Chapter 8

Venous Disease, Pulmonary Embolism, and Lymphatic System

Bruce E. Jarrell

R. Anthony Carabasi III

Mark B. Kahn

Robert A. Larson

I Venous Disease of the Lower Extremities

A Disorders

Superficial thrombophlebitis is inflammation or thrombosis of the superficial veins.

Clinical presentation

A tender, palpable cord along the course of a superficial vein

A red, warm, indurated vein

Treatment

Bed rest and elevation of the extremity

Local application of heat for relief of pain

Gradient compression stockings

Nonsteroidal anti -inflammatory drugs

Complications. Chronic recurrent superficial thrombophlebitis may require antibiotic therapy due to a streptococcal lymphangitis.

Suppurative thrombophlebitis usually is associated with intravenous infusions in immunocompromised or burn patients. It is treated by excision of the infected vein and antibiotics.

Varicose veins

Clinical presentation

Local pain and edema

Local inflammation

Local hemorrhage into the surrounding tissue

Dilated superficial veins

Diagnosis

Trendelenburg test: Elevate the leg with the patient supine to exsanguinate the superficial veins, then place an elastic tourniquet below the saphenofemoral junction. Have the patient

stand, and observe vein refilling. Normal venous filling is slow; early refilling indicates deep venous insufficiency. Rapid refilling after tourniquet removal indicates saphenofemoral junction (superficial venous) insufficiency.

Vascular laboratory

Venous duplex will identify the presence of deep venous thrombosis (DVT) as well as document venous reflux.

Air plesmythography documents ambulatory venous hypertension and calf muscle pump function.

Treatment

Nonoperative management: leg compression with gradient compression stockings and leg elevation

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Operative management

Indications for surgery

Previous or impending hemorrhage: usually controlled by a combination of elevation and direct compression

Recurrent pain over the varicosity or recurrent superficial phlebitis of the varicosity

Cosmetic considerations

Surgical procedures

Greater saphenous ligation and perforator phlebectomy. Surgical excision of the individual varicosities through small (>1 cm) incisions (the “stab avulsion technique”), with ligation of proximal incompetent perforators. The greater saphenous vein (GSV) is not removed distal to the knee due to risk of saphenous nerve injury.

Minimally invasive procedures. Thermal ablation uses radio frequency or laser coagulation and causes GSV thrombosis and fibrosis, eliminating reflux. Transilluminated powered phlebectomy is used for subcutaneous perforator vein removal under direct vision. These procedures offer equivalent results with improved recovery time and cosmesis (fewer incisions).

DVT occurs in approximately 500,000 individuals per year. About 10% of cases end in death from pulmonary embolism (PE). The incidence of DVT following major abdominal surgery is estimated at 30% and is even higher following open prostate surgery (38%) or orthopaedic procedures (50%–70%).

Etiology

DVT usually originates in the lower extremity venous system, starting at the calf vein level and progressing proximally. Approximately 80%–90% of pulmonary emboli originate here. The treatment of calf vein clot is controversial. Most surgeons recommend a follow-up scan in 1

week because up to 30% of patients will propagate proximally. Anticoagulation for 3 months helps to reduce the severity of post-thrombotic symptoms.

Other veins in which thrombi occasionally develop include:

Pelvic veins, especially during pregnancy and pelvic surgery and from gynecologic cancer

Renal veins, especially when intrinsic renal disease is present

Inferior vena cava

Ovarian veins

Upper extremity and neck veins, especially with athletic activity or the use of intravenous cannulas

The right atrium in the presence of intrinsic cardiac disorders

Clinical presentation

The classic clinical syndrome includes calf or thigh pain, edema, tenderness, and a positive Homans' sign (calf pain on dorsiflexion of the foot). Only 40% of patients with DVT are symptomatic. Physical exam has only a 50% accuracy rate, and confirmatory testing is required. PE is the presenting symptom in some patients.

Diagnosis of DVT is made by means of laboratory tests.

