Portal venous versus systemic venous drainage of pancreas grafts: impact on long-term results

Pancreatic Transplantation: Surgical Anatomy and Complications

Pancreatic transplantation is a complex surgical procedure performed for patients with chronic severe diabetes, often performed in combination with renal transplantation. Vascular and exocrine drainage anatomy varies depending on the surgical technique. Radiology plays a critical role in the diagnosis of postoperative complications, requiring an understanding of grayscale/Doppler ultrasound as well as computed tomography and MR imaging. In this review, we detail usual surgical methods and normal postoperative imaging appearances. We then review the most common complications following pancreatic transplants, emphasizing diagnostic features of vascular (arterial/venous), surgical, and diffuse parenchymal pathologic conditions on multiple imaging modalities.

Splenic Vessels as a Rescue for Pediatric Kidney Retransplantation in Children With Iliac-caval Agenesis or Thrombosis

BACKGROUND

Unavailability of the iliac-caval system due to thrombosis or aberrant anatomy may preclude kidney transplantation (KT) in small infants, exposing them to the complications of long-term dialysis. A tailored approach may enable KT also in these difficult patients.

METHODS

We report the cases of 2 pediatric patients with a history of long-term hemodialysis, a previously failed KT, pending exhaustion of vascular accesses for dialysis, and unsuitability of the iliac-caval axis as a site for KT. Both patients were successfully managed by using splenic vessels as a source of arterial inflow or venous drainage during KT. Notably, one patient also had a previous liver transplant.

RESULTS

Both kidney grafts showed primary function. Posttransplant courses were uneventful, and no rejection episode was observed. At 64- and 10-mo follow-ups, both children had optimal renal function and excellent quality of life.

CONCLUSIONS

When the iliac-caval system is unavailable, kidney graft implantation on splenic vessels represents a safe and effective option for pediatric KT.

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.

Pancreatic transplantation with duodenoduodenostomy drainage: technique, normal radiological appearance and complications

Pancreas transplantation is considered the curative treatment for severe type 1 diabetes mellitus in selected cases. Since the first procedure in 1966, surgical techniques have been improved. The current trend among most medical centers, as well as at our Institution, is enteric drainage and systemic venous or portal anastomosis. The aim of this pictorial essay is to describe the main imaging features of pancreatic transplantation with duodenoduodenostomy drainage.

A comparison of portal venous versus systemic venous drainage in pancreas transplantation

BACKGROUND

The decision to utilize portal or systemic venous drainage in pancreas transplantation is surgeon- and center-dependent. Information regarding the superior method is based on single-center reports and animal models.

METHODS

UNOS data on adults receiving pancreas and kidney-pancreas transplants from 1987 to 2016 were analyzed (n = 29 078). The groups analyzed were: systemic venous pancreas graft drainage (SVD, n = 24 512) or portal venous pancreas graft drainage (PVD, n = 4566). A Cox proportional hazard model compared patient and allograft survival between groups.

RESULTS

No statistically significant differences were observed for patient and allograft survival at 1, 3, 5, 10, or 15 years post-transplant at each time interval and cumulatively (patient - HR:1.041; 95% CI:0.989-1.095; allograft - HR:0.951; 95% CI:0.881-1.027). PVD reduced the risk of death by 22.0% (P = 0.017) compared to SVD for patients undergoing pancreas after kidney transplant (PAK); no statistically significant difference was found for patients undergoing other types of transplants.

CONCLUSION

There is no significant clinical difference in patient or allograft survival between PVD and SVD in pancreas transplantation for the majority of patients. For the subgroup of PAK, PVD was associated with decreased mortality. For individual surgeons, center and patient scenarios should dictate which technique is performed.

Pancreas Transplantation: Indications, Techniques, and Outcomes

Pancreas transplantation treats insulin-dependent diabetes with or without concurrent end-stage renal disease. Pancreas transplantation increases survival versus no transplant, increases survival when performed as simultaneous pancreas-kidney versus deceased-donor kidney alone, and improves quality of life. Careful donor and recipient selection are paramount to good outcomes. Several technical variations exist for implantation: portal versus systemic vascular drainage and jejunal versus duodenal versus bladder exocrine drainage. Complications are most frequently technical in the first year and immunologic thereafter. Graft rejection is challenging to diagnose and is treated selectively. Islet cell transplantation currently has inferior outcomes to whole-organ pancreas transplantation.

