Successful management of right ventricular failure with the ventricular assist pump following aortic valve replacement and coronary bypass grafting.

Right ventricular failure is an infrequent but potentially lethal complication of cardiac surgical procedures. We have successfully treated a patient with right ventricular failure with the use of a right ventricular assist pump (RVAP). This patient had aortic stenosis and coronary artery disease involving the circumflex and right coronary arteries. He also had chronic obstructive pulmonary disease with mild pulmonary hypertension (mean pulmonary artery pressure of 26 mm Hg) and evidence of mild right ventricular failure (right ventricular pressure of 40/14 mm Hg). Gated radionuclide angiography, performed preoperatively, showed that the right ventricle had normal wall motion. Right ventricular failure prevented discontinuation of cardiopulmonary bypass despite use of an intra-aortic balloon pump. The right atrial pressure was 20 mm Hg with a left atrial pressure of 8 to 10 mm Hg. Bypass was readily discontinued following implantation of the RVAP. Recovery of the patient's right ventricle was evaluated with serial determinations of right ventricular work. The RVAP was removed on the fifth postoperative day and the patient made a complete recovery. Postoperatively, gated radionuclide angiography demonstrated moderate recovery of right ventricular function. We suspect that the perioperative right ventricular failure was a result of unsatisfactory myocardial protection due to total occlusion of the proximal right coronary artery, which resulted in a maldistribution of the cardioplegic solution. This case demonstrates that right ventricular function can be restored following circulatory support with a mechanical assist device.

Cholecystectomy in the potential heart transplant patient.

The management of cholelithiasis with gallstone pancreatitis in the heart transplant candidate is a difficult problem. Biliary tract surgery in the heart transplant candidate presents an additional set of clinical risks in view of extensive heart disease. We report the cases of three patients with symptomatic cholelithiasis with gallstone pancreatitis who were successfully operated on while awaiting cardiac allografts. Each patient was preoperatively prepared with (1) a lumbar epidural catheter for postoperative pain control with epidural opioids, (2) a balloon-tipped (Swan-Ganz) catheter and arterial line for perioperative monitoring, and (3) an intraaortic balloon pump for circulatory support with full heparinization after epidural catheter placement. In addition, preoperative optimization of cardiovascular function with pharmacologic agents was carefully achieved for 6 to 12 hours before surgery. All three patients had stable intraoperative courses, with less than a 300 ml blood loss. Their postoperative outcomes were without surgical complication. We think that biliary tract surgery may be safely accomplished in the heart transplant candidate with careful, appropriate preparation and meticulous surgical technique. We also present our management algorithm for heart transplant patients with cholelithiasis before and after operation.

Mortality of coronary artery bypass grafting before and after the advent of angioplasty.

In an effort to determine whether the population of patients undergoing isolated coronary artery bypass grafting and the outcome of these operations have changed, we analyzed the records of two patient populations from our institution. Interventional cardiology techniques (angioplasty, thrombolysis) were not used at our institution before 1982. The records of 736 patients (group 1) who underwent isolated coronary artery bypass grafting from January 1975 to July 1981 were reviewed and compared with a group of 603 patients (group 2) who underwent operation from July 1985 to December 1987. The techniques of operation and myocardial preservation were virtually identical during the two periods. During the group 2 analysis period, 343 angioplasty procedures were performed. The patients in group 2 were significantly older, had increased preoperative New York Heart Association classification, had sustained more previous myocardial infarctions, and had more associated morbid medical conditions. There was a threefold increase in patients seen for reoperative revascularization procedures and a fourfold increase in emergency operations. Overall mortality, although not significantly different, did increase slightly from 2.69% in group 1 to 3.83% in group 2. Mortality after elective procedures remained essentially unchanged (2.05% for group 1 and 1.90% for group 2).

Survival following rupture of a pancreatic abscess in a heart transplant recipient.

