What Happened in M.L. v Van Der Merwe?
The defendant was a specialist gynaecologist and obstetrician who performed laparoscopic surgery on the plaintiff on 19 April 2016.
During the procedure, cystic masses around the plaintiff's ovaries were removed together with her right ovary. The surgery was complicated by the presence of extensive adhesions in her abdominal cavity.
It was common cause that the plaintiff subsequently developed a perforation in the dome of her bladder. The injury required further surgery on 4 May 2016.
The central question was not whether the bladder injury existed. It plainly did. The dispute was how the injury had occurred and whether it was caused by negligent surgical conduct.
Laparoscopic Surgery
The plaintiff underwent laparoscopic surgery for ovarian cystic masses and removal of her right ovary.
Bladder Perforation
A perforation developed in the dome of the bladder and required subsequent surgical repair.
Negligence
The Court had to determine whether the injury resulted from a failure to exercise the required standard of surgical care.
Medical Experts
Competing specialist evidence concerning anatomy, adhesions, surgical technique and thermal energy became central to the case.
What Did the Plaintiff Allege?
The plaintiff's case was advanced in contract and, alternatively, delict.
In broad terms, she alleged that the defendant had failed to exercise the degree of professional skill and care reasonably expected of a specialist surgeon in his position.
Her pleadings developed over the course of the litigation, but several important allegations concerning the surgery ultimately remained for determination.
Use of the LigaSure Device
It was alleged that the defendant used the LigaSure Maryland improperly when dissecting adhesions and failed to appreciate the potential for thermal injury to surrounding structures.
Identification of Anatomy
The plaintiff alleged that the defendant failed properly to identify the structures and organs involved when separating adhesions.
Protection of the Bladder
It was alleged that insufficient care was taken to avoid damaging the bladder while operating in the presence of extensive adhesions.
Conversion to Open Surgery
The plaintiff initially alleged that the defendant should have abandoned the laparoscopic approach and converted to a laparotomy because of the adhesions encountered.
Why Were the Adhesions Important?
Adhesions are bands of scar tissue that can cause organs and tissues that would ordinarily be separate to become attached to one another.
In this case, the plaintiff had previously undergone significant abdominal and gynaecological surgery, including a hysterectomy. Extensive adhesions were present when the defendant performed the laparoscopic procedure.
The adhesions increased the technical complexity of the surgery because structures such as the bowel, abdominal wall and bladder had to be carefully identified and separated.
The presence of difficult anatomy or extensive adhesions may increase the risk of complications. The legal enquiry remains whether the practitioner acted with the skill and care reasonably expected in those circumstances.
Why Did the LigaSure Device Become So Important?
Much of the expert dispute concerned the instrument used by the defendant when performing adhesiolysis, meaning the surgical separation of adhesions.
The plaintiff's original particulars referred to a LigaSure Atlas. Her pleadings were later amended to identify the instrument as a LigaSure Maryland.
This distinction mattered because the characteristics of the particular device, including the way in which it applies energy and the extent of thermal spread into surrounding tissue, were relevant to whether it could have caused the bladder injury alleged.
In medical negligence litigation, it may not be enough to refer generally to an “electrosurgical device”. The Court may need precise evidence about the actual instrument used, how it operates and the extent of the risks associated with it.
The Role of Expert Medical Evidence
Medical negligence cases frequently involve issues that fall outside ordinary judicial knowledge.
Expert witnesses therefore assist the Court in understanding the applicable medical standards, anatomy, accepted surgical techniques, possible mechanisms of injury and whether a practitioner's conduct departed from the standard expected of a reasonably competent practitioner.
Importantly, however, the Court is not required simply to choose the opinion of one expert over another.
Expert opinions must be based on established facts and supported by logical reasoning.
Standard of Care
Specialists can assist the Court in determining what a reasonably competent practitioner would have done in the circumstances.
Anatomy
Anatomical evidence can establish whether a proposed mechanism of injury is medically and physically plausible.
Medical Devices
Experts may explain how a particular surgical device operates and the extent of its recognised thermal or mechanical effects.
Causation
Medical opinion can assist in determining whether the alleged negligent conduct probably caused the injury complained of.
Should the Surgeon Have Converted to Open Surgery?
One of the plaintiff's allegations was that the defendant should have converted the laparoscopic procedure to a laparotomy, or open abdominal surgery, because of the extent and complexity of the adhesions.
This allegation did not survive the expert evidence.
By the end of the trial, the plaintiff's experts agreed with the defendant's experts that the decision not to convert to open surgery was not inappropriate in the circumstances, having regard to the number, location and nature of the adhesions and the defendant's experience.
The Court therefore did not find negligence based on the decision to continue laparoscopically. The real remaining dispute concerned the manner in which the LigaSure device had been used and whether that use caused the bladder injury.
