Extracorporeal membrane oxygenation for cardiac support in pediatric patients.

Extracorporeal membrane oxygenation (ECMO) has been used for pediatric cardiac support in settings of expected mortality due to severe myocardial dysfunction. We reviewed the records of 34 children (<18 years) placed on ECMO between March 1995 and May 1999. Demographic, cardiac, noncardiac, and outcome variables were recorded. Data were subjected to univariate analysis to define predictors of outcome. Eighteen patients were placed on ECMO after cardiac surgery (Group A); seven of 18 were weaned off ECMO, and four survived to discharge (22%). Thirteen patients were placed on ECMO as a bridge to cardiac transplantation (Group B), six of 13 received a heart transplant, one recovered spontaneously, and six survived to discharge (46%). Three patients were placed on ECMO for failed cardiac transplantation while awaiting a second transplant (Group C); one recovered graft function, two received a second heart transplant, and two of three survived (66%). The primary cause of death was multiorgan system failure (68%). Group A patients supported on ECMO for more than 6 days did not survive. Mediastinal bleeding complications and renal failure requiring dialysis were associated with nonsurvival. We conclude that ECMO as a bridge to cardiac transplant was more successful than ECMO support after cardiotomy. Mediastinal bleeding and renal failure were associated with poor outcome. Recovery of cardiac function occurred within the first week of ECMO support if at all. Longer support did not result in survival without transplantation.

Mechanical assist strategy using the BVS 5000i for patients with heart failure.

BACKGROUND: The BVS 5000i external pulsatile assist device is used to support patients with reversible cardiogenic shock. Its low cost and potential for insertion without cardiopulmonary bypass make it an attractive option. METHODS: Nineteen status I patients failing inotropic support were treated with the BVS 5000i with the intention of short-term bridge to transplant. Fourteen patients received left ventricular support whereas 5 received biventricular support. Cardiopulmonary bypass was used in less than 50% of patients. RESULTS: Median support time was 7 days. The 2 myocarditis patients were weaned from support. Twelve patients were transplanted and there were 5 deaths on support. Overall 14 of 19 were transplanted or weaned. One-year survival was 79%. Median hospital stay was 31 days. CONCLUSIONS: The BVS 5000i can be used for short-term mechanical assist toward transplantation in selected patients for whom a donor can be expected soon. The device may provide a cost-effective, short-term strategy to optimize end-organ function before orthotopic heart transplant, particularly for patients who are predictably not ideal to be discharged with implantable left ventricular assist device treatment.

Sixteen-year experience with 1,000 heart transplants at UCLA.

1. The consecutive pre- and post-1994 eras have demonstrated improved survival for all age groups. This is linked to improved preservation methods, surgical technique and immunosuppression agents. 2. The use of marginal donor hearts for Status I and alternate elderly patients has followed the model of matching donor and recipient risk without affecting patient outcome and minimized the use of implantable assist devices. 3. A donor history of systemic gram-negative infection, hypertension, or traumatic intracranial bleeds was an important marker for risk. Younger age and shorter ischemia time could compensate for other hazards. 4. Heart transplantation in carefully selected elderly recipients yielded clinical results similar to those of younger patients with less rejection. 5. An adult alternate recipient list proved useful to prevent diversion of standard donors away from younger recipients. 6. Retransplantation for TCAD is acceptable but much less satisfactory for acute graft failure. 7. Trends show an increase in the use of implantable devices; refinement in technology for mechanical assist and replacement is forthcoming.

Short-term bridge to transplant using the BVS 5000 in a 22-kg child.

The availability of pulsatile mechanical assist devices for bridge to transplant in pediatric patients is limited owing to the patients' small sizes. Pulsatile devices offer potential advantages over nonpulsatile devices but the risk of hypertensive bleeding must be balanced against that of device thrombosis. We describe our experience using the BVS 5000 external pulsatile device in an 8-year old patient with a body surface area of 0.88 m2.

