Technique of split-liver transplant for two adult recipients

Arterial Blood Supply of Liver Segment IV and Its Possible Surgical Consequences

The risk of ischemia of segment IV after split liver resection is high. This anatomical study was done to identify the arterial blood supply and the intrahepatic distribution of liver segment IV. The anatomy of segment IV was studied in 29 livers from adult cadavers. To identify the arterial blood supply of segment IV, water and ink were injected into the various branches of the hepatic artery and the outflow through segment IV and discoloration of the liver parenchyma were observed. In 23 of the 29 livers (79.3%), the arterial perfusion of segment IV was separated by a line drawn from the left side of the inferior vena cava at the top of and lateral to the falciform ligament to the medial point of the gallbladder bed. The area lateral to this line was supplied mainly by the right hepatic artery, and the area medial to it was supplied mainly by the left hepatic artery. In addition to the classification system of Couinaud, we describe here a new division of liver segment IV based on arterial blood supply. These anatomical findings may be useful in defining the resection line for split liver to prevent necrosis of segment IV.

Long-term results after adult ex situ split liver transplantation since its introduction in 1987

BACKGROUND

Split liver transplantation is still discussed controversially. Utilization of split liver grafts has been declining since a change of allocation rules for the second graft abolished incentives for German centres to perform ex situ splits. We therefore analysed our long-term experiences with the first ex situ split liver transplant series worldwide.

METHODS

A total of 131 consecutive adult ex situ split liver transplants (01.12.1987-31.12.2010) were analysed retrospectively.

RESULTS

Thirty-day mortality rates and 1- and 3-year patient survival rates were 13, 76.3, and 66.4 %, respectively. One- and three-year graft survival rates were 63.4 and 54.2 %, respectively. The observed 10-year survival rate was 40.6 %. Continuous improvement of survival from era 1 to 3 was observed (each era: 8 years), indicating a learning curve over 24 years of experience. Patient and graft survival were not influenced by different combinations of transplanted segments or types of biliary reconstruction (p > 0.05; Cox regression). Patients transplanted for primary sclerosing cholangitis had better survival (p = 0.021; log-rank), whereas all other indications including acute liver failure (13.6 %), acute and chronic graft failure (9.1 %) had no significant influence on survival (p > 0.05; log-rank). Biliary complications (27.4 %) had no significant influence on patient or graft survival (p > 0.05; log-rank). Hepatic artery thrombosis (13.2 %) had a significant influence on graft survival but not on patient survival (p = 0.002, >0.05, respectively; log-rank).

CONCLUSIONS

Split liver transplantation can be used safely and appears to be an underutilized resource that may benefit from liberal allocation of the second graft.

Liver transplantation using low-weight recipients from a graft split program

We present our experience with a split liver (SL) program shared with the children's liver transplantation (LT) program from 2 different hospitals in the use of partial grafts from cadaver donors in brain death. We describe an observational, retrospective study, which included patients who underwent a SL transplantation in our center between January 2006 and December 2012. Clinical variables were recorded of both donors and recipients and their data were analyzed using SPSS 19.0 software. Of a total of 204 LT, 4 (2%) patients were treated with a SL. The causes of LT were alcoholic cirrhosis in 2 cases, cryptogenic cirrhosis, and primary biliary cirrhosis (PBC). In all cases there was a temporary portocaval shunt. The confluence of the hepatic veins of the recipient was anastomosed to the donor vena cava and arterial anastomosis was performed. The reconstruction was hepato-choledochal in all cases. There were no cases of postreperfusion syndrome or vascular thrombosis and no retransplantation was necessary. Currently, 3 of the 4 cases are still alive. Death in the other patient was due to mesenteric ischemia. Our center has participated in the development of a protocol that considers the indication of this technique provided expert groups are involved in its development, regardless of hospital level. This will expand the pool of donors and partially solve the current problems with available grafting.

An experimental study of triple split-liver transplantation in dogs

AIM: To explore the feasibility of a strategy of tripartition of a whole deceased liver graft for use in 3 recipients in dogs to ultimately maximize donor organ use.

