Magnetic resonance colonography vs computed tomography colonography for the diagnosis of colorectal cancer: an indirect comparison

OBJECTIVE: The primary aim of this study was to use meta-regression techniques to compare the diagnostic accuracy of computed tomography colonography (CTC) and magnetic resonance colonography (MRC), compared with conventional colonoscopy for patients presenting with colorectal cancer (CRC). METHOD: Quantitative meta-analysis was performed using prospective studies reporting comparative data between CTC and MRC individually to conventional colonoscopy. Study quality was assessed and sensitivities, specificities, diagnostic odds ratios (DOR) were calculated. Summary receiver operating characteristic (SROC) curves and sensitivity analysis were utilized. Meta-regression was used to indirectly compare the two modalities following adjustment for patient and study characteristics. RESULTS: Overall sensitivity and specificity for CTC (0.96, 95% CI 0.92-0.99; 1.00, 95% CI 0.99-1.00 respectively) and MRC (0.91, 95% CI 0.79-0.97; 0.98, 95% CI 0.96-0.99 respectively) for the detection of CRC was similar. Meta-regression analysis showed no significant difference in the diagnostic accuracy of both modalities (beta=-0.64, P=0.37 and 95% CI of 0.12-2.39). Both tests showed high area under the SROC curve (CTC=0.99; MRC=0.98), with high DORs (CTC=1461.90, 95% CI 544.89-3922.30; MRC=576.41, 95% CI 135.00-2448.56). Factors that enhanced the overall accuracy of MRC were the use intravenous contrast, faecal tagging and exclusion of low-quality studies. No factors improved diagnostic accuracy from CTC except studies with more than 100 patients (AUC=1.00, DOR=2938.35, 95%CI 701.84-12 302.91). CONCLUSION: This meta-analysis suggested that CTC and MRC have similar diagnostic accuracy for detecting CRC. Study quality, size and intravenous/intra-luminal contrast agents affect diagnostic accuracies. For an exact comparison to be made, studies evaluating CTC, MRC and colonoscopy in the same patient cohort would be necessary.     

Heparin-bonded circuits versus nonheparin-bonded circuits: an evaluation of their effect on clinical outcomes

Heparinization of the blood contact surface in cardiopulmonary bypass circuits has been promoted as an important step in the development of open heart surgery. As it decreases the inflammatory response resulting from the extracorporeal circulation, it may have a positive effect on clinical outcomes. This meta-analysis was carried out to examine if heparin-bonded circuits (HBCs) reduce the need for blood products and improve overall clinical outcome. A systematic literature search was performed to identify randomized controlled trials reporting outcomes of HBCs compared with non-HBCs. Primary outcomes assessed were postoperative blood/blood-product transfusion and blood loss. Secondary outcomes included all-cause mortality, acute postoperative myocardial infarction, stroke, re-sternotomy for postoperative bleeding, wound infection, atrial fibrillation, duration of ventilation, intensive care unit (ICU) and hospital-length of stay (LOS). Random effects meta-analytical techniques were applied to identify differences in outcomes between the two groups. Quality of the included studies and heterogeneity were assessed. From an initial review of 762-published studies, 41-randomized trials fulfilled the inclusion criteria, leaving 3434-patients’ data for analysis. HBCs significantly decreased the incidence of blood transfusion required (OR = 0.8; 95% CI = 0.6:0.9, P = 0.004). It also significantly decreased re-sternotomy (OR = 0.6; 95% CI = 0.4:0.8, P = 0.002), duration of ventilation (WMD = −1.3 h; 95% CI = −1.9:−0.6, P < 0.001), ICU-LOS (WMD = −9.3 h; 95% CI = −14.7:−3.9, P < 0.001) and hospital-LOS (WMD = −0.5 day; 95% CI = −0.9:−0.1, P = 0.02). HBCs had no effect on other adverse events evaluated. Although HBCs showed a positive effect on some of the clinical outcomes, we identified only marginal differences for other outcomes. Further evaluation of the cost-effectiveness of this technology is required.     

