Organ preservation solutions in heart transplantation--patterns of usage and related survival.

Despite experimental advantages for certain heart preservation solutions (HPS), their clinical popularity and related survival are uncertain. We surveyed all active UNOS heart transplant centers to determine their HPS. HPS survival benefits were tested using the UNOS heart transplant registry. Centers used from 1 to 3 types of 167 solutions. Of these formulations, 55.1% were commonly cited solutions. The other (custom) mixtures differed from those usually reported. All solutions were classified as intracellular (I, [Na++] < 70 mEq/L) or extracellular (E, [Na++] > or = 70 mEq/L). Significant variations in solution usage were observed among major regions of U.S. transplant activity (Northeast [NE], Southeast [SE], and West [W], P < 0.001). For example, 62.5% of University of Wisconsin (UW) and 49.3% of "Other" usage occurred in the NE; 75% of Roe and 100% of Collins usage occurred in the SE; and 100% of Krebs and 46% of Stanford usage occurred in the W. Logistic regression analyses of 9401 patients who underwent transplantation from 10/87 to 12/92 showed a reduction in the adjusted one month mortality odds ratio for grafts preserved with I rather than E solutions (0.85, P < 0.05). Compared with the most commonly used solution, Plegisol (20.1% of cases), the following adjusted odds ratios for one-month mortality were observed: UW, 1.09 (ns); Stanford, 0.80 (P < 0.10); Roe, 0.36 (P < 0.001); Collins, 0.82 (ns); Krebs, 0.14 (P < 0.01). Using the same one month comparison with Plegisol, 16.8% of grafts that received Custom-I solutions also fared better (0.75, P < 0.05) than the 21.4% that had Custom-E mixtures (0.91, ns). HPS usage varies greatly and there are regional preferences. There may be early survival benefits for certain intracellular HPS--however, further study is warranted to explore such relationships.

Bronchial erosion by an indwelling central venous catheter.

Despite improved technology, central venous catheters are associated with many complications that occur usually within 48 h of placement. We report a 42-year-old man with a rare erosion of a venous catheter (Silastic) into a bronchus 2 years after its insertion.

Immunostaining of cardiac biopsy specimens in the diagnosis of acute vascular (humoral) rejection: a control study.

The diagnosis of acute vascular (humoral) rejection in heart transplant biopsies is classically based on immunofluorescent studies of frozen tissue that show vascular staining for immunoglobulin and complement. We have noted that some pathologists have used immunostaining of formalin-fixed, paraffin-embedded tissue in testing for vascular rejection. To determine the specificity of immunostaining of heart biopsy specimens in the diagnosis of vascular rejection, we studied tissue from 68 consecutive endomyocardial biopsies from 16 patients without clinical or histologic evidence of vascular rejection. In each case, routinely processed formalin-fixed, paraffin-embedded tissue was stained for immunoglobulin G and immunoglobulin M with an avidin-biotin immunoperoxidase technique. Frozen tissue from each case was also stained for immunoglobulin G, immunoglobulin M, C3, and Clq by immunofluorescence. Immunoperoxidase stains on formalin-fixed tissue showed vascular staining for immunoglobulin in 67 of 68 (99%) of the cases. Staining was ablated if the antibodies were absorbed with their appropriate immunoglobulin. Immunofluorescent studies on frozen tissue showed no vascular staining for immunoglobulin or complement. We conclude that immunoperoxidase studies of routinely processed, formalin-fixed, paraffin-embedded tissues are nonspecific in the diagnosis of heart acute vascular rejection. The positive staining in fixed tissues may be due to labeling of passive immunoglobulins that are "fixed" in the vessels during routine processing but are washed away in techniques using frozen tissue.

Load-Insensitive Measurements from an Isolated Perfused Biventricular Working Rat Heart.

