Primary repair of traumatic aortic disruption

Mechanism of development of aortic transection: a possible new angle

Aortic transection injury is a frequently fatal injury secondary to sudden deceleration. To date magnitude of deceleration is the only factor known to influence the development of an aortic transection injury. We hypothesise that different 3D geometries of the aortic arch in healthy young adult patients as a possible predisposing factor for transection injuries when undergoing sudden deceleration. We extend this to hypothesise that the direction of deceleration may be important as well. In addition we hypothesise that the stage in the cardiac cycle, which determines central aortic blood pressure, when the deceleration occurs as an important factor. We utilise known engineering principles such as Newton's second Law of motion, moment of inertia, law of Laplace, and the theory of superposition to explain our hypothesis. We present limited data to demonstrate the wide variation in aortic arch 3D geometry to explain the possible an individual's variable susceptibility to transection injuries via the principle of moment of inertia. Engineering principles suggest that 3D aortic arch geometry, direction of deceleration and stage in the cardiac cycle, in addition to the magnitude of deceleration are potentially important factors in predisposing certain individuals in a given situation to aortic transaction injuries.

Surgical management of traumatic rupture of aortic isthmus: a 25-year experience

OBJECTIVE

Traumatic rupture of the thoracic aorta is a surgical emergency with a high mortality rate. This condition requires prompt diagnosis and expeditious evaluation to improve patient survival. The aim of this study is to evaluate the outcomes of early and late management of traumatic rupture of aortic isthmus in patients with blunt thoracic trauma.

METHODS

Between February 1980 and June 2005, 64 patients sustained blunt thoracic trauma underwent open surgical repair for traumatic rupture of the aortic isthmus (7 women, 57 men, and mean age 38 ± 14.3 years). Clinical signs of diagnostic principles in our series of patients were: chest pain and dyspnea (48.5 %), hemoptysis (23.5 %), and hypotension (15.5 %). All patients underwent a left posterolateral thoracotomy through the fourth or fifth intercostal space or median sternotomy. Extracorporeal circulation for spinal cord protection was installed in all patients.

RESULTS

Of the 64 patients identified over the 25-year study period, 15 (23.5 %) underwent direct suture, 48 (75 %) underwent interposition graft repair, and 1 (1.5 %) experienced patch aortoplasty repair. The overall hospital mortality rate for the entire patient was 3 % due to multiple organ failure and myocardial infarction. No paraplegia occurred postoperatively. Three patients died during the follow-up period, two from myocardial infarction, and one from acquired immunodeficiency syndrome.

CONCLUSIONS

Traumatic aortic rupture remains a potentially lethal injury and an ongoing therapeutic challenge. Open surgical technique to repair the traumatic rupture of aorta is a safe procedure: postoperative outcome was excellent and the complications observed that were with aortic endoprosthetic stent-grafts were avoided.

Surgical treatment of traumatic thoracic aorta rupture: a 7-year experience

OBJECTIVES

Traumatic aortic rupture is highly lethal and an ongoing therapeutic challenge. We review our 7-year experience with traumatic aortic disruption.

METHODS

We treated 12 cases of traumatic rupture of the thoracic aorta (TRTA) from December 1994 to June 2001 at our institution. Of these, 9 were male, and the average age 26 years. Injuries were caused by traffic accidents in 9 cases and falls in 3. Contrast-enhanced helical computed tomography was used to diagnose10 cases and digital subtraction angiography to diagnose 2 at other hospitals. Six of 12 (50%) disruptions were located in the aortic isthms. All surgery was conducted under cardiopulmonary bypass. A percutaneous cardiopulmonary support system (heparin-bonded artificial lung and centrifugal pump) was used in 6 cases since 1998.

RESULTS

Among the 12 patients, 6 had early surgical repair within 2 days after the accident, and all survived free of neurological problems. Six other had repair delayed more than 2 days and all were doing well.

CONCLUSION

Immediate repair of aortic lesions should be the rule because the majority of deaths from TRTA occur within 24 hours. We believe, however, that immediate surgery may not be necessary for some patients with severe, multiple associated lesions who survive initial traumatic aortic disruption of the aorta.

Traumatic aortic rupture: recent outcome with regard to neurologic deficit

BACKGROUND

Traumatic aortic rupture is highly lethal, and its surgical treatment is complicated by a high rate of paraplegia.