METHODS: Adult healthy mongrel dogs were selected to be donors (n = 30, weighing between 20-25 kg) and recipients (n = 30, weighing between 8-15 kg). Donor/recipient pairs were randomly matched. For donor operation, transection of the parenchymal bridge was performed between the right lateral lobe and right middle lobe, and between the left middle lobe and the quadrate lobe. After in vivo perfusion, the left, middle and right liver grafts were procured, and their primary branches were cut near the main stem. Among the three liver grafts, the one was chosen to be implanted if it's GRWR (graft-to-recipient weight ratio) was more than 1.0% and was nearest to 1.5%. Recipients entered Groups A, B and C if the left, middle and right grafts were chosen, respectively. With the piggyback technique, the outflow orifice of liver graft was anastomosed to the anterolateral wall of the recipient vena cava. The graft was revascularized via reconstructed hepatic vein and portal vein, and then the hepatic artery and bile duct were anastomosed both in an end-to-end manner. Biliary and abdominal drainage was inspected postoperatively. Autopsies were performed promptly after recipients' death to investigate the possibility of technical complications.

RESULTS: By prominent fissures, the canine liver was divided into 7 lobes, among which the parenchymal bridges were thin. The parenchymal bridge connecting the right lateral lobe to the right middle lobe was much thinner than that connecting the left middle lobe to the quadrate lobe. No major conduit was found during transection of these two parenchymal bridges. The portal vein was split into three branches. The common bile duct was formed by the union of three hepatic ducts-the left, middle and right hepatic ducts. The hepatic vein consisted of the left, median and right hepatic veins. Anatomical variations in the hepatic arteries could be found. Among three recipient groups, the operation time, anhepatic time and blood loss did not show significant differences (P > 0.05), but the mean recipient weight, liver graft weight, and GRWR differed significantly (all P < 0.01). In the three groups, none of the recipients died during surgery. Once the hepatic vein and the portal vein were anastomosed and declamped, the implanted liver regained its color soon and its appearance returned to normal following arterial revascularization. There was no statistical difference in survival duration among the three groups (128.3 h ± 48.5 h vs 102.7 h ± 59.8 h vs 98.7 h ± 46.8 h, P = 0.234). Ascites and liver necrosis were not found at autopsy. Bile was present in the bile duct and all anastomoses were patent.

CONCLUSION: Our experimental results indicate that the whole liver of a big dog can be split into three parts, every one of which can be transplanted to a small recipient as an independent allograft.

Split liver transplantation: an overview

Liver transplantation (OLT) has become the only treatment modality for patients with end-stage liver diseases. Establishment of standard liver transplantation technique, development of better immunosuppressive medications and accumulated experience using them safely, and improvement of intensive care and anesthesia played major role to have current 88%-90% 1-year survival after liver transplantation. As liver transplantations became more successful with the growing experience and development in the field, the increased demand for liver allografts could not match the available supply of donor organs. As a result of this imbalance, each year nearly 3000 patients die in the United States awaiting liver transplantation on the national waiting list. Split liver transplantation (SLT) has been perceived as an important strategy to increase the supply of liver grafts by creating 2 transplants from 1 allograft. The bipartition of a whole liver also carries utmost importance by increasing the available grafts for the pediatric patients, where size-matched whole liver allografts are scarce, leading increased incidence of waiting list mortality in this group. In the common approach of the split liver procedure, liver is divided into a left lateral segment graft (LLS) to be transplanted to a child and a right extended liver lobe graft for an adult recipient. In a technically more challenging variant of this procedure, the principle is to split the liver into 2 hemigrafts and use the left side for a small adult or a teenager and the right for a medium-sized adult patient. Donor selection for splitting, technical expertise in both OLT and hepatobiliary surgery, logistics to decrease total ischemia time, and manpower of the transplantation team are important factors for successful outcomes after SLT. The liver can be split on the back table (ex situ) or in the donor hospital before the donor cross-clamp using in situ splitting technique, which was developed directly from living donor liver transplantation. The most important advantage of in situ splitting is to decrease the total ischemia time and increased the possibility of inter-center sharing. The in situ technique of splitting has other advantages, including evaluation of the viability of segment IV in case of LLS splitting and better control of bleeding from cut surface upon reperfusion on the recipient. Recipient selection for split liver grafts is also crucial for success after SLT. In this review, we aim to summarize the advances that have occurred in SLT. We also discuss anatomic and technical aspects, including both approaches to SLT, which is now considered by many centers to be a routine operation.

