Anesthesia management for pericardiectomy- a case series study

This is a retrospective single center clinical study at a university hospital. The study was approved by the Ethics Committee of Peking University International Hospital and consent was waived by this committee. From July 2018 to May 2022, a total of 66 consecutive patients (46 men and 20 women) who underwent pericardiectomy for CP were analyzed. All the methods were performed in accordance with the Declaration of Helsinki. After IRB approval, the following parameters were collected from the patients’ medical records: age, New York Heart Association (NYHA) cardiac function classification, hypertension, coronary artery disease, diabetes, previous myocardial infarction, pulmonary arterial hypertension, atrial fibrillation (AF), congestive hepatopathy, heart failure (HF), left ventricular ejection fraction (EF), surgical classification, surgical time, cardiopulmonary bypass (CPB) time, aortic cross clamp time, postoperative mechanical ventilation time, length of intensive care unit stay, length of hospital stay (LOS), redo-open heart surgery, blood loss, transfusion, preoperative and postoperative hemoglobin, postoperative complications and perioperative death.

The mean age of the patients was 48.24 years with an age range from 18 to 73 years. The procedures were all performed by the same surgical team and general anesthesia (GA) was utilized in all cases. Patients were induced with midazolam, etomidate, sufentanil or fentanyl and rocuronium. Maintenance anesthesia included sevoflurane, propofol, dexmedetomidine, cisatracurium and sufentanil or fentanyl. In addition to standard monitoring, invasive arterial blood pressures, central venous pressures (CVP), and transesophageal echocardiography (TEE) were utilized. The processed electroencephalogram (pEEG) monitoring was also used to titrate anesthesia level and prevent intraoperative recall.

Preoperatively, 50 patients (75.76%) had signs of congestive hepatopathy, 39 patients (59.09%) had a history of NYHA class III or IV HF and 51.52% of the patients had a diagnosis of AF. Other co-morbidities included coronary artery disease (7.58%), PHTN (13.64%), diabetes mellitus (12.12%), HTN (9.09%) and 1 patient with a previous myocardial infarction (1.52%). The thickness of pericardium before surgery is 7.42 ± 2.31 mm. The CVP before and after pericardiectomy is 14.82 ± 5.26mmHg and 5.20 ± 2.15mmHg, respectively. All patients showed having left ventricular diastolic dysfunction on preoperative transthoracic echocardiography (TTE). The demographic and clinical characteristics are summarized in Table 1.

Within the study period, 40 patients received an isolated pericardiectomy (60.60%). The remainder of the patients underwent a pericardiectomy in combination with other cardiac procedures, including, valvular surgery (23 cases, 34.85%), coronary artery bypass grafting (1 case, 1.52%), tumor resection (1 case, 1.52%) and pulmonary artery surgery (1 case, 1.52%). 31 cases (46.97%) underwent re-do surgery (Table 2).

Except for one case, all 40 isolated pericardiectomies were done without the use of CPB. The one case that utilized CPB was a third time redo pericardiectomy with severe preexisting adhesions. For the patients who received a pericardiectomy together with other cardiac procedures, the pericardiectomy portion of the case was performed first without CPB. After completion of pericardiectomy, the other procedures were done on CPB.

There was no difference in the preoperative hemoglobin concentration between the group of patients who had the procedure done on CPB and the group of patients who had the procedure done off-pump; however, the patients who underwent CPB had a lower hemoglobin concentration at end of surgery, more blood loss and a higher rate of transfusion (P < 0.001) when compared to the off-pump group. Inotropes were used in all patients. A total of 50 patients (75.76%) were extubated within 24 h after operation. Both the ICU stay and the LOS were shorter in the off-pump group when compared to the on-pump group, but there was no significant statistical difference (P = 0.070 and P = 0.074, respectively) (Table 3). The incidence of postoperative complications was 57.58%, including infection, re-exploration, acute kidney injury (AKI, based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria), tracheotomy, and low cardiac output (CO). (Table 4).

