Comparative analysis of linezolid, vancomycin, and hyperbaric oxygen therapies in a rat model of ventriculoperitoneal shunt infection

PURPOSE

Staphylococcus epidermidis is the most common causative microorganism of ventriculoperitoneal shunt infections. This study aimed to compare linezolid and vancomycin treatments and to examine the effect of these antibiotics alone and combined with hyperbaric oxygen therapy on the amount of bacterial colonies in the experimental S. epidermidis shunt infection model.

METHODS

A shunt catheter was placed in the cisterna magna of 49 adult male Wistar albino rats. The rats were randomly divided into seven groups, as follows: sterile control, infected control, vancomycin, linezolid, hyperbaric oxygen, vancomycin + hyperbaric oxygen, linezolid + hyperbaric oxygen. In all groups except the sterile control group, 0.2 ml 107 CFU/mL S. epidermidis was inoculated to the cisterna magna. Parenteral vancomycin was administered 40 mg/kg/day to the vancomycin groups, and 50 mg/kg/day of enteral linezolid to the linezolid groups. Hyperbaric oxygen groups were given 100% oxygen at a pressure of 2.4 ATA for 50 min a day. One day after the last treatment, colony quantities in the shunt catheters and CSF were analyzed.

RESULTS

The number of CSF colonies in the linezolid group was significantly lower than in the vancomycin group (p < 0.05). The number of CSF colonies in the linezolid + HBO group was significantly lower than in the vancomycin + HBO group (p < 0.05).

CONCLUSIONS

Linezolid treatment was found to be more effective than vancomycin in ventriculoperitoneal shunt infection caused by S. epidermidis. There was no statistical difference among other treatment groups. Hyperbaric oxygen therapy is shown to contribute to the sterilization of cultures.

Reconstruction of open wounds as a complication of spinal surgery with flaps: a systematic review

OBJECT

A systematic review of the available evidence on the prophylactic and therapeutic use of flaps for the coverage of complex spinal soft-tissue defects was performed to determine if the use of flaps reduces postoperative complications and improves patient outcomes.

METHODS

A PubMed database search was performed to identify English-language articles published between 1990 and 2014 that contained the following phrases to describe postoperative wounds (“wound,” “complex back wound,” “postoperative wound,” “spine surgery”) and intervention (“flap closure,” “flap coverage,” “soft tissue reconstruction,” “muscle flap”).

RESULTS

In total, 532 articles were reviewed with 17 articles meeting the inclusion criteria of this study. The risk factors from the pooled analysis of 262 patients for the development of postoperative complex back wounds that necessitated muscle flap coverage included the involvement of instrumentation (77.6%), a previous history of radiotherapy (33.2%), smoking (20.6%), and diabetes mellitus (17.2%). In patients with instrumentation, prophylactic coverage of the wound with a well-vascularized flap was shown to result in a lower incidence of wound complications. One study showed a statistically significant decrease in complications compared with patients where prophylactic coverage was not performed (20% vs 45%). The indications for flap coverage after onset of wound complications included hardware exposure, wound infection, dehiscence, seroma, and hematoma. Flap coverage was shown to decrease the number of surgical debridements needed and also salvage hardware, with the rate of hardware removal after flap coverage ranging from 0% to 41.9% in 4 studies.

CONCLUSIONS

Prophylactic coverage with flaps in high-risk patients undergoing spine surgery reduces complications, while therapeutic coverage following wound complications allows the salvage of hardware in the majority of patients.

Role of hyperbaric oxygen therapy in the treatment of bacterial spinal osteomyelitis

OBJECT

Hyperbaric oxygen therapy (HBO) is used as primary and/or adjunctive therapy in the treatment of various clinical conditions complicated by local hypoxia. It may have therapeutic potential in the treatment of neurosurgical infections such as spinal osteomyelitis that are associated with significant morbidity rates. The purpose of this study was to evaluate the efficacy of HBO therapy in the treatment of spinal osteomyelitis.

METHODS

The clinical records of patients diagnosed with spinal osteomyelitis who received HBO therapy during their treatment at the authors' institution over the past 10 years were retrospectively reviewed. Six adult patients were identified. Four patients had recently undergone spinal surgery and secondary spinal osteomyelitis had developed. These patients received adjunctive HBO therapy due to significant comorbidities and risk factors for poor healing.

RESULTS

All patients remained symptom and infection free over the subsequent follow-up period. Two patients had primary spinal osteomyelitis that had recurred despite a full course of appropriate antimicrobial therapy. Infection control was achieved after HBO therapy in 1 patient. The mean follow-up period for the study group was 2.9 years (range 5 months to 5 years).

CONCLUSIONS

Hyperbaric oxygen therapy enabled infection cure in 5 of 6 patients with spinal osteomyelitis complicated by medical comorbidities or the failure of primary therapy. These results show that HBO may be a useful adjunctive therapeutic modality in the treatment of spinal osteomyelitis, particularly when there are medical comorbidities that increase the risk of poor healing. Hyperbaric oxygen therapy may also be beneficial in patients with relapsing primary spinal osteomyelitis after standard therapy has failed.