Insulin growth factor 2 (IGF2) as an emergent target in psychiatric and neurological disorders. Review

Insulin-like growth factor 2 (IGF2) is abundantly expressed in the central nervous system (CNS). Recent evidence highlights the role of IGF2 in the brain, sustained by data showing its alterations as a common feature across a variety of psychiatric and neurological disorders. Previous studies emphasize the potential role of IGF2 in psychiatric and neurological conditions as well as in memory impairments, targeting IGF2 as a pro-cognitive agent. New research on animal models supports that upcoming investigations should explore IGF2's strong promising role as a memory enhancer. The lack of effective treatments for cognitive disturbances as a result of psychiatric diseases lead to further explore IGF2 as a promising target for the development of new pharmacology for the treatment of memory dysfunctions. In this review, we aim at gathering all recent relevant studies and findings on the role of IGF2 in the development of psychiatric diseases that occur with cognitive problems.

Hepatic venous outflow obstruction in pediatric liver transplantation: technical considerations in prevention, diagnosis, and management

HVOO creates significant diagnostic and management dilemmas in pediatric liver transplant recipients, particularly with TVGs (split or reduced-size grafts). Numerous technical variations for the hepatic vein to IVC anastomosis have been described to minimize the incidence of this complication, but no consensus for an optimal anastomotic technique exists. One hundred and thirty-four liver transplants (70 TVGs) were performed in 124 patients between 1994 and 2011. These were divided into two cohorts. Group 1 (95 transplants, 41 TVGs) utilized a continuous running anastomosis. Group 2 (39 transplants, 29 TVGs) implemented a triangulated (three-stitch) anastomosis. All were reviewed for demographics, diagnostics, interventions, and outcome. The overall HVOO incidence was seven of 134 transplants (5.2%) and six of 70 transplants utilizing TVGs (8.6%). Group 1 incidence was five of 41 (12.2%) compared with one of 29 (3.4%; p = 0.20, OR 3.89) in Group 2. Liver Doppler was employed in all patients, and only three suggested HVOO. All patients with HVOO underwent venogram, at a median of 81 days post-transplant. All underwent percutaneous venoplasty and required 1-6 treatments, all resulting in HVOO resolution. Incidence of HVOO has improved since adopting the triangulated anastomosis, although not to a level of statistical significance. US is not adequately sensitive to exclude HVOO. Venogram is recommended in patients with prolonged ascites, and venoplasty has been highly successful in HVOO treatment.

A novel organ donor facility: a decade of experience with liver donors

Transplant surgeons have historically traveled to donor hospitals, performing complex, time-sensitive procedures with unfamiliar personnel. This often involves air travel, significant delays, and frequently occurs overnight.In 2001, we established the nation's first organ recovery center. The goal was to increase efficiency,reduce costs and reduce surgeon travel. Liver donors and recipients, donor costs, surgeon hours and travel time, from April 1,2001 through December 31,2011 were analyzed. Nine hundred and fifteen liver transplants performed at our center were analyzed based on procurement location (living donors and donation after cardiac death donors were excluded). In year 1, 36% (9/25) of donor procurements occurred at the organ procurement organization (OPO) facility, rising to 93%(56/60) in the last year of analysis. Travel time was reduced from 8 to 2.7 h (p<0.0001), with a reduction of surgeon fly outs by 93% (14/15) in 2011. Liver organ donor charges generated by the donor were reduced by37% overall for donors recovered at the OPO facility versus acute care hospital. Organs recovered in this novel facility resulted in significantly reduced surgeon hours, air travel and cost. This practice has major implications for cost containment and OPO national policy and could become the standard of care.

The role of liver transplantation for hepatic adenomatosis in the pediatric population: case report and review of the literature

Hepatic adenomas are benign lesions often found in young women during childbearing age. These tumors are often solitary but can also be multiple in which case this is referred to as hepatic adenomatosis (HA). HA is defined as having greater than or equal to ten adenomas within an otherwise normal liver. We present a case of a teenager with HA who underwent an orthotopic liver transplant for complications of her HA. To date there are only four reports of teenagers, without an underlying glycogen storage disease, who have undergone a liver transplant for HA. Liver transplantation within the pediatric population is an acceptable treatment for HA that are deemed unresectable.

The effect of recipient-specific surgical issues on outcome of liver transplantation in biliary atresia

Biliary atresia (BA), the most common reason for orthotopic liver transplantation (OLT) in children, is often accompanied by unique and challenging anatomical variations. This study examines the effect of surgical-specific issues related to the presence of complex vascular anatomic variants on the outcome of OLT for BA. The study group comprised 944 patients who were enrolled in the Studies of Pediatric Liver Transplantation (SPLIT) registry and underwent OLT for BA over an 11-year period. 63 (6.7%) patients met the study definition of complex vascular anomalies (CVA). Patient survival, but not graft survival, was significantly lower in the CVA group, (83 vs. 93 % at 1-year post-OLT). The CVA group had a significantly higher incidence of all reoperations, total biliary tract complications, biliary leaks and bowel perforation. The most frequent cause of death was infection, and death from bacterial infection was more common in the CVA group. Pretransplant portal vein thrombosis and a preduodenal portal vein were significant predictors of patient survival but not graft survival. This study demonstrates that surgical and technical factors have an effect on the outcome of BA patients undergoing OLT. However, OLT in these complex patients is technically achievable with an acceptable patient and graft survival.

