Magnetic Liver Retraction Decreases Postoperative Pain and Length of Stay in Bariatric Surgery Compared to Nathanson Device.

Objective: Retrospective case-matched comparison of magnetic liver retraction to a bedrail-mounted liver retractor in bariatric surgery specifically targeting short-term postoperative outcomes, including pain and resource utilization. Background: Retraction of the liver is essential to ensure appropriate visualization of the hiatus in bariatric surgery. Externally mounted retractors require a dedicated port or an additional incision. Magnetic devices provide effective liver retraction without the need of an incision. Methods: The sample consisted of primary and revisional bariatric surgery patients, including Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and biliopancreatic diversion with duodenal switch (BPD-DS) operations. Propensity score analysis was used to match patients with magnetic retraction to patients with a bedrail-mounted retractor with a 1:2 ratio using preoperative characteristics. Baseline characteristics and postprocedure outcomes were compared using two-sample t-tests or Wilcoxon rank sum tests and chi-square or Fisher's exact test as appropriate. Results: One hundred patients met inclusion criteria for the use of magnetic liver retraction (45 RYGB, 35 SG, 20 BPD-DS) with 196 suitable matched external retractor patients identified. Patients were matched and comparable for all preoperative characteristics except for transversus abdominus plane block (27% versus 47%). Patients in the magnet cohort had significantly decreased mean 12-hour postoperative pain scores (2.9 versus 4.2, P = .004) and decreased hospital length of stay (LOS) (1.5 versus 1.9 days, P = .005) while operating room supply were higher in the magnet cohort ($4600 versus $4213, P = .0001). Conclusions: Magnetic liver retraction in bariatric surgery is associated with decreased postoperative pain scores, decreased hospital LOS, and increased operating supply costs.