Anatomical Distance Became Critical
The plaintiff's experts ultimately advanced the view that the defendant had caused thermal damage to the bladder while performing one of the adhesiolysis procedures.
The defendant and his experts disputed this mechanism.
Their evidence was that the dome of the bladder, where the eventual perforation occurred, was approximately 6 to 8 centimetres away from the relevant area of thermal dissection visible in the photographic evidence.
One of the plaintiff's experts conceded that the bladder dome was some distance away from the area of visible thermal damage.
The evidence referred to thermal spread from the LigaSure into surrounding tissue over a distance measured in millimetres, not centimetres. No evidence established that thermal energy from the instrument could travel the 6 to 8 centimetres required by the plaintiff's proposed mechanism of injury.
Could the Bladder Have Been Pulled Into the LigaSure?
Another theory was that the bladder tissue might have been drawn into the jaws of the LigaSure and directly burnt during the adhesiolysis.
The Court considered the expert evidence concerning what type of injury would be expected if this had occurred.
The defendant's evidence was that such direct involvement of the bladder would have caused a significant injury to the lower portion of the bladder and would probably have resulted in an almost immediate failure of the bladder.
That was inconsistent with the location of the eventual perforation in the bladder dome and with the plaintiff's clinical course, in which the significant complication became apparent considerably later.
It was not enough to show that the defendant used a heat-generating instrument and that the plaintiff later developed a bladder injury. The plaintiff still had to establish a probable medical mechanism connecting the use of that instrument to the particular injury that occurred.
Would a Different Cautery Device Have Been Safer?
The choice of surgical instrument was also examined in detail.
The plaintiff's case suggested that the use of the LigaSure device in the circumstances was inappropriate because of the risk of thermal injury.
However, the evidence did not establish that alternative monopolar or bipolar cautery would necessarily have reduced that risk.
The expert evidence ultimately recognised that alternative cautery methods could themselves cause thermal damage and were not demonstrated to have been a safer option in the circumstances.
A court does not determine negligence merely by identifying another technique that might conceivably have been used. The question is whether the technique actually selected fell below the standard reasonably expected of a competent practitioner at the time.
A Surgical Complication Is Not Automatically Medical Negligence
This is one of the most important principles illustrated by the judgment.
There was no dispute that the plaintiff sustained a bladder perforation following the surgery and that she required further treatment.
But the existence of an injury after medical treatment does not itself prove that the practitioner was negligent.
Medicine involves recognised risks and complications, some of which can occur even where appropriate care has been exercised.
A Poor Outcome
The fact that treatment had an unfortunate outcome does not automatically establish a breach of the required standard of care.
A Known Complication
The occurrence of a recognised complication does not, without more, establish negligent treatment.
Breach of Standard
The claimant must prove that the practitioner's conduct fell below the standard reasonably expected in the circumstances.
Causation
The claimant must also establish that the negligent conduct probably caused the injury for which damages are claimed.
How Do Courts Assess Medical Negligence?
Medical practitioners are not expected to guarantee successful treatment. The legal question is whether the practitioner exercised the degree of skill and care reasonably expected of a practitioner in the same field and circumstances.
In technically complex medical negligence litigation, that enquiry often requires the Court to consider several interconnected questions.
What Was the Appropriate Standard?
The Court considers what could reasonably have been expected from a competent practitioner in the defendant's position.
Did the Practitioner Depart From It?
The evidence must establish a negligent act or omission, rather than merely an unfortunate medical outcome.
What Actually Caused the Injury?
The mechanism of injury may need to be established through clinical records, operative photographs and expert evidence.
Was the Negligence Causally Connected?
Even where some aspect of treatment is criticised, liability requires proof that the negligent conduct probably caused the harm being claimed.
Why Were the Surgical Photographs So Important?
The case demonstrates the potential importance of contemporaneous medical evidence.
Photographs taken during the operation allowed the experts and the Court to examine the location of adhesions, the areas in which thermal dissection had occurred and the relationship between those areas and the bladder.
This evidence was particularly important when testing the plaintiff's proposed mechanism of injury against the actual anatomy visible during surgery.
Medical negligence cases can turn on more than competing recollections. Operative notes, photographs, scans, hospital records, pathology results and other contemporaneous evidence may provide an objective basis against which expert opinions can be tested.
Courts Do Not Simply Count the Experts
A medical negligence case is not decided according to which side calls the greatest number of specialists.
Expert evidence must be evaluated for its reasoning, factual foundation and consistency with the objective evidence.
Where an expert theory depends on a mechanism that is anatomically or scientifically improbable, the Court is entitled to reject that theory even though it is advanced by a qualified medical practitioner.
The purpose of expert evidence is to assist the Court with matters requiring specialist knowledge. The ultimate decision remains with the Court, which must determine whether the opinion is logically supported by the facts and medical evidence.
