An alternative technique of biliary reconstruction after liver transplantation

Memory T cells are significantly increased in rejected liver allografts of rhesus monkeys

The rhesus monkey (RM) is an excellent preclinical model in kidney, heart, and islet transplantation that has provided the basis for new immunosuppressive protocols for clinical studies. However, there remain relatively few liver transplantation (LT) models in nonhuman primates. In this study, we analyzed the immune cell populations of peripheral blood mononuclear cells (PBMCs) and secondary lymphoid organs along with livers of normal RMs and compared them with those of rejected LT recipients following withdrawal of immunosuppression. We undertook 5 allogeneic ABO compatible orthotopic LTs in monkeys using 5 normal donor monkey livers. We collected tissues including lymph nodes, spleens, blood, and recipient livers, and we performed flow cytometric analysis using isolated immune cells. We found that CD4 or CD8 naïve T cells were normally seen at low levels, and memory T cells were seen at high levels in the liver rather than lymphoid organs or PBMC. However, regulatory cells such as CD4+ forkhead box P3+ T cells and CD8+ CD28- cells remained in high numbers in the liver, but not in the lymph nodes or PBMC. The comparison of CD4/8 T subpopulations in normal and rejected livers and the various tissues showed that naïve cells were dramatically decreased in the spleen, lymph node, and PBMCs of rejected LT monkeys, but rather, the memory CD4/8 T cells were increased in all tissues and PBMC. The normal liver has large numbers of CD4 regulatory T cells, CD8+ CD28-, and myeloid-derived suppressor cells, which are known immunosuppressive cells occurring at much higher levels than those seen in lymph node or peripheral blood. Memory T cells are dramatically increased in rejected liver allografts of RMs compared with those seen in normal RM tissues. Liver Transplantation 24 256-268 2018 AASLD.

Long-term hepatic allograft acceptance based on CD40 blockade by ASKP1240 in nonhuman primates

Blockade of the CD40-CD154 costimulatory signal is an attractive strategy for immunosuppression and tolerance induction in organ transplantation. Treatment with anti-CD154 monoclonal antibodies (mAbs) results in potent immunosuppression in nonhuman primates (NHPs). Despite plans for future clinical use, further development of these treatments was halted by complications. As an alternative approach, we have been focusing on the inhibition of the counter receptor, CD40 and have shown that a novel human anti-CD40 mAb, ASKP1240, markedly prolongs renal allograft survival in NHPs, although allografts eventually underwent chronic allograft nephropathy. On the basis of our previous findings that a CD40-CD154 costimulation blockade induces tolerance to hepatic, but not cardiac, allografts in rodents, we tested here our hypothesis that a blockade of CD40 by ASKP1240 allows acceptance of hepatic allografts in NHPs. A 2-week ASKP1240 induction treatment prolonged liver allograft survival in NHPs; however, the graft function deteriorated due to chronic rejection. In contrast, a 6-month ASKP1240 maintenance monotherapy efficiently suppressed both cellular and humoral alloimmune responses and prevented rejection on the hepatic allograft. No serious side effects, including thromboembolic complications, were noted in the ASKP1240-treated monkeys. We conclude that CD40 blockade by ASKP1240 would be a desirable immunosuppressant for clinical liver transplantation.

[Orthotopic liver transplantation. Techniques and results]

Since 1963, orthotopic liver transplantation (OLT) has developed into an established interdisciplinary therapy concept for patients with end-stage liver disease, acute irreversible liver failure, and hepatic malignancies in selected cases. In 26 centers in Germany, around 900 full-size OLTs are performed annually. The classic technique has been replaced by the "piggyback" method, which has become the standard in many centres. Improvements in surgical techniques, anaesthetic protocols, and medical management along with the introduction of new immunosuppressive regimens and early adequate therapy against infections and transplant rejection have increased patient survival. These factors have resulted in 1-year survival rates of 80-90% and led to an increase in indications for OLT. Despite decades of experience, approximately 10% of the mortality in the first 3 months still can be traced to technical complications.

