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Ann Thorac Surg 2000;70:1362-1365
© 2000 The Society of Thoracic Surgeons

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Original articles: cardiovascular

Reliability of Allen’s test in selection of patients for radial artery harvest

^a Department of Cardiothoracic Surgery, Glenfield Hospital, Leicester, United Kingdom

Address reprint requests to Dr Martin A. Jarvis, Department of Cardiothoracic Surgery, Yorkshire Heart Centre, Great George St, Leeds LS1 3EX, UK
e-mail: martin-sie{at}cabg-jarvis.freeserve.co.uk

	Abstract

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Background. Allen’s test is widely used to assess the ulnar collateral blood supply of the hand before radial artery harvest for coronary bypass surgery. This study was performed to determine the optimum cut-off point for a positive Allen’s test and the clinical reliability of Allen’s test in this role.

Methods. Patients undergoing coronary artery bypass surgery were examined by independent observers using both Allen’s test and a Doppler ultrasound test of the ulnar collateral circulation.

Results. We examined 93 hands in 47 patients; mean age was 63.6 years. Receiver operating characteristic analysis found that at a conventional cut-off of 6 seconds on Allen’s test had a sensitivity of 54.5%, specificity of 91.7%, and diagnostic accuracy of 78.5%. At a cut-off of 5 seconds diagnostic accuracy was maximal (79.6%), with sensitivity of 75.8% and specificity of 81.7%; 100% sensitivity occurred at a cut-off of 3 seconds, with specificity of 27% and diagnostic accuracy of 52%.

Conclusions. At no cut-off point does Allen’s test perform satisfactorily as a discriminatory test. It should be replaced by more objective tests, such as Doppler ultrasound.

	Introduction

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
The demonstration by Carpentier and associates [1] of long-term radial artery graft patency has led to renewed interest in the use of the radial artery for coronary artery bypass. Early patency rates are good, approximately 95% after 1 year, and its use is thus likely to increase [1, 2]. However, concerns exist regarding the risk of hand ischemia should there be an inadequate ulnar collateral blood supply. In an unselected population the risk is approximately 5% [3], but this is likely to be higher in patients requiring myocardial revascularization because of concomitant peripheral vascular disease. To identify those patients at risk of ischemia a preoperative assessment of the ulnar collateral blood supply using Allen’s test is commonly practiced [4]. There is, however, no consensus regarding the optimum cut-off time for a positive Allen’s test. We therefore performed a clinical study to determine this, and to examine the overall reliability of Allen’s test as a clinical tool for selecting patients for safe radial artery harvest.

	Material and methods

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
This study was approved in July 1997 by the Local Research Ethics Committee.

Patients undergoing coronary bypass surgery at Glenfield Hospital were examined on the ward (ambient temperature 18 to 21°C) and asked to rest supine for 10 minutes before examination and to remove or loosen any tight clothing from around their arms. A modified Allen’s test and a Doppler ultrasound test of the ulnar collateral blood supply of both hands were performed by independent observers. The only exclusion criterion was inability to perform Allen’s test.

The modified Allen’s test was performed in the following manner. The patient made a tightly clenched fist for 10 seconds to exsanguinate the skin of the palm of the hand. With the fist still clenched, the examiner occluded the radial and ulnar arteries at the wrist and the patient was instructed to open the hand without hyperextending the wrist or fingers [5, 6]. The ulnar artery was then released and the capillary return time to the palm of the hand noted.

The Doppler ultrasound test was similar to that decribed by Marcillon and colleagues [7]. A continuous-wave 8-MHz hand-held Doppler ultrasound probe, linked to a thermal printer for permanent recording of the waveform (Huntleigh Diagnostics, Cardiff, UK) was positioned over the princeps pollicis artery (PPA) of the thumb as it crosses the flexor surface of the first metacarpophalangeal joint. The PPA was isonated before and during radial artery compression and, on the basis of the audio signal and chart record, the Doppler waveform was classified as triphasic, biphasic, monophasic, or absent [8]. The use of stereo earphones to listen to the audio signal made it very simple to distinguish between triphasic and biphasic flows because forward flow is heard in one ear and reverse flow in the other. Triphasic flow is characterized by prominent systolic forward flow, early diastolic flow reversal, and a second phase of forward flow throughout the rest of diastole. With biphasic flow the reverse flow during diastole is lost but forward flow throughout the whole cardiac cycle is preserved. Monophasic flow is characterized by flow during systole only. The normal Doppler waveform in the PPA was triphasic. For this study preservation of a triphasic Doppler signal on radial artery compression was defined as an adequate ulnar collateral blood supply (Fig 1) , whereas damping of the Doppler signal, reducing it to biphasic, monophasic, or absent, was taken to indicate an inadequate ulnar collateral blood supply [8].

