Decreased surgical risks of pancreas transplantation in the modern era

Transplantation for type I diabetes: comparison of vascularized whole-organ pancreas with isolated pancreatic islets

OBJECTIVE

We sought to compare the efficacy, risks, and costs of whole-organ pancreas transplantation (WOP) with the costs of isolated islet transplantation (IIT) in the treatment of patients with type I diabetes mellitus.

SUMMARY BACKGROUND DATA

A striking improvement has taken place in the results of IIT with regard to attaining normoglycemia and insulin independence of type I diabetic recipients. Theoretically, this minimally invasive therapy should replace WOP because its risks and expense should be less. To date, however, no systematic comparisons of these 2 options have been reported.

METHODS

We conducted a retrospective analysis of a consecutive series of WOP and IIT performed at the University of Pennsylvania between September 2001 and February 2004. We compared a variety of parameters, including patient and graft survival, degree and duration of glucose homeostasis, procedural and immunosuppressive complications, and resources utilization.

RESULTS

Both WOP and IIT proved highly successful at establishing insulin independence in type I diabetic patients. Whole-organ pancreas recipients experienced longer lengths of stay, more readmissions, and more complications, but they exhibited a more durable state of normoglycemia with greater insulin reserves. Achieving insulin independence by IIT proved surprisingly more expensive, despite shorter initial hospital and readmission stays.

CONCLUSION

Despite recent improvement in the success of IIT, WOP provides a more reliable and durable restoration of normoglycemia. Although IIT was associated with less procedure-related morbidity and shorter hospital stays, we unexpectedly found IIT to be more costly than WOP. This was largely due to IIT requiring islets from multiple donors to gain insulin independence. Because donor pancreata that are unsuitable for WOP can often be used successfully for IIT, we suggest that as IIT evolves, it should continue to be evaluated as a complementary alternative to rather than as a replacement for the better-established method of WOP.

Antifungal Prophylaxis in Solid-Organ Transplant Recipients: Considerations for Clinical Trial Design

BACKGROUND

There are several key issues regarding clinical trial design for antifungal prophylaxis in organ transplant recipients.

METHODS

The existing and emerging data on the epidemiology and risk factors for invasive mycoses in organ transplant recipients formed the basis for discerning the subgroups that may be targeted for prophylaxis, the unique end points to be considered, and the attributes of currently available drugs that may be suitable candidates for antifungal prophylaxis.

RESULTS

Epidemiological characteristics of invasive mycoses in organ transplant recipients have evolved sufficiently to warrant thoughtful reconsideration of the subsets of patients and the fungal pathogens to be targeted for antifungal prophylactic trials in the current era. Safety and tolerability of antifungal agents and outcome stratified by severity of illness are important end points given the potential for drug interactions with immunosuppressive agents and the fact that a beneficial effect of prophylaxis on outcome has been difficult to document in organ transplant recipients.

CONCLUSIONS

Clinical trial design for antifungal prophylaxis must carefully consider the unique issues pertaining to the selection of patients most likely to benefit, as well as the tolerability and drug interactions of antifungal agents in organ transplant recipients.

Pancreatic transplantation: Beta cell replacement

Diabetes is a leading cause of morbidity and mortality worldwide. Complications of diabetes including renal failure, retinopathy, neuropathy, and cardiovascular disease limit both survival and quality of life. Pancreatic transplantation can restore euglycemia thereby stabilizing or even reversing secondary complications of diabetes as well as improving quality of life particularly in patients with labile diabetes. Recent evidence also shows an improved survival in diabetic patients that undergo pancreatic transplantation when combined with a kidney transplant. Pancreatic transplantation should more properly be referred to as beta cell replacement as the field today encompasses both whole organ and islet cell transplantation. We have outlined herein the indications and contraindications to islet or whole organ pancreas transplantation and we have described periprocedure care and short- and long-term prognosis.

Advances in pancreas transplantation

Despite early obstacles impacting the success of pancreatic transplantation, the introduction of new procedures and new immunosuppressive therapies during the past 2 decades has improved outcomes for pancreatic transplant recipients. For example, the use of bladder drainage and better human leukocyte antigen matching has helped overcome some of the early obstacles of pancreatic transplantation. In addition, the introduction of tacrolimus in 1994 and mycophenolate mofetil in 1996 has helped lower rates of acute rejection and increase graft survival, with less nephrotoxicity than treatment with cyclosporine. Regimens allowing the tapering of corticosteroids have also helped reduce the rates of acute pancreas rejection. To further improve therapeutic options for patients with type 1 diabetes or end-stage renal disease, pancreatic islet transplantation and organ and islet xenotransplantation should be further explored.

