Reconstruction Of Middle Hepatic Vein Tributaries Research Articles

Innovative Technique Avoiding Bleeding After Reperfusion in Living Donor Liver Transplant Using a Modified Right Lobe Graft

Living donor liver transplant (LDLT) is a valuable therapeutic option for overcoming the deceased donor shortage. Modified right lobe graft (MRLG) keeps the middle hepatic vein (MHV) trunk with the remnant liver to improve donor safety. Hemostasis in the MHV tributary reconstruction can be tricky; surgical stitches and energy coagulation are ineffective. Fibrin glues are excellent vascular sealants but are poor in maintaining hemostasis in an active hemorrhage or preventing resection surface-related complications after liver resection. We propose applying fibrin sealant during back table graft preparation to seal the hepatic edge and MHV reconstruction to avoid bleeding after graft revascularization. Our retrospective cohort study included all adult patients undergoing LDLT between August 2017 and December 2021. During the back table procedure, we performed the reconstruction of the inferior right hepatic vein and/or MHV tributaries from segment 5 (V5) and segment 8 (V8) using a vein harvested from a nonrelated deceased donor. Before initiating the hepatic graft implantation, we applied fibrin sealant in the resected parenchyma, especially in the V5 and V8 anastomosis, to seal the hepatic edge and hepatic vein reconstruction. No bleeding was identified in the hepatic edge, and blood product transfusion was unnecessary for any recipients after reperfusion. In LDLT using MRLG with MHV reconstruction, the fibrin sealant, when applied on the raw hepatic surface, and vascular reconstruction during back table graft preparation avoided bleeding after graft revascularization.

Importance of reconstruction of middle hepatic vein tributaries of right-lobe grafts in living donor liver transplantation: demonstration of the reconstruction technique.

The aim of the present study on living donor liver transplantation (LDLT) using a right-lobe graft without the middle hepatic vein (MHV) was to investigate the clinical impact of MHV tributary reconstruction using our criteria and techniques. The medical records of 40 patients who underwent adult LDLT using a right-lobe graft without the MHV between April 2008 and December 2020 were retrospectively reviewed. In this cohort, the criterion for MHV tributary reconstruction was estimated drainage volume of each MHV tributary greater than 100mL. The drainage vein of segment 8(V8) was reconstructed as the common orifice of the right hepatic vein and V8 using a venous patch graft, and that of segment 5 was reconstructed using artificial vascular grafts. The outcomes were compared between the groups with and without MHV tributary reconstruction. Factors associated with postoperative massive ascites were also investigated. Twenty patients underwent MHV tributary reconstruction. There were no significant differences in the amount of postoperative ascites, Clavien-Dindo classification ≥ III postoperative complications, and 90-day in-hospital mortality between the groups (P = 0.678, P = 1.000, and P = 0.244, respectively). On multivariate analyses, a low-estimated functional graft-to-recipient weight ratio, which was calculated using estimated graft volume minus the territory of MHV tributaries that was not reconstructed, was identified as an independent predictor of postoperative massive ascites (odds ratio, 40.479; 95% confidence interval, 3.823-428.622). The present study suggests that selective MHV tributary reconstruction might be useful for achieving successful graft function.

Reconstruction of Middle Hepatic Vein Tributaries With Artificial Vascular Grafts in Living Donor Liver Transplant Using Right Lobe Grafts: A Case Series

