Short Necks Research Articles

Invited commentary

This study by Hicks et al interrogated the Vascular Quality Initiative database to examine the effect of being lost to follow-up (LTF) on survival after endovascular aneurysm repair (EVAR). Medicare data had suggested that a lack of imaging after EVAR did not confer a survival disadvantage.1Garg T. Baker L.C. Mell M.W. Postoperative surveillance and long-term outcomes after endovascular aneurysm repair among Medicare beneficiaries.JAMA Surg. 2015; 150: 957-963Crossref PubMed Scopus (51) Google Scholar In the Vascular Quality Initiative EVAR population, only 49.9% of elective patients had a follow-up visit recorded in the database (an astonishing low number). Of this group, ∼11% each had phone follow-up or were LTF. The LTF group was older, had more comorbid conditions, and had larger aneurysms. The LTF group (and the phone follow-up group) had significantly lower survival compared with those with in-person follow-up. A coarsened exact matching on 30 preoperative and perioperative variables demonstrated that those LTF still had reduced survival (vs in person follow-up), although the differences compared with the multivariate analysis with in-person follow-up, were considerably smaller. Phone follow-up patients had fewer imaging studies, and survival outcomes were equivalent to the LTF group. The authors conclude that EVAR patients with more comorbidities and a higher incidence of in-hospital complications tend to be more frequently LTF and ultimately have worse survival outcomes. This study's conclusions differ from a study of EVAR Medicare patients that used a propensity-matched study design.1Garg T. Baker L.C. Mell M.W. Postoperative surveillance and long-term outcomes after endovascular aneurysm repair among Medicare beneficiaries.JAMA Surg. 2015; 150: 957-963Crossref PubMed Scopus (51) Google Scholar The patients with incomplete postoperative EVAR surveillance had few ruptured abdominal aortic aneurysms postoperatively, fewer reinterventions, and no reduction in aneurysm-related survival. Nonadherence to Society for Vascular Surgery suggested guidelines for postoperative EVAR was surprisingly not associated with poorer outcomes. Other population-derived data published suggest that regular imaging after EVAR is associated with reduced mortality that becomes more pronounced as the length of follow-up increases.2de Mestral C. Croxford R. Roche-Nagle G. PC036. Ten years of endovascular aortic aneurysm repair: a population-based evaluation of postoperative imaging and mortality [Abstract].J Vasc Surg. 2016; 6: 163S-164SAbstract Full Text Full Text PDF Google Scholar All of these data demonstrate a failure to achieve the Society for Vascular Surgery EVAR follow-up guidelines. The preponderance of data, in my opinion, demonstrates those who are LTF have worse long-term outcomes and mortality than those with imaging and in-person follow-up. Key barriers to complete follow-up include patient factors (age, choice to come for follow-up, and comorbidities), provider factors (databases and coordinators dedicated to ensuring imaging and follow-up), and the lack of patient-specific follow-up guidelines that take into account the presence or absence of endoleaks at the first follow-up, anatomic considerations (short or angulated aortic necks or common iliac landing zones), sac shrinkage, and other factors. Database software dedicated to EVAR patient-specific follow-up should assist providers to improve follow-up compliance and determine whether this improves aneurysm-related mortality. Vascular surgeons need to ensure careful EVAR follow-up or risk compromising its promise of comparable outcomes to open repair.3Patel R. Sweeting M.J. Powell J.T. Greenhaugh R.M. EVAR trial investigatorsEndovascular versus open repair of abdominal aortic aneurysm in 15-years' follow-up of the UK endovascular aneurysm repair trial 1 (EVAR trial 1): a randomised controlled trial.Lancet. 2016; 388: 2366-2374Abstract Full Text Full Text PDF PubMed Scopus (606) Google Scholar Endovascular aneurysm repair patients who are lost to follow-up have worse outcomesJournal of Vascular SurgeryVol. 65Issue 6PreviewSociety for Vascular Surgery practice guidelines recommend 1- and 12-month follow-up with computed tomography imaging for the year after endovascular aneurysm repair (EVAR). We describe the incidence, risk factors, and outcomes of EVAR patients who are lost to follow-up (LTF). Full-Text PDF Open Archive

Ultrasound-Guided Subclavian Vein Cannulation in Low Birth Weight Neonates.

