Heparinless partial cardiopulmonary bypass for the repair of aortic trauma

Nationwide utilization of cardiopulmonary bypass in cardiothoracic trauma: A retrospective analysis of the National Trauma Data Bank

BACKGROUND

The American College of Surgeons Committee on Trauma requires that all level I trauma centers have cardiopulmonary bypass (CPB) capabilities immediately available. Despite this mandate, there are limited data on the utilization and clinical outcomes among trauma patients requiring CPB in the management of injuries. The aim of this study was to evaluate the current use of CPB in the care of trauma patients.

METHODS

This is a retrospective analysis of the National Trauma Data Bank from 2010 to 2015. Adult patients sustaining cardiothoracic injuries who underwent surgical repair within the first 24 hours of admission were included. Propensity score matching was used to compare outcomes (in-hospital mortality, hospital length of stay (LOS), intensive care unit LOS, and complications) between patients who underwent CPB within the first 24 hours of admission and those with similar injuries who did not receive CPB.

RESULTS

A total of 28,481 patients who met the inclusion criteria were identified, of whom 319 underwent CPB. Three-hundred three CPB patients were matched to 895 comparison patients who did not undergo CPB. Overall in-hospital mortality was 35%. Patients who were not treated with CPB had a significantly higher in-hospital mortality compared with those treated with CBP (odds ratio, 1.57; 95% confidence interval, 1.16-2.12; p = 0.003); however, complications were significantly lower in those who did not receive CPB (odds ratio, 0.63; 95% confidence interval, 0.47-0.86; p = 0.003). Hospital LOS (non-CPB: mean, 13.4 ± 16.3 days; CPB: mean, 14.7 ± 15.1 days; p = 0.23) and intensive care unit LOS (non-CPB: mean, 9.9 ± 10.7 days; CPB: mean, 10.1 ± 9.7 days; p = 0.08) did not differ significantly between groups.

CONCLUSION

The use of CPB in the initial management of select cardiothoracic injuries is associated with a survival benefit. Further investigation is required to delineate which specific injuries would benefit the most from the use of CPB.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Bypass Techniques for Descending Thoracic Aortic Surgery

The conduct of partial left heart bypass or partial car diopulmonary bypass (CPB) during surgery involving the descending thoracic aorta or thoracoabdominal aorta is one of the most unappreciated and misunder stood extracorporeal circulation procedures in cardio vascular surgery. It is different from conventional CPB, and although some uninitiated practitioners consider it simpler, it is in fact more complicated than conven tional CPB and involves different concepts. It requires expertise and skill in regulating the flow, pressure, and oxygenation of blood going to both the proximal and distal parts of the body and management of the special bypass or shunt procedures used, specialized monitor ing, and knowledge about the protection and preserva tion of organs both proximal and distal to the aortic clamping. It demands exquisite communication and un derstanding of the unique problems faced by the sur geon, anesthesiologist, and perfusionist.

Epidemiology of concomitant injuries in traumatic thoracic aortic rupture: a meta-analysis

Traumatic thoracic aortic rupture is a highly lethal injury. For those who arrive alive at the hospital, it is of utmost importance to quickly evaluate concomitant injuries and prioritize therapeutic interventions. We aimed to review the frequency of concomitant injuries in patients with thoracic aortic rupture, according to anatomic location and type of injury. A systematic literature search of six medical databases led to the identification of 90 publications; 27 categories of thoracic aortic rupture concomitant injuries were thereafter created. The respective pooled proportions and 95% confidence intervals were calculated and ranked in order of frequency. Among the 7258 patients studied, orthopedic fractures were the most frequent thoracic aortic rupture concomitant injury, amounting to a high pooled proportion of almost 70%, followed by thoracic injury in ∼50% and abdominal injury in over 40%. Pooled proportion for any type of head injury was also high (37%) pointing to the multiple-injury type of lesions among thoracic aortic rupture victims. Thoracic aortic rupture is a devastating injury, but rarely occurs as a sole traumatic entity. The recognition of concomitant thoracic, abdominal, head injuries and fractures after thoracic aortic rupture is of paramount importance. Future studies should focus on the impact of these injuries upon survival, morbidity and disability of multiple-injured thoracic aortic rupture patients.

