The Impact of Revascularisation on Quality of Life in Chronic Mesenteric Ischemia.

Background: Chronic mesenteric ischemia (CMI) is characterized by long-standing abdominal symptoms due to insufficient mesenteric circulation. Data on the effect of revascularisation on quality of life (QoL) for CMI are scarce. This study is the first to evaluate the impact of revascularisation on quality of life. Methods: Seventy-nine patients with CMI or acute-on-chronic mesenteric ischemia (AoCMI) underwent an intervention of one or more mesenteric arteries between January 2010 and July 2012. QoL before and after intervention was measured with the EuroQol-5D. Preintervention questionnaires were of standard care. Postintervention data were obtained by resending a questionnaire to the patients between February and May 2013. To investigate the clinical relevance of our findings, the minimal clinically important difference (MCID) was used. Since there is no established MCID for CMI, we used the literature reference MCID of inflammatory bowel syndrome (IBS) of 0.074. Results: Fifty-five (69.6%) of 79 patients returned their questionnaire and 23 (29.1%) were completely filled out. There was a significant increase of the median EQ-index score from 0.70 to 0.81 (p=0.02) and a significant reduction of symptoms in the domains usual activities (34.4%) and pain/discomfort (32.3%). There was a significant improvement of 17% in overall current health condition (VAS) (p=0.001). The MCID between baseline and postoperative EQ-5D index score was 0.162, indicating a clinically relevant improvement of quality of life after revascularisation. Conclusion: Quality of life of CMI patients is improved after mesenteric artery revascularisation.

Long-Term Results of Endovascular Treatment of Atherosclerotic Stenoses or Occlusions of the Coeliac and Superior Mesenteric Artery in Patients With Mesenteric Ischaemia.

INTRODUCTION: Over the past decade, primary percutaneous mesenteric artery stenting (PMAS) has become an alternative to open revascularisation for treatment of mesenteric ischaemia. Institutes have presented favourable short-term outcomes after PMAS, but there is a lack of data on long-term stent patency. METHODS: One hundred and forty-one patients treated by PMAS for acute and chronic mesenteric ischaemia over an 8 year period were studied. Anatomical success was assessed by duplex ultrasound and/or CT angiography. A stenosis ≥70% was considered to be a failure. RESULTS: Eighty-six coeliac arteries (CA) and 99 superior mesenteric arteries (SMA) were treated with PMAS in 141 patients. Nine CAs (10%) and 30 SMAs (30%) were occluded at the time of treatment. Median follow-up was 32 months (IQR 20-46). The overall primary patency rate at 12 and 60 months was 77.0% and 45.0%. The overall primary assisted patency rate was 90.3% and 69.8%. Overall secondary patency was 98.3% and 93.6%. CONCLUSION: This study shows excellent long-term secondary patencies after PMAS, comparable with published data on long-term patencies after open surgical revascularisation.

The Effect of Unenhanced MRI on the Surgeons' Decision-Making Process in Females with Suspected Appendicitis.

BACKGROUND: This prospective study evaluated the impact of the results of unenhanced magnetic resonance imaging (MRI) on the surgeon's diagnosis of acute appendicitis in potentially fertile females. METHODS: 112 female patients, aged 12-55, with suspected appendicitis underwent MRI of the abdomen. At three defined intervals; admission and clinical re-evaluation before and after revealing the MRI results, the surgeon recorded the attendance of each patient in operative treatment, observation or discharge. Appendicitis was confirmed or declined by pathology or by telephone follow-up in case of non-intervention. FINDINGS: Appendicitis was confirmed in 29 of 112 patients. At admission the surgeon's disposition had a sensitivity of 97 % and specificity of 29 %. After knowing the MRI results, sensitivity was 97 % and specificity 64 %. The sensitivity and specificity of MRI alone were 89 and 100 %, with a negative and positive predictive value of 96 and 100 %, respectively. CONCLUSION: We believe that MRI should perhaps be standard in all female patients during their reproductive years with suspected appendicitis. It avoids an operation in 32 % of cases and allows earlier planning for patients with an equivocal clinical picture. Trial number: OND1292733 (Narcis.nl).

[Preference for endovascular aortic aneurysm repair: results of RCTs versus nationwide audits]. / Voorkeur voor endovasculair aorta-aneurysmaherstel: Resultaten van RCT's versus landelijke audits.

