MACROCYSTIC LYMPHATIC MALFORMATION

Macrocystic LMs usually are managed best with sclerotherapy, because the treatment is more effective and safer than excision. This female was born with a large macrocystic LM of her right face and neck. She underwent resection of the lesion at an outside institution and suffered a facial nerve injury. Her appearance is shown at rest (A). An asymmetrical smile resulting from injury to her right marginal mandibular branch of the facial nerve is shown (B).

Macrocystic and combined LMs are managed with sclerotherapy, because this technique is safer and more effective than resection. Asymptomatic macrocystic lesions should generally be treated, because they are at risk of bleeding and infection. If a macrocyst has intralesional bleeding, the LM can be converted to microcysts, which are no longer amenable to sclerotherapy. Although sclerotherapy does not remove an LM, it effectively shrinks the lesion and improves symptoms. Resection of a macrocystic LM is reserved for:

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  Small lesions that may be completely removed for cure

  
  
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  Symptomatic LMs that can no longer be managed with sclerotherapy (all of the macrocysts have been treated)

MICROCYSTIC LYMPHATIC MALFORMATION

Asymptomatic microcystic LMs may be observed; intervention is reserved for problematic lesions. Generally first-line therapy is resection. Excision usually is subtotal, because microcystic LMs are often diffuse and involve multiple tissue planes. If a microcystic LM is in an unfavorable location for resection, other interventions are considered. Diffuse facial lesions may be improved by injecting bleomycin throughout the affected tissues. Extensive lesions of the skin can be managed with a carbon dioxide laser, cutaneous sclerotherapy, or cautery. Intraoral microcystic LMs may be improved with radiofrequency ablation. Recently oral sirolimus has shown efficacy for problematic LMs.

PRIMARY LYMPHEDEMA

Primary lymphedema is caused by hypoplastic lymphatic development. High-protein fluid is unable to be returned to the venous circulation, and pitting edema develops. Over time the fluid stimulates subcutaneous adipose deposition, which causes the area to enlarge. Ninety-five percent of patients managed in our lymphedema program can be treated conservatively with compression. Surgical intervention is reserved for individuals with subcutaneous adipose deposition that is causing lowered self-esteem, infections, and/or difficulty with the extremity.

TIMING OF INTERVENTION

LMs causing significant symptoms require intervention, regardless of the age of the child. If possible, treatment should be delayed until at least 6 months of age, because before this time the patient’s risk from anesthesia is greater than in an adult. In addition, a young infant is less able to tolerate a surgical procedure. If a large lesion is located on the scalp, removing it before 6 months of age should be considered to take advantage of scalp laxity that exists during infancy. Large, asymptomatic macrocystic LMs are treated prophylactically at 6 months of age, before the lesion bleeds or becomes infected, which would obviate future sclerotherapy.

If it is likely that a patient will require surgery to improve a deformity, I will commonly intervene between 3 and 4 years of age. Because long-term memory and self-esteem begin to form at approximately 4 years of age, removing an LM before this time will treat the deformity before it causes psychosocial distress; the patient will also likely not remember the procedure. Another period to intervene is during late childhood or early adolescence when the child is able to communicate whether he or she would like to have a procedure. If a patient has a minor deformity or a large lesion requiring significant reconstruction, the surgeon should wait until the child verbalizes the desire to have surgery. If the lesion is minor, it may be able to be removed with a local anesthetic by waiting until the patient is older. If the LM is significant, waiting until the child is a willing participant facilitates the process for the family and surgeon.

MACROCYSTIC LYMPHATIC MALFORMATION

Generally macrocystic/combined LMs should undergo sclerotherapy before resection because:

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  The lesion will be smaller.

  
  
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  Excision is facilitated, because cysts are converted to fibrotic tissue.

  
  
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  Peripheral vessels are permeated by the sclerosant, which theoretically reduces the recurrence rate.

Small lesions that can potentially be removed for a cure do not require preoperative sclerotherapy. Generally sclerotherapy is performed at 6-week intervals until the posttreatment ultrasound examination does not show that the remaining cysts are amenable to further injections.

Pure macrocystic LMs are most commonly located in the neck and axilla. These lesions can leave behind redundant skin after they have been deflated with sclerotherapy. In the axilla overresection of skin should be avoided to prevent a contracture. Large LMs can also have residual symptomatic microcystic disease after sclerotherapy, which may necessitate excision.

Most LMs are combined lesions containing both macrocysts and microcysts. These lesions should initially be managed with sclerotherapy to collapse the macrocysts. Usually the patient’s symptoms are adequately improved and resection is unnecessary. If the individual continues to have morbidity after sclerotherapy, extirpation of the area is facilitated.

