Congenital choledochal malformation: not just a problem for children

Current status of the biliary tract malformation

The choledochal cyst (CC) can be better termed as biliary tract malformation because of the close association of embryology and etiology in the causation of CC. Contrary to Babbitt's postulation of reflux, damage and dilatation, reflux was not demonstrable as the causative factor in all varieties of CC. High pressure in the biliary system, otherwise termed ductal hypertension, is put forth as an alternative to explain the evolution of CC. The forme fruste type, which does not find a place in the standard classification, typifies the ductal hypertension hypothesis. Hence a closer, in-depth review would be able to highlight this apt terminology of biliary tract malformation.

Progress in research of pancreaticobiliary maljunction and biliary dilatation

Pancreaticobiliary maljunction (PBM) is a congenital anomaly that is defined as a junction of the pancreatic and bile ducts located outside the duodenal wall during the embryonic stage, resulting in bile and pancreatic juice reflux and corresponding clinical symptoms. PBM is a high risk factor for cholangiocarcinoma. PBM can occur with or without biliary dilatation (BD). Early diagnosis of PBM can prevent complications. Ultrasonography, magnetic resonance imaging, multi-slice spiral computed tomography, endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography, and cholangiopancreatography are important modalities for diagnosis of this disease. The standard surgical procedure for PBM with BD is dilated cholangiectomy and choledochoenteroreconstruction. Cholecystectomy should be performed as early as possible for PBM without BD.

Defining an optimal surveillance strategy for patients following choledochal cyst resection: results of a systematic review

BACKGROUND

Choledochal cysts should be treated with complete surgical resection, or, rarely liver transplantation. Treated patients can remain at risk of developing metachronous cholangiocarcinomas and lifelong follow up is indicated. However, there is no agreement on what constitutes an acceptable follow up strategy. This review was undertaken to develop an evidenced based surveillance strategy.

METHODS

A systematic review of MEDLINE, EMBASE, PubMed, Web of Science, and Google Scholar was undertaken for reports (published up to 10 September 2021) describing late biliary complications and development of metachronous cholangiocarcinoma following choledochal cyst resection.

RESULTS

Twenty-five publications described 74 metachronous cholangiocarcinomas occurring in 3911 patients (overall incidence 2%). Cancers developed commonly at the hepatic hilus and were diagnosed after a median interval of 92 months (range 9-249 months) after the initial resection. While reporting is incomplete, the majority of cholangiocarcinomas developed following resection of type I and type IV cysts with few metachronous cancers recorded after treatment of type II or III cysts. Peak age range for presentation with metachronous cholangiocarcinoma is in the twenties following cyst resection in childhood suggesting that patients are at greatest risk for metachronous tumour development for up to 20 years (240 months).

CONCLUSION

A surveillance strategy is proposed for patients treated primarily for cyst types I and IV and unresected type V using annual liver function tests, Ca 19-9 measurement and biannual ultrasound assessment for 20 years post cyst resection, with biannual liver function testing, Ca 19-9 measurement and three yearly ultrasound assessment thereafter.

Long-term Morbidity of Choledochal Malformations in Children

OBJECTIVE

The aim of the study was to assess long-term morbidity in children operated for choledochal malformation (CM) by relating clinical complications to liver histopathology, follow-up imaging, liver stiffness, and biochemistry.

METHODS

A single-center retrospective follow-up study including all CM patients (n = 55, 71% girls) treated during 1976 to 2018 was performed. Mann-Whitney U test and Spearman rank correlation were used for statistical analyses.

RESULTS

During median follow-up of 5.8 (interquartile range, 2.5-12) years, 1 patient was lost to follow-up whereas all survived. Intraoperative liver biopsies showed fibrosis in 32%, and patients with Metavir stage ≥2 were younger at surgery (0.36 [0.11-1.9] vs 3.8 [0.72-10.5] years, P = 0.024) than those without fibrosis. Overall, 21% had long-term complications including cholangitis in 9 (>2 episodes in 5) patients, anastomotic stricture in 2 referred patients and adhesive volvulus or hepatocellular carcinoma in 1 each. Anastomotic strictures were successfully managed nonoperatively and hepatocellular carcinoma with thermoablation. In postoperative magnetic resonance cholangiography (MRCP) performed 6.4 (3.6-16) years after hepaticojejunostomy, diameters of both main intrahepatic ducts had decreased significantly to 3.0 (2.5-3.5) mm (P = 0.0001) but a distal cyst stump was remaining in 30% with a length of 6.0 (4.0-20) mm that associated with operation age (r = 0.71, P = 0.015) and fusiform CM type. Follow-up ultrasound revealed mild dilation of intrahepatic bile ducts in 6.3% and mildly to moderately elevated liver biochemistry in 23%, and liver stiffness (>7 kPa) in 22%.

