0115 966 7955 Today's Opening Times 10:00 - 20:00 (BST)

Abdominal Aortic Aneurysm Ultrasound Screening Programme

Published: Last Edited:

Disclaimer: This essay has been submitted by a student. This is not an example of the work written by our professional essay writers. You can view samples of our professional work here.

Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of UK Essays.

Susmi Suresh

Role of the National Abdominal Aortic Aneurysm Ultrasound Screening Programme in Improving Health Outcomes: a systematic review

Abstract

Background: Abdominal Aortic Aneurysm (AAA) is one of the common conditions that affect men aged 65 and older. Described as a 'ticking bomb'(1), rupture of such an aneurysm results in fatal bleeding and death. Early detection allows appropriate treatment to be given to patients as an effort to reduce mortality rates. The National Abdominal Aortic Aneurysm Screening programme, an initiative of Public Health England, offers screening to men in the prevalence group by following its objective of reducing mortality rates of preventable illnesses(2). Ultrasonography is the chosen imaging modality due to its high sensitivity and specificity(3). The aim of this study is to examine current literature on AAA and to understand whether screening programmes are effective enough to reduce mortality rates of AAA. Quality of life (QoL) as a health outcome will also be examined and evidence analysed, to see whether screening programmes affect patients' quality of life.

Method: A thorough search of prominent databases was carried out and the search-results underwent application of inclusion and exclusion criteria developed for this review. Four major randomised controlled trials were identified. Following data extraction, quality assessment was carried out using the CASP tool. Risk of bias was checked using the Cochrane's tool for assessing risk of bias. All of these ensured a valid conclusion to be drawn. 

Results: The four chosen RCTs were the MASS trial, the Chichester trial, the Viborg trial and the WA trial. The Mass and Chichester trials were conducted in the UK whereas the Viborg and WA trials were carried out in Denmark and Australia, respectively. The data pool of 125595 people added to the reliability of the findings of this review. A significant reduction in mortality rates of AAA was found in the intervention groups following an ultrasound screening of the abdominal aorta(4-7). QoL was looked at as the secondary outcome in the MASS trial which concluded that there was no adverse effect on QoL(4).

Conclusion: The review showed evidence on reduced AAA mortality rates in men aged 65 and older following ultrasound screening. No adverse effect in patients' QoL was found. The NAAASP is a commendable initiative of Public Health England and it is suggested that similar screening programmes be introduced through an evidence-based healthcare.

Introduction    

An aneurysm forms when a section of a weakened arterial wall dilates permanently. The walls of an artery can weaken and dilate due to cardiovascular diseases like arteriosclerosis, inflammation of the arterial wall or trauma. When this dilation occurs in the abdominal aorta, which runs from T12 to L5, it is considered to be an Abdominal Aortic Aneurysm (AAA)(8). Several studies have found smoking, hypertension and alcohol consumption to be the major risk factors of AAA(9). A family history of AAA is also considered to be a risk factor(10).

AAA is age and sex-dependent as concluded by a retrospective prevalence study that looked at a cohort of 100,000 men and women each. The prevalence among men was found to increase rapidly after the age of 55 and that among women increases after the age of 70(11). Therefore, women are considered to be at low risk of developing AAA and hence screening programmes focus on a male population of 65 years or older(12).

Patients are mostly asymptomatic and where symptoms do present, these could be abdominal pain, flank pain, back pain, groin pain, or syncope. A palpable pulsating abdominal mass could also be found during examination. An aneurysm once formed, grows in size until it bursts, leading to fatal bleeding. Only 2 in 10 people with a ruptured aneurysm survive if not treated with emergency AAA repair surgery(13). The survival rate among those who receive surgery is 94%(14).

AAAs are detected using an ultrasound scan (US), which is considered to be the most effective screening modality with high sensitivity (98%) and specificity (99%) rates(15). The US is safe, cheap, quick, and non-invasive, and provides results immediately. It is widely accepted as a valid screening method and the aorta can be visualised in 99% of patients(15). Compared to CT scans which can sometimes overestimate the diameter of aneurysms in the oblique plane(15), ultrasound continues to be the choice of screening modality.

