Small-for-size syndrome secondary to outflow block of the segments V and VIII anastomoses--successful treatment with trans-splenic artery embolization: a case report

A Novel Method for the Prevention and Treatment of Small-for-Size Syndrome in Liver Transplantation

BACKGROUND

Currently there is no consensus on the optimal management of small-for-size syndrome following liver transplantation. Here we describe a technique to alleviate portal hypertension and improve the hepatocyte reperfusion in small-for-size liver transplantation in a Lewis rat model.

METHODS

The rats underwent trans-portal vein intra-hepatic portosystemic shunt using a self-developed porous conical tube (TPIPSS: Fig. 1) on small-for-size liver transplants (SFS) with right lobe graft. The treatment effect was evaluated by comparing hemodynamic parameters, morphological changes, serum parameters, ET-1 and eNOS expression, hepatocyte proliferation and apoptosis, CYP3A2 levels, postoperative complications, and survival between the two groups with SFS liver transplants.

RESULTS

Porous conical prosthesis prolonged the filling time of small-for-size grafts. Moreover, grafts with TPIPSS showed a lower portal vein pressure, improved microcirculatory flow, alleviated histological changes, decreased ET-1 and increased eNOS expressions, and significantly less damage to liver function comparing to grafts without TPIPSS. Mean survival and overall 30-day survival were significantly higher in the TPIPSS group.

CONCLUSIONS

These results demonstrate that porous conical tube as trans-portal vein intra-hepatic portosystemic shunt device is an effective way to alleviate portal vein hypertension and improve hepatocyte reperfusion after small-for-size liver transplantation.

Randomized trial on extended versus modified right lobe grafts in living donor liver transplantation

Despite advances in the practice of living donor liver transplantation (LDLT), the optimum surgical approach with respect to the middle hepatic vein (MHV) in right lobe LDLT remains undefined. We designed a randomized trial to compare the early postoperative outcomes in recipients and donors between extended right lobe grafts (ERGs; transection plane was maintained to the left of MHV and division of MHV performed beyond the segment VIII vein) and modified right lobe grafts (MRGs; transection plane was maintained to the right of MHV; the segment V and VIII drainage was reconstructed using a conduit of recipient portal vein). Eligible patients (n = 86) were prospectively randomized into the ERG arm (n = 43) and the MRG arm (n = 43) at the beginning of donor hepatectomy. The primary endpoint considered in this equivalence trial was patency of the MHV or the reconstructed "neo-MHV" in the recipient. The secondary endpoints included biochemical parameters, postoperative complications, mortality in recipients as well as donors and volume regeneration of remnant liver in donors, measured at 2 months. The patency of the MHV was comparable in the ERG and MRG arms (90.7% versus 81.4%; difference, 9.3%; 95% confidence interval [CI], -5.8 to 24.4; z score, 1.245; P = 0.21). Volume regeneration of the remnant liver in donors was significantly better in the MRG arm (111.3% versus 87.3%; mean difference, 24%; 95% CI, 14.6-33.3; P < 0.001). The remaining secondary endpoints in donors and recipients were similar between the 2 arms. To conclude, MRG with reconstructed neo-MHV has comparable patency to native MHV in ERG and confers equivalent graft outflow in the recipient. Furthermore, it allows better remnant liver regeneration in the donor at 2 months. Liver Transplantation 24 888-896 2018 AASLD.

A portal pressure cut-off of 15 versus a cut-off of 20 for prevention of small-for-size syndrome in liver transplantation: A comparative study

AIM

Portal hypertension has recently been implicated in the pathogenesis of small-for-size syndrome (SFSS) in adult-to-adult living-donor liver transplantation (A-LDLT). The aim of our study is to compare the portal venous pressure (PVP) cut-off values of 15 mmHg and 20 mmHg in terms of prevention of SFSS in A-LDLT.

METHODS

Seventy-six patients underwent A-LDLT. A PVP <20 mmHg at the end of the operation was targeted using graft inflow modulation. Patients were divided into two groups: group A, final PVP <15 mmHg; and group B, final PVP 15-19 mmHg. Peak serum bilirubin and peak international normalized ratio in the first month after A-LDLT, as well as hepatic encephalopathy, SFSS, 90-day morbidity, and mortality were observed in both groups.

RESULTS

Final PVP was well controlled below 20 mmHg in all patients (group A, n = 39; group B, n = 37). Six patients suffered SFSS in group B (16.2%) compared to one patient (2.6%) in group A (P = 0.04). Nine patients died in group B (24.3%), four of whom died of SFSS, compared to three patients in group A (7.7%) (P = 0.047).

CONCLUSION

A PVP cut-off of 15 mmHg seems to be a more appropriate target level than a cut-off of 20 mmHg for prevention of postoperative SFSS in A-LDLT.

