Observer Variability of Iliac Artery Measurements in Endovascular Repair of Abdominal Aortic Aneurysms

Accurate measurement of iliac arteries is essential for successful delivery of aortic endografts without iliac limb endoleak. Although intravascular ultrasound measurements may be reliable, they require an invasive procedure. Therefore, helical computed tomography (hCT) has become the most commonly used modality for obtaining preprocedure arterial diameter measurements. The accuracy of hCT remains ill-defined, however, because an anatomic gold standard with which to compare the measurements is not available. We therefore assessed inter- and intraobserver variability of hCT measurements. We also applied accepted cutoff measurements to determine the clinical impact of observer variability in predicting the need for adjunctive iliac access and iliac limb seal procedures. hCT scans were analyzed in 30 patients who had undergone successful placement of a bifurcated endograft (26 Ancure, 4 Aneurex). Mean age of patients was 75 years, the male/female ratio was 27:3. Three blinded observers measured transverse diameters (maximal aortic aneurysm [Amax], narrowest infrarenal aortic neck [Amin], maximal common iliac [Imax], and narrowest iliac artery [Imin]). Inter- and intraobserver variability was calculated as standard deviation of mean pair differences according to the method of Bland and Altman. The true incidence of adjunctive procedures to facilitate delivery of the device into the aorta and ensure iliac limb seal was compared with that predicted by the observers to obtain sensitivity, specificity, and positive (PPV) and negative predictive value (NPV) for the measurements. Interobserver variability of iliac measurements was higher than intraobserver variability (p < 0.05). Interobserver variability of Amax ranged from 4.37 to 10.73% of the mean Amax. Conversely, variability of Amin was 8.91-18.89%, that of Imax was 12.11-22.23%, and that of Imin was 10.51-18.73% (p < 0.05 vs. Amax). Therefore, interobserver variability influenced aortic neck and iliac diameter twice as much as it did aneurysm measurements. To successfully place 30 endografts we performed 8 adjunctive access procedures (4 angioplasties, 4 common iliac artery conduits) and 17 adjunctive procedures in 60 limbs to ensure limb seal (9 unilateral IIA coil embolizations, 8 stents). We used 8.5 (Ancure) and 8.0 (Aneurex) mm as lower limits of acceptability for uncomplicated access, and 13.4 (Ancure) and 16 (Aneurex) mm as the upper limits of acceptability for uncomplicated iliac limb seal. These limits were applied to measurements from the three observers to predict need for adjunctive access or iliac seal procedures in this cohort. Sensitivity, specificity, PPV, and NPV of these observer measurements for a need to perform additional access procedures were 0.67, 0.80, 0.55, and 0.87; the same values for a need to perform additional seal procedures were 0.71, 0.74, 0.52, and 0.86, respectively. Interobserver variability was approximately 20% of measured iliac diameter. This explains why helical CT measurements were noted to have low PPV in predicting the need for an adjunctive access or limb seal procedure. These data establish PPV and NPV for hCT and provide objective evidence for the need to improve iliac artery imaging. Until more accurate imaging becomes available, we recommend oversizing of iliac limbs by 10-20% in patients with wide landing zones and that surgeons be prepared to resolve unexpected iliac artery access or seal problems intraoperatively.Presented at the 13th Annual Winter Meeting of the Peripheral Vascular Surgery Society, Steamboat Springs, CO, January 31-February 2, 2004.     

Intra- and interobserver variability in the measurements of abdominal aortic and common iliac artery diameter with computed tomography. The Troms? study.

OBJECTIVES: to assess intra- and interobserver variability in the measurement of aortic and common iliac artery diameter by means of computed tomography (CT). DESIGN: reproducibility study. MATERIAL AND METHODS: three radiologists performed measurements of aortic diameter at five different levels and of both common iliac arteries with CT. Fifty-nine subjects were examined, 29 with and 30 without abdominal aortic aneurysms (AAA) as assessed by ultrasound. RESULTS: intraobserver variability varied between radiologists, measurement plane (anterior-posterior vs transverse) and measurement level. The interobserver variability was markedly higher at the bifurcation than at the suprarenal level and higher than intraobserver variability for measurements at all levels. Both intraobserver and interobserver variability increased with increasing vessel diameter and were largest in patients with AAA. The absolute intraobserver difference of the maximal infrarenal aortic diameter was 2mm or less in 94% of intraobserver pairs. The corresponding interobserver difference was 82%. CONCLUSIONS: interobserver variability of CT measurements of aortic and common iliac artery diameter is not negligible and should be taken into account when making clinical decisions. When assessing change in aortic diameter, previous CT-scans should be reviewed simultaneously as a routine to exclude interobserver variability.     

