Refractory post-transplant airway strictures: successful management with wire stents.

OBJECTIVE: Bronchial stenosis, malacia and dehiscence are major airway complications of lung transplantation. Our success in managing this problem evolved from the use of semi-rigid dilators, to balloon dilation and placement of a stent, which were initially silicone, thereafter wire balloon-expandable and finally wire self-expandable. METHODS: From May, 1994 until July 1997, we performed a total of 49 single and 58 bilateral lung transplants. Symptoms of shortness of breath, verified by a drop in the forced expiratory volume in one second (FEV1), led to bronchoscopic inspection of the airway in lung transplant patients. Eighteen patients (16%) suffered a severe form of airway complication (dehiscence or stenosis) in 24 of 151 airways at risk (15.9%). These anastomotic strictures were recalcitrant to conventional therapy. Intervention consisted of rigid bronchoscopy, dilation of the stricture and placement of a stent. Flexible bronchoscopy and fluoroscopy were used for precise placement of the stent. As the initial stent, the Hood silicone stent was placed five times in four patients and the Dumont studded stent five times in four patients. The Palmaz wire stent was used as the initial stent 10 times in seven patients and the Wallstent used eight times in seven patients. Four patients had multiple stents. Balloon inflation moulded the wire stent to the airway. RESULTS: There was no mortality resulting from the airway complication or any intervention. The most serious complication was a perforation of the airway using the semi-rigid dilator that necessitated immediate thoracotomy and re-anastomosis of the bronchus. Other complications necessitated repeat interventions due to restenosis or failure of the stents. The success of the stent placement was measured subjectively by the immediate ease of breathing enjoyed by each patient and objectively by the significant increase of the FEV1 from a pre-operative mean of 1.19 l (SD 0.64 l) to a post-operative mean of 2.06 l (SD 0.70 l) (P < 0001). The mean number of interventions according to the type of wire stent first used was significantly fewer with Wallstent insertion (1.28 (SD 0.48)) than in those patients in whom a Palmaz stent was inserted (5.22 (SD 2.38)) (P < 0008). CONCLUSION: The airway complication of stricture, broncho-malacia or dehiscence following lung transplantation can be managed effectively and easily with the use of balloon catheter dilation followed by precise placement of a self-expandable wire stent. The Wallstent is the superior stent for this application.

Monoamine- and histamine-synthesizing enzymes and neurotransmitters within neurons of adult human cardiac ganglia.

BACKGROUND: Cardiac ganglia were originally thought to contain only cholinergic neurons relaying parasympathetic information from preganglionic brain stem neurons to the heart. Accumulating evidence, however, suggests that cardiac ganglia contain a heterogeneous population of neurons that synthesize or respond to several different neurotransmitters and neuropeptides. Reports regarding monoamine and histamine synthesis and neurotransmission within cardiac ganglia, however, present conflicting information or are limited in number. Furthermore, very few studies have examined the neurochemistry of adult human cardiac ganglia. The purpose of this study was, therefore, to determine whether monoamine- and histamine-synthesizing enzymes and neurotransmitters exist within neurons of adult human cardiac ganglia. METHODS AND RESULTS: Human heart tissue containing cardiac ganglia was obtained during autopsies of patients without cardiovascular pathology. Avidin-biotin complex immunohistochemistry was used to demonstrate tyrosine hydroxylase, L-dopa decarboxylase, dopamine beta-hydroxylase, phenylethanolamine-N-methyltransferase, tryptophan hydroxylase, and histidine decarboxylase immunoreactivity within neurons of cardiac ganglia. Dopamine, norepinephrine, serotonin, and histamine immunoreactivity was also found in ganglionic neurons. Omission or preadsorption of primary antibodies from the antisera and subsequent incubation with cardiac ganglia abolished specific staining in all cases examined. CONCLUSIONS: Our results suggest that neurons within cardiac ganglia contain enzymes involved in the synthesis of monoamines and histamine and that they contain dopamine, norepinephrine, serotonin, and histamine immunoreactivity. Our findings suggest a putative role for monoamine and histamine neurotransmission within adult human cardiac ganglia. Additional, functional evidence will be necessary to evaluate what the physiological role of monoamines and histamine may be in neural control of the adult human heart.

To resuscitate or not ... in the operating room: the need for hospital policies for surgeons regarding DNR orders.

As more Americans have become aware of end-of-life planning, health care professionals are faced with more "Do Not Resuscitate" orders. A patient with a terminal condition who has signed such an order may enter the operating room for a surgical procedure; few hospitals have developed protocols to assist the medical staff. In most hospitals, it is unclear whether the medical staff should honor the "DNR" or follow the traditional resuscitation protocol of the operating room.

Topography of cardiac ganglia in the adult human heart.

