Efficacy of closed wound suction drainage after single-level lumbar laminectomy. ACTA ACUST UNITED AC. 1996;9:401-403. [PMID: 8938608 DOI: 10.1097/00002517-199610000-00006]

Dressings and drains in posterior spine surgery and their effect on wound complications

The purpose of this study was to systematically search, critically appraise and summarize published randomized control trials (RCT) and non-RCT examining the effect of drains and dressings on wound healing rates and complications in posterior spine surgery. The use of post-operative drains and the type of post-operative dressing is at the discretion of the treating surgeon with no available clinical guidelines. Drains will theoretically decrease incidence of post-operative hematoma and therefore, potentially decrease the risk of neurologic compromise when the neural elements have been exposed. Occlusive dressings have more recently been advocated, potentially maintaining a sterile barrier for longer time periods post-operatively. A systematic review of databases from 1969-2013 was undertaken. All papers examining drains in spine surgery and dressings in primary healing of surgical wounds were included. Revman (version 5.2; The Nordic Cochrane Centre, The Cochrane Collaboration, Oxford, UK) was used to test for overall treatment effect, clinical heterogeneity and risk of bias. Of the papers identified, 1348 examined post-operative drains in spine surgery and 979 wound dressings for primary wound healing of all surgical wounds. Seven studies were included for analysis for post-operative drains and 10 studies were analyzed for primary wound healing. The use of a post-operative drain did not influence healing rates and had no effect secondarily on infection (odds ratio [OR] 1.33; 95% confidence interval [CI] 0.76-2.30). We were not able to establish whether surgical drains prevent hematomas causing neurologic compromise. There was a slight advantage to using occlusive dressings versus non-occlusive dressings in wound healing (OR 2.09; 95% CI 1.44-3.02). Incisional vacuum dressings as both an occlusive barrier and superficial drainage system have shown promise for wounds at risk of dehiscence. There is a relatively high risk of bias in the methodology of many of the studies reviewed. We recommend favoring of occlusive dressings based on heterogeneous and potentially biased evidence. Drain use does not affect wound healing based on similar evidence. Incisional vacuum dressings have shown promise in managing potentially vulnerable wounds.

Factors predictive of increased surgical drain output after anterior cervical discectomy and fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To identify factors that are independently associated with increased surgical drain output in patients who have undergone ACDF.

SUMMARY OF BACKGROUND DATA

Surgical drains are typically placed after ACDF to reduce the risk of complications associated with neck hematoma. The orthopedic literature has repeatedly challenged the use of surgical drains after many procedures, and there are currently no guidelines for determining which patients are most likely to benefit from drain placement after ACDF.

METHODS

Consecutive patients who underwent elective ACDF with surgical drain placement at a single academic institution between January 2011 and February 2013 were identified using billing records. Patient information was abstracted from the medical record. Patients were categorized on the basis of normal or increased total drain output, with increased drain output defined as total drain output 50th percentile (30 mL) or more. A multivariate logistic regression was used to determine which factors were independently associated with increased drain output.

RESULTS

A total of 151 patients with ACDF met inclusion criteria. Total drain output was in the range from 0 mL to 265 mL. The average drain output for this cohort was 42.3 ± 45.5 mL (mean ± standard deviation). Among all patients in the study, 80 patients had increased drain output (drain output ≥50th percentile or 30 mL).Multivariate analysis identified 3 independent predictors of increased drain output: age 50 years or more (odds ratio [OR] = 3.9), number of levels (2 levels, OR = 2.7; 3-4 levels, OR = 17.0), and history of smoking (OR = 2.8). One patient developed a postoperative neck hematoma while a drain was in place.

CONCLUSION

Patients with the factors associated with increased drain output identified in the earlier text may benefit most from surgical drain placement after ACDF. Nonetheless, neck hematoma is still possible even with drain use.

LEVEL OF EVIDENCE

3.

An evidence-based clinical guideline for antibiotic prophylaxis in spine surgery

BACKGROUND CONTEXT

The North American Spine Society's (NASS) Evidence-Based Clinical Guideline on Antibiotic Prophylaxis in Spine Surgery provides evidence-based recommendations to address key clinical questions regarding the efficacy and the appropriate antibiotic prophylaxis protocol to prevent surgical site infections in patients undergoing spine surgery. The guideline is intended to address these questions based on the highest quality clinical literature available on this subject as of June 2011.

PURPOSE

Provide an evidence-based educational tool to assist spine surgeons in preventing surgical site infections.

STUDY DESIGN

Systematic review and evidence-based clinical guideline.

METHODS

This guideline is a product of the Antibiotic Prophylaxis in Spine Surgery Work Group of NASS Evidence-Based Guideline Development Committee. The work group consisted of neurosurgeons and orthopedic surgeons who specialize in spine surgery and are trained in the principles of evidence-based analysis. A literature search addressing each question and using a specific search protocol was performed on English language references found in MEDLINE (PubMed), ACP Journal Club, Cochrane Database of Systematic Reviews Database of Abstracts of Reviews of Effectiveness, Cochrane Central Register of Controlled Trials, EMBASE (Drugs and Pharmacology), and Web of Science to identify articles published since the search performed for the original guideline. The relevant literature was then independently rated using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final recommendations to answer each clinical question were developed via work group discussion, and grades were assigned to the recommendations using standardized grades of recommendation. In the absence of Levels I to IV evidence, work group consensus statements have been developed using a modified nominal group technique, and these statements are clearly identified as such in the guideline.

RESULTS

Sixteen clinical questions were formulated and addressed, and the answers are summarized in this article. The respective recommendations were graded by the strength of the supporting literature, which was stratified by levels of evidence.

