Clinical and experimental studies of intraperitoneal lipolysis and the development of clinically relevant pancreatic fistula after pancreatic surgery.

BACKGROUND: Visceral obesity is one of the risk factors for clinically relevant pancreatic fistula after pancreatic resection. The objective of this study was to evaluate the impact of intraperitoneal lipolysis on postoperative pancreatic fistula. METHODS: The degree of intraperitoneal lipolysis was investigated by measuring the free fatty acid concentration in drain discharge in patients after pancreatic resection. An experimental pancreatic fistula model was prepared by pancreatic transection, and the impact of intraperitoneal lipolysis was evaluated by intraperitoneal administration of triolein (triglyceride) with, or without orlistat (lipase inhibitor). RESULTS: Thirty-three patients were included in the analysis. The free fatty acid concentration in drain discharge on postoperative day 1 was significantly associated with the development of a clinically relevant pancreatic fistula (P = 0·004). A higher free fatty acid concentration in drain discharge was associated with more visceral adipose tissue (P = 0·009). In the experimental model that included 98 rats, intraperitoneal lipolysis caused an increased amount of pancreatic juice leakage and multiple organ dysfunction. Intraperitoneal administration of a lipase inhibitor reduced lipolysis and prevented deterioration of the fistula. CONCLUSION: Intraperitoneal lipolysis significantly exacerbates pancreatic fistula after pancreatic resection. Inhibition of lipolysis by intraperitoneal administration of a lipase inhibitor could be a promising therapy to reduce clinically relevant postoperative pancreatic fistula. Surgical relevance Clinically, there are two types of pancreatic fistula after pancreatic resections: harmless biochemical leak and harmful clinically relevant pancreatic fistula. Visceral obesity is one of the known risk factors for clinically relevant pancreatic fistula; however, the underlying mechanisms remained to be elucidated. Patients with clinically relevant pancreatic fistula had a higher free fatty acid concentration in the drain discharge, suggesting a relationship between intraperitoneal lipolysis and pancreatic fistula. The experimental model of pancreatic fistula demonstrated that intraperitoneal lipolysis caused deterioration in pancreatic fistula, suggesting that intraperitoneal lipolysis is one of the mechanisms that drives biochemical leakage to clinically relevant pancreatic fistula. Intraperitoneal administration of a lipase inhibitor prevented lipolysis as well as pancreatic fistula deterioration in the experimental model, suggesting a future clinical application for lipase inhibitors in prevention of clinically relevant pancreatic fistula.

'Artery-first' approaches to pancreatoduodenectomy.

BACKGROUND: The technique of pancreatoduodenectomy (PD) has evolved. Previously, non-resectability was determined by involvement of the portal vein-superior mesenteric vein. Because venous resection can be achieved safely and with greater awareness of the prognostic significance of the status of the posteromedial resection margin, non-resectability is now determined by involvement of the superior mesenteric artery (SMA). This change, with a need for early determination of resectability before an irreversible step, has promoted the development of an 'artery-first' approach. The aim of this study was to review, and illustrate, this approach. METHODS: An electronic search was performed on MEDLINE, Embase and PubMed databases from 1960 to 2011 using both medical subject headings and truncated word searches to identify all published articles that related to this topic. RESULTS: The search revealed six different surgical approaches that can be considered as 'artery first'. These involved approaching the SMA from the retroperitoneum (posterior approach), the uncinate process (medial uncinate approach), the infracolic region medial to the duodenojejunal flexure (inferior infracolic or mesenteric approach), the infracolic retroperitoneum lateral to the duodenojenunal flexure (left posterior approach), the supracolic region (inferior supracolic approach) and through the lesser sac (superior approach). CONCLUSION: The six approaches described provide a range of options for the early determination of arterial involvement, depending on the location and size of the tumour, and before the 'point of no return'. Whether these approaches will achieve an increase in the proportion of patients with negative margins, improve locoregional control and increase long-term survival has yet to be determined.

