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

Heparin Thromboprophylaxis in Simultaneous Pancreas-Kidney Transplantation: A Systematic Review and Meta-Analysis of Observational Studies

Thrombosis is a leading causes of pancreas graft loss after simultaneous pancreas kidney (SPK), pancreas after kidney (PAK), and pancreas transplant alone (PTA). There remains no standardized thromboprophylaxis protocol. The aim of this systematic review and meta-analysis is to evaluate the impact of heparin thromboprophylaxis on the incidence of pancreas thrombosis, pancreas graft loss, bleeding, and secondary outcomes in SPK, PAK, and PTA. Following PRISMA guidelines, we systematically searched BIOSIS®, PubMed®, Cochrane Library®, EMBASE®, MEDLINE®, and Web of Science® on April 21, 2021. Primary peer-reviewed studies that met inclusion criteria were included. Two methods of quantitative synthesis were performed to account for comparative and non-comparative studies. We included 11 studies, comprising of 1,122 patients in the heparin group and 236 patients in the no-heparin group. When compared to the no-heparin control, prophylactic heparinization significantly decreased the risk of early pancreas thrombosis and pancreas loss for SPK, PAK and PTA without increasing the incidence of bleeding or acute return to the operating room. Heparin thromboprophylaxis yields an approximate two-fold reduction in both pancreas thrombosis and pancreas loss for SPK, PAK and PTA. We report the dosage, frequency, and duration of heparin administration to consolidate the available evidence.

Effective Technique for Pancreas Transplantation by Iliac Vascular Transposition, Without Heparin-Based Anticoagulation Therapy

BACKGROUND

To evaluate patients undergoing a new procedure, iliac vascular transposition, in pancreas transplantation regarding the risk of thrombosis and graft survival without heparin-based anticoagulation therapy.

METHODS

Iliac vascular transposition (IVT) involves changing the positions of the external iliac artery and vein relative to each other. In this study, this technique was evaluated in patients undergoing the procedure compared with patients not undergoing the procedure (iliac vascular parallel (IVP) group).

RESULTS

No patients received prophylactic heparin therapy. Two patients in the IVP group (n = 26) developed complete thrombosis and six developed partial thrombosis, compared with no patients with complete thrombosis and one with partial thrombosis in the IVT group (n = 29). The cumulative incidence of thrombosis was significantly higher in the IVP group (p < 0.01). Cox regression revealed that not receiving iliac vascular transposition was the only significant risk factor for thrombosis (odds ratio: 10.1, 95% confidence interval: 1.27-81.2; p = 0.03). One-year graft survival was significantly better in the IVT group vs IVP group (p = 0.03).

CONCLUSIONS

IVT in pancreas transplantation is a simple technique that results in a lower thrombosis risk and better graft survival rates without heparin-based anticoagulation therapy.

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.

Comparison of Ipsilateral and Contralateral Simultaneous Pancreas and Kidney Transplantation: A Single-Center Analysis with 5-Year Outcome

Background

It is routine to implant the pancreas on the right and the renal graft on the left iliac fossa during a simultaneous kidney and pancreas transplant (cSPK). Ipsilateral placement of both organs on the same side raises concerns that the pancreas graft might compromise the distally placed kidney. However, ipsilateral SPK (iSPK) can be faster than the conventional contralateral graft placement and allows for preservation of the other side for future transplants.

Material/Methods

In a single unit, 67 SPK transplantations (cSPK n=49, iSPK n=18) were performed from 2008 to 2011. The decision for graft placement was made during the procedure. Donor and recipient demographics, surgical complications, reoperations, surgical time, and patient and graft survival with 5-year follow-up were compared between the 2 groups.

Results

Duration of operation was shorter in the iSPK group. Recipient and donor demographics were comparable, apart from more females receiving ipsilateral graft placement. The broader female pelvis was probably the determining factor contributing to this outcome. The iSPK group included marginally younger recipients. The ipsilateral group also demonstrated a trend to improved survival of patient, pancreas, and kidney graft, at 1- and 5-year follow-up. There was no difference in complication rates between the 2 groups.

