Effects of hypoxemia on early postoperative course of liver transplantation in pediatric patients with intrapulmonary shunting

High-flow nasal cannula oxygen therapy: Alternative respiratory therapy for severe post-transplant hypoxemia in children with hepatopulmonary syndrome

Severe post-transplant hypoxemia, which is defined as <50 mm Hg of the partial pressure of oxygen in arterial blood/fraction of inspired oxygen (P/F) ratio, is a major post-operative complication with high mortality rates in patients with hepatopulmonary syndrome (HPS). Non-invasive positive pressure ventilation therapy and mechanical ventilation are options for respiratory support of patients with severe post-transplant hypoxemia. However, these therapies are associated with several problems, such as compliance, ventilator-associated pneumonia, and lung injury. We here firstly described two children with HPS who developed severe post-transplant hypoxemia (lowest post-operative P/F ratio, 49.7 and 34.0 mm Hg, respectively) that was successfully managed with high-flow nasal cannula (HFNC) oxygen therapy and vasodilation drugs without adverse complications or necessity of reintubation. We consider that HFNC oxygen therapy could become a safe alternative respiratory therapy or be added to the other such as inhaled nitric oxide (iNO), methylene blue (MB), inhaled epoprostenol, embolization of abnormal pulmonary vessels, and combination of iNO and MB for severe post-transplant hypoxemia in children with HPS.

Pediatric liver transplantation in severe hepatopulmonary syndrome and use of inhaled nitric oxide for post-transplant hypoxemia-a single center experience

Data on pediatric patients with HPS undergoing LT are limited. Our aim was to study the spectrum and outcomes of pediatric patients with HPS undergoing LDLT. The role ofiNO for post-LDLT refractory hypoxemia was also assessed. Patients (aged < 18 years) undergoing LT were retrospectively studied. HPS was diagnosed based on European Respiratory Society Taskforce 2004 criteria. HPS was graded based on oxygenation criteria and contrast-enhanced echocardiogram. Post-operative course was studied. Refractory post-operative hypoxemia was treated with iNO by institutionally developed protocol. 23/150 pediatric patients undergoing LDLT had HPS. BA was the most common underlying cause (52.2%). By oxygenation criteria, 6 (26.1%) had VS-HPS. VS-HPS was associated with longer LOS (p = .031) and prolonged oxygen requirement (p = .001) compared with other HPS patients. 4/6 patients with VS-HPS had pO2 < 45 mm Hg. Among these, 2 developed ICH post-operatively and 1 died. 3 developed refractory post-operative hypoxemia, successfully treated with iNO. Mean duration of iNO was 26.3 days. In the group of patients with HPS, the incidence of HAT and portal vein thrombosis was 17.3% and 4.3%, respectively. One year post-LDLT survival of patients with HPS was similar to non-HPS patients (86.9% vs 94.4%; p = .88). We concluded that, pediatric patients with VS-HPS, especially those with pre-operative pO2 < 45 mm Hg, have long and difficult post-LT course. Refractory postoperative hypoxemia can be successfully overcome with strategic use of iNO. Vigilant monitoring and good intensive care support are essential.

Bowel perforation after liver transplantation for biliary atresia: a retrospective study of care in the transition from children to adulthood

PURPOSE

We evaluated the outcomes of liver transplantation (LT) in pediatric and adult patients with biliary atresia (BA). We focused on bowel perforation after LT (BPLT) as the most common surgical complication and analyzed its risk factors.

METHODS

This was a retrospective analysis of 70 BA patients who underwent LT. The patients were divided into three groups according to the timing of LT: within the first year of age (Group A), between 1 and 12 years of age (Group B), and after 12 years of age (Group C). The outcomes of LT and the clinical presentations of BPLT were compared. The surgical variables of patients with and without BPLT were analyzed to assess the risk factors.

RESULTS

The timing of LT did not affect patient survival. The incidence of BPLT was significantly higher in Group C. In Group C, BPLT progressed to severe peritonitis. No cases of BPLT-associated mortality were observed. A multivariate analysis revealed that a prolonged operative time for LT was an independent risk factor (p = 0.03).

CONCLUSION

The clinical course after transplantation was complicated after adolescence. BPLT should be strongly suspected and relaparotomy should be performed in a timely manner for patients undergoing LT after adolescence.