Improved survival in patients with acute myocarditis using external pulsatile mechanical ventricular assistance.

BACKGROUND: Acute myocarditis remains a disease with a variable clinical course, from full ventricular recovery to complete heart failure; to date, few cases have been reported that describe the efficacy of temporary mechanical ventricular assistance for its treatment. METHODS: We evaluated the voluntary world registry with the use of an external pulsatile ventricular assist device (the ABIOMED BVS 5000 [BVS]) for acute myocarditis to determine the impact of mechanical ventricular assistance on outcome. Variables analyzed included patient demographics, serum chemistries, and overall hemodynamics prior to BVS, while on BVS support, and after BVS explanation. Postoperative parameters included re-operation, bleeding, respiratory failure, renal failure, and infections, neurologic, or embolic events. RESULTS: Eighteen patients in the ABIOMED world registry underwent BVS implantation for myocarditis; 11 (61.1%) had complete pre-operative and hemodynamic data for analysis. Patients were supported for 13.2 +/- 17.0 days, after which time 7 (63.6%) patients survived to explanation of the device and 2 (18.2%) underwent transplantation. Elevated admission serum chemistries (blood ureanitrogen [BUN], creatinine, transaminases) and hemodynamics (central venous pressure [CVP], mean pulmonary arterial pressure [PAP], pulmonary capillary wedge pressure [PCW], cardiac index [CI], all normalized during the period of device support. Estimated ejection fractions in the 7 explanted patients ranged between 50 to 60% at routine evaluation 3 years after device removal. CONCLUSIONS: Temporary mechanical ventricular assistance represents an efficacious therapy for acute myocarditis in patients with hemodynamic decompensation despite maximal medical therapy. Failure to achieve full ventricular recovery while on device support still allows for other surgical alternatives, including implantation of a long-term implantable ventricular assist device, or cardiac transplantation.

Minimally invasive mechanical cardiac support without extracorporeal membrane oxygenation in children awaiting heart transplantation.

BACKGROUND: Mechanical cardiac assist for small children (< 30 kg) requiring bridge strategy to orthotopic heart transplantation often requires sternotomy for cannulation access to ensure perfusion to the aortic arch. Extracorporeal membrane oxygenation (ECMO) through neck cannulation is an option in very small (< 10 kg) patients, but the risk of stroke is increased in larger children. Another disadvantage is poor decompression of the left atrium, which can cause persistent pulmonary edema. METHODS: Two cases are used to illustrate two methods of avoiding sternotomy during mechanical assist in children with dilated cardiomyopathy. One of these approaches avoids the need for extracorporeal oxygenation. RESULTS: Decompression of the left-sided chambers with a left atrial cannula decreased pulmonary edema and improved pulmonary function. CONCLUSIONS: Pediatric patients with dilated cardiomyopathy may benefit from a left ventricular assist technique using a centrifugal pump, which avoids the neck vessels and sternotomy, as well as ECMO.

Temporary mechanical support with the BVS 5000 assist device during treatment of acute myocarditis.

BACKGROUND: Ventricular support with the BVS 5000 (Abiomed) has been used as temporary circulatory assist for the failing heart. Our purpose is to summarize four cases illustrating the role of mechanical unloading in acute myocarditis. METHODS: Four patients aged 16- to 33-year old presented with congestive heart failure 4 to 20 days after a flu-like syndrome. All patients were in severe cardiogenic shock +/- renal and liver dysfunction. Ejection fraction ranged from 5% to 26%. Indications for ventricular assist were failure of maximal medical treatment with > or = two inotropes +/- intra-aortic balloon pump. Myocardial biopsy revealed acute myocarditis in three patients and severe edema in one despite a characteristic clinical course. Two patients received immunotherapy with OKT3. Biventricular assist was used in three patients and left ventricular assist only was used in one. Mean support time was 8.3 days (7 to 11). RESULTS: All patients had recovery of myocardial function and were discharged from the hospital in good condition. CONCLUSION: The BVS 5000 device provides a safe, simple, and effective method to support the circulation during acute myocarditis. We hypothesize that this may facilitate myocardial recovery by decompressing the distended ventricle. Ventricular assist devices should be used early in the presence of hemodynamic deterioration on maximal medical therapy.

