Edgar Van Nuys Allen

Edgar Van Nuys Allen (1900-1961) portrait

Edgar van Nuys Allen (1900-1961) was an American physician

Edgar V. Allen was best known for his work in cardiovascular and peripheral vascular disease. As a Professor of Medicine at the Mayo Clinic, Allen introduced the eponymous Allen test in 1929, a simple yet enduring clinical manoeuvre to assess arterial blood supply to the hand, originally aimed at diagnosing thromboangiitis obliterans (Buerger’s disease). Though later modified and questioned for its diagnostic accuracy, the test remains widely recognized, especially in preoperative assessments for radial artery cannulation and grafting procedures.

Beyond this single test, Allen’s influence extended significantly into the development and clinical validation of anticoagulant therapy. His collaboration with Edgar A. Hines Jr. and others led to the first therapeutic use of dicumarol in human subjects, marking a foundational moment in the treatment and prevention of thromboembolic disease. His 1941 publication on the anticoagulant’s use in postoperative venous thrombosis prophylaxis helped translate basic laboratory findings into clinical protocols, shaping decades of cardiovascular care. In recognition of this work, Allen was awarded the prestigious Albert Lasker Award in 1960.

Allen was also the author of Peripheral Vascular Diseases, first published in 1946, a seminal reference text in the emerging field of vascular medicine. Over subsequent editions, it evolved into a multi-author volume guiding generations of clinicians. His broader academic contributions included nearly 300 publications, long-standing editorial work for journals such as Circulation and the American Heart Journal, and leadership within the American Heart Association, where he served as president and received multiple honours.

Biographical Timeline
  • Born June 22, 1900 in Cozad, Dawson County, Nebraska
  • 1923 – Received Bachelor of Science and Master of Arts degrees from the University of Nebraska.
  • 1925 – Received Doctor of Medicine degree from the University of Nebraska. Began postgraduate training as a special student in medicine at the Mayo Clinic.
  • 1927 – Served as First Assistant in Medicine at Mayo.
  • 1929 – Published description of the “Allen test” for peripheral circulation evaluation, in the American Journal of the Medical Sciences.
  • 1929 – Studied abroad in Munich and London as a National Research Council Fellow.
  • 1930 – Appointed to the staff of the Mayo Clinic on June 1.
  • 1935 – 1949 – Became a member of the editorial board of the American Heart Journal
  • 1940 – Co-authored initial description of lipedema with Edgar A. Hines Jr..
  • 1941 – Published pioneering report on the clinical use of dicumarol in humans.
  • 1942–1946 – Served in the U.S. Army Medical Corps during World War II; commissioned as Lieutenant Colonel in 1942, promoted to Colonel in 1944.
  • 1946 – Published first edition of Peripheral Vascular Diseases, which became the standard textbook in the field.
  • 1950 – Vice President of the American Heart Association. President (1955); Gold Heart Award (1959)
  • 1954–1960 – Associate Editor of Circulation.
  • 1955 – President of the American Heart Association.
  • 1957 – Awarded the Distinguished Service Medal by the American Heart Association.
  • 1960 – Co-recipient of the Albert Lasker Award for confirming the clinical efficacy of dicumarol.
  • Died June 14, 1961 in St. Mary’s Hospital, Rochester, Minnesota, from bronchopneumonia due to acute renal failure.
  • 1963 – The Edgar V. Allen Memorial Scholarship was established by the American Heart Association and Mayo Graduate School of Medicine.
Medical Eponyms
Allen Test (1929)

The Allen test is a simple, non-invasive bedside manoeuvre developed to assess the patency of the radial and ulnar arteries and evaluate the adequacy of collateral circulation to the hand via the palmar arches.

1929 – Edgar Van Nuys Allen introduced his test while at the Mayo Clinic, as part of a broader strategy to diagnose thromboangiitis obliterans (Buerger’s disease) in patients with suspected chronic occlusive arterial lesions distal to the wrist. Dissatisfied with reliance on pulsations alone, Allen devised a simple bedside method to evaluate patency of the ulnar and radial arteries by observing the return of colour to the hand following deliberate occlusion and reperfusion.

His original description emphasised bilateral hand examination, occlusion of one artery at a time following fist clenching, and assessment of reactive hyperaemia i.e., the return of rubor, as a surrogate for adequate collateral flow. The classic bilateral Allen test is performed as follows:

  1. The patient elevates both arms and clenches their fists tightly for approximately one minute to exsanguinate the hands.
  2. The examiner locates both radial arteries by palpation and applies digital pressure to occlude both simultaneously at the wrist.
  3. The patient then opens both hands without hyperextension, and the examiner releases pressure from one artery at a time, observing for return of coluor to the hand and fingers.
  4. A rapid return of colour (usually within 5–10 seconds) indicates an intact and functional artery and palmar arch. Delayed or absent return suggests occlusion or inadequate collateral flow.

Allen emphasized that the test helps differentiate occlusion in the ulnar vs radial artery depending on which vessel is released.