Does treatment of cadaveric organ donors with desmopressin increase the likelihood of pancreas graft thrombosis? results of a preliminary study

Desmopressin (DDAVP) is commonly used in cadaveric organ donors to treat diabetes insipidus. The thrombogenic potential of DDAVP is well known. Recent animal data have demonstrated that DDAVP impairs pancreas graft (PG) microcirculation and perfusion. The aim of this study was too evaluate the effect of DDAVP on the incidence of PG thrombosis in clinical pancreas transplantation. A retrospective review of simultaneous kidney-pancreas transplant (SKPT) entered in the Scientific Registry of Transplant Recipients (SRTR) between 10/5/87 and 9/27/02 was performed. Patients were included for analysis if there was definitive documentation as to whether DDAVP was (DDAVP-Y) or was not (DDAVP-N) administered to the donor. Both dose and duration of DDAVP treatment were not recorded by SRTR. A total of 2804 SKPTs were available for analysis. Mean follow-up was 1.75 years (range, 1 month to 8.4 years). A total of 1287 SKPT patients (46%) received a PG from a DDAVP-Y donor. Graft ischemia times, donor and recipient ages, recipient gender distribution, surgical techniques, and immunosuppressive regimens were similar in both groups. The overall incidence of PG thrombosis was 4.3%. The incidence of PG thrombosis in recipients of grafts from DDAVP-Y donors was 5.1% compared to 3.5% in recipients of grafts from DDAVP-N donors (P =.04). Fifty-eight percent of thrombosed PG came from DDAVP-Y donors compared to 42% from DDAVP-N donors (P =.04). We conclude that there appears to be a relationship between donor treatment with DDAVP and PG thrombosis. A prospective study is needed to verify these findings and to determine their clinical significance.

Vascular complications of pancreas transplantation

OBJECTIVE

The purpose of our study was to focus on the early diagnosis and treatment of vascular complications after simultaneous pancreas-kidney (SPK) transplantation. Description of the technique for salvage of the graft after venous thrombosis (VT) is also provided.

METHODS

From July 1994 to December 2002, 14 patients of 206 SPK transplant recipients had partial VT. Partial splenic VT (PSVT) was documented in 10 patients (4.8%), two had complete thrombosis of the splenic vein, one partial superior mesenteric thrombosis, and one developed partial thrombosis of the splenic and superior mesenteric vein. Four patients developed complete VT of the pancreas allograft and one superior mesenteric artery thrombosis. Our experience with four arteriovenous fistulae is also reported. The immunosuppression included tacrolimus, steroids, and monoclonal antibody to the IL-2 receptor. Thymoglobulin was introduced in June 2000 in our protocol combined with rapamycin or mycophenolate mofetil. These cases were identified following the intravenous (iv) use of tacrolimus with or without anti-IL-2R therapy. One case of complete VT is also reported one month following transplantation in a recipient with high rapamycin levels. Diagnosis was established during routine color Doppler ultrasonography.

RESULTS

Partial VT was effectively treated with anticoagulation. Complete VT required surgical thrombectomy. In our series, the pancreas was salvaged successfully in all patients with the technique described here.

CONCLUSION

Early diagnosis of vascular complications after pancreas transplantation is of paramount importance for the appropriate treatment with organ salvage. Based on our experience, we suggest that VT can be effectively treated with anticoagulation. Aspirin is sufficient for PSVT.

Simultaneous pancreas-kidney transplantation: infectious complications and microbiological aspects

OBJECTIVE

The purpose of this study was to describe the clinical and microbiological characteristics of the infectious complications among simultaneous pancreas-kidney transplantations (SPKT).

MATERIALS AND METHODS

Among the first 45 SPKT the mean age was 34 years (range, 21 to 49) and the mean duration of follow-up 13 months (range, 2 to 27 months).

RESULTS

Twenty-three patients (51%) presented at least one to three episodes (1.7 mean) of infectious complications that needed hospitalization. The etiology of the infections included 71% bacterial (44% gram-negative rods and 27% gram-positive cocci), 16% viral (12% from CMV and 4% from Herpes sp) and 13% fungal (8% by Candida sp and 4% by others fungus). Wound and urinary infections were most frequent, occurring in 22% and 28% of the patients, respectively. All patients who were submitted to vesical drainage developed infections in contrast a rate of only 44% among patients undergoing enteric drainage.

CONCLUSION

Infectious complications are the main cause of morbidity and mortality following simultaneous pancreas-kidney transplantation, especially with vesical drainage. The use of enteric drainage combined with administration of broad spectrum prophylactic antibiotics is recommended.

The impact of donor obesity on outcomes after cadaver pancreas transplants

We examined the impact of donor obesity on surgical complications and graft function after pancreas transplants. From January 1994 through December 2001, we performed 711 cadaver pancreas transplants. We analyzed outcomes for three groups based on donor body mass index (BMI): <25 kg/m2 (n=434), 25-30 (n=196), and >30 (n=81). Donor characteristics were similar between the three groups except for donor cause of death. Cerebrovascular deaths were more common in the BMI >30 group (p=0.002), while trauma deaths were more common in the BMI <25 group (p=0.02). In the BMI >30 group, surgical complications, most notably surgical infections and thrombosis, were significantly more common; in addition, technical failure rates were higher and short-term graft survival was inferior. The incidence of technical failure was 9.7% in the BMI <25 group, 16.3% in the BMI 25-30 group, and 21.0% in the BMI >30 group (p=0.04). However, when we looked at only technically successful transplants, we found minimal differences in the three groups with regard to graft survival at 1 and 3 years posttransplant. Donor obesity increased the incidence of surgical complications in our pancreas recipients, but did not affect initial graft function posttransplant. Technically successful transplants using obese donors results in good graft function at 1 and 3 years posttransplant.