Central venous access in critically ill, small infants remains technically challenging even in experienced hands. Several vascular accesses exist, but the subclavian vein is often preferred for central venous catheter insertion in infants where abdominal malformation and/or closure of the vein preclude the use of umbilical venous catheters, as catheterization of the subclavian vein is easier in very short necks than the internal jugular vein for age-related anatomical reasons. The subclavian vein approach is yet relatively undescribed in low birth weight infants (i.e., < 2,500 g), and this study aims to explore the feasibility of this technique in very small infants. Retrospective data collection of prospectively registered data on central venous catheter insertion in infants. Neonatal ICU and PICU at a university hospital. One hundred and five newborn children hospitalized in at the ICU. An ultrasound-guided supraclavicular approach was applied on all infants who had an subclavian vein catheterization during a 30-month period from January 2013 to July 2015. One hundred seven supraclavicular subclavian vein catheters were placed in 105 children weighing less than 5,000 g. Among those, 40 patients weighed less than 2,500 g and 10 patients weighed less than 1,500 g. Successful central venous catheter insertion, defined as the correct placement of a functional double-lumen catheter (3F or 4F), was obtained in 97.3%. All three registered failed attempts were due to hematomas from venous bleeding and occurred in infants weighing greater than 2,500 g. No case of accidental arterial puncture or pleural puncture was registered. This large series of subclavian vein catheterizations in small infants demonstrates the feasibility of subclavian vein catheterizations even in very small neonates weighing less than 1,500 g.

Long-term results of outside "instructions for use" EVAR

Endovascular aneurysm repair (EVAR) has progressively expanded to more complex anatomies, frequently outside manufacturer's instructions for use (IFU). However, the long term results of off-label use of EVAR remain largely undocumented. The aim of this paper is to examine the long term results of outside IFU EVAR. English literature was searched to identify publications on long term results for outside IFU EVAR. A follow-up extending for at least 5 years was the minimum required as inclusion criteria. The outcomes measured were: overall mortality, aneurysm-related mortality (ARM), freedom from postimplant aneurysm rupture, aneurysm sac enlargement, type I endoleaks and secondary interventions. Results were compared to randomized clinical trials (RCTs) with long term results published (EVAR-1, DREAM, OVER and ACE Trial). Thirteen studies were included. 7 studies described outcomes associated to a specific breached IFU, while 6 studies presented general outside IFU results. In patients outside IFU, 3 to 8 years estimates of overall mortality ranged from 21.5% to 40% (RCTs:13.7-46%) and ARM from 0-11% (RCTs: 1.2-7%). Five-year estimates of sac enlargement was approximately 43%. Type I endoleak rates for outside IFU (follow-up 5-12 years) ranged from 3.8-15%, which is higher than found in RCT-derived data (6.6-6.9%). Comparable results are seen for postimplant rupture and secondary interventions. The long term results of off-label use of EVAR are scarcely published. Although overall mortality and ARM does not seem to differ significantly at long-term, higher rates of type I endoleaks may be expected, mainly in short necks. However, for patients with severe angulation or high thrombus load in the proximal neck, results of outside IFU EVAR seem to match the results of inside IFU.