Transesophageal echocardiography (TEE) showed that there were 6 patients with more than moderate regurgitation in mitral valve and 9 patients in tricuspid valve before pericardiectomy. However, the number was 16 and 19 respectively after pericardiectomy. Total of 17 patients (25.76%) underwent additional valvular repair.

All but two patients survived to discharge (96.97%). Both patients who died wereredo-surgeries with a history of AF and HF prior to surgery. One of the patients developed ventricular fibrillation post-CPB and required an intra-aortic balloon pump (IABP) placement for the reduced EF. The patient died on postoperative day (POD) 1 from refractory ventricular arrhythmias. The other patient developed acute respiratory failure and required prolonged mechanical ventilation. The patient went into ventricular fibrillation on POD 32 and subsequently died.

Constrictive pericarditis is characterized by the pathologic changes of the pericardium that occur over time with chronic inflammation. Pericardial fibrosis, calcification and stiffening leave the heart unable to fully expand and fill, resulting in ventricular constriction. This fundamental pathophysiologic change in diastolic filling leads to right HF and systemic congestion (Fig. 1) [2]. Patients often present with lower extremity edema, poor exercise tolerance and hypoproteinemia. Another important pathologic change of CP is the myocardial atrophy that can occur from myocardial infiltration and fibrosis which not only impairs ventricular diastolic filling, but also affects systolic contraction and further contributes to the development of HF [9].

While pericardiectomy is considered the gold standard for treatment, the physiologic changes associated with CP increase the risk of surgery. Myocardial atrophy and a higher NYHA classification are independent risk factors for a poor prognosis [10]. Hypoproteinemia can affect wound healing and infection rates. Chronic liver stasis can result in hepatic dysfunction and coagulation disorders [6]. When combined with the coagulation dysfunction caused by CPB, the presence of an underlying coagulopathy can significantly increase the surgical risk [7, 8]. A recent meta-analysis with 2,114 patients showed that the operative mortality of CP was 6.9% [11]. Results from other studies also demonstrated that the mortality and morbidity associated with pericardiectomy was significantly higher than that of other cardiac surgeries [12‐14]. Despite these statistics, all but two patients in this case series survived to discharge (96.97%) and almost all of these patients had extensive comorbidities (including congestive hepatopathy, HF, and AF) which are known to significantly increase the perioperative mortality [15, 16]. Though many factors can influence patient outcome, anesthetic perioperative management is crucial to achieving good outcomes after pericardiectomy.

In this case series, all patients underwent strict preoperative fluid management with a weight loss of 5-10 kg. As most patients were on chronic diuretics, the urine output was meticulously followed during the case. For off-pump pericardiectomies, the target urine output during the procedure was greater than 1000mL. The systolic blood pressure was maintained greater than 90mmHg to ensure adequate renal flow. Low-dose inotropes and, if necessary, administration of vasopressors were used to achieve this goal. Close monitoring of the CVP also helped to guide management decisions. Many patients were noted to have elevated CVPs (15-20mmHg) prior to the surgery. After pericardiectomy, the CVP was kept below 8mmHg. When patients appeared to be at high risk for volume overload, they were placed in a reverse Trendelenberg position. A nitroglycerin infusion was also used to help reduce left ventricular preload if the hemodynamics allowed [17]. Intraoperative TEE monitoring of ventricles can provide a good estimate of preload and guide the fluid management.

The utilization of CPB is an independent risk factor for morbidity and mortality after pericardiectomy [15, 16]. It is well known that CPB can lead to an inflammatory response, impaired coagulation function and significant organ dysfunction [27‐29]. Although majority of our patients underwent pericardiectomy without CPB, there were still a few patients went on CPB due to combined cardiac surgical procedures instead of the severity of pericarditis. However, the patients who underwent pericardiectomy on-pump lost more blood, required more blood products and had a higher postoperative infection rate when compared to the off-pump group. To minimize the risks of CPB, it is important to complete the pericardiectomy off-pump whenever possible. When CPB is required for concomitant procedures, the pericardiectomy portion of the case should be done prior to institution of CPB.