Percutaneous Thrombectomy in Patients with Occlusions of the Aortoiliac Segment: A Case Series.

OBJECTIVE: Thrombectomy of the aortoiliac segment remains a challenge for surgical and endovascular revision. This study aimed to evaluate the concept of percutaneous thrombectomy in patients with aortoiliac segment occlusions. MATERIALS & METHODS: Eighteen patients with aortoiliac occlusion who underwent percutaneous thrombectomy were retrospectively identified using the local picture archive and divided into the stent-graft (N = 10) and native vessels (N = 8) groups. The procedure was performed by placing a 12-24 French sheath adjacent to the distal end of the occluded vessel segment. The occlusion was passed with a balloon catheter which was retracted after inflation, to deliver the thrombus into the sheath. Technical success (reperfusion of the vessel and no residual thrombus/stenosis < 30%), complications and primary arterial patency were assessed. Follow-up included computed tomography angiography and evaluation of the clinical situation via telephone. RESULTS: Technical success was achieved in 38% (7/18) of patients after percutaneous thrombectomy alone and in 100% after additional procedures. The most common complication was peripheral embolism (44%, 8/18), which was treated successfully in all cases and was linked to a mismatch between the sheath and target vessel of ≥ 1 mm (P < .01). There were no significant differences in the incidence of complications between the two groups. Primary patency was 72% (13/18) with no significant difference between groups (P = .94). Follow-up CT scans were available for 13/18 patients (72%), with a mean follow-up time of 270 ± 146 days. All patients were contacted via phone (follow-up time, 653 ± 264 days). CONCLUSION: Percutaneous thrombectomy appears to be effective for revascularization of the aortoiliac segment, both in stent-grafts and in native vessels. The most common complication is peripheral embolism; however, the risk may be reduced by choosing an adequate sheath size.

Distribution of Mobile Health Applications amongst Patients with Symptomatic Peripheral Arterial Disease in Germany: A Cross-Sectional Survey Study.

BACKGROUND: Broadly available digital and mobile health applications (also known as mHealth) have recently gained increasing attention by the vascular community, but very little is known about the dissemination and acceptance of such technologies in certain target populations. The current study aimed to determine the user behaviour and acceptance of such digital technologies amongst patients with peripheral arterial disease (PAD). METHODS: A cross-sectional survey of consecutively treated inpatients at 12 university institutions, as well as one non-university institution, was conducted. All admitted patients with symptomatic PAD were surveyed for 30 consecutive days within a flexible timeframe between 1 July and 30 September 2021. The factors associated with smartphone use were estimated via backward selection within a logistic regression model with clustered standard errors. RESULTS: A total of 326 patients participated (response rate 96.3%), thereof 102 (34.0%) were treated for intermittent claudication (IC, 29.2% women, 70 years in median) and 198 were treated for chronic limb-threatening ischaemia (CLTI, 29.5% women, 70 years in median). Amongst all of the patients, 46.6% stated that they had not changed their lifestyle and health behaviour since the index diagnosis (four years in median), and 33.1% responded that they were not aware of the reasons for all of their medication orders. Amongst all those surveyed, 66.8% owned a smartphone (IC: 70.6%, CLTI: 64.1%), thereof 27.9% needed regular user support. While 42.5% used smartphone apps, only 15.0% used mobile health applications, and 19.0% owned wearables. One out of five patients agreed that such technologies could help to improve their healthy lifestyle. Only higher age was inversely associated with smartphone possession. CONCLUSIONS: The current survey showed that smartphones are prevalent amongst patients with peripheral arterial disease, but only a small proportion used mobile health applications and a considerable number of patients needed regular user support. Almost half of the patients did not change their lifestyle and one third were not aware of the reasons for their medication orders, emphasising room for improvement. These findings can further help to guide future projects using such applications to identify those target populations that are reachable with digital interventions.

Radiation-Free Thoracic Endovascular Aneurysm Repair with Fiberoptic and Electromagnetic Guidance: A Phantom Study.

