Multicentre observational study of surgical system failures in aortic procedures and their effect on patient outcomes.

BACKGROUND: Vascular surgical care has changed dramatically in recent years with little knowledge of the impact of system failures on patient safety. The primary aim of this multicentre observational study was to define the landscape of surgical system failures, errors and inefficiency (collectively termed failures) in aortic surgery. Secondary aims were to investigate determinants of these failures and their relationship with patient outcomes. METHODS: Twenty vascular teams at ten English hospitals trained in structured self-reporting of intraoperative failures (phase I). Failures occurring in open and endovascular aortic procedures were reported in phase II. Failure details (category, delay, consequence), demographic information (patient, procedure, team experience) and outcomes were reported. RESULTS: There were strong correlations between the trainer and teams for the number and type of failures recorded during 88 procedures in phase I. In 185 aortic procedures, teams reported a median of 3 (i.q.r. 2-6) failures per procedure. Most frequent failures related to equipment (unavailability, failure, configuration, desterilization). Most major failures related to communication. Fourteen failures directly harmed 12 patients. Significant predictors of an increased failure rate were: endovascular compared with open repair (incidence rate ratio (IRR) for open repair 0·71, 95 per cent c.i. 0·57 to 0·88; P = 0·002), thoracic aneurysms compared with other aortic pathologies (IRR 2·07, 1·39 to 3·08; P < 0·001) and unfamiliarity with equipment (IRR 1·52, 1·20 to 1·91; P < 0·001). The major failure total was associated with reoperation (P = 0·011), major complications (P = 0·029) and death (P = 0·027). CONCLUSION: Failure in aortic procedures is frequently caused by issues with team-working and equipment, and is associated with patient harm. Multidisciplinary team training, effective use of technology and new-device accreditation may improve patient outcomes.

Quantitative analysis of technological innovation in minimally invasive surgery.

BACKGROUND: In the past 30 years surgical practice has changed considerably owing to the advent of minimally invasive surgery (MIS). This paper investigates the changing surgical landscape chronologically and quantitatively, examining the technologies that have played, and are forecast to play, the largest part in this shift in surgical practice. METHODS: Electronic patent and publication databases were searched over the interval 1980-2011 for ('minimally invasive' OR laparoscopic OR laparoscopy OR 'minimal access' OR 'key hole') AND (surgery OR surgical OR surgeon). The resulting patent codes were allocated into technology clusters. Technology clusters referred to repeatedly in the contemporary surgical literature were also included in the analysis. Growth curves of patents and publications for the resulting technology clusters were then plotted. RESULTS: The initial search revealed 27,920 patents and 95,420 publications meeting the search criteria. The clusters meeting the criteria for in-depth analysis were: instruments, image guidance, surgical robotics, sutures, single-incision laparoscopic surgery (SILS) and natural-orifice transluminal endoscopic surgery (NOTES). Three patterns of growth were observed among these technology clusters: an S-shape (instruments and sutures), a gradual exponential rise (surgical robotics and image guidance), and a rapid contemporaneous exponential rise (NOTES and SILS). CONCLUSION: Technological innovation in MIS has been largely stagnant since its initial inception nearly 30 years ago, with few novel technologies emerging. The present study adds objective data to the previous claims that SILS, a surgical technique currently adopted by very few, represents an important part of the future of MIS.

Development of a virtual reality training curriculum for phacoemulsification surgery.

PURPOSE: Training within a proficiency-based virtual reality (VR) curriculum may reduce errors during real surgical procedures. This study used a scientific methodology to develop a VR training curriculum for phacoemulsification surgery (PS). PATIENTS AND METHODS: Ten novice-(n) (performed <10 cataract operations), 10 intermediate-(i) (50-200), and 10 experienced-(e) (>500) surgeons were recruited. Construct validity was defined as the ability to differentiate between the three levels of experience, based on the simulator-derived metrics for two abstract modules (four tasks) and three procedural modules (five tasks) on a high-fidelity VR simulator. Proficiency measures were based on the performance of experienced surgeons. RESULTS: Abstract modules demonstrated a 'ceiling effect' with construct validity established between groups (n) and (i) but not between groups (i) and (e)-Forceps 1 (46, 87, and 95; P<0.001). Increasing difficulty of task showed significantly reduced performance in (n) but minimal difference for (i) and (e)-Anti-tremor 4 (0, 51, and 59; P<0.001), Forceps 4 (11, 73, and 94; P<0.001). Procedural modules were found to be construct valid between groups (n) and (i) and between groups (i) and (e)-Lens-cracking (0, 22, and 51; P<0.05) and Phaco-quadrants (16, 53, and 87; P<0.05). This was also the case with Capsulorhexis (0, 19, and 63; P<0.05) with the performance decreasing in the (n) and (i) group but improving in the (e) group (0, 55, and 73; P<0.05) and (0, 48, and 76; P<0.05) as task difficulty increased. CONCLUSION: Experienced/intermediate benchmark skill levels are defined allowing the development of a proficiency-based VR training curriculum for PS for novices using a structured scientific methodology.

