Andrew Arentsen

He is smart and academically very vigorous, but brings a fierce practicality to his practice.

Legal 500 2020

Andrew Arentsen

  • Called in 1995

Clinical Negligence

An experienced Clinical Negligence practitioner conducting work both for Claimants and for Defendant trusts across the full range of claims including injuries caused at birth, negligent surgical procedures and cases of mis-diagnosis and failure to diagnose.

Recent Cases

  • Petra Walker. C suffered catastrophic neurological injury because of the long-term prescription of metoclopramide by several GP’s at her surgery. The Defendant GP’s initially denied liability but later admitted fault for the prescription of the drug between August 2014 to November 2016 and admitted that C had suffered significant neurological injury. C could no longer walk. She struggled to speak and to swallow. She required paid care and assistance and lived in assisted accommodation. The case settled at a JSM in late 2023 for a gross capital valuation of £1.5 million.

 

  • K v Betsi Cadwallader NHS Trust. Represented C who sustained an iatrogenic perforation of the bladder wall during a routine hysterectomy. Liability was in issue as was the extent of the bladder injury and the long-term consequences to C. C continued to suffer bowel and bladder incontinence. She needed further treatment and the assistance of her family and friends. The claim was listed for a trial but settled for over a million pounds at a JSM in 2023 in the weeks preceding the same.

 

  • GT (Deceased). Counsel for C in a tragic case where she lost her young husband to a malignant melanoma. The claim was against the Defendant GP for the failure to diagnose the melanoma at first presentation. Liability was in dispute as was causation. There was conflicting evidence from expert GP’s on the appropriate differential diagnosis, expert dermatologists on the treatment that would have been provided and expert oncologists on the staging of the cancer at first presentation. GT had recently re-trained as a teacher and the claim addressed the speculative success of his new career. The case settled at a JSM in 2023 shortly before the 4 day trial. Settlement was approved in September 2023.

 

  • AJ v The Dudley Group NHS Foundation Trust. Junior Counsel for the Claimant in a cerebral palsy injury sustained at birth as a result of a hypoxic ischaemic event. The liability part of the claim settled at a JSM. The assessment of quantum is ongoing. The claim has a value in excess of £10 million.

 

  • CG v Royal Liverpool University Hospital Trust. Counsel for the Claimant in a claim with the incorrect anastomosis of the ureter to the peritoneum rather than the bladder during a transplant operation. Liability was denied and the claim settled at a JSM for very close to the full value, shortly before the trial date.

 

  • SW (The executor of the estate of DW deceased). Counsel for the Claimant in a claim with the death of a young husband and father. He had no spleen and was inmuno-compromised. The claim was against his GP for failing to diagnose an infection and to refer him to hospital. Liability and causation were both denied. The claim settled for a significant proportion of the full value at a JSM and was approved by HHJ Harrison at the Cardiff County Court.

 

  • L v Nottingham University Hospital NHS Trust. Counsel for the Claimant in a dependency claim where his deceased wife had been admitted to hospital with a pulmonary embolism which was not diagnosed or treated in time. She died in consequence. Limited breaches of duty were admitted and the deceased should have been prescribed enoxaparin but causation was disputed and the evidence of the precise effect of anti-coagulation was controversial. The value of the claim was agreed in the sum of £535,000 and the claim settled for a sum based upon the assessment of the relative risks to both parties. Settlement at JSM.

 

  •  Jones v Betsi Cadwaladr UHB. Counsel for the Claimant where the Defendant had failed to diagnose cancer of the ileal pouch. The Claimant had undergone radical surgery to create the ileal pouch in 1998. The pouch then required regular monitoring but in 2006 the Claimant was allowed to fall out of the Defendant’s surveillance programme. Breach of duty for the same was admitted. As a result there was a delay in diagnosing and then treating the Claimant’s ileal pouch cancer. Had the cancer been identified at an early stage then the pouch could have been surgically removed and treatment would have led to a cure. In consequence of the delay the Claimant had developed secondary lung metastates and his cancer was terminal. The prognosis was that only months remained. The claim included losses to date and losses for the “lost years”. It settled at JSM for a sum of £300,000

 

  • Ridell v South Humberside NHS Trust. Counsel for the Claimant. A 40 year old nurse who developed Cauda Equna which was not diagnosed and treated with the requisite speed causing the Claimant to suffer disabling neurological symptoms. The claim settled for £850k

 

  • John Nicholl v Cardiff & Vale University Health Board. Counsel for the Defendant health board throughout in a claim brought by the Claimant with an allegation of injury following negligent surgery. The claim was pleaded in excess of £1 million. The claim compromised at a joint settlement meeting shortly before the trial date.