Evaluation of the outcome of traumatic thoracic aortic rupture in patients in a trauma and critical care center

OBJECTIVES

Multiple injuries may lead to traumatic thoracic aortic rupture (TTAR), which can be fatal. We evaluated the relationship between the clinical findings and outcomes of 26 patients with TTAR who were treated at our institution.

METHODS

A total of 26 patients (men, 21; women, 5; average age, 45.8 ± 19.6 years) with a diagnosis of TTAR received from 1999 to 2009 were studied. We categorized patients into groups based on the outcome (survival or death) and investigated the relationship between the outcome and the following factors: injury mechanism, vital signs, other combined injuries, injury severity score (ISS), revised trauma score, and probability of survival (Ps).

RESULTS

Of the 26 TTAR patients, 7 underwent emergency operations, 5 underwent delayed operations, 1 received conservative treatment, and 13 suffered cardiopulmonary arrest immediately after consultation and died. Of the 13 patients who died, 11 died within 2 hours after injury because of bleeding. Two of the 7 patients who underwent emergency operations died within 1 day of consultation, whereas all those who underwent delayed operations survived. Patients who underwent TTAR repair had a relatively favorable outcome. Analysis of the relationship between the clinical data and outcome showed that a young age was significantly correlated with survival, and that the Glasgow coma scale (GCS), heart rate, respiratory rate, or occurrence of shock were not significantly related to the outcome. The abbreviated injury scale (AIS) was used to score the severity of multiple injuries, and ISS was calculated from the AIS score. ISS was significantly higher in the death group (P = 0.007). ISS did not significantly differ among body parts (P = 0.077), but ISS of the extremities was higher than those of other parts. Pelvic fractures were frequent in the death group. Our strategy, whereby the patient initially underwent pelvic external fixation followed by TTAR repair was found to be very effective. The P-values calculated by the trauma and injury severity score method were significantly higher in the survival group (both, P = 0.007).

CONCLUSION

To treat TTAR, it is important to accurately evaluate the damage due to multiple injuries and apply an appropriate treatment strategy. Immediate repair of TTAR after bleeding due to combined injury improves the outcome. (English Translation of Jpn J Vasc Surg 2012; 21:5-9).

Endovascular intervention in thoracic arterial trauma

The management of thoracic vascular injury has improved dramatically over the past two decades. The availability of multi-row detector CT has facilitated early diagnosis and incorporation of minimally invasive endograft repair for traumatic aortic injury has improved mortality and paraplegia rates. This review evaluates the available data on stent-graft repair of acute blunt traumatic aortic injury and traumatic great vessel injury with regard to safety and efficacy in comparison with conventional open surgical repair.

Out-of-hospital cardiopulmonary arrest due to penetrating cardiac injury treated by percutaneous cardiopulmonary support in the emergency room: report of a case

Penetrating cardiac injury tends to generally be repaired without cardiopulmonary bypass in the operating room. We herein report the case of penetrating cardiac injury repaired using percutaneous cardiopulmonary support in an emergency room. A 57-year-old man attempted suicide by stabbing himself in the left anterior chest with a knife. Although the patient suffered cardiopulmonary arrest for 7 min in the ambulance, spontaneous circulation was restored following pericardiotomy through emergency left thoracotomy in the emergency room. To prevent coronary artery injury and control the massive bleeding, percutaneous cardiopulmonary support was instituted without systemic heparinization and the cardiac injury was repaired in the emergency room. The patient was then transferred to another hospital on day 46 for further rehabilitation. Percutaneous cardiopulmonary support might be helpful for treating critical patients in an emergency room, even in the case of trauma patients.

Endovascular repair of traumatic rupture of the aortic isthmus: Midterm results

OBJECTIVE

The endovascular management of aortic traumatic ruptures has been proposed as an alternative to classical surgical procedures. The aim of this work was to report the midterm results of the endovascular treatment of traumatic ruptures of the isthmic aorta.

