Multi-slice CT angiography for arterial evaluation in the injured lower extremity

Penetrating thoracic great vessel injury: impact of admission hemodynamics and preoperative imaging

BACKGROUND

The management of penetrating great vessel (PGV) injury is challenging. Patients in shock require rapid evaluation, whereas in stable patients, imaging studies may optimize the surgical approach. We reviewed our experience with PGV injury to determine the impact of admission blood pressure and accuracy of imaging studies, both angiography and computed tomographic angiography (CTA).

METHODS

Retrospective review of the trauma registry from 2001 to 2007 identifying patients with PGV injury. Demographics, admission systolic blood pressure, imaging studies, specific injuries, incision, methods of repair, hospital and intensive care length of stay, complications, and mortality were recorded. Shock was defined as systolic blood pressure <90 mm Hg.

RESULTS

Thirty-six consecutive patients were identified, average age was 28 (+/-10) years, of whom 20 (56%) presented in shock. Those in shock had more combined arterial-venous injuries (60% vs. 25%), concomitant thoracic injuries requiring resection (45% vs. 19%), and units of packed red blood cells (5.8 +/- 2 vs. 2.7 +/- 1.5), p < 0.01. For those in shock, the mean time to the operating room was 27 minutes +/- 9 minutes and 75% had sternotomy. Among stable patients, 56% had a periclavicular approach and 31% partial sternotomy. All 16 stable patients had imaging; angiography in 3 patients and CTA in 7 patients. In six patients who had both angiography and CTA, the results were concordant; therefore, CTA accurately diagnosed arterial injury in all 13 patients. Imaging changed the choice of incision in 4 (25%). Intensive care length of stay was significantly longer in the shock group 3.1 (+/-2.1) days versus 1.4 (+/-1.6) days (p = 0.01). There were 5 (14%) complications and no deaths.

CONCLUSION

Patients in shock require rapid evaluation. Sternotomy affords excellent exposure to all PGV injuries, and partial sternotomy is useful in stable patients. In stable patients, CTA can be valuable in defining the injury and may influence the surgical approach. Surgical results are surprisingly good, even in unstable patients and may be related to rapid transport and operation.

Knife inflicted penetrating injuries of the maxillofacial region: a descriptive, record-based study

Penetrating knife injuries of the face are more common in South Africa than the rest of the world. These injuries can be life-threatening, especially where the major blood vessels of the face are involved. The approach to treatment should be multidisciplinary, beginning with the trauma unit to provide airway maintenance and haemodynamic stabilisation. An interventional radiologist may be consulted for angiography. The aim of the present study was to retrospectively analyse all cases of knife-inflicted penetrating injuries to the maxillofacial region with the knife in situ and subsequently develop a management protocol to be used by maxillofacial surgery registrars when presented with such cases.

MATERIALS AND METHODS

It was a retrospective, cross-sectional and record-based study, analysing all penetrating knife injuries reported at various hospitals for a period of 11 years. In this study, 24 cases of knife injuries were analysed.

RESULTS

Twenty-one patients (87.5%) in this series were male and three (12.5%) were female. Of these 24 patients, 13 (54.2%) were coloured and 11 (45.8%) were black. There were no white or Indian patients. Post-surgical recovery of all patients was rapid and uneventful, and there were no fatalities.

CONCLUSION

Patients with knife injuries to the face with no definite signs of vascular injury can thus be safely and accurately managed on the basis of physical examination and plain-film radiography. An angiogram is mandatory if the patient presents with excessive bleeding, an expanding haematoma or if the knife blade is in the region of any large vessels.

Lower extremity arterial injury patterns and reconstructive outcomes in patients with severe lower extremity trauma: a 26-year review

BACKGROUND

Management of severe traumatic lower extremity injuries remains a considerable challenge. Free tissue transfer is now a standard part of reconstruction for Gustilo IIIB and IIIC injuries. There is limited information on arterial injury patterns in this population. We undertook a review of our experience to gain insight on vascular injury patterns and surgical outcomes.

