Case study - Renal foreign body

...After the stent is removed, Mr R suffers a number of urinary tract infections...

  • Date: 28 October 2020


Mr R attends his GP surgery complaining of pain in his lower right groin and blood in his urine. He is referred to a private consultant urologist Mr K and subsequent imaging reveals a 1cm calculus in the right renal pelvis.

Mr K advises surgery involving a flexible ureterorenoscope with laser dissolution of the stone. A discussion of risks and potential complications is conducted and Mr R signs a consent form.

Three weeks later Mr R is admitted to hospital for the procedure, which is performed under general anaesthetic with the guidance of an image intensifier. The renal stone is identified, repositioned and fragmented with a laser. A temporary double pigtail stent is inserted to assist the passage of fragments and avoid ureteric obstruction in the post-operative period.

Post-operative recovery is satisfactory and Mr R is discharged the next day. Two weeks later he returns for removal of the double pigtail stent using a flexible cystoscope under local anaesthetic.

Mr R is reviewed a month later and reports feeling well but a plain abdominal X-ray reveals a small residual calcified fragment in the lower pole of the right kidney measuring approximately 5 x 1mm. Mr K advises that further surgical intervention is not required at this stage given the residual stone is small and Mr R’s seems asymptomatic. Dietary advice is provided in relation to an elevated serum uric acid and urinary oxalate and Mr R is advised to drink plenty of fluids. A further review appointment is arranged.

Over the next few months Mr R suffers a number of urinary tract infections. An ultrasound scan reveals no evidence of the stone in the right kidney and Mr K advises conservative treatment with a long course of antibiotics and further imaging by CT KUB (computed tomography of kidneys, ureters and bladder).

In the meantime Mr R discusses the matter with his GP and requests a second opinion. He is referred to a consultant urologist at another hospital and undergoes a CT KUB, which confirms the presence of a calculus in the right lower pole calyx of the kidney. No other abnormality is seen.

Mr R is advised to undergo repeat surgery to remove the residual stone. Flexible ureteroscopy is undertaken revealing no stone but a small piece of blue coloured plastic material is removed from the urinary tract.

A letter of claim is later received by Mr K alleging clinical negligence in failing to carry out a flexible ureteroscopy with sufficient care to remove the stent intact. It also alleges a failure to devise or follow any procedure for inspection of the stents upon removal to ensure that no residual parts were left in the body prior to closure. This led to Mr K suffering recurrent UTIs and pain over a period of months before the renal foreign body was removed.


MDDUS provides legal support to Mr K and commissions an expert opinion from a consultant urologist. She reviews the patient records and all relevant correspondence and finds no evidence of breach of duty of care in the treatment of Mr R. In the operation to remove the stent there is no record of difficulty and as per normal procedure the stent was examined by both Mr K and the scrub nurse to ensure it was intact.

Given the high manufacturing standards of the silicon rubber stent, the expert considers it highly unlikely it would have fractured. A more likely source of the fragment would be the plastic sheath enclosing the laser fibre.

Degradation in the course of normal use can cause the sheath to break. Sometimes an operating surgeon can recover the tiny pieces but usually they are left to pass spontaneously. The expert opines that failure to identify such a tiny fragment does not represent a breach of duty of care but is a common, non-negligent occurrence.

In regard to causation (consequences of the alleged breach of duty) the urology expert opines that it is extremely unlikely that Mr R’s ongoing UTI was due to the tiny fragment of foreign body extracted from his urinary tract. It is also noted that the patient has continued to experience UTIs following removal of the stone and the foreign body.

MDDUS lawyers send a letter of response denying breach of duty and causation. The case is subsequently dropped.


  • Ensure strict adherence to routine surgical checklists.
  • Equipment failures do occur in operative procedures and do not always constitute negligence.
  • To succeed in a claim for clinical negligence, the claimant must be able to prove causation as well as breach of duty.

This page was correct at the time of publication. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.

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Insight - Secondary is published quarterly and distributed to MDDUS members throughout the UK who work in secondary care. It provides a mix of articles on risk, medico-legal and regulatory matters as well as general features and profiles of interest to our members.
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