Role of carcinoembryonic antigen as a marker for colorectal liver metastases.

Carcinoembryonic antigen (CEA), a marker for colorectal adenocarcinoma, can monitor disease progression and treatment response. This study aims to determine the accuracy of CEA in the detection and resectability of colorectal liver metastases. Patients with primary colorectal cancer were divided into three groups: resectable hepatic metastases (group 1), unresectable metastases (group 2), and disease-free cases (group 3). The CEA concentration was recorded pre- and post-hepatectomy in group 1 and on radiological confirmation of disease state in the other groups. It was expressed as median (95% confidence interval [CI]), with predictors of concentration determined. Group 1 (n=141) had pre-operative CEA of 8.9 (4.6-13.1), with 38.1% of patients being normal. Maximum tumour diameter correlated with CEA level (r=0.41, P<0.0001). Post-hepatectomy CEA was 2.3 (1.9-2.7; P<0.0001), with 81.1% of patients being normal. Group 2 (n=158) had CEA of 20.6 (9.4-31.9). Group 3 (n=361) had CEA of 2.0 (1.8-2.2). Sensitivity of CEA pre- and post-hepatectomy was 61.2% and 69.3%, respectively, while specificity was 79.8% for both groups. Concentration was elevated in hepatic colorectal metastases but is not a marker of resectability. A CEA reduction post-resection indicates that it may be used as an indicator of treatment response, while CEA is increased by tumour burden and lesion size.

PET-CT accurately predicts the pre-operative characteristics of colorectal hepatic metastases.

BACKGROUND: Since 2002, Positron Emission Tomography (PET-CT) has been considered to be an essential pre-operative investigation in the management of colorectal liver metastases (CRLM) in our institution. This study aimed to compare characteristics of hepatic metastases on PET-CT with post-operative histological findings and pathology of the primary tumour. METHODS: All patients with CRLM, who underwent surgical intervention from 2002 to 2008, were reviewed. PET-CT and pathology reports of hepatic resections and original colorectal resections were retrieved. Patient demographics, colorectal staging, number of metastases and their maximum diameter from both PET-CT and pathology reports were recorded. Values were expressed as mean (±SD). RESULTS: 141 patients were identified. The maximum diameter on PET-CT (4.2 ± 2.6) was similar to pathology (4.8 ± 3.6; p = 0.39), with significant correlation (r = 0.72, p < 0.0001). The number of lesions on PET-CT (1.6 ± 1.0) was similar to pathology (1.7 ± 1.3; p = 0.43) with significant correlation (r = 0.80, p < 0.0001). Mean SUV max was 9.22 (±4.39), with no correlation to lesion diameter (r = 0.25, p = 0.045), but significantly increased with decreasing differentiation (p = 0.01). CONCLUSIONS: PET-CT scanning accurately detected the number of lesions and their maximum diameter, with radiological evidence of poorer differentiation. Further studies of non-surgical patients are required to assess its overall accuracy.

The role of surgery for pancreatic cancer: a 12-year review of patient outcome.

INTRODUCTION: Pancreatic cancer has a poor prognosis with <5% alive at 5 years, despite active surgical treatment. The study aim was to review patients undergoing pancreatic resection and assess the effect of clinical and pathological parameters on survival. PATIENTS AND METHODS: All patients who had undergone radical pancreatic surgery, January 1996 to December 2008, were identified from the unit database. Additional information was retrieved from the patient records. The demographic, clinical, and pathological records were recorded using Microsoft Excel. Survival was assessed using Kaplan-Meier and predictors of survival determined by multinominal logistic regression and log rank test. RESULTS: 126 patients were identified from the database. The majority (106) had a Whipple's procedure, 14 had a distal pancreatectomy and 6 had local periampullary excision. The average age of the Whipple's group of patients was 61.7 years (± 11.7) with most procedures performed for malignancy (n=100). Survival was worse with adenocarcinoma compared to all other pathologies (p=0.013), while periampullary tumours had a better prognosis compared to other locations (p=0.019). Survival decreased with poorer differentiation (p=0.001), increasing pT (p<0.001) and pN stage (p<0.001). Survival was worse with perineural (p=0.04) or lymphovascular invasion (p=0.05). A microscopic postive resection margin (R1) was associated with a worse survival (p=0.007). Tumour differentiation (p=0.001) and positive nodal status (p<0.001) were found to be independent predictors of mortality. CONCLUSION: Tumour differentiation and nodal status are important predictors of outcome. A positive resection margin is associated with a poorer survival.

Biliary complications associated with laparoscopic cholecystectomy--an analysis of common misconceptions.

