Anatomical basis of the risk of injury to the right laryngeal recurrent nerve during thoracic surgery.

PURPOSE: Despite the intrathoracic part being short, the right laryngeal recurrent nerve is often injured during thoracic surgery. The aim of this cadaver study was to understand the mechanisms of right laryngeal recurrent nerve injuries during thoracic surgery and to describe anatomical landmarks for its preservation. METHODS: Dissections were performed on 10 fresh human cadavers. A right anterolateral thoracic wall segment was removed, preserving the first rib. Dissections were carried out to identify the following structures: first rib, esophagus, trachea, right main bronchus, right brachiocephalic and subclavian vessels, azygos vein, phrenic nerve, vagus nerve, and right laryngeal recurrent nerve. RESULTS: The distance between the origin of the right laryngeal recurrent nerve and its adjacent structures was assessed. Moderate traction of the thoracic part of the vagus nerve resulted in a downward translation of the right laryngeal recurrent nerve's origin. In such conditions, the right laryngeal recurrent nerve's origin was distant of 14.8 mm (±2.89 mm) from the subclavian artery. CONCLUSIONS: Intraoperative incidence of right laryngeal recurrent nerve direct injury could be decreased by understanding the detailed course of its intrathoracic part. Moreover, traction on the intrathoracic part of the right vagus nerve may result in indirect lesions of the right laryngeal recurrent nerve: stretch induced lesions and nerve vasculature's lesions.

Anatomic variations of the renal vessels: focus on the precaval right renal artery.

The aim of this study was to determine the prevalence of precaval right renal artery and to investigate the distribution of renal arteries and veins. We discuss a theory of development of renal vascular variants. We retrospectively reviewed 120 arterial phase contrast material-enhanced spiral computerized tomography scans of the abdomen (1- to 2-mm section thickness) performed during a two-month period. Forty percent of the study group (48 patients) had one artery and one vein on each side, with typical course. There was a 9.17% prevalence of precaval right renal artery: 10 patients had a lower pole accessory artery in precaval position and one patient had the main and the accessory arteries that pass anterior to the inferior vena cava. In these cases, associated variations of renal vessels were higher than in the patients without precaval artery variant. There were multiple arteries in 28.3% of the right kidneys and in 26.7% of the left ones. Variants of the right renal vein consisted in multiple veins in 20% (24 cases). We detected no case of multiple left renal veins, but we described variations of its course (circum- or retroaortic vein) in 9.17% (11 cases). Twenty-six patients (21.7%) had associated variations of the renal pedicle. The current technical support allows for a minimally invasive study of vessels anatomy. In our study the prevalence of a precaval right renal artery appears to be higher than previously reported (9.17%). Knowledge on anatomical variations of right renal artery and associated renal vessels variations has major clinical implications.

Relevance of functional imaging in dental implantology.

BACKGROUND: Despite it is widely used in many medicine fields, the use of functional imaging to examine dental implants has not been reported in the literature. This work aimed to evaluate the relevance of functional medical imaging in oral implantology. MATERIAL AND METHODS: This single-center observational study was conducted for 6 months at the Toulouse University Hospital, France. All patients who underwent positron emission tomography with 18-fluorodeoxyglucose integrated with X-ray computed tomography (FDG PET/CT) and had dental implants were included. Metabolic activity of the peri-implant tissues was assessed qualitatively and quantitatively jointly by a nuclear physician and a dental surgeon. RESULTS: In 31 patients (121 implants), peri-implant metabolic activity was normal. In 3 patients (4 implants), localized peri-implant hypermetabolism was observed. In all the patients presenting abnormal peri-implant activity, the implants with normal activity were clinicaly and radiogicaly normal, whereas those with hypermetabolism presented peri-implantitis. CONCLUSIONS: This study assess of the relevance of FDG PET/CT in oral implantology. It shows a link between peri-implant hypermetabolism and peri-implantitis. Therefore, FDG PET/CT could become a new tool for the assessment of peri-implant diseases. Key words:Dental implantation, dental implants, peri-implantitis, diagnostic imaging , imaging, three-dimensional, imaging processing, computer-assisted.

