Outcome of “Successful” Biliary Atresia Patients

A recent publication (J Pediatr 2014; 165: 539-546) from the Childhood Liver Disease Research and Education Network (CHiLDREN) provides a strong rationale for close followup of biliary atresia (BA) patients with their native livers.  The Biliary Atresia Study of Infants and Children (BASIC) is one of the ongoing longitudinal studies within CHiLDREN.

Among a cross-sectional study BASIC cohort of 219 children (median age 9.7 years) who survived with their native livers for at least 5 years, they had the following findings:

  • In preceding 12 months, cholangitis occurred in 17%, and 62% had experienced cholangitis at least once following hepatoportoenterostomy (HPE) (also called Kasai procedure.  The authors note wide discrepancy in usage of prophylactic antibiotics; some stop at 2 years following HPE and some never stop antibiotic prophylaxis.
  • In preceding 12 months, bone fractures occurred in 5.5%.  Overall, 15% had had at least one bone fracture at some point, which is higher than the general population. Only 14.6% of entire cohort were receiving vitamin D supplementation.
  • Portal hypertension: clinically detectable splenomegaly, thrombocytopenia, ascites, and variceal hemorrhage were seen in 56%, 43%, 17%, and 9% of patients in this cohort.
  • Health-related quality of life was reported as normal in 53%
  • Mean height and weight z-scores were normal in this cohort.
  • Over 98% had clinical or biochemical evidence of chronic liver disease.

Full-text Link

Bottomline: This BASIC study shows the need for careful followup of “successful” biliary atresia patients and provides more accurate data regarding risks of specific complications.

Briefly noted: J Pediatr 2014; 165: 547-55.  In this study with same first author (Vicky Ng), the investigators develop and validate a pediatric liver transplantation (LT) quality of live instrument for LT patients aged 8-18 years.

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Pulmonary Complications Associated with Chronic Liver Disease

A useful review of “pulmonary complications in chronic liver disease” (Hepatology 2014; 59: 1627-37) has been published.

The main topics included hepatopulmonary syndrome (HPS) , portopulmonary hypertension (POPH), and hepatic hydrothorax (HH).

A few of the key points:

HPS is most common of these conditions and is identified in 5-30% of cirrhosis patients.  It is identified with abnormal oxygenation (screening with pulse ox <96%) due to intrapulmonary vascular dilatations. There is no established medical therapy.  It is reversible with liver transplantation.

The hallmark of POPH is the development of pulmonary arterial hypertension associated with portal hypertension.  It occurs in 5-10% of cirrhosis patients and often presents as dyspnea on exertion/fatigue.  There are numerous pharmacologic treatments that may be useful, include the following:

  • prostacyclin analogs like epoprostenol
  • endothelin receptor antagonists like boesentan
  • phosphodiesterase-5 inhibitors like sildenafil, vardenafil, and tadalafil

Severe POPH is a relative contraindication for liver transplantation.

HH is a transudative pleural effusion seen in 5-10% of cirrhosis patients. Initial management includes salt restriction and diuretics.  Transjugular intrahepatic portosystemic shunt and thoracentesis are second-line options.  Liver transplantation is curative.

Related blog entries:

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

 

 

Expert advice on portal hypertension

A consensus report on portal hypertension has helpful advice on a broad range of management issues and should be kept in mind as a handy reference (Pediatr Transplantation 2012; 16: 426-37).  The report is concise and full of bullet points.  It is based on a meeting of pediatric experts to modify adult guidelines (Baveno V) for pediatrics.

In many instances, the experts indicate that there is not enough pediatric data. Specific subjects include the following (along with some points):

  • Treatment options for portal hypertension -consider screening for varices if thrombocytopenia and splenomegaly.  ‘No indication to use beta-blockers to prevent varices.’
  • Prevention of first bleeding episode -in the presence of varices (grade II or III), variceal ligation reasonable in selected children and/or within context of defined research protocols. Grade I varices can be flattened with insufflation, and grade III varices are confluent around circumference of esophagus (per Japanese Research Society for Portal HTN analysis)
  • Role of hepatic venous pressure gradient measurement (HVPG) -‘panel was undecided as to whether HVPG measurements in children’ should be ‘part of specialized clinical practice or’ a research tool.
  • Blood volume restitution -suggests use of platelets in cases of bleeding with profound thrombocytopenia (<20,000).
  • Antibiotic prophylaxis -unclear whether empiric antibiotics in children are needed in the presence of variceal bleeding.
  • Management of treatment failures -can retry endoscopy and if fails, consider transjugular intrahepatic portosystemic shunting (TIPS)
  • Management of gastric varices -only case reports in children, thus no evidence-based recommendations.
  • Prevention of rebleeding -variceal ligation (EVL) preferred in patients with cirrhosis.  EVL should be performed every 2-4 weeks up to five sessions to eradicate varices after 1st bleed.
  • Treatment of portal vein obstruction -diagnosis, natural history, anticoagulation, use of MesoRex bypass procedure, associated portal biliopathy -diagnosis and treatment.  With regard to MesoRex, ‘controversy exists as to the appropriateness of ..this procedure in an asymptomatic child.’ Surveillance endoscopy may assist in decision-making.
  • Hypersplenism with portal vein obstruction-in the presence of platelet count <50,000 and portal vein obstruction, strong consideration should be given to MesoRex procedure.
  • Portopulmonary hypertension and hepatopulmonary syndrome -important to monitor oxygen saturation in patients with portal vein obstruction/other causes of portal hypertension. If <97%, additional investigation may be needed.  Portopulmonary hypertension is best characterized with cardiac catheterization and hepatopulmonary syndrome with saline echocardiography.
  • Other topics: Prevention of hepatic encephalopathy, managing bleeding episodes, endoscopic treatment