CONCLUSIONS

The clinical guideline for antibiotic prophylaxis in spine surgery has been created using the techniques of evidence-based medicine and best available evidence to aid practitioners in the care of patients undergoing spine surgery. The entire guideline document, including the evidentiary tables, suggestions for future research, and all the references, is available electronically on the NASS Web site at http://www.spine.org/Pages/PracticePolicy/ClinicalCare/ClinicalGuidlines/Default.aspx and will remain updated on a timely schedule.

Negative pressure wound therapy (NPWT) for spinal wounds: a systematic review

BACKGROUND CONTEXT

The management of postoperative spinal wound complication remains a challenge, with surgical site infection (SSI) incidence rates ranging from 0.4% to 20% after spinal surgery. Negative pressure wound therapy (NPWT) has been highlighted as an intervention that may stimulate healing and prevent SSI. However, the wound healing mechanism by NPWT and its effectiveness in spinal wounds still remain unclear.

PURPOSE

To systematically search, critically appraise, and summarize randomized controlled trials (RCTs) and non-RCTs assessing the effectiveness of NPWT in patients with a spinal wound.

STUDY DESIGN

Systematic review.

METHODS

A systematic review based on search strategies recommended by the Cochrane Back and Wounds Review Groups was undertaken using Cochrane Library, MEDLINE, EMBASE, and CINAHL databases. Any publications between 1950 and 2011 were included. Funding to undertake the review was received from the University of Huddersfield Collaborative Venture Fund ($4,820) and KCI Medical ($4,820).

RESULTS

Ten retrospective studies and four case studies of patients with spinal wound complication were included in this systematic review. No RCTs were found. Only one study described more than 50 patients. Generally, a pressure of -125 mm Hg was used in adults. Duration of NPWT in situ ranged from 3 to 186 days. Wound healing was assessed every 2 to 3 days and generally completed between 7 days and 16 months. Negative pressure wound therapy is contraindicated in the presence of active cerebrospinal fluid leak, metastatic or neoplastic disease in the wound or in patients with an allergy to the NPWT dressing and in those with a bleeding diathesis.

CONCLUSIONS

Published reports are limited to small retrospective and case studies, with no reports of NPWT being used as a prophylactic treatment. Larger prospective RCTs of NPWT are needed to support the current evidence that it is effective in treating spinal wound complications. In addition, future studies should investigate its use as a prophylactic treatment to prevent infection and report data relating to safety and health economics.

A multi-disciplinary review of the potential association between closed-suction drains and surgical site infection

BACKGROUND

Despite the putative advantages conferred by closed-suction drains (CSDs), the widespread utilization of post-operative drains has been questioned due to concerns regarding both efficacy and safety, particularly with respect to the risk of surgical site infection (SSI). Although discipline-specific reports exist delineating risk factors associated with SSI as they relate to the presence of CSDs, there are no broad summary studies to examine this issue in depth.

METHODS

The pertinent medical literature exploring the relationship between CSDs and SSI across multiple surgical disciplines was reviewed.

RESULTS

Across most surgical disciplines, studies to evaluate the risk of SSI associated with routine post-operative CSD have yielded conflicting results. A few studies do suggest an increased risk of SSI associated with drain placement, but are usually associated with open drainage and not the use of CSDs. No studies whatsoever attribute a decrease in the incidence of SSI (including organ/space SSI) to drain placement.

CONCLUSIONS

Until additional, rigorous randomized trials are available to address the issue definitively, we recommend judicious use and prompt, timely removal of CSDs. Given that the evidence is scant and weak to suggest that CSD use is associated with increased risk of SSI, there is no justification for the prolongation of antibiotic prophylaxis to "cover" an indwelling drain.

Postoperative spinal epidural hematoma (SEH): incidence, risk factors, onset, and management

BACKGROUND CONTEXT

Spinal epidural hematoma (SEH) is a rare, yet potentially devastating complication of spinal surgery. There is limited evidence available regarding the risk factors and timing for development of symptomatic SEH after spinal surgery.

PURPOSE

To assess the incidence, risk factors, time of the onset, and effect of early evacuation of symptomatic SEH after spinal surgery.

STUDY DESIGN

Multicenter case control study.

PATIENT SAMPLE

All patients who underwent open spinal surgery between October 1, 1999, and September 30, 2006, at the National Hospital For Neurology and Neurosurgery (NHNN) and the Wellington Hospital (WH) were reviewed.

OUTCOME MEASURES

Frankel grade.

METHODS

Patients who developed SEH and underwent evacuation of the hematoma were identified. Two controls per case were selected. Each control had undergone a procedure with similar complexity, at the same section of the spine, at the same hospital, and under the same surgeon within 6 months of the initial operation.

RESULTS

A total of 4,568 open spinal operations were performed at NHNN and WH. After spinal surgery, 0.22% of patients developed symptomatic SEH. Alcohol greater than 10 units a week (p=.031), previous spinal surgery (p=.007), and multilevel procedures (p=.002) were shown to be risk factors. Initial symptoms of SEH presented after a median time of 2.7 hours (interquartile range [IQR], 1.1-126.1). Patients who had evacuation surgery within 6 hours of the onset of initial symptoms improved a median of 2 (IQR, 1.0-3.0) Frankel grades, and those who had surgery more than 6 hours after the onset of symptoms improved 1.0 (IQR, 0.0-1.5) Frankel grade, p=.379.

CONCLUSIONS

Symptomatic postoperative SEH is rare, occurring in 0.22% of cases. Alcohol consumption greater than 10 units a week, multilevel procedure, and previous spinal surgery were identified as risk factors for developing SEH. Spinal epidural hematoma often presents early in the postoperative period, highlighting the importance of close patient monitoring within the first 4 hours after surgery. This study suggests that earlier surgical intervention may result in greater neurological recovery.

