Traumatic tears of the thoracic aorta: improved results using the Bio-Medicus pump

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.

Comparison of Spinal Cord Protection Utilizing Left Atrial-Femoral with Femoral-Femoral Bypass in Patients with Traumatic Rupture of the Aortic Isthmus

INTRODUCTION

Postoperative paraplegia remains a dreaded complication of repair of traumatic rupture of the aortic isthmus. Claims have been made that left atrial-femoral bypass provides better spinal cord protection. To test the hypothesis that left atrial-femoral bypass is better than femoral vein-to-femoral artery bypass in regard to postoperative paraplegia, we concurrently compared the two techniques.

METHODS

We compared the occurrence of paraplegia in 18 patients whose ruptures were repaired utilizing left atrial-femoral bypass with 10,000 units of systemic heparin (group A) and 72 patients with femoral-femoral bypass with heparin 300 units/kg and an oxygenator (group B) operated on between January 1995 and July 2004.

RESULTS

The mortality rate was 5.6% (5/90), with no statistical difference between the two groups. Postoperative paraplegia was present in three (16.7%) group A patients and five group B (6.9%) patients. However, the specific etiology of the neurologic defect was not clear, as one patient's paraplegia was transient following a period of cardiac arrest, and four others had had neurologic injuries prior to the aortic repair. Median aortic cross-clamp times were shorter in group A (34 minutes vs. 49 minutes). No patient required reexploration for bleeding, and no patient developed a graft infection.

CONCLUSIONS

Paraplegia rates were higher in the left atrial-femoral group, but the difference was not statistically significant. This occurred despite the decreased cross-clamp times in this group. In patients undergoing repair of traumatic rupture of the aortic isthmus, left atrial-femoral bypass does not provide better spinal cord protection than femoral-femoral bypass.

Indications for, timing of, and results of catheter-based treatment of traumatic injury to the aorta

OBJECTIVE

The optimal treatment for and timing of surgery to repair traumatic aortic injury are still controversial. Endovascular treatment is a viable option in patients with both acute and chronic aortic trauma. However, appropriate patient selection criteria, treatment timing, and long-term durability of endovascular repair remain to be defined. We sought to identify appropriate selection criteria and optimal timing of treatment as well as to assess the long-term durability of endovascular repair.

SUBJECTS AND METHODS

From July 1997 to December 2001, 19 patients with traumatic aortic injury (11 patients with acute and eight with chronic injuries) were selected for endovascular treatment. In all patients, the lesions were sited at the proximal segment of the descending aorta at a distance of 10 +/- 17 mm (mean +/- SD) from the left subclavian artery. Nine of the patients with acute injuries were treated after clinical stabilization of other severe associated lesions, whereas two patients, in whom hemodynamic and imaging findings suggested an impending rupture, received emergency treatment. Single-detector helical CT or MR imaging was used for patient selection and stent-graft customization before treatment and for evaluation of patients during the follow-up period.

RESULTS

Endovascular stent positioning was successful in all patients. None of the patients developed complications. Aneurysm exclusion and shrinkage were confirmed at followup examinations. A partial covering of the subclavian artery occurred in six patients without interrupting the blood flow. All patients remain asymptomatic after a mean follow-up period of 20 months (range, 1-56 months).

CONCLUSION

Endovascular repair represents an alternative, minimally invasive treatment, particularly suitable for use in patients with traumatic aortic injuries. The decision of whether to provide immediate emergency treatment or to delay treatment should be based on the lesion characteristics on imaging and clinical findings. The durability of treatment seems to be related to the absence of alteration to the aortic wall at the extremities.

Traumatic rupture of the thoracic aorta: third decade of experience

BACKGROUND

Traumatic rupture of the thoracic aorta is a relatively common injury of deceleration accidents, usually high-speed motor vehicle accidents. Spinal cord injury has been a well-documented complication of surgical management. The use of nonheparinized partial bypass with a centrifugal pump was evaluated for protection against spinal cord injury and reduction of risk of associated injuries.