Duplex ultrasound has become the standard initial test. It has a 95% sensitivity/specificity for proximal DVT. Diagnosis of iliac vein DVT is less reliable.

Venography of the ascending venous system is the traditional diagnostic method for DVT. It can be useful for evaluating the pelvic veins. Twenty to 40% of studies are technically inadequate.

Magnetic resonance venography. Excellent sensitivity and specificity; especially useful for diagnosis of pelvic DVT

Treatment

Continuous heparin infusion is given for 5–10 days, followed by administration of warfarin or subcutaneous administration of heparin for 3–6 months. Low molecular weight heparin (LMWH) can be used to initiate outpatient treatment of uncomplicated DVT.

Thrombolytic therapy with urokinase or t -PA is used if extensive DVT results in impaired perfusion of the extremity. It is recommended for extensive iliofemoral DVT to reduce postthrombotic sequelae.

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Inferior venacaval filter or interruption is used if heparin is contraindicated or if a pulmonary embolus occurs despite adequate anticoagulation therapy.

Prevention

Simple preventive measures include leg elevation, early mobilization after surgery, and the use of gradient compression stockings.

Intermittent calf compression by means of a pneumatic cuff increases leg blood flow velocity and helps to prevent stasis as well as causing a poorly defined systemic lytic effect.

Preoperative and postoperative administration of prophylactic heparin is effective in preventing deep thrombosis. An intermittent subcutaneous dose of 5,000 U is given every 8–12 hours. The risk of perioperative bleeding complication is slightly increased with heparin prophylaxis (6% vs. 4% of controls), but the risk of major hemorrhage is only about 2%.

LMWH is thought to cause fewer bleeding complications than unfractionated heparin.

Complications of DVT

Postphlebitic syndrome is a common late complication of DVT, often occurring several years after the acute event.

Clinical presentation: swelling and ulceration

Chronic valvular incompetence occurs because of damage incurred during the acute episode.

Leg edema usually is worse as the day progresses and as the leg is dependent. It usually improves with elevation and rest.

Ambulatory venous hypertension , due to reflux or venous occlusion, leads to edema and interstitial exudation of plasma, cells, and protein.

This edema and exudation then lead to brawny induration from hemoglobin metabolism. Tissue necrosis and skin ulceration result from poor oxygen diffusion in the edematous tissues.

Treatment

Gradient compression stockings must be worn continually. If swelling can be prevented, most ulcers can be prevented.

An Unna boot, a medicated pressure bandage, is applied weekly or biweekly until the ulcer heals. Compression therapy will heal most ulcers.

Phlegmasia alba dolens is caused by acute occlusion of the iliac and femoral veins due to DVT.

Clinical presentation. This phlebitis results in a pale cool leg with a diminished arterial pulse due to spasm.

Treatment is thrombolytic therapy followed by heparin administration to prevent progression to phlegmasia cerulea dolens.

Phlegmasia cerulea dolens is secondary to acute and nearly total venous occlusion of the

extremity outflow, including the iliac and femoral veins. It is more common in the left leg.

Clinical presentation

Physical findings include cyanosis of the extremity with massive edema, severe pain, and absent pulses, followed by venous gangrene.

Shock may occur as a result of sequestration of a significant amount of blood in the leg.

Treatment

Thrombolytic therapy followed by heparin administration

Thrombectomy occasionally if nonoperative therapy is unsuccessful

Bed rest with leg elevation

II Pulmonary Embolism

A Overview

PE is one of the most common causes of sudden death in hospitalized patients.

Patients with pre -existing cardiac or pulmonary disease tolerate even smaller PEs poorly.

Ninety percent of deaths occur within 2 hours after the onset of the initial symptoms. Therefore, if the patient lives longer than 2 hours, the chance of survival is very high.

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PE develops in about 10%–40% of patients with DVT. However, approximately 33% of patients with PE have no antecedent symptoms of DVT.