This short comment puts into perspective the value of randomised controlled clinical trials in comparison with nationwide audits in the field of aortic aneurysm treatment. RCTs represent greater scientific value but nationwide audits represent daily practices and seem to be more appropriate for shared decision-making.

Long Term Results of Kissing Stents in the Aortic Bifurcation.

BACKGROUND: To evaluate the long-term outcome after aortoiliac kissing stent placement and to analyze variables, which potentially influence the outcome of endovascular reconstruction of the aortic bifurcation. METHODS: All patients treated with aortoiliac kissing stents at our institution between April 1995 and August 2011 were retrospectively identified from a prospective single-center database. Data regarding patient characteristics (age, gender, smoking, cardio- and cerebrovascular risk factors, hyperlipidaemia, diabetes mellitus and use of antihypertensive medication), symptoms, pre-interventional examination and imaging, procedural details and follow-up were retrieved. Patency rates were calculated with Kaplan-Meier analysis. Factors affecting the patency were determined with Cox uni- and multivariate analysis. RESULTS: A total of 215 patients (63% men, mean age 61 ±â€ˆ10 years) were included. The median follow-up period was 31 (IQR 47.1) months. Primary, primary assisted, and secondary patency rates were 97%, 97%, and 99%, respectively, at one month; 92%, 95% and 94% at four months; 75%, 86%, and 91% at two years; 70%, 81%, and 91% at 5 years; and 67%, 81%, and 91% at ten years. Younger age and previous aortoiliac treatment were predictors for reduced primary and primary assisted patency. Smoking, previous aortoiliac intervention, TASC C and D lesions were predictors for reduced secondary patency. CONCLUSIONS: Reconstruction of the aortoiliac bifurcation with kissing stents is feasible, safe and effective in all types of lesions with satisfying long term patencies. TASC C and D lesions are associated with a higher occlusion rate. Younger age and previous aortoiliac interventions are predictors for reduced primary and primary assisted patency.

[From CVA or TIA to carotid surgery: the clinical treatment course for patients with symptomatic carotid disease could be shorter]. / Van CVA of TIA tot carotischirurgie: zorgtraject voor patiënten met symptomatisch carotislijden kan korter.

OBJECTIVE: To gain insight into the duration and the various components of the clinical treatment course for patients with symptomatic carotid artery stenosis, in order to improve the care provided to these patients. DESIGN: Retrospective cohort study. METHODS: All patients who had undergone a carotid intervention for significant symptomatic carotid stenosis from 2001 to 2011 were included. Quantile regression analysis was used to assess the changes which had occurred in the median duration of the period from neurological event to intervention from 2001 onward. In order to chart the clinical treatment course, it was split up in different components. In addition, the impact of the referrer and the relationship between the time of the intervention and the risk of perioperative complications were also evaluated. RESULTS: The median duration of the entire clinical treatment course decreased during the study period from 79 days (interquartile range (IQR): 59-113) in the reference period 2001-2004 to 19 days (IQR: 13-28) in 2011. All components of the clinical pathway had contributed to this decline. The duration of the clinical course in patients who had been externally referred was more than 3 times longer (median 67 vs. 21 days, p < 0.01). The total duration of the process did not affect the number of perioperative complications. CONCLUSION: In the last decennium, the duration of the clinical treatment course of care in patients with symptomatic carotid artery disease was greatly reduced. Analyses of the processes which make up the chain of events, however, reveal that there is still much to be gained in the period before initial presentation at the hospital for patients who are referred by their general practitioners as well as those referred by other hospitals.

Superior two-year results of externally unsupported polyester compared to supported grafts in above-knee bypass grafting: a multicenter randomised trial.