METHODS

From 1989 to 1999, the third decade of the authors' experience, traumatic rupture was diagnosed in 58 patients (male 46 and female 12; mean age 39.9 years, range 17 to 85). Associated injuries were documented in 98.3% (57 patients). In all, 45 patients (77.6%) had the opportunity for definitive surgical management; 42 (93.3%) were managed with partial cardiopulmonary bypass, 35 without the use of heparin. Full cardiopulmonary bypass was utilized in 1 patient while 2 had repair without cardiopulmonary bypass support. Thirteen patients did not have the opportunity for definitive surgical management, 1 death on arrival, 8 (61.5%) suspected, and 4 (30.8%) diagnosed.

RESULTS

There were 6 deaths in the surgical group, 5 in nonheparinized patients. The causes were intraoperative hypovolemia (2), anoxic brain death after intraoperative cardiac arrest (1), sepsis (1), and adult respiratory distress syndrome (1). The other was in the simple aortic cross-clamp group from intraoperative pulmonary compromise. There was one spinal cord injury, paraparesis in 1 of the 2 patients managed without bypass support. The total hospital stay ranged from 8 to 112 days, primarily owing to management of associated injuries. Of the 13 patients who did not have the opportunity for definitive surgical management, 5 had unsuccessful emergency thoracotomy and 3 survived the hospital course without surgery. Of the total population, the overall mortality was 27.6%, whereas the mortality of the potentially operable patients was 25.8%. Of the surgical group, the intraoperative mortality was 6.7% and 30-day mortality was 13.3%.

CONCLUSIONS

Spinal cord injury was prevented by the use of partial cardiopulmonary bypass. Nonheparinized bypass was likely to be a contributory factor to lack of mortality directly related to associated injuries.

Advances in the diagnosis and treatment of thoracic trauma

With the exception of the use of ECG to screen patients for blunt cardiac injury, recent advances in the diagnosis of thoracic trauma involve new technology. Use of surgeon-performed pericardial and pleural ultrasound for the detection of tamponade or hemothorax, TEE or spiral CT to diagnose rupture of the thoracic aorta, and thoracoscopy to evaluate a hemothorax or the integrity of the left hemidiaphragm are all standard techniques in modern trauma centers. In terms of treatment, emergency center thoracotomy is performed more selectively and with the adjunct of staple closure for cardiac wounds. Pulmonotomy is used selectively to control deep lobar hemorrhage and to avoid the need for an emergent lobectomy. Finally, nonoperative management of an intimal tear of the thoracic aorta or delayed operative management of a full-thickness tear in the patient with multiple injuries, using beta-blocker-induced relative hypotension, is rapidly becoming the standard of care throughout the United States.

Recent clinical experience with left heart bypass using a centrifugal pump for repair of traumatic aortic transection

OBJECTIVE

To analyze the indications, results, and limitations of using left atrial to femoral artery (LA-FA) bypass to provide distal perfusion during repair of traumatic aortic injuries.

SUMMARY BACKGROUND DATA

There is no consensus about the best method for repair of traumatic aortic transection. Distal aortic perfusion with LA-FA bypass and a centrifugal pump has been the authors' preferred technique for injuries to the aortic isthmus and descending thoracic aorta.

METHODS

From 1988 to 1998, the authors operated on 30 patients with traumatic aortic transection using LA-FA bypass. The mean age of the group was 36+/-2 years. The mechanism of injury was from a motor vehicle accident in 97% of the cases. Distal aortic perfusion was maintained at 50 to 75 mm Hg with flow rates of 1.5 and 3 L/min. The mean aortic cross-clamp time was 38+/-2 minutes, and the mean bypass time was 49+/-2 minutes.

RESULTS

No complications related to cannulation, arterial thromboembolism, renal failure, mesenteric ischemia, or hepatic insufficiency occurred. There were no cases of postoperative paraplegia and no deaths.

CONCLUSION

Left atrial to femoral artery bypass is a safe, simple, and effective adjunct to the repair of traumatic injuries to the thoracic aorta. Active distal aortic perfusion preserves spinal cord, mesenteric, and renal blood flow and eliminates the potential catastrophic consequence of spinal cord ischemia from an unexpectedly prolonged aortic cross-clamp time.