In 2014, around 2000 men died from ruptured AAA, accounting for around 1% of all registered deaths in men aged 65 and over(16). Past records show a reduction in mortality in England from 7.5% in 2009 to 1.6% in 2012(17). This sheds light on the National AAA Screening Programme (NAAASP) offered by the NHS. Early detection via screening of a large aneurysm of above 5.5cm, means that patients are given the choice of repair surgery thereby increasing their survival rate by 69%(8, 18). Surveillance is offered to patients with a small or medium aneurysm of 3-4.4cm and 4.5-5.4cm, respectively(19, 20). This is through an ultrasound scan every twelve or three months for small and medium aneurysms, respectively.

Screening aims to reduce the risk of developing a disease in a healthy population who have no signs of illness with respect to the condition being screened. The NAAASP is based on the policies recommended by the UK National Screening Committee in 2005 following the results of the largest randomised controlled trial about AAA, the Multicentre Aneurysm Screening Study (MASS), which showed that screening reduces mortality by 40% after 10 years(21). Implemented in 2009, the programme achieved a nationwide coverage by the end of 2013.

The programme aims to 'reduce AAA mortality by providing a systematic population-based screening programme for the male population during their 65th year and on request, for men over 65'(22). This falls under Domain 2 and 4 of the Public Health Outcomes Framework provided by the Department of Health, with the objectives to help people to live healthy lifestyles and, to reduce the number of people living with preventable ill health and people dying prematurely(22), respectively.

NAAASP Annual Data 2014/15 shows that a total of 280,520 men were screened and 83.2% had a conclusive screen(23). During the screening year 2013/14, this was 82% out of a total of 287,126 men(24). Depending on the size of the aneurysm, either surveillance or surgery was offered.

Overall, the programme aims to achieve the health outcome of reduced mortality. Quality of life is also reported as a health outcome as shown by several retrospective, observational and cohort studies conducted on patients(25-27).

Knowledge on the success of screening programmes like NAAASP remains limited. The aim of this review, therefore, is to examine current evidence on whether a screening programme improves health outcomes, namely reduced mortality and improved quality of life, by critically and systematically reviewing literature using the quality assessment tools of the critical appraisal skills programme (CASP).

This will be achieved through the following objectives:

  • Develop inclusion and exclusion criteria based on PICOS relating to AAA and ultrasound scanning
  • Carry out a systematic search of databases- Medline, Web of Science, the Cochrane Database, OneSearch and the ISRCTN Registry (BioMed Central).
  • Filter the search using the inclusion and exclusion criteria and carry out data-extraction using the Cochrane Data Collection form
  • Carry out quality assessment using the CASP tool and use the Cochrane tool to assess risk of bias
  • Conduct an analysis, focusing on mortality and quality of life as the health outcomes

Methods

Although evidence exists on the accuracy of using ultrasonography for detecting abdominal aortic aneurysms(3) and the validity of the scan results is widely accepted due to its high sensitivity and specificity(3), the process of abdominal aortic scanning was decided to be reviewed first(Appendix A).

Prior to conducting the search, inclusion and exclusion criteria were set (Table 1)(28). Following this, databases were chosen for the search-topic 'Abdominal Aortic Aneurysm'. These included PubMed/MEDLINE, ISRCTN Registry, Web of Science, Lancaster University/OneSearch and the Cochrane Database. Search strategies were developed for each source and search filters were decided (Table 3-7). Medical Subject Heading (MeSH) terms were used to further refine the results (Table 2).

Overall, seventy-four articles were found and after removing duplicates, forty-nine remained. These were subjected to the inclusion and exclusion criteria, thus narrowing down the results to seventeen relevant articles. The reference lists of the retrieved articles were further reviewed for any relevant cited papers. This process was repeated until no relevant articles were found. Four major randomised clinical trials were identified from these. These were reviewed after undergoing data extraction and quality assessment.

Data extraction was carried out using Cochrane's data extraction tool and this allowed for a full-text screening that removed any ineligible studies. Moreover, the use of a standardised form increased the validity and reliability of this review whilst also reducing any risk of bias(28). Finally, the trials were critically appraised using the CASP tool. This enabled identifying risk of bias within the trials, particularly selection bias, performance bias and reporting bias.

