Peribiliary gland damage due to liver transplantation involves peribiliary vascular plexus and vascular endothelial growth factor.

Extrahepatic bile ducts are characterized by the presence of peribiliary glands (PBGs), which represent stem cell niches implicated in biliary regeneration. Orthotopic liver transplantation may be complicated by non-anastomotic strictures (NAS) of the bile ducts, which have been associated with ischemic injury of PBGs and occur more frequently in livers obtained from donors after circulatory death than in those from brain-dead donors. The aims of the present study were to investigate the PBG phenotype in bile ducts after transplantation, the integrity of the peribiliary vascular plexus (PVP) around PBGs, and the expression of vascular endothelial growth factor-A (VEGF-A) by PBGs. Transplanted ducts obtained from patients who underwent liver transplantation were studied (N=62). Controls included explanted bile duct samples not used for transplantation (N=10) with normal histology. Samples were processed for histology, immunohistochemistry and immunofluorescence. Surface epithelium is severely injured in transplanted ducts; PBGs are diffusely damaged, particularly in ducts obtained from circulatory-dead compared to brain-dead donors. PVP is reduced in transplanted compared to controls. PBGs in transplanted ducts contain more numerous progenitor and proliferating cells compared to controls, show higher positivity for VEGF-A compared to controls, and express VEGF receptor-2. In conclusion, PBGs and associated PVP are damaged in transplanted extrahepatic bile ducts; however, an activation of the PBG niche takes place and is characterized by proliferation and VEGF-A expression. This response could have a relevant role in reconstituting biliary epithelium and vascular plexus and could be implicated in the genesis of non-anastomotic strictures.

Experimentally Induced Biliary Atresia by Means of Rotavirus-Infection Is Directly Linked to Severe Damage of the Microvasculature in the Extrahepatic Bile Duct.

Vascular damage has been reported to contribute to atresia formation in several diseases including biliary atresia. This study focused on the extrahepatic biliary plexus in experimental biliary atresia. Newborn BALB/cAnNCrl-pups were infected with rhesus rotavirus within 24 hr after birth to induce experimental biliary atresia. The extrahepatic biliary plexus was examined by confocal microscopy on whole-mount preparations, scored by three independent researchers, and further evaluated at the subcellular level with transmission electron microscopy. Imaging results revealed a progressive destruction of the extrahepatic biliary vascular plexus in the course of experimental biliary atresia induced by rotavirus infection. Endothelial cell damage was already visible as cell swelling and necrosis in the first days after infection and a damaged microcirculation that rapidly deteriorated with progression of obliterative cholangiopathy, was observed in the infected mice as early as 72 hr after birth. In experimental biliary atresia, the destruction of the extrahepatic biliary vascular plexus starts already in the first days postinfection and clearly precedes the morphological symptoms of atresia. The deterioration of the vascular bed architecture continues with disease progression. Therefore, we conclude that the (ultra)structural changes in the extrahepatic biliary microvasculature occurring before the visible onset of atresia has a predictive diagnostic value and this impairment in blood supply to the extrahepatic bile duct may be an important contributing factor to the pathogenesis of acquired biliary atresia. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:818-824, 2019. © 2018 Wiley Periodicals, Inc.

Clinical Applications of Three-Dimensional Visualization Model of Arteries Supplying the Extrahepatic Bile Duct for Patients with Biliary Obstruction.

This study aimed to assess distribution characteristics and digital typing of arteries supplying the extrahepatic bile duct for patients with biliary obstruction, and evaluate the three-dimensional (3D) model in surgical decision-making. Forty-one patients with biliary obstruction were retrospectively evaluated. Clinical data obtained by 64-slice multidetector CT angiography scanning were introduced into Medical Image Three-Dimensional Visualization System; then, 3D model of extrahepatic bile duct and its supplying arteries were reconstructed. Based on the 3D model, the origination and bifurcations of the bile duct artery were observed, and the digital types established. Afterwards, plans for preoperative procedures were formulated. Finally, postoperative observations were performed and the biliary complications recorded in detail. The 3D model clearly displayed the origin, course, and distribution of individualized arteries supplying the extrahepatic bile duct, as well as variations. According to 3D model characteristics, the digital types were established. Blood supply to the superior segment of the extrahepatic bile duct encompassed 6 (14.6%), 17 (41.5%), 12 (29.3%), and 6 (14.6%) cases of Types IA, IB, IC, and II, respectively; meanwhile, blood supply to the inferior segment comprised 13 (31.7%), 13 (31.7%), 4 (9.8%), 7 (17.0%), and 4 (9.8%) cases of Types IA, IB, IC, II, and III, respectively. This classification helped in preoperative surgical planning and corroborated intraoperative findings. No postoperative biliary complications were recorded. The 3D model reconstructed using Medical Image Three-Dimensional Visualization System displayed individualized anatomical structures of the extrahepatic bile duct and associated blood supplying arteries, and could contribute to preoperative surgical planning.

