Punch excision techniques are utilized for depressed scars such as ice pick and boxcar scars. According to the diameter of the scar, a biopsy punch of appropriate size is used to excise the scar.
If the scar is > 3.5 mm in size, it is excised and sutured after undermining, in a direction parallel to the relaxed skin tension lines.
Procedure: Surgical preparation is done. Local anaesthesia infiltration and marking of the scar is done. Initial undermining of the scar is done. Based on the diameter of the scar, a biopsy punch of appropriate size is inserted till the subcutaneous fat layer and the punch graft is removed and discarded. After removal of the plug, the area becomes elliptical. Undermining with an artery forceps is done and is followed by suturing with 6-0 prolene. (Illustration 33.5) A linear scar ensues lying along the RSTL. Dressing is done. Antibiotics and NSAIDs are administered for 7 days.
Depressed pitted ice pick scars up to 4 mm in diameter, are excised and replaced with an autologous, full-thickness punch graft. The donor site is commonly the post-auricular region or the gluteal region. Care should be taken to avoid cobblestoning, which is a common complication.
Procedure: Surgical preparation is done. Local anaesthesia infiltration and marking of the scar is done. Initial undermining of the scar is done. Based on the diameter of the scar, a biopsy punch of appropriate size is inserted till the subcutaneous fat layer and the punch graft is removed and discarded. From the donor site, a full thickness punch graft> 0.5 mm than the excised scar is taken. This is then fit into the recipient area( Area of excised scar), if needed it is trimmed. Sutures or surgical glue is applied. (Illustration 33.6) Dressing is done. Antibiotics and NSAIDs are administered for 7 days.
All the punch techniques require a postoperative follow up after 1 week to check for the donor/ recipient site and removal of sutures, if required.
In selected cases, when scarring is linear and extensive, scar revision techniques such as Z, M and Y plasty may be useful. These need to be performed by a dermatosurgeon properly trained in performing these procedures. [41, 42]
Various techniques such as microneedling, threadlifts are being used in atrophic acne scars. Intralesional steroids and cytotoxics along with silicone sheets are the mainstay for hypertrophic scars.
Skin needling, also called “collagen induction therapy” or “needle dermabrasion” is the technique of rolling a device composed of a barrel studded with hundreds of needles, which create thousands of micropunctures in the skin to the level of the papillary to mid-dermis. [ 43] The optimal scars to treat with skin lesion are the same as fractional laser resurfacing— rolling acne scars, superficial boxcar scars, or erythematous or hypopigmented macular scars. A dermaroller device is used with needles of length 1.5 to 2.5mm is rolled across the skin with pressure in multiple directions until the area demonstrates uniform pinpoint bleeding through thousands of micropuncture sites. One study describes rolling the device four times in four different directions (horizontally, vertically, and diagonally right and left) for a total of 16 passes.  In the author’s experience, the number of passes required to achieve uniform pinpoint bleeding of the treatment area is variable and is inversely proportional to the density of the needles on the rolling barrel. Usually, three or more treatments are required to achieve optimal clinical benefit, separated by four-week intervals. Figure 33.6 shows good results with dermaroller microneedling.
Microneedling with fractional radiofrequency (MFR) technology is now being used for acne scars. MFR is useful for distensible scars and non- distensible scars with associated volume loss. The procedural details and clinical studies have been detailed in Chapter 10.
Non-surgical face lifts with threads are also being used for acne scar treatment. Polydioxanone (PDO) threads are used for lifting and tissue tightening and scar resurfacing; it stimulates production of collagen and fibroblasts in response to its implantation. Threadlift with PDO is indicated in patients of scars who cannot come repeatedly for multiple number of sittings for derma roller, or do not want to undergo laser/ lights or radiofrequency treatments. Evidence based studies are lacking with this technique. The procedure has been detailed in chapter 15.
