Chapter 101 Acute limb ischemia treatment

Question 1

Dose of heparin therapy in initial management of ALI

Answer 1

Heparin 100 Units/kg

Keep aPTT 50-80 (2-3x normal)

Question 2

Catheter-directed thrombolysis CDT indication

Answer 2

1) Class 1
2) Class IIa
3) occlusive event recently < 2 weeks
4) thrombosed grafts/stents

Question 3

CDT not used in these location of emboli

Answer 3

1) CFA easily accessible
2) brachial easily accessible
3) Aortic bifurcation - need expeditious revasc

Question 4

Thrombolytic agents

Answer 4

1) Streptokinase
2) Urokinase
3) Tissue plasminogen activator (TPA)

Question 5

Absolute contraindication to TPA

Answer 5

1) active bleeding disorder
2) GI bleed within 10 days
3) CVA within 6 months
4) intracranial or spinal surgery within 3 months
5) Head injury within 3 months

Question 6

Relative contraindications to TPA

Answer 6

1) major surgery/trauma within 10 days
2) hypertension (SPB > 180; DBP > 110)
3) CPR within 10 days
4) puncture of noncompressible vessel
5) Intracranial tumor
6) Pregnancy
7) diabetic hemorrhagic retinopathy
8) recent eye surgery
9) hepatic failure
10) bacterial endocarditis

Question 7

tpa catheter placements

Answer 7

Distal hole at end of thrombus

Proximal hole proximal to thrombus origin

Question 8

Rate of tpa infusion: bolus and rate

Answer 8

5-10mg bolus

infusion 0.05mg/kg/hr max 4mg/hr

Question 9

Fibrinogen level cut off to stop tpa

Answer 9

< 100 mg/dl

Question 10

Three studies on thrombolysis vs OR

Answer 10

1) Rochester
2) STILE
3) TOPAS II

Question 11

Rochester trial

Answer 11

Urokinase vs surgery
Amputation free survival better in urokinase (75% vs 52%)
attributed to perioperative cardiac mortality

Question 12

STILE (Surgery vs thrombolysis for ischemia of lower extremity) trial

Answer 12

Surgery vs tpa or urokinase
> 14 d surgery better
> 14 d surgery worse

Question 13

TOPAS (thrombolysis or peripheral arterial surgery

Answer 13

Only looked at < 14 d duration; urokinase vs OR

no difference in amputation

Question 14

Factors dictating success of endo in treating bypass occlusion

Answer 14

1) < 14d
2) wire traverses
3) graft patent for > 1 yr prior
4) presence of remedial lesion

Question 15

Success of tpa 2 year patency whether or not culprit lesion treated

Answer 15

Treated: 79%

Not treated: 9.8%

Question 16

Complications of TPA

Answer 16

1) Bleeding 5-10%
2) compartment syndrome 5-25%
3) Renal insufficiency 20%
4) distal emboli

Question 17

Use of cocomitant heparin with tpa: full vs low dose

Answer 17

Full dose 19% bleed

Low dose 9%

Question 18

Pharmacomechanical thrombectomy types

Answer 18

1) Ultrasound energy: EKOS

2) Pulse injection: angioget

Question 19

Benefit of pharmacomechanical vs tpa alone

Answer 19

1) lower dose of tpa
2) decrease duration of tpa
3) increase surface area of exposure and tpa absorption

Question 20

Mechanical thrombectomy without thrombolysis types

Answer 20

1) Hydrodynamic: old school angioget
2) Rotational/mechanical: cleaner rotational thrombectomy; arrow-trerotola thrombectomy
3) Stent retrieval device: Stryker trevo; Medtronic Solitaire, revive thrombectomy
4) Aspiration: penumbra indigo

Question 21

Surgical treatment options

Answer 21

1) balloon thrombectomy
2) bypass
3) endarterectomy + patch
4) hybrid procedure

Question 22

Surgical treatment mortality

Answer 22

25%

Question 23

Treatment of myoglobinuria

Answer 23

1) hydration to maintain urine o/p
2) Bicarb to alkalize urine
3) Dialysis as needed

Question 24

Fasciotomy indication

Answer 24

any motor function loss

Question 25

Pediatric acute limb ischemica cause

Answer 25

Catheter (iatrogenic)