B Risk factors

Surgery and critical illness

Pregnant and postpartum women have a five times increased incidence of PE.

Estrogen therapy is associated with a four to seven times increased risk of PE. The risk is dose dependent and is eliminated within several weeks after cessation of therapy.

Heart disease is associated with a three to four times higher risk of pulmonary embolus formation. This risk is directly related to the severity of the heart disease.

Obesity is associated with a 1.5–2 times greater risk of PE.

Carcinoma is associated with a two to three times greater risk of PE.

Major trauma , especially spinal cord injury and pelvic or femoral shaft fractures, carries an increased risk of pulmonary embolus formation.

A history of PE increases the risk of later pulmonary embolus formation, especially after surgery.

Varicose veins are associated with a two times greater risk of PE.

scan is normal. Matched ventilation -perfusion defect occurs when a defect in the same location is revealed by both tests.

A segmental or large perfusion defect mismatched with a normal ventilation scan is associated with PE in 91% of patients.

A subsegmental or small perfusion defect mismatched with a normal ventilation scan is associated with PE in only 27% of patients.

A perfusion defect matched with a ventilation defect is associated with PE in 23% of patients.

When pulmonary embolus is clinically suspected but the lung scan is equivocal, an additional test should be performed to increase the reliability of those results. A pulmonary arteriogram is most reliable. A venous duplex is also useful in documenting the presence of DVT in this situation and, therefore, the likelihood of PE.

E

Treatment of PE includes both supportive measures to maintain circulatory function and administration of heparin for systemic anticoagulation.

Cardiovascular support is frequently necessary in patients with significant PE and should be instituted immediately. The supportive measures include oxygen administration, assisted ventilation, correction of cardiac arrhythmias, and treatment of shock by means of adequate hydration and vasopressors.

Heparin as an anticoagulant should be administered in an initial bolus of 10,000–20,000 U to halt the thrombotic process and to stabilize platelets in the embolus to prevent the release of vasoactive and bronchoactive substances. Administration begins with a continuous intravenous drip of heparin at approximately 1000 U/hour; the dosage is then adjusted to maintain the partial thromboplastin time at 1.5–2 times the control time. Heparin is continued for a minimum of 7 days and is followed by long-term anticoagulation therapy for 3–6 months.

Thrombolytic therapy with urokinase or tissue plasminogen activator may be used in cases of acute life - threatening PE when cardiopulmonary function is severely compromised as evidenced by shock, profound hypoxemia, or elevated pulmonary arterial pressure. Thrombolysis is contraindicated in patients with recent intracranial hemorrhage, recent surgery, or conditions associated with bleeding, such as peptic ulcer disease.

Pulmonary embolectomy is reserved for very ill patients who cannot endure the several hours required for thrombolysis. A closed embolectomy using a suction catheter or open embolectomy on cardiopulmonary bypass are the two most common methods.

Long -term anticoagulation may be maintained by either oral administration of warfarin to an international normalized ratio (INR) of two to three times control or subcutaneous intermittent administration of heparin.

F Complications of anticoagulation therapy

Major hemorrhage requiring transfusions occurs in 1%–2% of patients on anticoagulants, minor bleeding episodes are common in more than 16%, and fatal hemorrhage occurs in 0.1%–1%. The risk of hemorrhage is greater if heparin is administered intermittently or is given to elderly or severely hypertensive patients.

PE recurs despite anticoagulation therapy in 1%–8% of patients.

Heparin-induced thrombocytopenia occurs in up to 5% of patients on heparin and may be related to the development of heparin -induced antibodies directed toward platelets. This response is not dose related and is usually seen 5–10 days after heparin is started. The main source of morbidity is due to small vessel

thrombosis. All heparin infusions must be discontinued if thrombocytopenia occurs. Anticoagulation is continued using lepirudin or argatroban, which are direct thrombin inhibitors.

III Lymphatic System

A

Lymphedema is a condition characterized by swelling of one or more extremities because of lymphatic insufficiency.