Systematic review of predictors of surgical performance.

BACKGROUND: Selection criteria for surgical training are not scientifically proven. There is a need to define which attributes predict future surgical performance. The aim of this study was to examine the predictive value of specific attributes that impact on surgical performance. METHODS: All studies assessing the predictive power of specified attributes with regard to outcome measures of surgical performance in MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and Educational Resources Information Centre databases, and bibliographies of selected articles from 1950 to November 2010 were considered for inclusion by two independent reviewers. Information on study identifiers, participant characteristics, predictors assessed, evaluation methods for predictors, outcome measures, results and statistical analysis was collected. Quality assessment was carried out using the Hayden criteria. RESULTS: Visual-spatial perception correlated with both subjective and objective assessments of surgical performance, including rate of skill acquisition. Visual-spatial perception did not correlate with operative ability in experts, although it did with operative ability at the end of a training programme. Psychomotor aptitude, assessed collectively, correlated with rate of skill acquisition. Academic achievement predicted completion of a training programme and passing end-of-training examinations, but did not predict clinical performance during the training programme. CONCLUSION: Intermediate- and high-level visual-spatial perception, as well as psychomotor aptitude, can be used as criteria for assessing candidates for surgical training. Academic achievement is an effective predictor of successful completion of training programmes and should continue to form part of the assessment of surgical candidates.

Inflammation of the residual appendix stump: a systematic review.

AIM: A systematic review of the literature was undertaken to examine reported cases of stump appendicitis (SA) to determine the relationship between SA and the original operative strategy (open vs laparoscopic), and to evaluate the clinical features and diagnosis. METHOD: A Pub-med search was conducted to identify cases of appendicitis of a residual stump following appendicectomy. Two original cases of SA following laparoscopic appendicectomy treated in our own hospitals are also included in the analysis. Sixty cases of SA reported in the English medical literature were analysed. RESULTS: The interval from the original appendicectomy ranged from 4 days to 50 years. SA followed appendicectomy in 58% of open and 31.6% of laparoscopic procedures. SA was frequently misdiagnosed as constipation or gastroenteritis, with a significant delay to surgery. Computerized tomography diagnosed SA in 46.6% of cases. Perforation with gangrene of the stump occurred in 40%. CONCLUSION: Stump appendicitis is rare. It may complicate open or laparoscopic appendicectomy. A high level of suspicion should be maintained in any patient with right sided abdominal pain and a history of prior appendicectomy.

Patient-specific endovascular simulation influences interventionalists performing carotid artery stenting procedures.

OBJECTIVE: The ability to perform patient-specific simulated rehearsal of complex endovascular interventions is a technological advance with potential benefits to patient outcomes. This study aimed to evaluate whether patient-specific rehearsal of a carotid artery stenting (CAS) procedure has an influence on tool selection and the use of fluoroscopy. METHODS: Following case note and computed tomography (CT) angiographic review of a real patient case, subjects performed the CAS procedure on a virtual reality simulator. Endovascular tool requirements and fluoroscopic angles were evaluated with a pre- and post-case questionnaire. Participants also rated the simulation from 1 (poor) to 5 (excellent). RESULTS: Thirty-three endovascular physicians with varying degrees of CAS experience were recruited: inexperienced (5-20 CAS procedures) n = 11, moderately (21-50 CAS procedures) n = 7 or highly experienced (>50 CAS procedures) n = 15. For all participants, 96 of a possible 363 changes (26%) were observed from pre- to post-case questionnaires. This was most notable for optimal fluoroscopy C-arm position 15/33 (46%), choice of selective catheter 13/33 (39%), choice of sheath or guiding catheter 11/33 (33%) and balloon dilatation strategy 10/33 (30%). Experience with the CAS procedure did not influence the degree of change significantly (p > 0.05), and all groups exhibited a considerable modification in tool and fluoroscopy preference. The model was considered realistic and useful as a tool to practice a real case (median score 4/5). CONCLUSION: Patient-specific simulated rehearsal of a complex endovascular procedure strongly influences tool selection and fluoroscopy preferences for the real case. Further research has to evaluate how this technology may transfer from in vitro to in vivo and if it can reduce the radiation dose and the number of endovascular tools used and improve outcomes for patients in the clinical setting.

