Surgical management of anatomical variations of the right lobe in living donor liver transplantation

Outcomes of Adult Right Graft Living Donor Liver Transplantation Utilizing the Robotic Platform-integrated Real-time Indocyanine Green Fluorescence Cholangiography Compared to the Open Approach

OBJECTIVE

This study aimed to assess short-term biliary outcomes in adult living donor liver transplants using right grafts, comparing robotic surgery with real-time indocyanine green fluorescence cholangiography for optimal hilar plate transection, against the conventional open approach.

BACKGROUND

Determining the optimal transection plane through the hilar plate is crucial in donor hepatectomies, impacting outcomes significantly.

METHODS

From 2011 to 2023, a total of 839 right graft living donor hepatectomies were performed, with 414 (49%) performed via the open approach and 425 (51%) utilizing the robotic platform.

RESULTS

The magnetic resonant cholangiopancreatography predictions correlated moderately with the actual count of graft ducts ( r =0.57, P <0.001). Out of all 839 right donor hepatectomies, 321 (44%) were single duct grafts, of which 193/425 (49%) were retrieved with the robotic while 128/414 (38%) were with the open approach (OR: 1.58, 95% CI: 1.16-2.14), P =0.003). Overall, 50 (6%) of the donors developed a biliary complication during their hospital stay, of whom 38 (9%) were grafts retrieved with the open, while 13 (3%) with the robotic approach (OR: 0.31, 95% CI: 0.15-0.61, P <0.001). Similarly, 63 (15%) of the adult recipients developed a biliary complication of any severity when grafts were retrieved with the open approach compared to 35 (8%) with the robotic approach (OR: 0.50, 95% CI: 0.31-0.79), P =0.002).

CONCLUSIONS

The robotic platform with integrated real-time indocyanine green fluorescence cholangiography during right donor hepatectomy offers improved safety for the donor by accurately addressing the right hilar corridor, resulting in fewer graft ducts and fewer complications for the donor and recipient when compared to the standard open approach.

Hilar Anatomy in 3035 Living Liver Donors: A Novel Classification for Donor Surgery and Suitability, Hepatic Surgeries, and Hepatobiliary Interventions

BACKGROUND

This study examines the vascular and biliary variations in 3035 liver donors. We propose a novel classification of hepatic arteries, portal veins, and bile ducts and clinically relevant donor classification.

METHODS

Preoperative imaging and operative details of 3035 donors from 2005 to 2020 were reviewed. Hilar anatomical variations were identified and grouped on the basis of incidence and clinical relevance.

RESULTS

Hilar structures are classified according to the numbers supplying or draining the graft: for the hepatic artery, right (R) and left (L), RA1/LA1 (1 artery), RA2/LA2 (2 arteries), and RA3/LA3 (3 arteries), respectively, further defined on the basis of the inflow trunk into C (for common hepatic artery), S (for superior mesenteric artery), and L (for left gastric artery); for the portal vein, RP1 (1 vein) and RP2 (2 veins) for the right lobe; and for the hepatic duct, RB1/LB1 (1 duct), RB2/LB2 (2 ducts), RB3 (3 right ducts), and RB4 (4 right ducts). Donors were classified on the basis of anatomical variations into 3 groups: class 1 and class 2 donors, who can donate liver with acceptable risks, and class 3 donors, who are high-risk donors because they are anatomically unacceptable ( Figures S1 to S4, SDC , http://links.lww.com/TP/C918 ).

CONCLUSIONS

Defining hilar anatomical variations and donor grouping into anatomy-based clinical classes helps in operative planning of donors, hepatobiliary surgeries, and interventional procedures.

Donor Safety First: Postoperative Hepatectomy Outcomes in Living Liver Donors

BACKGROUND

Living donor liver transplantation (LDLT) has become a popular treatment option because some countries lack a deceased organ program and the growing demand for liver transplants. Although postoperative outcomes are similar to deceased donor liver transplants, there is still an element of risk to the donor. The Clavien-Dindo classification system has been used to standardize reporting across different institutions and surgeons to categorize surgical outcomes.

METHODS

Between January 1, 2022, and December 31, 2022, 207 living donors underwent hepatectomies at our center. All donors underwent a 3-step process of mandatory screening. Postsurgical complications were classified using the Clavien-Dindo classification.

RESULTS

A total of 207 donor hepatectomies for LDLT were performed during our study period. Most donors (92.8%) were aged between 18 and 39 years. The most common type of graft used was a right lobe without the middle hepatic vein (82.6%). Most donors (91.7%) experienced an intraoperative blood loss of ≤500 mL. A total of 140 patients had an ordinary postoperative course. Grade 1 complications were observed in 16.9%, grade 2 in 12.1%, and grade 3 in 3.4% of the remaining patients. No grade 4 or grade 5 (patient death) complications were observed in this cohort.

CONCLUSIONS

Living donor liver transplantation remains the most practiced liver transplant surgery in Pakistan. Our findings highlight the safety of the LDLT program with minimal risk of significant complications. The study also underscores the importance of careful screening and monitoring of living donors and the need for standardized reporting of surgical outcomes using the Clavien-Dindo classification system.

Feasibility and outcomes of living-donor liver transplantation utilizing the right hemi-liver graft with portal vein anatomical variations

PURPOSE

Portal vein (PV) reconstruction is a key factor for successful living-donor liver transplantation (LDLT). Anatomical variations of right PV (RPV) are encountered among potential donors.

METHODS

To evaluate a single center experience of reconstruction techniques for the right hemi-liver grafts with PV variations during the period between May 2004 and 2022.

