Influence of mild obesity on outcome of simultaneous pancreas and kidney transplantation

Modern indications for referral for kidney and pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation (PTx) is currently the only therapy that can predictably achieve sustained euglycemia independent of exogenous insulin administration in patients with insulin-dependent diabetes mellitus. This procedure involves a complex abdominal operation and lifetime dependence on immunosuppressive medications. Therefore, PTx is most frequently performed in combination with other organs, usually a kidney transplant for end stage diabetic nephropathy. Less frequently, solitary PTx may be indicated in patients with potentially life-threatening complications of diabetes mellitus. There remains confusion and misperceptions regarding indications and timing of patient referral for PTx.

RECENT FINDINGS

In this review, the referral, evaluation, and listing process for PTx is described, including a detailed discussion of candidate assessment, indications, contraindications, and outcomes.

SUMMARY

Because the progression of diabetic kidney disease may be less predictable than other forms of kidney failure, early referral for planning of renal and/or pancreas transplantation is paramount to optimize patient care and allow for possible preemptive transplantation.

Pancreas Transplantation in Minorities including Patients with a Type 2 Diabetes Phenotype

Background: Prior to year 2000, the majority of pancreas transplants (PTx) were performed as simultaneous pancreas-kidney transplants (SPKTs) in Caucasian adults with end stage renal failure secondary to type 1 diabetes mellitus (T1DM) who were middle-aged. In the new millennium, improving outcomes have led to expanded recipient selection that includes patients with a type 2 diabetes mellitus (T2DM) phenotype, which excessively affects minority populations. Methods: Using PubMed® to identify appropriate citations, we performed a literature review of PTx in minorities and in patients with a T2DM phenotype. Results: Mid-term outcomes with SPKT in patients with uremia and circulating C-peptide levels (T2DMphenotype) are comparable to those patients with T1DM although there may exist a selection bias in the former group. Excellent outcomes with SPKT suggests that the pathophysiology of T2DM is heterogeneous with elements consisting of both insulin deficiency and resistance related to beta-cell failure. As a result, increasing endogenous insulin (Cp) production following PTx may lead to freedom checking blood sugars or taking insulin, better metabolic counter-regulation, and improvements in quality of life and life expectancy compared to other available treatment options. Experience with solitary PTx for T2DM or in minorities is limited but largely mirrors the trends reported in SPKT. Conclusions: PTx is a viable treatment option in patients with pancreas endocrine failure who are selected appropriately regardless of diabetes type or recipient race. This review will summarize data that unconventional patient populations with insulin-requiring diabetes may gain value from PTx with an emphasis on contemporary experiences and appropriate selection in minorities in the new millennium.

First World Consensus Conference on pancreas transplantation: Part II - recommendations

The First World Consensus Conference on Pancreas Transplantation provided 49 jury deliberations regarding the impact of pancreas transplantation on the treatment of diabetic patients, and 110 experts' recommendations for the practice of pancreas transplantation. The main message from this consensus conference is that both simultaneous pancreas-kidney transplantation (SPK) and pancreas transplantation alone can improve long-term patient survival, and all types of pancreas transplantation dramatically improve the quality of life of recipients. Pancreas transplantation may also improve the course of chronic complications of diabetes, depending on their severity. Therefore, the advantages of pancreas transplantation appear to clearly surpass potential disadvantages. Pancreas after kidney transplantation increases the risk of mortality only in the early period after transplantation, but is associated with improved life expectancy thereafter. Additionally, preemptive SPK, when compared to SPK performed in patients undergoing dialysis, appears to be associated with improved outcomes. Time on dialysis has negative prognostic implications in SPK recipients. Increased long-term survival, improvement in the course of diabetic complications, and amelioration of quality of life justify preferential allocation of kidney grafts to SPK recipients. Audience discussions and live voting are available online at the following URL address: http://mediaeventi.unipi.it/category/1st-world-consensus-conference-of-pancreas-transplantation/246.

Obesity and organ transplantation: successes, failures, and opportunities

The increasing rate of societal obesity is also affecting the transplant world through obesity in candidates and donors as well as its posttransplant repercussions. Being overweight and obese has been shown to have significant effects on both short- and long-term complications as well as patient and graft survival. However, much of the comorbidity can be controlled or prevented with careful patient selection and aggressive management. A team approach to managing obesity and its comorbidities both pre- and posttransplant is essential for successful transplant outcomes. Complicating understanding the results of obesity research is the inclusion different weight categories, use of listing vs transplant weights, patient populations large enough for statistical power, and changes in transplant management, especially immunosuppression protocols, anti-infection protocols, and operative techniques. Much more research is needed regarding many elements, including safe weight loss before transplantation, prevention of weight gain after transplant, genomic influences, and the role of bariatric surgery in the transplant process.