Management of postoperative spinal infections

Postoperative surgical site infection (SSI) is a common complication after posterior lumbar spine surgery. This review details an approach to the prevention, diagnosis and treatment of SSIs. Factors contributing to the development of a SSI can be split into three categories: (1) microbiological factors; (2) factors related to the patient and their spinal pathology; and (3) factors relating to the surgical procedure. SSI is most commonly caused by Staphylococcus aureus. The virulence of the organism causing the SSI can affect its presentation. SSI can be prevented by careful adherence to aseptic technique, prophylactic antibiotics, avoiding myonecrosis by frequently releasing retractors and preoperatively optimizing modifiable patient factors. Increasing pain is commonly the only symptom of a SSI and can lead to a delay in diagnosis. C-reactive protein and magnetic resonance imaging can help establish the diagnosis. Treatment requires acquiring intra-operative cultures to guide future antibiotic therapy and surgical debridement of all necrotic tissue. A SSI can usually be adequately treated without removing spinal instrumentation. A multidisciplinary approach to SSIs is important. It is useful to involve an infectious disease specialist and use minimum serial bactericidal titers to enhance the effectiveness of antibiotic therapy. A plastic surgeon should also be involved in those cases of severe infection that require repeat debridement and delayed closure.

Is closed-suction drainage necessary after intradural primary spinal cord tumor surgery?

PURPOSE

The efficacy of closed-suction drainage in primary intradural spinal cord tumor surgery has not been addressed. We investigated whether closed-suction drainage is essential after primary intradural spinal cord tumor surgery.

METHODS

From January 2003 to October 2011, 169 consecutive patients with primary intradural spinal cord tumors operated by a single surgeon were selected. Closed-suction drainage was inserted in patients before August 2007, but was not used after August 2007. After removal of tumor and meticulous hemostasis, the opened dura was closed and made watertight using 4-0 silk with interrupt suture and 1.0 cm(3) of surgical glue was applied in common. Closed-suction drainage was inserted below the muscular fascia in 75 patients (group I, M:F = 39:36; 46.20 ± 15.63 years) and was not inserted in 94 patients (group II, M:F = 46:48; 51.05 ± 14.89 years).

RESULTS

Neurological deficit precluding ambulation did not occur in all patients. Between group I and II, there were no significant differences in body mass index (22.75 ± 3.16 vs. 23.51 ± 3.22 kg/m(2); p = 0.13), laminectomy level (2.45 ± 1.46 vs. 2.33 ± 1.91; p = 0.65), operation time (260.65 ± 109.08 vs. 231.52 ± 90.08 min; p = 0.06), estimated intraoperative blood loss (456.93 ± 406.62 vs. 383.94 ± 257.25 cm(3); p = 0.18), and hospital stay period (9.25 ± 5.01 vs. 9.35 ± 5.75 days; p = 0.91). Two patients in group I underwent revision surgery due to wound problems, while revision surgery was not performed in group II (p = 0.20).

CONCLUSION

Closed-suction drainage may not be essential after primary intradural spinal cord tumor surgery.

Use and outcomes of wound drain in spinal fusion for adolescent idiopathic scoliosis

STUDY DESIGN

A multicenter retrospective analysis.

OBJECTIVE

To evaluate outcomes of closed-suction wound drainage after posterior spinal fusion with instrumentation for adolescent idiopathic scoliosis and to identify surgeon patterns of drain use in this cohort.

SUMMARY OF BACKGROUND DATA

There is little evidence on the use of drains in spinal surgery, particularly for repair of adolescent idiopathic scoliosis. Studies on hip and knee arthroplasty suggest no advantage to draining. There are few published reports on surgeon technique and rationale for drain use in spinal surgery.

METHODS

Patients were divided into drain and no drain cohorts and followed for 2 years. Primary outcome was complication rate. A separate survey was conducted from surgeons in the Spinal Deformity Study Group to evaluate drain practice patterns.

RESULTS

There were 324 drained and 176 undrained patients. Complication rate did not differ between the drain and no drain cohorts in any of the 4 categories (wound infection, neural injury, other infection, and other complication) at any time (all P > 0.1). More drained patients received postoperative transfusions compared with those without a drain (43% vs. 22%, P < 0.001). Of the 50 surgeons in the group, 36 used drains. Half of these did so out of habit. Surgeons tended to place deep drains with bulb suction, without drain manipulation. Half removed drains on the basis of output, whereas half removed them after 1 to 3 days.

CONCLUSION

More patients tended to receive wound drains than not receive wound drains. Drains did not impact complication rate and drained patients received more blood product. There are no universal criteria for draining and practice patterns vary widely.

Postoperative infections of the lumbar spine: presentation and management

PURPOSE

Postoperative surgical site infections (SSI) are a frequent complication following posterior lumbar spinal surgery. In this manuscript we review strategies for prevention, diagnosis and treatment of SSI.

METHODS

The literature was reviewed using the Pubmed database.

RESULTS

We identified fifty-nine relevant manuscripts almost exclusively composed of Level III and IV studies.

CONCLUSIONS

Risk factors for SSI include: 1) factors related to the nature of the spinal pathology and the surgical procedure and 2) factors related to the systemic health of the patient. Staphylococcus aureus is the most common infectious organism in reported series. Proven methods to prevent SSI include prophylactic antibiotics, meticulous adherence to aseptic technique and frequent release of retractors to prevent myonecrosis. The presentation of SSI is varied depending on the virulence of the infectious organism. Frequently, increasing pain is the only presenting complaint and can lead to a delay in diagnosis. Magnetic resonance imaging and the use of C-reactive protein laboratory studies are useful to establish the diagnosis. Treatment of SSI is centered on surgical debridement of all necrotic tissue and obtaining intra-operative cultures to guide antibiotic therapy. We recommend the involvement of an infectious disease specialist and use of minimum serial bactericidal titers to monitor the efficacy of antibiotic treatment. In the most cases, SSI can be adequately treated while leaving spinal instrumentation in place. For severe SSI, repeat debridement, delayed closure and involvement of a plastic surgeon may be necessary.