Proposed management algorithm for severe hypoxemia after liver transplantation in the hepatopulmonary syndrome

The hepatopulmonary syndrome (HPS) is defined as the triad of liver disease, intrapulmonary vascular dilatation, and abnormal gas exchange, and is found in 10-32% of patients with liver disease. Liver transplantation is the only known cure for HPS, but patients can develop severe posttransplant hypoxemia, defined as a need for 100% inspired oxygen to maintain a saturation of ≥85%. This complication is seen in 6-21% of patients and carries a 45% mortality. Its management requires the application of specific strategies targeting the underlying physiologic abnormalities in HPS, but awareness of these strategies and knowledge on their optimal use is limited. We reviewed existing literature to identify strategies that can be used for this complication, and developed a clinical management algorithm based on best evidence and expert opinion. Evidence was limited to case reports and case series, and we determined which treatments to include in the algorithm and their recommended sequence based on their relative likelihood of success, invasiveness, and risk. Recommended therapies include: Trendelenburg positioning, inhaled epoprostenol or nitric oxide, methylene blue, embolization of abnormal pulmonary vessels, and extracorporeal life support. Availability and use of this pragmatic algorithm may improve management of this complication, and will benefit from prospective validation.

Defining and characterizing severe hypoxemia after liver transplantation in hepatopulmonary syndrome

Hepatopulmonary syndrome is defined as a triad of liver disease, intrapulmonary vascular dilatations, and abnormal gas exchange, and it carries a poor prognosis. Liver transplantation is the only known cure for this syndrome. Severe hypoxemia in the early postoperative period has been reported to be a major complication and often leads to death in this population, but it has been poorly characterized. We sought to propose an objective definition for this complication and to describe its risk factors, incidence, and outcomes. We performed a systematic literature search and reviewed our single-center experience to characterize this complication. On the basis of the most commonly applied definition in 27 identified studies, we objectively defined severe postoperative hypoxemia as hypoxemia requiring a 100% fraction of inhaled oxygen to maintain a saturation ≥ 85% and out of proportion to any concurrent lung process. Nineteen of the 27 reports (70%) fulfilled this definition, as did 4 of the 21 patients (19%) at our center. We determined the prevalence and mortality of this complication from reports including 10 or more consecutive patients and providing sufficient postoperative details to determine whether this complication had occurred. In these reports, the prevalence of this complication was 12% (25/209). For the 11 cases with reported outcomes, the posttransplant mortality rate was 45% (5/11). There was a trend toward an increased risk of developing this complication in patients with very severe preoperative hypoxemia, defined as a partial pressure of arterial oxygen ≤ 50 mm Hg (8/41 with very severe hypoxemia versus 3/49 without severe hypoxemia, P = 0.053), and there was a significantly increased risk for patients with anatomic shunting ≥ 20% (7/25 with anatomic shunting ≥ 20% versus 1/25 without anatomic shunting ≥ 20%, P = 0.049). In conclusion, increased preoperative vigilance for this common complication is required among high-risk patients, and further research is required to identify the best management strategies.

Biliary atresia: 50 years after the first kasai

Biliary atresia is a rare neonatal disease of unknown etiology, where obstruction of the biliary tree causes severe cholestasis, leading to biliary cirrhosis and death in the first years of life, if the condition is left untreated. Biliary atresia is the most frequent surgical cause of cholestatic jaundice in neonates and should be evoked whenever this clinical sign is associated with pale stools and hepatomegaly. The treatment of biliary atresia is surgical and currently recommended as a sequence of, eventually, two interventions. During the first months of life a hepatoportoenterostomy (a "Kasai," modifications of which are discussed in this paper) should be performed, in order to restore the biliary flow to the intestine and lessen further damage to the liver. If this fails and/or the disease progresses towards biliary cirrhosis and life-threatening complications, then liver transplantation is indicated, for which biliary atresia represents the most frequent pediatric indication. Of importance, the earlier the Kasai is performed, the later a liver transplantation is usually needed. This warrants a great degree of awareness of biliary atresia, and the implementation of systematic screening for this life-threatening pathology.