Risk factors for rejection and infection in pediatric liver transplantation

Rejection and infection are important adverse events after pediatric liver transplantation, not previously subject to concurrent risk analysis. Of 2291 children (<18 years), rejection occurred at least once in 46%, serious bacterial/fungal or viral infections in 52%. Infection caused more deaths than rejection (5.5% vs. 0.6% of patients, p < 0.001). Early rejection (<6 month) did not contribute to mortality or graft failure. Recurrent/chronic rejection was a risk in graft failure, but led to retransplant in only 1.6% of first grafts. Multivariate predictors of bacterial/fungal infection included recipient age (highest in infants), race, donor organ variants, bilirubin, anhepatic time, cyclosporin (vs. tacrolimus) and era of transplant (before 2002 vs. after 2002); serious viral infection predictors included donor organ variants, rejection, Epstein-Barr Virus (EBV) naivety and era; for rejection, predictors included age (lowest in infants), primary diagnosis, donor-recipient blood type mismatch, the use of cyclosporin (vs. tacrolimus), no induction and era. In pediatric liver transplantation, infection risk far exceeds that of rejection, which causes limited harm to the patient or graft, particularly in infants. Aggressive infection control, attention to modifiable factors such as pretransplant nutrition and donor organ options and rigorous age-specific review of the risk/benefit of choice and intensity of immunosuppressive regimes is warranted.

The economic impact of preservation time in cadaveric liver transplantation

There has been considerable recent debate concerning the reconfiguration of the cadaveric liver allocation system with the intent to allocate livers to more severely ill patients over greater distances. We sought to assess the economic implications of longer preservation times in cadaveric liver transplantation that may be seen in a restructured allocation system. A total of 683 patients with nonfulminant liver disease, aged 16 years or older, receiving a cadaveric donor liver as their only transplant, were drawn from a prospective cohort of patients who received transplants between January 1991 and July 1994 at the University of California, San Francisco, the Mayo Clinic, Rochester, Minnesota, or the University of Nebraska, Omaha. The primary outcome measure was standardized hospitalization resource utilization from the day of transplantation through discharge. Secondary outcome measures included 2-year patient survival, and 2-year retransplantation rates. Results indicated that each 1-h increase in preservation time was associated with a 1.4% increase in standardized hospital resource utilization (p = 0.014). The effects on 2-year patient survival and retransplantation rates were not measurably affected by an increase in preservation time. We conclude that policies that increase preservation time may be expected to increase the cost of liver transplantation.

Renal transplantation following previous heart, liver, and lung transplantation: an 8-year single-center experience

BACKGROUND

Long-term follow-up of heart, liver, and lung transplantation has led to an increased recognition of secondary end-stage renal failure (ESRF) in transplant recipients. This study examines our center's experience with renal transplantation following previous solid organ transplantation.

METHODS

From January 1, 1992, to September 30, 1999, our center performed 18 renal transplants in previous solid organ recipients. During the same period, 815 total renal transplants were performed. One- and 3-year graft and patient survival, recipient demographics, donor type, and reason for transplantation were compared between these groups.

RESULTS

Of the 18 recipients, 7 had prior heart transplants, 4 had prior liver transplants, and 7 had prior lung transplants. Cyclosporine toxicity contributed to renal failure in 17 (94.4%) of the patients-either as a sole factor (11 patients) or in combination with hypertension, renal artery stenosis, or tacrolimus toxicity (6 patients). Kaplan-Meier 1- and 3-year patient survival was 82.9% and 73.7%, compared with 95.5% and 90.7% in all renal transplant recipients. No surviving patient has suffered renal allograft loss. Mean current creatinine level is 1.4 mg/dL.

CONCLUSIONS

Renal transplantation is an excellent therapy for ESRF following prior solid organ transplantation. One and 3-year patient and graft survival demonstrate the utility of renal transplantation in this patient population.

Effect of extended coverage of immunosuppressive medications by medicare on the survival of cadaveric renal transplants

Between 1993 and 1995, Medicare extended its coverage of maintenance immunosuppression medications following renal transplantation from 1 to 3 years. We hypothesized that Medicare's extension of immunosuppressive coverage would improve graft survival among low-income transplant recipients. We merged patient-level clinical data from the USRDS-distributed UNOS registry of kidney transplants throughout the USA with median family income for each patient's ZIP code from the 1990 Census. We were able to merge median incomes to 10,837 first cadaveric renal transplants performed in 1992-93 and 16,732 performed in 1995-97. Each of these chronological cohorts was divided into two groups, those with family incomes above (high-income group) and those below (low-income group) $36,033. There were no differences in graft survival at 1 year based on income in either chronological era. However, when Medicare covered immunosuppression medications for just 1 year, the low-income group of 1-year graft survivors had a 4.5% lower graft survival at the end of 3 years post-transplant (p < 0.001). During the 1995-97 period, during which Medicare provided 3 years' immunosuppression coverage, the low-income and high-income groups had equivalent graft survival at 3 years post-transplant.

The Barnes-Jewish Hospital/Washington University Renal Transplant Program: comparison of two eras 1991-1994 and 1995-2000

The first cadaveric transplant at Barnes-Jewish Hospital/Washington University was performed in 1963, the first living related transplant in 1965, and the first living unrelated transplant in 1983. Changes in the renal transplant program initiated in 1993 and 1994 resulted in many improvements over the past decade. Our comparison of 2 modern eras of transplant, 1991-1994 and 1995-2000, showed the following: 1. No significant differences in patient and donor characteristics. 2. Trends toward greater use of living donors (p = 0.07), older cadaveric donors (p = 0.084) and particularly cadaveric donors > 55 years of age (p = 0.09). 3. Decreasing mean CIT: 19.2 hours vs. 14.2 hours (p < 0.001). 4. Decreasing use of donors with CIT > 24 hours: 22% to 3%, (p < 0.001). 5. Decreased rate of DGF: 13% vs. 8% (p = 0.044). 6. Decreased rate of symptomatic CMV: 35% vs. 14% (p < 0.001). 7. Decreased rate of PTLD: 3.5% vs. 0.5% (p = 0.004). 8. Decreased one-year rate of acute rejection: 41% vs. 15% (p < 0.001). 9. Current one-year rate of acute rejection < 8%. 10. Decreased length of initial hospital stay: 12.7 days to 8.0 days (p < 0.001). 11. Decreased length of hospital in the first year after transplant: 10.6 days vs. 6.4 days (p < 0.001). 12. There were no improvements in patient and graft survival at one and 3 years. a. one-year patient survival rates: 95% vs. 96%. b. 3-year patient survival rates: 90% vs. 90%. c. one-year death-censored graft survival rates: 91% vs. 94%. d. 3-year death-censored graft survival rates: 87% vs. 88%.