Expression of an epitopic region of AspfI, an allergen/antigen/cytotoxin of Aspergillus fumigatus

The gene for an 18 kD allergen/cytotoxin of Aspergillus fumigatus was cloned in pUC-19 vector and expressed in Escherichia coli JM109. Digestion of this gene with AluI resulted in four fragments of 216bp, 120bp, 39bp and 21bp. These fragments were cloned in the Sma-I site of pUC-19. The recombinants thus, generated after transformation in E. coli JM109, were screened using monoclonal antibodies raised against the AspfI. The fusion protein containing 120 bp AluI fragment was recognised by the MoAb indicating presence of epitope(s) in the 120 bp region. The study indicates a viable strategy for identification and expression of an immunologically active domain of a major allergen/antigen of A. fumigatus for the first time.     

Preoperative embolization of hypervascular head and neck tumours

The embolization of vascular tumours of the head and neck has become an important adjunct to the surgical treatment of these tumours. A vascular tumour in the head and neck region in a surgically treatable patient may be a candidate for embolization. Palliative embolization may be the sole treatment for high risk patients. Reducing intraoperative bleeding may shorten surgery time thus decreasing morbidity and mortality. The purpose of this study is to assess the efficacy of embolization as an adjunct to surgery or as a curative measure in the management of hypervascular head and neck tumours. We retrospectively reviewed the records of 46 consecutive patients (27 men and 16 women; mean age, 37.8 years) with 48 hypervascular head and neck tumours that had undergone preoperative transarterial, direct puncture or combined mode of embolization. Diagnosis of tumours was made on the basis of findings of imaging studies. The 46 patients underwent embolization either through transarterial route, by direct puncture technique or both direct puncture and arterial route. The devascularization reached 90–95% with the use of NBCA. The amount of devascularization reached by transarterial particle embolization is a little lesser. One patient (carotid body tumour) developed mild unilateral seventh, ninth and 10th cranial nerve palsy after transarterial embolization, transient hemiparesis was seen in another patient (nasopharyngeal angiofibroma). Both patients improved completely with steroids and had no deficit on follow up. One patient developed delayed glue migration into the middle cerebral artery territory 6 h after the procedure with no reported increase in size of the lesion in the following 5 years. Preoperative embolization of hypervascular tumour of head and neck region appears to be safe and improves the chance of complete removal during surgery with minimal blood loss.     

Fluoroscopic‐guided balloon dilatation and stenting in tracheal stenosis with metallic self‐expandable stents and long‐term follow‐up results

The purpose of this study was to assess the safety and long‐term efficacy of self‐expandable stents in the treatment of benign tracheal stenosis. Nine patients (seven men) with tracheal stenosis (including one with fistula) of varied cause were treated by fluoroscopically guided balloon dilatation and stenting with self‐expandable metallic stents. The procedure was carried out under topical spray in eight patients and under general anaesthesia in one patient. The patients were followed up for a period ranging between 13 and 60 months. In eight of the nine patients, satisfactory positioning of the stent was achieved at the first instance, with immediate relief of dyspnoea. One patient with innominate artery aneurysm died 16 days after the procedure because of renal failure. At 1 month of follow up, six out of eight (75%) of our live patients were without any respiratory embarrassment. This dyspnoea‐free result reached almost 90% by the end of 1 year especially so in the fibrous strictures. Four out of the eight live patients (50%) had cough for 2 months and two (25%) had mild blood‐tinged sputum treated by inhalation and mucolytic agents. Secondary intervention was required in one patient at 1 month because of recurrent symptoms. The patient with tracheo‐oesophageal fistula required surgical intervention because of fracture of the stent. Fluoroscopically guided balloon dilatation and stenting of the tracheal stenosis is an effective non‐surgical therapy resulting in cure of fibrous strictures and palliation in cases of malignancy.