To determine whether a rat heart model can provide load-insensitive measurements of cardiac function, a recently developed biventricular perfused preparation was tested. Using 29 Sprague-Dawley rat hearts perfused with modified Krebs-Henseleit buffer, ventricles functioned simultaneously with adjustable independent preload (venous reservoirs) and afterload (compliance chambers). Ultrasonic crystal pairs provided continuous left (LV) and right ventricular (RV) short-axis dimensions. LV and RV pressure-length loops (loop area = work) were generated from paired intraventricular pressure and short-axis dimensions. Load-insensitive measurements were obtained from the slopes (elastance) and x-intercepts (L(0)) of regression lines generated from the end-systolic coordinates of these pressure-length loops over ranges of RV and LV preloads. Measurements were made after 15 min of stable function and after 20 min of warm (37 degrees C) ischemia. During perturbations in LV afterload, there were linear changes in dP/dt, but loop work remained relatively unchanged. RV dP/dt and work varied little with physiologic ranges of afterload. Increased RV afterload had little effect on LV function. Ischemia affected LV function more than RV function using these measurements. Elastance, however, increased after ischemia with diastolic 'creep' (increased L(0)) for both ventricles. Load-insensitive and other sophisticated hemodynamic measurements are possible with this new preparation. Copyright 1997 S. Karger AG, Basel

Minimally invasive lobectomy directed toward frail and high-risk patients: a case-control study.

BACKGROUND: To compare minimally invasive video-assisted thoracic surgery (VATS) with thoracotomy, cases were matched from a pool of pulmonary lobectomies performed by one surgeon who offered VATS for patients with unfavorable risk factors. METHODS: A thoracotomy case was paired to each of 19 VATS cases by age, sex, lobe, side, and forced expiratory volume in 1 second. Eleven VATS and 5 thoracotomy patients with severe activity impairments or reduced forced expiratory volume in 1 second (< 1.5 L or 50% predicted) were classified as higher risk than the others. RESULTS: Despite more high-risk cases, VATS yielded shorter hospitalizations (5.3+/-3.7 versus 12.2+/-11.1 days, p = 0.02), chest tube durations (4.0+/-2.8 versus 8.3+/-8.9 days, p = 0.06), and earlier returns to full preoperative activities (2.2+/-1.0 versus 3.6+/-1.0 months, p < 0.01). The VATS operations had no intraoperative complications and lasted 229+/-59 minutes. Pain 3 weeks later was dramatically better for the VATS group (none or mild, 63% versus 6%; severe, 6% versus 63%; p < 0.01). Six complications or deaths occurred in each group and were related to forced expiratory volume in 1 second, steroid usage, age, active smoking, and upper lobe resection (p < 0.01). Three VATS deaths occurred only in elderly, performance status 3 patients, with two caused by gastrointestinal-related problems masked by steroid use. CONCLUSIONS: A VATS lobectomy is less painful and may offer faster recovery for the frail or high-risk patient. Further study, particularly of its safety in severely activity-impaired patients, is warranted.

Strangulated parahiatal hernia: not just another paraesophageal hernia.

Exploratory thoracotomy was necessary to establish the diagnosis of a rare incarcerated parahiatal hernia. Symptomatology, signs, and radiographic findings are compared with those of paraesophageal hernias.

Severe dysphagia from an Angelchik prosthesis: futility of routine esophageal testing.

A 33-year-old woman presented with progressive dysphagia 3 years after implantation of an Angelchik prosthesis for esophageal reflux disease. Routine esophageal testing was normal. Esophagogastroduodenoscopy and computed tomography suggested migration of the prosthesis. Because of the persistent and progressive dysphagia, the device was removed. All symptoms of dysphagia or reflux have since resolved. Routine esophageal testing may not be helpful in the evaluation of dysphagia associated with the Angelchik prosthesis.

Isolated biventricular working rat heart preparation.

The isolated perfused heart from small animals has been used extensively for hemodynamic and metabolic studies. The left working heart preparation proved superior to the Langendorff model for functional evaluations but has not allowed study of right heart function. A simple and inexpensive biventricular working heart preparation has been developed by modifying the left working rat heart model. Under general anesthesia the heart was removed surgically leaving sufficient vessels attached to it. Cannulation of the aorta, left atrium, right atrium, and pulmonary artery was completed in 10 minutes. A pressurized compliance chamber allowed rapid and reliable regulation of aortic impedance. For the 7 hearts that were subjected to 3-hour biventricular perfusion (their end points expressed as percent of their initial values), the aortic output (95% +/- 3%), pulmonary flow (88% +/- 9%), mean aortic pressure (109% +/- 5%), mean pulmonary pressure (100% +/- 2%), heart rate (106% +/- 8%), myocardial adenosine triphosphate level (85% +/- 8%), and creatine phosphate level (89% +/- 4%) were all maintained at physiologic levels. For the 11 hearts that were converted from left working heart preparation to biventricular working mode, significant improvement in stroke volume, aortic and cardiac output, and pressure development were observed. Experimental results indicate that the biventricular working model for isolated perfused rat hearts is superior to the left working preparation for studying the function of the total heart. Further study of the biventricular perfused working rat heart appears warranted.

