Complications Analysis of Polytetrafluoroethylene Grafts Used for Middle Hepatic Vein Reconstruction in Living-Donor Liver Transplantation

Effect of Complex Venous Outflow Drainage Reconstruction on Postoperative Graft Function in Right-Lobe Living Donor Liver Transplantation

Background: Living donor liver transplantation (LDLT) is the predominant transplantation technique in regions with low rates of deceased donation. Right-lobe grafting is adopted in most clinical and radiological donor/recipient scenarios. Due to the considerable variations in right-lobe hepatic venous anatomy, many techniques have been used over the years for the purpose of appropriate venous outflow reconstruction during the recipient procedure. In this paper, we present the technical details and consequences of a complex venous outflow reconstruction model (CORM) based on experience, and the long-term patency results obtained using the model. Methods: Data of patients with end-stage liver disease who underwent LDLT between 21 December 2017 and 29 November 2022 were prospectively collected and retrospectively reviewed. The nomenclature of CORM was assigned when three or more hepatic vein anastomoses were performed. Patients with CORM (CORM group; n = 69) were compared with non-CORM patients (non-CORM group; n = 130) in terms of demographic, pre- and postoperative clinical, and follow-up features. Results: Sixty-nine recipients had three or more separate outflow reconstructions (RHV, RIHV, and one or more anterior sectoral veins); these constituted the CORM group. The estimated graft volume of the CORM group was significantly lower than that of the non-CORM group (833 vs. 898; p = 0.022), and the mean GRWR was also significantly lower (1.1 vs. 1.2; p = 0.004). CORM cases showed longer anhepatic phases, as well as longer times for cold and warm ischemia, than non-CORM cases (63 vs. 51 min, 46 vs. 38 min, and 48 vs. 33 min, p < 0.001), though no difference was found with respect to total operative duration. There were no statistical differences between the two groups with respect to rates of in-hospital re-exploration, length of ICU stay, or length of total hospital stay. Graft survival rates at 1 year, 3 years, and 5 years were 88.1%, 83.3%, and 83.3%, respectively, in the CORM group, and 82.9%, 80.2%, and 70.6%, respectively, in the non-CORM group (p = 0.167). Conclusions: Performing three or more CORMs in right-lobe LDLT is not associated with inferior outcomes, either with regard to perioperative variables or to patient and graft outcomes. Right-lobe graft with complex venous anatomy from a living donor should not be a determinant factor for donor exclusion.

Complications of e-PTFE Grafts in LDLT; Evaluation of Case Series

BACKGROUND

The expanded polytetrafluoroethylene (ePTFE) grafts are used to drain anterior sector veins during the living donor liver transplantation procedure. We aimed to analyze the potentially life-threatening complications, such as the infection and migration of ePTFE grafts.

METHODS

A total of 1264 liver transplantations (LTs) were performed for 1097 adult and 167 pediatric liver failure cases. In total, 1169 living and 95 cadaveric liver transplantation procedures were performed between 2011 and 2021. Right liver transplantation was performed in 1016 cases, including 1002 living donors and 14 cadaveric split right livers. Cadaveric LT was performed in 81 cases.

RESULTS

For 1002 right living liver grafts, 905 vascular grafts were used during the backtable for anterior sector outflow venoplasty. The most commonly drained segments were 5 and 8 (472 cases); there were isolated (5 or 8) and multiple drained segments. Vascular graft migration was described in 7 of 905 (0.77%) patients.

CONCLUSIONS

Although complication rates regarding ePTFE grafts are low, there are serious life-threatening causes of morbidity and mortality. We recommend cushioning the vascular graft with the omentum, which is effective in preventing graft migration.

Asymptomatic synthetic vascular graft migration to duodenum after living donor liver transplantation: report of two cases

BACKGROUND

In this study, we present the results of two patients with vascular graft migration to the duodenum after liver transplantation.

METHODS

The results of two patients who underwent living donor liver transplantation and vascular graft to the duodenum were evaluated.

RESULTS

In our center, 201 liver transplants were performed, including 154 a right lobe living donor liver transplant. A synthetic graft was used to reconstruct segment 5 and 8 hepatic veins in 78 of the 154 LDLT. During the mean follow-up 19.6 ± 12.1 months (1-44 months), graft migrated to the duodenum in two patients who were present in this study. Contrary to the literature, it was followed nonoperatively. No problem was observed in the follow-up process.