Institutional experience with a protocol of early primary repair of double-outlet right ventricle.

BACKGROUND: Our institution has adopted a protocol of primary repair for all patients with double-outlet right ventricle. METHODS: Since May 1989, 24 consecutive neonates and infants with double-outlet right ventricle and atrioventricular concordance (median age, 4 months) underwent anatomic biventricular repair. One patient (4%) received prior pulmonary artery banding but was still repaired as a neonate at 22 days of age. Twelve patients had a subaortic ventricular septal defect (VSD), 5 patients a subpulmonary VSD, 3 patients doubly committed VSD, and 4 patients a noncommitted VSD. Sixty-nine of 72 associated lesions were repaired simultaneously. Four types of repairs were used: intraventricular rerouting in 16 patients, arterial switch operation with VSD closure into the pulmonary artery in 4 patients, Rastelli-type repair with extracardiac conduit in 3 patients, and the Damus-Kaye-Stansel repair with concomitant repair of aortic arch obstruction in 1 patient. Ventricular septal defect enlargement was necessary in 15 patients. Repair of subpulmonary stenosis and of subaortic stenosis was carried out in 13 and 4 patients, respectively. Three patients underwent simultaneous repair of aortic arch obstruction with no mortality. Two of the patients with noncommitted VSD had simultaneous repair of complete atrioventricular canal and repair of severe pulmonary venous obstruction. RESULTS: The perioperative mortality was 8% (2 patients, and there was one late death (4%). Two patients (9%) underwent early successful reoperations (5 and 8 weeks postoperatively). The two reoperations were for residual VSD (1 patient) and severe mitral regurgitation (1 patient). All 21 survivors are alive at a mean follow-up of 40 months (range, 7 months to 6 years). The estimated 5-year actuarial survival is 88%, with no deaths after 2 months postoperatively. Ninety-five percent of long-term survivors have no restriction of physical activities because of cardiac status and are receiving no cardiac medications. CONCLUSIONS: An institutional protocol of early anatomic biventricular repair of double-outlet right ventricle in infants and neonates achieves excellent survival, making palliative operations unnecessary. Associated lesions should be repaired simultaneously. The complexity of these malformations requires a highly individualized and flexible surgical approach.

Laparoscopic closure of perforated duodenal ulcer.

Simple patch closure is a treatment option for perforated duodenal ulcer. A 46-year-old male was admitted with evidence of perforation of a duodenal ulcer. The decision was made to carry out laparoscopy to confirm the diagnosis and to close the perforation. This was accomplished without difficulty by suture closure of an anterior perforation and application of an omental patch. The patient had an uneventful recovery. Laparoscopy can be of value in the diagnosis and treatment of perforated duodenal ulcer. The principles of management should be essentially similar to those adhered to during open surgery.

The reversibility of impaired mucociliary function after lung transplantation.

Impairment of mucociliary function occurs after lung transplantation and may predispose patients to repeated pulmonary infections. The purpose of this study is to determine whether and how soon such mucociliary function may recover. Ten dogs underwent left lung autotransplantation. Within 3 weeks five of these dogs underwent study for proximal airway clearance by observation through a bronchoscope of the movement of carbon particles placed at different locations on the tracheobronchial mucosa. The mechanical properties of collected mucus from specific sites were determined by magnetic rheometry. The right lung, which was not operated on, served as a paired control. Similar studies were conducted in the remaining five dogs at 12 weeks after autotransplantation. Lung autotransplantation caused significant depression of proximal airway clearance and a 35% increase in mucous rigidity (p = 0.05) soon after operation. At 12 weeks after operation, there was a partial recovery of proximal airway clearance. Mucous changes were no longer consistent. Histologic and electron microscopic examinations initially revealed focal denudation of ciliated cells and loss of the bronchial glands. At 12 weeks there was a regeneration of cilia and a reappearance of the bronchial glands. We conclude that the mucociliary function, observed to be depressed early after lung autotransplantation, recovers partially during the late postoperative period. Thus the mucociliary functional recovery should be attributed to revascularization rather than to reinnervation, since the latter is unlikely to occur during this period.

