Intraoperative Perfusion Assessment in Enhanced Reality Using Quantitative Optical Imaging: An Experimental Study in a Pancreatic Partial Ischemia Model

To reduce the risk of pancreatic fistula after pancreatectomy, a satisfactory blood flow at the pancreatic stump is considered crucial. Our group has developed and validated a real-time computational imaging analysis of tissue perfusion, using fluorescence imaging, the fluorescence-based enhanced reality (FLER). Hyperspectral imaging (HSI) is another emerging technology, which provides tissue-specific spectral signatures, allowing for perfusion quantification. Both imaging modalities were employed to estimate perfusion in a porcine model of partial pancreatic ischemia. Perfusion quantification was assessed using the metrics of both imaging modalities (slope of the time to reach maximum fluorescence intensity and tissue oxygen saturation (StO2), for FLER and HSI, respectively). We found that the HSI-StO2 and the FLER slope were statistically correlated using the Spearman analysis (R = 0.697; p = 0.013). Local capillary lactate values were statistically correlated to the HSI-StO2 and to the FLER slope (R = −0.88; p < 0.001 and R = −0.608; p = 0.0074). HSI-based and FLER-based lactate prediction models had statistically similar predictive abilities (p = 0.112). Both modalities are promising to assess real-time pancreatic perfusion. Clinical translation in human pancreatic surgery is currently underway.

Pretreatment with Warfarin Attenuates the Development of Ischemia/Reperfusion-Induced Acute Pancreatitis in Rats

In acute pancreatitis (AP), pancreatic damage leads to local vascular injury, manifesting as endothelial damage and activation, increased vascular permeability, leukocyte rolling, sticking and transmigration to pancreatic tissue as well as activation of coagulation. Previous studies have shown that pretreatment with heparin or acenocoumarol inhibits the development of AP. The aim of the present study was to check the impact of pretreatment with warfarin, an oral vitamin K antagonist, on the development of ischemia/reperfusion-induced AP in rats. AP was induced by pancreatic ischemia followed by reperfusion of the gland. Warfarin (90, 180 or 270 µg/kg/dose) or vehicle were administered intragastrically once a day for 7 days before induction of AP. The effect of warfarin on the severity of AP was assessed 6 h after pancreatic reperfusion. The assessment included histological, functional, and biochemical analyses. Pretreatment with warfarin given at a dose of 90 or 180 µg/kg/dose increased the international normalized ratio and reduced morphological signs of pancreatic damage such as pancreatic edema, vacuolization of acinar cells, necrosis and the number of hemorrhages. These effects were accompanied by an improvement of pancreatic blood flow and a decrease in serum level amylase, lipase, pro-inflammatory interleukin-1β and plasma level of D-dimer. In contrast, pretreatment with warfarin given at a dose of 270 µg/kg/dose led to an increase in severity of pancreatic damage and biochemical indicators of AP. In addition, this dose of warfarin resulted in deaths in some animals. Pretreatment with low doses of warfarin inhibits the development of AP induced by pancreatic ischemia followed by reperfusion.

Hypoxia of pancreas in pathogenesis of fibrosis in chronic pancreatitis

The pathogenesis of chronic pancreatitis and pain syndrome had not been fully studied. The aim of the study was to evaluate the interrelation of fibrotic and ischemic changes in the parenchyma of pancreas, and pancreatic duct pressure in the pathogenesis of chronic pancreatitis. In a prospective study, a morphological, the immunohistochemical study of pancreatic preparations was performed, and the indicators of tissue oximetry and pancreatic duct pressure were studied intraoperatively in 40 patients operated for chronic pancreatitis. It was found that with the progression of fibrotic changes in the pancreatic tissue of patients with chronic pancreatitis, there was an increase in TGF-β1 expression (р < 0.001), an increase in the number of pancreatic stellate cells (r = 0.32, р < 0.05), a decrease in glycogen (ischemia marker). The intraoperative direct measurement revealed a high pancreatic duct pressure: 34.2 (26.6; 45.3) mm Hg, a decrease in oxygenation of the pancreatic tissue that correlate with a degree of fibrosis. The pancreatic tissue in chronic pancreatitis has chronic hypoxia associated with fibrosis and increased pancreatic ductal hypertension. So, secondary pancreatic ischemia can be a significant factor in the progression of fibrosis and chronic pain syndrome in chronic pancreatitis.

Hydrogen-Rich Saline Protects against Ischemia/Reperfusion Injury in Grafts after Pancreas Transplantations by Reducing Oxidative Stress in Rats

Purpose.This study aimed to investigate the therapeutic potential of hydrogen-rich saline on pancreatic ischemia/reperfusion (I/R) injury in rats.Methods.Eighty heterotopic pancreas transplantations (HPT) were performed in syngenic rats. The receptors were randomized blindly into the following three groups: the HPT group and two groups that underwent transplantation and administration of hydrogen-rich saline (HS, >0.6 mM, 6 mL/kg) or normal saline (NS, 6 mL/kg) via the tail vein at the beginning of reperfusion (HPT + HS group, HPT + NS group). Samples from the pancreas and blood were taken at 12 hours after reperfusion. The protective effects of hydrogen-rich saline against I/R injury were evaluated by determining the changes in histopathology and measuring serological parameters, oxidative stress-associated molecules, and proinflammatory cytokines.Results.Administration of hydrogen-rich saline produced notable protection against pancreatic I/R injury in rats. Histopathological improvements and recovery of impaired pancreatic function were observed. In addition, TNF-α, IL-1β, and IL-6 were reduced markedly in the HPT + HS group. Additionally, there were noticeable inhibitory effects on the pancreatic malondialdehyde level and considerable recruitment of SOD and GPx, which are antioxidants.Conclusion.Hydrogen-rich saline treatment significantly attenuated the severity of pancreatic I/R injury in rats, possibly by reducing oxidative stress and inflammation.