CONCLUSION

In patients with vascular graft migration to the duodenum after living liver transplantation, non-operative follow-up can be performed in appropriate patients.

Feasibility of modified endarterectomized aortic allograft for middle hepatic vein reconstruction in living donor liver transplantation: A retrospective cohort study

BACKGROUND

Cryopreserved allografts and artificial vascular grafts were introduced to meet the increasing demand for adequate vascular substitutes for middle hepatic vein (MHV) reconstruction during living donor liver transplantation (LDLT). This study evaluated patency outcomes after engraftment of a modified endarterectomized aortic allograft (MEAA) without any additional patches.

METHODS

This retrospective double-arm study was conducted in single tertiary referral center between January 2015 and July 2018. Of 1,047 adult patients who underwent single-graft LDLT with a modified right lobe (MRL), 111 patients who received grafts with MHV reconstruction using MEAA were selected. The control group comprised 434 patients who underwent MHV reconstruction using iliac vein allografts. The main outcome measure was the short-term patency of the MEAA. The secondary outcome was the incidence of graft-associated complications.

RESULTS

Clinically significant MHV stenoses requiring stenting occurred in 3 patients (2.7%) in the MEAA group and in 17 patients (3.9%) in the iliac vein group (P = 0.778). Three-month and one-year patency rates on Doppler ultrasonography and computed tomography were 88.5% and 54.0%, respectively, in the MEAA group and 84.0% and 42.2%, respectively, in the iliac vein group, indicating the superior patency outcomes with MEAA (P = 0.017).

CONCLUSIONS

MHV reconstruction using MEAA during LDLT of a MRL graft is technically simple, achieves clinical outcomes comparable to iliac vein grafts, and is effective in expanding the allograft vessel pool for LDLT.

The impact of standardized methods of hepatic vein reconstruction with an external iliac vein graft

Background

Liver tumors that invade the hepatic vein are surgically challenging, especially in patients with liver dysfunction. Preservation of as much of the parenchyma as possible is important; thus, when feasible, we perform hepatectomy with hepatic vein reconstruction (HVR) using an external iliac vein (EIV) graft. We conducted a retrospective study to investigate the benefit of HVR and to evaluate our procedure.

Methods

The study included patients treated by hepatectomy with HVR using EIV grafts and vascular clips. We reviewed the surgical outcomes, including total operation and HVR times, postoperative complications, and postoperative liver function.

Results

The surgeries included right HVR (n=13), left HVR (n=3), and middle HVR (n=1). The total operation time was 277±72 minutes (155-400 minutes), and the HVR time was 27±5 minutes (19-40 minutes). Graft patency was confirmed in 14 (82%) of the patients. One patient who underwent HVR with running sutures required emergency surgery due to graft thrombosis. Clavien-Dindo > grade IIIa postoperative complications occurred in 4 (23.5%) patients, but there were no treatment-related deaths.

Conclusions

In conclusion, our hepatic resections with HVR using the same techniques and graft materials showed acceptable surgical outcomes. From our experience, we believe that preparatory hepatic resection with HVR is an effective treatment, especially for patients with decreased liver function or with a small residual liver parenchyma.

Patency of Hemashield grafts versus ringed Gore-Tex grafts in middle hepatic vein reconstruction for living donor liver transplantation

Backgrounds/Aims

Owing to the short supply of homologous vein allografts, we previously used ringed Gore-Tex vascular grafts for middle hepatic vein (MHV) reconstruction in living donor liver transplantation. When ringed Gore-Tex grafts became unavailable, we used Hemashield vascular grafts. This study aimed to compare the patency and complication rates of Hemashield and ringed Gore-Tex grafts.

Methods

This retrospective two-arm study compared the study group that received Hemashield grafts (n=157) and the propensity score-matched control group that received ringed Gore-Tex grafts (n=157).

