Is the Kasai operation still indicated in children older than 3 months diagnosed with biliary atresia?

Integrin alphavbeta6 and mediators of extracellular matrix deposition are up-regulated in experimental biliary atresia

INTRODUCTION

Biliary atresia (BA) is a progressive obliteration of the extrahepatic bile ducts resulting in hepatic fibrosis. The underlying mechanisms have not been defined. We used an animal model of BA to evaluate mediators of extracellular matrix (ECM) processing to determine which factors may be involved.

METHODS

Newborn BALB/c mice received an intraperitoneal injection with rhesus rotavirus or saline within 24 h of birth. Livers were harvested on days 7 and 14 for histology and immunohistochemistry (IHC). RNA expression was determined using quantitative real-time PCR. Human liver from patients with BA and those having a resection for nonfibrosing diseases was also evaluated.

RESULTS

In experimental mice, mRNA expression for tissue inhibitor of metalloproteinase (TIMP)-1 and matrix metalloproteinase (MMP)-7 was increased 18-fold and 69-fold, respectively on day 7, with further increases on day 14. On day 14, mRNA expression for plasminogen activator inhibitor (PAI)-1 (38-fold), TIMP-4 (9.5-fold), and MMP-9 (5.5-fold) mRNA was also observed. Furthermore, integrin alpha(v) beta(6) mRNA expression was increased on days 7 (11-fold) and 14 (6-fold). Presence of integrin alpha(v) beta(6) protein was confirmed by IHC in both mouse and human specimens in the proliferating biliary epithelium.

CONCLUSIONS

Our data suggest experimental BA is associated with increased mRNA expression of ECM degradation inhibitors, TIMP-1, PAI-1, and TIMP-4. MMP-7 and MMP-9 expression is also elevated in this model. Furthermore, increased gene expression of integrin alpha(v)beta(6) was demonstrated and IHC confirmed protein expression. Integrin alpha(v)beta(6) or the inhibitors of ECM breakdown may be attractive targets for future treatment strategies.

Surgical outcome in biliary atresia: etiology affects the influence of age at surgery

OBJECTIVE

The exact nature of the relationship between age at Kasai portoenterostomy (KP) for biliary atresia (BA) and outcome is controversial.

METHODS

Single-center retrospective analysis of consecutive cases (January 1994-December 2005) undergoing KP, using 2 dichotomous measures of outcome (clearance of jaundice to <20 micromol/L and native liver survival at 2 years post-KP). Outcome was analyzed by age cohort (<30 days, 30-40 days, etc) and cumulatively. Data are quoted as median (interquartile range). Statistical analysis was by extended Fisher r x c analysis. P < 0.05 was regarded as significant.

RESULTS

Two hundred twenty-five infants with BA were divided into 3 groups based on possible etiology: isolated BA (n = 177), biliary atresia splenic malformation (BASM) syndrome (n = 28), and cystic BA (n = 23). Three infants had both BASM and a cyst. Age at KP was significantly greater in those with isolated BA [58 (48-61)] compared with both BASM [47 (39-59); P = 0.02] and cystic BA [47 (39-54); P = 0.02]. Overall, 127 (56%) cleared their jaundice and 145 (65%) survived to 2 years with their native liver. Children with isolated BA showed no statistical difference by age cohort for clearance of jaundice (P = 0.75) or for native liver survival (P = 0.14). In contrast, there was a marked detrimental effect of age at KP for both BASM and cystic BA groups (P = 0.02).

CONCLUSION

There is a marked detrimental effect of age at KP on groups with a presumed "developmental" origin, not seen in the majority with isolated BA.

Biliary atresia: Swiss national study, 1994-2004

OBJECTIVES

To determine the epidemiology of biliary atresia (BA) in Switzerland, the outcome of the children from diagnosis, and the prognostic factors.

PATIENTS AND METHODS

The records of all patients with BA born in Switzerland between January 1994 and December 2004 were analyzed. Survival rates were calculated with the Kaplan-Meier method, and prognostic factors evaluated with the log rank test. Median follow up was 58 months (range, 5-124).

