence proceeds on the basis that he was a thoroughly competent and experienced obstetrician whose normal practice included examining the patient for tears, including third-degree perineal lacerations, and repairing such damage.

Dr Osagie said that he had no specific memory of the pursuer's delivery, and all he could do was reconstruct the event from his own operation note, written shortly thereafter, which was among the hospital records. Given the narrative agreed in the Joint Minute, I need not repeat his reconstruction up to the point of delivery of the baby. Thereafter, according to his note, the placenta and membranes were delivered. He then recorded "intact cervix" and "intact rectum". He explained that this meant that he had examined the patient, following his normal practice, which I have already described, and found no cervical laceration and no injury involving the anal sphincters or rectum that he could detect. He did not detect any damage beyond the episiotomy incision. He then repaired the episiotomy, using chromic catgut. He said that he would tell the patient what he was doing. The pursuer's evidence was that all she could remember after delivery of the baby was being sutured. She did not remember being told by Dr Osagie that he was carrying out an examination. I am not disposed to place any great weight on this. The pursuer herself said that she was very exhausted by that stage, and Dr House said that he would not expect her to know if an inspection had been carried out or not. I see no reason to suppose that she would have been able to make out exactly what Dr Osagie was doing. In any event, she did not remember delivery of the placenta and membranes, which suggests that, quite understandably, her awareness and subsequent recollection were affected by all that was happening to her. Dr Osagie's note does not specifically mention an examination. Dr Mills described Dr Osagie's note as a "quite neatly written and comprehensive report of a forceps delivery", and said that this was what he would have written if he had found no tears apart from the episiotomy. The absence of any mention of an examination in the note does not appear to me to suggest that no examination was carried out. The purpose of the note is to record the obstetrician's procedures and findings, and it is implicit in the recording of these that an examination has been carried out. Nothing in Dr Osagie's reconstruction of what he did, under reference to his normal practice and his note, can in my opinion be relied on as serving to establish that there was a third-degree perineal tear which he failed to detect and accordingly failed to repair. It is therefore necessary to consider whether there is any other evidence which would support the pursuer's case.

After the delivery the pursuer remained in hospital until 30 July 1992. She said that before going home she felt very sore, badly swollen and bruised in the perineal area and could not sit without a rubber ring or an ice pack. The hospital records show "uncomfortable perineum" on 27 and 28 July 1992. Under the heading "Wound" in the records there is an entry "clean and dry" made by a different member of staff on each of 26, 27, 28 and 30 July 1992. For 29 July 1992 the entry is difficult to read but may be "clean bruised". The pursuer said in her evidence that the wound was not examined and it was possible that the information was provided by her when she was asked rather than inspected. I find this difficult to accept, particularly when it was known that she was suffering from discomfort in the perineum. These entries are covered by the Joint Minute, and I must therefore treat them as true and accurate; and in any event they appear to me to be more consistent with an examination having been carried out on each occasion than otherwise. Obviously, if the wound was clean and dry, this is inconsistent with there having been an unrepaired third-degree perineal tear. There are also entries made by the midwife who made home visits on each day from 1 to 4 August 1992, which under the heading "Wound" state either "healing well" or "well healed". Again, the pursuer said that the midwife did not inspect the wound, but just inspected the pad that the pursuer was wearing. Again, the same observations appear to me to be applicable.

As I have said, in the months following the birth the pursuer was suffering from incontinence of faeces, which she believed to be diarrhoea. Although she saw her general practitioner in October 1992, she first made him aware of this problem in March 1993. He examined her and could see swelling around the area of the episiotomy and thought that she should be referred back to the hospital to see a gynaecologist, Dr Farquharson, with a view to easing the swelling.