BackgroundCongestion of the anterior section of the grafted liver might be a problem when performing living donor liver transplant using a right lobe graft without middle hepatic vein (MHV). This can be prevented by MHV tributary reconstruction. We report our procedure and results of reconstructing MHV tributaries using artificial vascular grafts (AVGs). MethodsWe consider venous reconstruction when the estimated territory of each MHV tributary of the transplanted liver is more than 100 mL. For tributaries distant from the stump of the right hepatic vein of the graft, we use heparin-bonded AVGs made of expanded polytetrafluoroethylene with circular rings as the interposition graft between the MHV tributary and the inferior vena cava. During donor surgery, the suturing margin of the MHV tributary is secured before cutting, and it is anastomosed to the AVG during back-bench surgery. After restoration of portal flow in the recipient, we anastomose the AVG at a new position on the inferior vena cava. ResultsThe above procedure was performed for 4 cases. The estimated drainage territory of the vein that was reconstructed using the AVG ranged from 104 to 180 mL. The AVG patency was achieved for about 2 months in all cases. In terms of morbidity, biloma and pancreatic fistula were observed in 2 cases, although removal of the AVG was not required postoperatively in any of the cases. ConclusionThe heparin-bonded expanded polytetrafluoroethylene AVG with circular rings is a feasible option for MHV tributary reconstruction in living donor liver transplant using right liver lobe grafts without MHVs.

Thrombotic Ringed Polytetrafluoroethylene Graft With Infection After Living-Donor Liver Transplantation

BackgroundThe safety of the living donor in living-donor liver transplantation (LDLT) is always the first priority, meanwhile, the graft-to-recipient weight ratio (GRWR) and the anatomy of the liver allograft must also not be compromised in order to warrant tranplatation success. When it comes to the allograft of the right lobe of the liver without the middle hepatic vein (R–M), the outflow and adequate drainage for the territory of middle hepatic vein (MHV) is one critical concern. Despite publications in some high-volume transplant centers on the positive results of using expanded polytetrafluoroethylene (ePTFE) grafts to substitute those of autologous veins, complications related to the ePTFE graft have not been well discussed. MethodsFrom July 2012 to June 2016, 129 adult patients who underwent living donor liver transplantation in Taipei Veterans General Hospital were analyzed. There were 3 cases of adjacent organ erosion with gas bubbles in the lumen of an ePTFE graft, including gastrointestinal (GI) tract penetration in 2 out of the first 15 cases that used the venous graft of ringed expanded polytetrafluoroethylene (rPTFE). The patient survival rate during this period was compared and radiological findings of rPTFE function and clinical signs of erosion with infection were also examined to raise the concerns of safety as well as early detection of complications of rPTFE. ResultsThe overall 1-year patient survival rate was 90%, of which the right lobe wih MHV (R+M) group was 93.5% and the R–M group was 91.9%. For the mean of GRWR, the R+M group was 1.05 ± 0.19 and R–M group was 1.19 ± 0.27, while those who needed reconstruction with vein grafts was 0.96 ± 0.11. Among the R–M group, 24 out of 88 cases (27.3%) needed reconstruction of MHV tributaries. Of the 24 cases, 15 cases were done with rPTFE and the 1-year patient survival rate of the rPTFE group was 73%, which is significantly worse (P = .008) than the non-rPTFE (89%) and non-reconstructed (97%) groups. The mean GRWR is significantly higher (P = .001) in the non-reconstructed group (1.19 ± 0.27) than in the rPTFE (0.99 ± 0.11) and non-rPTFE (0.94 ± 0.11) groups. The venous grafts patency rate between the different graft types is no different, and there is also significance in warm ischemic time (P = .009) between the non-reconstructed (49 ± 15), rPTFE (81 ± 51), and non-rPTFE (56 ± 18) groups in the mean minutes. ConclusionIn cases of fever of unknown cause in patients receiving LDLT with rPTFE graft, a regular computed tomography (CT) scan with contrast and gas bubbles within the graft lumen is the best way for early detection of graft related infection and suspicious GI tract penetration. To decrease the risks of tissue reaction induced by ePTFE graft in LDLT, omentum patches or other inert agents can be introduced as a buffer between the graft and adjacent organs, especially the GI tracts. However, research in material science shall be explored to solve the problem in the future.

