Differences in outcomes for patients with bacteremia due to vancomycin-resistant Enterococcus faecium or vancomycin-susceptible E. faecium

To determine the differences in outcome in cases of enterococcal bacteremia due to vancomycin-resistant organisms, we compared consecutive patients on a liver transplant service who had clinically significant bacteremia due to vancomycin-resistant Enterococcus faecium (VREF) (n = 54) with a contemporaneous cohort of patients who had vancomycin-susceptible E. faecium (VSEF) bacteremia (n = 48). VREF bacteremia occurred significantly later in the hospitalization than did VSEF bacteremia (43 days vs. 24 days, respectively; P < .01); in addition, VREF was more frequently the sole blood pathogen isolated (91% of patients) than was VSEF (56% of patients) (P = .0002). Invasive interventions for intraabdominal and intrathoracic infection were required more often in the VREF cohort than in the VSEF cohort (34 of 45 patients vs. 20 of 41 patients, respectively; P = .01). Vancomycin resistance more frequently resulted in recurrent bacteremia (22 of 54 patients infected with VREF vs. 7 of 48 patients infected with VSEF; P = .006), persistent isolation of Enterococcus species at the primary site (27 of 33 patients infected with VREF vs. 7 of 18 patients infected with VSEF; P = .005), and endovascular infection (4 patients infected with VREF vs. none infected with VSEF). The decrement in patient survival, as measured from the last bacteremic episode, was greater in the VREF cohort (P = .02). Vancomycin resistance, shock, and liver failure were independent risk factors for Enterococcus-associated mortality. Higher rates of refractory infection, serious morbidity, and attributable death occurred in the VREF cohort and were partially mediated by the lack of effective antimicrobial therapy.

Small bowel transplantation: current progress and clinical application

Total parenteral nutrition (TPN) is used routinely to maintain patients with the Short Bowel Syndrome (SBS). Until recently, TPN has been the only available therapeutic modality for patients with SBS. Currently, it is the treatment of choice for such individuals and occasionally, when the loss of bowel is extensive, it may be the only way of maintaining life. Unfortunately, TPN is expensive and markedly restrains an individual's lifestyle. Despite the overall success of TPN, the numerous risks associated with its use and the many complications of having an intravenous indwelling for years have served as the stimulus for alternative treatments such as small bowel transplantation (SBT). The first attempts at small bowel transplantation in clinical medicine were by Detterling almost 25 years ago. Patient death or graft loss in these early attempts was caused by the failure to control graft rejection and/or the inability to prevent Graft Versus Host Disease (GVHD). A stimulus for renewed clinical interest in SBT was provided by Starzl et al in 1988 with a report of prolonged graft survival without graft rejection or GVHD in a patient who was the recipient of a multivisceral graft consisting of the entire small bowel and other abdominal organs. Since 1964, 78 Small Bowel transplants have been performed in humans. Several variations of the multivisceral procedure in which the liver and the small bowel constitute the major components of the graft were adopted. The longest survival has been in a child who is still alive with a working graft for more than two years, as reported by Goulet from Paris in 1989. The introduction in SBT of the new immunosuppressive agent FK 506 had provided results which are superior to those achieved with Cyclosporine A (CsA). This latter observation prompted the Pittsburgh group to initiate a large series of isolated and composite intestinal grafts. The remarkable results have demonstrated the clinical utility of intestinal transplantation. This paper will try to summarize the history of the small bowel transplantation until the end of the year 1992, with the current progress in use today.

Transjugular intrahepatic portosystemic shunt in patients with end-stage liver disease: results in 85 patients

Transjugular intrahepatic portosystemic shunt (TIPS) is becoming an accepted procedure as a bridge to orthotopic liver transplantation (OLT) in patients with end-stage liver disease (ESLD) and bleeding from portal hypertension. It allows the immediate control of acute bleeding and decreases the risk of recurrent acute bleeding while the patient is awaiting OLT. We review in this report, our experience with 85 patients who underwent a TIPS procedure for gastrointestinal variceal bleeding from September 1991 until April 1994. All patients had liver cirrhosis and all had previous sclerotherapy before TIPS. Child-Pugh score was calculated at enrollment, and all patients were evaluated for possible OLT. Thirteen patients were Child A, 49 were Child B, and 23 were Child C. Fifty-three patients were candidates for OLT, and 32 were not. TIPS was performed urgently in 25 patients. At a median follow-up of 582 days (range, 1 to 1,095), 35 patients underwent transplantation, 21 patients died, and 29 patients are still alive and did not undergo transplantation. Technical complications were observed in 7% of patients and new onset of clinical encephalopathy in 37%. The 30-day mortality rate after TIPS was 13%. Actuarial survival was 60% at 1 and 3 years. Child class C and urgent TIPS were shown to be two independent predictor factors for mortality. TIPS was shown to be a valuable procedure, not only as a bridge to OLT but also as palliation for bleeding from portal hypertension in patients who were not candidates for either surgical shunt or OLT. However, its role in bleeding patients with acceptable liver function needs further investigation.

