Catabolism and protein binding of Tc-99m pyridoxylideneglutamate.

Various Tc-99m-labeled compounds have been suggested as replacements for [I-131] rose bengal for imaging of the hepatobiliary system. Among such compounds are Schiff's bases, which are tin-free Tc-chelates easily prepared by 30-min autoclaving of an equimolar mixture of pyridoxal and an amino acid at pH 8.5. We have compared the properties of several Schiff's bases, including Tc-99m pyridoxylideneglutamate (Tc PyG) with [I-131] rose bengal. Under conditions described, Tc-PyG can be prepared free of Tc-pyridoxal and with less than 2% TcO4- radiochemical impurity. Blood clearance and biliary excretion were studied in three animal models, and in normal human volunteers. In all animal models, Tc-PyG initially cleared from the blood more rapidly than rose bengal, but a significant amount of Tc-PyG was excreted in the urine, this in contrast to [I-131] rose bengal which was almost completely excreted through the biliary system. Species differences were observed in the degree of urinary versus biliary clearance of Tc-PyG, with significantly greater urinary excretion in dogs than in monkeys and rabbits. Replacing glutamate with other amino acids did not significantly increase the blood clearance rate or decrease urinary excretion, so that Tc-PyG appears to be at least as good as any of the others studied. Tc-PyG was only 20% bound to plasma proteins, and electrophoretic and chromatographic studies did not reveal any in vivo changes of Tc-PyG before excretion in urine or bile.

Renal clearance and extraction parameters of ortho-iodohippurate (I-123) compared with OIH(I-131) and PAH.

o-[131I] iodohippurate [OIH(I-131)] has been used for many years in the estimation of effective renal plasma flow. This compound suffers from low photon yield and poor images when the quantity used is limited to stay within a reasonable radiation dose. To test the validity of substituting I-123 for I-131, a series of experiments was performed in a surgically prepared dog model. The extraction ratios and clearance values OIH(I-123) prepared from radionuclidically pure I-123 were compared with those of commercial OIH(I-131) and PAH. The extraction ratios for OIH(I-123) and OIH(I-131) were 0.65 and 0.67, representing 0.86 and 0.88 that of PAH, respectively. The clearance values (cc/min/kg) for the I123 and I-123) can be used to estimate effective renal plasma flow; moreover, because of the high yield within an acceptable radiation dose range, images of good quality can be produced.

Reversed ileal segment for treatment of ileostomy dysfunction. Clinical application.

Persistent, profuse ileostomy diarrhea developed gradually in a patient over a 12-hour period after proctocolectomy for ulcerative colitis. There was no evidence of ileostomy stenosis or dilation of the ileum proximal to the stoma. He was successfully treated with a reverse ileal segment of 10 cm, and gained 14 to 18 kg. ileostomy output became semisolid and decreased from 1,000 to 2,000 ml/day to 600 ml/day. The transit time changed from 12 minutes to 2 1/2 hours. Antiperistaltic segments of intestine prolong transit time and allow for greater absorption. While most patients with ileostomies are not troubled by severe diarrhea, the small proportion who are may be candidates for a reversed ileal segment.

Experimental evaluation of primary repair of colonic injuries.

To evaluate the management of colonic injuries, experimental models simulating acute injuries of the colon were studied utilizing New Zealand white rabbits. Seventy-nine rabbits underwent primary repair of colonic injuries in the presence of massive contamination and none showed any evidence of anastomotic leakage or breakdown. The fact that primary colonic repairs do heal even in the presence of infection suggests that breakdown of colonic anastomosis results from factors other than infection. Despite the absence of anastomotic leaks in this series, morbidity and mortality were high in those animals not given antibiotics. The high morbidity and mortality were due to peritonitis, intra-abdominal abscess, and wound infection, and were directly proportional to the length of time from colonic injury to repair. On the basis of this study, it is concluded that most isolated injuries of the colon can be closed primarily, if antibiotic therapy is begun immediately after injury and continued throughout the operative and postoperative periods.

Antiperistaltic ileal segment in the prevention of ileostomy diarrhea.