Preserved insulin secretion and kidney function in recipients with functional pancreas grafts 1 year after transplantation: a single-center prospective observational study

OBJECTIVE

Successful simultaneous pancreas and kidney transplantation (SPK) or pancreas transplantation alone (PTA) restores glycemic control. Diabetes and impaired kidney function are common side effects of immunosuppressive therapy. This study addresses glucometabolic parameters and kidney function during the first year.

METHODS

We examined 67 patients with functioning grafts (SPK n = 30, PTA n = 37) transplanted between September 2011 and November 2016 who underwent repeated oral glucose tolerance tests (OGTTs) 8 and 52 weeks after transplantation. Another 19 patients lost their graft the first year post-transplant and 28 patients did not undergo repeated OGTTs and could not be studied. All patients received ATG induction therapy plus tacrolimus, mycophenolate and prednisolone. Glomerular filtration rate was measured before and 8 and 52 weeks after transplantation by serum clearance methods.

RESULTS

From week 8 to 52 after transplantation, mean fasting glucose decreased (SPK: 5.4 ± 0.7 to 5.1 ± 0.8 mmol/L, PTA: 5.4 ± 0.6 to 5.2 ± 0.7 mmol/L; both P < 0.05), and also 120-min post-OGTT glucose (SPK: 6.9 ± 2.9 to 5.7 ± 2.2 mmol/L; P = 0.07, PTA: 6.5 ± 1.7 to 5.7 ± 1.2 mmol/L; P < 0.05). Fasting C-peptide levels also decreased (SPK: 1500 ± 573 to 1078 ± 357 pmol/L, PTA: 1210 ± 487 to 1021 ± 434 pmol/L, both P < 0.005). Measured GFR decreased from enlistment to 8 weeks post transplant in PTA patients (94 ± 22 to 78 ± 19 mL/min/1.73 m2; P < 0.005), but did not deteriorate from week 8 to week 52 (SPK: 55.0 ± 15.1 vs 59.7 ± 11.3 ml/min/1.73 m²; P = 0.19, PTA: 76 ± 19 vs 77 ± 19 mL/min/1.73 m²; P = 0.74).

CONCLUSION

Glycemic control and kidney function remain preserved in recipients with functioning SPK and PTA grafts 1 year after transplantation.

Surgery of pancreas transplantation

PURPOSE OF REVIEW

The surgical techniques of pancreas transplantation have been evolving and significantly improved over time. This article discusses different current techniques and their modifications.

RECENT FINDING

At this time, the most commonly used technique is systemic venous drainage (for venous outflow) and enteric drainage (for management of exocrine pancreatic secretions). However, new modifications of established techniques such as gastric or duodenal exocrine drainage and venous drainage to the inferior vena cava continue to be introduced.

SUMMARY

This article provides a state-of the-art review of the most prevalent up-to-date surgical techniques as well as a synopsis of their specific risks and benefits. The article also provides the most current registry data regarding utilization of different surgical techniques in the United State and worldwide.

Pancreas Transplantation With Portal-Enteric Drainage for Patients With Endocrine and Exocrine Insufficiency From Extensive Pancreatic Resection

Although the primary indication for pancreas transplantation is type I diabetes, a small number of patients requires pancreas transplantation to manage combined endocrine and exocrine insufficiency that develops after extensive native pancreatic resection. The objective of this case report was to describe the operative and clinical course in 3 such patients and present an alternative technical approach.

Diabetes and other endocrine-metabolic abnormalities in the long-term follow-up of pancreas transplantation

Pancreas transplantation (PTX) has been demonstrated to restore long-term glucose homeostasis beyond what can be achieved by intensive insulin therapy or islet transplants. Moreover, PTX has been shown to decrease the progression of the chronic complications of diabetes. However, PTX patients require chronic use of immunosuppressive drugs with potential side effects. The long-term follow-up of PTX patients demands special care regarding metabolic deviations, infectious complications, and chronic rejection. Diabetes and other endocrine metabolic abnormalities following transplantation are common and can increase morbidity and mortality. Previous recipient-related and donor-related factors, as well as other aspects inherent to the transplant, act together in the pathogenesis of those abnormalities. Early recognition of these disturbances is the key to timely treatment; however, adequate tools to achieve this goal are often lacking. In a way, the type of PTX procedure, whether simultaneous pancreas kidney or not, seems to differentially influence the evolution of endocrine and metabolic abnormalities. Further studies are needed to define the best approach for PTX patients. This review will focus on the most common endocrine metabolic disorders seen in the long-term management of PTX: diabetes mellitus, hyperlipidemia, and bone loss. The authors here cover each one of these endocrine topics by showing the evaluation as well as proper management in the follow-up after PTX.