RESULTS

BA was diagnosed in 48 children. Incidence was 1 in 17,800 live births (95% confidence interval 1/13,900-1/24,800), without significant regional, annual, or seasonal variation. Forty-three children underwent a Kasai portoenterostomy (PE) in 5 different Swiss pediatric surgery units. Median age at Kasai PE was 68 days (range, 30-126). Four-year survival with native liver after Kasai PE was 37.4%. Liver transplantation (LT) was needed in 31 in 48 children with BA, including 5 patients without previous Kasai PE. Four patients (8%, all born before 2001) died while waiting for LT, and 29 LT were performed in 27 patients (28 in Geneva and 1 in Paris). All of the transplanted patients are alive. Four-year overall BA patient survival was 91.7%. Four-year survival with native liver was 75% in patients who underwent Kasai PE before 46 days, 33% in patients operated on between 46 and 75 days, and 11% in patients operated on after 75 days (P = 0.02).

CONCLUSIONS

Overall survival of patients with BA in Switzerland compares favorably with current international standards, whereas results of the Kasai operation could be improved to reduce the need for LTs in infancy and early childhood.

Biliary atresia: the Canadian experience

OBJECTIVE

To determine the outcomes of Canadian children with biliary atresia.

STUDY DESIGN

Health records of infants born in Canada between January 1, 1985 and December 31, 1995 (ERA I) and between January 1, 1996 and December 31, 2002 (ERA II) who were diagnosed with biliary atresia at a university center were reviewed.

RESULTS

349 patients were identified. Median patient age at time of the Kasai operation was 55 days. Median age at last follow-up was 70 months. The 4-year patient survival rate was 81% (ERA I = 74%; ERA II = 82%; P = not significant [NS]). Kaplan-Meier survival curves for patients undergoing the Kasai operation at age < or = 30, 31 to 90, and > 90 days showed 49%, 36%, and 23%, respectively, were alive with their native liver at 4 years (P < .0001). This difference continued through 10 years. The 2- and 4-year post-Kasai operation native liver survival rates were 47% and 35% for ERA I and 46% and 39% for ERA II (P = NS). A total of 210 patients (60%) underwent liver transplantation; the 4-year transplantation survival rate was 82% (ERA I = 83%, ERA II = 82%; P = NS).

CONCLUSIONS

This is the largest outcome series of North American children with biliary atresia at a time when liver transplantation was available. Results in each era were similar. Late referral remains problematic; policies to ensure timely diagnosis are required. Nevertheless, outcomes in Canada are comparable to those reported elsewhere.

Biliary atresia: interdisciplinary initiatives focus on a rare disease

During the last decade, biliary atresia (BA) has attained more interest and the frequency of BA-related publications has increased continuously. Pediatric hepatologists and pediatric surgeons are very active in improving diagnosis and treatment modalities of BA patients, in order to prolong the survival rate of their native liver. Together with transplant surgeons, the bridging of BA patients to liver transplantation (LTx) becomes optimized and as a consequence of this interdisciplinary approach, the overall survival of babies with BA has already reached 90%. Furthermore, basic research into the still unknown origin of BA has advanced, and numerous scientific programs have already linked together. The overriding interest is to discover at least BA's etiology and to turn the treatment of BA patients from a symptomatic to a causative approach. Interdisciplinary and international programs are mandatory and already existing initiatives in Europe, the United States and Japan are going to coordinate their registries, clinical trials and basic research studies for the benefit of the patients and solve the riddle of BA.

Cholestasis associated with small bowel atresia: do we always need to investigate?

BACKGROUND/PURPOSE

Cholestasis occurs frequently in patients with small bowel atresia (SBA) and is often attributed to prolonged parental nutrition. When severe or prolonged, patients may undergo unnecessary intensive or invasive investigation. We characterized cholestasis and analyzed the pertinence of investigating this patient population.

