A new surgical technique for hepatic vein reconstruction in pediatric live donor liver transplantation

Reduced-Size Left Lateral Segment Grafts in Infants Weighing <10 kg

BACKGROUND

Live donor liver transplantation for infants weighing <10 kg has unique complexities, as patient/graft size discrepancies may cause vascular perfusion deficiencies. Failure of the abdominal closure further complicates this already challenging procedure. To overcome these potential problems, several techniques for graft size reduction-either anatomic or nonanatomic-have been proposed in the literature. Technically easier and less time-consuming, nonanatomic size reductions have the advantage of avoiding the risk of injury to the portal pedicle. This study aimed to evaluate and compare the effects of nonanatomic graft size reduction in infants weighing <10 kg with a large estimated preoperative graft recipient weight ratio.

METHODS

We enrolled 106 infants weighing <10 kg. Of these infants, 50 received reduced-size grafts. The outcomes were compared between the groups.

RESULTS

No difference was observed between the groups according to survival and vascular or biliary complications. None of the patients required an open abdomen or mesh closure.

CONCLUSION

Nonanatomic size reduction of left lateral segment grafts can be safely applied without compromising vascular supply, graft function, and patient survival with comparable vascular and biliary complication rates. This technique is safe and efficient in overcoming the complications caused by large-for-size syndrome in infants weighing <10 kg.

Hepatic venous reconstruction of the left lateral segment with emphasis on anomalous hepatic vein in pediatric liver transplantation

Left lateral segment grafts have become a suitable option in pediatric liver transplantation (PLT). The correlation between hepatic vein (HV) reconstruction and outcome is relevant when assessing the safe use of these grafts. We retrospectively reviewed the medical records prospectively collected from a pediatric living donor liver transplantation database and conducted a comparative analysis of the different left lateral segment graft types according to HV reconstruction. Donor, recipient, and intraoperative variables were analyzed. Post-transplant outcomes included vascular complications such as hepatic vein outflow obstruction, early (≤30 d) and late (>30 d) PVT, hepatic artery thrombosis, and graft survival. From February 2017 to August 2021, 303 PLTs were performed. According to venous anatomy, the distribution of the left lateral segment was as follows: single HV (type I) in 174 (57.4%), close HVs, simple venoplasty for reconstruction (type II) in 97 (32.01%), anomalous hepatic vein (AHV) with a distance between the HVs orifices that allowed simple venoplasty (type IIIA) in 25 (8.26%) and AHV with a distance between the HVs orifices requiring homologous venous graft interposition (type IIIB) in 07 (2.31%) grafts. Type IIIB grafts came from male donors ( p =0.04) and had a higher mean donor height ( p =0.008), a higher mean graft weight, and a higher graft-to-recipient weight ratio, both p =0.002. The median follow-up time was 41.4 months. The overall cumulative graft survival was 96.3%, and comparative graft survival showed no difference (log-rank p =0.61). No hepatic vein outflow obstructions were observed in this cohort study. There was no statistically significant difference in the post-transplant outcomes between the graft types. The venous reconstruction of the AHV with homologous venous graft interposition had similar outcomes in the short and long term.

Outflow reconstruction of left lateral graft with two widely spaced hepatic veins in pediatric living donor liver transplantation

BACKGROUND

Living donor liver transplantation using the left lateral segment of the liver is the most common type of pediatric liver transplantation. An appropriate surgical approach is crucial for decreasing the risk of vascular complications using these grafts with anatomical variations.

METHODS

Between January 2017 and December 2020, 631 living donor liver transplantations using left lateral segment grafts were performed at Tianjin First Central Hospital. The grafts from 162 (25.7%) donors have 2 hepatic vein openings. A total number of 21 transplantations using left lateral segment grafts with 2 widely spaced hepatic vein openings were performed. In group 1, the unification venoplasty technique with interposition vein graft was used at the back table for the reconstruction of hepatic vein from grafts. In group 2, dual hepatic vein reconstructions were performed, in which venoplasty of recipients' left hepatic vein, middle hepatic vein, and inferior vena cava was performed to create a large orifice for anastomosis with segment Ⅱ hepatic vein from the graft. Segment III hepatic vein from the graft was anastomosed with the recipient's right hepatic vein. The incidence, treatment, and outcomes of hepatic venous outflow obstruction were compared between the 2 groups.

RESULTS

The median follow-up time was 12.8 months. There was no significant difference in the incidence of hepatic venous outflow obstruction between the 2 groups.

CONCLUSION

Dual hepatic vein reconstruction is an alternate surgical option for grafts with 2 widely spaced hepatic veins, and it is associated with ideal graft recovery and vascular condition. However, long-term follow-up is still needed to verify the efficacy and safety of this approach.