Posttransplant lymphoproliferative disease in children: correlation of histology to clinical behavior

PURPOSE

To determine whether the morphologic features of posttransplant lymphoproliferative disease (PTLD) correlated to a response to therapy.

PATIENTS AND METHODS

We reviewed our experience with PTLD in the pediatric population. We identified 32 patients with a total of 36 episodes of PTLD. The diagnosis was confirmed by tissue examination and classified according to the degree of monomorphic features of the lesion. Thirty-four of 36 episodes were managed with immunosuppression reduction, and the patients were assessed for their response to this strategy. Chemotherapy was used to treat 10 of 15 patients who had progressive disease, and their subsequent course was also analyzed.

RESULTS

Sixteen of 17 (94%) patients with polymorphic morphology responded to immunosuppression reduction compared with only 5 of 17 (29%) patients with monomorphic features (P < 0.001). All of the patients with progressive disease who did not receive additional therapy died. Standard chemotherapy regimens for lymphoma were administered to 10 patients with progressive disease, with a high response rate (90%), durable remissions, and acceptable toxicity.

CONCLUSIONS

We conclude that the morphologic characteristics of PTLD provide information to potentially help guide treatment strategies in the management of this disease. Standard chemotherapy regimens for malignant lymphoma appear to be a viable treatment option for patients with progressive disease, although further investigation is needed.

Economic cost of expanded criteria donors in cadaveric renal transplantation: analysis of Medicare payments

BACKGROUND

The use of expanded criteria donors (ECDs) in cadaveric renal transplantation is increasing in the US. We assess the economic impact of the use of ECDs to the Medicare end stage renal disease program.

METHODS

The United Nations for Organ Sharing renal transplant registry was merged to Medicare claims data for 42,868 cadaveric renal transplants performed between 1991-1996 using USRDS identifiers. Only recipients for whom Medicare was the primary payer were considered, leaving 34,534 transplants. An ECD was defined as (1) age < or =5 or > or =55 years, (2) nonheart-beating donors, donor history of (3) hypertension or (4) diabetes. High-risk recipients (HRR) were age >60 years, or a retransplant. Medicare payments from the pretransplant dialysis period were projected forward to provide a financial "breakeven point" with transplantation.

RESULTS

There were 25,600 non-HRR transplants, with 5,718 (22%) using ECDs, and 8,934 HRR transplants, of which 2,200 (25%) used ECDs. The 5-year present value of payments for non-ECD/non-HRR donor/recipient pairings was $121,698 vs. $143,329 for ECD/non-HRR pairings (P<0.0001) and, similarly was $134,185 for non-ECD/HRR pairings vs. $165,716 for ECD/HRR pairings (P<0.0001). The break even point with hemodialysis ranged from 4.4 years for non-ECD/ non-HRR pairings to 13 years for the ECD/HRR combinations but was sensitive to small changes in graft survival. Transplantation was always less expensive than hemodialysis in the long run.

CONCLUSIONS

The impact of ECDs on Medicare payments is most pronounced in high-risk recipients. Cadaveric renal transplantation is a cost-saving treatment strategy for the Medicare ESRD program regardless of recipient risk status or the use of ECDs.

The economic benefit of allocation of kidneys based on cross-reactive group matching

BACKGROUND

Recently the United Network for Organ Sharing (UNOS) began a pilot study to evaluate prospectively the merits of an allocation of cadaveric kidneys based on broader classes of HLA antigens, called cross-reactive groups (CREG). The objectives of the pilot study consider patient outcomes, but not the potential economic impact of a CREG-based allocation. This study predicts the impact of a CREG-based local allocation of cadaveric kidneys on 3-year Medicare payments and graft survival.

METHODS

The UNOS renal transplant registry was merged to Medicare claims data for 1991-1997 by the United States Renal Data System. Average accumulated Medicare payments and graft survival up to 3 years posttransplant for first cadaveric renal transplant recipients were stratified by cross-reactive group mismatch categories. The economic impact was defined as the difference in average 3-year costs per transplant between the current and proposed allocation algorithms. Average 3-year costs were computed as a weighted average of costs, where the weights were the actual and predicted distributions of transplants across cross-reactive group categories.

RESULTS

Results suggest that an organ allocation based on cross-reactive group matching criteria would result in a 3-year cost savings of $1,231 (2%) per transplant, and an average 3-year graft survival improvement of 0.6%.

CONCLUSIONS

Cost savings and graft survival improvements can be expected if CREG criteria were to replace current criteria in the current allocation policy for cadaveric kidneys, although the savings appear to be smaller than may be achievable through expanded HLA matching.

Economics of the antithymocyte globulins Thymoglobulin and Atgam in the treatment of acute renal transplant rejection

OBJECTIVE

To evaluate the economic implications for transplant centres, Medicare and society of treatment of corticosteroid-resistant Banff Grades I, II and III acute kidney transplant rejection with the antithymocyte globulins Thymoglobulin or Atgam.

DESIGN AND SETTING

This was a cost analysis of a randomised double-blind multicentre clinical trial comparing the safety and efficacy of Thymoglobulin and Atgam that was performed at 25 centres in the US in 1994 to 1996.

