title: Correlation of intracystic pressure with cyst volume, length of common channel, biochemical changes in bile and histopathological changes in liver in choledochal cyst.
abstract: OBJECTIVE
  This study was undertaken to establish correlation between intracholedochal cystic pressure (ICCP) with biochemical changes in bile, liver histology, cyst wall histology, length of common channel, and cyst volume.
  
  
  METHODS
  In this cross-sectional study, ICCP was measured after surgical access before any mobilization by direct cyst cannulation. Bile was then aspirated for biochemical estimation (bilirubin, amylase, lipase, pH, and electrolytes). Common channel length and cyst volume were determined by preoperative magnetic resonance cholangiopancreatography (MRCP). Liver histology was assessed under parenchymal, bile duct, and portal parameters. Cyst wall was examined for ulceration, inflammation, fibrosis, and metaplasia.
  
  
  RESULTS
  ICCP was recorded in 31 patients; mean and median ICCP were 15.64 and 14 mmHg, respectively (range = 6-30 mmHg). Cases with median ICCP < 14 had median cyst volume of 48 cc (range = 36-115) and amylase 2052 IU/L (range = 190-5052) whereas those with ICCP ≥ 15 had volume of 20 cc (range = 10-100) (P = 0.004) and amylase 36 IU/L (range = 0-2806) (P = 0.0004) suggesting inverse correlation. No significant correlation was found with bilirubin and electrolytes. ICCP directly correlated with parenchymal changes like hepatocellular damage (P = 0.002) and cholestasis (P = 0.001). It also correlated with bile duct changes. ICCP inversely correlated with cyst wall changes (P = 0.003, 0.0001, 0.023, 0.0013, respectively). High pressure cysts had normal pancreaticobiliary junction.
  
  
  CONCLUSIONS
  High-pressure cysts tend to be smaller but have more severe backpressure changes in liver parenchyma. Low-pressure cysts have high volume and higher levels of amylase and lipase and therefore have more severe cyst wall changes.
authors.affiliation: Department of Pediatric Surgery, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
authors.forename: Nitin
authors.initials: N
authors.lastname: Sharma
authors.affiliation: Department of Pediatric Surgery, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
authors.forename: Veereshwar
authors.initials: V
authors.lastname: Bhatnagar
authors.affiliation: Department of Pediatric Surgery, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
authors.forename: M
authors.initials: M
authors.lastname: Srinivas
authors.affiliation: Department of Pediatric Surgery, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Agarwala
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Singh
authors.affiliation: Department of Radiodiagnosis, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
authors.forename: Raju
authors.initials: R
authors.lastname: Sharma
keywords: Choledochal cyst; cyst wall histology; intra choledochal cystic pressure; liver histology; long common channel