How We Do It: Narrow Hole Extrusion Technique for Lipoma Removal

Introduction

Lipomas are acquired, slow-growing, asymptomatic benign tu-mors of subcutaneous adipose tissue that are often fibroencap-sulated. Complete excision has been the gold standard, although adipolytic agents such as sodium deoxycholate may be a viable treatment option for deep (subfascial or subgaleal) lipomas or in patients who refuse or are not candidates for a surgical proce¬dure. While many providers still excise lipomas in toto by means of large incisions that result in unsightly scars, simple subcuta¬neous (extra-fascial) lipomas can be completely removed with narrow hole extrusion technique (NHET) through a 3-5 mm in¬cision with enhanced safety, minimal downtime, and vastly su¬perior cosmesis [1].

Methods

The lipoma is identified by visual inspection and palpation, and the borders of the round subcutaneous nodule are first demar¬cated with a surgical marking pen. A ring block of 1% lidocaine with epinephrine (1:100,000) outside the boundaries of the le¬sion achieves complete subcutaneous local anesthesia with min¬imal perturbation of the tumor (Figure 1A). The skin overlying the lesion is subsequently anesthetized by a relatively small in¬tradermal injection of local anesthetic solution.

Figure 1: (A) Complete anesthesia is achieved with a ring block using 1% lidocaine with epinephrine (1:100,000) injected along the periphery of the lesion. This is combined with intradermal injections of local anesthetic solution into the skin immediately overlying the center of the lesion (not shown). (B) A 4-5 mm punch biopsy instrument is used to create a round incision. (C) Following blunt dissection, the area is grabbed and lifted up, allowing for bimanual pressure to be exerted circumferentially around and beneath the lesion. (D) If adhered to the underlying fascia, the exposed fibrous capsule can then be excised with toothed forceps and scissors.

A 3 mm punch biopsy instrument is often sufficient (Figure 1B), although large lipomas (>5 cm) may benefit from as large as a 5 mm incision. Dissection of tissue surrounding a lipoma and penetration of the capsule is then achieved with blunt scissors or a blunt-tipped probe. The authors prefer a double-ended 5.5-inch round-tipped reusable probe (Integra Miltex, Plainsboro, NJ; Product #10-6-ST), as shown in Figure 2, although a similar 6-inch Arbuckle sinus probe (Becton Dickinson, Franklin Lakes, NJ; V. Mueller Catalog Product #RH300) has also been recom¬mended. Bimanual pressure is subsequently performed (Figure 1C), which for unencapsulated or small superficial encapsulated lipomas is sufficient to produce complete extirpation with little effort [2]. It is important to emphasize that the more extensive the subcision, the easier it will be to remove the tumor contents.

Figure 2: Double-ended 5.5-inch round-tipped reusable probe for subcision/dissection of tissue surrounding a lipoma and capsule penetration prior to extirpation.

Large encapsulated lipomas or lipomas adherent to underlying fascia, however, may require direct incision of their typically thick fibrous capsule with scissors or the punch biopsy instru-ment. Once all of the fatty intracapsular content is evacuated piecemeal with bimanual compression, the fibrous capsule can be easily excised with toothed forceps and scissors (Figure 1D). Patience and persistence may be required for these larger lesions in areas of thickened (e.g., truncal) skin. Once the tumor has been completely removed, a 4-0 or 5-0 synthetic, monofilament, nonabsorbable polypropylene suture is used for epidermal clo-sure in an interrupted fashion. Absorbable dermal sutures for deadspace closure are typically not required, although this may be necessary for very large or longstanding lipomas. The resect-ed specimen is placed in formalin and sent for histopatholog-ic confirmation. Figure 1a-d demonstrates the removal of a 7.5 cm deep subcutaneous lipoma of the right upper back that was excised through a 4-mm punch instrument incision using this technique.

Discussion

First reported in 1982, NHET allows for complete removal of relatively large extra-fascial subcutaneous lipomas through small incisions created by a punch biopsy instrument. The au¬thors have found that this is an ideal treatment for small to mod¬erately sized subcutaneous asymptomatic lipomas of the face, neck, and extremities, although lipomas in areas of thicker skin can also be successfully removed, as seen in our patient, albeit with greater provider effort [3]. The minimal downtime and en¬hanced cosmetic outcome afforded by a small incision makes this a vastly more appealing treatment option than traditional ex¬cision. A modified form of NHET, where the punched-out tissue is grafted back into the defect, may be worthwhile for cosmeti- cally sensitive sites such as the face [4].

Conclusion

Narrow hole extrusion technique is able to effectively remove relatively large extra-fascial subcutaneous lipomas, obviating the need for larger incisions and enhancing safety and cosmesis.

References

1. Christenson, L., Patterson, J., & Davis, D. (2000). Surgical pearl: use of the cutaneous punch for the removal of lipo-mas. Journal of the American Academy of Dermatology, 42(4), 675-676.
2. Otley, C. C., & Mensink, L. M. (1999). The phlebectomy probe: a new and useful instrument for ambulatory phlebec­tomy. Dermatologic surgery, 25(7), 573-575.
3. Hardin, F. F. (1982). Surgical Gem: A Simple Technique for Removing Lipomas. Dermatologic Surgery, 8(5), 316-317.
4. Gupta, S., Pandhi, R., & Kumar, B. (2001). ‘‘Pot-id’’tech-nique for aesthetic removal of small lipoma on the face. In­ternational journal of dermatology, 40(6), 420-424.