METHODS

With Research Ethics Board approval, patients with SBA between 1996 and 2005 were retrospectively reviewed. Demographics, location of atresia, operative findings, complications, investigations, resumption of feeding, duration of prolonged parental nutrition, and follow-up information were examined. Cholestasis was evaluated for incidence, severity, and evolution.

RESULTS

Fifty-five patients (29 male, 26 female), with a median gestational age and birth weight of 36 weeks and 2025 g, respectively, were reviewed. Care was withdrawn for 2 patients before repair. For the remaining 53 patients, SBA were duodenal atresia in 18, jejunoileal atresia in 32, and multiple atresia in 3. Of 53, 24 (45%) patients developed cholestasis postoperatively (direct/total bilirubin >20%). All patients with short bowel (4) and 60% (6/10) of patients with a delay of enteral feeding more than 14 days postoperatively had cholestasis. Ten patients (36%) proceeded with in-depth evaluations for cholestasis, with 8 (28%) undergoing liver biopsy. No patient had biliary atresia. No deaths were related to isolated cholestasis/cirrhosis. Cholestasis resolved spontaneously in all the survivors.

CONCLUSIONS

Small bowel atresia is frequently associated with postoperative cholestasis that will resolve with time. We recommend a more selective and expectant approach to SBA-associated cholestasis to minimize unnecessary investigations.

Minimal Access Portoenterostomy: Advantages and Disadvantages of Standard Laparoscopic and Robotic Techniques

PURPOSE

Minimal access portoenterostomy (Kasai procedure) for biliary atresia represents a technically challenging operation. The standard laparoscopic approach yields results comparable to the open technique. After an initial experience with standard laparoscopy, we assessed the potentially superior optics and dexterity of a surgical robotic system for performing portoenterostomy. We reviewed our experience with minimal access portoenterostomy to compare the relative advantages and disadvantages of standard laparoscopic and robotic approaches to biliary atresia.

MATERIALS AND METHODS

We reviewed the charts of all patients who underwent either laparoscopic or robotic portoenterostomy at our institution between October 2002 and October 2005. Outcome measures included the need to convert to laparotomy, complications, functional outcome expressed either as the direct bilirubin at most recent follow-up (> or = 3 months) or age at transplant, and density of adhesions at transplant. Surgeons' impressions of the two minimal access modalities were also reviewed.

RESULTS

A total of 10 patients underwent minimal access portoenterostomy (7 standard laparoscopy; 3 robotic-assisted). Mean follow-up was 20 months (range, 1-36 months). There were no conversions to laparotomy and no intraoperative complications. There was one port site infection that resolved with antibiotics. Five patients (4 laparoscopic, 1 robotic) had progressed to transplantation at the time of follow-up. At transplant, one patient had mild adhesions and two had dense adhesions. Adhesions were not noted for 2 patients.

CONCLUSION

We believe both surgical modalities are feasible from a technical point of view. However, the optical and dexterity advantages of the robotic system were offset by the large instrument size and lack of force feedback.

Neonatal liver disease

Establishing a rapid and accurate diagnosis of the cause of neonatal liver disease is an urgent matter. The initial detection of this condition relies on the sensitivity of the primary care provider or pediatrician to the signs and symptoms of jaundice and abnormal stool and urine color. It is critical to evaluate jaundice in any infant older than 2 weeks with measurement of fractionated bilirubin, and further assessment is necessary if the direct value is above 1.0 mg/dL in the setting of a total bilirubin of less than 5.0 mg/dL or a direct bilirubin of more than 20% of total if the total is more than 5.0 mg/dL. A diagnostic algorithm for the evaluation of infants who meet these criteria can guide physicians in selecting appropriate and timely diagnostic testing and referral to pediatric gastroenterology for these patients, whose outcome will rely on rapid diagnosis.