Henoch-Schönlein Purpura After Living Donor Liver Transplantation: Report of the First Case.

Henoch-Schönlein purpura (HSP) is a systemic vasculitis affecting the small vessels that mainly presents in children and young adults. It is characterized by tissue deposition of immunoglobulin A (IgA) immune complexes with the classic manifestations of purpura, arthritis, arthralgia, and gastrointestinal and renal involvements. We report a case of HSP nephritis that occurred 2 years after living-donor liver transplantation (LDLT). After pulse steroid administration, the patient's symptoms disappeared and blood markers normalized. To the best of our knowledge, this is the first HSP case to be reported in a liver transplant recipient.

Effects of synthetic kassinin on splanchnic circulation and exocrine pancreas in dogs.

Effects of intravenously administered synthetic kassinin on splanchnic circulation and exocrine pancreatic secretion were examined in six anesthetized dogs. Kassinin caused dose-related increases in the blood flow in superior mesenteric artery and portal vein, and produced an initial increase followed by a decrease in pancreatic blood flow, but did not affect the exocrine pancreatic secretion. This study demonstrates that kassinin affects splanchnic blood flow in dogs, and suggests that kassinin or a kassinin-like substance functions as a neuropeptide controlling the splanchnic circulation in mammalian species.

Effects of synthetic human pancreastatin on pancreatic secretion and blood flow in rats and dogs.

Effects of synthetic human pancreastatin-52 and human pancreastatin-29 on pancreatic secretion and blood flow were examined in rats and dogs. Synthetic human pancreastatin-52 and human pancreastatin-29 were equally potent in suppressing the release of amylase stimulated by cholecystokinin in rats in vivo. However, neither human pancreastatin-52 nor human pancreastatin-29 altered basal and cholecystokinin-stimulated amylase release from isolated dispersed rat pancreatic acini. In studies in dogs, human pancreastatin-29 suppressed releases of amylase and protein stimulated by cholecystokinin, but did not alter pancreatic blood flow. These results suggest that the inhibitory effects of pancreastatin on pancreatic secretion do not involve a direct action on pancreatic acinar cells nor alteration of pancreatic blood flow. Pancreastatin probably is important in regulating exocrine pancreatic secretions as well as endocrine pancreatic secretions.

Effect of synthetic neuromedin-N, a novel neurotensin-like peptide, on exocrine pancreatic secretion and splanchnic blood flow in dogs.

Neuromedin-N, a novel neurotensin-like peptide, has recently been identified from porcine spinal cord by using a bioassay for a stimulatory effect on guinea pig ileum. The amino acid sequence of the peptide has been determined to be Lys-Ile-Pro-Tyr-Ile-Leu, which is quite homologous to the COOH-terminal sequence of neurotensin. In this study, the effect of neuromedin-N on pancreas and splanchnic blood flow was investigated in eight dogs. Intravenous injections of graded doses of synthetic neuromedin-N caused a dose-dependent decrease of systemic arterial pressure and a dose-dependent increase in both portal and superior mesenteric arterial blood flow, which were measured with transit time ultrasonic flow meter. Volume and protein output of the pancreatic juice were also increased significantly by Neuromedin-N. Pancreatic capillary blood flow measured with laser Doppler flowmetry was increased in a dose-related manner. The present study first demonstrated that neuromedin-N retains a potent stimulatory effect on the pancreas and splanchnic circulation, indicating that this peptide is one of the biological active forms of neurotensin-like peptide in mammals. This study also leads to the suggestion that this peptide possesses physiological significance as a novel neuropeptide.

Role of angiotensin II in extracellular matrix and transforming growth factor-beta 1 expression in hypertensive rats.