Table 1                   

Inclusion Criteria

Exclusion Criteria

Population

  1. General population of males aged 65 years or older
  2. Patients who are asymptomatic and symptomatic who were involved in AAA screening
  3. Patients from all ethnicities
  4. Patients of all socioeconomic status
  1. Trials that include females, younger children and males younger than 65 years since AAA is age and sex specific

Intervention

Ultrasound Screening for AAA

  1. Any other imaging modalities like CT, MRI or radiography

Comparison

Non-screened population

  1. Aneurysm
  2. Aortic Aneurysm
  3. Thoracic Aneurysm

Outcome (s)

  1. Mortality
  2. Quality of Life

Study Design

  1. Randomised Controlled Trials (RCTs)
  2. Trials that look at AAA detection using Ultrasonography
  3. Articles in the English language
  4. Articles from the time period starting from approximately 20 years before the NAAASP programme came into effect, i.e., 1985 to present
  5. Full articles
  1. All other types of studies such as qualitative studies, observational studies, cohort or case-series studies.
  2. Articles in foreign languages
  3. Studies conducted outside this time period
  4. Articles that are not fully available

Table 2    Medical Search Headings (MeSH)

Abdominal Aortic Aneurysm

Mass Screening

Ultrasonography

Rupture

Table 3 PubMed

Search Strategy/Method

Results

Abdominal Aortic Aneurysm

23,807

Mass Screening

128,434

Ultrasonography

386,798

Rupture

109,121

AAA + MS

599

AAA + MS + US

300

AAA + MS +US + Rupture

102

AAA + MS +US + RCTs

23

AAA + MS +US + Rupture + RCTs

11

Table 4 Web of Science

Search Strategy/Method

Results

Abdominal Aortic Aneurysm

18,625

Mass Screening

43,081

Ultrasonography

80,257

Rupture

119,830

AAA + MS

131

AAA + MS + US

23

AAA + MS +US + Rupture

12

Limit 'English'

11

 

Table 5 Cochrane Library (RCTs only)

Search Strategy/Method

Results

Abdominal Aortic Aneurysm

702

Mass Screening

3827

Ultrasonography

11,318

Rupture

3097

AAA + MS

46

AAA + MS + US

23

AAA + MS +US + Rupture

10

Table 6 OneSearch

Search Strategy/Method

Results

Abdominal Aortic Aneurysm

27,819

Mass Screening

73,090

Ultrasonography

122,460

Rupture

94738

AAA + MS

604

AAA + MS + US

123

AAA + MS +US + Rupture

42

Limit 'Articles'

39

Table 7 ISRCTN Registry/BioMed Central

Search Strategy/Method

Results

Abdominal Aortic Aneurysm

37

Mass Screening

328

Ultrasonography

88

Rupture

176

AAA + MS

3


Results

Four dominant randomised controlled trials (RCTs) were identified- the Multicentre Aneurysm Screening Study(4) (MASS) conducted between 1997 to 1999; the Chichester Study(5), 1988 to 1991; the Viborg County Trial(6), 1994 to 1998 and; the Western Australia (WA) Trial(7), 1996. These collectively showed that AAA mortality rate can be significantly reduced in the population following an ultrasound scan of the abdominal aorta (Table 8).

The Mass and Chichester trials were carried out in the UK and had a participant number of 67,770 men aged 65 to 74 years and 6040 men aged 65-80 years, respectively. The Viborg Country trial was conducted in the Viborg county of Denmark with a participant number of  12,639 men aged 65-73 years; the WA trial, carried out  in the province of Western Australia included 41,000 men aged 65-79.

All these trials used ultrasound screening of the abdomen to detect AAA and measured AAA-mortality as the primary outcome(4-7). The secondary outcomes of all trials were all-cause mortality. However the Mass trial also measured quality of life and cost-effectiveness as the secondary outcomes. Cost-effectiveness was also measured by the Viborg trial as the secondary outcome. Participants were randomly selected and randomisation was computer-generated(4-7).

Mass and Chichester trials recruited participants via GP registers based on gender and date of birth. In the Mass trial, some were excluded if the GP considered them to terminally ill, had other health problems or had undergone AAA repair(4). In the Viborg trial, recruitment was through the county's health department and WA participants were selected from the electoral roll(6, 7). The WA trial excluded those men who were too far from the screening location; the Viborg trial had no such exclusions.

  1. MASS Trial

The intervention group composed of 33839 men and the control group, 1333 men. Attendance was 80% and the median follow-up was ten years(4). 65 men died in the intervention group and 113 died in the control group, due to AAA. Mortality data was taken from death registry provided by the Office of National Statistics (ONS).