STUDY DESIGN

A 26-year retrospective analysis was performed of all lower extremity Gustilo IIIB and IIIC injuries requiring microvascular reconstruction at New York University Medical Center. Patient demographics, Gustilo classification, angiographic findings (conventional/computed tomographic angiography/magnetic resonance angiography), recipient vessels, elapsed time from injury, flap choices, and outcomes were examined.

RESULTS

Two hundred twenty-two free flaps on 191 patients were performed from September 1982 until March 2008. There were 151 males and 40 females ranging in age from 4 to 83 years (median age 33 years). Patients sustained either Gustilo IIIB (170 patients) or IIIC (21 patients) open fractures. One hundred fifty-four patients had angiograms (78.2% IIIB, 100% IIIC). Sixty-six (42.9%) had normal 3-vessel runoff and 88 (57.1%) were abnormal. Sixty-one patients (31.9%) had anterior tibial injuries, 17 patients (8.9%) had posterior tibial injuries, and 30 (15.7%) had peroneal injuries. Sixty-three complications occurred (11 early thrombosis, 33 requiring secondary procedures, and 10 requiring amputation).

CONCLUSIONS

Angiography of severe lower extremity injuries requiring free flap reconstruction usually revealed arterial injury and is generally indicated. In our experience, the anterior tibial artery is most commonly injured and the posterior tibial artery is most likely to be spared and used as a recipient.

A prospective validation of a current practice: the detection of extremity vascular injury with CT angiography

INTRODUCTION

Arteriography is the current "gold standard" for the detection of extremity vascular injuries. Less invasive than operative exploration, conventional arteriography (CA) still has a 1% to 3% risk of morbidity and may delay definitive repair. Recent improvements in computed tomography (CT) technology has since broadened the application of CT to include the diagnosis of cervical, thoracic, and now extremity vascular injury. We hypothesized that CT angiography (CTA) provides equivalent injury detection compared with the more invasive CA, but is more rapidly completed and more cost effective.

METHODS

A prospective evaluation of patients, ages 18 to 50, with potential extremity vascular injuries was performed during 2006-2007. Ankle-brachial indices (ABI) of injured extremities were measured on presentation in all patients without hard signs of vascular injury. Patients whose injured extremity ABI was <0.9 were enrolled and underwent CTA followed by either CA or operative exploration if CTA findings were limb threatening. Interventionalists were blinded to CTA findings before performing and reading CAs.

RESULTS

Twenty-one patients (mean age, 26.1 +/- 7.1 years) had 22 extremity CTAs after gunshot (82%), stab (9%), or pedestrian struck by automobile (9%) injuries to either upper (32%) or lower (68%) extremities. Eleven of 22 (50%) extremities had associated orthopedic injuries while the mean ABI of the study population was 0.72 +/- 0.21. Twenty-one of 22 (96%) CTAs were diagnostic and all CTAs were confirmed by either CA alone (n = 18), operative exploration (n = 2), or both CA and operative exploration (n = 2). Diagnostic CTAs had 100% sensitivity and specificity for clinically relevant vascular injury detection. Unlike rapidly obtained CTA, CA required 131 +/- 61 minutes (mean +/- SD) to complete. In our center, CTA saves $12,922 in patient charges and $1,166 in hospital costs per extremity when compared with CA.

CONCLUSIONS

With acceptable injury detection, rapid availability, and a favorable cost profile, our results suggest that CTA may replace CA as the diagnostic study of choice for vascular injuries of the extremities.