RESULTS

A total of 915 recipients underwent LDLT, among them 52 (5.8%) had RPV anatomical variations. Type II PV was found in 7 cases (13.5%), which were reconstructed by direct venoplasty. Type III PV was found in 27 cases (51.9%). They were reconstructed by direct venoplasty in 2 cases (3.8%), Y graft interposition in 2 cases (3.8%), and in situ double PV anastomoses in 23 cases (44.2%). Type IV PV was found in 18 cases (34.6%) and was reconstructed by Y graft interposition in 9 cases (17.3%), and in situ double PV anastomoses in 9 cases (17.3%). Early right posterior PV stenosis occurred in 2 recipients (3.8%). Early PV thrombosis occurred in 3 recipients (5.8%). The median follow-up duration was 54.5 months (4 - 185). The 1-, 3-, and 5-years survival rates were 91.9%, 86%, and 81.2%, respectively. Late PV stenosis occurred in 2 recipients (3.8%) and was managed conservatively.

CONCLUSION

Utilization of potential living donors with RPV anatomic variations may help to expand the donor pool. We found that direct venoplasty and in situ dual PV anastomoses techniques were safe, feasible, and associated with successful outcomes.

Machine learning improves the accuracy of graft weight prediction in living donor liver transplantation

Precise graft weight (GW) estimation is essential for planning living donor liver transplantation to select grafts of adequate size for the recipient. This study aimed to investigate whether a machine-learning model can improve the accuracy of GW estimation. Data from 872 consecutive living donors of a left lateral sector, left lobe, or right lobe to adults or children for living-related liver transplantation were collected from January 2011 to December 2019. Supervised machine-learning models were trained (80% of observations) to predict GW using the following information: donor's age, sex, height, weight, and body mass index; graft type (left, right, or left lateral lobe); computed tomography estimated graft volume and total liver volume. Model performance was measured in a random independent set (20% of observations) and in an external validation cohort using the mean absolute error (MAE) and the mean absolute percentage error and compared with methods currently available for GW estimation. The best-performing machine-learning model showed an MAE value of 50 ± 62 g in predicting GW, with a mean error of 10.3%. These errors were significantly lower than those observed with alternative methods. In addition, 62% of predictions had errors <10%, whereas errors >15% were observed in only 18.4% of the cases compared with the 34.6% of the predictions obtained with the best alternative method ( p  < 0.001). The machine-learning model is made available as a web application ( http://graftweight.shinyapps.io/prediction ). Machine learning can improve the precision of GW estimation compared with currently available methods by reducing the frequency of significant errors. The coupling of anthropometric variables to the preoperatively estimated graft volume seems necessary to improve the accuracy of GW estimation.

CT and MR imaging evaluation of living liver donors

Preoperative cross-sectional imaging evaluation of potential living liver donors allows to exclude donors with an increased risk for morbidity and mortality, and to assure that a suitable graft for the recipient can be obtained, minimizing the risk of complications in both the donor and the recipient. CT is routinely performed to delineate the anatomy of the liver, relevant vasculature, and liver volumes in whole right or left lateral segment donation. MR imaging is the gold standard for the assessment of biliary anatomy and allows a better quantification of hepatic steatosis compared to CT. Knowledge of normal and variant vascular and biliary anatomy and their surgical relevance for liver transplantation is of paramount importance for the radiologist. The purpose of this review is to outline the current role of CT and MR imaging in the assessment of hepatic parenchyma, hepatic vascular anatomy, biliary anatomy, and hepatic volumetry in the potential living liver donor with short notes on acquisition protocols and the relevant reportable findings.

Celiac axis stenosis and digestive disease: Diagnosis, consequences and management

Arterial blood flow to the organs of the upper abdomen is provided by the celiac axis (CA) and the superior mesenteric artery (SMA) that communicate between each other via the gastro-duodenal artery, the anterior and posterior pancreatico-duodenal arcades, the branches of the dorsal pancreatic artery and inconsistently, though a supplementary arcade that connects the CA and the SMA (arcade of Bühler). Celiac axis stenosis may or may not have a hemodynamic impact on the splanchnic circulation. Hemodynamically significant CA stenosis can be asymptomatic, or symptomatic with variables clinical consequences. Management depends on whether the mechanism of stenosis is extrinsic or intrinsic. When upper gastrointestinal interventional radiology or surgery is indicated, stenosis can pose technical difficulties or create severe ischemia requiring good understanding of this entity in the planning of operative steps and adapted management. Management of CA stenosis is therefore multidisciplinary and may involve interventional radiologists, gastrointestinal surgeons, vascular surgeons as well as medical physicians. Even though the prevalence of CA stenosis is relatively low (between 5 and 10%) and irrespective of its etiology, surgeons, radiologists and physicians must be aware of it because it can intervene in the management of upper gastrointestinal disease. It must be sought, and treatment must be adapted to each particular situation to avoid potentially severe complications.

Importance of Imaging Plane of Gadoxetic Acid--Enhanced Magnetic Resonance Cholangiography for Bile Duct Anatomy in Healthy Liver Donors

PURPOSE

The purpose of this study was to compare the image quality and accuracy of axial vs coronal contrast-enhanced magnetic resonance cholangiography (CE-MRC) for assessing bile duct anatomy.

METHODS

Data from 313 healthy donors who underwent axial and coronal CE-MRC before liver donation were retrospectively analyzed. Motion artifacts and bile duct visibility were assessed using 4-point scales, with scores ≥3 considered interpretable. The sensitivity and specificity of axial and coronal CE-MRC for diagnosing anatomic variations were compared, as were the proportions of correctly categorized biliary anatomic types.