Imaging of Pancreas Transplantation and Its Complications

Whole pancreas transplantation is an effective treatment for obtaining euglycemic status in patients with insulin-dependent diabetes mellitus, and is usually performed concurrent with renal transplantation in the affected patient. This article discusses complex surgical anatomical details of pancreas transplantation including surgical options for endocrine and exocrine drainage pathways. It then describes several possible complications related to surgical factors in the immediate post operative period followed by other complications related to systemic issues, vasculature, and the pancreatic parenchyma.

Short and long-term outcomes of systemic drainage to IVC: a new technique for pancreas transplantation

Ninety-eight percent of the whole pancreas does not serve the purpose of pancreatic transplantation and it is a major cause of surgical complications. Up to 30% of pancreas transplant recipients experience surgical complications and require reoperation. Graft thrombosis and pancreatitis are the most common complications of pancreas transplantation (PT). Thus, different surgical techniques have been described to overcome the surgical hurdles and reduce surgical complications. In this study, for the first time, we report short- and long-term outcomes of PT with inferior vena cava (IVC) venous drainage. Forty-five PTs (22 simultaneous pancreas and kidney [SPK] transplantations and 23 pancreas after kidney [PAK] transplantations) were performed with this technique in our center. Sixty-eight percent of the donors were imported from outside of our area after they were declined by their local transplantation center. Patient and graft survival rates were 100% at 1 year. No graft thrombosis or pancreatitis occurred with this technique. Six patients (13.3%) required reoperation (3 bleeding, 2 anastomotic leak, and 1 small bowel perforation). No patient or graft loss occurred due to surgical complications. We conclude that this technique provides fast and easy dissection of the venous drainage of the PT without the need of complete occlusion of venous outflow. Surgical complication rates were lower with this technique compared with other reported techniques.

A comparison of long-term outcomes of portal versus systemic venous drainage in pancreatic transplantation: a systematic review and meta-analysis

Pancreas transplantation venous effluent can be drained via the portal vein or the systemic circulation; however, no recommendation exists for the ideal technique. A systematic review of the literature from 1989 through 2014 using PubMed, CINHAL, and Cochrane Library for portal versus systemic venous drainage was undertaken. Only studies on humans and published in English were considered. Measures of glycemic control and total cholesterol were synthesized for meta-analysis utilizing random-effects models. Of 166 articles retrieved, 15 articles were included for meta-analysis. Patient and graft survival were comparable in a large database study as well as in the only randomized control study. No differences in complications were seen when exocrine drainage was enteric for the systemic venous group. Fasting insulin (-34.13 pmol/mL, p < 0.001) was significantly lower within the portal drained group; however, fasting blood glucose levels (-3.4 mg/dL, p = 0.32) and hemoglobin A1C levels (mean difference 0.124%, p = 0.25) were comparable. Total cholesterol levels (-3.62 mg/dL, p = 0.447), as well as other measures of lipids, showed no difference. Based on this systematic review and meta-analysis, there is no evidence of differences in outcomes or metabolic control in patients undergoing pancreatic transplant with portal venous drainage compared to the systemic venous drainage.

Outcomes of pancreas retransplantation after simultaneous kidney-pancreas transplantation are comparable to pancreas after kidney transplantation alone

BACKGROUND

There is a paucity of contemporary data describing the results of pancreas retransplantation (PRT). As a measure of utility, we wished to determine whether PRT could produce equivalent short-term and long-term recipient outcomes to primary pancreas after kidney (PAK) transplantation.

METHODS

Retrospective analysis of 96 consecutive pancreas only transplants performed from 2003 to May 2012. Primary PAK transplants (n = 78) were compared to PRT (n=18).

RESULTS

Donor and recipient demographics were similar. Pancreas graft survival was similar for PAK and PRT at 1 year (88.2% vs. 100%) and 3 years (85.1% vs. 85.1%). Pancreas graft failure occurred in 14 PAK and two PRT patients with a mean follow-up of 61.6 ± 38.7 and 37.8 ± 26.1 months, respectively. There were no differences in postoperative length of stay (9.9 days vs. 8.7 days; P = 0.9) or postoperative complications in the first 3 months (47.4% vs. 38.9%, P = 0.6). At 3-year follow-up, both groups had comparable HBA1c (0.06 vs. 0.05; P = 0.8), serum creatinine (116.6 μmol/L v 131.7 μmol/L; P = 0.09), and oral glucose tolerance tests.

