Endovascular treatment of acute aortic isthmian ruptures: case study

Traumatic rupture of the aortic isthmus is a rare lesion occurring in patients subjected to violent deceleration. Because of the forces involved, it is frequently associated with concomitant life-threatening injuries. The endovascular intervention has been described to be a feasible and efficient technique which may be proposed as a therapeutic option for patients with multiple traumas instead of delayed classical surgical repair after stabilization. We report the case of an adult who has had an accident with a traumatic rupture of the aortic isthmus associated with other lesions, our patient received endovascular treatment. The aortic prosthesis was imported from France and the surgery was done 3 days after the patient's admission. This procedure was performed for the first time in Morocco in our hospital with a multidisciplinary team. The prosthesis was implemented successfully and the result was very satisfactory on the heart level.


Introduction
The aortic isthmus, located downstream of the left subclavian artery which is the most common location of acute traumatic rupture of the thoracic aorta [1]. Concerning practical part, the traumatic break of the aortic isthmus is a rare event arising in an almost constant context of polytrauma and the mortality-morbidity of which remains high [2,3]. Because of the violence of the trauma causal, it is unusual for the rupture of the isthmus to be isolated. Associated injuries affect all organs and their number is estimated to average four patients who die before they arrive at the hospital and two in survivors.
Moreover, these associated lesions complicate the diagnosis, present problems at hierarchy of surgical procedures and influence the overall prognosis due to their own gravity and/or their potential aggravation by aortic clamping and heparin therapy (conventional surgery). Among the associated injuries they are the multiple vascular lesions whom urgently posing the most difficult problems [1,3,5,6].

Patient and observation
Patient (32 years old) without significant medical history was victim of a road accident with a violent side impact. At admission, a patient was conscious (GCS 15) and stable hemodynamically. Several sizes of stents should be immediately or readily available.
Fattori et al [9] and report the case of two patients treated in emergency thoracotomy due to unavailability of appropriate diameter stent; 2) Surgically, the surgical approach for stenting is common femoral artery. At the patients with arteritis, a surgical access of a common iliac artery sometimes has of the realized being increasing the aggressiveness of the procedure. Similarly, the possible occurrence of various complications is still possible with this technique: a broken iliac artery requiring bypass surgery during the procedure [8]. Another case of acute compression of the bronchus left origin with atelectasis homolateral lungwort is due according to the author to a rough increase of the pressure inside the thrombosed pseudoaneurysm frankly; 3) For several authors [8,9] a healthy proximal neck is required downstream of the ostium of the left subclavian artery, in order to achieve the implementation of the stent. However, in several series, the ostium of the left subclavian artery was covered, sometimes completely without consequence [9]. The lesion severity score or ISS is a very important predictive and prognostic factor of morbidity and mortality. A score upper to 50 points is predictive of mortality superior to 50%. A score greater than 70 points is predictive of greater than 70% mortality. The multislice and spiral CT has become the gold standard; it is performed in emergency and first-line standard practice in cases of suspected rupture of the isthmus or systematically in case of polytrauma. Indeed, this test is realized easily and quickly. It allows the lesional assessment, not only of the thorax but also, and at the same time, the abdomen, head, spine (in particular cervical) frequently in a polytrauma patient.
In addition it allows a precise morphological assessment before endovascular treatment. It has a sensitivity of 100%, a specificity of 96% and a negative predictive value of 100% [12]. The transesophageal echocardiography (TEE) can be performed quickly, especially on a sedated patient in the intensive care unit or the operating room. The aortic isthmus is very well seen on transesophageal echocardiography. This examination allows besides estimating the myocardial function that can be altered in a context of chest trauma. TEE is a very specific examination (95-100%) and little sensitive (93%).
The isthmic aortic rupture remains a serious disease for which a high mortality persists. While few publications report a significant number of cases, there is a meta-analysis by Von Oppell [13] whose results are interesting; overall mortality was 32%, with a third before arrival in the operating room during surgery 7.8% and 13.5% postoperatively. Therefore endovascular treatment represents the treatment of choice at patients with multiple traumas, avoiding any significant heparinization and enabling the fast processing of associated lesions. The therapeutic management of isthmic aortic ruptures tends to change radically from the traditional surgical to endovascular treatment.
Endovascular techniques, less invasive and easier to implement at these trauma patient's they have multiple benefits. Indeed, this treatment may be immediately offered, and this, whatever the associated lesions because it is minimally invasive, it doesn't require a healthy vascular limited area; doesn't contain an aortic clamping and requires only limited heparinization. The procedure is quick as simple and can be performed in the immediate waning processing a "priority injury" in the same operative session. Furthermore, its relative safety broadens the indications for older patients with comorbidities.
The main technical limits are at the moment, the small diameter of the thoracic aorta and a sharp curve of the aortic arch. A small caliber femoral arteries justifies using a primitive aortic or iliac access. The left subclavian artery is usually near the rupture zone, its cover, brought back in 26% of cases is generally well tolerated.

Conclusion
The traumatic rupture of the isthmus remains a serious disease and the management of which over the years has been greatly upset. If the treatment of traumatic isthmian lesions is using increasingly endovascular techniques, given their excellent results in terms of immediate morbidity and mortality, only the long-term results will confirm that attitude.