Surgical therapies for pulmonary arterial hypertension

Surgical therapies for the treatment of pulmonary arterial hypertension typically are reserved for patients who are deemed to be refractory to medical therapy and have evidence of progressive right-sided heart failure. Atrial septostomy, a primarily palliative procedure, may stave off hemodynamic collapse from right-sided heart failure long enough to permit a more definitive surgical treatment such as lung or combined heart-lung transplantation. This article discusses indications for and results of atrial septostomy and lung and heart-lung transplantation in patients who have pulmonary arterial hypertension.

[Lung and heart-lung transplantation for Eisenmenger syndrome: report of 5 cases]

OBJECTIVE

To discuss the operative indications and peri-operational management of single lung transplantation (SLT) and heart-lung transplantation (HLT) for patients suffering from Eisenmenger's syndrome (ES).

METHODS

From September.2002 to March.2006, four ES patients, 1 males and 3 females, aged 16 approximately 19, 2 with atrial septal defect and 2 with ventricular septal defect, underwent single right lung transplantation, and one patients, male, aged 43, who suffered heart failure secondary to an interventional occlusion for atrial septal defect underwent cardiac repair and HLT.

RESULTS

Two patients, including the patient who received HLT and one, female, aged 15, who received SHT died of he died primary graft dysfunction on the 23rd day and 20th day post-operationally respectively. While the other 3 recipients kept a normal life for 5, 8, and 22 months respectively after operation with apparently decreased pulmonary artery pressure and improved cardiac-pulmonary functions.

CONCLUSION

Lung transplantation companies with cardiac repair is effective in the therapy of ES. Donor-recipient matching in size, proper removal and protection of the donor lung, and appropriate postoperational management are the key procedures for those patients to survive.

Assessment and treatment of pulmonary arterial hypertension: an Australian perspective in 2006

Pulmonary arterial hypertension is a group of diseases which forms a small subset of those with elevated pulmonary artery pressure (pulmonary hypertension). The recent development of selective pulmonary vasodilator has lead to a substantial resurgence of interest in what have been previously regarded as rare and incurable diseases. This review aims to describe the spectrum of pulmonary vascular diseases, the evolving understanding as to pathogenesis, the evolving evidence of efficacy for drug therapies, trying to put this into a contemporary Australian context. Several key pathogenic pathways may be involved: prostacycline, Nitric Oxide-cGMP-phosphodiesterase 5 and endothelin- all of which are exploited for therapeutic benefit by newly available drug therapies. A recently modified classification system reasserts the importance of precise diagnosis. The cardinal symptom of exertional dyspnea warrants careful evaluation in an attempt to prevent (frequently occurring) substantial delay in diagnosis. Echocardiogram is the cornerstone of screening for pulmonary arterial hypertension; however, a detailed evaluation including a carefully performed right heart catheterisation with sufficient data to allow calculation of pulmonary vascular resistance is key to accurate diagnosis. These new approaches to therapy are already substantially improving quality of life and prognosis.

[Lung transplantation]

Lung transplantation is now an effective therapy for patients of less than 60 years-old with chronic end-stage lung diseases which life expectancy is less than 12 to18 months in spite of maximal medical therapy. The various surgical procedures (single or bilateral lung or heart-lung transplantation) offer an adapted solution to all the candidates whatever the cause of the respiratory disease. The early postoperative mortality is less than 10% and the survival rates regularly improve and reach 65 to 7% at 3 years and more than 50% at 5 years for experienced programmes. Primary graft dysfunction, infections and airways complications are the main causes of early morbidity. Bronchiolitis obliterans is the main limiting factor of the long-term survival. Malignancies and drug toxicity, such as renal or vascular complications, occur also at that time.

