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Sensory Neuropeptides and Bronchial Hyperresponsiveness
Published in Sami I. Said, Proinflammatory and Antiinflammatory Peptides, 2020
D. Spina, C. P. Page, J. Morley
A loss of vagal afferent innervation and vagal efferent reinnervation with retention of cholinergic and VIP-containing nerves is characteristic of lung obtained from patients with heart-lung transplants in whom retransplantation has been required (135,136). In 8 of 15 patients who received heart-lung transplants, capsaicin induced a bronchodilator response that might be attributable to the activation of nonadrenergic, noncholinergic inhibitory nerves (128). In guinea pig airway, capsaicin-induced relaxation is dependent on the presence of an intact capsaicin-sensitive afferent innervation to the esophagus which leads to the activation of nonadrenergic, noncholinergic inhibitory nerves (64). No compatible process can be operative in heart-lung transplant patients. It should be noted that there is a possibility that capsaicin may have induced relaxation directly, and independently of sensory nerves. In this context, it may be noted that capsaicin did elicit inhibitory responses in human isolated bronchi that was not subject to tachyphylaxis, indicating a lack of involvement of sensory nerves in this response, and/or to the release of mediators from sensory nerves without inducing desensitization (82).
Respiratory Medicine
Published in Stephan Strobel, Lewis Spitz, Stephen D. Marks, Great Ormond Street Handbook of Paediatrics, 2019
Colin Wallis, Helen Spencer, Sam Sonnappa
Lung transplantation is a treatment option for those with end-stage parenchymal or vascular lung disease. Bilateral sequential lung transplantation is now the commonest procedure undertaken. Heart–lung transplants are becoming increasingly rare, not only because of the shortage of donors available but also because of increased recognition that right heart recovery is possible in patients with severe idiopathic pulmonary arterial hypertension. Heart–lung transplant is required if there is significant left ventricular dysfunction or an uncorrectable heart defect with pulmonary hypertension. Single lung transplantation is usually only considered in adult patients with non-suppurative lung disease. Living lobar donation (receiving two lower lobes from two living donors) is considered in a few centres in the world.
Therapeutics in pulmonary hypertension
Published in Anthony J. Hickey, Heidi M. Mansour, Inhalation Aerosols, 2019
Maria F. Acosta, Don Hayes, Jeffrey R. Fineman, Jason X.-J. Yuan, Stephen M. Black, Heidi M. Mansour
Lung transplantation: Transplantation must be considered when the therapies previously mentioned fail for the improvement of PH. Lung or heart-lung transplant is the best option for patients who are not responding to standard therapies and who are experiencing a poor or declining quality of life. It can elongate survival, improve quality of life, and offer a potential cure for patients with PH. As with all transplant surgeries, however, they carry several risks and significant complications. Hence many factors have to be contemplated before moving forward with the transplantation (1).
Individualized management of cytomegalovirus in solid organ transplant recipients
Published in Expert Review of Precision Medicine and Drug Development, 2021
Huma Saeed, Matthew Thoendel, Raymund R Razonable
The two major strategies for CMV prevention after solid organ transplantation are antiviral prophylaxis and preemptive therapy. The choice of which of the two strategies is most appropriate in a specific patient (or groups of patients) depends on the risk factors as we have described above. For example, antiviral prophylaxis is preferred in highest risk organ transplant groups such as lung and heart-lung transplant recipients, while preemptive therapy is a reasonable option for CMV-seropositive heart, liver, kidney transplant recipients. Studies comparing universal prophylaxis and preemptive therapy included mostly small comparative trials, and reported 65% reduction in CMV infection with antiviral prophylaxis and improved graft survival [62]. Hence, international consensus guidelines recommend prophylaxis in high-risk (D+/R-) recipients due to improved patient and graft survival [63]. More recently, a randomized controlled clinical trial that compared antiviral prophylaxis and preemptive therapy in CMV D+/R- liver transplant recipients indicated lower risk of CMV disease in patients who were managed with weekly CMV viral load surveillance and preemptive therapy, when compared to antiviral prophylaxis [64]. The significant difference could be explained by the higher proportion of CMV specific immunity that developed in patients managed with preemptive antiviral therapy [64]. It is suggested that allowing low-level replication could prime the development or reconstitution of CMV-specific immunity, thereby leading to lower rates of late-onset CMV disease in patients managed with preemptive therapy. Indeed, as we learn more about other risk factors, including the development of immunity, and how these factors impact clinical practice, it is reasonable to reconsider and further stratify the implementation of antiviral prophylaxis and preemptive therapy.
