Prognostic Factors Associated with Venous Thromboembolism Following Traumatic Injury: A Systematic Review and Meta-Analysis

INTRODUCTION

Trauma patients are at increased risk of venous thromboembolism (VTE), including deep venous thrombosis (DVT) and/or pulmonary embolism (PE). We conducted a systematic review and meta-analysis summarizing the association between prognostic factors and the occurrence of VTE following traumatic injury.

METHODS

We searched the EMBASE and MEDLINE databases from inception to August 2023. We identified studies reporting confounding adjusted associations between patient, injury or post-injury care factors and risk of VTE. We performed meta-analyses of odds ratios (ORs) using the random effects method and assessed individual study risk of bias using the QUIPS tool.

RESULTS

We included 31 studies involving 1,981,946 patients. Studies were predominantly observational cohorts from North America. Factors with moderate or higher certainty of association with increased risk of VTE include older age, obesity, male sex, higher injury severity score, pelvic injury, lower extremity injury, spinal injury, delayed VTE prophylaxis, need for surgery and tranexamic acid use. After accounting for other important contributing prognostic variables, a delay in the delivery of appropriate pharmacologic prophylaxis for as little as 24 to 48 hours independently confers a clinically meaningful two-fold increase in incidence of VTE.

CONCLUSION

These findings highlight the contribution of patient predisposition, the importance of injury pattern, and the impact of potentially modifiable post-injury care on risk of VTE after traumatic injury. These factors should be incorporated into a risk stratification framework to individualize VTE risk assessment and support clinical and academic efforts reduce thromboembolic events among trauma patients.Study TypeSystematic Review & Meta-Analysis.

LEVEL OF EVIDENCE

Level II.

Association Between Geospatial Access to Trauma Center Care and Motor Vehicle Crash Mortality in the United States

BACKGROUND

Motor vehicle crashes (MVCs) are a leading cause of preventable trauma death in the United States (US). Access to trauma center care is highly variable nationwide. The objective of this study was to measure the association between geospatial access to trauma center care and MVC mortality.

METHODS

This was a population-based study of MVC-related deaths that occurred in 3,141 US counties (2017-2020). ACS and state-verified level I-III trauma centers were mapped. Geospatial network analysis estimated the ground transport time to the nearest trauma center from the population-weighted centroid for each county. In this way, the exposure was the predicted access time to trauma center care for each county population. Hierarchical negative binomial regression measured the risk-adjusted association between predicted access time and MVC mortality, adjusting for population demographics, rurality, access to trauma resources, and state traffic safety laws.

RESULTS

We identified 92,398 crash fatalities over the four-year study period. Trauma centers mapped included 217 level I, 343 level II, and 495 level III trauma centers. The median county predicted access time was 47 min (IQR 26-71 min). Median county MVC mortality was 12.5 deaths/100,000 person-years (IQR 7.4-20.3 deaths/100,000 person-years). After risk-adjustment, longer predicted access times were significantly associated with higher rates of MVC mortality (>60 min vs. <15 min; MRR 1.36; 95%CI 1.31-1.40). This relationship was significantly more pronounced in urban/suburban vs. rural/wilderness counties (p for interaction, <0.001). County access to trauma center care explained 16% of observed state-level variation in MVC mortality.

CONCLUSIONS

Geospatial access to trauma center care is significantly associated with MVC mortality and contributes meaningfully to between-state differences in road traffic deaths. Efforts to improve trauma system organization should prioritize access to trauma center care to minimize crash fatalities.

LEVEL OF EVIDENCE

Level III, Epidemiological.

Emergency department versus operating room intubation of patients undergoing immediate hemorrhage control surgery

BACKGROUND

Hemorrhage control surgery is an essential trauma center function. Airway management of the unstable bleeding patient in the emergency department (ED) presents a challenge. Premature intubation in the ED can exacerbate shock and precipitate extremis. We hypothesized that ED versus operating room intubation of patients requiring urgent hemorrhage control surgery is associated with adverse outcomes at the patient and hospital-levels.