Graft weight/recipient weight ratio: how well does it predict outcome after partial liver transplants?

Partial graft liver recipients with graft weight/recipient weight (GW/RW) ratios < 0.8% are thought to have a higher incidence of postoperative complications, including small-for-size syndrome (SFSS). We analyzed a cohort of such recipients and compared those with GW/RW < 0.8% to those with GW/RW >or= 0.8%. Between 1999 and 2008, 107 adult patients underwent partial graft liver transplants: 76 from live donors [living donor liver transplantation (LDLT)] and 31 from deceased donors [split liver transplantation (SLT)]. Of these, 22 had GW/RW < 0.8% (12 with LDLT and 10 with SLT), and 85 had GW/RW >or= 0.8% (64 with LDLT and 21 with SLT). The baseline demographics and median length of follow-up were similar. SFSS developed in 3 recipients with GW/RW < 0.8% (13.6%) and in 8 recipients with GW/RW >or= 0.8% (9.4%; P = not significant). Other early complications were similar between the 2 groups. Inflow modification with splenic artery occlusion was performed in 13 recipients: 7 with GW/RW < 0.8% and 6 with GW/RW >or= 0.8%. Graft survival at 1 year post-transplant did not differ (91% versus 92%; P = not significant). In conclusion, GW/RW did not appear to be the only determinant of outcome after partial liver transplantation. Using techniques such as inflow modification may help to prevent some of the problems seen with smaller grafts.

Should we still offer split-liver transplantation for two adult recipients? A retrospective study of our experience

The role of split-liver transplantation (SLT) for two adult recipients is still a matter of debate, and no agreement exists on indications, surgical techniques, and results. The aim of this study was to retrospectively analyze the outcome of our series of SLT. From May 1999 to December 2006, 16 patients underwent SLT at our unit. We used 9 full right grafts (segments 5-8) and 7 full left grafts (segments 1-4). The splitting procedure was always carried out in situ with a fully perfused liver. Postoperative complications were recorded in 8 (50%) patients: 5 (55%) in full right grafts and 3 (43%) in full left grafts. No one was retransplanted. After a median follow-up of 55.82 months (range, 0.4-91.2), 5 (31%) patients died, and the 1-, 3-, and 5-year overall survival rate for patients and grafts was 69%. We considered as a control group for the global outcome 232 whole liver transplantations performed at our unit in the same period of time. Postoperative complications were recorded in 53 (23%) patients, and after a median follow-up of 57.37 months (mean, 55.11; range, 1-102.83), the 1-, 3-, and 5-year overall patient survival was 87%, 82%, and 80%, respectively. In conclusion, SLT for two adult recipients is a technically demanding procedure that requires complex logistics and surgical teams experienced in both liver resection and transplantation. Although the reported rate of survival might be adequate for such a procedure, more efforts have to be made to improve the short-term outcome, which is inadequate in our opinion. The true feasibility of SLT for two adults has to be considered as still under investigation.

Donation after cardiac death as a strategy to increase deceased donor liver availability

OBJECTIVE

This study examines donation after cardiac death (DCD) practices and outcomes in liver transplantation.

SUMMARY BACKGROUND DATA

Livers procured from DCD donors have recently been used to increase the number of deceased donors and bridge the gap between limited organ supply and the pool of waiting list candidates. Comprehensive evaluation of this practice and its outcomes has not been previously reported.

METHODS

A national cohort of all DCD and donation after brain-death (DBD) liver transplants between January 1, 2000 and December 31, 2004 was identified in the Scientific Registry of Transplant Recipients. Time to graft failure (including death) was modeled by Cox regression, adjusted for relevant donor and recipient characteristics.

