Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where A. Dennison is active.

Publication


Featured researches published by A. Dennison.


Pancreatology | 2008

Cystic Lesions of the Pancreas

G. Garcea; Seok Ling Ong; Arumugam Rajesh; C.P. Neal; Cristina Pollard; David P. Berry; A. Dennison

Background/Aims: Due to enhanced imaging modalities, pancreatic cysts are being increasingly detected, often as an incidental finding. They comprise a wide range of differing underlying pathologies from completely benign through premalignant to frankly malignant. The exact diagnostic and management pathway of these cysts remains problematic and this review attempts to provide an overview of the pathology underlying pancreatic cystic lesions and suggests appropriate methods of management. Methods: A search was undertaken with a Pubmed database to identify all English articles using the keywords ‘pancreatic cysts’, ‘serous cystadenoma’, ‘intraductal papillary mucinous tumour’, ‘pseudocysts’, ‘mucinous cystic neoplasm’ and ‘solid pseudopapillary tumour’. Results: The mainstay of assessment of pancreatic cysts is cross-sectional imaging incorporating CT and MRI. Fine-needle aspiration (FNA) (often with endoscopic ultrasound) may provide valuable additional information but can lack sensitivity. Symptomatic cysts, increasing age and multilocular cysts (with a solid component and thick walls) are predictors of malignancy. A raised cyst aspirate CEA, CA 19-9 and mucin content (including abnormal cytology), if present, can accurately distinguish premalignant and malignant cysts from benign ones. Conclusion: In summary, all patients with pancreatic cystic lesions, whether asymptomatic or symptomatic, must be thoroughly investigated to ascertain the underlying nature of the cyst. Small asymptomatic cysts (<3 cm) with no suspicious features on imaging or FNA may be safely followed up. Follow-up should continue for at least 4 years, with a repeat FNA if needed. An algorithm for the management of pancreatic cystic tumours is also suggested.


Pancreatology | 2005

Role of inflammation in pancreatic carcinogenesis and the implications for future therapy.

Giuseppe Garcea; A. Dennison; William P. Steward; David P. Berry

Background: The link between inflammation and pancreatic cancer has been observed for a number of gastrointestinal neoplasms. This review examines the role of inflammation in pancreatic carcinogenesis and how it can be utilised to develop new therapies against pancreatic cancer. Methods: A literature review of Pubmed, Medline and Web of Science databases was undertaken using the key words, pancreatic cancer, inflammation, inducible nitric oxide, interleukins, pro-inflammatory cytokines, cyclooxygenase-2, NF-kappa B, reactive oxygen species, DNA adducts, lipoxygenases, chemoprevention. Results: Epidemiological evidence and molecular studies both in vitro and in vivo all support the hypothesis that inflammation plays an important in the initiation and progression of pancreatic tumours. Conclusion: Sustained damage caused by chronic inflammation may precede the onset of frank malignancy by a significant interval. As such, suppression of inflammatory changes and oxidative damage, may help delay or even prevent the inception of pancreatic neoplasia.


Annals of The Royal College of Surgeons of England | 2012

Enhanced recovery programmes in hepatobiliary and pancreatic surgery: a systematic review

Tc Hall; A. Dennison; Dk Bilku; Metcalfe; G Garcea

INTRODUCTION The terms ‘enhanced recovery after surgery’, ‘enhanced recovery programme’ (ERP) and ‘fast track surgery’ refer to multimodal strategies aiming to streamline peri-operative care pathways, to maximise effectiveness and minimise costs. While the results of ERP in colorectal surgery are well reported, there have been no reviews examining if these concepts could be applied safely to hepatopancreatobiliary (HPB) surgery. The aim of this systematic review was to appraise the current evidence for ERP in HPB surgery. METHODS A MEDLINE® literature search was undertaken using the keywords ‘enhanced recovery’, ‘fast-track’, ‘peri-operative’, ‘surgery’, ‘pancreas’ and ‘liver’ and their derivatives such as ‘pancreatic’ or ‘hepatic’. The primary endpoint was length of post-operative hospital stay. Secondary endpoints were morbidity, mortality and readmission rate. RESULTS Ten articles were retrieved describing an ERP. ERP protocols varied slightly between studies. A reduction in length of stay was a consistent finding following the incorporation of ERP when compared with historical controls. This was not at the expense of increased rates of readmission, morbidity or mortality in any study. CONCLUSIONS The introduction of an ERP in HPB surgery appears safe and feasible. Currently, many of the principles of the multimodal pathway are derived from the colorectal ERP and distinct differences exist, which may impede its implementation in HPB surgery.


European Journal of Cancer | 2009

Evaluation of the prognostic value of systemic inflammation and socioeconomic deprivation in patients with resectable colorectal liver metastases.

