Living donor liver transplantation with hyperreduced left lateral segments

Three-dimensional Liver Model Application for Liver Transplantation

BACKGROUND

Children are removed from the liver transplant waitlist because of death or progressive illness. Size mismatch accounts for 30% of organ refusal. This study aimed to demonstrate that 3-dimensional (3D) technology is a feasible and accurate adjunct to organ allocation and living donor selection process.

METHODS

This prospective multicenter study included pediatric liver transplant candidates and living donors from January 2020 to February 2023. Patient-specific, 3D-printed liver models were used for anatomic planning, real-time evaluation during organ procurement, and surgical navigation. The primary outcome was to determine model accuracy. The secondary outcome was to determine the impact of outcomes in living donor hepatectomy. Study groups were analyzed using propensity score matching with a retrospective cohort.

RESULTS

Twenty-eight recipients were included. The median percentage error was -0.6% for 3D models and had the highest correlation to the actual liver explant (Pearson's R = 0.96, P < 0.001) compared with other volume calculation methods. Patient and graft survival were comparable. From 41 living donors, the median percentage error of the allograft was 12.4%. The donor-matched study group had lower central line utilization (21.4% versus 75%, P = 0.045), shorter length of stay (4 versus 7 d, P = 0.003), and lower mean comprehensive complication index (3 versus 21, P = 0.014).

CONCLUSIONS

Three-dimensional volume is highly correlated with actual liver explant volume and may vary across different allografts for living donation. The addition of 3D-printed liver models during the transplant evaluation and organ procurement process is a feasible and safe adjunct to the perioperative decision-making process.

Advances in pediatric liver transplantation from the pediatric surgeon's perspective

Pediatric liver transplantation is a lifesaving state-of-the-art operation for children with various liver diseases, including cholestatic diseases, metabolic disorders, acute liver failure, and primary malignant liver tumors. Among these indications, transplantation for biliary atresia and hepatoblastoma is discussed in this review because pediatric surgeons are usually involved in their initial treatments. For biliary atresia, pediatric surgeons are advised to keep dissection of the hilar structures to a minimum during Kasai portoenterostomy in order to make total hepatectomy easier at transplantation. Early referral to a transplant team is recommended when worrisome signs of liver dysfunction, cirrhosis, portal hypertension and growth retardation are noted. Hepatoblastoma with multiplicity or located close to major vessels may indicate unresectability, and the transplant team needs to be consulted early after neoadjuvant chemotherapy is started. The graft size, including its thickness, needs to be evaluated before transplantation for small children, as tailoring the shape of the partial graft may be necessary during the transplant procedure.

Anterior hepatic resection: A simple and safe technique for reducing the antero-posterior diameter of the liver graft for small pediatric recipients

BACKGROUND

The techniques involved in neonatal and infantile transplantation require approaches that can sculpt a left lateral segment (LLS) to the right shape and size and avoid large-for-size syndrome. The aim of this article is to describe the anterior hepatic resection (AHR) of the LLS in pediatric LDLT.

METHODS

A retrospective anatomical study of preoperative image studies, description of the technique for AHR, and short-term results.

RESULTS

The AHR was performed in eight cases. All donors were male, with average age, BW, and BMI of 28.3 ± 5.9 years, 74.2 ± 9.3 kg, and 24.3 ± 2.6 kg/m2, respectively. Donors were discharged at an average of 3.6 ± 0.8 days. The median recipient age and BW at transplantation were 6.9 (2.7 to 11) months and 5.9 (3.9 to 8) kg, respectively, and the recipient-to-donor body weight ratio (RDBW) was <0.1 in all but one case. The mean percentage reduction in graft weight and in the antero-posterior diameter were 33.2% ± 5.5% and 38.3% ± 12.6%, respectively. The average (SD) GRWR was 4.8% ± 1.7% before all the resections and 3.5% ± 1.0% after the procedures. Seven patients were primarily closed.

CONCLUSION

After LLS resection, a nonanatomical anterior resection of the LLS was accomplished without hilar vascular dissection to segments II/III. The final liver graft allowed primary abdominal wall closure in all but one patient, with meaningful adjustments in GRWR. AHR proved to be simple, safe, reproducible, and effective in the presented case series.

Hyperreduced left lateral living donor liver transplant in a 4.5 kg child-A first in Africa

BACKGROUND

Supply-demand mismatch in solid organ transplantation is particularly pronounced in small children. For liver transplantation, advanced surgical techniques for reducing deceased and living donor grafts allow access to life-saving transplantation. Living donor left lateral segment liver grafts have been successfully transplanted in small children in our center since 2013, the only program providing this service in Sub-Saharan Africa. This type of partial graft remains too large for children below 6 kg body weight and generally requires reduction.

METHODS

A left lateral segment graft was reduced in situ from a directed, altruistic living donor to yield a hyperreduced left lateral segment graft.

RESULTS

The donor was discharged after 6 days without complications. The recipient suffered no technical surgical complications except for an infected cut-surface biloma and biliary anastomotic stricture and remains well 9 months post-transplant.

CONCLUSIONS

We report the first known case in Africa of a hyperreduced left lateral segment, ABO incompatible, living donor liver transplant in a 4,5 kg child with pediatric acute liver failure (PALF).

Understanding Local Hemodynamic Changes After Liver Transplant: Different Entities or Simply Different Sides to the Same Coin?

Liver transplantation is an extremely complex procedure performed in an extremely complex patient. With a successful technique and acceptable long-term survival, a new challenge arose: overcoming donor shortage. Thus, living donor liver transplant and other techniques were developed. Aiming for donor safety, many liver transplant units attempted to push the viable limits in terms of size, retrieving smaller and smaller grafts for adult recipients. With these smaller grafts came numerous problems, concepts, and definitions. The spotlight is now aimed at the mirage of hemodynamic changes derived from the recipients prior alterations. This article focuses on the numerous hemodynamic syndromes, their definitions, causes, and management and interconnection with each other. The aim is to aid the physician in their recognition and treatment to improve liver transplantation success.