1950s – The test found a new application in assessing hand perfusion prior to radial artery cannulation and graft harvesting. However, Allen’s method was prone to false positives, especially when patients hyperextended their hands, inadvertently mimicking ischaemia.

1966 – Irving S. Wright proposed an initial refinement in 1952 and later published the Modified Allen Test (MAT) as a unilateral variant more practical in modern clinical settings. This technique avoids the need for bilateral comparison and allows for more controlled assessment of individual limb perfusion.

  1. The patient elevates one hand above the heart and clenches their fist tightly for about 10 seconds.
  2. The examiner applies pressure to both the radial and ulnar arteries at the wrist to occlude blood flow.
  3. The patient opens the hand in a relaxed and neutral position.
  4. The examiner releases pressure on the ulnar artery only, observing the palm for capillary refill and return of normal colour.
  5. Time to full perfusion is recorded; <6 seconds is generally considered normal. The process is then repeated for the radial artery, and again on the contralateral hand.
Technical Considerations and Variants
  • Pallor duration thresholds vary between 3 to 15 seconds in the literature; many protocols adopt 5–6 seconds as the standard cutoff.
  • False positives may occur due to wrist extension or inadequate compression; wrist flexion and complete hand relaxation are recommended to improve accuracy.
  • Three-digit compression of both arteries provides more reliable occlusion.
  • Use of pulse oximetry, plethysmography, or Doppler ultrasonography enhances objectivity and reduces user bias.

Despite subsequent critiques of its sensitivity and specificity, particularly in modern practice where Doppler ultrasonography or angiography are available, the Allen test has remained a ubiquitous screening tool in critical care, anaesthesia, and reconstructive surgery. Its endurance lies in its elegance: a non-invasive test requiring no equipment, born from a clinician’s demand for reliable, physiologic data at the bedside.

Key Medical Contributions
Anticoagulation and Dicumarol

Allen played a crucial role in transforming anticoagulant therapy from an experimental curiosity into a clinical mainstay. During the 1940s, Allen built on the experimental findings of Karl Paul Link (1901-1978) of the UW-Madison School of Agriculture who identified the coumarin derivative, dicumarol, as a haemorrhagic agent in spoiled sweet clover. Allen recognised its therapeutic potential and published a series of landmark clinical observations detailing the first successful human use of dicumarol for prophylaxis against postoperative venous thrombosis.

1941 – Allen et al published A preparation from spoiled sweet clover [3,3′-methylene-bis-(4-hydroxycoumarin)] which prolongs coagulation and prothrombin time of the blood a preliminary report of experimental and clinical studies. They detailed its use in vascular patients following surgery, and was among the first to suggest oral anticoagulation as a safe and controlled intervention, provided adequate laboratory monitoring was performed. Allen’s cautious yet innovative approach included defining dose-response relationships, managing bleeding risk, and emphasising the importance of prothrombin time.

1947 – Allen and his associates at the Mayo Clinic reported their experience with 2,307 patients and concluded

The expert use of anticoagulants, heparin and Dicumarol, has tremendously improved the outlook for patients who have vascular thrombosis. Our experience with ligation of veins has been limited. That is the natural result of the gratifying experience with anticoagulants that we have had. It is to be remembered that the sole purpose of the ligation of veins is to prevent pulmonary embolism. Anticoagulants are used to prevent pulmonary emboli and to prevent extension of venous thrombosis…Our carefully considered opinion after weighing all of the evidence, is that the use of anticoagulants is, in general, a much better method of treatment.

Allen, 1947

1960 – This work not only laid the foundation for the widespread adoption of oral anticoagulants but also catalysed research into vitamin K antagonists and newer agents. In recognition of his contributions, Allen was awarded the Albert Lasker Clinical Medical Research Award in 1960, shared with C. Walton Lillehei, for “confirmation and extension of the clinical value of dicumarol.”

Lipedema (1940)

1940 – Allen, together with Edgar Alphonso Hines Jr. (1905-1978), published what is widely considered the first clinical description of lipedema, a chronic disorder characterized by symmetrical, painful fat deposition primarily affecting the lower limbs in women. Their article, Lipedema of the legs: a syndrome characterised by fat legs and orthostatic edema, distinguished the condition from other causes of peripheral oedema such as lymphoedema and venous insufficiency.

Allen and Hines emphasised that lipedema was non-pitting, symmetrical, resistant to diuretics, and often misdiagnosed due to its superficial resemblance to obesity or congestive conditions. They recognized its disproportionate impact on women, particularly around puberty or pregnancy, and noted the lack of involvement of the feet, which helped differentiate it clinically from lymphedema.

Although the term lipedema did not enter mainstream medical usage for decades, Allen’s early observations remain foundational to modern understanding of this condition. In recent years, the syndrome has garnered renewed attention in vascular and metabolic medicine, with current diagnostic criteria and treatment approaches echoing Allen’s original insights from over 80 years ago.

Major Publications
References

Biography

Eponymous terms

Eponym

the person behind the name

more eponyms…

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital. Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | On Call: Principles and Protocol 4e| Eponyms | Books |

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