Performance of multi-layer feedforward neural networks to predict liver transplantation outcome

A novel multisolutional clustering and quantization (MCQ) algorithm has been developed that provides a flexible way to preprocess data. It was tested whether it would impact the neural network's performance favorably and whether the employment of the proposed algorithm would enable neural networks to handle missing data. This was assessed by comparing the performance of neural networks using a well-documented data set to predict outcome following liver transplantation. This new approach to data preprocessing leads to a statistically significant improvement in network performance when compared to simple linear scaling. The obtained results also showed that coding missing data as zeroes in combination with the MCQ algorithm, leads to a significant improvement in neural network performance on a data set containing missing values in 59.4% of cases when compared to replacement of missing values with either series means or medians.

A high incidence of native portal vein thrombosis in veterans undergoing liver transplantation

The incidence of native portal vein thrombosis (PVT) in liver transplant recipients has been reported to range from 2.1 to 13.8%. We have identified an inordinately high incidence of PVT in a consecutive series of U.S. veterans receiving liver transplants. Between October 1989 and February 1994, 88 consecutive U.S. veterans received 99 orthotopic liver transplants under primary Tacrolimus (Prograf, formerly FK506) based immunosuppression. A number of clinical features were examined in an effort to identify risk factors for PVT and outcome was compared to patients without PVT. Native PVT was present in 23/88 (26%) patients. All of these patients were male U.S. veterans with a mean age of 47 years. When compared to the 65 patients without PVT, we found no significant difference with respect to underlying liver disease, age, Childs-Pugh score (mean = 12), UNOS status as defined prior to April 1995 (95% UNOS 3 or 4), previous abdominal surgery, or liver volume. Median blood loss for patients with PVT (21 units of packed red blood cells) was greater than for those without PVT (14 units, P = 0.04). Portal thrombectomy was performed in 11 patients, 11 patients required mesoportal jump grafts, and 1 patient had an interposition graft. Standard veno-venous bypass was used in 10 patients with single bypass utilized for the remainder. Actuarial patient survival for all patients at 1, 2, and 4 years was 88, 85, and 79%, respectively. There was no significant difference in patients with or without PVT. Patients with PVT had poorer graft survival than patients without PVT (86% vs 65%, 1 year; 81% vs 65%, 2 years; 81% vs 61%, 4 years; P = 0.03); however, this was not related to technical problems with the portal venous inflow. PVT occurred in 26% of U.S. veterans undergoing liver transplantation. These patients had significantly higher operative blood loss and poorer graft survival. The high incidence of postnecrotic cirrhosis in a predominantly male group of patients with advanced disease, as is evident by the high mean Childs-Pugh score and UNOS status, perhaps accounts for our observations.

Cadaveric liver donors; what are the limits?

The current crisis in organ availability will only be solved by aggressive and innovative solutions. One approach, outlined here, is to more carefully assess current donors and determine how to safely "push the limits" of acceptable cadaveric liver donors. Our experience, as well as that of others, indicates that donors with these higher risk factors may be used in certain carefully defined situations. The key elements to an appropriate use of these donors are careful donor and recipient assessment, and avoiding the presence of multiple risk-factors. These guidelines form a foundation for continuing assessment of methods to increase, in an incremental fashion, the number of cadaver livers successfully transplanted.

Factors associated with the development of candidemia and candidemia-related death among liver transplant recipients

OBJECTIVE

The authors' objective was to identify factors associated with candidemia and candidemia-related death among adult liver transplant recipients.

SUMMARY BACKGROUND DATA

Invasive candidiasis is the most common severe fungal infection occurring after liver transplantation and is associated with high morbidity and mortality rates. Although candidemia is not always found during invasive candidiasis, it has been considered as an indicator of invasive candidiasis in immunocompromised patients.

METHODS

A time-matched case-control study of 26 patients with candidemia, which was defined as the isolation of Candida from at least one blood culture, and 52 control patients without candidemia was reported. Two control patients were matched with each case patient regarding time of transplantation and duration of follow-up.

