Multivariate Analysis of Risk Factors for Early Loss of Pancreas Grafts Among Simultaneous Pancreas–Kidney Transplants

Clinical Impact of Ischemic Time of the Pancreas or Kidney Graft on Simultaneous Pancreas-Kidney Transplantation: A Single-Institution Study in Japan

BACKGROUND

Total ischemic time (TIT) potentially affects graft survival in organ transplantation. However, in simultaneous pancreas-kidney (SPK) transplantation, the impact of TIT of the pancreas (P-TIT) and kidney graft (K-TIT) on posttransplant outcomes remains unclear. This study investigated the impact of P-TIT and K-TIT on postoperative outcomes in patients after SPK at our institution in Japan.

PATIENTS AND METHODS

This study included 52 patients who underwent SPK at our hospital from April 2000 to March 2022. Of this patient group, the 52 patients were divided into a short P-TIT group (n = 25), long P-TIT group (n = 27), short K-TIT group (n = 42), and long K-TIT group (n = 10). Short- and long-term postoperative outcomes were compared between the groups.

RESULTS

The long K-TIT group had a significantly higher rate of patients who did not urinate intraoperatively (50% vs 7%; P = .0007) and those requiring postoperative hemodialysis (80% vs 38%; P = .0169), as well as a significant longer duration of postoperative hemodialysis (97 ± 147 days vs 6 ± 9 days; P = .0016). These were not significantly different between the short and long P-TIT groups. Kidney or pancreas graft survival was not significantly different between the short and long P-TIT or K-TIT groups.

CONCLUSIONS

Patients with prolonged K-TIT during SPK exhibited poor short-term outcomes, but no significant influence of K-TIT was identified on long-term outcomes. The P-TIT did not affect any significant outcomes. These results indicate that shortening K-TIT may improve short-term outcomes after SPK.

Pancreas Donor Hypernatremia: Is it Really a Risk Factor for Simultaneous Pancreas-kidney Transplantation?

INTRODUCTION

Solid organ donor hypernatremia has been classically reported to be a risk factor for cell lysis and graft damage. National criteria for pancreatic donation consider severe hypernatremia (sodium level more than 160 mEq/L) to be relative exclusion criteria. The aim of our study is to review the postoperative outcomes of our simultaneous pancreas-kidney transplantation (SPKT) sample in terms of pancreatic fistula, intra-abdominal abscesses, pancreatitis, pancreas graft thrombosis, early pancreatectomy, and reoperation rates regarding different ranges of donor sodium levels.

MATERIAL AND METHODS

We performed a retrospective analysis among 161 SPKTs performed in our center between the years 2001 and 2017. We compared the aforementioned postoperative variables in two situations: 1) Whether the donor pancreas sodium levels were inferior to 149 mEq/L, or equal to or greater than 150 mEq/L; and 2) If they had severe hypernatremia (considering sodium levels greater than or equal to 160 mEq/L as threshold) or not. To ensure the comparability of the groups, a second comparison was performed on new samples after using propensity score matching. A Student t test or Mann-Whitney U test was used for intergroup comparisons of quantitative variables where appropriate, whereas a χ² test or Fisher's exact test was used to compare categorical data.

RESULTS

No statistically significant differences were found between the groups that relate high donor serum sodium levels with the morbidity variables included in our study or with early pancreatic graft loss.

CONCLUSIONS

In our cohort, early postoperative main morbidity and pancreas graft loss of SPKT recipients do not differ significantly regarding donor serum sodium levels.

What Is the Influence of Both Risk Donor and Risk Receiver on Simultaneous Pancreas-Kidney Transplantation?

INTRODUCTION

Some factors affect the pancreas of a marginal donor, and although their influence on graft survival has been determined, there is an increasing consensus to accept marginal organs in a controlled manner to increase the pool of organs. Certain factors related to the recipient have also been proposed as having negative influence on graft prognosis. The objective of this study was to analyze the influence of these factors on the results of our simultaneous pancreas-kidney (SPK) transplantation series.

MATERIALS AND METHODS

Retrospective analysis of 126 SPK transplants. Donors and recipients were stratified in an optimal group (<2 expanded donor criteria) and a risk group (≥2 criteria). A pancreatic graft survival analysis was performed using a Kaplan-Meier test and log-rank test. Prognostic variables on graft survival were studied by Cox regression. Postoperative complications (graded by Clavien classification) were compared by χ² test or Fisher test.

RESULTS

Median survival of pancreas was 66 months, with no significant difference between groups (P > .05). Multivariate analysis showed risk factors to be donor age, cold ischemia time, donor body mass index, receipt body mass index, and receipt panel-reactive antibody.

CONCLUSIONS

In our series, the use of pancreatic grafts from donors with expanded criteria is safe and has increased the pool of grafts. Different variables, both donor and recipient, influence the survival of the pancreatic graft and should be taken into account in organ distribution systems.

Selected Mildly Obese Donors Can Be Used Safely in Simultaneous Pancreas and Kidney Transplantation

BACKGROUND

Donor obesity, defined as donor body mass index (D-BMI) of 30 kg/m or greater, has been associated with increased risk of technical failure and poor pancreas allograft outcomes. Many transplant centers establish a threshold of D-BMI of 30 kg/m to decline donor offers for pancreas transplantation. However, no previous studies differentiate the impact of mild (D-BMI, 30-35 kg/m) versus severe obesity (D-BMI, ≥35 kg/m) on pancreas allograft outcomes.

