Negative pressure wound therapy reduces incidence of postoperative wound infection and dehiscence after long-segment thoracolumbar spinal fusion: a single institutional experience

Background contextWound dehiscence and surgical site infections (SSIs) can have a profound impact on patients as they often require hospital readmission, additional surgical interventions, lengthy intravenous antibiotic administration, and delayed rehabilitation. Negative pressure wound therapy (NPWT) exposes the wound site to negative pressure, resulting in the improvement of blood supply, removal of excess fluid, and stimulation of cellular proliferation of granulation tissue.PurposeTo assess the incidence of wound infection and dehiscence in patients undergoing long-segment thoracolumbar fusion before and after the routine use of NPWT.Study designRetrospective study.Patient sampleOne hundred sixty patients undergoing long-segment thoracolumbar spine fusions were included in this study.Outcome measuresPostoperative incidence of wound infection and dehiscence.MethodsAll adult patients undergoing thoracolumbar fusion for spinal deformity over a 6-year period at Duke University Medical Center by the senior author (CB) were included in this study. In 2012, a categorical change was made by the senior author (CB) that included the postoperative routine use of incisional NPWT devices after primary wound closure in all long-segment spine fusions. Before 2012, NPWT was not used. After primary wound closure, a negative pressure device is contoured to the size of the incision and placed over the incision site for 3 postoperative days. We retrospectively review the first 46 cases in which NPWT was used and compared them with the immediately preceding 114 cases to assess the incidence of wound infection and dehiscence.ResultsOne hundred sixty (NPWT: 46 cases, non-NPWT: 114 cases) long-segment thoracolumbar spine fusions were performed for deformity correction. Baseline characteristics were similar between both cohorts. Compared with the non-NPWT cohort, a 50% decrease in the incidence of wound dehiscence was observed in the NPWT patient cohort (6.38% vs. 12.28%, p=.02). Similarly, compared with the non-NPWT cohort, the incidence of postoperative SSIs was significantly decreased in the NPWT cohort (10.63% vs. 14.91%, p=.04).ConclusionsRoutine use of incisional NPWT was associated with a significant reduction in the incidence of postoperative wound infection and dehiscence.     

No difference in postoperative complications,pain, and functional outcomes up to 2 years after incidental durotomy in lumbar spinal fusion: a prospective,multi-institutional,propensity-matched analysis of 1,741 patients

BackgroundIncidental durotomies occur in up to 17% of spinal operations. Controversy exists regarding the short- and long-term consequences of durotomies.PurposeThe primary aim of this study was to assess the effect of incidental durotomies on the immediate postoperative complications and patient-reported outcome measures.Study designProspective study.Patient sampleA total of 1,741 patients undergoing index lumbar spine fusion were selected from a multi-institutional prospective data registry.Outcome measuresPatient-reported outcome measures used in this study included back pain (BP-Visual Analog Scale), leg pain (LP-Visual Analog Scale), and Oswestry Disability Index.MethodsA total of 1,741 patients were selected from a multi-institutional prospective data registry, who underwent primary lumbar fusion for low back pain and/or radiculopathy between January 2003 and December 2010. We collected and analyzed data on patient demographics, postoperative complications, back pain, leg pain, and functional disability over 2 years, with risk-adjusted propensity score modeling.ResultsIncidental durotomies occurred in 70 patients (4%). Compared with the control group (n=1,671), there was no significant difference in postoperative infection (p=.32), need for reoperation (p=.85), or symptomatic neurologic damage (p=.66). At 1- and 2-year follow-up, there was no difference in patient-reported outcomes of back pain (BP-Visual Analog Scale), leg pain (LP-Visual Analog Scale), or functional disability (Oswestry Disability Index) (p>.3), with results remaining consistent in the propensity-matched cohort analysis (p>.4).ConclusionWithin the context of an on-going debate on the consequences of incidental durotomy, we found no difference in neurologic symptoms, infection, reoperation, back pain, leg pain, or functional disability over a 2-year follow-up period.     

