Creating a reliable sterile field through exsanguination and arterial occlusion under tourniquet is a practise widely used in Orthopaedic Surgery in order to provide the surgeon with optimal visual capacity and to minimise blood loss. Achieving exsanguination can be time consuming and the effectiveness is variable due to variations in technique. It often employs the use of multi-patient devices such as the Rhys-Davies Exsanguinators which could increase the risk of surgical site infections through contamination of the field adjacent to the surgical site. This article reviews the current techniques and discusses a new concept for creating a sterile, bloodless field on a limb in around 15 seconds using a unique new product - the S-MART™ sterile exsanguinating tourniquet system.
History of Tourniquet use
The use of tourniquets for both upper and lower limb surgery has been common practice in amputations for many centuries. However, although methods of exsanguination used today (such as limb elevation and the Esmarch bandage) appear to date back to the early 19th century, it was not until around 1860 that the use of bloodless surgery was first applied, by Joseph Lister, in procedures other than amputations.
Exsanguinating the limb prior to surgery holds numerous advantages including establishing a clear operating field, reducing overall blood loss and reducing the risk of micro-emboli on tourniquet release. The limb is usually exsanguinated through elevation, Esmarch Bandage or Rhys-Davies techniques. The tourniquet is then applied to the limb to prevent the blood from returning to the exsanguinated limb during surgery. The tourniquet is usually a pneumatic cuff, which is placed on the upper arm or thigh and is inflated by a machine to a pre-determined pressure. This pressure is typically 200-250mmHg for upper and 300-350mmHg for lower limbs although this may vary with limb size and the systolic pressure of the patient. The ideal is to provide a clear bloodless field throughout the duration of surgery.
Tourniquet techniques and issues
In order to help reduce the risk of surgical site infections and cross contamination, the tourniquet is generally placed well away from the operative site as it is usually a non-sterile device with non-sterile attachments, but even then issues can arise when using pneumatic tourniquets on the thighs of obese patients where fixation and slippage can be a problem. Exsanguination is important for a clear visual operating field; however exsanguination devices are also often non-sterile, made of perishable materials, time consuming to apply and their effectiveness can be user dependant. Similarly, slippage can cause distal migration of the non-sterile items resulting in loss of pressure thereby reducing the effectiveness of the initial exsanguination.
A new concept and approach to exsanguination and arterial occlusion
So, S-MART™ is not just a tourniquet, it is a sterile, latex free, single use device that exsanguinates, places a sterile stockinette and occludes the artery. The S-MART™ device is placed on the patient by the scrubbed surgeon or a member of the scrub team after the limb has undergone skin preparation. The device can be used for any procedure from carpal tunnel work to Bilateral TKR.
This new practice concept provides several potential benefits over the traditional methods (Fig 2).
How the device works
The S-MART™ uses a simple yet innovative approach to limb exsanguination and arterial occlusion. The basis of the idea stems from the original Esmarch device invented by Johann T. Friederich von Esmarch in the 19th century. The name Esmarch is today widely associated with the elasticated bandages used for limb exsanguination but the original Esmarch device was an altogether more innovative approach
The Esmarch device was a rubber tube that was wound tightly around the limb and then moved proximally using a wooden roller. This process provided consistent pressure leading to good exsanguination but the device then also served as a tourniquet at the appropriate placement site. The S-MART™ uses a similar idea in order to provide superior exsanguination1 and tourniquet properties in a single device.
In the case of S-MART™, the rubber tube is replaced by a silicone ring, the tensile properties of which vary by device type, depending on the force required to generate the appropriate internal pressures. The device's pull straps facilitate placement and a stockinette unravels during application in order to provide a sterile barrier.
The dimensions of the patients' limbs vary as does their systolic pressure. An understanding of both is required to ensure that the correct S-MART™ is chosen for surgery. So, the device is available in sizes for upper and lower limbs. There are also sizes that are appropriate for extreme limb dimensions. The S-MART™ small is used for small or paediatric limbs2,3 and the extra large for oversized limbs4 covering thighs with a circumference of up to 90 cm. So, before selecting the appropriate S-MART™ device from the selection chart (Fig 3), the limb circumference at the desired placement site should be measured along with the patients' systolic pressure.
In practice, product selection is straightforward and quick. Generally, surgery on the arm5 or foot and ankle6 should employ the use of the S-MART™ yellow size; this will work for systolic pressures of 190mmHg and below. For thighs select the S-MART™ brown size, this too work for systolic pressures of up to 190mm Hg. For extra large thighs the S-MART™ XL black and white can be used.
