Lymphedema

Lymphedema is a set of pathologic conditions that are characterized by the regional accumulation of excessive amounts of interstitial protein-rich fluid. These occur as a result of an imbalance between the demand for lymphatic flow and the capacity of the lymphatic circulation. Lymphedema can result from either primary or acquired (secondary) disorders. In this review, the pathophysiology, classification, natural history, differential diagnosis, and treatment of lymphedema are discussed.

Lymphedema: classification, diagnosis and therapy

This review presents the diagnostic features, the pathophysiology and the available therapies for lymphedema. This disease is often able to be diagnosed by its characteristic clinical presentation, yet, in some cases, ancillary tests might be necessary to establish the diagnosis, particularly in the early stages of the disease and in edemas of mixed etiology. These diagnostic modalities are also useful in clinical studies. Available modalities include isotopic lymphoscintigraphy, indirect and direct lymphography, magnetic resonance imaging, computed tomography and ultrasonography. Lymphedema may be primary or secondary to the presence of other disease and/or to the consequences of surgery. Primary lymphedema may occur at any phase of life but it most commonly appears at puberty. Secondary lymphedema is encountered more often. The most prevalent worldwide cause of lymphedema is filariasis, which is particularly common in south-east Asia. In the USA, postsurgical lymphedema of the extremity prevails. Complications of chronic limb lymphedema include recurrent cellulitis and lymphangiosarcoma. Most patients are treated conservatively, by means of various forms of compression therapy, including complex physical therapy, pneumatic pumps and compressive garments. Volume reducing surgery is performed rarely. Lymphatic microsurgery is still in an experimental stage, although a few centers consistently report favorable outcomes.

Decongestive lymphatic therapy for patients with cancer-related or primary lymphedema

PURPOSE

A prospective evaluation was undertaken to assess the efficacy of intensive, short-term decongestive lymphatic therapy coupled with focused patient instruction in long-term self-care for the management of lymphedema.

METHODS

The therapeutic responses of 79 patients with lymphedema were analyzed prospectively. Each patient received intensive, short-term decongestive lymphatic therapy, with quantification of the extent and durability of the clinical response. Decongestive lymphatic therapy was performed by therapists trained in these techniques. The mean (+/-SD) duration of therapy was 8+/-3 days. Instruction in self-management techniques was incorporated into the therapeutic regimen by day 3 of the patient's treatment. The mean period of follow-up was 38+/-52 days. Changes in the volume of the affected limb were assessed with a geometric approximation derived from serial measurements of circumference along the axis of the limb.

RESULTS

The mean short-term reduction in limb volume was 44%+/-62% of the excess volume in the upper extremities and 42%+/-40% in the lower extremities. At follow-up, these results were adequately sustained: mean long-term excess volume reductions of 38%+/-56% (upper extremities) and 41%+/-27% (lower extremities) were observed.

CONCLUSION

Decongestive lymphatic therapy, combined with long-term self-management, is efficacious in treating patients with lymphedema of the extremity.

Lymphedema: anatomy, physiology and pathogenesis

The authors review the current understanding of lymphatic anatomy and physiology, and the pathophysiology of lymphedema. The skin lymphatic system consists of the initial lymphatics, which converge into lymphatic precollectors, collectors and lymphatic ducts; these in turn convey the lymph to the regional lymph nodes. Interstitial fluid and particles enter the initial lymphatics through interendothelial openings and by vesicular transport. Lymphatic uptake is enhanced by external compression. Lymphatic transport depends greatly on contraction of lymphangions, which generate the suction force that promotes absorption of interstitial fluid and expels lymph to collecting ducts. In lymphedema, various types of congenital and acquired abnormalities of lymphatic vessels and lymph nodes have been observed. These often lead to lymphatic hypertension, valvular insufficiency and lymphostasis. Accumulation of interstitial and lymphatic fluid within the skin and subcutaneous tissue stimulates fibroblasts, keratinocytes and adipocytes eventuating in the deposition of collagen and glycosaminoglycans within the skin and subcutaneous tissue together with skin hypertrophy and destruction of elastic fibers.

