Yasuaki Iida

Antimicrobial prophylaxis for spinal surgery

BackgroundThe concept of antimicrobial prophylaxis (AMP) did not exist in Japan until recently. Therefore, postoperative administration of antimicrobial drugs has long been practiced under the pretext of prophylaxis against surgical site infection (SSI). In recent years, however, the concept of AMP and prophylactic countermeasures against SSI, based on evidence of the effectiveness of AMP, has gradually spread in Japan. From 2000 onward, we have undertaken prophylactic countermeasures against SSI in patients undergoing spinal surgery referring to the Guideline for Prevention of Surgical Site Infection published by the Centers for Disease Control and Prevention in 1999. The purpose of this study was to investigate the type of AMP that would be appropriate for spinal surgery and the manner in which it should be used.MethodsThe subjects were 1415 patients who underwent spinal surgery at our department from January 1990 to March 2008. The patients were classified into four groups according to the method of AMP administration: group 1, AMP was employed for 7 days, only postoperatively; group 2, initial AMP dosing was administered at the time of anesthesia induction, followed by administration of AMP for 5 days, including the day of the operation; group 3, initial AMP dosing was administered at the time of anesthesia induction, and AMP was administered for 3 days, including the day of the operation; group 4, the initial dosing was administered at the time of anesthesia induction, and AMP was administered for 2 days, including the day of the operation. The frequency of SSI was assessed in the four groups.ResultsThe frequencies of SSI in groups 1—4 were 2.6% (14/539), 0.9% (5/536), 0% (0/257), and 0% (0/83), respectively. Thus, the frequency of SSI decreased as the duration of the AMP administration period decreased.ConclusionsAs a result of thorough implementation of preventive measures against perioperative occurrence of infections, which included additional preoperative and intraoperative administration of AMP, the incidence of SSI could be decreased despite shortening the duration of AMP administration to 2 days.

Effect of cage geometry on sagittal alignment after posterior lumbar interbody fusion for degenerative disc disease.

Purpose. To compare the sagittal alignment of the lumbar spine after one-segment posterior lumbar interbody fusion (PLIF) using the horizontal cylinder (HC) or open box (OB) type cage. Methods. 66 patients underwent instrumented one-segment PLIF with bone grafting for lower lumbar degenerative disease. HC-type cages were used in 33 men and 13 women aged 20 to 73 (mean, 47) years between September 2001 and July 2004. OB-type cages with a 3° lordotic angle were used in 9 men and 11 women aged 25 to 70 (mean, 53) years between July 2004 and September 2006. Pre- and post-operative lumbar lordosis and intervertebral body angles in the fused and upper adjacent levels in the 2 groups were compared. Results. There was no significant difference between the 2 groups with regard to changes in the lumbar lordosis and intervertebral body angle in the fused and upper adjacent levels. In both groups, the upper adjacent intervertebral body angle increased significantly by about 2°. Conclusion. Lumbar alignment was similar after the use of the HC- or OB-type cages. This may be due to the surgical procedure and insufficient cage lordotic angle.

Recurrent Lumbar Disc Herniation after Microendoscopic Discectomy

Recurrent Lumbar Disc Herniation after Microendoscopic Discectomy The purpose of this study was to investigate the incidence and risk factors of recurrent lumbar disc herniation (LDH) after microendoscopic discectomy (MED).

Spontaneous Symptomatic Pseudoarthrosis at the L2-L3 Intervertebral Space with Diffuse Idiopathic Skeletal Hyperostosis: A Case Report

Pseudoarthrosis at the intervertebral space in patients with ankylosing spondylitis has occasionally been reported, but symptomatic pseudoarthrosis at the intervertebral disc level is rare in patients with diffuse idiopathic skeletal hyperostosis (DISH). Here, we report a case of symptomatic pseudoarthrosis at the L2-L3 intervertebral space that was diagnosed based on clinical history. We first performed L1–L5 fixation, but back-out of the pedicle screw occurred in the early postoperative phase and may have been caused by a short fixation range and concomitant Parkinsons disease. However, the prognosis of the case was favorable after a second surgery. This case indicates that a fixation range of at least 3 above and 3 below is necessary for bone fracture of a thoracolumbar vertebra and pseudoarthrosis in patients with DISH.