CONCLUSIONS

Whilst cholangitis was the most common postoperative problem, individual patients experienced other more significant complications and one quarter of patients showed evidence of underlying liver dysfunction.

Insights into the pathophysiology and classification of type 4 choledochal malformation

INTRODUCTION

Type 4 choledochal malformations (CMs) can be defined as extra- and intrahepatic biliary dilatation. They are of uncertain etiology but make up about 20% of most series. The aim of this study was to investigate the pathophysiology and their natural history following surgical intervention.

METHODS

Ambispective review of a single-center series of type 4 CM between 1996 and 2017. Perioperative imaging, intraoperative pressure monitoring, bile amylase, and long-term follow-up data were analyzed based on extrahepatic morphology [(cystic (C), fusiform (F)]. Data were expressed as median (range). Statistical analysis was performed with nonparametric tests. P < 0.05 was considered significant.

RESULTS

37 children had type 4 CM in the study period [age at surgery 4 (0.2-16) years] and could be further subdivided into cystic (4C) (n = 22) or fusiform (4F) (n = 15). There was significantly greater dilatation of the extrahepatic component in the cystic group [30 (11-94) versus 15 (8-90) mm; P = 0.0002] though there was no difference in left duct diameter [cystic 7.5 (0-17) mm versus fusiform 7.5 (3-16) mm; P = 0.86]. There was a trend to higher choledochal pressure in the cystic group [19 (4-40) versus 9 (6-25) mmHg; P = 0.09] and those in the fusiform group had higher bile amylase [8650 (3-890,000) versus 592 (1-123,000) IU/L; P = 0.01] and were older [4.1 (0.92-16.43) versus 2.4 (0.15-15.48) years; P = 0.03]. Children with type 4 CM were then separated simply on the basis of bile amylase into LOW (characterized by high pressure, cystic morphology and young age at surgery) and HIGH bile amylase (low pressure, fusiform morphology and older at time of surgery).

CONCLUSIONS

We propose further division of type 4 CM into 4C and 4F on clinical and pathophysiological grounds.

LEVEL OF EVIDENCE

II (prospective cohort).

Antenatally-detected liver cysts: Causes and characteristics, indications for intervention

AIM

The prevalence of antenatally-detected hepatic cysts is increasing owing to increased use of maternal ultrasonography (USS). Diagnostic precision, however, is challenging and subsequently there is no clear consensus on postnatal management. The aim of the study was to evaluate the natural history and long-term follow up of congenital simple hepatic cysts.

METHODS

Single-center review of prospectively-maintained dataset collected over a 25-year period. Data are quoted as median (range).

RESULTS

In the period 1991-2016, 31 infants presented with an antenatally-detected cyst which, on postnatal imaging, was likely confirmed as a simple parenchymal hepatic cyst. These together with a further infant who presented at 4 days without any antenatal imaging comprised the study group (n = 32). Gestational age at detection was 23 (13-38) weeks. Maximum antenatal cyst diameter was measured at 19 (4-120) mm. Only the largest required percutaneous aspiration at 35 weeks' gestation being associated with polyhydramnios. Postnatally, serial USS was performed alongside MRI/CT or liver scintigraphy if there was diagnostic doubt. Initial maximum cyst diameter was 30 (12-120) mm. Five infants came to surgical intervention and this included excision ± marsupialization (n = 4), and a cyst-jejunostomy en Roux in one child thought to have a connection with the biliary tract on intraoperative cholangiography. The mucosal lining in two cysts showed areas of squamous metaplasia, with one more showing an intact squamous lining probably more consistent with an epidermoid cyst. In the remaining cases (n = 27), all asymptomatic, serial USS showed volume maintenance (n = 16) actual volume regression (n = 4) and resolution (n = 7). Median follow-up in these cases was 42 (4-252) months.

