Arterial Occlusive Disease - Part 3

Arterial Occlusive Disease - Part 3

By David Edelman

Multiple Choice

A 33-year-old woman is postoperative day 6 after an open reduction internal fixation (ORIF) for a left femoral shaft fracture sustained in a motor vehicle crash. This morning on rounds you notice acute swelling and erythema of her left thigh. While obtaining an ultrasound, which indicates deep venous thrombosis, she begins to complain of severe abdominal pain. Physical examination reveals a diffusely tender abdomen, and laboratory data are positive for an elevated lactate of 3.8 mmol/L and a white blood cell count of 16,000/μL. Computed tomography angiography shows a cutoff sign just distal to the middle colic artery. Which of the following studies would most likely identify the underlying etiology of this woman’s abdominal pathology?

• Mesenteric angiogram

• Flexible sigmoidoscopy

• Electrocardiogram

• Clostridium difficile level

• Echocardiogram with bubble study

This woman has a diagnosis of acute mesenteric ischemia from a paradoxical embolism. In a young, otherwise healthy individual, a rare cause of an embolic phenomenon to the mesenteric vasculature is deep vein thrombosis (DVT). Fragments of the thrombus can fracture and travel from the venous system to the arterial system through a patent foramen ovale (PFO). The diagnostic study that best assesses for a PFO is an echocardiogram with bubble study. 

Multiple Choice

A 52-year-old man with a history of pancreatitis, afib, and CAD who had percutaneous coronary intervention with bare-metal stents 5 years ago presents to the ED complaining of pain in his right leg. He first noticed numbness in his toes about 2 days ago, and this has now progressed to the entire forefoot. On further questioning, he reports pain in the foot along the metatarsal heads. On physical examination of his right leg, you note a palpable femoral pulse; absent pedal signals; and blue discoloration of all toes, with decreased sensation and dorsiflexion. His left lower leg is neuromotor intact with biphasic pedal signals. What would be the best next step in management of this man?

• Urgent guillotine amputation

• Computed tomography angiography

• Catheter-based angiography

• Heparin drip with delayed plan for intervention

• Venous duplex of the right leg

The man is presenting with signs and symptoms of acute limb ischemia. With warning signs of neuromotor dysfunction and absent pedal signals, quick clinical decision making is warranted. He would be classified as a Rutherford 2b acute limb ischemia and is in need of urgent revascularization. In the scenario, the man likely has peripheral arterial disease with examination showing no palpable pedal pulses in the contralateral leg. The acute limb ischemia likely is due to in situ thrombosis of a diseased infrageniculate or crural segment rather than an embolic event. Catheter-based angiography provides the surgeon an ability to perform a diagnostic and subsequent therapeutic intervention. 

Multiple Choice

A 68-year-old man with a history of uncontrolled diabetes, afib, and HTN presents to the ED for pain in his left leg. A CT angiogram shows a cutoff sign at the left femoral at the bifurcation of the superior femoral artery and the profunda femoris artery. Which of the following physical examination findings would be seen in this man if your suspected etiology is an acute arterial embolism?

• Reproducible buttock pain after ambulation, atrophy of calf muscles, erectile dysfunction, and absent femoral pulses

• Bilateral decreased foot sensation, bilateral lower leg pain that is relieved with elevation, and palpable pedal and femoral pulses

• Calf pain that is reproducible after ambulating 50 feet, which resolves with rest, monophasic pedal signals, and palpable femoral pulses

• Decreased foot and lower leg sensation, lower leg pain, leg pallor, decreased temperature compared to contralateral leg, and absent pedal and femoral pulses

• Loss of sensation over the foot, complete loss of motor function at the ankle joint, and mottling of the skin on the foot, absent pedal pulses, and palpable popliteal and femoral pulses

An arterial embolism refers to an acute event where thrombogenic material lodges in an arterial tree, usually at a branching point. In a patient with atrial fibrillation, a laminated thrombus with a cardiac origin is likely the cause of his embolus. One of the more common locations for obstruction is the common femoral artery at the bifurcation of the superficial femoral artery and profunda femoris, which can lead to an acute arterial cutoff sign as seen in the CT angiogram described in this case. Patients presenting with acute limb ischemia classically present with one or more of the six Ps: pulselessness, pallor, pain, paresthesia, paralysis, and poikilothermia. The man has several of these findings, making the diagnosis of an acute embolic event reasonable.

Multiple Choice

A 76-year-old man with a long list of comorbidities, including atrial fibrillation for which he takes warfarin, presented to the ED several days ago for GI bleeding. He was admitted to the ICU, and his anticoagulation was held. He received several units of blood, and ultimately the bleeding was successfully controlled via endoscopy. The patient improved and was stepped down to the floor; however, today the left leg is mottled, cold, and pulseless. He is experiencing paresthesia and decreased sensation in his left toes, but his motor function is intact. How should management of this patient proceed?

