Surgical Experience from the STASEY Study of Emicizumab Prophylaxis in People with Hemophilia A with Factor VIII Inhibitors

Background  Guidelines surrounding emicizumab prophylaxis and perioperative treatment for people with hemophilia A (PwHA) with factor (F)VIII inhibitors undergoing surgeries are limited. The phase IIIb multicenter, single-arm STASEY study evaluated safety and tolerability of emicizumab prophylaxis in PwHA aged ≥12 years with FVIII inhibitors. This analysis assesses surgeries during study conduct, associated hemophilia medications, and postoperative bleeds (treated and untreated). Methods  PwHA with FVIII inhibitors received emicizumab 3.0 mg/kg/week for 4 weeks, then 1.5 mg/kg/week until 2 years. Surgeries were managed and documented by treating physicians. Bleeds and treatments were recorded by physicians and participants. Results  Forty-six participants had ≥1 on-study surgery, 37 underwent 56 minor surgeries, and 13 underwent 22 major surgeries. Four participants underwent both minor and major surgeries. Of 18 (81.8%) and 4 (18.2%) major surgeries managed with/without additional hemostatic medication, 33.3 and 25.0% were associated with a treated postoperative bleed, respectively. Of 24 (42.9%) and 32 (57.1%) minor surgeries managed with/without additional hemostatic medication, 15.6 and 25.0% were associated with a treated postoperative bleed, respectively. Recombinant activated FVII was the most common medication for prophylaxis and bleed treatment. There were no thrombotic microangiopathies (TMAs). One hypertrophic clot, considered unrelated to emicizumab, occurred following tooth extraction. Conclusion  In this challenging population with a high bleeding risk, major surgeries were performed in PwHA receiving emicizumab with/without additional hemostatic medication. Postoperative bleeds occurred following 59.1% of major surgeries; 53.8% were treated. No arterial/venous thrombotic events or TMAs occurred due to concomitant emicizumab and bypassing agents. Trial registration  This trial is registered at ClinicalTrials.gov (NCT03191799).

Safety and efficacy of long‐term emicizumab prophylaxis in hemophilia A with factor VIII inhibitors: A phase 3b, multicenter, single‐arm study ( STASEY )

Background

The bispecific monoclonal antibody emicizumab bridges activated factor IX and factor X, mimicking the cofactor function of activated factor VIII (FVIII), restoring hemostasis.

Objectives

The Phase 3b STASEY study was designed to assess the safety of emicizumab prophylaxis in people with hemophilia A (HA) with FVIII inhibitors.

Methods

People with HA received 3 mg/kg emicizumab once weekly (QW) for 4 weeks followed by 1.5 mg/kg QW for 2 years. The primary objective was the safety of emicizumab prophylaxis, including incidence and severity of adverse events (AEs) and AEs of special interest (thrombotic events [TEs] and thrombotic microangiopathies). Secondary objectives included efficacy (annualized bleed rates [ABRs]).

Results

Overall, 195 participants were enrolled; 193 received emicizumab. The median (range) duration of exposure was 103.1 (1.1-108.3) weeks. Seven (3.6%) participants discontinued emicizumab. The most common AEs were arthralgia (n = 33, 17.1%) and nasopharyngitis (n = 30, 15.5%). The most common treatment-related AE was injection-site reaction (n = 19, 9.8%). Two fatalities were reported (polytrauma with fatal head injuries and abdominal compartment syndrome); both were deemed unrelated to emicizumab by study investigators. Two TEs occurred (myocardial infarction and localized clot following tooth extraction), also deemed unrelated to emicizumab. The negative binomial regression model-based ABR (95% confidence interval) for treated bleeds was 0.5 (0.27-0.89). Overall, 161 participants (82.6%) had zero treated bleeds.

Conclusions

The safety profile of emicizumab prophylaxis was confirmed in a large population of people with HA with FVIII inhibitors and no new safety signals occurred. The majority of participants had zero treated bleeds.

