Triple Arterial Reconstruction Improves Vascularization of Whole Pancreas for Transplantation

A Prospective Study of the Effect of Gastroduodenal Artery Reconstruction on Duodenal Oxygenation and Enzyme Content After Pancreas Transplantation

BACKGROUND

Whole pancreas transplantation provides durable glycemic control and can improve survival rate; however, it can carry an increased risk of surgical complications. One devastating complication is a duodenal leak at the site of enteroenteric anastomosis. The gastroduodenal artery (GDA) supplies blood to the donor duodenum and pancreas but is commonly ligated during procurement. Since we have not had expressive changes in pancreatic back table surgical techniques in the recent decades, we hypothesized whether back table GDA reconstruction, improving perfusion of the donor duodenum and head of the pancreas, could lead to fewer surgical complications in simultaneous pancreas-kidney (SPK) transplants.

MATERIAL AND METHODS

Between 2017 and 2021, we evaluated demographic information, postoperative complications, intraoperative donor duodenum, recipient bowel O2 tissue saturation, and patient morbidity through the Comprehensive Complication Index (CCI®).

RESULTS

A total of 26 patients were included: 13 underwent GDA reconstruction (GDA-R), and 13 had GDA ligation (GDA-L). There were no pancreatic leaks in the GR group compared to 38% (5/13) in the GDA-L group (p = 0.03913). Intraoperative tissue oxygen saturation was higher in the GDA-R group than in the GDA-L (95.18 vs.76.88%, p < 0,001). We observed an increase in transfusion rate in GDA-R (p < 0.05), which did not result in a higher rate of exploration (p = 0.38). CCI® patient morbidity was also significantly lower in the GDA-R group (s < 0.05).

CONCLUSIONS

This study identified improved intraoperative duodenal tissue oxygen saturation in the GDA-R group with an associated reduction in pancreatic leaks and CCI® morbidity risk. A larger prospective multicenter study comparing the two methods is warranted.

Working towards an ERAS Protocol for Pancreatic Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) initially started in the early 2000s as a series of protocols to improve the perioperative care of surgical patients. They aimed to increase patient satisfaction while reducing postoperative complications and postoperative length of stay. Despite these protocols being widely adopted in many fields of surgery, they are yet to be adopted in pancreatic transplantation: a high-risk surgery with often prolonged length of postoperative stay and high rate of complications. We have analysed the literature in pancreatic and transplantation surgery to identify the necessary preoperative, intra-operative and postoperative components of an ERAS pathway in pancreas transplantation.

Pancreas transplantation with isolated splenic artery blood supply - Single center experience

BACKGROUND

The blood supply of the native pancreas by three arterial lines from the celiac trunk system (splenic artery and common hepatic artery) and the superior mesenteric artery forces surgeons to perform vascular reconstruction to provide sufficient intra-organ blood flow into the graft. The purpose of our study was to assess the possibility of pancreas transplantation with an isolated splenic artery blood supply.

METHODS

From January 2012 to July 2018, simultaneous pancreas-kidney transplantation (SPKT) was performed in 21 patients. Gender: male - 11 (52,4%), female 10 (47,6%). Recipients aged 26 to 54, the median age was 38 [34; 42] years. In 6 (28,6%) recipients, the organ perfusion was carried out through the splenic artery alone; in the rest, it was performed through the splenic and inferior pancreaticoduodenal artery exiting from the superior mesenteric artery of the graft. The transplant function, the quality of carbohydrate metabolism compensation, the objective characteristics of intra-organ blood flow was assessed.

RESULTS

There were no statistically significant differences in the volume blood flow characteristics revealed by CT-perfusion and laboratory data in the study groups.

CONCLUSIONS

Based on the assessment of the function and quality of blood supply to the transplant, the possibility of performing pancreas transplantation with an isolated splenic artery blood supply had been proved.

[Pancreas transplantation with isolated blood supply through the splenic artery]

In multiple organ procurement, taking into consideration certain peculiarities of the vascular architectonics of the celiac trunk or an iatrogenic injury to the superior mesenteric artery, it is impossible to perform standard arterial reconstruction of a pancreas transplant with the use of a Y-shaped vascular allograft. This results in refusal from transplanting a potentially suitable organ. The purpose of our study was to assess the possibility of transplantation of the pancreatoduodenal complex with isolated blood supply via the splenic artery. Between January 2008 and November 2016, transplantation of the pancreas was carried out in a total of 20 patients (9 men and 11 women aged from 26 to 40 years, mean age 37.2±5.6 years). Depending on the number of the major arteries supplying the pancreas, the patients were divided into 2 groups. No statistically significant between-group differences in the parameters of volumetric blood flow determined by means of CT perfusion, in the majority of laboratory findings or therapeutic outcomes were revealed. Based on assessment of the function and quality of pancreatic blood supply, we proved feasibility of transplantation of the pancreatoduodenal complex with isolated blood supply through the splenic artery.