Elective colonic surgery for cancer in the elderly: an investigation into postoperative mortality in English NHS hospitals between 1996 and 2007.

BACKGROUND: This study was primarily aimed to quantify perioperative mortality risk in elderly patients undergoing elective colonic resectional surgery. In addition, the safety of minimally invasive colonic surgery in this patient group was evaluated. METHODS: All patients aged > 75 undergoing elective colonic resection for colorectal malignancy between 1996 and 2007 in English NHS hospitals were included from the Hospital Episode Statistics (HES) dataset. RESULTS: Between the study dates, 28,746 patients > 75 years underwent elective colonic resection. The national annual number of colonic excisions carried out amongst elderly patients increased from 2188 patients in 1996/7 to 3240 patients in 2006/7. Following adjustment for gender, comorbidity and surgical approach, advancing age was an independent predictor for 30-day mortality (OR 2.47 for patients aged 85-89 vs 75-79, P < 0.001). Use of laparoscopy was a significant predictor of reduced perioperative mortality (OR 0.56, P = 0.003) once adjusted for advancing age, gender and comorbidity. Comparison of 30-day and 1-year postoperative mortality following elective colonic resection in patients aged 90 revealed a large excess of patients dying outside of the immediate perioperative period (10.1% and 26.2% for proximal cancers, respectively; 12.9% and 36.1% for distal colonic resections, respectively). CONCLUSIONS: Advancing age is an independent risk factor for postoperative death in elderly patients undergoing elective colonic resection for cancer. The risk of death in the elderly is extremely high and surgical decision-making should incorporate the mortality risk that occurs outside the immediate perioperative period. In this national series, patients selected for a laparoscopic procedure were at lower risk of perioperative death than those undergoing the conventional approach.

Quality control and assurance in functional near infrared spectroscopy (fNIRS) experimentation.

Functional near infrared spectroscopy (fNIRS) is a rapidly developing neuroimaging modality for exploring cortical brain behaviour. Despite recent advances, the quality of fNIRS experimentation may be compromised in several ways: firstly, by altering the optical properties of the tissues encountered in the path of light; secondly, through adulteration of the recovered biological signals (noise) and finally, by modulating neural activity. Currently, there is no systematic way to guide the researcher regarding these factors when planning fNIRS studies. Conclusions extracted from fNIRS data will only be robust if appropriate methodology and analysis in accordance with the research question under investigation are employed. In order to address these issues and facilitate the quality control process, a taxonomy of factors influencing fNIRS data have been established. For each factor, a detailed description is provided and previous solutions are reviewed. Finally, a series of evidence-based recommendations are made with the aim of improving consistency and quality of fNIRS research.

Patient-specific simulation for endovascular procedures: qualitative evaluation of the development process.

BACKGROUND: Recent advancements in simulation permit patient-specific rehearsal of carotid artery stenting procedures. This study evaluates the feasibility of transferring patient-specific CT data into the simulator, creating a 3D reconstruction and performing a rehearsal. The face validity of the model was assessed. METHODS/RESULTS: By thematic analysis of qualitative data, an algorithm was generated, focusing on simulation set-up, time of data transfer, software/compatibility issues and problem-solving strategies. The face validity of the simulated case was evaluated by 15 expert interventionalists: realism (median 4/5), training potential (median 4/5) and pre-procedure rehearsal potential for challenging CAS cases (median 4/5) were rated highly. CONCLUSIONS: Setting up a procedure rehearsal is feasible and reproducible for different patients in different hospital settings without major software compatibility issues. The time to create a 3D reconstruction of patient-specific CT data is a major factor in the total time necessary to set up a rehearsal. The face validity is highly rated by experts.

