Surgical drains are frequently used in a wide range of surgical procedures, including lower limb arterial vascular surgery, despite a lack of firm evidence that they are beneficial (Barie 2002; Grobmyer 2002). Lower limb arterial surgery may be carried out electively, or as an emergency, to restore blood supply to the leg. The blood supply to the leg may be restricted due to partial blockages caused by the presence of an embolus (a substance formed from either a blood clot, air, fat or tumour tissue that is carried by the bloodstream) or a thrombus (blood clot attached to the wall of the artery), or by a condition known as atherosclerosis. In atherosclerosis an abnormal mass of fat, fibrous tissue and inflammatory cells (atheroma) within the artery combines with narrowing and hardening of the vessels (arteriosclerosis) to restrict blood flow. Blood flow blockages due to emboli or thrombi tend to be sudden in onset, whereas those blockages caused by atherosclerosis tend to occur gradually.
Surgical procedures to restore blood supply to the leg involve removing or bypassing the blockage. A thrombus or embolus can be removed by a thrombectomy or embolectomy procedure. If the blockage is caused by the slow build up of atheroma to a critical level, an endarterectomy may be performed. This is an operation in which a short deposit of atheroma is removed, thus improving blood flow. If removing the blockage is not a suitable option, the blockage may be bypassed using a graft. Grafts can be made of synthetic material or can be autologous (i.e. a portion of the patient's own vein). In some cases peripheral angioplasty - a technique in which narrowed or obstructed arteries are widened mechanically - is used in conjunction with surgical treatment. In this procedure, a collapsed balloon, known as a balloon catheter, is passed with X-ray guidance into the artery along a guide wire to the site of the obstruction. The balloon is inflated to open up the blood vessel for improved flow, then the balloon is deflated and withdrawn (Grace 1996)
Description of the condition
Peripheral arterial occlusive disease (PAOD), also known as peripheral vascular disease (PVD), refers to narrowing or blockage of the blood vessels bringing blood from the heart to distant parts of the body. PVD can occur in any blood vessel, but it most commonly affects the lower limbs. It is usually caused by atherosclerosis, although rare causes also exist. These rare causes include blockages caused by recurrent small emboli or arteritis (inflammation of the artery). People with PVD present with signs and symptoms that vary according to the severity of the arterial blockage and the subsequent reduction in arterial blood supply (ischaemia). Symptoms range from none, to intermittent claudication (leg pain when walking that is relieved by rest), to pain at rest, ulceration or gangrene (tissue death). Data from the National Health and Nutrition Examination Survey in the USA, report the prevalence of PVD in the general population as being 12% to 14%, with prevalence increasing to 20% in those over 75 years of age. Amongst those affected, 70% to 80% are asymptomatic, and only a minority require revascularisation (a procedure to restore blood supply) (Ostchega 2007; Selvin 2007; Shammas 2007). The incidence of symptomatic PVD increases with age, from about 0.3% per year for men aged 40 to 55 years, to about 1% per year for men aged over 75 years (Shammas 2007).
Lower limb arterial surgery is performed to restore blood flow to legs that are affected by acute or chronic ischaemia when non-operative treatment has not been successful (Grace 1996). These procedures are often complicated by groin haematomas (localised collection of blood outside blood vessels, within the tissue), lymphoceles (a collection of lymphatic fluid that can result from damage to lymph vessels during surgery), or seromas (a pocket of clear serous fluid that develops after surgery) (Youssef 2005; Karthikesalingam 2008).These complications can lead to infection, with resulting failure of vein grafts, and therefore should be avoided if possible (Youssef 2005; Karthikesalingam 2008).
Description of the intervention
Drains serve to remove blood, lymph, serum and other fluids that can accumulate in the wound bed after an operation. If allowed to collect, these fluids can form haematomas, seromas and lymphoceles that can put pressure on the surgical site and adjacent organs, vessels, and nerves. This increased pressure can cause additional pain, and reduce the delivery of blood to the micro vessels (reduced perfusion), which impairs healing. Accumulated fluid can also increase the risk of infection. The practice of placing drains routinely to safeguard against complications in surgical wound management following lower limb arterial surgery remains widespread (Grobmyer 2002). Some units employ a selective policy of using drains if there have been concerns over haemostasis (stopping bleeding) intra-operatively, while others use drains routinely (Karthikesalingam 2008). Drains can rely on pressure and gravity to help drainage (passive drainage), or can be helped by a suction mechanism (active drainage). Fluids can be removed from a wound using either open or closed systems. An open drain depends on gravity to remove fluid from a wound site into a wound dressing placed over the end of the drain; examples include corrugated, Penrose and Yeates drains. A closed drainage system consists of a tube left in the wound that drains fluids from the body into a closed container. Closed drains may be assisted by suction or a vacuum, as in the Redon or Jackson-Pratt drains. The type of drain upon which a surgeon decides depends upon the location of the operative site and the amount of drainage expected. In certain procedures the use of drains has been shown to be of no benefit, and it has been suggested they may cause harm to the patient (for instance providing a portal for invasion by bacterial pathogens) (Barie 2002). Open drains are associated with an increased risk of infection, as, not only do they provide a portal for infection, but they also provide the potential for drained fluid to come into contact with, and so contaminate, the incision site. They should be avoided, particularly if a prosthesis is present (Smith 1985). Debate regarding the use of drains following lower limb arterial surgery is on-going; this review aims to clarify the benefits and harms of this intervention to this patient group.
How the intervention might work
The potential benefits of drainage are many, and include prevention of fluid collections, reduction of infections and earlier identification of bleeding (Youssef 2005). Conversely, drains may cause infection due to delayed wound closure, and may prolong hospital stay (Karthikesalingam 2008).
Why it is important to do this review
The benefits of routine drainage have not materialised to the degree that one might expect, with numerous studies from a wide range of specialties suggesting that routine drainage is not advantageous (Karliczek 2006; Gurusamy 2007a; Gurusamy 2007b; Gurusamy 2007c; Hellums 2007; Parker 2007; Samraj 2007; Clifton 2008; Charoenkwan 2010; Diener 2011; Wang 2011; Zhang 2011; Gurusamy 2012). It is unclear whether routine placement of surgical drains is of benefit in lower limb arterial surgery. Currently, there are no formal guidelines for usage of drains following arterial surgery. A systematic review on this topic was published in 2008 (Karthikesalingam 2008) and concluded there was no clear evidence that closed-suction drainage reduced complications following lower limb revascularisation. The review included data from only four small trials which, combined with an absence of information on data extraction and validity assessment, limits the reliability of the findings. This review aims to provide a definitive appraisal of the evidence on drainage in lower limb arterial surgery. We aim to provide vascular surgeons with robust data, from a thorough evaluation of the literature, upon which to base their drain-usage policy. In addition it is hoped this review will provide policy makers with the evidence to support, or limit, this practice.