Wrong Segment Research Articles

Virtual reality and 3D printing improve preoperative visualization of 3D liver reconstructions-results from a preclinical comparison of presentation modalities and user's preference.

BackgroundPreoperative three-dimensional (3D) reconstructions for liver surgery planning have been shown to be effective in reduction of blood loss and operation time. However, the role of the ‘presentation modality’ is not well investigated. We present the first study to compare 3D PDFs, 3D printed models (PR) and virtual reality (VR) 3D models with regard to anatomical orientation and personal preferences in a high volume liver surgery center.MethodsThirty participants, 10 medical students, 10 residents, 5 fellows and 5 hepatopancreatobiliary (HPB) experts, assigned the tumor-bearing segments of 20 different patient’s individual liver reconstructions. Liver models were presented in a random order in all modalities. Time needed to specify the tumor location was recorded. In addition, a score was calculated factoring in correct, wrong and missing segment assignments. Furthermore, standardized test/questionnaires for spatial thinking and seeing, vegetative side effects and usability were completed.ResultsParticipants named significantly more correct segments in VR (P=0.040) or PR (P=0.036) compared to PDF. Tumor assignment was significantly shorter with 3D PR models compared to 3D PDF (P<0.001) or VR application (P<0.001). Regardless of the modality, HPB experts were significantly faster (24±8 vs. 35±11 sec; P=0.014) and more often correct (0.87±0.12 vs. 0.83±0.15; P<0.001) than medical students. Test results for spatial thinking and seeing had no influence on time but on correctness of tumor assignment. Regarding usability and user experience the VR application achieved the highest scores without causing significant vegetative symptoms and was also the most preferred method (n=22, 73.3%) because of the multiple functions like scaling and change of transparency. Ninety percent (n=27) stated that this application can positively influence the operation planning.Conclusions3D PR models and 3D VR models enable a better and partially faster anatomical orientation than reconstructions presented as 3D PDFs. User’s preferred the VR application over the PR models and PDF. A prospective trial is needed to evaluate the different presentation modalities regarding intra- and postoperative outcomes.

Pre-colectomy location and TNM staging of colon cancer by the computed tomography colonography: a diagnostic performance study

BackgroundThe Chinese Society of Clinical Oncology guidelines 2018 and the recent update of that (version 2020) recommends accurate examination before major treatment for decision(s) in cases of colon cancer. Also, the difficulty in the identification of the lesion during colectomy may lead to resection of a wrong segment of the colon or a more extensive resection than planned. Accurate pre-colectomy local staging of colon cancer is required to make decisions for treatment of colon cancer. The objective of the study was to evaluate the diagnostic performance of the computed tomography colonography (CTC) for pre-colectomy tumor location and tumor, node, and metastasis (TNM) staging of colon cancer.MethodsData of preoperative colonoscopies, CTC, surgeries, and surgical pathology of a total of 269 patients diagnosed with colon cancer by colonoscopy and biopsy and underwent pre-colectomy location and TNM staging by CTC were collected and analyzed. The consistency between the radiological and the surgery/surgical-pathological for location and TN stages of colon tumor were estimated with the weighted kappa or kappa coefficient (κ) at 95% confidence interval (CI).ResultsCTC detected 261 (93%) and colonoscopy detected 201 (72%) correct locations of tumors. Sensitivity and accuracy of CTC for detection of location of colon tumors were 100% and 92.58% (κ = 0.89; 95% Cl: 0.83–0.95). 72.48% sensitivity, 90.64% specificity, and 83.57% accuracy were reported for CTC in differentiation of tumors confined to the colon wall (T1/T2) from advanced tumors (T3/T4) (κ = 0.69, 95% Cl: 0.51–0.75). 81.01% sensitivity, 89.11% specificity, and 83.93% accuracy of CTC was reported for differentiation of tumors between low–intermediate risk and high risk (κ = 0.68, 95% Cl: 0.53–0.75). 69.31% sensitivity, 66.15% specificity, and 67.14% accuracy of CTC were reported for N staging of tumors (κ = 0.41, 95% Cl: 0.59–0.69).ConclusionsCTC has high diagnostic parameters for pre-colectomy location and T staging of colon tumors except patients of colon cancer who received neoadjuvant chemotherapy.Level of EvidenceIII.Technical Efficacy Stage2.

