Lower extremity amputation

Tried to focus on lower limb amputation , which is mostly performed by GP-EM in emergency and rural setups.

1. LOWER EXTREMITY
AMPUTATION
Anupam Ghimire
GP/EM Resident

2. Contents
•Introduction
•Epidemiology
•Goal of amputation
•Indication
•General principal of amputation
•Types and Complication
•Prosthesis

3. Introduction
•Major lower extremity amputations –integral part of all vascular
practices despite aggressive approach to salvage limbs
•Myth –viewed as treatment failure
•An important definitive treatment option

4. •Aging of population
•Increasing number of diabetes
and peripheral arterial disease
Suggest amputations will
increase in future

5. Epidemiology
•Diabetes and PAD –major risk factors for lower extremity amputation
worldwide
•Diabetes:
-25% -90% of all amputations
-10 fold greater risk of amputation
-Due to presence of neuropathy, infection and increased PAD
prevalence

6. Goal of amputation
•Remove all infected, gangrenous and ischemic tissue
•Provide patient with longest functional limb
•Avoidance of repeated amputations
and non-healing operative sitesCrucial for optimal
recovery and best
functional rehabilitation
or palliation

7. Indications
Traditionally, divided into
•Acute ischemia
•Chronic ischemia
•Foot infection
•Severe traumatic injury
•Amputation considered when part of limb is dead, deadly or dead
loss

8. Indication
•Dead
-Gangrene
•Deadly
-Moist gangrene, spreading cellulitis
-AV fistula, Neoplasm
•Dead loss
-Severe trauma
-Severe rest pain

9. Primary amputation VS revascularization
•Ratio of major primary amputation to revascularization differs among
facilities and surgeon’s experience
•DM, ESRD, tissue loss, poor functional status –predictors of
treatment with amputation

10. Report by Taylor etal analyzed that
In patients younger than 60 years, functional outcomes following below
knee amputation –similar to those undergoing successful
revascularization
Conclusion: Primary amputation should not be considered a failure of
therapy but a viable, important treatment option

11. Preoperative evaluation
Regional evaluation
•Duration and severity of limb ischemia
•Extent of tissue loss
•Presence of wound infection
Systemic evaluation
•Medical co-morbidities
•Ambulatory ability
•Mental status
•Life expectancy

12. •Thorough history, physical examination
•Patients may not manifest overt cardiac disease due to lack of
physical stress –minor cardiac symptoms should be concerning

13. Risk reduction
•Incidence of venous thromboembolism in perioperative period –high
•Rate of perioperative deep venous thrombosis –11% following major
amputation (Yeager et. Al)
•17% of amputation-related deaths –caused by pulmonary embolism
•Importance of surveillance and prophylaxis for venous
thromboembolism
•Prophylaxis with unfractionated heparin or LMWH –safe and
effective

14. Managing infection
•For pedal infection requiring amputation, aggressive control of
infection with
•Surgical extirpation of source
•IV antibiotics
•Two-stage approach
•Guillotine amputation, followed by
•Formal amputation several days later
–lower complication rate than single-stage amputation

15. Amputation level selection
•Length of preserved limb –important implications for rehabilitation
•Prosthetic use following major amputation –increased energy
demand of patient
•Unilateral BKA –10%-40% increase in energy expenditure for ambulation
•Unilateral AKA –50%-70% increase in energy expenditure for ambulation
•Optimizing level selection –important
•Revision rate of BKAs to AKAs –15-25%

16. Amputation level selection contd…
Objective testing and clinical judgement
Pulse palpation and physical findings
•First step
•Extent of gangrene and infection –determines maximal length
attainable
•Accurate assessment of pulse

17. Skin temperature measurements
•Subjective interpretation of skin temperature –not a reliable guide
for amputation
•Objective skin temperature measurement predict amputation healing
with accuracy of 80-90%
Amputation level selection contd…
Objective testing and clinical judgement

