Challenges in the diabetic foot 2016
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Transcript of Challenges in the diabetic foot 2016
Challenges in the Diabetic Foot
Diabetic Foot Protection ServiceTallaght Hospital, Dublin, Ireland
Sean Tierney
October 2016
Vascular surgery @ Tallaght
Vascular disease
Neuropathy
Deformity
Trauma
UlcerHealing Limb loss
Vascular surgery @ Tallaght
Vascular disease
Neuropathy
Deformity
Trauma
UlcerHealing Limb loss
Ischaemia
Infection/Osteomyelitis
Vascular surgery @ Tallaght
The challenges
• Is it neuropathic?
• Is it ischaemic? or both
• Is there osteomyelitis?
• Is it Charcot?
• What can we do about it?
Vascular surgery @ Tallaght
Is there neuropathy?
Sensory
Motor
Autonomic
Vascular surgery @ Tallaght
Sensory neuropathy
• -ve predictive value =
90%-98%
• +ve predictive value =
18%-36%
• 80% of foot ulcers and
100% of amputations
occur in those with loss of
sensation 32 mo followup
J Fam Pract. 2000;49:S30
Diabetes Care. 1992;15:1386
Vascular surgery @ Tallaght
Ipswich Touch test
• If ≥2 (of 6) missed
• Sensitivity 77%
• Equivalent to
SWMF
Rayman G. Diabetes Care. Jul 2011; 34(7): 1517–1518.
Vascular surgery @ Tallaght
Autonomic neuropathy
Vascular surgery @ Tallaght
Autonomic neuropathy
Vascular surgery @ Tallaght
Motor neuropathy
Diabetes Care. 2001;24:1442
Diabetes Metab. 2003;29:261
Vascular surgery @ Tallaght
Is it ischaemic?
Vascular surgery @ Tallaght
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
Vascular surgery @ Tallaght
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
Vascular surgery @ Tallaght
ABI in Diabetes
Poitier et al, Eur J Vasc Endovasc 2011
Vascular surgery @ Tallaght
ABI in Diabetes
Poitier et al, Eur J Vasc Endovasc 2011
Vascular surgery @ Tallaght
<120s
60o
<120s
Beurger’s test
-ve +ve
Vascular surgery @ Tallaght
Toe pressure
P>SBP
Vascular surgery @ Tallaght
Toe pressure measurements
• Less affected by medial calcification
(neuropathy, CRF)
• absolute toe pressure of <30 mmHg =
critical ischemia
• 1o healing of DFU
– 85% TP >45 mmHg
– 36% ≤45 mmHg (p < .001) *
Brooks et al. Diabetic Medicine 2001, 18(12):528-532.
* Apelqvist et al. Diabetes Care June 1989 12:6 373-378
Vascular surgery @ Tallaght
Tissue oxygenation
Vascular surgery @ Tallaght
Tissue oximetry & healing
Londahl et al. Diabetolgia 2011
Vascular surgery @ Tallaght
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
Vascular surgery @ Tallaght
• TcPO2 best in comparative
analysis
• Poor methodology
• More research required
Vascular surgery @ Tallaght
Is there osteomyelitis?
Vascular surgery @ Tallaght
Clinical assessment
• Debride –
diagnostic and
therapeutic
• Probe wound -
?probes to bone
• ?Bone biopsy
• Imaging
Vascular surgery @ Tallaght
Probes to bone
Malhotra et al Diabet Foot Ankle. 2014
Vascular surgery @ Tallaght
Plain XRay
• osteopenia
• periosteal thickening
• cortical erosions
• new bone formation
• sequestrum
• 30–50% bone loss required (2–3
weeks)
• ? OM vs Charcot
sensitivity 54% specificity 68%
But NPV?
Malhotra et al Diabet Foot Ankle. 2014
Vascular surgery @ Tallaght
MRI
Kapoor A et al. Arch Intern Med. 2007
• Early
• Bone oedema
(overdiagnosis)
• vs Charcot ??
• “investigation of choice”
sensitivity 90% specificity 80%
Vascular surgery @ Tallaght
Scintigraphy
• Tc-99m-Medronic
Acid
Bisphosphonate
• sensitivity 80-90%
specificity < 50%
• inflammatory or
trauma
Vascular surgery @ Tallaght
Spect
• CT
• Isotope
• Tc-99m + CT or MRI
• ↑ specificity
Vascular surgery @ Tallaght
Probes to bone
Malhotra et al Diabet Foot Ankle. 2014
Vascular surgery @ Tallaght
Is it Charcot?