METHODS

Patients who underwent hemorrhage control within 60 minutes of arrival at level 1 or 2 trauma centers were identified (National Trauma Data Bank 2017-2019). To minimize confounding, patients dead on arrival, undergoing ED thoracotomy, or with clinical indications for intubation (severe head/neck/face injury or Glasgow Coma Scale score of ≤8) were excluded. Two analytic approaches were used. First, hierarchical logistic regression measured the risk-adjusted association between ED intubation and mortality. Secondary outcomes included ED dwell time, units of blood transfused, and major complications (cardiac arrest, acute respiratory distress syndrome, acute kidney injury, sepsis). Second, a hospital-level analysis determined whether hospital tendency ED intubation was associated with adverse outcomes.

RESULTS

We identified 9,667 patients who underwent hemorrhage control surgery at 253 trauma centers. Patients were predominantly young men (median age, 33 years) who suffered penetrating injuries (71%). The median initial Glasgow Coma Scale and systolic blood pressure were 15 and 108 mm Hg, respectively. One in five (20%) of patients underwent ED intubation. After risk-adjustment, ED intubation was associated with significantly increased odds of mortality, longer ED dwell time, greater blood transfusion, and major complications. Hospital-level analysis identified significant variation in use of ED intubation between hospitals not explained by patient case mix. After risk adjustment, patients treated at hospitals with high tendency for ED intubation (compared with those with low tendency) were significantly more likely to suffer in-hospital cardiac arrest (6% vs. 4%; adjusted odds ratio, 1.46; 95% confidence interval, 1.04-2.03).

CONCLUSION

Emergency department intubation of patients who require urgent hemorrhage control surgery is associated with adverse outcomes. Significant variation in ED intubation exists between trauma centers not explained by patient characteristics. Where feasible, intubation should be deferred in favor of rapid resuscitation and transport to the operating room.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Predictors of Blunt Cerebrovascular Injury, Stroke, and Mortality in Patients with Cervical Spine Trauma

BACKGROUND

Blunt cerebrovascular injury (BCVI), defined as blunt traumatic injury to the carotid or vertebral arteries, is associated with significant risk of stroke and mortality. Cervical spine trauma is a recognized risk factor for BCVI.

OBJECTIVE

The objective of this study was to identify significant predictors of BCVI and its sequelae in patients with known cervical spine injury.

METHODS

Patients from 2007 to 2018 with blunt cervical spine injury diagnoses were identified in the National Trauma Data Bank. Multivariable logistic regression models were used to identify patient baseline and injury characteristics associated with BCVI, stroke, and mortality.

RESULTS

We identified 229,254 patients with cervical spine injury due to blunt trauma. The overall rate of BCVI was 1.6%. Factors associated with BCVI in patients with cervical spine injury included lower Glasgow Coma Scale, motor vehicle crash, higher Injury Severity Score, concomitant traumatic brain or spinal cord injury, and current smoking status. BCVI was a strong predictor of stroke (odds ratio, 8.2; 95% confidence interval, 5.7-12.0) and was associated with mortality (odds ratio, 1.7; 95% confidence interval, 1.3-2.2). Stroke occurred in 3.3% of patients with BCVI versus 0.02% for patients without BCVI.

CONCLUSIONS

While BCVI is rare following cervical spine injury due to blunt trauma, it is a significant predictor of stroke and mortality. The risk factors associated with BCVI, stroke, and mortality identified here should be used in the development of more effective predictive tools to improve care.

Urology Consult Association with Renal Trauma Imaging and Intervention

OBJECTIVE

To describe rates of urology consultation following renal trauma and assess subsequent impact on imaging and intervention. Renal trauma may be initially managed by either trauma or urologic surgeons alone or collaboratively. Differences in management between the specialties are not well studied.

METHODS

We conducted an IRB-approved retrospective review of patients at a Level I trauma center sustaining renal trauma between 2014 and 2021. Demographic, injury, radiologic, and intervention variables were extracted. Frequencies and medians were compared using chi-squared and Fischer's exact tests or Mann-Whitney U tests, respectively. Analyses were performed using STATA with p<0.05 considered significant.

RESULTS

From 2014 to 2021, 118 patients with median age 29 (IQR 22-41) sustained renal trauma. Urology was consulted in 18 (15.3%) cases. Demographic and injury characteristics were similar between the two groups. AAST renal injury grade was transcribed in the initial radiologic reports for 49 (41.5%) of patients. Those in the urology consult group were more likely to receive delayed contrast imaging during their admission (50.0% vs. 17.0%, p<0.01). Among those with high-grade injuries, those with urology consult were less likely to undergo nephrectomy (36.4% vs. 78.8%, p=0.02).