SIGNIFICANCE OF A T-LYMPHOCYTOTOXIC CROSSMATCH IN LIVER AND COMBINED LIVER-KIDNEY TRANSPLANTATION

BACKGROUND

In contrast to kidney transplants a positive crossmatch is no contraindication for liver transplantation (OLT). In liver transplantation, antibody mediated rejections are rarely reported and a liver graft is suspected to have protective effects for kidney grafts when transplanted simultaneously. The aim of this study was to evaluate the effect of a positive crossmatch on outcome after OLT and combined liver and kidney transplantation (CLKTx).

METHODS

We analyzed retrospectively the impact of a positive crossmatch on graft survival and rejection episodes after OLT (793pats) and CLKTx (18pats, 2.2%). Immunosuppression consisted of either Cyclosporine- or Tacrolimus-based regimens.

RESULTS

A total of 50/811 (6%) of patients had a positive crossmatch, 45/793 (5.6%) with liver transplantation alone and 5/18 (28%) of patients with CLKTx. Follow-up ranged from 1 to 122.5 months (median 45.8 months). One- and 5-year graft survival rates of liver transplants alone with a positive crossmatch were 89.6% and 75.3%, respectively and were 88% and 77.5% in crossmatch negative recipients. Additionally, the incidence of acute and steroid-resistant rejection (44% and 15.5%) was not significantly increased in patients with a positive crossmatch when compared with patients with a negative crossmatch (38% and 19%). None of the patients with a positive crossmatch and CLKTx underwent a hyperacute-rejection episode after transplantation, and kidney graft survival 100%.

CONCLUSIONS

In conclusion, a positive crossmatch is no contraindication for OLT and CLKTx. Furthermore, not having to wait for results of donor/recipient crossmatching can shorten cold ischemia time and may improve the clinical outcome.

Administration of prostacyclin after liver transplantation: a placebo controlled randomized trial

The shortage of suitable organs for liver grafts is responsible for the use of marginal donors for liver transplantation (OLT). If these liver grafts function poorly initially after OLT, a supportive therapy is necessary. The purpose of this study was to evaluate the effects of prostacyclin (PGI2) on postoperative liver graft function after OLT. A total of 30 adult recipients of primary OLT were randomized to either receive PGI2 (4 ng/kg per min body weight, n = 15) or a placebo for 6 d. To evaluate regional splanchnic oxygenation a fiberoptic pulmonary-artery catheter was inserted into a hepatic vein and the difference between mixed venous oxygen content and hepatic venous oxygen content was determined (deltaO2). Measurements were performed directly after transplantation and at 6, 12, 24 and 48 h postoperatively. A significant correlation between deltaO2 and the level of transaminases (ALT/AST) was observed 24 and 48 h after transplantation (p < 0.05). PGI2 treatment induced a significant decrease in deltaO2 after 24 and 48 h after reperfusion (p < 0.05). Peak AST levels tended to be lower in the PGI2 treatment group (418 +/- 99 vs. 638 +/- 156 U/L, p < 0.1). These results suggest that administration of PGI2 after OLT improves hepatic-splanchnic oxygenation and may thereby reduce reperfusion injury after OLT.

Bacterial and fungal colonization and infections using oral selective bowel decontamination in orthotopic liver transplantations

Bacterial and fungal infections are a major cause of morbidity and mortality after orthotopic liver transplantation. In the immunocompromised host, infections are thought to arise from the gut, which is almost always colonized with potential pathogens. Using oral selective bowel decontamination (SBD), potential pathogens can be eradicated from the gut and infections prevented. In this catamnestic study we have reviewed gastrointestinal colonization, bacterial and fungal infections, and bacterial resistance to standard antibiotics in our first 206 liver transplant patients while under SBD. With few exceptions, gram-negatives were eradicated from the gastrointestinal tract and secondary colonization was inhibited. In spite of unsatisfactory elimination of Candida, probably because nystatin doses were too low, Candida infections were rare (n = 4) and none was fatal. One and two-year survival rates were 93% and 92%, respectively. The bacterial and fungal infection rate was 27.8% with an infection-related mortality of 1.95%. Infections with aerobic gram-positive bacteria prevailed and only 11 gram-negative and 11 fungal infections occurred; among the latter, Aspergillus and Mucor were the most serious and responsible for three of the six deaths in this series. With regard to the development of resistance, we found an increasing number of enterococci and coagulase-negative staphylococci resistant to ciprofloxacin and imipenem, respectively, but unlikely as a consequence of SBD.

