Skin puncture versus exposing the femoral artery for minimally invasive repairs of abdominal aortic aneurysms

Background

Abdominal aortic aneurysms are a ballooning of the largest blood vessel in the abdomen, the abdominal aorta, due to weakness of the vessel wall. This ballooning may lead to life-threatening rupture. Repair of the aneurysm is recommended if the risk of rupture is calculated to be greater than the risk of surgery. Most repairs involve putting in an artifical graft, a tube composed of fabric, to help reinforce the artery wall. There are two main methods for repair. One is an open technique in which the whole abdomen is opened and the graft is used to replace the diseased part of the vessel. The other technique is an endovascular aneurysm repair. With this technique the graft is fed into the abdominal aorta through an artery in the groin (the femoral artery) and avoids the large abdominal incision. This review looked at an alternative method for introducing the graft into the femoral artery, percutaneous access. Instead of making an incision in the groin to expose the femoral artery (a cut-down), a needle is inserted to the femoral artery then a flexible guide wire inserted through the needle. The needle is removed and a plastic tube introduced into the femoral artery over the guide wire (percutaneous access), with a small cut in the skin to allow the passage of the plastic tube. Once introduced, the guide wire can be removed leaving the tube in place in the artery. The graft and all other materials can then be fed into the artery via the plastic tube. Once the procedure is complete the tube can be withdrawn. The surface incision can usually be closed with one stitch.

Study characteristics and key results

This update found two studies comparing the cut-down artery access with the percutaneous technique (current to October 2016). One was a small study with 30 participants, the other a larger more robust study with 151 participants. The large study was found to be of high quality with little risk of bias. The smaller study did not report on the methods of randomisation, how the randomisation was concealed and the pre-selected outcomes of interest. Combined, the studies had 181 participants; 116 underwent the cut-down technique and 65 the percutaneous technique.

Both studies compared rates of death, major complications, wound infections, bleeding complications, and length of the operation. Overall, we did not find any difference in the rates of death (moderate-quality evidence), major complications (moderate-quality evidence); or bleeding complications between the percutaneous and cut-down techniques (high-quality evidence). No one developed a wound infection (moderate-quality evidence). The surgery took less time (moderate-quality evidence) in the percutaneous group compared with the cut-down group.

Only one study reported if the aneurysm wall was successfully reinforced (checked by a CT scan, moderate-quality evidence), on complications at six months, (moderate-quality evidence); and on how long participants spent in an intensive treatment unit (ITU). We did not find any difference between the cut-down and percutaneous groups.

Quality of the evidence

This review shows moderate-quality evidence of no difference between the percutaneous approach compared with cut-down femoral artery access group for short-term mortality, aneurysm exclusion (sealing of the aneurysms), major complications, wound infection and long-term (six months) complications; and high-quality evidence for no difference in bleeding complications. There was a difference in operating time, with moderate-quality evidence showing that the percutaneous approach was faster than the cut-down femoral artery access technique. We downgraded the quality of the evidence to moderate due to the small number of studies, overall event rates and imprecision (differences around the level of effect).

Authors' conclusions: 

This review shows moderate-quality evidence of no difference between the percutaneous approach compared with cut-down femoral artery access group for short-term mortality, aneurysm exclusion, major complications, wound infection and long-term (six month) complications, and high-quality evidence for no difference in bleeding complications and haematoma. There was a difference in operating time, with moderate-quality evidence showing that the percutaneous approach was faster than the cut-down femoral artery access technique. We downgraded the quality of the evidence to moderate as a result of the limited number of studies, low event numbers and imprecision. As the number of included studies were limited, further research into this technique would be beneficial. The search identified one ongoing study, which may provide an improved evidence base in the future.

Read the full abstract...
Background: 

Abdominal aortic aneurysms (AAAs) are a vascular condition with significant risk attached, particularly if they rupture. It is, therefore, critical to identify and repair these as an elective procedure before they rupture and require emergency surgery. Repair has traditionally been an open surgical technique that required a large incision across the abdomen. Endovascular abdominal aortic aneurysm repairs (EVARs) are now a common alternative. In this procedure, the common femoral artery is exposed via a cut-down approach and a graft introduced to the aneurysm in this way. This review examines a totally percutaneous approach to EVAR. This technique gives a minimally invasive approach to femoral artery access that may reduce groin wound complication rates and improve recovery time. The technique may, however, be less applicable in people with, for example, groin scarring or arterial calcification. This is an update of the review first published in 2014.

Objectives: 

This review aims to compare the clinical outcomes of percutaneous access with surgical cut-down femoral artery access in elective bifurcated abdominal endovascular aneurysm repair (EVAR).

Search strategy: 

For this update the Cochrane Vascular Information Specialist (CIS) searched their Specialised Register (last searched October 2016) and CENTRAL (2016, Issue 9). We also searched clinical trials registries and checked the reference lists of relevant retrieved articles.

Selection criteria: 

We considered only randomised controlled trials. The primary intervention was a totally percutaneous endovascular repair. We considered all device types. We compared this against surgical cut-down femoral artery access endovascular repair. We only considered studies investigating elective repairs. We excluded studies reporting emergency surgery for a ruptured abdominal aortic aneurysm and those reporting aorto-uni-iliac repairs.

Data collection and analysis: 

Two review authors independently collected all data. Owing to the small number of trials identified we did not conduct any formal sensitivity analysis. Heterogeneity was not significant for any outcome.

Main results: 

Two studies with a total of 181 participants met the inclusion criteria, 116 undergoing the percutaneous technique and 65 treated by cut-down femoral artery access. One study had a small sample size and did not adequately report method of randomisation, allocation concealment or pre-selected outcomes. The second study was a larger study with few sources of bias and good methodology.

We observed no significant difference in mortality between groups, with only one mortality occurring overall, in the totally percutaneous group (risk ratio (RR) 1.50; 95% confidence interval (CI) 0.06 to 36.18; 181 participants; moderate-quality evidence). Only one study reported aneurysm exclusion. In this study we observed only one failure of aneurysm exclusion in the surgical cut-down femoral artery access group (RR 0.17, 95% CI 0.01 to 4.02; 151 participants; moderate-quality evidence). No wound infections occurred in the cut-down femoral artery access group or the percutaneous group across either study (moderate-quality evidence).

There was no difference in major complication rate between cut-down femoral artery access and percutaneous groups (RR 0.91, 95% CI 0.20 to 1.68; 181 participants; moderate-quality evidence); or in bleeding complications and haematoma (RR 0.94, 95% CI 0.31 to 2.82; 181 participants; high-quality evidence).

Only one study reported long-term complication rates at six months, with no differences between the percutaneous and cut-down femoral artery access group (RR 1.03, 95% CI 0.34 to 3.15; 134 participants; moderate-quality evidence).

We detected differences in surgery time, with percutaneous approach being significantly faster than cut-down femoral artery access (mean difference (MD) -31.46 minutes; 95% CI -47.51 minutes to -15.42 minutes; 181 participants; moderate-quality evidence). Only one study reported duration of ITU (intensive treatment unit) and hospital stay, with no difference found between groups.

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