Prevention and management of graft thrombosis in pancreatic transplant

Pancreatic transplant effectively cures type 1 diabetes mellitus and maintains consistent long-term euglycemia. However, technical failure, and in particular graft thrombosis, accounts for the vast majority of transplants lost in the early postoperative period. The pancreas' inherently low microvascular flow state makes it vulnerable to vascular complications, as does the hypercoagulable blood of diabetic patients. Ultimately, the phenomenon is most definitely multifactorial. Prevention, as opposed to treatment, is key and should focus on reducing these multiple risk factors. This will involve tactical donor selection, optimal surgical technique and some form of anticoagulation. Close monitoring and early intervention will be crucial when treating thrombosis once preventative methods have failed. This may be achieved by further anticoagulation, graft salvage, or pancreatectomy with retransplant. This article will explore the multiple factors contributing to graft thrombus formation and the ways in which they may be addressed to firstly prevent, or more likely, reduce thrombosis. Secondly, we will consider the management strategies which can be implemented once thrombosis has occurred.

Pancreas transplantation considering the spectrum of body mass indices

BACKGROUND

In kidney, liver, heart, and lung transplantation, extremes of body mass index (BMI) have been reported to influence post-operative outcomes and even survival. Given the limited data in pancreas transplantation, we sought to elucidate the influence of BMI on outcomes.

METHODS

We reviewed 139 consecutive pancreas transplants performed at our institution and divided them into four categories based on BMI: underweight (≤18.5 kg/m(2)), normal (18.6-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)), and obese (≥30 kg/m(2)). Parameters analyzed included post-operative complications, early graft loss, one-yr acute rejection rate (AR), non-surgical infections, and survival.

RESULTS

Demographic data were similar between the groups. Compared with normal, only obese patients trended toward more post-operative complications (p = 0.06). Underweight and obese patients had significantly more post-operative infectious complications than normal (p = 0.0005 and p = 0.03, respectively). Obese patients had more complications requiring percutaneous drainage compared with normal (p = 0.03). Overweight and obese patients had significantly more complications requiring re-laparotomy (p = 0.03 and p = 0.048, respectively). Early graft loss, AR, non-surgical infections, and patient and graft survival rates were not different between normal and underweight, overweight, or obese patients (p > 0.05).

CONCLUSIONS

Extremes of BMI were associated with increased morbidity. Donors and recipients should be carefully selected to maximize potential for successful outcomes.

Obesity was associated with inferior outcomes in simultaneous pancreas kidney transplant

BACKGROUND.: In kidney transplant, obesity was reported to be associated with increased posttransplant complications and worse survival outcomes. The impact of obesity in simultaneous pancreas-kidney (SPK) transplant is less known. METHODS.: Using Organ Procurement Transplantation Network/United Network for Organ Sharing data as of August 2008, we included all adults (>18 years) type 1 diabetic SPK recipients between years 2000 and 2007 with a pretransplant body mass index (BMI) of 18.5 to 40 kg/m. The cohort was divided in three groups: normal (BMI 18.5-24.9 kg/m, reference group), overweight (BMI 25-29.9 kg/m), and obese (BMI 30-40 kg/m). Covariate-adjusted relative risk of a combination of posttransplant complications and patient, pancreas and kidney allograft outcomes were evaluated. RESULTS.: Of 5725 recipients, 56%, 33%, and 11% were in normal, overweight, and obese groups, respectively. Overweight and obese recipients were older, had a higher percent of coronary artery disease, and private health insurance coverage. Overall posttransplant complications were higher in obese group (35.7% vs. 28.6%) when compared with normal BMI group. They were mainly due to increased delayed kidney graft function (11.8% vs. 7.4%), 1-year kidney acute rejection (17.0% vs. 12.1%), and pancreas graft thrombosis (2.6% vs. 1.3%). After adjusting for possible confounders, the odds ratios for overall transplant complications were 1.03 (95% confidence interval [CI]: 0.90-1.17) for overweight and 1.38 (95% CI: 1.15-1.68) for obese. Obesity, but not overweight, was associated with patient death (hazard ratio [HR]: 1.35; 95% CI: 1.00-1.81), pancreas graft loss (HR: 1.41; 95% CI: 1.17-1.69), and kidney graft loss (HR: 1.33; 95% CI: 1.05-1.67) at 3 years. The higher rates of death and graft failure in the first 30 days posttransplant mostly accounted for the 3-year survival differences. CONCLUSION.: Obesity in SPK recipients was associated with increased risk of posttransplant complications, pancreas and kidney graft loss, and patient death.

