Injection lipolysis in subcutaneous Lipoma- Tips and tricks
A lipoma is a benign tumor composed of adipose tissue (body fat). It is the most common benign form of soft tissue tumor. Lipomas are soft to the touch, usually movable, and are generally painless. The patient presents to physician for removal of lipoma for cosmetic reasons.
Surgical excision and Liposuction are two most common methods of treatment of lipomas in accessible areas. Surgical excision though preferred leaves a scar and undesirable results like hypertrophic scar and keloid may rarely develop. Liposuction though reduces scar the fact that it is a surgical procedure can deter patient who are anxious about surgery or surgically unfit.
With popularity of non invasive methods for all cosmetic procedures. Injection lipolysis is has gained popularity as a treatment for localized fat deposits in body. The need of hour is a non surgical treatment modality for the most common soft tissue tumor “Lipoma”.
New methods under development are supposed to remove the lipomas without scarring. One is removal by injecting compounds that trigger lipolysis, such as steroids or phosphatidylcholine.Phosphatidylcholine has been used since very long time inmanagement of fat embolism and end stage liver diseases. The clinical safety of phosphatidylcholine for lipolysis has been established in various studies.
Phosphatidyl choline (PDC) is a cell membrane component that is prepared as a solubilized, injectable formulation given with deoxycholate (DC), a bile acid.Prior to its experimental use in treating lipomas, PDC/DC preparations had been used for cosmetic reductions of local fat deposits. Due to the similar composition between these fatty tissues, injection therapy was experimentally applied to the management of lipomas.
PDC injected in adipose was found to induce the formation of liposomes from fat molecules contained within local adipocytes, with DC forming micelles. The micelles could subsequently be cleared from the body with the end effect of localized fat reduction. It has also been proposed that PDC acts as both an emulsifier and as a stimulator of lipase.
Mechanism of action
When injected into lipomas in vivo, PDC/DC causes fat necrosis. Histological evaluation of patients’ tissue at various points in time after receiving injections with PDC/DC demonstrated various cellular changes. Four hours following injection into the lipoma, the adipocyte was found to decrease in size and alter its shape focally around injected areas. Additionally, the tissue demonstrated supparative panniculitis, which progressed to a predominantly neutrophilic inflammation over the course of 48 hours with an ultimate progression toward an inflammation characterized by lymphocytes and macrophages. After 10 days following injection into the lipoma, lipophages were found to be present within the tissue. Thirty and 60 days removed from the injection, the tissue was devoid of neutrophils, but still exhibited a lymphocytic inflammation with large lipophages. Additionally, the lipoma was observed to exhibit a broadened capsule, which reportedly improved the surgeons’ ability to resect the mass.
Besides PDC/DC, β2 adrenergic agonists combined with corticosteroids have been shown in a study to be efficacious at reducing the size of lipomas. Isoproterenol, a non-selective β adrenergic agonist given as a subcutaneous injection, was found to cause localized fat reduction without causing systemic toxicity, likely by stimulating lipolysis. Subsequent downregulation of the β2 adrenergic receptor, however, causes decreased lipid breakdown products, suggesting the β2 receptor’s more dominant role in this fat reduction. Corticosteroids, in addition to their ability to directly induce lipolysis, have been found to prevent the downregulation of β2 adrenergic receptors by increasing the total quantity of receptors When injected into a lipoma, subsequent size reduction was found to average 50 percent.Thus, while this therapy appears limited in its ability to prevent surgery, it can serve as a preoperative treatment to reduce the surgical incision size, especially due to the lack of fibrosis and cellular changes caused by this.
There are more side effects when used for large area lipolysis and when maximum dose of 2500mg are exceeded. The most common complaint patients have is pain at injection site edema, diarrhea and dizziness. When given superficially into dermis it may cause bruising and rarely skin necrosis. In lipomas bruising, erythema, edema, and pruritis at the treated sites are common.
- Choose lipomas in subcutaneous plane and away from important structures like vessels, tendons and muscles. As Sodium deoxycholate has non specific cytolytic effect may damade underlying structures.
- Prefer pure Phosphotidyl choline injections to PPC/DC combinations.
- User lower concentrations of DC/PPC limit to 1% to avoid side effects.
- Limit volume of injections to 1/3 the volume of lesion or ½ the largest diameter of lesion in cm.
- When injecting multimple lipomas restrict total dose to 2500mg to avoid systemic side effects like dizziness, diarrhea hypotension etc.
- Inject in center of lesion for small lipomas, for larger lipomas inject at every 1 cm distance about 1 ml or in a fan shape. Avoid injecting close to dermis as may cause bruising and rarely skin necrosis.
- Combine xylocaine as per manufacturer instruction to reduce pain and also add steroid to reduce inflammation and fibrosis.
- Inform patient about the normal course of mild burning sensation for 24hrs, erythema for upto 5 days, mild swelling and tenderness upto 2wks. And prescribe an analgesic.
- Limit the number of injection sitting to 5 in non responders.
- In case of lower limb lipoma prefer to excise the lesion as there are more chances of turning to liposarcoma.