RESULTS

DCD livers were used for 472 (2%) of 24,070 transplants. Annual DCD liver activity increased from 39 in 2000 to 176 in 2004. The adjusted relative risk of DCD graft failure was 85% higher than for DBD grafts (relative risk, 1.85; 95% confidence interval, 1.51-2.26; P < 0.001), corresponding to 3-month, 1-year, and 3-year graft survival rates of 83.0%, 70.1%, and 60.5%, respectively (vs. 89.2%, 83.0%, and 75.0% for DBD recipients). There was no significant association between transplant program DCD liver transplant volume and graft outcome.

CONCLUSIONS

The annual number of DCD livers used for transplant has increased rapidly. However, DCD livers are associated with a significantly increased risk of graft failure unrelated to modifiable donor or recipient factors. Appropriate recipients for DCD livers have not been fully characterized and recipient informed consent should be obtained before use of these organs.

Donation after cardiac death as a strategy to increase deceased donor liver availability

OBJECTIVE

This study examines donation after cardiac death (DCD) practices and outcomes in liver transplantation.

SUMMARY BACKGROUND DATA

Livers procured from DCD donors have recently been used to increase the number of deceased donors and bridge the gap between limited organ supply and the pool of waiting list candidates. Comprehensive evaluation of this practice and its outcomes has not been previously reported.

METHODS

A national cohort of all DCD and donation after brain-death (DBD) liver transplants between January 1, 2000 and December 31, 2004 was identified in the Scientific Registry of Transplant Recipients. Time to graft failure (including death) was modeled by Cox regression, adjusted for relevant donor and recipient characteristics.

RESULTS

DCD livers were used for 472 (2%) of 24,070 transplants. Annual DCD liver activity increased from 39 in 2000 to 176 in 2004. The adjusted relative risk of DCD graft failure was 85% higher than for DBD grafts (relative risk, 1.85; 95% confidence interval, 1.51-2.26; P < 0.001), corresponding to 3-month, 1-year, and 3-year graft survival rates of 83.0%, 70.1%, and 60.5%, respectively (vs. 89.2%, 83.0%, and 75.0% for DBD recipients). There was no significant association between transplant program DCD liver transplant volume and graft outcome.

CONCLUSIONS

The annual number of DCD livers used for transplant has increased rapidly. However, DCD livers are associated with a significantly increased risk of graft failure unrelated to modifiable donor or recipient factors. Appropriate recipients for DCD livers have not been fully characterized and recipient informed consent should be obtained before use of these organs.

Technical refinements and results in full-right full-left splitting of the deceased donor liver

OBJECTIVE

Splitting of the liver at the line of Cantlie of otherwise healthy people is accepted worldwide as a reasonable procedure for the donors in adult living donor liver transplantation. A similar operation is still considered as experimental if performed in the deceased donor liver. The aim of this study is to evaluate the technical evolution and the results of this variant splitting technique.

PATIENTS AND METHODS

From January 1999 to August 2004, a total of 35 transplants of hemilivers from deceased donors (segments V-VIII: n = 16 and segments (I)II-IV: n = 19) were performed in our center. Seven splits were performed in situ and 12 ex situ. Splitting of the vena cava was applied in 18 splits and splitting of the middle hepatic vein in 8. Seven adults and 12 adolescents received the left hemiliver with a mean age of 12 years (range, 3-64 years), of whom 21% were UNOS status 1. Recipients of right hemilivers were exclusively adults with a mean age of 48 years (range, 31-65 years), none of them were high urgent. The outcome of these 35 recipients of hemilivers was prospectively evaluated.

RESULTS

Mean deceased donor age was 27 years (range, 12-57 years), the donor's body weight ranged between 55 kg and 100 kg. The mean weight of the right and left hemilivers was 1135 g (range, 745-1432 g) and 602 g (range, 289-1100 g), respectively. The mean graft recipient weight ratio in left and right hemiliver group was 1.46% (range, 0.88%-3.54%) and 1.58% (range, 1.15%-1.99%), respectively. Median follow-up was 27.4 months (range, 1-68.3 months). Four patients died (actual patient survival FR group: 87.5% versus FL group: 89.5%), 3 due to septic MOF and 1 due to graft versus host disease. In each of the 2 groups, 2 recipients had to undergo retransplantation, which resulted in an actual right and left hemiliver survival rate of 75% and 84%, respectively. The causes for retransplantation were primary nonfunction in 2 left hemilivers, chronic graft dysfunction in 1 right hemiliver, and recurrence of the primary disease in 1 recipient of a right hemiliver. Primary poor function was observed in 1 recipient of a right hemiliver. Early and late biliary complications occurred in both right and left hemiliver groups at the rate of 37.5% (n = 6) and 21% (n = 4), respectively. Arterial, portal, and venous complications were not observed in either group.