Endoscopic Preoperative Tattooing and Marking in the Gastrointestinal Tract: A Systematic Review of Alternative Methods.

Background: An accurate and reliable localization of endoluminal gastrointestinal (GI) lesions is crucial, particularly during minimally invasive surgery. As an extreme consequence, a misdetected GI lesion can lead to the resection of the wrong segment, especially in colorectal surgery. A preoperative endoscopic marking is recommended in case of GI lesions, which are expected to be difficult to detect from the serosal side. In clinical practice, three preoperative endoscopic marking methods are currently used: India ink, SPOT™, and endoclips with intraoperative fluoroscopy. All of them have substantial limitations. This has encouraged research on alternative solutions. Methods: In the current systematic review, animal and clinical studies about alternative preoperative endoscopic marking methods of GI lesions were analyzed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results: Thirty studies were found using PubMed/MEDLINE, EMBASE/Ovid, and the Cochrane Library for the qualitative analysis. Conclusion: Although several smart solutions have been proposed and tested successfully, all of them seem to have a substantial drawback related either to scarce stability on the marking site or potential spreading on the bowel wall or diffusion into the surgical planes.

PIVOTALboost Trial contouring RTQA.

373 Background: The PIVOTALboost trial (ISRCTN80146950) recruits patients with intermediate and high risk, localised prostate cancer; it tests the role of pelvic node radiotherapy and the effectiveness of a focal intra-prostate IMRT boost. Prior to opening to recruitment a contouring QA program was designed aiming to improve consistency in clinical outlining. Methods: Intra-prostatic boosting was a new treatment method for all but 3 trial centers. Guidelines for boost contouring and pelvic node outlining were circulated. Clinicians were sent two different cases with the clinical case description, biopsy details, the diagnostic pre-biopsy multi-parametric MRI (T2W and DWI sequences) and planning CT and MRI scans. They were asked to contour prostate, seminal vesicle (CTVp, CTVpsv), lymph node (CTVn) for 1 case and boost volume (GTVpb) for both cases. The 3 lead trial clinicians contoured the cases independently, agreed on gold standard outlines and criteria for failing the submission. Center’ benchmark case submissions were reviewed and standardized feedback forms returned to each clinician. General issues were addressed during a trial launch workshop. Results: There was good agreement of the contours for CTVp, CTVpsv and CTVn between the 3 lead clinicians for the gold standard; more discussions were required to agree GTVpb. Criteria for re-submission were: contours &gt;6mm beyond or &gt;3mm inside the superior and inferior level, included OARs, excluded SV base or extracapsular extension. In addition, for GTVpb, the wrong segment, extension outside CTVp, outlining abnormalities &lt;5mm in diameter or a volume &gt; or &lt; 50% of the gold standard. 35 center and 54 clinicians submitted outlines: for CTVp/psv 24/54 failed, CTVn 14/54 failed, GTVpb 23/48 failed (6 investigators did not submit a volume). All center passed the re-submission; for the on trial outlining review, 9 centres have not recruited a patient for the on trial review process, 18 passed and 8 failed. Conclusions: Errors and inconsistencies were common in the benchmark outlining exercises for the trial. Individual feedback, guidelines and clinical support has reduced outlining variations without delaying the opening of the trial; it has helped to standardize contouring and engage clinicians in the trial process. Clinical trial information: 80146950.

Radioisotope-guided localization and resection of non-palpable focal lesion of the rib.

Excisional biopsy of non-palpable rib tumors still represents a challenge for thoracic surgeons: in fact primary or metastatic tumors originating from a rib can be difficult to localize topographically at the time of excisional biopsy, thus potentially resulting in inappropriately placed skin incisions, incomplete tumor excision or even in wrong rib or segment resection (1).