Argatroban, an attractive anticoagulant, for left heart bypass with centrifugal pump for repair of traumatic aortic rupture

Systemic heparinization often increases the risk of fatal bleeding from other injured organs in surgical repair of the aorta using extracorporeal circulation in patients with traumatic aortic rupture associated with multisystem injuries. We used an antithrombin agent, argatroban, as an alternative anticoagulant in left heart bypass with the Bio-Medicus centrifugal pump in 7 of 9 recent patients who underwent aortic repair using left heart bypass. All these patients survived without obvious evidence of systemic thromboembolization. Surgical treatments for other organ injuries were carried out in 3 patients concomitantly or immediately after aortic repairs without undue blood loss. Argatroban may have a complementary effect for preventing thrombus formation without aggravating bleeding tendency because of its monotarget specificity to thrombin. We believe intravenous administration (0.5 to 2 micrograms/kg/min) of argatroban is a safe anticoagulant for left heart bypass in repairs of traumatic aortic rupture associated with multiple organ injuries.

Traumatic aortic rupture: diagnosis and management

BACKGROUND

Traumatic aortic rupture is a relatively uncommon lesion that presents the cardiothoracic surgeon with unique challenges in diagnosis and management. To address controversial aspects of this disease, we reviewed our experience.

METHODS

The study was performed by retrospective chart review.

RESULTS

Forty-two patients with traumatic thoracic aortic ruptures were managed between January 1988 and June 1997. Nine arrived without vital signs and died in the emergency department. Admission chest radiographs were normal in 3 patients (12%) and caused significant delays in diagnosis. Four of 30 patients admitted with vital signs had rupture before thoracotomy and died. Twenty-six underwent aortic repair. In 1 patient repair was performed with simple aortic cross-clamping, whereas a second was managed with a Gott shunt. The remaining 24 patients had repair with partial left heart bypass. In 1 patient hypothermic circulatory arrest was required. Two patients (7.7%) died. There were no cases of new postoperative paraplegia in the bypass group. There was no morbidity directly attributable to the administration of heparin for cardiopulmonary bypass.

CONCLUSIONS

In a discrete group of patients with traumatic rupture of the aorta, the rupture will become complete during the first few hours of hospital admission; aggressive medical treatment with beta-blockade and vasodilators in the interval before the operation is an essential aspect of management. Active distal circulatory support with partial left-heart bypass provides the optimal means of preventing spinal cord ischemia during repair of acute traumatic aortic rupture.

Hume Memorial lecture. Prevention of spinal cord complications in aortic surgery

Paraplegia or paraparesis after operations on the thoracic and abdominal aorta is a devastating event, both for the patient and the surgeon. While its incidence varies from under 1% with operations at the top and bottom of the aorta, its occurrence in the midportion of the aorta, just above the diaphragm, even in the best of hands exceeds 10%. Over a decade ago, Crawford et al (J Vasc Surg. 1986;3:389-404) introduced the use of inclusion and sequential clamping techniques for thoracoabdominal aneurysmectomy, lowering both morbidity and neurologic sequelae. Although these techniques have been widely adopted, newer ancillary adjuncts have been recommended by a number of investigators. This paper summarizes the possible causes of paraplegia secondary to the various operations on the aorta and analyzes the status and value of the various ancillary techniques in its prevention.

Cannulation of Left Inferior Pulmonary Vein and Distal Thoracic Aorta for Left Heart Bypass

We describe a simple safe technique of left heart bypass using cannulation of the posterior aspect of the left inferior pulmonary vein for repair of an aneurysm in the distal aortic arch.

Spinal cord protection during surgical procedures on the descending thoracic and thoracoabdominal aorta: a critical overview

During the past three decades, significant advances have been made in the surgical treatment of the diseases affecting the aorta. Despite these important advances, paraplegia remains a devastating complication of the surgical procedures on the thoracic and thoracoabdominal aorta. Paraparesis and paraplegia occur as a direct result of the interruption of blood flow to the spinal cord during the surgical procedures. A number of techniques have been advocated for the prevention of spinal cord ischemic injury. This article critically reviews our current understanding of the extent of this problem, the mechanism of injury, and the methods that have been devised to reduce the frequency of paraplegia following surgical procedures on the descending aorta.

