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Biomedical subjects

S Chagnon

Publications and source records attributed to S Chagnon.

At least 37 records · Page 2Linked to original sources

Subacute and chronic benign superior vena cava obstructions: endovascular treatment with self-expanding metallic stents.

OBJECTIVE: Our purpose is to report our clinical experience with patients who underwent endovascular treatment with Wallstents for subacute or chronic benign obstruction of the superior vena cava (SVC). SUBJECTS AND METHODS: Twelve patients who were an average of 54 +/- 12 years old were referred for treatment of severe SVC syndrome related to implanted central venous catheters (n = 8), postradiation fibrosis (n = 2), a permanent pacemaker (n = 1), or a benign tumor (n = 1). Symptoms were present for an average of 16 weeks (range, 4-48 weeks) before treatment. Diagnosis of SVC obstruction was confirmed with helical CT and pretherapeutic phlebography. Four patients had Stanford's type II stenosis; two, type III; and six, type IV. The mean clinical and radiologic follow-up intervals were 11 months (range, 1-36 months) and 7 months (range, 1 week to 32 months), respectively. RESULTS: Recanalization was successful in all patients. Fifteen stents were implanted in the 12 patients. Stents were placed after percutaneous balloon angioplasty in nine patients, and primary stent placement was attempted in three patients. We immediately achieved a satisfactory SVC diameter in all patients, whose symptoms were relieved completely within 1 week of stent placement. No technical or clinical complications occurred. SVC syndrome recurred in one patient 2 months after stent placement and was treated by placing a second stent. CONCLUSION: Endovascular treatment with stent placement should be considered relevant and safe for refractory benign SVC syndrome. However, a larger series and a longer follow-up period are needed to define the role of stent placement for this syndrome.

Adult↗

[Positional occlusion of the descending scapular artery in transverse thoraco-brachial syndrome with neurologic symptoms].

We report a thoracic outlet syndrome revealed by neurological complications. Angiography of the subclavian artery depicted an isolated positional occlusion of the descending scapular artery. This side branch of the subclavian artery is anatomically located close to and supplies the brachial plexus. Surgical treatment led to improvement of most symptoms and post-operative control angiography was normal. Not previously described, this sign illustrates the objective compression of the brachial plexus. Ischemia is perhaps intricated with compression, a well-known pathophysiological mechanism of neurological complications in this syndrome. This artery feeding the brachial plexus is usually ligated during surgical neurolysis but must be preserved in order to improve recovery of neurological function and prevent surgical failures.

Angiography↗

[Preoperative angiographic landmarks of the gluteal muscle regions using Patent Blue V].

Use of a gluteus musculocutaneous flap is the most reliable technique for surgical repair of sacral ulcers. Surgery could be ideally performed when the flap is designed using only the upper or the lower half of the glutens maximus muscle depending on the superior gluteal artery or the inferior gluteal artery, respectively. The authors have developed a technique for preoperative demonstration of the vascular supply to both muscle and overlying skin from a single gluteal artery using superselective catheterization and arterial administration of a dye (Patent Blue V). This technique facilitates the surgical procedure but assessment of its usefulness will require further evaluation.

Angiography↗

Percutaneous gastrostomy for enteral nutrition: long-term follow-up of 176 procedures.

OBJECTIVE: To evaluate the efficacy and safety of percutaneous gastrostomy (PG), using small catheters without gastropexy, to deliver enteral nutrition. METHODS: We reviewed the records of 176 consecutive patients in whom PG was attempted for enteral nutrition. Of these cases, 172 catheters were inserted by the Seldinger technique under fluoroscopic guidance alone, 2 were inserted under computed tomographic guidance, and 2 procedures failed. In primary procedures, 8.5- or 10.2-French catheters were used. RESULTS: The technical success rate was 98.9%. Of the 176 procedures, 2 failed because of the high position of the stomach. Seven-day follow-up was obtained in all patients; 30-day follow-up in 145 patients (83%), and long-term follow-up (30 to 1512 days) in 123 patients (70%). The 30-day mortality rate was 13.2%. One death (0.5%) was directly related to the procedure. Major complications occurred in 4 patients (2.2%), and minor complications in 12 patients (6.9%). No patient required surgery for complications attributable to the gastrostomy procedure. CONCLUSION: PG without gastropexy using small catheters is a simple, safe and effective technique for delivering enteral nutrition.

Adult↗

[Helical computed tomography of the aorta and its branches].

Imaging of the aorta has greatly benefited from the recent development of helical computed tomography. This noninvasive and widespread imaging technique could be considered as a viable alternative to invasive modalities in aortic disease assessment, especially in the acute onset. Radiologists should be familiar with the principles of this technique and its clinical applications. This report develops technical aspects, typical and atypical features of a variety of noncongenital aortic diseases including dissections, aortic trauma, aneurysms, nonaneurysmal atherosclerotic diseases and arteritis. The role of helical CT as noninvasive tool for imaging the aorta and its branches is compared to the other imaging methods.

Acute Disease↗

[Bronchial and pulmonary vaso-occlusions].

