Comparison between 1 g and 2 g of Intrawound Vancomycin Powder Application for Prophylaxis in Posterior Instrumented Thoracic or Lumbosacral Spine Surgery: A Preliminary Report.

Background: Surgical site infection (SSI) after instrumented spinal surgery is one of the most serious complications in spite of the routine use of prophylactic intravenous (IV) antibiotics. Many studies have suggested that intrawound vancomycin powder, applied during the intraoperative period, may decrease the incidence of SSI after surgery. However, the appropriate dose of vancomycin has not yet been reported.

Purpose: The purpose of the study is to compare between the use of 1 g and 2 g intrawound vancomycin powder and to find out which of these two groups can reduce the rate of deep wound infection in posterior instrumented thoracic or lumbosacral spine surgery.

Materials And Methods: The preliminary study was conducted from July 2013 to July 2015 at Lerdsin Hospital. A total of 400 patients were enrolled in the study, and their individual demographics were recorded. All patients underwent posterior instrumented thoracic or lumbosacral spine surgery. Of these, 131 patients received IV cefazolin and 2 g of vancomycin powder intrawound application, 134 patients received 1 g of intrawound vancomycin powder in addition to IV cefazolin, and 135 patients were given only IV cefazolin and were assigned as the control group.

Results: One hundred and thirty-one patients were treated with posterior instrumented thoracic or lumbosacral fusions using IV cefazolin and adjuvant 2 g of intrawound vancomycin powder. Five patients in this group developed deep infections (3.8%). One hundred and thirty-four patients were treated with posterior instrumented thoracic or lumbosacral fusions using IV cefazolin and adjuvant 1 g of intrawound vancomycin powder. Of these, four patients developed deep infections (2.98%). One hundred and thirty-five patients in the control group were treated with posterior instrumented thoracic or lumbosacral using only IV cefazolin as prophylaxis. Of these, four patients developed deep infections (2.96%). Coagulase-negative staphylococcus was the most common isolated organism. There were no adverse clinical outcomes or wound complications due to local application of vancomycin powder.

Conclusion: The preliminary result could not state the relation of intrawound vancomycin powder to the deep infection; further study with adequate sample size is required.