Analysis of negligence claims after carotid artery interventions over 20 years in Sweden.

Background: In recent years, as new strategies have been developed, there has been a reduction of invasive interventions for prevention or treatment of ischaemic cerebral events. Furthermore, surgical treatment has been centralized to major vascular centra.

Aim: This study analyzed registered malpractice claims to the insurance during two decades. Treatment policies (more pharmacological treatment, less intervention for asymptomatic carotid artery disease) and claiming patterns changed (Introduction of Patient Safety Act 2011).

Material and methods: During a 20-year period (2000-2019), 184 malpractice claims related to invasive treatment of carotid artery cerebral circulatory disorders were registered in the files of the Swedish National Insurance Company. These were analyzed in two 10-year cohorts regarding the indication for intervention, the intervention itself, and the sufferers' reasons motivating the claims and the final decision as judged by the Insurance Company's medical and juridical experts.

Results: The claim rate was on a 1% level (of all carotid artery interventions), no difference between the two decades. Between the first and second decade, claims concerning intervention for asymptomatic carotid artery disease decreased with 26%. In 51% of the claims, the damage was considered avoidable and the claimants were compensated for their financial losses. Motor nerve lesions were compensated for in 78% and stroke in 40%. Thrombolysis as a claimed procedure increased from 2 to 10 between the periods.

Conclusion: During a 20-year period, negligence claims after interventions for asymptomatic carotid artery disease or manifest carotid artery cerebral ischemia were stable at a 1% level of all interventions. The compensation rate was around 50%. Dominating injuries to be claimed and compensated for were perioperative motor cranial nerve injuries and postoperative stroke. Despite changes in treatment policy, the claim and compensation rate were stable.