Intraoperative assessment of hepatic venous congestion with direct clamping of the hepatic vein trunk for living donor liver transplantation

Current status of left lobe adult to adult living donor liver transplantation

PURPOSE OF REVIEW

This review describes the history and current state of left lobe living donor liver transplantation (LDLT). The transplant community continues to face an organ shortage on a global scale, and the expansion of LDLT is attractive because it allows us to provide life-saving liver transplants to individuals without drawing from, or depending on, the limited deceased donor pool. Donor safety is paramount in LDLT, and for this reason, left lobe LDLT is particularly attractive because the donor is left with a larger remnant.

RECENT FINDINGS

This article reviews the donor and recipient evaluations for left lobe LDLT, discusses small for size syndrome and the importance of portal inflow modification, and reviews recipient outcomes in right lobe versus left lobe LDLT.

SUMMARY

Left lobe LDLT was the first adult-to-adult LDLT ever to be performed in Japan in 1993. Since that time, the use of both right and left lobe LDLT has expanded immensely. Recent work in left lobe LDLT has emphasized the need for inflow modification to reduce portal hyperperfusion and early graft dysfunction following transplant. Accumulating evidence suggests, however, that even though early graft dysfunction following LDLT may prolong hospitalization, it does not predict graft or patient survival.

Impact of Graft Type in Living Donor Liver Transplantation: Remnant Liver Regeneration and Outcome in Donors

OBJECTIVES

Liver regeneration and donor safety in right-lobe (RL) and left-lobe (LL) grafts are essential for donors in living donor liver transplantation (LDLT). Our aim was to compare the liver regeneration rate and postoperative outcome between different donor graft types in LDLT.

MATERIALS AND METHODS

A total of 95 donors were divided into 2 groups: RL (n = 42) and LL (n = 53). The remnant liver of LL donors were subdivided into 3 subgroups according to the different hepatic venous drainage pattern that dominates from right hepatic vein (dominant RHV; n = 34), middle hepatic vein (dominant MHV; n = 10), and include MHV for left lateral segment (LLS) graft (n = 9). The demographic data, postoperative laboratory data, complications, remnant liver volume (RLV), and remnant liver regeneration rate (RLRR) 6 months after surgery were compared.

RESULTS

The postoperative total bilirubin (TB), prothrombin time (PT), and intensive care unit (ICU) stays of the LL group were lower than the RL group (P < .05). The LL group has no significant better regeneration rate 6 months after surgery than the RL group. However, dominant RHV and LLS groups have significantly better RLRR than the RL group (89.2% vs 86% and 95.1% vs 86%, respectively, P < .05), but no significance in the dominant MHV group.

CONCLUSION

In conclusion, different hepatic venous drainage patterns of remnant liver grafts may affect the regeneration rate in LL LDLT, especially with dominant RHV donors, may have more comparable outcomes with that of RL, and should be a favorable option during donor selection.

[Specific considerations in living-donor liver transplantation]

INTRODUCTION

Due to the limited number of cadaver donors, adult living liver donor transplantation became an alternative for liver transplantation. During living liver donor transplantation, the safety and uncomplicated recovery of the donor are as important as the appropriate volume and weight of the donated graft. The middle hepatic vein causes a significant dilemma, due to the special anatomical position. The reconstruction of the middle hepatic vein branches supplying S5, S8 is suggested when the anatomically right liver lobe is transplanted.

AIM

The aim of the present study was to investigate the requirements of the reconstruction of middle hepatic vein and to give an accurate description about the discrepancy between the portal vein in- and outflow.

METHOD

The authors analyzed the liver anatomic characteristics of 130 donors undergoing living liver donor transplantation with the use of MeVis software. The so-called porto-hepatic disparity index (shift) was introduced.

RESULTS

The right hepatic vein was dominant in 64.6% of all cases, while the left hepatic vein was never observed to be dominant. The territories of V5 and V8 were responsible for the 33.2±8.9% of the right hepatic lobe area. The correlation between portal venous territory and vein dominancy were as follows: R2 = 0.7811 in the left liver lobe; R² = 0.5463 in the area of middle hepatic vein and R² = 0.5843 in the case of the right hepatic vein. The average value of the shift was 28.2%.