RESULTS

Between December 1985 and December 1992, candidemia developed in 1.4% of adult liver transplant recipients a median of 25 days after transplantation (range, 2-1690 days). The overall mortality rate among patients with candidemia was 81%, and 71% of these deaths were related to candidemia. Conditional logistic regression analysis was used to identify factors associated with candidemia, which were 1) hyperglycemia treated with insulin up to 2 weeks before candidemia (odds ratio [OR], 16.15; p = 0.002), and 2) exposure to more than three different intravenous antibiotics before development of candidemia (OR, 11.15; p = 0.005). The variables predictive of death related to candidemia were abdominal surgery performed up to 1 week before candidemia (relative risk [RR], 7.25; p = 0.02), high white blood cell count (RR, 1.10; p = 0.01), lower platelet count (RR, 0.99; p = 0.02), and elevated AST with candidemia (RR, 1.001; p = 0.01).

CONCLUSIONS

Hyperglycemia that requires insulin and exposure to more than three antibiotics are the factors associated with the development of candidemia in liver transplant recipients. When candidemia develops shortly after abdominal surgery and in patients with elevated AST, high white blood cell count, or low platelet count, it is associated with a high mortality rate.

Orthotopic liver transplantation in U.S. veterans under primary tacrolimus immunosupression

The evolution and refinement of surgical techniques, per ioperative patient care, and immunosuppression hav~ estab~ished orthoto~ic li~er transplantation (OLTX) as a ~ighly successful therapeutic modality for patients wrth end-stage hver disease. In February 1989,Tacrohmus (Prograf®, formerly FK 506)was first used successfully at the University of Pittsburgh Medical Center to treat patients with rejection refractory to cyclosporine-based immunosuppression." Clinical trials utilizing Tacrolimus in solid organ transplantation followed, and in April of 1994 it was approved for use by the Food and Drug Administration,

Allogeneic hematolymphoid microchimerism and prevention of autoimmune disease in the rat. A relationship between allo- and autoimmunity

Conventional allogeneic bone marrow transplantation after myeloablation can prevent experimental autoimmunity and has been proposed as treatment for humans. However, trace populations of donor hematolymphoid cells persisting in solid organ allograft recipients have been associated in some circumstances with therapeutic effects similar to replacement of the entire bone marrow. We therefore examined whether inducing hematolymphoid microchimerism without myeloablation could confer the ability to resist mercuric chloride (HgCl2)-induced autoimmunity. Brown-Norway (BN) rats were pretreated with a syngeneic or allogeneic bone marrow infusion under transient FK506 immunosuppression before receiving HgCl2. They were compared with BN rats receiving either no pretreatment (naive) or FK506 alone. Administration of HgCl2 to naive BN rats induced marked autoantibody production, systemic vasculitis and lymphocytic infiltration of the kidneys, liver and skin in all of the animals and a 47% mortality. In contrast, BN rats pretreated with HgCl2-resistant allogeneic Lewis bone marrow and transient FK506 showed less clinical disease and were completely protected from mortality. More specifically, IgG anti-laminin autoantibody production was decreased by 40% (P < 0.05), and there was less histopathological tissue injury (P < 0.005), less in vitro autoreactivity (P < 0.05), less of an increase in class II MHC expression on B cells (P < 0.01), and 22% less weight loss (P < 0.01), compared with controls. Protection from the experimental autoimmunity was associated with signs of low grade activation of the BN immune system, which included: increased numbers of circulating B and activated T cells before administration of HgCl2, and less autoreactivity and spontaneous proliferation in vitro after HgCl2.

FK506 in solid organ transplantation

FK506 (Prograf) is a new immunosuppressive agent, recently approved for use in solid organ transplants. The first use of FK506 was for the indication of refractory liver allograft rejection. This revealed a marked ability to reverse ongoing rejection, even in cases where chronic changes were observed. Between 50 and 70% of patients converted to FK506 had shown improvement. In long-term follow-up of patients with chronic rejection, 75% of patients were still alive at 3 years following FK506 conversion, and 65% of liver allografts were still functioning. FK506 has been compared to cyclosporine in primary liver transplantation. In the three randomized trials, freedom from rejection was statistically greater in the FK506-treated group, as compared to the cyclosporine-treated group. By intent-to-treat analysis, the patient and graft survival in the FK506 group was the same or better than the cyclosporine group. The good results in the cyclosporine limb was due, in part, to the ability of FK506 to treat rejection in the cyclosporine group. Freedom from steroid use, and the lower incidence of hypertension, were prominent features of FK506 patients. FK506 has been used for rescue of rejecting kidney allografts, with results similar to the liver transplant trials. When used as primary immunosuppression, FK506 was shown to be effective, as measured by graft survival. FK506-based immunosuppression has also been used in primary heart transplantation, as well as for primary adult pulmonary transplantation. Results from these small series of patients are equally encouraging. The results of these studies suggest that FK506 is effective for solid organ transplantation. Both FK506 and cyclosporine administration have been associated with side effects, many of which are similar, and some of which are peculiar to a given organ transplant.