CONCLUSION

This is the largest case series to date of antenatally-detected simple hepatic cysts. Most can be managed conservatively, and relative regression or resolution is likely. Surgical intervention should be reserved for those: that are large at the outset; show rapid cyst growth - these being typically exophytic in nature; wall irregularity or where there is diagnostic doubt.

TYPE OF STUDY

Case series.

LEVEL OF EVIDENCE

Level IV.

Gene expression profiling reveals upregulated FUT1 and MYBPC1 in children with pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM) is associated with high risk of epithelial atypical growth and malignant transformation of the bile duct or gallbladder. However, overall changes in genetic expression have not been examined in children with PBM. Genome-wide expression was analyzed using peripheral blood samples from 10 children with PBM and 15 pediatric controls. Differentially expressed genes (DEGs) were identified using microarray. Bioinformatics analysis was conducted using Gene Ontology and KEGG analyses. The top 5 in the up-regulated genes in PBM were verified with qRT-PCR. Receiver operator characteristic curve analysis was conducted to evaluate the predictive accuracy of selected genes for PBM. The microarray experiments identified a total of 876 DEGs in PBM, among which 530 were up-regulated and the remaining 346 were down-regulated. Verification of the top 5 up-regulated genes (TYMS, MYBPC1, FUT1, XAGE2, and GREB1L) by qRT-PCR confirmed the up-regulation of MYBPC1 and FUT1. Receiver operating characteristic curve analysis suggested that FUT1 and MYBPC1 up-regulation could be used to predict PBM, with the area under the curve of 0.873 (95%CI=0.735-1.000) and 0.960 (95%CI=0.891-1.000), respectively. FUT1 and MYBPC1 were up-regulated in children with PBM, and could be used as potential biomarkers for PBM.

Pancreaticobiliary maljunction and congenital biliary dilatation

Pancreaticobiliary maljunction is a congenital malformation in which the pancreatic and bile ducts join outside the duodenal wall, usually forming a long common channel. Because the action of the sphincter of Oddi does not regulate the function of the pancreaticobiliary junction in patients with pancreaticobiliary maljunction, two-way regurgitation occurs. Reflux of pancreatic juice into the biliary tract is associated with a high incidence of biliary cancer. Biliary carcinogenesis in patients with pancreaticobiliary maljunction is thought to follow the hyperplasia, dysplasia, then carcinoma sequence due to chronic inflammation caused by pancreatobiliary reflux. Pancreaticobiliary maljunction is diagnosed when an abnormally long common channel is evident on imaging studies. Congenital biliary dilatation involves both local dilatation of the extrahepatic bile duct, including the common bile duct, and pancreaticobiliary maljunction. Extrahepatic bile duct resection is the standard surgery for congenital biliary dilatation. However, complete excision of the intrapancreatic bile duct and removal of stenoses of the hepatic ducts are necessary to prevent serious complications after surgery.

Genetic study of congenital bile-duct dilatation identifies de novo and inherited variants in functionally related genes

Background

Congenital dilatation of the bile-duct (CDD) is a rare, mostly sporadic, disorder that results in bile retention with severe associated complications. CDD affects mainly Asians. To our knowledge, no genetic study has ever been conducted.

Methods

We aim to identify genetic risk factors by a “trio-based” exome-sequencing approach, whereby 31 CDD probands and their unaffected parents were exome-sequenced. Seven-hundred controls from the local population were used to detect gene-sets significantly enriched with rare variants in CDD patients.

Results

Twenty-one predicted damaging de novo variants (DNVs; 4 protein truncating and 17 missense) were identified in several evolutionarily constrained genes (p < 0.01). Six genes carrying DNVs were associated with human developmental disorders involving epithelial, connective or bone morphologies (PXDN, RTEL1, ANKRD11, MAP2K1, CYLD, ACAN) and four linked with cholangio- and hepatocellular carcinomas (PIK3CA, TLN1 CYLD, MAP2K1). Importantly, CDD patients have an excess of DNVs in cancer-related genes (p < 0.025). Thirteen genes were recurrently mutated at different sites, forming compound heterozygotes or functionally related complexes within patients.

Conclusions

Our data supports a strong genetic basis for CDD and show that CDD is not only genetically heterogeneous but also non-monogenic, requiring mutations in more than one genes for the disease to develop. The data is consistent with the rarity and sporadic presentation of CDD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-016-0236-z) contains supplementary material, which is available to authorized users.

