The procedure begins with ultrasound visualization of the AVF, and an indelible marker is used to mark its course (Fig. 25.2). Ultrasound-guided tumescence technique is performed with a Klein pump, 18-gauge needle, and the tumescent solution (50 mL of 1 % lidocaine mixed with 1:100,000 units of epinephrine) in order to infiltrate the subcutaneous tissue overlying the AVF. This provides analgesia (lidocaine) and also some vasoconstriction (epinephrine) of smaller blood vessels for hemostasis and a less-systemic lidocaine effect. Adequate tumescence is confirmed by ultrasonic evidence of separation of the skin from the AVF accompanied by a firm turgor to the soft tissue (Fig. 25.2). The key principle is to infiltrate directly over the AVF and in the medial and lateral adipose tissue to allow for liposuction directly over the fistula and along the sides in order to create a visual and palpable “adipose valley.” Essential to the procedure is facility with ultrasound techniques as continuous ultrasound visualization of the 18-gauge needle tip to avoid iatrogenic injury to the AVF.

Once tumescence is deemed technically successful, liposuction superficialization is performed under ultrasound guidance. A small incision is made proximal to the area of interest and away from the AVF (this ensures that a surgical infection would not be directly over the fistula). A 2-mm aspiration cannula attached to a 30-mL syringe is introduced into the subcutaneous soft tissue, and the overlying adipose tissue is aspirated under direct ultrasound guidance while keeping continuous negative pressure on the 30-mL syringe. The cannula tip is visualized in real time using ultrasound guidance while the surgeon’s operative hand moves in a back and forth manner, similar to the technique when liposuction is performed in other anatomic locations. This adipose aspirate is removed directly overtop the fistula and in a radial manner suctioning the adipose tissue medially and laterally to create an “adipose valley” (Figs. 25.2 and 25.3). Adequate liposuction occurs when the AVF is easily palpable, and the fistula depth is decreased based on the ultrasound appearance and measurements.

The key to success during suction lipectomy is to perform the aspiration while continuously visualizing the tip of the cannula under ultrasound guidance. Loss of ultrasonic visualization has the potential to cause iatrogenic injury to the AVF. The lipoaspirate is adequate when there is an adequate “adipose valley” so that the fistula is easily palpable under the skin and should be visible through the skin. A post-procedure ultrasound will demonstrate a significant depth decrease of ideally 4 mm or less (Fig. 25.4). A completion ultrasound is performed to assess for injury to the fistula which would be seen with color flow Doppler and B-mode duplex (extravasation, hematoma, or pseudoaneurysm). Should these complications arise, management is dictated on ultrasound findings. Active extravasation from the fistula will likely require suture repair, while an isolated hematoma may respond to compression if there is no communication with the fistula (best visualized with color flow Doppler). Again, all of these complications are greatly minimized, and perhaps eliminated, by continuous ultrasound visualization of the cannula. Once the AVF is adequately superficialized, a sterile dressing is applied and the upper arm wrapped firmly in an elastic bandage while avoiding AVF compression. The elastic bandage is left in place for 72 h to provide continuous compression (not restrictive) and removed on the third post-procedure day. At 1 week, the arm is examined and AVF depth is assessed by ultrasound. Another ultrasound is performed at 4 weeks to assess for maturity and depth and clinical exam for wound healing, if necessary. Attempts at hemodialysis access may now be attempted if the arm is healed, the AVF mature, and the superficialization successful.

Data involving technical variations and outcomes of liposuction superficialization are mostly case reports. There are several other adjuncts that deserve mention such as the use of an endoscopic vein-harvesting device which serves as a shield for the fistula during adipose aspiration [12]. Another technique involves decremental liposuction cannulas beginning with a 4-mm cannula and progressing to smaller diameters as the subcutaneous tissue volume decreases [13]. Published outcomes for this technique are very sparse, but one retrospective study found that liposuction superficialization of radiocephalic and brachiocephalic AVFs led to an 85 % successful two-needle (17-gauge) cannulation rate at 33.7 days post-procedure. Increased body mass index correlated with a higher rate of surgical site infections and delays in successful cannulation [14].