Efficacy of Pneumatic Compression Stocking Prophylaxis in the Prevention of Deep Venous Thrombosis and Pulmonary Embolism Following 139 Lumbar Laminectomies With Instrumented Fusions

Enhanced Recovery After Surgery Protocols and Spinal Deformity

The authors outline a review of preoperative, intraoperative, and postoperative considerations surrounding adult spinal deformity. Preoperative management topics include imaging, hemoglobin A1c levels before spine surgery, osteoporotic management, and prehabilitation. Topics surrounding intraoperative management include the use of antibiotics, liposomal bupivacaine, and Foley catheters. The authors also discuss postoperative questions surrounding analgesia, nausea and vomiting, thromboembolic prophylaxis, and early mobilization. Throughout their discussion, the authors incorporate enhanced recovery after surgery protocols to hopefully lead to future discussions regarding optimizing complex spinal patients.

Chemoprophylactic Anticoagulation Following Lumbar Surgery Significantly Reduces Thromboembolic Events After Instrumented Fusions, Not Decompressions

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To quantify any reduction in venous thromboembolic events (VTEs) caused by chemoprophylaxis among lumbar surgery patients.

SUMMARY OF BACKGROUND DATA

Chemoprophylactic anticoagulation (chemoprophylaxis) is used to prevent VTE after lumbar surgery. However, the treatment effect of chemoprophylaxis has not been reported among spine surgery patients, as conventional statistical methods preclude such inferences.

MATERIALS AND METHODS

A total of 1243 consecutive lumbar fusions and 1433 noninstrumented lumbar decompressions performed at our institution over a six-year period were identified, and clinical and demographic data were collected, including on VTE events within 30 days postoperatively. Instrumented lumbar fusions and noninstrumented lumbar surgeries were analyzed separately. Patients who were given chemoprophylaxis (treatment) and controls were matched according to known VTE risk factors, including age, body mass index, sex, diabetes, chronic kidney disease, history of VTE, estimated blood loss, length of surgery, transfusion, whether surgery was staged, and whether surgery used an anterior approach. K-nearest neighbor propensity score matching was performed, and the treatment effect of chemoprophylaxis was calculated.

RESULTS

Unadjusted, there was no difference in the rate of VTE between treatment and controls in either population. Baseline clinical and demographic characteristics differed significantly between treatment and control groups. In all, 575 lumbar fusion patients and 435 noninstrumented lumbar decompression patients were successfully propensity score matched, yielding balanced models (Rubin B <25, 0.5<Rubin R <2.0) and >60% reduction in known bias for both populations. The treatment effect of chemoprophylaxis after lumbar fusion in our patient population was a reduction in VTE incidence from 9.4% to 4.2% ( P <0.05), and propensity score adjusted regression confirmed a reduced odds of VTE with chemoprophylaxis (odds ratio=0.37, P =0.035). The treatment effect was not significant for noninstrumented lumbar decompression patients.

CONCLUSION

Among patients undergoing instrumented lumbar fusions, chemoprophylactic anticoagulation causes a significant reduction in VTE, but causes no significant reduction among patients undergoing noninstrumented lumbar decompression.

Dose-dependent effects of red blood cell transfusion and case mix index on venous thromboembolic events in spine surgery

BACKGROUND AND OBJECTIVES

Venous thromboembolic (VTE) events represent a major source of morbidity and mortality in spine surgery. Our goal was to assess whether a dose-response relationship exists between red blood cell (RBC) transfusion and postoperative VTE events among spine surgery patients.

MATERIALS AND METHODS

A total of 786 spine surgery patients at a single institution who received at least 1 RBC unit perioperatively were included (2016-2019). Patients were stratified based on RBC transfusion volume: 1-2 units (39.3%), 3-4 units (29.4%), 5-6 units (15.9%) and ≥7 units (15.4%). Subgroup analyses were performed after stratification by case mix index, a standardized surrogate for patients' disease severity and comorbidities. Multivariable regression was used to assess risk factors for the development of postoperative VTE events.

RESULTS

The overall VTE event rate was 2.4% (n = 19). A dose-response relationship was seen between RBC transfusion volume and VTE events (1-2 units: 0.97%, 3-4 units: 1.30%, 5-6 units: 3.20%, ≥7 units: 7.44%; p < 0.01). Similar dose-response relationships were seen between case mix index and VTE events (1.00-3.99: 0.52%, 4.00-6.99: 2.68%, ≥7.00: 9.00%; p < 0.01). On multivariable regression, larger RBC transfusion volumes (adjusted odds ratio [OR] 1.18 per RBC unit, 95% confidence interval [CI] 1.07-1.29; p < 0.01) and higher case mix index scores (adjusted OR 1.39 per unit increase, 95% CI 1.14-1.69; p < 0.01) were associated with an increased risk of thrombosis.

CONCLUSION

Larger RBC transfusion volumes and higher case mix index scores were associated with an increased risk of VTE events. Physicians should be aware of how these dose-response relationships can influence a patient's risk of developing thrombotic complications postoperatively.

Factors Affecting the Decision to Initiate Anticoagulation After Spine Surgery: Findings From the AOSpine Anticoagulation Global Initiative

STUDY DESIGN

Cross-sectional, international survey.

OBJECTIVES

To identify factors influencing pharmacologic anticoagulation initiation after spine surgery based on the AOSpine Anticoagulation Global Survey.

METHODS

This survey was distributed to the international membership of AOSpine (n = 3805). A Likert-type scale described grade practice-specific factors on a scale from low (1) to high (5) importance, and patient-specific factors a scale from low (0) to high (3) importance. Analysis was performed to determine which factors were significant in the decision making surrounding the initiation of pharmacologic anticoagulation.

RESULTS

A total of 316 spine surgeons from 64 countries completed the survey. In terms of practice-specific factors considered to initiate treatment, expert opinion was graded the highest (mean grade ± SD = 3.2 ± 1.3), followed by fellowship training (3.2 ± 1.3). Conversely, previous studies (2.7 ± 1.2) and unspecified guidelines were considered least important (2.6 ± 1.6). Patient body mass index (2.0 ± 1.0) and postoperative mobilization (2.3 ± 1.0) were deemed most important and graded highly overall. Those who rated estimated blood loss with greater importance in anticoagulation initiation decision making were more likely to administer thromboprophylaxis at later times (hazard ratio [HR] = 0.68-0.71), while those who rated drain output with greater importance were likely to administer thromboprophylaxis at earlier times (HR = 1.32-1.43).