Outcome of blunt thoracic aortic injury in a level I trauma center: an 8-year review

BACKGROUND

The purpose of this study was to evaluate our experience with blunt thoracic aortic injury and identify factors predictive of outcome.

METHODS

Hospital charts, trauma registry data, and autopsies of 64 patients with blunt thoracic aortic injury from 1988 to 1995 were reviewed.

RESULTS

Patients were identified and segregated based on admission physiology. Group 1 patients (n = 19) arrived in arrest. Group 2 patients (n = 10) arrived in shock with systolic BP 90. Group 3 patients (n = 35) arrived with systolic BP>90. All patients in groups 1 and 2 expired. Injury Severity Scores for nonsurvivors in group 3 (n = 12) were significantly higher than survivors. There were no significant differences when comparing time of injury to repair or arrival between groups, or in mortality or paralysis comparing repair techniques or clamp/bypass times. Double lumen endotracheal tubes caused significant operative delays compared to single lumen tubes.

CONCLUSIONS

Predictors of survivability were hemodynamic stability on arrival and lower Injury Severity Scores. In thoracic aortic injury patients arriving hemodynamically stable, Injury Severity Score correlated with mortality but not paralysis.

Posterior circulation cerebral infarcts associated with repair of thoracic aortic disruption using partial left heart bypass

BACKGROUND

Partial left heart bypass is widely used in the repair of traumatic aortic disruptions. We recently encountered two patients with posterior circulation infarctions after repair of traumatic aortic disruptions using heparin-less partial left heart bypass.

METHODS/RESULTS

Both patients underwent interposition graft repair of thoracic aortic transections at the level of the isthmus. The first patient developed a left posterior inferior cerebellar artery infarct after a clamp time of 44 minutes. Swelling of this infarct necessitated ventriculostomy placement. The second patient developed a pontine infarct postoperatively after a cross-clamp time of 56 minutes and suffered a persistent left upper extremity paresis.

CONCLUSIONS

Partial left heart bypass may have predisposed these two patients to clamp-related embolic events via the left vertebral artery. This experience warrants further surveillance to detect these infarcts which can require neurosurgical intervention. Additionally, the events suggest reconsideration of systemic anticoagulation during aortic cross-clamp times exceeding 30 minutes.

Extracorporeal circuit design considerations for giant intracranial aneurysm repair

Clinical perfusionists must be able to modify the existing extracorporeal circuit in order to accommodate a specific surgical pathology. The clipping of a giant intracranial middle cerebral artery aneurysm, unapproachable with conventional neurosurgical techniques, required the use of a modified closed cardiopulmonary bypass circuit combined with deep hypothermia and total circulatory arrest. In-hospital discussions with anaesthesia, cardiac surgery, neurosurgery, and cardiology enabled an informed team approach directed towards the successful treatment of this complex neurosurgical lesion.

Surgical management of traumatic aortic disruption

BACKGROUND

Acute traumatic disruption of the descending thoracic aorta is a life-threatening injury that requires emergent operative intervention. From May 1988 to August 1996, 27 patients have undergone surgical repair at our institution.

METHODS

Diagnosis of aortic disruption was confirmed in all patients by aortogram prior to aortic repair. A Gott shunt was used in 24 patients (89%) and partial femoral-femoral bypass in 1 patient (4%) for distal perfusion. A clamp-and-sew technique was used in 2 patients (7%).

RESULTS

Mean aortic clamp time was 44 +/- 3 minutes (range 22 to 80 minutes) in patients with distal perfusion via a Gott shunt. One patient (4%) died within 30 days of aortic repair due to multisystem organ failure. Paraplegia occurred in 1 patient (4%).

CONCLUSIONS

With a disciplined, diagnostic and surgical approach for patients with traumatic disruption of the descending thoracic aorta, it is possible to achieve excellent outcomes. The use of a Gott shunt is a simple and effective method for distal perfusion during the repair of traumatic aortic rupture.

