Acute limb ischemia as a first presentation of a thyrotoxic patient: a Case Report

Musaab Yassin 1
Khalid Canna 2
Donald Bain 3

1 Glasgow Royal Infirmary, Department of general surgery, Foundation year 2
2 Glasgow Royal Infirmary, Department of general surgery, M.D, Specialist registrar
3 Southern General Hospital, Department of general surgery, M.D, F.R.C.S, Consultant surgeon

Abstract
Introduction:
Arterial embolism in thyrotoxic atrial fibrillation is more common than is realized and can be the first presentation of undiagnosed hyperthyroidism.
Report:
Acute limb ischemia as a first presentation of hyperthyroidism
Discussion:
A medical condition can modify a surgical approach to achieve successful results.
Keywords:
Thyrotoxic, AF, embolism, acute limb ischemia

Introduction:
Thyrotoxic artrial fibrillation is well known and occurs in 10-30% of all patients with thyrotoxicosis. The risk of systemic embolism has been found to be 10-40% in patients with thyrotoxic atrial fibrillation 1.

Case Report:
A 50 year old man presented to the emergency department with two weeks history of ischemic pain affecting his right foot. He had lost 3 stones in three months, and was constantly sweating and thirsty. His past medical history revealed recently investigated tremor which had been diagnosed as orthostatic tremor and been treated with clonazepam.

On physical examination, he was found to be slightly distressed, with a fine tremor. His left foot was warm and pink while the right foot was cold, pulseless from popliteal and below with patchy discolouration but normal sensation.

An electrocardiogram showed previously undiagnosed atrial fibrillation (AF) whilst blood tests were consistent with hyperthyroidism, demonstrating a significant increase in T4 and a decrease in TSH.

MR angiography showed occlusion of superficial femoral artery from the adductor hiatus to the tibio-peroneal trunk. Ultrasound of the neck demonstrated multi nodular goitre while abdominal ultrasound was normal apart from some gall stones.

 

 

The patient was started on digoxin, IV heparin.The clinical problem was either primary treatment of the hyperthyroidism or the acute ischemic right foot i.e. a thyrotoxic storm or limb salvage. This problem was addressed in a multidisciplinary approach involving anaesthetists, endocrinologists and vascular surgeons.

The patient was started on propranolol, carbimazole, propylthiouracil and Lugol’s iodine. Furthermore, the surgical procedure was modified and done under local anaesthesia as this was considered to reduce the risk of a thyroid crisis.

Femoral embolectomy and fasciotomy were performed. On table angiogram showed good distal run off and the right foot was well perfused at the end of the procedure. He was continued on therapeutic heparin for 3 days until his AF was controlled and then he was discharged on warfarin with an outpatient follow up appointment.

Discussion:
Arterial embolism in thyrotoxic atrial fibrillation is more common than is realised. There are no studies which have examined acute limb ischemia as a complication of hyperthyroidism. However, a few studies have reported arterial emboli as a complication of hyperthyroidism. This complication has been reported to be 8%, 11% and 24% 2-4. Nevertheless, to our knowledge, there have been no reported cases of acute limb ischemia as the first presentation in thyrotoxic patients with atrial fibrillation and furthermore, that modified surgical treatment can result in an excellent clinical outcome.

With regards to when to expect such complications, one study suggested that cardiac emboli were found to occur at an early stage, during uncontrolled hyperthyroidism, in patients with both atrial fibrillation and cardiac failure 3.

In the present case surgical treatment was essential but may have increased likelihood of the patient developing a post-operative thyroid crisis.

References

  1. Hendriksen, O. Petersen, C L. 1995, “Embolic episodes after treatment of atrial fibrillation in a patient with thyrotoxicosis”, Ugeskrift for Laeger, vol. 29, no. 157, pp. 4138-9.
  2. Staffurth, J.S., Gibberd, M.C. & Fui, S.N. 1977, "Arterial embolism in thyrotoxicosis with atrial fibrillation", British medical journal, vol. 2, no. 6088, pp. 688-690.
  3. Hurley, D.M., Hunter, A.N., Hewett, M.J. & Stockigt, J.R. 1981, "Atrial fibrillation and arterial embolism in hyperthyroidism", Australian & New Zealand Journal of Medicine, vol. 11, no. 4, pp. 391-393.
  4. Yuen, R.W., Gutteridge, D.H., Thompson, P.L. & Robinson, J.S. 1979, "Embolism in thyrotoxic atrial fibrillation", Medical Journal of Australia, vol. 1, no. 13, pp. 630-631.