Large for size in pediatrics liver transplant using left lateral segment grafts: A single center experience

BACKGROUND

There are still controversies in using the large left lateral segment in pediatrics LT, with the possibility of the problem of LFS grafts, and the use of monosegmental or reduced liver grafts in small infants. This study aimed to evaluate our experience with LFSG in pediatrics LT.

METHODS

A cohort retrospective analysis was conducted including pediatric recipients who underwent LT between January 2011 and October 2019. We compared recipients with GRWR ≥ 4% (LFS) vs GRWR < 4% as an average for size grafts.

RESULTS

There were 331 pediatric LT, 74 patients with GRWR ≥ 4%, and 257 patients with GRWR < 4%. In the group of LFS grafts, temporary abdominal closure by silicon patch was done in 39 patients (52.7%), 2 patients (2.7%) had postoperative HAT, 3 patients (4.1%) early PVT, 1 patient (1.3%) bile leak, and 3 patients (4.1%) had wound infection, with no significant difference in these complications between the 2 groups. In patients with LFS- grafts, the 1-, 3-, 5-, and 7-year patients survival rates were 94.6%, 91.7%, 91.7%, and 91.7%, respectively, while the survival rates in patients of the other group were 96.1%, 92.6%, 91.9%, and 91.9%, respectively, with no significant difference (p = .85).

CONCLUSION

Using LFS graft by left lateral segment in pediatric LT with potential delayed abdominal closure is a safe and feasible option with good outcomes and unnecessary need for graft reduction if performed by an experienced multidisciplinary team.

Pediatric deceased donor liver transplantation with in situ size reduction for recipient-graft size matching

We present a case of pediatric deceased donor liver transplantation using a reduced whole liver graft in a 25-month-old boy weighing 12.7 kg. After he had undergone Kasai portoenterostomy for biliary atresia, his general condition deteriorated progressively. He was enrolled on the waiting list for liver transplantation with Pediatric End-stage Liver Disease score of 15. The donor was a 51-monthold boy with body weight of 20 kg. The donor-to-recipient body weight ratio was 158%. The liver graft appeared to be larger than the recipient's abdominal cavity. Thus, we planned to do in situ size reduction. Recipient surgery was performed following standard procedures. We performed graft outflow vein reconstruction using a modified piggyback technique like the double inferior vena cava method. Since the portal vein was hypoplastic, a side-to-side anastomosis technique was used. We also performed intraoperative portogram to embolize venous collaterals. After completing the graft implantation, we found that the liver graft was too large to be accommodated within the abdomen. After in situ resection of the left lateral section parenchyma, we successfully performed primary closure of the abdominal wound. This patient experienced episodes of acute rejection. He has been doing well for four years after the transplantation.

3D-reconstruction and heterotopic implantation of reduced size monosegment or left lateral segment grafts in small infants: A new technique in pediatric living donor liver transplantation to overcome large-for-size syndrome

BACKGROUND

Monosegmental grafts and reduced left lateral segment grafts have been introduced to overcome the problems of large-for-size grafts in pediatric living donor liver transplantation. Here, we introduce a new method of reduced size monosegment or left lateral segment grafts transplanted in the right diaphragmatic fossa heterotopically in small infants.

METHODS

There were 4 infants who underwent living donor liver transplantation with heterotopically implanted reduced monosegmental or left lateral segment grafts at our center. The demographic, operative, postoperative, and follow-up data of these infants were collected from our prospectively designed database and reviewed. Technical details of the donor and recipient operation are shared and a supplemental provided.

RESULTS

The mean recipient age was 7.5 ± 0.9 months (range: 5-10 months), and body weight was 5.9 ± 0.7 kg (range: 4.6-7.8). Primary diagnoses of the recipients were biliary atresia (n:3) and progressive familial intrahepatic cholestasis (n:1). Mean graft-recipient weight ratio was 3.3 ± 0.2. Reduced monosegment III grafts were used in 2 cases, and reduced left lateral segment grafts were used in the other 2 patients. Bile duct reconstruction was done by Roux-en-Y hepaticojejunostomy in 3 patients and duct-to-duct anastomosis in the remaining patient. All patients recovered from the liver transplantation operation and are doing well at a mean follow-up of 8 months.

CONCLUSION

Living donor liver transplantation with heterotopically implanted reduced monosegmental or left lateral segment seems feasible for the treatment of neonates and extremely small infants. Further accumulation of cases and long-term follow-up are necessary to collect data for the establishment of this treatment modality.

Monosegment Liver Allografts for Liver Transplantation in Infants Weighing Less Than 6 kg: An Initial Indian Experience

BACKGROUND

Living donor liver transplantation in small infants is a significant challenge. Liver allografts from adults may be large in size. This is accompanied by problems of graft perfusion, dysfunction, and the inability to achieve primary closure of the abdomen. Monosegment grafts are a way to address these issues.

METHODS

Two recipients in our cohort weighed less then 6 kg. The prospective left lateral segments from their donors were large for size. Therefore, monosegment 2 liver grafts were harvested. Data regarding the preoperative, intraoperative, and postoperative events in the donor and the recipient were recorded.

RESULTS

We were able to achieve significant reduction in the sizes of the grafts harvested. The donors underwent surgery and hospital stay uneventfully. The recipients had normal graft perfusion and no graft dysfunction, and we could achieve primary abdominal closure. One recipient had self-limiting bile leak postoperatively.

CONCLUSIONS

Monosegment 2 liver allografts are safe and effective for use in living donor liver transplantation in small infants weighing less than 6 kg.

Technical Choices in Pediatric Living Donor Liver Transplantation: The Path to Reduce Vascular Complications and Improve Survival

Pediatric living donor liver transplantation (PLDLT) is a successful therapeutic option for children with chronic and acute liver disease. After early transplant results, many technical advancements were introduced in the field to reduce the rate of complications and improve survival. The aim of this study is to present the outcomes of 975 primary PLDLTs in 3 periods: initial practice (period 1, 29 patients, January 1995 to December 1999), second period (period 2, 331 patients, January 2000 to December 2009), and third period (period 3 [P3], 615 patients, January 2010 to September 2019). Among the technical refinements introduced in P3 are the use of hyperreduced left lateral segment grafts, abdominal wall prosthetic mesh closure, double hepatic artery anastomosis, and increased use of vascular grafts for portal vein reconstruction. The outcomes included significant reductions of hepatic artery thrombosis (HAT), early portal vein thrombosis (EPVT), and retransplantation, with better patient and graft survival in P3. Additional analyses showed that the factors independently associated with worse 90-day patient survival were HAT, EPVT, and increasing Pediatric End-Stage Liver Disease score. In conclusion, the introduction of technical refinements in P3, in addition to improvements in patient care, determined a reduction in EPVT, HAT, and retransplantation. Consequently, patient and graft survival rates increased in all time points studied.