PATIENTS AND PARTICIPANTS

The study enrolled 163 patients, 82 in the Thymoglobulin arm and 81 in the Atgam arm.

METHODS

Estimates of the cost of care from the initiation of rejection therapy to 90 days post-therapy were derived from various publicly available sources and applied to patient-specific clinical events documented in the clinical trial. Patients received either intravenous Thymoglobulin (1.5 mg/kg/day) for an average of 10 days or intravenous Atgam (15 mg/kg/day) for an average of 9.7 days.

RESULTS

On average, Thymoglobulin provided significant cost savings compared with Atgam from the perspective of society [$US5977 (1996 values); 95% confidence interval (CI) $US3719 to $US8254], Medicare ($US4967; 95% CI $US3256 to $US6678) and the transplant centre ($US3087; 95% CI $US1512 to $US4667). The overall advantage attributable to Thymoglobulin was primarily due to savings from fewer recurrent rejection treatments and less frequent return to dialysis.

CONCLUSIONS

Treatment of acute renal transplant rejection with Thymoglobulin is a cost saving strategy when compared with treatment with Atgam.

Cadaveric versus living donor kidney transplantation: a Medicare payment analysis

BACKGROUND

We found previously that the clinical advantages of living donor (LD) renal transplantation lead to financial cost savings compared to either cadaveric donation (CAD) or dialysis. Here, we analyze the sources of the cost savings of LD versus CAD kidney transplantation.

METHODS

We used United States Renal Data System data to merge United Network for Organ Sharing registry information with Medicare claims data for 1991-1996. Information was available for 42,868 CAD and 13,754 LD transplants. More than 5 million Medicare payment records were analyzed. We calculated the difference in average payments made by Medicare for CAD and LD for services provided during the first posttransplant year.

RESULTS

Average total payments were $39,534 and $24,652 for CAD and LD, respectively (P<0.0001) during the first posttransplant year. The largest source of the difference in payments was in inpatient hospitals, representing $10,653.67 (P<0.0001). For patients who had Medicare as the primary payer, average transplant charges were significantly higher for CAD donation ($79,730 vs. $69,547, P<0.0001); average transplant payments demonstrated no statistical differences ($28,483 vs. $28,447, P = 0.858). Therefore, inferred profitability was significantly higher for LD.

CONCLUSIONS

Medicare payments are remarkably lower for LD compared to CAD in every category. The single largest cost saving comes from inpatient hospital services. A portion of the savings from LD could be invested in programs to expand living kidney donation.

The economic implications of HLA matching in cadaveric renal transplantation

BACKGROUND

The potential economic effects of the allocation of cadaveric kidneys on the basis of tissue-matching criteria is controversial. We analyzed the economic costs associated with the transplantation of cadaveric kidneys with various numbers of HLA mismatches and examined the potential economic benefits of a local, as compared with a national, system designed to minimize HLA mismatches between donor and recipient in first cadaveric renal transplantations.

METHODS

All data were supplied by the U.S. Renal Data System. Data on all payments made by Medicare from 1991 through 1997 for the care of recipients of a first cadaveric renal transplant were analyzed according to the number of HLA-A, B, and DR mismatches between donor and recipient and the duration of cold ischemia before transplantation.

RESULTS

Average Medicare payments for renal transplant recipients in the three years after transplantation increased from 60,436 dollars per patient for fully HLA-matched kidneys (those with no HLA-A, B, or DR mismatches) to 80,807 dollars for kidneys with six HLA mismatches between donor and recipient, a difference of 34 percent (P<0.001). By three years after transplantation, the average Medicare payments were 64,119 dollars for transplantations of kidneys with less than 12 hours of cold ischemia time and 74,997 dollars for those with more than 36 hours (P<0.001). In simulations, the assignment of cadaveric kidneys to recipients by a method that minimized HLA mismatching within a local geographic area (i.e., within one of the approximately 50 organ-procurement organizations, which cover widely varying geographic areas) produced the largest cost savings (4,290 dollars per patient over a period of three years) and the largest improvements in the graft-survival rate (2.3 percent) when the potential costs of longer cold ischemia time were considered.

CONCLUSIONS

Transplantation of better-matched cadaveric kidneys could have substantial economic advantages. In our simulations, HLA-based allocation of kidneys at the local level produced the largest estimated cost savings, when the duration of cold ischemia was taken into account. No additional savings were estimated to result from a national allocation program, because the additional costs of longer cold ischemia time were greater than the advantages of optimizing HLA matching.

Reducing the shortage of donor livers: what would It take to reliably split livers for transplantation into two adult recipients?

This article examines the scientific, technical, and administrative barriers to splitting donor livers for use in two adults. The main scientific barrier is that cadaveric donor livers at their current level of postoperative function are not sufficiently large to support life in two adult recipients. However, glycogenation of livers from young donors may be a method to overcome this problem in the short term. The three technical obstacles to splitting the liver in the midplane are anatomic anomalies that complicate or prevent splitting, the means to detect these anomalies, and the surgical methods to accomplish the split. Anatomic anomalies affecting the biliary drainage and arterial supply of the liver are the most important limiting technical factors. Administrative accommodations in the current methods of organ allocation will be needed if split-liver transplantation in adults is to succeed. A nationwide view of organ allocation requires that the total number of lives saved by the procedure be the priority outcome nationally. If liver transplantation is viewed from this perspective, split-liver transplantation for adults would be a high priority, and incentives should be set to encourage it.

