The Ischaemic, Painful Foot.
With an ageing population, rising prevalence of diabetes, chronic kidney disease and heart disease, more patients are presenting with foot pain and ulcerations. The presence of any vascular risk factor, particularly diabetes, should alert the clinician to the presence of arterial disease that may have caused the ulcer and therefore prevent healing.
With advancements in technology and techniques, patients no longer need to travel to Sydney or Wollongong to access advanced vascular revascularisation procedures, which are now routinely performed at Southern Highlands Private Hospital. We have been running a Vascular Program at SHPH since 2014, and have seen many patients receive high quality vascular care in the Southern Highlands without the need for transfer out of town.
A 68 year old man was referred to me with right foot ulcers between the 3rd and 4th toes that were painful. Walking had become difficult and the ulcers had not responded to multiple course of antibiotics. He also had some difficulty sleeping due to pain in the foot overnight.
His medical co-morbidities made it highly likely that he had arterial disease. These included diabetes, chronic kidney disease (eGFR 40), ischaemic heart disease, hypertension and high cholesterol. His co-morbidities were all being managed well by his GP and local Bowral specialists, including regular podiatric review of his feet for diabetic foot changes.
On examination he had classic features of both diabetic foot disease as well as critical limb ischemia.
Diabetic foot changes include:
1) Changes in foot architecture
a. Clawing of the toes
b. Subluxation of the metatarsal heads
2) Drying of the skin due to autonomic neuropathy
3) Loss of protective sensation
Fig: Ulceration between the toes with obvious clawing of the toes associated with diabetic neuropathy
Signs of Critical Limb Ischemia can be subtle but include:
1) Trophic changes on the forefoot: thickening of the nails, thinning of the skin, loss of hair on the toes.
2) Lack of pedal pulses (popliteal and femoral pulses may still be present)
3) Coolness of the foot to touch (very late sign)
4) Changes in the colour of the skin of the foot (Buergers sign)
a. The foot may exhibit a deep rubor on being made dependant
b. The foot may go pale on elevation
The patient was referred to a general surgeon for review of his foot who then promptly referred him to Highlands Vascular Diagnostics, our local Vascular laboratory for further investigations.
Figure 2: Signs of Critical Limb ischaemia can be subtle but include thinning of the skin, thickening of the nails and loss of hair on the foot.
Vascular Laboratory investigations
The patient underwent a duplex scan of the right foot. This scan demonstrated heavily calcified vessels which made the scan difficult for the vascular sonographer. However specific vascular sonographic techniques were used to insonate through the calcification to allow for detection of an occluded popliteal artery with low flow into the foot (monophasic flow). An Ankle Brachial Index was also performed, with waveforms used to calculate an accurate systolic opening pressure of the tibial arteries.
Figure 3: Detailed Vascular diagnostics performed on patient demonstrating an occluded popliteal and tibioperoneal trunk arteries with reduced ABI.
Management of the ulcerated foot.
Based on the examination and ultrasound findings the patient was diagnosed with Diabetic foot disease complicated by critical limb ischaemia. Given he was already receiving appropriate podiatric care and wound care, he was therefore offered endovascular recanalization of the occluded popliteal and tibial arteries. The aim of the treatment was to improve the blood flow to the foot, thus allowing for wound healing.
He was admitted to Southern Highlands Private Hospital and recanalization of the popliteal and tibial arteries was performed through a small 5 French puncture (approx. 3-4mm hole) in the common femoral artery. The popliteal artery was crossed and stents placed to improve the blood flow to his foot.
Figure 4: Angiogram performed at Southern Highlands Private Hospital demonstrating an occluded popliteal artery
Figure 5: Angiogram after simple balloon angioplasty demonstrating flow down the popliteal artery into the posterior tibial artery
The patient was kept in hospital for 24 hours for ongoing intravenous hydration and repeat blood tests to ensure he did not develop an acute Kidney Injury from the contrast exposure or anaesthesia.
At follow up, he was happy that his pain had resolved and his foot ulcers had completely healed over.
Points for Discussion:
The patient was referred to a specialist as soon as the foot ulcer became evident. Diabetic foot problems, particularly when ischemia is present, can advance quickly, and result in the need for toe amputation if left too late.
The patient presented with significant medical co-morbidities. These were all being managed by local Bowral specialists and the patient was happy to undergo treatment at Southern Highlands Private Hospital. There was no need for the patient to travel away from home to either Sydney or Wollongong for further management.
After the duplex scans were completed, the patient did not require any further investigations such as CT angiogram or Catheter Angiogram to define the blockages in the lower limb vessels. High quality Vascular ultrasound is usually sufficient to plan for recanalization of an occluded lower limb artery. This is particularly important for patients who have chronic kidney disease, where contrast dyes can make the CKD worse.
Take home points:
Foot ulcers are becoming increasingly common. Any patient with a significant risk factor such as Age (>60), Diabetes, Ischaemic heart disease, Chronic Kidney Disease, Hypertension or High Cholesterol should be referred to Highlands Vascular Diagnostics for an ABI and duplex scan. The results of the scan will generally allow for care to be directed towards either ongoing conservative management (wound care, antibiotics, podiatric care of the foot) or interventional treatment (lower limb angiography and angioplasty).