Management of Adult Choledochal Cyst Coexisting with Gallbladder Carcinoma: A Case Report and Review of Literature

Choledochal cyst is a relatively rare condition. Even rarer is a choledochal cyst in association with a gallbladder carcinoma. This study reports a rare case of gallbladder carcinoma coexisting with a choledochal cyst in a Nigerian patient. Clinical records of the patient including preoperative evaluation, intraoperative findings, and postoperative care were reviewed. A 38-year-old woman presented with the recurrent right upper abdominal pain of 3 years duration associated with progressive weight loss, anorexia, recurrent vomiting, as well as, low-grade fever with chills and rigors. Physical examination revealed an anicteric woman with tenderness in the right hypochondrium and a positive Murphy's sign. A combination of abdominal ultrasound and computed tomography scan suggested a Type IV choledochal cyst and a distended gallbladder with thickened walls containing a heterogeneous hyperdense mass. Preoperative serum alkaline phosphatase was elevated while endoscopic retrograde cholangiopancreatography was inconclusive. At laparotomy, extrahepatic biliary dilatation and enlarged, the nodular gallbladder was found with a diffusely fibrotic pancreas. Intraoperative cholangiogram confirmed Type IV choledochal cyst. Excision of the common bile duct and radical cholecystectomy was performed, and a Roux-en-Y hepaticojejunostomy. Histopathology confirmed the diagnosis of gallbladder adenocarcinoma. She had adjuvant chemotherapy and is presently on follow-up. No evidence of recurrence after 5 years of follow-up. A high index of suspicion is required to detect a combination of these two rare entities. When detected, both conditions should be surgically addressed at the same sitting, and when combined with adjuvant chemotherapy, may increase the chances of achieving a cure.

Growth in children with choledochal malformations: effect of the Roux loop

PURPOSE

Excision and biliary reconstruction using a Roux loop is the current standard for choledochal malformation (CM). This is un-physiological, delivering bile beyond the duodenum and excluding a significant length of the jejunum from intestinal absorption. We investigated whether this had an effect on post-operative growth.

METHODS

Retrospective case-note analysis of children surgically treated for CM. Growth variables were converted to standard deviation scores (SDS) and compared against population norms. P < 0.05 was significant.

RESULTS

From 1994 to 2014, 135 children (<16 years) were identified. Median age at surgery was 3.3 (IQR 1.5-7) years. Morphology included: type 1 Cystic (n = 54, 40%), type 1 Fusiform (n = 58, 43%) and type 4 (intra and extra-hepatic) (n = 22, 16%). There was pre-operative growth failure [median weight SDS = -0.4 (-1.2 - 0.4), P = 0.0004] with a similar trend for height [SDS = -0.38 (-1.2 - 0.5), P = 0.08)]. This correlated with presentation bilirubin (r s = -0.24, P = 0.004), GGT (r s = -0.27, P = 0.002) and AST (r s = -0.27, P = 0.002) but not morphology (P = 0.82) or presentation (P = 0.4). Median follow-up was 1.9 (0.6-4.7) years, during which time both height (P = 0.73) and weight (P = 0.45) reverted to normal.

CONCLUSION

This is the first report of growth in children with CM following a Roux-loop reconstruction and showed pre-operative growth failure probably attributed to a period of biliary obstruction but catch-up growth when corrected.

Increasing occurrence of choledochal malformations in children: a single-center 37-year experience from Finland

OBJECTIVE

Few reports on choledochal malformations (CMs) in European populations exist.

MATERIALS AND METHODS

The medical records of pediatric CM patients managed in our nationwide referral center for pediatric hepatobiliary surgery between 1976 and 2013 (n = 38; 71% females) were reviewed.