Pediatric liver transplantation with hyperreduced left lateral segment graft

Backgrounds/Aims

To prevent large-for-size graft-related complications in small infant patients, the size of a left lateral segment (LLS) graft can be reduced to be a hyperreduced LLS (HRLLS) graft.

Methods

This study was intended to describe the detailed techniques for harvesting and implanting HRLLS grafts developed in a high-volume liver transplantation (LT) center.

Results

The mean recipient age was 4.0±1.7 months (range: 3-6) and body weight was 5.3±1.4 kg (range: 4.1-6.9). Primary diagnoses of the recipients were progressive familial intrahepatic cholestasis in 2 and biliary atresia in 1. The types of LT were living donor LT in 1 and split deceased donor LT in 2. Non-anatomical size reduction was performed to the transected LLS grafts. The mean weight of the HRLLS grafts was 191.7±62.1 g (range: 120-230) and graft-recipient weight ratio was 3.75±1.57% (range: 2.45-5.49). Widening venoplasty was applied to the graft left hepatic vein outflow orifice. Vein homograft interposition was used in a case with portal vein hypoplasia. Types of the abdomen wound closure were one case of primary repair, one of two-staged closure with a mesh, and one of three-staged repair with a silo and a mesh. All three patients recovered uneventfully from the LT operation and are doing well to date for more than 6 years after transplantation.

Conclusions

Making a HRLLS graft through non-anatomical resection during living donor LT and split deceased donor LT can be a useful option for treating small infant patients.

Pediatric split liver transplantation using a hyperreduced left lateral segment graft in an infant weighing 4 kg

We present a case of successful split liver transplantation (LT) using a hyperreduced left lateral segment (LLS) graft in a 106-day-old female infant patient weighing 4 kg. The patient was diagnosed with progressive familial intrahepatic cholestasis. Her general condition and liver function deteriorated progressively and she was finally allocated for a split LT under status 1. The deceased donor was a 20-year-old female weighing 63.7 kg. We performed in situ liver splitting and in situ size reduction sequentially. The weight of the hyperreduced LLS graft was 225 g, with a graft-recipient weight ratio of 5.5%. We performed recipient hepatectomy and graft implantation according to the standard procedures for pediatric living-donor LT. Since the graft was too large for primary abdomen closure, the abdominal wall was closed in three stages to make a prosthetic silo, temporary closure with a xenograft sheet, and final primary repair over 2 weeks. The patient has been doing well for more than 6 years after transplantation. In conclusion, split LT using a hyperreduced LLS graft can be a useful option for treating small infants. However, large-for-size graft-related problems, particularly in terms of graft thickness, still remain to be solved.

Living Donor Liver Transplantation in Children: Perioperative Risk Factors and a Nomogram for Prediction of Survival

BACKGROUND

Living donor liver transplantation (LDLT) in children has achieved promising outcomes during the past few decades. However, it still poses various challenges. This study aimed to analyze perioperative risk factors for postoperative death in pediatric LDLT.

METHODS

We retrospectively analyzed medical records of pediatric patients who underwent LDLT surgery from January 1, 2014, to December 31, 2016, in our hospital. Predictors of mortality following LDLT were analyzed in 430 children. Cox regression and Kaplan-Meier curve analysis were used for covariates selection. A nomogram was developed to estimate overall survival probability. The performance of the nomogram was assessed using calibration curve, decision curve analysis, and time-dependent receiver operating characteristic curve.

RESULTS

Among the 430 patients in this cohort (median [interquartile range] age, 7 [6.10] mo; 189 [43.9%] female; 391 [90.9%] biliary atresia), the overall survival was 91.4% (95% confidence interval, 89.2-94.4), and most of the death events (36/37) happened within 6 months after the surgery. Multivariate analysis indicated that the Pediatric End-stage Liver Disease score, neutrophil lymphocyte ratio, graft-to-recipient weight ratio, and intraoperative norepinephrine infusion were independent prognostic factors. A novel nomogram was developed based on these prognostic factors. The C index for the final model was 0.764 (95% confidence interval, 0.701-0.819). Decision curve analysis and time-dependent receiver operating characteristic curve suggested that this novel nomogram performed well at predicting mortality of pediatric LDLT.

CONCLUSIONS

We identified several perioperative risk factors for mortality of pediatric LDLT. And the newly developed nomogram can be a convenient individualized tool in estimating the prognosis of pediatric LDLT.

Short- and Long-Term Outcomes After Live-Donor Transplantation with Hyper-Reduced Liver Grafts in Low-Weight Pediatric Recipients

OBJECTIVE

To evaluate short- and long-term outcomes after live-donor liver transplantation (LT) with hyper-reduced grafts in low-weight pediatric recipients. LT is an established curative therapy for children with end-stage chronic liver disease or acute liver failure. A major problem in pediatric LT has been the lack of size-matched donor organs. The disadvantage of the use of large-for-size grafts is the insufficient tissue oxygenation and graft compression, which result in poor outcomes. The shortage of suitable donors is most notable in children under 10 kg. To overcome such obstacle, in situ hyper-reduced live-donor liver grafts have been introduced. Available articles in the literature are based on small samples and are deficient in long-term follow-up.

METHODS

A single-cohort, retrospective analysis was conducted including 59 pediatric patients under 10 kg who underwent hyper-reduced (in situ "a la carte" left lateral segment reduction) live-donor LT (LDLT) between February 1994 and February 2018.