CONCLUSION

Among our global cohort of spine surgeons, certain patient factors (ie, patient mobilization and body mass index) and practice-specific factors (ie, expert opinion and fellowship training) were considered to be most important when considering anticoagulation start times.

Consensus statement for perioperative care in lumbar spinal fusion: Enhanced Recovery After Surgery (ERAS®) Society recommendations

BACKGROUND

Enhanced Recovery After Surgery (ERAS) evidence-based protocols for perioperative care have led to improvements in outcomes in numerous surgical areas, through multimodal optimization of patient pathway, reduction of complications, improved patient experience and reduction in the length of stay. ERAS represent a relatively new paradigm in spine surgery.

PURPOSE

This multidisciplinary consensus review summarizes the literature and proposes recommendations for the perioperative care of patients undergoing lumbar fusion surgery with an ERAS program.

STUDY DESIGN

This is a review article.

METHODS

Under the impetus of the ERAS® society, a multidisciplinary guideline development group was constituted by bringing together international experts involved in the practice of ERAS and spine surgery. This group identified 22 ERAS items for lumbar fusion. A systematic search in the English language was performed in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Systematic reviews, randomized controlled trials, and cohort studies were included, and the evidence was graded according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Consensus recommendation was reached by the group after a critical appraisal of the literature.

RESULTS

Two hundred fifty-six articles were included to develop the consensus statements for 22 ERAS items; one ERAS item (prehabilitation) was excluded from the final summary due to very poor quality and conflicting evidence in lumbar spinal fusion. From these remaining 21 ERAS items, 28 recommendations were included. All recommendations on ERAS protocol items are based on the best available evidence. These included nine preoperative, eleven intraoperative, and six postoperative recommendations. They span topics from preoperative patient education and nutritional evaluation, intraoperative anesthetic and surgical techniques, and postoperative multimodal analgesic strategies. The level of evidence for the use of each recommendation is presented.

CONCLUSION

Based on the best evidence available for each ERAS item within the multidisciplinary perioperative care pathways, the ERAS® Society presents this comprehensive consensus review for perioperative care in lumbar fusion.

Perioperative Anticoagulation Management in Spine Surgery: Initial Findings From the AO Spine Anticoagulation Global Survey

STUDY DESIGN

Cross-sectional, international survey.

OBJECTIVES

This study addressed the global perspectives concerning perioperative use of pharmacologic thromboprophylaxis during spine surgery along with its risks and benefits.

METHODS

A questionnaire was designed and implemented by expert members in the AO Spine community. The survey was distributed to AO Spine's spine surgeon members (N = 3805). Data included surgeon demographic information, type and region of practice, anticoagulation principles, different patient scenarios, and comorbidities.

RESULTS

A total of 316 (8.3% response rate) spine surgeons completed the survey, representing 64 different countries. Completed surveys were primarily from Europe (31.7%), South/Latin America (19.9%), and Asia (18.4%). Surgeons tended to be 35 to 44 years old (42.1%), fellowship-trained (74.7%), and orthopedic surgeons (65.5%) from academic institutions (39.6%). Most surgeons (70.3%) used routine anticoagulation risk stratification, irrespective of geographic location. However, significant differences were seen between continents with anticoagulation initiation and cessation methodology. Specifically, the length of a procedure (P = .036) and patient body mass index (P = .008) were perceived differently when deciding to begin anticoagulation, while the importance of medical clearance (P < .001) and reference to literature (P = .035) differed during cessation. For specific techniques, most providers noted use of mobilization, low-molecular-weight heparin, and mechanical prophylaxis beginning on postoperative 0 to 1 days. Conversely, bridging regimens were bimodal in distribution, with providers electing anticoagulant initiation on postoperative 0 to 1 days or days 5-6.

CONCLUSION

This survey highlights the heterogeneity of spine care and accentuates geographical variations. Furthermore, it identifies the difficulty in providing consistent perioperative anticoagulation recommendations to patients, as there remains no widely accepted, definitive literature of evidence or guidelines.

Thromboprophylaxis in elective spinal surgery: A protocol for systematic review

BACKGROUND

Venous thromboembolism (VTE) is a serious, sometimes life-threatening complication that can occur following spine surgery. The incidence of VTE, and the optimal type and timing of thromboprophylaxis for this complication in elective spine surgery is a matter of debate.

OBJECTIVE

To perform a systematic review with the aim of clarifying the efficacy and adverse effects of mechanical and chemical prophylaxis for preventing thromboembolic complications in elective spine surgery for conditions other than trauma and malignant disease.

METHODS/DESIGN

A search strategy of related articles up to March 2018 was designed and executed in Medline and Embase.

PATIENTS

adolescents (>10 years) and adults undergoing elective surgery for spinal deformity or degenerative disease (from C1 to S1).

INTERVENTION

Perioperative mechanical and chemical thromboprophylaxis. Studies could be randomized controlled trials or observational studies that reported data on any relevant clinical outcomes.

RESULTS

In total, 2451 uniquecitations were identified and 35 studies were ultimately included in the systematic review. The overall mean incidence of complications was 3.7% for deep venous thrombosis, 0.0% for pulmonary embolism, and 3.7% for bleeding in chemoprophylaxis group; 2.9% for deep venous thrombosis, 0.4% for pulmonary embolism and 0.0% for bleeding in mechanoprophylaxis; and 0.7% for deep venous thrombosis, 0.1% for pulmonary embolism and 0.2% for bleeding in mixed prophylaxis group with no specific data on these rates for the type of patient and type and location of surgery. None of the articles retrieved provided information on the adolescent population.

DISCUSSION AND CONCLUSIONS

The poor design and high variability among the studies regarding characteristics of study population, details of interventions, and definitions of outcomes, determines a low quality of the available evidence and limits the interpretation of the results. We were unable to identify a clear advantage of one type of thromboprophylaxis over the other, although there was an increased risk of bleeding with chemoprophylaxis, which could favor the use of mechanoprophylaxis in this scenario.

Venous Thromboprophylaxis in Spine Surgery

STUDY DESIGN

Review article.

OBJECTIVE

A review of the literature on postoperative initiation of thrombophylactic agents following spine surgery.

METHODS

A review of the literature and synthesis of the data to provide an update on venous thromboprophylaxis following spine surgery.

RESULTS

Postoperative regimens of venous thromboprophylaxis measures following spine surgery remain a controversial issue. Recommendations regarding mechanical versus chemical prophylaxis vary greatly among institutions.

