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Surgical technique for epidermal cysts
Surgical technique for epidermal cysts
There are many surgical approaches to epidermal cyst removal. Whichever approach is utilized in removal, extraction of all components is important, as residual cyst wall and cyst contents will increase the chances of recurrence and infections. The punctum or dilated pore in the skin overlying the lesion should be identified whenever possible, as
the cyst adheres to skin at the site of the pore. In complete surgical excisions, the planned incision lines, oriented along relaxed skin tension lines, should include the epidermal pore if possible, and the goal is to create as small and/or imperceptible a scar as possible.
Slit incision with dissection After a single incision line is marked over the cyst, including the punctum centrally, a shallow incision is made along the marked line. As with traditional elliptical excision, care must be taken not to incise too deeply and inadvertently incise into the cyst. Beveling the scalpel blade outward (a reverse bevel) may decrease the chance of cyst wall rupture. If the punctum is large it may be removed. Once the cyst wall has been identified, grasp the epidermal edge with a skin hook and dissect the cyst wall free from the surrounding skin and subcutaneous tissue with iris or small gradle scissors. Firmly grasp the cyst with tissue forceps or hemostat and deliver it through the incision if possible. If the cyst is too large for the incision size, it may be decompressed by making a small incision in the wall and with gentle lateral pressure expressing some of the keratinous contents through the incision. The partially collapsed cyst sac may then be delivered more easily through the incision. Be careful to ensure complete removal of cyst wall and the cyst contents to prevent recurrence. Lengthening the incision may be necessary. Though partially expressing the cyst contents is possible, en bloc cyst removal after dissection obviates patient concerns regarding the malodorous cyst contents and mitigates the risk of leaving residual keratinous debris in the excision site postoperatively. Layered wound closure should be completed as for traditional elliptical excision, taking care to reduce dead space.
Minimal or punch incision with expression Squeezing the capsule and contents through a minimal incision is another option for cyst removal.11 Under local anesthesia, a stab incision is made in the center of the cyst using a no. 11 blade or trephine. When a punctum is visible, it should be included in the incision. Gentle lateral pressure is applied, expressing some of the cyst contents through the incision. The opening is extended using a hemostat, and the contents are gently expressed. A small curette may then be used to remove the remaining keratinous debris and to free the cyst wall from the surrounding tissue. Once visualized, the cyst wall is then grasped with the hemostat and removed. The cyst wall should be entirely removed, leaving no residue. Cyst contents may contaminate the wound during this procedure, and gentle irrigation should therefore be performed along with probing the wound with a curette to remove any residual keratinous fragments prior to closure.12 Skin hooks work well to retract the wound edges and thoroughly inspect the margins of the wound for any residual cyst wall.
Alternatively, substituting a biopsy punch for a scalpel has been described as another
minimally invasive method for cyst removal.13โ15 The punch hole may allow for better visualization and easier removal of the cyst wall as compared to a small linear incision, which often needs to be extended in order to remove the cyst completely, resulting in a longer scar. The biopsy punch is inserted perpendicular to the surface of the skin, preferably over a visibly enlarged punctum, until it penetrates the wall of the cyst. The overlying skin is then removed with iris or gradle scissors and the contents of the cyst are squeezed through the hole until no further material can be extruded. At this point the remaining cyst wall should be removed as described above. Usually, with appropriately chosen cysts, simple pressure is enough to dislodge the wall from the surrounding stroma, though it is sometimes necessary to dissect the wall away from the adjacent connective tissue with surgical scissors.
The resulting defect from incision or punch can be either sutured closed or allowed to heal by secondary intention. Warm compresses may be used for several days following surgery if the latter method is chosen. Healing by secondary intention is an acceptable option if the defect is very small (2 to 3 mm), if it is in a cosmetically unimportant area, or if there is any doubt that the entire cyst wall and its contents have been removed. The benefits of secondary intention healing should be weighed against the risk of the wound healing as a dilated pore or depressed scar.
Wide excision with layered closure This is a reliable technique to prevent recurrence,16 saving the patient further procedures, time, and expense. It is often indicated for larger cysts or those with previous inflammation, infection, or drainage suspected of having considerable surrounding fibrosis and scarring. The central disadvantage of this method is a longer scar and increased wound tension due to the removal of a fusiform ellipse of tissue.
After an ellipse is marked over the cyst, including the punctum centrally, and injection of local anesthetic around the cyst is complete, a shallow incision is made along the marked lines. As some cysts are quite superficial, care must be taken not to incise too deeply initially and inadvertently incise into the cyst. If the cyst has not previously been treated, the cyst wall may be visualized. Once the skin incision is made to the level of the cyst wall, the skin away from the ellipse can be carefully undermined to separate it from the cyst wall. A skin hook and iris or small gradle scissors work well for this approach. This process may be assisted by traction on the ellipse and underlying cyst using a hemostat, finely serrated tissue forceps, or stay sutures. The angles of the ellipse should be released to complete full cyst dissection. Often the cyst can be removed in its entirety without rupture. En bloc surgical excision may also remove considerable fibrosis or scar if present. This method also provides a large and well-oriented specimen for pathologic evaluation, useful when malignancy is suspected.11,16
Dead space closure is used to mitigate the risk of hematoma or seroma formation, as
well as the risk of a dimpled or depressed scar. Layered closure with fascial plication sutures may be particularly helpful in this regard, and a layered closure is very helpful.
Previously manipulated (excised, incised and drained, or infected) cysts may be multiloculated, with significant surrounding scar tissue and adhesions. Such cysts are challenging to remove through a small incision, and have an increased chance of recurrence. Therefore, wide en bloc excision is preferred in these cases to ensure complete removal.