RESULTS

Axial CE-MRC provided better image quality than coronal CE-MRC in terms of both motion artifacts (3.83 vs 3.17; P < .001) and duct visibility (3.50 vs 3.17, P < .001), resulting in more interpretable images with axial than coronal CE-MRC (92.7% vs 82.1%; P < .001). Among 249 donors with interpretable images, coronal CE-MRC performed significantly better for identifying duct anatomic variation than axial CE-MRC (sensitivity, 96.9% vs 80.4%, P < .001; specificity, 100% vs 96.7%, P = .025). Coronal CE-MRC was significantly better than axial CE-MRC at correctly categorizing anatomic types of right posterior hepatic duct into left hepatic duct and accessory duct with incomplete right hepatic duct.

CONCLUSIONS

With interpretable image quality, coronal CE-MRC performed better than axial CE-MRC for evaluating bile duct anatomy.

Impact of Hepatic Artery Variations and Reconstructions on the Outcome of Orthotopic Liver Transplantation

BACKGROUND

Donor variational arteries often require complex reconstruction.

METHODS

We analysed the incidence of different variations, types of arterial reconstructions and their impact on post-operative results from 409 patients undergoing liver transplantation at Karolinska Institute between 2007 and 2015.

RESULTS

A total of 292 (71.4%) liver grafts had a standard hepatic artery (SHA), and 117 (28.6%) showed hepatic artery variants (HAV). 58% of HAV needed reconstruction. The main variations were variant left hepatic artery (45.3%) from the gastric artery; variant right hepatic artery (38.5%); and a triple combination of variant right and left hepatic artery and the proper hepatic artery from the common hepatic artery (12.8%); other 3.4%. Patients/graft survival and arterial complications were not different between SHA and HAV. Incidence of biliary stricture was numerically higher in left hepatic artery variants (p = 0.058) and in variants where no arterial reconstruction was performed (p = 0.001). Operation and arterial warm ischaemia time were longer in the HAV group. The need for intraoperative re-reconstruction was higher in the HAV group (p = 0.04). Intraoperative bleeding was larger after back-table reconstruction than with intraoperative reconstruction (p = 0.04).

CONCLUSION

No overall differences were found between the HAV and the SHA groups. Occurrence of a variant left hepatic artery and HAV with no reconstruction seems to increase the risk of biliary strictures.

A Worldwide Survey of Live Liver Donor Selection Policies at 24 Centers With a Combined Experience of 19 009 Adult Living Donor Liver Transplants

BACKGROUND

Although surgical technique in living donor liver transplantation (LDLT) has evolved with a focus on donor safety and recipient challenges, the donor selection criteria remain considerably disparate.

METHODS

A questionnaire on donor selection was sent to 41 centers worldwide. 24 centers with a combined experience of 19 009 LDLTs responded.

RESULTS

Centers were categorized into predominantly LDLT (18) or deceased donor liver transplantation (6), and high- (10) or low-volume (14) centers. At most centers, the minimum acceptable graft-to-recipient weight ratio was 0.7 or less (67%), and remnant was 30% (75%). The median upper limit of donor age was 60 years and body mass index of 33 kg/m. At 63% centers, age influenced the upper limit of body mass index inversely. Majority preferred aspartate transaminase and alanine transaminase less than 50 IU/mL. Most accepted donors with nondebilitating mild mental or physical disability and rejected donors with treated coronary artery disease, cerebrovascular accident and nonbrain, nonskin primary malignancies. Opinions were divided about previous psychiatric illness, substance abuse and abdominal surgery. Most performed selective liver biopsy, commonly for steatosis, raised transaminases and 1 or more features of metabolic syndrome. On biopsy, all considered macrovesicular and 50% considered microvesicular steatosis important. Nearly all (92%) rejected donors for early fibrosis, and minority for nonspecific granuloma or mild inflammation. Most anatomical anomalies except portal vein type D/E were acceptable at high-volume centers. There was no standard policy for preoperative or peroperative cholangiogram.

CONCLUSIONS

This first large live liver donor survey provides insight into donor selection practices that may aid standardization between centers, with potential expansion of the donor pool without compromising safety.

Biliary reconstructive techniques and associated anatomic variants in adult living donor liver transplantations: The adult-to-adult living donor liver transplantation cohort study experience

Living donor liver transplantation (LDLT) is a technically demanding endeavor, requiring command of the complex anatomy of partial liver grafts. We examined the influence of anatomic variation and reconstruction techniques on surgical outcomes and graft survival in the 9-center Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Data from 272 adult LDLT recipients (2011-2015) included details on anatomic characteristics and types of intraoperative biliary reconstruction. Associations were tested between reconstruction technique and complications, which included first biliary complication (BC; leak, stricture, or biloma) and first vascular complication (VC; hepatic artery thrombosis [HAT] or portal vein thrombosis [PVT]). Time to patient death, graft failure, and complications were estimated using Kaplan-Meier curves and tested with log-rank tests. Median posttransplant follow-up was 1.2 years. Associations were found between the type of biliary reconstruction and the incidence of VC (P = 0.03) and BC (P = 0.05). Recipients with Roux-en-Y hepaticojejunostomy had the highest probability of VC. Recipients with biliary reconstruction involving the use of high biliary radicals on the recipient duct had the highest likelihood of developing BC (56% by 1 year) compared with duct-to-duct (42% by 1 year). In conclusion, the varied surgical approaches in the A2ALL centers offer a novel opportunity to compare disparate LDLT approaches. The choice to use higher biliary radicals on the recipient duct for reconstruction was associated with more BC, possibly secondary to devascularization and ischemia. The use of Roux-en-Y biliary reconstruction was associated with VCs (HAT and PVT). These results can be used to guide biliary reconstruction decisions in the setting of anatomic variants and inform further improvements in LDLT reconstructions. Ultimately, this information may contribute to a lower incidence of technical complications after LDLT. Liver Transplantation 23 1519-1530 2017 AASLD.

Outflow Reconstruction Using Cryopreserved Homologous Venous Grafts in Living Donor Liver Transplantation

OBJECTIVES

The techniques and outcomes of outflow reconstruction in living donor liver transplantation (LDLT) using cryopreserved homologous veins at the University of Tokyo Hospital are presented.

