**3. Management after specific cardiac surgical procedures**

#### *Coronary Artery Bypass Grafting*

Treatment of coronary artery disease can be medical or interventional. Catheterization procedures include balloon angioplasty, cardiac stenting and drug-eluding stents, which release drugs capable of preventing stenosis. Surgery includes CABG with the use of the cardiopulmonary bypass machine and OPCAB without the use of the CPB machine. OPCAB surgery may include sternotomy, thoracotomy (MIDCAB) or robotically assisted thoracotomy.

With increasing number of treatment options, it is crucial to establish for each patient which option is superior with regard to angina recurrence, graft patency, and long term survival with the least morbidity at the lowest costs. Several studies address this important issue. Analysis of individual patient data from ten randomized trials including 7812 patients concluded that long-term mortality after CABG and PCI in most patient subgroups with multivessel CAD is similar. (55) CABG versus PCI had lower mortality in diabetes and patients older than 65 years. The SYNTAX investigators concluded from their study that in low and intermediate risk patients with multivessel CAD, PCI and CABG have similar outcomes. In high risk patients with multivessel CAD, CABG is preferred. (56)

Although the COURAGE study, which provided optimal medical therapy (OMT) to all patients and demonstrated no incremental advantage of PCI on outcomes other than angina-related quality of life in stable CAD, a recent analysis by Borden et al reported that among patients with stable CAD undergoing PCI, less than half were receiving OMT before PCI and approximately two-thirds were receiving OMT at discharge following PCI. (57,58)

A number of randomized controlled studies comparing OPCAB to on pump CABG have been completed. Although outcomes have been largely comparable, the evidence of benefits of OPCAB from these trials has not been as convincing as was first anticipated. A large adequately powered RCT of OPCAB versus on pump CABG in high risk patients is needed to determine whether this undeniably harder technique is here to stay. (59,60,61)

#### *Aortic Valve Surgery*

Aortic valve replacement surgery may be complicated by heart block because the conduction system lies adjacent to the base of the right coronary cusp. If AV pacing is necessary for more than 4 to 5 days, during which time edema or hemorrhage should subside, placement of a permanent DDD pacemaker is necessary because the conduction system then probably has been damaged by sutures or débridement.

The hypertrophied, noncompliant left ventricle in aortic stenosis depends on adequate preload and on atrial contractions. Loss of sinus rhythm is associated with a 30 % reduction in stroke volume and requires AV pacing.

In aortic regurgitation, the left ventricle is volume and pressure overloaded resulting in a dilated and often hypertrophied chamber. Aortic valve repair for aortic regurgitation is evolving into a standard of care. The systematic classification of aortic regurgitation based on leaflet mobility within the functional aortic annulus makes it possible to study outcomes of the specific interventions. (62,63)

A recent RCT showed that transcatheter aortic valve implantation (TAVI) is significantly superior to medical management of severe aortic stenosis in patients judged to be at excessive risk for conventional aortic valve replacement. (64) TAVI significantly reduced allcause 1-year mortality. Recent studies have documented rates of cerebral embolism of 70-80 %. (65) Future trials should focus on interventions for stroke reduction after TAVI, including cerebral embolic protection. Techniques for reduction of embolic load may also improve renal dysfunction after TAVI. Although the short and medium term durability of the TAVI valve with preserved hemodynamic performance has been established, further studies are required to elucidate the long term effects. (66,67,68) To this term, guidelines for standardized endpoints in TAVI trials have been published.(69)

#### *Mitral valve surgery*

134 Perioperative Considerations in Cardiac Surgery

An essential element of postoperative care is the provision of adequate analgesia and sedation. In the patient in whom delayed extubation is anticipated, the residual effects of

With the trend toward earlier extubation, short-acting narcotics and analgesics are administered during surgery. This requires early postoperative administration of shortacting medications for pain relief and sedation. We prefer to give low dose continuous infusions of morphine in combination with propofol in the ICU. This usually produces adequate sedation and pain relief without respiratory depression and allows for fairly early

Treatment of coronary artery disease can be medical or interventional. Catheterization procedures include balloon angioplasty, cardiac stenting and drug-eluding stents, which release drugs capable of preventing stenosis. Surgery includes CABG with the use of the cardiopulmonary bypass machine and OPCAB without the use of the CPB machine. OPCAB surgery may include sternotomy, thoracotomy (MIDCAB) or robotically assisted

With increasing number of treatment options, it is crucial to establish for each patient which option is superior with regard to angina recurrence, graft patency, and long term survival with the least morbidity at the lowest costs. Several studies address this important issue. Analysis of individual patient data from ten randomized trials including 7812 patients concluded that long-term mortality after CABG and PCI in most patient subgroups with multivessel CAD is similar. (55) CABG versus PCI had lower mortality in diabetes and patients older than 65 years. The SYNTAX investigators concluded from their study that in low and intermediate risk patients with multivessel CAD, PCI and CABG have similar