Laboratory confirmation of clinical heart allograft preservation variability.

BACKGROUND: Previously, we reported survival differences from the national heart transplant registry favoring centers that used intracellular organ preservation solutions. To eliminate center selection bias, we tested some of these solutions in a biventricular working rat heart model to determine their relative efficacy. METHODS: Using 103 Sprague-Dawley rat hearts perfused with modified Krebs-Henseleit buffer, both ventricles functioned with adjustable independent preload and afterload and their pressure-length loops generated load-insensitive measurements of cardiac performance. After 15 minutes of stable function, each heart sustained 180 minutes of cold (4 degrees C) ischemia after a 5-minute perfusion by University of Missouri (UMC), Plegisol, Collins, University of Wisconsin, Custodiol, or Roe solutions. Eighty-two hearts were reperfused and the remainder were used for ATP analyses. RESULTS: Although the extracellular solution Plegisol showed good recovery of traditional hemodynamic values, including developed pressure and cardiac output, intracellular solutions like Roe had superior preservation of load-insensitive indices such as preload recruitable stroke work: Roe (intracellular) 103%+/-13%; Custodiol (intracellular) 96%+/-9%; UW (intracellular) 69%+/-12%; Collins (intracellular) 68%+/-9%; Plegisol (extracellular) 68%+/-7%; and University of Missouri (extracellular) 56%+/-10% (p = 0.04). Furthermore, recovery with intracellular solutions tended to be gradual but more progressive after ischemia in contrast to an early plateau shown by extracellular (p < 0.001). Right ventricular recovery and ATP measurements were similar between groups. CONCLUSIONS: These data support the superiority of certain intracellular preservation solutions and provide evidence that optimal heart organ protection may be difficult to judge clinically using hemodynamic values routinely available to the heart transplant surgeon. Care should be taken to verify the performance of some solutions used in heart organ transplantation.

Resuscitation of injured myocardium with adenosine and biventricular assist.

Recovery of energy metabolism and contractility in stunned myocardium requires several days, even when mechanical circulatory support is employed. This double-blind study was undertaken to determine if myocardial recovery could be accelerated by intracoronary infusion of adenosine during reperfusion. Ten mongrel dogs were subjected to 45 minutes of global normothermic ischemia while on biventricular support with centrifugal pumps. During initial reperfusion, 20 minutes later, and at hourly intervals for 4 hours, dogs received 100 mL/min of unaltered blood or blood enriched with adenosine (0.2 mmol/L) into the coronary arteries for 5 minutes. Circulatory support was discontinued after 4 hours or sooner if the first time derivative of left ventricular pressure exceeded 2,000 mm Hg/s. Animals that received adenosine were weaned sooner (72 +/- 27 versus 216 +/- 54 minutes) and had higher systolic pressure (110 +/- 21 versus 57 +/- 36 mm Hg), lower left ventricular end-diastolic pressure (23.8 +/- 4.8 versus 34.0 +/- 7.2 mm Hg), and higher first time derivative of left ventricular pressure (3,407 +/- 812 versus 1,510 +/- 1376 mm Hg/s) than controls at the completion of the experiment (p less than 0.05). Final myocardium adenosine triphosphate levels were higher in the adenosine group (20.0 +/- 3.6 versus 14.2 +/- 4.0 mumol/g protein; p less than 0.05). Determination of infusion and coronary sinus blood concentrations demonstrated a 90% uptake of adenosine. All adenosine animals survived, but 2 of 5 control animals died within 1 hour of weaning. Reperfusion with adenosine-enriched blood accelerated recovery of ischemic myocardium and should be considered for patients requiring mechanical circulatory support after a heart operation.

