Pulmonary Aspects of Liver Disease and Liver Transplantation

Histopathologic findings in lung biopsies from patients with primary biliary cholangitis

Primary biliary cholangitis (PBC) is a progressive autoimmune disease of the liver causing destruction of intrahepatic bile ducts, associated with lymphocytic and granulomatous inflammation. PBC has been associated with many extrahepatic manifestations including interstitial lung disease. However, comprehensive pulmonary histopathology in PBC has not been well documented. Sixteen PBC patients who underwent lung biopsies were identified from surgical pathology files in three institutions. Histopathologic review was performed. Patient age ranged 41 to 79 years (median 55 years) and 15 patients (94%) were women. Specimens consisted of lobectomy (n = 1), surgical biopsies (n = 12), transthoracic needle biopsy (n = 1) and transbronchial biopsy (n = 2). Fifteen of 16 (94%) cases showed lymphocytic inflammation, mainly localized to peribronchiolar stroma and alveolar septa. Thirteen (81%) cases revealed non-necrotizing granulomas, most of which were poorly formed, reminiscent of those seen in liver biopsies from PBC patients. Six cases also showed eosinophilic infiltrates. Organizing pneumonia was seen in 7 cases. Four cases showed diffuse interstitial fibrosis with nonspecific interstitial pneumonia and usual interstitial pneumonia patterns. One patient underwent lobectomy for a mass lesion and was diagnosed with light chain deposition disease with underlying κ-restricted extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. In summary, PBC-associated histopathologic changes in the lung include lymphocytic inflammation predominantly around small airways and non-necrotizing granulomas in multiple compartments of lung tissue, which parallel PBC-associated histopathology in liver biopsies, often associated with other common patterns of diffuse lung disease.

Platypnea-orthodeoxia syndrome: Importance of patient position for correct diagnosis at the time of (99m)Tc-MAA injection

A 65-year-old male presented with unexplained hypoxia that became exacerbated by an upright posture (platypnea-orthodeoxia syndrome) secondary to hepatopulmonary syndrome (HPS). A (99m)Tc-macroaggregated albumin pulmonary perfusion scan revealed a right to left shunt of 29% in the sitting position, which had not been previously detected when the radiotracer injection was performed with the patient in supine position, nor was it diagnosed using another non-invasive imaging method (transthoracic contrast echocardiography and angio-CT). A transesophageal echocardiography was contraindicated due to the presence of esophageal varices. The administration of the radiopharmaceutical in sitting position for the study of the pulmonary perfusion allowed us to confirm the presence of the shunt and consider the patient a candidate for liver transplantation.

Direct demonstration of 25- and 50-microm arteriovenous pathways in healthy human and baboon lungs

Postmortem microsphere studies in adult human lungs have demonstrated the existence of intrapulmonary arteriovenous pathways using nonphysiological conditions. The aim of the current study was to determine whether large diameter (>25 and 50 microm) intrapulmonary arteriovenous pathways are functional in human and baboon lungs under physiological perfusion and ventilation pressures. We used fresh healthy human donor lungs obtained for transplantation and fresh lungs from baboons (Papio c. anubis). Lungs were ventilated with room air by using a peak inflation pressure of 15 cm H(2)O and a positive end-expiratory pressure of 5 cm H(2)O. Lungs were perfused between 10 and 20 cm H(2)O by using a phosphate-buffered saline solution with 5% albumin. We infused a mixture of 25- and 50-microm microspheres (0.5 and 1 million total for baboons and human studies, respectively) into the pulmonary artery and collected the entire pulmonary venous outflow. Under these conditions, evidence of intrapulmonary arteriovenous anastomoses was found in baboon (n = 3/4) and human (n = 4/6) lungs. In those lungs showing evidence of arteriovenous pathways, 50-microm microspheres were always able to traverse the pulmonary circulation, and the fraction of transpulmonary passage ranged from 0.0003 to 0.42%. These data show that intrapulmonary arteriovenous pathways >50 microm in diameter are functional under physiological ventilation and perfusion pressures in the isolated lung. These pathways provide an alternative conduit for pulmonary blood flow that likely bypasses the areas of gas exchange at the capillary-alveolar interface that could compromise both gas exchange and the ability of the lung to filter out microemboli.

Late-onset sarcoidosis after liver transplantation for primary biliary cirrhosis

Primary biliary cirrhosis (PBC) and systemic sarcoidosis are granulomatous diseases of unknown etiology whose hepatic manifestations may infrequently be imitative of one another. Described herein is the first reported case in the medical literature of systemic sarcoidosis developing after liver transplantation for PBC. The presented patient, who suffered from typical clinical, laboratory, and pathologic manifestations of PBC, developed decompensated liver cirrhosis within a course of 8 years, necessitating orthotopic liver transplantation. A year and a half after transplantation, the patient developed diffuse, biopsy-proven, dermatologic and pulmonary manifestations of systemic sarcoidosis, which promptly responded to corticosteroid treatment. In retrospect, the patient's longstanding liver disease was probably caused by an unrecognizable, isolated hepatic form of sarcoidosis or an overlap between PBC and sarcoidosis. This patient illustrates the complexity that may be rarely encountered in differentiating between PBC and hepatic sarcoidosis. Discussed are the clinical, laboratory, and pathologic overlaps between hepatic sarcoidosis and PBC, and clues that may aid in the diagnosis and differentiation between the 2 disorders. Hepatologists and liver transplantation specialists should be aware of the rare possibility of hepatic sarcoidosis imitating PBC, and exacerbating systemically after liver transplantation.