Perioperative treatment with octreotide minimizes technical complications after enteric conversion of bladder-drained pancreas transplants

We review our experience with enteric conversion of previously bladder-drained pancreas transplants (PTx) using a short perioperative course of octreotide (OCT). Between July 1994 and December 2001, 45 consecutive primary bladder-drained PTx were performed. Immunosuppression consisted of a combination of tacrolimus, mycophenolate mofetil and steroids after induction with monoclonal or polyclonal antibodies. A total of 16 patients underwent enteric conversion at an average of 3 months after the initial transplant. Each patient received OCT perioperatively. We report no technical complications with the exception of one superficial wound infection and good early and late PTx survival rates. Perioperative treatment with octreotide is well tolerated and may reduce technical complications while performing enteric conversion of previously bladder-drained PTx.

High levels of C-reactive protein after simultaneous pancreas-kidney transplantation predict pancreas graft-related complications and graft survival

BACKGROUND

Although pancreas graft-related complications are frequent after simultaneous pancreas-kidney transplantation (SPK), there are no parameters predicting the risk for these complications.

METHOD

A two-center retrospective study was performed in 97 patients who underwent SPK to investigate the peak serum value of c-reactive protein (CRP) during the first 72 hr after SPK in view of graft-related complications and graft survival.

RESULTS

Mean peak CRP was 115.6 +/- 71.5 mg/L. Mean peak CRP was higher in patients needing relaparotomy (n=31) (136.4 vs. 105.8 mg/L, P=0.048), especially when postoperative bleeding was excluded (P=0.015); in patients with graft pancreatitis (P=0.03); and in patients with graft loss (n=19; P<0.001) compared with patients without these complications. With a cut-off of peak CRP at the level of mean plus 1 SD (187.05 mg/L), there was a significantly higher incidence of relaparotomies (P=0.01; bleedings excluded: P=0.003), graft pancreatitis (P=0.03), and pancreas graft loss (P<0.0001) in patients with high peak CRP compared with patients with low peak CRP. No differences were noticed with regard to rejection rate, mortality, and kidney graft loss.

CONCLUSION

Our findings suggest that peak CRP is a helpful parameter in predicting pancreas graft-related complications and pancreas graft survival after SPK. Our results also stress the importance of early graft damage in pancreas transplantation.

Simultaneous pancreas-kidney transplantation utilizing a common arterial conduit: early experience and potential applications

Simultaneous pancreas-kidney transplantation has gained acceptance as a therapeutic modality for patients with end-stage renal disease secondary to diabetes mellitus. In some instances, performing the procedure as conventionally described with renal revascularization from the left iliac vessels and pancreatic arterial inflow from the right iliac vessels may be difficult or undesirable. We describe our experience with an alternate operative technique utilizing a single arterial conduit to vascularize both organs. We believe that this technique may be of use in certain patients undergoing simultaneous pancreas-kidney transplantation.

Chronic rejection: the next major challenge for pancreas transplant recipients

OBJECTIVE

With newer immunosuppressive agents, acute rejection and graft loss resulting from acute rejection have become less common for pancreas transplant recipients. As long-term graft survival rates have improved, an increasing number of grafts are being lost to chronic rejection (CR). We studied the incidence of CR and identified risk factors.

METHODS

We retrospectively analyzed all cadaver pancreas transplants performed at the University of Minnesota between June 19, 1994, and December 31, 2002. We determined the causes of graft loss, the incidence of graft loss to CR and, using multivariate techniques, the major risk factors for CR.

RESULTS

A total of 914 cadaver pancreas transplants were performed in the following three categories: simultaneous pancreas-kidney (SPK) (n=321), pancreas after kidney (PAK) (n=389), and pancreas transplant alone (PTA) (n=204). The mean recipient age was 41.3 years and the mean donor age was 30.1 years. Of the 914 pancreas grafts, 643 (70.3%) continue to function (mean length of follow-up, 39 months). The most common cause of graft loss was technical failure, accounting for 118 (12.9%) of the failed grafts. The second most common cause was CR, accounting for 80 (8.8%) of the failed grafts. The incidence of graft loss to CR was highest for PTA (n=23 [11.3%]) and PAK (n=45 [11.6%]) recipients and lowest for SPK recipients (n=12 [3.7%]) (P=0.002). By multivariate analysis, the most significant risk factors for graft loss to CR were a previous episode of acute rejection (relative risk [RR]=4.41, P<0.0001), an isolated (vs. simultaneous) transplant (PAK or PTA [vs. SPK], RR=3.02, P=0.002), cytomegalovirus infection posttransplant (RR=2.41, P=0.001), a retransplant (versus primary transplant) (RR=2.27, P=0.004), and one or two (vs. zero) antigen mismatches at the B loci (RR=1.68, P=0.04).

CONCLUSIONS

As short-term pancreas transplant results improve and as isolated (PAK or PTA) pancreas transplants gain in popularity, CR will become increasingly common as a cause of pancreas graft loss.

Value of donor swabs for intra-abdominal infection in simultaneous pancreas-kidney transplantation

BACKGROUND

Simultaneous pancreas-kidney transplantation (SPK) has a higher rate of surgical complications compared with other whole organ transplantations. Graft thrombosis and intra-abdominal infections are the most frequent causes for relaparotomy. We evaluated risk factors for abdominal infections after SPK, with emphasis on the value of the routinely taken intraoperative swabs.

METHODS

Between June 1994 and December 2000, 177 SPK were performed. Immunosuppression consisted of antithymocyte globulin induction and triple-drug maintenance therapy. Routine swabs were taken from the graft perfusion solutions, from the donors' duodenum, and from the recipients' bladder and jejunum (in case of enteric drainage).