Diarrhea, often profuse, accompanied by skin excoriation and nutritional and electrolyte depletion is a major complication of ileostomy. In an attempt to improve the course of these patients, an experimental study using dogs was undertaken to investigate an antiperistaltic ileal segment for the prevention of ileostomy diarrhea. Ileostomies were created in dogs. All the dogs with ileostomies died within nine days of weight loss and massive electrolyte and water depletion. A second group of animals underwent creation of an ileostomy simultaneously, with an antiperistaltic ileal segment placed 30.5 cm proximal to the ileostomy. These dogs maintained their weight and electrolyte and water balance. The stools in the group with the reversed ileal segment became semisolid to solid, compared to the watery diarrhea of dogs with ileostomies only.

Assessment of gastric motility using meal labeled with technetium-99m sulfur colloid.

During a 2 year period, 83 patients with gastric motility problems were evaluated using radionuclide imaging. The patients presented with epigastric distress, postprandial fullness, pain, nausea, vomiting, and diarrhea; signs and symptoms suggestive of either gastroparesis or gastric outlet obstruction. Upper gastrointestinal series or endoscopy, or both, demonstrated no mechanical obstruction. After oral administration of a 300 g meal labeled with 600 muCi of technetium-99m sulfur colloid, a gastric emptying study consisting of serial images and data acquisition was performed. Of the patients studied, 52 had had peptic ulcer surgery, 17 were suspected of having gastroesophageal reflux, 8 were diabetic and suspected of having visceral enteropathy, and 6 had a history of irritable bowel syndrome. The normal mean gastric half emptying time was 77 +/- 16 minutes. Of the patients who had had gastric surgery, 90.4 percent had abnormal emptying: 69.2 percent had delayed gastric emptying and 21.2 percent had rapid gastric emptying time; 9.6 percent had normal emptying time. Of the gastroesophageal reflux group, all but two had normal gastric emptying time; 65 percent demonstrated gastroesophageal reflux within 15 minutes. Two of the patients with irritable bowel syndrome had prolonged emptying; the rest had normal emptying. All diabetic patients with gastroparesis had prolonged gastric emptying time, and all responded favorably to metoclopramide. Of the patients who previously had peptic ulcer surgery and had prolonged emptying time, 72 percent also responded favorably to metoclopramide. We conclude that radionuclide gastric imaging is a useful diagnostic test for the measurement of gastric emptying in patients with a variety of gastrointestinal motility disorders and may be helpful in assessing medical therapy and selecting those who may be candidates for surgery.

Selective embolization for control of gastrointestinal hemorrhage.

Transcatheter embolization using Gelfoam plugs or autologous clot is an alternative or adjunct to the conventional management of gastrointestinal hemorrhage. During a 12 month period we successfully treated 10 patients who had massive gastrointestinal hemorrhage with selective embolization; 6 patients had upper gastrointestinal hemorrhage and 4 had bleeding from the colon. Most of these patients were critically ill and were poor surgical candidates. Hemorrhage was controlled by selective catheterization of the bleeding vessel, followed by injection of Gelfoam pledgets. Since the procedure was accomplished with ease and prolonged hemostasis obtained, we recommend it for gastrointestinal hemorrhage, especially in patients who are poor surgical risks or are unresponsive to vasopressin infusion, or both. Operative intervention for the primary disease could subsequently be performed electively, if necessary, days or weeks after transcatheter embolization.

Intestinal necrosis and perforation in patients receiving immunosuppressive drugs.

Immunosuppressive agents are frequently used in transplant recipients for prevention of homograft rejection and in patients with leukemia for treatment of their primary disease. From 1973 to 1975, fifty-nine patients undergoing renal transplantation and forty-one patients with leukemia were treated at the University of California (Davis) Medical Center. Intestinal necrosis and perforation developed in four (7 per cent) of those receiving transplants and in four (10 per cent) of the patients with leukemia. One transplant receipient and all four patients with leukemia had extensive necrosis of both the small and large intestines. Two transplant recipients had isolated sigmoid perforations, and one had splenic flexure colonic perforation. All died from septicemia with septic shock. The etiology of these intestinal complication appears related to immunosuppressive agents, particularly high dosages of steroids. Despite the grave prognosis, early surgical intervention is the only method of dealing with these complications. Early diagnosis as well as properly timed and selected operations are necessary for the successful management of these patients.