PURPOSE: To evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom. MATERIALS AND METHODS: An anthropomorphic phantom was manufactured based on computed tomography (CT) angiography data from a patient. An aortic stent graft application system was equipped with a fiber Bragg gratings and 3 electromagnetic sensors. The stent graft was navigated in the phantom by 3 interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and CT angiography (before and after the intervention). Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent graft application system and the tip/end of the stent graft. RESULTS: The procedure resulted in technical success with a mean error below 3 mm for the entire application system and <2 mm for the position of the tip of the stent graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on par with comparable, routinely used stent graft application systems. CONCLUSIONS: The study demonstrates successful stent graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.

Automated segmentation and quantification of the healthy and diseased aorta in CT angiographies using a dedicated deep learning approach.

OBJECTIVES: To develop and validate a deep learning-based algorithm for segmenting and quantifying the physiological and diseased aorta in computed tomography angiographies. METHODS: CTA exams of the aorta of 191 patients (68.1 ± 14 years, 128 male), performed between 2015 and 2018, were retrospectively identified from our imaging archive and manually segmented by two investigators. A 3D U-Net model was trained on the data, which was divided into a training, a validation, and a test group at a ratio of 7:1:2. Cases in the test group (n = 41) were evaluated to compare manual and automatic segmentations. Dice similarity coefficient (DSC), mean surface distance (MSD), and Hausdorff surface distance (HSD) were extracted. Maximum diameter, effective diameter, and area were quantified and compared between both segmentations at eight anatomical landmarks, and at the maximum area of an aneurysms if present (n = 14). Statistics included error calculation, intraclass correlation coefficient, and Bland-Altman analysis. RESULTS: A DSC of 0.95 [0.94; 0.95] and an MSD of 0.76 [0.06; 0.99] indicated close agreement between segmentations. HSD was 8.00 [4.47; 10.00]. The largest absolute errors were found in the ascending aorta with 0.8 ± 1.5 mm for maximum diameter and at the coeliac trunk with - 30.0 ± 81.6 mm2 for area. Results for absolute errors in aneurysms were - 0.5 ± 2.3 mm for maximum diameter, 0.3 ± 1.6 mm for effective diameter, and 64.9 ± 114.9 mm2 for area. ICC showed excellent agreement (> 0.9; p < 0.05) between quantitative measurements. CONCLUSIONS: Automated segmentation of the aorta on CTA data using a deep learning algorithm is feasible and allows for accurate quantification of the aortic lumen even if the vascular architecture is altered by disease. KEY POINTS: • A deep learning-based algorithm can automatically segment the aorta, mostly within acceptable margins of error, even if the vascular architecture is altered by disease. • Quantifications performed in the segmentations were mostly within clinically acceptable limits, even in pathologically altered segments of the aorta.

Retrograde Revascularization of Tibial Arteries in Patients with Critical Limb Ischemia: Plantar-Arch Versus Transpedal Approach.

PURPOSE: To compare retrograde plantar-arch and transpedal-access approach for revascularization of below-the-knee (BTK) arteries in patients with critical limb ischemia (CLI) after a failed antegrade approach. MATERIALS AND METHODS: Retrospectively we identified 811 patients who underwent BTK revascularization between 1/2014 and 1/2020. In 115/811 patients (14.2%), antegrade revascularization of at least 1 tibial artery had failed. In 67/115 (58.3%), patients retrograde access to the target vessel was achieved via the femoral access and the plantar-arch (PLANTAR-group); and in 48/115 patients (41.7%) retrograde revascularization was performed by an additional retrograde puncture (TRANSPEDAL-group). Comorbidities, presence of calcification at pedal-plantar-loop/transpedal-access-site, and tibial-target-lesion was recorded. Endpoints were technical success (PLANTAR-group: crossing the plantar-arch; TRANSPEDAL-group: intravascular placement of the pedal access sheath), procedural success [residual stenosis <30% after plain old balloon angioplasty (POBA)], and procedural complications limb salvage and survival. Correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were tested. RESULTS: Technical success was achieved in 50/67 (75%) patients of the PLANTAR-group and in 39/48 (81%) patients of the TRANSPEDAL-group (p=0.1). Procedural success was obtained in 23/67 (34%) patients of the PLANTAR-group and in 25/48 (52%) patients of the TRANSPEDAL-group (p=0.04). In 14/49 (29%) cases with calcification at the pedal-plantar loop, technical success was not achieved (p=0.04), and in 33/44 (75%) patients with calcification at the tibial-target-lesion, procedural success was not attained (PLANTAR-group) (p=0.026). In the TRANSPEDAL-group, correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were not observed (p=0.2/p=0.4). In the PLANTAR-group, minor complications occurred in 13/67 (19%) and in the TRANSPEDAL-group in 4/48 patients (8%) (p=0.08). Limb salvage at 12 (18) months was 90% (82%) (PLANTAR-group; 95%CI 15.771-18.061) and 84% (76%) (TRANSPEDAL-group; 95%CI 14.475-17.823) (Log-rank p=0.46). Survival at 12 (18) months was 94% (86%) (PLANTAR-group; 95%CI 16.642-18.337) and 85% (77%) (TRANSPEDAL; 95%CI 14.296-17.621) (Log-rank p=0.098). CONCLUSION: Procedural success was significantly higher using the transpedal-access approach. Calcifications at pedal-plantar loop and target-lesion significantly influenced technical/procedural failure using the plantar-arch approach. No significant difference between both retrograde techniques in terms of feasibility, safety, and limb salvage/survival was found.