Immediate noninvasive ventilation may improve mortality in patients with hepatopulmonary syndrome after liver transplantation

Hepatopulmonary syndrome (HPS) is defined as hypoxemia induced by intrapulmonary vascular dilations associated with liver disease. Although liver transplantation (LT) is the only effective therapy established for severe HPS, patients with a partial pressure of arterial oxygen (PaO(2) ) less than 60 mm Hg have a poor prognosis. We treated a 4-year-old boy with HPS whose preoperative PaO(2) level was 48.8 mm Hg. After LT, he had persistent severe hypoxemia, although he was receiving high-flow oxygen. Noninvasive ventilation (NIV) was introduced, and his respiratory insufficiency promptly improved. Therefore, NIV therapy immediately after extubation following transplantation was administered to the next 4 consecutive HPS patients whose preoperative PaO(2) was less than 60 mm Hg. The NIV treatment of these 5 patients could have been responsible for preventing severe postoperative complications as well as reintubation and hospital death. NIV therapy for both pediatric and adult patients with severe HPS immediately after extubation might protect them from severe hypoxemia after transplantation and from complications necessitating reintubation and might improve their prognosis.

Liver transplantation using University of Wisconsin or Celsior preserving solutions in the portal vein and Euro-Collins in the aorta

INTRODUCTION

Orthotopic liver transplantation (OLT) is today the gold standard treatment of the end-stage liver disease. Different solutions are used for graft preservation. Our objective was to compare the results of cadaveric donor OLT, preserved with the University of Wisconsin (UW) or Celsior solutions in the portal vein and Euro-Collins in the aorta.

METHODS

We evaluated retrospectively 72 OLT recipients, including 36 with UW solution (group UW) and 36 with Celsior (group CS). Donors were perfused in situ with 1000 mL UW or Celsior in the portal vein of and 3000 mL of Euro-Collins in the aortia and on the back table managed with 500 mL UW or Celsior in the portal vein, 250 mL in the hepatic artery, and 250 mL in the biliary duct. We evaluated the following variables: donor characteristics, recipient features, intraoperative details, reperfusion injury, and steatosis via a biopsy after reperfusion. We noted grafts with primary nonfunction (PNF), initial poor function (IPF), rejection episodes, biliary duct complications, hepatic artery complications, re-OLT, and recipient death in the first year after OLT.

RESULTS

The average age was 33.6 years in the UW group versus 41 years in the CS group (P = .048). There was a longer duration of surgery in the UW group (P = .001). The other recipient characteristics, ischemia-reperfusion injury, steatosis, PNF, IPF, rejection, re-OLT, and recipient survival were not different. Stenosis of the biliary duct occured in 3 (8.3%) cases in the UW group and 8 (22.2%) in the CS (P = .19) with hepatic artery thrombosis in 4 (11.1%) CS versus none in the UW group (P = .11).

CONCLUSION

Cadaveric donor OLT showed similar results with organs preserved with UW or Celsior in the portal vein and Euro-Collins in the aorta.

Long-term outcome and management of hepatopulmonary syndrome in children

We aim to report a single center experience of the management and long term outcome of HPS in pediatric liver transplant recipients. A retrospective review of children with HPS from 1990 to 2004.

INCLUSION CRITERIA

liver disease or portal hypertension, hypoxemia (PaO(2) < 70 mmHg or SaO(2) < 95%) and intrapulmonary shunting documented by macroaggregated albumin scan ratio of >4% (classified mild group [<20%], moderate group [20-40%] and severe group [>40%]). Resolution of HPS post-liver transplant was defined as PaO(2) > 70 mmHg or SaO(2) > 95%. Eighteen children (six male [34%], median age at diagnosis of HPS 8.6 [1-15.5] yr) had HPS: biliary atresia (n = 8), idiopathic biliary cirrhosis (n = 4), progressive intrahepatic cholestasis (n = 2), miscellaneous (n = 4). The majority had mild shunting (n = 8). Fourteen underwent transplantation with resolution of HPS in 13. Six developed complications: hepatic artery thrombosis (n = 4), biliary (n = 2). Four children died (28%), two pretransplant. There was a tendency towards shunt fraction worsening to a slower degree over time. One-yr survival rate post-transplant was 93%. Median PaO(2) was significantly lower in non-survivors compared to survivors (43 vs. 55.2 mmHg, p = 0.03). There was correlation between oxygen parameters pretransplant and time to HPS resolution post-transplant. HPS is reversible after transplant, but is associated with increasing mortality and morbidity.