Efficacy and safety assessment of prolonged maintenance with subcutaneous rituximab in patients with relapsed or refractory indolent non-Hodgkin lymphoma: results of the Phase III MabCute study

Rituximab plus chemotherapy induction followed by rituximab maintenance for up to 2 years confers a long-term benefit in terms of progression-free survival in patients with indolent non-Hodgkin lymphoma. It is not known whether further prolonged maintenance with rituximab provides additional benefit. The phase III MabCute study enrolled 692 patients with relapsed or refractory indolent non-Hodgkin lymphoma. Patients who responded to induction with rituximab plus chemotherapy and were still responding after up to 2 years’ initial maintenance with subcutaneous rituximab were randomized to extended maintenance with subcutaneous rituximab (n=138) or observation only (n=138). The primary endpoint of investigator-assessed progression-free survival in the randomized population was un-addressed by the end of study because of an insufficient number of events (129 events were needed for 80% power at 5% significance if approximately 330 patients were randomized). In total, there were 46 progression-free survival events, 19 and 27 in the rituximab and observation arms, respectively (P=0.410 by stratified log-rank test; hazard ratio 0.76 [95% confidence interval: 0.37– 1.53]). The median progression-free survival was not reached in either randomized arm. There were no new safety signals; however, adverse events were seen slightly more frequently with rituximab than with observation during extended maintenance. Maintenance for up to 2 years with rituximab after response to initial induction therefore remains the standard of care in patients with relapsed or refractory indolent non- Hodgkin lymphoma. (Clinicaltrials.gov identifier: NCT01461928)

Obinutuzumab plus fludarabine and cyclophosphamide in previously untreated, fit patients with chronic lymphocytic leukemia: a subgroup analysis of the GREEN study

GREEN (NCT01905943) is a nonrandomized, open-label, single-arm, phase 3b study investigating the safety and efficacy of obinutuzumab alone or in combination with chemotherapy in chronic lymphocytic leukemia (CLL). We report the preplanned subgroup analysis of 140 previously untreated, fit CLL patients who received obinutuzumab plus fludarabine and cyclophosphamide (G-FC). The primary endpoint was safety and tolerability. Efficacy was the secondary endpoint. Obinutuzumab 1000 mg was administered intravenously on Day (D)1 (dose split D1‒2), D8 and D15 of Cycle (C)1, and D1 of C2-6 (28-day cycles). Standard intravenous/oral doses of fludarabine and cyclophosphamide were administered on D1-3 of C1-6. Overall, 87.1% of patients experienced grade ≥ 3 adverse events (AEs), including neutropenia (67.1%) and thrombocytopenia (17.1%). Serious AEs were experienced by 42.1% of patients. Rates of grade ≥ 3 infusion-related reactions and infections were 19.3% and 15.7%, respectively. Overall response rate was observed in 90.0%, with 46.4% of patients achieving complete response (CR; including CR with incomplete marrow recovery). Minimal residual disease negativity rates were 64.3% in peripheral blood and 35.7% in bone marrow (intent-to-treat analysis). After a median observation time of 25.6 months, 2 year progression-free survival was 91%. Frontline G-FC represents a promising treatment option for fit patients with CLL.

Obinutuzumab plus bendamustine in previously untreated patients with CLL: a subgroup analysis of the GREEN study

GREEN (NCT01905943) is a non-randomized, open-label phase IIIb study investigating obinutuzumab alone or plus chemotherapy in chronic lymphocytic leukemia (CLL). We report a preplanned subgroup analysis of 158 previously untreated CLL patients receiving obinutuzumab-bendamustine (G-B). Patients received six 28-day cycles (C) of G-B: obinutuzumab day (D)1/D2 of C1 (25 mg D1/975 mg D2), 1000 mg D8 and D15 of C1, and D1 of C2-6; and bendamustine 70/90 mg/m2 D1 and D2 of C1-6. The primary endpoint was safety/tolerability. Grade ≥3 adverse events (AEs) occurred in 82.3% of patients, including neutropenia (49.4%), thrombocytopenia (12.0%) and febrile neutropenia (10.8%). Serious AEs included neutropenia (12.7%), febrile neutropenia (9.5%) and pneumonia (7.6%). Rates of grade ≥3 infections and infusion-related reactions were 20.3% and 17.1%, respectively. Due to tumor lysis syndrome (TLS; 8.2%), including two associated fatalities (one in another study cohort), additional risk-minimization measures were implemented. Overall response rate was 81.0%. After 32.8 months' median observation time, 2-year progression-free survival was 81.8%. Minimal residual disease was undetectable in 59.5% (94/158) and 27.8% (44/158) of patients for blood and bone marrow, respectively. Frontline G-B appears to have manageable toxicity with clinical activity in CLL. Careful TLS risk assessment, pretreatment and monitoring is required.