Conclusions

There were no significant differences in overall outcomes. iSPK is a safe procedure, which proves similar patient and graft survival as with cSPK. Both procedures have comparable surgical complication rates. iSPK is a safe and quicker procedure that allows for preservation of the contralateral side for potential subsequent transplants.

Techniques of pancreas graft salvage/indications for allograft pancreatectomy

PURPOSE OF REVIEW

Despite improvements in pancreas allograft outcome, graft complications remain a significant cause of morbidity and mortality. This review analyses the issues involved in the management of conditions that may require graft pancreatectomy, including the indications and techniques for graft salvage.

RECENT FINDINGS

With early recognition of graft complications, liberal use of radiological interventions, improved infection control, access to critical care and innovative surgical techniques, graft salvage is now feasible in many circumstances where graft pancreatectomy would previously have been necessary.

SUMMARY

The outcome of pancreas transplantation continues to improve with advances in the management of graft-threatening complications.

Splenic Vein Thrombosis Following Pancreas Transplantation: Identification of Factors That Support Conservative Management

Prophylaxis for graft portal/splenic venous thrombosis following pancreas transplant varies between institutions. Similarly, treatment of venous thrombosis ranges from early re-exploration to conservative management with anticoagulation. We wished to determine the prevalence of graft splenic vein (SV) thrombosis, as well as the clinical significance of non-occlusive thrombus observed on routine imaging. Records of 112 pancreas transplant recipients over a 5-year period at a single center were reviewed. Venous thrombosis was defined as absence of flow or presence of thrombus identified in any part of the graft SV on ultrasound. Thirty patients (27%) had some degree of thrombus or absence of flow in the SV on postoperative ultrasound. There were 5 graft losses in this group. Four were due to venous thrombosis, and occurred within 20 days of transplant. All patients with non-occlusive partial SV thrombus but normal arterial signal on Doppler ultrasound were successfully treated with IV heparin followed by warfarin for 3-6 months, and remained insulin independent. Findings of arterial signal abnormalities, such as absence or reversal of diastolic flow within the graft, require urgent operative intervention since this finding can be associated with more extensive thrombus that may lead to graft loss.

Heparin infusion in simultaneous pancreas and kidney transplantation reduces graft thrombosis and improves graft survival

INTRODUCTION

Thrombosis of the pancreas after transplantation is the most common cause of relaparotomy and resultant graft loss. There is currently no standard protocol consistently proven to prevent thrombosis following transplantation. Our objective was to determine whether our protocol of post-operative low-dose intravenous (IV) heparin infusion would prevent graft thrombosis without additional complications in our patients.

METHODS

A total of 66 simultaneous pancreas kidney (SPK) transplants were performed at our institution from 2004 to 2014. Patients were divided into 2 retrospective cohort groups. Group 1 patients received only acetylsalicylic acid (ASA) 81 mg/d started on post-operative day 1. Group 2 patients received IV heparin infusion beginning in the recovery room at a rate of 500 IU/h for the first 24 hours, reduced by 100 IU/h every day to stop on day 5, and then received ASA 81 mg/d afterward. Outcome and complication rates were compared between the two groups for 5 years post-transplant.

RESULTS

We observed a significant reduction in graft thrombosis and graft loss with (0/29) patients in the heparin group vs (7/33) 25.7% from the non-heparin (P<.01) with no differences in complication rates.

CONCLUSIONS

We present a heparin infusion protocol which may help prevent graft thrombosis and graft loss in SPK transplantation.