Laparoscopically assisted vs. open elective colonic and rectal resection: a comparison of outcomes in English National Health Service Trusts between 1996 and 2006.

PURPOSE: This study was designed to compare outcomes after elective laparoscopic and conventional colorectal surgery over a ten-year period using data from the English National Health Service Hospital Episode Statistics database. METHODS: All elective colonic and rectal resections carried out in English Trusts between 1996 and 2006 were included. Univariate and multivariate analyses were used to compare 30 and 365-day mortality rates, 28-day readmission rates, and length of stay between laparoscopic and open surgery. RESULTS: Between the study dates 3,709 of 192,620 (1.9%) elective colonic and rectal resections were classified as laparoscopically assisted procedures. The 30-day and 365-day mortality rates were lower after laparoscopic resection than after open surgery (P < 0.05). After correction for age, gender, diagnosis, operation type, comorbidity, and social deprivation, laparoscopic surgery was a strong determinant of reduced 30-day (odds ratio, 0.57; 95% confidence interval, 0.44-0.74; P < 0.001) and one-year (odds ratio, 0.53; 95% confidence interval, 0.42-0.67; P < 0.001) mortality. Similarly, multivariate analysis confirmed that laparoscopic surgery was independently associated with reduced hospital stay (P < 0.001). Patients who received rectal procedures for malignancy, however, were more likely to be readmitted if laparoscopy rather than by a traditional method was used (11.9% vs. 9.1%, P = 0.003). CONCLUSION: In the present study, patients selected for laparoscopic colorectal surgery were associated with reduced postoperative mortality when compared with those undergoing the conventional technique. This finding merits further investigation.

Concurrent colorectal malignancy and abdominal aortic aneurysm: a multicentre experience and review of the literature.

OBJECTIVES: There is lack of consensus regarding concurrent vs. staged approaches, and the prioritisation of staged procedures in cases presenting with colorectal carcinoma (CRC) and abdominal aortic aneurysm (AAA) synchronously. We aim to present our experience, review the literature on this therapeutic dilemma and examine the role of endovascular aortic repair (EVAR). DESIGN, MATERIALS AND METHODS: An observational study of the experience of two centres and a systematic review of the published literature. RESULTS: Twenty-four patients were identified from the prospective databases of two tertiary referral centres between 2001 and 2006. Intervention for both malignancy and aneurysm was performed in 13 patients. In 10 patients, cancer resection was performed initially and was followed by open aneurysm repair (n=3) or EVAR (n=7). Two patients (AAA diameters: 7.0 and 8.0cm) underwent EVAR prior to colonic resection. One patient was selected for synchronous surgery. There were no interval AAA ruptures, graft infection or postoperative mortalities. Literature review identified 269 such cases; of these 101 were treated by combined surgery. In staged surgery, there were nine interval aneurysmal ruptures and one aortic graft infection. CONCLUSIONS: In our experience, staged management can be undertaken, without interval aneurysmal rupture. EVAR has an evolving role in preventing delay in CRC management, in high-risk patients, and during combined intervention.

Validation of orthopaedic bench models for trauma surgery.

The aim of this study was to validate the use of three models of fracture fixation in the assessment of technical skills. We recruited 21 subjects (six experts, seven intermediates, and eight novices) to perform three procedures: application of a dynamic compression plate on a cadaver porcine model, insertion of an unreamed tibial intramedullary nail, and application of a forearm external fixator, both on synthetic bone models. The primary outcome measures were the Objective Structural Assessment of technical skills global rating scale on video recordings of the procedures which were scored by two independent expert observers, and the hand movements of the surgeons which were analysed using the Imperial College Surgical Assessment Device. The video scores were significantly different for the three groups in all three procedures (p < 0.05), with excellent inter-rater reliability (alpha = 0.88). The novice and intermediate groups specifically were significantly different in their performance with dynamic compression plate and intramedullary nails (p < 0.05). Movement analysis distinguished between the three groups in the dynamic compression plate model, but a ceiling effect was demonstrated in the intramedullary nail and external fixator procedures, where intermediates and experts performed to comparable standards (p > 0.6). A total of 85% (18 of 21) of the subjects found the dynamic compression model and 57% (12 of 21) found all the models acceptable tools of assessment. This study has validated a low-cost, high-fidelity porcine dynamic compression plate model using video rating scores for skills assessment and movement analysis. It has also demonstrated that Synbone models for the application of and intramedullary nail and an external fixator are less sensitive and should be improved for further assessment of surgical skills in trauma. The availability of valid objective tools of assessment of surgical skills allows further studies into improving methods of training.