The study concluded that AAA mortality rate can be significantly reduced by up to half, following ultrasound screening. There was a 42% reduction in the intervention group, hazard ratio (HR) - 0.58 95% CI (0.42-0.78)(4).

The study also measured mood and health status outcomes such as state anxiety, depression, and health-status measures such as mental and physical health, and self-rated health(4, 13). These were calculated at intervals of six weeks after screening and, 3 and 12 months after detection of aneurysm or surgery. There were no significant changes in anxiety and depression and these remained within the recommendations(4). However, those screened negative and undergoing surveillance scored higher in health-status measures. This trend continued until 3 months after screening(4). However at 12 months, those who had undergone surgery scored higher than those in surveillance. They also self-rated higher, similar to those screened negative(4). Despite these results, the authors refrained from making a conclusive statement on quality of life.

In the intervention group, there was an increase in the number of elective surgeries, odds ratio (OR)- 2.45 95% CI (2.02-2.97)(4). Nevertheless, there was no significant difference in the overall 30-day mortality after elective surgery in the intervention and control groups; this remained at 6%. However, 'unnecessary surgery and the risk of overdiagnosis' are seen as factors reducing the overall quality of life(29). So even though this increase in elective surgery in the intervention group and its effects could be used as a measure of quality of life, the authors did not make such a link.

  1. Chichester Trial

The intervention group composed of 2995 men and the control group, 3045 men. The median follow-up was fifteen years and the attendance rate, 74%, decreased with age. About 33.8% of men in the age range of 76-80 years declined compared to 19.5% in the age group of 65 years(5). 10 men died in the intervention group and 17 died in the control group, due to AAA-related causes. Like the Mass trial, mortality data was taken from the ONS Death Registry.

The study found no differences in mortality rates in the two groups up to four years from screening. However, over 15 years, mortality was found to be reduced in the intervention group by 11%. This was not considered as a significant reduction, HR - 0.89 95% CI (0.60-1.32) (5).

  1. Viborg Trial

The intervention group composed of 6339 men and the control group, 6319 men. Attendance was 76% and the maximum follow-up was fourteen years(6). 6 men died in the intervention group, compared to 19 in the control group. Mortality data was taken from the national registry.

There was a significant reduction in AAA-related hospital mortality, OR-0.31 95% CI (0.13-0.79)(6). The study recommends screening men aged 65 years to reduce AAA-mortality. However since the study only noted deaths from AAA in a hospital setting in the county of Viborg, this finding cannot be expanded to other countries.

  1. Western Australia Trial

The intervention and control groups composed of 19352 men each. Attendance rate was 70% and the maximum follow-up was 43-months(7). 18 men died in the intervention group and 25 died in the control group. Mortality data was taken from the national death registry and the hospital registry.

The study found that there was no significant reduction in mortality following ultrasound scanning in the intervention group of men aged 65-83 years in Western Australia, OR- 0.72 95% CI (0.39-1.32)(7). However the study noted that in the subgroup of men aged 65-75 years, mortality was found to be reduced(7).

Table 8 AAA mortality: raw data

Trial

Deaths in Screened

Deaths in Unscreened

Odds Ratio (95% CI)

MASS

65/33,839

113/33,961

0.58 (0.42 to 0.78)

Chichester

10/3205

17/3228

0.59 (0.27 to 1.29)

Viborg

6/6339

19/6319

0.31 (0.13 to 1.79)

Western Australia (WA)

18/19352

25/19352

0.72 (0.39 to 1.32)

Total*

93/56,396

155/56,541

0.60 (0.46 to 0.78)

*Data from the Viborg trial is not included since the study noted deaths only in a hospital setting. Hence, results cannot be compared to the other studies(30)

Discussion

The pooled data of 125595 participants shows that AAA mortality rate can be significantly reduced in the population following an ultrasound scan of the abdominal aorta. Data from the four RCTs show that the Absolute Risk Reduction (ARR) for the Mass trial, Chichester, Viborg and WA are 0.14%, 0.21%, 0.21% and 0.04%, respectively (See Table 9 for the full data processed by the review author). Although these may appear insignificant, when applied over a population, the ARR is 140.7, 214.6, 206.0 and 36.2 per 100,000 respectively. Hence, the Numbers Needed to Screen (NNS) are 711, 466, 485 and 2765 respectively. On an average, this is an ARR of 149.4 out of every 100,000 people for an NNS of 1107. This NNS is lower than other screening programmes like breast cancer screening which has an NNS of 1339(31).  This confirms the benefits of a population-based screening programme such as the NAAASP.