Unusual presentations of nonmycotic hepatic artery pseudoaneurysms after liver transplantation

The clinical presentation and causes of hepatic artery pseudoaneurysm vary widely in the postoperative liver transplant recipient, although infection is the most common cause. Although uncommon, hepatic artery complications continue to be an important source of morbidity in liver transplant recipients. Thrombosis, stenosis, and pseudoaneurysm formation are the most common posttransplantation arterial complications. Pseudoaneurysms are most commonly mycotic in origin. Prompt recognition of hepatic artery pseudoaneurysms with aggressive intervention (both surgical and angiographic) may decrease the morbidity associated with this rare clinical entity. The records of 263 consecutive patients who underwent orthotopic liver transplantation between 1991 and 1996 were reviewed retrospectively and assessed for hepatic artery complications. Two patients (0.7%) developed hepatic artery pseudoaneurysm, neither associated with infection. Both patients required operative repair and are doing well without vascular complications at a mean follow-up of 22.5 months. The clinical presentation and causes of hepatic artery pseudoaneurysm vary widely in the postoperative liver transplant recipient. Prompt recognition of hepatic artery pseudoaneurysms with aggressive intervention (both surgical and angiographic) may decrease the morbidity associated with this rare clinical entity.

A randomized, double-blinded comparison of Thymoglobulin versus Atgam for induction immunosuppressive therapy in adult renal transplant recipients

BACKGROUND

The aim of this study was to compare the efficacy and safety of Thymoglobulin (a rabbit-derived polyclonal antibody) to Atgam (a horse-derived polyclonal antibody) for induction in adult renal transplant recipients.

METHODS

Transplant recipients (n=72) were randomized 2:1 in a double-blinded fashion to receive Thymoglobulin (n=48) at 1.5 mg/kg intravenously or Atgam (n=24) at 15 mg/kg intravenously, intraoperatively, then daily for at least 6 days. Recipients were observed for at least 1 year of follow-up.

RESULTS

By 1 year after transplantation, 4% of Thymoglobulin-treated patients experienced acute rejection compared with 25% of Atgam-treated patients (P=0.014). The rate of acute rejection was lower with Thymoglobulin than Atgam (relative risk=0.09; P=0.009). Rejection was less severe with Thymoglobulin than Atgam (P=0.02). No recurrent rejection occurred with Thymoglobulin compared with 33% with Atgam (P=NS). Patient survival was not different, but the composite end point of freedom from death, graft loss, or rejection, the "event-free survival," was superior with Thymoglobulin (94%) compared with Atgam (63%; P=0.0005). Fewer adverse events occurred with Thymoglobulin (P=0.013). Leukopenia was more common with Thymoglobulin than Atgam (56% vs. 4%; P<0.0001) during induction. The mean absolute lymphocyte count remained below baseline with Thymoglobulin throughout the study (P<0.007), but with Atgam, significant lymphocyte reductions occurred only at day 7. The incidence of cytomegalovirus disease was less with Thymoglobulin than Atgam at 6 months (10% vs. 33%; P=0.025).

CONCLUSIONS

Brief (7-day) induction with Thymoglobulin resulted in less frequent and less severe rejection, a better event-free survival, less cytomegalovirus disease, fewer serious adverse events, but more frequent early leukopenia than induction with Atgam. These results may in fact be explained by a more profound and durable beneficial lymphopenia.

Surgery of the small intestine

This article reviews both clinical and scientific advances in surgery of the small intestine that have been reported in the last year. The management of both pediatric and adult intussusception is considered. Multiple studies on the evolving role of ileal pouch-anal anastomosis are assessed. The treatment and epidemiology of a wide variety of intestinal neoplasms are reviewed. Advances in small bowel transplantation are also reported. The cause of small bowel obstruction is considered as well as new strategies to prevent adhesion formation. Finally, a number of diverse topics relating to intestinal surgery, including new data on laparoscopic surgery, treatment of enterocutaneous fistulas, reconstruction after total gastrectomy, intestinal transit after ileocecal segment transposition, and ischemia/reperfusion and anastomotic healing, are reviewed.

Transplantation of developing metanephroi into adult rats

BACKGROUND

Transplantation of developing metanephroi into adult hosts has been proposed as a means to augment host renal function.

METHODS

We implanted whole metanephroi from embryonic day 15 (E15) rats subcapsularly in kidneys or into the omentum of non-immunosupressed adult rat hosts. At the time of implantation, some host rats underwent unilateral nephrectomy (UNX) or unilateral nephrectomy and partial contralateral renal infarction (1 1/2 NX). E15 metanephroi contained only metanephric blastema, segments of ureteric bud, and primitive nephrons with no glomeruli.

RESULTS

Four to six weeks post-implantation, metanephroi from E15 rats had enlarged, become vascularized, and had formed mature tubules and glomeruli. Ureters of metanephroi transplanted into the omentum were anastomosed to hosts' ureters that remained after UNX. Four weeks following ureteroureterostomy, the contralateral kidney was removed. Inulin clearances of seven metanephroi implanted into UNX hosts averaged 0.11 +/- 0.02 microliters/min/100 g (2.42 +/- 0.70 microliters/min/g kidney wt) and the creatinine clearances averaged 0.65 +/- 0.18 microliters/min/100 g. Metanephroi weighed 71 +/- 15 mg (approximately 4% of the contralateral native kidney). The transplanted metanephroi were vascularized by arteries originating from the omentum. Both weights of transplanted metanephroi (145 +/- 24 mg) and inulin clearances of transplanted metanephroi (30.1 +/- 8.7 microliters/min/g kidney weight) were significantly increased in rats that underwent 1 1/2 NX compared to UNX. In contrast, transplantation of developed kidneys resulted in rejection.

CONCLUSIONS

Our findings establish that functional chimeric kidneys develop from metanephroi transplanted in adult hosts.

Prophylactic oral ganciclovir compared with deferred therapy for control of cytomegalovirus in renal transplant recipients

BACKGROUND

Treatment with prophylactic oral acyclovir, intravenous ganciclovir, or immunoglobulins to prevent cytomegalovirus (CMV) infection and disease in renal transplantation is associated with variable efficacy and significant expense. We studied control of CMV in renal transplant recipients using either prophylactic oral ganciclovir or deferred therapy with intensive monitoring with polymerase chain reaction (PCR) analysis.