Using CyclePhilly data to assess wrong-way riding of cyclists in Philadelphia

ProblemThe increasing use of smartphones and low cost GPS have provided new sources for collecting data and using them to explain travel behavior. This study aims to use data collected from a smartphone application (CyclePhilly) to explain wrong-way riding behavior of cyclists on one-way segments to help better identify the demographic and network factors influencing the wrong-way riding decision making. MethodsThe data used in this study consist of two different sources: (a) Route trips data downloaded from the CyclePhilly Website contained trips detailed up to segment level, collected from May 2014 to April 2016 (12,202 trips by 300 unique users); and (b) Open Street Maps (OSM). Using ArcGIS, we calculate detour routes for each wrong way segment. We then built a mixed logistic regression model to identify the trip and riders' characteristics affecting wrong-way riding behavior. Next, we explore the characteristics of road facilities associated with wrong-way riding behavior. Results and discussionOnly 2.7% of travel distance is wrong-way, yet 42% of trips include a wrong-way segment. Commute trips have a higher chance of wrong-way riding. The longer the trips also include more wrong-way riding. Segments with higher detour ratios (ratio of distance with a detour to the wrong-way distance) are found to be associated with more wrong-way behavior. Compared to roads with no bike lane, roads with sharrow markings and buffered bike lane discourage wrong way riding. Practical applicationsThis study proposes new methods that can be adapted to use naturalistic and probe data and analyze city-wide aberrant riders' behavior. These help planners and engineers choose between various types of bike infrastructure. Wrong-way riding is one application that can be investigated, but probe bicycle datasets provide unprecedented resolution and volume of data that will allow for more sophisticated safety and planning analyses.

Shocking fault component of abnormal sound signal in the fault engine extract method based on linear superposition method and cross-correlation analysis

An extracted fault component of an abnormal sound is useful for faulty diagnosis. The existing fault component extracting approaches based on time–frequency analysis should filter the original signal to eliminate the background noise. However, these approaches will significantly change the fault component. In this article, a method for extracting the fault component of an abnormal sound signal is presented. This method is based on the linear superposition method and cross-correlation analysis. The method can eliminate the background noise and acquire the waveform of fault component. According to the feature of the shocking fault component, the acquired signal was intercepted into several segments, and the cross-correlation analysis was adopted to remove the wrong segment without the fault shocking component. The correct components were then linearly superposed together to eliminate the background noise. Finally, two experiments were performed to evaluate the effectiveness of the proposed fault component extracting method. The results show that the approach satisfactorily extracts the fault shocking component. The precise faulty component can be extracted by this method, which judges the engine condition precisely. The fault type can be diagnosed easily by this method. This method can be used in other fields to extract a particular component from a complicated signal.

Colonoscopic Tattooing of Colonic Lesions

With the development of minimal invasive surgery including laparoscopic and robot surgery, colonoscopic tattooing of colonic lesions is becoming more important to ensure easy localization of the lesion during surgery. Lack of accurate lesion identification during minimal invasive surgery may lead to resection of wrong segment of the bowel. In this article, some topics including proper materials, injection technique, and safety of colonoscopic tattooing are reviewed.

Preoperative Colonic Lesion Localization with Charcoal Nanoparticle Tattooing for Laparoscopic Colorectal Surgery

The efficiency and safety of charcoal nanoparticle tattooing in localizing unpalpable colonic small lesions for later laparoscopy is described. Twenty six patients were enrolled for this prospective study. Tumor sites were localized with charcoal nanoparticles during colonoscopy for later laparoscopic colorectal operations. In all patients, the entire colon was examined preoperatively by colonoscopy and 0.5 ml (5 mg) of charcoal nanoparticle was injected submucosally near lesions or polypectomy sites. During laparoscopic colorectal operations for these biopsy-proven tumors, tumors were easily identified. The mean resection margin was 3.13 +/- 2.01 cm. The mean length of resected intestinal segment was 12.69 +/- 4.39 cm. No tumor was found at the resection line as indicated by postoperative pathological examination. Most importantly, no wrong segment was resected. Thus we show that easy identification of tumor can be achieved by preoperative tattooing with charcoal nanoparticles. Further studies regarding the long-term tattooing of tumor with charcoal nanoparticles are warranted.