Technique for treating complex aneurysms with Hercules stent graft modified by the surgeon

Endovascular treatment of thoracoabdominal aneurysms with fenestrated stent grafts expands its applicability because of good technical results. However, stent graft customization requires an average of 6 to 12 weeks, which makes this technique ineligible for symptomatic or ruptured aneurysms. Authors advocate perioperative fenestration by the surgeon, allowing this technique to be used for emergency cases with good results and favorable prognosis. This article describes a technique for intraoperative changes of the Hercules stent graft (MicroPort Scientific Corporation, Shanghai, China) to include the ostia of visceral arteries by making fenestrations and scallops, with a temporary diameter-reducing wire as a further modification to facilitate positioning and catheterization of fenestrations with guidewires.

Building 3D anatomical model of coiling of the internal carotid artery derived from CT angiographic data.

The purpose of this study is to recreate live patient arterial anomalies using new recent application of three-dimensional (3D) printed anatomical models. Another purpose of building such models is to evaluate the effectiveness of angiographic data. With the help of the DICOM files from computed tomographic angiography (CT-A), we were able to build a printed model of variant course of the internal carotid artery (ICA). Images of coiling of the ICA taken by CT-A, were then converted into 3D images using Google SketchUp free software, and the images were saved in stereolithography format. Imaging helped us conduct the examination in details with reference to geometrical features of ICA, degree of curve, its extension, location and presence of loop. Challenging vascular anatomy was exposed with models of adverse curve of carotid anatomy, including highly angulated necks, conical necks, short necks, tortuous carotid arteries, and narrowed carotid lumens. It assisted us to comprehend spatial anatomy configuration of life-like models. 3D model can be very effective in cases when anatomical difficulties are detected through the CT-A, and therefore, a tactile approach is demanded preoperatively. 3D life-like models serve as an essential office-based tool in vascular surgery as they assist surgeons in preoperative planning, develop intraoperative guidance, teach both the patients and the surgical trainees, and simulate to show patient-specific procedures in medical field.

Fenestrated Aortic Endografts in the Last 3 Years: An Update

Fenestrated endovascular aortic aneurysm repair (FEVAR) is an accepted treatment option for patients who are not suitable for conventional endovascular aortic aneurysm repair or open surgical repair (OSR). Five years ago, the FDA approved the use of FEVAR in patients with inadequate infrarenal aortic seal zones (short necks). This procedural paradigm continues to gain in popularity compared to OSR for complex aortic disease. We seek to define the current state of fenestrated endovascular repair by reviewing relevant literature over the past 3 years. FEVAR continues to prove to be efficacious with reasonable durability as a therapy for patients who are not candidates for OSR. As a second-line treatment, FEVAR is less morbid in the short-term with trade-off of high reintervention rates in the follow-up period. Mid- to long-term outcomes have proven to be comparable to OSR in selected patients with persistent excellent patency of the visceral target vessels. Recent publications have thrust FEVAR into consideration as the primary interventional modality in juxtarenal abdominal aortic aneurysms, a traditional indication for OSR. As FEVAR continues to evolve from surgeon-modified devices to custom built and eventually off-the-shelf grafts, it is anticipated to be employed widely for managing complex aortic aneurysms. Compared to OSR, FEVAR carries a low risk of perioperative morbidity while demonstrating continued safety and durability in early to mid-term reports.

Patient-specific simulation of endovascular repair surgery with tortuous aneurysms requiring flexible stent-grafts