Change of hepatic arterial systolic/diastolic ratio predicts ischemic type biliary lesion after orthotropic liver transplantation.

BACKGROUND: We conducted this prospective nested case-control study for the hepatic artery and portal vein hemodynamic changes after orthotopic liver transplantation. METHODS: A total 128 cases of orthotropic liver transplantation were analyzed, including 25 cases of ischemic type biliary lesions (ITBL). The portal vein and hepatic artery flow velocities were detected by ultrasound on days 28, 42, and 84 after liver transplantation. In the GLM analysis of Lg(S/D), the P values of Group Effect, Time Effect, and Time×Group were 0.014, 0.376, and 0.008, respectively. CONCLUSION: Our results show a relatively reduced hepatic artery S/D in ITBL, especially in extrahepatic ITBL.

Indocyanine green reinjection technique for use in fluorescent angiography concomitant with cholangiography during laparoscopic cholecystectomy.

BACKGROUND: For safe laparoscopic cholecystectomy, surgeons must possess detailed knowledge of the anatomy of the bile duct and arterial system as seen through a laparoscope. STUDY DESIGN: We developed an indocyanine green (ICG) reinjection technique for use in fluorescent angiography. Here, we evaluated the efficacy of the ICG reinjection technique in fluorescent angiography in discriminating the arterial system with the concomitant use of fluorescent cholangiography. RESULTS: Twenty-eight patients were enrolled in the study. All patients underwent laparoscopic cholecystectomy without complication. After reinjection of ICG during surgery, fluorescence of the cystic artery was visualized in 25 patients (89%). CONCLUSIONS: Fluorescent angiography using this ICG reinjection technique might enhance the safety of laparoscopic cholecystectomy.

Computed tomography virtual endoscopy with angiographic imaging for the treatment of type IV-A choledochal cyst.

Type IV-A choledochal cysts (CCs) are a congenital biliary anomaly which involve dilatation of the extrahepatic and intrahepatic bile ducts. We present the case of a 30-year-old woman with type IV-A CC, on whom three-dimensional computed tomography (3D CT) and virtual endoscopy were performed. 3D CT revealed partial dilatation in the posterior branch of the intrahepatic bile duct and a relative stricture between it and the extrahepatic bile duct. Virtual endoscopy showed that this stricture was membrane-like and separated from the surrounding blood vessels. Based on these image findings, complete cyst resection, bile duct plasty for the stricture, and hepaticojejunostomy were safely performed. To the best of our knowledge, there are no reports of imaging by virtual endoscopy of the biliary tract which show the surrounding blood vessels running along the bile duct.

[Magnetic resonance cholangiographic (MRCP) features of ischemic-type biliary lesions (ITBL): a case-control study]. / Magnetresonanz-Cholangiografie (MRCP) bei Patienten mit Ischemic-Type Biliary Lesions (ITBL): eine Fall-Kontroll-Studie.