Solitary Spinal Epidural Metastasis from Gastric Cancer

Solitary epidural space metastasis of a malignant tumor is rare. We encountered a 79-year-old male patient with solitary metastatic epidural tumor who developed paraplegia and dysuria. The patient had undergone total gastrectomy for gastric cancer followed by chemotherapy 8 months priorly. The whole body was examined for suspected metastatic spinal tumor, but no metastases of the spine or important organs were observed, and a solitary mass was present in the thoracic spinal epidural space. The mass was excised for diagnosis and treatment and was histopathologically diagnosed as metastasis from gastric cancer. No solitary metastatic epidural tumor from gastric cancer has been reported in English. Among the Japanese, 3 cases have been reported, in which the outcome was poor in all cases and no definite diagnosis could be made before surgery in any case. Our patient developed concomitant pneumonia after surgery and died shortly after the surgery. When a patient has a past medical history of malignant tumor, the possibility of a solitary metastatic tumor in the epidural space should be considered.

Comparison of the invasiveness of conventional discectomy and microendoscopic discectomy for lumbar disc herniation: Differences in the methods of approach.

The aim of this study was to investigate whether differences in the methods of approach to the vertebral arch influence the invasiveness of conventional discectomy and microendoscopic discectomy (MED).

Use of intrawound vancomycin powder against postoperative infection after spine surgery

Local application of vancomycin has recently become widely used in spine surgery. However, local application is not included in the indication and has not been approved by the US Food and Drug Administration (FDA). Thus, we searched for reports with “intra wound-vancomycin” and “SSI” as keywords in the MEDLINE database, and investigated the efficacy, problems with use, and future prospects based on these reports. Intrawound vancomycin was described as effective in most of the reports, but was found to have no effect or to aggravate the condition in some reports. A toxic effect on osteoblasts due to a high local concentration was described in some reports, whereas local application was found to be safe in other studies. The amount of vancomycin used and the administration method varied among the reports. Overall, the results suggest that intrawound vancomycin is clinically effective, but this has yet to be established in a randomized controlled trial. There is a need to identify cases that should be selected for this treatment and to investigate the dose and optimum concentration of vancomycin for clinical use.

Evaluation of antimicrobial prophylaxis against postoperative infection after spine surgery: Limit of the first generation cephem.

In our department, first-generation cephem (CEZ) are generally administered for 2 days as antimicrobial prophylaxis (AMP) for spinal surgery. However, the incidence of surgical site infection (SSI) has recently increased, particularly cases involving coagulase-negative Staphylococci (CNS) as an etiologic agent. The objective was to elucidate the problems with the current AMP and the risk factors of SSI through a retrospective investigation of affected cases. The subjects were patients who underwent spine surgery at our department between August 2007 and June 2013. The subjects were divided into those who developed SSI (S group) and who did not develop SSI (non-SSI (N) group), patients who developed CNS infection in the S group was subdivided as C group, and the risk factors were investigated. The significance of each factor was analyzed using cross tabulation, and multivariate logistic regression analyses were performed with 22 of the investigation factors as explanatory variables. The incidence of SSI was 2.55%, and the etiologic agent was CNS in 17 patients. Upon comparison between the S and N groups, the presence of 3 or more underlying diseases and blood loss were extracted as significant risk factors. Upon comparison between the C and N groups, emergency surgery and intra- and postoperative steroid administration were extracted as significant risk factors, in addition to the presence of 3 or more underlying diseases and blood loss. The effect of the current AMP using first generation cephem is limited, and reconsideration of the protocol may be necessary.

Surgical Strategy for a Retro-Odontoid Pseudotumor

Surgical Strategy for a Retro-Odontoid Pseudotumor Retro-odontoid pseudotumors that are not associated with rheumatoid arthritis or hemodialysis are clinically rare. A pseudotumor is a non-neoplastic mass in the retro-odontoid region that can occur in elderly people. Retro-odontoid pseudotumors are regarded as non-neoplastic masses that arise as a result of instability of the atlantoaxial joint. However, Retro-odontoid pseudotumor has occasionally been reported without instability on dynamic radiography.

Treatment of Renal Cell Carcinoma with 2-Stage Total en bloc Spondylectomy after Marked Response to Molecular Target Drugs

Metastatic renal cell carcinoma of the bone occurs at a high rate, and the prognosis is poor. In general, total en bloc spondylectomy is considered when there is only one vertebral metastasis and the primary disease is treated. However, palliative surgery is selected when the primary disease is not being treated or metastasis occurs to an important organ. We encountered a patient in whom lung and vertebra metastases were already present at the time of the first examination at our department and the prognosis was considered poor. However, molecular targeted therapy was markedly effective and enabled 2-stage total en bloc spondylectomy. As of one year after total en bloc spondylectomy, the condition has improved to cane gait, and surgery for lung metastasis is planned. Molecular target drugs might markedly change the current therapeutic strategy for renal cell carcinoma.