Hepatopulmonary syndrome: use of extracorporeal life support for life-threatening hypoxia following liver transplantation

Hepatopulmonary syndrome is an uncommon complication of nonacute liver failure, and in rare cases, hypoxia may be the presenting sign of liver dysfunction. The condition, once thought to be a contraindication, is improved in most cases by transplantation. There is a significant risk of postoperative, hypoxia-related morbidity and mortality in patients with hepatopulmonary syndrome. We present a case of life-threatening hypoxia following liver transplantation for liver failure and associated hepatopulmonary syndrome, with successful management using extracorporeal membrane oxygenation.

Pretransplant risk factors and optimal timing for living-related liver transplantation in biliary atresia: experience of one Japanese children's hospital and transplantation center

BACKGROUND/PURPOSE

Although living-related liver transplantation (LRLT) is effective for patients with biliary atresia (BA) after a failed Kasai operation, the pretransplant factors affecting post-LRLT mortality and the optimal timing of the procedure remain unclear.

METHOD

A retrospective review of 27 patients with BA after a failed Kasai operation (median age, 22 months; range, 6-237 months) who received LRLT from 1994 to 2005 was done. The clinical characteristics at the time of the pre-LRLT assessment of those who did and did not survive were compared. A simple regression analysis and receiver operating characteristic analysis were done to correlate the clinical data.

RESULTS

Among the 27 patients, 4 patients died within 1 year post-LRLT. The significant factors affecting posttransplant death were hepatopulmonary syndrome (HPS), age at LRLT, and graft-to-recipient weight ratio. The arterial blood gas analysis of HPS patients showed that there was a significant negative correlation between the SaO(2) value on room air and the intrapulmonary shunt ratio. The receiver operating characteristic analysis of age at LRLT showed that the optimal cutoff point was 103 months of age.

CONCLUSION

Older children with HPS or a lower graft-to-recipient weight ratio are not ideal candidates for LRLT. The correlation between the shunt ratio and SaO(2) suggests that HPS could be detected early using pulse oximetry.

Impact of Mild and Moderate Intrapulmonary Shunting in Children with End-Stage Liver Disease Undergoing Liver Transplantation

AIM

The aim of this study was to evaluate the impact of mild and moderate intrapulmonary shunting (IPS) in children with end-stage liver disease (ESLD) undergoing liver transplantation.

MATERIALS AND METHODS

A total of 73 patients (38 male, 35 female; mean age 31.5 +/- 35.2 months, range 6-180 months) with ESLD and subsequent liver transplantation were enrolled. Based on contrast echocardiography, patients without IPS were assigned to group 1 (n = 57), and patients with mild or moderate IPS were assigned to group 2 (n = 17). The preoperative age, body weight, O(2) saturation, length of hospital stay, duration of mechanical ventilation, postoperative complications, and 1-year survival rate were compared between groups.

RESULTS

The overall incidence of IPS and 1-year survival rate were 23.3% (17/73) and 96% (70/73), respectively. There were significant differences between group 1 and group 2 patients regarding age at transplant (35.9 vs. 16.6 months, p = 0.002) and body weight (12.6 vs. 8.5 kg, p = 0.002). There were no other statistically significant differences between the two groups.

CONCLUSION

Although children with mild and moderate IPS were younger at the time of transplantation and had significantly lower body weight than those without IPS, the presence of mild and moderate IPS in children with ESLD did not affect the overall outcome of liver transplantation.