CONCLUSION

Postoperative spine surgery initiation of thromboprophylaxis remains controversial regarding optimal timing and agent selection. The benefits of deep vein thrombosis/pulmonary embolism prophylaxis must be weighed against the possible postoperative complications associated with spine surgery.

Venous Thromboembolism Prophylaxis in Spine Surgery

Venous thromboembolism (VTE) is a source of morbidity and mortality in patients undergoing orthopaedic surgery. A substantial body of literature supports the use of VTE prophylactic agents in patients undergoing lower extremity surgery. Treatment options include early mobilization, mechanical prophylaxis via pneumatic compression devices, pharmacologic agents, and venous filters. No consensus has been established regarding utilization or timing of VTE prophylaxis measures after spine surgery. The risk of VTE in patients undergoing spine surgery is not well characterized and varies substantially by the procedure and degree of neurologic compromise. In addition, the risk of clinically notable VTE must be weighed against the risk of postoperative bleeding and epidural hematoma after spine surgery. A standardized approach to VTE prophylaxis in patients undergoing spine surgery must take into account the available studies of risk factors, choice of prophylactic agents, and timing of prophylaxis.

Thromboprophylaxis in Spinal Surgery

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

Determine the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) in spinal surgery patients receiving no thromboprophylaxis, mechanoprophylaxis, and chemoprophylaxis.

SUMMARY OF BACKGROUND DATA

The incidence of thromboembolic complications after spinal surgery is not well established. Although a variety of effective mechanical and chemical thromboprophylaxis interventions exist, their role in spinal surgery remains unclear. Spine surgeons are faced with the difficult decision of balancing the risk of death from a thromboembolic complication against the risk of permanent neurological damage from an epidural hematoma (EDH).

METHODS

The Medline database was queried using combinations of the terms related to the aforementioned subject matter. Articles meeting our predetermined inclusion criteria were reviewed and relevant data extracted. Meta-analyses were created using a random-effects model for incidence of DVT and PE by type of thromboprophylaxis, method of screening, and study type.

RESULTS

Twenty-eight articles were included in the final analyses. The higher mean incidence of DVT and PE in the mechanoprophylaxis group (DVT: 1%, PE: 0.81%) compared to the chemoprophylaxis group (DVT: 0.85%, PE: 0.58%) was not observed to be statistically significant. Six percent of PEs was fatal; the rate of EDHs was 0.3%. The incidence of DVT was higher in prospective studies (1.4%) compared to retrospective studies (0.61%); the incidence of DVT was not affected by whether the study screened only symptomatic patients.

CONCLUSION

Although the incidence of DVT and PE was relatively low regardless of prophylaxis type, the true incidence is difficult to determine given the heterogeneous nature of the small number of studies available in the literature. Our findings suggest there may be a role for chemoprophylaxis given the relatively high rate of fatal PE. Future studies are needed to determine which patient population would benefit most from chemoprophylaxis.

LEVEL OF EVIDENCE

2.

Risk of Deep vein thrombosis in neurosurgery: State of the art on prophylaxis protocols and best clinical practices

OBJECTIVE

To analytically discuss some protocols in Deep vein thrombosis (DVT)/pulmonary Embolism (PE) prophylaxis currently use in Neurosurgical Departments around the world.

DATA SOURCES

Analysis of the prophylaxis protocols in the English literature: An analytical and narrative review of literature concerning DVT prophylaxis protocols in Neurosurgery have been conducted by a PubMed search (back to 1978).

DATA EXTRACTION

80 abstracts were reviewed, and 74 articles were extracted.

DATA ANALYSIS

The majority of DVT seems to develop within the first week after a neurosurgical procedure, and a linear correlation between the duration of surgery and DVT occurrence has been highlighted. The incidence of DVT seems greater for cranial (7.7%) than spinal procedures (1.5%). Although intermittent pneumatic compression (IPC) devices provided adequate reduction of DVT/PE in some cranial and combined cranial/spinal series, low-dose subcutaneous unfractionated heparin (UFH) or low molecular-weight heparin (LMWH) further reduced the incidence, not always of DVT, but of PE. Nevertheless, low-dose heparin-based prophylaxis in cranial and spinal series risks minor and major postoperative haemorrhages: 2-4% in cranial series, 3.4% minor and 3.4% major haemorrhages in combined cranial/spinal series, and a 0.7% incidence of major/minor haemorrhages in spinal series.

CONCLUSION

This analysis showed that currently most of the articles are represented by case series and case reports. As long as clear guidelines will not be defined and universally applied to this diverse group of patients, any prophylaxis for DVT and PE should be tailored to the individual patient with cautious assessment of benefits versus risks.

24-48 hour preoperative "surveillance" lower extremity venous Doppler's: Aren't they worthwhile prior to spine surgery?

BACKGROUND

Most previous studies focused on the utility of Doppler surveillance to determine the incidence of deep venous thrombosis (DVT) following spine surgery. Here, we utilized Doppler surveillance to assess the frequency of DVT prior to spine surgery.

METHODS

We asked, how often do patients exhibit preoperative DVT? To answer this, for over a 7-month period, bilateral lower extremity venous Doppler's were prospectively obtained 24-48 hours prior to a variety of spinal operations among 45 patients. This did not include an analysis of postoperative venous Doppler's/incidence of pulmonary embolism for these patients.

RESULTS

Of the 45 patients, 3 (6.7%) exhibited preoperative positive/abnormal venous duplex studies (unilaterally) that led to cancellation of spinal surgery. One patient, a 56-year-old female, with a C6-C7 cervical disc, demonstrated a proximal right lower extremity DVT; she required full-dose anticoagulation and her surgery was cancelled. In two cases, a 42-year-old female and a 55-year-old male, exhibited DVT in the right posterior tibial and left peroneal veins respectively; both operations were cancelled, and they were placed on anticoagulants by their internists.

CONCLUSIONS

Over a 7-month period, prospective "surveillance Dopplers" of both lower extremities obtained 24-48 hours prior to spinal surgery documented 3 (6.7%) positive studies out of a series of 45 patients. One instance of DVT was proximal (e.g. femoral in local) whereas 2 were distal. These data showed that preoperative surveillance Doppler of both lower extremities was "worthwhile." However, performing these studies earlier than 24-48 hrs prior to surgery would help avoid last minute cancellations.

