John: A major development in health care in recent decades has been the ability of doctors to access difficult to reach parts of a patient’s body through their blood vessels. These endovascular procedures require access to the inside of an artery and need to finish by closing the hole that was created to enter the artery. The lead author of a new Cochrane Review in March 2016, Lindsay Robertson, from Freeman Hospital in Newcastle upon Tyne in the UK tells us about the evidence for one of the ways to do this.

Lindsay: When we do an endovascular procedure, we make a small hole in the artery at the groin, and a catheter is guided through the patient’s blood vessels until it reaches the site of interest. When the procedure is complete, we need to close the hole in the artery and stop any bleeding. This is called haemostasis, and it can lead to complications, such as damage to the artery and worse, bleeding. Traditionally, the main method of closing the artery is compression, during which manual pressure or mechanical clamps are applied directly to the patient's groin for up to 30 minutes. This manual pressure can be painful and requires up to eight hours of bedrest. Pressure applied to the artery also affects the nearby vein and may cause blood clots leading to deep vein thrombosis. An alternative procedure is to use a vascular closure device which is designed to close the hole and stop bleeding. These were developed in the 1990s in an attempt to reduce the time to stop bleeding, to enable earlier walking after a procedure and to improve patient comfort. There are four main types of vascular closure devices, depending on the material used: collagen plugs, suture-based, disc-based and metal clips; but there is uncertainty about the effectiveness of vascular closure devices in reducing procedure time, length of stay or time to mobilisation, and little is known about whether they cause additional complications.
Our review examined the effectiveness and safety of different types of vascular closure devices compared to one another and with traditional methods of manual compression, but shows that the current evidence base is not good enough to be sure about their effects. We assessed time to haemostasis and time to mobilisation, as well as safety outcomes: death and adverse events such as bleeding, arterial damage, infection and development of clots in the adjacent vein. We also measured the technical failure of vascular closure devices and the length of hospital stay associated with their use.
We found 52 randomised trials involving a total of nearly 20,000 patients. The studies compared different vascular closure devices with manual or mechanical compression or with one other, but they provided low-quality evidence for time to haemostasis and time to mobilisation. For the safety outcomes, we felt that the overall quality of evidence was moderate.
In summary, the studies were too different to be combined in a statistical analysis of vascular closure devices versus compression for time to haemostasis and time to mobilisation. For safety outcomes, there is no robust evidence that vascular closure devices reduce the number of serious puncture site complications, when compared with manual or mechanical compression. Furthermore, we found no difference in effectiveness or safety for one type of vascular closure device versus another, but few studies made these comparisons. This means that further good quality studies will be needed before the uncertainties are resolved and firm conclusions can be drawn.

John: If you would like to read more about the dozens of studies that are already in this review, and to watch for future updates as new research is done, log on to Cochrane Library dot com and run a search for 'vascular closure devices'.