The in vivo effects of alacepril (1-[(S)-3-acetylthio-2-methylpropanoyl]- L-prolyl-L-phenylalanine), an angiotensin converting enzyme inhibitor, and SC-52458 (5-[(3,5-dibutyl-1H-1,2,4-triazol-1- yl)methyl]-2-[2-(1H-tetrazol-5-ylphenyl)]pyridine), an angiotensin AT1 receptor antagonist, were examined on the cardiac and aortic gene expressions of extracellular matrices and TGF-beta 1 in young spontaneously hypertensive rats (SHR). In SHR, types I and III collagen mRNAs were increased in the left ventricle, and in contrast, fibronectin, collagen IV, and transforming growth factor-beta 1 (TGF-beta 1) mRNAs were increased in aorta, compared with those in Wistar-Kyoto rats. All the enhanced mRNAs in both organs in SHR were significantly inhibited by the short-term treatment with the above two drugs. Thus, angiotensin AT1 receptor may play an important role in the regulation of extracellular matrices and TGF-beta 1 expressions in SHR.

Microcirculatory response of the pancreas to feeding, sham feeding, and truncal vagotomy in conscious dogs.

In this study, changes in the microcirculatory dynamics of the pancreas in response to normal feeding, sham feeding, and truncal vagotomy were investigated to elucidate the involvement of a neural mechanism in the physiological modulation of pancreatic blood flow in the conscious state. Continuous measurement of changes in the microcirculation of the pancreas was performed in conscious dogs by the thermoelectric method. A meat meal was given to six normal dogs, seven dogs constructed with external esophagostomy (sham feeding), and four dogs with truncal vagotomy. In response to normal feeding, pancreatic blood flow attained the peak increase of 65.2 +/- 6.2%, showing a significant and biphasic response until approximately 120 min. After sham feeding, pancreatic blood flow was significantly increased with peak values of 89.0 +/- 19.0%, but thereafter showed a rapid decrease, returning to the basal level already at 7.2 +/- 1.1 min. Although truncal vagotomy significantly and greatly reduced the peak increase of pancreatic blood flow to 28.2 +/- 5.1%, blood flow showed still a significant and sustained elevation above basal. This study provides evidence for the involvement of the neural mechanism in the physiological modulation of the microcirculation of the pancreas in the conscious state. The results strongly suggest that the cephalic phase of the increase in pancreatic blood flow is vagally mediated.

Effects of diet on cholecystokinin-stimulated amylase secretion by pancreatic Acini and amylase mRNA levels in rat pancreas.

To investigate the mechanisms by which dietary compositions regulate the exocrine pancreas, we examined the effects of no-fat diet (NFD) and high-fat diet (HFD) on cholecystokinin (CCK)-stimulated amylase secretion from rat pancreatic acini. Rats were maintained for 4 weeks on NFD or HFD, which contained 0 or 45% fat and 58 or 29% carbohydrates, respectively. Pancreatic acini were isolated and stimulated by graded doses of CCK for 30 min. Maximal CCK-stimulated amylase secretion by pancreatic acini from rats on NFD (23.1 +/- 4.3 U/mg protein at 10(-10) M) was significantly higher than that of HFD (5.5 +/- 1.6 U/mg protein at 10(-10) M). In contrast, expressed as a percentage of the initial content, maximal CCK-stimulated amylase secretion by pancreatic acini from rats on NFD (15.0 +/- 0.8%) tended to be lower than that from rats on HFD (28.1 +/- 3.5%). To study further the effects of the diets on amylase mRNA levels, another group of rats was maintained on the respective diets for 4 weeks, sacrificed, and total pancreatic RNA isolated. Amylase mRNA levels in rats on NFD were 2.5 times higher than in rats on HFD. The results suggest that alterations in CCK-stimulated amylase secretion by pancreatic acini, as well as modifications in pancreatic amylase expression, may be involved in the mechanisms by which the exocrine pancreas adapts to diet.

Carbachol and cholecystokinin enhance accumulation of nicotine in rat pancreatic acinar cells.

