**7. Surgical treatment of constrictive pericarditis**

In 1898, the French physician, Dr. Delorme, first proposed surgical intervention in the treatment of pericarditis [84]. However, another fifteen years would pass before

*Constrictive Pericarditis: Surgical Management DOI: http://dx.doi.org/10.5772/intechopen.109794*

Dr. Ludwig Rehn would perform the first successful pericardiectomy as a treatment for constrictive pericarditis [85]. In the United States, the first successful surgical treatment for constrictive pericarditis was performed by Dr. Edward Delos Churchill at Massachusetts General Hospital in 1928 [86]. The surgery has evolved since then and continues to be a mainstay of treatment for pericardial disease. Today, pericardiectomy is the gold standard of treatment for constrictive pericarditis and considered the only curative, rather than palliative, option. For most patients, medical therapy is only effective in the treatment of acute pericarditis, where corticosteroids and antiinflammatory medications have shown to produce acceptable outcomes.

#### **7.1 Indications for surgery**

When determining whether a patient is a good candidate for pericardiectomy in the treatment of constrictive pericarditis, numerous factors must be taken into consideration. This procedure, while curative, is not without notable risks to the patient. Research into prognostic indicators is ongoing, though current recommendations focus on preoperative state and the patient's medical history,

Pericardiectomy produces the most positive outcomes in the treatment of constrictive pericarditis when performed early in the disease course [87, 88]. Clinical judgment is used to determine which patients are best suited to undergo pericardiectomy. Patients who fall into NYHA heart failure Classes I and II may remain clinically stable for years and be placed at unnecessary risk through surgery [41]. However, a delicate balance must be struck, as patients with advanced pericardial disease in NYHA Class IV who have significant left ventricular dysfunction or advanced fibrosis and calcification tend to have high mortality rates [41]. Therefore, outcomes depend largely on individual patient factors and a thorough risk-benefit analysis should be employed.

#### **7.2 Midline sternotomy approach**

The surgeon must not only determine whether the patient is a good candidate for pericardiectomy, but also which surgical technique is most appropriate given the patient's specific condition.

Approaching the pericardium through a median sternotomy is the most common technique used in the decortication procedure. This access provides the broadest view of the heart and its related structures, as well as the lungs and, crucially, the phrenic nerves.

The initial opening of the pericardium after a midline sternotomy may be easiest at the lower portion of the right ventricle, over the epicardial fat pad by the diaphragm. This provides the safest avenue of identifying the appropriate dissection planes, as the likelihood of damaging underlying structures is low. Dissection continues as the surgeon identifies the dissection plane that will separate the epicardium from its parietal pericardial adhesions, taking special care to avoid damaging the coronary vessels. It is also important to consider which portion of the heart will be decorticated first. Traditionally, the left ventricle is free first as, this helps to prevent pulmonary edema that may otherwise occur if the right ventricle were freed first. This particular approach can be quite challenging, though, and some surgeons elect to begin with the right ventricle and relieve the anterior plane first.

Avoiding damage to the underlying cardiac structures is of paramount importance when performing a pericardiectomy. As such, the surgeon must be cognizant of the dissection plane at all times. This can be particularly challenging in areas of especially thickened adhesions. In such instances, it may be necessary to dissect around a focal

adhesion and perform a waffle procedure to minimize the risk of inadvertent damage to underlying myocardium. A waffle procedure involves making multiple longitudinal and transverse incisions in the thickened area of pericardium to create a more distensible surface.

As the surgical treatment for constrictive pericarditis has evolved and outcomes have been analyzed, the preferred techniques for removal of the pericardium have also changed. Historically, a partial, or anterior, pericardiectomy was performed. Following decortication of the mid-anterior portion of the pericardium, dissection proceeds laterally toward the phrenic nerves, carefully separating the planes of tissue and ending approximately 1 cm anterior to the nerves. Immediate hemodynamic improvement is observed upon removal of the diseased pericardium from the ventricles. The surgeon then turns their attention to the atria and all stiff pericardial tissue is resected. At completion, only the anterior section of the pericardium is removed, leaving the posterior surfaces adhered. While this approach is thought to be considerably less challenging and, therefore, safer than the alternative total pericardiectomy, it leaves intact any posterior adhesions and does not provide full resolution of the constriction. It also leaves an opportunity for further adhesions to form on the posterior surface of the heart and lead to progressively increased constriction and worsened hemodynamics. As will be discussed in more depth in the "Outcomes" section, patients who undergo partial pericardiectomy tend to experience sub-optimal outcomes and increased risk of complications [5, 8, 9].

Today, the more accepted approach is the total, or radical, pericardiectomy. Most modern studies report improved outcomes with total pericardiectomy. Improved hemodynamics, as measured by right ventricular pressures and reduced instances of tricuspid regurgitation, have been noted with complete pericardial removal as compared with the partial removal procedure [9]. Lower long term mortality rates have also been reported in total versus partial pericardiectomy [9]. Despite the more favorable outcomes of total pericardiectomy, some patients may be more suited to the partial approach. This includes those with advanced pericardial disease, poor cardiac function, or those at risk of acute heart failure following surgery [41].

This procedure begins at the right atrium, where the appropriate dissection plane is identified, and the right atrium is freed from its pericardial adhesions. This dissection continues to the level of the pulmonary veins and inferior vena cava. It is at this point that the right phrenic nerve is delicately removed as a fat pedicle, and the pericardium can be resected from around the entirety of the inferior vena cava. The surgeon then turns their attention to the left side of the heart, dissecting over the left atrium to the diaphragmatic surface of the heart, again taking special care around the coronary arteries and particularly dense adhesions. The left phrenic nerve is detached and protected as a fat pedicle. The dissection continues, detaching the pericardium from the diaphragm, pulmonary ligaments, posterior mediastinum, and major blood vessels until it can be extracted in its entirety.