CONCLUSION

Pancreas retransplantation is a safe and effective therapy for select recipients after graft loss. Pancreas retransplantation is associated with the same risk of postoperative complications and has similar intermediate-term graft survival compared to primary PAK transplantation.

Changes in glucose and fat metabolism in response to the administration of a hepato-preferential insulin analog

Endogenous insulin secretion exposes the liver to three times higher insulin concentrations than the rest of the body. Because subcutaneous insulin delivery eliminates this gradient and is associated with metabolic abnormalities, functionally restoring the physiologic gradient may provide therapeutic benefits. The effects of recombinant human insulin (HI) delivered intraportally or peripherally were compared with an acylated insulin model compound (insulin-327) in dogs. During somatostatin and basal portal vein glucagon infusion, insulin was infused portally (PoHI; 1.8 pmol/kg/min; n = 7) or peripherally (PeHI; 1.8 pmol/kg/min; n = 8) and insulin-327 (Pe327; 7.2 pmol/kg/min; n = 5) was infused peripherally. Euglycemia was maintained by glucose infusion. While the effects on liver glucose metabolism were greatest in the PoHI and Pe327 groups, nonhepatic glucose uptake increased most in the PeHI group. Suppression of lipolysis was greater during PeHI than PoHI and was delayed in Pe327 infusion. Thus small increments in portal vein insulin have major consequences on the liver, with little effect on nonhepatic glucose metabolism, whereas insulin delivered peripherally cannot act on the liver without also affecting nonhepatic tissues. Pe327 functionally restored the physiologic portal-arterial gradient and thereby produced hepato-preferential effects.

A Simplified Technique of Pancreas Transplantation in a Porcine Model

Background: The incidence of diabetes has been steadily increasing. The only curative option for diabetes is pancreas transplantation (PTx). Porcine models are valuable because of their anatomical and physiological similarities to human beings. Our aim is to introduce a simplified technique of PTx in a porcine model. Methods: In Landrace pigs (n = 32), after median laparotomy, the pancreas was mobilized, and the portal and splenic veins were divided. The proper hepatic and splenic arteries and the bile duct were also prepared, and the duodenal bulb was prepared and stapled. The third portion of the duodenum was freed up to the ligament of Treitz and stapled, and the renal arteries were ligated. After systemic heparinization, the pancreas was perfused through the abdominal aorta with histidine-tryptophan-ketoglutarate solution. The portal and splenic veins were cut for evaluating the sufficiency of perfusion. Whole pancreaticoduodenal graft was procured along with an aortic jump graft containing mesenteric and celiac trunks. In recipients, after total pancreatectomy, the suprarenal inferior vena cava and infrarenal aorta were prepared for vascular anastomosis in an end-to-side manner. After pancreas reperfusion, duodenoduodenostomy was performed in an end-to-side manner. Results: Median cold and warm ischemia times were 10 h (range, 9-14 h) and 50 min (range, 35-80 min), respectively. The hemodynamic status was stable throughout the operation. The median follow-up period was 7 days (range, 4-10). There were no major intra- and postoperative complications. Conclusion: By using an aortic jump graft, there was no need to perform additional arterial reconstruction resulting in a short warm ischemic and operation time. End-to-side portocaval and duodenoduodenal anastomoses make this model of PTx a very feasible method for experimental evaluations.

The use of venous jump grafts in pancreatic transplantation - no difference in patient or allograft outcomes - an update of the UNOS database

Venous jump grafts are used in pancreas transplantation to salvage a pancreas with a short portal vein or to facilitate an easier anastomosis. There have been no large studies evaluating the safety of venous jump grafts in pancreas transplantation. We analyzed the UNOS database to determine whether venous jump grafts are associated with graft loss or patient death. Data from UNOS on all adult pancreas transplant recipients 1996-2012 were analyzed. Venous extension grafts were used in 2657 cases; they were not in 18 124. Kaplan-Meier/product-limit estimates analysis demonstrated similar patient survival (p < 0.641) and death-censored graft survival (p < 0.351) at one, three, five,10, and 15 yr between subjects with and without venous jump grafts. There was a statistically significant difference in one-yr unadjusted patient survival between the venous extension graft (94.9%) and the no-venous extension graft (95.8%) groups (p < 0.045) and a borderline difference in one-yr graft survival between the venous extension graft (84.1%) and the no-venous extension graft (82.6%) groups (p < 0.055). There was no significant difference in patient survival or allograft survival at the three-, five-, 10-, and 15-yr intervals. The use of venous jump grafts is not associated with increased graft loss or mortality.

