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

Robotic donor hepatectomy: A major breakthrough in living donor liver transplantation

Living donation in many countries is the main resource of organs. Healthy, volunteering individuals deserve the highest safety standards possible in addition to the least invasive technique to procure the organs. Since the introduction of living donor liver transplantation, many efforts have been made to minimize the surgical trauma inherent to living donor surgery. The journey started with a large Mercedes incision and evolved to reverse L-shaped and small upper midline incisions before the introduction of minimally invasive laparoscopic techniques originated. The technical difficulties of the laparoscopic approach due to suboptimal instrumentation, challenging ergonomics, and the long learning curve limited the application of the fully laparoscopic approach to a few centers. The recent introduction of the robotic platform with its superb optical system and advanced instruments allows for the first time, a genuine emulation of open donor surgery in a closed abdomen, thus allowing all liver donors to benefit from minimally invasive surgery (better cosmesis, less pain and morbidity, and better quality of life) without compromising donor safety. This attribute in combination with the ubiquitous presence of the robot in major transplant centers may well lead to the desired endpoint of this technology, namely, the widespread dissemination of minimally invasive donor surgery.

Robotic Versus Open Right Lobe Donor Hepatectomy for Adult Living Donor Liver Transplantation: A Propensity Score-Matched Analysis

Robotic right lobe donor hepatectomy (RRLDH) is rarely performed, and data concerning its safety and efficacy are lacking. Here we compare our series of RRLDHs with a similar cohort undergoing open right lobe donor hepatectomy (ORLDH) with a propensity score-matched (PSM) analysis. Among 263 consecutive adult patients undergoing right lobe living donor hepatectomy from January 2015 until July 2019, 35 RRLDHs were matched to 70 ORLDHs. A 1:2 PSM analysis was performed to make the groups comparable for donor sex, age, and body mass index (BMI) and for recipient sex, age, BMI, Model for End-Stage Liver Disease score, and indication for transplant. Operative time was longer in RRLDHs compared with ORLDHs (504 ± 73.5 versus 331 ± 65.1 minutes; P < 0.001) but significantly decreased with the number of patients (P < 0.001). No conversions occurred. First warm ischemia time was longer and blood loss significantly less in RRLDHs (P = 0.001 and 0.003, respectively). Overall donor complications were similar: 2 (6%) in RRLDHs versus 12 (17%) in ORLDHs (P = 0.13). Biliary leak occurred in 1 (3%) patient receiving a robotic procedure and 2 (3%) patients receiving the conventional approach. Donors undergoing robotic surgery required less patient-controlled analgesia and had a shorter hospital stay compared with the open surgery group (P < 0.001 and P = 0.001, respectively). No significant differences in graft anatomical data and recipient outcomes were recorded. RRLDH is feasible, safe, and reproducible, with significantly decreased blood loss and a shorter hospital stay compared with the open procedure. The first 35 patients receiving the robotic procedure showed a substantial reduction in operative time, reflecting a rapid shortening of the learning curve.

Assessment of biliary anatomy in potential living liver donors: Added value of gadoxetic acid-enhanced T1 MR Cholangiography (MRC) including utilization of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique in comparison to T2W-MRC

OBJECTIVES

To assess the added value of gadoxetic-acid-enhanced T1-weighted magnetic resonance Cholangiography (T1W-MRC) including controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-Volumetric Interpolated Breathhold (VIBE) technique compared to T2-weighted MR Cholangiography (T2W-MRC) in depicting biliary anatomy in potential living liver donors.

METHODS

Eighty-five potential donors including 34 men with a mean age of 35.6 years (range, 18-55 years) and 51 women with a mean age of 36.7 years (range, 23-57 years), were enrolled in this ethics-approved retrospective study. Image quality for depiction of bile ducts was evaluated by two readers in consensus in 3 separate reading sessions: 1) T2W-MRC alone, 2) T1W-MRC alone (including CAIPI-VIBE and generalized autocalibrating partially parallel acquisitions (GRAPPA)-VIBE techniques, and 3) combined T1W/T2W-MRC. Accuracy of T2W-MRC, T1W-MRC, and combined T1W/T2W-MRC for the identification/classification of the biliary variants was calculated using intraoperative cholangiogram (IOC) as the reference standard. Image quality and reader diagnostic confidence provided by CAIPI-VIBE technique was compared with GRAPPA-VIBE technique. Datasets were compared using the Wilcoxon signed-rank test.