RESULTS

A total of 19 (10.7%) of 177 patients underwent 41 relaparotomies as a result of intra-abdominal infections. Positive microbial results from any donor site and positive duodenal swabs were significant risk factors for intra-abdominal infections after SPK (P=0.01, P=0.02). There was a significantly higher incidence of abdominal infections when Candida was found in the donor duodenal swab (P=0.0048). Patient survival was significantly lower in cases with abdominal infection (P=0.02). Survival rates of patients with and without abdominal infection were 89.5% and 97.4% at 1 year and 72.3% and 92.8% at 5 years, respectively.

CONCLUSIONS

The results of this study confirm that abdominal infections significantly reduce patient survival and thus jeopardize the success of SPK. Positive donor duodenal swabs have been revealed to be a significant risk factor for a subsequent intra-abdominal infection, especially when Candida was found.

Lower gastrointestinal hemorrhage from an arterioenteric fistula in a pancreatorenal transplant patient

We report a case of a severe lower gastrointestinal hemorrhage caused by arterioenteric fistula formation in a pancreas transplant patient. A rare but potentially deadly complication of pancreas transplant surgery, arterioenteric fistulas should be considered in every transplant patient presenting with voluminous gastrointestinal bleeding. If diagnosed promptly, angiographic and surgical intervention can prevent serious morbidity and mortality.

Simultaneous pancreas-kidney transplant from living related donor: a single-center experience

BACKGROUND

Simultaneous pancreas and kidney transplantation (SPK) from cadaveric donors has become a widely accepted therapeutic option for insulin-dependent uremic patients. In 1996 the first SPK from a live donor was performed. This procedure offers the advantage of a better immunologic match, reduced cold ischemia injury, and decreased waiting time. As such, it is an attractive alternative treatment for diabetic patients with end-stage nephropathy with an available living donor.

METHODS

We performed six SPKs from living-related donors. There were four men and two women among the recipients; median age was 34 (range, 29-39) years. All donors were recipients' siblings with excellent HLA matching. Donors underwent standardized metabolic workup, anti-insulin and anti-islet antibody assays, and computed tomography of the abdomen. Both donors and recipients were treated with octreotide for 5 days perioperatively. After transplantation, the patients were maintained on tacrolimus-based immunosuppression, with the exception of one recipient of SPK from an identical twin, who received cyclosporine monotherapy.

RESULTS

All the donors are doing well and have normal renal function and blood glucose levels. One-year patient, renal, and pancreatic graft survival rates were 100%, 100%, and 83%, respectively. Acute kidney rejection was documented in two patients, and both recovered completely after OKT3 therapy. No rejection of pancreatic graft has been documented. Except for one patient who lost the graft because of hemorrhagic pancreatitis, all recipients maintained serum glucose levels at less than 130 mg/dL without insulin therapy. No major surgical complications such as graft thrombosis, intra-abdominal infection, or abscess were reported.

CONCLUSIONS

Living donor SPK can represent a successful alternative to cadaveric donor SPK. The procedure can be performed safely in the donor and with low morbidity in the recipient.

Insulin independence following isolated islet transplantation and single islet infusions

OBJECTIVE

To restore islet function in patients whose labile diabetes subjected them to frequent dangerous episodes of hypoglycemic unawareness, and to determine whether multiple transplants are always required to achieve insulin independence.

SUMMARY BACKGROUND DATA

The recent report by the Edmonton group documenting restoration of insulin independence by islet transplantation in seven consecutive patients with type 1 diabetes differed from previous worldwide experience of only sporadic success. In the Edmonton patients, the transplanted islet mass critical for success was approximately more than 9,000 IEq/kg of recipient body weight and required two or three separate transplants of islets isolated from two to four cadaveric donors. Whether the success of the Edmonton group can be recapitulated by others, and whether repeated transplants using multiple donors will be a universal requirement for success have not been reported.

METHODS

The authors report their treatment with islet transplantation of nine patients whose labile type 1 diabetes was characterized by frequent episodes of dangerous hypoglycemia.

RESULTS

In each of the seven patients who have completed the treatment protocol (i.e., one or if necessary a second islet transplant), insulin independence has been achieved. In five of the seven patients only a single infusion of islets was required. To date, only one recipient has subsequently lost graft function, after an initially successful transplant. This patient suffered recurrent hyperglycemia 9 months after the transplant.

CONCLUSIONS

This report confirms the efficacy of the Edmonton immunosuppressive regimen and indicates that insulin independence can often be achieved by a single transplant of sufficient islet mass.

Insulin independence following isolated islet transplantation and single islet infusions

OBJECTIVE

To restore islet function in patients whose labile diabetes subjected them to frequent dangerous episodes of hypoglycemic unawareness, and to determine whether multiple transplants are always required to achieve insulin independence.

SUMMARY BACKGROUND DATA

The recent report by the Edmonton group documenting restoration of insulin independence by islet transplantation in seven consecutive patients with type 1 diabetes differed from previous worldwide experience of only sporadic success. In the Edmonton patients, the transplanted islet mass critical for success was approximately more than 9,000 IEq/kg of recipient body weight and required two or three separate transplants of islets isolated from two to four cadaveric donors. Whether the success of the Edmonton group can be recapitulated by others, and whether repeated transplants using multiple donors will be a universal requirement for success have not been reported.