The rate of post-operative complications is the main drawback of endovascular repair, a technique used to treat abdominal aortic aneurysms. Complex anatomies, featuring short aortic necks and high vessel tortuosity for instance, have been proved likely prone to these complications. In this context, practitioners could benefit, at the preoperative planning stage, from a tool able to predict the post-operative position of the stent-graft, to validate their stent-graft sizing and anticipate potential complications. In consequence, the aim of this work is to prove the ability of a numerical simulation methodology to reproduce accurately the shapes of stent-grafts, with a challenging design, deployed inside tortuous aortic aneurysms. Stent-graft module samples were scanned by X-ray microtomography and subjected to mechanical tests to generate finite-element models. Two EVAR clinical cases were numerically reproduced by simulating stent-graft models deployment inside the tortuous arterial model generated from patient pre-operative scan. In the same manner, an in vitro stent-graft deployment in a rigid polymer phantom, generated by extracting the arterial geometry from the preoperative scan of a patient, was simulated to assess the influence of biomechanical environment unknowns in the in vivo case. Results were validated by comparing stent positions on simulations and post-operative scans. In all cases, simulation predicted stents deployed locations and shapes with an accuracy of a few millimetres. The good results obtained in the in vitro case validated the ability of the methodology to simulate stent-graft deployment in very tortuous arteries and led to think proper modelling of biomechanical environment could reduce the few local discrepancies found in the in vivo case. In conclusion, this study proved that our methodology can achieve accurate simulation of stent-graft deployed shape even in tortuous patient specific aortic aneurysms and may be potentially helpful to help practitioners plan their intervention.

Open abdominal aortic aneurysm repair is still necessary in an era of advanced endovascular repair

Recent advances in endovascular aneurysm repair have overcome substantial anatomic barriers associated with short and challenging necks. With greater range to treat more difficult anatomy from an endovascular approach, one would assume the need of open surgical repair (OSR) would be diminished. The purpose of our study was to determine the need for OSR for abdominal aortic aneurysms, in a tertiary academic setting, with a moderate volume (10-15 cases/year) of fenestrated endografting being performed. An Institutional Review Board approved retrospective review was performed of all patients who underwent elective aortic aneurysm repair between January 2010 and July 2014. Computed tomography scans for patients who underwent OSR were reviewed and anatomic characteristics obtained. Instructions for use of (IFU) a commercially available fenestrated device (Cook Medical, Bloomington, Ind) were used to determine if open repair patients had anatomy amenable to advanced endovascular repair. During the study interval, 415 patients underwent abdominal aortic aneurysm repair. Of those patients who underwent elective aneurysm repair, 105 patients had OSR. The study subsequently excluded 11 patients because they underwent secondary interventions after a failed endovascular repair and thus were not further evaluated. Also excluded were 18 patients who had OSR for an emergency intervention. The remaining 76 patients (35 female, 41 male; average age, 72± 8years) had OSR and were outside the IFU of the fenestrated endovascular aneurysm repair (FEVAR) device. The average diameter of the abdominal aorta was 5.9cm. Indications for OSR were an aneurysm neck<4mm (71%), inclusion of at least 1 visceral vessel (69.7%), unilateral iliac artery aneurysms (15.5%), bilateral iliac artery aneurysms (14.3%), iliac artery tortuosity >40° of angulation (37.6%), extensive aortic thrombus (23.2%), and aortic neck angulation >45° (11.8%). Rejected patients had an average of 1.7± 0.8 anatomic constraints (range 1-4) that prevented use of the FEVAR device. With evidence to support the strict adherence to IFU protocols of the FEVAR device in patients, our institution's practice has been to continue to perform open abdominal aortic aneurysm repair for patients with anatomy outside device protocols. Although it was thought that the decreased requirement of aortic neck required to deploy an endograft would lead to an increased patient population amenable to endovascular repair, there is still a clinically significant need for open aortic surgery.

Fenestrated stent grafts for the treatment of complex aortic aneurysm disease: A mature treatment paradigm.