Effect of donor age and sex on the outcome of liver transplantation

We correlated donor and recipient factors with graft outcome in 436 adult patients who underwent 462 liver transplants. Donor variables analyzed were age, gender, ABO blood group, cause of death, length of stay in the intensive care unit, use of pressors or pitressin, need for cardiopulmonary resuscitation, terminal serum transaminases, and ischemia time. Recipient variables analyzed were age, gender, primary diagnosis, history of previous liver transplant, ABO blood group, cytotoxic antibody crossmatch, United Network for Organ Sharing (UNOS) status, and waiting time (except for the cross-match results, they were all known at the time of the operation). The endpoint of the analysis was graft failure, defined as patient death or retransplantation. Using multivariate analysis, graft failure was significantly associated with donor age, donor gender, previous liver transplantation, and UNOS 4 status of the recipient. The effect of donor age became evident only when they were older than 45 years. Livers from female donors yielded significantly poorer results, with 2-year graft survival of female to male 55% (95% CI, 45% to 67%); female to female, 64% (95% CI, 54% to 77%); male to male, 72% (95% CI, 66% to 78%); and male to female, 78% (95% CI, 70% to 88%). The only donors identified as questionable for liver procurement were old (> or = 60 years) women in whom the adverse age and gender factors were at least additive. However, rather than discard even these livers, in the face of an organ shortage crisis, their individualized use is suggested with case reporting in a special category.

Effect of donor age and sex on the outcome of liver transplantation

We correlated donor and recipient factors with graft outcome in 436 adult patients who underwent 462 liver transplants. Donor variables analyzed were age, gender, ABO blood group, cause of death, length of stay in the intensive care unit, use of pressors or pitressin, need for cardiopulmonary resuscitation, terminal serum transaminases, and ischemia time. Recipient variables analyzed were age, gender, primary diagnosis, history of previous liver transplant, ABO blood group, cytotoxic antibody crossmatch, United Network for Organ Sharing (UNOS) status, and waiting time (except for the cross-match results, they were all known at the time of the operation). The endpoint of the analysis was graft failure, defined as patient death or retransplantation. Using multivariate analysis, graft failure was significantly associated with donor age, donor gender, previous liver transplantation, and UNOS 4 status of the recipient. The effect of donor age became evident only when they were older than 45 years. Livers from female donors yielded significantly poorer results, with 2-year graft survival of female to male 55% (95% CI, 45% to 67%); female to female, 64% (95% CI, 54% to 77%); male to male, 72% (95% CI, 66% to 78%); and male to female, 78% (95% CI, 70% to 88%). The only donors identified as questionable for liver procurement were old (> or = 60 years) women in whom the adverse age and gender factors were at least additive. However, rather than discard even these livers, in the face of an organ shortage crisis, their individualized use is suggested with case reporting in a special category.

Long-term results after liver transplantation for primary hepatic epithelioid hemangioendothelioma

BACKGROUND

Hepatic epithelioid hemangioendothelioma (PHEHE) is a multifocal, low-grade malignant neoplasia characterized by its epithelial-like appearance and vascular endothelial histogenesis. The outcome of 16 patients treated with orthotopic liver transplantation (OLT) is the subject of this report.

METHODS

A retrospective study of 16 patients with HEHE (7 men, 9 women) with ages ranging from 24 to 58 years (mean 37 +/- 10.6 years). Follow-up intervals ranged from 1 to 15 years (median of 4.5 years).

RESULTS

Actual patient survival at 1, 3, and 5 years was 100, 87.5, and 71.3%, respectively. Disease-free survival at 1, 3, and 5 years was 81.3, 68.8, and 60.2%, respectively. The 90-day operative mortality was 0. Involvement of the hilar lymph nodes or vascular invasion did not affect survival. The 5-year survival of HEHE compares favorably with that of hepatocellular carcinoma at the same stage (stage 4A): 71.3 versus 9.8% (p = 0.001)

CONCLUSIONS

The long-term survival obtained in this series justifies OLT for these tumors even in the presence of limited extrahepatic disease.