Diabetic foot 2015

Think Feet!

Diabetic Foot Protection ServiceTallaght Hospital, Dublin, Ireland

Sean Tierney

Vascular surgery @ Tallaght

“…the enormity of the global burden of

diabetic foot disease…this much neglected,

but potentially devastating, complication of a

disease that is reaching epidemic

proportions…Someone, somewhere, loses a

leg because of diabetes every 30 seconds of

everyday…”

Lancet 2005; 366:1674


The diabetic foot – natural history

• Diabetes– 3.5% population

– 5% of total healthcare spend

– 10% of hospital admissions

• Foot burden– 2.5–10% incident ulcers/yr

– .25-1.8% amputations/yr

– x 8 amputation risk

– 9/1000 diabetic have a foot ulcer at one time


• 50% of amputations

are above knee

• 50% of patients

require a second

major amputation

within 5 years

• 50% of patients dead

within 5 years

Clinical Care of the Diabetic Foot, 2005

Implications


Neuropathy

http://goo.gl/oOQG4q

High glucose x

time

• Sorbitol

accumulation

• Protein glycation

• Oxidative stress

• Micro-ischaemia


Neuopathy

http://goo.gl/oOQG4q

0

20

40

60

80

100

0 25

Yrs

%


Clawing of the toes

Risk LevelFoot Ulcer

%/yr

% in clinics

(diabetes clinics)

3: Prior amputation

Prior ulcer

28.1%

18.6%7%

2: Insensate and

foot deformity or

absent pedal

pulses

6.3% 10%

1: Insensate 4.8% 17%-30%

0: All normal 1.7% 66%

Diabetes Care. 2001;24:1442

Diabetes Metab. 2003;29:261


Clawing of the toes


%/yr

% in clinics

(diabetes clinics)

3: Prior amputation

Prior ulcer

28.1%

18.6%7%

2: Insensate and

foot deformity or

absent pedal

pulses

6.3% 10%

1: Insensate 4.8% 17%-30%



Diabetes Metab. 2003;29:261


Other foot deformity

• Claw toes

• Hammer toes

• Hallux valgus

• Pes Cavus

• Toe amputations

• Charcot


Autonomic neuropathy & Callous


Arterial supply

Poitier et al, Eur J Vasc Endovasc 2011

• PAOD prevalence

9.5% - 13.6%

• (~ 50% with ulcer)

• distal > proximal

• Medial artery

calcification more

common


Mechanism of ulceration

Neuropathy

Deformity

Trauma

Ulcer


Vascular disease

Neuropathy

Deformity

Trauma

UlcerHealing


Vascular disease

Neuropathy

Deformity

Trauma

UlcerHealing Limb loss

Ischaemia

Infection


Risk assessment for foot ulceration

Structural

Skin and soft tissue

Innervation

Perfusion


Semmes-Weinstein monofilament

• Loss of

– protective sensation in feet

– proprioception

– vibration

– Pain

• Asymptomatic

– 50% of insensate patients

have no symptoms

Sensory neuropathy

Diabetes Care. 2006;2 9: S24

Diabetes Care. 2004; 27: 1591


• Demonstrate on forearm or hand

• Place monofilament perpendicular

& bow into C-shape for 1 second

• 4 sites/foot

• Avoid

– Heel (does not predict ulcer)

– calluses, scars, and ulcers

Sensory neuropathy

Diabetes Care. 2006;2 9: S24

Diabetes Care. 2004; 27: 1591


Sensory neuropathy

• -ve predictive value

= 90%-98%

• +ve predictive value

= 18%-36%

J Fam Pract. 2000;49:S30



Ipswich Touch test

• If ≥2 (of 6) missed

• Sensitivity 77%

• Equivalent to

SWMF

Rayman G. Diabetes Care. Jul 2011; 34(7): 1517–1518.