Once all visible pericardial adhesions have been relieved, thoracic drains are inserted, the patient is monitored for hemodynamic stability, and echocardiography confirms appropriate cardiac blood flow.

#### **7.3 Anterolateral thoracotomy**

An alternative approach that is favored in some instances is the anterolateral thoracotomy. It provides for sufficient visualization of the lateral and diaphragmatic

#### *Constrictive Pericarditis: Surgical Management DOI: http://dx.doi.org/10.5772/intechopen.109794*

surfaces of the left ventricle without the need for excessive manipulation of the heart required of the midsternal approach. This approach is particularly beneficial for patients whose adhesions are primarily focused on the left side of the heart. It is less useful when the right side of the heart is involved as the field of view is very limited in that area.

The process of an anterolateral approach to pericardiectomy involves opening of the chest wall through the fourth or fifth intercostal space. If an expanded view is needed, the incision can be extended to the right side of the chest.

Once the thoracic cavity has been accessed, the left lung is displaced posteriorly, revealing the left side of the heart and left phrenic nerve. The pericardium is dissected anteriorly and posteriorly to the left phrenic nerve to a depth sufficient to identify the desired plane. Once the plane between the epicardium and parietal pericardium is localized, the pericardium is dissected away, beginning at the left ventricle, and proceeding over to the right ventricle. Finally, the adhesions overlying the pulmonary artery and aorta are removed, freeing the heart.

As previously stated, this approach does not allow for easy access to the right side of the heart. If pericardial adhesions extend to this area, it may be necessary to extend the thoracotomy to the right side of the chest. Then, a similar approach to that used on the left side can be taken to resolve any constrictions.

#### **7.4 Cardiopulmonary bypass**

Cardiopulmonary bypass in the surgical treatment of constrictive is not commonly utilized unless additional procedures are to be performed concomitantly and require it. More often, patients undergo the pericardiectomy with the femoral vessels prepared in case emergency bypass, but not as a standard part of the procedure. Having cardiopulmonary bypass at the ready can be useful in cases of extreme blood loss, large calcifications, or accidental damage to the heart during surgery [10].

Some research indicates that the use of cardiopulmonary bypass during a pericardiectomy procedure is an independent predictor of post-procedure complications [89]. It should be noted, though that because the use of cardiopulmonary bypass has traditionally been reserved for more hemodynamically unstable or higher-risk patients, it may not actually be a causative factor in negative outcomes but rather a marker for those already predisposed to such results [8]. Therefore, it seems to largely depend on surgeon preference whether a patient should undergo bypass during pericardial surgery.

### **8. Post-surgical prognoses**

Post-pericardiectomy outcomes have been the subject of much study in recent years. Common avenues of research investigate the relationship between the etiology of constrictive pericarditis and surgical outcomes. As mentioned previously, the most common underlying causes of constrictive pericarditis include tuberculosis infection, previous cardiac surgery, mediastinal radiation, and idiopathic means [2–5, 10–15, 27, 30]. It appears that, despite the common resultant pathophysiology, unique causative etiologies are associated with variable long-term prognoses. One study reported that patients presenting with constrictive disease arising from tuberculosis infection and idiopathic sources tend to experience

longer event-free survival than those having previously undergone cardiac surgery [90]. A second center found that the 5-year survival rate of patients treated for constrictive pericarditis arising from idiopathic causes stood at 79.8%, while those treated post-cardiac surgery or following mediastinal radiation demonstrated rates of 55.9% and 11.0%, respectively [13]. Previous mediastinal radiation, in particular, seems to be implicated with relative frequency in poor post-pericardiectomy outcomes [9].

Underlying etiology is not the only prognostic factor of post-surgical outcomes for constrictive pericarditis. Preexisting illness also seems to be significant contributor to patient prognosis. A retrospective study of patients at the Asian Medical Center found that diabetes mellitus represented an independent risk factor for post-procedure mortality, as did high early diastolic mitral inflow [91]. They also report that the patients who died following pericardiectomy had higher levels of aspartate aminotransferase, smaller left ventricular end-systolic dimension index, and higher early diastolic mitral inflow velocity prior to surgery compared with the patients who survived [91]. Other pre-surgery hemodynamic and structural parameters including reduced left ventricular ejection fraction, right ventricular dilation, central venous pressure, myocardial atrophy or fibrosis, and tricuspid regurgitation also appear to contribute to poor outcomes [41]. Perhaps unsurprisingly, advanced heart failure symptoms (NYHA III-IV) and arrhythmias are also associated with poor outcomes [41]. Likewise, advanced age and patients with end-stage renal disease, coronary artery disease, chronic obstructive pulmonary disease, sepsis, and other severe comorbidities also appear to experience poorer outcomes than other pericardiectomy patients [41, 92, 93].

### **9. Conclusions**

While constrictive pericarditis represents a relatively rare disease process, it provides several diagnostic and treatment challenges. Constriction of the heart within the pericardium negatively impacts ventricular filling, leading to poor hemodynamics which, over time, can result in heart failure. Early diagnosis and management are key to improving patient prognoses and minimizing complications. Diagnosis of this condition requires a high degree of suspicion from the treating physician and a thorough exam. Imaging modalities, including computed tomography and cardiac magnetic resonance imaging, help to differentiate constrictive pericarditis from other conditions that may present with similar exam findings. Constrictive pericarditis responds poorly to medical management and typically requires surgical decortication of the fibrous adhesions holding the pericardium to the heart. The evolution of this procedure from the partial removal of the pericardium to the radical pericardiectomy has led to improved patient outcomes.
