Biomedical subjects
Marc Noppen
Publications and source records attributed to Marc Noppen.
Fluorescein-enhanced autofluorescence thoracoscopy in patients with primary spontaneous pneumothorax and normal subjects.
RATIONALE: The exact site(s) and pathophysiology of air leakage in patients with primary spontaneous pneumothorax (PSP) are unknown. In one patient with PSP, fluorescein-enhanced autofluorescence thoracoscopy (FEAT) has shown areas of parenchymal abnormality unnoticed during white light thoracoscopy (WLT). OBJECTIVES: To prospectively perform and compare WLT and FEAT in patients with spontaneous pneumothorax and in normal subjects. METHODS: One-time FEAT and WLT inspection with systematic mapping of semiquantified lesions in 12 consecutive patients with PSP was compared with one-time FEAT and WLT during sequential bilateral thoracoscopy in 17 control subjects. RESULTS: WLT abnormalities (anthracosis, cobblestone malformation, and blebs/bullae) were more prevalent in PSP. FEAT, however, showed high-grade lesions in PSP only, which often were present at areas that were normal, or that only showed anthracosis at WLT. When blebs/bullae were present, bleb-associated FEAT abnormalities were only present in two. Actual fluorescein leakage was seen in two patients with PSP. CONCLUSIONS: Lungs in patients with PSP show significantly more abnormalities at WLT when compared with normal subjects. High-grade FEAT lesions were exclusively present in PSP, and predominantly at lung zones that appeared normal at white light inspection. These findings suggest that significant parenchymal abnormalities are not limited to lesions visible during WLT, such as blebs and bullae.
Do pulmonologists need to tighten up their sphincter tone? Do pulmonologists need more guts?
Explore the source record for details and available documents.
Percutaneous placement of marking coils before stereotactic radiation therapy of malignant lung lesions.
PURPOSE: To evaluate a technique for implantation of radiopaque markers in lung nodules as an aid in extracranial stereotactic radiation therapy. MATERIALS AND METHODS: An implantation technique was developed for marking intrapulmonary lung lesions by introducing a vascular coil through a coaxial needle in or near the target tumor. The markers were placed percutaneously through 15- or 20-gauge coaxial needles in 41 lesions (25 patients) under computed tomographic fluoroscopic guidance. Two different types of vascular helical coils where used. RESULTS: All lesions were accessible for puncture and coils could be placed in all lesions. Four types of complications were observed, some as a result of the learning curve in the technique: (i) coil misplacement subcutaneously (5%); (ii) small needle trajectory bleeding in the lung (10%); (iii) pneumothorax, for which one patient (10%) in whom the coil was placed through a 15-gauge coaxial needle needed chest tube drainage and required hospitalization; and (iv) one subcutaneous metastasis probably unrelated to the puncture (2.5%). CONCLUSION: With this technique, lung nodules can be marked with radiopaque implants in a safe and accurate way.
Removal of covered self-expandable metallic airway stents in benign disorders: indications, technique, and outcomes.
STUDY OBJECTIVES: To describe the technique and outcome of removal of self-expandable metallic airway stents (SEMAS) in a series of patients who underwent stenting for benign airway stenoses. DESIGN AND SETTING: A retrospective cohort analysis of patients with benign airway disorders treated with SEMAS between 1997 and 2003, who presented with an indication for stent removal in a tertiary-care hospital, and referral interventional pulmonology clinic. PATIENTS AND METHODS: During the study period, 49 SEMAS were inserted in 39 patients for treatment of benign airway disorders. Ten of these 39 patients (25.6%), bearing 12 covered stents, presented with an indication for stent removal. Data of these cases were extracted from electronic files kept in our institution archive. RESULTS: Indications for stent removal included excessive or recurrent granuloma formation (five cases), recurrence of stenosis after stent failure (one case), stent fracture (two cases), and accomplishment of treatment (two cases). In all of these cases, covered versions of SEMAS had been placed either in the trachea or in a main bronchus. In contrast to many previous reports, these stents proved to be absolutely retrievable even if some difficulties were encountered. In all cases, however, removal was successful without major complications. All patients resumed normal spontaneous ventilation postoperatively, and follow-up was uneventful. Average duration of stenting before removal was 16.2 +/- 17.5 months (+/- SD) [range, 1 to 60 months]. CONCLUSIONS: We conclude that although placement of SEMAS is assumed to be permanent in patients with benign airway disorders, an indication for stent removal is often observed (25.6% in our series). The covered SEMAS can be effectively and safely removed if needed without major sequelae. Nevertheless, new technical improvements in metallic stent design and materials may help reinforce the concept of a retrievable metallic airway stent, which may offer significant clinical advantages.