Hepatopulmonary syndrome and right ventricular diastolic functions: an echocardiographic examination

AIM

Liver functions are affected in the course of cardiac diseases, and similarly, liver diseases affect cardiac functions. Many studies in the literature have shown that left ventricular systolic and/or diastolic dysfunction may develop during chronic liver disease. However, there are limited studies investigating right ventricular functions during chronic liver diseases.

METHODS

A total of 84 patients who had no systolic and/or diastolic dysfunction in the left ventricle (LV) were evaluated; 46 patients with liver cirrhosis; 10 (21.74%) cirrhotic patients with hepatopulmonary syndrome (HPS) (group 1), 36 (78.26) cirrhotic patients without HPS (group 2), and 38 healthy individuals were treated as control.

RESULTS

Right ventricular diastolic dysfunction was determined in all patients of group 1 (100%), 26 of group 2 (72.22 %), and 4 of the controls (10.52%) (P<0.05). Tricuspid deceleration time (dt) was significantly different between the groups (P<0.05). In addition, right atrium (RA) diameters, right ventricle (RV) diameters, and RV wall thickness were significantly different between the groups (P<0.05). Pulmonary artery pressure (P<0.05) and pulmonary vascular resistance (P<0.05) were also seen to be higher in group 1 than those in group 2 and control group.

CONCLUSIONS

Right ventricular diastolic dysfunction rate is high in chronic liver diseases. In the presence of HPS, right ventricular diastolic dysfunction is more remarkable in patients than those without HPS. Right ventricular diastolic dysfunction may result in dilatation and hypertrophy in the right heart.

Sleep apnoea syndrome and early stage cirrhosis: a pilot study

OBJECTIVES

Hepatic encephalopathy in patients with end-stage liver cirrhosis is associated with alterations in sleep patterns. Cirrhosis may also affect pulmonary function and it might be involved in the development of obstructive sleep apnoea syndrome (OSAS) in patients with ascites. We carried out a study to evaluate the presence of OSAS in cirrhotic patients without evidence of ascites (early stage cirrhosis).

METHODS

We investigated 20 patients with Child A or B cirrhosis (19 and one, respectively) and 10 non-cirrhotic patients with chronic viral hepatitis (disease control group). All subjects were interviewed and underwent a thorough physical examination, a full polysomnographic study and a pulmonary function testing by spirometry. Serum samples were also obtained in order to determine the liver function tests.

RESULTS

The presence of OSAS and inverted sleep patterns was similar in cirrhotic patients and disease controls. However, significant correlations were revealed between age and hypopnoeas per hour of sleep; age and the Apneas/Hypopneas Index (AHI); age and FEV1/FVC; gamma-glutamyl transpeptidase and FEV1/FVC; and total bilirubin and total sleep time.

CONCLUSIONS

Early stage cirrhosis is not associated with sleep disorders and OSAS. However, total bilirubin levels might be a useful laboratory marker for early assessment of disturbance in sleep patterns and therefore of subclinical hepatic encephalopathy in Child A cirrhosis.

Recent advances in hepatopulmonary syndrome

Hepatopulmonary syndrome is defined as the clinical triad of advanced liver disease, arterial deoxygenation and intrapulmonary vascular dilatation. Its pathogenesis is not completely understood. Excessive pulmonary nitric oxide production seems to be one of the factors that contribute to the intrapulmonary vascular dilatation. Other mediators such as endothelin-1 and the heme oxygenase-1/carbon monoxide system have recently been found to be important contributors. The major clinical manifestations are arterial hypoxemia, clubbed fingers and spider nevi. Orthodeoxia is the characteristic clinical feature. Contrast-enhanced echocardiography is the preferred screening test. 99mTechnetium macroaggregated albumin (Tc-99m MAA) lung perfusion scan can further specify the diagnosis of hepatopulmonary syndrome and quantify the magnitude of shunting. No clearly effective medical treatments have been found. Although liver transplantation seems feasible to reverse this situation, it is associated with increased postoperative morbidity and mortality. A preoperative arterial oxygen tension of 50 mmHg or less and Tc-99m MAA shunt fractions of 20% or more are strong predictors of postoperative mortality that can be used to stratify patients with better outcome.

Anomalous Hepatic Venous Drainage

We present a 3-year-old boy born with anomalous hepatic venous drainage into the left atrium and a small sinus venosus atrial septum defect, in whom pulmonary arteriovenous malformations developed with progressive cyanosis. Surgical redirection of the hepatic venous drainage to the right atrium and closure of the atrial septal defect led to regression of the pulmonary arteriovenous malformations. However, in contrast to other reports, progressive pulmonary hypertension developed postoperatively.

Open lung biopsy in pediatric patients with respiratory failure after abdominal transplantation

To understand the utility of open lung biopsy (OLB) in the evaluation of respiratory failure in pediatric abdominal organ transplant we reviewed the records of nine children in this patient population who underwent an OLB. Eight of nine patients had undergone a previous non-diagnostic bronchoalveolar lavage. Biopsies were performed at the bedside in the pediatric intensive care unit and tissue was processed by the Department of Pathology with special stains for infectious agents. There were no significant complications of OLB. A specific treatable etiology was identified in four patients (respiratory syncytial virus, adenovirus, graft-vs.-host disease and post-transplant lymphoproliferative disease), leading to a change in therapy and survival in two. Overall survival was 44%. Given the low morbidity, OLB as performed in this study appears appropriate in this patient population.