Pulmonary arterial hypertension and women

Pulmonary arterial hypertension (PAH) is a progressive disorder with a poor prognosis. It is characterized by sustained elevation of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR). It is defined hemodynamically by a mean PAP over 25 mm Hg, a pulmonary arterial wedge pressure of 15 mm Hg or less (which excludes left sided lesions), and a PVR of 3 or more Wood units (240 dyn.sec.cm-5). Patients are limited by exertional dyspnea, pre- or true syncope, chest pain, and edema/ascites when right heart failure supervenes. PAH afflicts predominantly young women and the diagnosis is often delayed. Three processes contribute to progressive arterial narrowing: vasoconstriction, vascular remodeling, and thrombosis in situ. The diagnosis of PAH must be confirmed and its etiology must be identified before appropriate therapy can be instituted. Right heart catheterization is necessary to establish the diagnosis, severity, and prognosis of PAH and to ascertain its etiology and to evaluate vasoreactivity, which guides therapy. Treatment of PAH includes vasodilators, supplemental O2, anticoagulation, diuretics, digoxin, intravenous inotropic therapy for decompensated right ventricular failure, and lung or combined heart-lung transplantation for those patients who continue to deteriorate with a poor quality of life despite pharmacologic therapy. Calcium channel blockers are beneficial in a small minority of patients. Prospective, controlled, randomized trials of approved vasodilator agents have enrolled a large proportion of women (70-85%). Agents such as the endothelin-1 receptor antagonist bosentan, the phosphodiesterase-5 inhibitor sildenafil, and the prostanoids have been shown to improve symptoms, exercise capacity, and, in most instances, delay clinical worsening. The clinical outcomes of patients with PAH have improved with the judicious use of contemporary therapies.

Ocular complications in heart, lung and heart-lung recipients

AIM

To prospectively assess ocular morbidity and the need for ocular screening in patients on long term, high dose immunosuppression for the maintenance of solid organ transplants.

METHODS

Dilated ocular examinations were performed on patients receiving immunosuppression for the maintenance of heart, lung and heart-lung transplants. Patients were examined repeatedly in the post transplant period.

RESULTS

Of the 115 transplant recipients examined 62 (54%) had ocular findings. The most common findings were cataracts (17% of those examined) followed by hypertensive change (8%), chorioretinal scarring (5%) and diabetic retinopathy (3%). One patient developed ocular infective complications following surgery due to Aspergillus spp. endophthalmitis. 18 patients (16%) were symptomatic at examination with the most common symptom being blurred vision. The most common finding in symptomatic patients was cataract with almost a quarter of patients having posterior subcapsular lens opacity that could be attributed to steroid therapy.

CONCLUSION

Patients had surprising low incidences of ocular infective complications despite previous reports. It is likely that this is due to improved immunosuppression regimes and improved monitoring of immunosuppression in the early post-transplant period. The screening of asymptomatic individuals following heart, lung or heart-lung transplantation was not supported by this study.

Beneficial Effects of Supplemental Nitric Oxide Donor Given during Reperfusion Period in Reperfusion-Induced Lung Injury

BACKGROUND

Reperfusion injury is a perplexing cause of early graft failure after lung transplantation and today we know that reperfusion may be more harmful to tissues than the preceding ischemia. We hypothesized that administration of the nitric oxide donor nitroglycerin (NTG) during flush perfusion and reperfusion periods would ameliorate reperfusion-induced lung injury.

METHODS

Using an IN SITU normothermic ischemic lung rabbit model, three groups were studied (n = 7/group): (1) NTG given during flush perfusion (ischemia group); (2) NTG given in the flush perfusion and the reperfusion period (reperfusion group); and (3) no NTG (control group). All groups were flushed with low potassium dextran glucose solution. Blood gas analysis, tissue nitrite (nitric oxide metabolite) level analysis, bronchoalveolar lavage (BAL) fluid examination and morphological examinations were performed.