Clinical evaluation of 99mTc-pyridoxylideneglutamate for hepatobiliary scanning.

Clinical evaluation of hepatobiliary scanning using 99mTc-PG was done in twenty normal volunteers and eighty-three patients with liver and biliary tract disease. Satisfactory images of the biliary tract were obtained using small dosages of this agent. In normal humans, the agent reached the liver in 5 minutes, and the common bile duct, gallbladder, and duodenum in 10 to 20 minutes. The gallbladder was not visualized when the cystic duct was obstructed in patients with acute and chronic cholecystitis. In patients with partial common bile duct obstruction, a distended duct was visualized and there was delay in transit of radioactivity into the duodenum. With complete common bile duct obstruction, no radioactivity was seen in the biliary or gastrointestinal tracts up to 24 hours after injection. Hepatocellular disease was characterized by delayed liver clearance and delayed visualization of the biliary and gastrointestinal tracts. There were no toxic or other untoward effects in any patients.

Comparison of ultrasonography, computerized tomography, and radionuclide imaging in the diagnosis of acute and chronic cholecystitis.

Seventy-five patients with abdominal pain in the right upper quadrant who were subsequently confirmed operatively and histologically to have acute or chronic cholecystitis underwent radionuclide imaging of the biliary tree, ultrasonography, and/or computerized tomography before operation. fifty-eight of the patients had acute cholecystitis and 17 had chronic cholecystitis and cholelithiasis. Analysis of our data indicates that ultrasonography is an accurate and better screening test than cholescintigraphy in the diagnosis of chronic cholecystitis and cholelithiasis, but it is less accurate in the detection of acute cholecystitis. On the other hand, radionuclide imaging is highly sensitive and specific in the early diagnosis of acute cholecystitis, but it is poor in the diagnosis of chronic cholecystitis and cholelithiasis unless the cystic duct is obstructed. CT scanning is more expensive than ultrasonography but may be extremely helpful in problematic cases such as the diagnosis of the cause in biliary obstruction or in imaging of the pancreas.

Hepatobiliary scanning using 99mTc-pyridoxylideneglutamate.

Technetium 99m-pyridoxylideneglutamate (99mTc-PG) administered intravenously is excreted by hepatocytes into the bile canaliculi and enters the gallbladder through the cystic duct and consequently, can be used for scanning the hepatobiliary ductal system. A total of 166 patients representing 27 normal subjects, 84 patients referred for investigation for pain in the upper right quadrant of the abdomen and 55 jaundiced patients were evaluated with 99mTc-PG. In normal human volunteers, the agent reached the liver in five minutes, and the common bile duct, gallbladder, and duodenum within 15 minutes. Satisfactory images of the hepatobiliary tract were obtained using small dosages of 99mTc-PG. The gallbladder was not visualized when the cystic duct was occluded. In the presence of acute cholecystitis, cystic duct obstruction, or in chronic cholecystitis where other roentgenographic studies showd a nonfunctioning gallbladder, there was no concentration of 99mTc-PG in the gallbladder. In partial common bile duct obstruction is distended common bile duct was visualized along with delay in transit of radioactivity into the duodenum. Complete common bile duct obstruction was associatedwith no radioactivity in either the biliary or the gastrointestinal tracts up to 24 hours after injection. Hepatocellular disease was characterized by delayed liver clearance and delayed visualization of biliary and gastrointestinal tracts. 99mTc-PG scanning proved capable of differentiating between hepatocellular disease and extrahepatic biliary tract obstruction.

Biodistribution studies of labeled tryptophan: a potential pancreas-scanning agent.