RESULTS

Image quality for depiction of the bile ducts was significantly superior in the combined T1W/T2W-MRC group, when compared to each of T2W-MRC and T1W-MRC groups independently (P value = 0.001-0.034). The combination of CAIPI-VIBE and GRAPPA-VIBE was superior compared to each of the sequences individually. The accuracy of T2W-MRC and T1W-MRC was 93% and 91%, respectively. T1W-MRC depicted four biliary variants better than T2W-MRC. Two variants not well seen in T2W-MRC were clearly shown on T1W-MRC.

CONCLUSION

Gadoxetic-acid-enhanced T1W-MRC and conventional T2W-MRC techniques are complementary for depiction of biliary variants in potential liver donors and the combination of the two improves the results. The combination of CAIPI-VIBE and GRAPPA-VIBE techniques appear to be complementary for optimal diagnostic yield of T1W-MRC.

Living donor liver transplantation in Europe

Living donor liver transplantation (LDLT) sparked significant interest in Europe when the first reports of its success from USA and Asia were made public. Many transplant programs initiated LDLT and some of them especially in Germany and Belgium became a point of reference for many patients and important contributors to the advancement of the field. After the initial enthusiasm, most of the European programs stopped performing LDLT and today the overall European activity is concentrated in a few centers and the number of living donor liver transplants is only a single digit fraction of the overall number of liver transplants performed. In this paper we analyse the present European activities and highlight the European contribution to the advancement of the field of LDLT.

Application of 3D reconstruction for surgical treatment of hepatic alveolar echinococcosis

AIM: To evaluate the reliability and accuracy of three-dimensional (3D) reconstruction for liver resection in patients with hepatic alveolar echinococcosis (HAE).

METHODS: One-hundred and six consecutive patients with HAE underwent hepatectomy at our hospital between May 2011 and January 2015. Fifty-nine patients underwent preoperative 3D reconstruction and “virtual” 3D liver resection before surgery (Group A). Another 47 patients used conventional imaging methods for preoperative assessment (Group B). Outcomes of hepatectomy were compared between the two groups.

RESULTS: There was no significant difference in preoperative data between the two groups. Compared with patients in Group B, those in Group A had a significantly shorter operation time (227.1 ± 51.4 vs 304.6 ± 88.1 min; P < 0.05), less intraoperative blood loss (308.1 ± 135.4 vs 458.1 ± 175.4 mL; P < 0.05), and lower requirement for intraoperative blood transfusion (186.4 ± 169.6 vs 289.4 ± 199.2 mL; P < 0.05). Estimated resection liver volumes in both groups had good correlation with actual graft weight (Group A: r = 0.978; Group B: r = 0.960). There was a significant higher serum level of albumin in Group A (26.3 ± 5.9 vs 22.6 ± 4.3 g/L, P < 0.05). Other postoperative laboratory parameters (serum levels of aminotransferase and bilirubin; prothrombin time) and duration of postoperative hospital stay were similar. Sixteen complications occurred in Group A and 19 in Group B. All patients were followed for 3-46 (mean, 17.3) mo. There was no recurrence of lesions in Group A, but two recurrences in Group B. There were three deaths: two from cerebrovascular accident, and one from car accident.

CONCLUSION: 3D reconstruction provides comprehensive and precise anatomical information for the liver. It also improves the chance of success and reduces the risk of hepatectomy in HAE.

Comparison of different magnetic resonance cholangiography techniques in living liver donors including Gd-EOB-DTPA enhanced T1-weighted sequences

Objectives

Preoperative evaluation of potential living liver donors (PLLDs) includes the assessment of the biliary anatomy to avoid postoperative complications. Aim of this study was to compare T2-weighted (T2w) and Gd-EOB-DTPA enhanced T1-weighted (T1w) magnetic resonance cholangiography (MRC) techniques in the evaluation of PLLDs.

