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Dive into the research topics where Konstantinos Chouliaras is active.

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Featured researches published by Konstantinos Chouliaras.


Annals of Surgery | 2015

FAST ultrasound examination as a predictor of outcomes after resuscitative thoracotomy: a prospective evaluation.

Kenji Inaba; Konstantinos Chouliaras; Scott Zakaluzny; Stuart P. Swadron; Thomas Mailhot; Dina Seif; Pedro G. Teixeira; Emre Sivrikoz; Crystal Ives; Galinos Barmparas; Nikolaos Koronakis; Demetrios Demetriades

OBJECTIVE The objective of this study was to examine the ability of Focused Assessment Using Sonography for Trauma (FAST) to discriminate between survivors and nonsurvivors undergoing resuscitative thoracotomy (RT). BACKGROUND RT is a high-risk, low-salvage procedure performed in arresting trauma patients with poorly defined indications. METHODS Patients undergoing RT from 10/2010 to 05/2014 were prospectively enrolled. A FAST examination including parasternal/subxiphoid cardiac views was performed before or concurrent with RT. The result was captured as adequate or inadequate with presence or absence of pericardial fluid and/or cardiac motion. A sensitivity analysis utilizing the primary outcome measure of survival to discharge or organ donation was performed. RESULTS Overall, 187 patients arrived in traumatic arrest and underwent FAST. Median age 31 (1-84), 84.5% male, 51.3% penetrating. Loss of vital signs occurred at the scene in 48.1%, en-route in 23.5%, and in the ED in 28.3%. Emergent left thoracotomy was performed in 77.5% and clamshell thoracotomy in 22.5%. Sustained cardiac activity was regained in 48.1%. However, overall survival was only 3.2%. An additional 1.6% progressed to organ donation. FAST was inadequate in 3.7%, 28.9% demonstrated cardiac motion and 8.6% pericardial fluid. Cardiac motion on FAST was 100% sensitive and 73.7% specific for the identification of survivors and organ donors. CONCLUSIONS With a high degree of sensitivity for the detection of potential survivors after traumatic arrest, FAST represents an effective method of separating those that do not warrant the risk and resource burden of RT from those who may survive. The likelihood of survival if pericardial fluid and cardiac motion were both absent was zero.


Journal of Trauma-injury Infection and Critical Care | 2015

A multi-institution prospective observational study of small bowel obstruction: Clinical and computerized tomography predictors of which patients may require early surgery.

Narong Kulvatunyou; Viraj Pandit; Sadoun Moutamn; Kenji Inaba; Konstantinos Chouliaras; Marc DeMoya; Leily Naraghi; Bobby Kalb; Hina Arif; Reddy Sravanthi; Bellal Joseph; Lynn Gries; Andrew Tang; Peter Rhee

BACKGROUND For patients with adhesive small bowel obstruction (ASBO), early surgery after a failed trial of nonoperative treatment can improve outcome. However, deciding which patients require early surgery is difficult, given the lack of specific clinical or radiographic signs. The study goals were to identify clinical and computed tomography (CT) predictors of which patients may need early surgery and to evaluate the utility of the common CT findings. METHODS This was a multi-institution prospective observational study for patients who were admitted with ASBO. Patients were excluded if their SBO were not managed conservative initially; were within 30 days postoperatively; were caused by external hernias, small bowel tumor, or intussusception; and were related to Crohn’s disease. Clinical and laboratory variables were collected prospectively. CT findings were interpreted by a blinded designated radiologist. To identify significant predictors, we performed a multivariable regression analysis. RESULTS During 22 months, we enrolled 200 patients with ASBO. Patients’ mean (SD) age was 60 (18) years; 50% were male. Fifty-two patients (26%) underwent surgery. Of those who underwent surgery, the median duration of nonoperative treatment was 1.5 days (interquartile range, 1–2.5 days). In the regression model, we identified no flatus (odds ratio [OR], 3.28; 95% confidence interval [CI], 1.51–7.12; p = 0.003), presence of free fluid on CT (OR, 2.59; 95% CI, 1.13–5.90; p = 0.023), and high-grade obstruction by CT (OR, 2.44; 95% CI, 1.10–5.43; p = 0.028) to be significant predictors for ASBO patients who may need early surgery. CONCLUSION In this study, we prospectively derived one clinical and two CT predictors which ASBO patients may benefit from an early surgical intervention. However, a future study to validate these predictors is needed. LEVEL OF EVIDENCE Therapeutic study, level III; prognostic study, level II.


