Beneficial haemodynamic effects of insulin in chronic heart failure.
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OBJECTIVE: To characterise the central and regional haemodynamic effects of insulin in patients with chronic heart failure. DESIGN: Single blind, placebo controlled study. SETTING: University teaching hospital. PATIENTS: Ten patients with stable chronic heart failure. INTERVENTIONS: Hyperinsulinaemic euglycaemic clamp and non-invasive haemodynamic measurements. MAIN OUTCOME MEASURES: Change in resting heart rate, blood pressure, cardiac output, and regional splanchnic and skeletal muscle blood flow. RESULTS: Insulin infusion led to a dose dependent increase in skeletal muscle blood flow of 0.36 (0.13) and 0.73 (0.14) ml/dl/min during low and high dose insulin infusions (p < 0.05 and p < 0.005 v placebo, respectively). Low and high dose insulin infusions led to a fall in heart rate of 4.6 (1.4) and 5.1 (1.3) beats/min (p < 0.05 and p < 0.005 v placebo, respectively) and a modest increase in cardiac output. There was no significant change in superior mesenteric artery blood flow. CONCLUSION: In patients with chronic heart failure insulin is a selective skeletal muscle vasodilator that leads to increased muscle perfusion primarily through redistribution of regional blood flow rather than by increased cardiac output. These results provide a rational haemodynamic explanation for the apparent beneficial effects of insulin infusion in the setting of heart failure. (+info)
Successful endovascular repair of juxtarenal and suprarenal aortic aneurysms with a branched stent graft.
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This case report describes a new technique for repairing pararenal aortic aneurysms with a transluminally placed triple-branched stent graft with sidearms extending into the superior mesenteric artery and renal arteries. Endovascular repair with the branched stent graft was attempted in two patients with a pararenal aortic Aneurysm. Stent grafting was technically successful in both patients. Although postoperative transient renal function impairment and paralytic ileus occurred in patient 2, these complications were gradually resolved in the perioperative period. A substantial shrinkage of the aneurysm was revealed by means of computed tomographic measurements in patient 1. In both patients, complete exclusion of the aneurysm and patency of the bilateral renal arteries and the superior mesenteric artery were confirmed by means of follow-up computed tomographic images at 2 years. This minimally invasive approach for pararenal aortic aneurysms appears to be a viable therapeutic option for patients who are at high risk for open surgery. (+info)
Properties of smooth muscle hyperpolarization and relaxation to K+ in the rat isolated mesenteric artery.
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Smooth muscle membrane potential and tension in rat isolated small mesenteric arteries (inner diameter 100-200 microm) were measured simultaneously to investigate whether the intensity of smooth muscle stimulation and the endothelium influence responses to exogenous K+. Variable smooth muscle depolarization and contraction were stimulated by titration with 0.1-10 microM phenylephrine. Raising external K+ to 10.8 mM evoked correlated, sustained hyperpolarization and relaxation, both of which were inhibited as the smooth muscle depolarized and contracted to around -38 mV and 10 mN, respectively. At these higher levels of stimulation, raising the K+ concentration to 13.8 mM still hyperpolarized and relaxed the smooth muscle. Relaxation to endothelium-derived hyperpolarizing factor, released by ACh, was not altered by the level of stimulation. In endothelium-denuded arteries, the concentration-relaxation curve to K+ was shifted to the right but was not depressed. In denuded arteries, relaxation to K+ was unaffected by the extent of prior stimulation and was blocked with 0.1 mM ouabain but not with 30 microM Ba2+. The ability of K+ to stimulate simultaneous hyperpolarization and relaxation in the mesenteric artery is consistent with a role as an endothelium-derived hyperpolarizing factor activating inwardly rectifying K+ channels on the endothelium and Na+-K+-ATPase on the smooth muscle cells. (+info)
Color Doppler ultrasonography of the superior mesenteric artery for prenatal ultrasonographic diagnosis of a left-sided congenital diaphragmatic hernia.