Mortality and neurologic morbidity after repair of traumatic aortic disruption

BACKGROUND

Traumatic disruption of the thoracic aorta frequently results in death before operative repair. The determinants of mortality after repair, however, are uncertain. In addition, intraoperative strategies for reducing the incidence of spinal cord injury remain controversial.

METHODS

The records of 45 consecutive patients undergoing repair of traumatic disruption of the thoracic aorta at a single institution during a 9-year period were reviewed in a retrospective fashion. Patient age ranged from 15 to 81 years (mean age, 33.9 years). Twenty-two patients (49%) had multiple associated injuries, and 8 (18%) had isolated aortic injuries. Nine patients (20%) experienced preoperative hypotension (systolic blood pressure of less than 90 mm Hg). Repair was performed with partial bypass in 22 patients, a heparinized shunt in 2, and no distal perfusion (clamp and sew technique) in 21.

RESULTS

Nine patient (20%) died after operation. Multivariate logistic regression analysis of preoperative and intraoperative variables identified advancing age and preoperative hypotension as independent predictors of operative death. The presence of associated injuries was not an independent predictor of operative death. All 4 patients with injuries proximal to the aortic isthmus died. Ten patients were excluded from analysis of spinal cord injury either because of preoperative neurologic deficit or because of death before postoperative evaluation. Six (17%) of the remaining 35 patients had development of paraplegia: 5 of the 15 patients having the clamp and sew technique, 1 of the 2 with a shunt, and 0 of the 18 patients with bypass (p < 0.05, clamp and sew versus bypass). In the clamp and sew group, patients in whom paraplegia developed had significantly longer aortic clamp times than those without neurologic injury (40.6 +/- 4.4 minutes versus 28.7 +/- 2.9 minutes, respectively; p < 0.05).

CONCLUSIONS

Advancing age, preoperative hypotension, and perhaps injury location are important determinants of death after repair of traumatic disruption of the thoracic aorta. Adjunctive perfusion with partial bypass should be used during repair to reduce the incidence of spinal cord injury.

Traumatic occlusion of the left anterior descending artery and rupture of the aortic isthmus

A patient with occlusion of the left anterior descending artery and rupture of the aortic isthmus following blunt trauma is reported. Treatment of both lesions through a median sternotomy using cardiopulmonary bypass was accomplished successfully. Special considerations regarding the surgical management of combined cardiac and aortic isthmus lesions in trauma patients are discussed.

Prospective, randomized trial of survivor values of cardiac index, oxygen delivery, and oxygen consumption as resuscitation endpoints in severe trauma

The objective was to test prospectively supranormal values of cardiac index (CI), oxygen delivery index (DO2I), and oxygen consumption index (VO2I) as resuscitation goals to improve outcome in severely traumatized patients. We included patients > or = 16 years of age who had either (1) an estimated blood loss > or = 2000 mL or (2) a pelvic fracture and/or two or more major long bone fractures with > or = four units of packed red cells given within six hours of admission. The protocol resuscitation goals were CI > or = 4.5 L/min/m2, DO2I > or = 670 mL/min/m2, and VO2I > or = 166 mL/min/m2 within 24 hours of admission. The control resuscitation goals were normal vital signs, urine output, and central venous pressure. The 50 protocol patients had a significantly lower mortality (9 of 50, 18% vs. 24 of 65, 37%) and fewer organ failures per patient (0.74 +/- 0.28 vs. 1.62 +/- 0.45) than did the 75 control patients. We conclude that increased CI, DO2I, and VO2I seen in survivors of severe trauma are primary compensations that have survival value; augmentation of these compensations compared to conventional therapy decreases mortality.