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Types. Lymphedema may be idiopathic (primary lymphedema) or may be caused by acquired insufficiency due to infections, obstructions, or surgical destruction of the lymphatics (secondary lymphedema).

Primary lymphedema. Three types of primary lymphedema are distinguished by age of onset.

Congenital lymphedema is present at birth or occurs early in infancy.

It accounts for fewer than 10% of primary lymphedema cases.

Lymphedema that is both congenital and hereditary is known as Milroy's disease.

Lymphedema praecox occurs at any time from puberty until the end of the third decade.

Most cases of primary lymphedema are of this type.

It is three times more common in women than in men.

Lymphedema tarda occurs after age 30.

Secondary lymphedema is due to obstruction from a variety of causes, including infection (see III C), parasites, mechanical injury (including surgery), postphlebitic syndrome, and neoplasms.

In developed countries, the most common causes are obstruction by malignancies, postsurgical lymphedema (e.g., after mastectomy), and lymphatic destruction from therapeutic radiation.

In less well-developed countries, parasitic obstruction (elephantiasis) is a common cause. Wuchereria bancrofti is the most common offending parasite.

Diagnosis of lymphedema is usually made clinically.

The history characteristically includes edema, which begins at the foot and ankle and progresses proximally. Progression is slow, usually over the course of several months.

Physical examination. Lymphedema has no dark brawny edema or ulceration of the skin. Whereas the swelling secondary to venous disease usually starts at the ankle, lymphedema usually involves the dorsum of the foot.

Laboratory tests. The diagnosis can be proven by lymphangiography, but this test is not done routinely because it is difficult and hazardous.

Treatment

Simple measures are the first line of treatment.

Elevation of the affected limb, weight reduction, and salt restriction may be helpful.

Compressive stockings may be of benefit if worn properly.

It is extremely important to avoid trauma and infection because either will greatly exacerbate the condition.

Pneumatic compression boots may help to “squeeze” the edema from the swollen extremity in severe cases.

Surgery is indicated only infrequently for advanced and severely debilitating disease.

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Study Questions for Part III

Directions: Each of the numbered items in this section is followed by several possible answers. Select the ONE lettered answer that is BEST in each case.

1.A 65 -year-old woman with a long history of atrial fibrillation presents to the emergency department with a history of sudden onset of severe, constant abdominal pain. After the onset of pain, she vomited once and had a large bowel movement. No flatus has been passed since that time. Physical examination reveals a mildly distended abdomen, which is diffusely tender, although peritoneal signs are absent. Ten years ago, she underwent an abdominal hysterectomy. What is the most likely diagnosis in this patient?

A Acute cholecystitis

B Perforated duodenal ulcer C Acute diverticulitis

D Acute embolic mesenteric ischemia

E Small bowel obstruction secondary to adhesions View Answer

2.A 60 -year-old woman develops weakness in her right arm and leg, and she has some difficulty speaking. This condition resolves after 5 minutes, and she has no residual symptoms. Her physician does not hear a carotid bruit, and her electrocardiogram is normal. A carotid duplex ultrasound shows a 75% stenosis of the left carotid artery and an 80% stenosis of the right carotid artery; both are confirmed by a carotid arteriogram. What should be the next step in the management of this patient?

A Right carotid endarterectomy B Left carotid endarterectomy

C Superficial temporal artery to middle cerebral artery bypass

D Percutaneous transluminal angioplasty of the left carotid artery E Bilateral carotid endarterectomy

View Answer

Questions 3–4

A 70 -year -old man who is a new patient presents with a history of insulin -dependent diabetes mellitus; renal insufficiency (serum creatinine, 2.5); chronic obstructive pulmonary disease; and two myocardial infarctions, the most recent being 1 year ago. His ejection fraction is 35%, and he has a right below -the-knee amputation, which he says was secondary to “peripheral vascular disease.” Now, the patient has a large pulsatile nontender abdominal mass.