Effect of Middle Hepatic Vein Tributaries Preserving Technique Until Just Before Graft Retrieval on Donors' Surgical Outcomes in Living Donor Liver Transplantation

BackgroundThe technique of preserving the major tributaries of the middle hepatic vein (MHV) (V5 and V8) until just before graft retrieval is beneficial to minimize congestion time of the graft. However, it remains unclear whether this technique exerts a burden on donors in terms of operative time, blood loss, and postoperative hepatic dysfunction. In this study we investigated adverse effects of the MHV tributaries preserving technique until immediately before graft retrieval on donors' surgical outcomes. MethodsData from 71 donors who underwent right hepatectomy without MHV for a liver transplantation at our hospital from January 2002 to August 2016 were retrospectively reviewed. Donors were divided into 3 groups as follows: group 1 (n = 12), no MHV tributary reconstruction; group 2 (n = 33), single MHV tributary reconstruction; group 3 (n = 26), 2 or 3 MHV tributaries reconstruction. Donor operation time, blood loss, proportion of the remnant liver, maximum postoperative total bilirubin, aspartate aminotransferase, alanine transaminase, minimum platelets, prothrombin time, albumin level, number of days in hospital from surgery to discharge, and surgical complications were compared. ResultsCompared with groups 2 and 3, group 1 exhibited shorter average operational time and less average blood loss, but the difference was not significant. Comparisons of all other factors indicated no significant differences. ConclusionThe technique of preserving the major tributaries of the MHV until just immediately before graft retrieval does not appear to impose an apparent burden on donors.

Synthetic graft for reconstruction of middle hepatic vein tributaries in living-donor liver transplant.

In middle hepatic vein dominant livers, the anterior segment of the right lobe of the liver (segments V and VIII) drains mainly into the middle hepatic vein. In these donors, when right lobe grafts are procured without the middle hepatic vein, the graft may harbor large segment V and/or VIII veins that need reconstruction to avoid graft congestion and subsequent graft dysfunction. Draining these middle hepatic vein tributaries using autologous or cryopreserved vessels is a solution, despite the possible difficulties of their preparation. However, these vessels are not always available. Our objective was to evaluate the effectiveness and safety of using a synthetic vascular graft. Between January 2012 and October 2013, eighteen adult recipients underwent living-donor liver transplant using right lobe grafts without the middle hepatic vein at Dar Al Fouad Hospital, 6th of October City, Egypt. All grafts had a large tributary of the middle hepatic vein. Eight-mm ringed expanded polytetrafluoroethylene vascular grafts were used to drain 15 segment V vein tributaries and 3 segment VIII vein tributaries directly to the inferior vena cava. Follow-up was done using duplex ultrasound to evaluate the patency of the vascular graft and the liver congestion and the liver function tests including liver enzymes. Intraoperative Duplex ultrasound confirmed patency and absent segmental congestion in all 18 recipients. The vascular graft patency was 17/18 at 1 week (94.4%) and 15/18 at 1 month (83.3%). No recipients developed graft infection at 1 month. Synthetic vascular expanded polytetrafluoroethylene grafts could be used effectively and safely in middle hepatic vein tributary reconstruction to overcome the unavailability of autologous or cryopreserved vessel grafts or just to avoid the additional burden of recovering autologous grafts thus simplifying the procedure.

Clinical strategy for the reconstruction of middle hepatic vein tributaries in right liver living donor liver transplantation.

Venous drainage of the right paramedian sector (segments V and VIII), which is mainly via the middle hepatic vein (MHV), remains the major concern when using a right liver graft in living donor liver transplantation (LDLT). We herein describe our approach to decision making in the reconstruction of MHV tributaries in LDLT using a right liver graft without the MHV trunk. A total of 77 consecutive right liver LDLTs were performed between January 2011 and December 2012. The MHV trunk was not taken with the graft, and all MHV tributaries were ligated during donor hepatectomy. The right liver graft was subsequently assessed on the back table for congestion in the right paramedian sector as an indicator for the need to reconstruct MHV tributaries. Based on the algorithm, reconstruction of MHV tributaries was performed in 18 patients (23.4 %). Although a mild degree of congestion in the right paramedian sector was noted in a few liver grafts without venous reconstruction, this congestion was well tolerated by recipients and was not visible afterward. The recipients' outcomes were similar in groups with and without venous reconstruction, and the 1-year survival rates were 83.3 and 86.2 %, respectively. A right liver graft without the MHV trunk can be successfully performed in LDLT with a satisfactory outcome. However, these experiences show that this approach might be safely applied as a strategy for determining the necessity of reconstruction of MHV tributaries in a right liver graft without the MHV trunk in LDLT.

