What is the best management for an elderly lady with uncontrolled DM, severe limb ischemia, and complete occlusion of popliteal and infra-popliteal arteries?

Management of Severe Limb Ischemia in Elderly Diabetic Patient with Complete Popliteal and Infrapopliteal Occlusion

Below knee amputation is the most appropriate management for this elderly diabetic patient with extensive necrosis, complete occlusion of popliteal and infrapopliteal arteries, and no distal runoff. 1

Clinical Assessment and Decision-Making

This patient presents with several critical factors that guide management:

1. Severity of ischemia:

   • Blackish discoloration of left foot for 2 weeks
   • No palpable anterior or posterior tibial pulses
   • Leukocytosis (suggesting infection)
   • Complete occlusion of popliteal and infrapopliteal arteries
   • No collaterals or distal runoff

2. Patient factors:

   • Elderly patient
   • Uncontrolled diabetes mellitus
   • Likely chronic limb-threatening ischemia (CLTI)

Rationale for Below Knee Amputation

The 2017 ESC guidelines clearly state that "patients with extensive necrosis or infectious gangrene and those who are non-ambulatory with severe comorbidities may be best served with primary major amputation" 1. This patient has:

• Extensive tissue necrosis (blackish discoloration)
• Signs of infection (leukocytosis)
• Severe arterial disease with no revascularization options (complete occlusion with no runoff)

The guidelines further recommend that "infragenicular amputation should be preferred, because the knee joint allows better mobility with a prosthesis" 1. This supports the choice of below-knee rather than above-knee amputation.

Why Bypass is Not Appropriate

Bypass grafting (option A) would not be appropriate for several reasons:

1. Complete occlusion of the popliteal and infrapopliteal arteries with no distal runoff means there is no target vessel for bypass 1
2. No collaterals are present, further limiting revascularization options
3. The presence of infection (leukocytosis) increases the risk of graft failure and complications

The ESC guidelines state that revascularization should be performed when possible to improve distal blood flow 1, but in this case, the CTA findings indicate that revascularization is not technically feasible.

Why Below Knee is Preferred Over Above Knee Amputation

Below knee amputation (option B) is preferred over above knee amputation (option C) because:

1. "In any case, infragenicular amputation should be preferred, because the knee joint allows better mobility with a prosthesis" 1
2. Preservation of the knee joint significantly improves functional outcomes and mobility
3. Energy expenditure during walking is lower with below-knee compared to above-knee amputation
4. Better prosthetic options and rehabilitation potential

Management Algorithm

1. Confirm non-salvageability:

   • Complete occlusion of popliteal and infrapopliteal arteries
   • No distal runoff or collaterals
   • Presence of tissue necrosis and infection

2. Preoperative optimization:

   • Control diabetes
   • Treat infection with appropriate antibiotics
   • Optimize cardiovascular status

3. Surgical planning:

   • Plan for below-knee amputation at appropriate level
   • Ensure adequate soft tissue coverage
   • Consider vascular surgical consultation to confirm non-reconstructability

4. Postoperative care:

   • Wound care and infection management
   • Early rehabilitation and prosthetic fitting
   • Secondary prevention of cardiovascular disease

Important Considerations

• The decision for amputation should only be made after thorough vascular assessment confirms that revascularization is not feasible
• Optimizing glycemic control is critical both pre- and post-operatively 1
• Early rehabilitation and prosthetic fitting improve functional outcomes
• Long-term follow-up is essential to monitor the contralateral limb and prevent similar complications

In conclusion, while limb salvage is always preferred when possible, this patient's extensive disease with no revascularization options, presence of tissue necrosis, and signs of infection make below-knee amputation the most appropriate management strategy to preserve quality of life and reduce morbidity and mortality.