INTRODUCTION — Dermatologic surgical procedures performed in outpatient settings are generally low-risk procedures. Perioperative and postoperative complications in dermatologic surgery are infrequent, with an overall rate of 2 to 6 percent, and in most cases minor [1-3].
The most common complications related to surgical excisions of skin lesions and their prevention and management will be reviewed in this topic. Complications related to injury of nerves or other relevant anatomic structures during cutaneous surgery of the head and neck are discussed separately. (See "Anatomic danger zones for nerve injury in cutaneous surgery of the head and neck".)
OBTAINING INFORMED CONSENT — Clinicians must provide adequate information to the patient regarding the patient's diagnosis, proposed treatment, and risks and benefits of the treatment, and informed written consent should be obtained. Thoroughly discussing the risks of the procedure and alternative treatment options will set appropriate expectations regarding the outcome and will instill confidence in the patient that the clinician will be able to manage potential complications. Moreover, obtaining informed consent will help reduce discontent and litigation when complications occur. (See "Informed procedural consent".)
PERIOPERATIVE COMPLICATIONS — Pain, adverse effects of local anesthesia, and bleeding are the most common perioperative complications. Although they are, in most cases, mild and relatively easy to address, they can considerably impact the patient's perception of their overall experience in the office.
Pain control — The patient's perception that they may experience pain may lead to anxiety before or during the procedure. The two main sources of perioperative pain are the administration of the local anesthetic and the procedure itself, if insufficient anesthetic is administered.
The measures to decrease pain and discomfort associated with the administration of local anesthesia, including buffering the local anesthetic solution with sodium bicarbonate if it contains epinephrine, using a small-gauge needle, and distraction, are discussed in detail separately. (See "Subcutaneous infiltration of local anesthetics", section on 'Methods to decrease injection pain'.)
After the procedure has started, additional anesthesia is needed if the patient experiences pain, even if minimal. It is thus advisable to have anesthetic on the procedure tray to avoid delays with the procedure.
Adverse effects of local anesthetics — Adverse effects of local anesthetics, including lidocaine toxicity, catecholamine sensitivity, vasovagal syncope, and allergic reactions, are discussed separately. (See "Subcutaneous infiltration of local anesthetics", section on 'Complications' and "Reflex syncope in adults and adolescents: Clinical presentation and diagnostic evaluation".)
Intraoperative bleeding — A small amount of bleeding and bruising is expected during a surgical procedure. Excessive bleeding may be due to a combination of patient-related factors, including use of anticoagulants, comorbidities, and procedure-related factors, such as laceration of small arterioles or wide undermining [4,5].
Arterial bleeding — Arterial bleeding presents as a pulsatile, fast-rate flow of bright red blood coming from the wound. Although the prevention of arterial hemorrhage can be difficult, an understanding of the vascular anatomy of the procedure area, particularly in high-risk zones of the head and neck, will allow the surgeon to proceed with caution and avoid laceration of small arterioles. Areas such as the temple (where the temporal artery runs relatively superficial) or the scalp (where the fibrous stroma of the subcutis will often stent open a lacerated vessel) are common areas where difficult-to-control arteriolar hemorrhage can occur. (See "Anatomic danger zones for nerve injury in cutaneous surgery of the head and neck".)
Venous bleeding — Venous bleeding, or "oozing," occurs most frequently in patients taking anticoagulants and in those with underlying disorders of coagulation. In these patients, bleeding may be conspicuous and obscure the surgical field. This type of bleeding can be minimized by using anesthetics that contain epinephrine. If oozing is anticipated in a patient on anticoagulants, the clinician should wait approximately 10 minutes after administering the anesthesia before beginning the procedure as the vasoconstrictive effect of epinephrine is maximal after 10 to 15 minutes.
Intraoperative management of hemorrhage — Venous bleeding/oozing and small arteriolar hemorrhages during cutaneous procedures are in most cases easily controlled by applying direct pressure to the area and electrocautery:
●Have an assistant bring two hemostats (if not already on the tray) along with additional gauze, as needed. In areas such as the scalp, where there are several vascular anastomoses, the hemorrhage will often occur from both lacerated sides of the vessel, thereby requiring the two hemostats.
