Extracorporeal membrane oxygenator support for cardiopulmonary failure. Experience in 28 cases.

We have used extracorporeal membrane oxygenation (ECMO) for 28 patients (14 children and 14 adults) over a 5 year period. Nine patients improved on ECMO and 5 were long-term survivors. ECMO was used for pulmonary insufficiency in 24 patients. Initially, only moribund patients were treated, but recently the combination of open lung biopsy and pulmonary insufficiency index (PII) has been used to select patients. The best results have been obtained in newborn cases and the adult capillary leak syndromes; the major problem has been progression to fibrosis despite ECMO support. ECMO was used for cardiac failure in 4 patients. Children with postoperative cardiac failure did the best; profound shock was not reversed with venoarterial bypass. ECMO support is lifesaving in selected cases of pulmonary insufficiency. Initial trials in cardiac failure and the infant age group in this series suggest that ECMO will have an even greater role in those applications.

Right atrial thrombus secondary to peritoneovenous shunt: successful removal with use of cardiopulmonary bypass.

A patient who had had a functioning peritoneovenous (LeVeen) shunt for 10 months presented with recurrent ascites and the superior vena cava syndrome. He was found to have a thrombus occluding the superior vena cava and extending into the right atrium. The thrombus was removed and the shunt was declotted during cardiopulmonary bypass.

Extracorporeal membrane oxygenation for newborn respiratory failure: forty-five cases.

Almost all types of newborn respiratory failure are reversible. However, supportive treatment (oxygen and positive airway pressure) can damage the lung, and newborn respiratory failure remains a major cause of morbidity and death in infants. Prolonged extracorporeal membrane oxygenation (ECMO) provides life support while allowing the lung to "rest." We have used ECMO in 45 moribund newborn infants; 25 survived. Neonatologists referred patients who were unresponsive to maximal therapy. The right atrium and aortic arch were cannulated via the jugular vein and carotid artery. Heparin was infused continuously to main activated clotting time at 200 to 300 seconds. Airway oxygenation and pressure were reduced to low levels. Primary diagnoses were hyaline membrane disease, 14 (6 survived, 8 died); meconium aspiration, 22 (15 survived, 7 died); persistent fetal circulation including diaphragmatic hernia, 5 (3 survived, 2 died); and sepsis, 4 (1 survived, 3 died). Growth, development, and brain and lung function are normal in 20 of 25 survivors. ECMO decreased newborn respiratory failure mortality and morbidity rates in this phase I trial. A controlled randomized study is underway. The results suggest that ECMO may be effective in older patients if used before irreversible lung damage occurs.

Regional myocardial perfusion of cardioplegic solutions.

We compared the regional myocardial perfusion of blood cardioplegic solution (BCP) and crystalloid cardioplegic solution (CCP) in 14 mongrel dogs. Cardiopulmonary bypass was established at 28 degrees C, and a hydraulic occluder was placed around the proximal left anterior descending (LAD) coronary artery. In group 1 (N = 7) collateral coronary arteries were ligated; in group 2 (N = 7) collateral coronary arteries were left in situ. After the aorta was clamped, BCP and CCP were alternately perfused at 200 ml/min. The occluder was inflated to produce moderate, severe, and critical LAD stenosis, and regional perfusion was measured by xenon-133 washout with the Silicon Avalanche Radiation Detector. BCP infusion produced a consistently higher aortic pressure, but CCP flow was better than BCP flow under all conditions, particularly without coronary collaterals (p less than .05). Regional myocardial perfusion of CCP is superior to BCP.

Use of expanded polytetrafluoroethylene grafts for vascular access in hemodialysis: laboratory and clinical evaluation.

Vascular access for chronic hemodialysis has evolved considerably over the past 10 years with development of vascular substitutes. The bovine heterograft is the choice of most dialysis centers when a subcutaneous conduit is needed in lieu of an in situ arteriovenous fistula. Bovine grafts have solved some problems, but further improvement in blood access prostheses is needed. Polytetrafluoroethylene (PTFE) grafts were evaluated in a laboratory and clinical study. In animals, PTFE proved to be satisfactory for fistula construction based on patency, incorporation into tissue, and ease of puncture. Ten patients underwent 11 vascular access procedures using PTFE grafts as a conduit. There were no technical operative complications. One graft was occluded by extravasation during dialysis and flow could not be restored. Otherwise, all grafts are patent 9 to 18 months postoperatively. Grafts of 8.0 mm in diameter have not given desirable flow rates, whereas 6.0 mm grafts have. Prolonged bleeding from puncture has been a problem in some cases. Otherwise, PTFE appears to be a satisfactory conduit for hemodialysis vascular access.