Long-term outcome of adult-to-adult living donor liver transplantation for post-Kasai biliary atresia

Our objective was to analyze problems in the perioperative management and long-term outcome of living donor liver transplantation (LDLT) for biliary atresia (BA). Many reports have described the effectiveness of liver transplantation (LT) for BA, particularly in pediatric cases, but little information is available regarding LT in adults (> or =16 years old). Between June 1990 and December 2004, 464 patients with BA underwent LDLT at Kyoto University Hospital, of whom 47 (10.1%) were older than 16 years. In this study, we compared the outcomes between adult (> or =16 years old) and pediatric (<16 years old) patients. The incidence of post-transplant intestinal perforation, intra-abdominal bleeding necessitating repeat laparotomy and biliary leakage was significantly higher (p < 0.0001, <0.001 and <0.001, respectively) in adults. Overall cumulative 1-, 5- and 10-year survival rates in pediatric patients were significantly higher (p < 0.005) than in adults. Two independent prognostic determinants of survival were identified: a MELD score over 20 and post-transplant complications requiring repeat laparotomy. Outcome of LDLT in adult BA patients was poorer than in pediatric patients. It seems likely that LT will be the radical treatment of choice for BA and that LDLT should be considered proactively at the earliest possible stage.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Implications for Liver Transplantation

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are uncommon pulmonary vascular consequences of advanced liver disease. HPS, characterized by arterial hypoxemia caused by pulmonary vascular dilatation, may resolve completely after liver transplantation. POPH, caused by vasoproliferation/constriction and obstruction of pulmonary arterial blood flow, is associated with higher risk for liver transplantation and increased post-transplantation mortality. With or without transplantation, survival in patients who have these syndromes is associated with specific oxygenation and hemodynamic variables.

Rapid progression of intrapulmonary arteriovenous shunting in polysplenia syndrome associated with biliary atresia

This report describes a patient with biliary atresia (BA) associated with polysplenia syndrome who showed a rapid progression of intrapulmonary arteriovenous shunting (IPS), resulting in a fatal outcome. Intrauterine ultrasonography at 36 weeks of gestation revealed fetal abnormalities, including situs inversus, absent retrohepatic inferior vena cava, and azygous connection. She was diagnosed postnatally as BA because of persistent acholic stool and neonatal jaundice. She underwent hepatic portoenterostomy at age 158 days. The gallbladder and the hepatic ducts were hypoplastic, and the common bile duct was absent. Magnetic resonance image and operative findings also identified polysplenia and an absent portal trunk. Liver histology showed cirrhotic changes and bile duct proliferation. Postoperatively, she achieved good bile secretion, with gradual decrease of total bilirubin. However, she had repeated febrile episodes, and computerized tomography at age 7 months showed multiple liver cysts. Thereafter, she presented with exertional dyspnea. Contrast-enhanced echocardiography showed IPS with a degree of 2/III at age 8 months and 3/III at 10 months. (99m)Technetium-labeled macroaggregated albumin ((99m)Tc-MAA) scintigraphy revealed a shunt ratio of 25.5% at 9 months and 39.7% at 10 months. Percutaneous transhepatic drainage of the bile cysts was performed without success. Sludged bile was obtained. However, respiratory distress rapidly progressed, and she died at age 11 months. In the present patient, the association of polysplenia syndrome and absent portal vein with BA, as well as liver cirrhosis, seemed to be contributing factors to rapid progression of IPS in early life.

Liver transplantation for hepatopulmonary syndrome: a ten-year experience in Paris, France

BACKGROUND

Although the possibility of reversing hepatopulmonary syndrome (HPS) after liver transplantation is now well established, the proportion of patients in whom reversibility is observed and the time to resolution of HPS remain uncertain.

METHODS

We analyzed the outcome of all adult patients with HPS who underwent orthotopic liver transplantation in all the liver transplant centers in Paris, during a 10-year period.

RESULTS

Twenty-three adult patients (median age, 47 years; range, 14-64) underwent transplantation in four institutions. Median PaO(2) was 52 (range, 32-67) mm Hg and median alveolar-arterial oxygen gradient was 66 mm Hg. When patients were breathing 100% O(2), median PaO(2) was 310 (range, 74-663) mm Hg. Median isotopic shunt ratio was 33% (range, 0-80%). The overall mortality during the study period was 30.5% (7/23). Perioperative mortality was 8.5%, whereas late mortality was 22%. None of the preoperative characteristics of HPS (isotopic shunt ratio, PaO(2) on room air or on 100% oxygen) was associated with overall postoperative mortality. Of the 21 patients surviving the perioperative period (median follow-up, 17 months; range, 0.5-72), a decrease in alveolar-arterial oxygen gradient of at least 5 mm Hg and at least 10 mm Hg was observed in 21 of 21 and in 18 of 21 patients, respectively, with great variations in the time of improvement. The threshold of 70 mm Hg was reached in 15 patients. The lower the preoperative PaO(2), the longer the time to reach this point.