Serum bilirubin levels and mortality after myeloablative allogeneic hematopoietic cell transplantation

Many patients who undergo hematopoietic cell transplantation experience liver injury. We examined the association of serum bilirubin levels with nonrelapse mortality by day +200, testing the hypothesis that the duration of jaundice up to a given point in time provides more prognostic information than either the maximum bilirubin value or the value at that point in time. We studied 1,419 consecutive patients transplanted from allogeneic donors. Total serum bilirubin values up to day +100, death, or relapse were retrieved-along with nonrelapse mortality by day +200 as an outcome measure--using Cox regression models with each bilirubin measure modeled as a time-dependent covariate. The bilirubin value at a particular point in time provided the best fit to the model for mortality. With bilirubin at a point in time modeled as an 8th-degree polynomial, an increase in bilirubin from 1 to 3 mg/dL is associated with a mortality hazard ratio of 6.42. An increase from 4 to 6 mg/dL yields a hazard ratio of 2.05, and an increase from 10 to 12 mg/dL yields a hazard ratio of 1.17. Among patients who were deeply jaundiced, survival was related to the absence of multiorgan failure and to higher platelet counts. In conclusion, the value of total serum bilirubin at a particular point in time after transplant carries more informative prognostic information than does the maximum or average value up to that point in time. The increase in mortality for a given increase in bilirubin value is larger when the starting value is lower.

[TIPS - Transjugular intrahepatic portosystemic shunt. A review]

At the present time several therapeutic options are used for the treatment of bleeding esophageal varices in patients with portal hypertension. We will review the main medical publications on transjugular intrahepatic portosystemic shunt (TIPS), a procedure seldom used among us. TIPS works as a portocaval side-to-side shunt and decreases the risk of esophageal bleeding through lowering of the portal system pressure and a decrease of the portal hepatic pressure gradient. TIPS consists in the percutaneous insertion, through the internal jugular vein, of a metallic stent under fluoroscopic control in the hepatic parenchyma creating a true porta caval communication. There are several studies demonstrating the efficacy of TIPS, although only a few of them are randomized and control-matched to allow us to conclude that this procedure is safe, efficient and with a good cost benefit ratio. In this review, we search for the analysis of the TIPS utilization, its techniques, its major indications and complications. TIPS has been used in cases of gastroesophageal bleeding that has failed with pharmacologic or endoscopic treatment in patients Child-Pugh B and C. It can be used also as a bridge for liver transplantation. Others indications for TIPS are uncontrolled ascites, hepatic renal syndrome, and hepatic hydrothorax. The main early complications of TIPS using are related to the insertion site and hepatic encephalopathy and the stent occlusion is the chief late complication.

Liver transplantation. Selection, listing criteria, and preoperative management

Although only the expansion of the donor pool will have a major impact on the survival of patients with decompensated cirrhosis awaiting OLT, anticipation of complications such as SBP may improve the likelihood of a patient surviving until OLT, and may ameliorate some of the major causes of morbidity of cirrhosis, such as osteoporosis. Close communication between the treating physicians and the transplant center is crucial to ensure that the patients' UNOS status can be appropriately adjusted if additional complications of cirrhosis, such as intractable ascites, have occurred.

Diseases of the hepatopulmonary axis

Hepatopulmonary syndrome is the most widely recognized of the processes associated with end-stage liver disease. Chronic liver dysfunction is associated with pulmonary manifestations due to alterations in the production or clearance of circulating cytokines and other mediators. Hepatopulmonary syndrome results in hypoxemia due to pulmonary vasodilatation with significant arteriovenous shunting and ventilation-perfusion mismatch. Hepatic hydrothorax may develop in patients with cirrhosis and ascites. Rarely, pulmonary hypertension occurs in the setting of portal hypertension. A second group of disorders may primarily affect the lungs and liver (the hepatopulmonary axis). Among these are the congenital conditions alpha(1)-antitrypsin deficiency and cystic fibrosis. Autoimmune liver disease may be associated with lymphocytic interstitial pneumonitis, fibrosing alveolitis, intrapulmonary granulomas, and bronchiolitis obliterans with organizing pneumonia. Sarcoidosis affects the lung and liver in up to 70% of patients. Medications such as amiodarone can result in a characteristic radiologic appearance of pulmonary and hepatic toxic effects. Knowledge of these associations will assist the radiologist in forming a meaningful differential diagnosis and may influence treatment decisions.

Reversal of intrapulmonary arteriovenous shunting detected by two-dimensional contrast-enhanced echocardiography after liver transplantation

BACKGROUND

Intrapulmonary arteriovenous shunting (IPS), occasionally associated with advanced liver disease, may reverse after liver transplantation (LTx). Two-dimensional contrast-enhanced echocardiography, a convenient noninvasive study, has never been used to demonstrate disappearance of IPS after LTx.

METHODS

For an 8-month-old girl undergoing living-related LTx, two-dimensional contrast-enhanced echocardiography was performed with the microbubble injection. The opacification of the microbubble in the left heart emerging within 3-6 beats after detection in the right heart was compared with that in the right heart.

RESULTS

Microbubble opacification in the left heart was almost the same as that in the right heart (grade 3) shortly after LTx. However, the contrast in the left heart diminished (grade 1) as the respiratory condition improved and subsequently disappeared (grade 0).

CONCLUSIONS

Two-dimensional contrast-enhanced echocardiography may be a feasible noninvasive method to evaluate the degree of IPS in the peritransplant period and observe disappearance of IPS after LTx.

Pulmonary hypertension associated with postoperative biliary atresia: report of two cases

The authors report on 2 patients with biliary atresia in whom pulmonary hypertension (PH) developed in the long-term follow-up after hepatoportoenterostomy. Both had portal hypertension and had undergone distal splenorenal shunt. Dyspnea developed around 14 to 15 years of age. Cardiac catheterization showed pulmonary artery pressure (PAP) of 99/37 (58) and 67/32 (48) mm Hg, respectively, which did not respond to vasodilators. One patient suffered from respiratory tract infection followed by right heart failure and subsequent death at 20 years of age. Postmortum histological findings exhibited severe thickening of the pulmonary artery wall. PH may grow insidiously even after successful hepatoportoenterostomy. Careful monitoring of PAP and hemodynamic response of PAP to vasodilators is essential for evaluating the reversibility of PH and making treatment decisions.