View larger version (21K): [in this window] [in a new window]   Fig 1. Doppler ultrasound waveform recordings from the princeps pollicis artery (A) before and (B) during radial artery compression demonstrating no change in the arterial pulse waveform in a patient with an adequate ulnar collateral blood supply.

	Results

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Data were obtained from 93 hands (46 right, 47 left) in 47 patients (35 men, 12 women) undergoing coronary bypass surgery. Mean age was 63.6 years (SD ± 6.74 years). It was not possible to examine the right hand of one man because of previous traumatic amputation of his right thumb. The normal Doppler wave form in the PPA of all hands examined was triphasic.

Radial artery compression caused a damping of the Doppler signal in 33 hands (36%) in 23 patients, indicating a reduced ulnar collateral blood supply (Fig 2). With a conventional 6-second cut-off Allen’s test was positive in 23 hands (18 true positive, 5 false positive) and negative in 70 (15 false negative and 55 true negative). Thus it has a sensitivity of 54.5%, specificity of 91.7%, and diagnostic accuracy of 78.5%. ROC analysis found that the diagnostic accuracy was maximal (79.6%) at a cut-off of 5 seconds, yielding a sensitivity of 75.8% and a specificity of 81.7%. Allen’s test was then positive in 36 hands (25 true positive, 11 false positive) and negative in 57 (49 true negative, 8 false negative). The sensitivity is 100% at a cut-off of 3 seconds. At this cut-off Allen’s test is positive in 77 hands (33 true positive, 44 false positive) and negative in 16 (16 true negative, 0 false negative). The specificity is then 27% and the diagnostic accuracy 52%.

View larger version (23K): [in this window] [in a new window]   Fig 2. Doppler ultrasound waveform recordings from the princeps pollicis artery (A) before and (B) during radial artery compression demonstrating significant damping of the arterial pulse waveform a patient with an inadequate ulnar collateral blood supply.

	Comment

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

Is the Doppler ultrasound test valid? The physiologic basis of the test is quite simple and the anatomical considerations are discussed later. The normal Doppler waveform in the PPA is triphasic. A negative Doppler ultrasound test is thus classified as the preservation of the normal Doppler waveform in the PPA on radial artery compression. This may seem overly rigorous but it is a readily identifiable cut-off point thatdifferentiates a normal from an abnormal arterial hemodynamic state.

Which artery to examine with Doppler ultrasound is also an important consideration. In our initial studies we assessed the flow in a number of arteries in the hand, including the palmar arches, before the PPA was selected as the sole artery for Doppler ultrasound investigation, thus creating a simple test. Our rationale was as follows. The PPA is the last branch of the radial artery before the latter passes between the heads of the first dorsal interosseous muscle to become the deep palmar arch. In cases of incomplete palmar arches the PPA almost invariably arises on the radial side of the lesion, most discontinuities occurring at the level of the second or third ray [19]. In a study of 200 normal hands Kleinert and associates found the blood supply to the thumb to be radial artery dominant in 87%, ulnar artery dominant in 10.5%, and codominant in 2.5%. In the little finger the figures were 52%, 34%, and 14%, respectively [20]. Thus, after radial artery occlusion, the thumb is the digit most at risk of ischemia and evaluation of Doppler waveform in the PPA during radial artery compression can be used as a simple test of the ulnar collateral circulation [7, 18].

Compared to the Doppler ultrasound test our data show that Allen’s test is not reliable. Using a cut-off of 6 seconds the sensitivity is low (54.5%), so that approximately half of the patients with Doppler signs of an inadequate ulnar collateral circulation had a false-negative Allen’s test. ROC analysis found that the diagnostic accuracy was maximum at a cut-off of 5 seconds but the sensitivity is still only 75.8% and assumes equal value for the possible adverse outcomes of a false-negative and false-positive Allen’s test result. To increase the sensitivity to 100% requires a reduction in the cut-off to 3 seconds. In doing this the specificity falls to 27% and the diagnostic accuracy is only 52%. Thus to reduce the cut-off to the point where false negatives are abolished effectively renders the Allen’s test useless. At no cut-off point is Allen’s test able to accurately identify those patients with and those patients without an adequate ulnar collateral blood supply to the hand. Thus it is not possible to make recommendations regarding cut-off points. What our results do demonstrate clearly is that Allen’s test is not reliable and should be replaced. Ideally patients should be evaluated preoperatively in a vascular laboratory by one of the objective methods available, but in practice this may not be possible. We therefore advocate the use of the Doppler ultrasound test described here as a practical alternative to Allen’s test because the equipment is relatively inexpensive and easy to use, the test can be performed in the outpatient clinic or on the ward, and classification of the test result is less subjective.