Prophylaxis of Venous Thrombosis in Neurocritical Care Patients: An Evidence-Based Guideline: A Statement for Healthcare Professionals from the Neurocritical Care Society

The risk of death from venous thromboembolism (VTE) is high in intensive care unit patients with neurological diagnoses. This is due to an increased risk of venous stasis secondary to paralysis as well as an increased prevalence of underlying pathologies that cause endothelial activation and create an increased risk of embolus formation. In many of these diseases, there is an associated risk from bleeding because of standard VTE prophylaxis. There is a paucity of prospective studies examining different VTE prophylaxis strategies in the neurologically ill. The lack of a solid evidentiary base has posed challenges for the establishment of consistent and evidence-based clinical practice standards. In response to this need for guidance, the Neurocritical Care Society set out to develop and evidence-based guideline using GRADE to safely reduce VTE and its associated complications.

The Effect of Coagulopathies on Perioperative Complications and Clinical Outcomes in Patients Treated With Posterior Lumbar Fusions

STUDY DESIGN

A retrospective database review.

OBJECTIVE

The aim of this study was to compare complication rates following one to two-level lumbar spine surgery in patients with primary hypercoagulable states and coagulopathies.

SUMMARY OF BACKGROUND DATA

Both hypercoagulable states and coagulopathies are not uncommon conditions that have the potential to significantly alter perioperative patient management. However, there are few studies that document the added risk of medical complications following spine surgery in these patient populations.

METHODS

The PearlDiver database (2005-2012) was utilized to determine perioperative complication rates in patients with primary hypercoagulable states and coagulopathies who underwent primary one to two-level posterolateral lumbar spine fusion. Control cohorts without specific hematologic disorders were matched by demographics and comorbidities. Ninety-day complication rates were determined, along with revision rates at one and two years. When considering complication rate comparisons between matched cohorts, P < 0.005 was considered significant.

RESULTS

In total, 746 patients with coagulopathies and 2753 patients with primary hypercoagulable states were selected. Matched control cohorts contained 74,879 and 54,007 patients, respectively. Hypercoagulable patients had significantly increased rates of medical complications [odds ratio (OR) 1.4], infections (OR 1.6), and venous thromboembolisms (OR 9.0) during the three months following spine surgery and same-day transfusions (OR 1.2) when compared with matched controls (P < 0.001). Patients with von Willebrand disease or hemophilia had increased rates of three-month infections (OR 2.3) and transfusion (OR 2.0) when compared with a matched control group (P < 0.005). One- and two-year revisions rates were not significantly higher for either pathologic cohort when compared to matched controls.

CONCLUSION

Both primary hypercoagulable states and coagulopathies increase infection and transfusion rates following one to two-level lumbar spine surgery.

LEVEL OF EVIDENCE

3.

Thromboembolic Disease after Cervical Spine Surgery: A Review of 5,405 Surgical Procedures and Matched Cohort Analysis

STUDY DESIGN

Retrospective matched cohort analysis.

OBJECTIVE

The majority of the literature on venous thromboembolism (VTE) after spine surgery is limited to studies of thoracolumbar surgery. Less is known regarding the incidence of VTE and associated risk factors following cervical spine surgery.

METHODS

A total of 5,405 patients at our institution underwent cervical diskectomy, laminectomy, corpectomy, laminoplasty, or fusion between 1995 and 2012; 85 of the 5,405 patients (1.57%) suffered either a DVT (55) or pulmonary embolus (51) within 30 days postoperatively. The cases were matched 1:2 to controls based on age, sex, and date of surgery. Data regarding multiple perioperative factors, demographics, and comorbidities was collected.

RESULTS

Several risk factors were identified for VTE. Significant medical comorbidities included chronic venous insufficiency (odds ratio [OR] = 3.40), atrial fibrillation (OR = 2.69), obesity (OR = 2.67), and ischemic heart disease (OR = 2.18). Staged surgery (OR = 28.0), paralysis (OR = 19.0), combined approach (OR = 7.46), surgery for infection (OR = 18.5), surgery for trauma (OR = 11.1), comorbid traumatic injuries (OR > 10), oncologic procedures (OR = 5.2), use of iliac crest autograft (OR = 4.16), two or more surgical levels (OR = 3.48), blood loss > 300 mL (OR = 1.66), and length of stay 5 days or greater (OR = 3.47) were all found to be risk factors for VTE (p < 0.05) in univariate analysis. Multivariate analysis found staged surgery (OR = 35.7), paralysis (OR = 7.86), and nonelective surgery (OR = 6.29) to be independent risk factors for VTE.

CONCLUSIONS

Although the incidence of VTE following cervical spine surgery is low, we identified several risk factors that may be predictive. More aggressive approaches to prophylaxis and surveillance in certain patient populations may be warranted.

Prophylactic inferior vena cava filter placement prior to lumbar surgery in morbidly obese patients: Two-case study and literature review

Background:

Preoperative “prophylactic” placement of inferior vena cava (IVC) filters in morbidly obese patients (e.g., body mass index [BMI] >40 or BMI over 35 with hypertension/diabetes) undergoing multilevel decompressive lumbar laminectomies may reduce the risk of postoperative pulmonary embolism (PE), and death.

Methods:

Two patients, ages 69 and 68, with morbid obesity (BMI's of 40.4 and 37.5 both with hypertension and diabetes), received prophylactic IVC filters prior to L1–S1 laminectomies. Intraoperatively and postoperatively, both received alternating compression stocking prophylaxis, and received subcutaneous heparin 5000 U q12 h 48 h after surgery until discharge; none developed deep venous thrombosis (DVT) or PE, and both filters were uneventfully removed within 3 postoperative months.

Results:

The spinal surgical literature largely supports the placement of IVC filters for major risk factors; obesity (BMI >40), a history of DVT/PE, cancer, fusions, hypercoagulation syndromes, pulmonary/circulatory disorders, preoperative/postoperative immobility, staged procedures (five spinal levels), combined anterior-posterior surgery, iliocaval manipulation, age >80, and prolonged surgery (e.g., >261 min vs. >8 h). Although the safety and efficacy of prophylactic IVC filters for spine surgery in patients with morbidly obesity are well substantiated, those for bariatric patients are less clear.

Conclusions:

Prophylactic IVC filters were successfully placed/retrieved in 2 morbidly obese patients, ages 68 and 69, undergoing L1–S1 lumbar decompressions. Although the spine surgery literature documents the safety/efficacy of prophylactic IVC filters in patients with morbid obesity, the bariatric literature still has major concerns.