Aortoiliac morphologic correlations in aneurysms undergoing endovascular repair

PURPOSE: The feasibility of endovascular aneurysm repair depends on morphologic characteristics of the aortoiliac segment. Knowledge of such characteristics is relevant to safe deployment of a particular device in a single patient and to development of new devices for use in patients with a broader spectrum of anatomic variations. METHODS: We evaluated findings on computed tomography scans for 277 patients being considered for endovascular aneurysm repair. Aortic neck length and angulation estimates were generated with three-dimensional trigonometry. Specific centerline points were recorded, corresponding to the aorta at the celiac axis, lowest renal artery, cranial aspect of the aneurysm sac, aortic terminus, right hypogastric artery origin, and left hypogastric origin. Aortic neck thrombus and calcium content were recorded, and neck conicity was calculated in degrees. Statistical analysis was performed with the Spearman rank correlation. Data are expressed as median and interquartile range. RESULTS: Median diameter of the aneurysms was 52 mm (interquartile range, 48-59 mm) in minor axis and 56 mm (interquartile range, 51-64 mm) in major axis, and median length was 88 mm (interquartile range, 74-103 mm). Median proximal aortic neck diameter was 26 mm (interquartile range, 22-29 mm), and median neck length was 30 mm (interquartile range, 18-45 mm). The common iliac arteries were similar in diameter (right artery, 16 mm [interquartile range, 13-20 mm]; left artery, 15 mm [interquartile range, 11-18 mm]) and length (right, 59 mm [interquartile range, 50-69 mm]; left, 60 mm [interquartile range, 49-70 mm]). Median angulation of the infrarenal aortic neck was 40 degrees (interquartile range, 29-51 degrees), and median angulation of the suprarenal segment was 45 degrees (interquartile range, 36-57 degrees). By gender, sac diameter, proximal neck diameter, and iliac artery diameter were significantly larger in men. Significant linear associations were identified between sac diameter and sac length, neck angulation, and iliac artery diameter. As the length of the aneurysm sac increased the proximal aortic neck length decreased. Conversely, as the sac length decreased sac eccentricity increased. Mural thrombus content within the neck increased with increasing neck diameter. CONCLUSIONS: There is considerable variability in aortoiliac morphologic parameters. Significant associations were found between various morphologic variables, links that are presumably related to a shared pathogenesis for aberration in aortoiliac diameter, length, and angulation. Ultimately this information can be used to develop new endovascular devices with broader applicability and improved long-term results.     

The vascular anatomy anterior to the L5-S1 disk space

STUDY DESIGN: Dissection of 37 human cadavers was performed to assess the variability in the vascular anatomy anterior to the L5-S1 disc space. OBJECTIVES: To determine the variability of the anterior vascular anatomy at the L5-S1 disc space, and to assess its reliability as an anatomic landmark for the placement of anterior interbody fusion devices. SUMMARY OF BACKGROUND DATA: Although multiple studies have defined both the lumbar spinal anatomy and the anatomy of the great vessels, the relation of the great vessels to the anterior L5-S1 disc space has not been quantified directly. METHODS: This study investigated 35 human cadavers (17 males and 18 females). The anterior L5-S1 disc space and great vessel bifurcation were exposed through a transabdominal approach. Two independent observers each obtained 10 measurements in each specimen. RESULTS: The middle sacral artery was present in 100% of the specimens, averaging 2.5 mm in width. Its location in relation to the midline was quite variable, with a range greater than 2 cm in both the top and bottom of the disc. The distance from the bifurcation to the top of the L5-S1 disc averaged 18 mm (range, 7-36 mm). The total width between the left common iliac vein and the right common iliac artery averaged 33.5 mm (range, 12-50 mm). CONCLUSIONS: The middle sacral artery, present in 100% of the specimens, is a poor anatomic landmark for locating the midline at L5-S1. Because the average space available between the left common iliac vein and the right common iliac artery is 33.5 mm, and because the left common iliac vein averages only 12 mm from midline, the surgeon must be prepared to mobilize the local vasculature in most cases to expose the L5-S1 disc space adequately.     