Results

In the Hemashield and Gore-Tex groups, the recipient age was 54.7±9.4 and 53.3±6.3 years; Model for End-stage Liver Disease scores were 15.9±9.2 and 16.9±8.3; and graft-recipient weight ratios were 1.07±0.24 and 1.10±0.23, respectively. In the Hemashield group, V5 reconstruction was performed using single (n=113, 72.0%), double (n=39, 24.8%), and triple (n=3, 1.9%) anastomoses. The proportion of double and triple anastomoses for V5 and V8 was higher in the Hemashield group than in the Gore-Tex group. Two (1.3%) patients required MHV conduit stenting owing to early thrombosis of the Hemashield graft. There was no difference in conduit occlusion- free patient survival rates between groups (p=0.91). The incidence of accidental conduit migration in the Hemashield and Gore-Tex groups was 0 (0%) and 2 (1.3%), respectively.

Conclusions

Hemashield grafts used in MHV reconstruction demonstrated acceptably high short- and mid-term patency rates, no incidences of conduit migration, easy handling, and good flexibility for length adjustment. Therefore, we suggest that the Hemashield graft is the preferentially suitable prosthetic material for MHV reconstruction.

Venous outflow reconstruction using a polytetrafluoroethylene (PTFE) graft in right lobe living donor liver transplantation: A single center study

BACKGROUND

Venous outflow reconstruction is very important especially in right lobe living donor liver transplantation without middle hepatic vein. Various interposition (venous or synthetic) grafts have been recommended for reconstruction of anterior sector tributaries.

METHODS

We aimed to describe our surgical technique and analyze anterior sector venous reconstruction using expanded polytetrafluroethylene graft. Retrospective analysis of prospectively collected data for 760 primary right lobe living donor liver transplantations performed at our institute between December 2011 and June 2018. Reconstruction of anterior sector: expanded polytetrafluroethylene (group A, n = 705) and autologous vein (group B, n = 55).

RESULTS

Pretransplant characteristics were comparable among both groups. Group A has significantly lower cold ischemia time (68.7 ± .3.5 minutes vs 127.8 ± 7.2 minutes; P < .001) and anhepatic time (116.3 ± 5.5 minutes vs 190.81 ± 9.35 minutes; P < .001) compared with group B. There was no difference in recovery pattern of liver functions, morbidity, and mortality between the 2 groups. One- and 6-month patency rates of interposition grafts were 97.6% and 84.4% (group A) and 96.4% and 78.1% (group B), respectively.

CONCLUSION

In centers with limited access to homologous or autologous vascular grafts, use of expanded polytetrafluroethylene graft for anterior sector venous outflow reconstruction in right lobe living donor liver transplantation is a viable option with excellent patency and patient outcomes.

Complications of polytetrafluoroethylene graft use in middle hepatic vein reconstruction in living donor liver transplantation: a retrospective, single-centre, long-term, real-world experience

In living donor liver transplantation (LDLT) of the right lobe, polytetrafluoroethylene (PTFE) grafts may be used for anterior drainage. This study aimed to determine the risk factors of PTFE graft-associated complications. Data from patients who underwent LDLT of the right lobe with middle hepatic vein reconstruction using PTFE grafts between January 2005 and December 2012 were retrospectively reviewed. Among 360 patients, PTFE graft-associated complications occurred in 17 patients (group B) (4.7%); recipients without these complications comprised group A (95.3%). The 1-, 6- and 12-month patency rates were significantly lower in group B (P < 0.001, P = 0.002 and P = 0.007). In group B, eight patients (47.1%) required surgical intervention, three patients (17.6%) suffered from infectious complications, and 14 patients (82.4%) experienced PTFE graft migration into the adjacent organs, namely the common bile duct (n = 3, 17.6%), stomach (n = 1, 5.9%), duodenum (n = 5, 29.4%) and jejunum (n = 5, 29.4%). The proportion of recipients who underwent hepaticojejunostomy, had abdominal adhesions and received interventions in/around the liver after LDLT was higher in group B (P < 0.001). Although the incidence of PTFE graft-associated complication is low, close long-term follow-up is needed, especially in patients with risk factors.

Artificial vascular graft migration into hollow viscus organs in patients who underwent right lobe living donor liver transplantation

BACKGROUND

To share our experience with hollow viscus migration of artificial vascular grafts (AVG) used for venous reconstruction of the right anterior sector in living donor liver transplantations (LDLT).