CONCLUSIONS

We observed differences in imaging patterns between renal trauma patients who are managed primarily by trauma surgery versus urology. However, the impact of these differences in imaging remains to be elucidated. Among patients with high-grade renal trauma, urology consult was associated with decreased rate of nephrectomy, emphasizing the feasibility of renal salvage in a multidisciplinary trauma setting.

Impact of Geographic Socioeconomic Disadvantage on Minor Amputation Outcomes in Patients With Diabetes

BACKGROUND

Socioeconomic disadvantage is a known contributor to adverse events and higher admission rates in the diabetic population. However, its impact on outcomes after lower extremity amputation is unclear. We aimed to assess the association of geographic socioeconomic disadvantage with short- and long-term outcomes after minor amputation in patients with diabetes.

MATERIALS AND METHODS

Geographic socioeconomic disadvantage was determined using the area deprivation index (ADI). All patients from the Maryland Health Services Cost Review Commission database (2012-2019) who underwent minor amputation with a concurrent diagnosis of diabetes were included and stratified by the ADI quartile. Associations of the ADI quartile with 30-day readmission and 1-year reamputation were evaluated using Kaplan-Meier survival analyses and multivariable logistic regression models adjusting for baseline differences.

RESULTS

A total of 7415 patients with diabetes underwent minor amputation (70.1% male, 38.7% black race), including 28.1% ADI1 (least deprived), 42.8% ADI2, 22.9% ADI3, and 6.2% ADI4 (most deprived). After adjusting for demographic and clinical factors, the odds of 30-day readmission were greater in the intermediate ADI groups than those in the ADI1 group, but not among the most deprived. Adjusted odds of 1-year reamputation were greater among ADI4 than those among ADI1. Kaplan-Meier analysis confirmed a greater likelihood of reamputation with an increasing ADI quartile over a 1-year period (P < 0.001).

CONCLUSIONS

Geographic socioeconomic disadvantage is independently associated with both short- and long-term outcomes after minor diabetic amputations in Maryland. A targeted approach addressing the health care needs of deprived regions may be beneficial in optimizing postoperative care in this vulnerable population.

Management of difficult airway among patients with oropharyngeal angioedema

OBJECTIVE

The objective of our study was to assess the impact of a multidisciplinary difficult airway response team (DART), a quality improvement program, in the management of patients with difficult airway associated with oropharyngeal angioedema patients.

METHODS

Individual retrospective cohort study. Retrospective review of patient charts from July 2003 to June 2008 (pre-DART) and retrospective review of prospectively collected data from July 2008 to June 2013 (post-DART). Patients with angioedema were identified using International Classification of Disease codes 995.1 and 277.6. Patients were included in the study if an otolaryngologist was consulted for airway management. Patients were excluded if they had a history of angioedema but no active issues. Patient characteristics, airway evaluation, and interventions (intubation/surgical airway) were compared between the pre-DART and post-DART cohort.

RESULTS

The DART team attended to 27 patients with advanced oropharyngeal angioedema. Response time averaged 3.36 minutes. Preintubation fiberoptic airway evaluations were performed in 81% of the post-DART cohort and 56% of the pre-DART cohort. The incidence of patients requiring intubation was higher in the post-DART cohort (18 out of 27 [67%]) than the pre-DART (14 out of 36 [39%]) cohort. One emergency cricothyroidotomy was performed in each of the post-DART and pre-DART cohorts.

CONCLUSION

Angioedema of the larynx is a predictor of intubation or cricothyroidotomy. Fiberoptic-guided intubation is primarily used for establishing airway in angioedema patients. A multidisciplinary standardized approach such as the DART program offers adequate time and resources for airway evaluation prior to intervention and allows fewer number of attempts to secure an airway.