OBJECTIVES: The aim of this study was to compare externally supported thin wall knitted polyester (P-EXS) and externally unsupported thin wall knitted polyester (P-non-EXS) for above-knee (AK) femoro-popliteal bypass grafting. DESIGN: A prospective multicenter randomised clinical trial. MATERIAL AND METHODS: Between 1999 and 2008, 265 AK femoro-popliteal bypass grafts (6 mm in diameter) were performed, including 136 P-EXS and 129 P-non-EXS. The selection of patients was based on the presence of disabling claudication or critical ischaemia. Follow-up took place at 3, 6, 12, 18, and 24 months and included clinical examination and duplex ultrasonography. The main end points of this study were primary patency rates at one and two years. Secondary end points were mortality, and primary assisted and secondary patency rates. Cumulative patency rates were calculated with life-table analysis and log-rank testing. RESULTS: The 1-year primary, primary assisted and secondary patency rates were 65%, 70% and 84%, respectively, for P-EXS and 76% (p = 0.05), 82% (p = 0.03) and 88% (p = 0.35), respectively, for P-non-EXS. Two-year primary, primary assisted and secondary patency rates were 45%, 57% and 70%, respectively, for P-EXS and 62% (p = 0.003), 75% (p = 0.005) and 84% (p = 0.02), respectively, for P-non-EXS. The overall mortality rate after two years was 11.3%. CONCLUSION: In above-knee femoro-popliteal bypass grafting patency rates of externally supported knitted polyester grafts were inferior to their unsupported counterpart. ISRCTN: At the time this study started this number was not the standard.

Splanchnic artery stenosis and abdominal complaints: clinical history is of limited value in detection of gastrointestinal ischemia.

BACKGROUND: Splanchnic artery stenosis is common and mostly asymptomatic and may lead to gastrointestinal ischemia (chronic splanchnic syndrome, CSS). This study was designed to assess risk factors for CSS in the medical history of patients with splanchnic artery stenosis and whether these risk factors can be used to identify patients with high and low risk of CSS. METHODS: All patients referred for suspected CSS underwent a standardized workup, including a medical history with questionnaire, duplex ultrasound, gastrointestinal tonometry, and angiography. Definitive diagnosis and treatment advice was made in a multidisciplinary team. Patients with confirmed CSS were compared with no-CSS patients. RESULTS: A total of 270 patients (102 M, 168 F; mean age, 53 years) with splanchnic artery stenosis were analyzed, of whom 109 (40%) had CSS and 161 no CSS. CSS-patients more often reported postprandial pain (87% vs. 72%, p = 0.007), weight loss (85% vs. 70%, p = 0.006), adapted eating pattern (90% vs. 79%, p = 0.005) and diarrhea (35% vs. 22%, p = 0.023). If none of these risk factors were present, the probability of CSS was 13%; if all were present, the probability was 60%. Adapted eating pattern (odds ratio (OR) 3.1; 95% confidence interval (CI) 1.08-8.88) and diarrhea (OR 2.6; 95% CI 1.31-5.3) were statistically significant in multivariate analysis. CONCLUSIONS: In patients with splanchnic artery stenosis, the clinical history is of limited value for detection of CSS. A diagnostic test to detect ischemia is indispensable for proper selection of patients with splanchnic artery stenosis who might benefit from treatment.

Endovascular treatment of ruptured abdominal aortic aneurysm: is there a long-term benefit at follow-up?

AIM: Several studies have shown the feasibility of endovascular repair of ruptured abdominal aortic aneurysms (rEVAR). However, the role and value of rEVAR remains controversial due to selection bias and lack of long-term results. In the present study we describe our short- and long-term results of treating patients with rEVAR irrespective of hemodynamic condition and challenging anatomy. METHODS: In April 2006 we started the single centre prospective non-randomised Ruptured Aneurysm Study (RASA). During a four year enrolment period all consecutive patients presenting with infrarenal ruptured AAA (rAAA, N.=117) were assessed for preferential rEVAR treatment. A rAAA was defined as extravasation of blood or hematoma outside the AAA due to transmural tear in the infrarenal abdominal aorta wall documented by preoperative computed tomography (CT) angiography examination or during open repair. Patients with challenging anatomy (infrarenal neck length below 15 mm and neck angulation above 60 degrees) were included as part of a damage control concept. Complication and mortality rates were studied at 30 days and yearly afterwards. RESULTS: Thirty-five patients (33% of all admitted rAAA) were treated with rEVAR and 42% of them were considered hemodynamically unstable (systolic blood pressure <100 mmHg) and 30% had challenging AAA anatomy. The mortality rate at 30 days in the rEVAR group was 17%, in the open repair group 31%, and in the entire rAAA group (including abstained patients) 36%. During the first 30 days, 18 rEVAR patients experienced complications with nine re-interventions as a result. Long-term mortality of the rEVAR patients was 34% after a median follow-up of 3.4 years. All deaths after one year follow-up were non-AAA related. Multivariate analysis shows that Hardman index, presence of peripheral arterial obstructive disease and lowest systolic blood pressure during surgery are independently associated with long-term survival. Challenging rAAA anatomy was not associated with impaired survival. CONCLUSION: Our study shows that rEVAR is feasible irrespective of hemodynamic condition and that it is associated with relative low mortality rates. Challenging rAAA anatomy may not affect overall long-term survival, but six out of ten patients remain unsuitable for rEVAR because of inappropriate anatomy.