I require to mention at this point one event in the pursuer's previous medical history. On 10 January 1986 the pursuer was operated upon at the Western General Hospital in Edinburgh to treat a perianal abscess. She had been suffering from pain and tenderness to the left side of the anus. A senior house officer who carried out the operation wrote to her G.P. on her discharge after the operation, stating:

Thereafter the pursuer experienced no further problems in the region of the anus until after the birth in 1992. There must have been some scarring at the site of the abscess and incision, but it is not possible to establish from the evidence led at the proof how extensive the scarring was and whether it was more than superficial.

The pursuer was seen by Dr Farquharson, who wrote to her general practitioner on 23 March 1993:

Mr Rainey, a consultant surgeon, thereafter examined the pursuer. He described what he found as "the most awful anal sphincter injury I have seen for a long time". He continued:

He also said that she was to undergo sphincter mapping, endoanal ultrasound and anorectal physiological studies by his senior registrar, Mr Duthie, whom he described as "a world expert in this field". Mr Duthie reported to Mr Rainey on 3 May 1993. He started by stating:

He then went on to state:

On the basis of these documents, in particular Mr Duthie's report, Dr House expressed the opinion that at the time of delivery the pursuer had suffered a third-degree perineal tear. His reason for saying this was that it was not possible for there to be major disruption of an anal sphincter without there having been a perineal tear. He made this point repeatedly, saying:

He said this was not at all controversial. Sub-clinical minor damage to the anal sphincter was well recognised, but not major disruption without a tear; this was not recognised in obstetric practice. On this basis, he said that there must have been a third-degree perineal laceration, which Dr Osagie missed, either because he did not carry out an examination or because he carried it out in such a way as to miss the injury. On this basis, he expressed the opinion that Dr Osagie was negligent.

As I have already explained, it was not disputed that if there was in fact a third-degree perineal tear, Dr Osagie was negligent. What I require to consider therefore is whether to accept Dr House's evidence that there was such a tear. It amounted to saying that, because the anal sphincters were disrupted, there must have been a tear, despite Dr Osagie's evidence and despite the subsequent records about the condition of the episiotomy wound. An important point, emphasised by both Dr Osagie and Dr Mills, is that where an episiotomy has been performed, any third-degree perineal laceration takes the form of an extension of the episiotomy incision by tearing of the tissues towards the anus. While the tearing would tend towards the midline, it would remain on the side of the midline where the incision had been made. Accordingly, if an incision was made at 8 o'clock, as was Dr Osagie's normal practice, it and any extension of it by tearing would be on the right side of the midline. Dr House, and indeed Mr Galloway, were not asked to relate this to the damage found by Mr Duthie, which was not on the right side. Another theoretical possibility is that, in addition to the episiotomy incision, the pursuer sustained a third-degree perineal laceration to the left side of the midline. I am unable to regard this as more than a theoretical possibility, because it was not explained in the evidence how this could occur if an episiotomy had been performed, and in any event how it could occur without extension by tearing of the episiotomy incision. Dr Osagie said that if there had been a third-degree tear, it would have been obvious to him. He was speaking here about an extension of an episiotomy incision, but this is equally, or even more, applicable to a separate tear. Given Dr Duthie's findings, Dr Osagie said that if the episiotomy was on the right, this made his case.

Dr Mills, who was a very experienced consultant obstetrician and gynaecologist, said that it was possible for sphincters to be damaged without this being apparent. He said that a sphincter could be stretched and damaged without the surface tissues between the vagina and anus being broken. He explained this by reference to the pressure of the baby's head, and also of forceps in an assisted labour, stretching the tissue including the sphincter. Sometimes this was just too much and the sphincter would tear. Mostly he saw this when there had been a more extensive tear into the rectum. Mr Finlay said that there had been cases of internal damage through stretching but with no surface tear. Mr Galloway said that it was not unknown for there to be damage to an anal sphincter without there having been a tear in the vaginal wall. He described this as a bursting injury. It was apparent from the recent literature to which reference was made during the course of evidence that investigative methods are still being developed which are capable of detecting occult injuries of this kind: see, for example, Kamm, Obstetric damage and faecal incontinence, Lancet, 1994, 730. In this, which was a review article, and other articles, there was discussion of the technique of endosonography, which was the technique used on the pursuer by Mr Duthie. There is therefore a substantial body of evidence that occult injuries to the anal sphincters may occur without patent damage in the form of tears, and the body of knowledge about such injuries is growing with the aid of modern investigative techniques. It may be that Dr House, who had retired, was not fully abreast of these matters. In any event, he alone among the experts expressed the views I have quoted to the effect that there must have been a patent third-degree perineal tear because the anal sphincters could not have been damaged without such a tear. I was not impressed by his demeanour when he gave this evidence. He appeared to me to protest too much and to prefer to repeat an assertion rather than seek to justify it. In any event, I reject his evidence on this matter. It does not appear to me to be supported by the available facts relating to the pursuer or by the general body of knowledge about injuries involving the anal sphincters.

