Inter- and Intra-Observer Variability and the Effect of Experience in Cine-MRI for Adhesion Detection.

Cine-MRI for adhesion detection is a promising novel modality that can help the large group of patients developing pain after abdominal surgery. Few studies into its diagnostic accuracy are available, and none address observer variability. This retrospective study explores the inter- and intra-observer variability, diagnostic accuracy, and the effect of experience. A total of 15 observers with a variety of experience reviewed 61 sagittal cine-MRI slices, placing box annotations with a confidence score at locations suspect for adhesions. Five observers reviewed the slices again one year later. Inter- and intra-observer variability are quantified using Fleiss' (inter) and Cohen's (intra) κ and percentage agreement. Diagnostic accuracy is quantified with receiver operating characteristic (ROC) analysis based on a consensus standard. Inter-observer Fleiss' κ values range from 0.04 to 0.34, showing poor to fair agreement. High general and cine-MRI experience led to significantly (p < 0.001) better agreement among observers. The intra-observer results show Cohen's κ values between 0.37 and 0.53 for all observers, except one with a low κ of -0.11. Group AUC scores lie between 0.66 and 0.72, with individual observers reaching 0.78. This study confirms that cine-MRI can diagnose adhesions, with respect to a radiologist consensus panel and shows that experience improves reading cine-MRI. Observers without specific experience adapt to this modality quickly after a short online tutorial. Observer agreement is fair at best and area under the receiver operating characteristic curve (AUC) scores leave room for improvement. Consistently interpreting this novel modality needs further research, for instance, by developing reporting guidelines or artificial intelligence-based methods.

[Pneumomediastinum: intervention is not always necessary]. / Pneumomediastinum: ingrijpen is niet altijd vereist.

Pneumomediastinum is characterized by the presence of free air in the mediastinum. This can be a sign of a severe underlying disorder that requires urgent intervention. However, pneumomediastinum is also associated with other causes that can be treated conservatively. Here, we describe three patients who presented with a primary or spontaneous pneumomediastinum and a secondary pneumomediastinum due to traumatic or iatrogenic perforation. Recognition of the underlying cause of pneumomediastinum is essential for further diagnostic studies and patient management. Unnecessary investigations and interventions, which may cause further harm to and hospitalization of the patient, can thereby be prevented.

Through-Plane Movement at Multiple Aortic Levels on Dynamic Computed Tomography Angiography Is Limited in Patients With an Abdominal Aortic Aneurysm.

PURPOSE: To analyze the movement of the aorta in the craniocaudal direction (through-plane movement) during the cardiac cycle at several levels to determine any potential impact on endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA). METHODS: For this study, 30 patients (median age 73.0 years; 27 men) with an infrarenal AAA were randomly selected from a prospectively maintained EVAR database. All patients had undergone preoperative electrocardiogram-gated computed tomography angiography consisting of 8 phases. After semiautomatic segmentation, a 3-dimensional location probe was placed in the center of the aorta (center point) on the orthogonal slices at 12 different levels along the aorta and iliac arteries for all 8 phases. Movement of the center point during the cardiac cycle was analyzed for each level. Values are given as the median and interquartile range (IQR). RESULTS: The median through-plane movement of all levels was 3.0 mm (IQR 2.8-3.2) and appeared to be lower in the region of the celiac and renal arteries: 2.6 mm (IQR 1.7-3.1) at 3 cm proximal to the most distal renal artery and 2.4 mm (IQR 1.9-2.9) at 1 cm distal to the most distal renal artery, respectively. The thoracic part of the aorta showed the largest through-plane motion: 4.1 mm (IQR 2.7-4.6). CONCLUSION: This study quantifies aortic through-plane motion in the craniocaudal direction. Since through-plane movement appears to be limited, findings of previous studies investigating pulsatile in-plane distension seem to be representative for aortic distension.

Preoperative infra- and suprarenal aortic pulsatile distension is comparable between relatively young and older patients with an abdominal aortic aneurysm.

