What is Lymphedema:

• Progressive condition characterized by local or systemic failure of lymphatic transport. There are two different kinds of lymphedema- primary and secondary. Primary results from abnormally formed lymphatic channels resulting in congenital lymphedema or lymphedema developed later in life. Secondary lymphedema results from destruction or pathology of normally formed lymphatic channels.
• The primary role of the lymphatic system is to remove interstitial fluid from the body and return lymph (protein and fat) back into the blood circulation. 
• When the lymphatic system is interrupted by primary or secondary lymphedema, an accumulation of lymphatic fluid occurs. This increases the osmotic pressure and leads to fluid collection in the interstitium. This then leads to a chronic proinflammatory state. This results in ongoing inflammation and formation of fibrosis, decrease in lymphatic channels and increase in subcutaneous adipose tissue. 
• Types of Primary Lymphedema: Primary lymphedema is characterized by an early onset of symptoms, a lack of inciting events, or positive family history.
• Milroy’s disease: This is an X-linked autosomal dominant form of primary lymphedema. Typically presents at birth with unilateral pitting edema. Patients exhibit normal growth, normal MRI. There can be ocular involvement.  
• Lymphedema praecox: This is a non-congenital form of primary lymphedema occurring before puberty. 
• Lymphedema tarda: This is another example of primary lymphedema that mainly manifests mid-life.
• Proteus syndrome: vascular, lymphatic, skeletal and soft tissue abnormalities and overgrowth, lipomatosis, capillary malformations
• Klippel trenaunay: capillary malformations, varicosities, limb hypertrophy in absence of AV fistulae, limb-length discrepancy, MRI shows slow flow

 

• Types of secondary Lymphedema: Can occur after trauma, surgery, or radiation. Many symptoms occur months to years after inciting event. 
• Wuchereria bancrofti (filariasis): most common cause of secondary lymphedema worldwide
• Surgery: incidence of upper extremity lymphedema following surgery and radiation for breast cancer ranges from 4-49%
• SLNB results in 5-7% incidence of lymphedema, 39% after ALND, and 66% after inguinal lymph node dissection

 

• Diagnosis:
• Begin by ruling out other diagnoses including venous insufficiency, deep vein thrombosis, congestive heart failure, and renal failure. 
• Stage 0: clinically normal extremity but with abnormal lymph transport on lymphoscintigraphy
• Stage I: patients begin to experience early progressive swelling form distal to proximal. Improves with limb elevation. Pitting edema is observed.
• Serial limb measurements are helpful to follow the progression. 
• Stage II: pitting edema that does not resolve with elevation. Excess fibrosis and fat may begin in late stage II
• Stage III: aka lymphostatic elephantiasis, the tissues demonstrate induration, fibrotic skin changes, absence of pitting, and dermatologic changes (peau d’orange, hyperkeratosis, polypoid nodules)
• Stemmer sign: when skin cannot be tented, typically at base of second toe (dorsal skin of finger or toe)(distinguishes from venous insufficiency). This is a result of decreased skin pliability. 

 

• Workup:
• Radionuclide lymphoscintigraphy** (first line): assesses function of lymphatic channels and drainage into lymph node basins. Can evaluate the severity of lymphedema and assess for anatomical abnormalities such as obstruction or reduced lymphatic channels. Most commonly used.
• MR lymphangiography has been developed to provide superior high-resolution anatomical images of the lymphatic system and characterize the soft tissue changes associated with lymphedema. 
• Indocyanine green lymphangiography offers real time visualization of lymphatic flow and is helpful in patients who cannot undergo MR.

 

• Treatment of Lymphedema: 
• Nonsurgical Treatment: This includes elevation, skin care, elastic stockings (at least 20mmHg), physical therapy, and pneumatic compression devices. This is a lifelong commitment for patients and requires high compliance. 
• Called complete decongestive therapy and is the initial treatment
• Surgical Treatment: Goal of surgical treatment is to improve the patient’s functional status, lessen the burden of nonsurgical therapies by reducing reliance on compression, and decrease risk of infections. There are both physiologic surgeries and ablative surgeries.
• Physiologic: promote anterograde flow of lymph via bypasses or induction of lymph angiogenesis. Should be considered early in the course of the condition to optimize lymph drainage.
• Ablative: debulk areas of lymphedema to reduce morbidity. May be performed at any stage of lymphedema and are usually reserved for the later stages when physiologic intervention is not possible (lipomatous changes)
• In patients with morbid obesity (BMI > 50), the first step is bariatric surgery

 