PURPOSE: To evaluate the spectrum of MR cholangiography (MRCP) features of ischemic-type biliary lesions (ITBL) after orthotopic liver transplantation (OLT). MATERIALS AND METHODS: 30 patients (16 m, 14 f) with an average age of 52 years (9 - 69 y) were examined in two 1.5 MR units using breath-hold 2D-SS-FSE-sequences and 3D-MRCP sequences. 20 of the 30 patients had an established ITBL, and the remaining 10 patients were post-OLT controls. MRCPs were evaluated independently by two experienced radiologists that were blinded to the clinical history as well as the results of other imaging modalities. All images were analyzed for the presence of 16 different pathological features. Differences between ITBL patients and controls were analyzed using the Mann-Whitney-U Test. Inter-rater variability was tested using the Cohen's Kappa test. RESULTS: Abnormal findings of bile ducts were seen in all patients. The most common findings were (in percentage for reader 1 / 2) intrahepatic bile duct dilatation (95 % / 95 %) and extrahepatic bile duct stenoses (95 % / 85 %), followed by intrahepatic main duct stenoses (90 % / 95 %) and segmental duct stenoses (85 % / 85 %). Differences between ITBL patients and controls were significant for most of the analyzed features (Mann-Whitney-U test, p < 0.05). For 12 of 16 features, there was substantial or almost perfect agreement (κ = 0.61 - 1.00), for 2 of 16 features moderate agreement (κ = 0.41- 0.60) and for 2 of 16 features fair agreement (κ < 0.40). CONCLUSION: In patients with ITBL, MR cholangiography reveals characteristic features that may allow differentiation from other biliary complications after liver transplantation.

Development of an experimental model of cholestasis induced by hypoxic/ischemic damage to the bile duct and liver tissues in infantile rats.

BACKGROUND: We aimed to develop experimental models of hypoxia/ischemia-induced cholestasis using neonatal and infantile rats. METHODS: Hypoxia/ischemia was induced in the bile duct (BD) by injecting prostaglandin (PG) at birth and/or by coagulation of the hepatic artery (CHA) at about 3 weeks after birth. The rats were divided into 6 groups: control; PG-injected; sham-operated with or without PG; CHA; and CHA + PG. CHA was also performed in adult rats. Liver specimens and blood samples were obtained at 5 weeks after birth, and immunohistochemical and biochemical examinations were performed. RESULTS: (1) BD proliferation with fibrosis (BDPF) was found in the intrahepatic portal tract in the CHA and CHA + PG groups. Low-grade BDPF was observed in the PG group. (2) Cyst formation in the extrahepatic BD (EBD) was observed in the porta hepatis of some rats in the CHA and CHA + PG groups. In these groups, the number of peribiliary vascular plexuses (PVPs) decreased. BD proliferation and infiltration of inflammatory cells were observed in the EBD wall in the CHA + PG group. (3) Ki-67 was expressed in BD and EBD cells in the CHA + PG group. (4) BDPF was not detected in adult rats with CHA. (5) Serum liver function tests indicated obstructive changes in the EBD in the CHA and CHA + PG groups. CONCLUSION: Reduced blood flow in the EBD during infancy induced BDPF and obstructive changes in the EBD, which may, along with immature PVP and inflammatory changes in the EBD, contribute to hypoxia/ischemia of the EBD.

Microvessel density at different levels of normal or injured bile duct in dogs and its surgical implications.

BACKGROUND: Ischemic recurrent stricture after surgical repair for iatrogenic bile duct injury (BDI) remains a challenge in clinical practice. The present study was designed to investigate whether ischemia is universal and of varied severity at different levels of the proximal bile duct after BDI. METHODS: A total of 30 beagle dogs were randomly divided into control, BDI, and BDI-repaired groups. The BDI animal model was established based on the classic pattern of laparoscopic cholecystectomy-related BDI. The animals were sacrificed on postoperative day 15, and bile duct tissue was harvested to assess microvessel density (MVD) at selected levels of the normal, post-BDI and BDI-repaired bile duct with the CD34 immunohistochemistry technique. RESULTS: In the control group, MVD at level H (high level) was remarkably higher than that at level L (low level). No significant difference was found between MVDs at levels H and M (middle level), as well as at levels M and L. However, the tendency was noted that the closer the level to the hilus, the greater the MVD at that level. In both the BDI and BDI-repaired groups, MVDs at level H were generally greater than those at level L, despite the unremarkable differences between MVDs at neighboring levels. In these two groups, a similar tendency of MVD distribution to that in the control group was found; the closer the level to the injury site, the lower was the MVD at that level. Moreover, compared with the MDVs at the levels M and L in the control group, MVDs at the corresponding levels in the BDI and BDI-repaired groups were all remarkably reduced (P<0.05). In addition, MVDs at all three levels in the BDI group significantly declined further after BDI repair. CONCLUSIONS: After BDI, universal ischemic damage in the injured proximal bile duct develops close to the injury site, while close to the hilus, ischemia is relatively slight. High hepaticojejunostomy, rather than low biloenterostomy or end-to-end duct anastomosis, should be recommended for BDI repair. Great care should be taken to protect the peribiliary plexus during repair.