Safety of obinutuzumab alone or combined with chemotherapy for previously untreated or relapsed/refractory chronic lymphocytic leukemia in the phase IIIb GREEN study

The safety of obinutuzumab, alone or with chemotherapy, was studied in a non-randomized, open-label, non-comparative, phase IIIb study (GREEN) in previously untreated or relapsed/refractory chronic lymphocytic leukemia. Patients received obinutuzumab 1000 mg alone or with chemotherapy (investigator’s choice of fludarabine-cyclophosphamide for fit patients, chlorambucil for unfit patients, or bendamustine for any patient) on days 1, 8 and 15 of cycle 1, and day 1 of cycles 2–6 (28-day cycles), with the cycle 1/day 1 dose administered over two days. The primary end point was safety/tolerability. Between October 2013 and March 2016, 972 patients were enrolled and 971 treated (126 with obinutuzumab monotherapy, 193 with obinutuzumab-fludarabine-cyclophosphamide, 114 with obinutuzumab-chlorambucil, and 538 with obinutuzumab-bendamustine). Grade ≥3 adverse events occurred in 80.3% of patients, and included neutropenia (49.9%), thrombocytopenia (16.4%), anemia (9.6%), and pneumonia (9.0%); rates were similar in first-line and relapsed/refractory patients, and in first-line fit and unfit patients. Using expanded definitions, infusion-related reactions were observed in 65.4% of patients (grade ≥3, 19.9%; mainly seen during the first obinutuzumab infusion), tumor lysis syndrome in 6.4% [clinical and laboratory; highest incidence with obinutuzumab-bendamustine (9.3%)], and infections in 53.7% (grade ≥3, 20.1%). Serious and fatal adverse events were seen in 53.1% and 7.3% of patients, respectively. In first-line patients, overall response rates at three months post treatment exceeded 80% for all obinutuzumab-chemotherapy combinations. In the largest trial of obinutuzumab to date, toxicities were generally manageable in this broad patient population. Safety data were consistent with previous reports, and response rates were high. (clinicaltrials.gov identifier: 01905943).

Vemurafenib in metastatic melanoma patients with brain metastases: an open-label, single-arm, phase 2, multicentre study

Background

Vemurafenib has shown activity in patients with BRAFV600 mutated melanoma with brain metastases (BM). This phase 2 study evaluated vemurafenib in patients with/without prior treatment for BM.

Methods

Patients with BRAFV600 mutated melanoma with BM were enrolled into cohort 1 (previously untreated BM) and cohort 2 (previously treated BM) and received vemurafenib (960 mg BID) until disease progression (PD) or intolerance. Primary endpoint was best overall response rate (BORR) in the brain in cohort 1 that was evaluated using modified RECIST 1.1 criteria using lesions ≥0.5 cm to assess response.

Results

146 patients were treated (cohort 1 n = 90; cohort 2 n = 56), 62% of whom were male. Median (range) time since diagnosis of BM: 1.0 (0-9) month in cohort 1 and 4.2 (1-68) months in cohort 2. Median duration of treatment was 4.1 months (range 0.3-34.5) in cohort 1 and 4.1 months (range 0.2-27.6) in cohort 2. Intracranial BORR in cohort 1 by an independent review committee (IRC) was 18% (2 CRs, 14 PRs). Extracranial BORR by IRC was 33% in cohort 1 and 23% in cohort 2. Median PFS (brain only, investigator-assessed) was 3.7 months (range 0.03-33.4; IQR 1.9-5.6) in cohort 1 and 4.0 months (range 0.3-27.4; IQR 2.2-7.4) in cohort 2. Median OS was 8.9 months (range 0.6-34.5; IQR 4.9-17.0) in cohort 1 and 9.6 months (range 0.7-34.3; IQR 4.5-18.4) in cohort 2. Adverse events (AEs) were similar in type, grade and frequency to other studies of single-agent vemurafenib. Grade 3/4 AEs occurred in 59 (66%) patients in cohort 1 and 36 (64%) in cohort 2. Overall, 84% of patients died during the study (86% in cohort 1 and 80% in cohort 2), mainly due to disease progression.

Conclusions

The study demonstrates clinically meaningful response rates of melanoma BM to vemurafenib, which was well tolerated and without significant CNS toxicity.

