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Biomedical subjects

T H Baron

Publications and source records attributed to T H Baron.

At least 73 records · Page 4Linked to original sources

Pancreatic fluid collections prior to intervention: evaluation with MR imaging compared with CT and US.

PURPOSE: To evaluate the ability of magnetic resonance (MR) imaging to depict solid debris within pancreatic collections prior to intervention and to help assess drainability, as well as to compare MR findings with those obtained at computed tomography (CT) and ultrasound (US). MATERIALS AND METHODS: Nineteen collections in 18 patients were evaluated with MR imaging, CT, and US prior to drainage. Prospective, blinded interpretations of imaging studies by three independent readers (each interpreted all the images obtained with only one modality) evaluated collection characteristics (debris, consistency, septation, wall thickness, and irregularity) and predicted drainability. Findings were compared with clinical diagnosis and clinical outcome of drainage. RESULTS: MR imaging and CT depicted all collections; US failed to depict two collections. In nine patients with subacute necrotic collections, solid debris was seen in eight (89%) at MR imaging, in two (22%) at CT, and in eight (89%) at US. In seven patients with pseudocysts, debris was seen in two (28%) at MR imaging and in none at CT, as well as in six (100%) of six at US. A collection was defined as "not drainable" on the basis of the depiction of solid necrotic debris more than 1 cm in diameter. With this definition, statistically significant differences between sensitivity and specificity values, respectively, were found for the prediction of actual drainability: MR imaging, 100% and 100%; CT, 25% and 100%; US, 88% and 54%. CONCLUSION: Predrainage MR imaging should be performed in patients with subacute pancreatic collections to avoid infectious complications from unrecognized necrotic debris that cannot be removed with use of standard pseudocyst drainage techniques.

Abscess↗

Treatment of colonic obstruction with expandable metal stents: radiologic features.

OBJECTIVE: The purpose of this prospective study was to evaluate the efficacy of expandable metal stents for colonic decompression in patients presenting with acute malignant obstruction and to describe the associated radiographic findings. SUBJECTS AND METHODS: Using both fluoroscopic and endoscopic guidance, we placed expandable metal stents within the colons of 13 patients presenting with acute malignant obstruction. Stents were placed in four patients to permit a standard bowel cleansing before surgical resection with primary anastomosis. In the other nine patients, stents were placed for palliation of nonresectable tumors, obviating colostomy. Outcomes and complications were analyzed. The radiologic aspects of procedural planning, stent placement, assessment after placement, and detection of complications were evaluated. RESULTS: Of the four surgical candidates who were successfully resected with primary anastomosis, two received incomplete bowel cleansing because of stent migration with recurrent obstruction. Eight of the nine patients who had stents placed for palliation of nonresectable tumors had relief of acute obstruction. Complications in this group included two perforations, one that required immediate colostomy and one that was self-limited and conservatively treated. Two other patients of the eight developed early stent obstruction, requiring colostomy in one. The other patient who had a stent placed for palliation of a nonresectable tumor declined further treatment. Contrast-enhanced enema examination proved useful in assessing the suitability of lesions for stent decompression, directing the choice of stent type and the most appropriate position for the patient during the stent placement. Immediately after stent placement, plain abdominal radiographs and water-soluble contrast enema examinations helped us verify stent position and patency. CONCLUSION: These results suggest that placement of expandable metal stents in patients presenting with acute, malignant colonic obstruction is a viable alternative to colostomy and can potentially decrease morbidity and mortality. Radiologic assessment before, during, and after stent placement plays an integral role in the management of patients undergoing stent decompression of the colon.

Acute Disease↗

Solitary breast metastasis to the ampulla and distal common bile duct.

The indications for pancreaticoduodenectomy have continued to expand over the past 10 to 15 years. This is in large part due to improved diagnostic studies, endoscopic retrograde cholangiopancreaticogram and computed tomography, and decreases in hospital perioperative morbidity and mortality. One third of breast cancer patients will develop metastatic disease usually to the liver, lung, or bone (World J Surg 1994;18:98-111). However, the presentation of painless jaundice due to a single metastatic lesion to the distal common bile duct from ductal adenocarcinoma of the breast is extremely rare. In this case report and review of the literature, we discuss the indications and emerging evidence that pancreaticoduodenectomies can now be performed for localized metastatic disease.

Ampulla of Vater↗

Endoscopic therapy for organized pancreatic necrosis.