Endovascular repair of wide neck AAA--preliminary report on feasibility and complications.

AIM: To assess the feasibility of endovascular repair (EVR) of wide neck abdominal aortic aneurysms (AAA). STUDY DESIGN: Retrospective. METHOD: A cohort of patient was identified who had an AAA neck diameter of 28 mm or more and underwent EVR. These patients undergo regular follow-up by 6 monthly CT scan of abdominal aorta. Two independent observers quantified the diameter of the suprarenal aorta, the top of the neck, the bottom of the neck, the length of the neck and the transverse diameter of the AAA. RESULTS: The study cohort comprised 16 patients. Bland Altman Analysis determined that the 95% interobserver limits of agreement were -4.7 to 3.3 mm. The mean preoperative diameter of the suprarenal aorta, the top of the neck and bottom of the neck all were 31 mm. On the follow-up CT scan on average after 12 months the suprarenal aorta measured 29 mm, the top of the neck 28 mm and the bottom of the neck 30 mm. There was a statistically significant decrease in the size of the top of the neck (p = 0.03). CONCLUSION: This preliminary report suggests that the endovascular repair of AAA with a wide neck is feasible with available commercial devices. The necks do not appear to increase in size and there is no increased incidence of proximal endoleak.     

The Validity of Ultrasonographic Scanning as Screening Method for Abdominal Aortic Aneurysm

OBJECTIVE: the sensitivity and specificity of screening for abdominal aortic aneurysms (AAAs) with ultrasonographic scanning (US) is unknown. The aim of the study was to validate US as screening test for AAAs. METHODS AND MATERIAL: 4176 (76.3%) of 5470 men aged 65-73 attended hospital-based US screening for an AAA at their local hospital. Two observers and one scanner were used. The maximal anterior-posterior (AP) of the dilated aorta, or 2 cm above the bifurcation, and at the crossing of left renal vein was recorded. In 50 cases, blinded measurements were carried out by two observers. An AAA was defined as an AP diameter greater than 29 mm. RESULTS: the standard deviation (s.d.) of the interobserver variability of the distal AP diameter was 0.84. The mean distal AP diameter was 17. 9 mm (s.d. 2.92). Combining these data, the estimated diagnostic sensitivity was 98.9%, the estimated diagnostic specificity was 99. 9%. The interobserver s.d. of the proximal AP diameter was 1.76. The mean proximal AP diameter was 18.4 mm (s.d. 2.45). Combining these data, the estimated diagnostic sensitivity was 87.4%, the estimated diagnostic specificity was 99.9%. CONCLUSION: US seems to be a valid screening method for AAA. Screening for proximal infrarenal aorta aneurysm remains acceptable because the majority of aortic diameters in this segment are so much smaller than the diameters that define an AAA.     

Morphological study of abdominal aortic aneurysm: optimal stent-graft size for Japanese patients.

PURPOSE: We report on the optimal stent-graft (SG) size for Japanese patients with abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: Ninety three Japanese patients undergoing elective AAA repair were selected for this study. The parameters measured were the proximal neck (PN) diameter (D1), the diameter of the right and left common iliac arteries (D2 and D3, respectively), the diameter of the right and left external iliac arteries (D4 and D5, respectively), the distance between the lowest renal artery and the common iliac arterial bifurcation (L1), and the distance between the right and left common iliac arterial bifurcations and the internal iliac arterial bifurcation (L2 and L3, respectively). RESULTS: The following results were obtained: D1: 20.7+/-3.9 mm (14 to 28 mm); D2: 14.0+/-3.0 mm (9.5 to 20 mm); D3: 13.8+/-3.1 mm (9 to 19.5 mm); D4: 7.5+/-1.0 mm (6 to 10 mm); D5: 7.4+/-0.9 mm (6 to 10 mm); L1: 107.7+/-13.4 mm (80 to 130 mm); L2: 40.0+/-10.1 mm (20 to 61 mm); L3: 39.7+/-9.6 mm (20 to 60 mm). CONCLUSION: The results indicate the necessity of exercising adequate care when selecting a device for Japanese patients.     