• Place an endovascular catheter for thrombolysis for 24 hours, and then reevaluate.

• Perform endovascular embolectomy with catheter-directed thrombolysis for 24 hours, and then reevaluate.

• Place an endovascular catheter for thrombolysis for 48 hours, and then reevaluate.

• Perform endovascular embolectomy with catheter-directed thrombolysis for 48 hours, and then reevaluate.

• Book the operating room for operative exploration.

The first-line therapy for class IIa ischemia is endovascular intervention with placement of a thrombolysis catheter for 48 hours, with or without embolectomy or thrombectomy, depending upon achievability. Anticoagulation should be started immediately unless the risks outweigh the benefits (eg, if this patient was having ongoing, massive GI bleeding). In patients with class IIb ischemia (sensory and motor dysfunction), surgical embolectomy or thrombectomy is generally warranted. Although this patient has class IIa ischemia, his recent GI bleeding is an absolute contraindication for thrombolysis, and therefore proceeding directly to surgical embolectomy or thrombectomy is the right thing to do. Other absolute contraindications for thrombolysis include active bleeding diathesis, cerebrovascular events within the last 6 months, intracranial or intraocular or spinal surgery within the last 3 months, or a head injury within the last 3 months.

Multiple Choice

A 42-year-old woman presents with pain in the right hand and slight discoloration of thumb and index finger that she has had for the past 3 days. She admits to IV drug use and recent use 24 hours earlier. On examination, her right hand is warm with reduced sensation on the lateral aspect of thumb and complete inability to move the medial three fingers. Brachial and radial pulsations are well palpable; however, ulnar pulse is feeble. Computed tomography angiography reveals a short-segment occlusion of the distal brachial artery with good opacification of radial artery. What is the most appropriate next step in management?

• Perform an angiogram of the right upper limb.

• Take the woman to a hybrid operating room for catheter-directed thrombolysis.

• Start the woman on a heparin infusion.

• Immediately explore the right brachial artery with embolectomy.

• Provide adequate pain control, hand physiotherapy, and reassurance.

Inadvertent brachial artery injections may occur in health care settings or in people using injectable drugs. Acute ischemia, if not promptly addressed, can lead to irreversible tissue injury within 4 to 6 hours. This woman has Rutherford class III disease, which is irreversible ischemia (development of muscle contracture leading to claw hand deformity), and revascularization is futile. Hence, exploration of brachial artery will not be beneficial. The most immediate treatment would be to start heparin infusion and help develop collateral flow.

Multiple Choice

A 53-year-old man with severe post-COVID myocarditis is being treated with ventilatory support, multiple inotropes, and venoarterial extracorporeal membrane oxygenation. He develops mottling of his right foot, and his right foot and ankle are colder than his left. Both the arterial and venous cannula are in the right groin. What is the most immediate and appropriate management for this man?

• Remove the arterial cannula from the right groin and place in the left groin.

• Continue the heparin infusion with maintenance of higher activated clotting time levels.

• Immediately place a distal perfusion cannula.

• Perform a bedside arterial duplex scan.

• Taper vasoconstrictive inotropes if the man is hemodynamically stable.

Patients on peripheral ECMO should be monitored for distal limb perfusion apart from hemodynamic monitoring. Limb ischemia is the most common acute and late vascular complication of patients undergoing venoarterial ECMO. Bedside arterial duplex scanning can be conveniently and expeditiously performed to decide if any intervention for the limb is urgently required. Distal perfusion cannulas are routinely placed by some centers, suggesting an effective limb salvage intervention. However, this man has already developed limb ischemia, which needs further evaluation. Switching the arterial cannula to the other groin can be the last resort once thromboembolic complications have been ruled out and limb hypoperfusion is the due to the cannula itself.

Multiple Choice

A 70-year-old man with a history of CAD, DM, and HTN presents to the ED reporting 5 hours of acute left lower extremity pain, decreased sensation, and foot weakness. On exam, the patient is noted to have palpable femoral pulses bilaterally and palpable dorsalis pedis and posterior tibial pulses only in the right lower extremity. Doppler signals are inaudible in the left lower extremity. The patient is booked for an emergency open thromboembolectomy. During the procedure, the surgeon passes a Fogarty catheter distally and proximally until multiple passes are without return of thrombus. When releasing the clamps, there is good backbleeding and inflow. The arteriotomy is closed. Doppler signals of the pedal pulses are still inaudible. What is the next step in management?