Anastomosis between the hepatic artery and the extrahepatic collateral or between extrahepatic collaterals: observation on angiography.

Transcatheter arterial chemoembolisation for hepatocellular carcinoma is widely carried out not only through the hepatic artery but also through the extrahepatic collateral pathways. Anatomically, there are many anastomoses between the hepatic artery and the extrahepatic collateral as well as among the extrahepatic collaterals. However, these anastomoses may not be shown on angiography because the anastomosing branches are too small. These anastomoses may not only interfere with effective control of hepatocellular carcinoma by transcatheter arterial chemoembolisation but also cause unexpected procedure-related complications. Therefore, radiologists should have sufficient knowledge of these underlying anastomoses. In this report, we present our angiographic images.

Hilar liver resection in dogs.

OBJECTIVE: To describe hepatic vasculobiliary anatomy important to hilar liver lobe resection in the dog. STUDY DESIGN: Experimental study. ANIMALS: Canine cadavers (n=7). METHODS: The vasculobiliary system of 7 fresh canine livers was injected with a polymer. The parenchyma was dissected at the level of the hilus to determine the vascular and biliary supply to each liver lobe, and then macerated with a corrosion preparation. The information gathered was used to describe a surgical approach for hilar liver lobe resection. RESULTS: Each liver lobe had a single hepatic artery and biliary duct. The location of these structures was consistent, although minor variations existed (dorsal versus ventral to the lobar portal vein) in the left lateral lobe and papillary process in 2 specimens. Most liver lobes (34/49) were supplied by 1 lobar portal vein and drained by 1 lobar hepatic vein (39/49). The location of the portal and hepatic veins was consistent among specimens. CONCLUSIONS: The left division is the most mobile of the liver lobes and each lobe can be removed separately or en bloc. Because of the location of the hepatic veins, the central division is best removed as a single unit. The right lateral lobe can be removed individually or together with the caudate process. The papillary process is removed by itself. CLINICAL RELEVANCE: A hilar liver lobectomy technique can provide an alternative approach to conventional procedures for tumors that encroach upon the hilus of the liver.

[Prevention of iatrogenic injury of the extrahepatic ducts and vessels and diagnosis of choledocholithiasis during open and laparoscopic cholecystectomy].

The results of treatment of 334 patients, operated on for cholelithic disease, were analyzed. In 164 of them intraoperative transillumination (IT) was applied and in 170--the generally accepted methods of the hepatoduodenal ligament content exposure. There was established the expedience of the IT application for the extrahepatic biliary ducts (EBD) and vessels verification as well as for the choledocholithiasis diagnosis during performance of laparoscopic and open cholecystectomy. Application of IT and the laparoscopic cholecystectomy method proposed have ad permitted to reduce trustworthy the frequency of the EBD and the vessels iatrogenic injury.

Variant anatomy of the hepatic artery in adult Kenyans

Knowledge of the variant vascular anatomy ofthe subhepatic region is valuable to hepatobiliarysurgeons to limit operative complications due to unexpected bleeding. One hundred and two subhepatic regions were studied by gross dissection for the pattern of arterial blood supply. Measurements were made for the distance of hepatic bifurcation from the liver. The common hepatic artery (CHA) originated from the celiac trunk in 95.1% and from the superior mesenteric artery (SMA) in 4.9% of cases. The mean distance of bifurcation from the liver was 2.6cm and the CHA gave rise to 2 hepatic branches in 93.1% of cases. The right hepatic artery (RHA) passed anterior to the CHD in 48%, posterior in 41.2% and in 7.8% was related to the common bile duct (CBD). Accessory RHA and left hepatic arteries(LHA) were observed in 10.8% and 9.8% of the cases. There is wide variation in the pattern ofarterial supply to the liver and biliary apparatusin adult Kenyans. A comprehensive understandingand application of this aspect of surgical anatomy is essential for good results to be maintained and even improved when carrying out surgical procedures in this area (AU)

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Evaluation of VEGF A expression and microvascular density as prognostic factors in extrahepatic cholangiocarcinoma.