MICROCYSTIC LYMPHATIC MALFORMATION

Microcystic LMs are more difficult to manage compared with macrocystic lesions. Microcystic LMs usually involve the face and extremities. If the disease affects the integument, a patient may develop lymphatic vesicles that can bleed, become infected, and cause lymphorrhea. The best approach is to resect localized areas of skin involvement, which can recur along the scar. Larger regions of integument can be removed with serial excision. Diffuse lymphatic vesicles that are problematic to excise can be treated with a carbon dioxide laser. Alternatively, cutaneous vesicles can be managed with superficial sclerotherapy or cauterization. Intraoral lymphatic vesicles are best treated by radiofrequency ablation. This technique causes low-temperature tissue destruction, which reduces damage to adjacent structures. Compared with a carbon dioxide laser, there is less edema, which is particularly favorable in the oral cavity, because it minimizes the risk of airway obstruction.

Recent options to treat microcystic LMs are bleomycin sclerotherapy and oral sirolimus. Bleomycin can be diffusely injected throughout the tissues containing LM, and most patients will have a reduction in the size of the area and improvement in symptoms. Bleomycin is useful for patients with mild facial asymmetry, because the treatment may obviate the need for resection and a cutaneous scar. Individuals with diffuse, problematic microcystic LMs that have not responded to other interventions are candidates for sirolimus pharmacotherapy. Our center and others have had favorable outcomes with this medication; lesions have reduced size, bleeding, and lymphorrhea.

A large area of integument that has failed conservative therapies requires resection. Wounds are reconstructed by allowing them to heal secondarily, mobilization of local tissues, or skin grafts. Tissue expansion, regional muscle flaps, or free flaps are usually unnecessary. A recipient site containing a residual LM is more likely to accept a skin graft compared with a venous or an arteriovenous malformation. An underlying LM usually does not recur through the skin graft but may develop vesicles along the edges.

Localized LMs do not require preoperative imaging if only resection is planned. I prefer to obtain an MRI before I perform a resection of a large lesion to determine which surgical planes and anatomic structures are involved. Excision of an LM is associated with less bleeding compared with a venous or arteriovenous malformation. Blood loss is reduced by preoperative sclerotherapy and infiltrating the surgical area with epinephrine. If the volume of local anesthetic with epinephrine is limited by the amount of anesthetic that can be given based on the weight of the child, I will infiltrate an epinephrine-only solution to ensure maximum vasoconstriction of the surgical site (1 ml of 1:1000 epinephrine in 200 ml normal saline = 1:200,000 solution). The extirpation proceeds carefully by incising a localized area and controlling bleeding before continuing. Long, deep incisions should not be performed because of the risk of significant blood loss. None of the patients with an LM on whom I have operated has required a blood transfusion. I administer prophylactic intraoperative antibiotics to reduce the risk of postoperative infection, because LMs are predisposed to infection. If wide skin undermining is performed, drains should be placed, because tissues have a higher risk of lymph drainage.

Lesions located in anatomically sensitive areas (for example, the face) should have minimal margins included in the resection. An LM is not a malignancy, and evidence does not show that a wide margin lowers the recurrence rate. An LM often involves a larger area than is appreciated clinically and radiographically. Intraoperatively, subcutaneous tissues can be cauterized at the periphery of the LM without removing skin. Cautery and fibrosis may destroy a residual LM and reduce recurrence. If a lesion is located in a nonsensitive area (for example, the abdomen), larger margins can be taken as long as they do not complicate the extirpation and reconstruction.

Because most LMs are diffuse and involve multiple tissue planes, complete extirpation is rarely possible. Instead the goal is usually to alleviate symptoms and control the lesion. Despite subtotal and presumed “complete” extirpation, most LMs reenlarge. Patients and families are counseled that an LM is likely to recur after resection, and treatment may be needed in the future.

Surgical intervention for a diffuse facial LM should focus on improving the patient’s appearance or symptoms with localized, staged procedures without causing a significant deformity. Diseased tissue should not be removed if there is a risk of iatrogenic morbidity. Facial nerve dissections or parotidectomy generally should be avoided. When the lesion is throughout all structures of the face, strategies to improve the area include:

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  Excision of excess skin and subcutaneous tissue

  
  
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  Removal of the buccal fat pad

  
  
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  Contour burring of the zygoma

If overgrowth is located on the lateral cheek, a preauricular incision is used. Medial fullness is resected through a mesolabial incision. Alternatively, a circular excision can be used to access the overgrown tissue, and the purse-string closure can be revised at a second stage. Lip overgrowth is improved with a transverse mucosal resection along the keratinized and nonkeratinized border of the vermilion. Vertical resections of the lip should be avoided.

I typically do not use intraoral approaches to remove subcutaneous lesions. I prefer to make a cutaneous incision and remove abnormal subcutaneous tissues sharply under direct vision. I believe in the principle of trading scar for contour. Patients are most satisfied with achieving the best symmetry, which is noticed beyond conversational distance at the expense of a scar that can only be appreciated on close examination (similar to having a longer scar instead of a shorter scar and dog-ears at each end). Intraoral excision is more difficult and less predictable than direct cutaneous extirpation; there also is an increased risk of infection and facial nerve injury.