Photoangioplasty: An emerging clinical cardiovascular role for photodynamic therapy

Photodynamic therapy (PDT) has been studied and applied to various disease processes. The potential of PDT for selective destruction of target tissues is especially appealing in cardiovascular disease, in which other existing interventional tools are somewhat nonselective and carry substantial risk of damage to the normal arterial wall. Enthusiasm for photoangioplasty (PDT of vascular de novo atherosclerotic and, potentially, restenotic lesions) is fueled by more effective second-generation photosensitizers and technological advances in endovascular light delivery. This excitement revolves around at least 4 significant attributes of light-activated therapy: the putative selectivity and safety of photoangioplasty, the potential for atraumatic and effective debulking of atheromatous plaque through a biological mechanism, the postulated capability to reduce or inhibit restenosis, and the potential to treat long segments of abnormal vessel by simply using fibers with longer light-emitting regions. The available nonclinical data, coupled with the observations of a new phase I trial in human peripheral atherosclerosis, suggest a promising future for photoangioplasty in the treatment of primary atherosclerosis and prevention of restenosis.

An antiidiotypic antibody that recognizes the beta-adrenergic receptor

Antialprenolol rabbit antibodies were fractionated on an acebutolol affinity resin, followed by L-propranolol elution so as to separate a class of binding sites that mimic the beta-adrenergic receptor. Allotype-identicaL rabbits were immunized with this fraction. After 6 mo, antisera exhibited antiidiotypic activity inhibiting [3H]alprenolol binding to the original antibody and to rabbit antiacebutolol antibodies, which had a spectrum of ligand-binding properties identical to the original idiotype. Those antisera demonstrating the original idiotype. Those antisera demonstrating the most potent antiidiotypic activity also blocked [3H]alprenolol binding to the beta-adrenergic receptor of turkey membrane, canine pulmonary membrane, and rat reticulocyte. An idiotype affinity-purified fraction showed similar activity, inhibiting beta-receptor binding with a calculated dissociation constant (KD) of 53 nM. Isoproterenol-mediated adenylate cyclase activity was also inhibited in a competitive manner. The universality of recognition of these antiidiotypic antisera indicate that the three-dimensional structure of a receptor's binding site can be modeled by a subset of an elicited antibody population.

Quantitative radionuclide lymphoscintigraphy predicts outcome of manual lymphatic therapy in breast cancer-related lymphedema of the upper extremity

Secondary lymphedema is a localized, acquired lymphatic microcirculatory disturbance that affects large numbers of patients after breast cancer therapy. There is a paucity of objective methods to quantitate lymphatic function and to anticipate the response to therapeutic interventions. We applied radionuclide lymphoscintigraphy to evaluate lymphatic transport and axillary lymph node visualization in women following breast cancer therapy to determine the utility of these data in these patients. Lymphoscintigraphy was performed after subcutaneous injection of 0.25 mCi of Tc-filtered sulfur colloid. Subcutaneous accumulation of radiotracer ('dermal backflow') and the visualization of axillary lymph nodes were graded using our own scoring system. The ratio of radioactivity within the affected to normal axillae (ARR) was also quantified. Nineteen patients with lymphedema after breast cancer therapy were evaluated. The disease severity was documented by serial measurements of the limb volume using the truncated cone formula. Responses to therapy were quantified after completion of the therapy. There was a correlation between the ARR and the percentage reduction in edema volume. The lymphoscintigraphic score correlated with the initial arm volume excess and with the durationof lymphedema. It can be concluded that quantitative and semi-quantitative assessment by radionuclide lymphoscintigraphy represents a potentially useful tool for the clinical assessment of upper extremity lymphedema.

Photoangioplasty for human peripheral atherosclerosis: results of a phase I trial of photodynamic therapy with motexafin lutetium (Antrin)

BACKGROUND

In photoangioplasty, light activation of a photosensitive drug offers the potential for treatment of long segments of vascular disease. This is a brief description of a study designed to evaluate the safety and tolerability of a new photosensitizer, Antrin (motexafin lutetium), in the endovascular treatment of atherosclerosis.