RESULTS

The most frequent cause of liver failure was biliary atresia (70%). Median recipient weight was 8 kg. Vascular complications were confirmed in 15% of the sample, while 45% presented biliary complications. Median follow-up time was 40.3 months. Ten-year overall survival rate was 74%. Pediatric end-stage liver disease score > 23 was associated with a higher risk of post-operative complications.

CONCLUSION

LDLT can be undertaken in children with body weight < 10 kg achieving good results in high-volume centers by experienced surgeons.

Impact of graft thickness reduction of left lateral segment on outcomes following pediatric living donor liver transplantation

Reducing graft thickness is essential to prevent large-for-size graft problems in pediatric living donor liver transplantation (LDLT). However, long-term outcomes of LDLT using reduced-thickness left lateral segment (LLS) grafts are unclear. In 89 patients who underwent LDLT using reduced LLS grafts between 2005 and 2017, short-term and long-term outcomes were compared between a nonanatomically reduced LLS (NAR-LLS) graft group and a reduced-thickness LLS graft group. Estimated blood loss was lower and abdominal skin closure was less needed in the recipient operation in the reduced-thickness LLS graft group. Postoperatively, portal vein (PV) flow was significantly decreased in the NAR-LLS graft group, and there was shorter intensive care unit (ICU) stay and fewer postoperative complications, especially bacteremia, in the reduced-thickness LLS graft group. Graft survival at 1 and 3 years after LDLT using reduced-thickness LLS grafts was 95.2% and 92.4%, respectively, which was significantly better than for NAR-LLS grafts. Multivariate analysis revealed that fulminant liver failure, hepatofugal PV flow before LDLT, and NAR-LLS graft were associated with poor graft survival. In conclusion, LDLT using reduced-thickness LLS grafts is a safe and feasible option with better short- and long-term outcomes in comparison with NAR-LLS grafts.

Present State and Future Prospects of Pediatric Liver Transplantations

Regarding liver transplantations in Japan, with no progress having been made in deceased donor liver transplantations, a living donor liver transplantation performed on a boy with end-stage liver cirrhosis caused by biliary atresia by Nagasue et al. at Shimane University in November 1989 was the first case of its kind. Unlike deceased donor liver transplantations, living donor liver transplantations have two major advantages. First, because organs are donated from healthy adults, it is possible to transplant organs with better viability compared to deceased donor organs, which have been preserved in cold storage for a long time. Second, depending on the recipient’s condition, it is possible to conduct elective surgery at the optimal time. In Japan, the number of annual liver transplantation cases is approximately 400, with the number of annual pediatric liver transplantation cases stable at approximately 120 cases. The patient survival rate of pediatric liver transplantation cases is relatively good at 89.4% over the course of 1 year, 86.8% over 5 years, 84.4% over 10 years, and 80.9% over 20 years.

The liver transplantation program was initiated at the National Center for Child Health and Development, Tokyo, Japan, in November 2005, providing liver transplantation treatment to 510 pediatric patients with end-stage liver disease to date. This article outlines the history of liver transplantations in Japan along with the present state of liver transplantations at the National Center for Child Health and Development.

Graft reduction using a powered stapler in pediatric living donor liver transplantation

Large-for-size syndrome is defined by inadequate tissue oxygenation, which results in vascular complications and graft compression after abdominal closure in living donor liver transplantation recipients. An accurate graft reduction that matches the optimal liver volume for the recipient is essential. We herein initially present the feasibility and safety of graft reduction using a powered stapler to obtain an optimal graft size. From October 1996 to October 2015, a total of eight graft reductions were performed using a powered stapler (group A; n=4) or by the conventional method using a cavitron ultrasonic surgical aspirator and portal triad suturing (group B; n=4). The background, intraoperative findings and the post-operative outcomes of these eight patients were retrospectively investigated. There were no statistically significant differences in the background of the patients in the two groups. Graft reduction was successfully achieved without any intraoperative complications in group A, whereas intraoperative complications, such as bleeding and bile leakage, occurred in two patients of group B. No post-operative surgical complications were detected on computed tomography; moreover, the serum aspartate aminotransferase level normalized significantly earlier in group A (P<.05). In summary, graft reduction using a powered stapler was feasible and safe in comparison with the conventional method.

Does a meso-caval shunt have positive effects in a pig large-for-size liver transplantation model?

In pediatric liver transplantations with LFS grafts, higher incidences of graft dysfunction probably occur due to IRI. It was postulated that increasing the blood supply to the graft by means of a meso-caval shunt could ameliorate the IRI. Eleven pigs underwent liver transplantation and were divided into two groups: LFS and LFS+SHUNT group. A series of flowmetric, metabolic, histologic, and molecular studies were performed. No significant metabolic differences were observed between the groups. One hour after reperfusion, portal flow was significantly lower in the recipients than in the donors, proving that the graft was maintained in low portal blood flow, although the shunt could promote a transient increase in the portal blood flow and a decrease in the arterial flow. Finally, it was verified that the shunt promoted a decrease in inflammation and steatosis scores and a decrease in the expression of the eNOS gene (responsible for the generation of nitric oxide in the vascular endothelium) and an increase in the expression of the proapoptotic gene BAX. The meso-caval shunt was responsible for some positive effects, although other deleterious flowmetric and molecular alterations also occurred.

Pediatric living-donor liver transplantation

Living-donor liver transplantation is an important component of all liver transplant programs especially in those that care for the pediatric population. Over the last 30 years, innovations in surgical technique have converted living donation from an experimental procedure to a standard of care. Many of these innovations occurred in countries where culturally, deceased donation is limited leaving no alternatives but living donation. The Organ Transplantation Center at the National Center for Child Health and Development (NCCHD) in Tokyo, Japan, was established in 2005 where we have generated some of those innovations and in so doing, have performed living-donor liver transplantation in over 400 children. Here we review the indications, technical details, and outcomes of that cohort.

Recent Trends in the Diagnosis and Management of Biliary Atresia in Developing Countries

NEED AND PURPOSE OF REVIEW

Biliary atresia is a progressive obstructive cholangiopathy and is fatal if left untreated within 2 years of life. Delay in referral is because of difficulties in differentiating it from physiologic jaundice and identifying an abnormal stool color. This paper presents an overview on the diagnosis and discusses the current strategies in the management of this disease in developing countries.