Instrument localisation for endovascular aneurysm repair: Comparison of two methods based on tracking systems or using imaging.

BACKGROUND: In endovascular aneuysm repair (EVAR) procedures, medical instruments are currently navigated with a two-dimensional imaging based guidance requiring X-rays and contrast agent. METHODS: Novel approaches for obtaining the three-dimensional instrument positions are introduced. Firstly, a method based on fibre optical shape sensing, one electromagnetic sensor and a preoperative computed tomography (CT) scan is described. Secondly, an approach based on image processing using one 2D fluoroscopic image and a preoperative CT scan is introduced. RESULTS: For the tracking based method, average errors from 1.81 to 3.13 mm and maximum errors from 3.21 to 5.46 mm were measured. For the image-based approach, average errors from 3.07 to 6.02 mm and maximum errors from 8.05 to 15.75 mm were measured. CONCLUSION: The tracking based method is promising for usage in EVAR procedures. For the image-based approach are applications in smaller vessels more suitable, since its errors increase with the vessel diameter.

The Relationship Between Carotid Revascularization Procedural Volume and Perioperative Outcomes in Australia and New Zealand.

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) prevent stroke in selected patients. However, each intervention carries a risk of perioperative complications including stroke or death (S/D). We aimed to determine the relationship between operator volume, hospital volume, and the perioperative risk of S/D in carotid revascularization in Australia and New Zealand. Retrospective analysis was performed on prospectively collected data extracted from the Australasian Vascular Audit between 2010 and 2017. Annual caseload volume was analyzed in quintiles (Q) using multivariate regression to assess its impact on perioperative S/D. Carotid endarterectomy procedures (n = 16 765) demonstrated higher S/D rates for lower-volume operators (2.21% for Q1-Q3 [1-17 annual cases] vs 1.76% for Q4-Q5 [18-61 annual cases]; odds ratio [OR]: 1.28; 95% CI: 1.001-1.64; P = .049). Carotid artery stenting procedures (n = 1350) also demonstrated higher S/D rates for lower-volume operators (2.63% for Q1-Q3 [1-11 annual cases] vs 0.37% for Q4-Q5 [12-31 annual cases]; OR: 6.11; 95% CI: 1.27-29.33; P = .024). No significant hospital volume-outcome effect was observed for either procedure. An inverse relationship was demonstrated between operator volume and perioperative S/D rates following CEA and CAS. Consideration of minimum operator thresholds, restructuring of services and networked referral pathways of care in Australia and New Zealand, would likely result in improved patient outcomes.

Accuracy evaluation of patient-specific 3D-printed aortic anatomy.

