Increased Total Anesthetic Time Leads to Higher Rates of Surgical Site Infections in Spinal Fusions

Evaluation of anatomic landmarks to increase precision performing a mini-hemilaminectomy-an ex vivo study in dogs

The mini-hemilaminectomy is a frequently used surgical technique for decompressive disk surgery on dogs. The aim of the study was to assess landmarks in the canine thoracolumbar spine to perform a mini-hemilaminectomy, with the aim of achieving optimal exposure of the ventral aspect of the vertebral canal. We hypothesized that the accessory process is a useful landmark for the identification of the level of the vertebral canal floor (VCF) and for decreasing surgical time. To define the level of the VCF, different landmarks and their distance to the VCF from computed tomography images of 40 mature chondrodystrophic dogs were evaluated in the first part of the study. To test the predefined landmarks, a cadaveric experiment was subsequently performed in the second part of the study. An experienced surgeon and a second-year surgical resident performed mini-hemilaminectomies as precisely as possible, with and without using the landmark values. Surgery time, precision of the mini-hemilaminectomy, and iatrogenic damage of the spinal nerve roots were compared between the two groups. Based on the results in the first part of the study, the distance from the dorsal border of the accessory process to the VCF (DBAP-VCF) was chosen as a landmark due to the good intra- (0.96) and interobserver (0.83) agreement. However, the distance is highly variable between breeds. In the second part of the study, using the DBAP-VCF landmark value did not influence the surgery time in both surgeons (p = 0.467, p > 0.99). An improved accuracy of the VCF was seen for the surgical resident with limited experience (p = 0.014), but not for the experienced surgeon (p = 0.926). For both surgeons, the spinal nerve roots were injured in 20% of the cases unrelated to the use of landmark values. In conclusion, this study suggests that the DBAP-VCF has been described as a breed-specific landmark that can be determined in CT with good agreement. Using the previously evaluated landmark values can help improve precision in decompressive spinal surgery for a surgeon with limited experience without prolonging surgical time.

Initial single surgeon evaluation comparing C-arm fluoroscopy with the Cirq robotic assistance device for instrumentation of the thoracolumbar spine

OBJECTIVE

To compare our experience with pedicle screw insertion of the thoracolumbar spine utilizing the Cirq robot assistance device compared with traditional paradigm using fluoroscopy.

METHODS

We prospectively collected data of patients undergoing pedicle screw instrumentation in the thoracolumbar spine performed by a single surgeon at three different centers. One center took delivery of the Cirq robotic assistance device. Remaining two centers used C-arm fluoroscopy. Demographic information, diagnosis, total OR time, intraoperative complications, unexpected return to the operating room, and hospital readmissions within 90 days was compared between the two cohorts.

RESULTS

A total of 166 screws were placed during the study period. Forty percent were placed using the Cirq. Two thirds the patients had traumatic diagnoses with remaining degenerative spine disease. There were no misplaced pedicle screws in either group. While total OR time was longer in the Cirq cohort by 123 min (p = 0.04), actual procedural time was not statistically different (p = 0.11). Nonetheless there were also more hospital readmissions in the Cirq cohort compared with the C arm group (p = 0.04).

CONCLUSIONS

Thoracolumbar screws inserted using C-arm fluoroscopy utilize less total operating room time with similar accuracy compared with the Cirq robotic assistance device. Further studies are warranted.

Minimally invasive triangular lumboiliac and iliosacral fixation of posterior pelvic ring injuries with vertical instability: Technical note

To date, no strong consensus exists on the best way to treat posterior pelvic ring injuries when there is no neurological deficit. Various fixation methods have been described; more recently, constructs that combine lumboiliac and iliosacral fixation have been introduced. This type of fixation is mainly indicated in cases of spinopelvic dissociation with large displacement of fracture fragments in the sagittal plane. However, these techniques are associated with postoperative complications, particularly infections and severe skin complications. This led us to propose a minimally invasive lumboiliac and iliosacral fixation technique for posterior pelvic ring injuries. The procedure is done with the patient prone. It consists of pedicle screw insertion into L4 or L5 and screw fixation of the ilium with fluoroscopy guidance; intraoperative distraction can be done depending on the amount of displacement. An iliosacral screw is then inserted percutaneously to allow reduction in the transverse plane and yield a triangular construct. In the five patients that we have operated using this technique, the mean preoperative vertical displacement was 11.9±6.9mm (SD) (min 1.3, max 19.7) versus 3.7±3.2mm (min 0.3, max 6.7) postoperatively and the mean preoperative frontal displacement was 7.5±3.7mm (min 4.2, max 12.4) versus 2.5±2.0mm (min 0.3, max 4.3) postoperatively. Minimally invasive iliosacral and lumboiliac fixation is an option for treating posterior pelvic ring fractures free of neurological deficit and especially spinopelvic dissociation.