Antithrombotic management and thrombosis rates in children post-liver transplantation: A case series and literature review

Thrombosis is a major postoperative complication in pediatric liver transplantation. There is marked heterogeneity in prophylactic antithrombotic therapies used, without established guidelines. This review summarizes current worldwide incidence of thrombotic events and compares antithrombotic therapies in children post-liver transplant, with comparison to our institution's experience. Of the twenty-three articles with sufficient detail to compare antithrombotic regimens, the overall incidence of thrombosis ranged from 2.4% to 17.3%. Incidence of HAT ranged from 0% to 28.1%, of HVT from 0% to 4.7%, of PVT from 1.5% to 11.2%, and of IVC thrombosis from 0% to 2.8%. Re-transplantation due to thrombosis ranged from 0% to 4.8%. Prophylactic antithrombotic therapies varied between studies, and bleeding complications were infrequently reported. Since 2010, 96 children underwent 100 liver transplants at our institution with thrombosis incidence comparable to international literature (HAT 6%, PVT 5%, IVC 1%, and HVT 0%). Re-transplantation due to thrombosis occurred in 2% and major bleeding occurred in 10%. The prophylactic antithrombotic therapies used post-liver transplantation in children remain varied. Low rates of thrombosis have been reported with antiplatelet use both with and without anticoagulation. Standard definitions and consistent reporting of bleeding complications are required, in addition to thrombosis rates, so that true risk-benefit assessment of reported regimes can be understood.

Results of 1001 liver transplantations in 23 years: Ege University experience

BACKGROUND/AIMS

Liver transplantation (LT) is now the standard of care for most end-stage liver diseases. Over the next 30 years, advances in medicine and technology will greatly improve the survival rates of patients after this procedure. The aim of the present study was to analyze retrospectively the results of 1001 patients withLT.

MATERIALS AND METHODS

Medical reports of 989 patients were analyzed retrospectively. Data were obtained from the patient's data chart. Descriptive statistics were used to describe continuous variables (mean, median, and standard deviation).

RESULTS

A total of 1001 LTs for 989 recipients were performed at Ege University Organ Transplantation and Research Center between 1994 and 2017. Therewere 639 male and 350 female recipients. Among 1001 LTs, there were 438 deceased donors and 563 living donors. The age interval of the patients was 4 months to 71 years old. The median Model for End-Stage Liver Disease score was 20. There were 12 deceased liver donors using the split method. There were 12 cases subject to retransplantation. In living donor LT grafts, 423 right lobes, 46 left lobes, and 94 left lateral sectors were used. In the first monitoring,the total annual mortality rate was 130 cases (13%). The mortality rate in retransplantation was found to be 66%. A 1-year survival rate of 87% was generally stablished.

CONCLUSION

LThas been improving consistently over the last two decades. Ege University is one of the biggest liver transplant centers in Turkey for both technical and educational perspective.

Modified triangular hepatic vein reconstruction for preventing hepatic venous outflow obstruction in pediatric living donor liver transplantation using left lateral segment grafts

HVOO can be a critical complication in pediatric LDLT. The aim of this study was to evaluate a modified triangular technique of hepatic vein reconstruction for preventing HVOO in pediatric LDLT. A total of 298 pediatric LDLTs were performed using a left lateral segment graft by 2 methods for reconstruction of the hepatic vein. In 177 recipients, slit-shaped anastomosis was indicated with partial clamp of the IVC. A total of 121 recipients subjected to the modified triangular anastomosis with total clamp of the IVC. We compared the incidence of hepatic vein anastomotic complications between these 2 methods. Nine of the 177 cases (5.3%) treated with the conventional technique were diagnosed with outflow obstruction. All 9 cases underwent hepatic vein reconstruction with the slit-shaped hepatic vein anastomosis. In contrast, there were no cases of outflow obstruction in the 121 cases treated with the modified triangular anastomosis. The modified triangular technique of hepatic vein reconstruction with total clamping of the IVC was useful for preventing HVOO in pediatric LDLT.

Diagnosis, treatment and outcome of hepatic venous outflow obstruction in paediatric liver transplantation: 24-year experience at a single centre

BACKGROUND

Hepatic venous outflow obstruction after paediatric liver transplantation is an unusual but critical complication.

OBJECTIVES

To review the incidence, diagnosis and therapeutic modalities of hepatic venous outflow obstruction from a large national liver transplant unit.