CONCLUSION

Our data strongly support the role of orthotopic liver transplantation in adult patients with HPS, regardless of its severity.

Local expression of tumor necrosis factor-alpha and interleukin-10 on wound healing of intestinal anastomosis during endotoxemia in mice

BACKGROUND

This study aimed to evaluate the integrity of anastomotic wound healing after digestive surgery under septic conditions and define the participation of local expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) around the anastomotic segment.

MATERIALS AND METHODS

Experimental animals were divided into lipopolysaccharide (LPS) and control groups, which had either LPS or normal saline solution injected into the peritoneal cavity 24 h before transection and anastomosis of the colon. Anastomotic bursting pressure (ABP) and tissue hydroxyproline concentration (HP) were measured as indicators of wound healing. Immunohistochemical staining for TNF-alpha and IL-10 on tissue samples obtained from the anastomotic segment were examined 1, 6, and 24 h after the operation. The reactive cells were counted under light microscopy.

RESULTS

ABP and HP were significantly lower in the LPS group than in the control group 7 days after surgery. In the LPS group, TNF-alpha expression increased about threefold over that in the control group 1 h after the operation. TNF-alpha-reactive cells were observed until 24 h after the operation in the LPS group, but not in the control group. On the other hand, IL-10 was not expressed in the control group during the observed period, whereas IL-10 was observed 24 h after the operation in the LPS group.

CONCLUSIONS

It is suggested that anastomotic wound healing was impaired after the digestive surgery in animals treated with intraperitoneal LPS, and that local expression of TNF-alpha and IL-10 at the anastomotic site acts as an inhibitory factor in the wound healing process.

Early appearance of echo-contrast simulating an intracardiac shunt in a patient with liver cirrhosis and intrapulmonary shunting

Time of appearance of agitated saline contrast in the left atrium is one of the distinguishing features between intracardiac and intrapulmonary shunt. We report a patient with hepatic cirrhosis who had intrapulmonary shunting and had appearance of peripheral venous saline contrast injection in the left heart chambers within 3 cardiac cycles after its appearance in the right heart chambers despite absence of an intracardiac shunt. Thus, time of appearance of saline contrast in the left heart chambers should not be the sole criterion to distinguish intracardiac from intrapulmonary shunt.

Development of intrapulmonary arteriovenous shunting in postoperative biliary atresia: evaluation by contrast-enhanced echocardiography

PURPOSE

This report presents biliary atresia (BA) patients with intrapulmonary arteriovenous shunting (IPS), which was evaluated suitably by contrast-enhanced echocardiography (CEC).

METHODS

Of 88 BA patients seen in the last 20 years, 8 (9.1%) had IPS at 8 months to 16 years of age. Two were associated with polysplenia syndrome, 1 had persistent jaundice after hepatic portoenterostomy, and 2 underwent splenorenal shunt. According to the comparison between microbubbles in left atrium (LA) and in right atrium (RA) detected by CEC, IPS was classified as grade I, mild (LA << RA); grade II, moderate (LA < RA); grade II, severe (LA = RA).

RESULTS

Grade I consisted of 4 patients whereas grade II and III held 2 patients each. Clinical symptoms such as cyanosis, exertional dyspnea, or clubbing were present in 50% of grade I and all of grade II and IlI. Mean PaO2 in grade I, II, and III was 70.5, 50.4, and 35.3 mm Hg, respectively. In 1 patient with grade I, IPS spontaneously disappeared, but pulmonary hypertension developed later. One patient in grade II died of pulmonary complications, and the other is considered a candidate for livertransplantation (LTx). One patient in grade III died of liver failure, whereas the other is free of IPS after LTx.

CONCLUSION

IPS can lead to a life-threatening complication in postoperative BA patients, and CEC may be a convenient and useful method to evaluate the degree of IPS and determine therapeutic strategy.