A narrative review of infection prevention techniques in adult and pediatric spinal deformity surgery

Spinal infections associated with pediatric and adult spinal deformity surgery are associated with postoperative morbidity and mortality along with elevated health-care costs. Prevention requires meticulous technique by the spine surgeon throughout the perioperative period. There is significant variability in the current practices of spinal deformity surgeons with regard to infection prevention, stemming from the lack of reliable evidence available in the literature. There has also been a lack of literature detailing the difference in infection rates and risk factors between pediatric and adult patients undergoing deformity correction surgery. In this narrative review we looked at 60 studies in the adult population and 9 studies in the pediatric population. Most of these studies of surgical site infections (SSI) in spinal deformity surgery have been performed in adult patients, however it is clear that the pediatric neuromuscular patient requires particular attention that we discuss in detail. This narrative review of the literature outlines evidence and compares and contrasts data for preventive strategies and modifiable risk factors to decrease rates of SSI in the pediatric and adult spinal deformity patient populations. In this review we discuss techniques relating to preoperative cleansing protocols, antibiotic administration, gentle soft tissue handling, appropriate closure, drain usage, and intraoperative technique itself to minimize EBL and operative time.

Deep Surgical-Site Infection Following Thoracolumbar Instrumented Spinal Surgery: The Experience of 25 Years

BACKGROUND

Deep surgical-site infection following thoracolumbar instrumented spinal surgery (DSITIS) is a major complication in spine surgery and its impact on long-term morbidity and mortality is yet to be determined. This article describes the characteristics and evolution of DSITIS in our center over a period of 25 years.

METHODS

This single-center, retrospective cohort study included patients diagnosed with DSITIS between January 1992 and December 2016 and with a minimum follow-up after infection diagnosis of 1 year. The Infectious Diseases Society of America criteria and/or Centers for Disease Control and Prevention criteria were used to define DSITIS. Patient data (epidemiological and health status), surgical data, infection characteristics and presentation, isolated microorganisms, required surgical debridements, implant removal, and major complications linked to infection were evaluated.

RESULTS

A total of 174 patients (106 females) were included in the analysis. Mean follow-up after infection diagnosis was 40 months (56 patients with over 5 years follow-up). Adolescent idiopathic scoliosis, adult deformity, and degenerative lumbar stenosis were the most frequent etiologies for primary surgery. Presentation of infection was considered early (0-3 months since first surgery) in 59.2% of the cases, delayed (3-24 months) in 11.5%, and late (more than 24 months) in 29.3%. All patients were treated by surgical debridement. More than 1 surgical debridement was necessary in 20.7% of cases. Implants were removed in 46.6% of the patients (72.83% in the first surgical debridement). Most frequently isolated microorganisms were Staphylococcus spp, Enterobacteriaceae, and Cutibacterium acnes. Major complications appeared in 14.3% of the patients, and over 80% of them required major surgeries to resolve those complications.

CONCLUSIONS

Late DSITIS is more frequent than previously reported. In DSITIS culprits, Staphylococcus spp, Enterobacteriaceae, and Cutibacterium acnes predominate. DSITIS produce a high rate of major complications that usually require major surgery for treatment.

LEVEL OF EVIDENCE

3.

Do Surgical Site Infection Rates Differ Among Microscope-assisted Versus Loupe-assisted Lumbar Discectomies?

STUDY DESIGN

Retrospective study.

OBJECTIVE

The objective of this study was to compared surgical site infection (SSI) rates between patients under lumbar discectomy with an operative microscope versus surgical loupes.

SUMMARY OF BACKGROUND DATA

Lumbar decompressions for herniated disks or lumbar stenosis are common spine procedures. Some studies have raised the concern that drape contamination of the operative microscope may be an additional risk for SSIs. We hypothesize that the use of the operative microscope for lumbar decompression procedures does not increase infection rates.

METHODS

A retrospective cohort analysis was performed on patients undergoing lumbar spinal decompressions via microscopic assistance (MA) or loupe assistance (LA) by 2 orthopedic spine surgeons at a tertiary academic medical center. Patients treated from November, 2012 to October, 2016 were enrolled. Variables including age, sex, race, body mass index, smoking status, length of surgery, intraoperative complications, estimated blood loss, and postoperative SSIs within 30 days were collected.

