The morphology and evolution of chondrichthyan cranial muscles: A digital dissection of the elephantfish Callorhinchus milii and the catshark Scyliorhinus canicula.

The anatomy of sharks, rays, and chimaeras (chondrichthyans) is crucial to understanding the evolution of the cranial system in vertebrates due to their position as the sister group to bony fishes (osteichthyans). Strikingly different arrangements of the head in the two constituent chondrichthyan groups-holocephalans and elasmobranchs-have played a pivotal role in the formation of evolutionary hypotheses targeting major cranial structures such as the jaws and pharynx. However, despite the advent of digital dissections as a means of easily visualizing and sharing the results of anatomical studies in three dimensions, information on the musculoskeletal systems of the chondrichthyan head remains largely limited to traditional accounts, many of which are at least a century old. Here, we use synchrotron tomographic data to carry out a digital dissection of a holocephalan and an elasmobranch widely used as model species: the elephantfish, Callorhinchus milii, and the small-spotted catshark, Scyliorhinus canicula. We describe and figure the skeletal anatomy of the head, labial, mandibular, hyoid, and branchial cartilages in both taxa as well as the muscles of the head and pharynx. In Callorhinchus, we make several new observations regarding the branchial musculature, revealing several previously unreported or ambiguously characterized muscles, likely homologous to their counterparts in the elasmobranch pharynx. We also identify a previously unreported structure linking the pharyngohyal of Callorhinchus to the neurocranium. Finally, we review what is known about the evolution of chondrichthyan cranial muscles from their fossil record and discuss the implications for muscle homology and evolution, broadly concluding that the holocephalan pharynx is likely derived from a more elasmobranch-like form which is plesiomorphic for the chondrichthyan crown group. This dataset has great potential as a resource, particularly for researchers using these model species for zoological research, functional morphologists requiring models of musculature and skeletons, as well as for palaeontologists seeking comparative models for extinct taxa.

Asymptomatic right circumflex aortic arch associated with ventricular septal defect and biscuspid aortic valve.

INTRODUCTION: Anomalies of the aortic arch are frequent congenital malformations, which rarely form partial or complete vascular rings. A rare form of vascular ring is the encircling, or circumflex, aortic arch. CASE REPORT: A 19-month-old boy, with no respiratory symptoms, was referred for ventricular septal defect (VSD) repair. Cardiac magnetic resonance imaging and echocardiography confirmed the perimembranous VSD, a bicuspid aortic valve with normal function, and showed a right-sided ascending aorta, bifurcating to the left behind the esophagus and trachea above the tracheal bifurcation, with a left-sided descending aorta, a left ligamentum arteriosum and aberrant left subclavian artery, realizing a circumflex aortic arch. The child underwent successful VSD repair and ligamentum arteriosum division, with an uneventful postoperative course. CONCLUSIONS: Previous reports have described the association of circumflex aortic arch with VSD, but there is no previous report of its association with VSD and bicuspid aortic valve. Patients are usually symptomatic either preoperatively, or after VSD repair. For this reason, division of the ligamentum arteriosum, to open the vascular ring and free the trachea and esophagus from compression, should be performed in patients undergoing cardiac surgery for associated malformations.

Atresia of the aortic arch in 4-year-old child: a clinical case study.

Atresia of the aortic arch is a rare congenital heart defect with a high mortality when associated with other intracardiac defects. Cardiac magnetic resonance (CMR) provides the exact anatomy of the aortic arch and collateral circulation and is useful to diagnose-associated aortic arch anomalies. This report describes the case of a 4-year-old child with atresia of the aortic arch, referred to our institution with the diagnosis of aortic coarctation and bicuspid aortic valve. On clinical exam, the femoral pulses were not palpable and there was a significant differential blood pressure between the upper and lower limbs. The echocardiography showed a severely stenotic bicuspid aortic valve but was limited for the exact description of the aortic arch. CMR showed absence of lumen continuity between the ascending and descending aorta distal to the left subclavian artery, extending over 5 mm, with the presence of a bend in the arch and diverticulum on either side of the zone of discontinuity, suggesting the diagnosis atresia of the aortic arch rather than coarctation or interruption. The patient benefited from a successful surgical commissurotomy of the aortic valve and reconstruction of the aortic arch with a homograft. The post-operative CMR confirmed the good surgical result. This case emphasizes the utility of CMR to provide good anatomical information to establish the exact diagnosis and the operative strategy.

Airway compression management in late-presenting absent pulmonary valve syndrome.