Journal of Trauma-injury Infection and Critical Care | 2014

The peril of thoracoabdominal firearm trauma: 984 civilian injuries reviewed

Regan J. Berg; Kenji Inaba; Obi Okoye; Efstathios Karamanos; Aaron Strumwasser; Konstantinos Chouliaras; Pedro G. Teixeira; Demetrios Demetriades

BACKGROUND Thoracoabdominal firearm injuries present major diagnostic and therapeutic challenges because of the risk for potential injury in multiple anatomic cavities and the attendant dilemma of determining the need for and correct sequencing of cavitary intervention. Injury patterns, management strategies, and outcomes of thoracoabdominal firearm trauma remain undescribed across a large population. METHODS All patients with thoracoabdominal firearm injury admitted to a major Level I trauma center during a 16-year period were reviewed. RESULTS The 984 study patients experienced severe injury burden; 25% (243 of 984) presented in cardiac arrest, and 75% (741 of 984) had an Abbreviated Injury Scale (AIS) score of 3 or greater in both the chest and the abdomen. Operative management occurred in 86% (638 of 741). Of the patients arriving alive, 68% (507 of 741) underwent laparotomy alone, 4% (27 of 741) underwent thoracotomy alone, and 14% (104 of 741) underwent dual-cavitary intervention. Negative laparotomy occurred in 3%. Diaphragmatic injury (DI) occurred in 63%. Seventy-five percent had either DI or hollow viscus injury. Cardiac injury was present in 33 patients arriving alive. Despite the use of trauma bay ultrasound, 44% of the patients with cardiac injury underwent initial laparotomy. In half of this group, ultrasound did not detect pericardial blood. The need for thoracotomy, either alone or as part of dual-cavitary intervention, was the strongest independent risk factor for mortality in those arriving alive. CONCLUSION Greater kinetic destructive potential drives the peril of thoracoabdominal firearm trauma, producing clinical challenges qualitatively and quantitatively different from nonfirearm injuries. Severe injury, on both sides of the diaphragm, generates high operative need with low rates of negative exploration. The need for emergent intervention and a high incidence of DI or hollow viscus injury limit opportunity for nonoperative management. Even with ultrasound, emergent preoperative diagnosis remains challenging, as the complex combination of intra-abdominal, thoracic, and diaphragmatic injuries can provoke misinterpretation of both radiologic and clinical data. Successful emergent management requires thorough assessment of all anatomic spaces, integrating ultrasonographic, radiologic, and clinical findings. LEVEL OF EVIDENCE Epidemiologic study, level III.


Journal of Trauma-injury Infection and Critical Care | 2015

Pneumomediastinum following blunt trauma: Worth an exhaustive workup?

Konstantinos Chouliaras; Elias Bench; Peep Talving; Aaron Strumwasser; Elizabeth Benjamin; Lydia Lam; Kenji Inaba; Demetrios Demetriades