Massive phrenic perineurioma mimicking an unresectable cardiac tumor.

Malignant peripheral nerve sheath tumors of the phrenic nerve are rare. A 24-year-old woman presented with a massive perineurioma of the phrenic nerve that invaded the pericardium and left heart. Diagnosis, surgical treatment, and 1-year follow-up are discussed.

Lack of cardioplegia uniformity in clinical myocardial preservation.

Advances in myocardial preservation have led to improved patient survival after open heart operations. However, few studies have detailed the nature of national or regional patterns of cardioplegia use. To determine the regional pattern, all open heart surgery programs in Missouri were surveyed. During 1 year, it was found that cardioplegia was administered to 8,382 patients by 61 cardiothoracic surgeons at ten academic affiliated hospitals and 16 nonteaching hospitals. All cardioplegic solutions were hospital produced. Of 13 crystalloid solutions, 11 differed from one another and eight were intracellular formulations. Of 28 multidose blood-based cardioplegic solutions, there were 23 different mixtures. Most crystalloid (69%) and blood-based (89%) solutions differed substantially from commonly reported formulations. The incidences of the various additives to crystalloid solutions were as follows: bicarbonate, 92%; glucose, 69%; lidocaine, 54%; mannitol, 46%; magnesium, 31%; calcium, 23%; methylprednisolone, 15%; heparin, 8%; and acetate, 8%. Of the common blood-based cardioplegic solution additives, the following incidences were observed: glucose, 79%; bicarbonate, 43%; trishydroxyaminomethane, 36%; acetate, 29%; magnesium, 29%; procaine (or lidocaine), 25%; citrate-phosphate-dextrose, 18%; mannitol/albumin, 14%; nitroglycerin, 11%; glutamate/aspartate, 11%; calcium, 7%; insulin, 3%; and methylprednisolone, 3%. No calcium channel blocker or high-energy phosphate additives were reported. We conclude that many different cardioplegic admixtures that have not been tested experimentally are used routinely in clinical practice, presumably with acceptable results. Because the salutary effects of induced cardiac arrest and hypothermia may mask suboptimal solutions, further study of customized cardioplegia should be considered, particularly with regard to high-risk patients.

Coronary revascularization in the elderly: determinants of operative mortality.

Over a 13-year period, 668 patients 70 years of age or older underwent isolated primary coronary artery bypass grafting at our institution. There were 472 men and 196 women, ranging from 70 to 90 years of age (median age, 74 years). Hospital mortality was 5.2% (35/668). In patients 70 to 79 years of age, hospital mortality was 4.2% (25/600), whereas in patients 80 years of age or older, mortality was 14.7% (10/68; p < 0.001). Twenty-seven clinical or hemodynamic variables hypothesized as predictors of operative mortality were examined. Mortality was higher in women than in men (9% versus 3.6%; p = 0.006). Those who died were a mean of 3 years older (77 versus 74 years old; p < 0.05) and were more likely to have unstable angina or Canadian class III or IV angina (p < 0.01). Patients requiring urgent operations, preoperative intraaortic balloon assist, intravenous nitroglycerin, or inotropic agents, and those with preoperative hypotension or cardiac arrest were most likely to die in the hospital (p < 0.001). Multivariate logistic regression analysis revealed advancing age, female sex, bypass time, urgency of operation, preoperative cardiac arrest, and unstable angina as primary determinants of mortality (p < 0.05). Although mortality after coronary artery bypass grafting increases with age, the greatest risk of death is in the acutely ill patient with few options for management other than surgical intervention.

Centrifugal pumps: description of devices and surgical techniques.

BACKGROUND: Because of simplicity of application, universal access, and low cost, centrifugal pumps are commonly used for short-term mechanical cardiac assist. Indications and techniques for application of this technology continue to evolve. METHODS: The clinical experience with 151 patients undergoing centrifugal mechanical cardiac assist at the University of Missouri-Columbia has been reviewed. We have compared commonly available centrifugal pumping systems in vitro and in vivo for characteristics that might distinguish them. RESULTS: Centrifugal pumps have been found to be well suited for use in surgery on the thoracic aorta, for extracorporeal membrane oxygenation and for postcardiotomy cardiac mechanical assist. Complications associated with centrifugal mechanical assist are predictable and common but potentially can be reduced by improved surgical techniques and anticoagulation strategies. In vitro and in vivo experimentation with available centrifugal pumps reveals nuances characteristic of each of the devices. CONCLUSIONS: All centrifugal pumps presently available are less destructive to blood cellular elements compared with roller pumps. With familiarity, all can function satisfactorily for short-term mechanical assist with no compelling evidence that favors any particular centrifugal pump system clinically available. Centrifugal pumps are ideally suited for left heart bypass during surgery on a thoracic aorta and for short-term application as may be required for postcardiotomy mechanical assist. Centrifugal pump technology should be part of the armamentarium of all cardiothoracic surgeons.