METHODS

Articles were retrieved from the PubMed database using the terms biliary atresia, Kasai portoenterostomy and pediatric liver transplantation. Contents of the article are also based on personal experience of the authors.

CONCLUSION

A national screening program using stool color cards as part of standard care in the neonatal period will greatly improve early detection of biliary atresia. Outcomes will improve if it is diagnosed at the earliest after birth, the child is referred to an experienced pediatric hepatobiliary unit for evaluation, and undergoes an early Kasai procedure. If an early Kasai portoenterostomy is performed, nearly half of all children survive into adolescence, and about one-third are likely to have a long-term, symptom-free life with normal liver biochemistry. Sequential treatment combining Kasai as first line and liver transplantation as second line results in 90% survival for children with biliary atresia.

Roux-en-Y hepatico-jejunostomy for a left segmental graft: Do not twist the loop, stick it!

Biliary complications remain a major challenge for long-term success after LT, as it is, as a rule, the most common technical - early and late - complication that occurs, and because these complications contribute to a significant number of late graft losses and retransplantations. In the pediatric age group, both biliary atresia, as the patient's condition, and the use of a left liver graft, obtained by a liver division technique, make it necessary for the use of a Roux-en-Y jejunal loop for the biliary reconstruction in the majority of cases. A slight modification of the technique is presented, consisting of a straight positioning along the cut surface (rather than the conventional position that results in a harpoon shape). A favorable outcome in terms of a technical complication and graft survival was observed. This way of doing this is an interesting variation and adds to the surgical armamentarium.

Selection of living donor liver grafts for patients weighing 6kg or less

In the field of pediatric living donor liver transplantation (LDLT), physicians sometimes must reduce the volume of left lateral segment (LLS) grafts to prevent large-for-size syndrome. There are 2 established methods for decreasing the size of an LLS graft: the use of a segment 2 (S2) monosegment graft and the use of a reduced LLS graft. However, no procedure for selecting the proper graft type has been established. In this study, we conducted a retrospective investigation of LDLT and examined the strategy of graft selection for patients weighing ≤6 kg. LDLT was conducted 225 times between May 2001 and December 2012, and 15 of the procedures were performed in patients weighing ≤6 kg. We selected S2 monosegment grafts and reduced LLS grafts if the preoperative computed tomography (CT)-volumetry value of the LLS graft was >5% and 4% to 5% of the graft/recipient weight ratio, respectively. We used LLS grafts in 7 recipients, S2 monosegment grafts in 4 recipients, reduced S2 monosegment grafts in 3 recipients, and a reduced LLS graft in 1 recipient. The reduction rate of S2 monosegment grafts for use as LLS grafts was 48.3%. The overall recipient and graft survival rates were both 93.3%, and 1 patient died of a brain hemorrhage. Major surgical complications included hepatic artery thrombosis in 2 recipients, bilioenteric anastomotic strictures in 2 recipients, and portal vein thrombosis in 1 recipient. In conclusion, our graft selection strategy based on preoperative CT-volumetry is highly useful in patients weighing ≤6 kg. S2 monosegment grafts are effective and safe in very small infants particularly neonates.

Effect of graft size matching on pediatric living-donor liver transplantation in Japan

OBJECTIVES

The Japanese Liver Transplantation Society is a cooperative research consortium, established in 1980 to characterize and follow trends in patient and graft survival in all liver transplants in Japan. This study evaluated the effect of graft size matching on survival in pediatric recipients of living donor liver transplant.

MATERIALS AND METHODS

Between November 1989 and December 2010, there were 2224 patients aged < 18 years who received living-donor liver transplant in Japan. Survival was evaluated according to graft size matching.

RESULTS

There were 998 male and 1226 female donors (median age, 35.2 y). There was no donor mortality associated with surgery. The median age of recipients was 4.0 years (range, 13 d to 17.9 y) and body weight was 16.6 kg (range, 2.6 to 90 kg). The survival of living-donor liver transplant recipients was greater for pediatric than adult recipients at 1 year (adult, 81%; pediatric, 88%), 5 years (adult, 72%; pediatric, 85%), 10 years (adult, 66%; pediatric, 83%), and 15 years (adult, 57%; pediatric, 80%) after transplant (difference between adult and pediatric recipients: P ≤ .0001). In the 2224 recipients aged < 18 years, the graft types included left lateral segment in 1549 recipients (70%), left lobe in 500 recipients (23%), reduced left lateral segment in 96 recipients (4%), right lobe in 76 recipients (3%), and posterior segment in 3 recipients (0.1%). There was no significant difference in survival between recipients that had different graft types. However, recipients aged < 1 year (296 recipients) who received grafts with graft-to-recipient body weight ratio > 4.0% had significantly worse patient survival because of problems associated with large-for-size grafts.

CONCLUSIONS

Living-donor liver transplant had greater survival in children than adult recipients. Graft-to-recipient body weight ratio was a significant prognostic factor in recipients aged < 1 year.

Segment 4 architecture and proposed parenchyma-wise technique for Ex vivo graft procurement and implantation

A parenchyma-wise technique for the ex vivo procurement of segment 4 (S4) grafts, based on the detailed architecture of the segment, is proposed. Eighteen normal, fresh livers from adult cadavers were injected differentially with colored latex; dissection casts were prepared; and the intricate architecture of S4 was studied. The portal vein elements of the sheath forming most of the inferior part of S4 (S4b) and the superficial major fraction of its superior part (S4a) arose constantly from the medial aspect of the umbilical part of the left portal vein branch. The arterial elements arose constantly from a branch, whose diameter ranged from 2.00 to 3.35 mm (mean = 2.61 ± 0.54 mm) and whose length ranged from 15.15 to 45.65 mm (mean = 27.98 ± 12.13 mm). The biliary elements coalesced as a single duct at the corner, which was formed from the umbilical and transverse parts of the left portal vein branch; the duct's diameter ranged from 2.90 to 6.85 mm (mean = 3.90 ± 1.34 mm). Theoretically, this parenchymal mass-S4b and the superficial fraction of S4a-could be procured for implantation in an infant, and the rest of the liver could be split for an adult and a child. The portal vein branches of the graft would be procured with a patch from the medial aspect of the donor's umbilical portion of the left portal vein branch. This umbilical portion would be reconstructed with a patch from the donor's round ligament. The recipient's portal vein would be reconstructed through the fashioning of a conduit anastomosed with the graft's venous patch.