Hepatopulmonary syndrome: a prospective study of relationships between severity of liver disease, PaO(2) response to 100% oxygen, and brain uptake after (99m)Tc MAA lung scanning

BACKGROUND

Because of the spectrum of intrapulmonary vascular dilation that characterizes hepatopulmonary syndrome (HPS), PaO(2) while breathing 100% oxygen varies. Abnormal extrapulmonary uptake of (99m)Tc macroaggregated albumin (MAA) after lung perfusion is common.

GOAL

To describe relationships between (1) severity of liver disease measured by the Child-Pugh (CP) classification; (2) PaO(2) while breathing room air (RA) and 100% oxygen on 100% oxygen; and (3) extrapulmonary (brain) uptake of (99m)Tc MAA after lung scanning.

METHODS AND PATIENTS

We prospectively measured PaO(2) on RA, PaO(2) on 100% oxygen, and brain uptake after lung perfusion of (99m)Tc MAA in 25 consecutive HPS patients.

RESULTS

Mean PaO(2) on RA, PaO(2) on 100% oxygen, PaCO(2) on RA, and (99m)Tc MAA brain uptake were similar when categorized by CP classification. Brain uptake was abnormal (> or = 6%) in 24 patients (96%). Brain uptake was 29 +/- 20% (mean +/- SD) and correlated inversely with PaO(2) on RA (r = -0.57; p<0.05) and PaO(2) on 100% oxygen (r = -0.41; p<0.05). Seven patients (28%) had additional nonvascular pulmonary abnormalities and lower PaO(2) on 100% oxygen (215+/-133 mm Hg vs 391+/-137 mm Hg; p<0.007). Eight patients (32%) died. Mortality in patients without coexistent pulmonary abnormalities was associated with greater brain uptake of (99m)Tc MAA (48+/-18% vs 25+/-20%; p<0.04) and lower PaO(2) on RA (40+/-7 mm Hg vs 57+/-11 mm Hg; p<0.001).

CONCLUSION

The degree of hypoxemia associated with HPS was not related to the CP severity of liver disease. HPS patients with additional nonvascular pulmonary abnormalities exhibited lower PaO(2) on 100% oxygen. Mortality was associated with lower PaO(2) on RA, and with greater brain uptake of (99m)Tc MAA.

Nitric oxide production and hepatic dysfunction in patients with postoperative sepsis

1. Although hepatic function is well known to deteriorate following bacterial infection, the underlying mechanisms remain poorly understood. We have previously reported that nitric oxide (NO) radical leads to a decrease in the ketone body ratio (KBR) and in ATP content due to the inhibition of mitochondrial electron transport in primary cultured rat hepatocytes. 2. To evaluate the effects of NO radical on the liver in patients with postoperative sepsis, we analysed both the stable end-product of nitric oxide radical (NOx) as well as the arterial KBR (AKBR), which reflects liver tissue NAD+/NADH. 3. Twenty patients who had undergone general abdominal surgery and who developed postoperative sepsis were divided into two groups: (i) surviving; and (ii) non-surviving. Blood samples were collected before the development of postoperative sepsis and every 3 days until the patient either died or was discharged from hospital. 4. Plasma NOx levels in seven patients who subsequently died became progressively higher than those in the 13 surviving patients over the clinical course of postoperative sepsis. 5. In the non-surviving group, the AKBR was significantly lower than in surviving patients, indicating impaired hepatic function. In contrast, plasma NOx levels in non-surviving patients were significantly higher than in surviving patients. 6. Decreases in AKBR to levels below 0.7 in non-surviving patients followed high NOx levels. Moreover, plasma NOx levels were closely correlated with the AKBR, indicating that NO radical is associated with mitochondrial dysfunction in the liver. 7. It is likely that the overproduction of NO radical plays an important role in causing fatal metabolic disorders in patients with postoperative sepsis.

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.

Intrapulmonary shunting in biliary atresia before and after living-related liver transplantation

BACKGROUND

Intrapulmonary shunting (IPS) is frequently observed and causes hypoxaemia in liver cirrhosis. This study investigated the prevalence, predictors of reversibility and the effect of living-related liver transplantation (LRLT) on IPS using contrast echocardiography in patients with end-stage biliary atresia.

METHODS

Fifty consecutive patients with biliary atresia were examined for IPS using contrast echocardiography before and after LRLT until IPS disappeared. The severity of IPS was classified into five grades according to the extent of contrast in the left ventricle (0, none; 1, trivial; 2, apparent; 3, complete but less than in right ventricle; 4, as dense as in right ventricle).