Videothoracoscopic silver nitrate pleurodesis for primary spontaneous pneumothorax: an alternative to pleurectomy and pleural abrasion?

BACKGROUND: The optimal surgical management of primary spontaneous pneumothorax (PSP) is still controversial, especially in terms of the technique to be used. The aim of this paper was to report our experience of videothoracoscopic silver nitrate pleurodesis (VATSNP). METHODS: Between 1995 and 2004, all the medical records of the patients who had undergone silver nitrate videothoracoscopic pleurodesis (SNVTP) were reviewed. All the patients had systematic prospective clinical and radiological follow-up at 1 month. The last 250 patients were retrospectively recontacted for long-term follow-up. RESULTS: Six hundred and three patients underwent SNVP. No intra-operative death or major complication occurred during or after the procedures. Mean operating time was 40.2+/-10.7 min. The conversion to thoracotomy rate was 2.5%. Main postoperative complications were prolonged air leak (15.6%), partial residual pneumothorax (5.1%), pleural effusion (2.5%) and postoperative bleeding (2.0%). The follow-up was 100% complete 1 month after discharge; at 1 month, the recurrence rate was 0.5%. The last 250 patients were retrospectively recontacted with a mean follow-up of 2.9+/-2.3 years (184 patients). The long-term recurrence rate was 1.1%. CONCLUSIONS: It is one of the first reports on the use of video-assisted thoracoscopic silver nitrate pleurodesis for PSP. We demonstrate safety and effectiveness of the procedure with long-term results comparable with standard open pleural abrasion or pleurectomy.

Benefits of extracorporeal membrane oxygenation for major blunt tracheobronchial trauma in the paediatric age group.

Tracheobronchial rupture due to blunt chest trauma is a rare but life-threatening injury among children. The severity of this condition ranges from death before hospital admission to clinical stability resulting in delayed management. Diagnosis is difficult because there is sometimes no evidence of external trauma, in spite of severe chest crush injury and consecutive rupture of airways. Here, we report the case of a 32-month-old girl whose torso was crushed by a van, resulting in bilateral bronchi disconnection. She was admitted to our hospital with cardiac and respiratory arrest. After prompt resuscitation, flexible bronchoscopy permitted the accurate visualization of the rupture and its extent. The life-saving procedure consisted of surgical repair using extracorporeal membrane oxygenation (ECMO) as ventilatory support. This provided rapid relief from the injury, which was previously expected to result in death. These data suggest that ECMO could be beneficial as supportive therapy for selected paediatric patients with major tracheobronchial traumas.

Impact of meteorological conditions on the occurrence of acute type A aortic dissections.

The impact of meteorological conditions on the occurrence of various cardiovascular events has been reported. The aim of this work was to study the correlations between weather conditions and the occurrence of type A acute aortic dissections (AADs). Between 1997 and 2007, all the medical records of patients who underwent surgery for type A AADs in Toulouse University Hospital (France) were reviewed. The clinical data were confronted with the meteorological data provided by the French national meteorological office (MétéoFrance) over the same period. Two hundred and six patients with spontaneous type A AADs underwent surgery during this period. The incidence of aortic dissection was higher in winter time than in summer (P=0.018). The days with aortic dissections were colder than those without aortic dissections (P=0.017). Statistical analysis highlighted a decrease of atmospheric temperature during the three days preceding the upset of the symptoms (P=0.0009). This work demonstrates a correlation between spontaneous type A AADs and low atmospheric temperature.

Anatomical bases of left recurrent nerve lesions during mediastinoscopy.

