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PUT YOUR BEST FOOT FORWARD

Bala Ramanan, MBBS1st year vascular surgery fellow

Introduction• The epidemic of diabetes and ageing of

our population ensures critical limb ischemia will continue to grow.

• Estimated costs $150-300 billion (2010 data): range depends on data being used and cost counted.

• Exposed bones and/or tendons make limb salvage more difficult.

HPI • 57 year old woman• Chronic non-healing wound on the left foot. • Over the course of 1 year she underwent a series of

vascular and wound treatments at an OSH for the left foot including an atherectomy of the left popliteal and anterior tibial arteries and a popliteal stent.

• HBO therapy but no improvement. • TMA of the left foot which then necrosed and was slowly

worsening. • Advised BKA.• SH: 40 pack year smoker –stopped 6 years ago.

Physical Examination• Lower extremity pulse exam: Right lower extremity- all pulses were

palpable.• Left lower extremity- femoral pulse palpable, popliteal pulse non-palpable,

Pedal pulses non-palpable. Peroneal signal was heard at the distal ankle.

• Foot exam: Left open TMA with superficial necrosis of the distal end of the wound, plantar skin viable, normal sensation in the foot and good ankle range of movement, no venous stasis changes in leg.

• Non-invasive vascular studies:• ABI: Right-0.92, Left-0.10. • TcPO2 on the plantar surface of the Left foot- 12 mmHg.

• Ultrasound- Greater saphenous vein in the left leg measured >3mm throughout its length, no reflux, no deep vein thrombosis.

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Is this limb salvageable?A. YES?B. NO?

Y E S?

N O?

54%46%

Given the normal right lower extremitywhat most likely represents her

diagnosis?A. AtherosclerosisB. EmbolismC. Trash foot following

atherectomyD. Thrombosed popliteal artery

aneurysm

A t he r o

s c l er o s

i sE m

b o li s m

T r as h f

o o t f o l

l o wi n g

a t h. . .

T h ro m

b o se d

p o pl i t e

a l ar . . .

23%30%

40%

7%

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Imaging- Angiogram

What are the options for management?A. Below knee amputationB. Patient should be referred to a no

revascularization option: cell-based or gene therapy trial

C. Pedal access and recanalization of the anterior tibial and peroneal arteries

D. SFA to peroneal bypass with soft tissue coverage

E. Anterograde access and recanalization of the anterior tibial artery

B e lo w

k n ee a

m pu t a

t i o n

P a ti e n

t s ho u l

d be r e

f e r re . . .

P e da l a

c c es s a

n d r e c

a n al i . . .

S F A t o

p e ro n e

a l by p a

s s w. . .

A n te r o

g r ad e

a c ce s s

a n d . . .

19%

0%

15%

46%

19%

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Case Management• Left SFA-Peroneal Bypass with non-reversed greater saphenous vein

(Vascular surgery).

• Left foot debridement of subcutaneous tissue, muscles, tendons and metatarsals were debrided back to the base (Podiatry).

• Right rectus abdominis free flap to left TMA Stump (Plastic Surgery)-inferior epigastric artery and vein were anastomosed to a jump graft off the SFA-peroneal bypass and anterior tibial vena commitante.

• Split thickness skin graft placed over the muscle flap.

Postoperative course• Uneventful recovery in the hospital.

• Flap was closely monitored.

• Discharged to rehabilitation facility on POD 18 on aspirin.

• 1 week later the patient noted a change in the color of the flap and was readmitted.

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• She had no history of trauma to the flap or symptoms.

• On examination:

• The flap appeared dark with loss of about 30-40% of the skin graft.

• It had dopplerable arterial and venous signals.

• Ultrasound showed a patent bypass graft and no DVT in the leg.

What should be done?A. Systemic anticoagulation.B. Conservative management with wound

vac.C. Amputation.D. Apply leaches.E. OR for exploration of the flap and

excision of necrotic tissue.F. OR for exploration and revision of

anastomosis. G. New free flap.

S y st e m

i c an t i c

o a gu l a t

i o n.

C o ns e r v

a t i ve m

a n ag e m

e . .A m

p u ta t i o

n .A p p

l y l ea c h

e s .

O R f o r

e x pl o r a

t i o n o f

t h e. . .

O R f o r

e x pl o r a

t i o n a n d

r e .. .

N e w f r e

e f la p .

0%3%

16%

6%3%

56%

16%

Case Management

• Underwent debridement of the flap and was found to have a viable flap with an intramuscular hematoma.

• No further events postoperatively.

• Activity was gradually increased.

• Got another split thickness skin graft and was discharged home.

• On follow up in clinic, she had viable muscle flap, warm foot, 100% take of her skin graft

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Biomechanical issues with a TMA• Increased pressure in the forefoot- leads to ulcer development.

• Equinovarus is the most common complication.

• Parabola of the metatarsals may not be maintained leading to increased pressure over the elongated metatarsal.

• MANAGEMENT: Custom shoes and regular follow up.

• Tendoachilles lengthening or gastrocnemius recession for equinovarus deformity.

• Free muscle flap increases the outflow for lower extremity bypass.

• Neovascularization from surrounding ischemic tissues by collaterals occurs as soon as 3 weeks and the flap can survive even if the bypass occludes.

• Free flap can serve as the sole outflow for a bypass graft in patients with unacceptable or no runoff.

• Contraindications: ESRD, uncontrolled diabetes, current smoker. Relative- history of graft thrombosis.

FLAP FACTS Workup of a failing free flap

• Arterial duplex of the bypass graft to evaluate the inflow- angiogram if issue with the bypass.

• Venous ultrasound for deep venous thrombosis.

• Examination of the flap for temperature, color and arterial and venous signals.

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FLAP FAILURES• Flap thrombosis- occurs in a bimodal pattern. Usually within

1st 48 hours or after 1 week.

• Reasons- arterial or venous thrombosis (more common), pressure on the flap.

• Management –• All free flap patients are started on aspirin, subcutaneous

heparin immediately postop.• If trouble with anastomosis during surgery-some surgeons

use low dose heparin drip. • If flap thrombosis suspected- exploration in the OR within 6

hours of onset.

Conclusions• Combined lower extremity bypass with complex

foot reconstruction with free tissue transfer is an option for patients with good foot function and large soft-tissue defects.

• These procedures are associated with high rate of early perioperative revisions of both the bypass and the free flap.