 

  • Beryl Luke v Cwm Taf University Health Board. Counsel for the Defendant health board defending a claim for serious injury alleged to have been caused during bowel surgery.

 

  • Susan Selby v Public Health Wales NHS Trust. Counsel for the Defendant trust defending a claim for alleged negligence during breast cancer screening.
View full profile >>

Notable Cases

S v H
Acting as sole counsel for D, in a claim pleaded at circa £5 million. C was a passenger in a car who was aged 15 when he was involved in a catastrophic accident. C now in his early twenties. The claim involved complex and conflicting orthopaedic, neurological and psychiatric evidence on the extent of the injury, C's capacity to litigate the claim and manage any settlement funds and his future career as a mechanic. There were issues of future care and accommodation. The case settled at a JSM in the middle of 2024 for circa £2 million. C retained Leading Counsel.

H v Kronospan
Acted as sole counsel for C who lost his leg when trapped under a pile of MDF boards as he was unloading his lorry. Primary liability admitted but C's contribution remained in dispute. C lost his leg below the knee. He needed a prosthetic foot with a micro-processor. C had been an active man and wished to return to as many of his previous activities as he could. He needed an adapted bungalow. D assured C that he had a job for life but C was struggling to adapt to the return to employment. A JSM took place in December 2023 and the claim settled for £2 million. D retained Leading Counsel throughout.

MJ v Yuasa Ltd
Acted as sole counsel for C, a man who suffered a catastrophic above knee amputation injury when he was crushed by machinery. Liability was in dispute with a focus primarily on contributory negligence. C was eventually fitted with a modern prosthetic foot with a micro-processor. He had not been able to return to work and needed some ongoing care. The case settled at a JSM in 2023 for a capital valuation of £2.5 million. D retained Leading Counsel.

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GH
Counsel for the Claimant who sustained a significant arm injury in an RTA which led to the above elbow amputation of his dominant right arm. The most interesting aspect of the case was the array of prosthetic devices that were available for use and which the Claimant now needed. These were controlled by electrical pulses and allowed the Claimant to undertake dextrous technical work. The claim settled for £2.5 million at a JSM.

MI (A protected party)
Junior counsel in a claim for in excess of £10 million led by Stephen Killalea KC. A young man suffered a severe brain injury. A case manager and professional deputy were appointed but the Claimant remained resistant to any assistance and not involved any external help by the date of trial. The parties settled the case at a joint settlement meeting for £4 million.

DO v DR
Counsel for the Defendant. The Claimant sustained a significant head injury in an RTA which led to serious ongoing problems with concentration, memory and temper. The live issues were the extent of the Claimant’s recovery and his ability to retain his employment and work in the self-employed arena. There were extensive surveillance videos admitted into evidence . Medical evidence was in direct conflict and had to be assessed in connection with occupational records. The claim was pleaded in excess of £1.5 million and settled for a small fraction of that at a JSM.

Edward Thorn v Veolia Ltd
Counsel for the Claimant. A young refuse collector suffered an horrific leg injury when he was run over by the refuse lorry that he was working with. All experts felt that he would be functionally better off if he had a below knee amputation, something the Claimant had fought against. This refusal raised questions as to his likely pattern of work, his likely care needs and the validity of the claim for a prosthetic leg. The case settled at a JSM for more than £1 million.

DK v MOD
Counsel for the Claimant who was a Royal Marine who sustained a serious spinal and intestinal injury when he fell from a rope whilst descending from a helicopter. The Defendant was his employer who admitted partial fault for the accident but alleged that the injuries were also caused by his own negligence. The claim involved complex and conflicting orthopaedic and surgical evidence. The case was listed for trial but settled at a JSM.