Prevention of spinal cord injury after repair of the thoracic or thoracoabdominal aorta

Spinal cord injury occurring as the result of surgical repair of thoracic and thoracoabdominal aortic disease remains a devastating complication. The incidence of postoperative neurologic deficits varies from 4% to 38%. Factors associated with a greater risk for injury include the presence of dissection or extensive thoracoabdominal disease, and a prolonged cross-clamp time. Spinal cord ischemia initiates a deleterious cascade of biochemical events that ultimately result in an increased intracellular calcium concentration. Calcium-activated proteases, lipases, and nucleases mediate the processes that cause cell injury. The accumulation of oxygen-derived free radicals and the occurrence of hyperemia during reperfusion are also contributing causes of spinal cord injury. Increasing the spinal cord blood flow with shunts, oxygenated bypass circuits, cerebrospinal fluid drainage, the intrathecal administration of vasodilators, and the reattachment of intercostal arteries has been tried in an effort to increase spinal cord perfusion. Pharmacologically based measures to prevent spinal cord injury have been pursued, and these have consisted of hypothermia, anesthetic agents, calcium channel blockers, free radical scavengers, and immune system modulation. However, no single technique has proved to be consistently effective in preventing ischemia-induced spinal cord injury.

Spinal cord protection in the absence of collateral circulation: meta-analysis of mortality and paraplegia

A meta-analysis of paraplegia complicating aortic surgery on patients having neither intercostal nor spinal collaterals, epitomized by patients with acute traumatic aortic rupture, was done. Index Medicus and Medline were searched for all suitable English publications between 1972 and 1992. New paraplegia occurred in 9.9% of 1492 patients who underwent surgery. However, 19.2% of patients undergoing surgery with only simple aortic cross-clamping developed paraplegia, in contrast to 6.1% if distal aortic perfusion was augmented by either "passive" or "active" methods (p < 0.00001). The risk of paraplegia increased progressively as cross-clamp times lengthened if simple aortic cross-clamping was used (p < 0.00001), but only once did the cross-clamp time exceed 30 minutes (p < 0.05). Paraplegia occurred in 8.2% of patients with "passive" shunts from the ascending aorta (p < 0.001 vs simple cross-clamping). Shunts from the left ventricular apex, however, had an incidence of paraplegia of 26.1% and, therefore, did not decrease the risk of paraplegia. "Active" augmentation of distal perfusion had the lowest risk of paraplegia: 2.3% (p < 0.00001 vs simple cross-clamping or "passive" shunts). Mortality, however, was higher in these potentially polytraumatized patients when they were perfused distally using methods requiring full systemic heparinization (18.2%), compared to mortality with methods not requiring heparin (11.9%; p < 0.01). In conclusion, simple aortic cross-clamping has a high risk of paraplegia if the cross-clamp time extends beyond 30 minutes. "Active" modalities of augmenting distal perfusion provide optimal spinal protection.

Traumatic aortic rupture: twenty-year metaanalysis of mortality and risk of paraplegia

A metaanalysis of articles concerning the surgical management of acute traumatic rupture of the descending thoracic aorta published in the English-language literature between 1972 and July 1992 was performed. The overall mortality of 1,742 patients who arrived at the hospital alive was 32.0%, one-third died before surgical repair was started. Paraplegia was noted preoperatively in 2.6% of these hospitalized patients, and paraplegia complicated the surgical repair in 9.9% of 1,492 patients who reached the operating room in a relatively stable condition. Patients then were analyzed according to the surgical intervention used. Simple aortic cross-clamping (n = 443) was associated with a hospital mortality of 16.0% and incidence of paraplegia of 19.2%, despite lower average mean cross-clamp times (32 minutes; p < 0.01 versus passive or active methods of providing distal perfusion). In a subset of 290 patients in whom individual data were available, the cumulative risk of paraplegia was shown to increase substantially if the duration of aortic cross-clamping exceeded 30 minutes, but only when distal perfusion was not augmented (p < 0.00001). "Passive" perfusion shunts (n = 424) were associated with a mortality of 12.3%, and the incidence of paraplegia decreased to 11.1% (p < 0.001). However, shunts inserted from the apex of the left ventricle had a contradictory high 26.1% incidence of paraplegia compared with shunts from the ascending aorta (8.2%; p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Traumatic rupture of the thoracic aorta diagnosed by transoesophageal echocardiography

Transoesophageal echocardiography is a safe and rapid means of obtaining anatomical and dynamic information about the descending aorta. It was used to confirm a suspected diagnosis of ruptured descending aorta.