Segmental regeneration in right‐lobe liver grafts in adult living donor liver transplant

Our aim is to evaluate the relationship and impact of right-lobe (RL) liver grafts procured with or without the middle hepatic vein (MHV) trunk and MHV tributary reconstruction on segmental regeneration of these grafts in adult living donor liver transplantation (ALDLT). Patients underwent primary ALDLT using a RL liver graft were divided into three groups according to graft type: with MHV tributary reconstruction (group I), without MHV tributary reconstruction (group II), and with inclusion of the MHV trunk (group III). The overall graft volume and the volumes of the anterior and posterior segments of the grafts six months post-transplant, evaluated using computed tomography, were calculated as the regeneration indices. Optimal regeneration of the RL liver graft was achieved in the three groups of patients. There was no significant difference in the regeneration indices between groups I (149.4%) and III (143.6%). However, in group II (112.4%) without MHV or tributary reconstruction, the anterior regenerative index was lower than the other two groups and exhibited transient prolonged hyperbilirubinemia. Segmental graft regeneration is maximized by adequate venous drainage. Inclusion of the MHV trunk or MHV tributary reconstruction influences segmental liver regeneration and preclude transient hyperbilirubinemia in the early post-liver transplant phase.

Feasibility and Safety for Using Recipient's Middle Hepatic Vein for Drainage of the Right Paramedian Sector in Right Liver Graft

We reported that the use of the recipient's native middle hepatic vein (MHV) trunk for the reconstruction of MHV tributaries is a feasible and valuable surgical strategy in right liver living donor liver transplantation (LDLT), because the use of this MHV trunk does not require additional surgeries for both the donor and recipient (1). However, Ikegami et al. (2) asserted that in-site transection of a liver with hepatocellular carcinomas (HCCs) for obtaining the MHV carried the risk of disseminating HCCs in a recipient because of incomplete accuracy of the pretransplant radiological imaging. In order not to encounter HCC recurrence after transplantation, we have considered cases where the HCC lesion is located 2 cm away from the MHV trunk and not on the ventral side of the MHV trunk as the indication of obtaining the recipient's native MHV trunk. Until July 2008, we performed the reconstruction of the MHV tributaries of the liver graft by obtaining the recipient's MHV trunk in a total of 25 patients with HCC according to these strict criteria. Of the 25 HCC patients in whom the recipient's MHV trunk was used to reconstruct the MHV tributaries of the liver graft, no recurrence of HCC has been observed except one patient in whom the HCC ruptured before the LDLT surgery with a median follow-up of 18 months (6–34 months). Ikegami et al. (2) also suggested that the reconstruction of an accessory hepatic vein in site after reperfusion might be troublesome with the increase the risk of bleeding (2). However, we demonstrated (1) that the operative bleeding and ischemic time were not significant greater in patients with the reconstructed MHV tributaries than in those without reconstructed MHV tributaries. The mean operative bleeding of LDLT with and without the reconstruction of the MHV tributaries were 3954 and 5150 mL, respectively. Judging from our results, we consider our strategy as a clinically acceptable option. Longer-term follow-up is needed to ascertain the feasibility and safety of the in-site transection of a liver with HCC for obtaining the MHV. Hirotaka Tashiro Toshiyuki Itamoto Hironobu Amano Akihiko Oshita Tsuyoshi Kobayashi Kentaro Ide Toshimasa Asahara Hideki Ohdan Second Department of Surgery Hiroshima University Hospital Hiroshima, Japan