METHODS AND RESULTS

An open-label, single-dose, escalating drug- and light-dose study was performed in patients with atherosclerotic peripheral arterial insufficiency. Clinical evaluation, serial quantitative angiography, and intravascular ultrasonography were performed. Therapy was well tolerated, and only minor side effects were observed. Treatment produced no deleterious vascular effects. Although this study was not designed to examine clinical efficacy, several secondary end points suggested a favorable therapeutic effect.

CONCLUSIONS

This phase I study demonstrates that photoangioplasty with motexafin lutetium is well tolerated and safe. Preliminary efficacy data suggest a future role for the treatment of flow-limiting atherosclerosis.

Lesch-Nyhan syndrome: evidence for abnormal adrenergic function

Subjects with the Lesch-Nyhan syndrome (hypoxanthine-guanine phosphoribosyltransferase deficiency with self-mutilation) exhibit an apparently unique pattern of adrenergic dysfunction characterized by elevated plasma dopamine beta-hydroxylase activity and an absence of pressor response to acute sympathetic stimulation. Patients with a partial deficiency of hypoxanthine-guanine phosphoribosyltransferase without self-mutilation do not exhibit these abnormalities of adrenergic function.

Cellular mechanisms of impaired adrenergic responsiveness in neonatal dogs

The myocardial responsiveness of conscious, instrumental dogs to exogenously administered isoproterenol and norepinephrine was investigated in neonatal, 6-wk-old, and adult animals. Comparable base-line values for peak left ventricular derivative of pressure with respect to time were observed in all age categories. However, when compared with adult responses, the sympathomimetic amine-induced increases in neonatal left ventricular dP/dt were significantly blunted at each concentration of adrenergic agonist examined, whereas the 6-wk-old puppies displayed an intermediate inotropic response. To investigate the cellular mechanisms of this blunted neonatal response, we correlated physiologic and biochemical measurements of the myocardial responses to catecholamines in each age category. When compared with adult myocardial membrane preparations, neonatal cardiac membranes were characterized in vitro by an increased density of beta-adrenergic binding sites, comparable affinity for adrenergic agonists and antagonists, and an enhanced coupling of adenylate cyclase activation to receptor occupancy. Simultaneous changes in either the serum catecholamine concentration or the membrane content of other intrinsic proteins failed to account for the observed neonatal increase in beta-adrenergic receptor density. These findings are most consistent with a compensatory mechanism of the cardiac cell membrane, whereby an inherent depression in the adrenergic responsiveness of the immature myocardium appears to induce the increase in receptor density and activation of adenylate cyclase.

Myocardial ischemia and infarction due to multiple coronary-cameral fistulae: two case reports and review of the literature

The functional significance of coronary-cameral fistulae, and the effect of these arterial anomalies upon effective coronary blood flow, continue to be debated. Two cases of coronary cameral fistulae, each of which illustrates the likelihood of an ischemic substrate, are herein presented, along with a review of the relevant literature regarding this disorder.

Precipitating factors in lymphedema: myths and realities

BACKGROUND

Lymphedema is an all too common occurrence following breast carcinoma therapy. Despite its prevalence, the predisposing factors to the development of this secondary form of lymphedema remain poorly understood.

METHODS

Several studies have addressed these questions and are reviewed here.

RESULTS

Treatment factors that appear to predispose to the late, subjective appearance of lymphedema include the extent of axillary surgery and exposure to high dose axillary radiotherapy, particularly when combined with surgical clearance of the axilla. Other pertinent patient factors may include the presence of hypertension and exposure to airline travel. Clinical features unrelated to the risk of lymphedema development include patient age; drug therapy; time interval to presentation, surgery, or radiotherapy to the breast; total dose of radiation; and menopausal status. The potential importance of concomitant venous abnormalities in these patients is worthy of consideration.