METHODS

The authors report their treatment with islet transplantation of nine patients whose labile type 1 diabetes was characterized by frequent episodes of dangerous hypoglycemia.

RESULTS

In each of the seven patients who have completed the treatment protocol (i.e., one or if necessary a second islet transplant), insulin independence has been achieved. In five of the seven patients only a single infusion of islets was required. To date, only one recipient has subsequently lost graft function, after an initially successful transplant. This patient suffered recurrent hyperglycemia 9 months after the transplant.

CONCLUSIONS

This report confirms the efficacy of the Edmonton immunosuppressive regimen and indicates that insulin independence can often be achieved by a single transplant of sufficient islet mass.

Underutilization of pancreas donors

BACKGROUND

Transplantation of the pancreas has become the treatment of choice for selected patients with type 1 diabetes mellitus. With the current shortage of cadaver donors and the increasing number of diabetic patients on the transplant waiting list, there is a critical need to optimally use all available pancreas grafts for transplantation. We have therefore explored the use of traditionally "less-than-ideal" pancreas donors, including pediatric (4-10 years), older (>or=45 years), obese (weight >or=200 lb), and non-heart-beating donors and donors with an elevated amylase (75% greater than normal values).

METHODS

A total of 620 primary simultaneous pancreas-kidney transplantations were performed at our center. We analyzed the ratio of livers to pancreata transplanted at our center and compared this to the United Network for Organ Sharing database. Using univariate and multivariate analyses, we then assessed the impact of these less-than-ideal donors on patient survival, graft survival, and postsurgical complications after simultaneous pancreas-kidney transplantation.

RESULTS

A substantial nationwide underutilization of pancreata from donor procurements is demonstrated in the United Network for Organ Sharing database. By using these less-than-ideal donors, the ratio of liver to pancreata procured can be reduced to 1.25:1. Graft survival was not significantly different in patients receiving transplants from obese, non-heart-beating, pediatric, or hyperamylasemic donors compared with grafts from ideal donors. However, grafts from donors 45 years of age or older had significantly lower 1- and 5-year graft survival rates (76% and 65% vs. 90% and 80%, P=0.006).

CONCLUSIONS

This study demonstrates that utilization of pancreas grafts from selected, less-than-ideal donors results in good overall outcomes and could potentially expand the organ donor pool.

Dialysis, kidney transplantation, or pancreas transplantation for patients with diabetes mellitus and renal failure: a decision analysis of treatment options

Patients with type 1 diabetes mellitus and end-stage renal disease may remain on dialysis or undergo cadaveric kidney transplantation, living kidney transplantation, sequential pancreas after living kidney transplantation, or simultaneous pancreas-kidney transplantation. It is unclear which of these options is most effective. The objective of this study was to determine the optimal treatment strategy for type 1 diabetic patients with renal failure using a decision analytic Markov model. Input data were obtained from the published medical literature, the United Network for Organ Sharing registry, and patient interviews. The outcome measures were life expectancy (in life-years [LY]) and quality-adjusted life expectancy (in quality-adjusted life-years [QALY]). Living kidney transplantation was associated with 18.30 LY and 10.29 QALY; pancreas after kidney transplantation, 17.21 LY and 10.00 QALY; simultaneous pancreas-kidney transplantation, 15.74 LY and 9.09 QALY; cadaveric kidney transplantation, 11.44 LY and 6.53 QALY; dialysis, 7.82 LY and 4.52 QALY. The results were sensitive to the value of several key variables. Simultaneous pancreas-kidney transplantation had the greatest life expectancy and quality-adjusted life expectancy when living kidney transplantation was excluded from the analysis. These data indicate that living kidney transplantation is associated with the greatest life expectancy and quality-adjusted life expectancy for type 1 diabetic patients with renal failure. Treatment strategies involving pancreas transplantation should be considered for patients with frequent metabolic complications of diabetes and for those patients who favor kidney-pancreas transplantation over kidney transplantation alone. For patients without a living donor, simultaneous pancreas-kidney transplantation is associated with the greatest life expectancy.

Pancreatic Islet Cell Transplantation

Pancreatic islet cell transplantation as a treatment for diabetes has hitherto been confined to small patient cohorts with limited success. This article summarizes the results of islet cell transplantation before and after the advent of the new 'Edmonton protocol' of immunosuppression and management of the donor pancreas. Adopting this regimen has achieved unprecedented success and renewed interest in this potential cure for diabetes. Central to recent improvements in the technique has been the transplantation of an adequate islet mass. Improved methods to procure, isolate, and purify islets for clinical use are now being adopted as a new 'gold standard'. The use of new immunosuppressive drugs has further improved clinical results. Corticosteroid sparing-based regimens, and agents such as humanized monoclonal antibodies, are likely to form the mainstay of immunosuppressive protocols with the aim of achieving donor-specific tolerance. Alternative sources of islet cells are also required to expand the technique in an era of reduced numbers of donor pancreata. Manipulation of stem cells and xenotransplantation may yet yield sufficient islets to overcome the problem of donor shortage. Islet cell transplantation now forms the basis of a prospective multicenter trial under the aegis of the Immune Tolerance Network. The results of this are awaited, but it appears that islet cell transplantation may yet emerge as an effective treatment option for some members of the diabetic population.