Preservation of Recipient Middle Hepatic Vein for Drainage of Anterior Sector Veins in Adult-to-Adult Living-Donor Liver Transplantation

The inclusion of donor middle hepatic vein (MHV) in right-lobe living-donor grafts and the need for reconstruction of the MHV tributaries have long been controversial areas in living-donor liver transplantation. We report technical details in restoration of venous drainage of the anterior sector (segments V and VIII) of the right lobe of the liver graft using a preserved MHV from the recipient liver, and address the issue of reconstruction of donor MHV tributaries without use of an interposition graft. We review clinical situations in which restoration of outflow drainage of the anterior segment of the liver graft should be considered.

Reconstruction of middle hepatic vein in living donor liver transplantation with modified right lobe graft: a single center experience

Although a right liver graft without the middle hepatic vein (MHV) can cause congestion in the anterior segment, the reconstruction of MHV tributaries and the complex procedure remain controversial. Between November 2006 and October 2007, right liver transplantation without the MHV was performed in 31 cases. A retrospective analysis was conducted on clinical data and two groups were formed: with MHV reconstruction (Group I, n=16) and without MHV reconstruction (Group II, n=15). We analyzed the serum liver function markers at 3 weeks postoperatively and evaluated vascular flow in the graft and interpositional vein daily by Doppler ultrasonography during the hospital stay and monthly follow-up after discharge. One patient (6.7%) died of liver congestion and acute hepatic rejection on the postoperative day 10 in Group II. Congestion was observed in another three cases (20%) of Group II and one case (6.25%) of Group I. The levels of alanine transferase and aspartate transferase in Group II was higher than those in Group I in the first week after transplantation, albeit not significantly. In Group I, most of the interpositional vein grafts were the recipient's portal veins. Venoplasty in the graft was performed in three cases. All the interpositional veins and tectonic outflow orifices were detected to be patent by ultrasonography within 14 days after transplantation. The reconstruction of the MHV tributaries is necessary in the right liver graft without MHV according to our policy and better criteria for MHV reconstruction should be established. The recipient's portal vein is an optimal choice for the interpositional vein and hepatic venoplasty in living donor liver transplantation can simplify the operation and ensure excellent venous drainage.

Variation in the venous drainage of left lateral segment liver graft requiring reconstruction of segment III vein with donor iliac artery

Variation in the venous drainage of left lateral segment liver graft requiring reconstruction of segment III vein with donor iliac artery

Intrahepatic Venous Collaterals Formation Following Outflow Block in Adult-to-Adult Living Donor Liver Transplantation

A right liver graft without the middle hepatic vein (MHV) trunk is now commonly used in adult-to-adult living donor liver transplantation (LDLT), but it is unclear whether hepatic venous collaterals would develop in clinical patient just after occlusion of hepatic veins. Between January 2005 and October 2006, 56 consecutive adult patients underwent LDLT using right lobe grafts without MHV in our center. Twenty-four patients (42.9%) had MHV tributaries reconstruction. Vascular flow in the graft and interposition vein graft patency was checked by Doppler ultrasonography (US) daily during hospital stay and monthly follow-up after discharge for 2 y. Among 24 cases with MHV reconstruction, interpositional graft block occurred in one case within 7 d after transplantation. A reversed flow in MHV tributaries and collaterals between MHV and right hepatic vein (RHV) was detected by Doppler US. Vessel graft blocks were found in 10 of 22 cases of MHV tributaries reconstruction between 4 to 9 mo after transplantation. Collaterals formation between MHV and RHV developed in 4 of 10 cases of vessel graft block, and their graft function did not deteriorate. In conclusion, nearly half of the patients needed reconstruction of MHV tributaries when a right lobe graft without MHV was used in LDLT. The authors thought that the reconstruction of MHV tributaries should be established when the congested area was dominant by the clamping test or when the diameter of the tributaries was >5 mm. It was found that there may not be any problems if reconstructed vessel graft obstruction was found 3 mo after transplantation, as intrahepatic venous collaterals between MHV and RHV could develop.