Long-term outcomes of pediatric living donor liver transplantation in Japan: an analysis of more than 2200 cases listed in the registry of the Japanese Liver Transplantation Society

The Japanese Liver Transplantation Society (JLTS) was established in 1980 in order to characterize and follow trends in patient characteristics and graft survival among all liver transplant patients in Japan. This study analyzed the comprehensive factors that may influence the outcomes of pediatric patients who undergo living donor liver transplantation (LDLT) by evaluating the largest cohort in the world. Between November 1989 and December 2010, 2224 pediatric patients underwent LDLT in Japan. There were 998 male (44.9%) and 1226 female donors (55.1%) without donor mortalities related to transplant surgery. There were 946 male (42.5%) and 1278 female (57.5%) recipients with a median age of 4.0 years (range: 13 days to 17.9 years). Cholestatic liver disease was the leading indication for LDLT (n = 1649; 76.2%), followed by metabolic disorders (n = 194; 8.7%), acute liver failure (n = 192; 8.6%) and neoplastic liver disease (n = 66; 3.0%). The 1-, 5-, 10- and 20-year patient survival rates were 88.3%, 85.4%, 82.8% and 79.6%, respectively. Blood-type incompatibility, recipient age, etiology of liver disease and transplant era were found to be significant predictors of overall survival. We are able to achieve satisfactory long-term pediatric patient survival outcomes in the JLTS series without compromising the living donors.

Transgenic pig expressing the red fluorescent protein kusabira-orange as a novel tool for preclinical studies on hepatocyte transplantation

INTRODUCTION

Research on hepatocyte transplantation as an alternative or supplementary treatment for liver transplantation is progressing. However, to advance to clinical trials, confidence in the technique must be established and its safety must be validated by conducting experiments using animals of comparable sizes to humans, such as pigs. We used transgenic pigs expressing red fluorescence protein for investigating the distribution and survival of transplanted cells.

MATERIALS AND METHODS

Donor hepatocytes were isolated from transgenic Kusabira-Orange (KO)-expressing pigs (age, 41 days; weight, 10 kg) created by in vitro fertilization using sperm from a transgenic-cloned KO pig by Matsunari et al. and ova from a domestic pig. The hepatocyte transplant recipients were the nontransgenic, KO-negative littermates. In these recipient pigs, double lumen cannulae were inserted into the supramesenteric veins to access the hepatic portal region. KO-positive donor hepatocytes from the transgenic male pig were isolated using collagenase perfusion. Hepatocytes (1 × 10(9) cells) were transplanted through the cannula. For estimating allogeneic immunogenicity, full-thickness skin (3 × 3 cm) from the same donor was grafted orthotopically on the neck region of the recipients. Immunosuppressive treatment was not implemented. The recipient pigs were humanely killed at 7 and 39 days after transplantation, and the organs were harvested, including the lungs, heart, liver, pancreas, and kidneys.

RESULTS

Strong red fluorescence was detected in both the parenchymal and nonparenchymal hepatocytes of the transgenic male donor pig by fluorescent microscopy. Transplanted cells were detected in the liver and lung of the recipient pigs at 7 days after perfusion. Hepatocytes remained in the liver and lung of recipients on day 39, with lower numbers than that on day 7.

CONCLUSION

Transgenic pigs expressing the fluorescent protein KO serve as a useful model of cell transplantation in preclinical studies.

Living-donor liver transplantation with hyperreduced left lateral segment grafts: a single-center experience

BACKGROUND

In the setting of liver transplantation in small infants who receive left lateral segment (LLS) grafts, problems are encountered related to graft-size mismatching in the form of so-called "large-for-size" grafts. To address these problems, the feasibility of further reducing the size of LLS grafts to form hyperreduced LLS (HRLLS) grafts was investigated.

METHODS

Of the 175 pediatric living-donor liver transplantations performed between November 2005 and December 2011 at our institute, 31 cases were performed using HRLLS grafts. The medical records were reviewed and data were collected retrospectively.

RESULTS

The graft-to-recipient body weight ratio was successfully reduced from 5.2% ± 2.0% to 2.9% ± 0.5%. Portal vein thrombosis was observed in one case, and biliary stenosis was seen in two cases. No hepatic artery thrombosis was encountered. The graft and patient 2-year survival rate was 87%. When the results categorized according to the original disease were verified, patients with fulminant hepatic failure (FHF) weighed less and had smaller abdominal cavities compared with patients with cholestatic or metabolic disease. Patients with FHF frequently required skin or partial skin closure to avoid graft compression. For this reason, the anteroposterior diameters in the recipients' abdominal cavities were not adequately large to accommodate the graft thickness, especially in patients with FHF.

CONCLUSIONS

In conclusion, living-donor liver transplantation using HRLLS grafts offers a safe and useful option for treating smaller infants.

Reducing the thickness of left lateral segment grafts in neonatal living donor liver transplantation

Liver transplantation is now an established treatment for children with end-stage liver disease. Left lateral segment (LLS) grafts are most commonly used in split and living donor liver transplantation in children. In very small children, LLS grafts can be too large, and further nonanatomical reduction has recently been introduced to mitigate the problem of large-for-size grafts. However, the implantation of LLS grafts can be a problem in infants and very small children because of the thickness of the grafts, and these techniques do not address problems related to thickness. We herein describe a technique for reducing the thickness of living donor left lateral grafts and successful transplantation in a 2.8-kg infant with acute liver failure.