Prevalence and risk factors of deep vein thrombosis in patients after spine surgery: a retrospective case-cohort study

Deep vein thrombosis (DVT) is common seen in patients undergoing spine surgery. However, its prevalence and associated risk factors have not been well understood yet. This retrospective case-cohort study was designed to investigate risk factors for postoperative DVT using retrospectively collected data from department of spine surgery between 07/2013 and 07/2014. Univariate analysis and binary logistic regression analysis were used to determine risk factors for DVT. A total of 861 patients were admitted into DVT-associated analyses, including 410 males and 451 females, aged from 15 to 87 years old (median 54, IQR 18). Of them, 147 cases (17%) sustained postoperative DVT. DVT incidence was 15.9% in patients undergoing lumbar interbody fusion, 13.5% in patients treated by low-molecular-weight heparin (LMWH), while only 8.1% in patients without LMWH. However, it revealed no significant difference between LMWH group and non-LMWH group (χ² = 1.933, p = 0.164). Logistic regression equation was logit P = −4.09 + 0.05*X₁ − 0.55*X₂ + 0.41*X₃ + 1.41*X₇, (X₁ = age; X₂ = regions; X₃ = hypertension; X₇ = D-dimer). In this study, LMWH prophylaxis after spine surgery proved ineffective. Advanced age, D-dimer and hypertension have proved to be the risk factors for postoperative DVT in patients undergoing spine surgery.

Prevalence and countermeasures for venous thromboembolic diseases associated with spinal surgery: a follow-up study of an institutional protocol in 209 patients

STUDY DESIGN

A prospective study of 209 patients undergoing spinal surgery.

OBJECTIVE

To determine the incidence of venous thromboembolic diseases, including deep venous thrombosis (DVT) and pulmonary embolism (PE), and to evaluate the effectiveness of an institutional protocol for venous thromboembolic diseases during the spinal surgery perioperative period.

SUMMARY OF BACKGROUND DATA

Although patients undergoing spinal surgery are at risk of venous thromboembolism (VTE), there are no universally accepted guidelines for VTE prophylaxis.

METHODS

Between December 2006 and January 2011, 209 patients undergoing spinal surgery (121 males, 88 females; average age: 64 yr), who also had ultrasonographic assessments of both legs before and after surgery, were prospectively assessed. A pneumatic sequential compression device and standard compression stockings were used for primary VTE prophylaxis. In Mie University Hospital protocol, pharmacological agents were not used for VTE prophylaxis after surgery. However, when a distal type DVT was found preoperatively, an anticoagulant medication was administered until 6 hours prior to surgery. After detection of DVTs, weekly ultrasonography assessed the DVT.

RESULTS

Twenty-three patients (11.0%) showed VTE in the spinal surgery perioperative period. Nine patients (4.3%) had VTE (PE with proximal DVT, 1 [0.5%]; distal DVT, 8 [3.8%]) before surgery. In the one case of asymptomatic PE with proximal DVT, an inferior vena cava filter was placed before surgery. Fourteen patients (6.7%) developed new-onset VTE (PE with proximal DVT, 2 [1.0%]; distal DVT, 12 [5.9%]) after spinal surgery. New-onset PE with proximal DVT occurred in 2 patients after surgery. Follow-up ultrasonographic assessment showed that the DVT disappeared completely in 85% (17/20) of patients with a distal type DVT during the perioperative period.

CONCLUSION

DVT assessment using ultrasonography is important for proper management of VTE during the perioperative period of spinal surgery, especially for high-risk patients, such as those with advanced age or neurological deficit. The institutional protocol for VTE using pneumatic sequential compression device and compression stockings is effective, although the administration of chemoprophylaxis should be considered for high-risk patients, such as those with spinal tumors and spinal trauma.

Up-to-date thromboprophylaxis in elective spinal surgery. A systematic review

Deep vein thrombosis (DVT) and pulmonary embolism (PE) present a high incidence after surgery, posing a high risk in surgical practice. Although a consensus does exist on thromboprophylaxis in orthopedic surgery, this topic remains controversial in regard to spinal surgery. In this current paper, we review and discuss the different forms of prophyilaxis presented in literature, in order to develop guidelines on prophylactic measures in spinal surgery, improving patient´s outcomes and reducing any medical/legal problems that could arise from a thrombotic complication.

Low-molecular-weight heparin prophylaxis 24 to 36 hours after degenerative spine surgery: risk of hemorrhage and venous thromboembolism

STUDY DESIGN

Retrospective review.

OBJECTIVE

To assess the safety and efficacy of prophylactic low-molecular-weight heparin (LMWH) started 24 to 36 hours after degenerative spine surgery.

SUMMARY OF BACKGROUND DATA

Venous thromboembolism (VTE) is a significant postoperative complication best averted with dual mechanical/pharmacological prophylaxis. Pharmacological prophylaxis is widely used in patients with spinal cord injury, but there is no consensus on its role in degenerative spine surgery, particularly after laminectomy with the concurrent risk of epidural hematoma. The literature suggests a small but potentially devastating hemorrhage risk when LMWH is started within 24 hours of spine surgery. An intermediate strategy is delayed LMWH initiation to minimize hemorrhage risk and retain benefits of dual prophylaxis.

METHODS

Operative reports of the senior author were retrospectively reviewed for all cases of cervical and lumbar laminectomy from 2007 to 2011. Single-level decompressions without fusion and all nondegenerative cases were excluded. Baseline and operative details were recorded. Mechanical prophylaxis was used throughout admission, and prophylactic LMWH was started postoperative day 1 at 10 PM. All cases of postoperative hemorrhage (epidural hematoma, superficial hematoma, persistent wound drainage), deep venous thrombosis, and pulmonary embolism were noted.

RESULTS

A total of 367 patients underwent multilevel laminectomy or laminectomy and fusion for degenerative disease. VTE risk factors (age >60 yr, smoking, obesity) were common. No patients receiving LMWH 24 to 36 hours after surgery developed postoperative hemorrhage (95% confidence interval: 0-0.8%). Nearly half of the study population underwent lower extremity ultrasonography or chest computed tomography, and acute VTE was diagnosed in 14 patients (3.8%; 95% confidence interval: 2.1-6.3).

CONCLUSION

LMWH prophylaxis seems to carry a very low hemorrhage risk when started 24 to 36 hours after spine surgery. Larger, prospective studies are needed to assess the safety of early delayed LMWH administration more definitively. Even with aggressive prophylaxis, patients undergoing fusion or multilevel laminectomy for degenerative disease are at significant risk for VTE.