CONCLUSIONS

The differences among the pattern of portal in- and hepatic outflow is an important issue that should be taken into consideration when deciding the necessity for reconstruction of the middle hepatic vein.

Outflow modulation to target liver regeneration: something old, something new

BACKGROUND

Stimulation of hepatic hypertrophy is a useful aid to accomplish hepatic resections when the future liver remnant (FLR) is small. Although inflow occlusion, especially through portal flow, has been extensively studied, the role of outflow modulation has not yet been described.

METHODS

Description of outflow modulation to tailor hypertrophy of future liver remnant in the context of bilobar metastatic disease. A patient with small FLR (segments I and IV) was managed with a two-stage procedure. The first stage consisted of a right hepatectomy and modulation of the left hepatic vein outflow through reduction of its diameter, with macroscopic congestion of segments II-III. The second stage consisted of a left lateral sectionectomy six weeks later. Postoperative courses were uneventful without any sign of liver failure.

RESULTS

Following the first stage procedure computed tomography revealed distinct hypertrophy rates between sections. The non-congested area had an increase of 156% in the volume of segment IV (from 137 to 351 cm(3)) and 100% in the volume of segment I (from 20 to 40 cm(3)). The congested area, segments II-III, increased only 24% (from 205 to 253 cm(3)).

CONCLUSION

Modulation of liver outflow allows maintenance of function in the segments to be resected while avoiding their hypertrophy. This process prevents liver failure and optimizes regeneration of hepatic territories to be preserved.

Doppler Sonographic Abnormalities Suggestive of Venous Congestion in the Right Lobe Graft of Living Donor Liver Transplant Recipients

OBJECTIVE

Establishing optimal hepatic venous outflow is the key for a successful outcome of living donor liver transplantation using a right lobe graft. The purpose of this article is to illustrate the surgical techniques of middle hepatic vein reconstruction with an interposition vein graft in living donor liver transplant recipients using a modified right lobe graft, normal postoperative Doppler sonographic findings, and various Doppler sonographic abnormalities suggestive of hepatic venous congestion.

CONCLUSION

Hepatic venous congestion after living donor liver transplantation using a right lobe graft may produce various abnormalities on Doppler sonography. In addition to allowing the patency of the middle hepatic vein tributaries and interposition vein graft to be assessed during the early postoperative period, Doppler sonography can depict the flow direction in the portal vein and in the middle hepatic vein tributaries; therefore, Doppler sonography can reveal reversal of portal flow direction in patients with acute and severe venous congestion and can show the presence of a functional intrahepatic anastomosis between the hepatic vein tributaries during the follow-up period in those with improved congestion.

Lessons learned from 1,000 living donor liver transplantations in a single center: how to make living donations safe

Serious complications have occurred in a considerable proportion of living donors of liver transplants, but data from a single high-volume center has rarely been available. We analyzed the medical records of donors and recipients of the first 1,000 living donor liver transplants, performed at Asan Medical Center from December 1994 to June 2005, with a focus on donor safety. There were 107 pediatric and 893 adult transplants. The most common diagnoses were biliary atresia in pediatric recipients (63%) and hepatitis B-associated liver cirrhosis (80%) in adult recipients. Right lobe donors were strictly selected based on liver resection rate and steatosis. From 1,162 living donors, 588 right lobes, 6 extended right lobes, 7 right posterior segments, 464 left lobes, and 107 left lateral segments were obtained. Of these, 837 grafts were implanted singly, whereas 325, along with 1 cadaveric split graft, were implanted as dual grafts into 163 recipients. The 5-yr survival rates were 84.8% in pediatric recipients and 83.2% in adult recipients. There was no donor mortality, but 3.2% of donors experienced major complications. Until the end of 2001, the major donor complication rate was 6.7%, with most occurring in right liver donors. Since 2002, liver resection exceeding 65% of whole liver volume were avoided except for young donors with no hepatic steatosis, and the donor complication rate has been reduced to 1.3%. In conclusion, a majority of major living donor complications appear to be avoidable through the strict selection of living donor and graft type, intensive postoperative surveillance, and timely feedback of surgical techniques. Selection of right lobe graft should be very prudently considered if the donor right liver appears to be larger than 65% of the whole liver volume.