Endoscopic tattooing of small bowel by double - balloon endoscopy

ABSTRACTInflammatory vascular polyps that are complicated by bleeding are difficult to diagnose and localise during the operation. With the improvement in the diagnosis of the small bowel tumours with double balloon endoscopy, the preoperative localization of the lesion is essential to undertake appropriate surgery, and to reduce the time for surgery and avoid resection of wrong segment of small bowel. Double balloon endoscopic tattooing of small bowel tumours and lesions is a new modality to ease the surgery when resection of small bowel is indicated. The literature about double balloon endoscopic tattoo is scant. We present a rare case of small bowel polyp that caused bleeding and the successful use of double balloon endoscopic tattoo preoperatively for the localization of the lesion during surgical procedure. (Dig Endosc 2013;4(2):49-51)

The Turnaround of Tata Nano: Reinventing the Wheel

Tata Nano has rewritten the evolution of transport by creating history as the world’s cheapest car. The creation of Tata Nano is a result of innovation leading to new market creation to tap latent opportunities lying at the bottom of the pyramid in the automobile, four-wheeler segment. This is the turnaround story of Tata Nano which focuses on how the initial strategies for launching and positioning backfired, leading to attraction of the wrong segment towards the car. There were instances that made people lose their interest and trust in Nano resulting into its nose-diving sales. The case highlights how Tata Motors Ltd. recognized its shortcomings and mistakes that led to the rejection of Nano among the segment it was created for. It revamped its strategies keeping in mind only its targeted segment that is the bottom of the pyramid. Thereafter it bounced back to win the trust of its prospective customers and is presently on a path-breaking journey to win sales.

Comparison of clinical outcomes between microsurgical lumbar discectomy and microendoscopic discectomy

Objective To make a comparison between microsurgical lumbar discectomy(MSLD) and microendoscopic discectomy(MED) in terms of methods,feathers,and effectiveness for lumbar disc herniation (LDH).Methods A prospective clinical review was conducted.From January 2006 to December 2009,900patients with single segment lumber disc herniation were randomly divided into the MSLD group and the MED group.There were 450 patients in each group.Comparison would be made in terms of the length of skin incision,the operative time,amount of bleeding,incidence of complication,duration of hospitalization,the time of recovery to ordinary work or life,pre- and post-operative assessment based on the criteria of visual analogue scales (VAS),and the Oswestry disability index(ODI).Results The mean lengths of skin incision were (3.8±1.1) cm and (2.4±0.7) cm for MSLD and MED respectively; the operative time were (51.0±14.2) min and (62.0±16.3) min; and the blood loss were (60±35) ml and (106±43) ml,which showed a significant difference (P＜0.05).There was no significant differences in terms of the hospitalization time and the time of recovery to ordinary work or life between the two groups (P＞0.05).The results of VAS and ODI of two groups also showed no significant difference at final follow-up (P＞0.05).As for the complications,the incidence of dural tear,acute hematomas of sacrospinalis,nerve roots and cauda equina injury and recurrence in MSLD group were much lower than that of MED group (P＜0.01).There was no incidence of wrong segment,greater artery injury,or postoperative infection in each group.Conclusion The clinical effects of both minimal invasive methods are satisfactory.However,MSLD has advantages of simpler maneuvering,shorter learning curve,and less complication than MED. Key words: Lumbar vertebrae; Endoscopy; Intervertebral disk displacement; Diskectomy

Leaving a mark: the frequency and accuracy of tattooing prior to laparoscopic colorectal surgery