CONCLUSION

The technical development of splitting along Cantlie's line is almost complete with the last challenge being the reduction of biliary complications. The key to success is the choice of adequate deceased donors and recipients. Full-right full-left splitting is safely possible and should be considered as a reasonable instrument to alleviate mortality on the adult waiting list and to reduce the need for adult and adolescent living donation.

Right Hemiliver Transplant: Results From Living and Cadaveric Donors

Although right hemiliver transplant from living donors (LD) is gaining acceptance as a way to overcome the critical organ shortage, splitting a liver for two adults from cadaveric donor (CD) is still controversial.

METHODS

From May 1999 to August 2004 we performed nine right hemiliver transplants using segments 5-6-7-8 from CD and 18 from LD.

RESULTS

We compared the two procedures to evaluate both the technical aspects and the patients' outcomes. In the CD group, three recipients died (33%), two of whom were UNOS Status 2A. Patient and graft survivals were 67% (median follow-up: 23 months). Among the LD group, three recipients died (17%) and two were retransplanted; one because of arterial thrombosis and the other as a consequence of small-for-size syndrome. Patient and graft survivals were 83% and 72%, respectively (median follow-up: 8 months). There were five early complications in the CD group (55%) and five (27%) in the LD group. Two patients in the LD group experienced a late stenosis of the biliary anastomosis.

DISCUSSION

Data from our early experience show that better results are achieved by right hemiliver transplants from LD; the morbidity and mortality are higher among the CD group. We believe that this finding is probably a consequence of better preoperative donor evaluation, shorter ischemia time, better logistics, and learning curve. Recipient selection is crucial; this kind of graft is at high risk of poor function, technical complications, and infections. Further experience will help to clarify the reliability of right hemiliver transplants from CD.

Living donor and split-liver transplants in hepatitis C recipients: does liver regeneration increase the risk for recurrence?

Concern exists that partial liver transplants (either a living donor [LD] or deceased donor [DD] in hepatitis C virus (HCV)-positive recipients may be associated with an increased risk for recurrence. From 1999 to 2003, at our institution, 51 HCV-positive recipients underwent liver transplants: 32 whole-liver (WL) transplants, 12 LD transplants and 7 DD split transplants. Donor characteristics differed in that WL donors were older, and LD livers had lower ischemic times. Recipient characteristics were similar except that mean MELD scores in LD recipients were lower (p < 0.05). With a mean follow-up of 28.3 months, 46 (90%) recipients are alive: three died from HCV recurrent liver disease and two from tumor recurrence. Based on 1-year protocol biopsies, the incidence of histologic recurrence in the three groups is as follows: WL, 81%; LD, 50% and DD split, 86% (p = 0.06 for LD versus WL). The mean grade of inflammation on the biopsy specimens was: WL, 1.31; LD, 0.33 and DD split, 1.2 (p = 0.002 for LD versus WL; p = 0.03 for LD versus DD split). Mean stage of fibrosis was: WL, 0.96; LD, 0.22 and DD split, 0.60 (p = 0.07 for LD versus WL). Liver regeneration does not seem to affect hepatitis C recurrence as much, perhaps, as factors such as DD status, donor age and cold ischemic time.

Right hemiliver transplants from cadavers or living donors: a comparative analysis

INTRODUCTION

The aim of this article was to compare the results of right hemiliver transplants from living versus cadaver donors in a single institution.

METHODS

Between March 1999 and May 2003, we performed 10 right hemiliver transplants from living donors (LD) and 8 right hemiliver transplants from cadavers (CD). The procedure consisted of grafting liver segments 5, 6, 7, and 8. The procedure was performed with a fully perfused liver also in the CD group (in situ split).