Antithrombin: anti-inflammatory properties and clinical applications

Many humoral and cellular components participate in bidirectional communication between the coagulation and inflammation pathways. Natural anticoagulant proteins, including antithrombin (AT), tissue factor pathway inhibitor, and protein C, suppress proinflammatory mediators. Conversely, inflammation blunts anticoagulant activity and, when uncontrolled, promotes systemic inflammation-induced coagulation, such as those that occur in disseminated intravascular coagulation and severe sepsis. This review discusses the mechanisms of action and clinical use of AT concentrate in critically ill patients and in the settings of perioperative anticoagulation management for surgery and obstetrics. AT is a serine protease inhibitor with broad anticoagulant activity and potent anti-inflammatory properties. In clinical conditions associated with hereditary or acquired AT deficiency, administration of AT concentrate has been shown to restore proper haemostasis and attenuate inflammation. Of note, AT modulates inflammatory responses not only by inhibiting thrombin and other clotting factors that induce cytokine activity and leukocyte-endothelial cell interaction, but also by coagulation-independent effects, including direct interaction with cellular mediators of inflammation. An increasing body of evidence suggests that AT concentrate may be a potential therapeutic agent in certain clinical settings associated with inflammation. In addition to the well-known anticoagulation properties of AT for the treatment of hereditary AT deficiency, AT also possesses noteworthy anti-inflammatory properties that could be valuable in treating acquired AT deficiency, which often result in thrombotic states associated with an inflammatory component.

Analysis of the influence of antithrombin on microvascular thrombosis: anti-inflammation is crucial for anticoagulation

Purpose

Microvascular thrombosis during septic conditions is of essential clinical relevance, but the pathomechanisms are not yet completely understood. The purpose of this study was to study the distinguished differentiation of the interactions of inflammation and coagulation using antithrombin (AT), a mediator of anticoagulation and anti-inflammation.

Methods

Using a thrombosis model in a cremaster muscle preparation of male C57Bl/6J mice (n = 83), we quantitatively assessed microvascular thrombus formation by using intravital fluorescence microscopy. Experimental groups consisted of animals treated with AT or with tryptophan⁴⁹-blocked AT (TrypAT), which exerts only anticoagulant but no anti-inflammatory effects. To further see whether endothelial glycosaminoglycan (GAG) binding with consecutive prostacyclin (PGI₂) release is mandatory for the anticoagulant process of AT, animals were administered heparin or indomethacin either alone or in combination with AT.

Results

The antithrombotic capacity of AT significantly differs in the experimental groups in which anti-inflammation was antagonized. This is given by the significantly prolonged occlusion times (p < 0.05) and higher patency rates in case of application of AT alone; while all other groups in which the anti-inflammatory action of AT was blocked by TrypAT, heparin or indomethacin revealed thrombus kinetics comparable to controls.

Conclusions

The anti-inflammatory influence of AT is essentially linked to its anticoagulant effect in the microvascular system. Those specifications of the active profile of AT characterize the intimate interactions of the anticoagulant and anti-inflammatory pathways. This might be of relevance for AT as a therapeutic agent in critically diseased patients and the clinical understanding of microvascular thrombosis.

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.

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.

Impact of blood amylase peak over vascular graft thrombosis in pancreas transplantation

BACKGROUND

Vascular graft thrombosis (VGT) is still the achuilles heel in pancreas transplantation (PT); it is the main cause of nonimmunologic graft loss. Early diagnosis is essential to avoid transplantectomy. The aim of our study was to analyze the peak amylase during the first 3 days after PT as risk factor for VGT.

METHODS

This retrospective study included 58 pancreas transplants in 55 patients from January 2007 to November 2011. They underwent an anticoagulation protocol based on unfractionated heparin and low-molecular-weight heparin. The technique consisted of enteric drainage and systemic venous drainage. The primary endpoint was VGT with consideration of multiple relevant variables. The maximum amylase level was determined during the first 3 days after transplantation. A receiver operating characteristic analysis was performed to establish a cutoff point as (mean plus one standard deviation; 745 mg/dL), calculating the sensitivity, specificity, and predictive values.

