The Swollen Arm
Warren W. McMurry, M.D.

Virtually all physicians will encounter patients with arm swelling problems. Rarely seen in infants and young children where the cause is usually in-utero cord compression problem or a congenital cardiovascular abnormality, adults can have it for several reasons. Some require prompt intervention and must be recognized to prevent long-term side effects. Adult problems can generally be grouped into lymphatic problems, venous problems or both. Congenital lymphatic hypoplasia is rare but even these patients donÕt manifest problems before their teens or young adult years.

More common though, are cases secondary to other underlying or acquired problems. Their onset tends to be more insidious. In the absence of primary or secondary infection of the extremity, the pain in patients with lymphatic problems is mild to moderate and tends to be more of a dull ache and/or a sensation of heaviness. The edema often has a pitting quality. Frequent causes include prior surgical disruption of the axillary lymphatics,
prior radiation therapy, and tumor processes. Treatment for these patients involves combined use of arm elevation, elastic compression garments, pneumatic compression sleeves, and/or massage therapy. If a malignant process is involved, treating it will often help alleviate the swelling.

Well known surgical offenders are mastectomy procedures such as the classic radical mastectomy and even in some of the modified radical mastectomies. Mastectomy-related lymphatic problems are becoming less common with less aggressive lymph node retrieval policies for staging purposes and with the advent of the sentinel node technique where only one to three specific nodes are removed. Arm swelling is also seen in the dialysis population after repetitive surgical access procedures. The emergence of percutaneous thrombectomy and endovascular intervention techniques is helping to reduce this incidence.

Radiation therapy to the axilla and/or chest can cause lymphatic obliteration and, ultimately, a swollen arm. This usually is a late complication. However, the treating physician must be aware that late swelling in these patients can actually represent recurrence of their original tumor process as opposed to post-irradiation effects. Tumor processes most frequently related to lymphatic arm swelling problems tend to be in the chest and/or mediastinum. The biggest offenders are Hodgkins and non-Hodgkins lymphomas and some more advanced lung cancers.

By far, venous problems are the most frequent causes of a swollen arm. These generally involve thrombosis in extremity, or more central veins and can be grouped into two broad categories: primary and secondary. The primary form is also known as effort thrombosis or by the eponym, Paget-Schroetter Syndrome.

Effort thrombosis is uncommon, accounting for only around 2% of cases of upper extremity DVT. However, recognition and prompt institution of treatment are important as failure to do so can result in long term debilitating problems with arm swelling and discomfort. This form is typically seen in young healthy adults involved in repetitive muscular activities of the arm and shoulder area related to sports or working over their heads. The onset is usually rapid as compared to lymphatic problems and the patients tend to have much more pain. The swelling is often very tense and non-pitting, the arm discolored, and dilated superficial veins evident. Current early intervention involves use of thrombolytic agents to remove the clot burden and institution of anticoagulation. Occasionally, percutaneous thrombectomy is employed. Once the main venous channels are open, venography by conventional means, MRI or CT is important to look for intraluminal abnormalities as well as for extrinsic compression problems. Intraluminal problems usually require some form of endovascular intervention. Extrinsic compression problems can initially be treated conservatively with a course of rest, elevation, and anticoagulation. Some patients will ultimately require surgical intervention to release restrictive ligamentous or bony structures in the thoracic outlet/inlet area.

Secondary venous thrombosis of the upper extremity is the most common cause of the swollen arm. These cases represent nearly 8% of the cases (all areas) of DVT in this country and carry a 12-15% risk of pulmonary embolism. Recurrent thrombosis can be seen 10-14% of the time. Potential causes include hypercoagulable states, trauma, radiation, low Protein C or S levels, tumors (e.g. Pancoast tumor of lung or lymphoma), and especially intravenous catheters. Several causes can coexist. Adequate treatment usually requires removal of the catheter (if present), elevation, and anticoagulation.

Differentiating between lymphatic and venous causes for arm swelling can often be done based on a combination of history (risk factors), physical findings, and presentation. However, unless absolutely certain that there is not a venous problem, imaging studies are always indicated. Modalities available include conventional venography, MRI, high-resolution triple phase CT scanning, and venous duplex (doppler and ultrasound) scans. By far, the most economical and readily available modality is a good quality venous duplex scan done in a certified vascular lab. This study is noninvasive, without risk, and can usually be obtained in a timely fashion. Sensitivity ranges from 80-100% and specificity from 90- 100%. Treatment of the swollen arm depends on the cause. Various treatment options have been alluded to above. Primary caregivers can manage many of the problems. However, when effort thrombosis is suspected, getting a specialist capable of performing imaging studies as well as endovascular and/or
surgical interventions is advisable. Similarly, in those cases of venous thrombosis where anticoagulation is not an option or the patient has failed anticoagulation (i.e. pulmonary embolus while anticoagulated), specialist enlistment for placement of a superior vena cava filter is indicated.

In summary, the swollen arm is not an infrequent occurrence. Management and treatment of some cases is in the scope of practice for primary caregivers. However, vascular lab studies and specialist involvement is often necessary and should be sought sooner rather than later to prevent serious short and long term sequela.