LYMPHEDEMA PUMPS APPEAR "SIMILARLY" USEFUL REGARDLESS OF DEVICE TYPE, OHTA SAYS; DATA INSUFFICIENT TO DETERMINE "BEST" TREATMENT PROTOCOL

Executive Summary

Available types of pneumatic compression devices "appear to be similarly effective in the treatment of lymphedema," the Agency for Health Care Policy and Research's Office of Health Technology Assessment (OHTA) says in a recently published health technology review. According to the review, which was prepared at the request of the Health Care Financing Administration, lymphedema treatments "all are effective to some degree in reducing lymphedema in some patients." Treatments include single-chambered pumps, multichambered pumps with or without a calibrated pressure gradient, and manual massage. In general, "the application of external pressure represents a reasonable and successful method" of addressing the condition, OHTA says. Lymphedema, a swelling that occurs most commonly in the limbs, is associated with "an impairment of the normal clearance [of lymph] by the lymphatic system" or "excessive production of lymph" due to venous vessel obstruction. The condition may result from "congenital absence of or abnormalities in the lymphatic system" or may be a secondary consequence of events such as trauma, surgery and radiation therapy. Single-chambered pneumatic compression devices assist in moving excess fluid out of a limb, and thereby reduce lymphedema, by applying "relatively uniform pressure to the whole limb." With multichambered devices, pressure is applied sequentially from the distal to the proximal end of the limb, in effect "milking" fluid from the area. A multichambered device with a calibrated pressure gradient adjusts the pressure administered to limb conditions. OHTA says that it is unable to distinguish between the devices in terms of their effectiveness. "Comparison of the effectiveness of the various modes of external pressure therapies cannot be meaningfully done," the report says. OHTA analyzed the nine published studies on lymphedema pumps, which involved a total of 357 patients, and found that that patient populations "varied from study to study and the characteristics of the lymphedema among the patients were not defined." Therefore, neither patient subgroups likely to benefit from a particular type of device "nor the difference in effectiveness of the devices could be ascertained," OHTA concludes. One of the nine studies compared the effectiveness of three different treatment modes. The study involved 60 women, divided into three equal groups, who were experiencing lymphedema following radical mastectomies. The patient cohorts treated with single-chambered and multichambered pumps both experienced a 21% reduction in lymphedema. The 20 women treated with manual massage saw an 18% reduction in their conditions. The remaining eight studies each involved one device type, and had varied results. For example, in one study of 68 mastectomy patients who were treated with single-chambered pumps for six hours daily, there was an average reduction in lymphedema of 16.5% at two months. In another study of 17 patients with various etiologies who were treated with single-chambered devices for a 24-hour period, lymphedema was reduced by about 25% in the arms of 11 patients and 45% in the legs of six patients. Studies on multichambered pumps without calibrated pressure gradients "showed similar varied results." In a study in which multichambered pumps with the gradient feature were used on 15 mastectomy patients, individual reductions in lymphedema ranged from 13% to 68.7%, with an average of 49.4%. OHTA notes that although "multichambered devices...may be more effective than single-chambered devices in selected patients," the patient populations that would benefit from the multichambered devices "cannot be determined from the published information." OHTA suggests that it would be useful to have data from studies that evaluate whether patients whose lymphedema did not improve following one treatment might respond to a different therapy. "It is conceivable," OHTA says, "that most uncomplicated lymphedema could be treated satisfactorily by any of the external pressure modes of therapy, while others may respond more favorably to one or another therapy. Lymphedema difficult to control by one mode of therapy may benefit from the use of another." OHTA notes that the effectiveness of any treatment mode in reducing lymphedema "probably is dependent on a number of factors, including whether lymphatic channels or the venous vessels are obstructed." OHTA suggests that "mild or early cases" of lymphedema may be sufficiently controlled through "manual massage with elevation of the limb and use of elastic sleeves or wrapping" rather than with a pump. However, "more severe or longstanding lymphedema may benefit from the use of external pressure devices." According to the review, Medicare patients purchased slightly fewer single-chambered devices than multichambered devices with calibrated pressure gradients in 1991. Far more of each of those devices were purchased during 1991 than multichambered devices without the gradient feature. For the year, 8,299 single-chambered pumps were purchased at a total cost of $1.6 mil; under Medicare, the average allowed purchase charges were $198.15 per item. Medicare patients purchased 9,989 multichambered devices with the gradient feature (average allowed charge: $1,437.39) at a cost of $14.4 mil. AHCPR reports that 1,329 multichambered pumps without the gradients (average allowed charge: $535.01) were purchased, with an aggregate cost of $711,030.