INTRODUCTION: 3D printing has a wide range of applications in medicine. In surgery, this technique can be used for preoperative planning of complex procedures, production of patient specific implants, as well as training. However, accuracy evaluations of 3D vascular models are rare. OBJECTIVES: Aim of this study was to investigate the accuracy of patient-specific 3D-printed aortic anatomies. METHODS: Patients suffering from aorto-iliac aneurysms and with indication for treatment were selected on the basis of different anatomy and localization of the aneurysm in the period from January 1st 2014 to May 27th 2016. Six patients with aorto-iliac aneurysms were selected out of the database for 3D-printing. Subsequently, computed tomography (CT) images of the printed 3D-models were compared with the original CT data sets. RESULTS: The mean deviation of the six 3D-vascular models ranged between -0.73 mm and 0.14 mm compared to the original CT-data. The relative deviation of the measured values showed no significant difference between the 3D-vascular and the original patient CT-data. CONCLUSION: Our results showed that 3D printing has the potential to produce patient-specific 3D vascular models with reliable accuracy. This enables the use of such models for the development of new endovascular procedures and devices.

Feasibility of an endovascular training and research environment with exchangeable patient specific 3D printed vascular anatomy: Simulator with exchangeable patient-specific 3D-printed vascular anatomy for endovascular training and research.

PURPOSE: Endovascular interventions have become standard procedures for the therapy of abdominal aortic aneurysms. Therefore, endovascular surgeons need special skills which have to be learned and trained. Additionally, authentic simulators are needed for further development of new endovascular devices and procedures. The aim of this project was to develop an authentic and modular endovascular simulation environment with patient-specific vascular anatomy for training and research purposes. MATERIAL AND METHODS: We first designed a prototype with exchangeable 3D-printed patient-specific vascular anatomy. Then, the feasibility of the prototype was validated by a simulation of an EVAR procedure in a clinical setting. RESULTS: We developed an authentic endovascular simulator with an exchangeable patient-specific vascular anatomy and performed an EVAR procedure under realistic conditions. The evaluation of the accuracy of the vascular models showed little deviation when compared with the original CT data. CONCLUSION: Endovascular simulators based on patient-specific 3D-printed vascular models can realistically mimic endovascular procedures and have the potential to be used for further development of new devices and grafts as well as for training purposes. Furthermore, in our opinion they can reduce the use of animals during developmental processes.

[Laparoscopic Treatment of Splenic Artery Aneurysm]. / Laparoskopisches Ausschalten eines Aneurysmas der A. lienalis.

OBJECTIVE: Visceral artery aneurysms are a rare but dangerous vascular pathology. The branches of the coeliac trunc are most frequently affected, especially the splenic artery. A visceral aneurysm is usually diagnosed only when a bleeding complication occurs due to rupture. It is therefore recommended to treat this pathology at an early stage after diagnosis. Endovascular elimination is the preferred procedure. However, if endovascular elimination is not suitable, the visceral aneurysm can be successfully treated by minimally invasive surgery. INDICATIONS: Splenic artery aneurysms are located at the splenic hilum, and are therefore considered to be at high risk of splenic ischemia and secondary complications following endovascular coiling. PROCEDURE: Laparoscopic treatment of splenic artery aneurysm. CONCLUSION: In the case of complex vascular pathologies unsuitable for an endovascular approach, laparoscopic treatment of splenic artery aneurysm is a safe and effective minimally invasive option and alternative.

[Modern treatment of varicose veins]. / Moderne Behandlungsverfahren der Varikose der unteren Extremität.

Varicosis of the lower limb is a common disease that can lead to edema, trophic disturbances and skin ulcerations. In addition to the classic surgical procedure of crossectomy with stripping of the saphenous vein, a growing number of minimally invasive endoluminal treatment methods has been established over the past 15 years, offering a colorful array of procedures to the modern phlebologist. It is important to choose the optimal treatment option for each individual patient.

Confocal laser microscopy as novel approach for real-time and in-vivo tissue examination during minimal-invasive surgery in colon cancer.