Endoscopic guided percutaneous tracheostomy: early results of a consecutive trial.

Percutaneous tracheostomy is increasingly being used for patients needing prolonged ventilatory support. The purpose of this study was to assess the feasibility of widespread application of endoscopic guided percutaneous tracheostomy. Sixty-one consecutive ICU patients requiring prolonged mechanical ventilation underwent bedside endoscopic guided percutaneous tracheostomy. Using a modified Ciaglia technique, a #6-10 tracheostomy tube was introduced between the second and third tracheal rings. Bronchoscopic transillumination facilitated identification of the appropriate tracheostomy site, and verified satisfactory placement of dilators and tracheostomy tube. There was one procedure-related death due to arrhythmia. Procedure-related complications included (n = 7): bleeding (controlled with local pressure), two infections, two cuff tears, and two obstructions of the tracheal tube. The tracheostomy was eventually removed in 13 patients. Bronchoscopic evaluation of three patients at 4 months post-tracheostomy removal was normal and there has been no clinical evidence suggestive of tracheal stenosis in the remaining ten extubated patients. There was a 50% reduction in cost when compared to operative tracheostomy. Percutaneous tracheostomy is a simple, safe, cost-effective bedside procedure for critically ill ventilator-dependent patients. Endoscopic guidance appears to increase the safety of this procedure and may prevent complications of pneumothorax, subcutaneous emphysema, and paratracheal false passage previously reported with blinded percutaneous methods.

Does the addition of albumin to the prime solution in cardiopulmonary bypass affect clinical outcome? A prospective randomized study.

Colloid solution is commonly used to increase the oncotic pressures of priming solutions used in the cardiopulmonary bypass circuit. To study the effectiveness of this practice, we prospectively randomized 100 adult patients undergoing cardiac operations to receive Ringer's lactate solution plus 50 gm of albumin (group A) or Ringer's lactate solution alone (group B) as the prime solution for the bypass circuit. Personnel involved in the management of these patients were blinded concerning the group to which the patients had been randomized. Forty clinical parameters related to perioperative fluid balance, cardiopulmonary function, and renal function were studied. Although group B received a larger volume of crystalloid solution intraoperatively (p less than 0.05), had a lower mean cardiac filling pressure (p less than 0.05), and had a higher hematocrit value (p less than 0.05) in the immediate postoperative period, all mean values for both groups were within the normal range. There were no differences between the two groups with regard to postoperative clinical parameters of cardiopulmonary and renal function, nor was outcome affected by the addition of albumin to the prime solution. We conclude that there is no clinically detectable advantage for the practice of adding 50 gm of albumin to the priming solution of bypass circuits in adults undergoing cardiac operations. Routinely supplementing the bypass prime solution with albumin adds significant cost, estimated to be approximately $10,000 per 100 cases, without demonstrable clinical benefits. Whether this practice can be of value in selected cases needs to be further studied.

Mucociliary function in autotransplanted, allotransplanted, and sleeve resected lungs.

