Clinical Trial: Surgical Tourniquets and Cerebral Emboli

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Surgical Tourniquets and Cerebral Emboli Pilot Study

Brief Summary:

BACKGROUND In 2012 76,497 primary total knee (TKR) replacements were performed in England, Wales and Northern Ireland . Traditionally TKR surgery is undertaken with the aid of a surgical tourniquet. A surgical tourniquet is an occlusive device applied around a patient's leg. The tourniquet squeezes the leg (including blood vessels within the leg) and can therefore reduce the amount of bleeding that occurs while it is inflated. An intraoperative tourniquet can therefore help to improve the surgical field of view. Although the majority of surgeons prefer to undertake TKR surgery using a tourniquet a small but increasing number are now not pursuing these devices.

There is robust evidence that the risk of deep vein thrombosis is increased if a tourniquet is used for TKR surgery. In addition embolic material in the venous system have been observed following TKR surgery and have been noted to be present in the right atrium with transoesophageal (TOE) echo intra-operatively. , Significant and potentially life threatening emboli have been documented to enter the cerebral circulation via pulmonary arterio-venous shunts and patent foramen ovale (PFO) (27% of patients at autopsy) , . The clinical manifestations of cerebral emboli post tourniquet deflation in TKR are not fully understood. Fat embolism syndrome and post-operative confusion in TKR patients may be the result of emboli formed during a TKR. ,

AIM

  • Is there evidence of emboli entering the cerebral circulation following tourniquet deflation in TKR surgery?
  • Is there evidence of MRI detectable brain lesions and or any clinical change in cognition compared in patients undergoing TKR surgery with a tourniquet compared to those that do not have a tourniquet?

    • Detailed Summary:
    Sponsor: University Hospitals Coventry and Warwickshire NHS Trust

    Current Primary Outcome:

    • Number of Emboli on Transcranial Doppler [ Time Frame: Intra-operative ]
      2 independent technicians will verify the number of emboli detected. Non-invasive
    • MRI brain scan - presence of Emboli [ Time Frame: Post-operatively, prior to discharge ]
      Reviewed by Professor of radiology - presence, number and volume of diffusion weighted lesions


    Original Primary Outcome: Same as current

    Current Secondary Outcome: Mini-mental state examination [ Time Frame: Pre-operative vs Post-operative ]

    Set of 30 questions which test cognitive function


    Original Secondary Outcome: Same as current

    Information By: University Hospitals Coventry and Warwickshire NHS Trust

    Dates:
    Date Received: September 15, 2014
    Date Started: September 2014
    Date Completion:
    Last Updated: June 28, 2015
    Last Verified: June 2015