RESULTS

Over follow-up time, the relative proportion of fusiform CMs increased significantly (p = 0.007) and the estimated total incidence rose from 1:128,000 to 1:38,000 (p = 0.017). Cystic CMs (42%) presented at younger age than fusiform CMs (47%) (0.8 vs. 4.6 years, p = 0.001). Two-thirds had abdominal pain and half were cholestatic at presentation. Pancreatitis had occurred in 16%. In addition to ultrasound, 71% underwent magnetic resonance cholangiopancreatography and 39% underwent endoscopic retrograde cholangiopancreatography. Median CM dilatation was 15 (10-28) mm and a 12 (9-13) mm long common pancreaticobiliary channel was confirmed in 61%, increasingly during recent years. Intrahepatic biliary tree was dilated in 19%, whereas main ducts were dilated in 50%. Apart from two operated in the 1970s and one with choledochocele, patients underwent resection of extrahepatic bile ducts with Roux-en-Y hepaticojejunostomy at age of 4.2 (0.8-9.2) years. Postoperative bile leakage and hemorrhage required reoperations in two. At last follow-up 4.8 (1.3-13.2) years postoperatively, none had dilated intrahepatic biliary ducts or elevated plasma bilirubin (5 [3-7] µmol/l). Single cholangitis episodes had occurred in two, whereas others were asymptomatic.

CONCLUSION

CM incidence has increased significantly in Finland, being currently over threefold higher than previous estimates in the Western world would suggest. Removal of the extrahepatic biliary tree with hepaticojejunostomy for type I and IV CMs yielded excellent results.

Correlation of intracystic pressure with cyst volume, length of common channel, biochemical changes in bile and histopathological changes in liver in choledochal cyst

AIMS

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.

MATERIALS AND 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.

CONCLUSION

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.

Jaundice and life-threatening hemobilia: an uncommon presentation of choledochal cyst

Hemobilia with jaundice as a result of cholestasis and bleeding from choledochal cyst is uncommon. Ascertaining the diagnosis is often challenging and delayed diagnosis can lead to significant consequences due to hemodynamic instability, particularly in elderly patients. Although surgery remains the definitive treatment modality, interventional radiology for hemostasis has been increasingly recognized as an option. In this manuscript, we described two Malaysian cases of jaundice and hemobilia associated with choledochal cysts and the challenges related with clinical diagnosis and management.

Clinical Analysis of 221 Cases of Adult Choledochal Cysts

Choledochal cyst, usually recognized as a problem in infants, is increasingly reported in adult patients. The aim of this study was to share our experience in treating adult patients with choledochal cysts. Two hundred twenty-one adult patients with choledochal cysts who were treated in our hospital from January 2002 to December 2010 were enrolled. The clinical data were retrospectively collected and analyzed. There were 168 Type I, three Type II, three Type III, 26 Type IV, and 21 Type V cysts. The presentations were nonspecific with 177 patients having abdominal pain and a few patients having other rare symptoms including back pain, cirrhosis, occupying lesions, or spontaneous rupture. The cysts were completely removed in 169 patients, and 36 patients required liver resection. There was one death resulting from abdominal bleeding. Morbidity was limited to 27 patients, 11 of whom underwent invasive interventions. Choledochal cysts remain an interesting clinical problem. In some adult cases, the diagnosis is very difficult. Treatment is type-dependent, complete removal of the cysts is widely accepted, and lifelong follow-up for these patients is recommended.

Clinical characteristics of liver fibrosis in patients with choledochal cysts

PURPOSE

The aim of the study was to identify the clinical characteristics and outcome of patients with liver fibrosis in choledochal cyst (CC).

METHODS

Forty patients with CC who underwent liver biopsy were included. Liver fibrosis was classified as follows: grade 0, no fibrosis; grade 1, mild fibrosis localized in the portal area; grade 2, moderate fibrosis with occasional bridging; and grade 3, severe fibrosis with diffuse bridging.

RESULTS

Fourteen patients (35%) had liver fibrosis. Patients in the fibrosis group were significantly younger (1.2 vs 2.7 years) and had higher total bilirubin (5.3 vs 2.6 mg/dL). Severity of liver fibrosis was inversely correlated with age (P = .044). Amylase and lipase in bile were significantly lower in the fibrosis group (amylase, 531 vs 15,000 U/L; lipase, 783 vs 23,100 U/L). Postoperative serum analysis demonstrated no differences between the two groups. Most patients in both groups had normal aspartate aminotransferase, alanine aminotransferase, total bilirubin, and γ-glutamyl transpeptidase regardless of severity of fibrosis. Postoperative biliary complication or cholangiocarcinoma was not found in the fibrosis group.