Intra- and interhospital repeatability of radionuclide left ventricular ejection fraction in post-infarction patients

OBJECTIVE: To evaluate intra- and interobserver and interhospital repeatability of radionuclide left ventricular ejection fraction in post-infarction patients. DESIGN: The study comprised 131 patients who were examined in three different hospitals 2-7 days post infarction. The radionuclide examinations were conducted in a standardized manner, and different observers carried out repeated measurements blind on the stored raw data. RESULTS: The coefficients of variation were between 1.5% and 6.2%, and limits of agreement between +/- 0.012 and 0.056. There were no significant differences between the intra- and interobserver or interhospital repeatability in average, but some significant differences between individual observers were noted. CONCLUSION: The repeatability of LVEF was acceptable, with limits of agreement in the range +/- 0.012-0.056. Some differences between observers and hence hospitals were noted, which may be of clinical relevance.     

Is three-dimensional computed tomography reconstruction justified before endovascular aortic aneurysm repair?

OBJECTIVES: The endovascular management of abdominal aortic aneurysm (AAA) relies on accurate preoperative imaging for proper patient selection and operative planning. Three-dimensional (3-D) computed tomography (CT) with reformatted images perpendicular to blood flow has gained popularity as a method of AAA assessment and image-based planning before endovascular aneurysm repair (EVAR). The current study was undertaken to determine the interobserver agreement of AAA measurements obtained with axial CT and reformatted 3-D CT and to compare the consistency of the 2 methods in selecting patients for EVAR. METHODS: Eight observers assessed the axial CT and reformatted 3-D CT scans for 5 patients with AAAs to determine whether the patients were candidates for EVAR. 3-D CT with multiplanar reformatted images was performed by Medical Media Systems (MMS). Each observer measured the length and diameter of the proximal neck, maximal AAA, aortic bifurcation, common iliac diameter, and aortic angulation. The proximal neck and common iliac arteries were also assessed for thrombus, calcification, and tortuosity. Agreement of the measurements on axial CT scans was compared with those on MMS CT scans by calculating the kappa statistic. Complete agreement was defined as kappa = 1.0. The limits of agreement between observers were also calculated. RESULTS: The cumulative interobserver agreement of MMS CT scans (kappa =.81) was greater than for axial CT scans (kappa =.59). The kappa value for each of the diameter measurements was greater with the MMS CT scans. In 79% of cases the observers' measurements were less than 2 mm from the mean with MMS CT, compared with 59% for axial CT. The kappa value for deciding whether a patient was an endograft candidate on the basis of aortic neck was greater with the MMS CT (0.92 vs 0.63). The limits of agreement between observers were also better with the MMS CT. CONCLUSIONS: The interobserver agreement in planning EVAR is significantly better with MMS CT compared with traditional axial CT. The routine use of MMS CT appears justified before EVAR to improve the accuracy and consistency of patient selection.     

国人腹主动脉瘤累及髂动脉的解剖学特征与髂动脉分支支架适用性：单中心58例分析

目的:通过单中心临床调查,分析腹主动脉瘤(AAA)累及髂动脉国人患者的髂动脉解剖学特点与髂动脉分支支架(IBD)适用性的关系。方法:回顾性分析2015年7月—2017年3月复旦大学附属中山医院血管外科58例累及双侧或单侧髂总动脉的AAA患者,利用3D工作站分析其影像学资料,并进行相关数据测量分析,结合基于解剖特点的使用标准,分析两款IBD(Cook IBD,Gore IBE)在患者中的适用性及其限制因素。结果:58例AAA患中,49例累及双侧髂总动脉,9例累及单侧髂总动脉。病变髂总动脉的平均长度分别为左侧(57.9±18.1)mm,右侧(56.7±17.4)mm,平均最大直径分别为左侧(17.7±7.2)mm,右侧(25.1±9.4)mm。根据两款支架使用标准,Cook IBD与Gore IBE治疗病变髂动脉的适用比率分别为26.1%(28/107)、20.6%(22/107)。Cook IBD最主要的限制因素是髂内动脉直径6或9 mm(50/107,46.7%);Gore IBE最主要的限制因素是髂总动脉直径25 mm(67/107,62.6%)。结论:基于解剖标准的IBD在AAA累及髂动脉国人患者中适用性较低,髂总动脉和髂内动脉直径的不符合是其主要限制因素。     

The right retroperitoneal approach on abdominal aortic aneurysm with an isolated left-sided inferior vena cava. Report of a case

We report herein the case of a 78-year-old man found to have abdominal aortic aneurysm (AAA) with an isolated left-sided inferior vena cava (IVC). The patient was admitted to our hospital to undergo surgery for the AAA. The computed tomography revealed the sacular aneurysm of the infrarenal abdominal aorta (60 x 40 mm) and right common iliac aneurysm (30 x 30 mm). At the same time the left sided IVC was found by the CT. This IVC (13 mm wide) ascended 76 mm, dorsally to the ureter, the left side of the AAA from the right common iliac artery to the left renal artery. We performed aneurysmectomy and 20 mm knitted Dacron bifurcating graft replacement by the right retroperitoneal approach without manipulating the left-sided IVC. The procedure was completed without incident and the patient has continued to do well.     