MATERIALS AND METHODS

During the period from October 1992 to March 2016, 917 liver transplant procedures were performed with all types of grafts in 792 children. Transplants suspected to have early or delayed venous outflow obstruction were confirmed by percutaneous venography or surgical revision findings. Therapeutic intervention, recurrence and outcome were evaluated.

RESULTS

Twenty-six of 792 children (3.3%) experienced post-transplant hepatic venous outflow obstruction. These patients had been diagnosed from 1 day to 8.75 years after transplantation. Six occurred during the early post-transplant period; in three of them, the graft was lost. Seventeen patients were initially treated by balloon angioplasty with success; 11 of these experienced recurrences. Four stents were implanted; one was complicated by definitive occlusion. Three of the five surgical revisions were successful. The initial stenosis involved the inferior vena cava in 10 grafts, in isolation or associated with hepatic vein involvement. Mean follow-up was 79 months after transplantation. Eight grafts were lost.

CONCLUSION

Acute postoperative hepatic venous outflow obstruction was associated with poor prognosis. Diagnostic venography should be performed if there is any suspicion of venous outflow obstruction, even if first-line examinations are normal. Stenosis frequently involved the inferior vena cava. Angioplasty was a safe and efficient treatment for venous outflow obstruction despite frequent recurrence.

Doppler ultrasonography in living donor liver transplantation recipients: Intra- and post-operative vascular complications

Living-donor liver transplantation has provided a solution to the severe lack of cadaver grafts for the replacement of liver afflicted with end-stage cirrhosis, fulminant disease, or inborn errors of metabolism. Vascular complications remain the most serious complications and a common cause for graft failure after hepatic transplantation. Doppler ultrasound remains the primary radiological imaging modality for the diagnosis of such complications. This article presents a brief review of intra- and post-operative living donor liver transplantation anatomy and a synopsis of the role of ultrasonography and color Doppler in evaluating the graft vascular haemodynamics both during surgery and post-operatively in accurately defining the early vascular complications. Intra-operative ultrasonography of the liver graft provides the surgeon with useful real-time diagnostic and staging information that may result in an alteration in the planned surgical approach and corrections of surgical complications during the procedure of vascular anastomoses. The relevant intra-operative anatomy and the spectrum of normal and abnormal findings are described. Ultrasonography and color Doppler also provides the clinicians and surgeons early post-operative potential developmental complications that may occur during hospital stay. Early detection and thus early problem solving can make the difference between graft survival and failure.

Better innovate than compromise: a novel hepatic outflow reconstruction technique in pediatric living donor liver transplantation

Pediatric LDLT using donors with unfavorable vascular anatomy is challenging in terms of donor safety, and complexity of reconstruction in the recipient. We describe an innovative technique of hepatic venous outflow reconstruction involving the recipient RHV, in the presence of a rudimentary RHV in the donor. The postoperative course of the donor and recipient was uneventful with satisfactory venous outflow in both. This technique avoided the use of prosthetic material, an important consideration given the recipient age and requirement for growth. This shows that donors previously considered unsuitable for donation can be utilized safely as long as principles of vascular anastomosis are adhered to. Moreover, it highlights that innovation is sometimes necessary to avoid compromise in donor safety.

Successful percutaneous transluminal balloon dilatation for hepatic venous outflow obstruction after pediatric liver transplantation: A series of cases

AIM

Whether percutaneous transluminal balloon dilatation (PTBD) or stent placement should be used in children with hepatic venous outflow obstruction (HVOO) is still controversial. The aim of the present study was to retrospectively describe experience in diagnosis and treatment of HVOO and to evaluate the outcome of PTBD in HVOO patients after pediatric liver transplantation (P-LT).

METHODS

From January 2001 to January 2011, 54 children received P-LT at our center. The clinical features of children with HVOO analyzed included demography, type of donor and liver transplant, the new-onset symptoms, liver function test, interventional examination, and treatment and outcome.

RESULTS

Three children were treated successfully with PTBD without stenting. All patients received percutaneous interventional management successfully. In the total of eight episodes of PTBD across the stenosis, the mean pressure gradient ± standard deviation was 16.6 ± 7.90 mmHg before PTBD and 6.8 ± 2.27 mmHg after PTBD. The difference was significant (P < 0.05). All of the three HVOO patients were still surviving with primary graft functioning normally until the last follow up.

CONCLUSION

HVOO after P-LT should be taken seriously. PTBD is an effective and safe treatment for HVOO in younger patients subjected to P-LT and re-venoplasty is recommended even in patients with recurrent HVOO.