Nicotine is a possible risk factor for chronic pancreatitis and pancreatic cancer. To study the loci where nicotine might exert its effect, we examined interactions between nicotine and rat pancreatic acini. When pancreatic acini were incubated with [3H]nicotine, [3H]nicotine levels in pancreatic acini were increased in time-and dose-dependent manners, and the t1/2 for dissociation of [3H]nicotine was 63.8 min. At 4 degrees C, the association of [3H]nicotine was 33% of the association at 37 degrees C. Unlabeled nicotine had no significant effect on the accumulation of [3H]nicotine. In addition, surface-bound [3H]nicotine was not detected when acini were washed in a low-pH solution or when they were trypsinized. These results suggest that the accumulation of nicotine may be a biological phenomenon and that [3H]nicotine does not bind to surface receptors of acinar cells, but accumulates intracellularly. The addition of verapamil (0.1 mM) or 12-O-tetradecanoylphorbol-13-acetate (1 microM) had no effect on [3H]nicotine association, while 4-bromo-A23187 (2 microM) or EGTA (10 mM) significantly increased the accumulation of [3H]nicotine. Carbachol and cholecystokinin significantly enhanced the accumulation of [3H]nicotine in a dose-dependent manner. Taken together, the increasing effects of carbachol and cholecystokinin on the accumulation of nicotine may explain, at least in part, the mechanisms involved in the multiplicative effects of the combination of two risk factors, smoking habit and high-fat or high-protein diets, on human pancreatic diseases.

Inhibition of nitric oxide synthase causes cardiac phenotypic modulation in rat.

Cardiac gene expressions of collagen and contractile proteins were examined in rats treated with a nitric oxide (NO) synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), for 3 weeks. The rats became hypertensive, which caused left ventricular hypertrophy. Among the mRNAs examined, beta-myosin heavy chain was increased and alpha-myosin heavy chain was decreased in both left and right ventricles, whereas skeletal alpha-actin and atrial natriuretic polypeptide were increased in the left ventricle only. Furthermore, coadministration of losartan with L-NAME lowered blood pressure and caused regression of left ventricular hypertrophy, but did not affect beta- and alpha-myosin heavy chain mRNA levels, indicating that L-NAME directly regulates beta- and alpha-myosin heavy chain mRNA.

Intrarenal localization of renin binding substance in rats.

Renin binding substance is a protein that reacts with renin (Mw:40,000) to form a high-molecular-weight renin (Mw:60,000). There is evidence that this substance is present in the renal cortex. However, the exact localization has not been determined. We now report that when glomeruli and tubular segments were isolated from the rat kidney cortex and were frozen and thawed to extract proteins, the high-molecular-weight renin was detected by high performance liquid chromatography, when renin was mixed with an extract of tubular segments, but was not detected with an extract of the glomeruli. Thus, the renin binding substance was demonstrated in the cortical tubular cells but not in the glomeruli. Thus, the renin binding substance was demonstrated in the cortical tubular cells but not in the glomeruli, and the renin binding substance probably does not contribute to the process of biosynthesis of renin in juxtaglomerular cells. Rather, this substance may play a role in tubular functions in the kidney.

Effect of synthetic neuromedin U-8 and U-25, novel peptides identified in porcine spinal cord, on splanchnic circulation in dogs.