BACKGROUND: Young healthy individuals have a large aortic pulsatile distension during the cardiac cycle. In patients with an abdominal aortic aneurysm (AAA), aortic distension during the cardiac cycle is associated with stent graft migration. However, whether the pulsatile distension is larger in relatively young patients with an AAA compared to older AAA patients is unknown. This study investigated whether preoperative pulsatile aneurysm neck distension is related to age. METHODS: From our database of endovascular aneurysm repair (EVAR), we selected 25 consecutive male patients ≤65 years of age (group 1) and 25 consecutive patients >65 years of age (group 2). All patients had a preoperative electrocardiogram-triggered computed tomography angiography scan consisting of 8 phases. Aortic area and diameter changes per heartbeat were measured at 2 levels: (A) 3 cm above and (B) 1 cm below the most distal renal artery. RESULTS: In group 1 compared to group 2, distension during the cardiac cycle at level A was 1.6 ± 0.4 versus 1.5 ± 0.4 mm (P = 0.62), and the aortic area increase was 45.4 ± 19.6 versus 41.7 ± 20.8 mm(2) (P = 0.52). Aortic distension at level B was 1.4 ± 0.3 versus 1.5 ± 0.4 mm (P = 0.79), and the area increase was 35.5 ± 12.0 versus 35.0 ± 15.5 mm(2) (P = 0.90). CONCLUSIONS: Preoperative pulsatile aneurysm neck distension did not differ between younger and older patients; therefore, we do not expect young patients to have more pulsatile distension-related complications after EVAR.

Results of endovascular repair of infrarenal aortic aneurysms using the Endurant stent graft.

OBJECTIVE: Recent reports showed that the Endurant stent graft (Medtronic Cardiovascular, Santa Rosa, Calif) is safe and effective for endovascular repair of abdominal aortic aneurysms (AAAs). However, due to its relatively recent introduction, only short-term follow-up data are available. This study presents the 4-year results using this device. METHODS: All clinical data, including detailed anatomic information of the first 100 consecutive patients treated with the Endurant stent graft for an infrarenal AAA in three Dutch high-volume hospitals, were prospectively collected. Computed tomography angiography was routinely performed before the procedure, ≤ 1 month, and at 1 year post-endovascular aneurysm repair. Thereafter, the imaging modality during yearly follow-up was individualized (duplex ultrasound imaging or computed tomography angiography). Patients were classified as within or outside the instructions for use (IFU) for analysis. Study end points were primary clinical success, overall and AAA-related mortality, and sac morphology changes and endoleak during follow-up. Estimates were obtained using Kaplan-Meier plots. RESULTS: The study included 100 consecutive patients (88 men) with a median age of 74 years (interquartile range [IQR], 67-79 years) and median AAA diameter of 58 mm (IQR, 55-65 mm), between December 2007 and March 2009. Twenty patients (20%) were treated outside the IFU (18, outside proximal neck IFU, one outside iliac IFU, and one outside both IFUs). Median follow-up was 48 months (IQR, 36-53 months), and no patients were lost. One contained rupture was observed after 1.5 months due to graft infection. No patients had graft migration. Two type Ia endoleaks, 5 type Ib endoleaks, and 15 type II endoleaks were found. Primary clinical success was 97%, 90%, 84% and 77% at 1, 2, 3, and 4 years, respectively. Primary clinical success was comparable for patients treated within or outside IFU (P = .20), although both patients outside iliac IFU needed a secondary iliac intervention. Over time, maximum aneurysm diameter decreased ≥ 5 mm, remained stable, and increased ≥ 5 mm in 58%, 32%, and 10% of the patients, respectively. All-cause mortality was 20% at 4 years, with a 3% AAA-related mortality. CONCLUSIONS: The 4-year follow-up data of the Endurant stent graft for AAA treatment shows its use results in a low AAA-related mortality with adequate prevention of rupture or aneurysm growth. Although patients with very challenging anatomy were treated in our series, primary clinical success rates were comparable for patients treated within and outside the IFU. However, both patients outside the iliac IFU needed a secondary iliac intervention. The knowledge of the present results may aid in improving outcomes in the future.