• Physiologic Operations: There are two commonly performed physiologic transfers: lymphovenous bypass and vascularized lymph node transfers.
• Lymphovenous anastomosis (LVA): This is a bypass operation that serves to redirect excess lymphatic fluid into the venous circulation by anastomosing superficial lymphatic vessels at the dermis to nearby venules. Prior to surgery, indocyanine green lymphangiography is performed to determine the location of the lymphatic vessels. This is injected distally and a near infrared camera is used to detect the lymphatic channels. Their course is traced and transverse incisions are made over the marked channels. The lymphatic channels and venules are identified and anastomosed end/end or end/side with 11-0 or 12-0 suture. Patency is confirmed by visualizing anterograde flow. 
• Vascularized lymph node transfer: This technique is typically used when the native lymph node basins are dysfunctional. This technique is thought to promote local lymphangiogenesis through production of vascular endothelial growth factor. Common donor sites include supraclavicular lymph nodes or suprafascial inguinal lymph nodes. The supraclavicular nodes are located inferiorly within the posterior triangle of the neck in the fat between the omohyoid muscle and anterior scalene muscles. This is supplied by the transverse cervical vessels. Remember caution must be used when harvesting on the left side to avoid injury to the thoracic duct. Usually contralateral nodes are harvested to avoid further exacerbation of lymphedema. Superficial inguinal lymph nodes are supplied by the superficial circumflex iliac vessels (femoral artery) and located in the sub scarpas fat between the inguinal ligament and groin crease. It is important to remain superior to the groin crease to in order to not disrupt the lymph nodes that drain the lower extremity.  

 

• Outcomes:
• LVA: studies reveal 35-50% reduction in extremity circumference or volume with mean follow ups >1 year. Chang et al- Subjectively 96% of patients report improvement in symptoms and mean volume reduction was 42%.
• Same paper revealed that benefit is greater with performed in early stages of lymphedema over advanced lymphedema.
• VLNT: Reductions of extremity circumference or volume has been noted to be 30-60%. Patient reported outcomes to evaluate quality of life found improvements in all measured domains for both upper and lower extremity lymphedema patients. 

 

• Complications:
• VLNT may cause iatrogenic lymphedema of the ipsilateral extremity. Reverse lymphatic mapping may be used to identify critical lymph nodes of the lower extremity in order to avoid iatrogenic injury. 

 

• Ablative Surgery: The main goal of ablative techniques is to remove excess skin or subcutaneous tissue and serve to decrease bulk and improve functional status/hygiene. This is typically indicated in the more advanced stages of lymphedema that have progressed to fibrosis and fatty infiltration. 
• Charles Procedure: This technique is the earliest described procedure and involves resection of the skin and subcutaneous tissue to either the deep fascia or underlying epimysium. The wounds are resurfaced with skin grafts. These skin grafts may be taken from the resected tissue. This ablates the superficial lymphatics and may cause exacerbation of lymphedema along the foot. 
• Staged subcutaneous excision (Homan technique): Another method to debulk areas of chronic lymphedema without the need for skin grafting. Longitudinal incisions are made with wide elevation of skin/subcutaneous flaps. Fibrotic subcutaneous tissue is then resected down to epimysium. Redundant skin is removed. This is repeated in stages until extremity is sufficiently debulked. 
• Suction lipectomy: This has been used in advanced lymphedema patients who do not have significant pitting edema. Large volume lipoaspirate may be removed. It is important to utilize compression directly after the procedure and for the rest of their lives. 
• Examples requiring ablation:
• Panniculus morbidus: severe form of abdominal lipodystrophy, prevents weight loss –> panniculectomy with primary closure
• Penile lymphedema is treated with excision.
• Chronic lymphedema with recurrent infections is treated with excision over liposuction.
• Algorithm: 
• Patients in general are amenable to physiologic interventions if they are responsive to nonsurgical therapy and have significant pitting edema. Patients are not amenable to physiologic interventions such as VLNT or LVA if they have no improvement with nonsurgical techniques and no longer experience pitting edema (a sign of fibrosis and increasing adiposity).
• When choosing VLNT or LVA it is important to take into account reasons for lymphedema. If they are secondary to surgery or radiation therapy and do not have suitable lymphatic vessels based on imaging, vascularized lymph node transfer is optimal. If they do have suitable lymphatic vessels, you may include this in the treatment regimen or perform alone if the lymph node basins were not destroyed. 

• A word on lymphatic malformations:
• Treated typically with sclerotherapy (doxycycline). They may become infected and require excision although this is second line for a non-complicated lymphatic malformation.
• Cystic hygromas- lymph filled fluid sac that results from blockage in lymphatics, soft and compressible

 
 
Source:
ACAPS Inservice exam questions 2013-2020