BACKGROUND Incidental pneumomediastinum is a common radiologic finding following blunt thoracic injury; however, the clinical significance of pneumomediastinum on screening imaging is poorly defined (Curr Probl Surg. 2004;41(3):211–380; Injury. 2010;41(1):40–43). The purpose of this study was to define the incidence of aerodigestive injuries in patients with pneumomediastinum after blunt thoracic and neck injury. METHODS After institutional review board approval was obtained, a retrospective review was performed of all patients admitted to Los Angeles County + University of Southern California Medical Center with blunt neck and/or thoracic injuries between January 2007 and December 2012. All patients with pneumomediastinum on radiologic investigation were included. Data accrued included demographics, admission clinical data, injury severity patterns, incidence of aerodigestive injuries, operative findings, morbidity, mortality, as well as intensive care unit and hospital lengths of stay. RESULTS A total of 9,946 patients were included in the study. The predominant mechanism was motor vehicle collision (49%), disproportionately male (76%). Overall, 258 patients (2.6%) had a pneumomediastinum: 65 (25%) and 193 (75%) were diagnosed on a chest x-ray or on a computed tomography (CT) scan, respectively. A total of 21 patients (8.1%) had an aerodigestive workup with bronchoscopy, esophagram, and/or esophagoscopy. Overall, four aerodigestive lesions (1.6%) were diagnosed. Three tracheobronchial injuries were identified on CT scan, and one esophageal injury was diagnosed on an esophagram. Two tracheobronchial injuries required surgery, while the remaining cases were managed nonoperatively. The overall mortality in this cohort was 10.9%. CONCLUSION Isolated findings of pneumomediastinum on screening chest x-ray or CT following blunt trauma is a poor predictor of an aerodigestive injury. Highly selective workup in this clinical setting is warranted. LEVEL OF EVIDENCE Prognostic/epidemiologic study, level III; therapeutic study, level IV.


American Journal of Surgery | 2015

The origin of fatal pulmonary emboli: a postmortem analysis of 500 deaths from pulmonary embolism in trauma, surgical, and medical patients

Matthew D. Tadlock; Konstantinos Chouliaras; Martina Kennedy; Peep Talving; Obi Okoye; Hande Aksoy; Efstathios Karamanos; Ling Zheng; Daniel Grabo; Christopher Rogers; Thomas T. Noguchi; Kenji Inaba; Demetrios Demetriades

BACKGROUND The traditional theory that pulmonary emboli (PE) originate from the lower extremity has been challenged. METHODS All autopsies performed in Los Angeles County between 2002 and 2010 where PE was the cause of death were reviewed. RESULTS Of the 491 PE deaths identified, 36% were surgical and 64% medical. Venous dissection for clots was performed in 380 patients; the PE source was the lower extremity (70.8%), pelvic veins (4.2 %), and upper extremity (1.1%). No source was identified in 22.6% of patients. Body mass index (adjusted odds ratio [AOR] 1.044, 95% confidence interval [CI] 1.011 to 1.078, P = .009) and age (AOR 1.018, 95% CI 1.001 to 1.036, P = .042) were independent predictors for identifying a PE source. Chronic obstructive pulmonary disease (AOR .173, 95% CI .046 to .646, P = .009) was predictive of not identifying a PE source. CONCLUSIONS Most medical and surgical patients with fatal PE had a lower extremity source found, but a significant number had no source identified. Age and body mass index were positively associated with PE source identification. However, a diagnosis of chronic obstructive pulmonary disease was associated with no PE source identification.


Injury-international Journal of The Care of The Injured | 2016

Should we still use motor vehicle intrusion as a sole triage criterion for the use of trauma center resources

Kazuhide Matsushima; Konstantinos Chouliaras; William Koenig; Catherine Preston; Deidre Gorospe; Demetrios Demetriades