LEVEL OF EVIDENCE

3 Laryngoscope, 129:1360-1367, 2019.

Processes of Health Care Delivery, Education, and Provider Satisfaction in Acute Care Surgery: A Systematic Review

In recent years, significant workload, high acuity, and complexity of emergency general surgery conditions have led hospitals to replace the traditional on-call model with dedicated acute care surgery (ACS) service models. A systematic search of Ovid, EMBASE, and MEDLINE was undertaken to examine the impact of ACS services on health-care delivery processes and cost, education, and provider satisfaction. From 1827 papers, reviewers identified 22 studies that met inclusion criteria and subsequently used The Evidence-Based Practice for Improving Quality method and Newcastle–Ottawa Scale to score quality and level of evidence. Most studies found an increase in daytime operating, improved patient transit from emergency department to operating room to home, and decreased length of stay. Higher and more diverse case volumes improved resident education and operative experience. ACS services enhanced the educational experience of residents on subspecialty services by offloading emergency work from those services. Finally, surgeons generally felt that ACS services improved job satisfaction, productivity, and billing. The ACS model has demonstrated improvement in timeliness of care, diversified case mix, decreased costs, improved trainee learning, and increased surgeon job satisfaction.

Processes of Health Care Delivery, Education, and Provider Satisfaction in Acute Care Surgery: A Systematic Review

In recent years, significant workload, high acuity, and complexity of emergency general surgery conditions have led hospitals to replace the traditional on-call model with dedicated acute care surgery (ACS) service models. A systematic search of Ovid, EMBASE, and MEDLINE was undertaken to examine the impact of ACS services on health-care delivery processes and cost, education, and provider satisfaction. From 1827 papers, reviewers identified 22 studies that met inclusion criteria and subsequently used The Evidence-Based Practice for Improving Quality method and Newcastle-Ottawa Scale to score quality and level of evidence. Most studies found an increase in daytime operating, improved patient transit from emergency department to operating room to home, and decreased length of stay. Higher and more diverse case volumes improved resident education and operative experience. ACS services enhanced the educational experience of residents on subspecialty services by offloading emergency work from those services. Finally, surgeons generally felt that ACS services improved job satisfaction, productivity, and billing. The ACS model has demonstrated improvement in timeliness of care, diversified case mix, decreased costs, improved trainee learning, and increased surgeon job satisfaction.

Impact of Surgeon Specialty on Perioperative Outcomes of Surgery for Benign Esophageal Diseases: A NSQIP Analysis

BACKGROUND

Surgery for benign esophageal disease is mostly performed either by general surgeons (GS) or cardiothoracic surgeons (CTS) in the United States. The purpose of this study was to evaluate the effect of surgeon specialty on perioperative outcomes of surgery for benign esophageal diseases.

MATERIALS AND METHODS

We have conducted a retrospective analysis using the ACS-NSQIP during the period of 2006-2013. Patients who underwent paraesophageal hernia (PEH) repair, gastric fundoplication, or Heller esophagomyotomy were divided into two groups according to the specialty of the surgeon (GS or CTS). Outcomes compared between the two groups using multivariable logistic regression included 30-day mortality, overall morbidity, discharge destination, hospital length of stay (LOS), and readmission rates.

RESULTS

Most of the surgeries were performed by general surgeons (PEH: 97.1%; fundoplication: 97.6%; Heller: 91.6%). Patients had lower comorbidities, better physical condition, and underwent a laparoscopic approach more frequently in the GS group. Regression analysis showed that GS group had a lower mortality rate (operating room, 0.44; 95% confidence interval [CI]: 0.23-0.86; P = .017), shorter LOS, and more home discharge for patients undergoing PEH repair. Mortality, morbidity, readmission, LOS, and home discharge were comparable between GS and CTS in fundoplication and Heller esophagomyotomy.

CONCLUSION

GS perform most of esophageal surgeries for benign diseases. GS group has better outcomes in PEH repair compared with CTS, whereas there is no difference in the overall outcomes between GS and CTS in fundoplication and Heller esophagomyotomy. These results show that specialization is not always the answer to better outcomes. Difference in outcomes, however, might be related to disease severity, approach needed, or case volume.

Influence of Specialty Training and Trainee Involvement on Perioperative Outcomes of Esophagectomy

BACKGROUND

Hospitals' and surgeons' volume-outcome relationship have been reported in several esophagectomy studies with an inverse association of mortality and volume. The purpose of our study was to evaluate the outcomes of esophagectomy in the United States relative to the surgeon's specialty.

METHODS

This was a retrospective analysis using the American College of Surgeons National Surgical Quality Improvement Program database (2006 to 2013). All patients (18 years of age and older) who underwent esophagectomy were divided into 2 groups according to whether the operation was performed by a general surgeon (GS) or a cardiothoracic surgeon (CTS). A comparison of intraoperative and postoperative outcomes between the groups was conducted. The primary outcome was 30-day mortality. Secondary outcomes included overall and serious morbidity, discharge destination, and length of hospital stay.