CONCLUSIONS

Breast carcinoma-related secondary lymphedema is an important subjective and functional problem for affected patients. Additional research into the predisposing factors to this common problem is likely to foster enhanced patient education and to produce more efficacious measures to control this disease.

Anti-alprenolol antibodies in the rabbit. A new probe for the study of beta-adrenergic receptor interaction

We immunized rabbits with an antigen prepared by covalent linkage of alprenolol, a beta-adrenergic receptor antagonist, to bovine serum albumin. Competitive inhibition of [3H]dihydroalprenolol binding to antisera with a variety of unlabeled ligands revealed broad antibody specificity for beta-adrenergic antagonists and agonists. The antiserum was subjected to affintiy fractionation on hydroxybenzylpindolol-Sepharose 4B. Successive elution with 100 mM Tris HCl, 1M NaCl, 4 M LiBr, and 5 M guanidine yielded fractions with increasing affintiy for hydroxybenzylpindolol. The ligand-binding properties of these affinity-fractionated antibodies suggest that certain of these fractions recognize structural aspects of individual beta-adrenergic ligands which are irrelevant to their biological activity, whereas others can be used to distinguish shared functional properties, such as the ethanolamine side chain, within the structural heterogeneity of beta-adrenergic drugs. In particular, elution of hydroxybenzylpindolol-adsorbed antibody with (-)-propranolol allowed identification of an antibody fraction specific for the (-)-stereoisomer. Thus, affinity fractionation of antibodies raised against beta-adrenergic ligands can provide useful analogues for the further study of the recognition properties of the beta-adrenergic receptor.

Plasma dopamine-beta-hydroxylase activity in oral contraceptive hypertension

A prospective study was undertaken to evaluate the relative contribution of changes in sympathetic nervous system activity, as reflected by changes in dopamine-beta-hydroxylase (DBH) activity, to the pathogenesis of oral contraceptive-induced hypertension. Precontraceptive and serial post contraceptive determinations of blood pressure, plasma renin activity (PRA), DBH activity, and changes in body weight were obtained in twelve control patients and forty-one oral contraceptive users. Forty-four percent of oral contraceptive users had increases in blood pressure but remained normotensive and 17% became frankly hypertensive. The precontraceptive and average post contraceptive levels of mean arterial pressure (MAP), PRA and DBH activity in each patient were compared using paired group analysis. Control patients (group I) exhibited no significant changes in these variables, while the patients with contraceptive-induced increases in MAP (groups III and IV) underwent significant, parallel increases in DBH activity. Finally, the linear regression of changes in MAP on the percent change in DBH activity was examined. The positive slopes in groups III and IV differed significantly from the negative slope of the controls (group I). The data have been interpreted to reflect an inappropriate oral contraceptive-induced stimulus to sympathetic nervous system activity, leading to increases in MAP in susceptible individuals.

Formulating clinical strategies for angiotensin antagonism: a review of preclinical and clinical studies

Extensive animal studies and a growing number of human clinical trials have now definitively demonstrated the central role of the renin-angiotensin-aldosterone system in the expression and modulation of cardiovascular disease. In contrast to the original hypothesis, the benefits of angiotensin antagonism do not emanate from the antihypertensive effect alone. Subsequent extensive investigations of angiotensin blockade suggest that the benefits of this approach may also result from the pharmacologic alteration of endothelial cell function and the ensuing changes in the biology of the vasculature. The more recent availability of direct antagonists of the AT(1) angiotensin receptor has introduced an element of doubt into this realm of clinical decision making. The receptor antagonists and the more widely studied converting-enzyme inhibitors share many endpoint attributes. Nevertheless, the partially overlapping mechanisms of action for the two classes of angiotensin antagonists confer distinct pharmacologic properties, including side effect profiles, mechanisms of action, and theoretic salutary effects upon the expression of cardiovascular disease. The current review will attempt to contrast the biology of angiotensin converting-enzyme inhibition with angiotensin II receptor antagonism. A discussion of the differential effects of these drug classes on endothelial cell function and on the modulation of vascular disease will be utilized to provide a theoretic framework for clinical decision making and therapeutics.