●Slowly roll back the gauze to expose the lacerated vessel and immediately clamp it with the hemostat.
●Apply cautery directly to the clamped vessel or to the hemostat. When employing the latter technique, the vessel is grasped with a pair of pickups or the hemostat and elevated away from the skin. Then, the metal tip of the cautery device is applied to the instrument, and the cautery device is activated until an audible popping sound comes from the vessel. (See "Overview of electrosurgery", section on 'Cutting and coagulation currents'.)
Larger arterial hemorrhages can be controlled by placing an absorbable figure-of-eight ligating suture around the vessel proximal to the site of laceration. The clamping instrument is then slowly released to ensure that the suture is correctly placed and bleeding is controlled.
Continued hemostasis can be promoted by postoperative use of appropriate pressure dressings for 24 to 48 hours [6].
Patients on anticoagulants and antiplatelet agents — Data from several studies and meta-analyses indicate that the risk of severe bleeding in patients undergoing cutaneous surgery while taking direct oral anticoagulants or antiplatelet agents is generally low [7-10]. There is, therefore, general consensus that patients undergoing cutaneous surgery should continue their oral anticoagulant medications. In patients taking warfarin, the international normalized ratio (INR) should be maintained within the therapeutic range [11,12]. (See "Perioperative management of patients receiving anticoagulants".)
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) and other antiplatelet agents (eg, dipyridamole, P2Y12 platelet receptor blockers) can also be safely continued in patients at increased risk of thromboembolic complications undergoing cutaneous surgery. However, aspirin or NSAIDs taken for primary prevention or for the treatment of pain should be discontinued five to seven days before the procedure and then reinitiated within 24 hours after the procedure. (See "Management of antiplatelet agents in patients undergoing endoscopic procedures".)
POSTOPERATIVE COMPLICATIONS
Hematoma — A hematoma is a collection of blood underneath a wound that has been sutured closed. It results from poor coagulation of vessels that were lacerated during the procedure and presents as a tense, sometimes painful expansion underneath the wound, sometimes with surrounding ecchymoses (picture 1A-B). There is usually scant, if any, blood visible on the skin overlying the sutured wound, which can sometimes make diagnosis more difficult. Occasionally, the overlying skin may become necrotic from the intense pressure of the blood collection underneath.
Patients on anticoagulant therapy and those with congenital defects of coagulation have the highest risk of developing hematomas. In these patients, small vessels that appear to be no longer bleeding when closing the defect can bleed again after the wound is closed. Predisposing factors include inadequate hemostasis during the procedure, cessation of the vasoconstrictor effect of the epinephrine injected with the local anesthetic, wide undermining of tissues adjacent to the wound, and postsurgery trauma (even minor).
Prevention — Because hematomas, especially if large, can cause wound dehiscence and infection, meticulous hemostasis during surgery is essential to prevent this complication. The following measures can help reduce the likelihood of hematoma formation:
●Hemostasis – Electrocautery of the wound bed, especially the subcutaneous tissue, should be meticulously performed to ensure adequate hemostasis.
●Limiting undermining – In patients at risk for hematoma formation, undermining should be limited to the minimal amount necessary for proper wound healing and tissue mobility.
●Drain placement – In patients at increased risk for hematoma (anticoagulant use, large surgical wounds, wide undermining) the placement of a drain can help to prevent hematoma formation. A small-diameter, sterile Penrose drain or the finger of a sterile surgical glove (for smaller wounds) can be used. The drain should extend across the entire cavity of the wound and stick out of the lowermost side of the incision by approximately 1 cm, where it is sutured in place to prevent accidental removal. The patient should be seen in 24 hours, and if no further significant bleeding has occurred in the interim, the drain can be removed. If active bleeding is still occurring, the drain should be left in place for an additional 24 hours, or longer if necessary, until all bleeding has resolved. As an alternative to drain placement, the last 1 to 2 cm of the gravity-dependent end of the wound can be left open to allow drainage.
●Pressure dressings – Following all skin surgeries, a pressure dressing should be applied and left in place for 24 to 48 hours.
Management — Prompt management of hematomas is important to ensure proper wound healing and prevent infection. For small, stable hematomas (<2 cm and not expanding), observation is a reasonable approach. Larger hematomas or hematomas causing significant symptoms should be drained.