METHODS

Clinical, radiological, and endoscopic data of 13 right lobe LDLT patients (range: 26-67 years) with a diagnosis of postoperative AVG migration into adjacent hollow viscus were analyzed.

RESULTS

Biliary complications were detected in 12 patients. A median of four times endoscopic retrograde cholangiopancreatography (ERCP) procedures were performed in 11 patients prior to AVG migration diagnosis. A median of 2.5 times various percutaneous radiological interventional procedures were performed in eight patients prior to AVG migration diagnosis. The site of migration was the duodenum in eight patients, gastric antrum in four, and Roux limb in the remaining one patient. The migrated AVS were made of polytetrafluoroethylene (PTFE) in 10 patients and polyethylene terephthalate (Dacron) in three. The migrated AVGs were endoscopically removed in seven patients and surgically removed in six. Only one patient died due to sepsis unrelated to AVG migration.

CONCLUSION

AVG migration into the adjacent hollow viscus following right lobe LDLT is a rare and serious complication. Repetitive ERCP, interventional radiological procedures, infection related to biliary leakage, and thrombosis of AVGs are among the possible risk factors.

Refined surgical techniques to improve the patency of cryopreserved iliac artery homografts for middle hepatic vein reconstruction during living donor liver transplantation

Purpose

A cryopreserved iliac artery homograft (IAH) has not been considered suitable for middle hepatic vein (MHV) reconstruction during living donor liver transplantation (LDLT), primarily due to the low patency from its small diameter. We revised our surgical techniques for MHV reconstruction using an IAH to improve its patency.

Methods

This study analyzed the causes of early conduit occlusion and developed revised techniques to address this that had clinical application.

Results

The potential risk factors for early conduit occlusion were the small IAH size, small graft in the segment V vein (V5) and segment VIII vein (V8) opening, and small recipient MHV-left hepatic vein stump. These factors were reflected to our revised surgical methods which included endarterectomy of the atherosclerotic plaque, unification of the internal and external iliac artery branches for large V5, and branch-patch arterioplasty for large V8. IAH endarterectomy, branch unification technique, and branch-patch arterioplasty were applied to 8, 5, and 5 patients, respectively and resulted in 1-month occlusion rates of 37.5%, 20.0%, and 40.0%, respectively. The overall patency rates of the IAH-MHV conduits in our 18 patients were 66.7% at 1 month, 38.9% at 3 months, and 33.3% at 1 year.

Conclusion

Our refined MHV reconstruction using an IAH improved short-term MHV conduit patency, but did not effectively prevent early conduit occlusion, particularly with a small- or medium-sized IAH. Individualized reconstruction designs during LDLT operation are needed when an IAH is used for a modified right liver graft.

Usability of Inferior Vena Cava Interposition Graft During Living Donor Liver Transplantation: Is This Approach Always Necessary?

PURPOSE

To share the outcome of caval reconstruction technique in patients who underwent living donor liver transplantation (LDLT) with inferior vena cava (IVC) interposition grafting.

METHODS

Between January 2009 and December 2018, an artificial or homologous interposition vascular graft was used for the continuity of resected native (IVC) due to various reasons in 29 of 1740 patients who underwent LDLT at our institute. Demographic, clinical, and radiological data were prospectively collected and retrospectively analyzed.

RESULTS

Sixteen female and 13 male patients ranging 6-67 years of age were included. Right, left, and left lobe lateral segments were used in 22, 5, and 2 patients, respectively. The three leading LDLT indications were primary or idiopathic Budd-Chiari syndrome (BCS) (n = 12), alveolar echinococcosis (n = 7), and secondary BCS (n = 5). The three leading indications for IVC interposition grafting were thrombosis, dense fibrosis, and IVC invasion caused by tumor or echinococcosis. Homologous IVC graft was used in 17, homologous aortic graft in 7, and Dacron graft in 5 patients. Throughout the follow-up period, ascites ± pleural effusion and elevated liver enzymes were detected in 12 and 4 patients, respectively. Stenosis and/or thrombosis requiring one or more procedures such as 1-6 sessions balloon angioplasty, stent, and thrombus aspiration were observed in half of the patients.