BACKGROUND Motor vehicle intrusion (MVI) is one of the field triage criteria recommended by the American College of Surgeons Committee of Trauma (ACS-COT) and Centers for Disease Control and Prevention (CDC). However, the evidence supporting its validity is scarce. The purpose of this study was to evaluate the validity of this criterion and assess its impact on overtriage or undertriage. PATIENTS AND METHODS This was a retrospective study based on the Los Angeles County Trauma and Emergency Medicine Information System (TEMIS) Trauma database. Included in the analysis were patients with MVI as the sole criterion for trauma center triage. Physiological characteristics, severity of injury, and outcomes of the MVI patients were compared between different age groups. Further, a logistic regression model was used to identify factors significantly associated with the need for trauma center resources. RESULTS During the period 2002-2012, a total of 10,554 trauma patients involved in motor vehicle crashes had documentation of MVI. A subgroup of 3998 patients (37.9%) did not meet any other criteria that require immediate transportation to a designated trauma center. Only 0.7% of these patients had hypotension and 0.1% had deterioration of the Glasgow Coma Scale on admission to the emergency room. Overall, 18.8% of patients required trauma center resources defined as intubation in the emergency room, certain surgical procedures, in-hospital death, or intensive care unit admission. Age ≥65 years, male gender, prehospital heart rate >100/min, and systolic blood pressure <110 mmHg were significantly associated with the need for trauma center resources. CONCLUSIONS The MVI itself did not appear to be a strong indicator for the use of trauma center resources and is associated with excessive overtriage. However, age >65 years, systolic blood pressure <110 mmHg, and heart rate >100/min were significant predictors for the need of trauma center resources. The MVI criterion should be refined for better utilization of trauma center resources.


Journal of Trauma-injury Infection and Critical Care | 2017

Severe injuries associated with skiing and snowboarding: A national trauma data bank study

Amory de Roulet; Kenji Inaba; Aaron Strumwasser; Konstantinos Chouliaras; Lydia Lam; Elizabeth Benjamin; Daniel Grabo; Demetrios Demetriades

BACKGROUND Injuries after skiing and snowboarding accidents lead to an estimated 7,000 hospital admissions annually and present a significant burden to the health care system. The epidemiology, injury patterns, hospital resource utilization, and outcomes associated with these severe injuries need further characterization. METHODS The National Trauma Data Bank was queried for the period 2007 to 2014 for admissions with Injury Severity Score > 15 and International Classification of Diseases Codes—9th Revision codes 885.3 (fall from skis, n = 1,353) and 885.4 (fall from snowboard, n = 1,216). Demographics, emergency department data, diagnosis and procedure codes, and outcomes were abstracted from the database. RESULTS Severe (Injury Severity Score > 15) ski-associated and snowboard-associated injuries differed with respect to age distribution (median age, 38; interquartile range, 19–59 for skiers and median age, 20; interquartile range, 16–25 for snowboarders; p < 0.001) and sex (78.9% and 86.4% males, respectively, p < 0.001). Traumatic brain injury was common for both sports (56.8% of skiers vs. 46.6% of snowboarders, p < 0.001). Injuries to the spine (28.9%), chest (37.6%), and abdomen (35.0%) were also common. Eighty percent of patients used emergency medical services (50% ambulance, 30% helicopter) with a median emergency medical services transport time of 84 minutes. 50.8% of patients required interhospital transport. 43.2% of injuries required surgical intervention (21.3% orthopedic, 12.5% neurosurgical, 10.5% thoracic, 7.8% abdominal). Median hospital length of stay was 5.0 days. 60.0% of patients required intensive care unit admission with median intensive care unit length of stay 3.0 days. Overall mortality was 4.0% for skiers and 1.9% for snowboarders. CONCLUSION Severe injuries after ski and snowboard accidents are associated with significant morbidity and mortality. Differences in injury patterns, risk factors for severe injury, and resource utilization require further study. Increased resource allocation to alpine trauma systems is warranted. LEVEL OF EVIDENCE Prognostic/epidemiologic, level III.


Journal of Trauma-injury Infection and Critical Care | 2015

Witnessed aspiration in trauma: Frequent occurrence, rare morbidity--A prospective analysis.

Elizabeth Benjamin; Tobias Haltmeier; Konstantinos Chouliaras; Stefano Siboni; Joseph Durso; Kenji Inaba; Demetrios Demetriades