METHODS

Between January 1996 and July 2005, endovascular repair of blunt traumatic aortic ruptures was performed in 33 patients (mean age, 40 +/- 17 years). The stent grafts used were either Talent Medtronic (n = 27), Gore Excluder (n = 4), or Boston Vanguard (n = 2) grafts. Follow-up was 94.9% complete and averaged 32.4 +/- 28.8 months (maximum, 8 years).

RESULTS

Stent graft deployment was successful in all cases without need for surgical conversion. Except for one iliac rupture, which was treated with an iliofemoral bypass during the same procedure, there was no major perioperative complication. The early complications consisted of 3 primary endoleaks (1 type I and 2 type IV), 1 transient paraparesis, 1 occlusion of the main left bronchus, 1 thrombosis, and 2 pseudoaneurysms of the brachial artery. All the primary endoleaks healed within the first month. No patient died, and no aortic reinterventions were performed. The midterm complications were a mild circumferential thrombus at the distal part of the stent graft and a fracture of the nitinol stent. Both complications were asymptomatic and were discovered on systematic computed tomographic scan examination. Actuarial freedom from complication at 1 year was 96.1% +/- 3.8% and 85.5% +/- 10.6% at 3 and 5 years, respectively.

CONCLUSION

This study demonstrates that the endovascular treatment of blunt thoracic aortic traumatisms is a safe and effective therapeutic method without increased midterm morbidity and mortality rates.

The effect of changing presentation and management on the outcome of blunt rupture of the thoracic aorta

BACKGROUND

The management of traumatic aortic rupture has evolved from emergency surgery for all to incorporating nonoperative and endovascular approaches. In addition, the greater emphasis on restraint systems over the past decade might result in lower immediate mortality.

METHODS

We reviewed our contemporary experience with reference to a previous report from the same institution to determine whether there has been improvement in outcome related to these factors.

RESULTS

In 1990, a review of 104 patients admitted to our center over a 15-year period (1975-1990) noted an overall mortality of 65%. Forty-two patients died before they could reach the operating room, including 15 who were declared dead on arrival and 27 who died before reaching the operating room. All patients underwent angiography, followed by immediate operation. The mortality rate of those who reached the operating room was 34%, and paralysis-paraplegia occurred in 26% of survivors. A review of 53 patients admitted between January 1, 2000, and April 2005 documented an overall mortality of 26% and a paralysis rate of 4.5% in operative survivors. Only 3 patients died during initial evaluation, 2 who were in arrest on arrival. Eight patients were managed nonoperatively, and 13 were managed by means of deliberate delay before intervention to improve physiologic status. Finally, 19 patients were managed with endografts.

CONCLUSION

The improved outcome over the decade since the initial experience reflects both a reduced severity of injury attributable to restraint systems and a more flexible approach to the acute management, which can modify the effect of associated injuries.

Management Options in Blunt Aortic Injury: A Case Series and Literature Review

Blunt aortic injury (BAI) is a devastating consequence of high-energy trauma. The majority of its victims do not survive; those who do generally have significant associated injury. The standard treatment of BAI has been emergent replacement or repair of the damaged aorta via a posterolateral thoracotomy, with or without perfusion adjuncts. In addition to the substantial morbidity and mortality secondary to multisystem traumatic injuries, patients surviving to reach the operating room have been exposed to the risks related to their surgical treatment, namely death, paraplegia, hemorrhage, transfusion, organ dysfunction, prolonged intensive care unit stays, and extensive rehabilitation requirements. Contributions to the literature over the past several years have provided support for changing practice patterns in the management of BAI. Aggressive control of blood pressure has made it safe to delay high-risk interventions in patients with complex injuries. Advanced perfusion strategies using little or no anticoagulation appear to have positively affected bleeding complications and neurologic risk. Finally, endovascular stent grafting, though not yet rigorously evaluated in BAI, has been shown to be feasible and effective in the short term. This case presentation and literature review will examine treatment options and propose a management algorithm.