WITHDRAWN: Meta-analysis: the use of adhesion prevention membranes in abdominal surgery.

Ahead of Print article withdrawn by publisher.

Recombinant activated factor VII: a solution to refractory haemorrhage in vascular surgery?

OBJECTIVES: Post-operative haemorrhage is a recognised complication and independent predictor of outcome in complex vascular surgery. The off-license administration of activated Recombinant Factor VII (rFVIIa) to treat haemorrhage in other surgical settings has been investigated, but concerns over potential adverse events have limited its use in vascular surgery. This article reports rFVIIa's method of action and systematically reviews rFVIIa's role in complex vascular surgery. METHODS: A systematic literature search identified articles reporting on rFVIIa administration within vascular surgery patients. Patient-specific data regarding transfusion requirements was extracted and pooled statistical analysis performed. RESULTS: 15 articles reporting 43 patients were identified. RFVIIa has been administered in open and endovascular procedures and in both elective and emergency settings. Major aortic surgery accounted for 75% of cases. The range of rFVIIa administered as a cumulative dose was large, as was the variation in initial dose. Transfusion data from 9 patients was pooled and analysed. Significant differences were found between pre- and post- rFVIIa for packed red cell transfusions (mean 29.2 vs. 8.2, p=0.015). Intra-arterial thrombosis was reported in 3 cases. CONCLUSIONS: RFVIIa may reduce haemorrhage in selected vascular surgical patients. Randomized controlled trials are justified to definitively investigate its role within this setting.

Visual search behaviour in skeletal radiographs: a cross-specialty study.

AIM: To determine whether experience improves the consistency of visual search behaviour in fracture identification in plain radiographs, and the effect of specialization. MATERIAL AND METHODS: Twenty-five observers consisting of consultant radiologists, consultant orthopaedic surgeons, orthopaedic specialist registrars, orthopaedic senior house officers, and accident and emergency senior house officers examined 33 skeletal radiographs (shoulder, hand, and knee). Eye movement data were collected using a Tobii 1750 eye tracker with levels of diagnostic confidence collected simultaneously. Kullback-Leibler (KL) divergence and Gaussian mixture model fitting of fixation distance-to-fracture were used to calculate the consistency and the relationship between discovery and reflective visual search phases among different observer groups. RESULTS: Total time spent studying the radiograph was not significantly different between the groups. However, the expert groups had a higher number of true positives (p<0.001) with less dwell time on the fracture site (p<0.001) and smaller KL distance (r=0.062, p<0.001) between trials. The Gaussian mixture model revealed smaller mean squared error in the expert groups in hand radiographs (r=0.162, p=0.07); however, the reverse was true in shoulder radiographs (r=-0.287, p<0.001). The relative duration of the reflective phase decreases as the confidence level increased (r=0.266, p=0.074). CONCLUSIONS: Expert search behaviour exhibited higher accuracy and consistency whilst using less time fixating on fracture sites. This strategy conforms to the discovery and reflective phases of the global-focal model, where the reflective search may be implicated in the cross-referencing and conspicuity of the target, as well as the level of decision-making process involved. The effect of specialization appears to change the search strategy more than the effect of the length of training.

Diagnostic precision of magnetic resonance imaging for preoperative prediction of the circumferential margin involvement in patients with rectal cancer.

OBJECTIVE: Circumferential margin involvement (CMI) is an important prognostic indicator for patients with rectal cancer. This meta-analysis aims at evaluating the diagnostic precision of magnetic resonance imaging (MRI) for the preoperative evaluation of CMI in patients with rectal cancer. METHOD: Quantitative meta-analysis was performed comparing MRI against histology after total mesorectal excision. Sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for each study. Summary receiver operating characteristic (SROC) curves and subgroup analysis were undertaken. Study quality and heterogeneity were evaluated. Meta-regression meta-analysis was used to evaluate the significance of the difference in relative DORs. RESULTS: Nine studies evaluating 529 patients were included. Pooled results showed an overall sensitivity and specificity for MRI detecting CMI preoperatively of 94% and 85% respectively. The SROC analysis demonstrated an overall weighted area under the curve (AUC) of 0.92 (DOR 57.21, 95% CI 18.21-179.77), without significant heterogeneity between the studies (Q-value 14.66, P = 0.06). Good study quality further increased the sensitivity and specificity of MRI. The use of a 1.5 Tesla coil, a phased array coil and the inclusion of two interpreters also resulted in high preoperative diagnostic precision. Meta-regression meta-analysis showed a significant difference in the DOR for studies published in or since 2003 (P = 0.019). CONCLUSION: Magnetic resonance imaging can accurately predict CMI preoperatively for rectal cancer in single units and this is reproducible across different centres. This strategy has important implications for selection of patients for adjuvant therapy prior to surgery.