METHODS

The charts of 263 patients with traumatic aortic rupture from vehicular accidents treated between 1971 and 1998 were reviewed. Patients were grouped according to four periods: group 1, 1971 to 1975, (n = 31); group 2, 1976 to 1985, (n = 83); group 3, 1986 to 1994, (n = 82); and group 4, 1994 to 1998 (n = 67). Seventy-one patients died of exsanguination before definitive care. One hundred-ninety two patients had surgical repair with the following techniques: clamp and sew, 6 in group 1, 22 in group 2, 54 in group 3, none in group 4; shunt, 23 in group 1, 39 in group 2, 2 in group 3; cardiopulmonary bypass, 2 in group 1, 1 in group 3. Forty-three patients had partial bypass with the centrifugal pump and heparin-coated circuits in group 4.

RESULTS

Operative mortality was 6 of 31 (19%) in group 1, 22 of 61 (36%) in group 2, 15 of 57 (26%) in group 3, and 7 of 43 (16%) in group 4. There was one case of paraplegia in group 1 (4%), ten in group 2 (18%), 11 in group 3 (26%), and none in group 4. This difference of paraplegia between the groups was significant (p<0.002). Significant factors for paraplegia were intraoperative hypotension (p<0.000002), cross-clamp time longer than 30 minutes (p<0.008), pump versus no pump (p<0.008), and younger age group (28+/-11 versus 39+/-17 years) (p<0.03).

CONCLUSIONS

There were no statistically significant improvements in mortality rate over the four periods, although, the mortality rate was lowest in the last period when partial bypass with the centrifugal pump was used exclusively. Further, the use of the centrifugal pump with heparin-coated circuits, with femoral vein cannulation into the right atrium and distal aortic perfusion, reduced paraplegia significantly.

Computed tomography as a screening exam in patients with suspected blunt aortic injury

BACKGROUND

Chest computed tomography (CT) screening of patients with blunt trauma for thoracic aortic injury is controversial. This study was undertaken to determine whether CT could exclude aortic injury and be used to select patients for aortography.

METHODS

Computed tomography and aortography were used to evaluate 155 patients with blunt trauma. Computed tomography scans were reviewed separately by four attending radiologists who were unaware of the patients' clinical course and angiographic findings.

RESULTS

Eight of 155 patients had aortic injuries requiring operation. Computed tomography scans in five patients were read as positive by all reviewers. One scan was read as positive by three reviewers and as negative by one. Two scans were read as positive by two radiologists and as negative by two. After poor scans were excluded, the combined sensitivity of CT for detecting aortic injury was 88%, specificity was 54%, positive predictive value was 9%, and negative predictive value 99%.

CONCLUSIONS

The sensitivity of CT scan for indicating the need for aortography is observer dependent. As CT manifestations of aortic injury are often subtle, CT does not reliably exclude aortic injury.

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)

The successful surgical repair of a traumatic transection of the descending thoracic aorta: report of a case

An 18-year-old man involved in a traffic accident presented with a left-sided hemothorax. After undergoing left chest tube drainage, he showed temporary stable hemodynamics for 7 h. Later, an emergency left thoracotomy was performed because of abrupt hemorrhagic shock. The intima and media of the descending thoracic aorta was completely transected, and a tube graft was successfully interposed with a simple aortic clamp in 47 min. The patient was eventually discharged from the hospital with no sequelae, such as paraplegia.

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.

Determinants of outcome in lesions of the thoracic aorta in patients with multiorgan system trauma