Delayed presentation of lateral femoral circumflex artery injury post cannulated hip screw surgery--a case report

An elderly patient underwent cannulated hip screw surgery for a subcapital neck of femur fracture. Nine days post surgery, she was noted to have collapsed with a falling haemoglobin level. Computed tomography revealed a large haematoma to the thigh. Further angiography showed active bleeding from one of the branches of the lateral femoral circumflex artery (LFCA), which we postulate was caused by the sharp tip of a version guidewire used during fracture fixation surgery. Iatrogenic injury during hip fracture fixation is a rare event, particularly to the circumflex branches of the profunda femoris artery (PFA), and may occur from hard wire use intra-operatively or from the fracture itself. The LFCA branches laterally from the PFA, runs anterior to the femoral neck, where we suspect it was injured in our case. Whilst a version wire is a useful radiological guide intra-operatively, manually clearing a passage for its insertion into the femoral head/neck junction and using the blunt end is recommended. A combination of acute swelling in the operated region and falling haemoglobin post surgery should alert the clinician to possible vascular injury. Compared to duplex ultrasonography, CT angiography remains the gold standard in its specificity and sensitivity for diagnosing arterial injuries. With early recognition and prompt radiological intervention, this rare complication of fracture fixation surgery can be treated without the need for further surgery.

Value of computed tomographic angiography in neck and extremity pediatric vascular trauma

PURPOSE

We sought to define the sensitivity and specificity of computed tomographic angiography (CTA) in pediatric vascular injuries.

METHODS

All neck and extremity CTAs performed in pediatric patients at a level 1 trauma center were reviewed from 2001 to 2007.

RESULTS

Overall, 78 patients were identified with an average age of 15.0 +/- 4.0 (0-18 years). Males outnumbered females 3.6:1. CTA was performed for 41 penetrating and 37 blunt traumas. Most penetrating injuries were due to missile wounds (71%) or stab wounds (17%). Eleven major vascular injuries resulted from penetrating trauma. For penetrating trauma, CTA was 100% sensitive and 93% specific. CTA for penetrating trauma had a positive predictive value (PPV) of 85% and negative predictive value (NPV) of 100%. Most blunt injuries were due to motor vehicle accidents (57%), followed by pedestrian hit by car (27%). Eight major vascular injuries resulted from blunt trauma. For blunt trauma, CTA was 88% sensitive and 100% specific. CTA for blunt trauma had a PPV of 100% and an NPV of 97%. The accuracy for penetrating and blunt trauma was 95% and 97%, respectively.

CONCLUSIONS

CTA is highly sensitive, specific, and accurate for pediatric neck and extremity vascular trauma.

Role of Selective Management of Penetrating Injuries in Mass Casualty Incidents

Terrorist violence has emerged as an increasingly common cause of mass casualty incidents (MCI) due to the sequelae of explosive devices and shooting massacres. A proper emergency medical system disaster plan for dealing with an MCI is of paramount importance to salvage lives. Because the number of casualties following a MCI is likely to exceed the medical resources of the receiving health care facilities, patients must be appropriately sorted to establish treatment priorities. By necessity, clinical signs are likely to prove cornerstones of triage during MCI. An appropriate and effective application of experiences learned from the use of selective nonoperative management (SNOM) techniques may prove essential in this triage process. The present appraisal of the available literature strongly supports that the appropriate utilization of these clinical indicators to identify patients appropriate for SNOM is essential, critical, and readily applicable. We also review the initial emergent triage priorities for penetrating injuries to the head, neck, torso, and extremities in a mass casualty setting.

Extremities--indications and techniques for treatment of extremity vascular injuries

Traumatic vascular injuries involving the extremity are rare and penetrating trauma accounts for the majority of such injuries. The remaining arterial injuries are as a result of either blunt or iatrogenic injuries. The rapid detection, localisation and characterisation of vascular injuries in patients who have a traumatic extremity injury is essential for the effective management and treatment of such injuries. This review will discuss the expanding role of multi-detector computed tomography angiography in diagnosing vascular injuries and its implications on conventional diagnostic angiography. The roles of other non-invasive imaging modalities are reviewed. The presentation and types of vascular injuries in blunt and penetrating injuries are discussed. While surgery remains the gold standard in the management of vascular extremity injuries it has significant morbidity rates. Endovascular techniques are increasingly being used for the treatment of vascular traumatic injuries and various techniques including balloon occlusion, embolisation and stent/stent graft placement are discussed.