METHODS

We performed 540 LDLTs from January 1996 to March 2015. Graft types included right liver graft (n = 262), left liver graft (n = 196), left lateral sector graft (n = 53), and posterior sector graft (n = 28). We routinely use cryopreserved homologous vein grafts for the hepatic vein reconstructions to secure the large outflow of the graft. In addition to the presentation of our techniques, the cases with symptomatic outflow obstruction and the treatments were also investigated.

RESULTS

The 1-, 3-, and 5-year graft survival rates were 90.6%, 86.1%, and 83.5%, respectively. The incidence of severe complications (Clavien-Dindo grade IIIb and more) was 38%. The overall incidence of outflow obstruction requiring invasive treatment was 1.9% (10/540), including 3 left liver grafts (1.5%, 3/196) and 7 right liver grafts (2.7%, 7/262). Regarding the patency of the reconstructed veins, the left hepatic vein, middle hepatic vein, and right hepatic vein achieved nearly 100% patency. On the contrary, venous tributaries such as V5, V8, and inferior right hepatic vein were frequently occluded in the postoperative course.

CONCLUSIONS

Outflow reconstruction is a key for the successful LDLT. Cryopreserved homologous vein graft is useful for the promising hepatic vein reconstruction.

[Advisability of biliary drainage in liver fragments reconstruction]

AIM

to estimate the effect of decompressive stented drainage of biliary anastomosis on incidence of biliary complications.

MATERIAL AND METHODS

294 patients aged from 5 months to 61 years (mean 13.8±0.81) were enrolled. They underwent liver fragments transplantation in the Department of Liver Transplantation of Petrovsky Russian Research Center of Surgery for the period from March 1997 to January 2016. Decompressive stented drainage tubes were used in 28 (9.5%) patients. Reconstruction without drainage was applied in 266 (90.5%) cases. In the group of biliobiliary reconstruction drainage was used in 18 out of 89 cases (20.2%), in the group of biliodigestive reconstruction - in 10 out of 202 cases (4.9%). Incidence of specific biliary complications was assessed.

RESULTS

There was significant direct correlation of stented drainage of biliodigestive anastomosis with various biliary complications including bile leakage (r= -0,1253; p=0.06), obturation of anastomosis (r=0.045; p=0.501), stricture of anastomosis (r= -0.0665; p=0.320), other strictures of intrahepatic bile ducts (r= -0.0291; p=0.664), hepatolithiasis (r=0.0857; p=0.199). However significant direct correation was observed between stented drainage and incidence of intrahepatic bile ducts strictures (r=0.2117; p=0.046) and anastomosis obturation (r=0.2330; p=0.028) in case of biliobiliary reconstruction. Significant correation with other biliary complications was absent (p>0.05).

CONCLUSION

Unconstrained stented drainage during primary biliary reconstruction is associated with increased incidence of biliary complications and should not be indicated routinely. Clear need for drainage should be determined in further investigations.

Reconstruction of hepatic venous tributary in right liver living donor liver transplantation: The importance of the inferior right hepatic vein

Special care must be taken in hepatic vein reconstruction to avoid outflow block in living donor liver transplantation (LDLT) with a right liver graft. We have used cryopreserved homologous veins to reconstruct the right hepatic vein (RHV), middle hepatic vein (MHV), MHV tributaries (V5 and V8), and inferior right hepatic vein (IRHV). The reconstruction of V5, V8, and IRHV was based on the estimated congestive volume, calculated by the computed tomography volumetry, to secure the functional graft volume of 40% of the recipient standard liver volume. Among 262 right liver LDLT recipients, the number of reconstructed RHVs, MHVs, V5s, V8s, and IRHVs was 262, 48, 110, 111, and 147, respectively, and the overall patency was 95%, 100%, 36%, 58%, and 86%, respectively. Although the patency of the RHVs and MHVs was satisfactory, that of the V5s, V8s, and IRHVs was suboptimal. Patency of the IRHVs (86%, 126/147) was significantly better than that of both V5s (36%, 40/110) and V8s (58%, 64/111; P < 0.001). In addition, the estimated volume drained by IRHVs was significantly greater than that of V5s and V8s (IRHV, 176 ± 92 mL; V5, 105 ± 49 mL; V8, 127 ± 60 mL; P < 0.001). The patency of IRHV was significantly improved by applying the double inferior vena cava method (93%, 94/101) when compared to the direct anastomosis to vena cava (68%, 25/37; P < 0.001). The IRHV functioned as a main drainage route in cases of an obstructed RHV. In conclusion, reconstruction of the IRHV is recommended, not only to improve the functional reserve of the graft, but also to secure multiple drainage routes of the graft.

Evaluation of Numerical and Positional Variations of the Hepatic Veins: A Cadaveric Study

INTRODUCTION

Hepatic veins are the major linking vessels between systemic and portal circulation. Numerical and positional variation of the hepatic veins can play a significant role during surgical interventions on the liver.

MATERIALS AND METHODS

Gross anatomical study regarding the number and arrangement pattern of hepatic veins was undertaken on 88 adult livers which were stored in 10% formalin after the regular dissection classes.

RESULT

Six livers (7%) were found to be drained only by major hepatic veins, whereas 82 out of 88 livers (93%) had accessory (minor) hepatic veins. The total number of persistent hepatic veins ranged from 2 to 10 with the highest prevalence of four hepatic veins (35.2%) followed by 5 (19.3%) and 6 (17%). The presence of three major veins was seen in 45 (51%) livers while 41 (47%) livers had two major hepatic veins. Remaining two livers (2%) showed the presence of four major hepatic veins. In 95% specimens, the minor hepatic veins entered the inferior vena cava below the level of entry of major veins. In 2.5% cases, their entry point was above the major veins and in 2.5% cases, the entry point was below major veins.