Meta-analysis of short-term and long-term outcomes of J, W and S ileal reservoirs for restorative proctocolectomy.

OBJECTIVE: The choice of ileal pouch reservoir has been a contentious subject with no consensus as to which technique provides better function. This study aimed to compare short- and long-term outcomes of three ileal reservoir designs. METHOD: Comparative studies published between 1985 and 2000 of J, W and S ileal pouch reservoirs were included. Meta-analytical techniques were employed to compare postoperative complications, pouch failure, and functional and physiological outcomes. Quality of life following surgery was also assessed. RESULTS: Eighteen studies, comprising 1519 patients (689 J pouch, 306 W pouch and 524 S pouch) were included. There was no significant difference in the incidence of early postoperative complications between the three groups. The frequency of defecation over 24 h favoured the use of either a W or S pouch [J vs S: weighted mean difference (WMD) 1.48, P < 0.001; J vs W: WMD 0.97, P = 0.01]. The S pouch was associated with an increased need for pouch intubation (S vs J: OR 6.19, P = 0.04). The use of a J pouch was associated with a significantly higher prevalence of use of anti-diarrhoeal medication (J vs S: OR 2.80, P = 0.01; J vs W: OR 3.55, P < 0.001). CONCLUSION: All three reservoirs had similar perioperative complication rates. The S pouch was associated with the need for anal intubation. There was less frequency and less need for antidiarrhoeal agents with the W rather than the J pouch.

Apoptosis and chemo-resistance in colorectal cancer.

Systemic chemotherapy plays an integral part in treating advanced colorectal cancer. However 50% of patients respond poorly or have disease progression due to resistance to chemotherapeutic agents. This article reviews the pathways that regulate apoptosis, apoptotic mechanisms through which chemotherapeutic agents mediate their effect and how deregulation of apoptotic proteins may contribute to chemo-resistance. Also discussed are potential therapeutic strategies designed to target these proteins and thereby improve response rates to chemotherapy in colorectal cancer.

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.

Comparison of colonic stenting and open surgery for malignant large bowel obstruction.

BACKGROUND: Colonic stents potentially offer effective palliation for those with bowel obstruction attributable to incurable malignancy, and a "bridge to surgery" for those in whom emergency surgery would necessitate a stoma. The current study compared the outcomes of stents and open surgery in the management of malignant large bowel obstruction. METHODS: A literature search of the Medline, Ovid, Embase and Cochrane databases was performed to identify comparative studies reporting outcomes on colonic stenting and surgery for large bowel obstruction. Random effects meta-analytical techniques were applied to identify differences in outcomes between the two groups. Sensitivity analysis of high quality studies, those reporting on more than 35 patients, those solely concerning colorectal cancer and studies performing intention to treat analysis was undertaken to evaluate the study heterogeneity. RESULTS: A total of 10 studies satisfied the criteria for inclusion, with outcomes reported for 451 patients. Stent insertion was attempted for 244 patients (54.1%), and proved successful for 226 (92.6%). The length of hospital stay was shorter by 7.72 days in the stent group (p < 0.001), which also had lower mortality (p = 0.03) and fewer medical complications (p < 0.001). Stoma formation at any point during management was significantly lower than in the stent group (odds ratio, 0.02; p < 0.001), and "bridging to surgery" did not adversely influence survival. CONCLUSIONS: Colonic stenting offers effective palliation for malignant bowel obstruction, with short lengths of hospital stay and a low rate for stoma formation, but data on quality of life and economic evaluation are limited. There is no evidence of differences in long-term survival between those who have stents followed by subsequent resection and those undergoing emergency bowel resection.