The incidence and mortality of thromboembolic events in lumbar spine surgery

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

A population-based database was analyzed to identify the incidence, risk factors, and mortality associated with thromboembolic events after lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Pulmonary embolism (PE) and deep vein thrombosis (DVT) are potential complications that may occur after orthopedic procedures. The incidence of these complications is not well characterized after lumbar spine surgery.

METHODS

Data from the Nationwide Inpatient Sample was obtained from 2002-2009. Patients undergoing lumbar decompression (LD), or lumbar fusion (LF) for degenerative conditions were identified. Acute PE and DVT incidences and mortality rates were calculated. Comorbidities were calculated using a modified Charlson Comorbidity Index. Statistical analysis was performed using the Student t test for discrete variables and χ test for categorical data. Logistic regression was used to identify independent predictors of thromboembolic events. A P value of less than or equal to 0.0005 was used to denote statistical significance.

RESULTS

A total 578,457 LDs and LFs were identified from 2002-2009. DVT incidences were 2.4 and 4.3 per 1000 cases in the LD and LF groups, respectively. PE incidences were 1.0 and 2.6 per 1000 cases in the LD and LF groups, respectively. Patients who had undergone LF with thromboembolic events were younger, had fewer comorbidities, and incurred greater costs than patients who had undergone LD. Statistically significant predictors of DVT were pulmonary circulation disorders, coagulopathy, fluid/electrolyte disorders, anemia, obesity, teaching hospital status, and larger hospitals. Predictors for the development of PE were pulmonary circulation disorders, fluid/electrolyte disorders, anemia, black ethnicity and teaching hospital status.

CONCLUSION

Patients undergoing LD or LF are at inherent risk of thromboembolic events. DVT and PE are more common after LF procedures. Preoperative pulmonary circulation disorders, fluid/electrolyte disorders, deficiency anemia, and teaching hospital status were significant risk factors for developing both DVT and PE. Preventive measures in patients at risk may decrease the incidence of thromboembolic events.

LEVEL OF EVIDENCE

4.

The incidence and mortality of thromboembolic events in cervical spine surgery

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

A nationwide population-based database was analyzed to identify the incidence, risk factors, and mortalities associated with venous thromboembolism (VTE) after cervical spine surgery.

SUMMARY OF BACKGROUND DATA

Pulmonary embolism (PE) and deep vein thrombosis (DVT) are potential complications that may occur after orthopedic procedures. Incidences of these complications are not well characterized after cervical spine surgery.

METHODS

Data from the Nationwide Inpatient Sample database were obtained from 2002 to 2009. Patients undergoing anterior cervical fusion, posterior cervical fusion, and posterior cervical decompression (i.e., laminoforaminotomy, laminectomy, laminoplasty) for the diagnosis of cervical myelopathy and/or radiculopathy were identified. Incidences of PE and DVT were calculated. Comorbidities were calculated using the modified Charlson Comorbidity Index. Mortality associated with these complications was assessed in the 3 surgical subgroups. Statistical analysis was performed to assess significant differences between groups. Logistic regression was used to identify independent predictors of VTE. A P value of <0.0005 was used to denote significance.

RESULTS

There were 273,396 cervical procedures recorded in the Nationwide Inpatient Sample database from 2002 to 2009. Posterior cervical fusion-treated patients had statistically the highest incidences of DVT and PE, whereas the lowest PE and DVT rates were found in anterior cervical fusion-treated patients (P < 0.0005). All patients with thromboembolic events had significantly increased rates of mortality, hospitalization, and costs compared with patients without VTE across all procedural groups. Logistic regression analysis demonstrated statistically significant predictors of VTE to be male sex, pulmonary circulation disorders, fluid/electrolyte disorders, and teaching-hospital status.

CONCLUSION

Thromboembolic events are potential complications of cervical spine surgery. The highest rates of VTE were identified in those patients undergoing posterior cervical fusion. Regardless of approach, DVT and PEs resulted in increased mortality rates and hospitalization. We recommend a thorough preoperative assessment to identify patients at risk for VTE and treat accordingly to decrease the incidence of these thromboembolic events.

Incidence of deep vein thrombosis after major spine surgeries with no mechanical or chemical prophylaxis

Study design: Retrospective cohort study.

Clinical question: What is the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) after major spine surgery when no prophylactic measures were used?

Methods: A prospective evaluation of 121 patients who underwent 128 major spine surgeries was conducted to determine the incidence of clinically identifiable DVT. As a matter of practice, no patient was given thromboprophylaxis, either mechanical or chemical.

Results: Only one patient developed the signs and symptoms of DVT, which was further confirmed by a Doppler study. The overall incidence of DVT was 0.78%. There was no clinically evident case of PE.

Conclusions: Considering the low rate of incidence of DVT and PE, routine screening and prophylaxis for DVT appears unwarranted in major spine surgery.

How much medicine do spine surgeons need to know to better select and care for patients?

Background:

Although we routinely utilize medical consultants for preoperative clearance and postoperative patient follow-up, we as spine surgeons need to know more medicine to better select and care for our patients.

Methods:

This study provides additional medical knowledge to facilitate surgeons’ “cross-talk” with medical colleagues who are concerned about how multiple comorbid risk factors affect their preoperative clearance, and impact patients’ postoperative outcomes.

Results:

Within 6 months of an acute myocardial infarction (MI), patients undergoing urological surgery encountered a 40% mortality rate: similar rates may likely apply to patients undergoing spinal surgery. Within 6 weeks to 2 months of placing uncoated cardiac, carotid, or other stents, endothelialization is typically complete; as anti-platelet therapy may often be discontinued, spinal surgery can then be more safely performed. Coated stents, however, usually require 6 months to 1 year for endothelialization to occur; thus spinal surgery is often delayed as anti-platelet therapy must typically be continued to avoid thrombotic complications (e.g., stroke/MI). Diabetes and morbid obesity both increase the risk of postoperative infection, and poor wound healing, while the latter increases the risk of phlebitis/pulmonary embolism. Both hypercoagluation and hypocoagulation syndromes may require special preoperative testing/medications and/or transfusions of specific hematological factors. Pulmonary disease, neurological disorders, and major psychiatric pathology may also require further evaluations/therapy, and may even preclude successful surgical intervention.