Surgery in the patient with liver disease

Patients with liver disease often undergo surgery. With the increasing prevalence of liver disease and improved survival due to newer medications and treatments, a growing number of patients with liver disease will require preoperative assessment. Because of the multiple physiological roles of the liver, hepatic dysfunction places these patients at an increased risk of perioperative morbidity and mortality. The precise risks associated with specific liver diseases are poorly understood but are greater with increased impairment of hepatic function. Identifying preexisting problems that could be optimally and appropriately managed before surgery (e.g., coagulation status, intravascular volume, renal function, electrolytes, cardiovascular status, and nutrition) may reduce these risks and decrease mortality in patients with liver disease undergoing surgery.

Pneumonia in the compromised host including cancer patients and transplant patients

Pneumonia remains a major cause of morbidity and mortality in the immunocompromised host. The type and timing of immunosuppression will predispose the patient to infections with certain pathogens. This article discusses the types of immunosuppression and their infectious and noninfectious implications. Key points of the most commonly involved pathogens are mentioned. Finally, an approach to diagnosis and empiric therapy is discussed.

Intensive Care of the Intra-Abdominal Organ Transplant Recipient

The postoperative care of a patient who receives an intra-abdominal organ transplant is in some ways simi lar to that of any major intra-abdominal procedure. However, certain features unique to organ transplanta tion, such as the variable functional status of the newly transplanted graft, complications that are specific to the organ transplanted, and the side effects from immuno suppressive drugs, suggest that transplantation inten sive care is a distinct subspecialty in critical care medicine. Today, the majority of patients receiving an intra-abdominal transplant will have a relatively uncom plicated postoperative course. However, preoperative disposition, intraoperative misadventure, or immediate postoperative difficulty will require the availability of an intensivist experienced in transplantation. The future of intra-abdominal transplantation will be highly depen dent on progress in immunotherapy. Newer, more spe cific immunomodulators with fewer nonimmune toxici ties should result in improved organ receptance, less graft dysfunction, and improved patient survival.

Clinical factors that affect blood gases in non-smoking women with chronic liver disease

Chronic liver disease is often accompanied by hypoxaemia. We investigated the clinical factors that were related to the arterial oxygen tension (PaO2) in 40 women, all non-smokers with chronic liver disease. They were positive for hepatitis C virus (HCV) antibody and had no evidence of cardiopulmonary disease. Arterial blood was collected from patients at rest (> 15 min) for analysis of blood gases. We determined the correlation between blood gas tension and the clinical variables, i.e. the presence or absence of skin manifestations such as cutaneous spider nevi and palmar erythema, the presence or absence of splenomegaly, vital capacity, forced expiratory volume in one second, V25/body height, serum alanine aminotransferase (AST), serum asparate aminotransferase (ALT), serum cholinesterase, serum gamma-globulin/total protein, excretion of indocyanine green at 15 min (15-min retention rate, ICG level), blood level of ammonia, blood level of endotoxin, plasma level of glucagon and the serum level of type IV collagen-7S. The mean level of PaO2 was 78 +/- 11 (range: 43-95) torr. The mean alveolar-arterial oxygen tension gradient (A-aDO2) was 19 +/- 13 (range: 2-60) torr. Multiple regression analysis used PaO2 and A-aDO2 as objective variables, and the clinical findings as explanatory variables. The explanatory variables that were significantly correlated with blood gas values were ICG level, blood level of endotoxin and presence of skin manifestations. The ICG level showed a high correlation with blood gas values; the ICG level increased, the PaO2 decreased (r = -0.69), while the A-aDO2 showed a high positive correlation (r = +0.78, P < 0.001). Findings suggest that a reduction in hepatic blood flow and hepatocellular function interfere with the inactivation of vasoactive substances such as endotoxin by the liver, leading to the development of skin manifestations, the dilatation of intrapulmonary capillaries and the induction of hypoxaemia.

Cavocaval liver transplantation without venovenous bypass and without temporary portocaval shunting: the ideal technique for adult liver grafting?

The influence of the implantation technique on the outcome was studied prospectively in a series of 116 consecutive adult patients undergoing primary liver transplantation during the period January 1991-June 1994. Thirty-eight patients (32.8%; group 1) underwent classical orthotopic liver transplantation (OLT) with replacement of the recipient's inferior vena cava (R-IVC) and with venovenous bypass (VVB). Thirty-nine patients (33.56%) had a piggy-back OLT with preservation of the R-IVC (group 2); bypass was used in 17 of them (43.6%) because of poor hemodynamic tolerance of R-IVC occlusion. Thirty-nine patients (33.6%) had OLT without VVB and with side-to-side cavocaval anastomosis (group 3). The three techniques were performed irrespective of the anatomical situation and of the status of the recipient at the time of transplantation. The following parameters were assessed in all patients: implantation time, blood product use, morbidity (e.g., hemorrhagic, thoracic, gastrointestinal, neurological, and renal complications), and outcome. Thirty-one patients underwent detailed intraoperative hemodynamic assessment. The early (< 3 months) post-transplant mortality of 10.3% (12/116 patients) was unrelated to the implantation technique. Group 3 had a significantly shorter mean implantation time, a reduced need for intraoperative blood products, and a lower rate of reoperation due to intra-abdominal bleeding. After excluding two immediate perioperative deaths and eight patients requiring early retransplantation because of primary nonfunction, the frequency of immediate extubation was significantly higher in group 3. Detailed hemodynamic assessment did not show a difference between 6 group 1 patients and 17 group 3 patients, indicating that partial lateral clamping of the IVC fulfills the function of venous bypass. Similar results were obtained in 6 group 2 patients who did not have IVC occlusion. Cavocaval OLT has become our preferred method of liver implantation. It allows the transplantation to be performed without VVB, regardless of the anatomical situation and of the condition of the patient at the time of transplantation. Moreover, it avoids all of the potential complications and costs of VVB.

