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Dive into the research topics where Kofi Oppong is active.

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Featured researches published by Kofi Oppong.


Gut | 2016

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

B. Jais; V. Rebours; Giuseppe Malleo; Roberto Salvia; M. Fontana; Laura Maggino; Claudio Bassi; Riccardo Manfredi; R. Moran; Anne Marie Lennon; A. Zaheer; Christopher L. Wolfgang; Ralph H. Hruban; Giovanni Marchegiani; C. Fernandez del Castillo; William R. Brugge; Y. Ha; Mi-Jung Kim; D. Oh; Ichiro Hirai; Kimura W; Jin Young Jang; Sun Whe Kim; W. Jung; H. Kang; S. Y. Song; C. M. Kang; W. J. Lee; Stefano Crippa; Massimo Falconi

Objectives Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality. Design Retrospective multinational study including SCN diagnosed between 1990 and 2014. Results 2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16–99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2–200)), 9% had resection beyond 1 year of follow-up (3 years (1–20), size at diagnosis: 25 mm (4–140)) and 39% had no surgery (3.6 years (1–23), 25.5 mm (1–200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCNs related mortality was 0.1% (n=1). Conclusions After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN. Trial registration number IRB 00006477.


Gut | 2000

Effect of l-ornithine-l-aspartate on patients with and without TIPS undergoing glutamine challenge: a double blind, placebo controlled trial

Colin J. Rees; Kofi Oppong; H al Mardini; Mark Hudson; Christopher O. Record

BACKGROUND AND AIM An oral glutamine load in cirrhotic patients awaiting liver transplantation was shown to cause a rise in blood ammonia and psychometric abnormalities which were reversed by hepatic transplantation. l-Ornithine-l-aspartate (LOLA) has been shown to reduce ammonia and improve psychometric function in patients with hepatic encephalopathy. The aim of the present study was to assess the effect of LOLA in healthy patients with cirrhosis and no evidence of clinical encephalopathy after challenging the central nervous system by administration of oral glutamine. PATIENTS AND METHODS Eight cirrhotics (Childs B or C) without transjugular intrahepatic portosystemic shunts (TIPS) and seven with TIPS underwent two oral glutamine (20 g) challenges, receiving LOLA (5 g intravenously) on one occasion and placebo on the other in random order. Psychometric tests, including choice reaction time (CRT) and number connection test, were performed before and after glutamine, together with electroencephalography and blood ammonia. RESULTS Mean basal ammonia was 27 (SEM 5) μmol/l in non-TIPS and 76 (10) μmol/l in TIPS patients (p<0.05). Basal CRT 2 was 0.643 (0.033) s in non-TIPS and 0.825 (0.076) s in TIPS patients (p<0.02). In non-TIPS patients, ammonia increased to 36 (10) μmol/l when LOLA was administered and to 62 (13) μmol/l with placebo (p<0.02). There was no alteration in psychometric function in non-TIPS patients after glutamine when LOLA was given but when placebo was given, glutamine caused prolongation of CRT (p=0.02). Glutamine did not affect psychometric function in TIPS patients with or without LOLA. CONCLUSION This study showed that LOLA ameliorated the deleterious psychometric effects of glutamine in Childs grade B and C patients with cirrhosis without TIPS and supports its use in clinical practice in hepatic encephalopathy.


Gastrointestinal Endoscopy | 2012

Diagnostic accuracy of quantitative EUS elastography for discriminating malignant from benign solid pancreatic masses: a prospective, single-center study

Muhammad F. Dawwas; Hatim Taha; John S. Leeds; Manu Nayar; Kofi Oppong

BACKGROUND Recent data suggest that quantitative EUS elastography, a novel technique that allows real-time quantification of tissue stiffness, can accurately differentiate malignant from benign solid pancreatic masses. OBJECTIVE To externally validate the diagnostic utility of this technique in an independent cohort. DESIGN AND SETTING Prospective, single-center study. PATIENTS, INTERVENTIONS, AND METHODS: A total of 104 patients with evidence of a solid pancreatic mass on cross-sectional imaging and/or endosonography underwent 111 quantitative EUS elastography procedures. Multiple elastographic measurements of the mass lesion and soft-tissue reference areas were undertaken, and the corresponding strain ratios (SRs) were calculated. The final diagnosis was based on pancreatic cytology or histology. MAIN OUTCOME MEASUREMENTS The area under the receiver-operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of quantitative EUS elastography for discriminating malignant from benign pancreatic masses. RESULTS The final diagnoses were primary pancreatic carcinoma (71.2%), neuroendocrine tumor (10.6%), metastatic cancer (1.9%), and pancreatitis (16.3%). Malignant masses had a higher SR (P = .01) and lower mass elasticity (P = .003) than inflammatory ones. The areas under the receiver-operating characteristic curve for the detection of pancreatic malignancy of both SR and mass elasticity (0.69 and 0.72, respectively) were less favorable than reported recently. At the cut points providing the highest accuracy in this cohort (4.65 for SR and 0.27% for mass elasticity), quantitative EUS elastography had a sensitivity of 100.0% and 95.7%, specificity of 16.7% and 22.2%, positive predictive value of 86.1% and 86.4%, negative predictive value of 100.0% and 50.0%, and overall accuracy of 86.5% and 83.8%, respectively. LIMITATIONS Relatively small number of patients with benign disease. CONCLUSION In the largest single-center study to date, the diagnostic utility of quantitative EUS elastography for discriminating pancreatic masses was modest, suggesting that it may only supplement rather than supplant the role of pancreatic tissue sampling in the future.