Technique and results of biliary reconstruction using side-to-side choledochocholedochostomy in 300 orthotopic liver transplants

OBJECTIVE

The authors evaluated the complication rate and outcome of side-to-side common bile duct anastomosis after human orthotopic liver transplantation.

SUMMARY BACKGROUND DATA

Early and late biliary tract complications after orthotopic liver transplantation remain a serious problem, leading to increased morbidity and mortality. Commonly performed techniques are the end-to-end choledochocholedochostomy and the choledochojejunostomy. Both techniques are known to coincide with a high incidence of leakage and stenosis of the bile duct anastomosis. The side-to-side bile duct anastomosis has been shown experimentally to be superior to the end-to-end anastomosis. The authors present the results of 316 human liver transplants, in which a side-to-side choledochocholedochostomy was performed.

METHODS

Biliary tract complications of 370 transplants in 340 patients were evaluated. Three hundred patients received primary liver transplants with side-to-side anastomosis of donor and recipient common bile duct. Thirty-two patients with biliary tract pathology received a bilioenteric anastomosis, and in eight patients, side-to-side anastomosis was not performed for various reasons. Clinical and laboratory investigations were carried out at prospectively fixed time points. X-ray cholangiography was performed routinely in all patients on postoperative days (PODs) 5 and 42. In patients with suspected papillary stenosis, endoscopic retrograde cholangioscopy and papillotomy were performed.

RESULTS

One biliary leakage (0.3%) was observed within the early postoperative period (PODs 0 through 30) after liver transplantation. No stenosis of the common bile duct anastomosis was observed during this time. Late biliary stenosis occurred in two patients (0.6%). T tube-related complications were observed in 4 of 300 primary transplants (1.3%). Complications unrelated to the surgical technique, including papillary stenosis (5.7%) and ischemic-type biliary lesion (3.0%), which must be considered more serious in nature than complications of the anastomosis or T tube-related complications, were observed. Papillary stenosis led to frequent endoscopic interventions and retransplantations in 1.3%.

CONCLUSIONS

Side-to-side common bile duct anastomosis represents a safe technique of bile duct reconstruction and leads to a low technical complication rate after human orthotopic liver transplantation. Ischemic-type biliary lesion evoked by preservation injury, arterial ischemia, cholestasis, and cholangitis may represent a new entity of biliary complication, which markedly increases the morbidity after human liver transplantation. Therefore, this complication should be the subject of further research.

Bacterial and fungal colonization and infections using oral selective bowel decontamination in orthotopic liver transplantations

Bacterial and fungal infections are a major cause of morbidity and mortality after orthotopic liver transplantation. In the immunocompromised host, infections are thought to arise from the gut, which is almost always colonized with potential pathogens. Using oral selective bowel decontamination (SBD), potential pathogens can be eradicated from the gut and infections prevented. In this catamnestic study we have reviewed gastrointestinal colonization, bacterial and fungal infections, and bacterial resistance to standard antibiotics in our first 206 liver transplant patients while under SBD. With few exceptions, gram-negatives were eradicated from the gastrointestinal tract and secondary colonization was inhibited. In spite of unsatisfactory elimination of Candida, probably because nystatin doses were too low, Candida infections were rare (n = 4) and none was fatal. One and two-year survival rates were 93% and 92%, respectively. The bacterial and fungal infection rate was 27.8% with an infection-related mortality of 1.95%. Infections with aerobic gram-positive bacteria prevailed and only 11 gram-negative and 11 fungal infections occurred; among the latter, Aspergillus and Mucor were the most serious and responsible for three of the six deaths in this series. With regard to the development of resistance, we found an increasing number of enterococci and coagulase-negative staphylococci resistant to ciprofloxacin and imipenem, respectively, but unlikely as a consequence of SBD.