Hepatopulmonary syndrome: the paradigm of liver-induced hypoxaemia

The current chapter deals with the concept, clinical manifestations and diagnostic tools of the hepatopulmonary syndrome (HPS) and highlights its most salient pathophysiological, mechanistic and therapeutic aspects. Defined as a clinical triad, including a chronic liver disorder, pulmonary gas exchange abnormalities and generalized pulmonary vascular dilatations, in the absence of intrinsic cardiopulmonary disease, this entity is currently growing in interest with both clinicians and surgeons. The combination of arterial hypoxaemia, high cardiac output with normal or low pulmonary artery pressure, and finger clubbing in a patient with advanced liver disease should strongly suggest the diagnosis of HPS. Its potential high prevalence together with failure of numerous therapeutic approaches depicts a life-threatening unique clinical condition that may dramatically benefit with an elective indication of liver transplantation (LT). A better orchestration of the concepts of the pathophysiology of this lung-liver interplay may foster our knowledge and improve the clinical management and indications of LT.

The hepatopulmonary syndrome

The hepatopulmonary syndrome occurs in subjects with chronic liver disease and/or portal hypertension who develop intrapulmonary vasodilation resulting in arterial deoxygenation. Clinical and basic science studies investigating the pathophysiology of HPS are presented. A diagnostic algorithm is provided using contrast echocardiography, the lung perfusion scan, and pulmonary angiography. Medical therapy and experience with liver transplantation are reviewed.

Respiratory compliance during orthotopic liver transplantation

After liver transplantation, respiratory complications are frequent. The purpose of this study was to assess if intraoperative monitoring of respiratory compliance is of clinical value in predicting such complications. Respiratory compliance was continuously monitored with a side-stream respiratory gas flow and pressure sensor (Datex, Helsinki, Finland) at the endotracheal tube in 18 adult patients undergoing orthotopic liver transplantation without veno-venous bypass. Respiratory compliance decreased along with blood volume expansion under anaesthesia before the start of surgery (P < 0.05). Compliance improved as ascites was removed at the beginning of laparotomy (P < 0.001). The highest compliance values were seen during liver surgery. In the patients without ascites preoperatively, compliance was lower at the end of surgery than at anaesthesia induction (P < 0.001). In the patients with ascites, compliance at the end of surgery was equally low as at anaesthesia induction. Compliance at the end of surgery was lower in the patients with bilateral than in those with right-sided or no pleural effusions in the postoperative chest X-rays (P < 0.001). In conclusion, intraoperative monitoring of respiratory compliance is one useful method for clinical use in predicting postoperative bilateral pleural effusions.

Two-dimensional and dobutamine stress echocardiography in the preoperative assessment of patients with end-stage liver disease prior to orthotopic liver transplantation

Orthotopic liver transplantation is an established therapy for end-stage liver disease. This study evaluated the range of cardiovascular abnormalities in patients undergoing evaluation for orthotopic liver transplantation and determined the prognostic implications of abnormal echocardiographic features, including ischemia during dobutamine stress echocardiography, in predicting postoperative cardiac events. Two-dimensional echocardiography was performed in 190 patients for assessment of left ventricular function, valvular pathology, and pulmonary hypertension. Dobutamine stress echocardiography was performed in 165 patients for evaluation of inducible ischemia. Contrast echocardiography for detection of intrapulmonary shunting was performed in 125 patients at rest and in 99 during dobutamine stress. Left ventricular dysfunction, significant valvular regurgitation, and inducible ischemia were identified in <1O% of patients. Pulmonary hypertension, left ventricular hypertrophy and > or = moderate intrapulmonary shunting were present in 12%, 16%, and 26% of patients, respectively. Severe intrapulmonary shunting predicted death prior to transplantation (P=0.01). Of the 71 transplanted patients, major perioperative events included global left ventricular dysfunction in four patients and myocardial infarction in one patient with normal coronary arteries. No preoperative echocardiographic parameters, including ischemia on dobutamine echocardiography, predicted these perioperative events. No cardiac events related to obstructive coronary artery disease occurred in the 154 patients without ischemia on dobutamine stress echocardiography. The majority of patients with end-stage liver disease, including those with alcoholic cirrhosis, have normal cardiac function on two-dimensional echocardiography. Severe intrapulmonary shunting portends a poor prognosis in patients awaiting transplantation. A negative dobutamine stress echocardiogram appears useful in excluding patients at risk for perioperative cardiac events related to obstructive coronary artery disease.