18. Ankle and toe pressure measurements
•Ankle pressure > 60 mmHg –predict healing of BKA in 50%-90%
•Ankle-brachial index (ABI) –always be obtained regardless of palpable
pulse
•Toe pressures –predictive of forefoot amputation healing
Amputation level selection contd…
Objective testing and clinical judgement

19. Other methods of assessment of level of amputation
•Arteriography
•Radioisotope scans, scintigraphy and skin perfusion pressure
•Transcutaneous oxygen measurements
Amputation level selection contd…
Objective testing and clinical judgement

20. General Principles :
Stump Length
•Lower leg 14cm tibial stump
-< 8 cm : difficult for Prosthesis
•Above knee amputation :
-25-30 cm measured from tip of trochanter

21. Flap:
-2 flaps cut from opposite side of limb or
-Single longer flap
-Should be semicircular conical stump
* Combined length of 2 flaps or total length of single flap = 1.5 times of
diameter of limb at the level of bone to be divided

22. •Unequal flap:
-Shorter flap broader
-Skin edges to be sutured are of equal length
•Nerves
-Allowed to retract back in soft tissues
-Ligation is needed for major nerves

23. •Closure :
-Opposite muscles sutured together over bone ends
-Younger patient , myodesis is beneficial
-Tension free skin closure
-Vaccum drainage recommended

24. Types of amputations

25. Ray amputation
•Tennis racquet incision around base of affected toe
•For first toe amputation –handle of racquet oriented along medial
aspect of metatarsal head
•For fifth toe –oriented laterally
•For toes 2-4 –incision is along
dorsal midline

26. Transmetatarsal amputation
•Distal gangrene with adequate perfusion of hindfoot
•Curvilinear incision above metatarsal heads
•Longer flap on the plantar surface

27. More proximal incisions to transmetatarsalamputation include
•Lisfranc amputation
•Chopartamputation
•Syme amputation
–rarely used

28. Above knee amputation
•In general, the longer the stump, the better
•Fish-mouth incision

29. Below-knee amputation
NON-ISCHEMIC LIMB
•Use of tourniquet advocated
•Equal anterior and posterior flap
preferred
•Level of Amputation -12.5 to
17.5 cm
•Myoplasty is done
ISCHEMIC LIMB
•Refraining from use of
tourniquet
•Long posterior flap and short
anterior one
•Level of amputation 8.5 to
12.5cm

30. Ischemic limb

31. Non-Ischemic limb

32. Through-knee amputation
•Knee disarticulation
•Alternative to above-knee amputation if soft tissue viability permits
•Preserves full length of femur and patella
•Provides long mechanical level controlled by stronger muscles

33. Complications
Early complications
•Hemorrhage
•Hematoma
•Infection, abscess, gas gangrene
•Wound dehiscence
•Gangrene of flaps
•Risk of DVT –prophylaxis with subcutaneous heparin

34. Late complications
•Pain due to unresolved infection (sinus, osteitis, sequestrum)
•Bone spur
•Scar adherent to bone
•Amputation neuroma
•Phantom limb, phantom pain –reassurance, amitriptyline or
gabapentin
•Ulceration of stump –due to pressure effects of prosthesis or
increased ischemia

35. Prosthesis selection and training
•Prothesis –important role in rehabilitation
•Prosthesis individualized
•Different prosthesis available –based on needs of amputees, physical
conditioning and exercise demands

36. •Below knee prostheses –lightweight than above-knee prostheses
•Reasonable goals must be set for each patients
•Patient encouragement needed for patients to walk outside home
with prostheses
Prosthesis selection and training contd…

39. Summary
•An important definitive treatment option
•Diabetes and PAD –major risk factors
•length of flaps = 1.5 times of diameter of limb at the level of bone
•Reasonable goals must be set for each patients

40. References
•Rutherford’s vascular surgery, 7
th
edition
•Sabiston Textbook of surgery, 20
th
edition
•Bailey and Love’s short practice of surgery, 27
th
edition

41. THANK YOU