Within 24 to 48 hours of development, hematomas can be drained either by aspiration using a syringe and a 14-gauge needle or by making a small opening into the gravity-dependent portion of the wound and applying a gentle pressure on the area. For hematomas older than 48 hours, the wound is partially opened and evacuated.
After hematoma evacuation, it is advisable to monitor the wound for 10 to 15 minutes to ensure that the bleeding has stopped. If significantly more blood accumulates in that time, the wound should be completely reopened under local anesthesia, and the responsible vessel should be identified and dealt with appropriately. If no bleeding is evident after an additional 10 to 15 minutes, the wound can be repaired.
Once a wound has been opened, regardless of the opening size, the risk of dehiscence and infection is high. Wounds that have been reopened or show evidence of infection should be allowed to heal by secondary intention with the application of petrolatum and a protective dressing. (See "Basic principles of wound management".)
If clinical signs of wound infection develop, prompt antibiotic therapy should be initiated. (See 'Surgical site infection' below.)
Dehiscence — Surgical wounds occasionally dehisce despite a carefully performed layered closure. Wound dehiscence typically occurs within the first postoperative week but can occur later in patients with underlying conditions associated with poor wound healing. Reasons for dehiscence include:
●High-tension areas (superior trunk, proximal upper extremities)
●Atrophic skin (advanced age, previously irradiated skin)
●Poor patient compliance with postsurgical instructions
●Use of medications that inhibit wound healing, such as systemic corticosteroids, mechanistic target of rapamycin (mTOR) inhibitors (sirolimus, everolimus), or hedgehog pathway inhibitors (vismodegib, sonidegib)
●Poor circulation
●Underutilization of deep, absorbable sutures to close the wound
●Development of infection
In most cases, surgical wounds dehisce because of excessive mechanical stress placed on the wound too soon after surgery or inadequate reinforcement of the wound with sutures (picture 2).
Prevention — Surgical wounds healing by primary intention are approximately 5 to 10 percent healed after one week and 50 percent healed after one to two months, reaching a maximum of 80 percent of normal skin strength several months postoperatively [13]. Therefore, the wound must not experience significant stress in the first few weeks after surgery. Patients should be warned that the strength of the wound sutures may be overpowered even by mild activity. For trunk and upper extremity wounds, it is reasonable to limit patients to lifting no more than 15 pounds for two weeks after surgery, gradually increasing activity as tolerated. Aerobic activity such as walking is usually not an issue for wound healing and can be continued within a day or two of surgery. For lower extremity wounds, patients may need to elevate the extremity to decrease edema, which can also place significant stress on a healing wound.
Management — Wounds that have dehisced after cutaneous procedures are usually allowed to heal by secondary intention. Patients should apply a thin layer of petrolatum by using a cotton tip applicator and cover the wound with nonadherent gauze. The dressing is changed daily until complete re-epithelization has occurred. Topical or systemic antibiotics are not needed in these situations unless there is overt evidence of soft tissue infection.
Surgical site infection — Surgical site infection (SSI) is defined as an infection related to an operative procedure that occurs at or near the surgical incision within 30 days of the procedure [14].
In dermatologic surgery, SSIs are uncommon, with reported overall rates of approximately <1 to 2 percent [15-17]. Higher rates are reported for specific sites (eg, groin, lower extremities) or surgical technique (eg, flaps, grafts) and in patients with predisposing underlying conditions (eg, immunosuppression, corticosteroid use, diabetes, obesity) [18,19].
SSIs usually manifest within three to five days of the procedure. Pain is the most sensitive indicator of infection; other clinical findings, such as erythema, induration, and fluctuance, help distinguish an SSI from the expected inflammation that characterizes the early phase of wound healing. In severe infections, a purulent discharge from the wound may be present.
Although rarely associated with significant morbidity, postoperative infections can cause discomfort and interfere with normal wound healing. In high-risk patients (eg, immunosuppressed patients, patients at risk for infective endocarditis [IE] or prosthetic joint infection), SSI can be associated with significant morbidity and, rarely, mortality.