Incidence and predictors of supraventricular dysrhythmias after pulmonary resection.

BACKGROUND: Patients undergoing pulmonary resection were evaluated prospectively in an effort to determine the incidence of and predictors for the development of postoperative supraventricular dysrhythmias. Specifically, we wished to test the hypothesis that the incidence of postoperative supraventricular dysrhythmias is dependent on the magnitude of pulmonary resection. METHODS: One hundred sixteen patients undergoing pulmonary resection had continuous Holter monitoring preoperatively, the day of operation, and the second postoperative day, as well as continuous cardiac monitoring throughout hospitalization. Holter interpretation was blinded to extent of resection. RESULTS: Twenty-six patients underwent pneumonectomy, 7 bilobectomy, 47 lobectomy, and 36 wedge resection. Twenty-six patients (22.4%) had supraventricular dysrhythmias, all atrial fibrillation +/- flutter. The incidence of atrial fibrillation with pneumonectomy, bilobectomy, single lobectomy, and wedge resection was 46.1%, 14.3%, 17.0%, and 13.8%, respectively (p < 0.005 pneumonectomy versus others). Overall, 31% of patients having pneumonectomy required pharmacologic therapy for dysrhythmia compared with 16% of patients having lesser resections, (p = 0.03). The peak incidence of onset of atrial fibrillation occurred on postoperative days 2 and 3 and lasted for less than 1 to 7 days, average 2.5 days. The average age of patients with dysrhythmias (64 years) was greater than those without (58 years) (p = 0.039). Thirty pre- and postoperative variables tested were not found to be significant predictors for development of postoperative atrial fibrillation. CONCLUSIONS: Atrial fibrillation occurs commonly after pulmonary resections but is not predictable. Development of atrial fibrillation is not dependent on the magnitude of pulmonary resection but is associated with the procedure pneumonectomy for reasons not elucidated.

Multicenter VATS experience with mediastinal tumors.

BACKGROUND: The use of video-assisted thoracic surgery for diagnosis and treatment of mediastinal tumors in a multiinstitution patient population is not well understood. METHODS: We studied 48 cases from Cancer and Leukemia Group B thoracic surgeons. Of 21 men and 27 women, aged 41 +/- 16 years, 22 patients were asymptomatic. In the others, 92% of tumor-related symptoms improved or resolved after treatment. Five tumors involved the anterior compartment, 19 the middle, and 24 the posterior compartment. Diagnoses were typical for each compartment but also included uncommon problems such as superior vena cava hemangioma and a histoplasmosis cyst causing hoarseness. Of the lesions, a biopsy of 12 was done without excision and the rest were excised completely. Fifteen were cystic and 10 were malignant (8 biopsy only). Maximal dimensions were 5.2 +/- 3.3 cm. RESULTS: Operations were briefer for 24 posterior (93 +/- 41 min) than 5 anterior (195 +/- 46 min, p < 0.01) or 19 middle mediastinal tumors (170 +/- 78 min, p < 0.01). Although 96% had vital mediastinal relations, only six open conversions were performed because of bleeding (n = 3), large size, impaired exposure, or rib attachments, and no patient had morbidity beyond that expected for the thoracotomy. Postoperative stay was shorter for the nonconversion group (3.2 +/- 2.8 versus 5.5 +/- 2.1 days, p = 0.05), as was chest tube duration (1.7 +/- 1.4 days versus 3.2 +/- 1.9 days, p = 0.03). There were no postoperative deaths or major complications, but 7 patients had minor complications. During a mean of 20 months of surveillance (range, 1 to 52 months), one cyst recurred (asymptomatic) as did one sarcoma that was excised. CONCLUSIONS: Video-assisted thoracic surgery is a safe technique for benign mediastinal tumors, typically those in the middle and posterior mediastinum.