Based on the Doppler ultrasound test 36% of hands were classified as being at risk of hand ischemia after radial artery harvest. Would application of this test deny an unreasonably large proportion of patients undergoing coronary bypass the potential benefits of a radial artery graft? Hand ischemia has occurred after radial artery harvest, although rarely. However, it is also rare that the radial artery is the only autologous conduit available. The long-term results of coronary artery bypass with the radial artery also remain unknown. Thus, we believe that caution is justified in patient selection for radial artery harvest.

In conclusion, the radial artery is potentially a valuable conduit for coronary bypass. However, the use of Allen’s test for the preoperative assessment of the ulnar collateral blood supply of the hand in patients undergoing coronary bypass surgery is unreliable. It should be abandoned in favor of more objective tests.

	Acknowledgments

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Martin A Jarvis is a British Heart Foundation Junior Research Fellow. This study was supported by Glenfield Hospital NHS Trust research grants.

	References

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 

1. Acar C., Jebara V.A., Portoghese M., et al. Revival of the radial artery for coronary artery bypass grafting. Ann Thorac Surg 1992;54:652-660.[Abstract]
2. Chen A.H., Nakao T., Brodman R.F. Early postoperative angiographic assessment of radial artery grafts used for coronary artery bypass grafting. J Thorac Cardiovasc Surg 1996;111:1208-1212.[Abstract/Free Full Text]
3. DeBakey M., Simeone F. Battle injuries of the arteries in World War II. Ann Surg 1946;123:534-579.[Medline]
4. Dietl C.A., Benoit C.H. Radial artery graft for coronary revascularization. Ann Thorac Surg 1995;60:102-110.[Abstract/Free Full Text]
5. Ejrup B., Fischer B., Wright I.S. Clinical evaluation of blood flow to the hand. Circulation 1966;33:778-780.[Abstract/Free Full Text]
6. Kamienski R.W., Barnes R.W. Critique of the Allen test for continuity of the palmar arch assessed by Doppler ultrasound. Surg Gynecol Obstet 1976;142:861-864.[Medline]
7. Marcillon M., Maestracci P., Guillot F., Dulbecco P., Filippi C., Valici A. Doppler velocimetric evaluation of the reliability of Allen’s test for radial artery catheterization. Ann Fr Anesth Reanim 1982;1:403-406.[Medline]
8. Baxter B.T., Blackburn D., Payne K., Pearce W.H., Yao J.S. Noninvasive evaluation of the upper extremity. Surg Clin N Am 1990;70:87-97.
9. McNeil B.J., Keeler E., Adelstein S.J. Primer on certain elements of medical decision making. N Engl J Med 1975;293:211-215.[Abstract]
10. Metz C.E., Goodenough D.J., Rossman K. Evaluation of receiver operating characteristic curve data in terms of information theory with applications in radiology. Radiology 1973;109:297-303.[Medline]
11. Hirai M., Kawai S. False positive and negative results in Allen test. J Cardiovasc Surg 1980;21:353-360.[Medline]
12. Ritchie AJ. Certain confirmation of adequacy of ulnar collateral blood flow before radial artery harvest [Abstract]. Society of Cardiothoracic Surgeons of Great Britain and Ireland 1998 Annual Meeting.
13. Whitney R.J. The measurement of volume changes in human limbs. J Physiol (Lond) 1953;121:1-27.
14. Zweifler A.J., Cushing C., Conway J. The relationship between pulse volume and blood flow in the finger. Angiology 1967;18:591-598.
15. Gundersen J. Segmental measurements of systolic pressure in the extremities including the thumb and great toe. Acta Chir Scand 1972(Suppl);426:1–90.
16. Hirai M. Arterial insufficiency of the hand evaluated by digital blood pressure and arteriographic findings. Circulation 1978;58:902-908.[Abstract/Free Full Text]
17. Scavenius M., Fauner M., Walther-Larsen S., Buchwald C., Nielsen S.L. A quantitative Allen’s test. Hand 1981;13:318-320.[Medline]
18. Pola P., Serricchio M., Flore R., Manasse E., Favuzzi A., Possati G.F. Safe removal of the radial artery for myocardial revascularization. J Thorac Cardiovasc Surg 1996;112:737-744.[Abstract/Free Full Text]
19. Coleman S.S., Anson B.J. Arterial patterns in the hand based upon 650 specimens. Surg Gynecol Obstet 1961;113:409-424.[Medline]
20. Kleinert J.M., Flemming S.G., Abel C.S., Firrell J. Radial and ulnar artery dominance in normal digits. J Hand Surg 1989;14A:504-508.[Medline]

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