Coagulation Disorders and Blood Product Use in Patients Undergoing Thoracoabdominal Aortic Aneurysm Repair

Repair of thoracoabdominal aortic aneurysms (TAAA) is associated with major blood loss, often exceeding the patient's intravascular volume, and complex intraoperative and postoperative coagulopathies necessitating large-volume transfusion of blood products. Abnormalities sufficient to cause thrombocytopenia or clinically important prolongation of clotting parameters are rarely present before surgery in elective aneurysms but are more common with ruptured aneurysms. The finding of intraoperative and postoperative deficiencies of clotting factors, along with thrombin generation and activation of the thrombolytic system, is reflective of massive blood losses, visceral ischemia, and massive transfusions. An aggressive strategy of transfusion of blood products is critical to the prevention of clinically significant coagulopathy during surgery. Adjuncts to reduce blood losses and blood product use include low-dose aprotinin or epsilon -aminocaproic acid, intraoperative blood salvaging, and acute normovolemic hemodilution. In TAAA repair, an average blood loss of 5000 to 6000 mL and average transfusion of allogeneic blood products of 50 to 60 U are to be anticipated.

Selective Use of Cardiopulmonary Bypass in Trauma Patients

The need for cardiopulmonary bypass (CPB) in the treatment of trauma patients is controversial, and not all level I trauma centers have CPB readily available. Our purpose was to review the selective use of CPB in the management of trauma victims at a level I trauma center in Los Angeles County. We reviewed the records of all patients for whom the CPB team was called in from 1994 to 2002. Perfusionists were present for the initial operative management of 24 patients, 22 (92%) of which were male. Twelve patients had penetrating and nine had blunt injuries, two were severely hypothermic, and the last suffered embolization of a bullet to the pulmonary artery. Overall survival was 75 per cent. Sixteen (67%) patients required CPB due to the life-threatening nature of their injuries and/or hemodynamic instability; 11 (69%) survived. The remaining 8 patients were operated on with the CPB team present but on standby; 7 (88%) survived. Cardiopulmonary bypass could be life-saving in select trauma patients with major chest injuries. Hypothermia, acidemia, and shock can be reversed earlier while allowing increased time to gain adequate exposure and perform quality repairs. Level I trauma centers should have CPB capabilities immediately available.

Use of a Centrifugal Vortex Blood Pump and Heparin-Bonded Circuit for Extracorporeal Rewarming of Severe Hypothermia in Acutely Injured and Coagulopathic Patients

BACKGROUND

Standard rewarming methods for posttraumatic hypothermia are ineffective or require systemic heparinization. Centrifugal vortex blood pumps (CVBPs), heparin-bonded circuits, and, potentially, percutaneous access techniques, facilitate the institution of an extracorporeal circulation by noncardiac surgeons.

METHODS

Seven severely hypothermic patients requiring emergent operative intervention were rewarmed intraoperatively using the CVBP with heparin-bonded circuitry.

RESULTS

Patients were critically ill (average Injury Severity Score of 43.5 [SD, 13.6] for the traumatized patients). The mean temperature before rewarming was 31.5 degrees C (SD, 1.6 degrees C). The CVBP outflow site was the common femoral vein in all patients, with the inflow into the superficial femoral artery (n = 2), contralateral common femoral vein (n = 2), and internal jugular vein (n = 3). The mean time to rewarm to 37 degrees C was 73.3 (SD, 30.5) minutes. All patients survived the initial operation, although the ultimate survival was 43%.

CONCLUSION

Noncardiac surgeons can effectively use an extracorporeal rewarming strategy incorporating a heparin-bonded CVBP to rapidly rewarm hypothermic coagulopathic patients undergoing surgery.

Complex blunt aortic injury or repair: beneficial effects of cardiopulmonary bypass use

OBJECTIVE

To compare the outcomes and associated morbidity in patients with blunt aortic injury (BAI) repaired using cardiopulmonary bypass versus no bypass. Special consideration is given to the influence of bypass in the outcome of complex injuries or repair circumstances.