Foot assessment in diabetics

Structural

Skin and soft tissue

Innervation

Perfusion


Vascular assessment in diabetics

Clinical assessment

Peripheral pulses

Ankle brachial pressure indices

Toe (brachial) pressure indices

Tissue oximetry


Palpating pulses


Is palpation of pulses reliable?

DP only PT only Both

Sensitivity 64 70 73

Specificity 81 83 92

NPV * 91 92 94

PPV 43 49 81

Accuracy 77 81 95

absent pulses

• Negative predictive value of palpable pulses in excluding PAOD

is 94% (vs ABI <0.9 as gold standard)

Armstrong et al. Can J Cardiol 2010


Risk based ulcer prevention


%/yr

% in clinics

(diabetes clinics)

3: Prior amputation

Prior ulcer

28.1%

18.6%7%

2: Insensate and

foot deformity or

absent pedal

pulses

6.3% 10%

1: Insensate 4.8% 17%-30%





%/yr

% in clinics

(diabetes clinics)

3: Prior amputation

Prior ulcer

28.1%

18.6%7%

2: Insensate and

foot deformity or

absent pedal

pulses

6.3% 10%

1: Insensate 4.8% 17%-30%

0: All normal 1.7% 66%Education

Annual community screening




%/yr

% in clinics

(diabetes clinics)

3: Prior amputation

Prior ulcer

28.1%

18.6%7%

2: Insensate and

foot deformity or

absent pedal

pulses

6.3% 10%

1: Insensate 4.8% 17%-30%


Education

Regular podiatry & screening




%/yr

% in clinics

(diabetes clinics)

3: Prior amputation

Prior ulcer

28.1%

18.6%7%

2: Insensate and

foot deformity or

absent pedal

pulses

6.3% 10%

1: Insensate 4.8% 17%-30%


Regular podiatry & screening

Footwear & insoles


Active ulcer


Active ulcer

?infection

?ischaemia


Active ulcer

• Debride

• Xray

• ? Bone scan

• ? MRI

• Offload

– TCC

– Removable cast

• Reassess

• Footwear


Infection

• Clinical rather

than microbiology

Osteomyelitis

• Probes to bone

• MRI ?

• Bony destruction


Infection

• Antibiotics

• Sliding scale

• Surgical

Debridement

• Drainage

• Minor amputation


Infection

• Multiple

procedures

• VAC closure

• Offloading


Where is the patient on the spectrum?

Normal pulses

Impalpable pulses


Other clinical signs

• Colour

• Temperature

• Hair loss

• Shiny Skin

Inconsistent & unreliable


Beurger’s test - 1



60o

<120s



<120s


Beurger’s test

Insall et al, J R Soc Med 1989


Ankle brachial index


ABI in Diabetes



ABI in Diabetes



Toe pressures


Toe pressure

P>SBP


Toe pressure measurements

• Less affected by medial calcification

• (neuropathy, CRF)

• false positive results rare

• absolute toe pressure of <30 mmHg =

critical ischemia

• Probably not required in routine

assessment

Brooks B, Dean R, Patel S, Wu B, Molyneaux L, Yue DK: TBI or not TBI: that

is the question. Is it better to measure toe pressure than ankle pressure

in diabetic patients? Diabetic Medicine 2001, 18(12):528-532.


Tissue oxygenation


Tissue oximetry & healing

Londahl et al. Diabetolgia 2011


Tissue oximetry (summary)

• tissue hypoxia is defined as “a TcPO2 <40 mm Hg”

• associated with reduced likelihood of amputation

healing

• in critical limb ischemiaTcPO2 typically < 30 mm Hg

Oxygen response

• TcPO2 increases by > 40 mm Hg on 100% O2

usually associated with subsequent healing

Fife et al. Undersea and Hyperbaric Medicine. 2009


Choices

Structural &

neuropathy

Offload

Ischaemia

Revascularisation

Infection

Drain,

debride, ABx


Foot Protection Clinic

Nason et al. Ir J Med Sci 2013


Vascular Intervention


Pedal Bypass surgery

• 1998-2008

• N= 28 (4 asynchronous bilateral)

