Cystic Disorders of the Bile Ducts

Prospective evaluation of common hepatic duct histopathology at the time of choledochal cyst excision ranging from children to adults

PURPOSE

To evaluate common hepatic duct just distal to the HE anastomosis (d-CHD) prospectively for mucosal damage, inflammation, fibrosis, dysplasia, carcinoma in situ, malignant transformation, effects of serum amylase, and symptoms at presentation in CC cases ranging from children to adults.

METHODS

Cross-sections of d-CHD obtained at cyst excision 2018-2023 from 65 CC patients; 40 children (< 15 years old), 25 adults (≥ 15) were examined with hematoxylin and eosin, Ki-67, S100P, IMP3, p53, and Masson's trichrome to determine an inflammation score (IS), fibrosis score (FS), and damaged mucosa rate (DMR; damaged mucosa expressed as a percentage of the internal circumference).

RESULTS

Mean age at cyst excision ("age") was 18.2 years (range: 3 months-74 years). Significant inverse correlations were found for age and DMR (p = 0.002), age and IS (p = 0.011), and age and Ki-67 (p = 0.01). FS did not correlate with age (p = 0.32) despite significantly increased IS in children. Dysplasia was identified in a 4-month-old girl with cystic CC. Serum amylase was elevated in high DMR subjects.

CONCLUSIONS

High DMR, high IS, and evidence of dysplasia in pediatric CC suggest children are at risk for serious sequelae best managed by precise histopathology, protocolized follow-up, and awareness that premalignant histopathology can arise in infancy.

Choledochal cyst

Choledochal cyst (CC) or congenital biliary dilatation, has a skewed distribution with hereditary features that is far more common in East Asian females. CC is usually associated with pancreaticobiliary malunion (PBMU) forming a common channel. CC requires early definitive diagnosis, since there is a risk for malignancy occurring in the CC and/or intrahepatic bile ducts (IHBD). Complete CC excision and Roux-en-Y hepaticoenterostomy is required and can be performed by open or minimally invasive surgery with hepatojejunostomy the recommended procedure of choice. Principles of open surgical intervention form the basis of minimally invasive management with laparoscopy and robotic assistance. Current surgical management is associated with fewer early and late complications, such as hepaticoenterostomy anastomotic leakage, cholangitis, anastomosis stricture, and cholangiocarcinoma. Specific features of CC management at Juntendo include: intraoperative endoscopy of the common channel and IHBD for inspecting and clearing debris to significantly reduce post-operative pancreatitis or stone formation; near infra-red fluorescence with indocyanine green for visualizing tissue planes especially during minimally invasive surgery for CC; and a classification system for CC based on PBMU that overcomes inconsistencies between existing classification systems and clinical presentation.

Oncologic safety of Carrel patch hepaticojejunostomy for treating cystic-type choledochal cyst in children based on 20-plus years follow-up

AIM

During choledochal cyst (CC) excision, the hepaticojejunostomy anastomosis (HJA) can be performed conventionally (CHJA) or with a Carrel patch (CPA). CPA can increase CHD diameter to 10-13 mm, preventing anastomotic stenosis and intrahepatic bile duct (IHBD) stones but may be at risk for malignant transformation.

METHODS

The medical records of 83 cystic-type CC with CHD ≤ 9 mm followed up for at least 20 years were reviewed retrospectively. Available excised CC specimens (70/83) were re-examined blindly for pre-malignant changes. A questionnaire about suturing narrow lumens was conducted.

RESULTS

All 83 had pancreaticobiliary maljunction. Group data were similar. Anastomoses were CPA (n = 43) and CHJA (n = 40). Mean diameter for CPA was 11.4 mm (range: 10-13 mm); for CHJA was 7.4 mm (range: 5-9 mm). Mean follow-up was 27.7 years (range: 20-42). Postoperative anastomotic stenoses were less after CPA: 1/43 (2.3%) versus 5/40 (12.5%) (p = 0.10), but CHJA had significantly more postoperative IHBD stones: 0% versus 4/40 (10.0%) (p < 0.05). All IHBD stone patients had anastomotic stenosis. Excised specimens showed no pre-malignant cytology. Lumen diameter ≤ 9 mm was considered challenging by 10/10 surgical trainees and ≤ 7 mm by 16/22 pediatric surgeons.

CONCLUSIONS

CPA appears to be oncologically safe because of the absence of malignant transformation for at least 20 years.