METHODS

Forty-two recipients were followed for 6 months after transplantation. Ganciclovir (1000 mg p.o. t.i.d.; n=19) or acyclovir (200 mg p.o. b.i.d.; n=23) was begun at transplantation and continued for 12 weeks. PCR for CMV was performed on buffy-coat specimens every week for 15 weeks and at months 5 and 6.

RESULTS

No patients in the ganciclovir group, compared with 14 of 23 patients (61%) in the deferred-therapy group (P<0.0001), developed CMV disease during the first 12 weeks. In the ganciclovir group, 4 of 19 patients (21%) subsequently experienced 5 episodes, whereas 14 patients in the deferred-therapy group experienced 18 episodes (P=0.013 for subjects and P=0.026 for episodes). The time to disease was also delayed in the ganciclovir group compared with the deferred-therapy group (133+/-17 days vs. 51+/-7 days; P<0.0001). Oral ganciclovir also prevented CMV viremia during prophylaxis (2/19 patients [11%] vs. 23/23 patients [100%]). Time to CMV viremia was delayed in the ganciclovir group; however, 13/19 patients (68%) ultimately showed PCR evidence for CMV viremia (P=0.005).

CONCLUSIONS

An initial 12-week course of oral ganciclovir prevents CMV disease and infection in renal transplant recipients during prophylaxis, and the benefits persist after discontinuation.

Retransplantation in the diabetic patient with a pancreas allograft

BACKGROUND

Retransplantation has been considered a risk factor for both postoperative complications and diminished graft survival, especially in diabetic patients.

METHODS

A retrospective survey was performed of a consecutive case series of 196 pancreas transplants in 186 diabetic patients. All patients underwent whole organ pancreas transplantation with bladder drainage.

RESULTS

A total of 33 pancreas transplants (17%) in 30 patients were performed after previous transplant. The mean interval between transplants was 3.9 years. At the time of retransplantation, 16 patients had concomitant procedures. Venous extension grafts were used in 10 patients. The mean length of initial hospital stay was 19.5 days, and mean hospital charges were approximately $125,000. The incidences of rejection, infection, and operative complications were 61%, 67%, and 45%, respectively. Patient survival was 90%, kidney graft survival was 82%, and pancreas graft survival was 61% after a mean follow-up of 29 months. Complete rehabilitation was achieved in 73% of cases.

CONCLUSIONS

Pancreas transplantation after previous transplant is a challenging but safe treatment that often requires concomitant procedures, the use of vascular extension grafts, and atypical placement of the allograft. However, the good results justify an aggressive policy of retransplantation in the diabetic patient either with a failed allograft or functioning kidney transplant.

Evidence of a role for matrix metalloproteinases in cold preservation injury of the liver in humans and in the rat

Previous studies have determined that proteases are important in cold preservation injury to the liver. The purpose of this study was to determine the role of matrix metalloproteinases (MMPs) in cold preservation injury. Effluents were collected from rat livers after various periods of preservation either in Eurocollins solution or in University of Wisconsin (UW) solution. Effluents were also collected from 17 human donor livers stored in UW solution. To determine whether sinusoidal endothelial cells released MMPs when placed in the cold, these cells were isolated from rat livers and cultured at 4 degrees C. Gelatin zymography, quantitative assay of gelatinolytic activity, immunoprecipitation, and Western blotting were used to identify metalloproteinases and to measure their activity. Human and rat liver effluents contained gelatin-digesting bands on zymography. Their appearance was inhibited by specific metalloproteinase inhibitors and also by lactobionate, the major ingredient of UW solution. The most prominent bands in humans and the rat appeared at approximately 72 kd and 92 kd, suggesting that they were the MMPs 72-kd gelatinase and 92-kd gelatinase. Supernatants of isolated rat sinusoidal endothelial cells stored in the cold contained similar bands. In the rat, the proteinases were present in both latent and active forms, but, in humans, predominately the latent form was seen. In humans, there were four prominent bands in the gelatin zymography. By immunoprecipitation, two of the bands were identified as the 92-kd gelatinase and a dimer or polymer of 92-kd gelatinase. Using Western blotting with a monoclonal antibody, a third band was identified as 72-kd gelatinase. In quantitative terms, gelatinolytic activity increased with time of cold storage in humans and in the rat. In the rat, gelatinolytic activity was greater when Eurocollins was the preservative than when UW solution was used. Taken together, these results indicate an important role for MMPs in the injury produced by cold preservation of the liver.

Peripheral blood microchimerism in human liver and renal transplant recipients: rejection despite donor-specific chimerism

BACKGROUND

Development of donor-specific microchimerism (DSM) has been proposed as one of the possible mechanisms for induction and maintenance of allograft tolerance. The aim of this study was to determine: (1) the state of DSM in liver transplant (LTx) and renal transplant (RTx) recipients, (2) whether the persistent presence of an allograft is a requirement for maintenance of chimerism, and (3) whether donor-specific blood transfusions (DST) facilitate chimerism development in RTx recipients and whether this correlates with allograft function.

METHODS

Qualitative and quantitative analysis of DSM in peripheral blood of LTx and RTx recipients was assessed by polymerase chain reaction and competitive polymerase chain reaction using HLA-DR probes for mismatched antigens between the donor and recipient.

RESULTS

LTx recipients (11 of 12) who had or were having rejection were positive for DSM in circulation compared with 4 of 11 with normal allograft function (P<0.01). The number of donor cells did not correlate with allograft function. LTx recipients (4 of 4) who lost their first allograft and underwent retransplantation retained DSM for the first donors. RTx recipients who received DST (8 of 8) were positive for DSM compared with 6 of 12 of nontransfused recipients (P<0.045).