What About the Plaintiff's Post-Operative Treatment?
The plaintiff's original claim also contained allegations concerning the defendant's conduct after the initial operation, including complaints relating to her subsequent pain and diagnosis.
However, aspects of these allegations were later removed from the amended particulars of claim.
The decisive issue at trial ultimately centred on whether the defendant had negligently caused the bladder injury during the laparoscopic procedure itself.
This illustrates another important litigation principle: the Court determines the case ultimately pleaded and proved, not every possible criticism that may have arisen during the patient's treatment history.
Why Did the Medical Negligence Claim Fail?
After considering the factual evidence, surgical photographs and competing expert opinions, the Court was not satisfied that the plaintiff had established negligence on a balance of probabilities.
The theory that the relevant use of the LigaSure had thermally injured the dome of the bladder was inconsistent with the anatomical distance demonstrated by the evidence.
The alternative theory that bladder tissue had been drawn directly into the instrument was also inconsistent with the expected location and timing of such an injury.
In addition, the plaintiff's experts ultimately accepted that the defendant's decision not to convert the operation to open surgery was not inappropriate.
The Court concluded that the plaintiff had failed to prove that the defendant did not exercise the skill and care reasonably required of a competent practitioner in his position. The medical negligence claim therefore failed.
Why Does This Judgment Matter?
The judgment provides a useful illustration of how South African courts approach technically complex medical negligence disputes.
Three aspects are particularly important.
Surgical Judgment Must Be Assessed in Context
The reasonableness of a surgeon's decisions must be assessed against the circumstances encountered during the procedure, rather than solely through hindsight.
The Specific Instrument Matters
Device-specific evidence may be crucial where negligence is alleged to have resulted from thermal spread or the operation of specialised surgical equipment.
Anatomy Can Decide the Case
The location of an injury and the physical distance between anatomical structures can undermine an otherwise plausible theory of causation.
Reasoning Matters More Than Assertion
Expert conclusions must be tested against objective facts, scientific evidence and the logical plausibility of the proposed mechanism of injury.
What Must Be Investigated in a Surgical Negligence Claim?
A patient who suffers a complication following surgery may understandably want to know whether something went wrong. Determining whether that complication resulted from negligence usually requires a detailed investigation.
Obtain the Medical Records
Hospital records, operative reports, nursing notes, scans, pathology results and follow-up records may all be relevant.
Identify the Actual Injury
The nature, location, timing and consequences of the injury must be properly established.
Determine the Applicable Standard of Care
Independent specialist evidence may be required to determine what a reasonably competent practitioner should have done.
Establish a Breach
It must be shown that the treatment actually fell below the required professional standard.
Prove Causation and Damages
The negligent conduct must probably have caused the injury, and the resulting financial and non-financial losses must then be established.
When Does a Complication Become a Negligence Claim?
There is no universal answer. The fact that a recognised complication occurred does not automatically exclude negligence, just as the fact that a patient suffered a serious injury does not automatically prove it.
The correct enquiry is whether the complication occurred despite reasonable medical care or whether it probably resulted from a practitioner failing to meet the legally required standard.
Medical negligence law does not compensate patients simply because treatment had an unfortunate outcome. A successful claim requires evidence establishing negligence, causation and resulting damages.
The Key Takeaway
M.L. v Van Der Merwe demonstrates why medical negligence cases often depend heavily on detailed expert and scientific evidence.
The plaintiff suffered a genuine and serious complication. However, the Court had to determine a different question: whether the complication had probably been caused by negligent treatment.
On the evidence presented, the proposed mechanism involving the LigaSure device could not satisfactorily account for the location of the bladder injury. The criticism that the surgeon should have converted to open surgery also fell away during the expert evidence.
The claim therefore failed because negligence and the necessary causal connection had not been established on a balance of probabilities.
If a serious complication occurs following surgery, the question should not simply be whether the outcome was unexpected. The medical records and appropriate specialist evidence must be assessed to determine whether the treatment fell below the required standard and whether that failure caused the injury.
Concerned That a Medical Injury May Have Been Preventable?
Danel Campbell Attorneys assists clients with personal injury and medical negligence matters. Where a surgical complication, delayed diagnosis or other adverse medical outcome is suspected to have resulted from negligent treatment, the medical records and appropriate expert evidence can be assessed to determine whether a viable claim exists.
Explore Personal Injury & Medical Negligence Services →This article provides general legal information and commentary on M.L. v Van Der Merwe (5560/2019) [2025] ZAWCHC 88, judgment delivered on 7 March 2025, and does not constitute legal or medical advice. Medical negligence claims are highly fact-specific and generally require consideration of the complete medical records and appropriate expert evidence. A complication or adverse medical outcome does not by itself establish negligence. Legal advice should be obtained in relation to a specific matter.