Although the COURAGE study, which provided optimal medical therapy (OMT) to all patients and demonstrated no incremental advantage of PCI on outcomes other than angina-related quality of life in stable CAD, a recent analysis by Borden et al reported that among patients with stable CAD undergoing PCI, less than half were receiving OMT before PCI and approximately two-thirds were receiving OMT at discharge following PCI. (57,58) A number of randomized controlled studies comparing OPCAB to on pump CABG have been completed. Although outcomes have been largely comparable, the evidence of benefits of OPCAB from these trials has not been as convincing as was first anticipated. A large adequately powered RCT of OPCAB versus on pump CABG in high risk patients is needed

Aortic valve replacement surgery may be complicated by heart block because the conduction system lies adjacent to the base of the right coronary cusp. If AV pacing is necessary for more than 4 to 5 days, during which time edema or hemorrhage should subside, placement of a permanent DDD pacemaker is necessary because the conduction

outcomes. In high risk patients with multivessel CAD, CABG is preferred. (56)

to determine whether this undeniably harder technique is here to stay. (59,60,61)

system then probably has been damaged by sutures or débridement.

anesthetics and midazolam in combination with a narcotic are generally accepted.

**3. Management after specific cardiac surgical procedures** 

**Analgesia and sedation** 

*Coronary Artery Bypass Grafting* 

extubation.

thoracotomy.

*Aortic Valve Surgery*

Patients with chronic mitral stenosis often have pulmonary hypertension and usually are diuretic-dependent. They have a small left ventricular cavity with preserved LV function. Common postoperative problems are a low cardiac output syndrome associated with the small LV end-diastolic and end-systolic volumes, RV dysfunction and ventilatory failure due to the pulmonary hypertension, cachexia and fluid overload.

Due to the systolic unloading in patients with mitral valve regurgitation reducing LV wall stress, greater systolic wall stress is required after surgery to achieve adequate cardiac output. Therefore, the use of inotropic support and afterload reduction is often indicated.

In the postoperative period, cardiovascular management is often directed toward increasing filling pressures to above 15-20 mmHg, reduction of pulmonary hypertension and improvement of RV and LV failure. Guiding hemodynamic support with the use of a pulmonary artery catheter may be very helpfull. When atrial fibrillation has been present for more than 1 year or when LA dimension exceeds 50 mm, it is very unlikey to maintain sinus rhythm in the postoperative period. AV pacing is often possible after surgery and may improve cardiac performance. (6)

#### *Diseases of the thoracic aorta*

Multidisciplinary guidelines for thoracic aortic diseases were published in 2010. (70) We will highlight some concerns that concern the perioperative setting.

Ascending aortic *dilatation* should be carefully measured in patients with a bicuspid aortic valve presenting for surgery. Earlier surgical intervention is warranted to avoid rupture or dissection.

In aortic arch *aneurysm* surgery, hybrid repair has emerged as low risk aortic repair in highrisk patients. Type I repairs have adequate proximal and distal landing zones: after offpump anastomosis of the brachiocephalic vessels to the ascending aorta, an endovascular stent is deployed for complete arch repair. Type II repairs have adequate distal landing zone but insufficient ascending aorta to serve as a proximal stent landing zone: after ascending aortic replacement with aortic arch debranching, an endovascular stent is deployed for complete arch repair with the ascending aortic graft serving as proximal landing zone. Type III repairs have inadequate proximal and distal landing zones: after total arch replacement with a distal elephant trunk, the descending thoracic aortic repair is completed by endovascular stentingwith the elephant trunk serving as the proximal landing zone.

Concerning aortic *dissection*, the Penn classification of a type A dissection integrates type of clinical presentation with dissection extent to stratify perioperative outcome and facilitate decision-making about the type of surgical repair. (71)

The American Heart Association recently published a position paper on the integrated management of decending thoracic aortic disease that complements the recent guidelines from the Society of Thoracic surgeons. (72) These guidelines together summarize the paradigm shift in the management of descending thoracic aortic pathologies due to endovascular therapies. In Stanford type B aortic dissection, the conservative management of refractory pain and hypertension is associated with significant short-term mortality. Therefore, although a survival advantage has not been demonstrated yet, endovascular intervention of these type B dissections is now more often applied.

Depending on the type of organ protection applied during aortic surgery (deep hypothermic circulatory arrest, selective perfusion of brain and kidneys) coagulopathies and neurologic deficit may occur. Brain damage may be due to ischemia or embolisation and paraplegia may result from crossclamping of the descending aorta. Careful neurologic evaluation before and after surgery are important.

Also, the hypotensive regimen used in the early postoperative period must reduce systolic blood pressure and the force of cardiac contraction. The most common regimens include the use of beta-blockers.