The introduction of fenestrated stent grafts (SGs) to treat abdominal aortic aneurysms (AAAs) with short proximal necks began in 1999. Nowadays, the whole visceral aorta can be treated totally by endovascular means. The established use of fenestrated devices to treat complex AAAs as a first-line management option has been previously reported. An up-to-date evaluation of the literature was performed including all types of publications regarding the use of fenestrated technology to repair complex AAAs. Fenestrated repair is now an established alternative to hybrid/chimney/snorkel repairs. However, specific criteria and prerequisites are required for the use and improvement of this method. Multiple device morphologies have been used incorporating the visceral arteries in various combinations. This modular strategy connects different devices (bridging covered stents and bifurcated SGs) with the aortic main body, thus excluding the aneurysm from the circulation. Precise deployment of the fenestrated SG is mandatory for successful visceral vessel revascularization. Accurate SG sizing and customization, a high level of technical skill, and facilities with modern imaging techniques including 3D road mapping and dedicated hybrid rooms are required. Most experience has been with the custom-made Zenith Cook platform, although off-the-shelf devices have been recently implanted. More complex repairs have been performed over the last few years, but device complexity has also increased. Perioperative, mid-term, and a few recently reported long-term results are encouraging. Secondary interventions remain the main problem, similar to that observed after traditional endovascular abdominal aortic aneurysm repair (EVAR).

A Pilot Study Assessing the Impact of 3-D Printed Models of Aortic Aneurysms on Management Decisions in EVAR Planning.

Endovascular repair of aortic aneurysms with difficult anatomy is challenging. There is no consensus for planning such procedures. Six cases of aortic aneurysms with challenging anatomical features, such as short, angulated, and conical necks and tortuous iliacs were harvested. The computed tomography (CT) scans were anonymized. Lifesize 3-dimensional (3-D) printed models were created of the lumen. Endovascular operators were asked to review the CT angiography (CTA), make a management plan, and give an indication of their confidence. They were then presented with the equivalent model and asked to review their decision. Their attitudes to such models were briefly surveyed. A total of 28 endovascular operators reviewed 144 cases. After review of the physical model, the management plan changed in 29 (20.1%) of 144 cases. Initial plan after CTA review was endovascular 73.6%, open repair 22.9%, and second opinion 3.5%. After model review, this became endovascular 67.4%, open repair 19.4%, and second opinion 4.8%. Although the general trend was toward more open procedures, off-label techniques reduced from 19.4% to 15.2% following model review. When the management plan did not change, level of confidence did increase in 37 (43.5%) of 85 cases. The majority of operators stated that they would find models useful for planning in some procedures. For 1 case, the change in the percentage of participants being sure in the management plan was statistically significant (P = .031). The 3-D printed models may be potentially useful in planning cases with EVAR. It is a paradigm that warrants further investigation.

A Japanese familial case of hypochondroplasia with a novel mutation in FGFR3.

Gain-of-function mutations in the fibroblast growth factor receptor 3 gene (FGFR3) result in a group of skeletal dysplasias, such as prototypic achondroplasia (ACH: OMIM #100800) and lethal thanatophoric dysplasia (TD1: OMIM #187600). Hypochondroplasia (HCH: OMIM #146000) is the mildest of the FGFR3-associated skeletal dysplasias and is characterized by short stature with macrocephaly, brachydactyly, limited range of motion at the elbows, lumbar lordosis, and bowed legs. Radiological features of HCH are flared metaphyses, narrowed interpedicular distance, square ilia, and short femoral necks. These clinical and radiological signs are generally less pronounced than those seen with ACH and may not be noticeable until early or middle childhood. Because GH replacement is effective in some HCH patients (1, 2), genetic analysis to assist early diagnosis and intervention may improve the prognosis of these patients. Here, we present such an example and report the identification of a novel mutation in FGFR3 in a familial case of HCH and the effectiveness of GH treatment in the elder sister.

Preliminary results of adjunctive use of endoanchors in the treatment of short neck and pararenal abdominal aortic aneurysms.