Prevention — Prevention of SSI involves preoperative, intraoperative, and postoperative infection-control interventions, including skin antisepsis, use of gloves, and use of perioperative antibiotics. (See "Overview of control measures for prevention of surgical site infection in adults".)
Skin antisepsis — Common antiseptics include povidone-based preparations, chlorhexidine-based preparations, and ethyl alcohol. Among them, chlorhexidine-based preparations appear to be more effective than povidone-based preparations in preventing SSI [20,21]. (See "Overview of control measures for prevention of surgical site infection in adults", section on 'Skin antisepsis'.)
Sterile versus nonsterile gloves — Sterile glove use, which for many years was thought to decrease the risk of SSI in outpatient dermatologic procedures, has been shown to have no effect on the incidence of these infections. For this reason, we use nonsterile gloves when performing dermatologic procedures in the clinic.
In a 2016 systematic review and meta-analysis of eight randomized trials and five observational studies including over 11,000 patients undergoing minor surgery in outpatient settings, the SSI rates in the nonsterile and sterile glove groups were similar (2.1 and 2 percent, respectively; pooled relative risk [RR] 1.06, 95% CI 0.81-1.39) [22].
Antibiotic prophylaxis — Antibiotic prophylaxis for the prevention of SSI is indicated in the following circumstances (algorithm 1):
●If the wound is contaminated or infected. The degree of contamination of a surgical wound at the time of the operation is an important risk factor for infection [23].
●Patients who are at high risk for SSI, based on the site (lips, ears, nose, groin, or lower extremities), technique used (skin flaps or grafts), underlying conditions (eg, immunosuppression, diabetes, obesity, malnutrition), or lifestyle habits (eg, tobacco smoking).
●Patients at high risk for IE. (See "Prevention of endocarditis: Antibiotic prophylaxis and other measures".)
●Patients at high risk of hematogenous joint infection (HJI). (See "Prevention of prosthetic joint and other types of orthopedic hardware infection", section on 'Following hardware placement'.)
The antibiotic selection and regimens based upon the surgical site and potential pathogens present at specific sites are illustrated in the table (table 1) [24].
Postoperative topical antibiotics — The use of topical antibiotics in the postoperative period may have a small benefit in the prevention of SSI compared with no antibiotic. A 2016 meta-analysis of eight moderate-quality trials (5427 participants) found that topical antibiotics are associated with a modest reduction of SSI risk in people with surgical wounds healing by primary intention compared with no topical antibiotic (RR 0.61, 95% CI 0.42-0.87) [25].
However, the potential of topical antibiotics to induce allergic contact dermatitis (ACD) and antibiotic resistance have lead most dermatologists to recommend using only white petrolatum for the management of surgical wounds healing either by primary or secondary intention [26,27].
Management — In the absence of systemic symptoms (eg, fever, chills), SSIs can be treated on an outpatient basis. Patients with SSI and systemic symptoms should be transported to the emergency department for treatment. SSIs with evidence of fluctuance are treated with incision and drainage and a course of systemic antibiotics. Infections associated with cellulitis alone are treated with systemic antibiotics alone.
Before initiating antibiotic treatment, a culture from the wound should be obtained to identify the responsible organism. Empiric antibiotic treatment against methicillin-susceptible Staphylococcus aureus and beta-hemolytic streptococci (Streptococcus pyogenes), which are the most common causes of SSI, should be initiated immediately, pending culture and susceptibility results. Oral cephalexin is a common choice as first-line therapy (table 1). (See "Acute cellulitis and erysipelas in adults: Treatment".)
In patients at high risk for methicillin-resistant S. aureus (MRSA) colonization (table 2), empiric antibiotic treatment providing coverage against MRSA should be used as first-line therapy. Trimethoprim-sulfamethoxazole, clindamycin, and doxycycline or minocycline have good activity against MRSA (table 1). (See "Methicillin-resistant Staphylococcus aureus (MRSA) in adults: Treatment of skin and soft tissue infections".)
SSIs that are treated promptly and appropriately usually have an excellent prognosis. Patients with SSI should be seen in clinic approximately one week after the initiation of antibiotics to ensure resolution.
