Iodine-supported spinal instruments reduce infection risk after total en bloc spondylectomy


Hiroyuki Hayashi (Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan) and others report in The Spine Journal that the combined anterior and posterior approach and non-use of iodine-supported spinal instruments are independent risk factors for the development of surgical site infection after total en bloc spondylectomy (TES).

Hayashi et al state that the risk of surgical site infection is a concern in patients undergoing TES because the procedure is invasive and technically demanding (ie. so the risk of surgical site infection may be increased). Furthermore, the type of patients who undergo TES (ie, patients with vertebral tumours) “might have poor nutritional status and are prone to immunosuppression from the effect of the disease or treatments”. The authors add that a surgical site infection in these patients could affect surgical outcome and, therefore, it is important to understand the risk factors for this complication to prevent it from occurring.

The aim of their study was to identify the independent risk factors for surgical site infection after TES and also to evaluate the role of iodine-supported spinal instruments in preventing infection. Hayashi et al report that basic research indicates that iodine-supported titanium has “antibacterial activity, biocompatibility, and no cytotoxicity”.

Of 125 patients with vertebral tumours who underwent TES between 2006 and 2013 at their hospital, 69 were treated iodine-supported instruments and 56 were not. At the mean follow-up point of 14 months, eight patients (6.4%) had developed a surgical site infection and seven of these patients had not received iodine-supported instruments. Hayashi et al comment: “It is notable that the patient with surgical site infection even with the use of iodine-supported spinal instruments recovered without the removal of the instruments. It is usually difficult to cure infections without removing the instruments if an instrument-associated infection arises.”

In a multivariate analysis of six potential risk factors—age, tumour histology, previous surgery at surgical site, operation time, surgical approach, and spinal instruments—only surgical approach was found to be to a significant risk factor for surgical site infection. The authors write: “Combined anterior and posterior approach was significantly associated with an increased risk of surgical site infection with an adjusted odds ratio of 11.6.” However in a multivariate analysis excluding surgical approach, the use of iodine-supported spinal instruments was significantly associated with a decreased risk of surgical site infection with an adjusted odds ratio of 0.1.

Hayashi et al conclude: “Iodine-supported spinal instruments were effective for prevention of surgical site infection in patients with compromised status. Moreover, this clinical trial of iodine-supported spinal instruments was performed with no detection of cytotoxic or adverse effects on the patients.”

Study author Hiroyuki Tsuchiya (Department of Orthopedic Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan) told Spinal News International: “Iodine-coating is a very promising technology in orthopaedic implant surgery for preventing and treating infection from the standpoints of its efficacy and safety. Iodine is sensitive to bacterium, fungi, and viruses. Iodine-supported spinal instruments should be indicated to high-risk patients and conditions. For example, patients with cancer, those under chemotherapy, or those with diabetes mellitus.”