The Mass trial, which looked at the effects of ultrasound screening on the quality of life found its measures to be within normal standards. Since the NAAASP is based on the results of this trial, it can be said that ultrasound screening has no adverse effects on the quality of life of the screened population. However, a  limitation acts on the trial- quality of life was measured only up to twelve months after scan; no data is available for the period after that. If quality of life was continued to be measured during follow-ups or even separately via postal questionnaires or GP appointments, a more valid inference could have been drawn. It would also have provided a fuller picture on the long-term effects on quality of life.

One other limitation acting on this review is the possibility of selection bias as a result of excluding some articles in foreign languages. Despite this, the findings of this review remain unaffected and can be considered valid since an exhaustive search of the major databases was carried out systematically. Although the inclusion criteria of 'free-articles' was applied after this search, Lancaster University's subscription service ensured access to all available articles and a complete retrieval of the selected search was possible. The pooled study population consisted of 125,595 men and the MASS trial alone had a sample of 67800 people. So, conclusions on quality of life and AAA mortality can be considered reliable.

However, there are inconsistencies present in the four RCTs due to the different methods used. For example, the Viborg trial noted mortality only in a hospital setting. This makes its results incomparable to the other trials. Also, the source of mortality data varies in the four studies. All the trials looked at the national death registries but the Chichester and WA trials also looked at other sources(5, 7). This may have resulted in possible over-estimation or duplication of data. Similarly, the cause of death was re-checked by a clinician and two random vascular surgeons in the Chichester and WA trials, respectively. Whilst expert opinion regarding the cause of death could lead to precise and accurate mortality data, there could also be false-positives when opinions are formed on complex cases with multiple causes of mortality.

This subject of human error was also noted whilst carrying out the preparatory ultrasound screening (Appendix A). Individual measurements of the same abdominal aortic diameter were varied. Although this points to the possibility of human error that may adversely affect the accuracy the diagnosis, the NAAASP identifies staff training as a significant aspect of the programme to overcome this. Staffs are well-trained in the use of ultrasonography for AAA screening and in the overall delivery of the programme(8). Also, the programme itself has several failsafe procedures incorporated within all phases of the programme so that the performance thresholds are constantly maintained(8).

The result of this review can be applied to patient care in the UK. The NAAASP is successfully running its seventh year. Since its implementation in 2009, one million men have been screened(32). Accumulating evidence shows it is feasible to reduce AAA-mortality by ultrasound screening, thereby making it possible to achieve the programme's aim.

Public Health England could implement similar screening interventions in other disease areas. There is currently a long of list of conditions like atrial fibrillation, thyroid disease and lung cancer where a population-based screening is not offered (but privately available) due to the absence of 'enough evidence to inform a screening programme'(33). Evidence-based healthcare could be further expanded to diseases like these.

It is not just new and untreatable diseases that prove to be a challenge to 21st century medicine; it is the phenomenon of the disease-iceberg that proves most challenging. By detecting and treating early onset of illnesses, people live a longer and healthier life.

Table 9 Data processed by the review author using the results from the four RCTs

Trial

Experimental Event Rate (EER)

Control Event Rate (CER)

Absolute Risk Reduction

Relative Risk Reduction

Number(s) Needed to Screen (NNS)

Odds Ratio/Relative Risk

MASS

0.00192086

0.00332735

0.00140649

0.422705

710.992

1.73222

Chichester

0.00312012

0.00526642

0.00214629

0.407543

465.919

1.68789

Viborg

0.000946522

0.00300680

0.00206028

0.685207

485.370

3.17669

Western Australia

0.000930136

0.00129186

0.000361720

0.280000

2764.57

1.38889

Overall

0.00157807

0.00276806

0.00118999

0.429901

840.344

1.75408

Overall*

0.00164905

0.00274137

0.00109232

0.398457

915.482

1.66239

*Data from the Viborg trial is not included since the study noted deaths only in a hospital setting. Hence, results cannot be compared to the other studies(30)