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Learning a lot from ChiLDREN (part 2)

As noted in previous post (Learning a lot from ChiLDREN (part 1) | gutsandgrowth), several recent studies highlight the benefits of multisite collaboration to study infrequent pediatric liver problems.  In these studies, the Childhood Liver Disease Research and Education Network (ChiLDREN) has collected prospective longitudinal observational date from multiple centers; data from 10 centers provides useful information on the frequency of portal hypertension (PHT) in young adults with biliary atresia (BA) (JPGN 2012; 55: 57-73).

163 subjects were enrolled between May 2006 and December 2009.  Seven patients were excluded due to the presence of polysplenia which interferes with the assessment of PHT.

Demographics: subjects ranged in age from 1 to 25 years with a mean of 9.2 years.  56% were female, 75% were caucasian.

PHT was considered definite if there was either a history of a PHT complication (variceal bleeding, ascites) or if there were clinical findings c/w PHT (both splenomegaly and thrombocytopenia).  PHT was considered “possible” if either splenomegaly or thrombocytopenia was present and “absent” if no criteria were met.

  • PHT: definite in 80 (49%), possible in 27 (17%) and absent in 56 (34%)
  • 43 subjects had a history of PHT complications: 32 with esophageal variceal (EV) bleeding, 14 with ascites, and 8 with hepatopulmonary syndrome.
  • Of the patients with EV, only 3 had normal platelet count and normal spleen size.

Teaching points:

  1. One-third of subjects with EV bleeding survived with their native liver for at least 5 years.
  2. EV age of onset was highly variable; 7 had bleeding in the first two years of life.
  3. Growth parameters were fairly unremarkable in those with definite PHT.
  4. Long-term followup will be needed to identify factors which predict progression of PHT and the development of adverse outcomes.

Previous related blog posts:

Hepatic ciliopathies

As our understanding of pathophysiology improves, frequently this results in reclassification of diseases.  Perhaps the best example in pediatric hepatology is gestational alloimune liver disease/congenital alloimmune hepatitis, formerly called neonatal hemochromatosis  (see previous post).  Hepatic ciliopathies are less commonly discussed and thus far have not resulted in abandoning previous nomenclature. These hepatic ciliopathies are related to fibrocystic disease proteins which localize to the primary cilia.  Ductal plate malformation is the main pathology that underlies the liver disease in ciliopathies.  The characteristics of one of these disorders, congenital hepatic fibrosis (CHF) in autosomal dominant polycystic kidney diseae (PKD) involving 19 patients is described in this month’s JPGN (JPGN 2012: 54: 83-89).  Portal hypertension was the main manifestation.  “Hepatocellular function was preserved and liver enzymes were largely normal.”  In patients with AD-PKD-CHF, this was  due to PKD1 mutations with probable contributions from modifier genes.  One interesting finding was that in the identified families, the parents who were affected by polycystic kidney disease did not have CHF.

Although this study demonstrates that CHF and portal hypertension can occur with AD-PKD, CHF and portal hypertension are a characteristic finding with AR-PKD.  With AD-PKD, the liver cysts originate from biliary microhamartomas (von Meyenburg complexes) and are not in continuity with the biliary tree.  In contrast, patients with AR-PKD have cystic dilatations of the biliary system; this combination is called Caroli syndrome.  Due to these differences, unlike AR-PKD, AD-PKD does not typically result in portal hypertension.

Additional references on congenital hepatic fibrosis:

  • -Hepatology 2010; 52: 2223. Review. Medical/Surgical & Tx options.
  • -Am J Med Genet C Semin Med Genet 2009; 151C: 296-406.  Liver disease and kidney disease in ciliopathies.
  • -NEJM 2008; 359: 1477.  Review of autosomal dominant polycystic kidney disease.  ~80% develop liver cysts.
  • -NEJM 2007; 356: 1560. Nice pic of resected liver with polycystic liver disease in 51 year old.
  • -J Pediatr 2006; 149: 159. Review and NIH protocol for enrolling patients. Clinical GI issues: recurrent cholangitis, portal htn, cholelithiasis, and cholangiocarcinoma.
  • -Pediatr Transplantation 2005; 9: 634-9.
  • -Hepatology 2004; 40: 774-82.
  • -Surg Endosc 2005; 19: 130-32.
  • -Gastorenterol Clin N Am; 2003; 32: 857-75. “Heritable disorders of the bile ducts”