Interventional techniques in vascular trauma

Evaluations for New Healthcare Environment Commissioning and Operational Decision Making Using Simulation and Human Factors: A Case Study of an Interventional Trauma Operating Room

PURPOSE

The aim of this article is to provide a case study example of the preopening phase of an interventional trauma operating room (ITOR) using systems-focused simulation and human factor evaluations for healthcare environment commissioning.

BACKGROUND

Systems-focused simulation, underpinned by human factors science, is increasingly being used as a quality improvement tool to test and evaluate healthcare spaces with the stakeholders that use them. Purposeful real-to-life simulated events are rehearsed to allow healthcare teams opportunity to identify what is working well and what needs improvement within the work system such as tasks, environments, and processes that support the delivery of healthcare services. This project highlights salient evaluation objectives and methods used within the clinical commissioning phase of one of the first ITORs in Canada.

METHODS

A multistaged evaluation project to support clinical commissioning was facilitated engaging 24 stakeholder groups. Key evaluation objectives highlighted include the evaluation of two transport routes, switching of operating room (OR) tabletops, the use of the C-arm, and timely access to lead in the OR. Multiple evaluation methods were used including observation, debriefing, time-based metrics, distance wheel metrics, equipment adjustment counts, and other transport route considerations.

RESULTS

The evaluation resulted in several types of data that allowed for informed decision making for the most effective, efficient, and safest transport route for an exsanguinating trauma patient and healthcare team; improved efficiencies in use of the C-arm, significantly reduced the time to access lead; and uncovered a new process for switching OR tabletop due to safety threats identified.

Early administration of fibrinogen concentrates improves the short-term outcomes of severe pelvic fracture patients

Aim

Hemorrhage from pelvic fracture is a major cause of mortality after blunt trauma. Several studies have suggested that early fibrinogen supplementation improves outcomes of traumatic hemorrhage. Thus, we revised our massive transfusion protocol (MTP) in April 2013 to include early off‐label administration of fibrinogen concentrate. The objective of this study was to evaluate the impact of the revision on the short‐term outcomes of pelvic fracture patients.

Methods

This was a single‐center, retrospective, cohort study. A total of 224 consecutive pelvic fracture patients hospitalized in Saitama Medical Center (Saitama, Japan), 115 before the revision (Group E) and 109 after (Group L), were enrolled. Characteristics of the patients were compared between the groups. Impacts of the revision were evaluated by hazard ratios adjusted for characteristics, injury severity, and coagulation status using Cox's multivariate proportional hazard model. The impact was also evaluated by log–rank test and relative risk of 28‐day mortality between the groups.

Results

The characteristics were equivalent between the groups. The multivariate analysis revealed that the revision of MTP was significantly related to improved survival with an adjusted hazard ratio (95% confidence interval) of 0.45 (0.07–0.97). The log–rank test gave χ²‐test values of 5.2 (P = 0.022) and 6.7 (P = 0.009), and the relative risks were 0.37 (0.15–0.91) and 0.33 (0.13–0.84), in patients with all Injury Severity Scores and Injury Severity Score ≥21, respectively.

Conclusion

The revision of MTP to include aggressive off‐label treatment with fibrinogen concentrate was related to improved short‐term outcomes of severe pelvic fracture patients. However, due to the limitations of the study, the improvement could not be attributed totally to the revision.

Endovascular Repair of Blunt Popliteal Arterial Injuries

OBJECTIVE

To evaluate the feasibility and effectiveness of endovascular repair for blunt popliteal arterial injuries.

MATERIALS AND METHODS

A retrospective analysis of seven patients with clinical suspicion of popliteal arterial injuries that were confirmed by arteriography was performed from September 2009 to July 2014. Clinical data included demographics, mechanism of injury, type of injury, location of injury, concomitant injuries, time of endovascular procedures, time interval from trauma to blood flow restoration, instrument utilized, and follow-up. All patients were male (mean age of 35.9 ± 10.3 years). The type of lesion involved intimal injury (n = 1), partial transection (n = 2), complete transection (n = 2), arteriovenous fistula (n = 1), and pseudoaneurysm (n = 1). All patients underwent endovascular repair of blunt popliteal arterial injuries.