CONCLUSION

The data resulting from this study provides a clear idea about the number and drainage pattern of the hepatic veins into the liver. Knowledge of numerical and positional variations of hepatic veins could be useful in normal Doppler ultrasound hepatic vein flow velocities and their variation with respiration in healthy adults as comparable with the similar approach of superior vena cava.

Contrast-enhanced MR cholangiography with Gd-EOB-DTPA for preoperative biliary mapping: correlation with intraoperative cholangiography

BACKGROUND

Gd-EOB-DTPA-enhanced magnetic resonance (MR) could be used for preoperative evaluation of bile duct anatomy in addition to conventional information of focal hepatic lesions.

PURPOSE

To evaluate accuracy of contrast-enhanced MR cholangiography (CE MRC) reconstructed from Gd-EOB-DTPA-enhanced MR images for depicting biliary anatomy with intraoperative cholangiography.

MATERIAL AND METHODS

We retrospectively identified 71 patients who underwent both preoperative Gd-EOB-DTPA-enhanced MR imaging (MRI) and intraoperative cholangiography for hepatic resections. Two readers independently analyzed biliary anatomy using CE MRC reconstructed from transverse and coronal images separately in 4 weeks. The accuracy and diagnostic confidence were evaluated in correlation with intraoperative cholangiography. The accuracy and confidence score (3-point scale) were compared on CE MRCs from transverse versus coronal images.

RESULTS

CE MRCs correctly depicted biliary anatomy in 91.5% and 88.7% with coronal images and in 81.7% and 73.2% with transverse images for readers 1 and 2, respectively. CE MRCs from coronal images tended to show greater accuracy (P = 0.12 and 0.01, for readers 1 and 2) and higher confidence score (P = 0.11 and P = 0.04, for readers 1 and 2) than those from transverse images.

CONCLUSION

Accurate preoperative biliary mapping can be achieved on CE MRC reconstructed from Gd-EOB-DTPA-enhanced MR images. The diagnostic performance was better on CE MRC reconstructed from coronal than those from transverse images.

Clinical Outcomes of Donor Hepatic Artery to Recipient Replaced Right Hepatic Artery Anastomosis in Living-Donor Liver Transplantation

OBJECTIVE

The aim of this work was to evaluate the clinical outcomes of donor hepatic artery to recipient replaced right hepatic artery anastomosis in living-donor liver transplantation.

METHODS

A retrospective analysis of 12 patients with donor hepatic artery to recipient replaced right hepatic artery anastomosis in living-donor liver transplantation from January 2012 to July 2014 was performed. Age, sex, clinical diagnosis of the liver disease, ABO mismatch, hepatic artery thrombosis, biliary strictures and leakage, graft loss, and mortality rates were evaluated.

RESULTS

Female-to-male ratio was 4:8. Right lobe was transplanted in 11 (91.7%) of the patients. In 1 patient, left lobe was transplanted. In 9 patients, single duct-to-duct biliary anastomosis was performed with cystic duct catheterization. In 2 patients, double duct-to-duct biliary anastomosis was performed. In 1 patient, double biliary duct-to-duct anastomosis was performed after ductoplasty to achieve a single ductal orifice. No hepatic artery thrombosis was observed. Biliary complications were observed in 6 patients (50%: biliary leaks in 2 patients, biliary stricture in 3 patients, and both in 1 patient). ABO mismatch was not observed. No graft loss due to hepatic artery thrombosis was observed. Mortality was observed in 2 patients (16.6%).

CONCLUSIONS

Donor hepatic artery to recipient replaced right hepatic artery anastomosis in living-donor liver transplantation is somewhat related to biliary complications, but not associated with increased rates of hepatic artery thrombosis.

Adult right living-donor liver transplantation with special reference to reconstruction of the middle hepatic vein

Two hundred fifty-three consecutive living-donor liver transplant recipients with a right liver graft (RLG) were divided into three groups: an extended right liver graft (ERLG) group (n = 47) in which the middle hepatic vein (MHV) trunk was included in the graft, a modified right liver graft (MRLG) group (n = 114) in which the MHV tributaries were reconstructed with cryopreserved homologous veins and a simple RLG group (n = 92) in which the MHV tributaries were sacrificed. The volume of the anterior sector was significantly impaired in the RLG group compared to the other two groups, whereas the volume of the posterior sector was significantly improved in the RLG group, indicating that the impaired anterior sector regeneration by MHV deprivation was compensated by the posterior sector regeneration. The regeneration rate of the anterior sector was highest in the ERLG group (92%), moderate in the MRLG group (71%) and lowest in the RLG group (52%). The whole graft regeneration rate of the ERLG group was significantly higher than that of the other two groups. Poor regeneration, however, was not correlated with delayed functional recovery or long-term outcome. Short-term, the patency of reconstructed MHV tributaries was over 90%, but occlusion occurred frequently over the long-term, especially in V5.

Outcome of duct-to-duct vs. Roux-en-Y hepaticojejunostomy biliary anastomoses in below 15-kg pediatric liver transplant recipients

The best type of biliary anastomosis to use in lower weight pediatric liver transplant recipients is debatable. In this study, we share a single center's experience comparing the rate of anastomotic biliary complications based on the type of biliary anastomosis performed in this population of patients. A retrospective review of pediatric liver transplants for recipients weighing <15 kg from 11/2003 till 12/2011 was performed. Patients were grouped based on the type of biliary anastomosis into two groups: duct-to-duct (d-d) and Roux-en-Y hepaticojejunostomy (h-j) anastomoses. A total of 24 patients (12 males, 12 females) with a mean age of 26 ± 20 months and a mean weight of 9.27 ± 2.63 kg (range = 5.3-13.9 kg) were studied. All anastomotic complications occurred in patients who received left lateral segments. No statistical differences were found in the post-operative biliary (p = 0.86) or vascular (p = 0.99) complications between the two groups. Acknowledging the limited sample size, our data suggest that duct-to-duct anastomosis can be performed safely in pediatric liver transplantation recipients weighing below 15 kg.