The reliability of the Mankin score for osteoarthritis.

For the histopathological classification of the severity of osteoarthritic lesions of cartilage, the Mankin score is frequently used. A necessary constraint on the validity of this scoring system is the consistency with which cartilage lesions are classified. The intra- and interobserver agreement of the Mankin score was determined. The intra- and interobserver agreement of the 14-point Mankin score was adequate. Between observers 95% of differences were less than approximately 7 points. By a more strict definition of the elements of the Mankin score, the intraobserver differences were reduced only for some observers. The interobserver differences were only slightly reduced: between observers 95% of differences were less than approximately 6 points. We found the Mankin score to be an adequate histopathological tool.     

Simultaneous coronary artery bypass grafting and ascending aorta bifemoral bypass in small aorta syndrome.

A 55-year-old man with severe coronary artery disease and aortoiliac occlusive disease with small aorta syndrome was admitted to our department with angina pectoris and bilateral claudication. Intravenous subtraction angiography showed total occlusion of the right common iliac artery and 99% stenosis of the left common iliac artery with a markedly hypoplastic infrarenal aorta only 9 mm in diameter. It also revealed 90% stenosis at the origin of the left subclavian artery. Coronary angiography showed total occlusion of the left anterior descending artery and 90% stenosis of the circumflex artery. Simultaneous coronary artery bypass grafting and an ascending aorta-bifemoral bypass were conducted using an in-situ right internal mammary artery graft, an autologous saphenous vein graft, and a Y-figured expanded polytetrafluoroethylene graft. Postoperative angiography showed grafts to the coronary and bifemoral arteries were patient. This combined procedure is useful for patients with coronary artery disease and aortoiliac occlusive disease, especially in those with small aorta syndrome.     

Impact of aortoiliac tortuosity on endovascular repair of abdominal aortic aneurysms: evaluation of 3D computer-based assessment.

OBJECTIVE: The purpose of this study was to examine the effect of aortoiliac tortuosity, as assessed by observers and 3-dimensional (3D) computer-based methods, on the conduct and outcome of endovascular repair of abdominal aortic aneurysms. METHODS: Infrarenal aortoiliac tortuosity was measured in 75 patients (mean follow-up, 14.8 +/- 10.4 months) who underwent endovascular repair of abdominal aortic aneurysms by using the following four methods: (1) grading by 2 experienced observers; (2) tortuosity index measured as the inverse radius of curvature (cm(-1)) at 1-mm intervals along the median luminal centerline (MLC) on 3D reconstructions of computed tomography (CT) angiograms and was calculated as the sum of values greater than 0.3 cm(-1); (3) MLC-straight line length ratio from renal to hypogastric arteries; (4) manual measurement of angles at points of angulation on anteroposterior and lateral projections of 3D CT reconstructions. In evaluating association between these measures, correlation between human observers was accepted as the gold standard. RESULTS: For rating of overall aortoiliac tortuosity, interobserver correlation (r = 0.67) was comparable with correlation of observers with tortuosity index (r = 0.67 and 0.56), whereas correlations of each observer with MLC-straight line ratio (r = 0.50 and 0.56) and cumulative angulation (r = 0.44 and 0.44) were significant but weaker. For determining the relative tortuosity of right and left aortoiliac access, agreement between observers and tortuosity index (54% and 58%; P < .05; kappa, 0.33 and 0.38) was not as good as between observers (68%; P < .001; kappa, 0.53). This difference was primarily related to evaluation of the aorta, where interobserver correlation (r = 0.71) was better than that between each observer and tortuosity index (r = 0.47 and 0.55), whereas correlations in the iliac arteries were comparable (r = 0.64 and 0.67) (all coefficients P < .01). Increased tortuosity was associated with a more complex endovascular repair, as reflected by longer fluoroscopy time (P = .05), use of more contrast material (P = .03), use of extender modules (P = .04), and more frequent use of arterial reconstruction (P = .01), but was not associated with a higher overall complication rate. Increased tortuosity, when it occurred in the aortic neck, was associated with predischarge endoleak (P = .03) but not with late endoleak, intervention, or aneurysm-related adverse events. CONCLUSION: Aortoiliac tortuosity is associated with increased complexity of endovascular aneurysm repair and with predischarge endoleak but does not appear to affect intermediate-term results. Computer-based 3D measurement of aortoiliac tortuosity is feasible and clinically meaningful. Its ultimate role in relation to human assessment must be further defined in future studies.     