The in vivo organ distributions of dl- and l-[side 3-14C]-tryptophan and dl-(75Se)-selenomethionine were studied in normal Long-Evans rats to determine which tryptophan isomer had the best pancreas/liver ratio. The commercially available radiochemical agents were injected into the tails of adult rats, and three animals were sacrificed for each compound at 15, 30, 45, 60, and 90 minutes. Samples of blood, pancreas, liver, kidney, spleen, and flank muscles were excised, weighed wet, digested, and counted by standard liquid scintillation technics. A standard fraction of the injected dose was also counted so that results could be reported as per cent injected dose per gram tissue (per cent ID/gm) and per whole organ. The spleen and muscle concentrations (per cent ID/gm) were indistinguishable for the three compounds at all times studied. The kidney concentration of dl-tryptophan was higher than that of l-tryptophan at 60 and 90 minutes, reflecting the renal excretion of the nonmetabolic isomer. The concentration of l-tryptophan was two to three times higher than that of dl-tryptophan and selenomethionine in the pancreas at the earlier times, but after 1 hour they became equivalent. All three compounds had equivalent concentrations in the liver, except for l-tryptophan at 15 minutes. We conclude that pancreas/liver ratios are much higher for tryptophan than for selenomethionine and that for l-tryptophan they are at least tenfold higher. Since the rat is able to partially metabolize d-tryptophan via an inversion step, differences between l- and dl-tryptophan might be even larger for humans. L-tryptophan labeled with a short-lived gamma-emitting nuclide (13N or 11C) should, therefore, be a much better radiopharmaceutical agent for pancreatic scintigraphy.

Surgical management of subclavian artery injury.

During a 10 year period, we have had operative experience with 13 injuries to the subclavian artery. The factors that led to the successful management in 10 consecutive patients were analyzed. Nonspecific signs, such as pain and swelling, were present in all of the patients. Some aspect of vascular injury was present in each patient and included change in the quality of the distal pulse, hematoma, active hemorrhage, and bruit. Roentgenologic signs such as lung opacification, fractured clavicle, fracture of the first or second rib, and pulmonary opacification were present in each patient. Arteriograms were obtained from all stable patients in whom this injury was suspected. There were no false-positive or false-negative findings. The operative approach for the right subclavian vessels was midline sternotomy, whereas for exposure of proximal left subclavian injuries, anterolateral thoracotomy was utilized. Claviculectomy permitted excellent exposure for distal subclavian artery injuries. This exposure was associated with minimal blood loss and permitted direct repair of complex injuries of the arteries and veins. All patients who reached the emergency room with measurable vital signs survived, and all those who underwent subclavian vascular repair had circulation restored. Principal morbidity was due to associated brachial plexus and lung injuries. A high index of suspicion, rapid transportation, aggressive resuscitation, and proper surgical exposure and repair are essential for the successful management of these rare vascular injuries.

Radionuclide imaging of the biliary tree.

The new 99mTc biliary scintigraphy agents are highly sensitive and specific in detecting biliary tract disease and use of them is the initial procedure of choice in evaluating patients with suspected acute cholecystitis. Other clinically useful indications are evaluation of biliary kinetics; evaluation of patients with suspected traumatic bile leakage, gallbladder perforation, or postsurgical biliary tract complications; and evaluation of patients with suspected biliary obstruction. In 99mTc we have a simple radiopharmaceutical of low radiation for evaluating congenital abnormalities and neonatal jaundice. In the Orient 99mTc cholescintigraphy is extremely important in evaluating patients with suspected intrahepatic stones. The overall advantages of this technique include availability, safety, simplicity, and accuracy. In addition, it may be performed in those patients who are allergic to iodinated contrast agents.

Acute suppurative cholangitis.

Acute suppurative cholangitis is characterized by obstruction, inflammation, and pyogenic infection of the biliary tract associated with the clinical pentad of fever (and chills), jaundice, pain, shock, and central nervous system depression. The disease occurs most commonly in the elderly who have a history of calculous biliary tract disease. The disease represents a true surgical emergency. Appropriate antibiotic therapy and immediate surgical decompression of the biliary tract are essential and carry a mortality rate of approximately 33 per cent. Nonoperative management is uniformly fatal. If inadequately treated or untreated, the disease follows a fulminant course of progressive systemic sepsis, hepatic abscess formation, and heptic failure leading ultimately to death. Acute suppurative cholangitis, the most serious sequela of calculous biliary tract disease, is preventable by early elective surgical treatment for benign biliary tract disease.