CONCLUSIONS

The results suggest that LTx and RTx recipients undergo rejection despite DSM. The development of DSM may not be a prerequisite for normal allograft function. Once DSM is established, the presence of the allograft is not required for maintenance of chimerism. DST facilitated the development of DSM in RTx recipients. Direct correlation was not observed between the development of DSM and allograft function in either DST or nontransfused RTx recipients.

Liver transplantation after jejunoileal bypass for morbid obesity

BACKGROUND

Jejunoileal (JI) bypass was developed as a therapy for morbid obesity in the late 1960s but has since been abandoned because of a high rate of complications, including cirrhosis. The need for liver transplantation after JI bypass has been infrequent, with only four previous patients reported in the literature; however, because the time to develop symptomatic end-stage liver disease after JI bypass may be quite long (25 years or more), the incidence of patients who will require liver transplantation may only now be increasing.

STUDY DESIGN

We reviewed our experience with JI bypass and liver transplantation in 380 consecutive adult patients since 1985.

RESULTS

Four patients underwent liver transplantation for cirrhosis after JI bypass, all within the last 48 months. The mean duration of time from JI bypass to transplantation was 22.3 years. All patients had complications, in addition to their liver disease, which were related to the JI bypass, which included nephrolithiasis, cholelithiasis, vitamin deficiencies, renal insufficiency, and d-lactic acidosis. One patient had the JI bypass taken down before transplantation, which precipitated acute liver and renal failure, necessitating urgent transplantation. One patient, who had the JI bypass taken down at the time of transplant, has developed recurrent morbid obesity, while the other three patients have not. The one patient who has not had the JI bypass taken down has not developed evidence of recurrent liver disease and is followed with monthly liver function tests and yearly biopsies.

CONCLUSIONS

The incidence of patients who require liver transplantation after JI bypass may be on the increase. Take down of the JI bypass may precipitate acute liver failure in the cirrhotic patient. JI bypass should be accomplished either at the time of transplantation or if signs of liver dysfunction occur after transplantation. Liver transplant recipients can be at risk for recurrent obesity after takedown of the JI bypass. Transplantation for those patients with decompensated cirrhosis after JI bypass has demonstrated excellent early results.

Experience with enteric conversion after pancreatic transplantation with bladder drainage

BACKGROUND

Bladder drainage by the duodenal segment technique is currently the preferred method of handling the exocrine secretions after vascularized pancreatic transplantation. Despite improving results, however, the management of metabolic and urologic complications associated with bladder drainage remains problematic.

STUDY DESIGN

A retrospective survey was performed of a consecutive case series of 196 pancreatic transplantations in 186 patients with diabetes over an 80-month period. All patients underwent whole organ pancreatic transplantation with bladder drainage by the duodenal segment technique.

RESULTS

A total of 25 conversions (13 percent) from bladder drainage to enteric drainage were performed in 24 patients (24 side-to-side duodenoenterostomies, one Roux-en-Y limb duodenoenterostomy). The mean time of enteric conversion after pancreatic transplantation was 22 +/- 18 months (range, 1 to 72 months). All but two of the enteric conversions were performed at least 6 months after pancreatic transplantation. Indications for enteric conversion included dehydration with intractable metabolic acidosis (n = 18; 9 percent), urologic complications (n = 5; 3 percent), or problems with the duodenal segment (n = 2; 1 percent). The mean length of hospitalization for enteric conversion was 12 +/- 7 days (range, 6 to 30 days). All patients experienced improvement in their symptoms after enteric conversion. Anastomotic leaks developed postoperatively in five patients; two were managed operatively and three were managed nonoperatively. Oral bicarbonate supplementation was eliminated in all but one patient after enteric conversion. Patient survival is 100 percent and pancreatic graft survival (insulin independence) is 96 percent after a mean follow-up of 22 months after enteric conversion.

CONCLUSIONS

Enteric conversion after pancreatic transplantation with bladder drainage is a safe and effective therapy for refractory problems related to the duodenal segment, altered physiologic function, or urologic complications and should be considered after 6 months for patients with persistent side effects.

A pharmacoeconomic comparison of antithymocyte globulin and muromonab CD3 induction therapy in renal transplant recipients

Antithymocyte globulin (ATG) and muromonab CD3 (OKT3) are currently the only antilymphocyte preparations that are commercially available for induction immunosuppressive therapy for renal allograft transplantation in the US. ATG, in the usually prescribed doses, is more expensive than muromonab CD3, but muromonab CD3 is associated with more severe adverse effects that may affect clinical outcome and overall cost. We performed a retrospective study of all adult recipients of a first cadaveric renal allograft, who underwent transplantation between January 1991 and December 1994 who received either ATG (n = 92) or muromonab CD3 (n = 91) for induction therapy at our transplant centre. The average age of recipients was older (50 vs 44 yrs; p = 0.001) and extended donors were more commonly used in the ATG group (41 vs 13%; p = 0.0001) compared with the muromonab CD3 group. Nevertheless, at 1 year post-transplant, the incidence of rejection was lower (34 vs 47%) and graft survival was better (93 vs 85%; p = 0.03) in the ATG group. Patients who received ATG were discharged earlier (9.4 vs 13.3 days; p = 0.0001) and had similar serum creatinine levels on the day of discharge (2.4 +/- 1.5 vs 2.1 +/- 1.1 mg/dl; p = 0.25). Overall, the 1-year hospitalisation costs of transplantation and readmissions were similar [$US39,937 +/- 17,014 vs $US42,850 +/- 20,923 (currency year 1994); p = 0.22]. This is the first comparison of ATG and muromonab CD3 in renal transplant recipients to consider clinical as well as economic outcomes. For renal transplant patients in whom induction therapy is used at our centre, the initial expense of ATG can be justified by improved graft survival, fewer rejection episodes, and shorter hospital stays, which are associated with similar overall transplantation costs.