RESULTS

With follow-up between 7 days and 26 months in the LD group, 2 patients died with functioning grafts: 1 patient died because of massive pulmonary bleeding due to Rendu-Osler Syndrome; the other one died as a consequence of systemic aspergillosis. One patient underwent retransplantation due to arterial thrombosis. In the CD group with a follow-up between 31 days and 48 months, 3 patients died due to sepsis, including 2 who were status 2A. There were 4 early complications among the LD group and 5 in the CD group. The patient and graft survival rates were 80% and 70%, respectively, in the LD group; and both about 62% in the CD group.

CONCLUSION

Right hemiliver grafts are at high risk due to technical and septic complications. A higher morbidity is observed in the CD group, where the vascular and biliary tree anatomy cannot be investigated with accuracy. We must avoid transplanting status 2A recipients with this kind of graft.

Liver regeneration after adult living donor and deceased donor split-liver transplants

As the number of living donor (LD) and deceased donor (DD) split-liver transplants (SLTs) have increased over the last 5 years, so too has the interest in liver regeneration after such partial-liver transplants. We looked at liver regeneration, as measured by computed tomography (CT) volumetrics, to see if there were significant differences among LDs, right-lobe LD recipients, and SLT recipients. We measured liver volume at 3 months postoperatively by using CT, and we compared the result to the patient's ideal liver volume (ILV), which was calculated using a standard equation. The study group consisted of 70 adult patients who either had donated their right lobe for LD transplants (n = 24) or had undergone a partial-liver transplant (right-lobe LD transplants, n = 24; right-lobe SLTs, n = 11; left-lobe SLTs, n = 11). DD (vs. LDs) were younger (P < 0.01), were heavier (P = 0.06), and had longer ischemic times (P < 0.01). At 3 months postoperatively, LDs had attained 78.6% of their ILV, less than the percentage for right-lobe LD recipients (103.9%; P = 0.0002), right-lobe SLT recipients (113.6%; P = 0.01), and left-lobe SLT recipients (119.7%; P = 0.0006). When liver size at the third postoperative month was compared with the liver size immediately postoperatively, LDs had a 1.85-fold increase. This was smaller than the increase seen in right-lobe LD recipients (2.08-fold), right-lobe SLT recipients (2.17-fold), and left-lobe SLT recipients (2.52-fold). In conclusion, liver regeneration, as measured by CT volume, seems to be greatest in SLT recipients. LD recipients seem to have greater liver growth than their donors. The reason for this remains unclear.

Split-liver transplantation: a review

Split-liver transplantation (SLT), a procedure where one cadaver liver is divided to provide for two recipients, offers immediate expansion of the existing cadaver donor pool. To date, the principal beneficiaries of SLT have been adult/pediatric recipient pairs with excellent outcomes reported; however, the current scarcity of cadaver organs has renewed interest in expanding these techniques to include two adult recipients from one adult cadaver donor. Significant obstacles to the widespread application of SLT exist and must be resolved by the transplant community before greater utilization can be realized. This manuscript reviews the historic background, surgical techniques, current results, and obstacles impeding further application of SLT.

Recurrent deep-vein thrombosis based on homozygous factor V Leiden mutation acquired after liver transplantation

Several genetic liver diseases can be treated by liver transplantation (LT). However, some genetic defects also may be acquired by this procedure. We describe a patient who developed recurrent deep-vein thromboses after LT for hepatitis C virus-associated hepatocellular carcinoma on the basis of a homozygous Leiden mutation of the factor V gene in the donor liver. Liver donors with a history of venous thrombosis should be screened for the presence of activated protein C (APC) resistance. In addition, we recommend looking for APC resistance in liver recipients who develop venous thromboembolic disease in the post-LT course. Molecular analysis of donor tissue may be necessary to make a definite diagnosis of factor V Leiden mutation in these patients. As a consequence, intensified postoperative thromboprophylaxis or lifelong anticoagulant therapy may be necessary if this thrombophilic gene defect is detected.