The technique of vaso-occlusion (or embolisation) consists in occluding one or several vessels which are causing haemoptysis. Either of the pulmonary circulations (systemic bronchial or pulmonary) may be the cause and sometimes both are. In systemic pulmonary hypervascularization the pathological issues are affected by high pressure vascularisation at the expense of functional vascularisation and are the source of frequent episodes of bleeding. Bronchial and systemic vaso-occlusion has proven efficacy and safety on condition that strict rules are respected to avoid complications; the detection of potentially dangerous arteries (spinal, coronary and visceral) and a choice of material for embolisation which is adapted to the therapeutic strategy and the clinical and angiographic presentation. The indications for the procedure are dictated by severe or recurrent haemoptysis. Vaso-occlusion of pulmonary arteries which is a rarer indication dominated by conditions such as arteriovenous malformation (MAVP). The technique is adapted to the number, to the size and to the diffusion of MAVP which is characterised precisely by computed tomography. Vaso-occlusion is the treatment of first choice for MAVP only leaving failures of vaso-occlusion to surgery and certain pedicular forms have a very short afferent of large calibre.

Arteriovenous Malformations↗

[Late solitary metastasis of a renal cancer to the contralateral adrenal gland].

We report a case of metachronous metastasis from renal cell carcinoma to the contralateral adrenal gland detected one year after radical nephrectomy. The initial tumor was incidentally discovered in the setting of acute aortic dissection. A large left adrenal tumor was detected on CT follow-up at two years. Retrospectively, a hypervascular lesion was present on the first yearly CT examination. Adrenalectomy was performed. There is no evidence of recurrent disease at 12 months. The patient was also treated with oral steroids. Because of their location and of the particularities of available therapeutic options, and because these metastases can occur late, long-term sonographic and CT follow-up should be performed. The clinical, imaging, therapeutic and prognostic aspects of these lesions will be discussed.

Adrenal Gland Neoplasms↗

[Value of multidisciplinary consultation in diagnosis and survival of Marfan syndrome].

OBJECTIVES: To facilitate diagnosis, define a strategy for prevention and treatment and obtain further insight concerning Marfan's disease, we conducted a series of multidisciplinary consultations in French clinics. PATIENTS AND METHODS: Five specialists (a genetics specialist, a pediatrician or a rheumatologist, an ophthalmologist, and a psychologist) saw all the patients successively in the same clinic. A synthesis of the clinical files was prepared for analysis. Since the first consultation on 1 January 1995 and the study end on 30 June 1997, 494 patients (67% adults) participated in primary consultations, 143 were seen at follow-up consultations. RESULTS: The diagnosis of Marfan's disease was affirmed in 41% of the patients, disaffirmed in 48% and uncertain in 11%. Among the Marfan's patients, 75% were seen again within the framework of a multidisciplinary follow-up consultations. Annual work-up included cardiology (echocardiography with measurement of the proximal aorta diameter in search for indication for beta-blocker therapy or preventive valve replacement), ophthalmology (lens, retina) and rheumatology examinations (skeletal involvement). CONCLUSION: Early diagnosis and rigorous follow-up can help prevent ocular and cardiac complications in Marfan's disease. The multidisciplinary approach provides more precise data for diagnosis and possible phenotype-genotype correlations.

Adult↗

[Angiographic identification of spinal cord arteries before bronchial artery embolization].

Ischemic spinal cord injury is the major risk of bronchial artery embolization. The spinal artery may be overlooked on initial intercostobronchial trunk arteriography, as a result of reverse flow within the intercostal branch. Its identification, conversely, is easier on postembolization angiography. An illustrative case is presented, with angiographic correlation. The pathophysiology of the reverse flow is discussed. Technical recommendations are proposed for its detection.

Adult↗

[Failures and complications of bronchial artery embolization].

Bronchial artery embolization (BAE) is well accepted and widely used for management of massive and recurrent hemoptysis. Recurrent hemoptysis occurs in 20% of cases. It may be due to partial embolization, recruitment of other systemic collaterals, recanalization of an embolized artery, or progression of primary disease. Severe complications of BAE are limited to spinal cord injury, oesophageal necrosis, and bronchial ischemia. The proper application of bronchial arteriography and embolization techniques depends on a thorough knowledge of the arterial anatomy, a meticulous catheterization technique, the use of nonionic or lowosmolarity contrast materials, and adequate positioning of the catheter. In these optical conditions of safety, BAE is the treatment of choice for severe and recurrent hemoptysis.

Bronchi↗

Reliability of three methods of radiologic assessment in patients with rheumatoid arthritis.

RATIONALE AND OBJECTIVES: To assess the intraobserver reliability of three methods used frequently to evaluate joint destruction in rheumatoid arthritis: the Sharp method, the Larsen method, and the carpo:metacarpal ratio. METHODS: One observer analyzed twice within a 6-week interval 71 radiographs from patients with rheumatoid arthritis. Reliability was estimated by intraclass correlation coefficient (R) and by Altman-Bland graphical method. Correlations were examined by the Spearman's coefficient (r). RESULTS: The intraobserver reliability of each method appeared satisfactory with a good result for the Sharp method (R = 0.97). The correlation was strong (r > 0.80) between the results obtained by Sharp's and Larsen's methods and weaker between the results of the two former methods and the carpo: metacarpal ratio. CONCLUSIONS: Sharp's method should be used preferentially in studies evaluating the radiologic changes in rheumatoid arthritis over time, especially in clinical trials. The carpo:metacarpal ratio may be considered as a complementary method, when wrist destruction is of conceptual importance.

Adult↗