RESULTS

Of the 5,142 esophagectomies identified, 70.3% were performed by GS and 29.7% by CTS. Overall, CTS patients had significantly higher comorbidities and cancer rates (61% versus 53%). Both specialties preferred the transthoracic approach (59.41% for CTS versus 44.90% for GS). Trainee involvement was higher for CTS. There was no significant difference in mortality or overall morbidity. Patients operated on by GS had higher rates of wound infection, sepsis, shock, prolonged or unplanned intubation, and a longer hospital stay, whereas patients operated on by CTS had higher chance for bleeding and return to the operating room. Trainees' involvement in esophagectomy was not associated with worse outcome.

CONCLUSIONS

Our study showed that a large number of esophagectomies in the United States are performed by GS, with the transthoracic approach being the most popular among both specialties. Trainees' involvement in esophagectomy did not significantly affect patients' outcomes. However CTS specialty was associated with lower incidence of infection and a shorter hospital stay.

Do trauma center levels matter in older isolated hip fracture patients?

BACKGROUND

Younger, multi-trauma patients have improved survival when treated at a trauma center. Many regions now propose that older patients be triaged to a higher level trauma centers (HLTCs-level I or II) versus lower level trauma centers (LLTCs-level III or nondesignated TC), even for isolated injury, despite the absence of an established benefit in this elderly cohort. We therefore sought to determine if older isolated hip fracture patients have improved survival outcomes based on trauma center level.

METHODS

A retrospective cohort of 1.07 million patients in The Nationwide Emergency Department Sample from 2006-2010 was used to identify 239,288 isolated hip fracture patients aged ≥65 y. Multivariable logistic regression was performed controlling for patient- and hospital-level variables. The main outcome measures were inhospital mortality and discharge disposition.

RESULTS

Unadjusted logistic regression analyses revealed 8% higher odds of mortality (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.00-1.16) and 10% lower odds of being discharged home (OR, 0.90; 95% CI, 0.80-1.00) among patients admitted to an HLTC versus LLTC. After controlling for patient- and hospital-level factors, neither the odds of mortality (OR, 1.06; 95% CI, 0.97-1.15) nor the odds of discharge to home (OR, 0.98; 95% CI, 0.85-1.12) differed significantly between patients treated at an HLTC versus LLTC.

CONCLUSIONS

Among patients with isolated hip fractures admitted to HLTCs, mortality and discharge disposition do not differ from similar patients admitted to LLTCs. These findings have important implications for trauma systems and triage protocols.

Defining incidence and risk factors of venous thromboemolism after hepatectomy

BACKGROUND

The incidence of venous thromboembolism (VTE) among patients undergoing hepatic surgery is poorly defined, leading to varied use of VTE prophylaxis among surgeons. We sought to define the incidence of VTE after liver surgery and identify risk factors associated with VTE.

METHODS

Incidence of VTE and associated risk factors within 90 days of hepatic resection between 2006 and 2012 at a major academic center was analyzed. Risk factors for VTE were identified using univariate and multivariate analyses.

RESULTS

A total of 599 patients were included in the study cohort; 30 (5.0 %) had a prior history of VTE. The indications for surgery were malignant (90.8 %) and benign lesions (9.2 %). The majority of patients underwent a minor hepatectomy (<3 Couinaud segments; n = 402, 67.1 %) while 195 (32.6 %) patients underwent a major hepatectomy (≥3 Couinaud segments). Three hundred seven (51.3 %) patients were started on VTE chemoprophylaxis preoperatively with 407 (67.8 %) patients receiving VTE chemoprophylaxis within 24 h of surgery. Twenty-eight (4.7 %) patients developed VTE; 20 (3.3 %) had deep venous thrombosis (DVT), 11 (1.8 %) had pulmonary embolism (PE), and three (0.5 %) developed both DVT and PE. Among the VTE patients, 23 (82.1 %) had received VTE chemoprophylaxis. On multivariate analyses, history of VTE (odds ratio [OR] 4.51, 95 % confidence interval [CI] 1.81-17.22, P = 0.03), prolonged operative time (OR 1.17 per additional hour, 95 % CI 1.04-1.32, P = 0.009), and increased length of stay (LOS) (OR 1.07, 95 % CI 1.02-1.12, P = 0.01) were independent risk factors for VTE.