Technical considerations and results of chimney grafts for the treatment of juxtarenal aneursyms.

OBJECTIVE: To present our initial experience and technical considerations for the use of chimney grafts in the treatment of patients that require endovascular aneurysm repair with aortic branch preservation. METHODS: All patients treated with a chimney procedure between October 2009 and June 2011 were included in our analyses. Chimney procedures were only performed in patients that were unsuitable for open repair and without opportunity to use fenestrated grafts (because of unsuitable anatomy or emergency operation). Open brachial or axillary access was used to deploy covered chimney grafts in the target vessels, and subsequently, a stent graft was deployed via femoral cut-down access. RESULTS: Thirteen patients (12 males; mean age, 77.2 ± 6.2 years; mean maximal diameter, 71.4 ± 10.2 mm) underwent a chimney procedure with the preservation of 22 aortic side branches. Primary technical success was 92.3% due to occlusion of one renal artery within 24 hours. Thirty-day mortality was 0%. Infrarenal mean neck length was 2.6 mm ± 3.2 mm (range, 0-8 mm) and could be extended to 27.3 mm ± 9.9 mm (range, 18-53 mm) by the use of chimney grafts. During follow-up (median, 10.8 months; interquartile range, 7.4-19.4), one patient died from complications from mesenteric ischemia based on a stenosis of the celiac trunk attributable to the bare stent of the stent graft, and one patient died from aneurysm rupture. Other complications included late occlusion of one renal artery and a type II endoleak, which was unsuccessfully treated with coil embolization and required laparotomy. If we disregard the ruptured patient who had an enormous increase of aneurysm diameter, mean aortic aneurysm diameter reduced from 70.7 ± 10.3 mm (range, 54-89 mm) to 66.7 ± 13.9 mm (range, 48-96 mm) during follow-up (P = .13). In three patients, the aneurysm diameter decreased by more than 5 mm and in two patients, the diameter increased by more than 5 mm. The aneurysm diameter remained stable in the other eight patients. CONCLUSIONS: Until off-the-shelf fenestrated or branched stent grafts become available, the chimney procedure offers a minimally invasive treatment option in patients requiring aneurysm exclusion with side branch revascularization. Although long-term follow-up has to be awaited, the initial results show that chimney grafts can help to decrease or stabilize the aneurysm diameter in most patients, but aneurysm rupture was not prevented in all patients.

The double two-chimney technique for complete renovisceral revascularization in a suprarenal aneurysm.

Suprarenal pathologies can be treated with immediately available devices with the chimney technique, which offers a bail-out in patients not eligible for a branched or fenestrated stent graft. We present an adjusted chimney technique for total renal and visceral revascularization in a patient with a suprarenal aneurysm. Although short-term results look promising, longer follow-up is anticipated.

Incidence and treatment results of Endurant endograft occlusion.

OBJECTIVE: The Endurant endograft (Medtronic Inc, Minneapolis, Minn) is a new-generation device specifically developed to perform well in complex abdominal aortic aneurysm anatomy. Previous reports on the 1- and 2-year results of endovascular aneurysm repair (EVAR) with the Endurant endograft showed excellent outcome, including prevention of migration and type I endoleaks, but occurrence and outcome of post-EVAR occlusion have not been determined in a large multicenter patient cohort with midterm follow-up, which is the objective of this study. METHODS: Data of consecutive patients treated with the Endurant from December 2007 to April 2012 in three Dutch tertiary vascular referral hospitals were prospectively gathered and retrospectively analyzed. Follow-up consisted of regular office visits, computed tomography angiography at 1 and 12 months after EVAR, and subsequently, duplex ultrasound imaging or computed tomography angiography at regular intervals. Patients with ruptured aneurysms or with earlier abdominal aortic surgery were excluded. The incidence and clinical outcome of endograft occlusions were analyzed. An expert review board assessed all cases in the search for possible causes of occlusion. RESULTS: Included were 496 patients (87.7% male), who were a median age of 74 years (range, 68-78 years). Median follow-up was 1.7 years (range, 0-4.6 years). Twenty graft occlusions (4.0%) occurred during follow-up. Median time between primary EVAR and detection of the occlusion was 1 month, with 55% occurring ≤ 60 postoperative days and 90% ≤ 1 year. No association was found between occlusion and sex (P = .28), age (P = .96), or use of an aortouniiliac device (P = .66). Technical error was the considered cause of the occlusion in 12 patients (60%). The estimated freedom from occlusion was 98.4% at 30 days, 95.7% at 1 year, and 95.3% at 3 years. Presenting symptoms of occlusion were acute limb ischemia in 50%. Treatment was surgical (75%) or percutaneous (25%). Successful revascularization was achieved in 17 of 20 patients, but reocclusions occurred in five, resulting in a transfemoral amputation in one patient. Occlusion-related mortality was 0.6% (3 of 496). CONCLUSIONS: At a median follow-up of 1.7 years, Endurant endograft occlusion occurred in 4.0% of 496 patients. Most occlusions occurred ≤ 2 months after EVAR, and rarely after 1 year. A technical justification for occlusion could be found for 60% of patients. A more liberal intraoperative and early postoperative (re)intervention strategy may reduce the occlusion rates and improve outcome.

