The patients were operated on under general anesthesia. An arterial catheter for blood pressure monitoring was placed. A venous catheter for central venous pressure monitoring was also in place. Two peripheral venous lines were in place for infusions. A Cardio Pulmonary bypass (CPB) was provided, as well as a femoral approach, so as to be able to cannulate through this route in case of major problems during pericardial decortication. However, CPB was not used in our context. The approach was a vertical median sternotomy. The sternum was opened with a circular electric saw, with great care. The pericardium was opened (Figure 1) along a vertical and median line, i.e., opposite the anterior aspect of the right ventricle, to avoid a “blind” start of this dissection in the region of the left coronary vessels. The dissection was continued bi-laterally, from the ends of the initial incision, Pericardectomy was performed with round-tipped scissors, held closed, convex side against the myocardium. On the left, the dissection passed anterior to the anterior aspect of both ventricles and then over the lateral wall of the left ventricle. The pericardium was then excised approximately 1 cm anterior to the left phrenic nerve. Dissection was continued posterior to the left phrenic nerve in the plane between the myocardium and epicardium until the left ventricle was freed, and inferiorly above the diaphragm to free the tip of the heart. Release of the basal vessels, including the trunk of the pulmonary artery, is necessary to avoid postoperative gradients. On the right, the dissection was passed carefully over the right atrioventricular groove and the coronary vessels running through it, as well as the anterior and lateral walls of the right atrium. The pericardium was then excised approximately 2 cm anterior to the right phrenic nerve. The cava orifices were freed from any stricture without touching the posterior aspect of these vessels, since it is sufficient to break the cerclage effect sufficiently to achieve the desired result. The effectiveness of this release was monitored by intraoperative pressure measurement. Some calcified plaques, adherent to the myocardium, were sometimes left in place, their removal involving too great a risk of lesions on the coronary vessels, particularly at the level of the anterior interventricular groove.

It was performed in a descriptive and analytical manner using EPI info software, version 6. Quantitative data were described by the mean and the standard deviation, while qualitative variables were described by the proportions. Statistical tests were performed with the same software and we used the Fisher exact test for qualitative variables and the student test for quantitative variables. The

threshold of significance was 0.05.

The procedure allowed a good diastolic re-expansion of the heart, especially of the two ventricles, with a clear improvement of myocardial contractility. We also noted a significant decrease in the pressure at the level of the right atrium (Central Venous Pressure), on the monitor. We also observed an improvement in the hemodynamic state of the patients with an improvement in systolic blood pressure. The average length of stay in the intensive care unit was 3 days [extremes: 2 - 5 days]. The average length of hospitalization was 8 days [extremes: 6 - 18 days]. The postoperative course was simple in 62 cases. Regression of functional signs was noted in 61 cases (82.43%). We noted a regression of dyspnea from NYHA stages III and IV to NYHA stages I and II. The surgical results were also marked by a complete regression of physical signs in 66.2% of cases and partial in 29.7% of patients.

Post-operative complications were marked by 1 case of hemorrhage following a injury of the right atrium, a right hemothorax was found in 2 cases, atrial fibrillation in 3 cases, and a low cardiac out put in 6 cases. The patient with bleeding was taken back to the operating room. Hemostatic stitches were placed on the right atrial injury. The hemothoraxes were treated by placing chest drains. The evolution was satisfactory after the thoracic drainage. We recorded 4 deaths (a mortality of 5.4%). The deaths were due to hemorrhage following a right atrium injury in one case. Two (2) patients died as a result of low cardiac output. And one 37-year-old patient died at 30 days postoperatively of hepatocellular failure in a context of hepatic cirrhosis (Table 2).

The predictive factor of immediate postoperative mortality in our series was the

preoperative NYHA functional stage III-IV (p = 0.022) (Table 3).

After an average follow-up of 5.17 years ± 4.76 (Extreme 0.5 and 25 years) we observed 2 deaths. That is a mortality of 2.9%. One patient in atrial fibrillation died of thrombo-embolic complications following poor compliance with the anticoagulant treatment. The second patient died following refractory right heart failure one year after pericardectomy. All other survivors were asymptomatic and no re-intervention for recurrence was performed.

RVEDP: Right Ventricle End Diastolic Pressure.