Expectations from imaging for pre-transplant evaluation of living donor liver transplantation

Living donor liver transplant (LDLT) is a major surgical undertaking. Detailed pre-operative assessment of the vascular and biliary anatomy is crucial for safe and successful harvesting of the graft and transplantation. Computed tomography (CT) and magnetic resonance imaging (MRI) are currently the imaging modalities of choice in pre-operative evaluation. These cross-sectional imaging techniques can reveal the vascular and biliary anatomy, assess the hepatic parenchyma and perform volumetric analysis. Knowledge of the broad indications and contraindications to qualify as a recipient for LDLT is essential for the radiologist reporting scans in a pre-transplant patient. Similarly, awareness of the various anatomical variations and pathological states in the donor is essential for the radiologist to generate a meaningful report of his/her observations. CT and MRI have largely replaced invasive techniques such as catheter angiography, percutaneous cholangiography and endoscopic retrograde cholangiopancreatography. In order to generate a meaningful report based on these pre-operative imaging scans, it is also mandatory for the radiologist to be aware of the surgeon’s perspective. We intend to provide a brief overview of the common surgical concepts of LDLT and give a detailed description of the minimum that a radiologist is expected to seek and report in CT and MR scans performed for LDLT related evaluation.

Use of right lobe graft with type IV portal vein accompanied by type IV biliary tree in living donor liver transplantation: report of a case

Anatomic variations of the portal vein (PV) and bile duct (BD) are more common on the right lobe as compared with left lobe grafts in living donor liver transplantation (LDLT). We recently experienced a case of LDLT for hepatocellular carcinoma combined with liver cirrhosis secondary to hepatitis B virus and hepatitis C virus infection. The only available donor had right lobe graft with type IV PV associated with type IV BD. The patient underwent relaparotomy for PV stenting due to PV stenosis. Percutaneous transhepatic biliary drainage was done for a stricture at the site of biliary reconstruction. Thereafter, the patient was discharged in good health. Our experience suggests that, the use of right lobe graft with type IV PV accompanied by type IV BD should be the last choice for LDLT, because of its technical difficulty and risks of associated complications.

MR imaging of the biliary system

Although ultrasound, computed tomography, and cholescintigraphy play essential roles in the evaluation of suspected biliary abnormalities, magnetic resonance (MR) imaging and MR cholangiopancreatography can be used to evaluate inconclusive findings and provide a comprehensive noninvasive assessment of the biliary tract and gallbladder. This article reviews standard MR and MR cholangiopancreatography techniques, clinical applications, and pitfalls. Normal biliary anatomy and variants are discussed, particularly as they pertain to preoperative planning. A spectrum of benign and malignant biliary processes is reviewed, emphasizing MR findings that aid in characterization.

Liver segmentation: practical tips

The liver segmentation system, described by Couinaud, is based on the identification of the three hepatic veins and the plane passing by the portal vein bifurcation. Nowadays, Couinaud's description is the most widely used classification since it is better suited for surgery and more accurate for the localisation and monitoring of intra-parenchymal lesions. Knowledge of the anatomy of the portal and venous system is therefore essential, as is knowledge of the variants resulting from changes occurring during the embryological development of the vitelline and umbilical veins. In this paper, the authors propose a straightforward systematisation of the liver in six steps using several additional anatomical points of reference. These points of reference are simple and quickly identifiable in any radiological examination with section imaging, in order to avoid any mistakes in daily practice. In fact, accurate description impacts on many diagnostic and therapeutic applications in interventional radiology and surgery. This description will allow better preparation for biopsy, portal vein embolisation, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy for transplantation. Such advance planning will reduce intra- and postoperative difficulties and complications.

Biliary and vascular anomalies in living liver donors: the role and accuracy of pre-operative radiological mapping

BACKGROUND

The aim of the present study was to determine the utility of computed tomography (CT) and magnetic resonance imaging (MRI) anatomic mapping in the detection of biliary and vascular anomalies prior to a living liver donor (LLD) operation.

METHODS

A retrospective study of all LLD patient charts, operative and radiology reports from 1 January 2002 to 1 January 2012 was conducted. Primary post-operative outcomes assessed included mortality, re-operation, readmission and need for endoscopic or percutaneous intervention. Sensitivity and specificity of MR and CT pre-operative screening was calculated against the gold standard of intra-operative findings.

RESULTS

A total of 34 donors had an average age of 38 years (range: 22-58) with a body mass index (BMI) of 25.6 kg/m(2) (range: 19.8-32.5) and a length of stay (LOS) of 10.1 days (range: 5-41). There were no donor mortalities. Sensitivity and specificity of CT was 70.0% and 91.3%, and of MRI screening 23.1% and 100.0%, respectively. Patients with inaccurate pre-operative CT or MRI did not have an increased risk of complications.

CONCLUSIONS

Even although it was specific, pre-operative MR screening missed up to 77.0% of biliary anomalies. An impeccable surgical technique remains the key in preventing biliary complications of a living donor hepatectomy where pre-operative MRI screening is false.

Variations in biliary ductal and hepatic vascular anatomy and their relevance to the surgical management of choledochal cysts

PURPOSE

An aberrant biliary ductal and vascular anatomy presents a technical challenge for choledochal cyst (CDC) surgery. Mismanagement may have unfavourable implications. This study highlights the spectrum, approach to their identification and management.