INTRODUCTION: Patients with absent pulmonary valve syndrome often present early with airway compression from aneurysmal pulmonary arteries. This study reviews our experience in managing absent pulmonary valve syndrome in later presenting children, and techniques used for managing airway compression. METHODS: This study is a retrospective chart review of all patients who underwent repair of absent pulmonary valve syndrome from 2000 to 2012 at our institution. The primary endpoints were post-operative bronchoscopic and clinical evidence of persistent airway compression and need for reinterventions on the pulmonary arteries. RESULTS: A total of 19 patients were included during the study period. The mean age at repair was 4.1±3.0 years (range 10 months-11 years). In all, seven patients had pre-operative bronchoscopic evidence of airway compression, which was managed by pulmonary artery reduction plasty in four patients and Lecompte manoeuvre in three patients. There were no peri-operative deaths. In patients with pulmonary artery plasty, two had no post-operative airway compression, one patient had improved compression, and one patient had unchanged compression. In patients managed with a Lecompte manoeuvre, two patients had no or trivial airway compression and one had improved compression. There were six late reinterventions or reoperations on the pulmonary arteries - two out of four in the pulmonary artery plasty group and one out of three in the Lecompte group. CONCLUSIONS: Most late-presenting patients with absent pulmonary valve syndrome do not have airway compression. Either pulmonary artery reduction plasty or the Lecompte manoeuvre can relieve proximal airway compression, without a significantly different risk of pulmonary artery reintervention between techniques.

Eating with a saw for a jaw: functional morphology of the jaws and tooth-whorl in Helicoprion davisii.

The recent reexamination of a tooth-whorl fossil of Helicoprion containing intact jaws shows that the symphyseal tooth-whorl occupies the entire length of Meckel's cartilage. Here, we use the morphology of the jaws and tooth-whorl to reconstruct the jaw musculature and develop a biomechanical model of the feeding mechanism in these early Permian predators. The jaw muscles may have generated large bite-forces; however, the mechanics of the jaws and whorl suggest that Helicoprion was better equipped for feeding on soft-bodied prey. Hard shelled prey would tend to slip anteriorly from the closing jaws due to the curvature of the tooth-whorl, lack of cuspate teeth on the palatoquadrate (PQ), and resistance of the prey. When feeding on soft-bodied prey, deformation of the prey traps prey tissue between the two halves of the PQ and the whorl. The curvature of the tooth-whorl and position of the exposed teeth relative to the jaw joint results in multiple tooth functions from anterior to posterior tooth that aid in feeding on soft-bodied prey. Posterior teeth cut and push prey deeper into the oral cavity, while middle teeth pierce and cut, and anterior teeth hook and drag more of the prey into the mouth. Furthermore, the anterior-posterior edges of the teeth facilitate prey cutting with jaw closure and jaw depression. The paths traveled by each tooth during jaw depression are reminiscent of curved pathways used with slashing weaponry such as swords and knifes. Thus, the jaws and tooth-whorl may have formed a multifunctional tool for capturing, processing, and transporting prey by cyclic opening and closing of the lower jaw in a sawing fashion.

Acute hand ischemia after unintentional intraarterial injection of drugs: is catheter-directed thrombolysis useful?

Unintentional intraarterial injections are rare but may have devastating consequences. No consensus on treatment has been established owing to the wide variety of possible injected substances, incomplete understanding of the underlying pathophysiology, and the absence of case-controlled, prospective human studies. The aim of the present study and literature review was to evaluate the benefit of intraarterial thrombolysis combined with systemic anticoagulation therapy when an artery of the upper extremity is accidentally punctured and ischemia of the hand ensues.

Holocephalan embryo provides new information on the evolution of the glossopharyngeal nerve, metotic fissure and parachordal plate in gnathostomes.

The phylogenetic relationships between the different groups of Paleozoic gnathostomes are still debated, mainly because of incomplete datasets on Paleozoic jawed vertebrate fossils and ontogeny of some modern taxa. This issue is illustrated by the condition of the glossopharyngeal nerve relative to the parachordal plate, the otic capsules and the metotic fissure in gnathostomes. Two main conditions are observed in elasmobranchs (shark and rays) and osteichthyans (bony fishes and tetrapods). The condition in the other chondrichthyan taxon, the holocephalans, is still poorly known, and without any information on this taxon, it remains difficult to polarize the condition in gnathostomes. Based on the anatomical study of an embryo of the holocephalan Callorhinchus milii by means of propagation X-Ray Synchrotron phase contrast microtomography using both holotomography and single distance phase retrieval process, we show that, contrary to what was previously inferred for holocephalans (i.e. an osteichthyan-like condition), the arrangement of the glossopharyngeal nerve relative to the surrounding structure in holocephalans is more similar to that of elasmobranchs. Furthermore, the holocephalan condition represents a combination of plesiomorphic characters for gnathostomes (e.g., the glossopharyngeal nerve leaves the braincase via the metotic fissure) and homoplastic characters. By contrast, the crown osteichthyans are probably derived in having the glossopharyngeal nerve that enters the saccular chamber and in having the glossopharyngeal foramen separated from the metotic fissure.