CONCLUSION

Retrohepatic IVC damages are not a contraindication for LDLT. The presence or absence of venous collateral circulation is an important indicator of the need for IVC interposition graft use.

Impact of the Reconstruction Material on the Patency of Middle Hepatic Vein in Living Donor Liver Transplantation Using the Right Liver

BACKGROUND

A right liver graft with middle hepatic vein (MHV) reconstruction is the standard graft for adult-to-adult living donor liver transplantation (LDLT). The patency of reconstructed MHV affects the recovery and regeneration of graft. The aim of the study is to evaluate the patency rate of reconstructed MHV according to the reconstruction material in LDLT using the right liver.

METHODS

The data was collected retrospectively on 521 patients who underwent LDLT with right liver graft form August 2003 to December 2012 at the Seoul St. Mary's Hospital in Seoul. Two serial comparisons were performed. At first, patients were divided into 2 groups: biologic graft group (n = 252) and synthetic graft group (n = 177). Second, patients were divided into 6 groups: No MHV reconstruction (n = 92); MHV was reconstructed by greater saphenous vein (GSV) (n = 20); recipient's portal vein (PV) (n = 219); cryopreserved iliac artery (CIA) (n = 2); cryopreserved iliac vein (CIV) (n = 11); polytetrafluoroethylene (PTFE) graft (n = 105); and polyethylene terephthalate (PETE) graft (n = 72). We compared the patency of reconstructed MHV among these groups by computed tomography angiography at 7 days, 20 days, 90 days, and 1 year.

RESULTS

At the first comparison, the patency rate of the biologic graft group on the seventh postoperative day was 61.9%, and the synthetic graft group was 72.4% (P = .029). At postoperative 1 year, the patency rate of the biologic graft group was 42.9%, and the synthetic graft group was 24.1% (P = .001). At the second comparison, the MHV patency of GSV, PV, CIA, CIV, PTFE, and PETE was 65.0%, 62.5%, 50%, 63.6%, 75%, 72% on the seventh postoperative days (P = .318); 60%, 57.1%, 50%, 54.5%, 69%, 55.6% on the 20th postoperative days (P = .444); 40%, 48.8%, 50%, 27.3%, 47%, 34.1% on the 90th postoperative days (P = .294); and 30%, 45.2%, 50%, 27.3%, 27%, 26.4% at 1 postoperative year (P = .008).

CONCLUSION

Although there was no statistical difference in comparison of each material, there were significant differences in MHV patency rates between the biologic and the synthetic group. Therefore, the synthetic graft could be considered in living donor liver transplantation with MHV reconstruction.

Hemashield Vascular Graft Is a Preferable Prosthetic Graft for Middle Hepatic Vein Reconstruction in Living Donor Liver Transplantation

Background

Because of the supply shortage for homologous vein allografts, we previously used ringed Gore-Tex vascular grafts for middle hepatic vein (MHV) reconstruction in living donor liver transplantation. However, owing to the subsequent unavailability of ringed Gore-Tex grafts, we replaced them with Hemashield vascular grafts. This study aimed to compare the patency of Hemashield grafts with that of ringed Gore-Tex grafts.

Material/Methods

This was a retrospective double-arm study between the study group that used Hemashield grafts (n=63) and the historical control group that used ringed Gore-Tex grafts (n=126).

Results

In the Gore-Tex and Hemashield groups, mean age was 53.1±6.2 and 54.3±10.4 years; model for end-stage liver disease score was 16.5±8.3 and 17.5±9.9; and graft-recipient weight ratio was 1.11±0.23 and 1.12±0.25, respectively. In the Gore-Tex graft group, V5 reconstruction was done in single (n=107, 84.9%), double (n=17, 13.5%), and none (n=2, 1.6%). V8 reconstruction was done in single (n=95, 75.4%), double (n=1, 0.8%), and none (n=30, 23.8%). In the Hemashield group, V5 reconstruction was done in single (n=43, 68.3%), double (n=19, 30.2%), and triple (n=1, 1.6%). V8 reconstruction was done in single (n=45, 71.4%), double (n=9, 14.3%), and none (n=9, 14.3%). One-year conduit patency rates in the Gore-Tex and Hemashield groups were 54.8% and 71.6%, respectively (p=0.048).