CONCLUSION

VTE within 90 days of hepatic resection is common, occurring in nearly one in 20 patients. Most VTE events occurred among patients who received current best practice prophylaxis for VTE. More aggressive strategies to identify and reduce the risk of VTE in patients at highest risk of VTE, including those with a history of VTE, extended operative time, and prolonged LOS, are warranted.

Safety of percutaneous dilational tracheostomy in coagulopathic patients

Coagulopathy is one of the relative contraindications to percutaneous dilational tracheostomy (PDT). We conducted a retrospective analysis of the records of 483 patients who had undergone PDT at Johns Hopkins Hospital from January 2000 through December 2007 to investigate the safety of PDT in those who were coagulopathic. The number of patients classified as coagulopathic varied greatly according to the particular diagnostic criteria used; 164 patients (33.95%) met one of the three diagnostic criteria (an abnormality in either prothrombin time, partial thromboplastin time, or platelet count), and 32 patients (6.63%) met two or three of these criteria. Complications occurred in 16 patients (3.31%), none of whom met two or more diagnostic criteria; bleeding accounted for 5 of these complications (1.04%). No statistically significant difference was seen in complication rates between the coagulopathic patients and the controls (noncoagulopathic patients). We conclude that in the hands of an experienced surgeon, PDT can be safely performed in patients with abnormal coagulation factors provided that the surgical team strictly adheres to a standardized protocol.

Anemia management program reduces transfusion volumes, incidence of ventilator-associated pneumonia, and cost in trauma patients

BACKGROUND

Strategies to restrict transfusions are gaining acceptance in critical care. We implemented an anemia management program (AMP) for trauma patients in the Surgical Intensive Care Unit. AMP was based on a transfusion trigger of 7 g/dL hemoglobin once hemodynamic sufficiency was achieved. We hypothesized that AMP would decrease the transfusion of packed red blood cells (PRBCs) and cost without detriment in clinical outcomes.

METHODS

Transfusion data were retrospectively collected for all trauma patients treated in our Surgical Intensive Care Unit between July 2002 and December 2003. AMP was implemented in a step-wise fashion during a 6-month period (January to June 2003). Data were compared for the 6-month period before (Group I, July to December 2002) and after (Group II, July to December 2003) complete AMP implementation. Blood transfusion volumes were compared using negative binomial regression. Clinical outcomes (length of stay [LOS], death, myocardial infarction [MI], and ventilator-associated pneumonia [VAP]) were compared using risk ratios. Age, sex, and injury severity score (ISS) were examined as potential confounders.

RESULTS

In all, 514 trauma patients were treated during the study period (n = 270 in Group I and n = 244 in Group II). Group I and Group II were similar in age (mean: 43.6 versus 42.9) and ISS (mean: 18.3 versus 17.0). Mean PRBCs per patient transfused decreased from 23.1 units to 17.1 units (p = 0.057), reflecting a 22.5% reduction adjusted for confounders (p = 0.097). Outcome data revealed no differences in LOS (mean: 6.4 versus 5.9, p = 0.920), risk of death (4.1% versus 6.1%, p = 0.158), or MI (0.7% versus 0.8%, p = 0.974), but a significant reduction in the incidence of VAP (8.1% versus 0.8%, p = 0.002). Total PRBC cost decreased during the study period from 503,000 dollars to 397,000 dollars.

CONCLUSIONS

An anemia management program appears to be safe when applied in the acute ICU phase of trauma care. Implementation of AMP in the ICU reduced the volume of PRBCs transfused with significant cost savings. No significant differences in length of stay, mortality rate, or MI rate were seen. The significant decrease in the rate of VAP requires further elucidation. Further long-term and larger studies are indicated.

Timing of Pulmonary Emboli after Trauma: Implications for Retrievable Vena Cava Filters

BACKGROUND

Four recent reports of the retrieval of optional vena cava filters (VCF) in trauma patients had average implant durations of 10, 19, and 19 days (one not specified). Two patients in these studies had pulmonary emboli after VCF removal. No evidence-based guidelines exist on the appropriate time to remove optional VCF. The purpose of this study was to examine the timing of pulmonary emboli (PE) and determine the optimal time to remove optional VCFs.