Feasibility and reliability of rapid diagnosis of myocardial infarction

BACKGROUND

Prevailing hospital practice dictates a protracted phase of observation for patients with chest pain to establish or exclude the diagnosis of myocardial infarction. Early diagnosis of acute myocardial infarction may improve patient care and reduce both complications and hospital costs. A study was performed to investigate the feasibility of early diagnosis of myocardial infarction within the first 9 hours of the hospital stay.

METHODS

The records of all patients admitted with chest pain within one calendar year were analyzed. The timing of creatine kinase-MB (CK-MB) quantification was determined with reference to the initial phlebotomy (time 0). An enzymatic diagnosis of myocardial infarction was assigned if any determination of CK-MB exceeded the upper limit of normal, and the diagnosis of each patient at or before 9 hours (early diagnosis) was compared to the ultimate diagnosis at 14 to 24 hours (final diagnosis) beyond initial assessment.

RESULTS

Of the 528 included patients, 523 patients (99.1%) had identical early and final diagnostic outcomes; 5 patients (0.9%) had conflicting results. An early diagnosis of myocardial infarction was assigned to 195 of the 528 patients (36.9%). Of these, 190 achieved the diagnosis within 9 hours (sensitivity 97.4%). The negative predictive value was 98.5%.

CONCLUSION

Standard CK-MB mass measurements within 9 hours of arrival provided an accurate clinical assessment in > 99% of the cases. The high sensitivity and negative predictive values suggest that early diagnosis of myocardial infarction is feasible and reliable.

Lymphoscintigraphic manifestations of Hennekam syndrome--a case report

Hennekam syndrome is a rare, recently described genetic disorder in which facial anomalies and mental retardation accompany congenital lymphedema and intestinal lymphangiectasia. Several other somatic abnormalities have variously been described, as have milder degrees of lymphatic dysfunction. The authors herein describe a case of Hennekam syndrome in which the diagnostic difficulties were partially overcome by the judicious use of radionuclide scintigraphy to verify the lymphedematous component of the patient's presentation.

Plasma dopamine-beta-hydroxylase in the diagnosis of neuroblastoma

An atypical case of neuroblastoma is described, in which the diagnosis was facilitated by the application of a new biochemical procedure, the assay of plasma dopamine-beta-hydroxylase activity. This laboratory tool is proposed as a useful adjunct to established techniques in the diagnosis of neural crest tumors.

Fibroblast growth factor as therapy for critical limb ischemia: a case report

In an attempt to avert impending, primary amputation, an 85-year-old woman with chronic critical leg ischemia was enrolled in an experimental protocol to induce therapeutic angiogenesis. Treatment consisted of six consecutive, weekly intravenous infusions of recombinant basic fibroblast growth factor (bFGF). Angiographic evaluation was performed before and after therapy. The patient's clinical response was monitored through serial measurements of the ankle/brachial index and by repetitive assessment of limb flow by mercury strain-gauge plethysmography. A beneficial clinical response was detectable by week 4 of therapy, which was characterized by an improved walking distance, relief of ischemic pain, a marked reduction in analgesic consumption, and healing of persistent, unresponsive, painful inflammation of the hallux. The clinical improvement was sustained throughout the remaining weeks of therapy and follow-up evaluation. Plethysmography documented improved blood flow; specifically, the augmentation of digital flow was sustained and correlated with the marked improvement in the patient's clinical status.

Benefits of lipid-lowering agents in stroke and coronary heart disease: pharmacoeconomics

Coronary heart disease remains the leading cause of death in the United States. Although coronary heart disease and stroke entail very expensive therapies and extensive hospital utilization, the cost of preventive measures is also quite expensive. In this review, the factors that determine the cost-effectiveness of statin therapy for the primary and secondary prevention of coronary heart disease are discussed. A risk-based strategy for the selection of patients seems to provide cost-effective utilization of this potent treatment strategy. Appropriate patient selection should be accompanied by aggressive measures to improve utilization and compliance through improved physician and patient education.