JPC (A protected Party through his Litigation Friend LCM) v Paul Watts
Approval before HHJ Harrison sitting as a Deputy High Court Judge. Counsel for the Claimant in an approved settlement. The Claimant sustained catastrophic brain injuries when he was knocked off his bicycle into the path of an oncoming car. The claim resolved for the capital sum of £13.5 million in addition to the Defendant transferring legal title of a bungalow which they had purchased for the Claimant into his name.

W v B (Settlement at JSM)
Counsel for the Claimant in a claim by a young male passenger who sustained serious spinal injuries in a road traffic accident. The Claimant suffered incomplete tetraplegia and was left with restricted mobility and limited motor power. The claim resolved at a JSM for the gross sum of £4.9 million.

Grant v Dawn Meats
Counsel for the Defendant in the Court of Appeal in the hugely significant procedural case involving the effect of a general stay on the requirement to serve a Part 8 Claim Form.

P v The Welsh Ambulance NHS trust. High Court of Justice. Cardiff District Registry
Counsel for the Defendant in a claim brought by a motorcyclist for catastrophic injuries suffered when in collision with an ambulance. The claim was approved at a little under 4 million.

Ridell v South Humberside NHS Trust
Counsel for the Claimant. A 40 year old nurse who developed Cauda Equina which was not diagnosed and treated with the requisite speed causing the Claimant to suffer disabling neurological symptoms. The claim settled for £850k.

Various v Depuy International Limited
Counsel for a number of Claimants in claims for injury arising from the provision of metal on metal hip prostheses.

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If you would like to instruct Andrew Arentsen or would like help or advice in doing so, please call and talk to our excellent clerking team, led by Chief Executive/Director of Clerking, Paul Cray. Our phone number is +44 (0)20 7583 9241. Alternatively, please email us at chambers@farrarsbuilding.co.uk

For more information about our clerking team, please click here for the clerks page.

Appointments & Memberships

  • Chairman of the Welsh Rugby Union Independent Tribunal (2008 – present).
  • Tier 1 Panel Counsel to the Welsh Government for personal injury.
  • Panel Counsel to the British Boxing Board of Control Limited.
  • Panel Counsel to the Australian Rugby Football Union and the Georgia Rugby Football Union for their 2010 and 2012 tours.
  • Company, Commercial and Clinical Negligence tutor on the Cardiff University Bar Vocational course (1999 – 2007).

Education & Qualifications

  • Inns of Court School of Law (1994 – 1995)
  • MA Law 2:1, Corpus Christi College, Cambridge University (1991 – 1994)
  • Cardiff High School (1983 – 1990)

Directory Quotes

Andrew Arentsen is known for his impressive representation of claimants and defendants in spinal, catastrophic and closed head injury litigation. He specialises in claims involving highly complex medical issues, such as neurological, orthopaedic or psychiatric disputes. He is ranked as a Leading Junior in London and Wales for Personal Injury and Clinical Negligence in the leading legal directories.

“Andrew has an amazing way with clients and explains complicated issues in a way that clients, from all walks of life, can understand.”  Legal 500 2025 – London: Clinical Negligence

“He is thorough, practical, and turns paperwork around promptly, and he is excellent on his feet.” Legal 500 – Wales & Chester: Personal Injury

“He is excellent on paper and also on his feet, where his experience and determination to get the right result come to the fore.” Chambers UK 2025

“Andrew is highly experienced in acting for defendants and good on his feet.” Chambers UK 2025

“He is very good with clients.” Chambers UK 2025

“Andrew is personable, very bright and efficient.” Chambers UK 2025

“Andrew Arentsen is a standout name in the set, this year acting for the dog owner in a case, in which liability is disputed, after a financial adviser suffered a tetraplegic injury after falling from a horse, provided by a supervised riding school, which had been scared by a West Highland terrier.” Legal 500 2024

“Andrew is very personable, good with clients, and gives clear sound advice.” Legal 500 2024

“He has an ability to get straight to the crucial matters in a case and will always make a decision rather than leave things up in the air. He commands the respect of judges by nailing the important issues and has excellent client care skills.” Legal 500 2024

“Andrew is a skilled and effective advocate.” Chambers UK 2023

“Andrew is calm, thorough, has a good attention-to-detail. He is thoroughly charming to work with.” Legal 500 2023

“He is eminently sensible and pragmatic in his approach. He has a good personable manner with clients in conference and carries appropriate gravitas in court.” “Absolutely excellent, he produces very high-quality work. He is very thorough and good on his feet in trial.” Chambers UK 2022

“Andrew is a very smart advocate, who is very calm and pragmatic in dealing with complex personal injury claims.” Legal 500 2022

“He gets to the heart of the matter with the minimum of fuss and provides straightforward, no-nonsense advice. He is excellent with clients. I would have no hesitation in recommending him.” Legal 500 2020

“He is efficient and alive to the key points in his cases.” “He has a very approachable and caring manner with clients and offers pragmatic and sensible advice.”

