W. Scott Helton

Duplex Ultrasound Measurement of Postprandial Intestinal Blood Flow: Effect of Meal Composition

Duplex ultrasound was used to evaluate the effects of 350-cal, 300-ml protein, fat, carbohydrate, and mixed (Ensure-Plus) liquid meals on celiac, superior mesenteric, and femoral artery blood flow in 7 healthy volunteers. Ingestion of separate water and mannitol solutions served as controls for volume and osmolarity. Duplex parameters of peak systolic velocity, end-diastolic velocity, mean velocity, and volume flow were determined before, and serially for 90 min after, ingestion of each test meal. Maximal changes were compared with baseline values. There were no significant changes in any of the blood flow parameters derived from the celiac or femoral arteries after any test meal ingested. In contrast, maximal changes in all superior mesenteric artery parameters were increased significantly over baseline (p less than 0.05) after each of the test meals except water, with end-diastolic velocity showing proportionally the greatest increase. The study demonstrates that duplex ultrasound can provide a noninvasive means of studying the reactivity of the splanchnic arterial circulation to different stimuli and documents differing blood flow responses to variation of nutrients.

NUTRIENT ANTIOXIDANTS IN GASTROINTESTINAL DISEASES

Oxidative stress appears to play a role in the pathogenesis of a number of gastrointestinal disease states, including pancreatitis; gastric and duodenal ulcer disease; IBD; gastric, esophageal, and colon cancers; and hepatic injury secondary to alcohol, metal storage disorders, hepatitis, and ischemia/reperfusion injury. The nutritional antioxidants are attractive potential therapeutic and chemopreventive agents because they are inexpensive and have a relatively low toxicity profile. A word of caution should be noted: Some antioxidants, such as vitamin C, can be prooxidant under certain conditions, and systemically altering the redox state may have untoward effects on the inflammatory response in certain disease states. Thus, at the current time, antioxidant therapy should be restricted to randomized, controlled clinical trials, in which treatment effects can be closely monitored, and therapeutic efficacy can be determined with scientific accuracy.

Use of laparoscopic techniques improves outcome from adrenalectomy

BACKGROUND Laparoscopic adrenalectomy is a promising alternative to open approaches but safety and efficacy remain unproven. METHODS A recent experience with laparoscopic adrenalectomy at the University of Washington was analyzed for efficacy, complications, evolution of technical steps, and clinical outcome. RESULTS Nineteen adrenalectomies were performed in 16 patients with a mean age of 52 years. Indications included pheochromocytoma (4), functional adenoma (12), and uncontrolled Cushings disease (3). All patients had computed tomography scans. Meta-iodo-benzyl-guanidine (MIBG) or iodocholesterol scans were done in selected patients. Three patients had bilateral procedures, 7 were on the left and 6 on the right, all via a transperitoneal flank approach. There were no conversions and all procedures were successful. Complications included subcapsular liver hematomas (2), one transfusion, and a bleeding port site requiring repeat laparoscopy. Except for 1 patient with COPD, the mean length of stay was 2.9 days. CONCLUSIONS Laparoscopic adrenalectomy in appropriate patients is safe and effective. For endocrine surgeons with advanced laparoscopic skills, it should be considered a new standard therapy for benign adrenal tumors.

Transcatheter arterial embolization of two symptomatic giant cavernous hemangiomas of the liver

Cavernous hemangiomas are usually asymptomatic; however, a small percetage may cause symptoms. This case report discusses palliation by transcatheter arterial embolization with polyvinyl alcohol particles.

Enterolith Causing Afferent Loop Obstruction: A Case Report and Literature Review

Enterolith formation is a rare cause of afferent limb obstruction following Billroth II gastrectomy and Roux-en-Y hepaticojejunostomy surgery. A case of ascending cholangitis caused by an enterolith incarcerated in the afferent loop of a 15-year-old Roux-en-Y hepaticojejunostomy was emergently decompressed under direct ultrasound guidance prior to surgery. This is the thirteenth reported case of an enterolith causing afferent loop obstruction. A discussion of our management approach and a review of the relevant literature are presented.