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The incidence of congenital diaphragmatic hernia (CDH) has been estimated as 1 per 2000 to 1 per 4000 births. The etiology of the malformation is unknown, but it has been reported in association with maternal administration of medications such as thalidomide or antiepileptics before closure of the pleuroperitoneal canal at 9 to 10 weeks' gestation as well as having a familial inheritance pattern. Congenital diaphragmatic hernia is associated with other congenital anomalies in 25% to 57% of cases and with chromosomal abnormalities in 10% to 20% of cases. Posterolateral, anterolateral, and pars sternalis defects of closure of the pleuroperitoneal canal encompass the 3 types of CDH. The most frequent type is the left-sided posterolateral defect or Bochdalek's hernia, which accounts for 81% of cases. (+info)
Evaluation of simultaneous excision of pancreatic cancer and the surrounding blood vessels.
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Of the 139 patients who underwent excision for invasive cancer in the pancreatic duct at Kurume University Hospital between January 1965 and December 1998, the subjects were 38 patients in whom blood vessels around the cancer were simultaneously excised. The surgical methods were pancreatoduodenectomy (PD) in 31 patients, distal pancreatectomy (DP) in 5, and total pancreatectomy (TP) in 2. The excised blood vessels were the portal vein alone in 32 patients, the artery alone in 1, and both portal vein and artery in 5. Excision of the portal vein was performed by circumcision in 25 patients and by segmentectomy in 12. The range of circumcision was 1.0-7.0 cm (mean, 3.5 +/- 1.4 cm), and the blocking time of the portal vein was 8-36 min (mean, 19.5 +/- 8.8 min). Of the 25 patients who underwent circumcision, reconstruction was performed by end-to-end anastomosis in 23 and by transplantation of the autologous vein between the ends in 2. Of the 12 patients who underwent segmentectomy, direct suture was performed in 10, and transplantation of an autologous vein patch was performed in 2. Postoperative complications occurred in 14 of the 32 patients. In 5 of the 6 patients who underwent excision of the artery, reconstruction was performed by end-to-end anastomosis in 3 and by transplantation of the autologous vein between the ends in 2. Postoperative complications did not occur in the patient who had undergone excision of the artery alone, but 4 of the 5 patients who had undergone simultaneous excision of the portal vein and artery had postoperative complications, of whom 2 died during the period of hospitalization. Three patients with pv0, pv1 or pv2 survived for more than 3 years. Because some of the patients who had undergone excision of the portal vein alone survived for a long time and this method is relatively safe, this surgery can be generally applied, but simultaneous excision of the portal vein and artery should be carefully applied because the incidences of postoperative complications and death during the period of hospitalization are high. With the development of surgical techniques and postoperative control, simultaneous excision of pancreatic cancer and the surrounding blood vessels has become safe, but this method should only be applied to patients who have the potential to recover completely. (+info)
Prediction of early tolerance to enteral feeding in preterm infants by measurement of superior mesenteric artery blood flow velocity.
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AIMS: To evaluate whether serial Doppler measurements of superior mesenteric artery (SMA) blood flow velocity after the first enteral feed could predict early tolerance to enteral feeding in preterm infants. METHODS: When clinicians decided to start enteral feeds, Doppler ultrasound blood flow velocity in the SMA was determined before and after a test feed of 0.5 ml milk. The number of days taken for infants to tolerate full enteral feeding (150 ml/kg/day) was recorded. RESULTS: Fourteen infants (group 1) achieved full enteral feeding within seven days. Thirty infants (group 2) took 8-30 days. There was no difference in the preprandial time averaged mean velocity (TAMV) between the groups at a median age of 3 (2-30) days. In group 1, there was a significant increase in TAMV (p<0.01) above the preprandial level at 45 and 60 minutes, but this did not occur in group 2. An increase in TAMV by more than 17% at 60 minutes has a sensitivity of 100% and a specificity of 70% for the prediction of early tolerance to enteral feeds. CONCLUSIONS: There is a significant correlation between an increase in mean SMA blood flow velocity and early tolerance of enteral feeding. Doppler measurements of SMA blood flow velocity may be useful for deciding when to feed high risk preterm infants. (+info)
A novel branching pattern of the superior mesenteric artery found in the bullfrog (Rana catesbeiana) amphibian.