Conclusions

MHV reconstruction using Hemashield vascular grafts demonstrated higher short-term patency rates than those associated with ringed Gore-Tex vascular grafts. We suggest that the Hemashield vascular graft is one of the best prosthetic materials for MHV reconstruction.

Analysis of Risk Factors Affecting the Development of Infection in Artificial Vascular Grafts Used for Reconstruction of Middle Hepatic Vein Tributaries in Living Donor Liver Transplantation

BACKGROUND

To analyze the risk factors affecting the development of infection in artificial vascular grafts (AVGs) used for reconstruction of middle hepatic vein (MHV) tributaries in living donor liver transplantation (LDLT).

METHODS

Between January 2009 and January 2018, 1253 right lobe LDLTs were performed at our Transplant Institute, and MHV tributaries of the 640 right lobe liver grafts were reconstructed with AVG. Reconstructed MHV tributaries were removed due to AVG infection in 25 of these patients (case group; n = 25). To determine risk factors for AVG infection, right lobe LDLT patients without AVG infections were selected as control group (n = 615). Both groups were compared about demographic parameter, transcystic catheter usage, bile leakage, type of biliary anastomosis (duct-to-duct, telescopic duct-to-duct), number of graft biliary duct (=1 versus >1), number of biliary anastomosis (=1 versus >1), AVG thrombosis, AVG types (Dacron versus polytetrafluoroethylene). Univariate analyses were used for comparison of different variables, and variables with P ≤ 0.20 were taken into logistic regression model.

RESULTS

Univariate analysis shows that statistically significant differences were found between groups regarding bile leakage (P < 0.001), graft thrombosis (P = 0.002), transcystic catheter (P = 0.049), and AVG types (P = 0.013). Variables with P ≤ 0.20 were taken into logistic regression model. Multivariate analysis shows that bile leakage (odds ratio, 13.3) and AVG thrombosis (odds ratio, 9.8) were determined as independent and strong risk factors for development of AVG infection.

CONCLUSIONS

This study revealed that bile leakage and graft thrombosis are independent and strong risk factors for infections of AVGs used for anterior sector drainage reconstruction.

Explant portal vein for reconstructing middle hepatic vein in right lobe living donor liver transplantation-outcome analysis

BACKGROUND

The aim of the study was to study the four week patency rates of the reconstructed neo middle hepatic vein specifically using the explant portal vein (PV) in right hemiliver live donor liver transplantation (LDLT). We hypothesized that short term patency of the neo-MHV should result in good graft and patient outcomes.

METHODS

Pre, intra and post operative variables were prospectively collected for 88 consecutive patients undergoing right hemiliver LDLT from January 2014 to October 2015.

RESULTS

Explant PV was used to reconstruct neo-MHV in 76 (86.4%, 76/88) patients. Neo MHV patency rate at 28 days with explant PV was 89.4% (59/66) and with other conduit (PTFE) was 90.9% (10/11). All occlusions were detected after 7 days. There was no impact of the patency of the neo-MHV on the incidence of early allograft dysfunction, sepsis, rejection, morbidity or mortality, despite the contribution of the anterior sector to the graft volume being more than 50% in close to two-thirds of patients.

CONCLUSION

The reconstructed neo-MHV has excellent short term patency rates at 4 weeks. Perhaps due to the absence of early occlusions, there was no impact on graft or patient outcomes in the study population.

Assessing the Safety of Expanded Polytetrafluoroethylene Synthetic Grafts in Living Donor Liver Transplantation: Graft Migration Into Hollow Viscous Organs - Diagnosis and Treatment Options

Background

Our recent studies have highlighted the importance and safety of backtable venoplasty for middle hepatic vein (MHV) and inferior right hepatic veins (IRHV) reconstruction using expanded polytetrafluoroethylene (ePTFE) vascular grafts. In this study, we aim to analyze the complications associated with ePTFE graft use and discuss the management of the rare, but, potentially life threatening complications directly related to ePTFE conduits.

Material/Methods

From January 2012 to October 2015 a total of 397 patients underwent living donor liver transplantation (LDLT). The ePTFE vascular grafts were used during the backtable venoplasty for outflow reconstruction in 262 of the liver allografts. Recipients who developed ePTFE-related complications were analyzed.