RESULTS

A total of 225 patients were included in the study. Sixty-three patients underwent LA lumbar decompression, and 162 underwent MA lumbar decompression. There were 72 female individuals/90 male individuals in the MA group and 31 female individuals/33 male individuals in the LA group. The MA was significantly older 45.2 versus 40.4 in LA, P-value of 0.02 and had a significantly higher body mass index (30.64 vs. 27.79, P<0.002). SSI rates were not significantly different, MA 3.7% (6/162) and LA 7.9% (5/63), P-value of 0.14. The MA group had a significantly longer operative time (92 vs. 50 min, P<0.001). Dural tears rates were 3.1% in MA and 1.6% in LA, P-value of 0.3 and were associated with longer operative time in the MA group, 162.2 versus 90.2 minutes, P-value of <0.0001. Multivariate regression analysis did not identify any significant differences between the 2 groups.

CONCLUSIONS

The use of the operative microscope had similar infection rates as LA microdiscectomies. In academic institutions, the operative microscope may allow more opportunities for residents or fellows to partake/assist in the procedure as compared with LA procedures.

Synthetic Mesh Versus Acellular Dermal Matrix for Oncologic Chest Wall Reconstruction: A Comparative Analysis

BACKGROUND

Management of chest wall defects after oncologic resection is challenging due to multifactorial etiologies. Traditionally, skeletal stabilization in chest wall reconstruction (CWR) was performed with synthetic prosthetic mesh. The authors hypothesized that CWR for oncologic resection defects with acellular dermal matrix (ADM) is associated with a lower incidence of complications than synthetic mesh.

METHODS

Consecutive patients who underwent CWR using synthetic mesh (SM) or ADM at a single center were reviewed. Only oncologic defects involving resection of at least one rib and reconstruction with both mesh and overlying soft tissue flaps were included in this study. Patients' demographics, treatment factors, and outcomes were prospectively documented. The primary outcome measure was surgical-site complications (SSCs). The secondary outcomes were specific wound-healing events, cardiopulmonary complications, reoperation, and mortality.

RESULTS

This study investigated 146 patients [95 (65.1%) with SM; 51 (34.9%) with ADM] who underwent resection and CWR of oncologic defects. The mean follow-up period was 29.3 months (range 6-109 months). The mean age was 51.5 years, and the mean size of the defect area was 173.8 cm². The SM-CWR patients had a greater number of ribs resected (2.7 vs. 2.0 ribs; p = 0.006) but a similar incidence of sternal resections (29.5% vs. 23.5%; p = 0.591) compared with the ADM-CWR patients. The SM-CWR patients experienced significantly more SSCs (32.6% vs. 15.7%; p = 0.027) than the ADM-CWR patients. The two groups had similar rates of specific wound-healing complications. No differences in mortality or reoperations were observed.

CONCLUSIONS

The ADM-CWR patients experienced fewer SSCs than the SM-CWR patients. Surgeons should consider selectively using ADM for CWR, particularly in patients at higher risk for SSCs.

Comparison of Short-term Outcomes After Lumbar Fusion Between an Orthopedic Specialty Hospital and Tertiary Referral Center

STUDY DESIGN

A retrospective review of all elective single-level lumbar fusions performed at a single orthopedic specialty hospital (OSH) and tertiary referral center (TRC).

OBJECTIVE

This study compared the perioperative outcomes for lumbar fusion procedures performed at an OSH and TRC.

SUMMARY OF BACKGROUND DATA

The role of an OSH for lumbar fusion procedures has not been defined.

METHODS

A large institutional database was searched for single-level lumbar fusions performed between 2013 and 2016. Comparisons were made between procedures performed at the OSH and TRC in terms of operative time, total operating room (OR) time, length of stay (LOS), inpatient rehabilitation utilization, postoperative 90-day readmission, reoperation, and mortality rates.

RESULTS

A total of 101 patients at the OSH and 481 at the TRC were included. There was no difference in gender, age, age adjusted Charlson comorbidity Index (AACCI), body mass index, mean number of concomitant levels decompressed, and use of interbody fusion between OSH and TRC patients. The mean operative time (149.5 vs. 179.7 minutes, P < 0.001), total OR time (195.1 vs. 247.9 minutes, P < 0.001), and postoperative LOS (2.61 vs. 3.73 days, P < 0.001) were significantly shorter at the OSH. More patients required postoperative inpatient rehabilitation at the TRC (7.1% vs. 2%, P < 0.001). There was no difference in 90-day readmission or reoperation rates. There was one mortality at the TRC and two patients required transfer from the OSH to the TRC due to medical complications. Regression analysis demonstrated that procedures performed at the TRC (P < 0.001), total OR time (P = 0.004), AACCI (P < 0.001), current smokers (P = 0.048), and number of decompressed levels (P = 0.032) were independent predictors of LOS.

CONCLUSION

Lumbar fusion procedures may be safely performed at both the OSH and TRC. OSH utilization may demonstrate safe reduction in operative time, total OR time, and postoperative LOS in the appropriately selected patients.