Allopurinol dose is important for attenuation of liver dysfunction after normothermic ischemia: Correlation between bile flow and liver enzymes in circulation

We have investigated the effect of two doses of allopurinol (ALL) (100 and 50 mg/kg) administered i.v. on liver function after 1 h of normothermic ischemia. ALL given in a concentration of 100 mg/kg significantly improved bile output after 1 and 24 h of reperfusion. Hepatocyte injury reflected by alanine aminotransferase (ALT) and lactic dehydrogenase (LDH) in plasma was also significantly reduced at 24 h, but not at 1 h of reperfusion compared with controls. ALL administered at a concentration of 50 mg/kg had some protective effect. Significant correlation between circulating liver enzymes and bile output at 24 h after reperfusion indicates an important pathophysiologic link between hepatocyte function and injury in this time window.

PORTAL HYPERTENSION AND BLEEDING ESOPHAGEAL VARICES

SummaryBleeding from esophageal varices exacts a high mortality and extraordinary societal costs. Prophylaxis—medication, sclerotherapy, or shunt surgery to prevent an initial bleeding episode—is ineffective. In patients who have bled from varices, endoscopic injection sclerotherapy can control acute bleeding in more than 90% of patients. Because recurrent bleeding frequently occurs and survival without definitive therapy is dismal, selection of a permanently effective treatment is mandatory once variceal bleeding has been controlled.Long-term injection sclerotherapy can be performed in compliant patients; it is relatively safe but is associated with a 30–50% rebleeding rate. Betablockers significantly reduce portal pressure and recurrent bleeding but have not been shown to diminish mortality from BEV. Portal decompressive surgery permanently halts bleeding in more than 90% of patients; the risk of operative mortality is high in decompensated cirrhotics, and long-term complications of encephalopathy and accelerated liver failure may limit indications for shunt surgery to good-risk cirrhotics who are not liver transplant candidates. Devascularization procedures have a low operative mortality and encephalopathy rate but unacceptably high rates of recurrent bleeding.Liver transplantation is curative therapy for bleeding esophageal varices and the associated underlying hepatic dysfunction; cost and availability of donor organs generally limit its use in this setting to variceal bleeders with end-stagè liver disease not associated with active alcoholism.

Duplex sonography accurately assesses portacaval shunt patency

Among 42 patients who had undergone portacaval shunt (PCS) to treat bleeding esophageal varices, shunt patency was assessed with duplex sonography 1 month to 5 years postoperatively. Patency was confirmed in all patients (100%). Correlative angiograms confirming the sonographic findings were obtained in 24 patients. Duplex scanning showed hepatofugal or stagnant flow in the distal portal vein in all 42 patients. Very low rates of liver-failure-related mortality (6%) and morbidity (6% incidence of encephaloparthy) in this series despite loss of portal perfusion of the liver in patients incriminate factors other than magnitude and direction of portal vein flow as the cause of complications occurring after PCS. Duplex sonography offers accurate and relevant clinical and physiologic data about shunt hemodynamics in patients who have undergone PCS.

Shunt operations to relieve portal hypertension

Shunt operations to decompress the portal circulation into a systemic vein — usually the inferior vena cava or a branch thereof — have been performed for more than a century. Since 1945, portacaval shunts have been widely used to treat the haemorrhagic complications of portal hypertension induced by hepatic cirrhosis, but it soon became clear that, although portosystemic shunts may be highly effective in treating portal hypertension, they frequently do so at the cost of accelerated liver failure and a disabling neuropsychiatric dysfunction called portosystemic encephalopathy. Early prospective randomized trials suggested that portosystemic shunts did not prolong survival in patients with bleeding varices but only changed the cause of their demise.