Pancreas transplantation: a treatment option for people with diabetes

Since the first pancreas transplants in the early 1960s, whole-organ pancreas transplantation, either alone or combined with kidney transplantation, has become commonplace in many countries around the world. Whole-organ pancreas transplantation is available in the UK, with ~200 transplants currently carried out per year. Patient survival and pancreas graft outcome rates are now similar to other solid organ transplant programmes, with high rates of long-term insulin independence. In the present review, we will discuss whole-pancreas transplantation as a treatment for diabetes, focusing on indications for transplantation, the nature of the procedure performed, graft survival rates and the consequences of pancreas transplantation on metabolic variables and the progression of diabetes-related complications.

Pancreas transplantation: solid organ and islet

Transplantation of the pancreas, either as a solid organ or as isolated islets of Langerhans, is indicated in a small proportion of patients with insulin-dependent diabetes in whom severe complications develop, particularly severe glycemic instability and progressive secondary complications (usually renal failure). The potential to reverse diabetes has to be balanced against the morbidity of long-term immunosuppression. For a patient with renal failure, the treatment of choice is often a simultaneous transplant of the pancreas and kidney (SPK), whereas for a patient with glycemic instability, specifically hypoglycemic unawareness, the choice between a solid organ and an islet transplant has to be individual to the patient. Results of SPK transplantation are comparable to other solid-organ transplants (kidney, liver, heart) and there is evidence of improved quality of life and life expectancy, but the results of solitary pancreas transplantation and islets are inferior with respect to graft survival. There is some evidence of benefit with respect to the progression of secondary diabetic complications in patients with functioning transplants for several years.

Evolution of pancreas transplantation: long-term results and perspectives from a high-volume center

OBJECTIVE

To describe the evolution of pancreas transplantation from 1979 to 2011. The aim was to examine factors influencing long-term patient and graft survival, surgical methods, and risk factors influencing organ performance after transplantation.

BACKGROUND

Pancreas transplantation has become the therapy of choice for patients suffering insulin-dependent diabetes and end stage renal failure.

METHODS

Retrospective analysis of 509 consecutive pancreas transplants (442 simultaneous pancreas and kidney [SPK], 20 pancreas transplanted alone [PTA], and 47 pancreas transplanted after kidney [PAK]), performed at the University Hospital Innsbruck. The data were statistically analyzed using the Kaplan-Meier method and log-rank test.

RESULTS

After overcoming initial immunological and technical problems between 1979 and 1988 (5-year pancreas graft survival rate, 29.7%), pancreas transplantation evolved during the second decade (1989-1996; 5-year pancreas graft survival rate, 42.2%). Technical changes, optimized immunosuppression, careful pretransplant evaluation, and improved graft monitoring have become standard in the last decade and result in excellent 5-year patient (94.3%), kidney (89.4%), and pancreas (81.5%) graft survival. Five-year graft survival was superior in SPK (68.8%) compared with PAK (62.5%) and PTA (16.4%). SPK retransplantation can be carried out safely with 5-year patient (87.5%) and pancreas graft (75.0%) survival. Overall 5-year patient survival after loss of the first pancreas graft is significantly better in patients who underwent retransplantation (89.4% vs. 67.9%, P = 0.001). Long-term pancreas graft survival is independent of donor body mass index, sex, and cause of death, anastomosis time and the number of human leukocyte antigen (HLA) mismatches, recipient age, body mass index, sex, current panel reactive antibodies, and waiting time. Significant risk factors for reduced graft survival are cold ischemia time and donor age.

CONCLUSIONS

During the last 32 years, many problems in pancreas transplantation have been overcome and it may currently represent the therapeutic gold standard for some patients with diabetes and end stage renal failure.

Transplantation of the pancreas

Pancreas transplantation consistently induces insulin-independence in beta-cell-penic diabetic patients, but at the cost of major surgery and life-long immunosuppression. One year after grafting, patient survival rate now exceeds 95 % across recipient categories, while insulin independence is maintained in some 85 % of simultaneous pancreas and kidney recipients and in nearly 80 % of solitary pancreas transplant recipients. The half-life of the pancreas graft currently averages 16.7 years, being the longest among extrarenal grafts, and substantially matching the one of renal grafts from deceased donors. The difference between expected (100 %) and actual insulin-independence rate is mostly explained by technical failure in the postoperative phase, and rejection in the long-term period. Death with a functioning graft remains a further major issue, especially in uremic patients who have undergone prolonged periods of dialysis. Refinements in graft preservation, surgical techniques, immunosuppression, and prophylactic treatments are expected to further improve the results of pancreas transplantation.