Pulmonary complications of liver transplantation

The preoperative pulmonary evaluation of organ transplant candidates involves the diagnosis of unexplained pulmonary infiltrates or symptoms, interpretation of pulmonary function abnormalities, and an assessment of surgical risk. Pretransplant pulmonary considerations in patients with end-stage hepatic diseases relate primarily to hypoxemia from poorly understood intrapulmonary vascular dilatations, mechanical dysfunction, and states of increased extravascular lung water. Except in severe cases, however, these generally do not prohibit liver transplantation, and even are likely to improve after transplant surgery. Early postoperative complications may be categorized as those expected from extensive intra-abdominal surgery that requires significant volume resuscitation, which typically are managed in the usual manner for those clinical situations. As immunosuppression begins to have an effect, the LTx recipient becomes susceptible to the same opportunistic infectious organisms (with their frequent pulmonary involvement) that cause significant morbidity and mortality in recipients of other solid organ transplants. Because many of the immunosuppressive agents also are the same, noninfectious side effects such as pulmonary edema and malignancy also are similar. As with all immunocompromised patients, prophylaxis, when possible, persistent infection surveillance, and an aggressive diagnostic and therapeutic approach help decrease the impact of pulmonary dysfunction in LTx recipients.

Recent pulmonary observations in alpha 1-antitrypsin deficiency, primary biliary cirrhosis, chronic hepatitis C, and other hepatic problems

Patients with metabolic, immunologic, viral, and other types of hepatic disorders can have a spectrum of complicating pulmonary abnormalities. The natural history of these associations is poorly understood. Significant reversibility in hepatic and pulmonary dysfunction, however, has been well documented in the era of organ transplantation. The continued relationship among pulmonologists, hepatologists, and transplant surgeons hopefully will provide enlightening data on these interesting clinical associations, their natural histories, and their response to evolving therapeutic approaches.

Mechanisms of gas exchange impairment in patients with liver cirrhosis

This article reviews the basic pathophysiologic mechanisms underlying the abnormal pulmonary gas exchange often seen in patients with cirrhosis. To summarize, the following keypoints seem appropriate: (1) Patients with cirrhosis have a low pulmonary vascular tone characterized by a poor or absent hypoxic pressor response. This results in a marked dilation of the pulmonary vasculature. (2) This abnormal pulmonary vascular tone, independently of airway disease, causes VA/Q mismatch and mild to moderate hypoxemia. Yet, as liver disease progresses and hepatocellular function deteriorates, more severe degrees of intrapulmonary shunt emerge and, probably, O2 diffusion limitation ensues, causing severe respiratory failure (see Table 1). (3) At rest, the high cardiac output and minute ventilation of cirrhosis minimize the degree of arterial hypoxemia that otherwise would be expected from the observed degree of both VA/Q inequality and intrapulmonary shunt. During exercise, the relative "normalization' (with respect to metabolic demands) of the hemodynamic and ventilatory status of the patient explains the fall in PaO2. (4) A clear pathogenic mechanism of these pathophysiologic abnormalities is still lacking, although available evidence suggests that both the liver and the endothelial cells may play a pivotal role in the regulation of the pulmonary vascular tone in these patients. (5) To date, no pharmacologic intervention has been effective in treating hypoxemia in these patients. Yet liver transplantation helps in most of them. This observation reinforces the functional nature of the gas exchange abnormalities of cirrhosis.

The hepatopulmonary syndrome. Effect of liver transplantation

The role of liver transplantation as a treatment for the hepatopulmonary syndrome (HPS) has had an evolving and controversial history. Although early experience was disappointing, more recent experience has documented resolution of HPS-associated hypoxemia after liver transplantation. This article reviews the history of liver transplantation for patients with the hepatopulmonary syndrome. In addition, we discuss the clinical features that have been considered to predict successful reversibility and the time frame over which reversal occurs. Despite this evolution of thought, many basic questions still remain.

Diagnostic utility of contrast echocardiography and lung perfusion scan in patients with hepatopulmonary syndrome

BACKGROUND & AIMS

Two modalities, contrast echocardiography and lung perfusion scan, are used to identify intrapulmonary vascular dilatation and diagnose hepatopulmonary syndrome (HPS), but a comparison of these two procedures has not been performed. The aim of this study was to compare the use of these diagnostic modalities in detecting intrapulmonary vascular dilatation and diagnosing HPS.

METHODS

Forty consecutive outpatients with biopsy-proven cirrhosis had contrast echocardiography, a lung perfusion scan, and arterial blood gases analyzed.

RESULTS

Fifteen of 40 cirrhotics (38%) had positive contrast echocardiogram results. Seven patients with positive echocardiogram results had gas exchange abnormalities and could be considered to have HPS (7 of 40 [17.5%]). Three of these patients were hypoxemic and had no concurrent cardiopulmonary disease, and each had positive contrast echocardiogram and lung perfusion scan results and were readily diagnosed as having HPS. The other 4 patients (3 hypoxemic and 1 normoxemic with an elevated alveolar-arterial gradient) had coexisting intrinsic lung disease and/or chest radiograph abnormalities complicating the diagnosis of HPS, and each had positive echocardiogram and negative lung scan results. The remaining 8 patients with positive echocardiogram results had normal lung scan and normal gas exchange results. No patient had positive lung scan and negative contrast echocardiogram results.

CONCLUSIONS

Contrast echocardiography is the most useful screening test for intrapulmonary vasodilatation and may be positive more frequently than lung perfusion scans in patients with HPS.

Hepatic venous blood and the development of pulmonary arteriovenous malformations in congenital heart disease

BACKGROUND

Pulmonary arteriovenous malformations (PAVMs) are a known complication after some types of cavopulmonary anastomoses (CVPAs). Their cause is unknown, but they may be related to the absence of pulsatile flow or the presence or absence of circulating factors. These PAVMs are diffuse and are presumed to be progressive and irreversible.