RESULTS

Thirty-two patients (grade 1, n = 15; grade 2, n = 7; grade 3, n = 4; grade 4, n = 6) had IPS before LRLT. Forty-four patients have survived for 9-26 months after LRLT. Among patients with grade 3 or 4 IPS (n = 8), there was a significant correlation between age at LRLT and the duration of IPS persistence after LRLT (P = 0.044).

CONCLUSION

IPS takes longer to disappear in older children than in younger ones, but always disappears eventually. LRLT is an effective treatment for biliary atresia with IPS. Presented to the 31st annual meeting of the Pacific Association of Pediatric Surgeons, Maui, Hawaii, June 1998

Long-term outcome of living related liver transplantation for patients with intrapulmonary shunting and strategy for complications

BACKGROUND

In 320 living related liver transplantation performed between June 1990 and September 1997, there were 21 living related liver transplantation for patients with intrapulmonary shunting, manifested by digital clubbing, cyanosis, and dyspnea. We report the long-term outcome for more 6 months and our strategy to overcome complications in these recipients.

PATIENTS

A total of 21 patients (age range 2-33 years, 19 children and 2 adults, 6 males and 15 females) were classified into three grades according to shunt ratio calculated by TcMAA pulmonary scintigraphy; 5 in mild group (shunt ratio: less than 20%), 6 in moderated group (20%-40%), and 10 in severe group (more than 40%). The original underlying liver disease was biliary atresia in all patients.

RESULTS

Spearmen's correlation coefficient rank test revealed that shunt ratio correlated significantly with PaO2 in room air (P=0.0001), PaO2 in 100% oxygen (P=0.0004), hematocrit (P=0.0276), and period of dyspnea before transplantation (P=0.023).

COMPLICATIONS

Wound infection occurred in 80, 66, and 80%, and bile leakage in 20, 0, 40% in mild, moderate, and severe group, respectively. Patients who had portal vein thrombosis, and intracranial complication were classified as severe group and the incidence was 20 and 20%, respectively. The patient actuarial one year survival was 80, 66.7, and 48%, in mild, moderate, and severe group, respectively, although there was no significant difference. All patients who survived improved hepatopulmonary syndrome and the length of period required for the resolution was significantly correlated to the preoperative shunt ratio (P=0.023).

COMMENTS

Patients with severe shunting are susceptible to wound infection and bile leak. The trend of higher incidence of portal thrombosis and intracranial complications in the severe group was closely related high hematocrit. Secure surgical technique to reduce bile leak and delayed primary wound closure to reduce wound infection were found to be effective. Anticoagulant therapy by infusing heparin through the portal vein followed by coumadin could prevent fatal portal vein thrombosis without counter risk of fatal cerebral hemorrhage.

Biliary complications in pediatric living related liver transplantation

BACKGROUND

The goal of this study was to evaluate cause and outcome of biliary complications occurring after pediatric living related liver transplantation (LRLT).

METHODS

A database of 205 pediatric patients (71 male and 134 female) undergoing 208 LRLT from June 1990 to April 1996 was reviewed.

RESULTS

The overall incidence of bile duct complications was 13.9% (29 patients). There were 19 bile leaks, 7 anastomotic strictures, 8 intrahepatic biliary complications, and the bile duct was ligated inadvertently in 2 cases. Logistic regression analysis revealed hepatic artery thrombosis, ABO incompatible transplantation, intrapulmonary shunting in recipients, mode of artery reconstruction, and cytomegalovirus infection were all significant risk factors for biliary complications.

CONCLUSIONS

Avoidance of ABO incompatible transplantation where possible, routine use of microvascular techniques for hepatic artery reconstruction to minimize the risk of artery thrombosis, earlier transplantation for patients with intrapulmonary shunt, and prophylaxis against cytomegalovirus infection should all reduce the rate of biliary complications after LRLT in pediatric recipients.

Pediatric solid organ transplantation

Solid organ transplantation offers hope for long-term survival and more normal lifestyles for children. Many of the procedures used are scaled-down versions of those used in adults and are associated with distinct challenges in children. Recent studies have provided insights into how transplantation can best serve these patients.