I do not think that it is possible to reach with confidence any concluded view as to what had in fact happened to the pursuer. It seems likely, however, as was the opinion of Dr Mills, that the prolonged labour and the forceps-assisted delivery resulted in stretching and crushing of the soft tissues in the relevant area. As I have said, Dr House based his opinion on what could be taken from the documents. Mr Galloway and Dr Mills had carried out their own examinations of the pursuer. Mr Galloway said that he saw gross scarring of perineum in the space between the posterior aspect of the vagina and the anterior aspect of the anus. He said that the whole area was replaced by firm scar tissue. The scarring did not look like a straightforward healed surgical incision, there was much more disorganisation of the skin and uncontrolled damage. He said that this was suggestive of a tear. Mr Finlay, who also examined the pursuer, said that when he saw her the entire area was scarred, all round the front of the perineum, encompassing all of the episiotomy and the lesion which Mr Duthie saw. He said that the whole area was scarred from 9 o'clock to 3 o'clock. Dr Mills thought that the scarring suggested a marked stretching of the tissues, replaced by laxity and scar tissue. Despite Mr Galloway's view, the scarring described by him and Mr Finlay appears to me to be suggestive of a more general disruption of the tissues, of the kind envisaged by Dr Mills, than of a laceration. While the processes may not be fully understood, and were in any event not fully explored in evidence, there is no feature which was found in the various examinations of the pursuer that cannot in my view be explained by reference to mechanisms other than a third-degree perineal tear. It may also be that the tissues affected by the perianal abscess and the operation in 1986 were more susceptible to damage of the kind envisaged by Dr Mills. However that may be, it is sufficient for present purposes that I do not hold it to be established, on the balance of probabilities, that the pursuer had suffered a third-degree perineal tear. The pursuer has accordingly failed to prove negligence on the part of Dr Osagie.

The conclusion I have just reached, that the pursuer has failed to prove that at the time of the delivery she had sustained a third-degree perineal tear and accordingly that she has failed to prove negligence on the part of Dr Osagie, is sufficient to dispose of the action. I should, however, express my view about the question of causation. The submissions of counsel on this matter included some discussion about the formulation of the appropriate test. In the course of this discussion reference was made to Wardlaw v Bonnington Castings Ltd 1956 S.C. (H.L.) 26, McGhee v National Coal Board 1973 SC (HL) 37, Kay's Tutor v Ayrshire & Arran Health Board 1987 SC (HL) 145 and Porter v Strathclyde Regional Council 1991 S.L.T. 446. In the latter case it was held that the appropriate test was whether the pursuer had established that the taking of the desiderated precautions would probably have prevented the accident. Counsel for the pursuer told me, during the course of the discussion, that the parties were agreed that the pursuer must be able to prove that if her anal sphincters had been repaired at the time of the delivery, she would probably have been, on the balance of probabilities, sufficiently continent to avoid the need for a colostomy. Counsel for the defenders made a submission in very similar terms. On my reading of the authorities this is the correct approach. I think it necessary to make this point because at times counsel for the pursuer appeared to suggest that it was enough to establish that there would have been a materially better chance of avoiding the need for a colostomy if the anal sphincters had been repaired at the time of the delivery. As a matter of law this does not appear to me to be sound, because it does not take account of the requirement of proof on the balance of probabilities.