To present our initial experience with the use of EndoAnchors for endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) with little to no infrarenal landing zone. EndoAnchors have been reported to assist in the prevention and treatment of type 1a endoleaks in patients with hostile aortic necks who undergo EVAR. Between July 2013 and July 2014, nine patients with AAAs and short proximal aortic necks (i.e., 0-10 mm in length) underwent EVAR. In five patients, utilization of the chimney graft technique was necessary. A mean of 2.5 (range 1-4) visceral vessels underwent chimney graft. The prophylactic use of EndoAnchors was utilized in all 9 patients. The decision to use the EndoAnchors was made in the preoperative planning phase. Technical success was achieved in 100% of cases. In two cases, type 1a endoleaks were noted before the deployment of any EndoAnchors. In both cases, a final angiogram depicted resolution of the type 1a endoleak after insertion of the EndoAnchors. Mean follow-up time was 8 months. At 30 days, 3 months, and 6 months, 100% of the endografts remained patent and free from type 1a endoleaks. No adverse renal complications or mortality was reported. EndoAnchors are an applicable adjunct to EVAR as treatment for short infrarenal neck and pararenal AAAs. Further investigations are needed to determine the durability of this novel application.

Proximal Scallop in Thoracic Endovascular Aortic Aneurysm Repair to Overcome Neck Issues in the Arch

To evaluate initial experience with a custom made proximal scalloped stent graft for thoracic endovascular aortic repair (TEVAR) of aortic aneurysms involving the arch. Between September 2012 and November 2014, patients presenting with a thoracic aortic aneurysm (TAA) with short or angulated neck were selected for treatment by custom made proximal scalloped Relay Plus stent grafts (ABS Bolton Medical, Barcelona, Spain). Prospectively acquired data relating to patient demographics, procedure details, clinical outcomes, and complications were analyzed retrospectively. Ten selected patients (50% male, mean age 77 ± 8 years) were treated using a thoracic custom made Relay Plus stent graft, three of whom underwent additional cervical supra-aortic trunk revascularizations. TAA were fusiform in four cases, saccular in three, and three patients were treated for proximal type I endoleaks after previous standard TEVAR. The graft was landed in zone 2 in 3 cases, in zone 1 in 4 cases, and in zone 0 in 3 cases. The custom made scallop was designed to preserve flow in the left subclavian artery in three patients, in the left common carotid artery in four, and in the innominate artery in three. No proximal type I endoleak occurred and proximal sealing was achieved in all cases, with a technical success rate of 100%. All targeted vessels were patent. During a mean follow up of 12 ± 5 months, no conversion to open surgical repair and no aortic rupture occurred. One patient died post-operatively from myocardial infarction and one patient suffered a stroke with complete recovery. One patient had a distal type I endoleak on the 6 month CT scan and is scheduled for distal extension. No paraplegia, retrograde dissection and no other aortic related complications were recorded. Proximal scalloped stent grafts appear to be an effective additional tool for TEVAR of TAA when dealing with short or angulated proximal necks.

Metric and morphological analysis of the foot in the Middle Pleistocene sample of Sima de los Huesos (Sierra de Atapuerca, Burgos, Spain)

The preservation of Homo fossil foot remains prior to modern humans and Neandertals is very scarce throughout the fossil record. Understanding foot morphology in human evolution is essential to know taxonomic processes and to acquiring information about corporal size. Here, we present a comprehensive study of the large foot remains sample recovered from the Middle Pleistocene site of Sima de los Huesos (SH). The minimum number of individuals (MNI) has been established at 16 by the foot remains. As is the case with other elements of the foot, metric and morphological differences in the feet between Middle and Late Pleistocene hominins tend to be subtle. However, an exclusive combination of traits can be recognized in the feet of the SH hominins. The SH hominins and Neandertals display tali with short necks and broad lateral malleolar facets, broad calcanei with long bodies and projected sustentaculum tali, stout naviculars, as well as robust metatarsals and phalanges. Nevertheless, the feet from SH are characterized by a very broad lateral malleolar facet in the talus and a very broad sustentaculum tali in the calcaneus, even more so than in Neandertals with respect to both traits. More importantly, the head of the talus from SH is narrower than the Neandertal's broad talus head, and the short intermediate cuneiforms found at SH distinguish them from the other comparative samples. The body mass estimation based on the trochlear breadth of the talus provides a mean of 69.7 ± 10.0 kg for the SH hominins, similar to that determined by the femoral head and significantly lower than that obtained from the bi-iliac breadth.