Pathogenesis of cholesterol gallstones.

The factors leading to cholesterol cholelithiasis are probably multiple. Although the secretion of bile supersaturated with cholesterol seems to be a common feature among all patients who form cholesterol stones, a variety of pathophysiologic events can produce an increase in lithogenicity. Dietary factors, particularly in the grossly obese, lead to an absolute increase in secretion of cholesterol into bile. Occasionally, excessive loss of the bile salt pool, for example with regional ileitis, may decrease the ability of bile salts to solubilize cholesterol. In many other, subtle alterations in the enterohepatic circulation of bile salts may adversely affect solubility by both decreasing the secretion of bile salts and increasing the secretion of cholesterol. Regardless of its cause, supersaturation of bile with cholesterol appears to be a prerequisite for gallstone formation. However, additional factors within the gallbladder, such as increased secretion of glycoprotein, increased absorption of fluids, infection, and stasis, appear to contribute to the formation of macroscopic stones.

Malignant schwannoma: report of a case mimicking lumbar disk disease.

Primary neurogenic retroperitoneal tumors in the adult are rare. This case presentation reviews an unusual history of a patient who presented with pain and neurologic deficits suggesting lumbar disk disease but who was unrelieved by laminectomy and disk removal. Later he was found to have a malignant schwannoma arising from the right L nerve root. Experience such as this reminds physicians that when the result of treatment is not as expected the original diagnosis must be questioned.

Selective intraoperative cholangiography during laparoscopic cholecystectomy: how selective?

The necessity for intraoperative cholangiography during laparoscopic cholecystectomy has been debated for some time. Numerous retrospective studies favor selective intraoperative cholangiography. Surgeons in favor of the selective policy differ in their personal selective criteria. The aim of this prospective study was to evaluate whether intraoperative cholangiography can be safely omitted during laparoscopic cholecystectomy on all patients who fit a standard set of criteria: normal liver function tests, common bile duct diameter less than 10 mm, and no history of gallstone pancreatitis or jaundice. We undertook a prospective study on 155 consecutive patients treated in a county teaching hospital with symptomatic gallbladder disease who met the above standard set of criteria. One hundred and fifty-five patients meeting these criteria underwent laparoscopic cholecystectomy during a 2-year period from February 1996 through February 1998. Data analyzed included patient history, laboratory and ultrasound findings, operative results, postoperative stay, and intraoperative and postoperative complications. The patients were followed by periodic interviews, physical examination, liver function tests, and/or biliary ultrasound for up to 3 1/2 years with a mean follow-up of 26 months for retained common bile duct stones. Intraoperative cholangiography was performed in only one of the 155 patients studied to confirm common bile duct injury. There were four postoperative complications (2.6%) and one common bile injury (0.6%). Postoperative stay averaged one day. No patients, by history, biliary ultrasound, liver function tests or endoscopy, were found to have retained common bile duct stones during the follow-up period. Our study shows that intraoperative cholangiography is not necessary for patients undergoing laparoscopic cholecystectomy who have normal liver functions tests, common bile duct diameter less than 10 mm, and no history of gallstone pancreatitis or jaundice.

Complications following operation in the previously irradiated abdominopelvic cavity.

Twenty-three patients underwent 32 operations in a previously irradiated abdominopelvic cavity. The overall postoperative morbidity rate was 62% and the mortality rate was 6.2%. The data from this series do not support small bowel bypass as the only acceptable method of management of surgical radiation enteritis. Wide resection with primary anastomosis reduces the long-term morbidity of the "blind-loop syndrome", perforation and fistulization of the isolated loop, and does not have an increased mortality.

Localization of nonpalpable breast lesions detected by xeromammography.

A technique for localizing nonpalpable lesions of the breast using methylene blue dye is described. This technique is recommended for its accuracy, patient acceptance, and reduction in size of the biopsy specimen.