Jaws for a spiral-tooth whorl: CT images reveal novel adaptation and phylogeny in fossil Helicoprion.

New CT scans of the spiral-tooth fossil, Helicoprion, resolve a longstanding mystery concerning the form and phylogeny of this ancient cartilaginous fish. We present the first three-dimensional images that show the tooth whorl occupying the entire mandibular arch, and which is supported along the midline of the lower jaw. Several characters of the upper jaw show that it articulated with the neurocranium in two places and that the hyomandibula was not part of the jaw suspension. These features identify Helicoprion as a member of the stem holocephalan group Euchondrocephali. Our reconstruction illustrates novel adaptations, such as lateral cartilage to buttress the tooth whorl, which accommodated the unusual trait of continuous addition and retention of teeth in a predatory chondrichthyan. Helicoprion exemplifies the climax of stem holocephalan diversification and body size in Late Palaeozoic seas, a role dominated today by sharks and rays.

Technical innovation: Multidimensional computerized software enabled subtraction computed tomographic angiography.

Computed tomographic angiography (CTA) is a frequent noninvasive alternative to digital subtraction angiography. We previously reported the development of a new subtraction software to overcome limitations of adjacent bone and calcification in CT angiographic subtraction. Our aim was to further develop and improve this fast and automated computerized software, universally available for free use and compatible with most CT scanners, thus enabling better delineation of vascular structures, artifact reduction, and shorter reading times with potential clinical benefits. This computer-based free software will be available as an open source in the next release of OsiriX at the Web site http://www.osirix-viewer.com.

Submitral left ventricular aneurysm: a rare but challenging pathology to treat.

Submitral left ventricular aneurysm is a rare cardiac pathology. Etiology remains still mysterious, but it is believed to be due to a congenital defect of the fibrous layer of the atrioventricular junction. Surgical closure of aneurysm rim is the therapy of choice, despite the diversity of surgical approaches and techniques. We present a young patient operated with a transmitral approach in our clinic. Posterior mitral leaflet (PML) detachment and then extension valvuloplasty by using autologous pericardium was performed in order to save the native mitral valve. We believe that respecting the integrity of native valve is of crucial importance in this young population of patients.

Preoperative embolization of hypervascular Castleman's disease of the mediastinum.

We report the case of a 31-year-old woman with mediastinal Castleman's disease of the hyaline vascular type. This large tumor was safely resected after arterial embolization. We describe the steps of this interventional procedure and discuss related necessary precautions.

Effects of non-ionic iodinated contrast media on patient heart rate and pressures during intra-cardiac or intra-arterial injection.

PURPOSE: To compare the effects on heart rate (HR), on left ventricular (LV) or arterial pressures, and the general safety of a non-ionic low-osmolar contrast medium (CM) and a non-ionic iso-osmolar CM in patients undergoing cardiac angiography (CA) or peripheral intra-arterial digital subtraction angiography (IA-DSA). MATERIALS AND METHODS: Two double-blind, randomized studies were conducted in 216 patients who underwent CA (n=120) or peripheral IA-DSA (n=96). Patients referred for CA received a low-osmolar monomeric CM (iomeprol-350, n=60) or an iso-osmolar dimeric CM (iodixanol-320; n=60). HR and LV peak systolic and end-diastolic pressures were determined before and after the first injection during left and right coronary arteriography and left ventriculography. Monitoring for all types of adverse event (AE) was performed for 24 h following the procedure. t-tests were performed to compare CM for effects on HR. Patients referred for IA-DSA received iomeprol-300 (n=49) or iodixanol-320 (n=47). HR and arterial blood pressure (BP) were evaluated before and after the first 4 injections. Monitoring for AE was performed for 4 h following the procedure. Repeated-measures ANOVA was used to compare mean HR changes across the first 4 injections, whereas changes after the first injection were compared using t-tests. RESULTS: No significant differences were noted between iomeprol and iodixanol in terms of mean changes in HR during left coronary arteriography (p=0.8), right coronary arteriography (p=0.9), and left ventriculography (p=0.8). In patients undergoing IA-DSA, no differences between CM were noted for effects on mean HR after the first injection (p=0.6) or across the first 4 injections (p=0.2). No significant differences (p>0.05) were noted in terms of effects on arterial BP in either study or on LV pressures in patients undergoing CA. Non-serious AE considered possibly CM-related (primarily headache and events affecting the cardiovascular and digestive systems) were reported more frequently by patients undergoing CA and more frequently after iodixanol (14/60 [23.3%] and 2/47 [4.3%]; CA and IA-DSA, respectively) than iomeprol (10/60 [16.7%] and 1/49 [2%], respectively). CONCLUSIONS: Iomeprol and iodixanol are safe and have equally negligible effects on HR and LV pressures or arterial BP during and after selective intra-cardiac injection and peripheral IA-DSA. CLINICAL APPLICATION: Iomeprol and iodixanol are safe and equally well tolerated with regard to cardiac rhythm and clinical preference should be based on diagnostic image quality alone.

