Guidance

AAA screening: monitoring waiting times to surgery

Updated 1 October 2024

Waiting times are important standards in the NHS abdominal aortic aneurysm (AAA) screening programme pathway standards. Waiting times standards have been monitored by the national AAA programme team and screening quality assurance service (SQAS) since June 2013. This process has resulted in significant improvement in waiting times for patients to be seen in outpatients. Although there has been some improvement in waiting times for treatment for screen referred patients, national standards have not yet been achieved by all local AAA screening programmes. The monitoring process has also identified the need for production of additional guidance.

1. Current waiting times standards

Screening standard 11: proportion of patients appropriately referred with AAA ≥5.5cm seen by vascular specialist within 2 weeks of their last successful screen.

Thresholds:

• Acceptable: ≥90%
• Achievable: ≥95%

Screening standard 12: proportion of patients appropriately referred with AAA ≥5.5cm, deemed fit for intervention and not declining, operated on by vascular specialist within 8 weeks of their last successful screen.

Thresholds:

• Acceptable: ≥60%
• Achievable: ≥80%

2. Additional guidance

In additional to the 8 weeks wait for treatment, there is a maximum wait of 12 weeks after which further action is required. Any patient waiting over 12 weeks for treatment should be reported to the local screening programme board and the regional SQAS. Unless there is an acceptable reason for delay, this should be investigated by the treatment pathway provider as a screening safety incident in accordance with UKNSC/national screening programmes guidance on managing safety incidents in screening programmes.

3. Standard AAA (most patients)

After clinical assessment at first vascular specialist appointment, the patient is thought likely to be fit for intervention, and booked to follow standard investigation pathway for that institution. Investigation may subsequently show the patient is actually not fit (cardiac or respiratory testing) or unsuitable for conventional open infrarenal AAA repair or endovascular repair (EVAR). Only patients who are inappropriately referred, unsuitable for surgery or decline surgery are excluded from the 8 week standard. All other situations are accounted for by acceptable percentage of 60%.

4. Non-standard AAA (minority of patients)

The patient is thought unlikely to be fit for intervention and booked for non-standard investigation or referred for medical treatment (coronary angioplasty / bypass or chest referral). This may also include referral to a tertiary centre outside of the ‘usual’ screening programme referral pathways. These patients remain in denominator for the 8 weeks standard and are accounted for by acceptable percentage of 60%.

5. Failure to have AAA intervention within 12 weeks

Acceptable reasons for not having surgical repair include:

• medical reasons - undergoing medical treatment for cardiac (angioplasty / bypass), respiratory (incidental lung cancer) or other conditions that would otherwise increase the risks of intervention for AAA
• technical reasons - CTA shows complex AAA (juxtarenal or thoracoabdominal) that either needs more complex treatment (branched or fenestrated stent) or referral to a tertiary centre (referrals to a tertiary centre should continue to be monitored to determine outcomes and to ensure timely management)
• patient factors - patient declines or defers treatment

Unacceptable reasons include:

• delays in investigations
• multi-disciplinary team meetings
• outpatient appointments
• hospital delays including capacity or lack of critical care beds

Any deaths in patients waiting over 8 weeks for surgery should be investigated as a potential serious incident in accordance with UKNSC/national screening programmes guidance on managing safety incidents in screening programme and NHS England’s Serious Incident Framework. There may be an acceptable reason for delay and this should be identified in the initial assessment process.

6. Tracking referrals

For any patient referred, it is the screening provider’s responsibility to track each referral with the receiving trust and ensure they are monitoring any delays in the patient being seen for assessment or subsequent treatment. They should also be aware of all final outcomes for each patient referred. The screening provider should ensure that appropriate systems are in place to support a high quality interface between screening and treatment services. This should include:

• developing joint audit and monitoring processes
• agreeing jointly what failsafe mechanisms are required to ensure safe and timely processes across the whole screening pathway