Abstract
Introduction
Veno-arterial extracorporeal life support (ECLS) is a well-established bridging therapy in patients with cardiac or pulmonary failure to maintain organ function and is frequently performed in patients who are not intubated. However, severly impaired cardiac function can occur pulmonary edemy in these patients, necessitating left ventricular unloading.
Methods and Results
In this study we report a 37-year old female patient with familiar dilated cardiomyopathy suffering from acute biventricular heart failure. After implantation of a peripheral ECLS, the decreased ventricular led to refractory pulmonary edema. To unload the left ventricle, an percutaneous balloon atrioseptostomy was performed without intubating the patient. The left ventricle was vented by the venous cannula resting inside the atrioseptostomy. After twelve days on ECLS, the patient underwent orthotopic heart transplantation. The postoperative course was uneventful and the patient discharged from intensive care unit four days after surgery.
Conclusions
In this report we present a patient in which the hybrid technique of ECLS with secondary left ventricular unloading was successfully used as a bridge to transplant therapy. This procedure may offer an alternative bridge-to-decision options in selected patients, including those that were not intubated or anaesthetized.
Keywords
Introduction
Veno-arterial extracorporeal life support (ECLS) is a well-established bridging therapy in patients with severe heart failure that is refractory to conventional therapy (1). However, peripheral ECLS fails to sufficiently reduce end-diastolic pressure and increases the ventricular afterload. Therefore, further decrease in left ventricular function can lead to ventricular distension resulting in pulmonary edema, which likely necessitates additional left heart decompression. In this case report we demonstrate a percutaneous hybrid technique of ECLS and left ventricular unloading as a successful bridge-to-transplant strategy in a non-anaesthetized and non-intubated patient.
Case Report
A 37-year-old female patient with dilated cardiomyopathy was admitted to our hospital with severely reduced biventricular ejection fraction (LVEF 15%, RVEF 26%) as shown by echocardiography. Left heart catheterization and endomyocardial biopsy ruled out coronary artery disease and acute viral myocarditis. The patient was stabilized and scheduled for high urgency heart transplantation. Due to a confirmed heparin-induced thrombocytopenia (HIT), the anticoagulation treatment was managed by administering argatroban. Upon an urogenital infection, the patient decompensated again with signs of end organ failure. Conservative treatment options were exhausted at this point, and an ECLS had to be implemented. To maintain the physical condition of our patient, the coated ECLS system (Deltastream® Medos Medizintechnik, Stolberg (Rhineland), Germany) was implanted percutaneously via the femoral vessels under local anesthesia (arterial: 18 Fr, OptiSite; venous: 24 Fr, FemTrak; Edwards Lifescience®, Irvine, CA, USA), complemented by a 5 Fr distal limb perfusion. Liver and kidney functions recovered rapidly, however, the left ventricular function further declined, resulting in refractory lung edema (Fig. 1A). To decompress the left ventricle, a percutaneous balloon atrioseptostomy had to be performed. Therefore, the atrial septum was punctured with a Brockenbrough needle guided through the femoral vein and the septal defect was dilated with a 20 mm and 30 mm balloon (Figs. 2A + B). The venous cannula, which came to rest inside the septal defect, directly drained the left atrium, as shown in Figure 3. The patient showed an immediate recovery, presenting with a decrease in dyspnea and an improved chest X-ray (Fig. 1B). As the patient was not intubated or under general anesthesia, the overall pre-operative status could be improved by active and passive physiotherapy. After twelve days on ECLS, the patient received an orthotopic heart transplantation. The standard cardiopulmonary bypass protocol with unfractionated heparin anticoagulation was used since HIT antibodies could not be confirmed by repeated ELISAs. The postoperative course was uneventful. The patient was extubated after Day 1 post surgery and discharged from our ICU after four days. At the six-month follow-up examination, she was still in good condition.
Chest X-ray with (A) pulmonary congestion before atrioseptostomy and (B) two days after intervention.
Peri-interventional X-ray with (A) the trans-septal positioning of the balloon and (B) the inflated balloon across the atrial septum defect, guided by a stiff wire in the upper left pulmonary vein.
CT scan reconstruction with the venous cannula venting the left atrium via septum defect. LA = left atrium, PA = pulmonary artery, RA = right atrium.
Discussion
Peripherally implanted ECLS systems do not decrease the end-diastolic pressure of an impaired left ventricle; instead, it increases the afterload. In patients with refractory pulmonary edema, additional decompression of the left heart may be necessary. Several approaches ranging from surgical to interventional have been published to achieve decompression. Besides establishing a left ventricular bypass by direct venous cannulation of the pulmonary vein, the placement of an additional vent into the pulmonary artery or vein integrated into the venous line of the ECLS is the simplest approach (2). But at the very least, these techniques require a thoracotomy. A transjugular placement of a pulmonary artery venting is feasible but difficult to sustain (3). A less traumatic approach that allows direct ventricular venting is the percutaneous transaortic access (4). The venting can be performed by a special catheter or a pigtail catheter (5). However, the standard technique to decompress the left atrium is an atrioseptostomy. Seib and colleagues applied atrioseptostomy secondary to extracorporeal circulatory support in 10 patients and succeeded in unloading the left ventricle (6). Bignon et al also found improved pulmonary and left ventricular function with this hybrid approach in five patients with myocardial dysfunction and refractory pulmonary edema (7). The reported outcome from these studies is hard to interpret, as the cohorts are small, and the patients were multimorbid and critically ill. Left ventricle unloading was achievable at sufficient levels in both studies, nevertheless, the mortality rates were still high due to multiorgan failure. However, the precise shunt volume needed to achieve an effective decompression remains unclear and the experience with that hybrid procedure is limited, especially in non-intubated patients.
In the presented case, we tried to avoid mechanical ventilation to not further exacerbate the patient's physical condition. Therefore, we opted to implant the ECLS peripherally under local anesthesia, leading to a refractory pulmonary edema due to impaired cardiac function. The patient rejected the implantation of the biventricular assist device. Further surgical venting strategies were also refused to avoid intubation and sedation of the patient. Under those circumstances, a hybrid technique of ECLS with percutaneous atrioseptostomy under transesophageal echocardiography guidance was chosen and performed successfully. The venous cannula supported the ventricular unloading by being positioned inside the atrioseptal defect.
Bridging strategies in awake and non-intubated patients by veno-venous extracorporeal membrane oxygenation (ECMO) represents an established and increasingly-used strategy in patients awaiting lung transplantation. Using this approach, Fuehner et al demonstrated that the overall physical condition of these patients improved. Consequently, they had better outcomes upon lung transplantation compared to intubated and non-ECMO recipients (8). Similar results can be anticipated for patients with end-stage cardiac failure. However, due to the long waiting period to receive heart transplantation, this strategy is more suitable as bridge-to-decision.
Conclusions
The hybrid technique of percutaneous ECLS therapy and atrioseptostomy to decompress the left ventricle is an effective and quickly available bridging option in cardiogenic shock with refractory pulmonary edema, even in awake and non-intubated patients. Regarding the encouraging results of ECMO therapy in non-intubated patients awaiting lung transplantation we thought to expect to maintain the improved physical condition and hence improved outcomes after the bridging period.