Liver graft volumetric changes after living donor liver transplantation with segment 2 graft for small infants

LT for small infants weighing <5 kg with liver failure might require innovative techniques for size reduction and transplantation of small grafts to avoid large-for-size graft, but little is known about post-transplant graft volumetric changes. Five of 172 children who underwent LDLT received monosegment or reduced monosegment grafts using a modified Couinaud's segment II (S2) graft for LDLT. Serial CT was used to evaluate the changes in the GV and other factors before LDLT and one and three months after LDLT. The shape of these grafts was classified into an OL type and an LL type. The GV increased in all patients one month after LDLT, whereas the GV decreased three months after LDLT in OL in comparison with one month after LDLT. The GRWR of the OL type has tended to decrease at three months, whereas the LL type showed a continuous increase with time, but finally they had adapted graft size for their body size. In conclusion, the volume of S2 grafts after LDLT had unique changes toward the ideal volume for the child weight when they received the appropriate liver volume.

A formula for determining the standard liver volume in children: a special reference for neonates and infants

Accurately evaluating the ratio of GV to the SLV (GV/SLV) is important in successful pediatric liver transplantation. However, the formula used to calculate the SLV of children, including neonates and infants, has not yet been established. The aim of the current study was to estimate the SLV of children, including neonates, and to establish an accurate formula. The LV of 100 children (including 7 neonates and 15 infants) were measured using thin slice (3-5 mm) helical CT images. Their BSA was calculated from height and weight. A new formula to estimate the SLV was established as follows: SLV (mL) =689.9 × BSA (m(2)) -24.7. The SLV of children was significantly lower than that in previous reports (p < 0.001). A formula for calculating the SLV of children including neonates was established. This new formula will be useful in pediatric liver transplantation.

Portal vein reconstruction in pediatric living donor liver transplantation for patients younger than 1 year with biliary atresia

BACKGROUND/PURPOSE

Infants with biliary atresia undergoing living donor liver transplantation (LDLT) are at increased risk of portal vein (PV) complications because of their smaller vascular caliber and sclerosis because of previous Kasai portoenterostomy and recurrent cholangitis.

METHOD

Of 154 children who underwent transplantation between November 2005 and January 2011, 34 with biliary atresia received a transplant while younger than 1 year. Six patients underwent PV reconstruction with an interposition vein graft, and the others underwent the branch patch technique. The clinical characteristics of those who underwent the interposition reconstruction or the branch patch technique were compared, and the PV complications were assessed.

RESULTS

Portal vein complications occurred in 5 patients (14.7%) in the branch patch group. There were 4 patient deaths, and all of them had received branch patch reconstruction. The branch patch reconstruction cases with a sclerotic small caliber (<4 mm) determined by using preoperative ultrasonography showed a significantly high mortality rate (44.4%). All patients with interposition vein graft reconstruction are still alive with excellent graft function without anticoagulation therapy.

CONCLUSION

The interposition vein graft appears to be a feasible option with better graft survival and less PV complications when performing LDLT for biliary atresia in infants younger than 1.

Hepatobiliary scintigraphy for the assessment of biliary stricture after pediatric living donor liver transplantation for hepaticojejunostomy reconstruction: the value of the excretion rate at 60 min

HBS is performed to determine the presence of biliary stricture after liver transplantation. We focused on the Ex-60 after an intravenous injection of tracer during HBS. The aim of this study was to review the cutoff values for the diagnosis of biliary stricture by HBS after pediatric LDLT. We analyzed 114 HBS studies using (99m) Tc-PMT in 80 cases after pediatric LDLT. HBS was performed three months after LDLT on a routine basis and/or was performed when ultrasonography and blood test findings indicated biliary stricture. A ROC curve analysis was performed to identify the cutoff value for the correlation between Ex-60 and biliary stricture. The Ex-60 (mean ± s.d.) in the cases diagnosed as having biliary stricture and in normal subjects were 49.1 ± 20.2% vs. 78.0 ± 9.7% (p < 0.01), respectively. As a result of an ROC curve analysis of the Ex-60, the recommended cutoff value to diagnose biliary stricture was set at 69.2% (sensitivity 87.0%, specificity 81.8%). In cases where the Ex-60 by (99m) Tc-PMT HBS is <69.2%, it is recommended that further treatment for biliary stricture should be provided.

Implications for the usage of the left lateral liver graft for infants ≤10 kg, irrespective of a large-for-size situation--are monosegmental grafts redundant?

Organ donor shortage for infant liver transplant recipients has lead to an increase in splitting and living donation. For cases in which even transplantation of the left lateral graft (Couinaud's segments II + III) results in a "large for size situation" with an estimated graft body weight ratio (GBWR) of >4%, monosegmental liver transplantation was developed. This, however, bears complications because of greater parenchymal surface and suboptimal vascular flow. We exclusively use the left lateral graft from living donors or split grafts. Temporary abdominal closure is attempted in cases of increased pressure. We report of 41 pediatric transplants in 38 children ≤10 kg. Within this group, there were 23 cases with a GBWR of ≥4, and 15 cases with a GBWR <4. There was no statistical difference in vascular or biliary complications. Despite a more frequent rate of temporary abdominal closure, we did not find a higher rate of intra-abdominal infections. Overall, patient and graft survival was excellent in both groups (one death, three re-transplants). We noticed, however, that the ventro-dorsal diameter of the graft appears to be more relevant to potential graft necrosis than the actual graft size. In conclusion, the usage of monosegmental grafts seems unnecessary if transplantation of left lateral grafts is performed by an experienced multidisciplinary team, and temporary abdominal closure is favored in cases of increased abdominal pressure.

Living-donor liver transplantation for carbamoyl phosphate synthetase 1 deficiency

CPS1 is a mitochondrial matrix enzyme that catalyzes the first committed step of the urea cycle, the primary system for removing nitrogen produced by protein metabolism using N-acetylglutamate. Patients with CPS1 deficiency have severe hyperammonemia that results in serious neurologic sequelae and sometimes death. LT has been indicated for neonatal-onset CPS1 deficiency. This study retrospectively reviewed five children with a diagnosis of CPS1 deficiency who underwent LDLT from heterozygous donors. Between November 2005 and May 2010, 124 children underwent LDLT with an overall patient and graft survival of 91.0%. Five patients were indicated for LDLT because of CPS1 deficiency. All recipients achieved resolution of their metabolic derangement, without donor complication, with a normal feeding regimen without medication for their original metabolic liver disease. LDLT, even from heterozygous donors, appears to be a feasible option, associated with a better quality of life for treating patients with CPS1 deficiency. Long-term observation may therefore be necessary to collect sufficient data to confirm the efficacy of this treatment modality.