Tracheobronchial mucociliary function in dogs that underwent left upper sleeve lobectomy was compared with that of dogs that underwent left lung autotransplantation or allotransplantation (n = 5 each). Proximal airway clearance was measured by observing the movement of carbon particles through a bronchoscope. Preoperative and postoperative clearance rates for the right lungs in these dogs were unchanged. Although preoperative clearance rates in the transplanted left lungs were comparable with those of the right lungs, these left lungs were unable to clear the carbon particles during a 15-minute observation period 3 weeks postoperatively. In contrast, preoperative and postoperative clearance rates for the dogs that underwent sleeve resection were unchanged for both lungs. Mucus rigidity was studied by microrheometry and was found to be significantly increased postoperatively for samples collected from the autotransplanted and allotransplanted lungs than for samples collected from the untreated right lungs. These changes in mucus were noted for forces representing both normal ciliary beat and coughing. Viscoelastic properties of mucus were not significantly altered after sleeve lobectomy. Microscopic study showed squamous cell metaplasia and relative disappearance of bronchial glands distal to the anastomosis in all transplanted lungs. These changes were less pronounced in the sleeve resected bronchi. We conclude that changes in rheologic characteristics of mucus can impair mucociliary clearance and may be related to denervation after lung transplantation. Bronchial devascularization may have an additional effect of altering mucosal structures and function in the early postoperative period after lung transplantation. These effects are avoided by preserving peribronchial tissue in sleeve resection.

Does the surgical trauma of "exploratory thoracotomy" affect survival of patients with bronchogenic carcinoma?

A retrospective review was carried out to assess the possible adverse immunosuppressive effect of exploratory thoracotomy on the survival of patients with non-small cell carcinoma of the lung with N2 nodal metastases. Between 1960 and 1982, 48 patients with non-small cell bronchogenic carcinoma underwent exploratory thoracotomy; lung resection was not done because mediastinal lymph nodes were involved. The survival of these patients was compared with that of 64 patients in whom N2 disease was established by mediastinoscopy alone and who did not undergo thoracotomy. There were no significant differences with respect to age, sex, tumour type and adjunctive radiotherapy. There were slightly more T4 tumours in the thoracotomy group (50% versus 30%). The hospital stay was longer in the thoracotomy group (2.3 +/- 1.1 versus 1.5 +/- 0.9 months [mean +/- SD]). However, follow-up studies showed that, although these patients had a more traumatic procedure, the actuarial survival curves for the two groups were virtually identical, and the 12-month survival rates were less than 20% for both groups. The median survival was 6.0 months for the thoracotomy group and 7.0 months for the mediastinoscopy group. These findings failed to demonstrate an adverse immunosuppressive effect of thoracotomy on lung cancer patients.

Percutaneous endoscopic tracheostomy.

Bedside percutaneous tracheostomies are increasingly performed. This avoids patient transport to the operating room. Complications of this procedure are largely related to the blind nature of the technique. After laboratory studies, 4 patients underwent percutaneous endoscopic guided tracheostomy in a selective clinical trial. There were no procedure-related complications. Endoscopic guidance ensures precise low tracheostomy position, prevents paratracheal tube misplacement, and avoids inadvertent injuries.

Residual hypothermia in patients recovering in the intensive care unit from cardiac surgery.

Because of inadequate rewarming or equilibration of body temperature, patients who undergo cardiac surgery with hypothermia often are still hypothermic after arrival in the intensive care unit. The incidence of residual hypothermia and its hemodynamic effects were assessed in this study. Of 82 adults who underwent cardiac surgery, 41 were normothermic with core temperatures of 35.5 degrees C or higher (mean 36.0 +/- 0.1 degrees C) and 41 were hypothermic with temperatures below 35.5 degrees C (mean 34.9 +/- 0.1 degrees C) on arrival at the intensive care unit (p less than 0.005). Patients with hypothermia had significantly (1.9 +/- 0.1 versus 2.2 +/- 0.1, p less than 0.05) lower cardiac indices. Although not statistically significant, there was a trend toward higher systemic vascular resistance in the patients with hypothermia. The authors conclude that mild residual hypothermia is still common after cardiac surgery and may contribute to the depressed hemodynamic status of these patients.