Filarial Hydrocele Treatment & Management
- Author: Bradley Fields Schwartz, DO, FACS; Chief Editor: Edward David Kim, MD, FACS more...
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 4.9 billion doses of medicine to 1 billion people.
Epidemiological studies indicate that several countries have demonstrated a near-total absence of transmissions as a result of mass drug administration. 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.
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 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.
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.
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).
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.
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.
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.
Outcome and Prognosis
Established filarial lymphedema is a progressive condition that tends to follow a stable course within 10-15 years of clinical presentation. No medical treatment has been proven to reverse this pathology; therefore, early diagnosis and treatment are of utmost importance.
A review of surgical reconstruction techniques of 48 patients over 10 years demonstrates excellent outcomes.
Future and Controversies
Because of the recent advances in medical treatment with single-dose therapies, global elimination of lymphatic filariasis is now considered possible. To interrupt transmission, districts where lymphatic filariasis is endemic must be identified and community-wide programs must be implemented to treat the entire at-risk population. Community education programs are necessary to raise awareness in affected patients.
In January 1998, the pharmaceutical company SmithKline Beecham (now Glaxo SmithKline) announced a massive donation program of albendazole (several billion doses) to support this effort. This donation was coupled with a decision by Merck & Co, Inc, to expand its ongoing ivermectin (Mectizan) donation program to include treatment of lymphatic filariasis.
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