Medical treatment in carotid artery intervention.

Medical treatment has a pivotal role in the treatment of patients with occlusive carotid artery disease. Large trials have provided the justification for operative treatment besides medical treatment in patients with recent significant carotid artery stenosis two decades ago. Since then, medical therapy has evolved tremendously. Next to aspirin, antiplatelet regimens acting on a different level in the modulation of platelet aggregation have made their entry. Moreover, statin therapy has been introduced. These changes among others in secondary stroke prevention, along with better understanding in life-style adjustments and perioperative medical management, have led to a decrease in stroke recurrence. Secondary prevention is therefore now the most important pillar of medical therapy. It consists of antiplatelet therapy, statins and blood pressure lowering agents in all patients. Small adjustments are recommended for those patients referred for invasive treatment. Moreover, long-term medical treatment is imperative. In this article, we summarize current evidence in literature regarding medical management in patients with previous stroke or TIA.

Surgical options for the management of visceral artery aneurysms.

Visceral artery aneurysm (VAA) is a rare entity but increased use of abdominal imaging has led to an increased prevalence. Rupture is related to a high mortality rate. Open repair, endovascular treatment and laparoscopic techniques have been described as treatment options. In this systematic review we describe the surgical options for treating VAA. A literature search identified articles focussing on the key issues of visceral artery aneurysms and surgical options using the Pubmed and Cochrane databases. Case reports dominate the literature about VAA. Twenty-seven small case series and ten review articles have been published in the last 20 years concerning the surgical options for VAA. The evidence does not exceed level 3. Surgical treatment is dictated by both patient and aneurysm characteristics. Whether VAA should be treated largely depends upon age, gender, presence of hypertension (e.g. in renal aneurysm), aneurysm size and presentation. Aneurysm size and characteristics, anatomical location and presence of collateral circulation dictate the surgical option to be chosen. The mortality and morbidity rates after elective open repair are low. Literature about surgical options for treating VAA remains scarce. Only a few clinical trials have shown the possibilities and results of open surgical repair. In general, there is no consensus on the surgical treatment of VAA and the highest level of evidence is based upon expert opinions.

Association of the TGF-beta receptor genes with abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is a multifactorial condition. The transforming growth factor beta (TGF-beta) pathway regulates vascular remodeling and mutations in its receptor genes, TGFBR1 and TGFBR2, cause syndromes with thoracic aortic aneurysm (TAA). The TGF-beta pathway may be involved in aneurysm development in general. We performed an association study by analyzing all the common genetic variants in TGFBR1 and TGFBR2 using tag single nucleotide polymorphisms (SNPs) in a Dutch AAA case-control population in a two-stage genotyping approach. In stage 1, analyzing 376 cases and 648 controls, three of the four TGFBR1 SNPs and nine of the 28 TGFBR2 SNPs had a P<0.07. Genotyping of these SNPs in an independent cohort of 360 cases and 376 controls in stage 2 confirmed association (P<0.05) for the same allele of one SNP in TGFBR1 and two SNPs in TGFBR2. Joint analysis of the 736 cases and 1024 controls showed statistically significant associations of these SNPs, which sustained after proper correction for multiple testing (TGFBR1 rs1626340 OR 1.32 95% CI 1.11-1.56 P=0.001 and TGFBR2 rs1036095 OR 1.32 95% CI 1.12-1.54 P=0.001 and rs4522809 OR 1.28 95% CI 1.12-1.46 P=0.0004). We conclude that genetic variations in TGFBR1 and TGFBR2 associate with AAA in the Dutch population. This suggests that AAA may develop partly by similar defects as TAA, which in the future may provide novel therapeutic options.

The Anaconda AAA stent graft system: 2-year clinical and technical results of a multicentre clinical evaluation.

