Sensory changes after traditional and ultrasound-assisted liposuction using computer-assisted analysis

Postoperative sensory changes (i.e., hypesthesias) that occur after suction-assisted lipoplasty (SAL) are expected clinical sequelae. These disturbances usually return to normal within several weeks to months postoperatively. The presumed mechanism of injury is direct trauma to the peripheral nerves from the suction cannula. In addition, the potential for demyelination of peripheral nerves secondary to cavitation during ultrasound-assisted liposuction (UAL) is well known. Quantitative data describing hypesthesia after both procedures are limited. The purpose of this study was to objectively evaluate the severity and duration of postoperative hypesthesia after liposuction to better educate patients preoperatively. Furthermore, the authors use the three-stage UAL technique and wanted to determine whether a clinical difference in sensory return existed between suction- and ultrasound-treated areas. A total of 21 patients underwent liposuction performed by the senior author (R.J.R.). The abdomen, flanks, thighs, and medial knees were tested for objective sensation with the Pressure Specified Sensory Device preoperatively and at 2, 6, and 10 weeks postoperatively. A total of 102 sites were tested. On average, the SAL-treated areas improved to normal sensation by 6 weeks, whereas the UAL-treated areas took, on average, 10 weeks to recover. The severity of the hypesthesia was not correlated with larger aspiration volumes or longer UAL exposure time per site. At 10 weeks, 90 percent of UAL-treated patients and 89 percent of liposuction patients overall had recovered normal sensation. This study provides the body-contouring surgeon with good, objective data with which to educate patients regarding sensory return after liposuction.