RESULTS

Compared with the ischemia group, the reperfusion group had significantly improved arterial oxygenation (318 +/- 31.4 mmHg vs. 180 +/- 14.7 mmHg, P < 0.05), decreased BAL fluid neutrophil percentage (21 +/- 1.9 % vs. 30 +/- 5.6 %, P < 0.05), increased tissue nitrite level (32.55 +/- 4.12 nmol/g vs. 27.81 +/- 1.05 nmol/g, P < 0.05), and decreased tissue histopathological lesion scores (0.42 +/- 0.53 vs. 1.14 +/- 0.37, P < 0.05).

CONCLUSIONS

This study suggests that nitric oxide donors supplemented during flush perfusion and reperfusion have more beneficial effects on lung functions against reperfusion injury than any other treatment modalities during IN SITU normothermic ischemic lung model.

Predictors of chronic kidney disease in long-term survivors of lung and heart-lung transplantation

Renal insufficiency is common after non-renal organ transplants. The predictors of long-term renal outcomes are not well established. A total of 219 lung and heart-lung transplant recipients surviving more than 6 months after transplantation were studied to determine predictors of time to doubling of serum creatinine and end-stage kidney disease (ESKD) with death as a competing risk. Median follow-up was 79 months (range 9-222 months). Baseline estimated glomerular filtration rate (GFR) was 96.3+/-34.5 mL/min/1.73 m2. One hundred twenty-two recipients (55%) doubled their serum creatinine, 16 (7.3%) progressed to ESKD and 143 (65%) died. The majority of recipients who survived >6 years had a GFR<60 mL/min at both 1 and 7 years. Most of the loss of renal function occurred in the first year post-transplant. Older age at transplant, lower GFR at 1 month and cyclosporine use in the first 6 months predicted shorter time to doubling of serum creatinine when death was handled as a competing risk. Based on this prevalence data and using GFR decay and death as study endpoints, we offer sample size estimates for a prospective, interventional trial that is aimed at slowing or preventing the progression of kidney disease.

Heart and lung transplantation in children

During the past two decades, several advances have resulted in marked improvement in medium-term survival for infants and children undergoing heart transplantation. Unfortunately, progress has been less dramatic in the field of lung and heart-lung transplantation, where there is little evidence of improved outcomes. The procedures remain palliative and all transplant recipients are at risk for the adverse effects of non-specific immunosuppression, including infections, lymphoproliferative disorders, and non-lymphoid malignancies. In addition, current immunosuppressive agents have narrow therapeutic windows and exhibit a wide array of organ toxicities, posing special challenges for the young patient who must endure life-long immunosuppression. New immunosuppressive regimens have lowered the rates of acute rejection but appear to have had relatively little impact on the incidence of chronic rejection, the principal cause of late graft loss. The ultimate goal is to induce a state of donor-specific tolerance, wherein the recipient will accept the allograft indefinitely without the need for long-term immunosuppression. This quest is currently being realised in animal models of solid organ transplantation, and offers great hope for children undergoing heart and lung transplantation in the future.

Transplantation as a treatment for end-stage pulmonary hypertension in childhood

Despite advances in drug therapy, severe sustained pulmonary arterial hypertension can be a fatal disease. When medical therapy is exhausted, transplantation may be an option. The most common approaches are heart-lung transplantation or double-lung transplantation, with repair of the cardiac defect if necessary. Single-lung transplantation optimises the use of scarce donors but leads to particular management problems. Heterotopic cardiac transplantation has occasionally been employed in subjects with pulmonary vascular disease secondary to cardiac disease. Timing of transplantation is a difficult decision and depends largely on the aetiology of pulmonary arterial hypertension and the rate of decline. Outcomes following transplantation are steadily improving but remain poorer than for other solid organ transplants, mainly because of the high incidence of post-transplant bronchiolitis obliterans syndrome.