Results

ePTFE-related complications developed in 1.52% (4/262) of the patients. One patient (0.38%) developed complete thrombosis with sepsis at 24 months post-transplantation and died due to multiorgan failure. Three patients (1.1%) developed graft migration into the second portion of the duodenum, without overt peritonitis. Surgical exploration and ePTFE graft removal was done in all the patients. One patient died due to overwhelming sepsis.

Conclusions

ePTFE graft migration into the duodenum causing perforation is a new set of complications that has been recently described in LDLT and can be treated effectively by surgical removal of the infected vascular graft and duodenal perforation closure. Despite of such complications, in our experience, ePTFE use in LDLT continues to have wide safety margin, with a complication rate of only 1.52%.

Adult-to-adult living donor liver transplantation: Operative techniques to optimize the recipient's outcome

Adult-to-adult living donor liver transplantation (LDLT) is widely accepted today with good outcomes and safety reported worldwide for both donor and recipient. Nonetheless, it remained a highly demanding technical and complex surgery if undertaken. The last two decades have seen an increased in adult-to-adult LDLT following our first report of right lobe LDLT in overcoming graft size limitation in adults. In this article, we discussed the operative techniques and challenges of adult right lobe LDLT incorporating the middle hepatic vein, which is practiced in our center for the recipient operation. The various issues and challenges faced by the transplant surgeon in ensuring good recipient outcome are explored and discussed here as well. Hence, it is important to understand that a successful recipient operation is dependent of multifactorial events starting at the preoperative stage of planning, understanding the intraoperative technical challenges and the physiology of flow modulation that goes hand-in-hand with the operation. Therefore, one needs to arm oneself with all the possible knowledge in overcoming these technical challenges and the ability to be flexible and adaptable during LDLT by tailoring the needs of each patient individually.

Surgical outcomes of hepatocellular carcinoma invading hepatocaval confluence

BACKGROUND

Combined liver and inferior vena cava (IVC) resection followed by IVC and/or hepatic vein reconstruction (HVR) is a curative operation for selected patients with hepatocellular carcinoma (HCC) invading the hepatocaval confluence. The present study aimed to elucidate the prognostic factors for patients with HCC invading the hepatocaval confluence.

METHODS

Forty-two consecutive patients underwent hepatectomy, combined with IVC replacement and/or HVR for HCC between January 2009 and December 2014 were included in this study. The cases were divided into three groups based on the surgical approaches of HVR: group 1 (n=13), tumor invaded the hepatocaval confluence but with one or two hepatic veins intact in the residual liver, thus only the replacement of IVC, not HVR; group 2 (n=23), the hepatic vein of the residual liver was also partially invaded, and the hepatic vein defect was repaired with patches locally; group 3 (n=6), three hepatic veins at the hepatocaval confluence were infiltrated, and the hepatic vein remnant was re-implanted onto the side of the tube graft. The patient characteristics, intra- and postoperative results, and long-term overall survival were compared among the three groups. The survival-related factors were analyzed by univariate and multivariate analysis.

RESULTS

The group 1 had higher preoperative alpha-fetoprotein level (P<0.001), shorter operation time, hepatic ischemic time and hospital stay compared with groups 2 and 3 (P<0.05). The 1-, 3-, and 4-year overall survival rates of group 1 were 84.6%, 23.1% and 23.1%, respectively; group 2 were 78.3%, 8.7% and 8.7% respectively and group 3 were 83.3%, 0 and 0, respectively. The multivariate analysis showed that the independent poor prognostic factors of overall survival were preoperative higher HBV DNA level (≥10³ copies/mL; P=0.001), tumor size (≥9 cm; P<0.0001), age (≥60 years; P=0.010) and underwent HVR (P<0.0001).

CONCLUSIONS

Patients with reconstructing hepatic vein with patches locally (group 2) or to the artificial graft (group 3) had worse long-term survival than those without HVR (group 1). HVR was one of the unfavorable prognostic factors of overall survival.