Extracorporeal membrane oxygenation (ECMO): a team approach in critical care and life-support research.

ECMO may be used clinically in selected cases to provide life support when all other modes of therapy have been exhausted. Survival of moribund patients has been demonstrated. Results might be improved if the severity of the disease is recognized and defined early in the clinical course to prevent the development of irreversible complications. ECMO requires a large, fully trained team to interface with the attending physicians and nursing staff in providing complete life support. The ECMO team provides continued evaluation of the status and treatment of the patient, detection of complications, and correction of any minor or major emergency. It also conducts laboratory and clinical research programs in pulmonary insufficiency as an adjunct to clinical life-support research.

Control of pelvic cancer with hyperthermic isolation-perfusion.

Eight patients with refractory pelvic cancer were treated with a technique of hyperthermic pelvic isolation-perfusion (rectosigmoid colon 7, bladder 1). The procedure was successful in achieving regional hyperthermia in all patients. All five patients experiencing severe pelvic pain prior to surgery had resolution of pain, although in one patient this relief was transient. Five patients had additional intraabdominal procedures at the time of laparotomy to control unsuspected foci of recurrent cancer. There were no operative deaths. Five complications occurred in four patients although only one was considered life threatening (fracture of aorta at the time of cross-clamping). Sloughing of necrotic tumor occurred between 1 and 2 weeks postperfusion and at times was dramatic. The efficacy of this technique is impressive and it is suggested that it be utilized earlier in the course of disease in patients with uncontrolled pelvic cancer.

Left atrial-to-aortic assistance with in-line left ventricular venting.

Left atrial-to-aortic assistance (LA-A) has been employed for left ventricular failure (LVF) refractory to intra-aortic balloon counterpulsation. Although clinical success has been reported, LA-A is limited by incomplete left ventricular (LV) decompression. We have developed a method to augment LA-A with an in-line LV apical vent (LA-lv-A). LVF was produced in 12 dogs by ligation of the circumflex coronary artery. Circulatory assistance was established with LA (28-32 Fr), LV apex (12-14 Fr) and femoral artery cannulation and a centrifugal pump. LA-A assistance was compared to LA-lv-A. Left atrial pressure was reduced from 10 +/- 3 torr to 5 +/- 3 torr (p less than 0.001), left ventricular systolic pressure was reduced from 48 +/- 4 torr to 9 +/- 2 torr (p less than 0.001) and left ventricular end-diastolic pressure was reduced from 10 +/- 2 torr to 1 +/- 1 torr (p less than 0.001). We conclude that LA-lv-A results in complete LV decompression. LA-lv-A should be considered as an alternative method for temporary left heart bypass.

Extracorporeal membrane oxygenation (ECMO) in newborn respiratory failure: technical consideration.

ECMO support has been evaluated in 29 newborn infants with respiratory failure. Lung function improved in 16 and 13 surivived. Important technical factors include venoarterial bypass with full support capability, careful measurement and treatment of coagulation and platelet status, and a skilled and experienced team. Detecting high risk infants early in life is important. Intracranial bleeding is the most common cause of death.

Cardiac assist by extracorporeal membrane oxygenation with in-line left ventricular venting.

We have used a canine heart failure model and extracorporeal circulation to study the limitations of extracorporeal membrane oxygenation (ECMO) for the treatment of cardiac failure. ECMO does not routinely achieve total biventricular bypass and does not effectively decompress the failing left ventricle. The addition of an in-line left ventricular vent (ECMO-lv) provided total biventricular bypass and complete left ventricular decompression in every experiment. ECMO-lv merits consideration as a biventricular bypass system for total mechanical support of the failing heart.

Extracorporeal membrane oxygenation (ECMO) cardiopulmonary support in infancy.

We have used prolonged extracorporeal membrane oxygenation (ECMO) in the treatment of 13 moribund infants (including 9 neonates), with 4 survivors (3 neonates). Successfully treated cases include post-operative cardiac failure, infant respiratory distress syndrome, massive meconium aspiration, and persistent fetal circulation. All cases have been managed with veno-arterial bypass at flow rates of 80-100 cc/Kg/min. Carotid cannulation for arterial access and careful control of heparin anticoagulation based on whole blood activated clotting time are among the techniques which have contributed to this success. Progressive pulmonary or cardiac failure has been the major problem in older infants, intracranial bleeding is the major problem in neonates. Both of these problems could be minimized by instituting ECMO earlier in the clinical course, but this awaits development of reliable early predictors of mortality.