Holding Pressure AKA/BKA Shownotes

 

Name of Surgery: Above Knee Amputation/Below Knee Amputation

 

Authors:

Dominique Dockery, MS3, Alpert Medical School of Brown University

Robert Patterson, MD, FACS, Alpert Medical School of Brown University/Providence Surgical Care Group

 

Editor: 

Yasong Yu

 

Reviewer:

Ryan Meyer

 

Core Resources:

• Rutherford's Vascular and Endovascular Therapy 9th Edition Chapters 104, 105, 111, 112
• Anson and McVeigh’s Surgical Anatomy

 

Additional Resources:

• Article Explaining WIfI (https://www.jvascsurg.org/article/S0741-5214(13)01515-2/fulltext) 
• Links to Apps for CLTI Calculators (https://vascular.org/news-advocacy/society-vascular-surgery-launches-mobile-apps-staging-chronic-limb-threatening) 
• Callander Technique Original Article (https://jamanetwork.com/journals/jama/article-abstract/1155011)
• Logan, Meryl Simon & Bush, Ruth L. Vascular surgeons are health disparities doctors. JVS. Vol 74; Issue 5p1437. November 2021. 

 

Underlying disease featured in episode: Peripheral arterial disease (PAD)/chronic limb threatening ischemia (CLTI)

1. Pathophysiology/etiology
   • Blockage of the arteries supplying blood to the lower limbs usually secondary to atherosclerosis
     • Affects an estimated 8-12 million Americans
     • Associated with smoking, diabetes, hypertension, obesity
     • CLTI is more severe form of PAD (up to 20% of PAD patients)- associated with rest pain, ischemia ulceration, or gangrene

1. Patient presentation

• Varies based on disease progression and prior intervention
  • Ranges from asymptomatic to major tissue loss
  • Often have patients with intermittent claudication, rest pain, or wounds/ulceration
• Patients can be classified using Rutherford scale or WIfI classification

1. Diagnosis

• Ankle-brachial index is diagnostic (1.3)
• Often obtain CTA with run-off to visualize vessels prior to angiogram
• Angiogram to plan intervention

1. Surgical treatment 

• Revascularization: either endovascular (angioplasty vs stenting) or open (bypass based on targets with either vein or graft)
• Amputation: after failed revascularization or irreversible/severe ischemia with no revascularization options
  • Minor (toe/foot) vs major (below knee/through knee/above knee)

 

Indications for surgery: 

1. acute ischemia: for irreversible ischemia, for severe ischemia with no revascularization options, or following unsuccessful attempts at revascularization
2. chronic ischemia: failure of revascularization, lack of suitable conduit or target arteries, severe patient comorbidities, poor functional status, or extensive gangrene or infection such that foot salvage is not possible
3. foot infection
4. severe traumatic injury
5. lower extremity skeletal or soft tissue malignancy

 

Preop Preparation: linking the patient with a prosthetist prior to surgery is ideal and helps with surgical planning, addressing patients’ fears and concerns, determining level of amputation (pulses/blood flow, level of infection, etc.)

 

Surgical steps with relevant images: 

Below the knee amputation (posterior flap technique):

1. Create a hemi-circular incision anteriorly (generally about 1 handbreadth below the tibial tuberosity that goes from just anterior to the fibula to an equidistant portion of the other side) and a long posterior flap 
2. Cut through the muscles of the anterior compartment (muscle bundle on the lateral side of the tibia) and expose the anterior tibial artery and vein- ligate and suture ligate
3. Using a periosteal elevator, which is something like a chisel, strip the periosteum proximally from the tibia and divide the tibia with an oscillating saw. Then strip the periosteum and attachments of the fibula at this level and divide either with the saw or a bone shear. 
4. Use an amputation knife to create the posterior flap along the skin and fascia incision lines (fashion it to make sure it will reach anteriorly without muscle bulk/tension). The remaining tibial vessels are then identified and individually suture ligated. Identify the tibial nerve, bluntly dissect it quite proximally and divide it with electrocautery. 
5. After hemostasis has been established, remove a wedge of bone from the anterior portion of the tibia so that that doesn’t provide a pressure point on the prosthesis and resect the fibula 1-2 centimeters above the line of tibial transection with a rib cutter to be sure that the fibula doesn’t wear against the prosthesis laterally and create an ulceration or painful protrusion.
6. Loosely approximate the posterior flap to the anterior fascia with several interrupted Vicryl sutures and then carefully re-approximate the skin with vertical mattress sutures of Prolene using a Keith needle to avoid traumatizing the skin with forceps. 

 

Above knee amputations (Callander technique): Does not cut across any muscle bellies but is purely dividing all muscular attachments through the tendinous insertions. It is similar to a through the knee amputation, but it involves dividing the femur immediately above the flare of the condyle with curved anterior and posterior fish mouth type flaps that again allow division without the trauma of muscular transection.

 

Postoperative care: knee immobilizer post-operatively after BKA to reduce risk of contractures, non–weight bearing on the stump until the fitting of a prosthesis 4 to 6 weeks after surgery, close follow up with vascular surgeon

 

Complications: primary healing fails in 20% to 30% of patients and approximately 1 in 5 patients undergoing BKA need a higher-level amputation due to wound problems

 

Top Asked Questions:

 

1. What ankle-brachial index is diagnostic of peripheral arterial disease?

 

Less than 0.9, severe PAD is less than 0.4. An ABI greater than 1.3 or 1.4 is considered non-diagnostic and further workup is indicated.

 

1. What is the Rutherford classification for peripheral arterial disease?

 

0- asymptomatic, 1- mild claudication, 2- moderate claudication, 3- severe claudication, 4- ischemic rest pain, 5- minor tissue loss, 6- major tissue loss 

 

1. Which amputation level requires more energy to ambulate with a prosthesis? 

 

Above knee amputations require 50-70% more energy than below knee amputations

1. What are the compartments of the lower leg, and which major vessels and nerves are in each compartment?

 

Anterior- anterior tibial artery and vein, deep peroneal nerve

Lateral- superficial peroneal nerve

Deep posterior- posterior tibial artery and vein, peroneal artery and vein, tibial nerve

Superficial posterior- mostly musculature