Embolectomy

Peripheral arterial emboli
Aetiology
80% from heart, AF, Rheumatic heart disease, anticedent MI, endocarditis etc.
Atheromatous debris, aortic aneurysms and popliteal.
Can either lodge in major vessel or shower into distal vessels (microembolization)
Presentation
No antecedent history of claudication unlike in PAD limb threat; sudden onset.
 Six Ps: pain, pallor, pulseless, poikilothermia (cold), parasthesia, paralysis.
- elevation --> distal pallor; dependency --> rubor.
Careful pulse examination throughout limb.
Assess venous filling; some filling suggests some flow
Doppler exam and ABI if pulse determined.
Neural tissue is most sensitive to ischemia --> numbness may be first objective feature.
Associated other embolic disease.
In microvascular disease, get a severe sharp pain localized to the digits
Management
1. Decide if viable, under urgent or immediate threat, or if unsalvagable (rigor mortis limb).
- Viable / threatened --> urgent CTA to show cause
- Immediate threat --> urgen revasculrization based solely on above hx and physical.
2. Immediate anticoagulation with 100U/kg bolus then 10-14 U/kg/hr infusion.
- prevent propagation of the thrombus,
3. Need operating suite with imaging / fluoroscopic capability.
- prep chest, abdo, legs.
- angiogram from other side ---> sudden cutoff in flow.
4. Catheter-directed mechanical and pharmacological thrombolysis if time permits
- limited by severity and degree of ischaemia, extent of clot, and time to resolution.
- works well for thrombosis; less effective for emboli from heart, which may have well organized thrombus inside.
- may take 24-48h to full effect so not appropriate if urgent situation
5. If severe, rapid restoration of flow; if no immediate effect from percutaneous aspiration and thrombolysis, then surgical embolectomy indicated.

Embolectomy - General

· Dissect & control branches

— Sling proximal & distally

— Clamp proximally

· Arteriotomy

 

Femoral Embolectomy

·In an appropriately investigated, prepared and consented patient.

·Limb marked. Patient should be heparinized. Single dose prophylactic Cefazolin.

·Supine. Thigh abducted GA. Perpare and drape both groins and legs to the feet and place feet in a clear plastic bag (bowel bag). Towel & adhesive drape over perineum

· Incision over mid-inguinal point just above inguinal ligament and longitudinally down for 5cm. Deepen incision down to inguinal ligament using scissors dividing subcutaneous tissue, superficial & deep fascia

· Ligate any tribuitaries of great saphenous vein which obscure exposure using 3/0 Vicryl ties.

· In self retaining retractor

· Open the Femoral sheath and identify and protect the femoral N, femoral branch of genitofemoral & medial cutaneous N of thigh on fem artery

· Dissect out with lahey from lateral side to avoid lymphatics

· Sling the Common femoral using silastic sling

· Pull up on sling and tease the tissues away from the artery using a pledget on an artery forceps.

About 5cm distal to the inguinal ligament find the Profunda and SFA.

· Sling each of these passing the sling twice round the vessel.

— Superficial femoral

—   Profunda

· Check that Fogary embolectomy catheters are available in sizes 2-7 (7 largest). I use catheters with a central irrigating lumen to facilitate flushing of vessels and angiography.

· Apply angled Debakey clamps to each vessel.

· Make an ateriotomy using an 11 blade and Potts scissors just proximal to the bifurcation of the CFA.

· Whether it is a longitudinal or transverse arteriotomy depends on that state of vessel and it caliber. If a vessel larger than 4mm with no evidence of vascular disease (soft pliable wall) then transverse. If a small vessel or with evidence of vascular disease then longitudinal with plan for vein patch closure.

3F Below knee popliteal, 4F femoral, 5F aortic bifurcation

— Check balloon with saline

· The initial approach depends on whether there is a femoral pulse.

· If no palpable femoral pulse I pass the balloon first retrograde to re-establish inflow and then antegrade.

· Remove clamp, get assistant to control flow with sling and pass uninflated catheter proximally, not forcing it.

