Filarial Hydrocele Treatment & Management

Contrary to the conclusions in previous literature, a 2001 double-blind study in Tanzania found that medical treatment with diethylcarbamazine (DEC) does not affect hydrocele size. ^[13]

Surgery is the treatment of choice for filarial hydrocele. Indications for hydrocele surgery include the following:

• Medical ineligibility due to untreated hydroceles

• Interference with work

• Interference with sexual function

• Interference with micturition

• Negative impact on the patient’s family

• Dragging pain

• Susceptibility to trauma because of the patient’s work or mode of transport

• Possible effect on the testis of long-standing hydroceles

Because of the scarcity of information regarding surgical treatment of filarial hydrocele, clear contraindications have not been elucidated. Standard contraindications to surgical procedures probably apply.

In 1997, the World Health Assembly (WHA) passed a resolution calling for the initiation of lymphatic filariasis–elimination programs by the governments of endemic areas. By 2013, the Global Programme to Eliminate Lymphatic Filariasis (GPELF) had implemented mass drug administration of the two-drug regimens (diethylcarbamazine [DEC] plus albendazole or ivermectin plus albendazole) or administration of DEC-fortified salt in 60 countries. Since 2000, the program has resulted in the delivery of a cumulative total of 6.2 billion doses of medicine to 1 billion people. ^[14]

Epidemiological studies indicate that several countries have demonstrated a near-total absence of transmissions as a result of mass drug administration. ^[14] Programs aimed at alleviating and preventing disability from lymphatic filariasis are also under way.

Subclinical cases should be treated to prevent lymphatic damage because most patients develop full clinical disease. Young adults in endemic areas should be screened for the presence of the parasite and treated if test results are positive.

Diethylcarbamazine

DEC is effective against both microfilariae and adult worms and is considered the drug of choice. It clears the blood of microfilariae, reduces the opportunity for mosquito-borne transmission of the parasite, and reverses filarial-associated hematuria and proteinuria.

DEC does not reverse existing lymphatic damage and does not change the course of pathology in patients with established disease. Patients should be tested every 6-12 months for the presence of the parasite, and patients whose test results are positive should be re-treated.

DEC is only partially effective against adult worms; therefore, ultrasonography of the scrotum should be performed 1 month after treatment; the presence of any residual worms is an indication for re-treatment.

Recommended schedules are 6 mg/kg/d for a total of 72 mg/kg for Wuchereria bancrofti infection and 4 mg/kg/d for a total of 60 mg/kg for infection with Brugia malayi.

DEC causes allergic reactions (Mazzotti reactions), especially in patients with high microfilarial counts. Headache, fever, nausea, vomiting, local pain, and swelling over lymph nodes and along lymphatic vessels have been reported. Therefore, patients with heavy infection should start with low doses (3 mg/kg body weight/d) and gradually increase the dose.

Ivermectin

Ivermectin is a newer antiparasitic drug that causes fewer adverse effects. It has proven to be an effective microfilaricide after a single oral dose of 20-25 mcg/kg of body weight. Because of its low cost, single oral dose, and few adverse effects, it is becoming the drug of choice for early filarial infection. However, ivermectin does not affect adult filarial worms.

Foot care and skin care are essential in patients with lymphedema. Patients should be encouraged to use antiseptic soap to clean their skin daily. Early infections should be treated vigorously.

Combination Therapies

The recommended drug regimen for elimination of lymphatic filariasis outside sub-Saharan Africa is single dose of diethylcarbamazine (DEC) plus albendazole (ALB). Multiple annual treatments are required for elimination since this regimen does not sustainably reduce blood microfilaria (Mf) counts below the threshold required to interrupt transmission. 

 

Various surgical procedures have been developed to remove the edematous tissue in patients with genital elephantiasis. The principles of these operations follow general plastic-surgery principles. Antibiotics should be initiated the night prior to surgery and continue for a total of 5 days. Analgesics in the form of nonsteroidal anti-inflammatory drugs or oral acetaminophen should be administered as appropriate.

The penile and scrotal skin and subcutaneous tissues can be excised and reconstructed using a partial-thickness graft from normal skin in the upper part of the body without lymphedema. Unmeshed grafts yield a better cosmetic appearance to the penis, while meshed grafts are preferred for scrotal reconstruction. In females, split-thickness grafts can be used to reconstruct the vulva and the perineal skin.

Filarial hydroceles are more difficult to excise surgically than idiopathic hydroceles because of scarring and fibrosis. The ideal procedure is to excise the hydrocele completely with an intact sac. In some cases, this is impossible, and partial excision and eversion of sac edges behind the testis is sufficient.

To determine the appropriate level of care for patients requiring surgical repair, Capuano and Capuano have proposed using their clinical classification of filarial hydrocele (see Clinical). They conclude that a stage I or II hydrocele, associated with grade 0 or 1 penis burial, could be considered a simple hydrocele; surgical treatment is simple, with no anticipated early complications, and can be performed at a level II facility (as defined by the World Health Organization). ^[12]

A stage III or IV hydrocele associated with grade 2, 3 or 4 penis burial could be considered a complicated hydrocele. These require a longer, more demanding operation and seem to pose a greater risk for complications, so a level III health care facility would be better adapted. ^[12]

Standard postoperative care applies. Most patients may be discharged home the same day. Patients with undue swelling, pain, or oozing from the wound or those in whom a drain has been placed should be observed for 24-48 hours. Patients should return for a follow-up visit within 7-10 days.

Wound healing is slow and complicated in patients with filariasis because of the lymphedema and chronic scarring. Patients who require excision and grafting of the scrotal or penile skin are at higher risk for graft failure. Wound infections are also common in these patients.

The World Health Organization (WHO) has targeted lymphatic filariasis for global elimination by 2020 by means of mass drug administration (MDA) that uses one of three anti-filarial drug regimens ^[15] :

• Diethylcarbamazine (DEC) plus albendazole (ALB) in lymphatic filariasis endemic areas outside Africa and in countries within Africa that do not have onchocerciasis or loiasis
• Ivermectin (IVM) combined ALB in African countries that have both lymphatic filariasis and onchocerciasis
• ALB alone in countries that have both lymphatic filariasis and loiasis.

MDA is intended to reduce the microfilariae (Mf) reservoir below a level that is required to sustain transmission of the infection by mosquitoes. Because a single dose of these treatments fails to sterilize or kill all adult filarial worms and reduce the community Mf reservoir to sufficiently low levels, many rounds of MDA are required to interrupt transmission. ^[15]

 

Assessing and monitoring changes in filarial lymphedema improves clinical management of patients. The gold standard for measuring limb volume is water displacement (WD). Other methods include tape measures of limb circumference (TMLC) and skin thickness ultrasound (STU). Each examination method has different strengths and weaknesses. WD is the most reliable but also the slowest method and it is difficult to use in patients with advanced lymphedema. TMLC is easier for the patients but is less reliable than WD, and it was relatively labor and time intensive. STU is the difficult method to standardize and the results are operator dependent. 

A promising new option is and infrared three-dimensional imaging (3DI). In a studie of 52 patients with lymphedemao stages 0–6 (N = 28, 19, 20, 21, 2, 4, and 10, respectively), 3DI measurements correlated nearly perfectly with WD (r2 = 0.9945) and TMLC values (r2 > 0.9801). In addition, the infrared 3DI system was much faster, providing volume and circumference measurements for both legs in less than one-tenth of the combined time required for WD and TMLC and it does not require physical contact with the patient, which is important for patients with skin ulcers or infected wounds that are common in patients with advanced lymphedema. ^[16]