腔内修复术治疗孤立性髂动脉瘤14例

目的探讨腔内治疗孤立性髂动脉瘤的疗效。方法回顾性分析2004年10月至2006年5月腔内修复孤立性髂动脉瘤14例的临床资料。其中,右髂总动脉瘤8例,左髂总动脉瘤5例,左髂内动脉瘤破裂1例。髂动脉瘤腔内修复的标准是瘤体直径〉3．0cm。结果14例均取得技术成功。8例右髂总动脉瘤,钢圈栓塞右髂内动脉后选用分叉支架型人工血管行腔内修复术。其中1例右髂总动脉瘤累及腹主动脉下端,选用AUl支架型人工血管腔内修复加股．股动脉旁路术。5例左髂总动脉瘤栓塞同侧髂内动脉后选用直型支架型人工血管。1例左髂内动脉瘤破裂急诊行钢圈栓塞后选用直型支架覆盖左髂内动脉开口。术后即刻数字减影血管造影显示动脉瘤消失,远近端支架型人工血管与宿主动脉结合处均未见明显渗漏。1例术后出现急性左心功能不全和肺水肿,经抢救痊愈,其余13例无手术并发症。术后CTA随访10．2个月（3～19个月）,瘤体无增大,支架无移位,无内漏,旁路人工血管通畅。结论腔内修复术治疗孤立性髂动脉瘤具有可行、安全、微创等特点,近期疗效较好,远期效果需进一步随访。     

Type B aortic dissection with rupture of the left common iliac artery: a case report

Type B aortic dissection involves the appearance of a false lumen distal to the left subclavian artery and extending distally into the descending thoracic aorta and into the abdominal aorta. Complications of the dissection include rupture of the thoracic aorta, leg ischemia, visceral ischemia, and renal failure. A 37-year-old man presented with complaints of sudden onset of chest pain, left leg pain, and numbness. Examination revealed no femoral, popliteal, or distal pulses with decreased sensory and motor function on the left lower extremity. A CT scan revealed an aortic dissection at the proximal descending aorta extending into the iliac arteries with a left retroperitoneal hematoma at the iliac bifurcation. An MRI confirmed the dissection distal to the left subclavian artery into the iliac artery with a distal occlusion. Exploration revealed rupture of the left iliac artery dissection with arterial occlusion and a contained hematoma. The common iliac artery was ligated and an 8-mm Dacron bypass graft from the right common femoral artery to the left femoral artery was performed. Type B aortic dissection can present as rupture of the common iliac artery. Revascularization of the extremity with a femoral-femoral crossover graft is the recommended procedure in the absence of visceral ischemia. The surgeon should have a keen suspicion of this rare complication and its management.     

Intraoperative detection of segmental wall motion abnormalities with transesophageal echocardiography

PURPOSE: To compare two methods of analysis of regional wall-motion (RWM) using transesophageal echocardiography (TEE). METHODS: Thirty patients undergoing coronary artery bypass surgery were studied. The transgastric short axis view at the mid-papillary level was recorded before and after cardiopulmonary bypass. All images were reviewed by an anesthesiologist trained in TEE and an echocardiographer. Regional wall motion was graded: 1 normal, 2 hypokinetic, 3 akinetic, and 4 dyskinetic. The left ventricle was evaluated according to the guidelines of the American Society of Echocardiography using 6-segment, and 4-segment models. Agreement between observers (interobservers), and for one observer at two different moments (intraobservers), for grading each segment was defined as RWM abnormality scores within 1 grade. A wall-motion score index (WMSI), which is the sum of individual scores divided by the number of segments visualized, was calculated. A Bland Altman analysis was used to assess interobserver variability. RESULTS: Agreement between observers occurred in 96% and 94% of the examined segments, using 4- and 6-segment models respectively. Intraobserver agreement was 99% and 97% for the 4- and 6-segment models. The mean differences (bias) of the interobserver variability in grading the segments were 0.04 +/- 0.79 and 0 +/- 0.72 using a 4- or 6-segment model. The mean difference of the interobserver variability in WMSI were -0.05 +/- 0.42 and 0.05 +/- 0.37 using a 4- or a 6-segment model. CONCLUSION: Both methods, using either a 4- or a 6-segment model, result in a high intraobserver and interobserver agreement, and a low interobserver variability.     