Surgery for constrictive pericarditis remains the only effective treatment for this potentially curable disease [6] [8], with good medium and long term results, knowing that these results depend on the delay of the surgery initiation [9]. The treatment consists of freeing the heart from extrinsic compression. The approach to the heart was a vertical median sternotomy in all our operated patients (100%). Currently, pericardectomy is performed by median sternotomy or left anterolateral thoracotomy [8]. Median sternotomy is considered the classical route and is widely used by many surgical teams [5] [8] [10] [11]. This approach allows sufficient pericardial resection to decompress the myocardium and improve cardiac function. Therefore, it is clear that the teams that perform both approaches preferentially use it in 76% to 97.5% of patients [3] [12] [13] [14]. We performed subtotal anterior pericardectomy in all our patients. Like us, several teams [10] [15] had the same surgical approach. Until very recently, there was no series in the literature to confirm the interest of a total pericardial resection [16]. It seems reasonable to consider the widest possible exeresis to allow the re-expansion of the 2 ventricles [17] at the price of a longer surgery; of poorly tolerated manipulations and of cardiac injuries. Some authors think that one should not hesitate to use cardiopulmonary bypass (CPB) to widen the pericardectomy procedure because the risk inherent in CPB seems to be less than the benefit brought by the widening of the pericardectomy that it will allow [18]. Others only use it in case of technical problems or associated cardiac procedures because of the increased risk of bleeding that it entails [16]. Hemorrhage is the main danger of this procedure [19]. Tearing of the pellucid and fragile right atrium was the cause of one death in our early practice. It is therefore necessary to be more careful and meticulous during this pericardial decortication in order to limit or even avoid intraoperative accidents [20]. Furthermore, intraoperative incidents were represented by 3 right atrial injuries. These lesions were corrected by hemostatic stitches during the same operation.

Pericardial decortication allowed the improvement of the functional status of our patients. The postoperative status was favorable; since more than 80% of the patients showed a clear improvement of their symptomatology [1]. Pericardectomy improves most of the patients very quickly since 80% to 90% of the patients are in class I or II of the NYHA (New York Heart Association), whereas 73% were in class III or IV preoperatively, whatever the etiology. The functional results in the short, medium and long term are satisfactory [21]. The functional improvement obtained is maintained on the long run, except in the rare cases of incomplete intervention with recurrence of the constriction [1] [22]. In terms of postoperative morbidity, low cardiac output was the most common complication in our series. Similarly, Zhu [23] in China reported that low cardiac output represented more than half of the complications observed. Low cardiac output was the most common complication after total pericardectomy in China. The most common complication after pericardectomy is the occurrence of congestive heart failure in 10% - 35% of cases [21]. There is a relationship between preoperative functional class (class III and IV) and the occurrence of low cardiac output syndrome. Furthermore, the use of CEC increases the incidence of low cardiac output. Intraoperative mortality is considered to be low; less than 1% in the study by Ling et al. [4]. In-hospital mortality varies from 5.4% to 18.6% in the literature. [6] [10] [14] [23] [24] [25]. The most frequent cause of mortality in the perioperative period is of cardiovascular origin: massive hemorrhages in the intraoperative or immediate postoperative period and then episodes of low cardiac output [6]. Secondary death by myocardial decay is due to inflammatory phenomena secondary to epicardial injury [25]. The most common cause of early death was low cardiac output [26], which is consistent with our observation. Surgical removal of the pericardium is associated with an operative mortality rate of 5% to 20% in various large series. Myocardial atrophy after prolonged constriction, residual constriction, or concomitant myocardial process could lead to prolonged heart failure despite successful pericardectomy. [27]. Poor prognostic parameters have been reported by several authors. We have noted as a risk factor the functional stage III-IV of the NYHA in the preoperative period. This parameter has also been reported by several authors [10] [14] [15]. We did not find the involvement of other risk factors such as age, female gender, RVEDP, calcification and Atrial fibrillation. Indeed, operative mortality and episodes of low cardiac output correlated in McCaughan’s study [16] with preoperative functional stage. Seifert et al. [21] demonstrated a correlation between functional class and operative mortality; and identified a relationship between right ventricular end-diastolic pressure (RVEDP) and risk of death after surgery. Age was the second independent prognostic factor also found in the series of Bertog et al. [12] and Ling et al. [5]. The role of calcifications in postoperative outcomes is controversial, with no influence in the series of Bertog [12], it is an independent predictor of postoperative mortality in the series of Ling et al. [28], but without influence on survival.

- The retrospective nature of the study with data recruitment bias.

- The follow-up of patients was not complete.