Materials and Methods

30 PLLDs underwent MRC on a 1.5 T Magnetom Avanto (Siemens, Erlangen, Germany) using (A) 2D T2w HASTE (Half Fourier Acquisition Single Shot Turbo Spin Echo) fat saturated (fs) in axial plane, (B) 2D T2w HASTE fs thick slices in coronal plane, (C) free breathing 3D T2w TSE (turbo spin echo) RESTORE (high-resolution navigator corrected) plus (D) maximum intensity projections (MIPs), (E) T2w SPACE (sampling perfection with application optimized contrasts using different flip angle evolutions) plus (F) MIPs and (G) T2w TSE BLADE as well as Gd-EOB-DTPA T1w images without (G) and with (H) inversion recovery. Contrast enhanced CT cholangiography served as reference imaging modality. Two independent reviewers evaluated the biliary tract anatomy on a 5-point scale subjectively and objectively. Data sets were compared using a Mann-Whitney-U-test. Kappa values were also calculated.

Results

Source images and maximum intensity projections of 3D T2w TSE sequences (RESTORE and SPACE) proved to be best for subjective and objective evaluation directly followed by 2D HASTE sequences. Interobserver variabilities were good to excellent (k = 0.622–0.804).

Conclusions

3D T2w sequences are essential for preoperative biliary tract evaluation in potential living liver donors. Furthermore, our results underline the value of different MRCP sequence types for the evaluation of the biliary anatomy in PLLDs including Gd-EOB-DTPA enhanced T1w MRC.

Rodent models and imaging techniques to study liver regeneration

The liver has the unique capability of regeneration from various injuries. Different animal models and in vitro methods are used for studying the processes and mechanisms of liver regeneration. Animal models were established either by administration of hepatotoxic chemicals or by surgical approach. The administration of hepatotoxic chemicals results in the death of liver cells and in subsequent hepatic regeneration and tissue repair. Surgery includes partial hepatectomy and portal vein occlusion or diversion: hepatectomy leads to compensatory regeneration of the remnant liver lobe, whereas portal vein occlusion leads to atrophy of the ipsilateral lobe and to compensatory regeneration of the contralateral lobe. Adaptation of modern radiological imaging technologies to the small size of rodents made the visualization of rodent intrahepatic vascular anatomy possible. Advanced knowledge of the detailed intrahepatic 3D anatomy enabled the establishment of refined surgical techniques. The same technology allows the visualization of hepatic vascular regeneration. The development of modern histological image analysis tools improved the quantitative assessment of hepatic regeneration. Novel image analysis tools enable us to quantify reliably and reproducibly the proliferative rate of hepatocytes using whole-slide scans, thus reducing the sampling error. In this review, the refined rodent models and the newly developed imaging technology to study liver regeneration are summarized. This summary helps to integrate the current knowledge of liver regeneration and promises an enormous increase in hepatological knowledge in the near future.

The "carving" liver partitioning technique for graft hepatectomy in live donor liver transplantation: a single-center experience

BACKGROUND

In adult live donor liver transplantation, postoperative venous congestion of graft and remnant livers can lead to life-threatening complications. The purpose of this study was to evaluate the safety and benefits of our 3-dimensional, computed tomographic, computer-assisted donor hepatectomy using the "carving" partitioning technique.

METHODS

Eighty-three consecutive adult live donor liver transplantations were performed based on data obtained from individualized preoperative 3-dimensional, computed tomographic reconstructions and virtual graft hepatectomies.

RESULTS

There were 71 right and 12 left grafts. Small grafts (graft volume body weight ratio, <1.0) were used in 20 cases. We observed no clinically important differences in postoperative function between right and left grafts. Four recipients developed lethal small-for-size syndrome. Reversible small-for-size syndrome was observed in a right graft recipient and in 2 right graft donors.

CONCLUSION

Preoperative 3-dimensional, computed tomographic, computer-assisted planning using virtual liver partitioning allowed for: (1) an individualized carving technique based on specific donor anatomic characteristics, (2) donor safety based on individualized patterns of venous outflow, and (3) optimized drainage of the medial area of the graft based on the preferential inclusion of the middle hepatic vein.