Which is the best technique for hepatic venous reconstruction in pediatric living-donor liver transplantation? Experience from a single center

BACKGROUND/PURPOSE

The introduction of the piggyback technique for reconstruction of the liver outflow in reduced-size liver transplants for pediatric patients has increased the incidence of hepatic venous outflow block (HVOB). Here, we proposed a new technique for hepatic venous reconstruction in pediatric living-donor liver transplantation.

METHODS

Three techniques were used: direct anastomosis of the orifice of the donor hepatic veins and the orifice of the recipient hepatic veins (group 1); triangular anastomosis after creating a wide triangular orifice in the recipient inferior vena cava at the confluence of all the hepatic veins (group 2); and a new technique, which is a wide longitudinal anastomosis performed at the anterior wall of the inferior vena cava (group 3).

RESULTS

In groups 1 and 2, the incidences of HVOB were 27.7% and 5.7%, respectively. In group 3, no patient presented HVOB (P = .001). No difference was noted between groups 2 and 3.

CONCLUSIONS

Hepatic venous reconstruction in pediatric living-donor liver transplantation must be preferentially performed by using a wide longitudinal incision at the anterior wall of the recipient inferior vena cava. As an alternative technique, triangulation of the recipient inferior vena cava, including the orifices of the 3 hepatic veins, may be used.

Hepatic venous outflow obstruction in pediatric living donor liver transplantation using left-sided lobe grafts: Kyoto University experience

The goals of this study were to evaluate the incidence of hepatic venous outflow obstruction (HVOO) in pediatric patients after living donor liver transplantation (LDLT) using left-sided lobe grafts and to assess the therapeutic modalities used for the treatment of this complication at a single center. Four hundred thirteen primary LDLT procedures were performed with left-sided lobe grafts between 1996 and 2006. All transplants identified with HVOO from a cohort of 380 grafts with survival greater than 90 days were evaluated with respect to the patient demographics, therapeutic intervention, recurrence, and outcome. Seventeen cases (4.5%) were identified with HVOO. Eight patients experienced recurrence after the initial balloon venoplasty. Two patients finally required stent placement after they experienced recurrence shortly after the initial balloon venoplasty. A univariate analysis revealed that a smaller recipient-to-donor body weight ratio and the use of reduced grafts were statistically significant risk factors. The cases with grafts with multiple hepatic veins had a higher incidence of HVOO. In conclusion, the necessity of repeated balloon venoplasty and stent placement was related to poor graft survival. Therefore, the prevention of HVOO should be a high priority in LDLT. When grafts with multiple hepatic veins and/or significant donor-recipient size mismatching are encountered, the use of a patch graft is recommended. Stent placement should be carefully considered because of the absence of data on the long-term patency of stents and stent-related complications. New stenting devices, such as drug-eluting and biodegradable stents, may be promising for the management of HVOO.

Incidence, impact, and treatment of portal and hepatic venous complications following pediatric liver transplantation: a single-center 12 year experience

PVT or PVS and HVOO are known causes of graft and patient loss after pediatric liver transplantation. Increased incidences of these complications have been reported in partial livers including DDSLT or LDLT. From 1997 to 2008, 241 consecutive pediatric patients received 271 hepatic grafts at a single center. Median follow-up is 1856 days. Surgical technique, demographics, lab values, and radiologic imaging procedures were obtained utilizing OTTR to evaluate the relationship of portal and hepatic complications with risk factors, patient and graft survival. Grafts were composed of 115/271 (42.4%) partial livers of which 90 (33.2%) were DDSLT and 25 (9.2%) LDLT. Of 271 patients, 156 (57.6%) received whole-sized grafts. There were six PVC in five patients with one patient requiring retransplantation (0.34%) and no patient deaths. Utilizing all three hepatic vein orifices on the recipient hepatic vena cava and the donor hepatic vein cut short enables a wide hepatic outflow tract unlikely to twist. None of the 241 patients developed early or late complications of the hepatic vein. None of the last 128 consecutive patients who received 144 grafts over seven and a half yr have developed either early or late complications of the hepatic or portal vein. Partial-graft actuarial survival was similar to whole-graft survival (87.2% vs. 85.3% at one yr; 76.6% vs. 80.2 at three yr; p = 0.488). Likewise, patient survival was similar between partial grafts and whole grafts (93.8% vs. 93.1% at one yr; 89.8% vs. 87.2% at three yr; p = 0.688) with median follow-up of 1822 (+/-1334) days. Patients receiving partial livers were significantly younger and smaller than patients receiving whole livers (p < 0.001). Portal and hepatic venous complications may have negative effects on patient or graft survival after pediatric liver transplantation. In our series, there was one graft and no patient loss related to portal or hepatic venous complications after pediatric liver transplantation over 12 yr.