Clinical trial NCT02240732: Surgical Tourniquets and Cerebral Emboli
Official title: Surgical Tourniquets and Cerebral Emboli Pilot Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Osteoarthritis
RA
Trauma
Lead sponsor: University Hospitals Coventry and Warwickshire NHS Trust
Sponsor class: OTHER
First posted: 2014-09-16
Enrollment: 12
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Patients who are due to have a total knee replacement.

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?


Eligibility criteria: Inclusion Criteria:

* i.Aged \>18
* ii.Undergoing elective TKR
* iii.Able to give written informed consent
* iv.No contraindications to MR imaging

Exclusion Criteria:

* i. Ages \<16
* ii. Not able to give written informed consent
* iv. Contraindications to MR imaging

Primary outcomes:
measure: Number of Emboli on Transcranial Doppler
timeFrame: Intra-operative
measure: MRI brain scan - presence of Emboli
timeFrame: Post-operatively, prior to discharge
Secondary outcomes:
measure: Mini-mental state examination
timeFrame: Pre-operative vs Post-operative
Other outcomes:
Locations:
city: Coventry
country: United Kingdom
facility: University Hospital Warwickshire and Coventry
Study officials:
affiliation: UHCW
name: Victoria Gibbs, BA, MBBS
role: PRINCIPAL_INVESTIGATOR
References:
citation: Tai TW, Lin CJ, Jou IM, Chang CW, Lai KA, Yang CY. Tourniquet use in total knee arthroplasty: a meta-analysis. Knee Surg Sports Traumatol Arthrosc. 2011 Jul;19(7):1121-30. doi: 10.1007/s00167-010-1342-7. Epub 2010 Dec 15.
citation: Parmet JL, Horrow JC, Pharo G, Collins L, Berman AT, Rosenberg H. The incidence of venous emboli during extramedullary guided total knee arthroplasty. Anesth Analg. 1995 Oct;81(4):757-62. doi: 10.1097/00000539-199510000-00017.
citation: Parmet JL, Berman AT, Horrow JC, Harding S, Rosenberg H. Thromboembolism coincident with tourniquet deflation during total knee arthroplasty. Lancet. 1993 Apr 24;341(8852):1057-8. doi: 10.1016/0140-6736(93)92414-o.
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citation: Pugsley W, Klinger L, Paschalis C, Treasure T, Harrison M, Newman S. The impact of microemboli during cardiopulmonary bypass on neuropsychological functioning. Stroke. 1994 Jul;25(7):1393-9. doi: 10.1161/01.str.25.7.1393.
citation: Riding G, Daly K, Hutchinson S, Rao S, Lovell M, McCollum C. Paradoxical cerebral embolisation. An explanation for fat embolism syndrome. J Bone Joint Surg Br. 2004 Jan;86(1):95-8.
citation: Caillouette JT, Anzel SH. Fat embolism syndrome following the intramedullary alignment guide in total knee arthroplasty. Clin Orthop Relat Res. 1990 Feb;(251):198-9.