— Inflate balloon

— Withdraw adjusting balloon P as necessary to allow resistance free withdrawal

- i.e. pass balloon through clot, gently inflate to oppose without injuring native vessel, and draw back to remove debris.

— Assistant to control back bleeding with loop and relaxing as the balloon and extruded clot emerges from the arteriotomy.

— Repeat in 10cm increments until no more clot / good back flow is achieved

· Heparinise proximally using 5000iu in 250 ml saline. Re-apply clamp

The procedure is repeated passing a 3F catheter 4-5cm down the PFA to establish good back flow.

Attention is then turned to the SFA. Catheter is passed in increments down the SFA until good backflow is re-establised and no further clot is retrieved.

· Clamp distally & flush from distal.

· Close arteriotomy using 5/0 Prolene.

· Flush debris from vessels above and below the clamps

— Back bleed, heparinised saline flush & reclamp, proximal bleed, flush & reclamp

· Close arteriotomy and release the distal clamps just before final sutures are placed to flush clot from the vessel and then flush with heparinized saline. Release proximal clamp as final flush and then complete closure of the arteriotomy and release proximal clamp.

· Check extremities pinking – arterial spasm may occur so allow a few minutes for the limb to pink up.

· Suction drain & close in layers of 2/0 vicryl to fascia and 3/0 Monocryl subcuticular to skin.

· You cannot achieve proximal inflow. What do you do?

Suggest an iliac occlusion or that the catheter has been passed in a subintimal plane. Call for help assistance of another surgeon. Can consider angiogram from contrelateral groin. Usually the best options here are extra-anatomic bypass if outflow can be established (either ax-fem or fem-fem X-over). Aorto-iliac reconstruction in this setting carries excessive risk.

· You cannot achieve back-bleeding from PFA or SFA.

I would perform an on table angiogram if I can’t pass cathetrer, no clot, no back flow.

Often this will show disease in the popliteal vessels or below. This is best apporahced via a direct infra-genicular approach to the below-knee popliteal.

· On which patients might you need a fasciotomy

If there has been complete ischaemia ³ 4hrs.

· How does your approach change if the patient has loss of both femoral pulses.

I would perform bilateral simultaneous femoral artery cutdowns with both femoral arteries simultaneously clamped to prevent fragmentation and distal embolization.

· What if the contre-lateral leg turns white after embolectomy

I would repeat the procedure on the contrelateral limb as thrombus was probably dislodged from the proximal iliac or aorta into the other iliac.

· What if the popliteal pulse is palpable but the limb still appears ischaemic.

This suggests embolization to below knee vessels. Often passing the catheter blind down from the CFA selectively canulates the peroneal artery. Selective canulation of ant. and post. Tibial arteries requires a below knee popliteal artery exposure. A distal popliteal arteriotomy is performed. 3F Fogarty is passed proximally and then a 2F Fogarty is passed down each of the crural vessels. If the mid-tibial vessels cannot be embolecomized then direct intra-operative instillation of 50,000u of Urokinase can be tried.

 

Brachial embolecomy

I perform a brachial embolecomy via distal brachial exposure in the antecubital fossa

·In an appropriately investigated, prepared and consented patient.

· I mark the limb. Patient should be heparinized. Single dose prophylactic Cefazolin.

·Supine. GA. Prepare and drape the arm free and the hand in a clear plastic bag (bowel bag).

· Arm placed on hand table

· I make a lazy S antecubital fossa incision over the artery. The incision begins vertically in the medial side of the arm, crosse the antecubital fossa in the skin crease of the elbow and continues on the radial side of the forearm.

· The artery is immediately medial to biceps tendon.

· I divide the bicipital aponeurosis and protect the median nerve which is immediately medial to artery.

· I  control the artery proximally and distally with silastic slings and clamp using small bulldog clips

· I make a longitudinal arteriotomy using an 11 blade a Pott’s scissors and pass a 3 F Fogarty balloon catheter proximally and then distally to clear the clot as for femoral embolecomy.

· Clamp distally & flush from distal.

· Close arteriotomy using 5/0 Prolene and a small vein patch harvested from the brachial or cephalic vein.