METHODS AND RESULTS

All patients with congenital heart disease (CHD) seen at Children's Hospital, Boston, Mass, between 1970 and 1993 were reviewed. We report on the 10 patients with CHD who were found to have developed PAVMs, as diagnosed by cardiac catheterization. Diagnoses included heterotaxy syndrome/polysplenia, with interrupted inferior vena cava and hepatic veins draining to the right atrium (n = 6); heterotaxy/asplenia (n = 1); corrected transposition with pulmonary stenosis (n = 1); and biliary atresia and associated CHD (n = 2). PAVMs were diagnosed 0.1 to 7.0 years (median, 3.5 years) after creation of a CVPA that resulted in exclusion of hepatic venous flow from one or both lungs in 8 of the 10 patients; the remaining 2 patients had normal drainage of hepatic veins to the lungs but had biliary atresia. In all, the common anatomic feature was the exclusion of normal hepatic venous return from the affected pulmonary arterial circulation. All patients with interrupted inferior vena cava, azygous continuation to the superior vena cava, and hepatic veins draining to the right atrium (polysplenia syndrome) were reviewed to determine the incidence of PAVMs in those with CVPA (ie, hepatic venous flow excluded from the pulmonary arteries) and without CVPA. Six of 28 (21%) of those with versus 1 of 56 (1.8%) of those without CVPA developed PAVMs (P = .004). The 1 patient without CVPA who had PAVMs also had biliary atresia. Among patients with CVPA, the probability of developing PAVMs was 15% and 28% at 3 and 5 years, respectively, after CVPA. The histological and angiographic appearances of PAVMs after CVPA are similar to those seen in PAVMs associated with hepatic cirrhosis.

CONCLUSIONS

We postulate that PAVMs after CVPA are related to the diversion of normal hepatic venous flow from the pulmonary circulation. In this sense, these PAVMs may be analogous to those associated with liver disease, which have been found to resolve after liver transplantation. Redirection of hepatic flow to the pulmonary bed in some patients with CHD and PAVMs may lead to reversibility of the PAVMs.

Primary biliary cirrhosis: lung involvement

Sub-clinical lung impairment, mostly represented by a reduced diffusion of alveolar gases, is a recognised complication of advanced primary biliary cirrhosis. The aim of the study was to evaluate the prevalence and type of pulmonary involvement in primary biliary cirrhosis and the relationship between lung function abnormalities and selected epidemiological and clinical variables. Sixty-one patients with different stages of primary biliary cirrhosis consecutively seen in our outpatient clinic were evaluated. The advancement of primary biliary cirrhosis was characterised by the histological stage, the presence of signs of portal hypertension and the Mayo Risk Score: a Cox regression model using serum bilirubin and albumin levels, prothrombin time, age and degree of oedema as selected variables. We measured static and dynamic lung volumes, by means of a spirometer, and diffusing capacity for carbon monoxide. Rheumatological disorders were evaluated by an independent rheumatologist. No patient complained of respiratory symptoms. Airway obstruction was present in one patient. In 24 patients (39%) the alveolar diffusion capacity was reduced. We did not find any significant relationship between diffusing capacity and smoking habits, advancement of liver disease and concomitant Sjogren syndrome. Reduced diffusion capacity showed a significant correlation with the presence of complete or incomplete CREST syndrome (p < 0.01) and with the presence of circulating anti-centromere antibodies (p < 0.05). Alveolar diffusion capacity is frequently impaired in patients with primary biliary cirrhosis, usually in the absence of clinical manifestations. These alterations mostly affect patients with concomitant CREST syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary arteriovenous shunting in children with liver disease

Pulmonary arteriovenous shunting (PAVS) with hypoxemia is a severe complication of cirrhosis that may regress after liver transplantation. We report PAVS in 25 children with cirrhosis and in 1 with portal vein obstruction; proof of shunting was obtained by technetium Tc 99m microaggregated albumin pulmonary scanning or a high alveoloarterial O2 gradient or both. Cyanosis or dyspnea or both occurred at ages ranging from 6 months to 14 years, earlier in children with biliary atresia and polysplenia syndrome (p < 0.01). Mean arterial oxygen tension (PaO2) was 57 mm Hg (range, 42 to 81 mm Hg) during breathing of 21% O2 and 367 mm Hg (range, 179 to 535 mm Hg) in 100% O2. Cardiac index was always raised, significantly more in children with biliary atresia and polysplenia syndrome (p < 0.01). Seven untreated children died 3 months to 8 years after the diagnosis of PAVS. Eleven underwent liver transplantation: seven are alive (follow-up, 1 to 4 years) and have no signs of PAVS. The PaO2 value during breathing of 100% O2 was > 300 mm Hg in the survivors and < 200 mm Hg in the four nonsurvivors (p < 0.01). These results indicate (1) that PAVS can occur at any age in children with portal hypertension, and that the risk is highest and earliest in children with biliary atresia and polysplenia syndrome, (2) that early liver transplantation allows regression of PAVS, and (3) that the prognosis may in part be related to the level of PaO2 while the patient is breathing 100% O2. The results indicate that systematic screening for PAVS should be part of the examination of these children.

Pulmonary hypertension associated with primary biliary cirrhosis in the absence of portal hypertension: a case report

Pulmonary hypertension is well described in association with portal hypertension of any cause including end stage primary biliary cirrhosis (PBC). The essential feature of this association is the presence of portosystemic shunting, including surgically created shunts. A patient with primary pulmonary hypertension and PBC without portal hypertension is reported. This suggests that primary pulmonary hypertension may be associated with PBC in the absence of portal hypertension. Decisions regarding appropriate organ transplantation may depend on whether pulmonary hypertension is primary or secondary to portal hypertension.