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The branching and distribution patterns of the superior mesenteric artery were studied in 10 adult bullfrogs (Rana catesbeiana) after injection of coloured latex solution into the vasculature. The abdominal digestive organs in the bullfrog were mainly supplied by the coeliac artery and the superior mesenteric artery, both of which arose as a common trunk, the coeliacomesenteric artery, from the abdominal aorta. The coeliac artery supplied the stomach, liver, gallbladder and the pancreas, whereas the first branch of the superior mesenteric artery was the splenic artery with other branches supplying the greater part of intestine. The apex of the intestinal loop was defined as the region supplied by the trunk of the superior mesenteric artery, and its intestinal branches constituted a 'nested formation' which had the following characteristics. (1) The branches of the trunk were distributed to both sides of the apex, and the distribution regions of younger branches were located more distant from the apex than those of older branches. (2) Two branches directed towards both sides of the trunk frequently made a common stem arising from the trunk. The second branch of the superior mesenteric artery constituted a secondary trunk and its distribution region could be defined as a secondary apex, since 1 of its branches also constituted a nested formation which was distributed to both sides of the primary and secondary apices. The intestinal branches of the superior mesenteric artery were divided into 4 types on the basis of their pattern of branching and course. It is suggested that the nested formation of the superior mesenteric artery in the bullfrog is a remnant of the vascular pattern of the tadpole, which possesses a double spiral mode of intestinal convolution, probably supplied by arteries with the nested formation in a latent form. (+info)
Endoleak after endovascular repair of abdominal aortic aneurysm.
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PURPOSE: We sought to assess the role of endovascular techniques in the management of perigraft flow (endoleak) after endovascular repair of an abdominal aortic aneurysm. METHOD: We performed endovascular repair of abdominal aortic aneurysm in 114 patients, using a variety of Gianturco Z-stent-based prostheses. Results were evaluated with contrast-enhanced computed tomography (CT) at 3 days, 3 months, 6 months, 12 months, and every year after the operation. An endoleak that occurred 3 days after operation led to repeat CT scanning at 2 weeks, followed by angiography and attempted endovascular treatment. RESULTS: Endoleak was seen on the first postoperative CT scan in 21 (18%) patients and was still present at 2 weeks in 14 (12%). On the basis of angiographic localization of the inflow, the endoleak was pure type I in 3 cases, pure type II in 9, and mixed-pattern in 2. Of the 5 type I endoleaks, 3 were proximal and 2 were distal. All five resolved after endovascular implantation of additional stent-grafts, stents, and embolization coils. Although inferior mesenteric artery embolization was successful in 6 of 7 cases and lumbar embolization was successful in 4 of 7, only 1 of 11 primary type II endoleaks was shown to be resolved on CT scanning. There were no type III or type IV endoleaks (through the stent-graft). Endoleak was associated with aneurysm dilation two cases. In both cases, the aneurysm diameter stabilized after coil embolization of the inferior mesenteric artery. There were two secondary (delayed) endoleaks; one type I and one type II. The secondary type I endoleak and the associated aneurysm rupture were treated by use of an additional stent-graft. The secondary type II endoleak was not treated. CONCLUSIONS: Type I endoleaks represent a persistent risk of aneurysm rupture and should be treated promptly by endovascular means. Type II leaks are less dangerous and more difficult to treat, but coil embolization of feeding arteries may be warranted when leakage is associated with aneurysm enlargement. (+info)