Intraluminal abdominal aortic aneurysm thrombus is associated with disruption of wall integrity.

OBJECTIVE: An association of intraluminal thrombus (ILT) with abdominal aortic aneurysm (AAA) growth has been suggested. Previous in vitro experiments have demonstrated that aneurysm-associated thrombus may secrete proteolytic enzymes and may develop local hypoxia that might lead to the formation of tissue-damaging reactive oxygen species. In this study, we assessed the hypothesis that ventral ILT thickness is associated with markers of proteolysis and with lipid oxidation in the underlying AAA vessel wall. METHODS: Ventral AAA tissue was collected from asymptomatic patients at the site of maximal diameter during open aneurysm repair. Segments were divided, one part for biochemical measurements and one for histologic analyses. We measured total cathepsin B, cathepsin S levels, and matrix metalloproteinase (MMP)-2 and MMP-9 activity. Myeloperoxidase and thiobarbituric acid reactive substances were determined as measures of lipid oxidation. Histologic segments were analyzed semiquantitatively for the presence of collagen, elastin, vascular smooth muscle cells (VSMCs), and inflammatory cells. Preoperative computed tomography angiography scans of 83 consecutive patients were analyzed. A three-dimensional reconstruction was obtained, and a center lumen line of the aorta was constructed. Ventral ILT thickness was measured in the anteroposterior direction at the level of maximal aneurysm diameter on the orthogonal slices. RESULTS: Ventral ILT thickness was positively correlated with aortic diameter (r=0.25; P=.02) and with MMP-2 levels (r=0.27; P=.02). No biochemical correlations were observed with MMP-9 activity or cathepsin B and S expression. No correlation between ventral ILT thickness and myeloperoxidase or thiobarbituric acid reactive substances was observed. Ventral ILT thickness was negatively correlated with VSMCs (no staining, 18.5 [interquartile range, 12.0-25.5] mm; minor, 17.6 [10.7-22.1] mm; moderate, 14.5 [4.6-21.7] mm; and heavy, 8.0 [0.0-12.3] mm, respectively; P=.01) and the amount of elastin (no staining, 18.6 [12.2-30.0] mm; minor, 16.5 [9.0-22.1] mm; moderate, 11.7 [2.5-15.3] mm; and heavy 7.7 [0.0-7.7] mm, respectively; P=.01) in the medial aortic layer. CONCLUSIONS: ILT thickness appeared to be associated with VSMCs apoptosis and elastin degradation and was positively associated with MMP-2 concentrations in the underlying wall. This suggests that ILT thickness affects AAA wall stability and might contribute to AAA growth and rupture. ILT thickness was not correlated with markers of lipid oxidation.

Annual rupture risk of abdominal aortic aneurysm enlargement without detectable endoleak after endovascular abdominal aortic repair.