SUMMARY BACKGROUND DATA

There are conflicting data concerning the utility of bypass techniques in the operative management of BAI, and controversy over the subject persists. During the last decade, surgeons at the authors' institution have undergone a change in philosophy concerning management of these injuries and began almost exclusively using cardiopulmonary bypass for the repair in 1996. This project explores the effects of this change in the management of BAI.

METHODS

The records of all patients with BAI admitted to a level 1 trauma center over a period of 12 years were reviewed for demographics, injury characteristics, operative technique, and outcome. The bypass group was compared to the no bypass group with respect to morbidity and mortality. Those with a complex injury or repair (CI/R) were examined as a subgroup. CI/R was defined as the presence of an injury with extension proximal to the subclavian artery, involvement of branch vessels, or requirement of maneuvers interfering with anastomosis construction, such as cardiac massage.

RESULTS

From January 1, 1990, to December 31, 2001, 91 patients were admitted to Wake Forest University Baptist Medical Center with BAI. Sixty-five of these underwent operative repair. Sixty (32 no bypass, 28 bypass) survived to the immediate postoperative period. Injury Severity Score was similar (33 no bypass, 31 bypass, P =.48), as was admission base deficit (-9.2 m Eq/L no bypass vs. -7.0 mEq/L B, P =.13). Paraplegia occurred in four (12%) of the no bypass group as opposed to 0 of the bypass group (P =.05). No patient in the bypass group experienced complications related to heparinization, and two (7%) experienced bypass-related complications (cerebral edema, femoral vein laceration). Mean clamp time for the entire group was 27 minutes. Examination of the 10 patients with CI/R who survived the operating room showed markedly longer clamp times (59 minutes vs. 22 minutes, P <.0001) and a higher rate of paraplegia/paresis (30% vs. 2%, P =.01) as compared to those without CI/R. Logistic regression demonstrated a significant relationship between increasing clamp time and the CI/R classification (P =.007). All three (100%) of the CI/R patients repaired via clamp-and-sew technique developed paraplegia, while none of the seven CI/R patients repaired on bypass developed neurologic changes (P =.008).

CONCLUSIONS

With the use of cardiopulmonary bypass in the repair of BAI, the incidence of paraplegia/paresis has fallen. While patients with typical injuries and uncomplicated repair can expect good results with either technique, cardiopulmonary bypass provides significant advantages in the repair of those with CI/R. With the use of bypass, no CI/R patient developed paraplegia, while all CI/R patients experienced paraplegia before bypass use. Although others have reported the importance of clamp time, in this series clamp time appeared largely to be a surrogate variable for complexity of injury.

Intra-operative autologous blood management

The evolution of cardiac surgery has been accompanied by a wide variety of techniques and equipment available for blood conservation. It has also given us data that allows identification of preoperative risk factors for transfusion needs in other surgical specialties. There is however great diversity of opinion as to how this technology should be applied. Examples can be found in the literature of discrepancies between countries but also individual institutions . The authors encounter differences in opinion between practitioners regularly. The authors believe that the variance in opinion may be based on the experiences of single techniques and that a broader depth of practice is required to achieve best practices for intra-operative transfusion management. The most performed procedure in our experience is red cell salvage and processing with a cell-washing device (CS). There are two primary issues related to CS, cost and reduction in allogenic blood exposure. A recent meta-analysis has shown that cell salvage in orthopedic surgery decreases the proportion of patients requiring allogeneic blood transfusion peri-operatively, but post-operative cell salvage is only marginally effective in cardiac surgery. There are close analogies to be drawn from issues surrounding the whole picture of transfusion. Medical practice guidelines are frequently promoted as a way to improve the cost-effectiveness of healthcare. But non-compliance with guidelines is still a major issue. Guiding the decision to transfuse or autotransfuse can improve transfusion practices, but effective processes must first identify problem(s) in transfusion practice and then include the attending medical practitioner as an educational target. Process improvements that have been shown to be effective include, briefly meeting one-on-one with physicians, teaching at scheduled conferences, making daily clinical rounds of patients who receive transfusion, concurrently reviewing orders for transfusion before issue of the blood product, and installing algorithms and guidelines in the operating room. Transfusion practices improved with these process improvements. The success of a change of practice patterns relies on hospital administration, education and feedback, written and immediately available guidelines, employment of specially trained personnel, and establishing long-standing actions. It is the authors' observation that the success of an intra-operation blood management program is twofold, early identification of patients and a multi-team approach of Surgeon, Haematologist, Transfusion services, Anaesthetist and Perfusionist. This team approach offers far greater depth for management of intra-operative blood conservation and transfusion practice. Interventions must be patient specific and targeted toward the best possible patients outcome.