PURPOSE: The mechanism of left recurrent laryngeal nerve palsy after cervical mediastinoscopy remains unclear. Our aim is to describe the anatomical bases of this complication. METHODS: Video-assisted mediastinoscopy was performed on ten fresh human cadavers with simultaneous dissection of the left recurrent nerve. RESULTS: Three dissection areas could be described regarding the risk of left recurrent nerve damage: a low risk area, along the right wall and before the upper part of the anterior wall of the trachea; an area at high risk of indirect stretch-induced lesions, between the lower part of the anterior wall of the trachea and the aorta; -an area at high risk of direct injury, against the lower part of the left wall of the trachea. CONCLUSIONS: Dissection between the trachea and the aorta causes traction on the left recurrent nerve. Indirect stretch-induced injury is probably a frequent mechanism of left recurrent nerve palsy during mediastinoscopy.

Malignancy of congenital cystic adenomatoid malformation of lung in aged.

Congenital cystic adenomatoid malformation is rare in adults, and often asymptomatic. We describe a case of malignant degeneration of a congenital cystic adenomatoid malformation in a 77-year-old man. Congenital cystic adenomatoid malformation must be considered a premalignant lesion, even in older patients. Rigorous preoperative staging must be undertaken. Anatomic resection with extensive lymphadenectomy remains the treatment of choice.

Estradiol accelerates endothelial healing through the retrograde commitment of uninjured endothelium.

Although the accelerative effect of 17beta-estradiol (E2) on endothelial regrowth has been clearly demonstrated, the local cellular events accounting for this beneficial vascular action are still uncertain. In the present work, we compared the kinetics of endothelial healing of mouse carotid arteries after endovascular and perivascular injury. Both basal reendothelialization as well as the accelerative effect of E2 were similar in the two models. Three days after endothelial denudation, a regenerative area was observed in both models, characterized by similar changes in gene expression after injury, visualized by en face confocal microscopy (EFCM). A precise definition of the injury limits was only possible with the perivascular model, since it causes a complete and lasting decellularization of the media. Using this model, we demonstrated that the migration of uninjured endothelial cells precedes proliferation (bromodeoxyuridine incorporation) and that these events occur at earlier time points with E2 treatment. We have also identified an uninjured retrograde zone as an intimate component of the endothelial regeneration process. Thus, in the perivascular model, the regenerative area can be subdivided into a retrograde zone and a reendothelialized area. Importantly, both areas are significantly enlarged by E2. In conclusion, the combination of the electric perivascular injury model and EFCM is well adapted to the visualization of the endothelial monolayer and to investigate cellular events involved in reendothelialization. This process is accelerated by E2 as a consequence of the retrograde commitment of an uninjured endothelial zone to migrate and proliferate, contributing to an enlargement of the regenerative area.

The estrogen effects on endothelial repair and mitogen-activated protein kinase activation are abolished in endothelial nitric-oxide (NO) synthase knockout mice, but not by NO synthase inhibition by N-nitro-L-arginine methyl ester.

We have previously shown that estrogen exerts a vasoprotective effect by accelerating reendothelialization after perivascular artery injury through activation of the estrogen receptor alpha. Because 17beta-estradiol (E2) is known to increase the bioavailability of nitric oxide, in this study, we used the same perivascular model to characterize the role of the endothelial nitric oxide synthase (eNOS) pathway in reendothelialization. Surprisingly, we found that the stimulatory effect of E2 on reendothelialization was not altered following pharmacological inhibition of nitric-oxide synthase enzymatic activity by N-nitro-L-arginine methyl ester, whereas it was abolished in eNOS-deficient (eNOS-/-) mice. This discrepancy between eNOS gene inactivation and the pharmacological inhibition of eNOS was confirmed in a classical model of endovascular injury. When assessing the involvement of eNOS in short-term membrane-associated signaling events induced by E2, we found that E2 stimulated phosphorylation of extracellular signal-regulated kinase 1/2 in isolated perfused carotid arteries from wild-type mice in the absence or presence of N-nitro-l-arginine methyl ester, whereas this stimulation was abolished in carotid arteries from eNOS-/- mice. Similar results were obtained in primary cultures of mouse aortic endothelial cells. These data reveal an original and unexpected role of eNOS, in which its presence but not its enzymatic activity appears to be a determinant for estrogen signaling in the endothelium. The consequences of this novel function of eNOS with respect to vascular diseases should be explored.