Christopher P. Neal; Christopher D. Mann; C. D. Sutton; G. Garcea; Seok Ling Ong; William P. Steward; A. Dennison; David P. Berry

BACKGROUND There is increasing evidence that the presence of a pre-operative systemic inflammatory response (SIR) independently predicts poor long-term outcome in patients with colorectal cancer (CRC). Socioeconomic deprivation was reported to correlate with the presence of the SIR and to independently predict poor outcome following primary CRC resection. The aim of this study was to determine the prognostic value of pre-operative systemic inflammatory biomarkers and socioeconomic deprivation in patients undergoing resection of colorectal liver metastases (CLM) and to examine correlations between these variables in this context. PATIENTS AND METHODS Clinicopathological data, including the Memorial Sloan-Kettering Cancer Centre Clinical Risk Score (CRS), were obtained from a prospectively maintained database for 174 patients who underwent hepatectomy for CLM between January 2000 and December 2005 at a single United Kingdom (UK) tertiary referral hepatobiliary centre. Inflammatory biomarkers (total and differential leucocyte counts, neutrophil-lymphocyte ratio, platelet count, haemoglobin, and serum albumin) were measured from routine pre-operative blood tests. Socioeconomic deprivation was measured using the Carstairs deprivation score. RESULTS On multivariable analysis, poor CRS (3-5), high neutrophil count (>6.0 x 10(9)/l) and low serum albumin (<40g/dl) were the only independent predictors of shortened overall survival following metastasectomy, with neutrophil count representing the greatest relative risk of death. These factors were also the only independent predictors of shortened disease-free survival following hepatectomy. Socioeconomic deprivation was associated with neither systemic inflammation nor long-term outcome in this context. CONCLUSIONS The presence of a pre-operative systemic inflammatory response, but not socioeconomic deprivation, independently predicts shortened survival following resection of CLM.


Surgical Endoscopy and Other Interventional Techniques | 2010

Liver ablation techniques: a review

Neil Bhardwaj; Andrew D. Strickland; Fateh Ahmad; A. Dennison; David M. Lloyd

BackgroundAblation techniques for unresectable liver carcinomas have evolved immensely since their introduction. Results of studies involving these techniques are restricted to reports of patient case series, which are often not presented in a standardised manner. This review aims to summarise the major studies in ablation technologies and present them in a way that may make comparison between the major modalities easier.MethodsAll major databases (Medline, Cochrane, Embase and Pubmed) were searched for studies using microwave, radiofrequency or cryoablation to treat unresectable liver tumours. Only studies with at least 30 patients and 3-year follow-up were included. Complication, recurrence and survival rates of all studies are summarised and presented.Results and conclusionIt is difficult to compare ablation modalities, as probe design and energy sources have evolved rapidly over the last decade. Ablation offers an invaluable palliative option and in some cases it may offer rates of cure approaching that of surgical resection with lower morbidity and mortality. Perhaps the time has come, therefore, for prospective large-scale randomised control trials to take place comparing ablation modalities to each other and surgical resection.


Hpb Surgery | 1994

The Effect of Communication Between the Right and Left Liver on the Outcome of Surgical Drainage for Jaundice due to Malignant Obstruction at the Hilus of the Liver

Hans U. Baer; M. Rhyner; Steven C. Stain; P. W. Glauser; A. Dennison; Guy J. Maddern; L. H. Blumgart

Debate continues regarding the optimal management of irresectable malignant proximal biliary obstruction. Controversy exists concerning the ability of unilateral drainage to provide adequate biliary decompression with tumors that have occluded the communication between the right and left hepatic ductal systems. Between October 1986 and October 1989, 18 patients with malignant proximal biliary obstruction were treated by an intrahepatic biliary enteric bypass. Patients were divided into two groups based on the presence or absence of a communication between the right and left biliary systems. In Group I (n = 9), there was free communication; and in Group II (n = 9) there was no communication. There were two perioperative deaths (11%) one due to persistent cholangitis and the other to myocardial insufficiency both with one death in each group. The median survival (excluding perioperative deaths) was 5.6 months. Comparison of pre- and postoperative serum levels of bilirubin and alkaline phosphatase showed a significant decrease in each group, but no difference between the groups in the size of the reduction. Sixteen patients survived at least three months and the palliation was judged as excellent in eight, fair in five, and unchanged in three. These results demonstrate the effectiveness of biliary enteric bypass regardless of communication between the left and right biliary ductal systems.


Pancreatology | 2009

A Fuller Understanding of Pancreatic Neuroendocrine Tumours Combined with Aggressive Management Improves Outcome

Seok Ling Ong; G. Garcea; Cristina Pollard; P.N. Furness; William P. Steward; Arumugam Rajesh; Laura Spencer; David M. Lloyd; David P. Berry; A. Dennison

Background: Neuroendocrine tumours of the pancreas (PNETs) represent 1–2% of all pancreatic tumours. The terms ‘islet cell tumours’ and ‘carcinoids’ of the pancreas should be avoided. The aim of this review is to offer an overview of the history and diagnosis of PNETs followed by a discussion of the available treatment options. Methods: A search on PubMed using the keywords ‘neuroendocrine’, ‘pancreas’ and ‘carcinoid’ was performed to identify relevant literature over the last 30 years. Results: The introduction of a revised classification of neuroendocrine tumours by the World Health Organisation (WHO) in 2000 significantly changed our understanding of and approach to the management of these tumours. Advances in laboratory and radiological techniques have also led to an increased detection of PNETs. Surgery remains the only treatment that offers a chance of cure with increasing number of non-surgical options serving as beneficial adjuncts. The better understanding of the behaviours of PNETs together with improvements in tumour localisation has resulted in a more aggressive management strategy with a concomitant improvement in symptom palliation and a prolongation of survival. Conclusion: Due to their complex nature and the wide range of therapeutic options, the involvement of specialists from all necessary disciplines in a multidisciplinary team setting is vital to provide optimal treatment of this disease.