Risk factors for surgical site infections following spinal fusion procedures: a case-control study

BACKGROUND

Spinal fusion procedures are associated with a significant rate of surgical site infection (SSI) (1%-12%). The goal of this study was to identify modifiable risk factors for spinal fusion SSIs at a large tertiary care center.

METHODS

A retrospective, case-control (1:3 ratio) analysis of SSIs following posterior spine fusion procedures was performed over a 1-year period. Clinical and surgical data were collected through electronic database and chart review. Variables were evaluated by univariate analysis and multivariable logistic regression.

RESULTS

In total, 57 deep SSIs were identified out of 1587 procedures (3.6%). Infections were diagnosed a mean of 13.5 ± 8 days postprocedure. Staphylococcus aureus was the predominant pathogen (63%); 1/3 of these isolates were methicillin resistant. Significant patient risk factors for infection by univariate analysis included ASA score >2 and male gender. Among surgical variables, infected cases had significantly higher proportions of staged procedures and thoracic level surgeries and had a greater number of vertebrae fused. Notably, infected fusion procedures had a longer duration of closed suction drains than controls (5.1 ± 2 days vs 3.4 ± 1 day, respectively; P < .001). Drain duration (unit odds ratio [OR], 1.6 per day drain present; 95% confidence interval [CI], 1.3-1.9), body mass index (OR, 1.1; 95% CI, 1.0-1.1), and male gender (OR, 2.7; 95% CI, 1.4-5.6) were significant risk factors in the multivariate analysis.

CONCLUSIONS

Prolonged duration of closed suction drains is a strong independent risk factor for SSI following instrumented spinal fusion procedures. Therefore, removing drains as early as possible may lower infection rates.

Prophylactic intraoperative powdered vancomycin and postoperative deep spinal wound infection: 1,512 consecutive surgical cases over a 6-year period

PURPOSE

The purpose of this study is to evaluate the effect of intraoperative powdered vancomycin on the rates of postoperative deep spinal wound infection. The use of intraoperative powdered vancomycin as a prophylactic measure in an attempt to reduce the incidence of postoperative spinal wound infection has not been sufficiently evaluated in the existing literature. A retrospective review of a large clinical database was performed to determine the rates of deep wound infection associated with the use of intraoperative operative site powdered vancomycin.

MATERIALS AND METHODS

During the period from 2005 to 2010, 1,512 consecutive spinal surgery cases were performed by the same fellowship-trained spinal surgeon (RWM) at a level 1 trauma-university medical center. One gram of powdered vancomycin was placed in all surgical sites prior to wound closure. Eight hundred forty-nine cases were uninstrumented, 478 cases were instrumented posterior thoracic or lumbar, 12 were instrumented anterior thoracic or lumbar, 126 were instrumented anterior cervical, and 47 were instrumented posterior cervical cases. Fifty-eight cases were combined anterior and posterior surgery and 87 were revision surgeries. A retrospective operative database and medical record review was performed to evaluate for evidence of postoperative deep wound infection.

RESULTS

15 of the 1,512 patients (0.99%) were identified as having evidence of postoperative deep wound infection. At least one pre-existing risk factor for deep infection was present in 8/15 pts (54%). Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) were the most commonly identified organisms (11/15 cases). The rate of deep wound infection was 1.20% (8/663) for instrumented spinal surgeries, and 0.82% (7/849) for uninstrumented surgeries. Deep infection occurred in only 1.23% (4/324) of multilevel instrumented posterior spinal fusions, 1.37% (1/73) of open PLIF procedures, and 1.23% (1/81) of single-level instrumented posterior fusions. Deep infection was not observed in any patient who had uninstrumented spinal fusion (0/64). The deep infection rate for revision surgeries was 1.15% (1/87) and 0.55% (1/183) for trauma surgery. Increased rates of complications related to powdered vancomycin use were not identified in this series. Conclusion In this series of 1,512 consecutive spinal surgeries, the use of 1 g of powdered intraoperative vancomycin placed in the wound prior to wound closure appears to associated with a low rate deep spinal wound infection for both instrumented and uninstrumented cases. Rates of deep infection for instrumented fusion surgery, trauma, and revision surgery appear to be among the lowest reported in the existing literature. Further investigation of this prophylactic adjunctive measure is warranted.

Incidence of postoperative symptomatic epidural hematoma in spinal decompression surgery

Object

Neurological deterioration due to spinal epidural hematoma (SEH) is a rare but significant complication of spinal surgery. The frequency of hematoma evacuation after spinal surgery is reportedly 0.1%–3%. The objective of this study was to investigate the symptomatology of SEH and the frequency of evacuation for each surgical procedure after spinal decompression surgery.

Methods

This is a retrospective study of 26 patients who underwent SEH evacuation after spinal decompression surgery between 1986 and 2005. During this period, 6356 spinal decompression surgeries were performed. The factors studied were the frequency of SEH evacuation for each surgical procedure, symptoms, time to SEH evacuation, comorbidities, and neurological recovery.

Results

The frequency of SEH evacuation was 0.41% (26 of 6356) for all operations. The frequency for each surgical procedure was 0% (0 of 1568) in standard lumbar discectomy, 0.50% (8 of 1614) in lumbar laminectomy, 0.67% (8 of 1191) in posterior lumbar interbody fusion, 4.46% (5 of 112) in thoracic laminectomy, 0.44% (4 of 910) in cervical laminoplasty, and 0.21% (1 of 466) in cervical anterior spinal fusion. Nine patients had comorbidities involving hemorrhage. Spinal epidural hematoma evacuation was performed between 4 hours and 8 days after the initial operation. Whereas severe paralysis was observed within 24 hours in most patients undergoing cervical and/or thoracic surgery, half of the patients undergoing lumbar surgery had symptoms of SEH such as leg pain or bladder dysfunction after suction drain removal. The shorter the period to evacuation, the better were the results of neurological recovery.

