1. Complication rates following 4-Fr versus 6-Fr transfemoral vascular access – prospective audit at a single centre Chung R1, Weller A1, Bowles C1, Sedgwick P2, Ratnam L1 1Interventional Radiology, St. George’s Hospital, London, UK.
2Division of Population Health Sciences & Education, St. George’s Medical School, London, UK.
Background
Safe Femoral Artery Puncture
Results
The principles of safe femoral arterial puncture forms the stepping stone to many endovascular procedures. Training in safe femoral arterial puncture technique and regular audit of outcomes are essential in minimising the morbidity associated with complications from arterial puncture. We present the results of a 3 year audit at a UK trauma centre that has allowed us to evaluate both patient related risk factors and the impact of utilising 4Fr vs 6Fr sheaths to reduce complications.
Table 3 – Arterial puncture complications
Figure 1 –Antegrade puncture (a), retrograde puncture (b), and confirmatory angiogram post procedure to assess suitability for arterial closure device (c).
(a)
Inguinal ligament
puncture into CFA
wire in SFA
(b)
(c)
Complication
4-Fr
6-Fr
Total
Haematoma 2 15 17
Pseudoaneurysm 1
Distal embolism -
Arterial dissection
Other
Need for surgical intervention
3 (0.8%)
Aims
A) Identify potential risk factors for trans-femoral arterial
entry site complications, including:
Patient co-morbidities (DM/HTN): obesity; vessel calcification; clotting; anti-coagulation.
Procedure related factors: Vascular access sheath size (4-Fr versus 6-Fr systems).
B) To evaluate the cost implications of using 4-Fr versus 6-Fr systems.
• 392 procedures performed total.
• 26 (6.6%) complications, of which 23 were either 4 or 6-Fr system (sheath size not recorded in 3 cases ).
Post procedure complication rates were significantly greater using 6-Fr sheath catheterisations than 4-Fr sheath systems, 19/157 (12.1%) versus 4/177 (2.3%), p<0.001.
However, of the 19 complications seen in the 6-Fr group, 9 were minor resulting in no delay in discharge or escalation of treatment (no significant difference between 4 vs 6-Fr systems for major complications).
Antegrade punctures (11/97 – 11.3%) were also associated with significantly greater complication rates than retrograde punctures (15/295 – 5.1%), p<0.05.
However; comparison of complications rates between seniority of operator, number of arterial passes, vessel calcification, scarred groin, body habitus, use of closure device, artery punctured (CFA vs SFA) or puncture safeguarding techniques (manual palpation vs image guided) did not reach statistical significance.
Patients and Methods
Prospective single centre study at a UK trauma centre, over three 6 month audit cycles.
Vascular interventions performed between 07/04/2010 and 10/05/2013 included.
Procedure related complications were recorded on an audit pro-forma immediately following each procedure and by clinical review of each patient prior to discharge.
Parameters recorded include: patient co-morbidities; body habitus; vessel calcification; clotting; anti-coagulation; operator experience; sheath size and number of passes for access.
Association of these factors, especially sheath size, with post-procedural complications was evaluated using chi-squared analysis or Fisher’s exact test (SPSS software) and adjusted for confounding factors.
In our institution, all inexperienced operators received formal training in the basics of safe femoral arterial puncture, followed by close senior supervision, until competent in gaining safe femoral arterial access. Competence is assessed on the basis of 50 observed retrograde and 50 observed antegrade punctures.
Results
Table 2 – Arterial puncture characteristics
Patient side of puncture
Left 172, Right 217
(unavailable 3)
Seniority of operator
Junior
Fellow
Consultant 34
298 58
Direction of puncture
Retrograde
Antegrade
295 97
Artery punctured
EIA
CFA
SFA
Brachial
Popliteal 2
364 15 9
Number of passes 1
>1
329 63
Sheath size
4-Fr
6-Fr
Other
177
157
Vessel calcification
Nil
135
257
Groin scarred
Not scarred 65
327
Habitus
Not obese
Obese
Not recorded
278
109 5
Puncture safeguarding technique
Manual palpation
Screening
Ultrasound
Combination 56 19
175
142
Anticoagulation during procedure
Intraarterial heparin ( Units)
183
209
Closure method
Manual compression
Angioseal
Exoseal
Additional femstop
307 68 12 3
Cost Implications
The 4-Fr system has the following additional costs compared
with 6-Fr:
Assuming a straightforward procedure using a single wire/balloon combination, the 4-Fr system requires an additional wire, with an average cost of £73.90 per wire in our institution
Average balloon costs are £86.66 for the 4-Fr system compared with £46.25 for 6-Fr.
This leads to a minimum extra cost of £ for the 4-Fr
system, in a procedure requiring no extra balloons or wires.
Even in the event of using an available closure device in the 6-Fr system, the overall procedural cost of using a 4-Fr system is £9.85 greater.
Table 1 – Patient demographics
Age – mean (range) years
64.9 (20-94)
Sex M:F
227:165
Hypertension (HTN)
151
Diabetes (DM)
108
Anticoagulation
Nil
Warfarin
Aspirin
Clopidogrel
Treatment dose heparin
Prophylactic dose heparin
Multiple
206 7 58 9 52 43
INR
<1.5
>1.5
377 16
Platelets
<50
>50, <100
>100 2
381
Conclusion
Intuitively, due to their smaller size, 4-Fr vascular access sheaths are expected to reduce the risk of post-procedural complications. Our data supports this hypothesis, however most of these complications are minor. The overall number of groin complications is low, with an even smaller number of major complications. Larger numbers are required to assess differences in major complication rates between 4-Fr and 6-Fr systems.
Antegrade punctures are also associated with significantly greater groin access complications.
Given the higher cost and practical limitations encountered when using a smaller system, the results to date do not suggest that the routine use of 4-Fr sheath system is indicated as the primary sheath size for all endovascular procedures.