Traumatic rupture of the thoracic aorta: cohort study and systematic review

PURPOSE

Through a systematic review of the literature, we identified the optimal management of traumatic ruptures of the thoracic aorta (TRTA) and reported the results of a cohort of patients treated with the clamp-and-sew technique (CAS) at a tertiary trauma center.

METHODS

Studies were identified through Medline and the Cochrane library and from reference lists and papers from the authors' files. Studies with a single consistent protocol (CAS, Gott shunt [GS], left heart bypass [LHB], or partial cardiopulmonary bypass [PCPB]) that reported mortality and neurologic outcomes were included. Relevance, validity, and data extraction were performed in duplicate. A retrospective review of charts from June 1992 to August 2000 provided the database for our experience.

RESULTS

Twenty studies reporting on 618 patients were found to be relevant. Interobserver agreement for relevance and validity decisions was high. Mortality rates for repair with CAS, GS, LHB, and PCPB were 15%, 8%, 17%, and 10%, respectively, and for paraplegia they were 7%, 4%, 0%, and 2%, respectively. The difference in mortality rates was not statistically significant. CAS had a higher incidence of neurologic deficits than GS (odds ratio [OR], 1.8; 95% CI, 0.4-8), LHB (OR, 6.4; 95% CI, 0.8-50), and PCPB (OR, 3.4; 95% CI, 1-10). In our cohort of 25 patients, 21 underwent surgery with CAS. The median abbreviated injury severity score was 20 (range, 4-50). The mean aortic clamp time was 30 +/- 12 minutes. Aortic repair was achieved with graft interposition in 43% of patients, and simple suture was achieved in 57% of patients. Mortality (10%) and neurologic complication (paraplegia, 11%; paraparesis, 5%) rates were not statistically different from those reported in the literature.

CONCLUSION

CAS is associated with a similar mortality rate but a higher incidence of neurologic deficits than methods with distal aortic perfusion.

Alternatives to unfractionated heparin for anticoagulation in cardiopulmonary bypass

Despite the progress made in the development of cardiopulmonary bypass (CPB) equipment, systemic anticoagulation with unfractionated heparin and post-bypass neutralization with protamine are still used in most perfusion procedures. However, there are a number of situations where unfractionated heparin, protamine or both cannot be used for various reasons. Intolerance of protamine can be addressed with extracorporeal heparin removal devices, perfusion with (no) low systemic heparinization and, to some degree, by perfusion with alternative anticoagulants. Various alternative anticoagulation regimens have been used in cases of intolerance to unfractionated heparin, including extreme hemodilution, low molecular weight heparins, danaparoid, ancrod, r-hirudin, abciximab, tirofiban, argatroban and others. In the presence of heparin-induced thrombocytopenia (HIT) and thrombosis, the use of r-hirudin appears to be an acceptable solution which has been well studied. The main issue with r-hirudin is the difficulty in monitoring its activity during CPB, despite the fact that ecarin coagulation time assessment is now available. A more recent approach is based on selective blockage of platelet aggregation by means of monoclonal antibodies directed to GPIIb/IIIa receptors (abciximab) or the use of a GPIIb/IIIa inhibitor (tirofiban). An 80% blockage of the GPIIb/IIIa receptors and suppression of platelet aggregation to less than 20% allows the giving of unfractionated heparin and running CPB in a standard fashion despite HIT and thrombosis. Likewise, at the end of the procedure, unfractionated heparin is neutralized with protamine as usual and donor platelets are transfused if necessary. GPIIb/IIIa inhibitors are frequently used in interventional cardiology and, therefore, are available in most hospitals.