Usability of Cryopreserved Aortic Allografts for Middle Hepatic Vein Reconstruction During Living-Donor Liver Transplantation

Iliac vein allografts are suitable for middle hepatic vein (MHV) reconstruction during living-donor liver transplantation (LDLT), but their supply is often limited. Polytetrafluoroethylene (PTFE) grafts are easily available but have drawbacks of accidental gastric penetration and non-degradable foreign body. To replace the use of PTFE grafts, we started using cryopreserved aorta allografts (CAAs). This study presents the technical details and patency outcomes of using CAAs in MHV reconstruction. We reviewed the surgical techniques of CAA interposition and analyzed the patency rates in 74 patients who underwent LDLT during the 6-year study period. The two control groups received either cryopreserved iliac veins (n = 122) or PTFE grafts (n = 84). The surgical techniques for MHV reconstruction used to implant the CAA and PTFE grafts are very similar because the techniques developed for PTFE grafts were also applied to CAAs. We inserted an arterial patch at the liver cut surface because the CAA wall is too thick to perform direct anastomosis. Two patients (2.7 %) underwent MHV stenting during the first month. The 1-year patency rate was 69.7 % in the CAA group vs. 39.2 % in iliac vein group vs. 57.2 % in PTFE group (p = 0.000). The overall graft and patient survival rates did not differ depending on the MHV interposition vessel materials (p > 0.1). CAAs combined with small-artery patches demonstrated high patency rates that surpass other vessel grafts, and thus, we suggest that CAA can be reliably used for MHV reconstruction when CAA is available.

Duodenal Penetration by the Ringed Expanded Polytetrafluoroethylene Graft for Middle Hepatic Vein Reconstruction During Living-Donor Liver Transplant: A Case Report

Expanded polytetrafluoroethylene grafts are widely used for middle hepatic vein reconstruction during living-donor liver transplant because they have comparable patency to autologous or cryopreserved vessels. Mechanical complications like gastric or duodenal penetration by expanded polytetrafluoroethylene grafts have been infrequently reported. We recently experienced a case of duodenal penetration by the expanded polytetrafluoroethylene graft. The patient was a 57-year-old man who had undergone a living-donor liver transplant for cryptogenic liver cirrhosis. At an annual follow-up computed tomography scan performed 3 years after transplant, the expanded polytetrafluoroethylene graft appeared to have penetrated into the first to the second portion of the duodenum, and abnormal air shadow and partial thrombus were identified within the expanded polytetrafluoroethylene graft. The patient underwent exploratory laparotomy, the expanded polytetrafluoroethylene graft was removed, and the perforated duodenum was repaired. Pyloric exclusion with gastrojejunostomy and feeding jejunostomy was additionally performed because of a wide defect in the duodenum. Adjacent organ injuries such as duodenal or gastric penetration by the expanded polytetrafluoroethylene graft after living-donor liver transplant is rare but not uncommon. Because the use of expanded polytetrafluoroethylene grafts is essential when an adequate vessel allograft is unavailable, we can consider transposition of the omental flap between the expanded polytetrafluoroethylene graft and the stomach or duodenum to reduce this unexpected complication.

Circumferential Fence With the Use of Polyethylene Terephthalate (Dacron) Vascular Graft for All-in-One Hepatic Venous Reconstruction in Right-Lobe Living-Donor Liver Transplantation

Integration of hepatic vein tributaries with a diameter ≥ 5 mm into the drainage system in right-lobe living-donor liver transplantation (LDLT) is of vital importance for graft function. Recently, the most commonly emphasized hepatic venous reconstruction model is the all-in-one reconstruction model. In the final stage of this model that aims to form a common large opening, allogeneic vascular grafts are almost always used to construct a circumferential fence. To date, no other study has reported the use of polyethylene terephthalate (Dacron) vascular graft as a circumferential fence in LDLT. We aimed to present the 1st 4 cases of circumferential fences created with Dacron vascular graft. Four right-lobe grafts weighing 522-1,040 g were used. A polytetrafluoroethylene vascular graft was used for the integration of segment 5 vein and segment 8 vein into the drainage model, whereas a Dacron graft was used to creating a circumferential fence. The patency of hepatic outflow evaluated with the use of multidetector computerized tomography at postoperative day 7. Venous outflow obstruction was not detected in any cases. This study suggested that owing to its flexible structure the polyethylene terephthalate vascular graft can be an alternative to allogeneic vascular grafts in forming circumferential fence.