INTRODUCTION: This study reports the technical and mid-term clinical results of the second-generation Anaconda AAA Stent Graft System endovascular device for treatment of abdominal aortic aneurysm (AAA). The design of the Anaconda AAA Stent Graft System is characterised by a three-piece system consisting of two proximal independent saddle-shaped nitinol self-expandable rings with hooks fixation, zero body support and vacuum-cleaner tube leg design. METHODS: From July 2002 to April 2005, a total of 61 patients with AAA were enrolled in a multicentre, prospective, non-randomised controlled design study. All patients received a second-generation Anaconda AAA Stent Graft System. They entered a standard follow-up protocol at discharge for 3, 6, 12 and 24 months. Follow-up data included survival; rupture-free survival; incidence of aneurysm rupture, death from aneurysm rupture, aneurysm-related death; freedom from aneurysm expansion; freedom from Types I and III endoleaks; endograft patency and technical and clinical success rates. RESULTS: Successful access to the arterial system was achieved in all patients. The primary technical success was 59 out of 61 and the primary assisted technical success was 60 out of 61. All endovascular grafts were patent without significant twists, kinks or obstructions. Migration was not observed in any of the grafts. During the first 30-day period, two serious adverse events (3%), both not related to the procedure, were observed. Nine patients (15%) needed a secondary intervention; two of these interventions were related to stent graft (3%). The mean aneurysm sac diameter decreased significantly from 57 mm pre-operative to 45mm after 24 months, without aneurysm growth. There was one Type I endoleak at initial implantation, which was corrected using a proximal extension cuff. In total, three Type II endoleaks were still present after 24 months without any signs of aneurysm growth. CONCLUSION: The design features of the second-generation Anaconda AAA Stent Graft System are effective in the treatment of AAAs on mid-term evaluation.

Dacron or ePTFE for femoro-popliteal above-knee bypass grafting: short- and long-term results of a multicentre randomised trial.

OBJECTIVES: To compare expanded polytetrafluoroethylene (ePTFE) prosthesis and collagen-impregnated knitted polyester (Dacron) for above-knee (AK) femoro-popliteal bypass grafts. DESIGN: A prospective multicentre randomised clinical trial. PATIENTS AND METHODS: Between 1992 and 1996, 228 AK femoro-popliteal bypass grafts were randomly allocated to either an ePTFE (n=114) or a Dacron (n=114) vascular graft (6mm in diameter). Patients were eligible for inclusion if presenting with disabling claudication, rest pain or tissue loss. Follow-up was performed and included clinical examination and duplex ultrasonography at all scheduled intervals. All patients were treated with warfarin. The main end-point of this study was primary patency of the bypass graft at 2, 5 and 10 years after implantation. Secondary end-points were mortality, primary assisted patency and secondary patency. Cumulative patency rates were calculated with life-table analysis and with log-rank test. RESULTS: After 5 years, the primary, primary assisted and secondary patency rates were 36% (confidence interval (CI): 26-46%), 46% (CI: 36-56%) and 51% (CI: 41-61%) for ePTFE and 52% (CI: 42-62%) (p=0.04), 66% (CI: 56-76%) (p=0.01) and 70% (CI: 60-80%) (p=0.01) for Dacron, respectively. After ten years these rates were respectively 28% (CI:18-38%), 31% (CI:19-43%) and 35% (CI: 23-47%) for ePTFE and 28% (CI: 18-38%), 49% (CI: 37-61%) and 49% (CI: 37-61%) for Dacron. CONCLUSION: During prolonged follow-up (10 years), Dacron femoro-popliteal bypass grafts have superior patency compared to those of ePTFE grafts. Dacron is the graft material of choice if the saphenous vein is not available.

[Gastrointestinal ischaemia during physical exertion as a cause of gastrointestinal symptoms]. / Maag-darmischemie tijdens lichamelijke inspanning als oorzaak van gastro-intestinale klachten.