OBJECTIVES: Angiogenesis is essential for tumor growth and metastasis. An association between microvessel density, a measure of tumor angiogenesis, and conventional prognostic variables has been shown for many different tumor entities. In extrahepatic cholangiocarcinoma, the VEGF expression and microvessel density have rarely been investigated. METHODS: Paraffin-embedded specimens from 51 resected adenocarcinomas of the extrahepatic bile duct were immunostained for vascular endothelial growth factor A (VEGF A) and CD 34 to evaluate the microvessel density (MVD). VEGF A staining was evaluated by combining intensity and percentage of positive tumor cells, as low (expression equal or below the median), or high (above the median). Microvessel density was assessed using a method published by Weidner et al. RESULTS: Median disease free survival (DFS) of the study group was 12.5 months (range, 1-66.3 months). DFS was calculated in the 39 patients with complete resection. It was significantly better in patients with low microvessel density than DFS in patients with high microvessel density (33 months (range, 3-66.3 months) vs. 21.8 months (range, 1.6-31.6 months); p=0.022). In contrast, VEGF A expression did not correlate with survival. There was a trend toward a higher VEGF A expression in highly vascularized tumors (p=0.08), but failed to reach statistic significance. CONCLUSIONS: The present study indicates, that vascularisation has an important impact on survival of extrahepatic cholangiocarcinoma patients. Other molecules than VEGF A are probably involved in neovascularization in extrahepatic cholangiocarcinoma.

Reconsideration of the histologic definitions used in the pathologic staging of extrahepatic bile duct carcinoma.

The histologic boundaries of the extrahepatic bile ducts (EBDs) are not well defined, despite the fact that pathologic staging of carcinomas arising in these structures requires the determination of extent of tumor invasion in this area. Perhaps in part, because the smooth muscle band in the EBD wall is not well formed throughout the length of these structures, a previous definition of the outer portion of the bile duct wall included "loose, richly vascularized connective tissue, interlaced with large nerve fibers." We have experienced difficulty in the application of these criteria in staging EBD carcinomas, which requires the histologic determination of the extent of the EBD wall. To systematically study the histologic features of EBD tissue boundaries, 34 EBD specimens obtained from autopsy were analyzed with attention to the distribution of blood vessels and nerve fibers along the length of this system. The EBD specimens were divided into lower, middle, and upper portions, and the locations of blood vessels and nerve fibers were then analyzed separately at each location. We defined the fibromuscular wall as the dense concentric arrangement of collagen and smooth muscle fibers surrounding the EBD mucosa. The location of blood vessels and nerve fibers was categorized as either (1) within, (2) junctional to, or (3) outside of the fibromuscular wall. Blood vessels and nerve fibers are located predominantly outside of the fibromuscular wall and are usually surrounded by adipose tissue throughout the entire EBD, however, their distribution in this location is not consistent. Because of these histologic features, we propose that the bile duct wall is more precisely defined as occurring between the mucosa and the outermost boundary of dense fibromuscular tissue, without consideration of the presence or absence of blood vessels and nerve fibers.

Ischaemic cholangiopathy and sickle cell disease.

We report a case of a 6-year-old girl of Afro-Caribbean origin, known to have sickle cell disease (SCD), with recurrent history of jaundice and abdominal pain. She was extensively investigated, including endoscopic retrograde cholangiopancreatography (ERCP), which revealed diffuse cholangiopathy of both extrahepatic and intrahepatic bile ducts. A pigtail stent was placed and balloon dilatation was performed for stricture of the extrahepatic duct. Since then, she remains well and asymptomatic. We suggest that cholangiopathy is the consequence of sickling in the end arteries of the biliary arterial tree.

The finest branches of the biliary tree might induce biliary vascularization necessary for biliary regeneration.

