Evaluation of risk factors associated with femoral Pseudoaneurysms after cardiac catheterization

1. Evaluation of risk factors associatedwith femoral Pseudoaneurysms aftercardiac catheterization

2. From the Departments of Cardiovascular Surgery and Radiology, Siyami Ersek Thoracic and Cardiovascular Surgery Center.

3. Study Aim To evaluate factors associated with FPA of sufficient clinical significance that they required surgical treatment after diagnostic or interventional cardiac catheterisation. Specifically to assess if: Diabetes mellitus Hypertension Elevated BMI High room catheterisation turnover Increasing catheter size Coronary artery disease Are independent risk factors for pseudoaneurysm requiring surgical repair

4. Study population Case control study: 41322 femoral catherisation procedures were done and 630 surgically managed femoral pseudoaneurysms developed. 36218 procedures were diagnostic and 5104 were interventional 30 cardiologists performing 250-300 cases per year in four catheterisation-laboratories Two controls were selected per patient matched for age, sex and catheterisation day.

5. Methods Routine management If diagnostic: No anticoagulation was given Introducer was removed at completion and 20 minutes direct compression at insertion site by RMO/ physician’s assistant, then sandbag compression for 2 hours and hospitalised for 8 hours. Six French catheter as standard If interventional: 300mg clopidogrel given to start then 75mg per day OR 10000 unit bolus of heparin followed by 5000 units per hour Post procedure. introducer stabilized by suturing to the skin, then removed at 6 hours and follow the same pathway as for diagnostic catheterisation (except hospitalised overnight). Note 7 French catheter as standard

6. Methods If the pseudoaneurysm was less than 5cm2 in 2 dimensions or neck length = 8mm If Pseudoaneurysm overall 2D size greater than 5cm2 or neck <8mm … Femoral pseudoaneurysm was diagnosed with colour-flow Doppler, as was neck location and length. then it was managed by external compression (ultrasound-guided) and these results were excluded from the trial (n = 85)

7. Methods Surgical correction: Also only Performed if: Distal ischaemia Expanding haematoma New murmur Pulsatile mass Tenderness Marked pain Hypotension I.e. one of the above had to be present for surgical correction to go ahead. Surgical management Grafting (saphenous or prosthetic) Primary suturing ± Embolectomy

8. Analysis SPSS software Pearson test Spearman test Stepwise backward logistic regression analysis Pearson test was used for numerical values and Spearman test for non-parametric variables. Parametric tests assume a normal distribution of results Nonparametric tests are distribution free in that they do not rely on the data to have any particular underlying distribution The logistic analysis was used to analyse the association between risk factors and FPA formation.Pearson test was used for numerical values and Spearman test for non-parametric variables. Parametric tests assume a normal distribution of results Nonparametric tests are distribution free in that they do not rely on the data to have any particular underlying distribution The logistic analysis was used to analyse the association between risk factors and FPA formation.

9. Results Reasonable correlation for age and sex with controls Time for procedure: 16 ± 6 for diagnostic studies 37 ± 12 for interventions Time until FPA diagnosed: 2.1 ± 0.7 days Likelihood of FPA requiring surgical repair: 1.1% diagnostic procedures (n= 398) 4.7% interventional procedures (n = 232) Overall 1.5% (or 1.7% if all FPAs included)

11. Independent Risk factors Hypertension Odds ratio 1.52, CI 1.03-1.90 with (p = 0.011) Diabetes Mellitus Odds ratio 1.11, CI 1.06 – 1.25 (p = 0.035) Coronary artery disease Odds ratio 1.21, CI 1.05 -1.22 (p = 0.022) Higher BMI Odds ratio 2.21(p < 0.01) Larger Catheter diameter Odds ratio 2.39 (p < 0.01) Elevated number of cases performed that day in the same room Odds ratio 2.82 (p <0.01)

12. In addition… Numerically speaking: BMI > 28kg/m2 > 17 cases per room per day Use of a 7 French or larger sheath All were associated with higher pseudoaneurysm risk

13. Results

14. Discussion Increased numbers of arterial punctures being done and increased complexity of interventions ? increasing rate of pseudoaneurysm Prevention of FPA relies upon non-traumatic arterial puncture good post-operative compression use of closure devices

15. Acknowledged that they failed to address the distinction between interventional and diagnostic catheterisations but dismissed its significance Felt that the increasing rate of FPA with increasing number of patients done per day had to do with the decreased compression time afforded by the faster turn over rate.

16. Point given most emphasis Compression time was seen to be the most important factor in reducing the risk of Femoral pseudoaneurysm

17. Appraisal Level 3, case-control study Selection bias is an inherent problem with the style of trial Hypothesis clear FPA incidence: Other trials have ranges 0 – 14%1

18. Appraisal Reference population = Only those having catheterisation and developing an aneurysm worth surgically correcting It is made clear that they are focusing on the group of people whose pseudoaneurysms required surgical correction, but can you really distinguish risk factors for pseudoaneurysm from those of pseudoaneurysm requiring surgical repair? i.e. is exclusion of the 85 patients whose aneurysms were managed conservatively a bias? Indicators for surgical correction initially seem somewhat arbitrary but make some sense when you note that size and neck length are not all that determines the need for correction

19. Selection bias No mention of failure rates for ultrasound-guided compression of pseudoaneurysm 63 – 88% success rate at most in other trials 1 Failure ? surgery Likelihood of requiring surgical repair very high in this trial (88%) – usually 20-40%2 Morgan and Belli: trend towards reduced success with larger pseudoaneurysms but as much as 67% success rate in individual trials with pseudoaneurysm 4-6cm in size. No relationship shown between neck length, age of patient, neck width, mulitloculation of pseudoaneurysm or chronicity.

20. Selection bias Unclear how they chose people to ultrasound were all people given a Doppler ultrasound or only those with symptoms/ signs? No clinical parameters for diagnosis of pseudoaneurysm or surveillance for ultrasound referral.

21. Confounders Confounding value for interventional v diagnostic procedures quantified as percentage 4.7 versus 1.1 % procedures. Widely recognized as an influence on the incidence1 All interventional patients also received 10000 unit heparin bolus and then 5000 units/hour EXCEPT in the last 2 years of the trial when 300mg clopidogrel was given initially followed by 75mg/day. Anticoagulation alone has been shown to increase incidence2 The practice of suturing their introducers has not been shown to change the overall incidence of pseudoaneurysm or complications2 Confounder of diagnostic v interventional recognized then not applied to processing of results.

22. No drop out rate, nor any defined length of time for follow-up outside of hospital Most patients had diagnostic procedures and thus would have been discharged from the cardiology service, if not the hospital… No Power given for the results obtained Many of their conclusions have little to do with their results No audit of actual compression times therefore no evidence that compression time was important No use of closure devices (and the conclusion is contrary to major literary sources2)

23. References Morgan R, Belli A-M, Current Treatment Methods for Post catheterization Pseudoaneurysms. Vascular Interventional Radiology 2003; 14:697–710 Koreny M, Reidmuller E, Nikfardjam M, Siostrzonek P, Mullner M, Arterial puncture closure devices compared with standard manual compression after cardiac catheterisation: Systematic review and meta-analysis. JAMA jan 21, 2004 vol 291 [3] 350-357