Pathogenesis and treatment opportunities for biliary atresia

Biliary atresia is the single most common cause of chronic cholestasis in children and is the leading indication for liver transplantation worldwide. It results from an inflammatory and fibrosing obstruction of the extrahepatic bile ducts in the first few months of life. Early diagnosis and timely surgical portoenterostomy are necessary for improved biliary drainage, but the liver disease progresses to end-stage biliary cirrhosis in most patients. Although the pathogenesis of disease is largely unknown, recent patient- and animal-based experiments indicate interactions between infectious agents and inflammatory circuits may be important pathogenic mechanisms of disease.

Seamless management of biliary atresia in England and Wales (1999-2002)

BACKGROUND

Before 1999, infants born in the UK with suspected biliary atresia were investigated in regional centres, and, if confirmed, a Kasai operation was done there. Since 1999, all infants with suspected biliary atresia in England and Wales, UK, have been referred to one of three designated centres where both the Kasai operation and liver transplantation (if necessary) could be done.

METHODS

We assessed clearance of jaundice (bilirubin <20 micromol/L) as an early outcome in all cases of biliary atresia referred from one of the three centres. We then estimated survival using the Kaplan-Meier method with endpoints of liver transplantation or death.

FINDINGS

148 infants with biliary atresia were treated between January, 1999, and June, 2002. A primary portoenterostomy was done in 142 (96%) infants and a primary liver transplant in five (3%). One child died before any intervention. Early clearance of jaundice after portoenterostomy was achieved in 81 of 142 (57%) infants. Liver transplantation was done in 52 (37%) of those undergoing portoenterostomy. 13 (9%) infants died. Of the 135 children who survived, 84 (62%) still have their native liver and 51 (38%) had transplantation. The median follow-up of survivors was 2.13 (range 0.5-4.1) years. The overall 4-year estimated actuarial survival was 89% (95% CI 82-94). The 4-year estimated actuarial survival with native liver was 51% (42-59%).

INTERPRETATION

Our early results suggest that surgical outcome can be improved by centralisation of care to supra-regional centres.

The outcome of the older (> or =100 days) infant with biliary atresia

BACKGROUND

There is a detrimental effect of increasing age on the results of the Kasai portoenterostomy for biliary atresia (BA), and some centers routinely advocate primary liver transplantation for the older infant, irrespective of other criteria. This perception that such infants are indeed irretrievable was tested by retrospective analysis.

METHODS

All infants who had undergone surgery for BA during the period 1980 through 2000 aged > or =100 days were reviewed. Actuarial survival was calculated using 2 end-points (death and transplantation). A retrospective review of their ultrasonography (n = 12) and preoperative liver histology (n = 22) was also undertaken to ascertain possible predictive criteria.

RESULTS

A total of 422 infants had BA diagnosed during this period, of which 35 (8.2%) were > or =100 days at surgery (median [interquartile range], 133 [range, 108 to 180] days). Surgery included portoenterostomy (n = 26), hepaticojejunostomy (n = 7), and a resection and end-to-end anastomosis (n = 1). A laparotomy only was performed in 1. Five- and 10-year actuarial survival rate with native liver was 45% and 40%, respectively. Currently, 12 (35%) patients are alive with their native liver (8 are anicteric), 9 (28%) have undergone transplantation, and 13 have died. Although there were some survival advantages for types 1 or 2 BA and "noncirrhosis" at time of surgery, neither reached statistical significance. Individual histologic features (eg, degrees of fibrosis, giant cell transformation, bile duct destruction) in the retrospective review of available material were not discriminatory. The finding of a "heterogeneous" parenchyma on ultrasonography was predictive of poor outcome but lacked sensitivity.

CONCLUSIONS

The potential for reasonable medium-term survival is present in about one third of infants 100 days or older coming to primary corrective surgery. In the absence of accurate discrimination, the authors continue to favor this option rather than subject all to transplant simply on the basis of age.