Vascular surgery @ Tallaght
Is it Charcot?
• Swelling
• Erythema
• Neuropathy 100%
• Pain 75%
vs cellulitis
vs osteomyelitis
Vascular surgery @ Tallaght
Is it Charcot?
• Xray – normal
• MRI
• Antibiotics ↓
Vascular surgery @ Tallaght
What to do?
Structural &
neuropathy
Vascular surgery @ Tallaght
Neuropathic ulcer
Structural &
neuropathy
Offload
Lewis J et al. Cochrane Database Syst Rev. 2013
Vascular surgery @ Tallaght
Neuropathic ulcer
Vascular surgery @ Tallaght
What to do?
Structural &
neuropathy
Offload
Ischaemia
Osteomyelitis
Acute Charcot
Vascular surgery @ Tallaght
Osteomelitis – antibiotics tx
• No sequestrum on Xray
• No systemic sepsis
+/- bone debridement/bx
• 4 studies highly selected
• 6/52 – 3/12 therapy + offloading
• Healing in 60-80%
• Urgent Sx in 1/3
• Recurrence in 1/3
Malhotra et al Diabet Foot Ankle. 2014
Vascular surgery @ Tallaght
Osteomelitis - surgery
• Antibiotics
• Sliding scale
• Surgical
Debridement – all
infected bone
• Drainage
Vascular surgery @ Tallaght
Infection
• Multiple
procedures
• VAC closure
• Offloading
Vascular surgery @ Tallaght
What to do?
Structural &
neuropathy
Offload
Ischaemia
Osteomyelitis
Drain,
debride, ABx
Acute Charcot
Vascular surgery @ Tallaght
Acute Charcot
• Offload
• Non-wt bearing
• Assess stability
clinical & Xray
• Wait
• 9-12 months
Vascular surgery @ Tallaght
What to do?
Structural &
neuropathy
Offload
IschaemiaOsteomyelitis
Drain,
debride, ABx
Acute Charcot
Offload
Vascular surgery @ Tallaght
Vascular Intervention
Ischaemia
Revascularisation
Vascular surgery @ Tallaght
Imaging
• Popliteal pulse
– Angio
• Femoral pulse
– Duplex
• ? Femoral pulse
– CT
Popposelli F. JVS 2010
Vascular surgery @ Tallaght
Pedal Bypass surgery
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
Time after surgery (months)
Limb Salvage
Good et al Ir J Med Sci 2010
Vascular surgery @ Tallaght
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
Vascular surgery @ Tallaght
Patient Survival after Popliteo-pedal bypass
0
20
40
60
80
100
0 6 12 18 24 30 36 42 48 54 60
Time after surgery (months)
Su
rviv
al a
s a
pe
rce
nta
ge
Pedal Bypass surgery
Good et al Ir J Med Sci 2010
Vascular surgery @ Tallaght
Options
Vascular surgery @ Tallaght
Technical considerations
• Consent
• Ipsilateral
(antegrade)
• Local
• ? 4/5Fr
• ? ultrasound
Vascular surgery @ Tallaght
Tibial angioplasty - results
• 40 mo
• 61 limbs in 53 patients
(41 male, median age
73)
• Rest pain /tissue loss)
• TASC D
O Connor et al ASGBI 2014
Vascular surgery @ Tallaght
Tibial angioplasty – results 2
• Technical success
81.3% (49/61 limbs)
• 2o procedure
n=12 (4 distal bypass)
• Survival (3 y) 72%
• AFS (3 yr) 64%
O Connor et al ASGBI 2014
Vascular surgery @ Tallaght
Tibial angioplasty – meta-analysis
• N = 2653
• Technical success = 90%
@ 3 years
• 1o patency 49%
• 2o patency 63%
• Limb salvage 80%
• Survival 68%
Romiti et al J Vas Surg 2008
Vascular surgery @ Tallaght
Tibial angioplasty – meta-analysis
• N = 2653
• Technical success = 90%
• @ 3 years
• 1o patency 49%
• 2o patency 63%
• Limb salvage 80%
• 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.
Vascular surgery @ Tallaght
Tibial artery disease
• Sub-intimal vs luminal
• Target vessels
• 50% better healing
rates
• Re-assessment
Lida O et al. J Vasc Surg. 2012; 55(2):363-370
Vascular surgery @ Tallaght
The evidence?
Vascular surgery @ Tallaght
Multidisciplinary care
Nason et al. Ir J Med Sci 2013
Vascular surgery @ Tallaght
www.perfuse.net
@theseant
http://www.slideshare.net/stierney/diabetic-foot-2016