Links To And Excerpts From “Diagnostic approach to lower limb edema”

Posted on May 5, 2024 by Tom Wade MD

Today, I review, link to, and excerpt from Diagnostic approach to lower
limb edema [PubMed Abstract] [Full-Text HTML] [Full-Text PDF]. Phlebology. 2020 Oct;35(9):650-655. doi: 10.1177/0268355520938283. Epub 2020 Jul 6.

There are 97 similar articles in PubMed.

Today’s resource has been cited by 13 articles in PubMed.

All that follows is from today’s resource.

Abstract

Patients with lower limb edema are frequently referred to vascular specialists for evaluation. Multiple etiologies must be considered and often more than one cause may be present. Notably, the role of lymphatic system regardless of the underlying pathology has been underestimated. A thorough history and physical examination and a carefully considered laboratory and imaging evaluation are critical in differentiating causes. In this opinion article, we propose a diagnostic algorithm that incorporates a systematic approach to the patient with leg swelling and provides an efficient pathway for the differential diagnosis for this problem.

Keywords: Chronic venous disease; lymphedema; vascular medicine.

Introduction

Lower limb edema is a common and challenging diagnostic problem often with a significant impact. It is defined as swelling caused by an increase in interstitial fluid that exceeds the capacity of physiologic lymphatic drainage. In most cases it occurs when fluid accumulates in subcutaneous tissues leading to volume expansion, although congenital etiologies and lipedema may result in excessive soft tissue in the lower extremities. Fluid collection can be a result of many etiologies including a range of local or systemic disorders, including infra-inguinal superficial and deep venous reflux, supra and infra inguinal deep vein obstruction, and primary and secondary lymphatic diseases. Although the most likely singular cause of unilateral lower limb edema in individuals over 50 years old is venous disease, the etiology is often multifactorial. Symptoms can be debilitating and subsequently impact quality of life with significant costs to society.– Recent work has demonstrated that chronic edema negatively impacts physical and psychological health and reduces quality of life. As such, in this opinion article, we propose a practical diagnostic approach to accurately and efficiently identify the causes of chronic edema in affected patients and to institute appropriate therapy.

History

Lower limb swelling may present to the clinician in several ways. It is essential to take a complete patient history to facilitate accurate, efficient, and cost-effective diagnostic testing and management. The site of swelling and any associated manifestations should be assessed, including whether it is unilateral, bilateral equal or bilateral but asymmetric, along with any changes that occur with its severity with position and time of day. Swelling may be asymptomatic, although it can be associated with symptoms such as aching, pain, heaviness, characteristic venous or lymphatic skin changes or prior or active ulcerations of the lower limb. Patients may describe a sudden onset of limb swelling, a gradual onset or a more long-standing condition. Common causes of leg swelling based on acuity and unilateral or bilateral symptoms are shown in Table 1.

Unilateral swelling favors primary and secondary causes of venous or lymphatic compromise and bilateral or generalized swelling suggests systemic etiologies as noted in Table 1. Bilateral but asymmetric cases can have unilateral causes on each leg of different etiologies or varying degrees, or a unilateral cause superimposed on a background of systemic disease. Lymphedema and venous edema can also be bilateral unequal and bilateral equal, although bilateral equal is less common with venous etiologies below the IVC since the disease is often asymmetric at any one point in time.

Assessing the duration of symptoms is important, with acute swelling (<72 h) more characteristic of etiologies such as DVT, infection, trauma, exacerbation of a medical condition such as congestive heart failure, or recent medication changes. Chronic swelling may be due to venous insufficiency, lymphatic dysfunction, static foot disorders, or more longstanding medical etiologies. Additionally, swelling due to venous disease typically worsens with dependency during the day and improves with elevation. Venous edema is also commonly associated with complaints of aching, heaviness, or fatigue of the limbs. Focal pain may suggest a musculoskeletal or joint issue. Reflex sympathetic dystrophy (complex regional pain syndrome) must also be considered with a significantly painful chronically swollen limb. Lymphedema is usually painless and may present with classic signs of foot involvement and skin changes or with just mild swelling that is pitting.– Lipedema almost always is bilateral, spares the feet, and presents with disproportionate pain, tenderness, and an unusual tendency to bruise easily. It is important to recognize that the often-referenced clinical findings are not always the rule with these conditions.