Conclusion

Following critical appraisal of the current available evidence provided by four major RCTs, it was found that mortality from AAA can be significantly reduced in males aged 65 years and older, through a population-based screening programme. Ultrasonography continues to be the chosen imaging modality due to its accuracy and ease-of-use.  It was also found that such a screening programme has no adverse effects on the quality of life. Due to the different methods employed by the chosen four RCTs, a valid and direct comparison could not be made, thus acting as a limitation on this review. However, the large data pool of 125595 people ensured a valid conclusion to be drawn. It is suggested that future systematic reviews employ more rigorous inclusion criteria that also look at standardised methods. This will add to the validity of its findings. It is also suggested that future studies adopt a longer timespan to measure the quality of life. This will provide a fuller picture of the long term effects of a screening programme on patient's quality of life. The NAAASP is a commendable initiative of Public Health England. An evidence-based approach, by means of conclusions drawn from randomised controlled trials and systematic reviews, can be used to shape and deliver similar beneficial screening programmes.

Reference

1.Maegdefessel L, Spin JM, Tsao PS. New ways to dismantle a ticking time bomb: microRNA 712/205 and abdominal aortic aneurysm development. Arterioscler Thromb Vasc Biol. 2014;34(7):1339-40.

2.England PH. Abdominal Aortic Aneurysm Screening: 2014 to 2015 overview: Government Publications,; 2015. Available from: https://www.gov.uk/government/publications/abdominal-aortic-aneurysm-screening-2014-to-2015-data.

3.Thomas PR, Shaw JC, Ashton HA, Kay DN, Scott RA. Accuracy of ultrasound in a screening programme for abdominal aortic aneurysms. J Med Screen. 1994;1(1):3.

4.Scott RAP. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial. The Lancet. 2002;360(9345):1531-9.

5.Ashton HA, Gao L, Kim LG, Druce PS, Thompson SG, Scott RA. Fifteen-year follow-up of a randomized clinical trial of ultrasonographic screening for abdominal aortic aneurysms. Br J Surg. 2007;94(6):696-701.

6.Lindholt JS, Juul S, Fasting H, Henneberg EW. Hospital costs and benefits of screening for abdominal aortic aneurysms. Results from a randomised population screening trial. Eur J Vasc Endovasc Surg. 2002;23(1):55-60.

7.Norman PE, Jamrozik K, Lawrence-Brown MM, Le MT, Spencer CA, Tuohy RJ, et al. Population based randomised controlled trial on impact of screening on mortality from abdominal aortic aneurysm. BMJ. 2004;329(7477):1259.

8.Public Health England. Abdominal Aortic Aneurysm (AAA) Screening: a free test for men aged 65 years and over: National Archives; 2015. Available from: https://www.gov.uk/government/publications/abdominal-aortic-aneurysm-screening-invitation-leaflet.

9.Wong DR, Willett WC, Rimm EB. Smoking, hypertension, alcohol consumption, and risk of abdominal aortic aneurysm in men. Am J Epidemiol. 2007;165(7):838-45.

10.Salo JA, Soisalon-Soininen S, Bondestam Sr, Mattila PS. Familial Occurrence of Abdominal Aortic Aneurysm. Ann Intern Med. 1999;130(8):637-42.

11.Bengtsson H, Bergqvist D, Sternby NH. Increasing prevalence of abdominal aortic aneurysms. A necropsy study. Eur J Surg. 1992;158(1):19-23.

12.Scott RA, Bridgewater SG, Ashton HA. Randomized clinical trial of screening for abdominal aortic aneurysm in women. Br J Surg. 2002;89(3):283-5.

13.Thompson SG, Ashton HA, Gao L, Scott RAP. Screening men for abdominal aortic aneurysm: 10 year mortality and cost effectiveness results from the randomised Multicentre Aneurysm Screening Study. BMJ. 2009;338.

14.Greenhalgm RM BL, et.al. Endovascular versus Open Repair of Abdominal Aortic Aneurysm. N Engl J Med. 2010;362(20):1863-71.

15.Lindholt JS, Vammen S, Juul S, Henneberg EW, Fasting H. The Validity of Ultrasonographic Scanning as Screening Method for Abdominal Aortic Aneurysm. Eur J Vasc Endovasc Surg. 1999;17(6):472-5.

16.Office for National Statistics. Mortality Statistics: Deaths Registered in 2014 (Series DR) Table 5 2015.