A 43-year-old man underwent orthotopic heart transplantation for end-stage ischemic cardiomyopathy. Immunosuppressive therapy consisted of cyclosporine and corticosteroids. The diagnosis of acute pancreatitis was made on the ninth postoperative day and was based on clinical symptoms and an upper gastrointestinal barium study. Both serum and urine amylase values were normal. Abdominal ultrasound examination was nondiagnostic. Two weeks postoperatively, the patient's clinical condition deteriorated sharply. Chest and abdominal roentgenograms revealed free intraperitoneal air, as well as air in the lesser sac. Diagnosis of a ruptured pancreatic abscess was made, and he underwent immediate exploratory laparotomy. Four liters of purulent fluid were present in the peritoneal cavity. A ruptured pancreatic abscess was found, and it had dissected above the superior mesenteric vessels and down the right gutter over the inferior vena cava. After extensive retroperitoneal debridement and copious irrigation, multiple surgical drains were placed. The patient is now well and is performing normal daily activities 16 months after the transplantation procedure. The incidence and proposed causes of pancreatitis occurring after heart transplant are reviewed, and we discuss our management of this complication.

The compliance problem: a major obstacle in the development of implantable blood pumps.

The compliance problem represents a major obstacle in the development of implantable blood pumps. The motor-driven pumps are enclosed in an airtight casing with gas in the motor space. The trapped gas in the motor space either increases the load on the motor during systole or impedes blood sac filling. Potential solutions to the compliance problem include the use of a conventional blood pump with a compliance chamber, a blood pump with an isolated blood sac and accumulator, or a volume-compensated blood pump. Most experimental studies designed to investigate this problem have been performed with compliance chambers. An ideal compliance chamber should accept 100 ml gas with less than a 15-mm Hg increase in pressure and should automatically compensate for changes in atmospheric pressure. To date, two designs have been shown to be effective in laboratory and animal studies: a collapsible rectangular sac design developed by our group, and a lenticular chamber developed by Nosé and associates. Compliance chambers of the former design have now been employed to provide the required compliance for motor-driven assist pumps in long-term calf studies.

Extracardiac surgical complications in heart transplant recipients.

As the population of patients undergoing orthotopic heart transplantation increases, more patients are likely to develop surgical complications unrelated to the transplant procedure. This article reviews 38 extracardiac surgical complications sustained in 18 of 48 patients undergoing orthotopic heart transplantation at our institution over a 4-year period. Twenty-seven complications (71.1%) required operative intervention most commonly in an urgent or emergent manner (59.3%). Three patients underwent six laparotomies. Infection was the cause in almost half of all complications and in 65% of those requiring surgery. Gastrointestinal hemorrhage was common and successfully managed nonoperatively in all cases. The overall operative mortality was 11% with only two deaths related to a surgical complication. The satisfactory outcome in these patients can be attributed to the early diagnosis of complications, timely therapeutic intervention, careful adjustment of immunosuppressive agents, and close patient follow-up with the transplant institution.

Survival and complications following ventricular assist pumping for cardiogenic shock.

Thirty patients (pts) have undergone ventricular assist pumping for up to 25.4 days (mean 6.8 days). Twenty-eight pts could not be weaned from cardiopulmonary bypass (CPB) after open heart operations and two pts sustained myocardial infarctions (MI), with cardiogenic shock unresponsive to medical therapy previous to surgery. Twenty-two pts required left ventricular assistance (LVA); 55% (12/22) were weaned from the pump and 32% (7/22) survived. Two pts required right ventricular assistance (RVA); both were weaned from the pump and survived. Six pts required right and left ventricular assistance (BVA) and none survived. Postoperative survival for program years 1976 through 1979 (14 pts) was 14% (2/14). Postoperative survival for program years 1980 through 1982 (16 pts) was 44% (7/16), reflecting improved pump insertion techniques (left atrial cannulation) and pt management. Since 1980, 12 pts have required LVA, nine have been weaned from the pump, and six pts have survived (50%). One pt has required RVA and has survived, and three pts requiring BVA did not survive. Seven pts have been alive and well 5, 9, 14, 19, 24, 30 and 36 months after surgery. Five are NYHA functional Class I status and two pts are NYHA Class II status. Current data indicates that single ventricular assistance in pts who cannot be weaned from CPB is "reasonable and therapeutic treatment to extend life."

Results of mechanical circulatory assistance before heart transplantation.

Between February 1984 and December 1987, 63 patients were accepted as candidates for heart transplantation. Eighteen patients (29%) required some form of mechanical circulatory support before transplantation; eight patients received an intraaortic balloon pump, five patients had left ventricular assist devices, two patients received biventricular assist devices, and in three patients the total artificial heart was implanted. Fourteen of the 18 patients underwent transplantation with seven longterm survivors.