Conclusions:

Although we as spinal surgeons utilize medical consultants for preoperative clearance and postoperative care, we need to know more medicine to better select and care for our patients.

Use and outcomes of venous thromboembolism prophylaxis after spinal fusion surgery

BACKGROUND

The number of spinal fusion operations in the USA is rapidly rising, but little is known about optimal venous thromboembolism prophylaxis after spinal surgery.

OBJECTIVES

To examine the use of and outcomes associated with venous thromboembolism prophylaxis after spinal fusion surgery in a cohort of 244 US hospitals.

PATIENTS/METHODS

 We identified all patients with a principal procedure code for spinal fusion surgery in hospitals participating in the Premier Perspective database from 2003 to 2005, and searched for receipt of pharmacologic prophylaxis (subcutaneous unfractionated heparin, low molecular weight heparin, or fondaparinux) and/or mechanical prophylaxis (compression devices and elastic stockings) within the first 7 days after surgery. We also searched for discharge diagnosis codes for venous thromboembolism and postoperative hemorrhage during the index hospitalization and within 30 days after surgery.

RESULTS

Among 80,183 spinal fusions performed during the time period, cervical fusions were the most common (49.0%), followed by lumbar fusions (47.8%). Thromboembolism prophylaxis was administered to 60.6% of patients within the first week postoperatively, with the most frequent form being mechanical prophylaxis alone (47.6%). Of the 244 hospitals, 26.2% provided prophylaxis to ≥ 90% of their patients undergoing spinal fusion; however, 33.2% provided prophylaxis to fewer than 50% of their patients. The rate of diagnosed venous thromboembolism within 30 days after surgery was 0.45%, and the rate of postoperative hemorrhage was 1.1%.

CONCLUSIONS

 Substantial variation exists in the use of thromboembolism prophylaxis after spinal fusion surgery in the USA. Nevertheless, overall rates of diagnosed thromboembolism after spinal fusion appear to be low.

Thromboembolic Complications Following Spine Surgery Assessed with Spiral CT Scans: DVT/PE Following Spine Surgery

Spine surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). The goal of this study was to determine which symptoms and risk factors were associated with spiral CT scans positive for PE and/or DVT in the postoperative spine surgery patient. We conducted a retrospective review of all spine patients who underwent a postoperative CT to rule out PE during the period of March 2004-February 2006. The type of surgical procedure, risk factors, symptoms prompting scan ordering, anticoagulation, and treatment were recorded. Logistic regression models were used to determine significant predictors of a positive CT in this patient population. Of the 3,331 patients that had spine surgery during the study period, 130 (3.9%) had a spiral CT scan to rule out PE and/or proximal DVT. Thirty-three of the 130 (25.4%) CT scans were positive for PE only, five (3.8%) for PE and DVT, and three (2.3%) for DVT only. Only 24.5% (32) patients had risk factors for thromboembolic disease, and of these, a history of PE and/or DVT was the only significant risk factor for a positive scan (p = 0.03). No presenting symptoms or demographic variables were noted to have a significant association with PE and/or DVT. The type of surgical procedure (i.e., anterior, posterior, and percutaneous) was not associated with an increased risk for PE and/or DVT. Patients who are undergoing spine surgery with a history of thromboembolic disease should be carefully monitored postoperatively and may benefit from more aggressive prophylaxis.

Pulmonary embolism in spine surgery: a comparison of combined anterior/posterior approach versus posterior approach surgery

STUDY DESIGN

retrospective review.

OBJECTIVE

to determine if Anterior/Posterior Combined approach spine surgery is associated with an increased risk of pulmonary embolism (PE) compared to Posterior Only approach surgery.

SUMMARY OF BACKGROUND DATA

combined anterior/posterior approach spine surgery is associated with a significantly increased risk for PE. However, it is uncertain if there is any difference in risk between combined approaches versus a posterior-only approach.

METHODS

a prospective cohort of patients who underwent anterior/posterior combined approach spine surgery from January 2002 to January 2006 was compared to a retrospective cohort of consecutive patients who underwent posterior only approach spine surgery from September2007 to September 2008. Patient demographics, medical history, body-mass indexes, type of surgery, length of surgery, transfusions, and instrumented vertebral levels were collected from hospital and office records. Hospital records were used to identify patients who developed PE based on diagnosis by spiral CT scan. CT scans were only performed when a patient's clinical picture raised suspicion of PE. Fisher exact test for significance, χ test and odds ratios were used for analysis.

RESULTS

a total of 119 patients were included in the study: 63 patients underwent posterior approach spine surgery and 66 patients underwent combined anterior/posterior approach surgery. One patient (1.6%) developed PE after posterior approach surgery while 5 patients (7.5%) developed PE in the combined approach group. Those undergoing combined approaches were 5.08 times more likely to suffer from PE, but this increase was not significant (P = 0.208). Overall, increased risk for PE was associated with the number of levels fused (P = 0.006), total blood loss (P = 0.029), and number of units transfused (P = 0.030). The combined approach was associated with older age (P < 0.001), higher BMI (P = 0.023), more instrumented vertebrae (P < 0.001), greater total blood loss (P < 0.001) and cell saver infusion (P = 0.004) compared to the posterior only approach.

CONCLUSION

combined anterior/posterior approach spine surgery is associated with an increased risk for pulmonary embolism compared to posterior only approaches. However, regardless of the surgical approach, risk factors for PE common in both groups were operative time, total blood loss, number of levels fused, and the number of units transfused. Patients who undergo spine surgery with prolonged operative times and greater blood loss should be recognized as higher risk patients.

Complications in spinal deformity surgery: issues unrelated directly to intraoperative technical skills

STUDY DESIGN

Literature review of complications unrelated directly to surgical skills involved in spinal deformity surgery.

OBJECTIVE

Highlight complications associated with perioperative issues.

SUMMARY OF BACKGROUND DATA

Complications can arise from mundane events that arise during the operative experience, but are not directly related to surgical skills.

METHODS

Literature reviews that touches on the more common potential complication events that do not involve direct surgical expertise.

RESULTS

The topics of positioning, nutrition, blood loss, comorbidities, OR time, and pulmonary and GI concerns are discussed as basics that could derail a surgical outcome even with an otherwise uneventful surgical technique. The need for vigilance is stressed and the nuances of understanding these are discussed.

CONCLUSION

Mundane events can derail a perfectly executed surgical undertaking. Attention to detail, team work, close monitoring, and checklist type focus will help to improve, focus, and avoid these preventable complications that have nothing to do with direct surgical skills.