Metal ion levels in ceramic-on-ceramic THR with modular necks: analysis of cobalt and chromium serum levels in 30 healthy hip patients.

Modular necks in total hip replacement (THR) can be a source of metal ion release. There are no data to date on the level of cobalt and chromium ions in the serum of patients with a cobalt-chrome stem and a titanium modular neck. Serum ion levels were measured in healthy volunteers with a well-functioning ceramic-on-ceramic THR. Average cobalt in serum was 1.21 µg/l for unilateral THR and 2.2 µg/l for bilateral THR. No patient had cobalt levels higher than 2.4 µg/l. No patient had measurable chromium levels. There were no differences in cobalt levels for hips with short necks versus hips with long necks. The hybrid THR Profemur® Xm - Procotyl® L with a titanium modular neck on a cobalt-chrome stem design shows no signs of abnormal toxic ion levels (cobalt or chromium) in a randomly selected group of well-functioning hip patients.

Evolution and End Point of the Black String Instability: Large D Solution.

We derive a simple set of nonlinear, (1+1)-dimensional partial differential equations that describe the dynamical evolution of black strings and branes to leading order in the expansion in the inverse of the number of dimensions D. These equations are easily solved numerically. Their solution shows that thin enough black strings are unstable to developing inhomogeneities along their length, and at late times they asymptote to stable nonuniform black strings. This proves an earlier conjecture about the end point of the instability of black strings in a large enough number of dimensions. If the initial black string is very thin, the final configuration is highly nonuniform and resembles a periodic array of localized black holes joined by short necks. We also present the equations that describe the nonlinear dynamics of anti-de Sitter black branes at large D.

Systematic review and meta-analysis of migration after endovascular abdominal aortic aneurysm repair

To identify patients who are under higher threat for migration because of an old generation stent graft application. A systematic review and meta-analysis of the literature was undertaken to identify all studies which included older generation endografts and data reporting on graft migration after EVAR. Outcome data were pooled and combined, and were calculated using fixed or random effects models. From 2000 to 2014, 22 retrospective studies were identified reporting on stent- graft migration after EVAR (8.6%). From those patients, 39% received re-intervention with the mean time of identification ranging from 12 to 36 months. Six of these retrospective nonrandomized studies were eligible for meta-analysis. AAA diameter (AAA diameter: 0.719 mm; 95% confidence interval [CI]: 0.00065-1.4384 mm; p = 0.00497) and neck length (neck length: 4.36 mm; 95% CI: 1.3277-7.394; p = 0.0048) were the only significant factors associated with stent- graft migration. Neck diameter and neck angulation did not have any important influence on stent-graft migration. Patients with large AAA and short necks who were treated with older generation stent grafts such as AneurX and Talent are in higher risk for endograft migration than others. Stent- graft migration consists of an insidious and underestimated threat.

Strategies for the management and prevention of conformation-related respiratory disorders in brachycephalic dogs.

Brachycephalic (short-muzzled) dogs are increasingly popular pets worldwide, with marked increases in registrations of breeds such as the Pug and French Bulldog over the past decade in the UK. Despite their popularity, many brachycephalic breeds are affected by an early-onset, lifelong respiratory disorder, brachycephalic obstructive airway syndrome (BOAS). This disorder arises due to a mismatch in the proportions of the skull and the soft tissues held within the nose and pharynx, resulting in obstruction of the airway during respiration. Increased airway resistance encourages secondary changes such as eversion of the laryngeal saccules and collapse of the larynx. Clinical signs of BOAS are often early onset and chronic, including dyspnea, exercise intolerance, heat intolerance, and abnormal and increased respiratory noise. Episodes of severe dyspnea can also occur, leading to cyanosis, syncope, and death. BOAS may have a severe impact upon the welfare of affected dogs, compromising their ability to exercise, play, eat, and sleep. Although a well-described condition, with surgical treatments for the palliation of this disorder published since the 1920s, many dogs still experience airway restrictions postsurgically and a compromised quality of life. In addition, the prevalence of this disorder does not appear to have substantially reduced in this time, and may have increased. Ultimately, strategies to improve the breeding of these dogs to prevent BOAS are required to improve brachycephalic health and welfare. Recent studies have revealed conformational risk factors associated with BOAS, such as short muzzles and thick necks, which should be discouraged to avoid perpetuating this serious disorder. Positive changes to brachycephalic health may be impeded by a perception of BOAS being “normal for the breed”. This perception must be avoided by owners, breeders, and vets alike to prevent undertreatment of individuals and the perpetuation of this serious disorder to future generations of dogs.