RESULTS

Recipient characteristics were 71% males with an overall mean age of 39 years (range, 23-55) and body mass index 24 (range, 19-36). The donor sex was similar. Mean donor age was 32 years with occurrences of hypotension in 9%, cerebrovascular brain death in 46%. Mean ischemia time was 10 hours and 45 minutes. Mean blood amylase peak was 395 mg/dL. Seven VGT cases were diagnosed during the postoperative period including six with complete thrombosis requring transplantectomy. Bivariate analysis showed the group of subjects with amylase levels above 745 mg/dL to display on eight-fold greater risk for VGT (odds ratio = 8.6; P = .032). The area under the curve of blood amylase peak during the first 3 days to detect VGT was 0.630 (95% confidence interval 0.41-0.84).

CONCLUSIONS

A blood amylase peak above 745 mg/dL in the first 3 days after transplantation was associated with risk for VGT.

Pancreas graft thrombosis: causes, prevention, diagnosis, and intervention

PURPOSE OF REVIEW

Pancreas graft thrombosis remains one of the most common reasons for pancreas transplant loss. Patients with a history of thrombotic events should be identified and evaluated for thrombophilia to identify transplant candidates at highest risk.

RECENT FINDINGS

Early after transplant, vascular thrombosis is multifactorial, but beyond 2 weeks, inflammation or acute rejection predominate as the cause of thrombosis. Most pancreas transplant centers utilize some form of anticoagulation following transplantation. Aspirin is highly recommended. Unfractionated or low-molecular-weight heparin is often administered, but some centers use heparin selectively and typically at low dose to avoid postoperative bleeding. Warfarin is less frequently given and its use should probably be limited to patients with thrombophilia.

SUMMARY

Thrombectomy, either surgical or percutaneous, may salvage the pancreas graft if performed early after the occurrence of thrombosis.

How to avoid graft thrombosis requiring graftectomy: immediate posttransplant CT angiography in pancreas transplantation

BACKGROUND

Graft thrombosis immediately after surgery remains a problem for successful pancreas transplantation. The present study evaluated the efficacy of computed tomography (CT) angiography for monitoring of graft patency in the immediate postoperative period.

METHODS

The study involved 119 patients who underwent pancreas transplantation between July 1992 and December 2009 in a single center. The anticoagulation strategy was heparin during and after transplantation and then oral warfarin for 1 to 6 months. Graft thrombosis was monitored using color Doppler ultrasonography until July 2005 (group A) and, thereafter, using CT angiography (group B). We retrospectively analyzed the efficacy of diagnosis of graft thrombosis in two groups. Graft survival was assessed using Kaplan-Meier analysis.

RESULTS

Group A comprised 51 patients, and group B comprised 68 patients. Total vascular thrombosis was diagnosed in three (5.9%) group A and one (1.4%) group B patients, and partial venous thrombosis was diagnosed in 1 (2.0%) group A and 19 (31.6%) group B patients. Eighteen of the 19 grafts with partial thrombosis in group B were successfully treated using heparin-based anticoagulant therapy. There were no CT contrast media-related complications in group B. In group B, graft survival rates were the same for grafts with partial thrombosis and grafts without thrombosis.

CONCLUSIONS

CT angiography was safe and effective for evaluating graft patency after pancreas transplantation. Partial vascular thrombosis in the immediate posttransplantation period showed no effect on graft survival under intensive anticoagulation and monitoring by CT angiography.

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.