Living donor liver transplantation for neonates using segment 2 monosubsegment graft

The prognosis of liver transplantation for neonates with fulminant hepatic failure (FHF) continues to be extremely poor, especially in patients whose body weight is less than 3 kg. To address this problem, we have developed a safe living donor liver transplantation (LDLT) modality for neonates. We performed LDLTs with segment 2 monosubsegment (S2) grafts for three neonatal FHF. The recipient age and body weight at LDLT were 13-27 days, 2.59-2.84 kg, respectively. S2 or reduced S2 grafts (93-98 g) obtained from their fathers were implanted using temporary portacaval shunt. The recipient portal vein was reconstructed at a more distal site, such as the umbilical portion, to have the graft liver move freely during hepatic artery (HA) reconstruction. The recipient operation time and bleeding were 11 h 58 min-15 h 27 min and 200-395 mL, respectively. The graft-to-recipient weight ratio was 3.3-3.8% and primary abdominal wall closure was possible in all cases. Although hepatic artery thrombosis occurred in one case, all cases survived with normal growth. Emergency LDLT with S2 grafts weighing less than 100 g can save neonates with FHF whose body weight is less than 3 kg. This LDLT modality using S2 grafts could become a new option for neonates and very small infants requiring LT.

Reduction of left-lateral segment from living donors for liver transplantation in infants weighing less than 7 kg: technical aspects and outcome

LLS reduction has been frequently used in infants weighing <7 kg. Twenty recipients weighing <7 kg at the time of LDLT, median age 11.0 months and body weight 5.6 kg, were treated with an RLLS (n = 12) or LLS (n = 8) graft. Absolute indication of size reduction was that the estimated GRWR was >4.0%. Even if the preoperative GRWR was <4.0%, the RLLS graft was considered to ensure a size match. A flatfish-type LLS was preferred to a blowfish-type to make an RLLS graft for such a small infantile population. The RLLS recipients had significantly more flatfish-type grafts, while the LLS recipients had more blowfish-type grafts. Primary full-layer wound closure could be performed successfully in all LLS recipients, while in the RLLS group, two patients were forced to have partial skin closure. There were no graft losses related to graft compression. Reducing an LLS is a useful procedure to promote the comfortable accommodation of the graft in an infant weighing <7 kg. Flatfish-type LLS allowed more flexibility to make the suitable volume.

Successful Treatment of Biliary Atresia in Very Small Infants through Living Related Liver Transplantation

Improving outcomes in very small children is a major goal of pediatric liver transplantation. This report describes our experience of living related liver transplantation in an infant weighing 3.98 kg. The recipient, a 80-day-old male infant with congenital biliary atresia, was treated with living donor liver transplantation and then followed up for 6 months. The left lateral segment (segment II, III) with reduced size from the donor, his 26-year-old mother, was used as the graft. The graft weighed 200 g. The graft weight to recipient body weight ratio was 5.025%. The donor regained her liver function within 3 days and was discharged on day 8. The patient showed good results. Liver function returned to normal 9 days after the operation with bilirubin level almost decreased to normal. Cyclosporin, mycophenolate mofetil and prednisone were used for postoperative immunosuppression. No bleeding, thrombosis, infection or bile leakage occurred. The patient had slight fever because of a little collection in the abdomen and recovered after paracentesis and drainage. He was discharged on day 16. The donor and recipient are in satisfactory condition at present. Improvement of technique in hepatic surgery, microsurgical technique in vascular surgery and postoperative intensive care are the keys to ensure the success of the procedure.

Liver transplantation in children with hyper-reduced grafts - a single-center experience

In small infants and babies who receive split or living-related adult left lateral segmental liver grafts, further reduction (hyper-reduction) of the graft may be necessary to optimize the size of the graft for the child. We report our experience with hyper-reduction of adult left lateral segment grafts in nine children. A retrospective review of the medical records of children who received hyper-reduced grafts at the Children's Hospital at Westmead, Australia was performed. Of 215 liver transplants performed on 186 children between 1986 and May 2009, 147 were reduced grafts. Nine grafts were further reduced (hyper-reduced) after an on-table assessment of graft size relative to the available abdominal space was made. Mean graft size reduction was by 30%. The pledgetted technique of resection was used in four patients. All required delayed closure of the abdomen, and in three patients, fascial closure was not possible and a Surgisis patch (Cook Surgical International, West Lafayette, IN, USA) was placed to augment the abdominal capacity. Two children had hepatic artery thrombosis. One was successfully thrombectomized. In the other, technical problems with the donor liver contributed to death 10 days post-transplant. Two bile leaks, one from the cut surface and the other at the anastomotic site, were oversewn at the time of abdominal closure. On follow-up (median 33 months), two developed biliary strictures requiring dilatation. Hyper-reduction of segmental grafts can be safely performed when needed. In view of its versatility, it may be preferable to hyper-reduce a graft rather than use a monosegment graft. Comparable long-term results are possible. The pledgetted technique of resection is easy, quick, and safe. The fact that it can be performed after revascularization with minimal blood loss adds great flexibility to this technically challenging procedure.

Innovative surgical techniques address the organ donation crisis, ... don't they?

PURPOSE OF REVIEW

Retrospectively analysing the role that innovative technique and strategies have played to face organ shortage during the last decades, and elaborating rationally about their potential contribution to expand organ availability in the coming future.

RECENT FINDINGS

Current organ donation crisis proceeds from both decreasing offers, qualitatively and quantitatively, and steadily increasing demand. Innovative surgical techniques using the existing donor pool have been extensively used for paediatric transplantation, but these techniques both have been insufficiently implemented in overall transplant activity to meet the demand, and are less usable on the emerging potential pool of donors ('extended-criteria' and nonheart-beating donors), as combining both approaches could carry a higher risk of complications.

SUMMARY

The future is emerging through complementary approaches and strategies in which innovative techniques have a role to play to match the existing pool with the paediatric demand, with an increasing attention to donor management and organ care and with development of preprocurement and postprocurement new therapies.