Reduction of blood glucose variability in type 1 diabetic patients treated by pancreatic islet transplantation: interest of continuous glucose monitoring

OBJECTIVE

To compare the glycemic profiles of patients with type 1 diabetes treated with either an implantable insulin pump or pancreas or islet transplantation by the means of the continuous glucose monitoring system (CGMS; Minimed, Sylmar, CA).

RESEARCH DESIGN AND METHODS

The CGMS enabled recording of subcutaneous glucose concentrations (range 2.2-22 mmol/l) over 72 h (288 measurements per day). Over 3 days, 26 patients with type 1 diabetes were connected to a CGMS: 10 patients were treated with intraperitoneal insulin infusion through an implantable pump (IPII), 9 patients were treated with simultaneous pancreas-kidney transplantation (SPK), and 7 patients were treated with pancreatic islet transplantation after kidney grafting (IAK). All SPK patients and four IAK patients were insulin independent, whereas three IAK patients had partial graft function and reduced exogenous insulin needs. Glucose control was evaluated by the mean glucose concentration, glucose variability, and the number and duration of hypoglycemic events (<3.3 mmol/l) over 3 days.

RESULTS

The mean glucose concentration and the glucose variability in SPK and IAK patients were significantly lower than those observed in patients treated with IPII: 5.38 +/- 1.12 and 5.83 +/- 0.81 vs. 7.81 +/- 1.55 mmol/l (P < 0.001) and 1.40 +/- 0.42 and 1.32 +/- 0.53 vs. 3.47 +/- 1.66 mmol/l (P < 0.001), respectively. Furthermore, the mean glucose concentration and the glucose variability were comparable between SPK and IAK patients. Over 3 days, no hypoglycemic events were observed in SPK patients and insulin-independent IAK patients. A total of 4.12 +/- 1.66 hypoglycemic events were detected in the IPII patient group, whereas only 0.66 +/- 0.57 events were observed in IAK patients with partial graft function (P < 0.001). The duration of the hypoglycemic events was significantly longer in IPII patients as compared with IAK patients: 64 +/- 33 vs. 30 +/- 15 min for the day period and 130 +/- 62 vs. 30 +/- 27 min for the night period (P < 0.001).

CONCLUSIONS

Use of subcutaneous CGMS confirms that islet transplantation can be as efficient as pancreas transplantation in restoring good metabolic control and reducing blood glucose variability. Metabolic improvement due to use of an implantable insulin pump requires insulin delivery by a closed loop.

Transplante de Pâncreas e de Ilhotas Pancreáticas: Visão de Nefrologista

Os autores, após dimensionarem o problema do diabetes mellitus e da nefropatia diabética no Brasil e no mundo, fazem uma revisão, sob a ótica do nefrologista, sobre transplante de pâncreas e de ilhotas pancreáticas, centrada nos riscos e benefícios do transplante combinado de pâncreas e rim (TCPR) para o diabético urêmico. No texto é ressaltada a importância da colaboração entre o endocrinologista e o nefrologista para melhorar a sobrevida dos diabéticos com nefropatia e para uma definição local sobre a viabilidade e validade do estabelecimento de um programa de TCPR.

Pancreas transplantation in Ohio: a 15-year outcomes analysis

BACKGROUND

Beginning in 1984, all pancreas transplantations performed in the state of Ohio have been tracked by the Ohio Solid Organ Transplantation Consortium (OSOTC). In this study the outcomes of these transplantations were compared across 3 eras to determine whether increasing experience has been beneficial.

METHODS

Between July 1984 and December 1999, 765 kidney-pancreas (KPTx) and 76 pancreas only (Ptx) transplantations were performed. Outcomes measures for these 841 pancreas transplantations were compared over 3 eras, 1984 to 1989, 1990 to 1994, and 1995 to 1999.

RESULTS

One-year patient survivals for KPTx patients were 87%, 92%, and 94% in the 3 eras, respectively. Graft survival at 1 year was also markedly improved between era 1 and era 3, increasing for PTx patients from 21% to 85% and for KPTx patients from 68% to 85%. Average waiting time increased from 132 to 318 days between era 1 and era 3. Conversely, average length of stay in hospital was significantly decreased from 34 to 18 days. The cost of the procedure, as measured by hospital charges, also decreased when compared in 1985 dollars as a technique to control for inflation.

CONCLUSIONS

These data suggest that pancreas transplantation in Ohio has become a very successful and cost-effective therapeutic intervention for patients with type I diabetes with or without concomitant end-stage renal failure.

Pancreas after kidney transplants

BACKGROUND

For certain uremic diabetic patients, a sequential transplant of a kidney (usually from a living donor) followed by a cadaver pancreas has become an attractive alternative to a simultaneous transplant of both organs. The purpose of this study was to compare outcomes with simultaneous pancreas-kidney (SPK) versus pancreas after kidney (PAK) transplants to determine advantages and disadvantages of the two procedures.

METHODS

Between January 1, 1994, and June 30, 2000, we performed 398 cadaver pancreas transplants at our center. Of these, 193 were SPK transplants and 205 were PAK transplants. We compared these two groups with regard to several endpoints, including patient and graft survival rates, surgical complications, acute rejection rates, waiting times, length of hospital stay, and quality of life.