Simplified technique for left heart bypass to repair aortic transection

Described is a simple technique to use partial left heart bypass for repair of aortic transection. Left heart bypass may be instituted through the left thoracotomy incision without need for groin dissection or opening of the pericardium.

Blunt traumatic disruption of the thoracic aorta: a rare injury in children

Rupture of the thoracic aorta secondary to blunt chest trauma is an exceedingly uncommon injury in pediatric patients. We present a case of blunt traumatic aortic disruption in a 10-year-old child who was successfully managed by primary aortic repair using partial cardiopulmonary bypass. The epidemiology and pathophysiology of this injury, with particular reference to children, is reviewed. The ongoing controversies regarding the diagnosis and operative management of this injury are summarized.

Acute traumatic disruption of the thoracic aorta: emergency department management

STUDY OBJECTIVE

To evaluate the safety and effectiveness of temporary IV antihypertensive therapy in patients with acute traumatic thoracic aortic disruption.

DESIGN

Retrospective chart review of all patients treated for proven traumatic aortic disruption during the ten-year period of 1980 through 1989.

SETTING

Emergency department of a large, urban, Level I trauma center.

INTERVENTIONS

Preoperative IV beta-blockade and nitroprusside after initial resuscitation in hemodynamically stable patients.

RESULTS

Thirty-seven patients with angiographically proven aortic disruption were separated retrospectively into one of three groups. Group 1 (15 patients without preoperative antihypertensive therapy) had two deaths. Group 2 (15 patients treated for two to seven hours [mean, 3.8 hours] before surgery with antihypertensives) had one death. Group 3 (seven patients treated with antihypertensives for 24 hours to four months before surgery to allow recovery from associated severe injuries) had one death. There were no complications resulting from antihypertensive therapy.

CONCLUSION

Temporary antihypertensive therapy appears to be safe and effective in patients with aortic disruption.

Blunt injuries of the thoracic aorta

We managed 51 patients with thoracic aortic injuries caused by blunt trauma between 1977 and 1990. Forty-nine injuries were located in the upper descending aorta and one each in the ascending aorta and aortic arch. Three patients arrived moribund and underwent thoracotomy for resuscitation, and all died. The diagnosis was confirmed by aortography in 48. One patient died of aortic rupture, 1 died of hypoxemia, and 1 refused operation and died. Forty-four patients had aortic repair, 42 with graft insertion. Gott shunts were placed in 23 with 3 cases of paraplegia (13%). Simple cross-clamping was used in 19 with 1 case of paraplegia (5.2%). We found statistically significant differences between the cross-clamp times of patients without paraplegia compared with those in whom paraplegia developed in both the shunt and no-shunt groups. Logistic regression analysis showed that the only factor significantly associated with paraplegia was cross-clamp time. There were two postoperative deaths (4.4%). Seven patients had medical therapy initially and aortic repair was delayed to allow other injuries to stabilize. Before aortic repair, 18 patients had intraarterial pressure monitoring and 34 received beta-blockers or antihypertensive drugs. We conclude that aortic repair with graft insertion is usually successful in nonmoribund patients, simple cross-clamping is associated with a relatively low risk of paraplegia, the incidence of paraplegia is directly associated with the duration of cross-clamp time, and selected patients can be managed medically while awaiting aortic repair.

A unified approach to the torn thoracic aorta

In a 3-year experience treating 12 patients with blunt torn thoracic aorta, the repair technique was "clamp and sew" with an intraluminal graft in the initial six patients and partial left heart bypass using a centrifugal pump in the more recently treated six. Patients in the two groups were similar in regard to age, sex, and injury severity score. In the intraluminal graft group, graft insertion was abandoned for sutured anastomosis in two patients. Two patients sustained spinal cord ischemia, and two developed hypertension due to "pseudo-coarctation" syndrome. Because of these side effects related to the performance of intraluminal graft, partial left heart bypass was adopted as our routine procedure and was successful in all subsequent patients. Based on our experience and on reports in the current literature, we recommend left atrial-femoral bypass with the centrifugal pump for repair of the torn thoracic aorta.