Two novel peptides which exert a potent stimulant effect on rat uterus smooth muscle have recently been identified in porcine spinal cord. These peptides designated neuromedin U-8 and U-25 have been reported to exert a hypertensive effect in rats. But further biological activities are not known. In the present study, the effect of these peptides on blood flow in portal vein, superior mesenteric artery and pancreatic tissue and on blood pressure were examined in dogs, utilizing recently developed ultrasonic transit time volume flow meter and laser Doppler flow meter. Neuromedin Us potently reduced blood flow in superior mesenteric artery. The minimum reductions could be observed even at very small doses of neuromedin U-25 (32 fmol/kg) and U-8 (90 fmol/kg), while the maximal reductions of 48.4 and 51.0% were attained at the doses of 320 pmol/kg (U-25) and 900 pmol/kg (U-8), respectively. These peptides also reduced portal vein blood flow, and the maximal reductions of 42.1 and 37.2% were attained at the doses of 32 pmol/kg (U-25) and 90 pmol/kg (U-8), respectively. On the other hand, blood flow in pancreatic tissue increased slightly with the maximal increases of 13.8% at 3.2 pmol/kg (U-25) and 11.8% at 9 pmol/kg (U-8), respectively. The maximal increases of blood pressure were 5.2% at 320 pmol/kg (U-25) and 4.3% at 90 pmol/kg (U-8). Furthermore, neither neuromedin U-25 nor U-8 influenced the axillary artery blood flow, suggesting their selective effect on splanchnic blood flow. Because of the potent and probably selective activity on splanchnic circulation, neuromedin U-25 and U-8 may well be recognized as physiologically significant novel neuropeptides or hormones.

Effects of endothelin on microcirculation of the pancreas.

Endothelin, a newly described endothelial-derived peptide, has potent vasoconstrictive properties and has been speculated to play a physiological role in the regulation of blood flow in some organs. The present study was designed to evaluate the effects of endothelin-1, endothelin-2 and endothelin-3 on the pancreatic microcirculation. Pancreatic tissue blood flow was measured by a laser Doppler flow meter in anesthetized dogs and endothelin-1, endothelin-2 or endothelin-3 was injected intravenously in graduated doses. Endothelins induced dose-dependent decreases in pancreatic tissue blood flow. Endothelin-1, endothelin-2 and endothelin-3 at a dose of 100 pmol/kg reduced pancreatic blood flow by 45.4%, 19.6% and 51.9%, respectively, whereas systemic arterial blood pressure was not significantly affected. When endothelin-3 was administered at a dose of 1000 pmol/kg, pancreatic blood flow was decreased by 73.5% with a concomitant increase of systemic arterial blood pressure by 17.6%. Endothelins potently decreased pancreatic tissue blood flow, suggesting a possible role of these agents in regulating the pancreatic microcirculation.

Effect of human epidermal growth factor (hEGF) on splanchnic circulation in dogs.

The effect of intravenous administration of human epidermal growth factor on the splanchnic blood flows was examined in anesthetized dogs, using an ultrasonic transit-time volume flow meter. Human epidermal growth factor (0.1, 0.5 and 1 microgram/kg) significantly increased blood flows in the portal vein (36.9 +/- 7.4% at 1 microgram/kg) and the superior mesenteric artery (49.0 +/- 16.8% at 1 microgram/kg). Systemic blood pressure monitored simultaneously was significantly decreased (8.4 +/- 1.2% at 1 microgram/kg). This study is the first to demonstrate that intravenous administration of epidermal growth factor increases the portal venous blood flow.

Effect of synthetic physalaemin on splanchnic circulation in dogs.

Physalaemin has been reported as one of the most potent vasodilator and hypotensive peptides (1-4). In spite of these studies, however, the effect of the peptide on splanchnic circulation is not known precisely. In the present study, the effect of synthetic physalaemin on superior mesenteric arterial blood flow, portal venous blood flow and pancreatic capillary blood flow was investigated in dogs. Dose dependent increases of superior mesenteric arterial blood flow and portal venous blood flow were induced in response to physalaemin (0.1-10.0 ng/kg). Superior mesenteric arterial blood flow and portal venous blood flow attained maximal increases of 77 +/- 8.9% and 70 +/- 8.6%, respectively, at a dose of 5 ng/kg. Physalaemin caused a dose-related decrease in systemic arterial blood pressure. Pancreatic capillary blood flow did not show significant change with the administration of physalaemin. These data suggest that physalaemin may play some physiological roles in the regulation of splanchnic circulation.

[Study on splanchnic circulation: measurement of the liver blood flow].