Anticoagulation risk in spine surgery

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine the high-risk populations for thromboembolic events in spine surgery patients, the risk of anticoagulation in spine surgery patients by type of anticoagulation, and whether there is a safe perioperative window of nonanticoagulation for these high-risk patients.

SUMMARY OF BACKGROUND DATA

Thromboembolic complications after major spinal surgery is a significant risk for patients. Anticoagulation to reduce this risk is of concern because of the possibility of excessive bleeding or postoperative hematomas and associated neurologic deficits. There seems to be a paucity of literature on this topic.

METHODS

A systematic review of the English-language literature was undertaken for articles published between January 1990 and December 2008. Electronic databases and reference lists of key articles were searched to identify published studies examining coagulopathy in major spine surgery. Two independent reviewers assessed the strength of literature using the Grading of Recommendations Assessment, Development, and Evaluation criteria, assessing quality, quantity, and consistency of results. Disagreements were resolved by consensus.

RESULTS

A total of 93 articles were initially screened, and 29 ultimately met the predetermined inclusion criteria. The risk of thromboembolism in patients not receiving chemical prophylaxis was slightly higher in surgery to correct deformity (5.3%) and trauma patients (6.0%) than in surgery for degenerative conditions (2.3%). Fatal pulmonary embolism was rare. Bleeding complications occurred rarely with the use of anticoagulation; risk of major bleeding ranged from 0.0% to 4.3% across several types of anticoagulants. Postoperative hematoma was reported in only 10 of 2507 patients.

CONCLUSION

Venous thromboembolism is uncommon after elective spine surgery. Trauma patients are at increased risk, and chemical prophylaxis should be considered. The safe timing of the administration of anticoagulation agents is unknown.

The prevalence of and specific risk factors for venous thromboembolic disease following elective spine surgery

BACKGROUND

Venous thromboembolic disease, including deep venous thrombosis and pulmonary embolism, is a serious and potentially life-threatening complication following orthopaedic surgical procedures. We sought to investigate the prevalence of thromboembolism as well as the efficacy and complications of various prophylactic measures in a population of patients who had undergone elective spine surgery.

METHODS

A meta-analysis and univariate logistic regression were performed on selected studies to determine the prevalence of and risk factors for deep venous thrombosis and pulmonary embolism following elective spine surgery. Studies were included on the basis of the selection criteria (specifically, the inclusion of only patients undergoing spine surgery, or the treatment of patients undergoing spine surgery as an independent cohort; the use of an objective diagnostic modality for the diagnosis of deep venous thrombosis, including Doppler ultrasonography or venography; the use of an objective diagnostic modality for the diagnosis of pulmonary embolism, including computed tomography of the chest or a ventilation-perfusion scan; and a study population of more than thirty patients). Patients with a known spinal cord injury were excluded.

RESULTS

Fourteen studies (including a total of 4383 patients) met our selection criteria. On the basis of the meta-analysis, the prevalence of deep venous thrombosis was 1.09% (95% confidence interval, 0.54% to 1.64%) and the prevalence of pulmonary embolism was 0.06% (95% confidence interval, 0.01% to 0.12%) following elective spine surgery. The use of pharmacologic prophylaxis significantly reduced the prevalence of deep venous thrombosis relative to either mechanical prophylaxis (p = 0.047) or no prophylaxis (p < 0.01). One fatal pulmonary embolism was reported. An epidural hematoma requiring surgical evacuation was reported in eight of 2071 patients receiving pharmacologic prophylaxis; three of these patients had a permanent neurologic deficit.

CONCLUSIONS

The risk of deep venous thrombosis and pulmonary embolism is relatively low following elective spine surgery, particularly for patients who receive pharmacologic prophylaxis. Unfortunately, pharmacologic prophylaxis exposes patients to a greater risk of epidural hematoma. More evidence is needed prior to establishing a protocol for prophylaxis against venous thromboembolic disease in patients undergoing elective spine surgery. Future prospective studies should seek to define the safety of various prophylactic modalities and to identify specific subpopulations of patients who are at greater risk for venous thromboembolism.

Critical Care of the Patient with Acute Pancreatitis

Acute pancreatitis is an inflammatory process of the pancreas with variable involvement of regional tissues and remote organs. This review gives a comprehensive overview of the aetiology, pathophysiology, diagnosis and therapy of acute pancreatitis relevant to the intensivist. Recent international guidelines on the management of acute pancreatitis are summarised.

Eighty percent of acute pancreatitis episodes are related either to gallstones or to alcohol abuse. Independent of its aetiology, the pathophysiologic hallmark of acute pancreatitis is the premature activation of trypsin, which leads to massive pancreas inflammation, systemic overproduction of pro-inflammatory mediators and ultimately remote organ dysfunction. All guidelines agree that the diagnosis of acute pancreatitis should include clinical symptoms, increased serum amylase or lipase levels and/or characteristic findings on computed tomography. Endoscopic retrograde cholangiopancreatography is recommended as a causative therapy in patients with acute cholangitis or a strong suspicion of gallstones. All guidelines underline the importance of vigorous fluid resuscitation and supplemental oxygen therapy and prefer enteral over parenteral nutrition, with the majority favouring the nasojejunal route. In view of lacking scientific evidence, antibiotic prophylaxis to prevent infection of pancreatic necroses is discouraged by most guidelines. Computed tomography-guided fine needle aspiration is the technique of choice to differentiate between sterile and infected pancreas necrosis. While sterile pancreatic necrosis should be managed conservatively, infected pancreatic necrosis requires debridement and drainage supplemented by antibiotic therapy. Surgical necrosectomy is the traditional approach, but less invasive techniques (retroperitoneal or laparoscopic necrosectomy, computed tomography-guided percutaneous catheter drainage) may be equally effective.

Venous thromboembolism in spine surgery

Venous thromboembolism is a life-threatening adverse event in spine patients and presents difficult decisions for the surgeon and patient. Prophylactic protocols have been established to prevent the occurrence of venous thromboembolism and its sequelae, including venous occlusion, edema, postthrombotic syndrome, and death. Despite the known benefits of prophylaxis, some surgeons choose not to use it because of concerns over increased bleeding complications and possible iatrogenic neurologic injury. Although mechanical prophylaxis remains an important element in venous thromboembolism prevention, low-molecular-weight heparin is better than other pharmacologic therapies in decreasing the incidence of major events.