METHODS

A multicenter retrospective chart review of trauma patients who had a postinjury PE between January 2001 and December 2004 was performed. We examined the demographics, prophylaxis at the time of PE (pharmacologic [unfractionated or low molecular weight heparin] or sequential compression devices [SCD]), diagnostic test used, timing of PE from the date of injury, and survival outcome.

RESULTS

In all, 146 patients were identified, mean age 45.1 (+/- 21.1 SD); Injury Severity Score 18.0 (+/- 12.1 SD). Diagnosis was obtained by spiral computed tomography (N = 93), pulmonary arteriogram (N = 18), V/Q (N = 26), autopsy (N = 6), clinical (N = 6), and unknown (N = 3). Overall mortality was 17.8% (N = 26). Pulmonary embolism was felt to contribute to or was the cause of death in 85% (N = 22) of these patients. Two late PE deaths occurred (days 21 and 43). Sixty (37%) patients had pharmacologic prophylaxis at the time of PE and 83 (50.9%) had SCDs. Average time from injury to PE was 7.9 days (+/- 8.1 SD), the longest being 43 days postinjury. Eleven percent of PE occurred after 21 days, including fatal PE.

CONCLUSIONS

Clinical criteria defining the time to remove optional VCFs without exposing patients to the risk of PE by removing a filter too soon should be determined.

Platelet-endothelial cell adhesion molecule-1-directed immunotargeting to cardiopulmonary vasculature

Therapeutic molecules conjugated with antibodies to the platelet-endothelial cell adhesion molecule-1 (PECAM-1) accumulate in the pulmonary endothelium after i.v. injection in mice. In this study, we characterized PECAM-directed targeting to the lung and heart after local versus systemic intravascular administration in a large animal model, pigs. Radiolabel tracing showed that 1 h post-i.v. injection, 35% of anti-PECAM versus 2.5% of control IgG had accumulated in the lungs. Infusion of anti-PECAM via a catheter placed in the right pulmonary artery (RPA) resulted in a 3-fold elevation of the uptake in the right lower lobe and 2-fold reduction of uptake in the left lobes in the lung. Cardiac uptake of anti-PECAM was negligible after i.v. and RPA infusion. In contrast, delivery with a catheter placed in the right coronary artery (RCA) resulted in a 4-fold elevation of cardiac uptake of anti-PECAM, but not IgG, compared with i.v. injection. To estimate the targeting of an active reporter enzyme, streptavidin-conjugated beta-galactosidase (beta-Gal) was coupled to anti-PECAM or IgG (anti-PECAM/beta-Gal and IgG/beta-Gal) and injected into the RCA. Beta-Gal activity was markedly elevated in the heart and lungs (5- and 25-fold increased, respectively) after injection of anti-PECAM/beta-Gal, but not IgG/beta-Gal. Image analysis confirmed endothelial targeting of anti-PECAM/beta-Gal in the heart and lung. In summary, anti-PECAM antibody conjugates deliver agents to the pulmonary endothelium regardless of injection route, whereas local arterial infusion permits targeting to the cardiac vasculature. This paradigm may be useful for drug targeting to endothelium in lungs, heart, and possibly other organs.

Long-term evaluation of the Elmslie-Trillat-Maquet procedure for patellofemoral dysfunction

We evaluated 55 knees in 51 patients after Elmslie-Trillat-Maquet procedures. The procedure involves medialization of the tibial tubercle on a distal pedicle and elevating the tibial tubercle anteriorly 10 mm with a local bone graft. At a mean followup of 74.2 months (range 13 to 196), all patients completed postoperative surveys and 38 underwent postoperative examinations. Subjectively, 9 knees (16%) had excellent results, 24 knees (44%) obtained good results, and 13 knees (24%) had fair results for a total of 84% improvement overall. Using Fulkerson's functional knee score, 19 knees (35%) had excellent results, 10 knees (18%) had good results, and 11 knees (20%) had fair results for a total of 73% improvement overall. A total of 24 knees (44%) required later screw removal. The most significant findings of this study include 1) an 84% overall subjective improvement in symptoms; 2) the findings that young patients without evidence of progressive osteoarthrosis and with patella instability as a primary symptom tend to have the most favorable outcome; and 3) 24 knees (44%) required later screw removal.