BACKGROUND/AIMS: The finer branches of the biliary tree play an important role in biliary regeneration. They are consistently escorted by microvessels. Defects in the vascularization of these structures could impair bile duct regeneration. Therefore, we investigated the pattern of the escorting microvessels during the development of bile duct loss in the human liver, using chronic rejection as a model. METHODS: The number of interlobular bile ducts, bile ductules and extraportal biliary cells with and without escorting microvessels and the expression of VEGF-A were studied in follow-up biopsies of 12 patients with chronic rejection and 16 control patients with acute rejection without progression to chronic rejection. RESULTS: The controls showed a proliferation of bile ductules at 1-week and 1-month. Proliferation of bile ductules without microvessels preceded proliferation of bile ductules with microvessels. Proliferation of the microvascular compartment followed biliary proliferation. This sequence of events was not observed in the chronic rejection group, in which all biliary structures decreased in time. VEGF-A expression was increased at 1-week and 1-month in both groups. CONCLUSIONS: An immediate proliferative response of the finer branches of the biliary tree followed by proliferation of the microvascular compartment after biliary injury seems to be a prerequisite for bile duct regeneration.

Angioarchitecture of the rabbit extrahepatic bile ducts and gallbladder.

The angioarchitecture of extrahepatic bile ducts and gallbladder of the miniature rabbit was studied by scanning electron microscopy (SEM) of vascular corrosion casts. Light microscopy of Masson-stained, paraffin-embedded transverse tissue sections served to attribute cast vascular structures to defined layers of bile ducts and gallbladder. In all segments of the bile tract, a mucosal and a subserosal vascular network was found. In glandular segments, the mucosal network was composed of a meshwork of subepithelial and circumglandular capillaries, which serve the mucosal functions. Differences in the angioarchitectonic patterns existed only in the subserosal networks as hepatic ducts own one supplying arteriole only, while the common bile duct owns a well-defined rete arteriosum subserosum. A well-developed dense subserosus venous plexus was present throughout the bile tract. Vascular patterns of the gallbladder body resembled those of the bile duct, whereby the dense subserous venous plexus was located close to the mucosal capillary network. The subserosal network in the neck of the gallbladder resembled that of the cystic duct. Spatial changes of the mucosal vascular network during volume changes of the gallbladder were documented. Measurements from tissue sections revealed bile tract diameters of 220-400 microm (extrahepatic ducts), 500-650 microm (cystic duct), and 4-6 mm (common bile duct). Data gained from high-powered SEM micrographs of vascular corrosion casts revealed vessel diameters of 200 microm (cystic artery), 90-110 microm (cystic vein), 30-40 microm (feeding arterioles), and 25-110 microm (subserosal venules). Crypt diameters in the filled gallbladder were 300-1,500 mum; those in the contracted organ were 100-600 microm.

Histological characteristics of tumor cells and stromal cells in vessels and lymph nodes are important prognostic parameters of extrahepatic bile duct carcinoma: a prospective study.

Extrahepatic bile duct carcinomas (EHBDCs) consist of primary tumors, tumors in vessels, and tumors in lymph nodes. The purpose of this study was to prospectively investigate whether the histological characteristics of tumor cells and tumor stromal cells in vessels and lymph nodes were significantly associated with the outcomes of 60 EHBDC patients as compared with the histological characteristics of tumor cells and tumor stromal cells in primary tumors. Multivariate analyses, using the Cox proportional hazard regression model, showed that in EHBDCs without nodal metastasis, blood vessel tumor emboli with an angiomatous stroma significantly increased the hazard ratios (HRs) of tumor recurrence and death ( P < .05). In EHBDCs with nodal metastasis, the presence of tumor necrosis in the nodal tumors significantly increased the HRs of tumor recurrence and initial distant organ metastasis ( P < .05). In EHBDCs located in the distal to middle portion of the extrahepatic bile duct, blood vessel tumor emboli with an angiomatous stroma significantly increased the HRs of tumor recurrence, initial distant organ metastasis, and death ( P < .05). Severe nuclear atypia of the tumor cells in lymph vessels significantly increased the HRs of tumor recurrence and initial distant organ metastasis ( P < .05). In EHBDCs located in the hilar portion of the extrahepatic bile duct, the presence of nodal tumors with more than 4 mitotic figures significantly increased the HRs of tumor recurrence and initial distant organ metastasis ( P < .05). Several histological characteristics of tumor cells and tumor stromal cells in vessels and lymph nodes have significant effects on tumor progression of EHBDCs.