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Autologous fat transfer
Autologous fat transfer
Autologous fat transfer is yet another method that can augment the volume of the dorsal hand. The general procedure involves harvesting fat from a donor site and introducing it into a host tissue. Aside from being abundantly available, adipose tissue has the benefit of being biocompatible.1 Autologous fat transfer has been shown to last 4 months to 3 years on the dorsal hand.21,37 For a detailed discussion of fat transfer, see Chapter 61.
This procedure first showed promise for dorsal hand augmentation in the 1980s.21 Thereafter, both Fournier and Coleman published their methods for autologous fat transfer to the dorsal hand. Fournier applied a single large bolus to the dorsal hand, while Coleman produced multiple small tunnels in order to increase the surface area of contact between the transplanted adipose and recipient tissues.1,38,39 Studies have shown this increase in surface area contact is beneficial, as 60% of adipocytes die if they are more than 1 mm away from blood supply.40 In addition, Carpeneda showed that the diameter of the fat injected must be 3 mm or less in order for revascularization to occur.1,40
Many methods exist for harvesting, preparing, and delivering adipose tissue.1,37,38 In a review of autologous fat transfer for the hand, Hoang et al. recommend choosing adipose tissue from the abdomen, flank, thigh, or medial knees, as these area produce a more bloodless fat.36 First, the donor site is anesthetized with a tumescent solution of lidocaine and epinephrine 15 minutes prior to collection. A 2- to 3-mm cannula is attached to a 10-mL harvesting syringe, and 15 to 40 mL is harvested per hand.1
The harvested fat is then set upright for 15 minutes to allow the supernatant fat to separate, and the fluid is then poured off.1,37 A 10-mL syringe is filled with supernatant fat and may be centrifuged at 3,000 to 3,600 revolutions per minute for 3 minutes.1,37 While Butterwick suggested that, on the dorsal hand, centrifuged fat has increased longevity and better clinical results compared to noncentrifuged fat, the question of
whether centrifugation results in a net benefit is controversial.41 Fat is then placed into 1-mL syringes.
Before proceeding with injections, the hands are prepped in a sterile fashion. One to 2 mL of tumescent anesthesia solution may be introduced through the dorsal wrist crease.37 The bolus of anesthesia is then massaged onto the remainder of the dorsal hand. Agostini et al. perform median and ulnar nerve blocks instead.42
The next injection methods vary by author. Butterwick uses an 11 blade to create an entry point on the dorsal wrist crease.37 Then, a number 10 Amar or Byron needle is introduced on the dorsal wrist crease toward the web space, and aliquots of approximately 0.3 mL are placed with each retrograde linear thread. A weaving crisscross pattern is used to place these aliquots throughout the dorsal hand. The hand should appear slightly overfilled, but the total injection volume to be kept to less than 10 to 12 mL per hand in order to limit the amount of postoperative edema.
Other authors use higher volumes. Bank et al. place 10 to 15 mL onto the dorsal hand, 1 to 2 mL onto the second, third, and fourth web spaces, and 2 to 3 mL onto the first web space and over the area of the anatomic snuffbox.43 Using a 16-G needle, Agostini makes six total entry points at the dorsal wrist crease, each of the web spaces, and one at the proximal radial aspect of the first MCP joint. All injections are performed using cannulas. From the entry on the dorsal wrist crease, 5 to 10 mL of fat is placed onto the dorsal hand, using 6 total passes in a fanning distribution. From the entry on the web spaces and first MCP, the cannula is pointed proximally and an additional 5 to 10 mL is placed on the dorsal hand, in a retrograde linear fashion. Agostini also treats the digits. By entering the perforations in the web spaces or first MCP, linear anterograde injection is used to place 0.5 mL of fat onto the radial and ulnar aspect of each digit. In their study, 21 of 22 patients were either โsatisfiedโ or โvery satisfiedโ with the treatment, and independent plastic surgeons rated 18 of 22 patients โvery improvedโ and the remainder โsignificantly improved.โ
Some authors apply Steri-Strips (3M Nexcare, St. Paul, MN) or Octylseal (Medline Industries, Mundelein, IL) to the incisions sites.43 Butterwick recommends starting a 10- day course of oral antibiotics the evening prior to the procedure.37 After injection, a soft dressing can be applied for 5 days.1 To minimize edema, the hand is elevated for the first 24 hours and the patient should avoid strenuous activity for 1 week.21
Patients should expect to experience edema and bruising lasting 1 to 2 weeks. Infection (including mycobacterial), cyst formation, and transient dysesthesia have also been reported.37,44 In the Agostini study, 3 of the 22 patients developed sensory dysfunction of the distal phalanges, which resolved within 1 month. Furthermore, rejuvenation of the digits led to 16 of the 22 patients unable to wear their rings postoperatively. Only 5 of the 16 patients considered the increase in ring size an
inconvenience. Agostini argues that finger rejuvenation contributed to a high satisfaction rate with the global appearance of the dorsal hand. On the other hand, Coleman contends fat injection to the fingers should be avoided to maintain the same volume and ring size of the digits. Many dermatologic surgeons do not volumize the fingers.