Impact of non-congestive graft size in living donor liver transplantation: New indicator for additional vein reconstruction in right liver graft

Addition of the middle hepatic vein (MHV) or reconstruction of its tributaries to increase noncongestive graft volume is expected to improve graft function in right liver living donor liver transplantation (LDLT). However, the relationship between noncongestive graft volume and graft function after transplantation has not been clarified and definitive criteria for the reconstruction of MHV tributaries have yet to be established. We analyzed 29 right liver LDLT cases. The noncongestive graft weight was calculated as the total weight of the graft regions drained by hepatic veins reconstructed without postoperative occlusion. We calculated the noncongestive graft-to-recipient weight ratio (ncGRWR) by comparing it to the GRWR. Indocyanine green (ICG) clearance results on days 1 and 3 were significantly correlated with ncGRWR, but not with GRWR. Patients were then divided into 2 groups based on ncGRWR: lower than the median (L-ncGRWR group) and above the median (H-ncGRWR group). ICG clearance in the H-ncGRWR group was significantly better on days 1 and 3. For a different analysis, the patients were again divided into 2 groups, those with and without prolonged cholestasis after transplantation. ncGRWR was significantly lower in patients with prolonged cholestasis, and 7 of 9 patients with an ncGRWR value lower than 0.65 suffered from prolonged cholestasis. Our results demonstrated that the noncongestive volume of a right liver graft has a significant association with early graft function. Further, ncGRWR can play a key role in preoperative determination for additional vein reconstruction of MHV tributaries. When the estimated ncGRWR value with reconstruction of only the right hepatic vein (RHV) (+ inferior right hepatic vein [IRHV]) is less than 0.65, additional vein reconstruction of MHV tributaries should be planned.

Simplified technique for middle hepatic vein tributary reconstruction of a right hepatic graft in adult living donor liver transplantation

A simple procedure of direct end-to-end anastomosis between the middle hepatic vein tributary of the right hepatic graft and the preserved recipient middle hepatic vein is described. During the final step of total hepatectomy in the recipient, the middle hepatic vein was preserved, while crushing the liver tissue for a sufficient length of middle hepatic vein to perform tension-free anastomosis with the middle hepatic vein tributary of the graft. This procedure enabled us to avoid using an interposition graft.

Technical progress in living donor liver transplantation for adults

Liver transplantation from a living donor (LDLT) was introduced during the 1990 s to overcome the shortage of donor organs, particularly among children and in those countries in which cadaveric grafts were seldom available. In Japan alone, some 1700 LDLTs were performed in the first 12 years with a 5-year survival rate of 70% in adults and an even higher rate (82%) in children. The major limitation to successful LDLT is inadequate graft size, which usually necessitates the use of the whole right liver unless (I) the caudate lobe is included in a left liver graft, (2) only the right lateral sector is employed (segments VI and VII) or (3) left livers from two donors are implanted into one recipient. From a technical standpoint, the main problem with the various types of LDLT has been the venous reconstruction in the recipient. For the left-sided graft, the hepatic vein of the caudate lobe should be re-anastomosed to prevent congestion of this segment. For the right-sided graft, there has been uncertainty about the need to reconstruct the middle hepatic vein (MHV). Implantation is clearly simpler without this additional step, but there is a risk of dysfunction and sepsis in the right paramedian sector. Venous congestion in this sector can be observed during operation, both visually after clamping the MHV and by ultrasonographic assessment of the direction of blood flow in the portal vein. These techniques can be used to determine which patients require bench reconstruction of MHV tributaries or indeed of the inferior right hepatic vein. These manoeuvres should improve graft function and survival.