RESULTS

Technical success rate was 100%. Intimal injury was treated with a bare-metal stent. Pseudoaneurysm and popliteal artery transections were treated with bare-metal stents. Arteriovenous fistula was treated with bare-metal stent and coils. No perioperative death and procedure-related complication occurred. The average follow-up was 20.9 ± 2.3 months (range 18-24 months). One patient underwent intra-arterial thrombolysis due to stent thrombosis at 18 months after the procedure. All limbs were salvaged. Stent migration, deformation, or fracture was not found during the follow-up.

CONCLUSION

Endovascular repair seems to be a viable approach for patients with blunt popliteal arterial injuries, especially on an emergency basis. Endovascular repair may be effective in the short-term. Further studies are required to evaluate the long-term efficacy of endovascular repair.

The elimination of anastomosis in open trauma vascular reconstruction: A novel technique using an animal model

BACKGROUND

The standard approach to vascular trauma involves arterial exposure and reconstruction using either a vein or polytetrafluoroethylene graft. We have developed a novel technique to repairing arterial injuries by deploying commercially available vascular stents through an open approach, thus eliminating the need for suture anastomosis. The objective of this study was to evaluate the feasibility, stent deployment time (SDT), and stent patency of this technique in a ewe vascular injury model.

METHODS

After proximal and distal control, a 2-cm superficial femoral arterial segment was resected in 8 Dorper ewes to simulate an arterial injury. Two stay sutures were placed in the 3- and 9-o'clock positions of the transected arterial ends to prevent further retraction. Ten milliliters of 10-IU/mL heparinized saline was flushed proximally and distally. An arteriotomy was then created 2.5 cm from the transected distal end through which we deployed Gore Viabahn stents with a 20% oversize and at least 1-cm overlap with the native vessel on either end. The arteriotomy was then closed with 3 (1) interrupted 6-0 Prolene sutures. The ewes were fed acetylsalicylic acid 325 mg daily. Duplex was performed at 2 months postoperatively to evaluate stent patency. SDT was defined as time from stay suture placement to arteriotomy closure.

RESULTS

The 8 ewes weighed a mean (SD) of 34.4 (4.3) kg. The mean (SD) superficial femoral arterial was 4.3 (0.6) mm. Six 5 mm × 5 cm and two 6 mm × 5 cm Gore Viabahn stents were deployed. The mean (SD) SDT was 34 (19) minutes, with a trend toward less time with increasing experience (SDTmax, 60 minutes; SDTmin, 10 minutes). Duplex performed at 2 months postoperatively showed stent patency in five of eight stents. There was an association between increasing SDT and stent thrombosis.

CONCLUSION

Open deployment of commercially available vascular stents to treat vascular injuries is a conceptually sound and technically feasible alternative to standard open repair. Larger studies are needed to refine this technique and minimize stent complications, which are likely technical in nature.

The evolution of a purpose designed hybrid trauma operating room from the trauma service perspective: the RAPTOR (Resuscitation with Angiography Percutaneous Treatments and Operative Resuscitations)

Traumatic injury is the leading cause of potentially preventable lost years of life in the Western world and exsanguination is the most potentially preventable cause of post-traumatic death. With mature trauma systems and experienced trauma centres, extra-abdominal sites, such as the pelvis, constitute the most frequent anatomic site of exsanguination. Haemorrhage control for such bleeding often requires surgical adjuncts most notably interventional radiology (IR). With the usual paradigm of surgery conducted within an operating room and IR procedures within distant angiography suites, responsible clinicians are faced with making difficult decisions regarding where to transport the most physiologically unstable patients for haemorrhage control. If such a critical patient is transported to the wrong suite, they may die unnecessarily despite having potentially salvageable injuries. Thus, it seems only logical that the resuscitative operating room of the future would have IR capabilities making it the obvious geographic destination for critically unstable patients, especially those who are exsanguinating. Our trauma programme recently had the opportunity to conceive, design, build, and operationalise a purpose-designed hybrid trauma operating room, designated as the resuscitation with angiographic percutaneous techniques and operative resuscitation (RAPTOR) suite, which we believe to be the first such resource designed primarily to serve the exsanguinating trauma patient. The project was initiated after consultations between the trauma programme and private philanthropists regarding the greatest potential impacts on regional trauma care. The initial capital construction costs were thus privately generated but coincided with a new hospital wing construction allowing the RAPTOR to be purpose-designed for the exsanguinating patient. Many trauma programmes around the world are now starting to navigate the complex process of building new facilities, or else retrofitting existing ones, to address the need for single-site flexible haemorrhage control. This manuscript therefore describes the many considerations in the design and refinement of the physical build, equipment selection, human factors evaluation of new combined treatment paradigms, and the final introduction of a RAPTOR protocol in order that others may learn from our initial efforts.