The device comes double wrapped and should be offered into the sterile field using normal aseptic technique. The patient's fingers or toes are placed into the device aperture and the straps pulled outwards and proximally along the limb. This rolls the S-MART™ proximally along the limb. Exsanguination takes place during proximal movement of the device as does the application of the stockinette. The final resting position of the S-MART™ is the point where occlusion occurs. Due to the facts that as it is both sterile and has a narrow profile, versatility in site placement can be achieved. Once in position the S-MART™ has exsanguinated the limb and occluded the vessels at the point of placement so the stockinette can be cut away, or a window opened through it at the surgical site. The whole process of rolling the S-MART™ on and achieving a sterile bloodless field with occlusion takes approximately 15 seconds once initial training has been completed.
In practice, once the S-MART™ is on it stays in position and does not roll or slip even on tapered or obese limbs. At the end of the procedure removal of the device is achieved by using a scalpel to cut through the top layers of stockinette and the blue silicone rubber ring that lies just below the stockinette around the device. The S-MART™ gently parts and can be removed, thereby refusing the exsanguinated limb.
Batch traceability stickers are available on the outer packaging, and the device pressure is also printed on the outer package should this need to be recorded. In practise the pressures produced by the S-MART™ are often less than the standard pneumatic tourniquet pressures.
Discussion, Practical and Safety Issues
Using this product offers many potential advantages to the clinician and the patient. As it is a new technique there are some practical points to consider too. The draping procedure might need to be slightly modified in some cases. There is no need for the traditional method of exsanguination, as this is achieved by the surgeon as the product is applied. Full support is provided by the supplier during evaluations to make any minor modifications to practise and run the trials as smoothly as possible.
The tourniquet time should be started once the S-MART™ is in position on the limb, and the product can stay on the limb for a maximum of 120 minutes as indicated for standard tourniquets.
During the development of this device, particular attention was paid to ensuring the continued safety of the patient. Issues such as neuropraxia and tourniquet burns have been reported at a frequency approximating 1 in 8,0009 uses of the pneumatic tourniquet, however, the S-MART™ has undergone over 80,000 uses in Europe and the USA with no such reported incidents.
This is a relatively new concept for the UK, but it is being well received for a wide range of orthopaedic and plastic surgical procedures including total knee arthroplasty, foot and ankle procedures6,7,8, hand5 and elbow surgery. Although the S-MART™ will not completely replace the pneumatic tourniquet it is ideal for use in elective cases and is being readily adopted. The use of S-MART™ is being driven by the infection control benefits of single patient use coupled with the creation of a superior bloodless field, improved access to operative sites, versatility of site placement and time saving capabilities make S-MART™ an important and significant development in the use of tourniquets.
- Superior Exsanguination with S-MART™ in Lower and Upper Extremities - a photographic testimonial. OHK Medical Devices Ltd.
- Eidelman M et al. A novel elastic exsanguination tourniquet as an alternative to the pneumatic cuff in paediatric orthopaedic limb surgery. Journal of paediatric orthopaedics B 2006 Sept; 15 (5): 379-384
- GP de Kiewiet. Moving to a new type of sterile and single use tourniquet for orthopaedic surgery. Orthopaedic Product News. March/April 2006.
- Prof Gavriely, S Freer, N Suchard and O Gavriely. Tourniquet and the Obese patient. Prepared by OHK Medical devices.
- Boiko M and Roffman M Evolution of a Novel tourniquet device for bloodless surgery of the hand. Journal of Hand Surgery (British and European Volume, 2004) 29B: 2: 185 – 187
- Henderson M. Exsanguinating Tourniquet Assessed. The Clinical Services Journal. September 2006.
- Melamed E et al. The use of a surgical exsanguination Tourniquet (SET) in Foot and Ankle surgery. White paper from Rambam Medical centre, Haifa, Israel.
- Mohan A et al. A randomized controlled study looking at the use of S-MART™and Pneumatic tourniquet in foot surgery. White paper from Kingston General Hospital, Kingston Hospital NHS Trust, UK.
- Ochoa J et al. Anatomical changes in peripheral nerves compressed by a pneumatic tourniquet. J.Anat. (1972), 113, 3. pp. 433-455
- Walsh E, Ben-David D, Ritter M, Mechrefe A, Mermel L and DiGiovanni C. Microbial colonization of tourniquets used in orthopedic surgery. Orthopedics 2006; 29: 709