Patient selection for shorter femoral stems.

The right patient selection with the correct surgical treatment are prerequisite for a positive result in total hip arthroplasty (THA). Short stem implants demand a shorter anchoring length in accordance with the proper indication. Although appropriate indications for short stems have been discussed in the literature, there currently is no clear definition. The lack of an accepted categorization of short hip stems complicates the situation further. This article briefly reviews the literature and highlights the authors' results and experiences in short stem THA in an effort to establish a proper discrimination between indications and contraindications for the Metha short stem. Results presented include a retrospective data collection and follow-up examination of 126 patients who underwent short stem THA with 2- and 4-year results. Anchoring principles of the short stem are reviewed, and a complication and failure analysis based on 7 femoral revisions in 1092 short stem THAs is presented. Selection criteria for short stem THA are patients younger than 70 years with primary osteoarthritis and dysplastic femoral deformities, and indications of avascular head necrosis. Adequate bone quality must be confirmed intraoperatively, assessing whether the bone structure in the area of the femoral neck is strong enough to support the short stem load transmission. Coxa vara and high dysplastic femoral neck antetorsion are contraindications for short stems. Wide and short femoral necks, implant undersizing, and a deep stem position below the femoral osteotomy compromise stability and must be avoided with an appropriate surgical technique. Long-term data are not yet available.

The effect of aortic morphology on peri-operative mortality of ruptured abdominal aortic aneurysm.

AimsTo investigate whether aneurysm shape and extent, which indicate whether a patient with ruptured abdominal aortic aneurysm (rAAA) is eligible for endovascular repair (EVAR), influence the outcome of both EVAR and open surgical repair.Methods and resultsThe influence of six morphological parameters (maximum aortic diameter, aneurysm neck diameter, length and conicality, proximal neck angle, and maximum common iliac diameter) on mortality and reinterventions within 30 days was investigated in rAAA patients randomized before morphological assessment in the Immediate Management of the Patient with Rupture: Open Versus Endovascular strategies (IMPROVE) trial. Patients with a proven diagnosis of rAAA, who underwent repair and had their admission computerized tomography scan submitted to the core laboratory, were included. Among 458 patients (364 men, mean age 76 years), who had either EVAR (n = 177) or open repair (n = 281) started, there were 155 deaths and 88 re-interventions within 30 days of randomization analysed according to a pre-specified plan. The mean maximum aortic diameter was 8.6 cm. There were no substantial correlations between the six morphological variables. Aneurysm neck length was shorter in those undergoing open repair (vs. EVAR). Aneurysm neck length (mean 23.3, SD 16.1 mm) was inversely associated with mortality for open repair and overall: adjusted OR 0.72 (95% CI 0.57, 0.92) for each 16 mm (SD) increase in length. There were no convincing associations of morphological parameters with reinterventions.ConclusionShort aneurysm necks adversely influence mortality after open repair of rAAA and preclude conventional EVAR. This may help explain why observational studies, but not randomized trials, have shown an early survival benefit for EVAR.Clinical trial registration:ISRCTN 48334791.