Open-label, multicentre safety study of vemurafenib in 3219 patients with BRAFV600 mutation-positive metastatic melanoma: 2-year follow-up data and long-term responders' analysis

BACKGROUND

The orally available BRAF kinase inhibitor vemurafenib is an effective and tolerable treatment option for patients with metastatic melanoma harbouring BRAF^V600 mutations. We assessed the safety of vemurafenib in a large population of patients with few alternative treatment options; we report updated 2-year safety.

METHODS

This was an open-label, multicentre study of vemurafenib (960 mg bid) in patients with previously treated or untreated BRAF mutation-positive metastatic melanoma (cobas^® 4800 BRAF V600 Mutation Test). The primary end-point was safety; efficacy end-points were secondary. An exploratory analysis was performed to assess safety outcomes in patients with long duration of response (DOR) (≥12 or ≥24 months).

RESULTS

After a median follow-up of 32.2 months (95% CI, 31.1-33.2 months), 3079/3219 patients (96%) had discontinued treatment. Adverse events (AEs) were largely consistent with previous reports; the most common all-grade treatment-related AEs were arthralgia (37%), alopecia (25%) and hyperkeratosis (23%); the most common grade 3/4 treatment-related AEs were squamous cell carcinoma of the skin (8%) and keratoacanthoma (8%). In the exploratory analysis, patients with DOR ≥12 months (n = 287) or ≥24 months (n = 133) were more likely to experience grade 3/4 AEs than the overall population. No new specific safety signals were observed with longer vemurafenib exposure.

CONCLUSIONS

After 2 years' follow-up, safety was maintained in this large group of patients with BRAF^V600 mutation-positive metastatic melanoma who are more representative of routine clinical practice than typical clinical trial populations. These data suggest that long-term vemurafenib treatment is effective and tolerable without the development of new safety signals.

Mapping dominant annual land cover from 2009 to 2013 across Victoria, Australia using satellite imagery

There is a demand for regularly updated, broad-scale, accurate land cover information in Victoria from multiple stakeholders. This paper documents the methods used to generate an annual dominant land cover (DLC) map for Victoria, Australia from 2009 to 2013. Vegetation phenology parameters derived from an annual time series of the Moderate Resolution Imaging Spectroradiometer Vegetation Indices 16-day 250 m (MOD13Q1) product were used to generate annual DLC maps, using a three-tiered hierarchical classification scheme. Classification accuracy at the broadest (primary) class level was over 91% for all years, while it ranged from 72 to 81% at the secondary class level. The most detailed class level (tertiary) had accuracy levels ranging from 61 to 68%. The approach used was able to accommodate variable climatic conditions, which had substantial impacts on vegetation growth patterns and agricultural production across the state between both regions and years. The production of an annual dataset with complete spatial coverage for Victoria provides a reliable base data set with an accuracy that is fit-for-purpose for many applications.

Recurrent mutations, including NPM1c, activate a BRD4-dependent core transcriptional program in acute myeloid leukemia

Recent evidence suggests that inhibition of bromodomain and extra-terminal (BET) epigenetic readers may have clinical utility against acute myeloid leukemia (AML). Here we validate this hypothesis, demonstrating the efficacy of the BET inhibitor I-BET151 across a variety of AML subtypes driven by disparate mutations. We demonstrate that a common 'core' transcriptional program, which is HOX gene independent, is downregulated in AML and underlies sensitivity to I-BET treatment. This program is enriched for genes that contain 'super-enhancers', recently described regulatory elements postulated to control key oncogenic driver genes. Moreover, our program can independently classify AML patients into distinct cytogenetic and molecular subgroups, suggesting that it contains biomarkers of sensitivity and response. We focus AML with mutations of the Nucleophosmin gene (NPM1) and show evidence to suggest that wild-type NPM1 has an inhibitory influence on BRD4 that is relieved upon NPM1c mutation and cytosplasmic dislocation. This leads to the upregulation of the core transcriptional program facilitating leukemia development. This program is abrogated by I-BET therapy and by nuclear restoration of NPM1. Finally, we demonstrate the efficacy of I-BET151 in a unique murine model and in primary patient samples of NPM1c AML. Taken together, our data support the use of BET inhibitors in clinical trials in AML.