RESULTS

Overall, surgical complications were more common for SPK recipients. The total relaparotomy rate was 25.9% for SPK recipients versus 15.1% for PAK recipients (P = 0.006). Leaks, intraabdominal infections, and wound infections were all significantly more common in SPK recipients (P = 0.009, P = 0.05, and P = 0.01, respectively, versus PAK recipients). Short-term pancreas graft survival rates were similar between the two groups: at 1 year posttransplant, 78.0% for SPK recipients and 77.9% for PAK recipients (P = not significant). By 3 years, however, pancreas graft survival differed between the two groups (74.1% for SPK and 61.7% for PAK recipients), although this did not quite reach statistical significance (P = 0.15). This difference in graft survival seemed to be due to increased immunologic losses for PAK recipients: at 3 years posttransplant, the incidence of immunologic graft loss was 16.2% for PAK versus 5.2% for SPK recipients (P = 0.01). Kidney graft survival rates were, however, better for PAK recipients. At 3 years after their kidney transplant, kidney graft survival rates were 83.6% for SPK and 94.6% for PAK recipients (P = 0.001). The mean waiting time to receive the pancreas transplant was 244 days for SPK and 167 days for PAK recipients (P = 0.001).

CONCLUSIONS

PAK transplants are a viable option for uremic diabetics. While long-term pancreas graft results are slightly inferior to SPK transplants, the advantages of PAK transplants include the possibility of a preemptive living donor kidney transplant, better long-term kidney graft survival, significantly decreased waiting times, and decreased surgical complication rates. Use of a living donor for the kidney transplant expands the donor pool. Improvements in immunosuppressive regimens will hopefully eliminate some of the difference in long-term pancreas graft survival between SPK and PAK transplants.

Clinical outcomes and insulin secretion after islet transplantation with the Edmonton protocol

Islet transplantation offers the prospect of good glycemic control without major surgical risks. After our initial report of successful islet transplantation, we now provide further data on 12 type 1 diabetic patients with brittle diabetes or problems with hypoglycemia previous to 1 November 2000. Details of metabolic control, acute complications associated with islet transplantation, and long-term complications related to immunosuppression therapy and diabetes were noted. Insulin secretion, both acute and over 30 min, was determined after intravenous glucose tolerance tests (IVGTTs). The median follow-up was 10.2 months (CI 6.5-17.4), and the longest was 20 months. Glucose control was stable, with pretransplant fasting and meal tolerance-stimulated glucose levels of 12.5+/-1.9 and 20.0+/-2.7 mmol/l, respectively, but decreased significantly, with posttransplant levels of 6.3+/-0.3 and 7.5+/-0.6 mmol/l, respectively (P < 0.006). All patients have sustained insulin production, as evidenced by the most current baseline C-peptide levels 0.66+/-0.06 nmol/l, increasing to 1.29+/-0.25 nmol/l 90 min after the meal-tolerance test. The mean HbA1c level decreased from 8.3+/-0.5% to the current level of 5.8+/-0.1% (P < 0.001). Presently, four patients have normal glucose tolerance, five have impaired glucose tolerance, and three have post-islet transplant diabetes (two of whom need oral hypoglycemic agents and low-dose insulin (<10 U/day). Three patients had a temporary increase in their liver-function tests. One patient had a thrombosis of a peripheral branch of the right portal vein, and two of the early patients had bleeding from the hepatic needle puncture site; but these technical problems were resolved. Two patients had transient vitreous hemorrhages. The two patients with elevated creatinine levels pretransplant had a significant increase in serum creatinine in the long term, although the mean serum creatinine of the group was unchanged. The cholesterol increased in five patients, and lipid-lowering therapy was required for three patients. No patient has developed cytomegalovirus infection or disease, posttransplant lymphoproliferative disorder, malignancies, or serious infection to date. None of the patients have been sensitized to donor antigen. In 11 of the 12 patients, insulin independence was achieved after 9,000 islet equivalents (IEs) per kilogram were transplanted. The acute insulin response and the insulin area under the curve (AUC) after IVGTT were consistently maintained over time. The insulin AUC from the IVGTT correlated to the number of islets transplanted, but more closely correlated when the cold ischemia time was taken into consideration (r = 0.83, P < 0.001). Islet transplantation has successfully corrected labile type 1 diabetes and problems with hypoglycemia, and our results show persistent insulin secretion. After a minimum of 9,000 IEs per kilogram are provided, insulin independence is usually attained. An elevation of creatinine appears to be a contraindication to this immunosuppressive regimen. For the subjects who had labile type 1 diabetes that was difficult to control, the risk-to-benefit ratio is in favor of islet transplantation.

Lessons learned from more than 1,000 pancreas transplants at a single institution

OBJECTIVE

To determine outcome in diabetic pancreas transplant recipients according to risk factors and the surgical techniques and immunosuppressive protocols that evolved during a 33-year period at a single institution.

SUMMARY BACKGROUND DATA

Insulin-dependent diabetes mellitus is associated with a high incidence of management problems and secondary complications. Clinical pancreas transplantation began at the University of Minnesota in 1966, initially with a high failure rate, but outcome improved in parallel with other organ transplants. The authors retrospectively analyzed the factors associated with the increased success rate of pancreas transplants.

