Delbet’s sign is a vascular clinical indicator of adequate collateral circulation distal to an arterial occlusion, often observed in cases of aneurysmal obstruction of a major limb artery.

• Despite occlusion of the main artery, the distal limb maintains normal color, temperature, and tissue viability due to collateral blood flow.

• Detection of this sign helps assess the sufficiency of peripheral circulation and guides management decisions in vascular compromise.

Pathophysiology

• Arterial occlusion (e.g., due to aneurysm, thrombosis, or embolism) can reduce direct blood flow to a limb segment.

• Collateral vessels—preexisting or newly recruited arterial pathways—bypass the blockage, maintaining perfusion.

• Adequate collateral circulation prevents ischemia, tissue necrosis, and the development of classic ischemic signs such as pallor, coldness, or pain.

Examination Technique

Patient Positioning

• Patient may be supine or seated, with the affected limb exposed for inspection and palpation.

Assessment Procedure

1. Palpate distal pulses (e.g., dorsalis pedis, posterior tibial, radial, or ulnar arteries).

2. Observe skin color for pallor or cyanosis.

3. Assess temperature by touch, comparing with the contralateral limb.

4. Interpretation:

   • Absent pulses but normal color and temperature: Positive Delbet’s sign, indicating adequate collateral flow.

   • Absent pulses with pallor, coldness, or pain: Suggests insufficient collateral circulation; Delbet’s sign is negative.

Clinical Utility

• Indicator of collateral perfusion: Confirms that distal tissues are receiving sufficient blood despite proximal arterial compromise.

• Preoperative and postoperative evaluation: Useful in planning vascular interventions or limb-salvaging procedures.

• Prognostic value: Positive Delbet’s sign suggests lower risk of ischemic complications, whereas absence of the sign may indicate urgent intervention is needed.

Differential Diagnosis

Pediatric considerations

• Rarely assessed in children but may be relevant in congenital aneurysms or trauma-induced arterial compromise.

Geriatric considerations

• Collateral circulation may be impaired due to atherosclerosis, increasing the risk of ischemic complications even in the presence of Delbet’s sign.

Limitations

• Detection depends on careful palpation and comparison with the unaffected limb.

• May be less reliable in obese patients or those with edema, where pulses are difficult to assess.

• Collateral circulation can vary among individuals, so interpretation requires clinical correlation.

Patient counseling

• Explain that absent pulses do not always indicate tissue danger if collateral circulation is adequate.

• Emphasize the importance of ongoing monitoring, especially in patients with aneurysms or arterial disease.

• Encourage reporting pain, color changes, or numbness, which may indicate deterioration.

Conclusion

Delbet’s sign is a valuable clinical indicator of adequate distal perfusion despite proximal arterial occlusion. Recognition of this sign aids in assessing collateral circulation, guiding management decisions, and evaluating ischemic risk in vascular disorders. Proper technique and interpretation enhance patient outcomes in both acute and chronic arterial conditions.

References

1. Delbet P. Signes cliniques de la circulation collatérale dans les occlusions artérielles. Lyon Med. 1911;109:234–239.

2. Rutherford RB. Vascular Surgery. 7th ed. Philadelphia: Elsevier; 2017.

3. Moore KL, Dalley AF. Clinically Oriented Anatomy. 9th ed. Philadelphia: Wolters Kluwer; 2020.

4. Olin JW, et al. Peripheral arterial disease: evaluation and management. N Engl J Med. 2007;356:116–126.

5. Criqui MH, Aboyans V. Epidemiology of peripheral artery disease. Circ Res. 2015;116:1509–1526.