Current concepts in the simultaneous transplantation of kidney and pancreas

Diabetes mellitus (DM) represents an enormous health care concern for the United States and other countries. According to the American Diabetes Association in 2007, there were more than 23 million Americans living with diabetes. This is a 13.5% increase from 2005, likely representing increases in Type II DM (DMII). Diabetes mellitus results when the beta cells of the pancreas are unable to produce sufficient insulin to prevent hyperglycemia. Simultaneous pancreas and kidney transplantation, or SPK, may be indicated for patients that have experienced renal failure as a complication of DM (either type I or type II). Until recently, technical failure represented a significant impediment to the success of pancreas transplantation. At the turn of the century, however, both renal and pancreatic graft survival dramatically improved. Immunologic and nonimmunologic causes of graft failure continue to challenge inpatient and outpatient management. With vigilance in the ICU postoperatively and in the clinic, SPK can provide significant benefit both in patient survival and quality of life.

Pancreas allograft thrombosis

Thrombosis of the transplanted pancreas is a common and often catastrophic event. Predisposing factors include the hypercoagulable state of many patients with diabetic renal failure, preservation-related graft endothelial injury, and low-velocity venous flow. Clinical management includes optimization of modifiable risk factors, controlled anticoagulation, graft monitoring, and early therapeutic intervention.

Incidence of pancreas graft thrombosis using low-molecular-weight heparin

INTRODUCTION

Simultaneous pancreas-kidney transplantation is the current treatment of choice for patients with type I diabetes and end stage renal disease. Vascular graft thrombosis (VGT) after pancreas transplantation is the main cause of early graft loss.

METHODS

A total of 188 consecutive pancreas transplantations were performed between January 2000 and December 2006. A retrospective study was carried out in order to compare incidence of VGT and relaparotomy-for-bleeding rate of once daily fixed dose low-molecular-weight-heparin (LMWH) to dose-adjusted intravenous unfractionated heparin (UFH).

RESULTS

Fifty-eight patients receiving LMWH and 129 receiving UFH were identified. There were 7% (4/58) VGTs in the LMWH and 17% (22/129) in the UFH group (p = 0.047). The frequency of major bleeding requiring relaparatomy was not significantly different in the groups related to LMWH and UFH, respectively (6.9% vs. 7.8%). One yr patient and pancreas graft survival was 98.9/89.6% in the LMWH and 97.8/74.4% in the UFH group. Donor and recipient characteristics were similar.

CONCLUSION

In our experience once daily fixed dose LMWH might not be inferior to dose-adjusted intravenous heparin in preventing pancreas graft thrombosis.

Antithrombin III for critically ill patients

BACKGROUND

Critical illness is associated with uncontrolled inflammation and vascular damage which can result in multiple organ failure and death. Antithrombin III (AT III) is an anticoagulant with anti-inflammatory properties but the efficacy and any harmful effects of AT III supplementation in critically ill patients are unknown.

OBJECTIVES

To assess the benefits and harms of AT III in critically ill patients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); MEDLINE; EMBASE; Science Citation Index Expanded; International Web of Science; CINAHL; LILACS; and the Chinese Biomedical Literature Database (up to November 2006). We contacted authors and manufacturers in the field.

SELECTION CRITERIA

We included all randomized clinical trials, irrespective of blinding or language, that compared AT III with no intervention or placebo in critically ill patients.

DATA COLLECTION AND ANALYSIS

Our primary outcome measure was mortality. We each independently abstracted data and resolved any disagreements by discussion. We presented pooled estimates of the intervention effects on dichotomous outcomes as relative risks (RR) with 95% confidence intervals (CI). We performed subgroup analyses to assess risk of bias, the effect of AT III in different populations (sepsis, trauma, obstetric, and paediatric patients), and the effect of AT III in patients with or without the use of concomitant heparin. We assessed the adequacy of the available number of participants and performed a trial sequential analysis to establish the implications for further research.

MAIN RESULTS

We included 20 randomized trials with a total of 3458 participants; 13 of these trials had high risk of bias. When we combined all trials, AT III did not statistically significantly reduce overall mortality compared with the control group (RR 0.96, 95% CI 0.89 to 1.03; no heterogeneity between trials). A total of 32 subgroup and sensitivity analyses were carried out. Analyses based on risk of bias, different populations, and the role of adjuvant heparin gave insignificant differences. AT III reduced the multiorgan failure score among survivors in an analysis involving very few patients. AT III increased bleeding events (RR 1.52, 95% CI 1.30 to 1.78).