Peripheral endografts for the treatment of traumatic arterial injuries

Catheter-based endovascular techniques for vascular trauma management are being increasingly reported. Covered stents may be inserted and deployed through a remote site of percutaneous access under local anesthesia and are ideal for treating arterial ruptures and pseudoaneurysms and to seal off arteriovenous communications. Advantages of endovascular stent-graft repair of peripheral traumatic arterial injuries include less blood loss and tissue damage, reduced operative time and morbidity, shortened hospital stay and recovery periods, and reduced healthcare costs. The present report provides an overview of the role of balloon-expandable and self-expandable covered stents in the minimally invasive treatment of various types of traumatic arterial injuries.

A multi-dimensional approach for describing internal bleeding in an artery: implications for Doppler ultrasound guiding HIFU hemostasis

Doppler ultrasound has shown promise in detecting and localizing internal bleeding. A mathematical approach was developed to describe the internal bleeding of the injured artery surrounded by tissue. This approach consisted of a two-dimensional (2D) model describing the injured vessel and a one-dimensional model (1D) mimicking the downstream of the vessel system. The validity of this approach was confirmed by both the numerical simulation and in vivo measurement of a normal porcine femoral artery. Furthermore, the artery was injured using a 16-gauge needle to model a penetrating injury. The velocity waveform at the puncture site was modeled and compared with those at the upstream and downstream of the artery. The results demonstrated that there was a significant increase in magnitude and a phase lag for the peak systolic velocity at the injury site. These results were qualitatively in agreement with the in vivo experiment. Flow turbulence indicated by this approach was also observed in a color Doppler image in the form of a checkered color pattern. This approach might be useful for quantitative internal bleeding detection and localization. Also, the phase lag of the peak systolic velocity was indicated to be potential in the application of internal bleeding detection.

Detecting vascular injury in lower-extremity orthopedic trauma: the role of CT angiography

As a screening tool, CT angiography has excellent sensitivity and specificity combined with fewer complications compared to conventional arteriography.

Computed tomographic angiography in pediatric blunt traumatic vascular injury

Pediatric vascular injuries are rare but can be difficult to diagnose and challenging to manage. We present our experience with computed tomographic angiography in 3 pediatric patients with vascular injuries secondary to blunt trauma. Computed tomographic angiography is noninvasive, fast, rapidly available in most centers, and can evaluate for other injuries. We present a review of the literature and recommend computed tomographic angiography as the diagnostic tool of choice in the evaluation of pediatric blunt vascular trauma.

Vascular abnormalities as assessed with CT angiography in high-energy tibial plafond fractures

OBJECTIVE

The purpose of this study was to examine the results of computed tomography angiography (CTA) obtained in patients with high-energy tibial plafond fractures and assess if the information gleaned from CTA could be useful to the treating orthopedic surgeon.

DESIGN

Consecutive patient series.

SETTING

Level 2 trauma center.

PATIENTS

Consecutive patients treated between October 1, 2004 and June 31, 2006 for high-energy injury of the tibial plafond according to a protocol of early temporizing external fixation, CT, and elevation, followed by delayed reconstruction of the tibial plafond.

INTERVENTION

Addition of angiography to CT scan (CTA) in treatment protocol.

MAIN OUTCOME MEASUREMENTS

CTA abnormalities were identified and categorized to define the pattern of arterial lesions present. Characteristics of patients, injuries, treatments, and complications were evaluated and related to CTA findings.