A Baylor milestone: Combined heart/lung-heart “domino” transplant
Published in Baylor University Medical Center Proceedings, 2018
Tom Lee lived with his wife in Garland, a suburb of Dallas, and in spite of the dyspnea that forced him to use oxygen around the clock, he worked as a manager in a printing house. He had been diagnosed with the rare absence of an enzyme that was insidiously but steadily destroying his lungs and would lead to his death. Up to the 1980s there was no cure for the pulmonary emphysema he was suffering from, or for many other lung diseases. This changed with the first combined heart/lung transplant at Stanford in 1961.1 The experimental work for this procedure started 10 years earlier (1961) by the same pioneers, Richard Lower and Norman Shumway, who developed the technique for heart transplantation.2,3 Survival in primates after heart-lung transplantation was reported by Stanford in the early 1980s.4 In the years that followed, large centers, including Harefield Hospital in the United Kingdom under the leadership of the brilliant British surgeon Magdi Yacoub,5 offered this difficult operation with good short-term results. At first the operation was destined for patients with simultaneous cardiac and pulmonary disease. It was soon extended, however, to those who only had lung disease but whose heart was healthy. So they received two lungs to replace their own and a heart that they did not need. It was the only operation available at that time. Of course, Joel Cooper at the University of Toronto had already started transplanting just one lung, but this procedure was still in its infancy. Clearly, the correct operation for patients with lung disease was the replacement of the lungs only, without the unnecessary removal of the heart. It was good, then, for the standards of the day, that in December 1988, after assessment by pulmonologists and cardiologists, Tom was placed on the waiting list for the combined transplantation of two lungs and a heart. The difficulty of finding a suitable donor was increased by the fact that he belonged to the less common blood group B.
A challenging ECG in a heterotopic heart transplant: double the trouble
Published in Acta Cardiologica, 2020
Christophe Vandenbriele, Richard Fisher, Susanna Price
Nowadays, most cardiologists are familiar with orthotopic heart transplantation (OHT) for end-stage heart failure. Nevertheless, in the pre anti-rejection-therapy era (early seventies of the previous century), surgeons rather connected the transplant organ to the native heart, a technique called heterotopic heart transplantation (HHT). By not explanting the native heart, a kind of parallel biventricular support system to the native circulation was designed, causing less harm upon (acute) graft-rejection, which was very common at that time. We present a 29-year-old man with a previous HHT at the age of four for idiopathic dilated cardiomyopathy. He presented with new onset of continuous palpitations. At first sight, the underlying rhythm on the ECG at presentation (Figure 1) seems confusing but when studied more in detail, two different QRS-morphologies and two different rhythms (one right bundle-branch block in sinus rhythm and one atypical bundle-branch block in atrial fibrillation (AFib)) can clearly be distinguished. Echocardiography confirmed the native heart to be in AFib (mitral valve inflow pattern), although both native and donor hearts showed sinus rhythm on previous traces (Figure 2). This ECG illustrates a tachyarrhythmia of the native heart, known to be an important disadvantage of HHT. HHT is, at present, a far less useful technique compared to orthotopic heart transplantation because of the improvements in immunosuppressive therapy, the development of efficient long-term mechanical circulatory support and HHT's potential disadvantages such as increased rates of thromboembolic events and rhythm disorders [1]. Although HHT is still very rarely performed, it is still common in selected cases, such as patients with fixed pulmonary hypertension to avoid heart-lung transplant (the additional pump function of the donor right ventricle to the failing native right ventricle has shown to be beneficial in overcoming pre-existing (fixed) pulmonary hypertension) or in patients with major donor-recipient bodysize mismatch as was the case in our patient [1,2]. Therefore, comparable ECG-traces are nowadays rarely seen and unknown to most cardiologists.