BACKGROUND: Histological analysis of surgical specimen is the gold standard for cancer classification. In particular, frozen histological diagnosis of vague peritoneal spots or uncertain excision of tumors plays a crucial role in the decision to proceed with or abandon an operation. Confocal laser microscopy (CLM) enables in-vivo and real-time high-resolution tissue analysis. This method has already been used during endoscopic assessments analyzing transformation of esophageal or colon mucosa. We examined whether a CLM device enables to distinguish between non-malignant and malignant tissue in vivo and real time and enables to assign peritoneal carcinomatosis spots to their primary tumor. In addition, we investigated whether the newly developed CLM camera device causes any tissue damage. METHODS: CC531 colon carcinoma cells were implanted on the serosa side of the colon and intraperitoneally in Wag/Rija rats via laparotomy. After 7 days of tumor growth, confocal laser microscopy in vivo was performed by re-laparotomy. Images of non-malignant and malignant tissue were characterized in terms of specific signal pattern. No fluorescent dye was used. Correlations to findings in conventional histology were systematically recorded and described. Potential tissue damage was examined by conventional histology. RESULTS: All animals survived the operative procedure and could be evaluated 7 days following surgery. No unexpected death occurred after surgery. Non-malignant colon is defined by small cycles of the microvilli of the colon. There is repetitive deregulated structure in colon carcinoma. Peritoneal carcinomatosis showed the same structural pattern as in primary colon carcinoma. In all examined cases, it was possible to differentiate between peritoneal carcinomatosis spots and non-malignant peritoneum. The CLM device did not cause any tissue damage. CONCLUSIONS: The CLM camera device reported here is feasible to identify peritoneal carcinomatosis spots, assign these spots to the primary tumor, as well as distinguish between non-malignant and malignant tissue in without using any fluorescent dye.

Navigation and visualisation with HoloLens in endovascular aortic repair.

INTRODUCTION: Endovascular aortic repair (EVAR) is a minimal-invasive technique that prevents life-threatening rupture in patients with aortic pathologies by implantation of an endoluminal stent graft. During the endovascular procedure, device navigation is currently performed by fluoroscopy in combination with digital subtraction angiography. This study presents the current iterative process of biomedical engineering within the disruptive interdisciplinary project Nav EVAR, which includes advanced navigation, image techniques and augmented reality with the aim of reducing side effects (namely radiation exposure and contrast agent administration) and optimising visualisation during EVAR procedures. This article describes the current prototype developed in this project and the experiments conducted to evaluate it. METHODS: The current approach of the Nav EVAR project is guiding EVAR interventions in real-time with an electromagnetic tracking system after attaching a sensor on the catheter tip and displaying this information on Microsoft HoloLens glasses. This augmented reality technology enables the visualisation of virtual objects superimposed on the real environment. These virtual objects include three-dimensional (3D) objects (namely 3D models of the skin and vascular structures) and two-dimensional (2D) objects [namely orthogonal views of computed tomography (CT) angiograms, 2D images of 3D vascular models, and 2D images of a new virtual angioscopy whose appearance of the vessel wall follows that shown in ex vivo and in vivo angioscopies]. Specific external markers were designed to be used as landmarks in the registration process to map the tracking data and radiological data into a common space. In addition, the use of real-time 3D ultrasound (US) is also under evaluation in the Nav EVAR project for guiding endovascular tools and updating navigation with intraoperative imaging. US volumes are streamed from the US system to HoloLens and visualised at a certain distance from the probe by tracking augmented reality markers. A human model torso that includes a 3D printed patient-specific aortic model was built to provide a realistic test environment for evaluation of technical components in the Nav EVAR project. The solutions presented in this study were tested by using an US training model and the aortic-aneurysm phantom. RESULTS: During the navigation of the catheter tip in the US training model, the 3D models of the phantom surface and vessels were visualised on HoloLens. In addition, a virtual angioscopy was also built from a CT scan of the aortic-aneurysm phantom. The external markers designed for this study were visible in the CT scan and the electromagnetically tracked pointer fitted in each marker hole. US volumes of the US training model were sent from the US system to HoloLens in order to display them, showing a latency of 259±86 ms (mean±standard deviation). CONCLUSION: The Nav EVAR project tackles the problem of radiation exposure and contrast agent administration during EVAR interventions by using a multidisciplinary approach to guide the endovascular tools. Its current state presents several limitations such as the rigid alignment between preoperative data and the simulated patient. Nevertheless, the techniques shown in this study in combination with fibre Bragg gratings and optical coherence tomography are a promising approach to overcome the problems of EVAR interventions.