Risk factors for surgical complications in distal pancreatectomy

BACKGROUND

Pancreatic fistula (PF) represents a major complication after distal pancreatectomy. In a consecutive series of 110 patients, risk factors for the incidence of PF and surgical morbidity were identified.

METHODS

Patients having undergone distal pancreatectomy between 2003 and 2007 were identified. Clinicopathologic parameters as well as perioperative data were correlated with the incidence of PF and overall surgical morbidity using univariate and multivariate models.

RESULTS

In 72 patients (65%), malignant disease was present. Splenectomy and multivisceral resection were performed in 84 (76%) and 47 (42%) patients, respectively. Overall major surgical morbidity was 18%, and 12 patients (11%) developed PFs. A body mass index > 25 kg/m(2) was the only independent significant predictive factor for PF. Malignancy, splenectomy, multivisceral resection, transfusion, comorbidity, and stapler use did not show statistical significance. For overall surgical morbidity, there was no significant indicator.

CONCLUSIONS

A body mass index > 25 kg/m(2) contributes to the incidence of PF after distal pancreatectomy. Other parameters did not show a significant influence on PF or on overall surgical morbidity.

Pretransplant obesity: a weighty issue affecting transplant candidacy and outcomes

Because of the global increase in prevalence of obesity, many more overweight and obese individuals are undergoing evaluation for transplantation than in the past. Although obesity seems to provide a survival benefit in dialysis patients, obesity has traditionally been considered a contraindication for transplantation of most organs. It is theorized that obesity will contribute to worse transplant outcomes, including lower rates of graft and patient survival and higher rates of delayed graft function and infection. This review evaluates the available literature evaluating outcomes of obese patients with end-stage organ failure who undergo transplantation. Obesity seems to be associated with increased rates of wound infection after transplantation. However, other adverse transplant outcomes related to obesity seem to be dependent on the type of organ being transplanted and the degree of obesity. For example, a body mass index (BMI) of 30 kg/m(2) may reduce short-term survival in lung transplant recipients; however, obesity does not seem to confer an adverse effect on short- or long-term survival in liver transplant patients until a much higher BMI is reached (such as 35 or 40 kg/m(2)). Each transplant center must determine weight guidelines and criteria for identifying the level of obesity as a contraindication for transplantation. This must be based on organ type, each center's transplant and complication statistics, and available donor pools. Guidelines must also consider the morbidity and mortality risks of the obese patient with organ failure who does not receive a transplant.

Obesity and infection

Obesity increases morbidity and mortality through its multiple effects on nearly every human system. However, the various aspects of the association between obesity and infection have not been reviewed. Thus, we reviewed the relevant literature focusing on clinical aspects of this association. Obesity has a clear but not yet precisely defined effect on the immune response through a variety of immune mediators, which leads to susceptibility to infections. Data on the incidence and outcome of specific infections, especially community-acquired infections, in obese people are so far limited. The available data suggest that obese people are more likely than people of normal weight to develop infections of various types including postoperative infections and other nosocomial infections, as well to develop serious complications of common infections. Large prospective studies are required to further define the burden of infectious morbidity and mortality conferred by obesity.

Single-shot antithrombin in human pancreas-kidney transplantation: reduction of reperfusion pancreatitis and prevention of graft thrombosis*

Reperfusion pancreatitis and graft thrombosis often induce early graft loss in simultaneous pancreas-kidney (SPK) transplantation. Antithrombin (AT) is a coagulatory inhibitor with pleiotropic activities that reduces experimental ischemia/reperfusion injury. This study retrospectively analyses prophylactic high-dose AT application in patients with first SPK. In an university transplantation center, 53 consecutive patients with SPK were studied without randomization. In one group, 3000 IU of AT was given intravenously before pancreatic reperfusion (AT, n = 24). Patients receiving standard therapy including postoperative AT supplementation (controls, n = 29) served as controls. Daily blood sampling was performed as a part of the clinical routine during four postoperative days. There were no differences in demographic and laboratory parameters [donor/recipient age, ischemia time, perfusion solution, body weight, mismatches] between both groups. Baseline creatinine values were lower in the control group versus AT group (P < 0.05). Coagulatory parameters and bleeding incidence were not influenced by AT, while incidence of graft thrombosis was reduced (control: 7/29; AT: 4/24; relative reduction of risk: -33%; P < 0.05). Single-shot AT application during SPK modulated serum lipase activity on postoperative days 2 and 3, and minimized risk for graft thromboses without increasing perioperative bleeding. This new concept should deserve testing in a prospective clinical trial.