3. All of the following studies would be appropriate except

A Computed tomography (CT) scan of the abdomen B Pulmonary function tests

CArteriogram

DColonoscopy

EPersantine thallium scan View Answer

His workup demonstrates a 6.0-cm infrarenal abdominal aortic aneurysm with a 4-cm left common iliac artery

aneurysm and normal renal arteries. He has normal external iliac arteries bilaterally, with relatively normal femoral vessels. Pulmonary function tests indicate a forced expiratory volume in 1 second (FEV 1 ) to be 75% of the

predicted value. The Persantine thallium scan shows an old scar but no reperfusion defect.

4. What is the next step in this patient's management ?

A Letting the patient live with the aneurysm because he is too high a surgical risk for elective surgery B Checking the size of the aneurysm with ultrasound every year until it starts to enlarge

C Not performing surgery until he develops back pain because he is currently asymptomatic

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DPerforming an aorto -bi -iliac bypass

ERepairing the abdominal aortic aneurysm with a tube graft View Answer

5.A 67 -year-old woman notices a swollen right leg following a 6-hour plane flight. Which of the following would be a reasonable next step for the treating physician?

APrescribe compression stockings and leg elevation

BStart 6 months of warfarin anticoagulation

CPrescribe one baby aspirin per day

DOrder a venous duplex evaluation

EOrder a pelvic CT scan to look for lymphadenopathy

View Answer

Questions 6–9

A 59 -year -old patient undergoes a craniotomy for a benign meningioma. On the tenth postoperative day, he is noted to have a swollen left calf and thigh.

6. What is the least accurate method to diagnose the cause of the swollen leg? A Physical examination

B Left leg venogram

C125 I Fibrinogen scan

DImpedance plethysmography

EDuplex ultrasonography

View Answer

7.If deep venous thrombosis is documented, initial treatment should include which of the following? A Subcutaneous unfractionated heparin therapy

B Intravenous heparin therapy

C Thrombolytic therapy with urokinase D Aspirin therapy

E Warfarin treatment View Answer

8.After recovery from the acute illness, the patient returns in 6 months, complaining of persistent leg swelling. Which of the following would be the optimal long -term management as initial treatment?

A Chronic diuretic therapy B Venous thrombectomy

C Venous bypass using an autologous vein D Venous bypass using a prosthetic graft E Support hose

View Answer

9.This complication may have been prevented by all of the following measures except

A Early mobilization after surgery B Routine use of support hose

C Routine use of pneumatic sequential compression devices on both lower legs

D Daily administration of a single dose of subcutaneous unfractionated heparin starting 12 hours after the completion of surgery

E Daily administration of low molecular weight heparin starting in the preoperative holding area

View Answer

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Answers and Explanations

1. The answer is D (Chapter 7, V A 1 a). The triad of a cardiac arrhythmia, the sudden onset of severe abdominal pain, and gut emptying is a classic indicator of embolic mesenteric ischemia. This combination constitutes a surgical emergency, and the patient should be treated promptly with vigorous rehydration followed by arteriography to confirm the diagnosis. Rapid embolectomy of the superior mesenteric artery could save this patient, provided that no delay occurs in her definitive surgical treatment.

Cholecystitis usually presents with right upper quadrant pain and diverticulitis with left lower quadrant pain. A perforated ulcer will have associated diffuse abdominal tenderness but also wil have signs of peritoneal irritation (guarding and rebound). A small bowel obstruction usually presents with colic or intermittent pain.

2. The answer is B (Chapter 7, VIII E 2 a–e ). The symptomatic artery is usually repaired first because it carries the highest risk of stroke. Percutaneous transluminal angioplasty of the carotid artery is presently under investigation as an alternative to carotid endarterectomy, but it is not considered to be the standard of care at this point. Percutaneous transluminal angioplasty is sometimes used for smooth, regular lesions associated with fibromuscular dysplasia. The superficial temporal artery to middle cerebral artery bypass has not been shown to be effective for this patient's disease. Bilateral carotid endarterectomy is usually not performed because of the risk of recurrent laryngeal nerve trauma, which, if bilateral, could result in a tracheostomy.