Chambers UK 2021

‘He is smart and academically very vigorous, but brings a fierce practicality to his practice.’

Legal 500 2020

“Calm, pragmatic and approachable.” “He’s very good with clients and is extremely efficient.”
Chambers UK 2019, Personal Injury (London Bar)

He is further recognised for his ability to handle cases involving complex medical evidence. He is also experienced acting for and advising clients in contentious industrial disease claims.

“A very reliable and creative barrister who is an expert in all aspects in the field. His paperwork is timely and thorough, and his advocacy skills are pointed, direct and well considered.” “He’s impressive in court and excellent in cross-examination. He has an eye for detail and is easy to work with.”

Recent work: Acted for a claimant in a high-value claim against a construction company. The claimant had fallen from scaffolding and suffered catastrophic brain injuries as a result.
Chambers UK 2019, Personal Injury (Wales & Chester) 

Continues to act in Wales-focused cases from London. He represents claimants and defendants in a range of catastrophic injury cases, and is noted for his dedication and client-oriented approach.

‘A compelling and fiercely practical advocate.’
Legal 500 2018

Strengths: “He clearly has a great intellect, is very good with clients, is very approachable, and is very good at explaining things in lay language.” “He’s a very hard-working junior, who puts a lot of time into his practice.”
Chambers UK 2017

Has a wealth of experience in noise-induced hearing loss and medical causation. Interviewees have also commented on his expertise in highways trips and slips.

Strengths: “He is very down to earth and has a great manner with clients.”
Chambers UK 2016

‘Refreshingly straight-talking and a formidable presence in the courtroom.’
The Legal 500 2016

“He is a great tactician and is very practical. He will really roll up his sleeves to look at the legal issues.”
Chambers UK 2015

“A specialist in claims where there is complex and often conflicting evidence.”
The Legal 500 2015

The entry notes the ability of Andrew Arentsen to handle numerous high-value damages claims.
Chambers UK 2014

Andrew Arentsen is “a sensible, pragmatic, and highly efficient” barrister whose personal injury practice is predominantly focused on catastrophic brain and spinal injury cases. He recently appeared in Andrew Jones v Ribbons Ltd, a catastrophic injury claim concerning an individual rendered disfigured when he caught his arm in an unguarded machine.
Legal 500 2014

The “fluent, persuasive and personable” Andrew Arentsen heads the group at Civitas Law, which has a national reputation for industrial disease claim.
Chambers UK 2013

The “brilliant” Andrew Arentsen’s honesty is recognised and appreciated by clients, who also value his “effective arguments and performances in court”. He is recommended.
The Legal 500 2013

Solicitors appreciate the “reliable and decisive” Andrew Arentsen who has recently been acting in a case which involved a nuisance and negligence claim against Welsh Water. He is also well known for representing clients in a number of RTAs.
Chambers UK 2012

Andrew Arentsen is “not afraid to make difficult decisions”.
Chambers UK 2011

Sources commend “the sound and practical” Andrew Arentsen for being “extremely approachable but also straight with you – he will tell you if you are going down the wrong route”.
The Legal 500 2011

 

Personal Interests

Andrew is a keen skier and father of 3 teenage children.

Cycled in 2012 from Yosemite to San Francisco as part of the Velindre Cancer Charity Cycle that raised over £500,000 for cancer services at the Velindre Centre in Cardiff. Then persuaded to complete the second Velindre Cancer Charity Cycle from Boston to New York in September 2014 which raised close to £750,000.

Cycled the 2009, 2022 and currently training for the 2023 Etape du Tour, a 120 mile stage of the Tour de France including an ascent of Mont Ventoux.

First class professional rugby player for Richmond, Newport and Glamorgan Wanderers. Cambridge Rugby Union Blue 1993. U18 Welsh schoolboy rugby international.