Die stentgestützte Aneurysmaausschaltung mit dem TALENT-System

Introduction The TALENT system has made it feasible for the first time to use endovascular stent placement in the treatment of infrarenal aneurysms of the abdominal aorta with neck diameters greater than 26 mm. The following paper presents the experience of 29 German vascular surgical centers using the TALENT system. Materials and Methods Between October 1996 and September 1997, a total of 123 aortic aneurysms in 122 patients were treated endovascularly. Ninety-five infrarenal aneurysms of the abdominal aorta were treated using bifurcated stents, while in 28 cases tube stents were implanted. In nine cases, tube stents were used to treat aneurysm of the thoracic aorta. A total of 111 patients (112 aneurysms) presented for follow-up. The average proximal diameter of the bifurcated stents in infrarenal aneurysms was 30 mm (range 24–36 mm), while the average iliac stent diameter was 14 mm (range: 10–20 mm). In tube stents, diameters ranged from 24–30 mm in abdominal stents and from 32–40 mm in thoracic stents, respectively. In this series, each stent was individually manufactured for the patient on the basis of findings from computed tomography (CT) and calibrated angiography. Results Endovascular treatment of aneurysms was successful technically in 96% of patients. During a follow-up period averaging 4.3 months, the following complications were observed: 5 perioperative death (4.1%), 4 conversions to open surgical therapy (3.3%), 7 endoleaks (5.7%), 2 stent dislocations, 2 iliac stent thromboses, 2 perforations of iliac arteries, 1 inguinal hematoma, and 1 inguinal infection. Conclusions These preliminary findings show that aneurysms with larger neck diameters are amenable to endovascular treatment. Despite the wide distribution of participating vascular surgery centers with varying degrees of experience and many first-time implantations, the results of the present multicenter study hardly differed from those reported in larger series in established institutions. Through the use of larger-diameter stents, up to 50% of all infrarenal aneurysms of the abdominal aorta may be possibly successfully treated using endovascular methods.     

Comparison of a computer-assisted laser pachometer with two ultrasonic pachometers in normal corneas

A computer-assisted laser pachometer was compared with two ultrasonic pachometers for intra- and interobserver error. Two observers each performed two examinations at 11 predetermined locations on the corneas of six subjects. The laser pachometer was found to have intra- and interobserver errors comparable to both of the ultrasonic pachometers. By performing multiple examinations on three subjects, the laser pachometer was found to have an average standard deviation of +/- 0.012 mm. Unlike ultrasonic pachometers, the laser pachometer has the advantage of being a noncontact method of evaluating corneal thickness, and does not require topical anesthesia; the trauma and anesthesia might alter corneal thickness by inducing epithelial edema. The nasal cornea was found to be slightly thicker than the temporal cornea in most patients. Lid closure for three hours caused a consistent thickening (about 6.3%) of central and peripheral cornea.     

Simultaneous pancreaticoduodenal-kidney transplantation in rats.

AIMS: To establish a stable and simple simultaneous pancreaticoduodenal-kidney transplantation model in rats. METHODS: Pancreaticoduodenal-kidney (left) and 1 cm of the inferior vena cava (IVC) with 0.5 cm left and right iliac communis vein were harvested from donors. We performed 'cuff' anastomoses between (1) portal vein and right iliac communis vein and (2) left kidney vein and left iliac communis vein, converging donor portal vein and left kidney vein into IVC together. Next, we performed an anastomosis of donor arterial segment and recipient abdominal aorta and a 'cuff' anastomosis between donor IVC and recipient left kidney vein. RESULTS: Of 40 transplanted rats in which diabetes was induced, 33 survived over 7 days, and 31 rats have survived over 4 months. 30 rats' nonfasting plasma glucose levels were euglycemic. CONCLUSIONS: We performed three 'cuff' anastomoses to simplify the surgical procedure and to shorten the ischemic period of the graft. The recipient vein system has an integrated membrane to avoid thrombi in venous anastomosis sites, enhancing the transplantation success rate.