Control of cytomegalovirus-associated morbidity in renal transplant patients using intensive monitoring and either preemptive or deferred therapy

The objective of this randomized, prospective study was to compare preemptive to deferred treatment of cytomegalovirus (CMV) infection in high-risk renal transplant recipients. Conducted at a university-affiliated transplant center, the study included 36 renal allograft recipients with donor or recipient CMV-seropositivity who received anti-thymocyte induction therapy. Ganciclovir was administered intravenously for 21 days upon detection of CMV viremia (preemptive, N = 15) or detection of CMV viremia associated with a CMV syndrome (deferred, N = 21). Shell vial culture, conventional culture, and polymerase chain reaction (PCR) were performed upon buffy-coat specimens weekly for 12 to 16 wk. CMV and non-CMV-associated charges were calculated. The comparative sensitivities of PCR, shell vial culture, and conventional culture were 91%, 44%, and 47%, respectively. A delay in specimen processing of > 24 h severely compromised the sensitivity of culture techniques but not that of PCR. Preemptive therapy tended to decrease symptomatic CMV episodes (0.4 versus 0.6 episodes per patient randomized; P = 0.22). One patient in each group had organ involvement, and no patient died. Allograft function and survival were similar. Ganciclovir use was increased in the preemptive group (1.2 versus 0.6 courses per patient randomized; P = 0.02). CMV-associated charges were $10,368 (preemptive) versus $5,752 (deferred); P = 0.13. PCR is superior to conventional monitoring to detect CMV viremia. Culture cannot be considered the "gold standard" for detection of CMV viremia, especially when transport of specimens over distances results in processing delays. Preemptive therapy may reduce symptomatic CMV infections in renal transplant recipients. It was associated with higher CMV-related charges but equivalent overall charges versus deferred treatment with intensive monitoring. Either strategy can achieve control of CMV infection after renal transplantation.

Comparison of survival of an expanded polytetrafluoroethylene graft designed for early cannulation to standard wall polytetrafluoroethylene grafts

BACKGROUND

Placement and maintenance of a well-functioning vascular access are essential for delivery of adequate hemodialysis. Newly placed polytetrafluoroethylene (PTFE) arteriovenous grafts require a period of wound healing and incorporation of fibrous tissue before use, a period typically lasting two to three weeks. An ideal PTFE graft would be one that can be used for vascular access immediately, obviating the need for temporary dialysis catheters. Recently an expanded PTFE (ePTFE) graft with a mesh cannulation segment (Diastat graft) has been proposed for early cannulation.

STUDY DESIGN

This is a retrospective single-center study comparing ePTFE graft survival to contemporaneously placed standard wall PTFE (GORE-TEX) grafts.

RESULTS

Forty-seven consecutive new or established patients receiving chronic hemodialysis had grafts (25 ePTFE, 22 standard PTFE) placed between November 1994 and July 1995. There were no significant differences between the groups in age, race, gender, incidence of diabetes mellitus, or peripheral vascular disease. By the end of the study, 21 of 25 ePTFE grafts had clotted, compared with 11 of the 22 patients receiving a standard PTFE graft. Median time to first clotting was 53 days for the ePTFE grafts and 164 days for the standard PTFE grafts (p < 0.0001). Nine patients with ePTFE grafts required a temporary catheter after their first clotting episode.

CONCLUSIONS

The ePTFE grafts thrombosed at a significantly higher rate than standard wall PTFE grafts. Further experience with the Diastat graft might improve graft survival. However, early experience does not suggest that the avoidance of short-term temporary access outweighs the problem of high clotting rate, and its attendant morbidity.

Nutritional assessment and therapy in patients requiring liver transplantation

Pretransplant nutritional assessment in the patient with ESLD is problematic. The best system for nutritional assessment uses a "global" evaluation of the patient's nutritional reserves. With such a technique, the vast majority of transplant candidates have been shown to have evidence of malnutrition. Several investigators have demonstrated the risk of significant malnutrition on posttransplant outcome. An aggressive approach to nutritional repletion is necessary to improve the ESLD patient's metabolic reserves, maintain remaining hepatic function, and better the outcome after liver transplantation.

Insulin-like growth factor-I attenuates delayed graft function in a canine renal autotransplantation model

BACKGROUND

Insulin-like growth factor-I (IGF-I) has been shown to accelerate recovery in animal models of ischemic or toxic acute renal injury. Ischemic renal injury is frequently encountered after cadaveric transplantation manifested as delayed graft function. This study was performed to determine whether perfusion of kidneys with preservation solution supplemented with IGF-I would improve the course of renal injury in a canine autotransplantation model of delayed graft function.

METHODS

Dogs underwent unilateral nephrectomy with kidneys perfused and stored in Euro-Collins solution supplemented with vehicle (n = 11) or IGF-I (n = 8). After 24 hours of kidney preservation, a contralateral nephrectomy was performed and the stored kidney was autotransplanted. Renal function was examined for 5 days after the transplantation, and an inulin clearance was obtained at the time of death.

RESULTS

Compared with dogs that received kidneys preserved in the vehicle, dogs receiving the IGF-I preserved kidneys had significantly lower daily serum creatinine and blood urea nitrogen levels during the course of 5 days after transplantation. Inulin clearance at death was nearly double in the IGF-I treated animals compared with the vehicle-treated controls (1.37 +/- 0.16 ml/min/kg versus 0.77 +/- 0.13 ml/min/kg; p < 0.05).

CONCLUSIONS

Perfusion and storage of kidneys with preservation solution supplemented with IGF-I can attenuate the course of delayed graft function in a canine renal autotransplantation model. IGF-I may have potential for use in cadaveric human renal transplantation.