Pancreas allograft thrombosis.
ABSTRACT 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.
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ABSTRACT: Whole pancreas transplantation is an established treatment for selected patients with diabetic nephropathy or poorly controlled diabetes. Surgical techniques vary and have evolved over the past 4 decades. Imaging evaluation of the whole-pancreas transplant should begin with an understanding of the most commonly used surgical techniques and the spectrum of postoperative complications. Ultrasonography (US) should be the first-line modality in evaluating the pancreas allograft and vasculature. Computed tomography (CT) is useful in the assessment of extra-allograft processes, particularly in ruling out abscess formation or evaluating suspected bowel complications. Magnetic resonance (MR) imaging is reserved for cases in which complete evaluation with US or CT is not possible. MR angiography can help provide an accurate assessment of vascular abnormalities. The radiologist must be familiar with the spectrum of surgical techniques and the normal postoperative imaging appearances of the whole-pancreas transplant so as to be able to recognize abnormal postoperative findings. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115144/-/DC1.Radiographics 03/2012; 32(2):411-35. · 2.79 Impact Factor
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ABSTRACT: Two main histopathological types of acute rejection are recognized in solid organ transplantation: T-cell-mediated rejection (TCMR) and antibody-mediated rejection (AMR). In pancreas allografts the contrasting morphological features of these entities have only recently been described. Acute TCMR is characterized by active septal infiltrates composed predominantly of T cells and often involving veins (venulitis) and ducts (ductitis). Inflammation of the arterial endothelium (intimal arteritis or endarteritis) may be present. Focal or diffuse acinar inflammation (acinitis) is also typical of TCMR. Acute AMR in contrast, is characterized by predominantly macrophagic (± neutrophilic) inflammation, concentrated in, and around the interacinar microvasculature (interacinar inflammation, capillaritis) and typically shows focal or diffuse C4d staining of the interacinar capillaries. Architectural preservation is common in milder forms of AMR, whereas severe or untreated forms lead to extensive vascular injury and secondary parenchymal hemorrhagic necrosis. These morphological features strongly correlate with the presence of circulating donor-specific antibody (DSA)+. Stereotypical TCMR and AMR, as well as mixed forms of rejection can be confidently diagnosed in pancreas allograft biopsies with the combination of three elements: systematic analysis of the histological features; evaluation of C4d staining; and determination of the DSA status.Current opinion in organ transplantation 02/2012; 17(1):93-9. · 1.22 Impact Factor
Article: Early pancreas allograft thrombosis.[show abstract] [hide abstract]
ABSTRACT: OBJECTIVES: To determine factors associated with early pancreatic allograft thrombosis (EPAT). Thrombosis is the leading non-immunological cause of early pancreatic allograft failure. Multiple risk factors have been postulated. We hypothesized that recipient perioperative hypotension was a major risk factor and evaluated the correlation of this and other parameters with EPAT. METHODS: We retrospectively reviewed the records of the 118 patients who received a pancreatic allograft at our center between October 1992 and January 2010. Multiple donor and recipient parameters were analyzed as associates of EPAT by univariate and multivariate analysis. RESULTS: There were 12 episodes of EPAT, resulting in an incidence of 10.2%. On univariate analysis, EPAT was associated with perioperative hypotension, vasopressor use, and neuropathy in the recipient (p ≤ 0.04 for all). On multivariate analysis corrected for age, sex, and peripheral vascular disease, only vasopressor use retained a significant association with EPAT with a hazard ratio of 8.74 (CI 1.11-68.9, p = 0.04). Factors associated with vasopressor use included recipient ischemic heart disease, peripheral vascular disease, retinopathy or neuropathy, and any surgical complication. CONCLUSIONS: Significant hypotension, measured by the need for perioperative vasopressor use was associated with EPAT, suggesting that maintenance of higher perfusion pressures may avoid this complication.Clinical Transplantation 03/2013; · 1.63 Impact Factor