BACKGROUND Aspiration events (AEs) are a well-recognized complication in trauma patients and have traditionally been considered a risk factor for pneumonia. Despite this, there is no consensus on the incidence or clinical significance of AE in the trauma population. METHODS All patients admitted as trauma team activations at our Level I trauma center who were intubated in the field or on arrival from September 2013 to August 2014 were prospectively collected. Field and admission data including witnessed AEs were analyzed. Additional hospital data included imaging, associated injuries, laboratory, and clinical data. Early respiratory failure, pneumonia, and hospital mortality were collected. RESULTS During the study period, 228 patients met inclusion criteria. Median age was 35.5 years, and Injury Severity Score (ISS) was 21.0. Overall, 58 patients (25.4%) had witnessed AEs. Patients with AE had significantly higher ISS (26.0 vs. 17.0, p = 0.027) and lower Glasgow Coma Scale (GCS) score on admission (median, 4.0 vs. 7.0; p = 0.003), despite similar field GCS score (p = 0.946). Body mass index (median, 27.2 vs. 26.2; p = 0.374) and intoxication rates (86.2% vs. 83.5%, p = 0.835) were similar between groups. Early pneumonia and respiratory failure were rare in all patients and were not higher in those with AE. Although mortality was higher after AE in patients who died directly after admission (51.7% vs. 30.0%, p = 0.004), in patients who survived to intensive care unit admission, there was no longer a difference between groups and aspiration was not an independent predictor of mortality (p = 0.107) on multivariable regression analysis. CONCLUSION The rate of aspiration in trauma is high and more likely to occur in patients with increased injury burden or depressed GCS score. In patients who survive past admission, early pneumonia rates are similar, regardless of AE. These data suggest that aspiration is a marker of severe illness and is associated with but not an independent predictor of mortality. LEVEL OF EVIDENCE Prognostic/epidemiologic study, level III.


Digestive Surgery | 2017

The Relationship between Age, Common Bile Duct Diameter and Diagnostic Probability in Suspected Choledocholithiasis

Efstathios Karamanos; Kenji Inaba; Regan J. Berg; Shelby Resnick; Obi Okoye; Sophoclis Alexopoulos; Konstantinos Chouliaras; Demetrios Demetriades

Background: Aging has been associated with increasing common bile duct (CBD) diameter and reported as independently predictive of the likelihood of choledocolithiasis. These associations are controversial with uncertain diagnostic utility in patients presenting with symptomatic disease. The current study examined the relationship between age, CBD size, and the diagnostic probability of choledocolithiasis. Methods: Symptomatic patients undergoing evaluation for suspected choledocolithiasis from January 2008 to February 2011 were reviewed. In the cohort without choledocolithiasis, the relationship between aging and CBD size was examined as a continuous variable and by comparing mean CBD size across stratified age groups. Multivariate analysis examined the relationship between increasing age and diagnostic probability of choledocolithiasis in all patients. Results: Choledocolithasis was diagnosed by MR cholangiopancreatography (MRCP) or endoscopic retrograde (ERCP) in 496 of 1,000 patients reviewed. Mean CBD was 6.0 mm (±2.8 mm) in the 504 of 1,000 patients without choledocolithiasis on ERCP/MRCP. Increasing age had no correlation with CBD size as a continuous variable (r2 = 0.011, p = 0.811). No difference occurred across age groups (Kruskal-Wallis, p = 0.157). Age had no association with diagnostic likelihood of choledocolithiasis (AOR [95% CI] 0.99 [0.98-1.01], adjusted-p = 0.335). Conclusion: In a large population undergoing investigation for biliary disease, increasing age was neither associated with increasing CBD diameter nor predictive of the likelihood of choledocolithiasis.


American Surgeon | 2014

The use of the anatomic 'zones' of the neck in the assessment of penetrating neck injury.

Low Gm; Kenji Inaba; Konstantinos Chouliaras; Bernardino C. Branco; Lydia Lam; Elizabeth Benjamin; Jay Menaker; Demetrios Demetriades

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Demetrios Demetriades

University of Southern California

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Kenji Inaba

University of Southern California

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Efstathios Karamanos

University of Southern California

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Elizabeth Benjamin

University of Southern California

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Obi Okoye

University of Southern California

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Lydia Lam

University of Southern California

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Aaron Strumwasser

University of Southern California

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Pedro G. Teixeira

University of Texas at Austin

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Daniel Grabo

University of Southern California

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Regan J. Berg

University of Southern California

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