A case report of split liver transplantation for two adult recipients in Korea

We report a case of split liver transplantation (SLT) for two adult recipients, which was the first successful case in Korea. The brain-dead donor was a 22-year-old man weighing 65 kg, but his liver volume was estimated as 2120 mL on computed tomographic volumetry. As it seemed to be too large for a 60-kg recipient candidate, SLT was planned after assessment of lobar liver volume and middle hepatic vein anatomy. The right lobe was mobilized first and the liver parenchyma transected along the right border of the middle hepatic vein. The 1240-g right lobe (segments 5 to 8) graft was implanted into a 57-year-old male patient with acute-on-chronic liver failure in the same manner as a living-donor graft. After that, routine procedures of cadaveric multiorgan procurement were performed. The 670-g left lobe (segments 1 to 4) with a retrohepatic vena cava, common bile duct, and aortic patch was implanted into another 37-year-old male recipient. These two recipients recovered uneventfully surviving 12 months to date. We integrated the surgical techniques learned from hundreds of adult-to-adult living donor liver transplants into this first trial of two adult SLT.

Cryopreserved iliac artery is indispensable interposition graft material for middle hepatic vein reconstruction of right liver grafts

Cryopreserved iliac vein grafts (IVGs) have often been used for reconstruction of middle hepatic vein (MHV) branches in right liver grafts, but their storage pool has often been exhausted in our institution due to the low incidence of deceased donor organ procurement. To overcome this shortage of IVG, we started to use cryopreserved iliac artery graft (IAG). During September and October 2004, we carried out 41 cases of adult living donor liver transplantation, including 29 right lobe grafts with MHV reconstruction. Interposition vessel grafts were autologous vein (n = 6), IVG (n = 13), and IAG (n = 10). IAG was used in 3 (21%) of 13 cases during the first month. For the next month, it was more frequently used (7 [44%] of 16) because handling of cryopreserved IAG was not difficult and its outcome was favorable. On follow-up with computed tomography for 3 months, outflow disturbance occurred in 1 (17%) of 6 autologous vein cases, in 2 (15%) of 13 IVG cases, and in 1 (10%) of 10 IAG cases. Two-month patency rate of IAG was not lower than that of IVG. In conclusion, we feel that cryopreserved IAG can be used as an interposition vessel graft for MHV reconstruction of right liver graft when cryopreserved IVG is not available.

Hepatic vein anatomy of the medial segment for living donor liver transplantation using extended right lobe graft

Hepatic vein anatomy (V4) of the medial segment (S4) has been a matter of concern since introduction of extended right lobe (ERL) graft. To assess risk of hepatic venous congestion (HVC) in ERL donors, we tried to newly classify V4 anatomy. We analyzed V4 anatomy of 328 living donor livers by using 3-dimensional reconstruction (3-DR) and volumetry of computed tomography (CT). Variations of V4 were divided into type A (middle hepatic vein [MHV] dominant: n = 142, 43.3%), type B (MHV-dominant, but enabling preservation of dorsal V4 branch [V4b]: n = 40, 12.2%), type C (mixed: n = 92, 28%), and type D (left hepatic vein dominant: n = 54, 16.5%). We analyzed the amount of HVC at S4 in 143 donor livers of right lobe (RL) and ERL grafts. Occlusion of MHV trunk induced HVC equivalent to 85.2%, 85.4%, 55.2%, and 35.4% of S4 volume and 34%, 33.9%, 20.3%, and 14.2% of left liver volume in livers of types A, B, C, and D, respectively. Tailored V4b preservation reduced HVC significantly in type B livers. Considering that functional capability may be decreased in HVC portion, functional hepatic resection rate (FHRR) of ERL graft procurement ranged as follows: 62.3%-75% in type A; 62.2%-75% and 62.2%-68.7% in type B with and without V4b preservation, respectively; 63.2%-70.7% in type C; and 61.8%-67.2% in type D. These results support the theory that these categories of V4 types are closely correlated with potential amount of HVC at S4, reflect the possibility of V4b preservation, and are compatible with CT findings. We believe that this V4 classification is applicable to assess donor V4 anatomy in practice.