BET protein inhibition shows efficacy against JAK2V617F-driven neoplasms

Small molecule inhibition of the BET family of proteins, which bind acetylated lysines within histones, has been shown to have a marked therapeutic benefit in pre-clinical models of mixed lineage leukemia (MLL) fusion protein-driven leukemias. Here, we report that I-BET151, a highly specific BET family bromodomain inhibitor, leads to growth inhibition in a human erythroleukemic (HEL) cell line as well as in erythroid precursors isolated from polycythemia vera patients. One of the genes most highly downregulated by I-BET151 was LMO2, an important oncogenic regulator of hematopoietic stem cell development and erythropoiesis. We previously reported that LMO2 transcription is dependent upon Janus kinase 2 (JAK2) kinase activity in HEL cells. Here, we show that the transcriptional changes induced by a JAK2 inhibitor (TG101209) and I-BET151 in HEL cells are significantly over-lapping, suggesting a common pathway of action. We generated JAK2 inhibitor resistant HEL cells and showed that these retain sensitivity to I-BET151. These data highlight I-BET151 as a potential alternative treatment against myeloproliferative neoplasms driven by constitutively active JAK2 kinase.

Cerebral infarction in patient with minimal change nephrotic syndrome

We report a case of 68-year-old Caucasian man who presented with cerebral infarcts secondary to arterial thrombosis associated with nephrotic syndrome. His initial presentation included edema of legs, left hemiparesis, and right-sided cerebellar signs. Investigations with computed tomography and magnetic resonance imaging of brain showed multiple cerebral infarcts in middle cerebral and posterior cerebral artery territory. Blood and urine investigations also showed impaired renal function, hypercholesterolemia, hypoalbuminaemia, and nephrotic range proteinuria. Renal biopsy showed minimal change disease. Cerebral infarcts were treated with antiplatelet agents and nephrotic syndrome was treated with high dose steroids. Patient responded well to the treatment and is all well till date.

Radiotherapy for oncologic emergencies on weekends: examining reasons for treatment and patterns of practice at a Canadian cancer centre

Purpose

Radiotherapy for oncologic emergencies is an important aspect of the management of cancer patients. These emergencies—which include malignant spinal cord compression, brain metastases, superior vena cava obstruction, and uncontrolled tumour hemorrhage —may require treatment outside of hospital hours, particularly on weekends and hospital holidays. To date, there remains no consensus among radiation oncologists regarding the indications and appropriateness of radiotherapy treatment on weekends, and treatment decisions remain largely subjective. The main aim of the present study was to document the incidence and indications for patients receiving emergency treatment on weekends or scheduled hospital holidays at a single institution. The secondary aim was to investigate the compliance of such treatment with the institution’s quality assurance policies, both local and provincial.

Methods

From September 1, 2002, to September 30, 2004, patients being treated over weekends (defined as commencing at 6 pm on a Friday and concluding at 8 am of the next scheduled workday) and hospital holidays were retrospectively identified using the Oncology Patient Information System scheduling module. Relevant patient data—including patient age, sex, primary cancer site, specific radiation field, rationale for treatment, referring hospital, total treatment dose, radiation dose fractionation, inpatient or outpatient status, and duration of treatment—were collected and subsequently analyzed. Comparison to local policy was performed subjectively.

Results

Over the 2-year period, 161 patients were prescribed urgent radiotherapy over a weekend or on a hospital holiday. Of this cohort, 68% were treated on both Saturday and Sunday, 22% on Saturday alone, and 10% on Sunday alone. Most patients presented with lung (31%), prostate (18%), and breast cancer (17%). The top reasons for referral for emergency weekend treatment included spinal cord compression (56%), brain metastases (15%), and superior vena cava obstruction (6%). Most of the indications for treatment generally followed the quality assurance policies implemented both locally and provincially.

Conclusions

Patients treated over a weekend or on a hospital holiday were generally found to be treated with appropriate intent. Most treatment indications within this study both complied with provincial policy and showed a pattern of care similar to that seen in other studies in the literature. Local policy appears to be robust; however, policy improvements may allow for more cohesiveness across radiation oncologists in patterns of care in this important group of patients. Comparisons with practice at other institutions would be valuable and also a key step in developing sound guidelines for all members of the radiotherapy community to follow.

