EFFECTS OF LENGTH AND REGION OF SMALL INTESTINAL GLUCOSE EXPOSURE ON BLOOD PRESSURE, SUPERIOR MESENTERIC ARTERY BLOOD FLOW AND PLASMA NORADRENALINE IN HEALTHY OLDER PARTICIPANTS

Background: A substantial postprandial reduction in blood pressure (BP), triggered by the interaction of nutrients with the small intestine and associated with increases in heart rate (HR) and splanchnic blood flow, occurs frequently in healthy older people. Objective: The aim of this study was to determine whether these responses are influenced by the length and/or region of small intestine exposed to nutrients. Design: Randomized, single blind study. Setting: Clinical research laboratory. Participants: Ten healthy older participants (9M, 1F; age 65 – 79 yr). Intervention: On 3 separate study days, participants were intubated with a small intestinal catheter incorporating two duodenal infusion ports and an aspiration port, as well as an occluding balloon, which was positioned ~ 60 cm beyond the pylorus. Each participant then received a 60 min (t = 0 – 60 min) intraluminal infusion of glucose (3 kcal/min) into either the proximal (< 60 cm “GP”), or the distal (> 70 cm “GD”), or both (i.e. proximal and distal “GPD”), small intestinal segments. Measurements: BP, HR (automated device), superior mesenteric artery (SMA) blood flow (Doppler ultrasound) and plasma noradrenaline (NA). Results: Small intestinal glucose infusion was associated with reductions in systolic (GP: P = 0.004, GD: P = 0.001, GPD: P = 0.001) and diastolic (GP: P = 0.007, GD: P = 0.004, GPD: P = 0.003) BP and increases in HR (GP: P = 0.001, GD: P = 0.001, GPD: P = 0.002) and plasma NA (GP: P = 0.001, GD: P = 0.002, GPD: P = 0.001), without any difference between the three days. Conclusion: In healthy older participants, the effects of small intestinal glucose to decrease BP and increase SMA flow in healthy older participants appear to be independent of the region, or length, of small intestine exposed.

Percutaneous embolization of renal arteriovenous fistula

Acquired renal arteriovenous fistula is a rare complication following a nephrectomy and its diagnosis may be made many years after the intervention. The closure of the fistula is advisable in most cases, since it represents a risk for heart failure and rupture of the vessel. There are an increasing number of publications describing different techniques of occlusion. The case of a 70-year-old woman with abdominal discomfort due to a large renal arteriovenous fistula, 45 years after nephrectomy, is presented and current literature is reviewed. Percutaneous embolization was performed by placing an occluding balloon through the draining vein followed by the release of nine coils through arterial access. One day after successful occlusion of the fistula, clinical symptoms disappeared.

Salvage of an Acutely Ruptured Thoracic Aortic Aneurysm during CPR

Purpose: To report the successful endovascular treatment of a ruptured thoracic aortic aneurysm during cardiopulmonary resuscitation. Case Report: A 72-year-old woman with a type B aortic dissection treated conservatively for 8 years was referred for rupture of a 16-cm aneurysm of the descending thoracic aorta. During transfer to the operating room, the patient suffered cardiac arrest; cardiopulmonary resuscitation (CPR) was initiated. A few minutes later during CPR, the surgical procedure began with a cutdown of the right femoral artery and insertion of a guidewire and an aortic occlusion balloon, which was inflated at the origin of the left subclavian artery (LSA). Blood pressure was immediately measurable. By only partially deflating the occluding balloon, a thoracic stent-graft was advanced above it and deployed at the origin of the LSA while rapidly deflating and retracting the occluding balloon. Three stent-grafts were required to cover 27 cm of the descending aorta. The patient was partly ventilator dependent for 3 months due to a massive pleural hematoma that was not evacuated. At the 10-month follow-up, the patient is fully recovered without any sign of respiratory dysfunction or any other sequela. CT scans reveal that the massive hematoma is almost completely resolved. Conclusions: This case illustrates that optimal collaboration between anesthesiologists, interventional radiologists, and vascular surgeons with appropriate resources can significantly expand the possibilities of emergent treatment in the face of aortic rupture.

The Effect of Conjugated and Unconjugated Bile Acids on Water and Electrolyte Absorption in the Human Jejunum

1. The effect of conjugated and unconjugated bile acids in various concentrations on the absorption of water, sodium and chloride in the proximal jejunum in man has been studied using a perfusion system incorporating a proximal occluding balloon. 2. Unconjugated cholic acid and its glycine and taurine conjugates had no significant effect on water and electrolyte absorption. Unconjugated deoxycholic acid significantly inhibited water and electrolyte absorption at 3 mm concentration and net secretion occurred at concentrations of 5 mm, 7 mm and 10 mm. Similar results were found when taurodeoxycholic and glycodeoxycholic acid solutions were used. A greater effect was noted when higher concentrations of bile acids were used. 3. Unconjugated chenodeoxycholic acid caused net water and electrolyte secretion at 3 mm concentration and this effect became more marked with higher bile acid concentrations. Inhibition of absorption also occurred with taurochenodeoxycholic acid in a concentration of 3 mm and net secretion occurred at a concentration of 10 mm. 4. The results show that dihydroxy bile acids, conjugated or unconjugated, inhibit water and electrolyte absorption in the proximal jejunum in low concentration and cause net secretion in high concentration.