Conclusions

Postoperative SEH was most frequent after thoracic laminectomy. In cervical and thoracic surgeries, symptoms of SEH were noted within 24 hours, mostly severe paralysis, and almost half of the lumbar surgery patients had symptoms after suction drain removal.

Spinal epidural hematoma

Spinal epidural hematoma is a rare condition that usually presents with acute, severe pain at the location of the hemorrhage, with radiation to the extremities. It can rapidly develop to include progressive and severe neurologic deficit. The pathophysiology often remains unclear. However, epidural hematoma in the lumbar spine is best described as the result of internal rupture of the Batson vertebral venous plexus. Clinical evaluation of pain control and neurologic deficit is the most important tool in early diagnosis. Currently, MRI is the diagnostic method of choice. Regardless of the setting, symptomatic spinal epidural hematoma is typically managed with urgent surgical decompression of the spinal canal.

The influence of perioperative risk factors and therapeutic interventions on infection rates after spine surgery: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

The objectives of this systematic review were to determine the patient and perioperative risk factors that contribute to infections after spine surgery and to examine the level of evidence to support the use of therapeutic interventions to reduce infection rates.

SUMMARY OF BACKGROUND DATA

Infection continues to be one of the most common and feared complications after spine surgery. As such, it is used as a sentinel event for quality assurance processes. It is clear that the causes of infections after spine surgery are multifactorial and numerous patient- and procedure-related factors have been proposed as contributory elements. In addition, numerous perioperative adjuncts have been suggested to reduce infection rates.

METHODS

A systematic review of the English-language literature (published between January 1990 and June 2009) was undertaken to identify articles examining risk factors associated with and adjunct treatment measures for preventing surgical-site infections. Two independent reviewers assessed the level of evidence quality using the Grading of Recommendations Assessment, Development, and Evaluation criteria, and disagreements were resolved by consensus.

RESULTS

Of the 127 articles identified, 32 met the criteria to undergo full-text review. Individual patient, operative, and perioperative variables have been identified that are associated with increased infection rates (i.e., older age, obesity, diabetes, malnutrition, higher American Society of Anesthesiologists score, posterior approaches, and blood transfusions) but these variables have not been combined to provide individual patient risks based on a composite of factors (e.g., risk stratification). Of the surgical adjuncts investigated, only irrigation with dilute betadine solution showed moderate support for reducing infection rates.

CONCLUSION

It is clear that the causes of postoperative spinal site infections are multifactorial and related to a complex interplay of patient and procedural influences. Because of these complexities, for any individual and surgical procedure, predictable infection rates likely exist that do not extrapolate to 0. Although we have identified factors associated with increased infection rates, further studies will be required to allow multifactorial risk stratification for individual patients and to further investigate the use of therapeutic adjuncts.

Major neurologic deficit immediately after adult spinal surgery: incidence and etiology over 10 years at a single training institution

STUDY DESIGN

Retrospective study of adult patients who underwent spinal surgery over a 10-year period at a single institution.

OBJECTIVE

New onset postoperative paralysis remains one of the most feared complications of spinal surgery. The goal of this study was to determine the incidence and etiology of new onset major neurologic deficit immediately after adult spinal surgery.

SUMMARY OF BACKGROUND DATA

Previous studies, focusing on specific disease entities, have shown incidence rates of significant spinal cord or cauda equina injury after spinal surgery ranging from approximately 0% to 2%.

METHODS

The authors reviewed the quality assurance records for adult patients who underwent spinal surgery over a 10-year period (July 1, 1996 to June 30, 2006) by surgeons in the Department of Neurosurgery, University of Cincinnati College of Medicine at hospitals affiliated with the neurologic surgery residency program. Patients with new onset major neurologic deficit immediately after spinal surgery were identified.

RESULTS

Of 11,817 adult spinal operations, 21 patients experienced new onset major neurologic deficit immediately after spinal surgery, yielding an overall incidence of 0.178%; in the cervical spine 0.293%, thoracic spine 0.488%, and lumbar/sacral spine 0.0745%. The difference in incidence between spinal regions was statistically significant (P = 0.00343). The etiology of the neurologic deficits was confirmed with reoperation and/or postoperative imaging studies: epidural hematoma in 8 patients, inadequate decompression in 5 patients, presumed vascular compromise in 4 patients, graft/cage dislodgement in 2 patients, and presumed surgical trauma in 2 patients. Placement of spinal instrumentation was performed in 12 of 21 patients (57.1%) and was associated with a significantly higher risk of new onset major neurologic deficit immediately after spinal surgery (P = 0.022).

CONCLUSIONS

The incidence of new onset major neurologic deficit immediately after adult spinal surgery is low. Epidural hematoma and inadequate decompression were the most common etiologies in this series of patients.

Antibiotic prophylaxis in spine surgery: an evidence-based clinical guideline for the use of prophylactic antibiotics in spine surgery

BACKGROUND CONTEXT

The objective of the North American Spine Society's (NASS) Evidence-Based Clinical Guideline on Antibiotic Prophylaxis in Spine Surgery is to provide evidence-based recommendations on key clinical questions concerning the use of prophylactic antibiotics in spine surgery. The guideline is intended to address these questions based on the highest quality clinical literature available on this subject as of December 2006. The goal of the guideline recommendations is to assist in delivering optimum, efficacious treatment to prevent surgical site infection.

PURPOSE

To provide an evidence-based, educational tool to assist spine surgeons in preventing surgical site infections.

STUDY DESIGN

Evidence-based Clinical Guideline.