Biliary tract reconstruction in liver transplantation

Biliary tract complications are often referred to as the "Achilles' heel" of liver transplantation and various techniques have been developed to overcome them. The two major methods of bile duct reconstruction currently in use consist of either (1) choledochocholedochostomy over a T-tube or, when duct-to-duct approximation is not feasible, choledochojejunostomy over an internal stent, or (2) interposition of the donor gallbladder as a conduit between the donor bile duct and either the recipient bile duct or a jejunal loop. Although these standardizations of biliary tract reconstruction have resulted in a reduction of biliary complications after liver transplantation, further advancement in the elucidation of ampullary obstruction and viability of the donor bile duct is needed.

Biliary complications in orthotopic liver transplantation: experience with a modified technique of duct-to-duct reconstruction

Biliary complications are described as frequent causes of morbidity during the postoperative course of orthotopic liver transplantation (OLTx), even in recent papers. The authors report here on their experience with duct-to-duct anastomosis as their method of choice for biliary reconstruction in a consecutive series of 100 OLTx in adult patients. The original technique, as described by Starzl, was modified by the authors by performing a wide, longitudinal plasty of both the donor and recipient bile ducts, joined together with two polidioxanone running sutures, producing the effect of a side-to-side anastomosis. This technique was used in all procedures, even when a significant discrepancy was evident between the ducts (n = 10). Follow-up was completed in 100% of the patients for a period of 2-40 months (mean 13.1 months). Four major complications (4%) occurred including hepatic abscesses due to ascending cholangitis, T-tube dislocation, partial occlusion by a branch of the T-tube at the anastomotic site, and disruption of the bile duct after T-tube removal. In four other patients, transient abdominal pain followed removal of the stent. Neither strictures nor fistulas were observed. Choledochocholedochostomy on a T-tube stent represents, in our experience, the technique of choice for biliary reconstruction in OLTx. The procedure, as described in the present study, proved to be safe in preventing strictures and leakages and appears to be feasible in nearly 100% of all adult patients undergoing OLTx.

[Problems in the reconstruction of bile flow in orthotopic liver transplantation]

In hepatic transplantation complications of the biliary drainage were frequently observed. Ischemia of the extrahepatic bile duct which occurs for anatomical reasons can cause necrosis of the bile duct. The reconstruction of biliary drainage by biliodigestive anastomosis results in ascending infections of the graft. Biliary sludge could obstruct the intra- or extrahepatic bile duct. Recently, operation methods are mainly applied in which the function of Oddi's sphincter is preserved, i.e. choledocho-choledochostomy or gallbladder conduit method. If it is not possible to perform these methods the Roux-y-jejunum loop is used. Finally, an immediate operative revision of the biliary drainage is indicated if its complication is diagnosed.

Experiences with liver transplantation in Hannover

Ninety orthotopic liver transplantations in 86 patients performed between 1972 and 1983 in the Medical University of Hannover are reviewed. Results in tumor patients (n = 46) are characterized by a high rate of early tumor recurrence. A few patients survived for prolonged periods, and some were cured. More experience is required to define more precisely suitable kinds and stages of malignancies so that liver grafting in tumor patients can be confined to situations with a favorable prognosis. The main problem of liver transplantation in cirrhotics (n = 40) is the appropriate time of indication. It is suggested that liver grafting be performed more often in an "elective" situation. This phase during the course of cirrhosis must be optimally defined by analysis of the underlying disease and by individual situation. Results of liver grafting in elective situations are better than those in emergency situations and may offer a tangible chance for cure. Liver grafting in pediatric patients gives the best results, although procurement of small donor organs is a major problem. More experience, better immunosuppression with cyclosporin A, and the search for the appropriate time of indication contribute to improvement in the results of liver grafting.