BACKGROUND: Several views are expressed by surgeons on biliary complications following laparoscopic cholecystectomy as follow: most are caused by trainees; complications occur in the presence of difficult anatomy/pathology; injuries occur more proximally than at open cholecystectomy; most injuries are recognised immediately and most can be managed non-operatively. The aim of our study was to determine if these views are substantiated in clinical practice. METHODS: The mode of presentation, management and outcome of thirty-two patients referred to a hepatobiliary unit over a seven year period were analysed. RESULTS: In 72% of cases the initial operator was a consultant. Five of the 32 complications (16%) occurred in the presence of difficult anatomy/pathology. Two patients had proximal biliary tree injuries, the only mortalities (two) occurring in this group. Only 41% of injuries were detected immediately; 87% required surgical intervention, hepaticojejunostomy being the most common procedure performed (75%). CONCLUSION: Our study shows that the majority of bile duct injuries are not caused by trainees, do not occur because of unusual anatomy/pathology, do not occur in the proximal biliary tree and are not recognised at the time of operation. Most injuries ultimately require major reconstructive surgery for definitive management.

Nitric oxide regulates basal but not capsaicin-, CGRP-, or bile salt-stimulated rabbit esophageal mucosal blood flow.

BACKGROUND/AIMS: Esophageal mucosal blood flow is a dynamic phenomenon that is altered by luminal content that probably represents an important intrinsic method of defense. This study investigated the role played by endogenous nitric oxide in the regulation of esophageal mucosal blood flow at rest and in response to luminal capsaicin, a specific stimulant for visceral afferent nerves, as well as calcitonin gene-related peptide, and the bile salt deoxycholate. METHODS: The L-arginine analog L-NAME was used to block nitric oxide synthesis. Radiolabeled microspheres were used to measure blood flow in a well-characterized rabbit model. Phenylephrine was used to mimic the hemodynamic effects of L-NAME to show the specificity of positive findings. RESULTS: Administration of L-NAME led to a significant reduction in mucosal blood flow at rest, an effect that was not shared by phenylephrine. The blood flow responses to luminal capsaicin, intra-arterial calcitonin gene-related peptide (CGRP), and luminal deoxycholate, however, were not diminished in the presence of L-NAME. CONCLUSIONS: Although nitric oxide may play a role in the maintenance of normal resting esophageal mucosal blood flow, the reactive responses to luminal capsaicin, luminal deoxycholate, and intra-arterial CGRP are not nitric oxide dependent.

Esophageal mucosal blood flow: a central role for calcitonin gene-related peptide.

BACKGROUND: Esophageal mucosal blood flow is a dynamic phenomenon dependent on luminal content. Reactive hyperemia, likely a factor in mucosal protection, follows luminal exposure to noxious substances, including bile. The mediators of this response are unknown, although the likelihood is that visceral afferent nerves play a major role. The purpose of this study was to determine whether substance P, calcitonin gene-related peptide (CGRP), or adenosine could mediate this reactive blood flow response. METHODS: Esophageal mucosal blood flow was studied in a rabbit model with the radiolabeled microsphere technique. The effect of intraarterial infusion of CGRP and substance P and intravenous adenosine was studied. Subsequently, the hyperemic response to luminal deoxycholate was measured in the presence of antagonists to CGRP, substance P, and adenosine. Immunohistochemical studies were performed to determine the distribution of CGRP and substance P in the esophagus. RESULTS: CGRP proved to be a potent stimulus to mucosal blood flow. The presence of a CGRP antagonist reduced mucosal blood flow at baseline and after exposure to deoxycholate. Antagonists to substance P and adenosine had no effect on baseline and deoxycholate-stimulated blood flow. CONCLUSIONS: CGRP is likely a major mediator involved in the regulation of esophageal mucosal blood flow.

Nitric oxide mediates the blood flow response to intravenous adenosine in the rabbit.

The objective of this study was to determine if nitric oxide mediates the effects of exogenously administered adenosine on peripheral blood flow. An intravenous infusion of adenosine (1.0 mumol/kg/min) into male New Zealand white rabbits caused an increase in blood flow, measured using radiolabeled microspheres, throughout the gastrointestinal tract, as well as in the heart and kidneys. Prior administration of nitro-L-arginine methyl ester (L-NAME) 10 mg/kg i.v. completely blocked the hyperemic effect of adenosine on all organs studied. Administration of L-arginine (300 mg/kg bolus and 50 mg/kg/min infusion) together with L-NAME restored the hyperemic effect of adenosine. This phenomenon was specified to the L-arginine/nitric oxide pathway in that a similar pressor response induced by phenylephrine (1.5 micrograms/kg/min) did not block the effects of adenosine. We conclude that the peripheral vasodilator response to intravenously administered adenosine in the rabbit is mediated by nitric oxide.

Initial experience of laparoscopic cholecystectomy in a district hospital.

Fifty-five consecutive unselected patients were submitted for laparoscopic cholecystectomy, and the procedure completed laparoscopically in fifty cases. The outcome is presented with particular reference to the duration of surgery, postoperative pain and nausea, the length of hospital stay and the time taken to recover normal activities. This technique is shown to have major advantages over conventional gallbladder surgery for the majority of patients.