Section 4 Plastic and Reconstructive Problems

Holcomb

Fig. 1. ( A ) Preoperative view of LAFC treatment area with lower facial fullness and jowling in a 58-year-old woman in upright seated position. ( B ) Intraoperative view of LAFC treatment area in the same patient in 20 reverse Trendelenburg position. LAFC treatment zone is outlined with purple marker. LAFC entry site is located approximately 2 cm posterior to inked posterior extent of LAFC treatment zone and 2 cm above the caudal mandibular margin. The 600- m m bare laser fiber is present at the LAFC entry point and the red aiming beam at the fiber tip is seen faintly between the surgeon’s gloved thumb and index finger. Note that the laser fiber is engaged in fatty tissue at the superior extent of the jowl fat compartment.

local anesthesia (dry technique)—typical parame- ters include power 5.4 W, pulse energy 180 mJ, pulse duration 100 m s (fixed), pulse rate 30 Hz, and total energy delivered 200 to 300 J. 1,7 Although the unique thermal signature of the micropulsed 1444-nm Nd:YAG interstitial fiber laser enables safe treatment without the need for internal or external temperature monitoring, it is important to keep the fiber continuously moving through the tissue during active lasing—this facili- tates even distribution of laser energy and limits the potential for clinical thermal confinement fail- ure. Certainly some latitude exists with regard to these treatment parameters; however, in a prior study of mid- and lower face LAFC, complications, such as prolonged inflammatory edema and over- correction, were associated with faster energy de- livery (40 Hz) and with a doubling of the total energy delivered (eg, 500 J). 1 Immediately after energy delivery, a similar volume (eg, 3 mL) of room temperature sterile saline is infiltrated into the treatment area as a postcooling or thermal quenching step that attempts to minimize collat- eral thermal spread to adjacent tissues as well as reduce PIE. Removal of emulsified tissue and liquefied fat via manual lipoaspiration with a small dual port aspira- tion cannula (eg, 19 gauge) and a 6-mL syringe (prefilled with 1-mL sterile saline) enables definitive tissue contouring. Fig. 2 shows the full minimal instrumentation requirement for LAFC. It is not un- common for a small-diameter aspiration cannula to become blocked with fibrous tissue during lipoaspiration—when this occurs, the cannula is

and forefinger during local anesthesia infiltration, laser energy delivery, and lipoaspiration. Limiting exogenous water infiltration to 3 mL minimizes distortion of the anatomy during treatment and fa- cilitates endpoint identification but also limits thermal confinement. The fatty tissue ablation efficiency of the micropulsed 1444-nm Nd:YAG interstitial fiber laser, however, enables sufficient local tissue effect with preserved thermal confine- ment within the suggested total energy usage parameters. The local anesthetic mixture that the author fa- vors includes 0.5% lidocaine; 0.25% Bupivacaine hydrochloride; and 1:200,000 epinephrine and hyaluronidase, 2 to 4 IU per mL (eg, Hylenex re- combinant, Halozyme Therapeutics, San Diego, CA, USA). Initially, approximately 1.0 mL of this local anesthetic mixture is used to provide anes- thesia to the percutaneous entry site and the intervening tissue toward the LAFC treatment zone as well as a field block that includes the tis- sue for debulking and contouring. A narrow (eg, 21-gauge) multihole infiltration cannula is then used to deliver 3 mL of local anesthetic to the LAFC treatment area. With the thermally confined micropulsed 1444-nm Nd:YAG interstitial fiber laser, energy de- livery occurs via a 600- m m silica multimode fiber with the fiber used either free (bare) or assembled with a disposable or nondisposable cannula. Prior studies have demonstrated general safety guide- lines for energy delivery during LAFC of the lower face when using the micropulsed 1444-nm Nd:YAG interstitial fiber laser and minimal volume