METHODS

From December 16, 1966, to March 31, 2000, the authors performed 1,194 pancreas transplants (111 from living donors; 191 retransplants): 498 simultaneous pancreas-kidney (SPK) and 1 simultaneous pancreas-liver transplant; 404 pancreas after kidney (PAK) transplants; and 291 pancreas transplants alone (PTA). The analyses were divided into five eras: era 0, 1966 to 1973 (n = 14), historical; era 1, 1978 to 1986 (n = 148), transition to cyclosporine for immunosuppression, multiple duct management techniques, and only solitary (PAK and PTA) transplants; era 2, 1986 to 1994 (n = 461), all categories (SPK, PAK, and PTA), predominantly bladder drainage for graft duct management, and primarily triple therapy (cyclosporine, azathioprine, and prednisone) for maintenance immunosuppression; era 3, 1994 to 1998 (n = 286), tacrolimus and mycophenolate mofetil used; and era 4, 1998 to 2000 (n = 275), use of daclizumab for induction immunosuppression, primarily enteric drainage for SPK transplants, pretransplant immunosuppression in candidates awaiting PTA.

RESULTS

Patient and primary cadaver pancreas graft functional (insulin-independence) survival rates at 1 year by category and era were as follows: SPK, era 2 (n = 214) versus eras 3 and 4 combined (n = 212), 85% and 64% versus 92% and 79%, respectively; PAK, era 1 (n = 36) versus 2 (n = 61) versus 3 (n = 84) versus 4 (n = 92), 86% and 17%, 98% and 59%, 98% and 76%, and 98% and 81%, respectively; in PTA, era 1 (n = 36) versus 2 (n = 72) versus 3 (n = 30) versus 4 (n = 40), 77% and 31%, 99% and 50%, 90% and 67%, and 100% and 88%, respectively. In eras 3 and 4 combined for primary cadaver SPK transplants, pancreas graft survival rates were significantly higher with bladder drainage (n = 136) than enteric drainage (n = 70), 82% versus 74% at 1 year (P =.03). Increasing recipient age had an adverse effect on outcome only in SPK recipients. Vascular disease was common (in eras 3 and 4, 27% of SPK recipients had a pretransplant myocardial infarction and 40% had a coronary artery bypass); those with no vascular disease had significantly higher patient and graft survival rates in the SPK and PAK categories. Living donor segmental pancreas transplants were associated with higher technically successful graft survival rates in each era, predominately solitary (PAK and PTA) in eras 1 and 2 and SPK in eras 3 and 4. Diabetic secondary complications were ameliorated in some recipients, and quality of life studies showed significant gains after the transplant in all recipient categories.

CONCLUSIONS

Patient and graft survival rates have significantly improved over time as surgical techniques and immunosuppressive protocols have evolved. Eventually, islet transplants will replace pancreas transplants for suitable candidates, but currently pancreas transplants can be applied and should be an option at all stages of diabetes. Early transplants are preferable for labile diabetes, but even patients with advanced complications can benefit.

Human islet cell transplantation--future prospects

BACKGROUND

Islet transplantation has the potential to cure diabetes mellitus. Nevertheless despite successful reversal of diabetes in many small animal models, the clinical situation has been far more challenging. The aim of this review is to discuss why insulin-independence after islet allotransplantation has been so difficult to achieve.

METHODS

A literature review was undertaken using Medline from 1975 to July 2000. Results reported to the International Islet Transplant Registry (ITR) up to December 1998 were also analysed.

RESULTS

Up to December 1998, 405 islet allotransplants have been reported the ITR. Of those accurately documented between 1990 and 1998 (n = 267) only 12% have achieved insulin-independence (greater than 7 days). However with refined peri-transplant protocols insulin independence at 1 year can reach 20%.

CONCLUSIONS

There are many factors which can explain the failure of achieving insulin-independence after islet allotransplantation. These include the use of diabetogenic immunosuppressive agents to abrogate both islet allo-immunity and auto-immunity, the critical islet mass to achieve insulin-independence and the detrimental effects of transplanting islets in an ectopic site. However recent evidence most notably from the Edmonton group demonstrates that islet allotransplantation still has great potential to become an established treatment option for diabetic patients.

Optimal timing for a pancreas transplant after a successful kidney transplant

BACKGROUND

For certain uremic, diabetic patients, a sequential transplant of a kidney (usually from a living donor) followed by a cadaver pancreas has become an attractive option. But how long to wait after the kidney transplant before proceeding with a pancreas transplant is unclear. We studied outcomes in recipients of a pancreas at varying times after a kidney to determine the optimal timing for the second transplant.

METHODS

We compared pancreas after kidney (PAK) transplants performed early (< or =4 months) and late (>4 months) after the kidney transplant to determine any significant differences in surgical complications or outcomes between the two groups.

RESULTS

Between January 1, 1994, and September 30, 1998, we performed 123 cadaver PAK transplants. Of these, 25 (20%) were early and 98 (80%) were late. Characteristics of the two recipient groups were similar. We found no significant differences in outcome between the two groups. The incidence of surgical complications (bleeding, leaks, thrombosis, infections) and of opportunistic infections (such as cytomegalovirus) did not significantly differ between the two groups. Graft and patient survival rates were also equivalent (P=NS). The incidence of acute rejection by 3 months posttransplant was 20% in both groups.

CONCLUSION

The timing of the pancreas transplant for PAK recipients does not seem to influence outcome. As long as an acceptable organ is available and the recipient is clinically stable, a PAK transplant can be performed relatively soon after the kidney transplant.