Carotid Doppler microembolic signals in patients one year after heart valve surgery

Abstract

Doppler ultrasound has been used to detect microemboli during and after cardiopulmonary bypass (CPB). The aim of the present study was to examine the frequency of microembolic signals (MES) in patients one year after heart valve replacement, to look for possible risk factors associated with MES and for any correlation with cerebral events. One hundred patients, 69 male and 31 female, mean age 66.3±12.4 years, were examined one year after heart valve replacement. Thirty patients, 61% male and 39% female, mean age 62.5±8.7 years, who had undergone cardiovascular operations without heart valve pathology served as controls. A newly developed micro-emboli detector, EMEX-25 (Hatteland Instrumentering, Norway) was used to detect MES from both carotid arteries. MES were detected in 61% of the valve patients. A correlation was found between the number of MES, previous cardiovascular operations, emergency surgery and EuroSCORE (p<0.05). There was no correlation between the number of MES and the level of anticoagulation expressed as international normalization ratio (INR), atrial fibrillation, serum-cholesterol, New York heart association (NYHA) class, gender, age, valve type or valve position. The average number of MES was not increased in seven patients who had experienced major (three) or minor (transient, four) cerebral events during follow-up. In the 30 nonvalve controls, MES were detected in 46% of the patients. MES were detected in valve patients as well as in nonvalve patients one year after surgery. In valve patients, a significant correlation was found between MES and previous surgery, emergency surgery and EuroSCORE. There was no correlation between the number of MES and INR level or postoperative cerebral events.

Get full access to this article

View all access options for this article.

References

Koertke H , Minami K , Bairaktaris A , Wagner O , Koerfer R. INR self-management following mechanical heart valve replacement . J Thromb Thrombolysis 2000; 9: 41-45 .

Svennevig JL. Off-pump vs on-pump surgery. A review . Scand Cardiovasc J 2000; 34: 7-11 .

Braekken S , Russell D , Brucher R , Abdelnoor M , Svennevig J. Cerebral microembolic signals during cardiopulmonary bypass surgery . Stroke 1997; 28: 1988-1992 .

Brucher R , Russell D. Background and principles. In Tegeler CH , Babikian VL , Gomes CR eds. Neurosonology. St Louis, MO: Mosby-Year book , 1996: 231-234.

Gallagher EG , Pearson DT. Ultrasonic identification of sources of gaseous microemboli during open heart surgery . Thorax 1973; 28: 295-305 .

Hatteland K , Semb BK. Gas bubble detection in fluid lines by means of pulsed Doppler ultrasound . Scand J Thorac Cardiovasc Surg. 1985; 19: 119-123 .

Spencer MP , Lawrence GH , Thomas GI , Sauvage LR. The use of ultrasonics in the determination of arterial aeroembolism during open-heart surgery . Ann Thorac Surg 1969; 8: 489-497 .

Padayachee TS , Parsons S , Theobold R , Linley J , Gosling RG , Deverall PB. The detection of the micro-emboli in the middle cerebral artery during cardiopulmonary bypass . Ann Thorac Surg 1987; 44: 298-302 .

Padayachee TS , Parsons S , Theobold R , Gosling RG , Deverall PB. The effect of arterial filtration on reduction of gaseous microemboli in the middle cerebral artery during cardiopulmonary bypass . Ann Thorac Surg 1988; 45: 647-649 .

10.

Russell D , Madden KP , Clark WM , Sandset PM , Zivin JA. Detection of arterial microemboli using Doppler ultrasound in rabbits . Stroke 1991; 22: 253-258 .

11.

Harrison MJG , Pugsley W , Newman S , et al. Detection of middle cerebral emboli during coronary artery bypass surgery using transcranial Doppler sonography . Stroke 1990; 21: 1512-1512 .

12.

Stump DA , Newman SP. Embolus detection during cardiopulmonary bypass, In Tegeler CH , Babikian VL , Gomes CR eds. Neurosonology. St Louis, MO: Mosby-year book , 1996: 252-255.

13.

Clark RE , Brillman J , Davis DA , Lovell MR , Price TRP , Magovern GJ. Microemboli during coronary artery bypass grafting: genesis and effect on outcome . J Thorac Cardiovasc Surg 1995; 109: 249-258 .

14.

Barbut D , Hinton RB , Szatrowski TP , et al. Cerebral emboli detected during bypass surgery are associated with clamp removal . Stroke 1994; 25: 2398-2402 .

15.

Baker AJ , Naser B , Benaroia M , Mazer CD. Cerebral microemboli during coronary artery bypass using different cardioplegia techniques . Ann Thorac Surg 1995; 59: 1187-1191 .

16.

D’Alfonso A , Milano AD , Codecasa R , et al. High-intensity transcranial Doppler signals in patients wearing heart valve prostheses: a prospective study . G Ital Cardiol 1999; 29: 401-410 .