Intra-operative localization of small cancers and polyps during laparoscopic colorectal surgery is difficult due to reduced tactile feedback. The consequences of failing to identify the lesion for resection can result in open conversion or removal of the wrong segment of bowel. Data were collected from a prospectively-kept database over a 12-month period from April 2008 to March 2009 and analysed retrospectively. Details concerning the documentation, visibility and accuracy of tattoos were recorded. Eighty-five patients (88 lesions) underwent laparoscopic resection for a benign or malignant colorectal tumour during 1 year from April 2008. Eighty-one patients underwent endoscopic visualization of the tumour as a first or second procedure. Of these 81 patients, 83 lesions were visualized endoscopically and 54 (65.1%) were tattooed in 52 patients. In the 52 patients, 36 (69%) of the tattoos were carried out on the first endoscopy. At operation the tattoo was judged to be visible and accurate in 70%, visible but inaccurate in 7% and not visible in 15%. It was significantly easier to see the tattoo in women (19/21 women vs 21/29 men; P=0.03) but there was no relationship between tattoo visibility and BMI. An accurate tattoo did not reduce the conversion rate (P=0.71). No tattoo-related complications were encountered. The practice of tattooing colorectal cancers is variable in frequency, technique and accuracy. We advocate that all colonic lesions suspicious for cancer should be tattooed during endoscopy at a defined distance below the tumour, adhering to a departmental protocol in case surgery is required.

Accuracy of colonoscopic localization

The objective of this study was to evaluate the accuracy of preoperative colonoscopic localization of colonic lesions. Localization of the colonic lesion plays a key role in determining the type of operation a patient may require. Inaccurate localization may result in removal of the wrong segment of colon and/or a change in the operation performed. A retrospective review of patients who had a colon resection by a single surgeon after preoperative colonoscopic localization between 1991 and 2008 was performed. A comparison of the preoperative colonoscopic localization and the final intraoperative localization was made. Clinical and demographic information was gathered to determine accuracy rates and identify predictive factors. Three hundred and seventy-four patients were included and 184 (49%) were male. The mean age was 61.6 years. Three hundred and sixty-two (97%) patients underwent colon resection for cancer. Fifteen (4%) patients had nonconcordant colonoscopic and intraoperative findings. Fourteen of the 15 (93%) were resected for cancer and 1 for inflammatory bowel disease (IBD). Seven (47%) lesions were inaccurately localized in the sigmoid colon, four (27%) in the descending colon, two (13%) in the ascending colon, one (7%) in the rectum, and one (7%) lesion was not visualized preoperatively. Eleven of the 15 (73%) patients with nonconcordant localization had a modification of their planned procedure. Ten patients underwent a different segmental colectomy and one patient had an extended resection. Preoperative colonoscopic localization of colorectal lesions was reasonably accurate (96%) in this large series. The majority of inaccurately identified lesions occurred in the sigmoid and descending colon. Erroneous localization, even though not common, can result in significant changes in the intraoperative plan and the ultimate outcome. Therefore, every effort should be made to localize the lesion before surgery, especially when thought to be in the left or sigmoid colon, to reduce the need for intraoperative localization efforts, the need for an intraoperative change in procedure, and the risk of a surprise for the patient after surgery.

The impact of treatment couch modelling on RapidArc

A planning and dosimetric study was carried out on a cohort of six CT datasets from patients treated for prostate cancer to assess the impact of couch modelling on the accuracy of dose calculation for the volumetric modulated arc technique RapidArc. For each patient, RapidArc plans were optimized using the couch while final dose calculation was performed with different conditions (thin, medium, thick and no couch). Analysis was performed in terms of dose volume histograms, dose difference histograms and 3D-γ tests. Pre-treatment verification measurements were performed using the PTW-729 array in conjunction with the Octavius phantom (PTW, Freiburg); similarly, HU characterization of couch was performed with the same phantom and ion chamber measurements comparing calculations and experimental data. A set of Hounsfield Units (HU) valid for low and high energy and the entire couch length was found as internal structure HU = −960, surface shell HU = −700. Analysis of dose plans showed that differences larger than 1.5 Gy for a 70 Gy prescription might be observed on significant fractions of PTVs. Smaller differences are visible in the medium low-dose regions. Pre-treatment verification on composite delivery confirmed these observations and, at the same time, showed good accuracy of dose calculations in the presence of couch modelling compared to delivery in the same conditions (GAI ranging from 95% to 100%). Results confirmed the reliability of the geometrical model build in the planning system Eclipse, and (i) there is no measurable effect if the wrong segment of the couch is used in the calculations; (ii) there are significant discrepancies of potential clinical impact at the level of the target volumes if calculations are performed without couch and delivery is performed with couch, and (iii) the effect is particularly relevant at low energy (6 MV in this case) that is the configuration clinically used by most of the centres adopting technologies based on intensity-modulated arcs.

