Two-Lines-Four-Regions: A New Concept in Endoscopic-Assisted Surgery of Parotid Gland Tumors

Abstract

Endoscopic-assisted surgery of parotid gland tumor is challenging due to the complex anatomic structures. This study compared an innovative endoscopic-assisted operation called the two-lines-four-regions method to a traditional endoscopic-assisted surgery in the treatment of parotid gland tumors. In this retrospective cohort study, patients were assigned to the traditional endoscopic group (Trad-En group) and the two-lines-four-regions endoscopic group (Tlfr-En group) according to whether two-lines-four-regions concept was used before the surgery. The primary outcomes are operation time (minutes) and postoperative complications present or absent. Other outcomes including intraoperative blood loss (milliliter), whether to increase auxiliary incision (yes/no), postoperative drainage (milliliter), and retention time (day) are the secondary outcomes. χ2 analysis or Fisher exact test was used to compare the statistical differences of those variables in 2 groups, and a P value of less than .05 was considered to indicate statistical significance. A total of 121 patients with parotid gland tumors underwent endoscopic-assisted surgery; 59 patients were assigned to the Trad-En group, and 62 patients were assigned to the Tlfr-En group. The mean operation times (65.24±14.82min), blood loss (9.85±3.38mL), and the amount of drainage (10.52±3.17mL) in the Tlfr-En group were shorter than the values in the Trad-En group (75.75±14.16min, 10.52±3.17mL, and 16.54±3.21mL, respectively; P<.05). The median follow-up time was 34months (range 4 to 70months). No tumor recurrence was found in all patients. This study demonstrated that the new concept of two-lines-four-regions of parotid gland makes the endoscopic-assisted surgery of parotid gland tumors more simplified, efficient, and minimally invasive.