• Perform cutdown of the below-knee popliteal artery, and perform additional passes of the Fogarty catheter.

• Reopen the arteriotomy, and perform additional passes of the Fogarty catheter.

• Perform an intraoperative angiogram to assess for distal occlusion.

• Finish the case, and continue to monitor distal pulses in the PACU.

• Perform cutdown at the ankle to access the pedal vessels, and perform additional passes of the Fogarty catheter.

An intraoperative angiogram should be performed to evaluate for residual occlusion. Before additional cutdowns are performed, the extent and location of residual occlusion must be determined. Depending on the location of the residual disease, endovascular approaches may be more appropriate than open techniques. Although the arteriotomy closure may have narrowed the vessel, reopening the arteriotomy is a time-consuming step, and an on-table angiogram will help determine if it is necessary. It would be inappropriate to end the case without identifying and potentially correcting ongoing malperfusion.

Multiple Choice

A 75-year-old man with a known AAA arrives at the ED reporting 8 hours of left leg pain. On examination, he has a water hammer left femoral pulse and no Doppler signals in the left popliteal or pedal arteries. He also has left foot sensory deficits and weakness with plantar flexion. He is booked for an emergency open thromboembolectomy. In this patient, what is the strongest indication for performing a 4 compartment fasciotomy?

• Age of the patient

• Duration of ischemic insult

• Degree of sensory deficits

• Degree of motor deficits

• Lack of pedal signals

This patient is presenting with Rutherford IIb acute limb ischemia, likely secondary to dislodged thrombus from his AAA. Patients with >6 hours of limb ischemia are at high risk for developing compartment syndrome after reperfusion, and four-compartment fasciotomies should be performed. The findings of the physical examination (Doppler signals, sensory deficits, and motor function) determine the classification of acute limb ischemia, but they are generally not used to determine the necessity of a fasciotomy, though profound paralysis may indicate the need for an amputation.

Multiple Choice

A 35-year-old woman with moderate mitral stenosis and afib presents with acute right limb ischemia that she has had for the past 10 hours. She is taken to the operating room for femoral embolectomy. A proximal and distal balloon Fogarty catheter are used to retrieve the heavy clot burden and establish good blood flow. After the closure of the groin incision, it is noticed that although the dorsalis pedis is well palpable, the posterior tibial artery is feeble and the calf appears very tense. What is the most appropriate next step in management?

• Shift her to the recovery room and monitor right lower limb compartment pressure.

• Immediately perform 2 incision, 4 compartment fasciotomy of the right lower limb.

• Elevate the right lower limb in the recovery room.

• Perform right lower limb venous Doppler in the operating room.

• Reopen the groin incision to perform the distal Fogarty embolectomy again.

Reperfusion injury following embolectomy can lead to compartment syndrome or myoglobinuria with renal damage. Urgent fasciotomy with release of both superficial and deep compartment is essential to maintain limb viability. Because the dorsalis pedis artery is well palpable, reopening the groin incision for repeat distal embolectomy is not indicated. In late stages of acute compartment syndrome (tense calf and diminished pulsation), the chance of limb salvage is very low, most often leading to amputation.

Multiple Choice

A 65-year-old man with a history of diabetes and HTN, as well as a 55 pack-year smoking history, comes into the ED with a nonhealing wound and pain in his left foot that is more painful on elevation. Digits 1 through 4 are exquisitely tender and he is noted to have a wound on the bottom of his foot that he says has been present for months and is nonresponsive to bacitracin ointment. He undergoes vascular workup and CT angiography shows a lesion treatable by endovascular approach. What on CTA would make him a candidate for endovascular versus open repair of his occlusive artery disease?

• A 2-cm external iliac artery stenosis and a 4-cm occlusion of the distal superficial femoral artery (SFA) on angiogram

• Multiple stenosis of 16-cm without heavy calcification

• Total occlusion of the SFA

• Occlusion of the proximal bifurcation of vessels

• Heavy calcification stenosis approximately 15-cm in length

A 2-cm external iliac artery stenosis and 4-cm occlusion of the distal SFA are both TASC II class A and are best treated by endovascular intervention. Multiple stenosis of 16-cm without heavy calcification is TASC II class C. Total occlusion of the patient’s SFA is TASC II class D. Occlusion of the proximal bifurcation of vessels is TASC II class D. Heavy calcification stenosis approximately 15-cm in length is TASC II class C. Endovascular therapy is the treatment of choice for TASC A and B lesions, and surgery is the preferred treatment for type C and D lesions. It should be noted that there are no evidence-based guidelines that show improved outcomes between endovascular versus open repair. The TASC II classification system is merely used as a guide. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed no significant differences in overall mortality.