Simultaneous Kidney-Pancreas Transplantation With an Original "Transverse Pancreas" Technique: Initial 9 Years' Experience With 56 Cases

An innovative technique for pancreas transplantation is described. The main aspect consists of the horizontal positioning of the pancreas, which allows a better venous outflow, thus preventing thrombosis and graft loss. The program of pancreas transplantation in this national reference center for pancreatic and liver surgery was started in 2007; the initial results were considered poor, resulting in the loss of half of the grafts due to venous thrombosis. After analyzing the possible causes, this technique was proposed and successfully implemented, reducing the postoperative complications, particularly the problem of venous thrombosis. A detailed description of the new surgical technique is provided. The main clinical and demographic characteristics of the 56 patients who underwent the surgery are analyzed. The incidence of venous thrombosis was 5.3% (3 patients) and graft loss was 3.5% (2 patients). Due to the good results, this technique became the standard surgery for transplantation of the pancreas in our center. The technique proved to be safe and successful. Due to the unique pancreas graft implantation, we called it "transverse pancreas surgery."

Retrieval of the pancreas allograft for whole-organ transplantation

Proper pancreas retrieval during multi-organ recovery is one of the cornerstones of technically successful whole-organ pancreas transplantation. With evolving surgical approaches for organ retrieval and implantation, it has become standard to procure the pancreas in conjunction with other abdominal organs without compromising either vasculature, graft quality, or transplant outcomes. This review summarizes the major steps required for proper whole-organ retrieval of the pancreas allograft with suggestions and tips whenever alternative approaches are available.

Expanding the donor pool in pancreas transplantation

PURPOSE OF REVIEW

The current era of organ shortage has necessitated expansion of the currently available organ donor pool, to increase the number of pancreases available for transplant. This review summarizes the cumulative efforts of various centers in making this possible.

RECENT FINDINGS

Various centers are consistently reporting their experience with marginal donors; recent additions to the cohort have been increase in pancreases from donors after cardiac death (controlled and uncontrolled), update on long-term outcomes of live pancreas donors, as well as efforts at objectively assessing donor risk.

SUMMARY

It has become important for the transplanting surgeon to make difficult decisions on organ suitability and appropriateness depending upon the recipient's status. Further more, limiting further damage to these vulnerable grafts is important in improving utilization as well as successful transplantation.

Preparation of the pancreas allograft for transplantation

Meticulous preparation of the allograft on the back bench is one of the cornerstones of technically successful whole-organ pancreas transplantation. With evolving surgical approaches for organ retrieval and implantation, it has become routine to procure the pancreas in conjunction with other abdominal organs without sacrificing vasculature or graft quality and without compromising excellent outcomes. This review article summarizes the major steps required for proper back table preparation of the pancreas allograft with suggestions and tips whenever alternative approaches are presented.

The pancreas allograft donor: current status, controversies, and challenges for the future

The pancreas allograft is a scarce resource that is currently underutilized. The selection of appropriate deceased donors for pancreas procurement is of paramount importance for minimizing technical failure and optimizing long-term outcomes in pancreas transplantation. Despite the increasing demand for pancreas transplantation, increases in overall organ donation rates and the evolution of criteria that constitute an "acceptable" pancreas donor, the number of deceased donor pancreas transplants being performed in the United States has actually declined in recent years. Although there are many factors that must be considered during evaluation of the potential pancreas allograft donor to minimize morbidity and graft loss, it is evident that there are transplantable organs that are not used. In this review, deceased donor pancreas identification, management, selection, allocation, assessment, preservation, and the problem of pancreas underutilization will be discussed.

Complications after pancreas transplantation

PURPOSE OF REVIEW

The history of transplantation of the pancreas, unlike that of transplantation of other abdominal organs, has largely been shaped by the associated surgical complications. After more than three decades of progress, surgical-technical pancreas graft failure rates have decreased to approximately 8%. The most recent developments in this area are systematically reviewed in this article.

RECENT FINDINGS

Vascular graft thrombosis remains, by far, the most common cause of technical graft failure. Recent reports suggested that pancreas preservation with histidine-tryptophan-ketoglutarate solution (HTK) might be a risk factor for reperfusion pancreatitis, graft thrombosis and decreased short- and long-term graft survival. It remains unclear whether these results are, at least in part, related to HTK flush volumes and extended preservation (e.g.,>12 h). For selected thrombosed pancreas grafts, there has been renewed interest in pharmacological, interventional, and surgical salvage. For selected recipients with early pancreas graft thrombosis not amenable to a salvage intervention, transplant pancreatectomy in conjunction with immediate retransplantation has emerged as a viable option. For graft thrombosis prevention, the enhanced backtable pancreas vascular reconstruction techniques (e.g., gastroduodenal artery revascularization) proposed by some authors await more formal study. For prevention of native vascular complications in high-risk recipients, several technical modifications have been reported. Developments with respect to other surgical complications (wound infection, pancreatitis, leak, and bleeding) have been more incremental.

CONCLUSION

Recent evidence underscores the importance of judicious donor and recipient selection and of optimization of preservation and surgical factors for excellent short- and long-term pancreas transplant outcomes.

Surgical techniques for pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation reproducibly induces insulin independence in beta-cell penic diabetic patients. The difference between full insulin independence, partial graft function, and graft loss, mostly results from technical failure, graft rejection, and patient death with function graft. The purpose of this review is to examine recent surgical advances and discuss their contribution to improved graft function.