Published descriptions of the topography of cardiac ganglia in the human heart are limited and present conflicting results. This study was carried out to determine the distribution of cardiac ganglia in adult human hearts and to address these conflicts. Hearts obtained from autopsies and heart transplant procedures were sectioned, stained, and examined. Results indicate that the largest populations of cardiac ganglia are near the sinoatrial and atrioventricular nodes. Smaller collections of ganglia exist on the superior left atrial surface, the interatrial septum, and the atrial appendage-atrial junctions. Ganglia also exist at the base of the great vessels and the base of the ventricles. The right atrial free wall, atrial appendages, trunk of the great vessels, and most of the ventricular myocardium are devoid of cardiac ganglia. These findings suggest modifications to surgical procedures involving incisions through regions concentrated with ganglia to minimize arrhythmias and related complications. Repairs of septal defects, valvular procedures, and congenital reconstructions, such as the Senning and Fontan operations, involve incisions through areas densely populated with cardiac ganglia. The current standard procedure for orthotopic heart transplantation severs cardiac ganglia and their projections to nodal and muscular tissue. One modification of the current heart transplantation procedure, involving bicaval anastomosis, preserves atrial anatomy and the cardiac ganglia. Preservation of cardiac ganglia within the donor heart may provide additional neuronal substrate for intracardiac processing and targets for regenerating nerve fibers to the donor heart.

Arterial impedance in patients during intraaortic balloon counterpulsation.

BACKGROUND: Symptomatic improvement of a patient's hemodynamic condition during intraaortic balloon counterpulsation (IABC) is considered to result largely from a reduction in afterload. Afterload can be accurately quantified by arterial input impedance measurements. Here we report the effect of IABC on arterial impedance in humans. METHODS: To characterize the effects of IABC on arterial input impedance, impedance measurements were obtained using aortic annulus Doppler flow and pressure from the aortic balloon catheter. Impedance spectra were compared between the cardiac cycles preceding and following the cycle with IABC in 25 patients. RESULTS: Intraaortic balloon counterpulsation increased stroke volume (23%; p = 0.001), reduced myocardial oxygen demand (11%; p = 0.02), and decreased the aortic pressure at the onset of systole (16%; p = 0.001). There was also a decrease in systemic vascular resistance (24%; p = 0.001), characteristic arterial impedance (21%; p = 0.002), and pulse wave reflection (20%; p = 0.006). Linear regression analysis showed that an increase in stroke volume was predicted only by the decrease in systemic vascular resistance (r = -0.81; p = 0.001). CONCLUSIONS: The reduction in systemic vascular resistance appeared to be the major mechanism by which IABC improved cardiac pumping efficiency. This effect may result from the passive distention of the peripheral vascular bed due to the propagation of the balloon-augmented diastolic pressure through the arterial system.

Effect of HeartMate left ventricular assist device on cardiac autonomic nervous activity.

BACKGROUND: Clinical performance of a left ventricular assist device is assessed via hemodynamic parameters and end-organ function. This study examined effect of a left ventricular assist device on human neurophysiology. METHODS: This study evaluated the time course change of cardiac autonomic activity of 3 patients during support with a left ventricular assist device before cardiac transplantation. Cardiac autonomic activity was determined by power spectral analysis of short-term heart rate variability. The heart rate variability before cardiac transplantation was compared with that on the day before left ventricular assist device implantation. RESULTS: The standard deviation of the mean of the R-R intervals of the electrocardiogram, an index of vagal activity, increased to 27 +/- 7 ms from 8 +/- 0.6 ms. The modulus of power spectral components increased. Low frequency (sympathetic activity) and high frequency power (vagal activity) increased by a mean of 9 and 22 times of each baseline value (low frequency power, 5.2 +/- 3.0 ms2; high frequency power, 2.1 +/- 0.7 ms2). The low over high frequency power ratio decreased substantially, indicating an improvement of cardiac sympatho-vagal balance. CONCLUSIONS: The study results suggest that left ventricular assist device support before cardiac transplantation may exert a favorable effect on cardiac autonomic control in patients with severe heart failure.

Concurrent cisplatin/etoposide plus chest radiotherapy followed by surgery for stages IIIA (N2) and IIIB non-small-cell lung cancer: mature results of Southwest Oncology Group phase II study 8805.

