Role and management of extracorporeal life support after surgery of chronic thromboembolic pulmonary hypertension

Abstract

Background: Pulmonary endarterectomy (PEA) is a surgical intervention reserved for patients with chronic thromboembolic pulmonary hypertension (CTEPH). In some cases, temporary circulatory support [extracorporeal life support (ECLS)] is required after PEA. Rates of ECLS requirement varies between centers. Reasons for institution of ECLS include respiratory failure, cardiac failure (or both respiratory and cardiac failure), bleeding, and reperfusion edema. This article reviews the experience of ECLS after PEA from the current literature, as well as our own institution's experience as a CTEPH multidisciplinary center. Methods: A literature review was conducted along with a retrospective chart review from 15 years of our PEA program. Results: The literature demonstrates many different approaches are used for mechanically supporting patients who develop complications after PEA. Variations in approach stem from differing indications such as, respiratory failure rather than hemodynamic compromise (or vice versa), time of implantation (immediately in operating room or delayed after surgery) and many other causes. In our center, 12.3% (19/154) of patients need ECLS with extracorporeal membrane oxygenator (ECMO) after PEA procedure. Implantation was mainly in the operating room before or immediately after weaning from cardiopulmonary bypass and mostly peripheral cannulation was used. ECMO lasted an average of 11±8 days. And 52.6% (10 of 19 patients) of patients were weaned from ECLS and of this, 70% (7 of 10 patients) were discharged. Conclusions: In some cases of PEA, ECLS is needed post-operatively. Expert teams should consider this possibility pre-operatively based on predisposing characteristics. The need for ECMO shouldn't be "di per se" a contraindication to surgery but might be considered in the surgical risk estimation. The ideal setup is not fixed and depends on the center's practices as well as indication. Even though complications do occur with ECMO, in general, results are good, being a bridge to further recovery of pulmonary hypertension (PH) or also to transplantation.

Pulmonary thrombo-endarterectomy for chronic thromboembolic pulmonary artery hypertension

“…Previously, we have also analyzed the different hemodynamic profiles of our population, to identify those most at risk or not (9). As previously reported by the Canadian group, dysfunction of the right ventricle represents a risk factor for mortality (13) while the degree of PH affects the hemodynamic result after PTE: patients with PVR values greater than 1,200 dynes•sec•cm -5 are more likely to have residual PH although improved.…”

“…Specifically, in group 1, ECMO was needed exactly in 16.6% of cases where DHCA was avoided (8/48) respect 10.9% in those operated on DHCA (14/128). More data about ECMO after PEA, and our management policy can be found in a recent published article, based on 154 PTE cases(9).…”

Treating the “Untreatable”. Recent advances in chronic thromboembolic pulmonary hypertension

“…Reperfusion edema occurs in 5-20% of patients, especially in patients with high pre-operative pulmonary pressure (2, 6, 7). When supportive treatment with mechanical ventilation, diuresis and drugs approved for PAH are not enough, ECMO may be indicated (2,8,9). ECMO both intra and post-operative has become standard of care in centers performing high-risk PEA (2, 8, 9).…”

Mechanical circulatory supports after pulmonary thrombo-endarterectomy: why, when and how

“…Complications, such as increased pulmonary pressures with increased flow, hemorrhage, and pulmonary edema, have been reported. Although, some of the complications may be mitigated by using lower flows with the device; extracorporeal membrane oxygenation (ECMO) remains the preferred mechanical device in CTEPH patients (8)(9)(10).…”

“…The debate about the indications/timing of ECMO after PEA still remains open, even if the literature reports that it's most widely used as a bridge to heart or lung transplantation (7)(8)(9)(10). VA-ECMO may be implanted preoperatively to stabilize patients with decompensated RVF who are waiting for PEA, but it's most currently used in postoperative RVF in the case of difficult weaning from cardiopulmonary bypass (CPB) due to severe pulmonary hemorrhage and/or lung reperfusion edema syndrome (up to 19%) (8-10).…”