In anesthetized patients during abdominal surgery, hepatic artery and portal vein flows were measured simultaneously utilizing an ultrasonic transit-time volume flowmeter. The total hepatic blood flow was 994.6 +/- 52.4 ml/min. The hepatic artery flow and the portal vein flow were 260.0 +/- 23.8 ml/min and 730.8 +/- 41.3 ml/min, respectively. The ratio of hepatic artery flow to portal vein flow was 0.37 +/- 0.04. A significant increase in hepatic artery flow (p less than 0.01) followed portal vein occlusion, whereas no significant change was observed in portal vein flow after hepatic artery occlusion. Common hepatic artery occlusion resulted in a significant decrease in hepatic artery flow (p less than 0.05), but no significant change was observed in portal vein flow. The present study firstly demonstrated that ultrasonic transit-time volume flowmeter is a device to quantitatively assess hepatic artery and portal vein flows with good reproducibility and stability in human subjects. This easy and simple technique seemed to have wide clinical application to abdominal surgery and would have a promising in studying splanchnic blood flows in various situations such as in cases of hepatectomy and portal hypertension.

Intracellular pH in platelets from spontaneously hypertensive rats and Wistar-Kyoto rats.

Intracellular pH in platelets from spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto rats (WKY) was measured using a pH-sensitive fluorescent dye, 2',7'-bis(carboxyethyl)carboxyfluorescein tetraacetoxy methyl ester (BCECF). Intracellular pH in platelets was significantly higher in SHR than in WKY (7.12 +/- 0.04 versus 7.06 +/- 0.02, P less than 0.01; n = 10). There was a close correlation between intracellular pH and systolic blood pressure (r = 0.66, P less than 0.01). Addition to platelets of 1-(5-isoquinolinesulphonyl)-2-methylpiperazine (H-7), a specific inhibitor of protein kinase C, produced a significantly larger decrease in intracellular pH in SHR than in WKY (0.06 +/- 0.02 versus 0.03 +/- 0.00, P less than 0.01, n = 5). These results suggest that protein kinase C may play an important role in the increased intracellular pH in SHR.

Laparoscopic common hepatic artery ligation and staging followed by distal pancreatectomy with en bloc resection of celiac artery for advanced pancreatic cancer.

INTRODUCTION: Adeno-carcinomas of pancreatic body are usually asymptomatic and progress to advanced stage with involvement of major arteries. Resection of advanced cancer along with en bloc resection of a common hepatic artery and celiac trunk enables a "curative" resections and only possible treatment. However, the celiac axis resection always has a risk of compromising blood supply to liver, resulting in the hepatic insufficiency. We evaluated practicability of a two-stage procedure for the advanced pancreases body cancer, laparoscopic clamping of a common hepatic artery followed by open distal pancreatectomy with en bloc celiac arterial resection to prevent the hepatic insufficiency. MATERIALS AND SURGICAL TECHNIQUE: Seventy-five-year-old woman diagnosed with a 50-mm pancreatic body mass, invading splenic artery, common hepatic artery, splenic vein, and portal vein at the confluence. STAGE-1: At laparoscopy, after confirming absence of the peritoneal, superficial liver metastases and negative peritoneal cytology; we approached the common hepatic artery through the lesser sac and ligated. STAGE-2: Her liver function tests were normal after 2 weeks, and CT angiography showed complete blockage of the common hepatic artery with sufficient collateral circulation to the liver through inferior pancreatico-duodenal artery and gastro-duodenal artery. We performed an open distal pancreatectomy with en bloc resection of celiac artery. Histopathology examination confirmed R0 resection. DISCUSSION: The celiac axis resection with distal pancreatectomy improves the chance of R0 resection and potentially, survival of the patient. Preoperative laparoscopic ligation of the common hepatic artery is a safe, effective, and in-expensive technique to prevent postoperative hepatic insufficiency and improves the safety of en bloc celiac artery resection with a distal pancreatectomy. Also these patients have high risk of peritoneal dissemination. Diagnostic laparoscopy is useful to detect occult metastasis, which are missed by per-operative CT scan.