PURPOSE: To assess the feasibility of concurrent chemotherapy and irradiation (chemoRT) followed by surgery in locally advanced non-small-cell lung cancer (NSCLC) in a cooperative group setting, and to estimate response, resection rates, relapse patterns, and survival for stage subsets IIIA(N2) versus IIIB. PATIENTS AND METHODS: Biopsy proof of either positive N2 nodes (IIIAN2) or of N3 nodes or T4 primary lesions (IIIB) was required. Induction was two cycles of cisplatin and etoposide plus concurrent chest RT to 45 Gy. Resection was attempted if response or stable disease occurred. A chemoRT boost was given if either unresectable disease or positive margins or nodes was found. RESULTS: The median follow-up time for 126 eligible patients [75 stage IIIA(N2) and 51 IIIB] was 2.4 years. The objective response rate to induction was 59%, and 29% were stable. Resectability was 85% for the IIIA(N2) group eligible for surgery and 80% for the IIIB group. Reversible grade 4 toxicity occurred in 13% of patients. There were 13 treatment-related deaths (10%) and 19 others (15%) died of causes not related to toxicity or tumor. Of 65 relapses, 11% were only locoregional and 61% were only distant. There were 26 brain relapses, of which 19 were the sole site or cause of death. There was no survival difference (P = .81) between stage IIIA(N2) versus stage IIIB (median survivals, 13 and 17 months; 2-year survival rates, 37% and 39%; 3-year survival rates, 27% and 24%). The strongest predictor of long-term survival after thoracotomy was absence of tumor in the mediastinal nodes at surgery (median survivals, 30 v 10 months; 3-year survival rates, 44% v 18%; P = .0005). CONCLUSION: This trimodality approach was feasible in this Southwest Oncology Group (SWOG) study, with an encouraging 26% 3-year survival rate. An Intergroup study is currently being conducted to determine whether surgery adds more to the risk or to the benefit of chemoRT.

Successful use of the total artificial heart as a bridge to transplantation with no mediastinitis.

UNLABELLED: High rates of infection, especially mediastinitis, have been reported with the use of the total artificial heart (TAH), thereby limiting its usefulness. We have used the TAH as a bridge to transplantation with only minor infectious complications and a zero incidence of mediastinitis. Between February 1988 and August 1990, the TAH was inserted at Loyola University Medical Center in 19 patients, ages 16 to 64 years (mean, 44 years). Seventeen patients (89%) underwent transplantation within 1 to 34 days (mean, 9.8 days). Of the patients who did not undergo transplantation, one was brain dead and the other died of bleeding diathesis. Early (30-day) deaths occurred in two patients (11.7%): acute rejection at 18 days and multiple cerebral infarcts at 14 days. Three late deaths (17.6%) occurred: one patient, cytomegalovirus and pneumocystis pneumonia at 4 months; one patient, bronchopneumonia and multisystem failure at 9 months; and one patient, chronic rejection at 14 months. Minor infectious complications during the TAH implantation included Enterobacter pneumonia treated with antibiotics and positive sputum cultures (Escherichia coli; Candida), with no clinical evidence of infection in two patients. No cases of mediastinitis occurred either while the TAH was implanted or after transplantation. All patients were on antibiotics while the device was in place. CONCLUSION: Our experience with the TAH shows this to be an excellent device for successful bridging of patients for heart transplantation. We have had minimal infectious complications and none directly attributed to the use of this device. This device should continue to be used safely as a bridge to transplantation.

Primary lymphoma of the heart. Prolonged survival with early systemic therapy in a patient.

Primary lymphoma of the heart is an uncommon malignancy usually recognized at autopsy or fatal within a few weeks of diagnosis. Recently, it was reported in patients with acquired immune deficiency syndrome. A patient with diffuse large cell lymphoma of the heart is reported who had chest pain and rapidly evolving cardiac arrhythmias. The human immune deficiency virus antibody test was negative. Because of an aggressive diagnostic approach, therapy with cyclophosphamide, doxorubicin, vincristine, and prednisone was started on the third day after diagnosis. The patient has survived 18 months with an objective response. To the authors' knowledge, this is the longest reported survival in primary cardiac lymphoma. The diagnosis in this patient was aided by excellent tumor delineation by nuclear magnetic resonance scanning. The authors believe that better survival in this patient was a result of prompt diagnosis and treatment because the behavior of the lymphoma was similar to aggressive lymphomas arising elsewhere.

Central venous pulsations associated with a falsely low oxygen saturation measured by pulse oximetry.

Venous pulsations are thought, but to our knowledge have never been demonstrated, to result in underestimation of oxygen saturation measured by pulse oximetry (SpO2); however, to our knowledge, this has never been demonstrated. A patient with ischemic cardiomyopathy requiring intra-aortic balloon counterpulsation (IABC) had to withstand a temporary cessation of IABC (period I), during which she had marked central venous pulsations and a pulse oximeter bias of -18%. After IABC was reinstituted (period II), the venous pulsations disappeared and the bias was reduced to 0%. Cardiac output, systemic vascular resistance, and temperature during both periods were comparable. Pulmonary vascular resistance, however, was much lower during period II. We postulate that the bias was caused by venous pulsations significantly contributing to the AC, or variable component, of light absorption.