Contact dermatitis — ACD and irritant contact dermatitis are relatively common complications of cutaneous surgery. Certain topical antibiotics (eg, neomycin, bacitracin), topical anesthetics (eg, benzocaine), and surgical tapes and adhesives are common topical sensitizers that can elicit a delayed allergic response. Depending on whether the patient has been previously exposed to the offending substance, the reaction can take hours to several days to become apparent.
ACD from surgical tapes and adhesives typically has a sharply demarcated, geometric appearance matching that of the tape (picture 3). (See "Clinical features and diagnosis of allergic contact dermatitis" and "Management of allergic contact dermatitis".)
ACD is often misdiagnosed as an infection as the cutaneous manifestations, including erythema, scaling, and crusting, resemble those of a superficial infection. An important distinguishing feature, however, is the primary symptom. While pain in the wound area is the predominant complaint of patients with SSI, pruritus is the cardinal symptom of ACD and is often intense and unrelenting.
Prevention — ACD can be prevented by counseling patients about avoidance of known sensitizers (eg, topical antibiotics, topical analgesics) for the care of their surgical wounds. Although topical antibiotics may slightly reduce the risk of SSI compared with petrolatum [25], we prefer petrolatum for the care of surgical wounds because of its wound healing and nonsensitizing properties. Systemic nonopioid analgesics (eg, acetaminophen) rather than topical anesthetics should be used for pain control.
Management — The most important step in treating ACD is to remove the offending agent (see "Management of allergic contact dermatitis"). If a topical antibiotic is suspected, the patient should be instructed to apply only white petrolatum to the wound. If tape is suspected, alternative options include using paper tape, which is less adherent but generally less sensitizing, to keep the dressing in place or, if the wound is on an extremity, using a rolled gauze to wrap the wound. Small wounds can be left open after the second postoperative day, covered only with a thin layer of petrolatum.
Simply removing the offending agent may not provide symptomatic relief to a patient with severe ACD. For localized reactions (1 to 2 percent of the total body surface area), a high-potency topical corticosteroid ointment (eg, clobetasol propionate 0.05% ointment) applied once or twice daily will provide symptomatic relief without adversely affecting wound healing. Once the pruritus has subsided, the patient may discontinue the use of the topical corticosteroid. Thereafter, patients should be instructed to apply white petrolatum only to the wound.
Oral H1 antihistamines, such as hydroxyzine, can be used as an adjunctive therapy to control pruritus, if not contraindicated. Typically, sedating antihistamines, such as diphenhydramine or hydroxyzine, both given orally at doses of 25 to 50 mg every six hours, are the most effective at providing relief from the pruritus. (See "Pruritus: Therapies for localized pruritus".)
Suture reactions — A suture reaction is an inflammatory, foreign body reaction against the absorbable suture material left in place. It typically presents with erythema around the wound, often with a linear arrangement of small, erythematous papules or pustules. Suture reactions are commonly misdiagnosed by patients as SSIs because they often have a purulent discharge. Two important features differentiating a suture reaction from an SSI are the appearance of discrete erythematous papules, pustules, or erosions in a linear fashion (corresponding to the location of the deep, absorbable sutures that were placed) and the timeframe of occurrence. Suture reactions most commonly manifest one to three months after the procedure, whereas infections occur mostly within the first postoperative week.
Most suture reactions are mildly symptomatic and do not require treatment. However, if sutures are visible, they should be removed. Occasionally, the knots tied in the absorbable subcutaneous sutures may perforate through the wound, preventing full wound healing. The knots can usually be gently grasped with pickups and removed painlessly. Patients can be reassured that the final appearance of the wound will not be affected by this temporary setback.
Hypergranulation — Granulation tissue is the result of the combined production of collagen and growth of capillaries that occurs in secondary intention healing. (See "Basic principles of wound healing", section on 'Phases of wound healing'.)
On occasion, this physiologic process can become excessive, leading to the formation of an exuberant, exophytic mass of granulation tissue that rises above the level of the wound and prevents re-epithelialization, a phenomenon called hypergranulation or over-granulation. Excessive granulation tissue can form focally or involve the entire wound base. It is most commonly seen in large defects allowed to heal by secondary intention, in particular, when excessive moisture builds up underneath an occlusive dressing.