Of all patients presenting at our level 1 trauma center with multiorgan system injuries, 33 have been identified with acute lesions of the thoracic aorta. Mean severity injury score was 24 +/- 3. Four patients underwent resuscitative thoracotomy upon arrival in the emergency department. One survived and fully recovered. The rest underwent diagnostic procedures and repair of aortic lesions in conjunction with surgical treatment of other injured organ systems. The overall survival rate was 82 percent. Survivors arrived significantly faster to the ED and had lesser degree of multiorgan system injuries. There was no difference in the time spent to make the diagnosis of acute aortic disruption for survivors and nonsurvivors, nor was a difference in time to arrive in the operating room once the diagnosis of aortic injury has been established. Morbidity was related to ischemia to distal organs in four patients of whom two presented with multiple lesions of the thoracic aorta; two remained paralyzed and two had only lower limb spasticity. All discharged survivors were alive at 12 months' follow-up. The type of surgical repair did not influence the outcome of patients with single, typical aortic lesions; however, "clamp/sew" technique was not adequate when multiple aortic tears were found intraoperatively. The outcome of surgical treatment of the traumatic aortic lesions of patients with polytrauma may be influenced by the speed of arrival to the ED, the magnitude of multiorgan system involvement, and the application of appropriate surgical technique for repair according to the intrathoracic findings and the timing of aortic repair vis-a-vis other surgical treatment.

Paraplegia and traumatic rupture of the aorta: a disease process or surgical complication?

Surgical repair of traumatic rupture of the aorta results in an excellent survival rate especially among the young, although paraplegia continues to be a serious postoperative complication. The authors present nine cases admitted to Stoke Mandeville Hospital, England, including detailed post-mortem findings on one of the cases. Although it was difficult to be certain of the patients' general and neurological status prior to surgery, as it was not well documented in the patients' case notes, it was evident that systemic hypotension and poor distal aortic perfusion were responsible for the disabling complication. A review of the initial medical management of these patients and the surgical techniques employed in repairing such injuries is urgently needed.

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

Traumatic disruption of the descending thoracic aorta is a relatively rare but dramatic injury. Controversy remains regarding the use of shunts during operative repair. Discouraged by our results using the "no shunt" technique, we adopted the recently reported technique using the Bio-Medicus pump for left atrium-femoral artery bypass without heparin sodium. At Charlotte Memorial Hospital and Medical Center, 39 patients were treated for tears of the descending thoracic aorta between January 1979 and October 1988. Eight patients died before repair could be completed. Four patients underwent repair using femorofemoral bypass with 1 death and no instances of paraplegia. Fifteen patients had repair using the no-shunt technique with 4 deaths and three instances of paraplegia. Since January 1986, 12 patients have been treated using the Bio-Medicus heparinless pump with no deaths and no instances of paraplegia. We present our experience to confirm the reports of others regarding the efficacy of this technique. We believe it reduces the morbidity and mortality associated with this serious injury and aids in the hemodynamic management of the patient during aortic clamping.

Traumatic aortic transection: repair using left atrial to femoral bypass

Traumatic aortic transection is a life-threatening surgical emergency. Therapy must be directed at rapid repair and prevention of postoperative complications, the most serious being paraplegia. Controversy over the optimal method of repair exists-specifically whether the use of a shunt modifies the outcome. Our series of 17 patients using left atrial to femoral bypass with the Biomedicus pump will be discussed. Preoperative preparation and operative technique will be outlined. Mortality in this series was 18%, the incidence of paraplegia was 0.

Traumatic rupture and aneurysm of the aortic isthmus: late results of repair by direct suture

Between 1979 and 1986, 28 patients underwent surgery for subadventitial rupture of the aortic isthmus from blunt trauma; 16 had an acute lesion which was operated within three days after the trauma, three had a delayed repair between the first and third months, while nine had a chronic post-traumatic aneurysm (2 to 27 years after the initial accident). Transection was complete in 13 cases. A left atrium-to-descending thoracic aortic bypass or ilioiliac extracorporeal bypass were used in 14 (50%) patients whereas simple clamping was employed in the 14 remaining patients. Aortic repair was performed in 22 cases by direct suture (78.5%), more often in acute ruptures (84%) than in chronic aneurysms (66%). Five of the 16 patients operated on within three days of their accident died during the first postoperative month from associated lesions. There were no in-hospital or late deaths among the patients operated on for chronic aneurysm. All of the 23 surviving patients (82%) were followed postoperatively for six to 90 months (mean: 36 months). Of the 19 who had direct suture, 15 underwent digital subtraction arteriography which demonstrated an excellent reconstruction of the aortic isthmus. Of the techniques available for repair of traumatic aortic lesions, direct suture allows the shortest clamping time (mean: 25 minutes in our series). The long-term risks of prosthetic replacement, i.e. late infection, false aneurysm due to suture breakdown, and secondary embolism arising from mural thrombosis, can therefore be avoided.