Marginally low copper causes lesions of the midbrain in animal models: the implications for man

Serum copper levels must be maintained between very strict limits for the maintenance of good health. High levels have recently been linked to Alzheimer's disease while low levels during pregnancy cause enzootic ataxia (swayback disease) in offspring. In this study, we investigated the prolonged effect of serum copper that was maintained at and around 0.5 ppm, the level presently regarded as safe. Pregnant sheep and rabbits in the last trimester (1-4 weeks) of pregnancy were treated with the copper chelator ammonium tetrathiomolybdate (ATM). Treatment was continued until the young were one month old at which time the animals were sacrificed Serum copper levels of the parents and offspring were monitored by atomic absorption. The difference spectra (400-630 nm) was examined and SDS PAGE was used to evaluate the protein composition of the brain mitochondria. The anatomy of the midbrain was also studied. Although the young sheep and rabbits from the ATM-treated mothers showed no visible signs of disability or swayback disease, the midbrain of those young animals with serum copper between 0.3-0.9 ppm showed evidence of vacuolation, cavitation and chromatolysis. In contrast, the difference spectra and the protein composition of the brain mitochondria from these animals were all normal. These results suggest that although animals may appear normal and exhibit some normal biochemical markers, serum copper in the region of 0.5 ppm may not be safe for some breeds of sheep or rabbits. It is possible that a similar situation applies to man.     

Cytochrome-c oxidase isolated from the brain of swayback-diseased sheep displays unusual structure and uncharacteristic kinetics

Swayback disease, a neurodegenerative disorder of lambs, and Menkes disease, the human equivalent, are caused by a deficiency of dietary copper. Reports of low enzymic activity suggest that several copper-containing enzymes, including cytochrome-c oxidase (COX), may influence the progress of these diseases. To investigate its role in the development of neurodegenerative disorders, in particular swayback disease, we isolated COX from the brains and livers of swaybackdiseased lambs. Comparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) combined with densitometric analysis revealed that whereas the structure of COX from the liver of diseased amimals was normal, the corresponding brain enzyme was subunits II-, III-, and IV-deficient; the deficiency was 55, 30, and 65%, respectively. The activities of liver and brain COX from normal and diseased lambs were compared by polarographic assay at low ionic strength. Whereas the enzyme from normal brains and both forms of the liver enzyme yielded characteristic biphasic Eadie-Hofstee plots, the brain enzyme from diseased animals displayed a single phase with aK _m of 4.7±2.4×10^?6 M: theK _m values of COX from the normal brain were 12±2.5×10^?6 and 5.5±0.5×10^?7 M. We conclude that the altered enzyme structure accounts for the uncharacteristic kinetics and low activity we have observed for the isolated brain enzyme. We also conclude that the altered enzyme structure partly accounts for the low oxidase activity and decreased ATP synthesis that has been widely reported for brain tissue from swayback-diseased animals. We postulate that the subunit deficiency probably results from incomplete crosslinking between the subunits and the membrane, and predict that similar structural and kinetic factors may also account for low COX activity in Menkes disease.     

Wound‐healing potential of an ethanol extract of Carica papaya (Caricaceae) seeds

Carica papaya L. (Linn) (Caricaceae) is traditionally used to treat various skin disorders, including wounds. It is widely used in developing countries as an effective and readily available treatment for various wounds, particularly burns. This study evaluated the wound‐healing and antimicrobial activity of C. papaya seed extract. Ethanol extract of C. papaya seed (50 mg/kg/day) was evaluated for its wound‐healing activity in Sprague‐Dawley rats using excision wound model. Animals were randomly divided into four groups of six each (group 1 served as control, group 2 treated with papaya seed extract, group 3 treated with a standard drug mupirocin and papaya seed extract (1:1 ratio) and group 4 treated with a mupirocin ointment. Rate of wound contraction and hydroxyproline content were determined to assess the wound‐healing activity of the seed extract. The group 2 animals showed a significant decrease in wound area of 89% over 13 days when compared with groups 1 (82%), 3 (86%) and 4 (84%) respectively. The hydroxyproline content was significantly higher with the granulation tissue obtained from group 2 animals which were treated with C. papaya seed extract. Histological analysis of granulation tissue of the group 2 animals showed the deposition of well‐organized collagen. The extract exhibited antimicrobial activity against Salmonella choleraesuis and Staphylococcus aureus. Our results suggest that C. papaya promotes significant wound healing in rats and further evaluation for this activity in humans is suggested.