Biliary atresia

Biliary atresia (BA) is a congenital obliterative cholangiopathy of unknown aetiology, affecting both the intra- and extrahepatic bile ducts. Although relatively rare, BA must be excluded in any infant with conjugated hyperbilirubinaemia since the prognosis is improved by early diagnosis and prompt surgery. At least two phenotypes of BA are currently recognized; the syndromic variety is associated with other congenital anomalies and a poorer outcome. The results of treatment have steadily improved and, with a combination of timely expert surgery (Kasai portoenterostomy) and liver transplantation in specialist centres, good quality long-term survival is now possible in more than 90% of affected patients. A better understanding of the aetiology of BA and the pathogenesis of hepatic fibrosis is needed in order to develop new therapeutic strategies.

Portoenterostomy for biliary atresia: Long-term survival and prognosis after esophageal variceal bleeding

BACKGROUND/PURPOSE

Portoenterostomy is the procedure of choice in patients with biliary atresia. The authors analyzed the long-term survival rate and complications of the procedure in children operated on at The University of Hong Kong Medical Centre between 1979 and 2000.

METHODS

Seventy-seven consecutive patients were analyzed by retrospective chart review. The patients were divided into groups according to postoperative bile flow, decade of operation, and age at operation. The data were analyzed statistically.

RESULTS

The overall actuarial transplant-free survival rate was 68% at 10 years after operation. For patients with poor, partial, and good postoperative bile flow, transplant-free survival rate was 0%, 22%, and 96%, respectively (P <.001). Age and decade of operation were not significant risk factors. Esophageal variceal bleeding occurred in 13 patients and was a prognostic indicator for end-stage liver failure (P =.044); the poor prognosis of patients with variceal bleeding, however, was related to poor or partial initial bile drainage.

CONCLUSIONS

The postoperative serum bilirubin level is the most important predictor of long-term survival in patients with portoenterostomy for biliary atresia. Esophageal hemorrhage is not an absolute indication for urgent liver transplantation in patients with good bile drainage.

The neonatal liver: Part III: Pathophysiology of liver dysfunction

The liver, the largest organ in the body, is critical to a number of key metabolic functions. Its also plays an important role in removing the waste products of metabolism (particularly ammonia) and in detoxifying drugs and other substances such as endogenous hormones and steroid compounds. In addition, the liver plays a major role in the production of clotting factors, plasma proteins, bile salts, and bilirubin. Many neonates display signs of hepatic dysfunction such as hyperbilirubinemia, hepatomegaly, or elevated liver enzymes. These often occur secondary to systemic illness, such as sepsis or hypoxic injury, or following the use of drugs or parenteral nutrition to treat other problems. Although rare, primary liver disease does occur in neonates and must be recognized promptly, with treatment initiated in a timely manner to prevent unnecessary sequelae. This article, the third in a series on the liver, examines causes of liver dysfunction in neonates, beginning with an overview of jaundice and hepatomegaly and moving to a discussion of specific diseases.

Update on the etiologies and management of neonatal cholestasis

The early detection of cholestatic liver disease is one of the major challenges facing pediatricians when evaluating the jaundiced infant. Early recognition of liver disease greatly facilitates the care and outcome of infants, because several serious life-threatening disorders may have cholestasis as a major presenting sign of underlying neonatal liver disease. A key component of the work-up is measurement of serum conjugated bilirubin levels, which if elevated should prompt the clinician to initiate a work-up to determine the cause of neonatal cholestasis. In general, if a patient is developing progressive jaundice soon after birth, is still jaundiced at 2 weeks of life, or develops jaundice within the first month of life, a work-up for neonatal cholestasis should begin. A number of previously undiagnosed causes of neonatal cholestasis are beginning to be assigned genetic and infectious etiologies, with significant implications for the work-up and management of cholestatic infants.

Biliary atresia: an update on our understanding of the disorder

Biliary atresia is the leading cause of cholestasis in infants younger than 3 months. It is also the leading indication for liver transplantation in children. This review focuses on recent advances in the etiology, diagnosis, and management of biliary atresia.