Digestive Diseases and Sciences | 2007

Nine-Year Single-Center Experience with Nonparastic Liver Cysts: Diagnosis and Management

G. Garcea; C.J. Pattenden; J. Stephenson; A. Dennison; David P. Berry

This study presents the experience with laparoscopic deroofing of nonparasitic liver cysts at a single center over a 9-year period. A total of 25 patients, undergoing 32 operations, were identified. Median cyst diameter was 10 cm for de novo cysts and 9.5 cm for recurrent cysts. Six patients had multiple cysts consistent with polycystic liver disease. In total, there were 26 laparoscopic procedures and 2 open conversions. Four procedures were commenced as open, three of which were for recurrent cysts. Minor complications were bleeding from a port site (n=1), pneumothorax (n=2), and intra-abdominal collection (n=1). One major complication of bile leak and relaparotomy occurred following an open deroofing. No major complications were recorded for laparoscopic procedures. Symptomatic recurrence of cysts occurred in four patients with simple cysts (5%) and one patient with polycystic liver disease. We conclude that laparoscopic liver cyst deroofing is an effective method of dealing with symptomatic nonparasitic liver cysts.


British Journal of Surgery | 2007

Clinical Risk Score predicts yield of staging laparoscopy in patients with colorectal liver metastases

Christopher D. Mann; C.P. Neal; Matthew S. Metcalfe; C.J. Pattenden; A. Dennison; David P. Berry

Resection offers the only realistic chance of cure for hepatic colorectal metastases. The aim of this study was to examine the potential of laparoscopy and laparoscopic intraoperative ultrasonography (IOUS) for detecting incurable disease, and to determine whether the Clinical Risk Score (CRS) is useful in selecting patients for laparoscopy before hepatic resection.


Surgical Endoscopy and Other Interventional Techniques | 2007

Assessment of pancreatic malignancy with laparoscopy and intraoperative ultrasound

Helena Doucas; C. D. Sutton; A. Zimmerman; A. Dennison; David P. Berry

BackgroundStaging laparoscopy for pancreatic malignancy is controversial. This study aimed to assess the efficacy of laparoscopy with intraoperative ultrasound in the management of patients with pancreatic carcinoma.MethodsThe study involved patients undergoing laparoscopy and intraoperative ultrasound over a period of 42 months. The entry criteria specified radiologic (computed tomography) diagnosis of pancreatic carcinoma and no evidence of metastases.ResultsThe study enrolled 100 patients (52 men and 48 women) ages 21 to 83 years (mean, 63 years). On the basis of imaging, 75 patients had lesions judged to be operable, and 25 patients had a pancreatic head lesion larger than 4 cm radiologically, considered to be unresectable, but with no evidence of metastatic disease. At laparoscopy, three patients had a normal examination, with no evidence of a pancreatic mass, and an additional seven patients had other pathology including one lymphoma, one ampullary tumor, two cases of chronic pancreatitis, and three sarcomas. Of the patients with radiologically inoperable disease, 16% had previously undetected metastases, but 24% were judged to be suitable for curative resection. Half of these patients underwent successful resection. Of the patients with radiologically operable disease, undetected liver or peritoneal metastases were found in 20% of the body or tail lesions and in 26% of the pancreatic head lesions. Of the pancreatic head tumors, 12% were found to be larger than 4 cm and therefore unsuitable for curative resection. Consequently, only 53% were confirmed to be suitable for resection. Of the patients explored with a view to curative resection, 42% actually underwent resection, with clearance of resection margins achieved in 77.8%.ConclusionOf the patients thought to have a resectable tumor on the basis of good quality preoperative imaging, 44% had their management approach altered after laparoscopy and avoided an open procedure. Laparoscopy should therefore be used in the preoperative staging of pancreatic tumors.

Collaboration


Dive into the A. Dennison's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

G. Garcea

Leicester General Hospital

View shared research outputs
Top Co-Authors

Avatar

David P. Berry

Leicester General Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

A. Arshad

Leicester General Hospital

View shared research outputs
Top Co-Authors

Avatar

A. Eltweri

University Hospitals of Leicester NHS Trust

View shared research outputs
Top Co-Authors

Avatar

W. Chung

Leicester General Hospital

View shared research outputs
Top Co-Authors

Avatar

J. Isherwood

Leicester General Hospital

View shared research outputs
Top Co-Authors

Avatar

C.P. Neal

Leicester General Hospital

View shared research outputs
Top Co-Authors

Avatar

D. Al-Leswas

Leicester General Hospital

View shared research outputs
Researchain Logo
Decentralizing Knowledge