Fulminant hepatic failure

FHF is an uncommon but devastating condition affecting otherwise healthy persons which causes significant morbidity and mortality. The etiologic factor is most commonly viral infection, with drugs and metabolic disorders being relatively less common causes. Hopefully, newer diagnostic techniques such as PCR will increase our understanding of the causes and pathogenesis of this disorder. Medical management at the present time must focus on anticipating, preventing, and rapidly identifying and treating complications that may affect every major organ system. Encouraging research continues on the clinical application of hepatotrophic drugs and artificial liver support systems, both as potentially definitive therapies and as maintenance for patients awaiting transplantation. Consultation with physicians at a transplant center should be sought early in the course of the patient's hospitalization when OLT is being considered. Liver transplantation has dramatically changed the outlook for patients with FHF, with current survival rates in the 55% to 75% range. The continuing challenge for the transplant team is to allocate available donor organs to those patients who would not otherwise survive, but also to provide OLT in a timely fashion to ensure the best chance of post-transplantation recovery. Newer techniques such as heterotopic liver transplantation, reduced-size organ transplantation, and the utilization of living related donors may further improve the survival of these patients.

Pulmonary complications of orthotopic liver transplantation

We retrospectively reviewed the pulmonary complications and associated morbidity and mortality of 44 consecutive patients who underwent 52 orthotopic liver transplantations (OLTs) at the Mayo Clinic during 1987. All survivors participated in follow-up for 1 year after OLT. Of the five deaths in the study group, three were associated with pulmonary infections. On postoperative chest roentgenograms, 24 cases of pulmonary infiltrates were noted; 12 were caused by infections. Ten opportunistic pulmonary infections developed in nine patients: four cytomegalovirus, three Pneumocystis carinii pneumonia, and one each of Cryptococcus, Aspergillus, and Candida. All except one of the opportunistic infections were diagnosed after the sixth postoperative week. Fiberoptic bronchoscopy was helpful for diagnosing opportunistic pulmonary infections in six patients. One Aspergillus pulmonary infection was diagnosed by transthoracic needle aspiration. Bacterial pneumonia occurred in five patients. Preoperative pulmonary function tests, performed in 40 patients, revealed a restrictive ventilatory defect in 28% and impaired gas transfer in 52%. Pleural effusion was present in 18% of patients preoperatively and in 77% during the first week after OLT. Preoperative severity of liver disease and results of arterial blood gas determinations, pulmonary function tests, and chest roentgenography were not associated with postoperative mortality and pulmonary infections. Infectious and noninfectious pulmonary complications are common in liver transplant recipients. Attempts to decrease the frequency and severity of pulmonary complications by early diagnosis and effective treatment may diminish the morbidity and mortality associated with OLT.

Resolution of severe intrapulmonary shunting after liver transplantation

A major complication of hepatic cirrhosis is arterial hypoxemia, often the result of intrapulmonary arteriovenous shunting. While previously such hypoxemia was thought to preclude successful hepatic transplantation, more recent studies have suggested that hepatic transplantation should be considered if the hypoxemia is corrected by supplemental oxygen. We report the findings in a cirrhotic patient with severe hypoxemia associated with intrapulmonary arteriovenous shunting. The patient did not respond to supplemental oxygen (PaO2 < 40 mm Hg on O2 at 4 L/min). The patient underwent successful hepatic transplantation, with complete resolution of intrapulmonary shunting. We believe that patients with cirrhosis-associated intrapulmonary shunting, even with hypoxemia resistant to supplemental oxygen, are acceptable candidates for hepatic transplantation.

Mechanisms of impaired arterial oxygenation in patients with liver cirrhosis and severe respiratory insufficiency. Effects of indomethacin

The mechanisms of impaired arterial oxygenation that occur in certain patients with chronic liver cirrhosis are still debated. In the present study, we investigated nine cirrhotic patients with severe respiratory disability (mean PaO2, 64 +/- 5 mm Hg), using the inert gas elimination technique to assess the distribution of ventilation-perfusion (VA/Q) ratios. We also determined shunt fraction during pure oxygen breathing, both in supine and sitting positions. To test the hypothesis that vasodilating prostaglandins could contribute to alter gas exchange in such patients with cirrhosis, we examined the hemodynamic and gasometric responses to indomethacin, 50 mg IV, in six of them. During baseline conditions, patients had high cardiac index (CI, 4.9 +/- 0.2 L/min/m2), and low pulmonary (PVR, 1.78 +/- 0.37 mm Hg/L/min/m2) or systemic (SVR, 17.7 +/- 1.15 mm Hg/L/min/m2) vascular resistances. Large intrapulmonary shunt fraction was documented in each patient with a mean value of 19.6 +/- 2.7 percent. Small perfusion in low VA/Q areas was associated with shunt in only three patients (2.5 to 5.3 percent of blood flow). Arterial PO2 was negatively related to shunt (p < 0.01) and to the dispersion of blood flow distribution (p < 0.02). There was no difference between measured and predicted PaO2. Shunt estimates from the inert gas and the 100 percent O2 breathing techniques were, respectively, 19.6 +/- 2.7 percent and 21.7 +/- 3.0 percent. During 100 percent oxygen breathing, changing from supine to sitting position decreased PaO2 from 401 +/- 50 to 333 +/- 64 mm Hg (p < 0.02), while O2 shunt remained unchanged, arteriovenous difference widened, and mixed venous PO2 decreased, from 61 +/- 3 to 47 +/- 4 mm Hg (p < 0.001). Indomethacin did not improve gas exchange or VA/Q distribution and did not affect systemic or pulmonary hemodynamics. The results show that in cirrhotic patients with severe respiratory disability, intrapulmonary shunting is the main determinant of impaired gas exchange, with no evidence of a defect in oxygen diffusion or an extrapulmonary shunt. Vasodilating prostaglandins do not appear to contribute to these alterations.