Should Price Increases Be Targeted?—Pricing Power and Selective vs. Across-the-Board Price Increases

Firms in many industries experience protracted periods of pricing power, the ability to successfully enact price increases. In these situations, firms must decide not only whether to raise prices, but to whom. Specifically, in a competitive context, they must determine whether it is more profitable to increase prices across-the-board or to a specific segment of their customer base. While selective price decreases are ubiquitous in practice (e.g., better deals to potential new customers by phone carriers; better deals to current customers by various magazines), to our knowledge selective price increases are relatively rare. We illustrate the benefits of targeted price increases, and, as such, we expand the repertoire of firms' promotional policies. To that end, we explore a scenario where two competing firms must decide whether to increase prices to the entire market or only to a specific segment. Targeted price increases (TPI), i.e., being offered an unchanged price (selectively) when others are subject to price increases, can be offered to Loyals (those who bought from the firm in the previous period) or Switchers (those who did not). The effects of TPIs are estimated through a laboratory experiment and an associated stochastic model, each allowing for both rational (Loyalty, Switching) and behaviorist (Betrayal, Jealousy) effects. We find that TPIs can indeed yield beneficial results (greater retention for Loyals or greater attraction of Switchers) and greater profits in certain circumstances. Results for TPI are additionally benchmarked against those for targeted price decreases and are found to differ. The range of effects stemming from the experiment can be used in a competitive analysis to yield equilibrium strategies for the two firms. In this case, we find that—depending on the magnitude of the price increase, market shares of the two firms, and price knowledge across consumer segments—a firm may wish to embrace targeted price increases in some situations, to institute across-the-board price increases in others, and to not enact any price increases in still others. We show that a firm can sacrifice considerable profit if it settles on a suboptimal pricing strategy (e.g., wrongly instituting an across-the-board increase), favors the wrong segment (e.g., Switchers instead of Loyals), or ignores “behaviorist” effects (Betrayal or Jealousy).

Integration of Spatial Point Features with Linear Referencing Methods

The Global Positioning System (GPS) offers a cost-effective and accurate method for inputting, updating, and analyzing spatial data. However, many data-storage and reporting methods at state departments of transportation and other transportation agencies rely on linear referencing methods (LRMs) for managing transportation data. Consequently, GPS data must be able to coexist with linear referencing systems (LRSs). Unfortunately, the two systems are fundamentally different in the way they collect, integrate, and manipulate data. For spatial data collected with GPS to be integrated into an LRS or shared among LRMs, several issues must be addressed. Various issues are discussed for integrating point features from a typical inventory system with an LRM or between LRMs, including two- or three-dimensional GPS to one-dimensional LRM, linear offset error, lateral offset error, matching to the wrong segment, and locating points between LRMs.

Do we care what others Get? A Behaviorist Approach to Targeted Promotions

Increased access to individual customers and their purchase histories has led to a growth in targeted promotions, including the practice of offering different pricing policies to prospective, as opposed to current, customers. Prior research on targeted promotions has adopted a tenet of the standard economic theory of choice, whereby what a consumer chooses depends exclusively on the prices available to that consumer. In this article, the authors propose that consumer preference for firms is affected not just by prices the consumers themselves are offered but also by prices available to others. This departure from the conventional strong-rationality approach to targeted promotion results in a decidedly different optimal policy. Through a laboratory experiment, calibration of a stochastic model, and game-theoretic analysis, the authors demonstrate that ignoring behaviorist effects exaggerates the importance of targeting switchers as opposed to loyals. This occurs, though with intriguing differences, even when only part of the market is aware of firms’ differing promotional policies. The authors show that both the deal percentage and the proportion of aware consumers affect the optimal strategy of the firm. Furthermore, the authors find that offering lower prices to switchers may not be a sustainable practice in the long run, as information spreads and the proportion of aware consumers grows. The model cautions practitioners against overpromoting and/or promoting to the wrong segment and suggests avenues for improving the effectiveness of targeted promotional policies.