Improvement in consistency of response to ovarian stimulation with recombinant human follicle stimulating hormone resulting from a new method for calibrating the therapeutic preparation

Traditionally, therapeutic preparations of gonadotrophins are quantified with a rat in-vivo bioassay in biological international units (IU). This method was developed to cope with variability of production batch quality. The bioassay, however, presents some limitations, and differences in clinical responses when using different batches of urine-derived gonadotrophins have been reported. The production of human FSH by recombinant technology now allows the use of advanced physicochemical methods for quantifying FSH, which can be measured in microg of FSH proteins (in mass). The study reported here was designed and conducted to assess the clinical relevance of this new method for quantifying therapeutic preparation of FSH. Four bulk lots of recombinant human FSH (r-hFSH) were used to prepare batches filled by IU (FbIU) and four batches filled by mass (FbM). These eight batches were compared in a double-blind, randomized study in patients undergoing assisted reproductive technology. One hundred and thirty-one patients were enrolled in this study and met protocol criteria (66 in the FbM group and 65 in the FbIU group). The starting dose of recombinant human FSH (r-hFSH) was either 150 IU or 11 microg/day. Both preparations induced multiple follicular development and all patients underwent oocyte retrieval. The number of follicles >/= 11mm was 14.85 and 14.91, serum oestradiol concentration on day of human chorionic gonadotrophin (HCG) administration was 6524 and 6350 pmol/l, number of oocytes retrieved was 10.76 and 11.28, number of two-pronuclear (2 PN) oocytes was 5.2 and 5.00, number of viable embryos (replaced or cryopreserved) was 4.15 and 3.72, and clinical pregnancy rate was 30.3 and 26.2% respectively in the FbM and FbIU groups. Overall, the patients' response consistency was found to be superior with FbM (P = 0.039), and in particular for clinical pregnancy rates (P < 0.001). This new method for quantifying r-hFSH delivers an improved consistency in clinical outcome.

Disordered cellular migration and angiogenesis in cd39-null mice

BACKGROUND

Nucleoside triphosphate diphosphohydrolase-1 (NTPDase1)/CD39 is the major ectonucleotidase of endothelial cells and monocytes and catalyzes phosphohydrolysis of extracellular nucleoside diphosphates (NDP) and triphosphates (NTP, eg, ATP and UTP). Deletion of cd39 causes perturbations in the hydrolysis of NTP and NDP in the vasculature. Activation of P2 receptors appears to influence endothelial cell chemotactic and mitogenic responses in vitro. Therefore, aberrant regulation of nucleotide P2 receptors may influence angiogenesis in cd39-null mice. Methods and Results- In control mice, implanted Matrigel plugs containing growth factors were rapidly populated by monocyte/macrophages, endothelial cells, and pericytes, with the development of new vessels over days. In cd39-null mice, migrating cells were completely confined to the tissue-Matrigel interface in a clearly stratified manner. Absolute failure of new vessel ingrowth was consistently observed in the mutant mice. Linked to these findings, chemotaxis of cd39-null monocyte/macrophages to nucleotides was impaired in vitro. This abnormality was associated with desensitization of nucleotide receptor P2Y-mediated signaling pathways.

CONCLUSIONS

Our findings demonstrate a role for NTPDase1 and phosphohydrolysis of extracellular nucleotides in the regulation of the cellular infiltration and new vessel growth in a model of angiogenesis.

Micromovements at the aortic aneurysm neck measured during open surgery with close-range photogrammetry: implications for aortic endografts

PURPOSE

To describe the motion of abdominal aortic aneurysm (AAA) as a first step toward determining if stent-graft migration may be due to propulsive movements at the neck.

METHOD

In an initial laboratory validation test, a silicone AAA model was imaged with a stereo-pair configuration of calibrated digital cameras using retro-reflective and ink dot surface targets. This technique was then applied to 4 aneurysm necks imaged at open surgery. In each case the paired images were measured and analyzed to produce sequences of accurate three-dimensional (3-D) surface models of the anterior aspect of the aortic neck. Engineering techniques were used to visualize and identify differences between the generated surfaces, allowing changes in shape of the aortic wall to be determined.

RESULTS

The correlation between stereoscopic digital imaging with electronic caliper measurements of linear dimensions was accurate, irrespective of the type of surface targets used (r2 = 0.98). The AAA neck demonstrated complex 3-D movements that ranged from 1.0 to 1.5 mm in the radial direction to 0.6 to 1.0 mm along the longitudinal axis, with a 0.44 to 0.59-mm rotational component (p < 0.05).

CONCLUSIONS

This pilot study raises questions about the validity of accepted models of arterial wall movements and compliance in which rotation has not been described. The technique used to measure dynamic neck morphology appears promising as a means to further define the mechanical parameters of the human aorta, which may assist in designing stent-grafts.