Postoperative Details

Patients who have undergone ascending aneurysm repairs are observed for signs of coronary ischemia, particularly if the coronary ostia were reimplanted, and for signs of aortic insufficiency when the aortic valve is repaired. Following the repair of arch aneurysms, particular attention must be given to neurological status, and patients who have had the elephant trunk repair must be observed for signs of paraplegia because the telescoped sleeve in the descending aorta may obstruct critical spinal vessels.

Paraplegia is the main concern in patients who have had repair of the descending and thoracoabdominal aorta. Cerebrospinal fluid drainage may be continued for up to 72 hours postoperatively if necessary, along with motor evoked potential monitoring. Paraplegia and paraparesis may be acute or delayed postoperatively. If paraparesis or paraplegia is delayed, increased mean arterial pressure with pressors and reinstitution of cerebrospinal fluid drainage may augment spinal cord perfusion to reverse this complication. Paraplegia due to occlusion of critical spinal arteries that were not reimplanted cannot be reversed by these maneuvers. Acute postoperative renal dysfunction may be due to extended periods of ischemic cross-clamping or to hypothermic circulatory arrest.

Patients undergoing endovascular stenting are often extubated early postoperatively with a decreased ICU length of stay.

Follow-up

Development of another aneurysm postoperatively is not uncommon in these patients. For this reason, serial evaluations (ie, CT scans or MRI for ascending, arch, or descending aneurysms; echocardiography for ascending aneurysms) may be performed every 3-6 months during the first postoperative year and every 6 months thereafter.

A recent study evaluated the differences between male and female patients undergoing thoracic endovascular aneurysm repair in a Food and Drug Administration-approved trial. Femake patients had higher rates of periprocedural complications, requiring more blood transfusions, a longer hospital length of stay, and more major adverse events after 30 days. However, female patients also more often had successful aneurysm treatment at 1 year of follow up.^[38]

For patient education resources, see Aortic Aneurysm.

Complications

Early morbidity and mortality are related to bleeding, neurologic injury (eg, stroke), cardiac failure, and pulmonary failure (eg, acute respiratory distress syndrome [ARDS]). Risk factors include emergent operation, older age, dissection, congestive heart failure (CHF), prolonged cardiopulmonary bypass time, arch replacement, previous cardiac surgery, need for concomitant coronary revascularization, and reoperation for bleeding. Late mortality is usually related to cardiac disease or distal aortic disease.

Bleeding is a potential complication for all aneurysm repairs. It is minimized by the use of antifibrinolytics, felt strips, and factors, including fresh frozen plasma and platelets. For patients who undergo hypothermic circulatory arrest, the use of aprotinin is controversial, but most groups routinely use aminocaproic acid (Amicar). Coagulopathy and bleeding in severe cases may warrant the use of recombinant factor VII.

Aprotinin (Trasylol), an antifibrinolytic agent used to reduce operative blood loss in patients undergoing open heart surgery, is now only available via a limited-access protocol. Fergusson et al reported an increased risk for death compared with tranexamic acid or aminocaproic acid in high-risk cardiac surgery.^[39]

Stroke is a major cause of morbidity and mortality and typically results from embolization of atherosclerotic debris or clot. Transesophageal echocardiography and epiaortic ultrasound may be beneficial in localizing appropriate areas to clamp. Patients undergoing arch repairs are at the highest risk of permanent and transient neurologic injury. Retrograde cerebral perfusion is beneficial for flushing out embolic debris, but it may be detrimental, with increased intracranial pressure and cerebral edema. Antegrade cerebral perfusion is beneficial for reducing neurologic injury during hypothermic circulatory arrest. Stroke incidence for open surgical repair versus endovascular repair of descending thoracic aneurysms is equivalent.

Myocardial infarction may occur with technical problems with coronary ostia implantation during root replacement for ascending aortic aneurysms and may require reoperation. Pulmonary dysfunction and renal dysfunction are other potentially morbid complications.

Paraparesis and paraplegia, either acute or delayed, are the most devastating complications of descending thoracic aneurysm and thoracoabdominal aneurysm repairs. Despite cerebrospinal drainage, reimplantation of intercostal arteries, evoked potential monitoring, mild hypothermia, and atrial femoral bypass, spinal cord injury still occurs. Endovascular stent grafting has not eliminated spinal cord paraplegia; the incidence varies widely, with an overall incidence of 2.7%.^{[26, 27, 29, 30]}

Complications specific to endovascular stenting include endoleaks, stent fractures, stent graft migration or thrombosis, iliac artery rupture, retrograde dissection, microembolization, aortoesophageal fistula, and complications at the site of delivery (eg, groin infection, lymphocele, seroma).

Date: 2015-12-11; view: 707