Intralesional triamcinolone 10-40 mg/mL with or without cytotoxics, like 5-fluorouracil, is indicated for the treatment of hypertrophic scars and keloids. These are repeated at 3-4 weekly intervals until resolution; care is taken to avoid atrophy. [45, 46, 47, 48]
Administration of fluorouracil (5-FU) or bleomycin into the scars, results in gradual flattening of the scars. [49, 50, 51] 5-FU inhibits rapidly proliferating fibroblasts found in dermal wounds. The therapy is efficacious for facial acne scars as monotherapy, [53, 54] and in combination with intralesional corticosteroids and a 585 nm pulsed dye laser. [50 ] Studies with 5-FU use a concentration of 50 mg/mL with a total dose per session ranging from 50 mg to 150 mg and can be given multiple times a week to increase treatment efficacy. Bleomycin is another antineoplastic agent that inhibits collagen synthesis through cytotoxic effects on rapidly dividing fibroblasts. [55, 56]
Silicone dressings are chemically and biologically inert; silicon sheets or gels are found to be useful in flattening keloids and hypertrophic scars, reducing discoloration and making scars cosmetically acceptable. [57, 58]
Scarring in areas which are subjected to repeated movements (chin, marionette lines) are prone to become more obvious with aging. The synergistic combination of botulinum toxin and fillers may prove to be a useful modality in these scars. Botulinum toxin relaxes the muscles and hence decreases the tensile forces surrounding the scar. 
Combining 2 or 3 modalities of acne scar treatment in a single session or sequential planning of the procedure can prove advantageous to a monotherapy. Various combination therapies are practiced. Combination of different interventions can result in satisfactory improvement of acne scarring.
It is useful to combine subcision with various modalities. Subscision treatments followed by microneedling performed immediately the day after and TCA 15% peel done a fortnight later was found to improve the grade of scar.  Another sequential combination therapy is TCA peeling, subcision, and subsequent fractional laser irradiation. Dot peeling and subcision is done twice at an interval of 2-3 weeks and fractional laser irradiation is done every 3-4 weeks. The duration of therapy is 12 months. A marked decrease in acne scar severity was noted.  Combination of PRP with microneedling, fractional CO2 and erbium YAG also constitutes an effective alternative that produces synergistic benefits with fewer adverse effects. [61, 62, 63]
The aim of good postoperative care is to prevent or minimize complications and ensure early recovery. Preventive actions must be taken promptly to avert complications, which may lead to unacceptable aesthetic or functional result. This is most important in ablative resurfacing procedures, particularly in darker skinned patients, where pigmentary alterations are common. Supportive medical therapy and a careful maintenance program are essential to maintain results of surgical treatment in most patients.
Complications related to individual procedures are discussed in details in respective chapters. In general, the complications include conditions such as active herpes simplex, immunosuppressive conditions, which may predispose to infection and delayed healing. Post inflammatory hyperpigmentation is a common and dreaded complication of acne surgery, especially in dark skinned patients. Patients with unrealistic expectations or uncooperative patients who do not follow treatment regimens are more prone to develop complications. Adequate counselling, priming the skin and supportive medical therapy, apart from good intra- and postoperative care are essential for satisfactory surgical outcomes.
The tips for management based on the author’s experience are outlined in Box 33.4
Box 33.4: Pearls and Pitfalls
PEARLS: TIPS FOR MANAGEMENT
Treat active acne before procedures for acne scars are initiated
PITFALLS: TO AVOID
Procedural treatment in acne provides gratifying results. These are an adjunct treatment in active acne, however post acne scarring is being better managed with the advent of various procedural interventions. Fractional resurfacing lasers have proven to be one of the most beneficial technologies for post acne scarring. Judicious use of combination therapies in a single or sequential sessions have a synergistic role and are increasingly being used in clinical practice. Appropriate patient selection and a good understanding of patient expectations are vital to achieve an optimal therapeutic outcome.
Acne surgery involves the use of appropriate surgical interventions for treatment of active acne as well as improving cosmetic outcomes in postacne scarring. In active acne, surgical intervention is used as an adjunctive to medical therapy. The treatment of post acne scars involves a multimodal approach as different types of scars may exist in an individual. Each scar and each patient must be evaluated and treated accordingly. The main goal of treatment is to achieve maximal improvement rather than perfection. The procedures can be classified as resurfacing, lifting, excisional modalities.For superficial scars, non-invasive or minimally invasive techniques such as microdermabrasion, superficial chemical peels or the newer non ablative lasers, are better treatment options. For deeper scars, a combined approach with subcision, punch excision techniques in conjunction with resurfacing procedures, are essential to achieve optimum results. Many complications can be prevented by thorough preoperative evaluation, sound surgical technique, and careful follow-up care. Good patient rapport and effective communication with patients are invaluable.