Gastrointestinal (GI) symptoms are reported by up to 70% of endurance athletes. Although exercise leads to decreased gastrointestinal blood flow, GI-ischaemia is rarely reported as a cause. Mucosal ischaemia may result in nausea, abdominal cramps and bloody diarrhoea. After exercise, reperfusion damage and endotoxaemia may cause systemic symptoms as well. In three patients, two women aged 46 and 25 respectively and a man aged 40, with a heterogeneous presentation of exercise induced GI-symptoms, GI-ischaemia was demonstrated using gastric exercise tonometry. Gastric tonometry is mandatory for the diagnosis and follow-up. In the first patient, an isolated celiac artery stenosis was found; after incision of the left crus of the diaphragm, she was asymptomatic and the results of gastric tonometry improved. The other two patients had non-occlusive ischaemia associated with high exercise intensity. Reduction of the exercise intensity resulted in the complaints disappearing.

Acute stress-related gastrointestinal ischemia.

We report a case of acute gastrointestinal ischemia during a very stressful event in whom the diagnosis was made by 24-hour tonometry. This case report unequivocally links a stressful event with increased catecholamine release and subsequent severe symptomatic gastrointestinal ischemia. The role of ischemia as potential pathophysiological mechanism has never been studied in detail. The clinical significance of finding such an association is underscored by this case report, where a vasoactive drug normally used for hypertension treatment resulted in greatly improved abdominal symptoms.

Clinical significance of splanchnic artery stenosis.

BACKGROUND: The clinical relevance of splanchnic artery stenosis is often unclear. Gastric exercise tonometry enables the identification of patients with actual gastrointestinal ischaemia. A large group of patients with splanchnic artery stenosis was studied using standard investigations, including tonometry. METHODS: Patients referred with possible intestinal ischaemia were analysed prospectively, using duplex imaging, conventional abdominal angiography and tonometry. All results were discussed within a multidisciplinary team. RESULTS: Splanchnic stenoses were found in 157 (49.7 percent) of 316 patients; 95 patients (60.5 percent) had one-vessel, 54 (34.4 percent) two-vessel and eight (5.1 percent) had three-vessel disease. Chronic splanchnic syndrome was diagnosed in 107 patients (68.2 percent), 54 (57 percent) with single-vessel, 45 (83 percent) with two-vessel and all eight with three-vessel stenoses. Treatment was undertaken in 95 patients, 62 by surgery and 33 by endovascular techniques. After a median follow-up of 43 months, 84 percent of patients were symptom free. CONCLUSION: Gastric exercise tonometry proved crucial in the evaluation of possible intestinal ischaemia. Comparing patients with single- and multiple-vessel stenoses, there were significant differences in clinical presentation and mortality rates.

Towards a VR trainer for EVAR treatment.

Endovascular repair of aortic abdominal aneurysms (AAA) is more and more becoming part of clinical practice. Up to approximately 30 clinical procedures however are necessary to obtain the surgical skills to make the procedure reliable and safe. The current study aims to generate a VR trainer to speed up the training process of experienced vascular surgeons to become experienced EVAR (endovascular AAA repair) surgeons by introducing a VR environment. This manuscript describes the contents and validation of the first step in the VREST - EVAR trainer, i.e. the proper definition of the knowledge and skills that need to be transferred.

Validation of open-surgery VR trainer.

VREST (Virtual Reality Educational Surgical Tools) is developing a universal and autonomous simulation platform which can be used for training and assessment of medical students and for continuing education of physicians. With the VREST - Virtual Lichtenstein Trainer, simulating the open surgery procedure of the inguinal hernia repair according to Lichtenstein, the validation of the simulator is ongoing. Part of this trajectory is the evaluation of the transfer of training of the virtual incision making. One group of students trained incision making on the VREST platform where the control group did not. In an experiment both groups has to perform several incision tasks on a manikin. The results are not available yet but will be presented at the MMVR14 conference.

Open surgery in VR: inguinal hernia repair according to Lichtenstein.

VREST (Virtual Reality Educational Surgical Tools) is developing a universal and autonomous simulation platform which can be used for training and assessment of medical students and for continuing education of physicians. A workstation consisting of two haptic devices and a 3D vision system is part of the VREST platform. Another part of the platform is a generic software environment in which lessons can be built by the teacher and performed by their students. Using the platform one can see, feel and decide as in reality. With the assessment tool the progress and skills of the students can be supervised. The first lesson build on the VREST platform is an inguinal hernia repair according to Lichtenstein. This is an open surgery procedure. The VREST platform is used prior to the first operating room surgery of the resident. Interactive models and case dependent feedback is used to enlarge the residents' cognition. This should reduce the training time in the operating room.