17.

Lievense AM , Bakker SL , Dippel DW , Taams MA , Koudstaal PJ , Bogers AJ. Intracranial high-intensity transient signals after homograft or mechanical aortic valve replacement . J Cardiovasc Surg (Torino) 1998; 39: 613-617 .

18.

Kofidis T , Fischer S , Leyh R , et al. Clinical relevance of intracranial high intensity transient signals in patients following prosthetic aortic valve replacement . Eur J Cardiothorac Surg 2002; 21: 22-26 .

19.

Georgiadis D , Braun S , Uhlmann F , et al. Doppler microembolic signals in patients with two different types of bileaflet valves . J Thorac Cardiovasc Surg 2001; 121: 1101-1106 .

20.

Braekken SK , Reinvang I , Russell D , Brucher R , Svennevig JL. Association between intraoperative cerebral microembolic signals and postoperative neuropsychological deficit: comparison between patients with cardiac valve replacement and patients with coronary artery bypass grafting . J Neurol Neurosurg Psychiatry 1998; 65: 573-576 .

21.

Pugsley W , Klinger L , Paschalis C , Treasure T , Harrison M , Newman S. The impact of microemboli during cardiopulmonary bypass on neuropsychological functioning . Stroke 1994; 25: 1393-1399 .

22.

Buhre W , Buhre K , Aleksic I , Zenker D , Sonntag H , Weyland A. Doppler-sonographic evidence of cerebral microembolism originating from a biventricular assist device . Thorac Cardiovasc Surg 2000; 48: 300-302 .

23.

Knappertz VA , Tegeler CH , Furberg CD , Wesley DJ , Stewart KP , Kitzman DW. Carotide Doppler high intensity transient signals in dilated cardiomyopathy . Am Heart J 2000; 140: 1-4 .

24.

Batista P , Oliveira V , Ferro JM. The detection of microemboli in patients at risk of recurrent cardioembolic stroke: possible therapeutic relevance . Cardiovasc Dis 1999; 9: 314-319 .

25.

Eicke BM , Barth V , Kukowski B , Werner G , Paulus W. Cardiac microembolism: prevalence and clinical outcome . J Neurol Sci 1996; 136: 143-147 .

26.

Rambod E , Beizaie M , Shusser M , Milo S , Gharib M. A physical model describing the mechanism for formation of gas microbubbles in patients with mitral mechanical valves . Ann Biomed Ing 1999; 27: 774-792 .

27.

Telman G , Kouperberg E , Sprecher E , Yarnitsky D. The nature of microemboli in patients with artificial valves . J Neuroimaging 2002; 12: 15-18 .

28.

Baumgartner RW , Frick A , Kremer C , et al. Microembolic signal counts increase during hyperbaric exposure in patients with prosthetic valves . J Thorac Cardiovasc Surg, 2001; 122: 1142-1146 .

29.

Laas J , Kseibi S , Perthel M , Klingbeil A , El-Ayoubi L , Alken A. Impact of high intensity transient signals on the choice of mechanical aortic valve substitutes . Eur J Cardiothorac Surg 2003; 23: 93-96 .

30.

Braekken SK , Russell D , Brucher R , Svennevig JL. Incidence and frequency of cerebral embolic signals in patients with a similar bileaflet mechanical heart valve . Stroke 1995; 26: 1225-1230 .

31.

Perthel M , Hasenkam JM , Nygaard H , Kupper W , Laas J. Turbulence and high intensity transient signals (HITS) as a parameter for optimum orientation of mechanical heart valves . Z Kardiol 2001; 90(Suppl 6): 100-104 .

32.

Roques F , Nashef SAM , Michel P , et al. Risk factors and outcome in European cardiac surgery: analysis of the EuroSCORE multinational database of 19030 patients . Eur J Cardio Thorac Surg 1999; 15: 816-823 .

33.

Deklunder G , Lecroart JL , Conger JL , et al. Effects of myocardial contractility on microemboli production by mechanical heart valves in a bovine model . Tex Heart Inst J 2000; 27: 236-239 .

34.

Conger JL , Deklunder GM , Lecroart JL , et al. A bovine model for detecting high intensity transient signals originating from mechanical heart valves . ASAIO J 2000; 46: 344-350 .

35.

Georgiadis D , Baumgartner RW , Karatschai R , Lindner A , Zerkowski HR. Further evidence of gaseous embolic material in patients with artificial heart valves . J Thorac Cardiovasc Surg 1998; 115: 808-810 .

36.

Rambod E , Beisaie M , Shusser M , Milo S , Gharib M. A physical model describing the mechanism for formation of gas microbubbles in patients with mitral mechanical valves . Ann Biomed Ing 1999: 27: 774-792 .