OBJECTIVES: Whether abdominal aortic aneurysm (AAA) enlargement after endovascular aneurysm repair (EVAR), without an identifiable endoleak, is a risk factor for AAA rupture remains controversial. To our knowledge, studies including large patient numbers investigating this topic have not been done. Therefore, a considerable number of conversions to open AAA repair have been performed in this patient group. This study evaluated AAA rupture risk in patients without detectable endoleaks but with AAA enlargement after EVAR treatment. METHODS: Baseline characteristics and follow-up data were collected prospectively by case record forms. Follow-up visits were scheduled at 1, 3, 6, 12, 18, and 24 months, and annually thereafter. The follow-up assessment included clinical examination and imaging studies. Patients were divided into three groups according to the degree of shrinkage or enlargement of the aneurysm. Group A included patients with >8 mm aneurysm shrinkage, group B consisted of patients with ≤ 8 mm shrinkage to ≤ 8 mm enlargement, and group C patients had an aneurysm enlargement of >8 mm. RESULTS: The basis for this analysis was 6337 patients who were enrolled prospectively in the European Collaborators on Stent-Graft Techniques for Aortic Aneurysm Repair (EUROSTAR) database between 1996 and 2006. Group A included 691 patients; group B, 5307 patients; and group C, 339 patients. Ruptures occurred in 3 patients in group A, in 14 patients in group B, and in 9 patients in group C. The annual rate of rupture in group C was <1% in the first 4 years but accelerated to 7.5% up to 13.6% in the years thereafter. The mortality rate of elective conversion to open AAA repair was 6.0%. CONCLUSIONS: The risk of rupture in patients with an AAA enlargement of 8 mm after EVAR, without detectable endoleaks, is <1% in the first 4 years. No ruptures were seen in patients with AAA enlargement without detectable endoleaks who were not treated with Vanguard stent grafts (Boston Scientific Corp, Natick, Mass) and had AAA diameters <70 mm. For this group, conversion to open repair might not be mandatory, and regular follow-up can be advised instead. After 4 years of follow-up, this study observed an increased annual rupture risk, which might indicate the need for conversion; however, groups are small, and follow-up bias could play a role.

How to define a positive circumferential resection margin in T3 adenocarcinoma of the esophagus.

A positive circumferential resection margin (CRM) is associated with poor survival after esophagectomy for cancer. The Royal College of Pathologists (RCP) defines a CRM when tumor is found <1 mm of the lateral margin whereas the College of American Pathologists (CAP) defines CRM when tumor cells are located at the lateral margin. This study evaluates the clinical prognostic significance of CRM on overall survival (OS) and disease-free survival (DFS) in patients who underwent esophagectomy for T3 esophageal adenocarcinoma. Analysis included 132 patients. CRM was found in 26 cases (19.7%) corresponding to CAP criteria versus 89 cases (67.4%) corresponding to RCP criteria. Median OS using RCP criteria was 16.4 (95%CI, 8.5-24.2) months for CRM patients versus 21.0 (95%CI 16.3-25.6) months in CRM patients (P=0.144). With CAP criteria, median OS in CRM and CRM patients was 9.4 (95%CI, 7.6-11.2) months versus 21.6 (95%CI, 18.9-24.3) months, respectively (P=0.000). Median DFS using RCP criteria was 18.0 (95%CI, 11.5-24.6) months for CRM patients versus 11.0 (95%CI, 8.1-14.0) months for CRM patients (P=0.257). Applying the CAP criteria, median DFS in CRM and CRM patients was 16.3 (95%CI, 10.6-22.0) months versus 7.0 (95%CI, 6.3-7.8) months, respectively (P=0.000). Effects of a CRM according to CAP criteria remained significant after multivariate testing [OS: hazard ratio (HR), 2.43; 95%CI, 1.52-3.90; DFS: HR, 2.09; 95%CI, 1.32-3.30]. Only with the CAP criteria, CRM is an independent prognostic factor for survival and recurrence in patients with T3 adenocarcinoma of the esophagus. The circumferential margin should only be considered positive (ie, R1) if the tumor is found at the inked lateral margin of resection in accordance with the CAP criteria.