17.England PH. NAAASP Annual Data Tables and Reports. 2009 to 2014.

18.Public Health England. Your screening result: you have a large abdominal aortic aneuyrsm (AAA): National Archives; 2015. Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/415687/Large_AAA_leaflet_final_131014.pdf.

19.Public Health England. Your screening result: you have a small abdominal aortic aneurysm (AAA): National Archives; 2015. Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/415617/Small_AAA_leaflet_final_draft_for_printing_061014.pdf.

20.Public Health England. Your screening result: you have a medium abdominal aortic aneurysm (AAA): National Archives; 2015. Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/415642/Medium_AAA_final_draft_for_printing_061014.pdf.

21.Ashton HA, Buxton MJ, Day NE, Kim LG, Marteau TM, Scott RA, et al. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial. Lancet. 2002;360(9345):1531-9.

22.Department of Health. The Public Health Outcomes Framework for England, 2013-2016. 2012.

23.UK National Screening Committee. Overview of the movement of men through the AAA screening programme 2014/15.

24.UK National Screening Committee. Overview of the movement of men through the AAA screening programme during the screeninf year 2013/14. 2014.

25.Korhonen SJ, Kantonen I, Pettilä V, Keränen J, Salo JA, Lepäntalo M. Long-term survival and health-related quality of life of patients with ruptured abdominal aortic aneurysm. Eur J Vasc Endovasc Surg. 2003;25(4):350-3.

26.Aljabri B, Al Wahaibi K, Abner D, Mackenzie KS, Corriveau MM, Obrand DI, et al. Patient-reported quality of life after abdominal aortic aneurysm surgery: a prospective comparison of endovascular and open repair. J Vasc Surg. 2006;44(6):1182-7.

27.Tambyraja AL, Fraser SCA, Murie JA, Chalmers RTA. Quality of Life After Repair of Ruptured Abdominal Aortic Aneurysm. Eur J Vasc Endovasc Surg. 2004;28(3):229-33.

28.S.J. TEEW. Systematic Reviewing for Evidence-Based Pratice: An Introductory Workshop: Peabody Research Institute Vanderbilt University; 2013 [cited 2016 30th January ]. Available from: https://my.vanderbilt.edu/emilytannersmith/files/2013/11/Workshop-Slides-SUN.pdf.

29.Sidloff DA, Bown MJ. Primum Non Nocere: Does Screening For Abdominal Aortic Aneurysm Do More Harm Than Good? Eur J Vasc Endovasc Surg.50(4):409-10.

30.Ahmad KI. The role of ultrasound in reducing AAA mortality: a review. Medical Students Research Journal. 2013;02(Winter).

31.Dabare D, Lo TT, McCormack DJ, Kung VW. What is the role of screening in the management of abdominal aortic aneurysms? Interact Cardiovasc Thorac Surg. 2012;14(4):399-405.

32.North Bristol NHS Trust. Men encouraged to take up Abdominal Aortic Aneurysm screening as national programme scans millionth man: North Bristol NHS Trust; 2016. Available from: https://www.nbt.nhs.uk/news-media/latest-news/men-encouraged-take-abdominal-aortic-aneurysm-screening-as-national-programme.

33.England PH. Private screening for health conditions: NHS recommendations: Gov.uk; 2014. Available from: https://www.gov.uk/guidance/private-screening-for-health-conditions-nhs-recommendations.

34.Nelson BP. Ultrasound assessment of the abdominal aorta including aortic aneurysm: Department of Emergency Medicine Mt. Sinai School of Medicine; 2013. Available from: http://sinaiem.us/.

35.NHS Choices. About the NHS 2015. Available from: http://www.nhs.uk/NHSEngland/thenhs/about/Pages/nhscoreprinciples.aspx.

 

Appendix A

Reflective essay on the preparatory work carried out by the review author

The preparation for this review was carried out as a team involving four medical students including myself, under the guidance of our convenor. As part of the preparatory methods, we decided to review the process of abdominal scanning. The primary objective was to understand the scanning process and how it aids in the diagnosis of an abdominal aortic aneurysm. Although it was clear that this preparatory work is only a simulation of the real AAA scanning, we understood that in a real-life setting, AAA screening is carried out very similarly- a patient walks in for his appointment, gets scanned and gets his results- sometimes life-changing- within the span of few minutes. Therefore, I felt it necessary to adopt a secondary objective to understand the effects of scanning on the patient. This included using the biopsychosocial model to see whether a holistic care is possible to be delivered to those patients who undergo scanning. This links well with health and social theories set out in our first year curriculum of Lancaster Medical School.