In vitro and in vivo evaluation of a right ventricular assist device.

A simple right ventricular assist device (RVAD) has been developed. This device will be useful in situations where biventricular failure has been partially treated by placement of a left ventricular assist device, or when right ventricular failure occurs in isolation. This pneumatically actuated, R-wave synchronized, sac type pump contains no valves, and is connected by a graft to the pulmonary artery. The RVAD was tested in a circulation simulator to verify its hemodynamic efficacy and then implanted in six calves for 2-4 weeks to evaluate its biocompatibility. In vitro testing of the RVAD demonstrated that it restored normal hemodynamics in the presence of severe simulated RVF. In six animal implantations, a small amount of thrombus was found in one pump. No anticoagulants were employed. Thrombus was present in the connecting graft in three animals; in two this was clearly related to technical implant errors. No evidence of significant hemolysis was found. This simple RVAD has been found to be hemodynamically effective, is simple to use, and is well tolerated. Refinements in the interconnection graft between the pulmonary artery and the device are necessary.

Staged cardiac transplantation. Total artificial heart or ventricular-assist pump?

Because of donor organ unavailability, staged cardiac transplantation has been performed in eight patients with The Pennsylvania State University pneumatic total artificial heart (two patients) or with the Pierce-Donachy ventricular-assist pump (six patients). Of the six patients who received the ventricular-assist pump, four received cardiac allografts after 3, 11, 21, and 31 days of pump support, respectively. Two patients died before transplantation; the causes of death were non-device-related complications. One additional patient died of Pseudomonas sepsis after staged cardiac transplantation. The remaining three patients are alive and have been followed up for as long as 2 years after staged cardiac transplantation. Of the two patients who were supported with the total artificial heart, one underwent staged cardiac transplantation after 11 days of support. Unfortunately, this patient succumbed to fungal sepsis 17 days later. The remaining patient, who received the total artificial heart after rejection of a transplanted heart, expired 379 days later before a suitable donor organ could be located. These experiences indicate that 1) the ventricular-assist pump and total artificial heart can provide reasonably safe effective circulatory support until a patient's overall physiological status is optimal, until a donor organ can be located for transplantation, or both; 2) there is a need for short-, intermediate-, and long-term support system capabilities; and 3) regardless of the patients' underlying pathology (ischemic versus nonischemic cardiomyopathy), in most instances, the simpler external ventricular-assist pump is capable of satisfactory hemodynamic circulatory assistance.

Hemodynamic effects of a new right ventricular assist device.

A right ventricular assist device (VAD) based on the principle of counterpulsation has been developed at our institution. The device is a valveless, pneumatically actuated, 40 cc, sac-type pump, with a single inlet-outlet port. For right ventricular support, the "Uniport" pump is anastamosed end-to-side to the pulmonary artery. In previous experimental trials, the device has been shown to impart minimal trauma to blood components. In this study, biventricular failure was induced in eight Holstein calves by normothermic ischemia during cardiopulmonary bypass. A Pierce-Donachy left VAD (LVAD) was used for left ventricular support following the ischemic insult. Hemodynamic measurements were obtained throughout the study, and each animal served as its own control. A significant increase in post injury cardiac output (33.5 +/- 11.4%) was obtained with use of the Uniport and LVAD, as compared to use of the LVAD alone (p less than or equal to 0.005). Other hemodynamic parameters of right heart failure, including right atrial pressure (RAP), pulmonary artery pressure (PAP), and left atrial pressure (LAP) were not significantly affected. These data suggest that the Uniport right ventricular assist device significantly improves cardiac output in this model of moderate right ventricular failure. Additional studies are required, however, to optimize pump stroke volume, and to further define the performance envelope of the device.

Disseminated Trichosporon beigelii (cutaneum) infection in an artificial heart recipient.

A 44-year-old man with end-stage ischemic cardiomyopathy was supported with an intra-aortic balloon and The Penn State Heart (artificial) prior to orthotopic cardiac transplantation on the 14th hospital day. At the time of transplantation, intraoperative cultures of pericardial and mediastinal fluid showed growth of Trichosporon beigelii (cutaneum). Shortly thereafter the patient developed visceral dissemination of T beigelii with no associated skin lesions. He was treated with amphotericin B and rifampin, but postmortem examination showed persistent, disseminated infection.