LEVEL OF EVIDENCE

3.

Management of Adolescent Idiopathic Scoliosis: Institutional Experience, Integration into Neurosurgical Practice, and Impact on Resident Training

OBJECTIVE

Management of adolescent idiopathic scoliosis (AIS) in neurosurgery residency training may have a significant impact on resident experience, even though few trainees are likely to pursue careers in the field of AIS. The impact of this exposure on resident knowledge in adult spinal disease management is the subject of our retrospective analysis.

METHODS

An analysis was performed of all adolescent patients undergoing surgical correction of spinal deformity between 2006 and 2016. Patient characteristics, including age at operation, Cobb angles, length of stay, operative time, blood loss, and complications, were collected. Objective benchmarks were created for resident education in the management of AIS. A survey was sent to the last 7 years of graduates to assess the impact of exposure to AIS during neurosurgery training on their current practice.

RESULTS

Nine male and 37 female patients ages 11 to 22 years were identified. Neurosurgical residents assisted in all procedures without fellows or surgical assistants. Average operative time was 336 minutes (range, 215-575 minutes), and blood loss per procedure was 603 mL (range, 200-4000 mL). The average Cobb angle correction was 72.2% (range, 35.3%-90.9%). Zero of the past 7 graduates currently treat AIS surgically. All 7 graduates agreed that exposure to AIS during residency enhanced their knowledge of adult spinal disease management.

CONCLUSIONS

Treatment of AIS by surgeons with specialized training can be effective and safe. Resident exposure to these patients enhances their understanding of spinal biomechanics and deformity correction, which is applicable to treating AIS and adult spinal deformity.

Deep surgical site infection following thoracolumbar instrumented spinal surgery. Ten years of experience

OBJECTIVE

To describe the characteristics and evolution of deep surgical site infection following thoracolumbar instrumented spinal surgery (DSITIS) in our centre over a period of ten years.

MATERIAL AND METHOD

Descriptive retrospective study. Patient data (epidemiological/health status), surgical data, infection characteristics/presentation, isolated microorganisms, required surgical debridements, implant removal and major complications linked to infection were evaluated.

RESULTS

We included 110 patients (80 females). Median follow-up after infection diagnosis was 3.6years. Adolescent idiopathic scoliosis, adult deformity and degenerative lumbar stenosis were the most frequent aetiologies. Sixty-two percent of the patients had at least one clinical feature that made them prone to infection. Infection presentation was early (0-3months from first surgery) in 60.4% of the cases, delayed (3-24months) in 11.7%, and late (more than 24months) in 27%. All patients were treated by surgical debridement. Twenty-five percent needed more than one surgical debridement. Implants were removed in 46% of the patients (71% in the first surgical debridement). The most frequent isolated microorganisms were coagulasa-negative Staphylococcus, Propionibacterium acnes and Enterococcus. Major complications appeared in 15% of the patients, and 88% of them required major surgeries.

CONCLUSIONS

Late DSITIS is more frequent than previously reported. Skin microorganisms predominate among the DSITIS culprits. DSIITS produce a high rate of major complications that usually require major surgery for treatment.

Predicting critical care unit-level complications after long-segment fusion procedures for adult spinal deformity

Background

To identify predictive factors for critical care unit-level complications (CCU complication) after long-segment fusion procedures for adult spinal deformity (ASD).

Methods

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database [2010-2014] was reviewed. Only adult patients who underwent fusion of 7 or more spinal levels for ASD were included. CCU complications included intraoperative arrest/infarction, ventilation >48 hours, pulmonary embolism, renal failure requiring dialysis, cardiac arrest, myocardial infarction, unplanned intubation, septic shock, stroke, coma, or new neurological deficit. A stepwise multivariate regression was used to identify independent predictors of CCU complications.

Results

Among 826 patients, the rate of CCU complications was 6.4%. On multivariate regression analysis, dependent functional status (P=0.004), combined approach (P=0.023), age (P=0.044), diabetes (P=0.048), and surgery for over 8 hours (P=0.080) were significantly associated with complication development. A simple scoring system was developed to predict complications with 0 points for patients aged <50, 1 point for patients between 50-70, 2 points for patients 70 or over, 1 point for diabetes, 2 points dependent functional status, 1 point for combined approach, and 1 point for surgery over 8 hours. The rate of CCU complications was 0.7%, 3.2%, 9.0%, and 12.6% for patients with 0, 1, 2, and 3+ points, respectively (P<0.001).

Conclusions

The findings in this study suggest that older patients, patients with diabetes, patients who depend on others for activities of daily living, and patients who undergo combined approaches or surgery for over 8 hours may be at a significantly increased risk of developing a CCU-level complication after ASD surgery.