RESULTS

CTA was performed at an average of 3 days postinjury in 25 consecutive patients treated for high-energy tibial plafond fractures. Abnormalities of the arterial tree of the leg were seen in 13 of 25 (52%) patients. One patient had 2 of 3 vessels notably injured. Fourteen arteries showed acute changes at the level of injury and 1 showed significant chronic atherosclerotic disease at the trifurcation. Acute arterial abnormalities included 7 arteries with complete occlusion, 2 with partial occlusion/diminished flow, and 5 with normal flow but with anatomic disturbances (4 tenting over and 1 entrapped by fracture fragments). Open fractures were associated with arterial abnormalities (P<0.05), but no other characteristics correlated with arterial injury. No patients had dye reactions or other problems relating to CTA. Patients with CTA-diagnosed vascular abnormalities were treated with more minimally invasive surgery than those without at the discretion of the surgeon, and no patients with vascular abnormalities had wound problems or infection.

CONCLUSIONS

In more than half of high-energy tibial plafond fractures, CTA identified significant abnormalities to the arterial tree of the distal leg. These injuries most commonly involved the anterior tibial artery and included a variety of lesions. CTA appears to be a safe and potentially useful tool for the assessment and preoperative planning of high-energy tibial plafond fractures.

Color and pulsed Doppler sonography for arterial bleeding detection

OBJECTIVE

Hemorrhage resulting from penetrating injuries in the extremities is the leading cause of preventable death in the modern battlefield. Development of methods for detection and localization of vascular bleeding is needed that could be applied emergently without special training outside the hospital setting. Our objective was to assess whether Doppler sonography can provide quantitative parameters that characterize the bleeding site in the extremities.

METHODS

Twenty-four rabbit femoral arteries (diameter of approximately 1 mm) were punctured transcutaneously with an 18-gauge needle. Doppler interrogations were performed at 5 locations in the injured vessels (site of injury, distal and proximal locations relative to the injury, and neck and tip of the bleeding jet).

RESULTS

Compared with the normal signals obtained before the vessel was punctured, pulsed Doppler observations of the injury site showed a statistically significant increase in the systolic and diastolic velocities (systolic: mean +/- SD, 30.1 +/- 12.5 cm/s [injury] versus 15.1 +/- 4.2 cm/s [normal]; diastolic: 17.8 +/- 6.5 cm/s [injury] versus 0.7 cm/s [normal]). Similar increases in velocities were observed at the neck of the bleeding jet, whereas the tip of the bleeding jet showed venouslike patterns. These patterns are unique only at the bleeding site. Color Doppler observations showed turbulence (in the form of checkered color patterns) localized at the injury site.

CONCLUSIONS

Our results indicate that both color and pulsed Doppler sonography can be used to accurately localize the site of injury, which may facilitate application of hemorrhage control therapies in battlefield situations.

Acute Complications of Extremity Trauma

In addition to the large number of patients with isolated limb injuries, many patients with major blunt or penetrating trauma harbor extremity injuries as a component of their overall clinical picture. Extremity injuries range from gross deformities and amputations to more subtle injuries, potentially difficult to diagnose, or may escape detection in unconscious or intoxicated patients. However, many soft tissue and vascular injuries require time sensitive interventions to ensure salvage of the limb and the best outcome for the patient. This article reviews the acute management of vascular and soft tissue injuries in the emergency department.

CT Angiography of Extremity Trauma

With the advent of multi-detector computed tomography, CT angiography (CTA) has rapidly become the first line imaging modality for detecting extremity arterial injuries in blunt and penetrating trauma patients. A variety of significant injuries are detected with high sensitivity and specificity. The information provided by CTAs in this patient population is often sufficient for making therapeutic decisions, such as the need for and type of surgical or endovascular interventions. Technological advances have allowed for isotropic imaging and improved quality of multi-planar and three-dimensional reformations, which aid in diagnosis and surgical planning. The rapid acquisition speed of 64 multi-detector CT scanners has facilitated integration of CTA into routine trauma CT imaging using a single contrast bolus injection.