3–4. The answers are 3-D (Chapter 7, VIII A ), 4-D (Chapter 7, VIII A 3). Colonoscopy is not indicated if the patient's stool is heme negative. Computed tomography (CT) can help to evaluate the proximal extent of the aneurysm. Pulmonary function tests can help to assess risk and to help plan perioperative care. An arteriogram acts as a road map, showing the renal arteries in relation to the aneurysm and the extent of occlusive disease in the iliac and femoral arteries. A Persantine thallium scan helps to define perioperative cardiac risk.

Elective repair of an abdominal aortic aneurysm (AAA) can be performed with a mortality rate lower than 5%. The leading cause of death in these patients with AAA is rupture. A 6-cm AAA has a 35% rupture rate, and surgery should be recommended unless the patient has a life expectancy of less than 1 year. Rate of enlargement is not a safe predictor of risk of rupture. Patients with symptomatic or rupturing AAA have a 75% mortality rate when operated on as an emergency. An aorto -bi -iliac graft is the appropriate procedure in this patient, rather than a tube graft, to repair the associated iliac aneurysm. With no iliac occlusive disease, an aortoiliac bypass avoids groin incisions.

5. The answer is D (Chapter 8, I B 3). A swollen leg following a period of immobilization is a typical history leading to a deep venous thrombosis (DVT). While lymphedema or other causes can also lead to leg swelling, a pelvic CT scan would not be the next step for this patient. Physical examination is reliable only 50% of the time for DVT, so an accurate diagnostic study such as a venous duplex ultrasound is needed before starting long-term anticoagulation. If no other reason for the swelling can be found, a pelvic CT scan may be reasonable. Leg elevation is helpful to reduce swelling, but compression stockings are not recommended in the acute phase for fear of dislodging the clot. Aspirin is of no proven benefit in treating DVT.

6–9. The answers are 6-A [Chapter 8, I B 3 c (1)–(4) ], 7-B [Chapter 8, I B 3 d (1)], 8-E [Chapter 8, I B 3 f (1)]. Physical examination is the least likely method to diagnose the cause of acute leg swelling. Currently, such a patient would undergo duplex ultrasonography or venography to confirm the presumed diagnosis of DVT. Impedance plethysmography can detect increased resistance to venous flow but does not identify the

cause. 125 I Fibrinogen scanning can identify ongoing thrombosis, but the scan takes 24 hours to complete and is therefore not useful in acute situations.

Intravenous heparin therapy is the most appropriate initial treatment. Subcutaneous unfractionated heparin

therapy in its current form is not acceptable treatment for DVT. Thrombolytic therapy would be contraindicated in a patient with a recent craniotomy because it would increase the risk of hemorrhage. P.175

Aspirin therapy has no role in the treatment of DVT. Warfarin can be used once the patient is discharged but not as the initial treatment. Transition from intravenous heparin to warfarin therapy should occur on the fourth or fifth day of heparin administration.

Support hose is the mainstay of treatment for patients with chronic postphlebitic syndrome. Thrombectomies have been unsuccessful, and the efficacy of venous bypass has yet to be established. There is interest in transplanting venous valves and segments of a vein to replace short-segment thromboses, but this area is still experimental. Prosthetic grafts have no role in venous reconstruction. Chronic diuretic therapy may be useful for short-term therapy but is certainly not optimal long-term management for this problem.

9. The answer is D (Chapter 8, I B 3 e). The risk of DVT can be reduced by simple measures such as leg elevation, early mobilization, support hose, and sequential compression devices. Unfractionated heparin administered subcutaneously either two or three times a day or low molecular weight heparin can both reduce the risk of DVT, but either should be started prior to surgical procedures.