BACKGROUND & AIMS: The treatment of patients with extensive pancreatic necrosis remains controversial; a subpopulation of patients with extensive acute pancreatic necrosis develop complex, organized collections. This study examined the feasibility of endoscopic drainage in patients with extensive organized pancreatic necrosis. METHODS: Eleven patients with organized pancreatic necrosis (8 sterile and 3 infected) after severe acute necrotizing pancreatitis underwent attempted endoscopic drainage. Dynamic contrast-enhanced computerized tomography showed > or = 50% pancreatic necrosis in 10 of 11 patients in whom endoscopic drainage was performed. In 8 patients, an intrapancreatic nasobiliary lavage catheter was placed into the collection concurrently with 10F stents. RESULTS: Complete resolution was achieved nonoperatively in 9 patients. At a mean follow-up of 12 months, 1 patient developed a pseudocyst, which was successfully drained endoscopically. Complications occurred in 5, including bleeding that precluded entry into one collection. CONCLUSIONS: Endoscopic therapy may be a viable management option for a subset of patients who remain symptomatic after an episode of acute pancreatic necrosis after the necrosis has become organized and partially liquefied. Intrapancreatic lavage catheter placement is essential to the success of this procedure. Further evaluation of this technique is needed before this method can be adopted into clinical practice.

Adolescent↗

Palliative procedures for pancreatic cancer: when and which one?

Pancreatic cancer usually requires palliative rather than curative therapy. Palliative procedures should have low morbidity and mortality, provide a good quality of life, and necessitate minimal hospitalization. The surgeon, endoscopist, and radiologist all play a role in delivering effective palliation to properly selected patients.

Anastomosis, Roux-en-Y↗

Mast cell cholangiopathy: another cause of sclerosing cholangitis.

A 75-year-old woman with known systemic mastocytosis presented with abdominal pain, ascites, and bile duct thickening on computed tomography and ultrasonography. A liver biopsy specimen showed infiltration with mast cells. Endoscopic retrograde cholangiography showed ductal changes compatible with those found in primary sclerosing cholangitis. Brush cytology of the intrahepatic bile ducts confirmed mast cell infiltration. Systemic mastocytosis can infiltrate the biliary system, producing a cholangiopathy radiographically similar to primary sclerosing cholangitis.

Aged↗

Leaking gallbladder remnant with cholelithiasis complicating laparoscopic cholecystectomy.

Since its introduction in 1989, laparoscopic cholecystectomy has rapidly become the preferred alternative to open cholecystectomy for symptomatic cholelithiasis. Although possible complications of laparoscopic cholecystectomy are essentially the same as for open cholecystectomy, we report a case of an inadvertent subtotal cholecystectomy, a complication that we believe has not been previously reported.

Bile↗

The effect of propofol on the canine sphincter of Oddi.

To assess the effect of propofol on the canine sphincter of Oddi(SO), sphincter of Oddi manometry (SOM) was performed in fasting dogs which had undergone cholecystectomy and placement of modified Thomas duodenal cannulae. Using two water-perfused, single-lumen manometric catheters, SO and duodenal pressures were measured simultaneously. Baseline SO activity was recorded for at least one complete interdigestive cycle followed by bolus injections of propofol (Diprivan) (N = 31) from 0.1 to 4.0 mg/kg during Phase I of the Migrating Motor Complex (MMC). When propofol was administered in bolus doses < or = 0.4 mg/kg, no change in SO or duodenal motor function was seen. In doses > or = 0.5 mg/kg, SO basal pressure, amplitude, and frequency of contractions increased significantly. Increases in duodenal activity paralleled SO activity. Our results suggest that propofol in low doses may be useful for sedation during Sphincter of Oddi manometry in humans. Further studies of the effect of propofol on the human sphincter of Oddi are warranted.

Animals↗

Gastrointestinal motility disorders during pregnancy.

PURPOSE: To review the pathophysiology of gastrointestinal motility disorders during pregnancy, their clinical manifestations, and their management. DATA SOURCES: Studies published from 1963 to 1992 identified by computerized literature searches of Index Medicus and MEDLINE; hand searches; contact with pharmaceutical representatives for information on drug therapy during pregnancy; and selected texts on drugs and obstetrics. STUDY SELECTION: Selected studies were those involving controlled design of physiology related to pregnancy or to hormonal effects on the gastrointestinal tract or both, and clinical studies or previous reviews that contributed to the understanding of the gastrointestinal effects of pregnancy. DATA EXTRACTION: Data concerning the epidemiology, causes, clinical manifestations, and complications of altered gastrointestinal motility during pregnancy as well as the strength of association between gastrointestinal disorders of pregnancy and hormonal changes were evaluated and used to develop a practical approach to evaluate and manage these patients. RESULTS OF DATA SYNTHESIS: Effects on the gastrointestinal tract during pregnancy are caused primarily by hormonal changes and not the physical effects of the gravid uterus. Motility changes occur throughout the gastrointestinal tract, including a reduction in lower esophageal sphincter pressure and its physiologic function with resulting gastroesophageal reflux and the risk for aspiration; alterations in gastric motor function associated with nausea and vomiting; and a decrease in the rate of small-bowel and colonic transit manifested primarily as abdominal bloating and constipation. These effects are mediated by progesterone, with estrogen probably acting as a primer. CONCLUSIONS: Given the large number of pregnancies each year complicated by gastrointestinal motility disorders, many physicians (including internists and gastroenterologists) must manage these problems. Knowledge of the underlying physiologic alterations in gastrointestinal motility during pregnancy and of safe treatment options is essential to the care of the pregnant patient.

Animals↗