A complete history of venous disorders including the presences of varicose veins, prior VTE, or prior events that could provoke VTE, and of personal or familial clotting issues and a history of prior superficial and deep venous interventions should be obtained. Provoking events could be trauma, prolonged bedrest, history of lower limb interventions including joint arthroplasty, arterial interventions, or vein harvesting for heart bypass. Previous abdominal or pelvic surgery, malignancy, or radiation history is also important as an antecedent to both venous and lymphatic etiologies of edema.–

Assessment for systemic diseases is necessary, particularly in older patients with multiple comorbid conditions that could be contributing to their primarily bilateral leg edema. New onset or exacerbations of cardiac, renal, hepatic, endocrine issues may be a cause. A history of unexplained weight loss or adenopathy might suggest malignant venous compression.

A detailed review of the patient’s medications must also be performed. Any changes in regimens should be considered in relation to swelling onset. Numerous medications (Table 2) can lead to lower limb edema. Calcium channel blockers, especially of the dihydropyridine class such as amlodipine, are common culprits, with lower limb edema found in nearly 50% of patients on this agent.–

It is very important to note that there are often several factors responsible for swelling in any given patient and it is incumbent on the physician to determine the relative contribution of each. This will allow a more complete diagnosis and help the physicians to prioritize management to address the most important or impactful etiologies.

Physical examination

A complete physical examination is as essential to the clinical history in establishing the etiology of swelling. Although the main complaint is in the lower limbs, evaluation of the heart, lungs, and abdomen are important to assess for systemic etiologies or contributing factors. Increased jugular venous distension or crackles in the lungs may be due to heart failure, a distended abdomen with ascites or scleral icterus suggests hepatic disease, and abdominal incisions can reveal past surgeries. Extensive prominent veins in the lower abdomen may be a sign of inferior vena cava occlusion. Obesity with a large abdomen also may contribute to bilateral lower limb edema.–

Diagnostic testing

If a systemic issue is suspected, appropriate laboratory tests should be performed. Complete blood count, a metabolic panel including evaluation of creatine, urinalysis, thyroid panel, atrial natriuretic peptide, hepatic enzymes, and albumin level may reveal abnormalities depending on the etiology. A D-dimer level may be helpful in evaluating for a possible acute DVT in the appropriate context., These tests can usually be performed by the primary care physician or cardiologist with concurrent imaging studies by the vascular specialist if needed.

Duplex ultrasound (DUS) is the initial and often the only imaging test in patients with swollen lower limbs without a clear cause based on history, physical and laboratory exam, or when further details are required to make therapeutic decisions. This non-invasive, low cost exam can survey the extremities for vascular and non-vascular causes of both acute and chronic swelling and offers a reproducible method of viewing venous anatomy, valve function, and patency. With sensitivity and specificity rate >90% for DVT, venous reflux, and non-vascular etiologies, swelling can be readily and robustly evaluated.,

DUS can also assess the venous anatomy in the abdomen and pelvis to look for thrombosis or compression by adjacent arteries or masses. Visualization of pelvic anatomy may be difficult for less experienced operators, or because of gas-filled intestinal loops, or obesity., If additional imaging of the abdomen or pelvis is necessary after DUS, contrast-enhanced venous phase computed tomography (CT) or magnetic resonance (MR) imaging are alternatives. Mass effect by tumor or enlarged lymph nodes, iliocaval compression/obstruction, and general venous anatomy can be easily visualized. Additionally, MR imaging can be used for evaluating musculoskeletal or neurologic etiologies.

This entry was posted in Peripheral Edema. Bookmark the permalink.