Angiographic embolization in the treatment of arterial pelvic hemorrhage: evaluation of prognostic mortality-related factors

Purpose

The control of arterial bleeding associated with pelvic ring and acetabular fractures (PRAF) remains a challenge for emergency trauma care. The aim of the present study was to uncover early prognostic mortality-related factors in PRAF-related arterial bleedings treated with transcatheter angiographic embolization (TAE).

Methods

Forty-nine PRAF patients (46 pelvic ring and three acetabular fractures) with arterial pelvic bleeding controlled with TAE (within 24 h) were evaluated.

Results

All large arterial disruptions (n = 7) were seen in type C pelvic ring injuries. The 30-day mortality in large vessel (iliac artery) bleeding was higher (57 %) than in medium- or small-size artery bleeding (24 %). Overall 30-day mortality was 29 %. No statistically significant difference in the first laboratory values between the survivors and nonsurvivors was found. However, after excluding patients dying of head injuries (n = 5), a reasonable cut-off value was identified for the base excess (BE; lower than −10 mmol/l) obtained on admission.

Conclusions

PRAF patients with exsanguinating bleeding from the large pelvic artery have the worst prognosis. Very low BE values (<−10.0 mmol/l) on admission for exsanguinating patients have a negative predictive value for survival, thus anticipating a poor outcome in bleeding controlled with TAE only and an increased risk of death. In critical cases, an aggressive bleeding control protocol prompts extraperitoneal pelvic packing prior to TAE. PRAF-related rupture of the external iliac artery is rare and indicates surgical techniques in controlling and restoring blood supply to the lower leg.

Multidetector row computed tomography in the management of penetrating neck injuries

Penetrating neck trauma may occur from gun shots, stabbings, and accidental injury. Approximately 50% of gunshot and 10%-20% of stab-wound patients are reported as having severe injuries and the mortality from severe vascular injuries is reported as high as 50%. Penetrating traumatic neck injury is no longer best managed with exploratory surgery or conventional angiography in the stable patient. Computed tomography angiography has proven to be a useful, safe, and reliable means of diagnosis. Experience with interpreting and reconstructing computed tomography images, understanding the clinically important findings, and avoiding pitfalls is critical for successful patient care. Therefore, radiologists and clinicians who treat trauma patients need to familiarize themselves with the computed tomography angiography technique and appearances of vascular injury and know when to recommend further evaluation, such as interventional angiography or open surgery.

Pulsatile flow phantom for ultrasound image-guided HIFU treatment of vascular injuries

A pulsatile flow phantom was developed for studies of ultrasound image-guided high intensity focused ultrasound (HIFU) application in transcutaneous hemostasis of injured blood vessels. The flow phantom consisted of a pulsatile pump system with instrumented excised porcine carotid artery, which was imbedded in a transparent agarose gel to model structural configuration of in vivo tissues. Heparinized porcine blood was circulated through the phantom. The artery was injured using an 18-gauge needle to model a penetrating injury in human peripheral vasculature. A HIFU transducer with the diameter of 7 cm, focal length of 6.3 cm and frequency of 3.4 MHz was used to seal the puncture. Ultrasound imaging was used to localize and target the puncture site and to monitor the HIFU treatment. Triphasic blood flows present in the human arteries were reproduced, with flow rates of 50 to 500 mL/min, pulse rates of 62 to 138 beats/min and peak pressures of 100 to 250 mm Hg. The penetrating injury of an artery was mimicked successfully in the flow phantom setting and was easily visualized both optically through the transparent gel and with power Doppler ultrasound imaging. Hemostasis was achieved in 55 +/- 31 s (n = 9) of HIFU application. Histologic observations showed that a HIFU-sealed puncture was filled with clotted blood and covered with a fibrin cap. The pulsatile flow phantom provides a controlled and repeatable environment for studies of transcutaneous image-guided HIFU application in hemostasis of a variety of blood vessel injuries.