Surgical repair of a congenital left ventricular aneurysm.

Congenital left ventricular aneurysm is an uncommon cardiac malformation. A 9-year-old boy with complaints of dyspnea and palpitation was diagnosed with a left ventricular aneurysm originating from the left ventricle free wall. Aneurysm resection and endoventricular patch repair was performed. Postoperative follow-up was uncomplicated and follow-up echocardiographs showed normal left ventricular contractility.

Operative correction of cor triatriatum sinister with systemic venous return anomaly (inferior vena cava-left atrium).

Cor triatriatum sinister is a rare cardiac anomaly. It is characterized by the presence of a fibromuscular membrane in the left atrium, thus forming a proximal chamber receiving the pulmonary veins and a distal chamber communicating with the mitral valve and the left atrial appendage. This rare pathology tends to coexist with a persistent left superior vena cava, whereas the presence of an anomalous systemic venous return is unusual. In this article, we report successful treatment of a patient with cor triatriatum sinister who has an additional systemic venous return anomaly.

Long-term outcome after surgical intervention and interventional procedures for the management of Takayasu's arteritis in children.

OBJECTIVE: There is little information available on the results of reconstructive arterial surgery for Takayasu's arteritis in children. This study evaluates midterm to long-term outcome after surgical, as well as interventional, procedures. METHODS: From 1984 through 2004, 10 children (5 boys and 5 girls; age, 12.7 +/- 2.6 years) with Takayasu's arteritis were referred to our center. Baseline cardiovascular assessment included contrast angiography (n = 4), magnetic resonance imaging-angiography (n = 3), and combined contrast angiography plus magnetic resonance imaging-angiography (n = 3). Two patients had disease confined to the thoracic aorta, 4 had disease confined to the abdominal aorta, and 4 had combined thoracoabdominal aortic disease. Steno-occlusive lesions were predominant in 92% of cases. Seven patients were maintained on steroid therapy throughout the follow-up period. Eight children underwent complex surgical procedures, 1 patient had balloon dilatation of the renal and mesenteric arteries, and 1 patient had combined vascular surgery with percutaneous transluminal angioplasty. Overall, 24 grafts (polytetrafluoroethylene, Dacron grafts, and cryopreserved homografts) were implanted in various locations. RESULTS: There were no perioperative deaths. Arterial hypertension regressed in all patients, and cardiac function normalized in all 4 patients with dilative cardiomyopathy. Over a 20-year period, 1 patient presented with sudden death and 2 showed nonfatal disease progression, one of whom required surgical reintervention. The occlusion rate was higher in Dacron grafts. CONCLUSIONS: Our study shows that despite the extent and severity of vascular lesions, children with Takayasu's arteritis could benefit from reconstructive surgery, with low mortality, morbidity, and satisfactory long-term results.

Late cardiac tamponade after percutaneous closure of a patent foramen ovale.

We report the case of a 35-year-old man who had a transient ischemic cerebral attack and then underwent a percutaneous closure of the patent foramen ovale (PFO) with a Cardiastar device. One year later, the patient developed a cardiac tamponade due to an important hemorrhagic pericardial effusion. Transoesophageal echocardiography showed that one of the struts had impinged on the aortic root in the region adjacent to the transverse pericardial sinus. Therefore, we speculated that the strut had passed through the aortic wall by slow erosion, leading to the pericardial effusion. Cardiac CT and subsequent surgery confirmed the perforation of the left atrial roof and the aortic root by two struts of the device. This is the first reported case of late cardiac tamponade and underscores the importance of long-term follow-up after PFO closure device implantation.