RECENT FINDINGS

Few actual surgical innovations were described in the period reviewed. Duodenoduodenostomy is an interesting option for drainage of digestive secretions, when the pancreas is placed behind the right colon and is oriented cephalad. The main advantage of this technique is easy endoscopic assessment of donor duodenum but, when allograft pancreatectomy is necessary, repair of native duodenum may be troublesome. Selective revascularization of the gastroduodenal artery, at the back-table, possibly improves blood supply to the head of the pancreas graft and duodenal segment. There is no proof that this additional maneuver is always beneficial, although it can be graft saving in case of poor segmental graft perfusion.

SUMMARY

Transplant surgeons should be familiar with all techniques for pancreas transplantation. Long-term graft function is possible only after technically successful pancreas transplantation. There is clearly a need for more objective assessment and standardization of surgical techniques for pancreas transplantation.

Expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats

AIM

To study the expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats.

METHODS

pCMV.Ins, an expression plasmid of the human insulin gene, was constructed. In total, 100 microg pCMV.Ins wrapped with chitosan nanoparticles (chitosan-pCMV.Ins) was transfected to NIH3T3 cells and diabetes rats through lavage and coloclysis, respectively. The transfected cells were grown in Dulbecco's modified Eagle's medium, containing G418, for 72 h after transfection. The clones were selected and continued to grow in G418 medium for 24 d. The expression of human insulin was detected by immunohistochemistry. Human insulin in the culture medium of transfected cells was measured. Fasting blood glucose and plasma human insulin of diabetic rats were measured for 5 d after transfection. RT-PCR and Western blotting were performed to confirm the expression of the human insulin gene in diabetic rats.

RESULTS

Approximately 10% of NIH3T3 cells transfected by chitosan-pCMV.Ins expressed human insulin. Human insulin in the culture medium of NIH3T3 cells transfected by chitosan-pCMV.Ins significantly increased compared with that of the control group (P<0.01). Fasting blood glucose levels of the lavage group and the coloclysis group decreased significantly in 5 d (P<0.01) in comparison, while plasma insulin levels were much higher (P<0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and the coloclysis groups.

CONCLUSION

The human insulin gene can be transfected and expressed successfully by chitosan- pCMV.Ins in NIH3T3 cells and diabetes rats, which indicates that chitosan is a promising, non-viral vector for gene expression.

Gene therapy for type 1 diabetes mellitus in rats by gastrointestinal administration of chitosan nanoparticles containing human insulin gene

AIM: To study the expression of human insulin gene in gastrointestinal tracts of diabetic rats.

METHODS: pCMV.Ins, an expression plasmid of the human insulin gene, wrapped with chitosan nanoparticles, was transfected to the diabetic rats through lavage and coloclysis, respectively. Fasting blood glucose and plasma insulin levels were measured for 7 d. Reverse transcription polymerase chain reaction (RT-PCR) analysis and Western blot analysis were performed to confirm the expression of human insulin gene.

RESULTS: Compared with the control group, the fasting blood glucose levels in the lavage and coloclysis groups were decreased significantly in 4 d (5.63 ± 0.48 mmol/L and 5.07 ± 0.37 mmol/L vs 22.12 ± 1.31 mmol/L, respectively, P < 0.01), while the plasma insulin levels were much higher (32.26 ± 1.81 &mgr;IU/mL and 32.79 ± 1.84 &mgr;IU/mL vs 14.23 ± 1.38 &mgr;IU/mL, respectively, P < 0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and coloclysis groups.

CONCLUSION: Human insulin gene wrapped with chitosan nanoparticles can be successfully transfected to rats through gastrointestinal tract, indicating that chitosan is a promising non-viral vector.

Revascularization of the gastroepiploic artery in pancreas transplant

Thrombosis accounted for 52.0% of all transplant failures in one recent large series and is felt to result from devascularization of the pancreas during organ procurement. A technique to revascularize the pancreas is described. The operative notes and angiograms of 110 consecutive pancreas transplants were reviewed. Eight pancreata were found deprived of blood supply to the head and the neck of the pancreas on indigocarmine-renograffin table angiograms. During back table reconstruction a distal branch of the superior mesenteric artery (SMA) was dissected and anastomosed end to end to the gastroepiploic artery using 8-0 monofilament suture. Repeated table angiogram showed excellent blood supply to the head of the pancreas, the duodenum and the body and tail of the pancreas. The pancreas transplantation proceeded with iliac artery graft inflow, portal venous outflow and enteric drainage. Simultaneous quadruple therapy with thymoglobulin, CNI, MMF and a 4-day course of steroids was used. All patients became insulin independent and euglycemic. No duodenal leak was observed in the entire series. In summary, 1-ligation of the gastroduodenal artery (GDA) is not a safe procedure, especially when arterial blood supply from the inferior pancreaticoduodenal artery is poor or inexistent, 2-table angiogram helps delineate the high risk hypo-perfused pancreas, 3-preservation of the right gastroepiploic artery and the branches of the SMA allows an easy revascularization of the pancreatic graft.