The scanning was carried out in Lancaster Medical School's Clinical and Anatomical Learning Centre (CALC) using a Sonosite ultrasound scanner. A 60mm curved array transducer of 5-2 megahertz was used and this allowed for a compromise between high penetration and resolution. Since the results were not intended to be used in any stages of this review, ethical approval was not required. However, written procedures were provided for all individuals and student participants signed to indicate understanding and acceptance of the procedures. Thus, Lancaster Medical School's consent procedures were strictly followed.

A young male adult-one of our team members- was scanned by our convenor, after gaining informed consent. Images from five views were taken (See Appendix B for images of a normal abdominal aorta) to help us familiarise with the ultrasound scan. The following focused questions(34) were asked to diagnose AAA:

  • Is the abdominal aorta >3cm?
  • Are the iliac arteries >1.5cm wide?

We chose an image in the transverse plane that clearly showed the abdominal aorta in its widest location.  My team and I measured the abdominal aortic diameter individually. Our convenor ensured that no one saw each other's measuring techniques. Finally, the convenor himself measured the aortic diameter. See Table 1 for the results obtained by the team.

Table 1 Results from the ultrasound scan of Abdominal Aorta

Designation

Measurement (cm) of the widest part of the abdominal aorta in the transverse plane

Medical Student 1

1.23

Medical Student 2

1.49

Medical Student 3

1.02

Medical Student 4

1.73

Sonographer

1.53

Results were varied, most probably due to our inexperience with ultrasound scans. However, this prompted us to think about the issue of human error that may affect the accuracy of the diagnosis.  I was intrigued as to how a nation-wide programme like NAAASP overcomes this and therefore accessed the programme specification. The NAAASP identifies staff training as a significant aspect of the programme. Staffs are well-trained in ultrasonography for AAA screening and in the overall delivery of the programme (8).

The young adult was found not to have an AAA, as expected by the team due to his very young age. However, in a real setting, around 1 in 70 patients screened will be diagnosed with an aneurysm (8) and for them, it is indeed a life-changing experience. With either imminent surgery or life-long surveillance, the two treatment options for those with a diagnosis, there ought to be an emotional response from the patients.

He was almost relieved to be in the clear even though he was well-aware of the statistics that vividly showed his diminished chances of having an AAA. It was a remarkable experience for me to see this reaction first-hand. I realised that a holistic approach is very necessary here. Men receive an invitation to attend a five-minute scan after turning 65 years old. They receive the results then and there, and with a positive diagnosis, the patients often have to deal with the challenges of coping that follow. I was reminded of the significance of the biopsychosocial model, which places equal emphasis on the emotional reactions of a patient as well as the disease itself. Patients have to be well supported no matter how short the appointment is. The NAAASP has several informative leaflets on all types of diagnosis. In addition to that, several decision-making tools are available online specifically for the patients, to help them make an informed decision about the treatment options.

The experience that I gained will help me appreciate the use of ultrasonography in AAA scanning. More than that, it will help me understand and always remember that Abdominal Aortic Aneurysm is not just a list of numbers that get published in the end of year reports of a screening programme- it is indeed a 'ticking bomb (1)' that affects real people. It is assuring to know that  the NAAASP takes this into consideration by following one of the guiding principles of NHS, which is 'aspiring to put patients at the heart of everything it does…by meeting the needs and preferences of patients, their families and their carers.(35)'

 

Appendix B

Ultrasonography images of a normal abdominal aorta

Table 1 Ultrasonography Images

Plane

Image (Source: American College of Emergency Physicians)

Transverse

  1. Proximal Abdominal Aorta

0510

  1. Mid Abdominal Aorta

0510

  1. Distal Abdominal Aorta
  2. Iliac Bifurcation

0510

Longitudinal

  1. Distal

0510


To export a reference to this article please select a referencing stye below:

Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.

Request Removal

If you are the original writer of this essay and no longer wish to have the essay published on the UK Essays website then please click on the link below to request removal:


More from UK Essays

We can help with your essay
Find out more