METHODS

Forty of 117 (34 %) cases were identified to have an aberrant biliary ductal (n = 17) or arterial (n = 26) anatomy; 3 had both. The pancreaticobiliary anatomy was defined by an intraoperative cholangiogram (IOC) before January 2005 and a preoperative magnetic resonance cholangiopancreatogram (MRCP) subsequently.

RESULTS

IOC missed 3 of 4 aberrant biliary ducts, while an MRCP accurately delineated 10 of 13 aberrant bile ducts. The significant biliary anomalies were: an aberrant right sectoral/segmental duct joining the common hepatic duct (CHD) or the cyst itself (n = 14), cystic duct (n = 1) and cystic duct-CHD junction (n = 1). The aberrant duct was incorporated into the biliary-enteric anastomosis (B-EA) by: (i) double ostia B-EA (n = 1), (ii) ductoplasty with single ostium B-EA for aberrant duct and CHD (n = 2), and (iii) transection of the CHD/cyst distal to the aberrant duct orifice with a single ostium B-EA (n = 13). The arterial anomalies were (i) replaced or accessory right hepatic artery (RHA) (n = 11) and (ii) RHA crossing anterior to the cyst (n = 15), which was repositioned posterior to the B-EA.

CONCLUSION

It is important to consciously look for, appropriately identify and manage aberrant biliovascular anatomy. MRCP facilitates accurate preoperative delineation of aberrant duct anatomy. All major aberrant ducts need to be incorporated into the B-EA and aberrant arteries should not be ligated.

Preoperative hepatobiliary imaging: what does the radiologist need to know?

Accurate preoperative reporting is essential in guiding the surgeon in deciding when and how to operate safely and effectively. Critically, this relies on an understanding of the operative issues faced by the surgeon, which is not always appreciated by the radiologist. This paper therefore aims to address this, first focusing on relevant anatomical variants, and then issues specific to laparoscopic cholecystectomy, hepatic transplantation, and finally hepatic resection (including cholangiocarcinoma resection). Throughout the paper, there is an emphasis on associated surgical techniques to add context to the discussion.

One-step reconstruction of the right inferior hepatic veins using auto-venous grafts in living-donor liver transplantation

PURPOSES

Reconstruction of the right inferior hepatic vein (RIHV) presents a major technical challenge in living donor liver transplantation (LDLT) using right lobe grafts.

METHODS

We studied 47 right lobe LDLT grafts with RIHV revascularization, comparing one-step reconstruction, performed post-May 2007 (n = 16), with direct anastomosis, performed pre-May 2007 (n = 31).

RESULTS

In the one-step reconstruction technique, the internal jugular vein (n = 6), explanted portal vein (n = 5), inferior vena cava (n = 3), and shunt vessels (n = 2) were used as venous patch grafts for unifying the right hepatic vein, RIHVs, and middle hepatic vein tributaries. By 6 months after LDLT, there was no case of occlusion of the reconstructed RIHVs in the one-step reconstruction group, but a cumulative occlusion rate of 18.2 % in the direct anastomosis group. One-step reconstruction required a longer cold ischemic time (182 ± 40 vs. 115 ± 63, p < 0.001) and these patients had higher alanine transaminase values (142 ± 79 vs. 96 ± 46 IU/L, p = 0.024) on postoperative day POD 7. However, the 6-month short-term graft survival rates were 100 % with one-step reconstruction and 83.9 % with direct anastomosis, respectively.

CONCLUSION

One-step reconstruction of the RIHVs using auto-venous grafts is an easy and feasible technique promoting successful right lobe LDLT.

Primary graft dysfunction after living donor liver transplantation is characterized by delayed functional hyperbilirubinemia

The purpose of this study is to propose a new concept of primary graft dysfunction (PGD) after living donor liver transplantation (LDLT), characterized by delayed functional hyperbilirubinemia (DFH) and a high early graft mortality rate. A total of 210 adult-to-adult LDLT grafts without anatomical, immunological or hepatitis-related issues were included. All of the grafts with early mortality (n = 13) caused by PGD in LDLT had maximum total bilirubin levels >20 mg/dL after postoperative day 7 (p < 0.001). No other factors, including prothrombin time, ammonia level or ascites output after surgery were associated with early mortality. Thus, DFH of >20 mg/dL for >seven consecutive days occurring after postoperative day 7 (DFH-20) was used to characterize PGD. DFH-20 showed high sensitivity (100%) and specificity (95.4%) for PGD with early mortality. Among the grafts with DFH-20 (n = 22), those with early mortality (n = 13) showed coagulopathy (PT-INR > 2), compared with those without mortality (p = 0.002). Pathological findings in the grafts with DFH-20 included hepatocyte ballooning and cholestasis, which were particularly prominent in the centrilobular zone. PGD after LDLT is associated with DFH-20 caused by graft, recipient and surgical factors, and increases the risk of early graft mortality.

Transhilar passage in right graft live donor liver transplantation: intrahilar anatomy and its impact on operative strategy

The passage through the hilar plate during right graft live donor liver transplantation (LDLT) can have dangerous consequences for both donors and recipients. The purpose of our study was to delineate hilar transection and biliary reconstruction strategies in right graft LDLT, with special consideration of central and peripheral hilar anatomical variants. A total of 71 consecutive donors underwent preoperative three-dimensional (3D) CT reconstructions and virtual 3D hepatectomies. A three-modal hilar passage strategy was applied, and its impact on operative strategy analyzed. In 68.4% of cases, type I and II anatomical configurations allowed for an en block hilar transection with simple anastomotic reconstructions. In 23.6% of cases, donors had "difficult" type II and types III/IV hilar bile duct anatomy that required stepwise hilar transections and complex graft biliary reconstructions. Morbidity rates for our early (A) and recent (B) experience periods were 67% and 39%, respectively. (1) Our two-level classification and 3D imaging technique allowed for donor-individualized transhilar passage. (2) A stepwise transhilar passage was favored in types III and IV inside the right-sided hilar corridor. (3) Reconstruction techniques showed no ameliorating effect on early/late biliary morbidity rates.