METHODS

This report is from the Antibiotic Prophylaxis Work Group of the NASS's Evidence-Based Clinical Guideline Development Committee. The work group comprised multidisciplinary surgical spine care specialists, who were trained in the principles of evidence-based analysis. Each member of the group formatted a series of clinical questions to be addressed by the group. The final questions agreed upon by the group are the subjects of this report. A literature search addressing each question and using a specific search protocol was performed on English language references found in MEDLINE, EMBASE (Drugs and Pharmacology), and four additional, evidence-based, databases. The relevant literature was then independently rated by at least three reviewers using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final grades of recommendation for the answer to each clinical question were arrived at via Webcast meetings among members of the work group using standardized grades of recommendation. When Level I to Level IV evidence was insufficient to support a recommendation to answer a specific clinical question, expert consensus was arrived at by the work group through the modified nominal group technique and is clearly identified in the guideline.

RESULTS

Eleven clinical questions addressed the efficacy and appropriateness of antibiotic prophylaxis protocols, repeat dosing, discontinuation, wound drains, and special considerations related to the potential impact of comorbidities on antibiotic prophylaxis. The responses to these 11 clinical questions are summarized in this document. The respective recommendations were graded by the strength of the supported literature which was stratified by levels of evidence.

CONCLUSIONS

A clinical guideline addressing the use of antibiotic prophylaxis in spine surgery has been created using the techniques of evidence-based medicine and the best available evidence. This educational tool will assist spine surgeons in preventing surgical site infections. The entire guideline document, including the evidentiary tables, suggestions for future research, and references, is available electronically at the NASS Web site (www.spine.org) and will remain updated on a timely schedule.

Prospective study of postoperative lumbar epidural hematoma: incidence and risk factors

STUDY DESIGN

Prospective clinical series.

OBJECTIVE

To determine the incidence, volume, and extent of postoperative epidural hematoma resulting in thecal sac compression, and to identify risk factors correlated with measured hematoma volumes.

SUMMARY OF BACKGROUND DATA

Risk factors for postoperative hematoma development have been retrospectively determined in small populations of symptomatic patients. A prospective study of hematoma characteristics and associated risk factors in a consecutive series of patients could significantly enhance our understanding of postoperative hematoma.

METHODS

Preoperative magnetic resonance imaging and clinical data on 13 pre- and intraoperative risk factors were prospectively collected on 50 consecutive patients undergoing lumbar decompression surgery with or without fusion. Postoperative magnetic resonance imagings were performed within 2 to 5 days of surgery. Thecal sac cross-sectional area was calculated at each disc space. Relative thecal sac compression due to hematoma was calculated at all levels where postoperative cross-sectional area was smaller than preoperative. Hematoma volumes were calculated. Multivariate analysis identified risk factors associated with postoperative hematoma volume.

RESULTS

After decompression, 58% of patients developed epidural hematoma of sufficient magnitude to compress the thecal sac beyond its preoperative state at one or more levels. None developed new postoperative neurologic deficits. A mean of 1.4 levels were decompressed. Hematoma extended over a mean of 1.9 levels. Maximal thecal sac compression due to hematoma occurred at an adjacent, nondecompressed level in 28% of patients. Multivariate analysis found age greater than 60, multilevel procedures, and preoperative international normalized ratio to be associated with larger hematoma volumes.

CONCLUSION

Lumbar decompression surgery results in a 58% incidence of asymptomatic compressive postoperative epidural hematoma. Adjacent level compression by hematoma occurs in 28% of patients. Advanced age, multilevel procedures, and international normalized ratio are independently associated with postoperative hematoma volume.

Closed suction surgical wound drainage after orthopaedic surgery

BACKGROUND

Closed suction drainage systems are frequently used to drain fluids, particularly blood, from surgical wounds. The aim of these systems is to reduce the occurrence of wound haematomas and infection.

OBJECTIVES

To evaluate the effectiveness of closed suction drainage systems for orthopaedic surgery.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (March 2006), and contacted the Cochrane Wounds Group. We also searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 1), and MEDLINE (1966 to March 2006). Articles of all languages were considered.

SELECTION CRITERIA

All randomised or quasi-randomised trials comparing the use of closed suction drainage systems with no drainage systems for all types of elective and emergency orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality, using a nine item scale, and extracted data. Where appropriate, results of comparable studies were pooled.

MAIN RESULTS

Thirty-six studies involving 5464 participants with 5697 surgical wounds were identified. The types of surgery involved were hip and knee replacement, shoulder surgery, hip fracture surgery, spinal surgery, cruciate ligament reconstruction, open meniscectomy and fracture fixation surgery. Pooling of results indicated no statistically significant difference in the incidence of wound infection, haematoma, dehiscence or re-operations between those allocated to drains and the un-drained wounds. Blood transfusion was required more frequently in those who received drains. The need for reinforcement of wound dressings and the occurrence of bruising were more common in the group without drains.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised trials to support the routine use of closed suction drainage in orthopaedic surgery. Further randomised trials with larger patient numbers are required for different operations before definite conclusions can be made for all types of orthopaedic operations.

Delayed Epidural Hematoma After Spinal Surgery A Report of 4 Cases

Symptomatic postoperative epidural hematoma is a rare and potentially devastating complication of spinal surgery. The overwhelming majority of reported cases have occurred in the immediate postoperative period. A recent publication defined the clinical entity of delayed postoperative epidural spinal hematoma as neurologic deterioration due to an epidural hematoma occurring at least 3 days after the index procedure. Only 2 such cases have been reported in the lumbar spine to date. Four cases of delayed postoperative spinal epidural hematoma were identified over a 6-year period among the spine surgeons at a single large academic institution. Each case involved the lumbar spine. The details of each patient's initial surgery, presentation, and hospital course were then gathered from a retrospective chart review. The 4 patients presented are unusual in their delayed symptomatic presentations of postoperative spinal epidural hematoma. Despite the longer time to onset, however, our patients exhibited many of the characteristics common to cases that presented in the acute postoperative period. The spine surgeon must remain vigilant for the possibility of postoperative spinal epidural hematoma in at-risk patients, even weeks after the original surgical procedure.

