Biomedical subjects

Rowan W Parks

Publications and source records attributed to Rowan W Parks.

7 recordsLinked to original sources

PubMed2006

Identification of severe acute pancreatitis using an artificial neural network.

BACKGROUND: The aim of this study was to construct and validate an artificial neural network (ANN) model to identify severe acute pancreatitis (AP) and predict fatal outcome. METHODS: All patients who presented with AP from January 2000 to September 2004 were reviewed. Presentation data on admission and at 48 hours were collected. Acute Physiology and Chronic Health Evaluation (APACHE) II and Glasgow severity (GS) score were calculated. A feed-forward ANN was created and trained to predict development of severe AP and mortality from AP; 25% of the data set was withheld from training and was used to evaluate the accuracy of the ANN. Accuracy of the ANN in predicting severity of AP was compared with APACHE II and GS scores. RESULTS: A total of 664 patients with AP were identified of whom 181 (27.3%) fulfilled the clinical and radiologic criteria for severe pancreatitis and 42 patients died (6.3%). Median APACHE II score at 48 hours was 4 (range, 0 to 23). ANN was more accurate than APACHE II or GS scoring systems at predicting progression to a severe course (P < .05 and P < .01, respectively), predicting development of multiorgan dysfunction syndrome (P < .05 and P < .01) and at predicting death from AP (P < .05). CONCLUSIONS: An ANN was able to predict progression to severe disease, development of organ failure and mortality from acute pancreatitis with considerable accuracy and outperformed other clinical risk scoring systems. Further studies are required to assess its utility in aiding management decisions in patients with AP.

APACHE↗

PubMed2006

Nutritional risk index predicts a high-risk population in patients with obstructive jaundice.

BACKGROUND: Malnutrition is common in obstructive jaundice but is difficult to define. The aim of this study was to compare definitions of malnutrition in patients with obstructive jaundice to identify correlation with mortality, complications and length of hospital stay after intervention. METHODS: Prospective case-control study comparing 39 inpatients with obstructive jaundice with 21 controls. Body mass index (BMI), skin-fold thickness (TSF), mid-arm muscle circumference (MAMC), percentage weight loss, nutritional risk index (NRI) and malnutrition universal screening tool (MUST) were measured and compared. Duration of admission, interventions, complications and outcome were recorded prospectively. RESULTS: Patients with obstructive jaundice were significantly malnourished compared to controls. Severe malnutrition was equally prevalent in benign and malignant disease. Malnourished patients had higher mortality and longer duration of stay after intervention compared to non-malnourished patients. NRI<83.5 was significantly associated with mortality and longer duration of hospital admission but not complication rate. CONCLUSION: NRI is simple to use and defines a high-risk sub-group of patients with obstructive jaundice.

Aged↗

PubMed2006

Hepatic progenitor cells in human fetal liver express the oval cell marker Thy-1.

Hepatic progenitor cells play a major role in regenerating diseased liver. In rodents, progenitors forming hepatocytes or cholangiocytes are identified by the stem cell marker Thy-1. The aim of this study was to ascertain whether progenitor cells expressing Thy-1 could be identified in human fetal liver. Midtrimester human fetal liver was immunostained for Thy-1, cytokeratins 18 and 19, vimentin, CD34, CD45, and fibrinogen. Thy-1+ and Thy-1+CD34+ populations were purified using fluorescence-activated cell sorting (FACS). Immunofluorescence and mRNA expression were used to examine the bipotential nature of purified stem cells. We found that Thy-1+ cells were concentrated in portal tracts but were also scattered in parenchyma. In FACS-prepared cells, 0.18-3.08% (median 0.65%, n = 14) of cells were Thy-1+. Immunophenotyping revealed that some Thy-1+ cells coexpressed cytokeratins 18 and 19, others, fibrinogen and cytokeratin 19. RT-PCR demonstrated that Thy-1+ cells expressed mRNA for Thy-1, cytokeratin 18, and cytokeratin 19, and Thy-1+CD34+ cells expressed mRNA for alpha-fetoprotein, transferrin, and hepatocyte nuclear factor-4alpha. Thy-1+ cells were identified in fetal liver. These cells expressed several lineage markers, including coexpression of biliary and hepatocellular proteins and mRNA. These data suggest that Thy-1 is a marker of liver stem cells in human fetal liver.