Initial experience with the E-ventus® stent-graft for endovascular treatment of visceral artery aneurysms.

BACKGROUND: To evaluate the safety and efficacy of a novel balloon-expandable stent-graft for endovascular treatment of visceral artery aneurysms (VAA). METHODS: Between 9/2014 and 1/2017 seven patients (69±15 years) with true (N.=4) and false (N.=3) VAAs were treated by implantation of balloon-expandable stent-grafts (E-ventus®, Jotec, Hechingen, Germany) using a transfemoral (N.=2) or transbrachial (N.=5) vascular access. The stent-graft was placed without prior passing of the landing zone with a sheath. In 3 of 7 patients (42.9%) additional coil or plug embolization was performed to prevent retrograde VAA perfusion. Endpoints were technical success (defined as delivery and implantation of the stent-graft in the intended position with complete exclusion of the VAA), peri-procedural complications and patency. RESULTS: Mean diameters of true VAAs (splenic artery: N.=2, common hepatic artery: N.=1, celiac trunk: N.=1) were 26±9 and of false (common hepatic artery: N.=2, gastroduodenal artery: N.=1) 29±14 mm. False aneurysms presented as emergencies with active bleeding. Technical success was 100%. One peri-procedural complication was noted: pseudoaneurysm of the accessed brachial artery. After a mean follow-up of 187 days 6/7 stent-grafts (85.7%) were patent. One patient (fVAA) died two days after the emergency procedure owing to multi-organ failure which was assessed to be non-procedure-related. Another patient (fVAA) died 7 months from the procedure owing to cancer. CONCLUSIONS: Endovascular treatment of true and false visceral artery aneurysms by use of the E-ventus® stent-graft is safe and effective. Flexibility of the stent-graft and shaft allows for implantation without passing the lesion with a sheath, enabling treatment of distal as well as complex visceral lesions. Long-term results regarding patency in a larger patient cohort are needed to confirm these findings.

Accuracy of pre-interventional computed tomography angiography post-processing software and extravascularly calibrated devices to determine vessel diameters: comparison with an intravascularly located calibrated catheter.

Background Accurate vessel sizing might affect treatment outcome of endovascular therapy. Purpose To compare accuracy of peripheral vessel diameter measurements using pre-interventional computed tomography angiography post processing software (CTA-PPS) and extravascularly located calibrated devices used during digital subtraction angiography (DSA) with an intravascular scaled catheter (SC). Material and Methods In 33 patients (28 men, mean age = 72 ± 11 years) a SC was used during DSA of the femoro-popliteal territory. Simultaneously, one scaled radiopaque tape (SRT) was affixed to the lateral thigh, one scaled radiopaque ruler (SRR) was positioned on the angiography table. For each patient, diameters of five anatomic landmarks were measured on DSA images after calibration using different scaled devices and CTA-PPS. Diameters were compared to SC (reference) and between groups of non-obese (NOB) and obese (OB) patients. Results In total, 660 measurements were performed. Compared to the reference, SRT overestimated the diameter by 1.2% (range = -10-12, standard deviation [SD] = 4.1%, intraclass correlation coefficient [ICC] = 0.992, 95% confidence interval [CI] = 0.989-0.992, P = 0.01), the SRR and CTA-PPS underestimated it by 21.3% (range = 1-47, SD = 9.4%, ICC = 0.864, 95% CI = 0.11-0.963, P = 0.08) and 3.2% (range = 17-38, SD = 9.7%, ICC = 0.976, 95% CI = 0.964-0.983, P = 0.01), respectively. Underestimation using the SRR was greatest in the proximal superficial-femoral artery (31%) and lowest at the P2 level of the popliteal artery (15%). In the NOB group, diameter overestimation of the SRT was 0.8% (range = 4-7, SD = 4.2%, B = 0.071, 95% CI = 0.293-0.435, P = 0.08) compared to the OB group of 1.6% (range = -7-4, SD = 2.9%, B = 0.010, 95% CI = 0.474-0.454, P = 0.96). Diameter underestimation of the SRR was 17.3% (range = 13-21, SD = 3.1%, B = 0.946, 95% CI = 0.486-1.405, P = 0.002) in the NOB group, 23.3% (range = 11-36, SD = 6.6%, B = 0.870, 95% CI = 0.268-1.472, P = 0.007) in the OB group. Conclusion For calibrated measurements SRT and CTA-PPS prove accurate compared to the reference, while SRR does not. Obesity has a significant impact on underestimation of diameter if SRR is used.