Excess granulation tissue can be treated with various techniques:
●Silver nitrate – Silver nitrate is a cauterizing chemical available in liquid or solid form (stick) commonly used for removal of granulation tissue [28]. It is applied to the involved area by the surgeon in the office for a few consecutive days until the granulation tissue has receded.
●Intralesional or topical corticosteroids – Intralesional or topical corticosteroids have been reported as effective in reducing exuberant granulation tissue and promoting healing in surgical and burn wounds [29-31].
●Electrocautery – After the wound is anesthetized, the wound base is cauterized to reduce the vascular supply to the granulation tissue and induce regression.
●Laser therapy – Laser therapy using the 595 nm pulsed-dye laser followed by hydrocolloid dressing has been successfully used in a few series of patients with nonhealing surgical wounds due to hypergranulation [32,33].
●Curettage – Curettage can be done with or without local anesthesia, depending upon the area's sensitivity. Using a 3 to 5 mm curette, the granulation tissue can be gently debrided away. Hemostasis is achieved with silver nitrate or electrocautery.
Limiting excessive moisture in the wound area is important to prevent recurrence. This can be accomplished in several ways, including:
●Applying dressings that contain aluminum acetate solution to the wound or a 1:4 dilution of table vinegar to water
●Using less occlusive dressings that maintain the slightly moist wound environment
●Applying to the wound a thin film of petrolatum, rather than a thick glob
Patients with excess granulation tissue should be seen on a regular basis until the wound has healed to assess for any recurrence and to treat as needed.
Scarring — Scarring is an unavoidable consequence of cutaneous surgery. Although in many cases the resulting scar is cosmetically and functionally acceptable, at times scarring can be extensive and even cause functional limitations.
The main two types of abnormal scarring are keloids and hypertrophic scars [34]. The risk of abnormal scarring should be discussed with all patients prior to surgery. Patients with a history of keloids should be counseled that they have a high risk of developing one following surgery.
A keloid typically extends beyond the original defect (picture 4), whereas a hypertrophic scar presents as a raised, firm scar along the surgical wound that does not extend beyond the original defect (picture 5). Both keloids and hypertrophic scars may be pruritic and painful.
The pathogenesis, clinical manifestations, and management of keloids and hypertrophic scars are discussed separately. (See "Keloids and hypertrophic scars" and "Laser therapy for hypertrophic scars and keloids".)
SUMMARY AND RECOMMENDATIONS
●Perioperative and postoperative complications in dermatologic surgery, including hemorrhage, hematoma, surgical site infection (SSI), dehiscence, and allergic contact dermatitis (ACD), are uncommon and, in most cases, minor. Clinicians must provide adequate information to the patient regarding the risks and benefits of treatment, and informed written consent should be obtained. (See 'Introduction' above.)
●Excessive bleeding may be due to a combination of patient-related factors, including use of anticoagulants, comorbidities, and procedure-related factors, such as laceration of small arterioles or wide undermining. Venous bleeding/oozing and small arteriolar hemorrhages during cutaneous procedures are in most cases easily controlled by applying direct pressure to the area and electrocautery. Larger arterial hemorrhages can be controlled by placing an absorbable figure-of-eight ligating suture around the vessel proximal to the site of laceration. (See 'Intraoperative bleeding' above.)
●A hematoma is a collection of blood underneath a wound that has been sutured closed and presents as a tense expansion underneath the wound (picture 1A-B). Meticulous hemostasis during surgery and application of a pressure dressing after surgery are essential to prevent this complication. Observation is reasonable for small, stable hematomas (<2 cm and not expanding). Larger hematomas or hematomas causing significant symptoms should be drained. (See 'Hematoma' above.)
●Antibiotic prophylaxis for the prevention of SSI is indicated if the wound is contaminated or infected; in patients at high risk for SSI, based on the site, technique used, or underlying conditions; and in patients at high risk for infective endocarditis or hematogenous joint infection (algorithm 1 and table 1). (See 'Prevention' above.)
●SSIs present with pain, erythema, induration, and sometimes fluctuance or purulent discharge. SSIs with evidence of fluctuance are treated with incision and drainage and a course of systemic antibiotics. Infections associated with cellulitis alone are treated with systemic antibiotics alone. (See 'Surgical site infection' above.)