Use of centrifugal pumps for postcardiotomy ventricular failure: technique and anticoagulation.

BACKGROUND: Centrifugal pumps have been employed most commonly for postcardiotomy mechanical support after intraaortic balloon pumping has failed. Despite their effectiveness in some patients, morbidity remains high. METHODS: Our clinical experiences with centrifugal pumps were reviewed with particular attention to common morbidity such as bleeding, coagulopathy, and thromboembolism. Evolution of cannulation techniques and anticoagulation strategies were defined. Morbidity during early and more recent experience was compared. RESULTS: Deranged coagulation and excessive mediastinal bleeding were commonly observed in patients undergoing centrifugal mechanical assist for postcardiotomy cardiogenic shock. Evolved strategies to reduce blood loss included meticulous cannulation techniques, early use of blood components, and an aggressive policy of mediastinal reexploration. Thromboembolism occurred with centrifugal mechanical assist, was underestimated by clinical events, and dictated pursuit of improved anticoagulation strategies and device refinement. A clinically significant trend of decreasing morbidity from early to recent experience was observed. CONCLUSIONS: Increasing clinical experience with centrifugal mechanical assist appears to result in a clinically relevant decrease in morbidity.

Recent experience with major sternal wound complications.

During a recent 1-year period, 31 patients sustained a major sternal wound infection and sternal dehiscence developed in 6 patients. Multiple potential risk factors were tabulated in these patients and in a control group selected from 1,521 patients undergoing sternotomy during the same time period. The overall infection rate was 2.1%, and the mortality rate in the patients with sternal infection or dehiscence was 16.2%. Chronic obstructive pulmonary disease, prolonged intensive care unit stay, respiratory failure, connective tissue disease, and male sex were significantly higher in the group with sternal infection or dehiscence (p less than 0.05). Advanced age and low cardiac output episodes were more frequent in this group, but only approached statistical significance. Although several risk factors may have been interrelated, male sex and the presence of pulmonary disease were statistically independent predictors of sternal wound infection. Risk factors may be helpful in identifying high-risk patients for additional prophylactic measures.

Tracheostomy: a risk factor for mediastinitis after cardiac operation.

BACKGROUND: We studied whether tracheostomy after coronary artery bypass grafting (CABG) is associated with higher incidence of mediastinitis and mortality, and whether shorter intervals between median sternotomy and tracheotomy are associated with higher incidence of mediastinitis. METHODS: Patients (n = 6,057) undergoing CABG since March 1977 were reviewed. Patients requiring tracheostomy and those developing mediastinitis were identified. Mediastinitis diagnosis required positive culture of mediastinal tissue or fluid. RESULTS: After CABG, 88 patients had tracheostomy performed (1.45%). Seven patients receiving tracheostomy after developing mediastinitis were excluded. Of the remaining 81 patients, 7 developed mediastinitis (8.6%) compared with 44 of 5,969 (0.7%) who did not require tracheostomy (p < 0.001). Mortality in tracheostomy patients was 24.7% (20 of 81) compared with 5.2% in patients not requiring tracheostomy (316 of 5,969; p < 0.001). Patients not developing mediastinitis had tracheostomy placement an average of 25 days after CABG compared with 18.7 days for those developing mediastinitis (p = 0.141). CONCLUSIONS: Tracheostomy after CABG is associated with increased incidence of mediastinitis and mortality. In this review, the time interval between CABG and tracheostomy was not predictive of mediastinitis. A larger sample size would be required to be confident that there is no correlation.

Comparison of multiple-parameter prognostic systems in acute pancreatitis.

A database of laboratory and clinical values was collected from 200 patients with acute pancreatitis. This database was analyzed using several multiple-parameter indicator systems. All systems tested demonstrated a similar ability to predict accurately both mortality and severity in these patients. The predictive power was maintained whether the scores were grouped or presented individually. The superiority of one system over another could not be demonstrated. It is probable that systems could be devised that would be just as effective as those analyzed; on the other hand, a trend toward unification is very desirable.