Colorectal cancer: evolving concepts in diagnosis, treatment, and prevention

Colorectal cancer: evolving concepts in diagnosis, treatment, and prevention

Laparoscopic resection of colorectal cancer—high art or access artistry?

Since its introduction to visceral surgery some 10 years ago, laparoscopic access has been practised in almost every surgical department. For some operations, e.g. elective cholecystectomy, in which the open access trauma is high relative to the trauma of the actual operation, open access has largely been abandoned and the preferred route is now via a number of trocars. For more complex procedures, in which the access trauma is small compared to the trauma of the operation, however, the laparoscopic technique has not received such wide acceptance. Notably, reservations persist among surgeons regarding the use of laparoscopic access for potentially curable cancer of the colon or rectum, whereas amongst the lay public, high expectations of laparoscopic techniques prevail, even for oncological operations. Many publications have indeed reported technical feasibility, rapid recovery and apparently acceptable immediate complication rates of colorectal operations performed laparoscopically, including those for cancer. Few of these reports, however, meet the strict requirements applicable to clinical research and hardly any long-term results for laparoscopically treated colorectal cancer have been reported. The public, however, is impressed and equates laparoscopic access, as opposed to open access, with a gentler procedure. These expectations are supported by randomized trials, e.g. of cholecystectomy or appendectomy, which claim to demonstrate less pain, earlier mobilization, earlier hospital discharge and return to work for patients. However, most trial designs do not stand up to critical evaluation: highly subjective parameters such as pain or tiredness can only be assessed objectively in comparative trials, when the patient (and preferably also the evaluating doctor) is blinded as to the actual treatment received. If patients are aware of the access route, open or laparoscopically, their personal expectations are likely to influence the results of the trials. For example, imagine a randomized comparison of analgesic treatment, in which the patient is fully aware of whether he has received the potential pain-killer or the placebo. It is not entirely surprising, therefore, that the only randomized trial performed, one in which neither patients nor examiners were aware of whether laparoscopic or open cholecystectomy had been performed, did not confirm the purported advantages of laparoscopic surgery. Both open and laparoscopically treated patients started oral diet on the same day, were discharged on the same day and resumed full physical activity after 3 weeks. Laparoscopically treated patients, however, returned to work later than patients who had undergone open cholecystectomy/ Similarly strict protocols have not been implemented for colorectal operations. In all randomized studies reported to date, patients were aware of the route of access. Although no differences were recorded regarding postoperative ileus,- start of oral diet, 2 pulmonary function 3 or postoperative fatigue 3 after open or laparoscopic operations for colorectal cancer, laparoscopically treated patients were discharged 3 days earlier 34 and reported less pain) Again the expectations of patients could have introduced bias and we cannot be certain that laparoscopic colorectal resections are indeed much gentler than the open operation. It can be concluded, however, that laparoscopically performed colorectal surgery takes significantly longer than conventional colorectal resections, because the laparoscopic access restricts operative manipulations. It is, therefore, not surprising that randomized trials have determined higher complication rates for laparoscopic colorectal operations. 2~ Specific complications, such as removal of the wrong bowel segment or bowel injury by trocars or cautery (also euphemized as 'enterotomy'), have become apparent which are rarely encountered during open access operations for colorectal cancer. As a consequence of this, many surgeons routinely perform additional pre-operative diagnostic or therapeutic procedures to avoid these specific complications and reduce the conversion rate? These procedures include routine placement of ureteric stents, 5 contrast enema in addition to colonoscopy, 6 routine intraoperative colonoscopy 6 and preoperative computed tomography in all colon cancers to exclude local infiltration) .~ It stands to reason that these procedures are inconvenient for the patient and are expensive.