Management of infants and young children with combined heart and kidney failure

Most infants and children referred for cardiac transplantation have low cardiac output with concurrent renal hypoperfusion leading to renal insufficiency and failure. This article is a review of the literature of and a single center's experience with combined heart and kidney failure in infants and children less than 10 yr of age. While 39 infants less than 10 yr of age were dialyzed pre- or peri-operatively, none required dialysis support at the time of discharge or in 5-10 yr follow-up. Based on our experience we recommend heart transplant alone in infants and young children with primary heart disease even though they have renal dysfunction.

Update for nurse anesthetists. Eisenmenger syndrome: an anesthetic conundrum

Eisenmenger syndrome is an insidious disease entity. This disease is characterized by an unrepaired congenital heart defect and left-to-right cardiac shunting. After many years of increased blood flow through the pulmonary system as a result of the shunting, damage to the pulmonary vessels occurs, culminating in severe pulmonary hypertension. The pulmonary hypertension eventually causes the cardiac shunt to reverse direction. The right-to-left shunt results in a very debilitated patient. There is no known medical cure for this disease; the only curative option is heart-lung transplantation or bilateral lung transplantation with repair of the patent heart defect. Because of the great strides in medical care, more patients with Eisenmenger syndrome require anesthesia. Maintaining the patient's systemic vascular resistance at the preoperative level is of paramount importance. Choosing the best anesthesia technique is difficult, at best.

Advanced therapy may delay the need for transplantation in patients with the Eisenmenger syndrome

AIMS

Advanced therapies (prostacyclin analogues, endothelin receptor antagonists) are successfully used in the treatment of idiopathic pulmonary arterial hypertension. In addition, patients with the Eisenmenger syndrome (ES) seem to benefit from these news drugs regarding symptoms, but there is still no evidence for changes in outcome.

METHODS AND RESULTS

The clinical course of 43 patients (M/F 13/30, age 34.0 +/- 12.7 years), registered with unstable ES in our database, was retrospectively analysed. These patients were divided into two groups: those treated with and those treated without advanced therapy. The primary endpoint was defined as death from any cause. Death or inscription on the active waiting list of heart-lung transplantation was considered as secondary endpoint. Kaplan-Meier survival and log rank testing were performed to determine differences in outcome between the two groups. The total cohort was followed for a median period of 4.9 (range 0.2-14.9) years. Mean survival time for patients treated with (n = 26) and without (n = 17) advanced therapy therapies were 8.5 +/- 1.5 and 8.5 +/- 0.9 years, respectively (log rank testing, P = 0.31). However, the mean time to death or inscription on the active waiting list was significantly longer for patients treated with advanced therapy when compared with those without (7.8 +/- 1.0 vs. 3.4 +/- 0.9 years, P = 0.006).

CONCLUSION

For the given follow-up period, no improvement in survival time could be documented in adult patients with unstable ES treated with advanced therapy. However, we might suggest with these data that the need for heart-lung transplantation can be substantially delayed with new drugs.

Comparison of induced sputum and bronchoalveolar lavage in lung transplant recipients

BACKGROUND

Chronic lung rejection is characterized by obliterative bronchiolitis (OB) diagnosed based on spirometric criteria reflecting an already advanced process. Biologic markers such as bronchoalveolar lavage (BAL) neutrophilia or increased levels of chemokines (interleukin-8, RANTES [regulated on activation: normal T cell expressed and secreted]) have been proposed as early diagnosis tools. However, BAL is too invasive to be used as a routine strategy. Induced sputum (IS), however, is a non-invasive method of recovering bronchial cells.

METHODS

The aim of this study was to compare BAL and IS differential cellular counts as well as IL-8 and RANTES levels between patients with bronchiolitis obliterans syndrome (BOS), recipients with good outcome and well-preserved lung function (non-BOS) and non-transplanted controls. We compared 34 BAL and IS findings obtained consecutively from 34 lung transplant recipients (LTRs), including 22 non-BOS and 12 BOS patients.