METHODS

We examined Organ Procurement Transplant Network database records for 9916 simultaneous pancreas-kidney transplants (SPKT) performed between 2000 and 2013. We categorized donor body mass index (D-BMI) into 4 groups: 20 to 25 (n = 5724), 25 to 30 (n = 3303), 30 to 35 (n = 751), and 35 to 50 kg/m (n= 138). Associations of D-BMI with pancreas and kidney allograft failure were assessed by multivariate Cox regression adjusted for recipient, donor, and transplant factors.

RESULTS

Compared with D-BMI 20 to 25 kg/m, only D-BMI 35 to 50 kg/m was associated with significantly higher pancreas allograft [adjusted hazard ratio [aHR], 1.37; 95% confidence interval (CI], 1.04-1.79] and kidney allograft (aHR, 1.36; CI, 1.02-1.82) failure over the study period (13 years). Donor BMI 30 to 35 kg/m did not impact pancreas allograft (aHR, 0.99; CI, 0.86-1.37) or kidney allograft (aHR, 0.98; CI, 0.84-1.15) failure. Similar patterns were noted at 3 months, and 1, 5, and 10 years posttransplant.

CONCLUSIONS

These data support that pancreata from mildly obese donors (BMI, 30-35 kg/m) can be safely used for transplantation, with comparable short-term and long-term outcomes as organs from lean donors. Consideration of pancreata from obese donors may decrease the pancreas discard rate.

Clinically significant peripancreatic fluid collections after simultaneous pancreas-kidney transplantation

BACKGROUND

Peripancreatic fluid collections (PPFC) are a serious complication after simultaneous pancreas-kidney transplantation (SPKTx).

METHODS

Retrospective study for all 223 SPKTx performed from December 8, 1996, to October 10, 2011, to evaluate the risk factors (RF) and impact of PPFCs on outcomes was conducted.

RESULTS

Clinically significant PPFCs were seen in 36 (16%) cases, all within 3 months after transplantation. Radiologic drainage resolved 2 (6%) cases, and 34 required laparotomy (mean [SD], 4 [7]). Compared with the non-PPFC group (n=186), the PPFC group had similar patient and total kidney graft survivals but significantly lower total pancreas survival (68% vs. 85%) and greater incidence of infections (75% vs. 46%, all P<0.05) at 5 years. PPFCs were associated with early graft pancreatitis in 18 (50%), pancreatic fistula in 20 (56%, 9 with obvious duodenal stump leak) and infection in the collection in 20 (56%) cases. Comparison of PPFCs with pancreas graft loss to the PPFCs with surviving grafts showed that the incidence of pancreatic fistula was greater in the former (90% pancreas graft loss vs. 42% pancreas graft survival, P<0.01). Binary logistic regression analysis of RF for developing PPFC showed a donor age >30 years to be significant (P=0.03; odds ratio, 3.4; confidence interval, 1.1-10.5) and a trend of association with donor body mass index >30 and pancreas cold ischemia time greater than 12 hr.

CONCLUSIONS

PPFCs are associated with significant reduction in pancreas allograft survival and impact resource use. Donor age >30 years is a significant RF for their development. PPFCs associated with pancreatic fistula carry a greater risk for pancreas graft loss.

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 and venous thrombosis: multivariate analysis of risk factors]

OBJECTIVE

Portal veinous thrombosis (VT) in the pancreatic transplant (6 to 20% of the cases) is the first cause of early loss of the transplant. Our objective was to identify the risk factors of VT in our experiment.

METHOD

The sample group includes 106 patients who underwent pancreas transplantation (portal venous drainage, enteric-drained pancreas) within our institute of transplantation from 2004 until 2010. We completed a portal vein extension graft in 25% of the cases. First of all, risk factors were selected from preoperative and operative data with an univariate analysis. We then carried out a multivariate analysis of these factors (binary logistic regression). The threshold P was 0.05.

RESULTS

Sixteen patients (15%) showed a VT. Eight of them developed a total thrombosis and required a transplantectomy. Three risk factors of VT were isolated by the multivariate analysis: a BMI of the receiver>25kg/m(2) (Odds Ratio [OR]=6.977), a portal vein extension graft (OR=4.1) and an age of the donor>45 years (OR=4.432).

CONCLUSIONS

The knowledge of these risk factors of thrombosis allows the implementation of preventive measures (selection of the donor, nutritional support of the receiver in the registration if BMI>25kg/m(2)). The portal lengthening should be avoided by an attentive retrieval of the transplant (without shorter section of the portal vein). Nevertheless, the presence of one of these risk factors in a transplant patient should lead to start an antithrombotic treatment.

Comparison of recipient outcomes following transplant from local versus imported pancreas donors

The shortage of deceased donor organs for solid organ transplantation continues to be an ongoing dilemma. One approach to increase the number of pancreas transplants is to share organs between procurement regions. To assess for the effects of organ importation, we reviewed the outcomes of 1014 patients undergoing deceased donor pancreas transplant at a single center. We performed univariate and multivariate analyses of the association of donor, recipient and surgical characteristics with patient outcomes. Organ importation had no effect on graft or recipient survival for recipients of solitary pancreas transplants. Similarly, there was no effect on technical failure rate, graft survival or long-term patient survival for simultaneous kidney-pancreas (SPK) recipients. In contrast, there was a significant and independent increased risk of death in the first year in SPK recipients of imported organs. SPK recipients had longer hospitalizations and increased hospital costs. This increased medical complexity may make these patients more susceptible to short-term complications resulting from the longer preservation times of import transplants. These findings support the continued use of organ sharing to reduce transplant wait times but highlight the importance of strategies to reduce organ preservation times.