State of the art: noninvasive imaging and management of neurovascular trauma

Neurotrauma represents a significant public health problem, accounting for a significant proportion of the morbidity and mortality associated with all traumatic injuries. Both blunt and penetrating injuries to cervicocerebral vessels are significant and are likely more common than previously recognized. Imaging of such injuries is an important component in the evaluation of individuals presenting with such potential injuries, made all the more important since many of the vascular injuries are clinically silent. Management of injuries, particularly those caused by blunt trauma, is constantly evolving. This article addresses the current state of imaging and treatment of such injuries.

The Evolving Role of Interventional Radiology in Trauma Care

BACKGROUND

Although the traditional role of radiology in trauma care has been diagnostic, therapeutic interventional radiology (IR) techniques have now become essential in the management of many injuries. We hypothesized that IR has evolved at our institution over the last decade from a largely diagnostic to a more therapeutic role in the care of the injured patient.

METHODS

Demographic information, computed tomographic scans of the chest and abdomen, and angiographic procedures (APs) performed within 48 hours of admission were reviewed in all patients evaluated at a Level I trauma center for the periods 1993 to 1995 and 2000 to 2002. All APs performed with the intent to embolize, stent, or insert a device into a vessel were designated as therapeutic. Analysis by means of chi provided between-group comparisons for questions of interest and the Student's t test was used for comparison of means.

RESULTS

A total of 4,750 patients were reviewed, 1,677 from the time period 1993 to 1995 and 3,073 from the period 2000 to 2002. Overall injury severity as measured by the Injury Severity Score (ISS) was similar in both groups (9.6 vs. 9.9, p = not significant). The number of angiograms obtained decreased significantly from 7.1% to 4.0% of all patients (p < 0.01). Concurrently, the fraction of all angiograms that were considered therapeutic rose from 10% to 22% (p < 0.05). The overall number of aortic arch angiograms decreased over time (from 3.6% to 0.9%, p < 0.01), and the percentage of positive examinations increased from 5.0% to 21.4%. In comparison, the number of computed tomographic scans of the chest increased from 1.6% of all patients to 10.8% (p < 0.01).

CONCLUSION

Axial imaging studies are being used more frequently to screen trauma patients for injury. Concurrently, diagnostic APs are less frequently performed but are more frequently positive. In addition, IR studies are increasingly focused on therapeutic intervention. IR program development and support is an integral aspect of modern trauma care. These findings have prompted our institution to equip the IR suite to function as an active resuscitation area similar to the trauma bay and intensive care unit.

Endovascular-covered stent treatment of posttraumatic cervical carotid artery pseudoaneurysms

Pseudoaneurysm involving the cervical portion of the carotid artery can result from prior trauma or dissection. Two patients are reported with posttraumatic carotid artery pseudoaneurysms. In both cases, endovascular-covered stents were placed across the diseased portion of the artery resulting in thrombosis of the aneurysm and preservation of the parent artery without any significant complication. It is therefore concluded that covered stent placement is an alternative approach in treating carotid artery pseudoaneurysms.

Vascular Injuries to the Extremities in a Suburban Trauma Center

The purpose of this study was to examine the experience with extremity vascular injuries of a level II suburban trauma center. A retrospective chart review was undertaken to include all patients admitted in a 6-year period with vascular injuries to the extremities. The vessels injured were identified along with the mechanism of injury. The method of repair was recorded. All associated neurologic injuries were investigated. Follow-up records, when available, were reviewed. Between January 1, 1996, and November 30, 2002, 48 patients were admitted with 56 vascular injuries to the extremities. Blunt trauma was the mechanism in 24 patients while penetrating trauma was the mechanism in the other 24 patients. The limb salvage rate was 95 per cent. Of the 28 injuries to upper extremity vessels, 24 were associated with neurologic injuries. In contrast, only 3 neurologic injuries were found in patients with lower extremity vascular injuries. In contrast to most urban centers, the distribution of vascular injuries to the extremities in a suburban setting was equally divided between blunt and penetrating injuries. The majority of functional impairment was related to neurologic injury rather than tissue ischemia from vascular injury.