RESULTS

IS results were compared with 19 samples from non-transplanted controls. IS was well tolerated. There was no correlation between BAL and sputum cell populations. BAL neutrophils and IL-8 levels were increased in BOS, and these parameters were positively correlated. Moreover, BAL neutrophils and IL-8 levels were both negatively correlated with respiratory function. Sputum evaluation allows discrimination of BOS from non-BOS by the presence of higher neutrophil and eosinophil counts. Moreover, IS neutrophils and eosinophils were both correlated with lung function parameters. In contrast to BAL, IL-8 level in sputum was not a useful predictive marker of BOS development. IS RANTES levels were higher in BOS than in healthy recipients and correlated significantly with IS eosinophils.

CONCLUSIONS

IS and BAL provide different but complementary data. In this study, IS appeared to be a useful, non-invasive tool for LTR monitoring. Furthermore, IS provides new insights into BOS pathogenesis, especially with regard to implication of eosinophils and its chemokine, RANTES, at the bronchial level.

Pulmonary tuberculosis in lung and heart-lung transplantation: fifteen years of experience in a single center in Spain

The increase in the number of solid organ transplants has resulted in an increased incidence of opportunistic infections, including infection by typical and atypical mycobacteria, with risk of developing tuberculosis. Pretransplant chemoprophylaxis with isoniazid has become increasingly common in an attempt to prevent the disease. The source of infection in tuberculosis (TB) may be difficult to identify. Infection may be caused by reactivation of a primary infection in the recipient, reactivation of a lesion from the donor lung, or primary infection. There are few reports on TB in lung transplantation. Incidence in the reported series ranges from 6.5% to 10%. Our series of 7 patients out of a total 271 patients (2.58%) represents a rate higher than reported for the general Spanish population, 26.7/10(5) inhabitants and for lung transplant candidates (0.18%). Our aim was to evaluate the incidence, clinical signs, and outcome of TB in our series of patients undergoing lung transplantation in the 15 years since inception of the program (February 1990 to December 2004). Morbidity and mortality was high (42.8%), but limited to patients in whom treatment was not administered or could not be successfully completed. However, early detection and treatment are essential.

Conversion to Sirolimus and Mycophenolate Can Attenuate the Progression of Bronchiolitis Obliterans Syndrome and Improves Renal Function after Lung Transplantation

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is the major problem after lung and heart-lung transplantation (LTx/HLTx). Sirolimus (Sir) and Mycophenolate (MMF) showed a promising efficacy in the treatment of BOS in animal models. The first clinical experience in converting LTx/HLTx-recipients with BOS from calcineurin inhibitor-(CNI)-based immunosuppression to a Sir-MMF based immunosuppression is reported herein.

METHODS

Six LTx- and five HLTx-recipients (eight men; 0.9 to 8 years after transplantation) with CNI-based immunosuppression (plus MMF) in whom BOS was diagnosed were included in the study. Mean patient age was 37+/-13 years (range 17-62 years). Sir was started with 6 mg and continued adjusted to according target trough levels (8-14 ng/ml). Subsequently, the CNIs were tapered down and finally stopped. Follow up included self determined pulmonary function tests, microbiological screening, chest radiographs, and laboratory studies

RESULTS

Two acute rejection episodes occurred during the study period. The incidence of infection was 2.2+/-1.3 infections/patient-year after conversion. Mean FEV1 decreased after a mean follow up of 14.8+/-1.4 months: from 2.1+/-0.7 l prior conversion to 1.3+/-0.6l after conversion (P=0.03). However, graft function remained stable in three patients and progression of BOS slowed down in three patients. Overall, 2 of 10 patients died due to ongoing BOS while awaiting retransplantation

CONCLUSIONS

After BOS was diagnosed, conversion to MMF and Sir stabilized graft function only in some of the converted patients. Therefore, earlier administration of Sir-based immunosuppression might be a more promising approach. Whether conversion to CNI-free immunosuppression can actually ameliorate the extent or progression of BOS has to be investigated in randomized trials.