Postoperative spinal epidural hematoma: risk factor and clinical outcome

We report a series of epidural hematomas which cause neurologic deterioration after spinal surgery, and have taken risk factors and prognostic factors into consideration. We retrospectively reviewed the database of 3720 cases of spine operation in a single institute over 7 years (1998 April- 2005 July). Nine patients who demonstrated neurologic deterioration after surgery and required surgical decompression were identified. Factors postulated to increase the postoperative epidural hematoma and to improve neurologic outcome were investigated. The incidence of postoperative epidural hematoma was 0.24%. Operation sites were cervical 3 cases, thoracic 2 cases, and lumbar 4 cases. Their original diagnoses were tumor 3 cases, cervical stenosis 2 cases, lumbar stenosis 3 cases and herniated lumbar disc 1 case. The symptoms of epidural hematomas were neurologic deterioration and pain. After decompression, clinical outcome revealed complete recovery in 3 cases (33.3%), incomplete recovery in 5 cases (55.6%) and no change in 1 case (11.1%). Factors increasing the risk of postoperative epidural hematoma were coagulopathy from medical illness or anticoagulation therapy (4 cases, 44.4%) and highly vascularized tumor (3 cases, 33.3%). The time interval to evacuation of complete recovery group (29.3 hours) was shorter than incomplete recovery group (66.3 hours). Patients with coagulopathy and highly vascularized tumor were more vulnerable to spinal epidural hematoma. The postoperative outcome was related to the preoperative neurological deficit and the time interval to the decompression.

The use of closed-suction irrigation systems to manage spinal infections

OBJECT

Management of infection in the hardware system-fixated spine has proven to be problematic. In many cases, instrumentation is required to provide stability or to maintain correction of deformity, and removal could be hazardous. The authors describe the use of closed continuous irrigation to treat spinal wound infections in patients with fixation systems; irrigation can be used in all parts of the spine with excellent results.

METHODS

The authors conducted a retrospective chart-based review of cases in which spinal instrumentation procedures were performed consecutively during a 10-year period. Infection developed in 36 patients. The infections involved the cervical, thoracic or thoracolumbar, and lumbar regions. Anterior and posterior drains were placed in one patient. In one patient refractory infections responded to replacement of the dual-inflow port drainage system. In all cases the wound infection completely resolved. There were no cases that required the removal of the fusion mass or instrumentation. In all cases progression to solid fusion was achieved.

CONCLUSIONS

Closed irrigation systems can be used effectively to manage anterior or posterior cervical, thoracic, and lumbar wound infections. These systems preclude the explantation of the instrumentation and allow spinal stability to be preserved. The authors noted no evidence of recurrent infection or failed fusion.

Die Wertigkeit von Wunddrainagen mit und ohne Sog

Even though the discussion for desisting from wound drainage has arisen, this is not reflected in the reality of surgical treatment. In more than 90% of all procedures wound drainage is used. It remains to be proven whether suction drainage actually is superior to gravity drainage in everyday use. In a random study with 200 patients it was proven that suction drainage shows no significant advantage in liquid quantum, haematoma and the frequency of complications. We conclude that the economically favourable gravity drainage can replace the more expensive suction drainage in most cases.

Analysis of the risk factors for the development of post-operative spinal epidural haematoma

In order to identify the risk factors and the incidence of post-operative spinal epidural haematoma, we analysed the records of 14 932 patients undergoing spinal surgery between 1984 and 2002. Of these, 32 (0.2%) required re-operation within one week of the initial procedure and had an International Classification of Diseases (ICD)-9 code for haematoma complicating a procedure (998.12). As controls, we selected those who had undergone a procedure of equal complexity by the same surgeon but who had not developed this complication. Risks identified before operation were older than 60 years of age, the use of pre-operative non-steroidal anti-inflammatories and Rh-positive blood type. Those during the procedure were involvement of more than five operative levels, a haemoglobin < 10 g/dL, and blood loss > 1 L, and after operation an international normalised ratio > 2.0 within the first 48 hours. All these were identified as significant (p < 0.03). Well-controlled anticoagulation and the use of drains were not associated with an increased risk of post-operative spinal epidural haematoma.

The use of postoperative subcutaneous closed suction drainage after posterior spinal fusion in adolescents with idiopathic scoliosis

BACKGROUND The purpose of this prospective study was to assess the impact of closed suction drainage on transfusion requirements, frequency of dressing changes, and wound healing following posterior spinal fusion in adolescents with idiopathic scoliosis. METHODS Thirty patients were randomly assigned to one of two groups: drain or no drain. Although the group with drains received more postoperative autologous blood transfusions than the group with no drains (0.88 vs 0.5 unit), the difference was not statistically significant (P = 0.2131). In the undrained group, 58% of the patients had moderate to completely saturated dressings on the second postoperative day compared with only 17% of patients in the drained group. Three of 12 patients in the undrained group demonstrated a wound complication rate compared with no complications in the drained group. CONCLUSION In conclusion, subcutaneous closed suction drainage can improve immediate postoperative wound care without significantly increasing blood loss and transfusion requirements for patients undergoing surgery for idiopathic scoliosis.

A randomized study of closed wound suction drainage for extensive lumbar spine surgery

STUDY DESIGN

A prospective randomized study.

OBJECTIVES

To study the risk of infection, hematoma, and neurologic deficits following extensive lumbar spine surgery in patients with or without prophylactic closed wound suction drain placement.

SUMMARY OF BACKGROUND DATA

One randomized study assessing prophylactic drain placement in one-level lumbar spine surgery suggested that the use of a wound drain is not effective at preventing infection and may actually increase the rate of this complication. Our study was designed to determine the efficacy of closed wound suction drainage in preventing complications after extensive lumbar spine surgery.