• M:F = 5:1

• Mean age 63y (37 – 92)

• Autologous vein used in all patients

Good et al Ir J Med Sci 2010




Proximal site

• Popliteal (n=28)

Distal sites

• Dorsalis paedis (n=13)

• Plantar artery (n= 15)



Primary graft patency

0

20

40

60

80

100

0 6 12 18 24 30 36 42 48 54 60

Time after surgery (months)

Gra

ft p

ate

nc

y a

s a

pe

rc

en

tag

e

Primary

patency


Vascular surgery @ Tallaght Primary & Secondary graft patency

0

20

40

60

80

100

0 6 12 18 24 30 36 42 48 54 60


Gra

ft p

ate

nc

y a

s a

pe

rc

en

tag

e

Primary

Secondary





0

20

40

60

80

100

0 6 12 18 24 30 36 42 48 54 60

Lim

b s

urv

iva

l a

s a

pe

rce

nta

ge


Limb Salvage



Patient Survival after Popliteo-pedal bypass

0

20

40

60

80

100

0 6 12 18 24 30 36 42 48 54 60


Su

rviv

al a

s a

pe

rce

nta

ge




Meta-analysis (pop pedal bypass)

• N=1,2320 (79

studies)

• @ 5 years

• 1o patency 63%

• 2o patency 71%

• Limb salvage 78%

• * 5 yr mortality ~50%

Albers et al J Vasc Surg. 2006 43:498-503.

*Hinchcliffe et al Diabetes Metab Res Review 2012


Innovation


Tibial artery disease






Tibial angioplasty - results

• Jan 2010-June 2013

• 61 limbs in 53 patients (41 male, median age

73)

• Rest pain /tissue loss)

• Infrapopliteal disease extent: TASC D

• Co-morbidities

– 36/53 Diabetic

– 31/53 Smoker

– 18/53 Chronic kidney disease stage 4-5

O Connor et al ASGBI 2014


Tibial angioplasty – results 2

• Technical success 81.3% (49/61 limbs)

• 55% (29/53) > one tibial vessel treated

• 24% (13/53) proximal lesion (SFA or Pop)

treated synchronously

• Adjuvant procedures:

– Minor amputation or debridement :12/61 limbs

– Mechanical thrombectomy(Rotoarex): 6/61 limbs

– Intra-op thrombolysis: 6/61 limbs



Tibial angioplasty - followup

• Mean follow up 17months (1-42)

• Major Amputation rate 10% (6/61 limbs)

• Revascularisation required in 12 pts

– 8 repeat angioplasty

– 4 distal bypass

• Overall survival at 3 years: 72%

• Amputation free survival at 3 years : 64%

• Poor survival associated with chronic kidney

disease



Tibial angioplasty – meta-analysis

• N = 2653

• Technical success = 90%

• @ 3 years

• 1o patency 49%

• 2o patency 63%


• Survival 68%

Romiti et al J Vas Surg 2008


Tibial angioplasty – meta-analysis

• N = 2653

• Technical success = 90%

• @ 3 years

• 1o patency 49%

• 2o patency 63%


• Survival 68%

Romiti et al J Vas Surg 2008

vs Bypass (@5 years)

63%

71%

78%

50%

Albers et al J Vasc Surg. 2006 43:498-503.


Tallaght data



Amputations

AKA

BKA

0

2

4

6

8

10

12

Study Period

ControlPeriod



Length of stay

15 days 12 days



Total bed days used

2842

2485

Bed Days Used

Control Period Study Period

13%



Total bed days used

2842

2485

Bed Days Used

Control Period Study Period

€300,000

*€ 890 per dayNason et al. Ir J Med Sci 2013


Think feet… think vascular

www.perfuse.net

@theseant

http://www.slideshare.net/stierney

http://goo.gl/jmtHb3

Health & Medicine

Diabetic foot 2015