Computed tomographic cholangiography in living liver transplant donors: factors determining the degree of contrast enhancement

OBJECTIVE

To determine factors affecting liver and bile duct contrast enhancement during computed tomographic cholangiography (CTC) in living-donor transplant candidates.

METHODS

Forty-four candidates underwent preoperative triphasic CT followed by intravenous infusion of 20 mL of iodipamide for CTC. Body size indices and liver volume were correlated to parenchymal and biliary enhancement. Bile duct visibility was compared to duct enhancement.

RESULTS

Poorly visualized first- and second-order bile ducts demonstrated diminished enhancement (P < 0.015). Both CTC parenchymal and biliary enhancement correlated inversely with body surface area, height, and weight (P < 0.001); inverse correlation was also seen between liver volume and parenchymal enhancement (P < 0.001). A moderately positive correlation was noted between CTC biliary and parenchymal portal venous enhancement (r = 0.421; P = 0.004).

CONCLUSIONS

Computed tomographic cholangiography parenchymal and biliary enhancement diminishes with increased body size and liver volume, supporting a need for adjustable contrast dosing. Portal venous parenchymal enhancement may serve as a preinfusion indicator.

Reconstruction of the middle hepatic vein tributary in adult right lobe living donor liver transplantation

BACKGROUND

In adult-to-adult living donor liver transplantation (LDLT), the use of a right lobe graft without the middle hepatic vein (MHV) can cause hepatic congestion and disturbance of venous drainage. To solve this problem, we successfully used cadaveric venous allografts preserved in 4 °C University of Wisconsin (UW) solution within 10 days as interposition veins for drainage of the paramedian portion of the right lobe in adult LDLT.

METHODS

From June 2007 to January 2008, 11 adult LDLT patients received modified right liver grafts. The major MHV tributaries (greater than 5 mm in diameter) of 9 cases were preserved and reconstructed using cadaveric interposition vein allografts that had been stored for 1 to 10 days in 4 °C UW solution. The regeneration of the paramedian sector of the grafts and the patency of the interposition vein allografts were examined by Doppler ultrasonography after the operation.

RESULTS

MHV tributaries were reconstructed in 9 recipients. Only 1 recipient died of renal failure and severe pulmonary infection on day 9 after transplantation without any hemiliver venous outflow obstruction. The other 8 recipients achieved long-term survival with a median follow-up of 30 months. The cumulative patency rates of the 8 recipients were 63.63% (7/11), 45.45% (5/11), 45.45% (5/11) and 36.36% (4/11) at 3, 6, 12 and 24 months, respectively. Regeneration of the paramedian sectors was equivalent.

CONCLUSION

The cadaveric venous allograft preserved in 4 °C UW solution within 10 days serves as a useful alternative for interposition veins in facilitating implantation of a right lobe graft and guarantees outflow of the MHV.

Biliary complications after living donor liver transplantation

Biliary complications occur more frequently after living donor liver transplantation (LDLT) versus deceased donor liver transplantation, and they remain the most common and intractable problems after LDLT. The anatomical limitations of multiple tiny bile ducts and the differential blood supplies of the graft ducts may be significant factors in the pathophysiological mechanisms of biliary complications in patients undergoing LDLT. A clear understanding of the biliary blood supply, the Glissonian sheath, and the hilar plate has contributed to new techniques for preparing bile ducts for anastomosis, and these techniques have resulted in a dramatic drop in the incidence of biliary complications. Most biliary complications after LDLT can be successfully treated with nonsurgical approaches, although the management of multiple biliary anastomoses and nonanastomotic strictures continues to be a challenge.

Consensus report of the 4th International Forum for Gadolinium-Ethoxybenzyl-Diethylenetriamine Pentaacetic Acid Magnetic Resonance Imaging

This paper reports on issues relating to the optimal use of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid magnetic resonance imaging (Gd-EOB-DTPA MR imaging) together with the generation of consensus statements from a working group meeting, which was held in Seoul, Korea (2010). Gd-EOB-DTPA has been shown to improve the detection and characterization of liver lesions, and the information provided by the hepatobiliary phase is proving particularly useful in differential diagnoses and in the characterization of small lesions (around 1-1.5 cm). Discussion also focused on advances in the role of organic anion-transporting polypeptide 8 (OATP8) transporters. Gd-EOB-DTPA is also emerging as a promising tool for functional analysis, enabling the calculation of post-surgical liver function in the remaining segments. Updates to current algorithms were also discussed.

Variability of the extrahepatic arterial anatomy in 500 hepatic grafts

PURPOSE

To review the extrahepatic arterial anatomy in 500 consecutive liver grafts.

MATERIALS AND METHODS

From April 1990 to January 2005 we performed 500 liver transplantations. We received 108 deceased donor liver grafts (21.4%) from other centers. Donor arterial anatomy was recorded as described in the surgical notes of both the donor harvest and the recipient procedures. We used the modified Michels classification scheme proposed by Busuttil. We assessed incidences of mortality, retransplantation, postreperfusion syndrome, intraoperative arrest, hemorrhagic complications, and primary malfunction, comparing with chi-squared tests.

RESULTS

There were 376 type I (75.2%), 51 type II (10.2%), 32 type III (6.4%), 18 type IV (3.6%), 3 type V (0.6%), 2 type VI (0.4%) and 18 others (3.6%). No significant associations were found between arterial vascular anomalies of the graft and the studied variables.

CONCLUSION

In our experience, extrahepatic arterial anomalies of the donor graft did not influence the short-term outcomes of liver transplantation.