Nature Reviews Gastroenterology & Hepatology | 2011

The role of fecal elastase-1 in detecting exocrine pancreatic disease

J S Leeds; Kofi Oppong; David S. Sanders

Exocrine pancreatic disease is thought to be uncommon in clinical practice and usually secondary to excess alcohol intake. Although excess alcohol intake does account for many cases of exocrine pancreatic disease, other conditions are associated with exocrine pancreatic insufficiency and such dysfunction perhaps occurs more frequently than conventionally expected. A reliable, patient-friendly, cheap and easy to use test for exocrine pancreatic disease is yet to be established; however, in many countries the main (and often only available) method of assessment of exocrine pancreatic function is the fecal-elastase-1 test. This Review examines the role of fecal-elastase-1 testing in detecting exocrine pancreatic insufficiency in a number of gastrointestinal and nongastrointestinal conditions and determines the value of pancreatic enzyme supplementation in these settings.


British Journal of Surgery | 2008

Comparison of multislice computed tomography and endoscopic ultrasonography with operative and histological findings in suspected pancreatic and periampullary malignancy

S.D. Mansfield; J. Scott; Kofi Oppong; D. L. Richardson; Gourab Sen; Bc Jaques; Derek Manas; Richard Charnley

This study compared multislice computed tomography (MSCT) with endoscopic ultrasonography (EUS) in the diagnosis and staging of pancreatic and periampullary malignancy.


Journal of the Pancreas | 2010

EUS-FNA versus Biliary Brushings and Assessment of Simultaneous Performance in Jaundiced Patients with Suspected Malignant Obstruction

Kofi Oppong; Dan Raine; Manu Nayar; Viney Wadehra; Subramaniam Ramakrishnan; Richard Charnley

CONTEXT Individuals with suspected malignant biliary obstruction commonly undergo ERCP for drainage and tissue sampling via biliary brushings. EUS with EUS-FNA facilitates staging and potentially more accurate tissue sampling. OBJECTIVE The aim is to compare the diagnostic performance of EUS-FNA and ERCP with biliary brushings (ERCP-BB) in the diagnosis of pancreatobiliary carcinoma and the utility of combining the two procedures under conscious sedation. DESIGN Retrospective analysis of a prospectively maintained database. PATIENTS Thirty-seven patients with suspected malignant obstructive jaundice underwent 39 paired procedures, either combined (n=22) or within a few days (n=17). RESULTS Using strict cytological criteria the sensitivity of EUS-FNA in the diagnosis of malignancy was 52.9% (95% CI: 35.1-70.2%) versus 29.4% (95% CI: 15.1-47.5%) for ERCP-BB. Combining the two tests improved sensitivity to 64.7% (95% CI: 46.5-80.3%) which was significantly better than ERCP-BB alone (P=0.001) but not EUS-FNA alone (P=0.125). When both procedures were performed under the same conscious sedation, there was a significant difference (P=0.031) between the sensitivity of EUS-FNA (52.6%; 95% CI: 28.9-75.6%) and that of ERCP-BB (21.1%; 95% CI: 6.1-45.6%). When both procedures were performed together the mean±SD in-room time was 79±14 min (range: 45-105 min). Two of the patients (9.1%) had a complication. CONCLUSIONS In patients undergoing EUS-FNA and ERCP-BB under the same sedation, EUS-FNA was significantly more sensitive in diagnosing malignancy. Combining the results of both tests improved diagnostic accuracy. Combining therapeutic ERCP and EUS-FNA under the same conscious sedation is feasible, with a complication rate similar to that of ERCP alone.


Endoscopy | 2015

Endoscopic drainage of walled-off pancreatic necrosis using a novel self-expanding metal stent.