Severe gastroparesis causing splenic rupture: a unique, early complication after heart-lung transplantation

Several weeks or even months after heart-lung transplantation, gastroparesis-or delayed gastric emptying-commonly presents with cough, early satiety, and bloating. As it progresses, gastroparesis can cause substantial malnutrition and impair drug absorption. Gastroparesis after heart-lung transplantation can be attributed to bilateral vagus nerve injury, which probably occurs just above the level of the carina, where the recipient's trachea is resected. We report a highly unusual case wherein gastroparesis presented early after heart-lung transplantation and was managed conservatively. However, 19 days postoperatively, the patient developed acute abdominal pain and hypotension. Laparotomy revealed a massively dilated stomach and total avulsion of the splenic capsule with hemorrhage. The patient was fed via jejunostomy tubes until the gastroparesis resolved spontaneously. This case illustrates an important sequela of heart-lung transplantation. In order to decrease the morbidity from gastroparesis in these fragile patients, a drainage procedure should be considered as an adjunct to heart-lung transplantation.

[Lung transplant]

A lung transplant is usually the final therapeutic option for patients with respiratory insufficiency. In spite of the many advances in immunology and the management of complications, mortality and morbidity associated with this transplant are far higher than with others. Acute rejection is an almost universal problem in the first year, while obliterative bronchitis reduces long term survival. Respiratory infections also play a significant role in the complications associated with lung transplants due to the constant exposure of the graft to the outside. However, the success of this therapeutic option, which basically depends on a suitable selection of donor and recipient, are evident, above all with respect to quality of life.

Acupuncture for Persistent Hiccups in a Heart and Lung Transplant Recipient

Hiccup is an intermittent, abrupt, involuntary contraction of the diaphragm resulting in sudden inspiration abruptly opposed by the closure of the glottis. Persistent hiccups can interfere with daily activities and cause sleep disturbance and fatigue. We report a case of persistent hiccups occurring in a heart and lung transplant recipient that was successfully treated with acupuncture.

[The most common infections in the transplanted patient]

Organ transplantation has become one of the most important areas of medical research and, at present, is still the only therapeutical tool for several diseases. However, there are a number of factors related to transplantation, like immunosuppression and prolonged neutropenia that affect the incidence of infection. These infections are somehow peculiar to transplant recipients. In fact, there are infectious diseases that only occur in immunodepression situations and, moreover, clinical expression of these infectious diseases can be quite different from that in immunocompetent patients. Besides these aspects, some infections, due to the high prevalence described, must be considered for prevention strategies because they continue to be a principal cause of morbidity and mortality, either due to direct effects or to their implication in the pathogenesis of rejection. These strategies commence before transplantation by active immunization through vaccine administration to the patient and to people in the milieu and continue after transplantation with prophylaxis or pre-emptive therapy. The importance of infectious diseases in the evolution and prognosis of transplant recipients gives a special meaning to the understanding of associated infections, their clinical expression and ways of prevention and treatment.

Current treatment strategies for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a disease characterized by an elevation in pulmonary artery pressure that can lead to right ventricular failure and death. Although there is no cure for PAH, newer medical therapies have been shown to improve a variety of clinically relevant end-points including survival, exercise tolerance, functional class, haemodynamics, echocardiographic parameters and quality of life measures. Since the introduction of continuous intravenous prostacyclin, the treatment armamentarium of approved drugs for PAH has expanded to include prostacyclin analogues with differing routes of administration, a dual endothelin receptor antagonist, and a phosphodiesterase-5 inhibitor. Selective endothelin-A receptor antagonists have shown promise in clinical trials and are likely to be added to the list of options. As the number of medications available for PAH continues to increase, treatment decisions regarding first-line therapy, combination treatments, and add-on strategies are becoming more complex. This article reviews the current treatments strategies for PAH and provides guidelines for its management.