AUTHORS' CONCLUSIONS

AT III cannot be recommended for critically ill patients based on the available evidence. A randomized controlled trial of AT III, without adjuvant heparin, with prespecified inclusion criteria and good bias protection is needed.

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.

Efficacy of antithrombin in the prevention of microvascular thrombosis during endotoxemia: An intravital microscopic study

INTRODUCTION

The KyberSept trial in septic patients showed that antithrombin (AT) reduced 90-day mortality significantly in a subgroup of patients not receiving concomitant heparin for thrombosis prophylaxis. Microvascular thrombosis is a key pathophysiologic mechanism during sepsis, ischemia/reperfusion and disseminated intravascular coagulation (DIC). Therefore, this study investigated the antithrombotic property of AT as potential monotherapy in an experimental endotoxemia model in order to omit concomitant heparin.

MATERIALS AND METHODS

Using a light/dye injury model in the ear and the cremaster muscle preparation of mice, we quantitatively assessed microvascular thrombus formation in a total of 30 endotoxemic mice by means of intravital fluorescence microscopy. Before thrombus induction animals received a single i.v. bolus of AT (100 or 250 IU/kg), heparin (100 IU/kg) or saline (NaCl).

RESULTS

In NaCl-treated endotoxemic animals, light/dye exposure led to complete thrombotic occlusion in arterioles and venules within <450 s in the ear model. Heparin delayed thrombotic vessel occlusion by more than 50%. AT significantly prolonged times until thrombotic vessel occlusion in a dose-dependent manner and more effectively than heparin (p<0.05 vs. NaCl and heparin). This anti-coagulative effect of AT was especially pronounced in arterioles. Upon light/dye exposure to cremaster muscle preparations in endotoxemic mice AT also caused a 4-fold delay in microvascular thrombus growth with 827+/-77 s until complete thrombotic occlusion.

CONCLUSIONS

We could characterize for the first time AT-mediated antithrombotic activity during endotoxemia in two models of phototoxicity-induced microvascular thrombosis. Our results clearly demonstrate an additional AT mechanism of action that may be responsible for beneficial effects observed during endotoxemia and DIC. This AT profile may allow future high-dose AT application without giving heparin for thrombosis prophylaxis, an intriguing strategy that is to be tested under clinical conditions.

Microcirculatory disorders in sepsis and transplantation: therapy with natural coagulatory inhibitors antithrombin and activated protein C

PURPOSE OF REVIEW

Modern technologies allow visualization of microcirculatory disorders. This review describes how the coagulatory inhibitors antithrombin and activated protein C (APC) can improve microcirculation in sepsis and transplantation.

RECENT FINDINGS

The effects of antithrombin and APC on microcirculatory disorders in ischemia reperfusion and experimental sepsis have been reported recently. In addition, antithrombin has recently been clinically used to reduce graft pancreatitis after pancreas-kidney transplantation, and to improve kidney perfusion. It was demonstrated that septic capillary perfusion failure as well as leukocyte-endothelial cell interactions can be reversed by high-dose prophylactic antithrombin application. APC was also highly effective in this context. Thus, APC could improve microcirculatory blood flow in septic patients as recently measured by in-vivo orthogonal polarization spectral imaging techniques. For antithrombin, comparable measurements in humans are currently not available.

SUMMARY

Microcirculatory dysfunction plays a key role in the development of organ dysfunction in septic patients and after solid organ transplantation. The exogenous application of coagulatory inhibitors may provide a new important strategy for prevention and treatment of microcirculatory disorders. This mode of action may be the reason why coagulatory inhibitors could improve mortality in septic patients without directly influencing inflammatory mediator concentrations.