Mt Huggett; Kofi Oppong; Stephen P. Pereira; Margaret G. Keane; Mitra; Richard Charnley; Manu Nayar

BACKGROUND AND STUDY AIMS This report describes the use of a novel, fully covered, self-expanding metal stent (FCSEMS) for endoscopic ultrasound (EUS)-guided drainage of walled-off pancreatic necrosis (WON). PATIENTS AND METHODS Patients with WON, as defined by the revised Atlanta Criteria, were included in this open-lable, two-center, observational study. The WON was punctured using a cystotome, and the FCSEMS was inserted under fluoroscopic guidance. Necrosectomy procedures were performed as necessary. RESULTS A total of 19 patients were included. The median maximum collection size was 15 cm with a median of 50 % necrosis. A total of 14/19 patients underwent necrosectomy, requiring a median of 4 procedures. Resolution or reduction in the size of collection by at least 80 % was achieved in all patients. Percutaneous or surgical drainage was required in three patients. Five stents migrated or dislodged. One patient had abdominal pain post-procedure. Five patients died during follow-up (three from multi-organ failure, and two unrelated to pancreatitis). CONCLUSIONS Use of this stent is feasible and safe for drainage of WON. However, stent displacement rates were high, and improvements to the stent design are required before it can be advocated for routine use in WON.


Surgical Oncology-oxford | 2014

What to do for the incidental pancreatic cystic lesion

Stuart Robinson; J. Scott; Kofi Oppong; Steven White

BACKGROUND Incidental pancreatic cysts are identified in 1% of all patients undergoing CT scans of the abdomen for whatever reason. The aim of this review was to provide an overview of the current evidence relating to the investigation and management of these lesions. METHODS PubMed was searched to identify relevant studies relating to the investigation and management of incidentally discovered pancreatic cystic lesions. RESULTS Initial investigation of incidentally discovered pancreatic cysts should be with either specific pancreas protocol CT or contrast enhanced MRI with MRCP. The diagnostic yield of these investigations can be increased with the addition of EUS/FNA and cyst fluid analysis in appropriately selected patients. Surgical intervention may be indicated in otherwise fit patients who are identified as having mucinous neoplasms. CONCLUSION Applying a systematic approach to the investigation of incidentally discovered pancreatic cysts means that in the majority of cases cyst aetiology can be accurately determined and appropriate management plans developed.


Frontline Gastroenterology | 2011

Service provision and training for endoscopic ultrasound in the UK

J Meenan; K Harris; Kofi Oppong; Colin J. McKay; I Penman; N Carroll; S Norton

Endoscopic ultrasound (EUS) is a standard procedure that plays an important role in the management of both malignant and benign disease. The development of EUS services in the UK has been haphazard and training inconsistent. The British Society of Gastroenterology has charged a working group with the task of laying down a national framework for how such services might be commissioned, structured and regulated; with particular attention to defining how endoscopist skills might be acquired, assessed and maintained. This report lays out a map for this process and its future revision.


Scandinavian Journal of Gastroenterology | 2014

Diagnostic utility of single-user peroral cholangioscopy in sclerosing cholangitis.

Evangelos Kalaitzakis; Richard Sturgess; Harry Kaltsidis; Kofi Oppong; Venkata Lekharaju; Per Bergenzaun; Panagiotis Vlavianos; Hemant Sharma; David Westaby; George Webster

Abstract Objective. To evaluate the diagnostic utility of single-operator peroral cholangioscopy (SOC) in patients with sclerosing cholangitis. Methods. All patients with sclerosing cholangitis who underwent SOC procedures due to suspicious biliary strictures, in one Swedish and four UK tertiary centers in 2008–2012, were retrospectively enrolled. For each SOC procedure in sclerosing cholangitis, another one attempted due to a single biliary stricture in the same center and calendar year was randomly selected as control. Patients were followed up until death or last clinic visit until November 2012. Results. Fifty-four SOC procedures were attempted in 52 sclerosing cholangitis patients (48 with primary sclerosing cholangitis, 4 with IgG4-related sclerosing cholangitis). Cannulation with the SOC system failed more frequently in sclerosing cholangitis (15% vs. 2% in controls; p = 0.015). The sensitivity, specificity, and accuracy of SOC (including tissue sampling) for cancer diagnosis were similar in sclerosing cholangitis and controls (50% vs. 55%, 100% vs. 97%, and 88% vs. 80%, respectively) with largely overlapping confidence intervals. Adverse events were more common in sclerosing cholangitis, due to an increased frequency of cholangitis (11% vs. 2% in controls; p = 0.051). Conclusions. SOC is equally accurate in cancer diagnosis in sclerosing cholangitis and patients with single biliary strictures. However, cholangioscope insertion may be hampered by bile duct narrowing and post-SOC cholangitis is more common in sclerosing cholangitis.

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