Early Graft Dysfunction in Living Donor Liver Transplantation and the Small for Size Syndrome

LDLT has arisen as a viable means to reduce waitlist mortality. However, its widespread embrace by the liver transplant community has been met with frustration centered on donor morbidity and small-for-size-syndrome. Focusing on the later entity, we describe the initial recognition of this early graft dysfunction, the theorized pathophysiology and solutions to remedy its emergence.

Outcome of patients undergoing right lobe living donor liver transplantation with small-for-size grafts

AIM: To investigate the outcome of living donor liver transplantation (LDLT) recipients transplanted with small-for-size grafts (SFSGs).

METHODS: Between November 2001 and December 2010, 196 patients underwent LDLT with right lobe liver grafts at our center. Recipients were divided into 2 treatment groups: group A with an actuarial graft-to-recipient weight ratio (aGRWR) < 0.8% (n = 45) and group B with an aGRWR ≥ 0.8% (n = 151). We evaluated serum liver function markers within 4 wk after transplantation. We also retrospectively evaluated the outcomes of these patients for potential effects related to the recipients, the donors and the transplantation procedures based upon a review of their medical records.

RESULTS: Small-for-size syndrome (SFSS) developed in 7 of 45 patients (15.56%) in group A and 9 of 151 patients (5.96%) in group B (P = 0.080). The levels of alanine aminotransferase and aspartate aminotransferase in group A were higher than those in group B during early period after transplantation, albeit not significantly. The cumulative 1-, 3- and 5-year liver graft survival rates were 82.22%, 71.11% and 71.11% for group A and 81.46%, 76.82%, and 75.50% for group B patients, respectively (P = 0.623). However, univariate analysis of risk factors associated with graft survival in group A demonstrated that the occurrence of SFSS after LDLT was the only significant risk factor affecting graft survival (P < 0.001). Furthermore, multivariate analysis of our data did not identify any additional significant risk factors accounting for poor graft survival.

CONCLUSION: Our study suggests that LDLT recipients with an aGRWR < 0.8% may have liver graft outcomes comparable to those who received larger size grafts. Further studies are required to ascertain the safety of using SFSGs.

Influence of larger graft weight to recipient weight on the post-liver transplantation course

Size matching between recipient and donor livers is an important factor in organ allocation in the context of liver transplantation (LT). The aim of this study was to determine whether a large graft for recipient size influenced the post-transplant course. One hundred and sixty-two successive LT recipients were included and retrospectively divided into two groups: 25 (15%) had a graft-to-recipient weight ratio (GWRW) ≥ 2.5% and 137 (85%) had a GWRW <2.5%. Postoperative complications and outcomes were recorded. In the GWRW >2.5% group, more end-to-end caval replacement (72% vs. 38%, p = 0.003) and veno-venous bypass (48% vs. 23%, p = 0.01) were used. Peak AST/ALT values were higher in the GWRW >2.5% group (AST: 596 [70-5876] vs. 453 [29-5132] IU/l, p = 0.03; ALT: 773 [101-5025] vs. 383 [36-4921] IU/l, p = 0.02). Among postoperative complications, the rate of respiratory failure was higher in the GWRW >2.5% group (32% vs. 14%, p = 0.04). The rates of other complications did not differ between the two groups. Both groups had similar graft and patient survival rates at one yr. Using large grafts for recipient size did not impair liver function and did not modify graft and patient outcomes at one yr. However, a GWRW >2.5% appeared to be a determining factor for respiratory morbidity following LT.

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.

Delayed splenic artery occlusion for treatment of established small-for-size syndrome after partial liver transplantation

We looked at the impact of delayed splenic artery occlusion (SAO) on recipients with established small-for-size syndrome (SFSS) after partial graft liver transplantation [either from a living donor (LD) or split from a deceased donor (DD)]. Between 1999 and 2007 we performed a total of 100 partial liver transplantations in adult recipients: 66 LD transplantations and 34 DD split transplantations. Of these, 7 (7%) developed SFSS, diagnosed by the clinical features of cholestasis, coagulopathy, and ascites. Mean graft weight/recipient weight (GW/RW) ratio in these 7 recipients was 0.94%. Five of these 7 recipients underwent relaparotomy at a mean of 10 days post-transplantation to rule out a technical complication, and then intraoperative splenic artery ligation was performed. The other 2 recipients were treated radiologically by splenic artery coiling-at 9 and 13 days post-transplantation. Median serum bilirubin at the time of the splenic artery procedure was 20 mg/dL; by 3 weeks postprocedure this had decreased to 2.5 mg/dL. Of the 7 recipients with SFSS, 6 improved and eventually obtained normal graft function; 1 recipient did not improve and ultimately underwent retransplantation because of persistent cholestasis and failure to thrive. Delayed SAO represents a potential option for the treatment of recipients with established SFSS after partial liver transplantation.