· Flush debris from vessels above and below the clamps

— Back bleed, heparinised saline flush & reclamp, proximal bleed, flush & reclamp

· Close arteriotomy and release the distal clamps just before final sutures are placed to flush clot from the vessel and then flush with heparinized saline. Release proximal clamp as final flush and then complete closure of the arteriotomy and release proximal clamp.

· Check extremities pinking – arterial spasm may occur so allow a few minutes for the limb to pink up.

 

Popliteal embolectomy

· This is required when there is acute ischaemia and a palpable popliteal pulse or femoral embolecomy has failed to clear the below knee vessels.

— Leg abducted, hip & knee flexed, externally rotated

— I make an incision parallel to long axis of the tibia fb posterior to its medial border » 10cm longer if fat / muscular beginning 1-2cm distal to medial femoral condyle

I seek and preserve the LSV

— I divide the fat and deep crura fascia

— I retract the semi-membranosus and semitendinosus tendons anteriorly or divide them at their attachment to the tibia.

— I mobilize the medial head of gastroc from the medial tibial condyle, popliteus and the capsule of the knee joint and retrat posteromedially

— Medial fibres of soleus are reflected from their origin on the soleal line of the tibia, just distal to the insertion of popliteus.

— The distal popliteal vessels are then exposed in a common sheath.

— By diving soleus from its origin I expose the anterior and posterior tibial ateries.

— If I wish to visualize the peroneal vessesl I completely detach the soleus from its tibial origin as the peroneal arises from the posterior tibial 2-3cm from the bifurcation of the popliteal artery into anterior and posterior tibial arteries.

— Longitudinal & distal arteriotomy

— Embolectomy as above

— Close with vein patch from distal LSV.

 

SMA Embolectomy

· In appropriately Investigated, consented and prepared patient

· IV Heparin, IV Abx

· Supine. Midline laparotomy.

· Lift transverse colon.

· Run small bowel from ligament of Treitz distally. The distal ileum and proximal right colon is usually affected first.

If entire bowel is frankly necrotic and projected survival and low and abdominal closure with institution of palliative measures may be appropriate depending on patient age and co-morbidity.

· Eviscerate and reflect the small bowel to right side

· Assess viability of bowel – which vascular territory involved.

· Ligament of Treitz fully incised to mobilize root of mesentery

· Place right hand behind mesentery and located the SMA by palpation (firm tubular structure which may or may not be pulsitile).

· If difficulty locating SMA, follow it from the middle colic in the transverse mesocolon.

· Isolate artery from SMV (to right) and pass silastic slings to obtain proximal and distal control. May need to sling jejunal branches or Middle colic if this is site of arteritomy.

· Perform a longitudinal arteriotomy in most cases unless soft pliable disease-free artery in young patient.

· Pass 3F Fogarty balloon catheter proximally and distally until inflow and back-bleeding is achieved.

· Revascularization will lead to a fall in BP and release of K and acid so warn anesthetist.

· Close arteritomy with a patch.

If revascularization is doubtful or inflow poor can consider the arteriotomy as the distal site for an bypass from Aorta or Iliac.

· Re-inspect the viscera. If viability is doubtful then can use CW Doppler on the anti-mesenteric wall of bowel, IV flourescein injection, Trancutaneous O2 probe.

· If there is any doubt about the viability, leave the bowel and perform a second look laparotomy in 24 hours.

· Can resect frankly necrotic bowel and leave ends in abdomen pending second look

· If there is any question as to increased intra-abdominal pressure when closing, leave abdomen open pending second look.

· Continue IV heparin, IV abx, Take patient to ICU to correct acid-base and fluid status.


Complications
Post-operative mortality and limb loss rates are high (10%)
Return of perfusion associated with hyperkalemia, myoglobinuria, acidosis, and hypotension
- Haemodyalysis in extreme cases.
- Sodium bicarb for alkalynization of urin to minimize myoglobin effect and offset acidosis; hydration and mannitol for diuresis; potassium control with diuresis, insulin and glucose infusion.
Four compartment fasciotomy may be required after relief of severe lower limb ischemia.
Continue anticoagulation to prevent repeat emboli
Determine etiology; Holter, Echo, CT chest / abdo / pelvis; treat source.