The issue of causation arises in this way. I require to assume for present purposes that the pursuer had suffered a third-degree perineal tear involving the anal sphincters, and that Dr Osagie saw the tear and performed a reasonably competent primary repair of it. That is as much as it is open to me to assume for present purposes. It is necessary now to consider the anatomy of anal sphincters. As I understand it, each anal sphincter consists of a ring of muscle which, when contracted, serves to provide faecal continence. In order for the muscle to contract it is necessary that it should receive an adequate stimulus through the nervous system. The evidence focused on the innervation of the external anal sphincter. Each side of the external anal sphincter is innervated by a branch of the pudendal nerve on that side. The route of this nerve and its branches was not described in detail in the evidence, but as I understand it, it leaves the pelvis some distance from the midline then runs beneath the pelvic floor. The process of childbirth can lead to stretching and crushing of the pudendal nerve, in common with other soft tissues in the region of the pelvic floor. Damage of this kind can result in the slowing of nerve conduction in the distal portion of the pudendal nerve. It is possible with the use of electrodes to measure the pudendal nerve terminal motor latency ("PNTML"). This is expressed in metres per second ("msec"). A normal reading is about 1.8 - 2 msec. A more prolonged PNTML is indicative of a reduced stimulus to the muscle.

In his report to Mr Rainey dated 3 May 1993 Mr Duthie stated:

In a later passage he stated:

As I have said, this report is covered by the terms of the Joint Minute and I must proceed on the basis that the passages I have quoted are true and accurate.

The principal evidence about this issue came from Mr Galloway and Mr Finlay. While each of these witnesses had an impressive range of relevant experience, Mr Finlay appeared to me to be the more knowledgeable because, while the main emphasis of Mr Galloway's work was in pure colorectal surgery, principally in patients with cancer, and he had not published any article on anal sphincter damage or pudendal nerve neuropathy, Mr Finlay had a special interest in the effects of childbirth on anal function.

There was some discussion in the evidence of both these witnesses about what could be taken from Mr Duthie's report about the state of the pudendal nerve on the left side. Mr Finlay said that on the balance of probabilities, it was likely that the left pudendal nerve would also have a prolonged PNTML, given the conduction time on the right, and Mr Galloway said that pudendal nerve damage is more commonly bilateral rather than unilateral and that the nerve on the left side was more likely to be abnormal than normal. Counsel for the pursuer attempted to submit, somewhat faintly, at one point that there was insufficient evidence that there was in fact damage to the pudendal nerve on the left side, but he went on to accept that it would be difficult to resist the proposition that there was some damage. Given that the damage to the soft tissues on the left side was greater than on the right, and indeed that the major defect in the external anal sphincter was on the left side, it seems to me to be likely that even if there had been primary repair of the sphincter the PNTML of the pudendal nerve on that side, if measurable, would have been found to be significantly prolonged. I proceed therefore on the basis that the pudendal nerve damage was bilateral.

The expert witnesses each referred to articles in learned journals. It appeared to be common ground between them, and was consistent with these articles, that faecal incontinence can be experienced by a significant number of women who have suffered third-degree perineal tears, notwithstanding primary repair of the disrupted anal sphincters. For example, in Poen and others, Third-degree obstetric perineal tear: long-term clinical and functional results after primary repair, British Journal of Surgery 1998, 85, 1433, it was concluded inter alia that anal incontinence prevails in 40% of women five years after primary repair of a third-degree perineal rupture. In the same article it is stated:

Mr Galloway was inclined to place more emphasis on the restoration of the mechanical integrity of the sphincter, and regarded pudendal nerve damage as a secondary feature. But, as Mr Finlay pointed out, an adequate nerve supply is required to stimulate a mechanically intact sphincter in order to achieve continence. In an article by Sangwan and others, Unilateral Pudendal Neuropathy: Impact on Outcome of Anal Sphincter Repair, Dis Colon Rectum, June 1996, 686, it was concluded inter alia that both pudendal nerves must be intact to achieve normal continence after sphincter repair. Patients with unilateral pudendal neuropathy were more likely to have poor than to have good postoperative function. While this article was concerned with unilateral neuropathy, bilateral pudendal neuropathy would a fortiori be likely to result in poor postoperative function. A number of articles had statistics about the outcomes found in groups of patients. Sangwan and others, op cit, in particular gave PNTML figures for each of the patients in the group discussed in the article. PNTML readings were discussed in a number of other articles. Mr Duthie's PNTML reading on the pursuer's right side was greater than that for any of the patients in the group discussed in the article by Sangwan and others, and neither in this nor in any other article was it stated that a patient with a PNTML reading this high, even unilateral, had been found to have an acceptable degree of faecal continence.

The literature appears to me to provide no support for Mr Galloway's approach, which was to concentrate on the mechanical repair of the anal sphincter. On the contrary, the literature appears to me to establish that, even if the pudendal neuropathy was confined to the pursuer's right side, and even more so if, as was likely, there was significant neuropathy also on the left side, the pursuer would have been unlikely to experience an acceptable degree of faecal continence. Moreover, as Mr Finlay was at pains to emphasise, the pursuer had suffered both severe damage to the sphincter muscle itself and also severe damage to the nerve supply. The literature shows that even where the nerve supply is not significantly impaired, anal function is still inadequate in a substantial proportion of women whose external anal sphincters have been ruptured, notwithstanding primary repair. Mr Finlay said that, although the reasons for this were not yet fully understood, it might be that although the integrity of the sphincter was restored, the muscle nevertheless lost its power to contract.

Mr Galloway said that his view was that if the muscle ring of the pursuer's external anal sphincter had been restored by repair at the time of delivery, even with the nerve damage that was present, she would have had a chance of a good result, and he would have been amazed if she had gone on to require a colostomy. He went on to express this chance in terms of a 50%-60% likelihood of a good result, and said that on the balance of probabilities the pursuer would have been able to regain a reasonable function. Mr Finlay, on the other hand, said that on the balance of probabilities there was a well under 50% chance that the pursuer would have been made continent. In addition to the matters I have already discussed, he pointed to the pursuer's evidence about the diarrhoea from which she had suffered in the period before the colostomy operation. He said that this was indicative of her having liquid rather than solid stool, which required firmer muscle tone. He also pointed to the findings of poor anal sensation, which added to the difficulty in achieving a satisfactory outcome.

Weighing the competing views of the expert witnesses as best I can, I prefer the evidence of Mr Finlay. For the reasons given in the foregoing discussion, Mr Finlay's approach appears to me to be more soundly based on the facts and on the literature than does Mr Galloway's. I am accordingly not persuaded that the pursuer has proved on a balance of probabilities that had Dr Osagie carried out a primary repair of inter alia the disrupted external anal sphincter she would have been likely to achieve a level of faecal continence sufficient to avoid the need for a colostomy. The damage to the sphincter itself was very serious. This alone would have a material effect on the outcome, though the state of the evidence does not allow me to state this more precisely. What appears to me to be of greater evidential significance, because of the availability of Mr Duthie's findings, is the evidence of serious damage to the right pudendal nerve and the likelihood that the left pudendal nerve had also suffered significant damage. As I have already discussed, this damage in itself would have been likely to lead to a poor result even if the mechanical repair had achieved an acceptable result. The pursuer has accordingly, in my view, failed to discharge the burden of proof on this issue also.

For the reasons I have given I shall therefore sustain the second and third pleas-in-law for the defenders, repel the pleas-in-law for the pursuer, and grant decree of absolvitor.