Cell Differentiation↗

PubMed2005

The utility of laparoscopic assessment in the preoperative staging of suspected hilar cholangiocarcinoma.

The aim of this study was to review the role of laparoscopic assessment in the staging algorithm of suspected hilar cholangiocarcinoma and to identify factors highly likely to be associated with unresectable disease. Data prospectively collected between 1992 and 2003 were analyzed. Demographics, symptoms, preoperative radiologic staging, laparoscopic assessment, and final outcome were recorded. Yield was defined as the number of unresectable patients detected by laparoscopic assessment divided by the total number of patients undergoing laparoscopic assessment. Accuracy was defined as the number of unresectable patients detected by laparoscopic assessment divided by the total number of unresectable cases. Eighty-four patients underwent laparoscopic assessment for suspected hilar cholangiocarcinoma, of which 20 (23.8%) underwent resection. The yield from laparoscopy alone was 24.3% (20 of 82), which increased to 41.5% (35 of 82) with the addition of intraoperative ultrasound. The overall accuracy was 53.1% (35 of 66). The use of a preoperative radiologic staging system predicted the likelihood of unresectable disease (P=0.007). The use of laparoscopic assessment in the preoperative staging of patients with suspected hilar cholangiocarcinoma is justified given it will spare 42.2% of patients an unnecessary laparotomy. Accurate staging of cholangiocarcinoma remains a challenge, but the use of a preoperative radiologic staging system may help to stratify a patient's risk of unresectable disease.

Bile Duct Neoplasms↗

PubMed2003

Early and long-term results of surgery for severe necrotising pancreatitis.

BACKGROUND: Necrotising pancreatitis is a challenging problem for the surgeon, as it is associated with considerable morbidity and mortality. The indications, timing of surgical intervention and type of procedure continue to be debated in an effort to improve the outcome of this devastating disease process. METHODS: A retrospective analysis of early and long-term results in a series of 44 consecutive patients (34 men, 10 women, median age 46.5, range 13-74 years) who underwent necrosectomy for severe necrotising pancreatitis. In 16 patients necrosectomy and primary abdominal closure with drains was performed, 14 patients had planned staged necrosectomy and delayed abdominal closure with drains, and in 14 patients necrosectomy with open laparostomy was undertaken. RESULTS: There were 8 deaths (18%) and 14 cases (32%) of significant hospital morbidity (fistula 10, pseudocyst 2, renal failure 2). Variables which correlated with mortality were: high APACHE II score, acute renal failure requiring dialysis, and requirement for surgical intervention at an early stage (within the first two weeks). A total of 28 late complications occurred in 21 of the surviving patients (endocrine pancreatic insufficiency 10, exocrine pancreatic insufficiency 2, pseudocyst 2, chronic renal failure 2, incisional hernia 10, recurrent pancreatitis 1, and chronic pain 1). CONCLUSIONS: Low mortality can be achieved in patients with severe necrotizing pancreatitis with aggressive surgical intervention and careful perioperative management. Long-term morbidity remains high, and emphasises the need for prolonged follow-up.

APACHE↗

PubMed2003

Diagnosis and early management of acute pancreatitis.

Acute pancreatitis is a common emergency with the potential for significant complications. Despite advances in the understanding of the pathogenetic mechanisms of acute pancreatitis and the completion of a number of randomized trials studying specific therapies, the early management of patients remains supportive.

Acute Disease↗

PubMed2002

Biliary tract emergencies.

Gallstones are responsible for the majority of biliary tract emergencies and will be the main focus of this article. Gallstones present with features related to the site of the calculi and are therefore considered separately. Cholecystolithiasis refers to gallstones confined to the gallbladder, whereas choledocholithiasis refers to gallstones within the common bile duct.

Acute Disease↗