CONCLUSIONS

Our data suggest that liver fibrosis is mainly influenced by obstructive cholangiopathy rather than refluxed pancreatic secretion. Prognosis of patients with CC and liver fibrosis was as good as that of patients without fibrosis.

Role of pressure and pancreatic reflux in the aetiology of choledochal malformation

Background

The aetiology of choledochal malformation is not known. Babbitt's hypothesis remains a popular concept, and assumes that activated pancreatic juice refluxes through the common pancreatobiliary channel causing mural damage and subsequent biliary dilatation. This hypothesis was tested clinically by evaluating the relationship between epithelial histology, choledochal pressure and degree of pancreatic reflux.

Methods

Children with choledochal malformation (cystic, type 1c; fusiform, type 1f; both intrahepatic and extrahepatic dilatation, type 4) operated on between January 1999 and October 2009 were identified. Where practical, choledochal pressure was measured on entry to the abdominal cavity, by puncture of the common bile duct, and bile was sampled for amylase content. Archival bile duct sections were scored using a semiquantitative epithelial lining/mural score (ELMS).

Results

A total of 90 children with choledochal malformations were operated on during the study interval. Histology was available for 73 children (median age 2·9 (interquartile range 1·3–7·9) years), 29 with type 1c, 31 with type 1f and 13 with type 4 malformations. There was a significant stepwise increase in pressure with choledochal morphology (median pressure 13, 17 and 20 mmHg for types 1f, 1c and 4 respectively; P = 0·037). There was an inverse relationship between choledochal pressure and bile amylase activity (rs = − 0·45, P &lt; 0·001). High ELMS values were associated with higher choledochal pressure (P = 0·057) and low bile amylase activity (P = 0·002).

Conclusion

High choledochal pressure (not bile amylase) was associated with more severe histopathological changes and choledochal morphology. These findings suggest that distal bile duct obstruction (and therefore high intraluminal pressure) contributes more to the key features of choledochal malformation than does pancreatic reflux.

Biliary disease in children

Biliary diseases in children are infrequent; however, they can be associated with high morbidity and mortality if an accurate diagnosis is not made and adequate treatment provided in a timely fashion. Biliary atresia, choledochal cysts, gallbladder disease, and Alagille syndrome can be associated with similar clinical symptoms, laboratory findings, and radiographic findings, which makes accurate diagnosis difficult. The correct treatment for each of these clinical entities is different and can significantly reduce morbidity and mortality from these diseases. In this article, we discuss the epidemiology, approach to diagnosis, prognosis, and treatment modalities for these four disease processes.

Intrahepatic duct dilatation in type 4 choledochal malformation: pressure-related, postoperative resolution

BACKGROUND

Type 4 choledochal malformations (CMs) may be defined as those with both intrahepatic and extrahepatic bile duct dilatation. The aims of this study were to investigate possible causes of intrahepatic duct (IHD) dilatation in CM and to define the effect of surgery over time.

METHODS

This study was a single-center retrospective review of a database of all children with CM undergoing surgery (excision of extrahepatic bile duct dilatation and hepaticojejunostomy) and identified as type 4 (on imaging and at surgery). Data included intraoperative choledochal pressure measurements and biliary amylase content and were expressed as median (interquartile range [IQR]). All comparisons used nonparametric statistical tests. P ≤.05 was regarded as significant.

RESULTS

Twenty children were identified as type 4 CM (age, 4.3 years; range, 2.7-10.4 years) with preoperative IHD dilatation (right duct: diameter [range], 8.5 [4.5-14] mm; left: 8 [4-14.5] mm). Median intraoperative choledochal pressure was 17 (8-27) mm Hg (normal, <5 mm Hg), and intraoperative bile amylase was 3647 (range, 500-58,000) IU/L (normal, <100 IU/L). Preoperative IHD diameter correlated with choledochal pressure (right: r(s)=0.46, P = .03; left: r(s)=0.34, P = .07) but not with biliary amylase (P = .28 and P = .39, respectively). At 1 year postsurgery, median (range) IHD diameter had decreased to 1 (1-2.5) mm for right duct (P = .0002) and 1.5 (1-3) mm for left duct (P = .0006) and remained stable for up to a 10-year follow-up.

CONCLUSION

Our data suggest that IHD dilatation is related to sustained increased intrabiliary pressure rather than any intrinsic intrahepatic CM. Effective surgery invariably reduces measured IHD toward normal values.