Laparoscopic Confocal Laser Microscopy Without Fluorescent Injection: A Pilot Ex Vivo Study in Colon Cancer.

Introduction Histological analysis of surgical specimen is the gold standard for cancer classification. In particular, frozen histological diagnosis of vague peritoneal spots or uncertain excision of tumors plays a crucial role for proceeding with or without change of the operation procedure. Confocal laser microscopy (CLM) enables in vivo and real-time high-resolution tissue analysis. To evaluate a novel technique of CLM without any fluorescent dye, this pilot ex vivo study demonstrates a CLM camera device for minimal invasive surgical approach. Methods In 5 cases, a laparoscopic CLM camera was used for examining colon and rectum specimen. Images of nonmalignant and malignant intestinal mucosa were characterized in terms of specific signal-patterns. No fluorescent dye was used. Correlations to findings in conventional histology were systematically recorded and described. Results Using this CLM camera device, it is possible to analyze colon specimen mucosa. Nonmalignant and malignant intestinal mucosa show specific signal patterns. Nonmalignant mucosa is defined by honeycomb structure. There is deregulated structure in colon and rectum carcinoma mucosa. The inside lumen is irregular. The radial border appears swollen with reduced contrast. Discussion This pilot study shows that the assessment of colon mucosa with a prototype of CLM camera for minimally invasive surgical approach without any fluorescent dye is feasible. It is possible to differentiate between benign and malignant mucosa in colon specimen by easy to evaluate and reproducible parameters. These first steps of this pioneering achievement to establish CLM in minimal invasive surgical procedures show a great potential for a more reliable intraoperative evaluation of suspect foci.

Hippocampal volume differences between healthy young apolipoprotein E ε2 and ε4 carriers.

The apolipoprotein E (APOE) ε4 allele is the major genetic risk factor for the development of late-onset Alzheimer's disease (AD), whereas the presence of the APOE ε2 allele seems to confer protection. Here, we report that healthy young APOE ε4 carriers have statistically significantly smaller hippocampal volumes than APOE ε2 carriers, while no differences were detected between the two groups in memory performance. The difference in hippocampal morphology is cognitively/clinically silent in young adulthood, but could render APOE ε4 carriers more prone to the later development of AD possibly due to lower reserve cognitive capacity.

Influence of brain-derived neurotrophic-factor and apolipoprotein E genetic variants on hippocampal volume and memory performance in healthy young adults.

Unravelling the impact of genetic variants on clinical phenotypes is a challenging task. Apolipoprotein E (ApoE) and brain-derived neurotrophic factor (BDNF) play an important role in cell growth, regeneration, synaptic plasticity, learning and memory processes. The aim of the present study was to examine the impact of BDNF Val66Met- and ApoE-polymorphisms and their interactions on hippocampal morphology and memory functions in healthy young adults. Hippocampal volume and memory performance of 135 healthy individuals, aged 24.6 ± 3.2 years, were assessed, using magnetic resonance imaging and the Inventory for Memory diagnostics. The performance of BDNF-Met66 carriers was significantly lower in working memory (P = 0.03) compared with non carriers, whereas no further differences were observed either in cognitive performance or in hippocampal volumes between the groups. Age, BDNF Val66 Met polymorphism and the interaction factor BDNF genotype x age were significantly associated with the variation of working memory scores (P = 0.01, 0.01, 0.02 respectively). No statistically significant differences were detected in the volumes of hippocampi and in memory phenotypes between individuals carrying the ApoE E4 allele and those without it. The analysis did not reveal an impact of gene-gene interaction between BDNF and ApoE genes on hippocampal volumes or memory performance. BDNF Val66Met polymorphism seems to influence working memory function and modulate the effects of ageing on working memory in healthy young adults.