METHODS

Eighty-three consecutive patients undergoing extensive lumbar spine surgery were prospectively randomized to one of two groups. Forty-two patients had a closed wound suction drain placed before wound closure and 41 patients did not have a drain placed. The two groups were then assessed for differences in postoperative infection rate, incidence of hematoma and neurologic deficits, operating room time, estimated blood loss, hemoglobin and hematocrit values, temperature, dressing drainage, and length of hospital stay. RESULTS.: No infections, epidural hematomas, or new neurologic deficits were encountered in either group of patients. The only significant finding was a higher temperature in the "no drain" group the first day after surgery (P = 0.0437).

CONCLUSIONS

Based on the findings in this and other studies, the decision to use or not use a wound drain following lumbar spine surgery should be left to the surgeon's discretion.

Effect of drain use in the early postoperative period after arthroscopically assisted anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft

BACKGROUND

Little data exist on the effect of routine use of postoperative drainage after arthroscopic anterior cruciate ligament reconstruction, although clinical studies of other procedures have not shown benefit to this practice.

HYPOTHESIS

Use of a postoperative drain will not result in decreased suprapatellar girth, increased range of motion, and decreased pain compared with nonuse.

STUDY DESIGN

Prospective randomized clinical trial.

METHODS

Twenty-one patients undergoing arthroscopically assisted bone-patellar tendon-bone anterior cruciate ligament reconstruction were randomly assigned to receive a drain for 24 hours (12 patients) or no drain (9 patients). Data for comparison of groups were collected daily through postoperative day 7.

RESULTS

Pain scores on a visual analog scale demonstrated the same improving trend over time for both treatment and control groups; however, the treatment group had significantly higher average pain scores, except on day 7. Differences in suprapatellar girth, flexion, and extension were not found to be statistically significant between groups.

CONCLUSION

Use of a drain after arthroscopically assisted anterior cruciate ligament reconstruction provided no benefit in terms of range of motion, effusion, or pain in the early postoperative period.

Closed suction surgical wound drainage after orthopaedic surgery

BACKGROUND

Closed suction drainage systems are frequently used to drain fluids, particularly blood, from surgical wounds. The aim of these systems is to reduce the occurrence of wound haematomas and infection.

OBJECTIVES

To evaluate the effectiveness of closed suction drainage systems for orthopaedic surgery.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Injuries Group specialised register (May 2001), MEDLINE (1996-May 2001) and references from articles.

SELECTION CRITERIA

All randomised or quasi-randomised trials comparing the use of closed suction drainage systems with no drainage systems for all types of elective and emergency orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

Both reviewers independently assessed trial quality, using a nine item scale, and extracted data. Wherever appropriate and possible, the data are presented graphically.

MAIN RESULTS

Twenty-one studies involving 2772 patients with 2971 wounds were included in the analysis. The types of surgery involved were hip and knee replacement, shoulder surgery, hip fracture surgery, spinal surgery, cruciate ligament reconstruction, open meniscectomy and fracture fixation surgery. Many of the studies had poor methodology and reporting of outcomes. Pooling of results indicated no difference in the incidence of wound infection, haematoma or dehiscence between those allocated to drains and the un-drained wounds. There was a tendency to an increased risk of re-operation for wound complications in the group with drains (relative risk (RR) 2.25, 95% confidence intervals (CI) 0.95 to 5.33), but due to the small numbers of cases involved definite conclusions cannot be made for this outcome. Blood transfusion was required more frequently in those who received drains (RR 1.41, 95% CI 1.10 to 1.80). The need for reinforcement of wound dressings (RR 0.22, 95% CI 0.13 to 0.40) and bruising around the operation site was more common in the group without drains.

REVIEWER'S CONCLUSIONS

There is insufficient evidence from randomised trials to support or refute the routine use of closed suction drainage in orthopaedic surgery. Further randomised trials are required before definite conclusions can be made.

Reduction of blood loss and transfusion requirement by aprotinin in posterior lumbar spine fusion

Aprotinin reduces blood loss in many orthopedic procedures. In posterior lumbar spine fusion, blood loss results primarily from large vein bleeding and also occurs after the wound is closed. Seventy-two patients undergoing posterior lumbar spine fusion were randomly assigned to large-dose aprotinin therapy or placebo. All patients donated three units of packed red blood cells (RBCs) preoperatively. Postoperative blood loss was harvested from the surgical wound in patients undergoing two- and/or three-level fusion for reinfusion. The target hematocrit for RBC transfusion was 26% if tolerated. Total (intraoperative and 24 h postoperative) blood loss, transfusion requirements, and percentage of transfused patients per treatment group were significantly smaller in the aprotinin group than in the placebo group (1935 +/- 873 vs 2809 +/- 973 mL per patient [P = 0.007]; 42 vs 95 packed RBCs per group [P = 0.001]; 40% vs 81% per group [P = 0.02]). Hematological assessments showed an identically significant (a) intraoperative increase in both thrombin-antithrombin III complexes (TAT) and in activated factor XII (XIIa) and (b) decrease in activated factor VII (VIIa), indicating a similar significant effect on coagulation in patients of both groups (P = 0.9 for intergroup comparisons of postoperative VIIa, XIIa, and TAT). Intraoperative activation of fibrinolysis was significantly less pronounced in the aprotinin group than in the placebo group (P < 0.0001 for intergroup comparison of postoperative D-dimer levels). No adverse drug effects (circulatory disturbances, deep venous thrombosis, alteration of serum creatinine) were detected. Although administered intraoperatively, aprotinin treatment dramatically reduced intraoperative and 24-h postoperative blood loss and autologous transfusion requirements but did not change homologous transfusion in posterior lumbar spine fusion.

IMPLICATIONS

In our study, aprotinin therapy significantly decreased autologous, but not homologous, transfusion requirements in posterior lumbar spine fusion.