Bronchopleural fistulas: an overview of the problem with special focus on endoscopic management.
A bronchopleural fistula (BPF) is a communication between the pleural space and the bronchial tree. Although rare, BPFs represent a challenging management problem and are associated with high morbidity and mortality. By far, the postoperative complication of pulmonary resection is the most common cause, followed by lung necrosis complicating infection, persistent spontaneous pneumothorax, chemotherapy or radiotherapy (for lung cancer), and tuberculosis. The treatment of BPF includes various surgical and medical procedures, and of particular interest is the use of bronchoscopy and different glues, coils, and sealants. Localization of the fistula and size may indicate potential benefits of surgical vs endoscopic procedures. In high-risk surgical patients, endoscopic procedures may serve as a temporary bridge until the patient's clinical status is improved, while in other patients endoscopic procedures may be the only option. Therapeutic success has been variable, and the lack of consensus suggests that no optimal therapy is available; rather, the current therapeutic options seem to be complementary, and the treatment should be individualized.
Fluorescein-enhanced autofluorescence thoracoscopy in primary spontaneous pneumothorax.
The exact site of air leakage in a patient with primary spontaneous pneumothorax is difficult to determine and locate. In particular, the role of rupture of emphysema-like changes (blebs and bullae) versus that of enhanced porosity of lung parenchyma in the pathophysiology of primary spontaneous pneumothorax remains unclear. This is the first description of a patient with recurrent primary spontaneous pneumothorax in whom inhalation of aerosolized fluorescein followed by autofluorescence thoracoscopy allowed in vivo localization of various lung areas of extensive subpleural fluorescein accumulation which were not, or only partly, visibly abnormal during normal white light thoracoscopy. No air leak was present at the time of thoracoscopy. No emphysema-like changes were seen. Our findings suggest substantial areas of parenchymal abnormality that remain unnoticed by white light thoracoscopic inspection of the parenchymal surface. In this respect, fluorescein-enhanced autofluorescence thoracoscopy may become an exciting tool in the study of the pathophysiology of primary spontaneous pneumothorax, and could prove useful in clinical practice in determining the sites of surgical staple resection whenever this treatment modality is considered.
Normal volume and cellular contents of pleural fluid.
Because of the technical difficulties in obtaining a-traumatical access to the normal pleural space, the exact volume and cellular content of normal pleural fluid in humans were still unknown until very recently, and animal-derived extrapolation data had to be used. After having developed a minimally invasive thoracoscopic technique for performing sympathectomy in patients suffering from essential hyperhidrosis, but with otherwise absence of thoracic disease, we have been able to achieve minimally traumatic access to normal pleural spaces. Using pleural lavage, a technique consisting of injection and immediate aspiration of 150 mL of prewarmed saline into the pleural space, we were able to determine the total and differential cell content of the few milliliters of original pleural fluid. The exact volume of this original pleural fluid could be measured using urea as an endogenous marker of dilution. Expressed per kilogram of body mass, total pleural fluid volume in healthy, non-smoking humans was 0.26+/-0.1 mL kg(-1). Total white blood cell count (after correction for dilution) was 1.716 x 10(3) cells mL(-1). Differential cell counts yielded median 75% (IR 16%) macrophages, 23% (IR 18%) lymphocytes, and marginally present mesothelial cells (1%, IR 2%), neutrophils (0%, IR 1%) and eosinophils (0%, IR 0%). There was no significant correlation between age and pleural lavage results in a study population aged 17 to 54 years old, which suggests that these results may be extrapolated to the situation in children and adolescents.
Pneumothorax.
Spontaneous pneumothoraces can occur without obvious underlying lung disease (primary) or in patients with known underlying lung disease (secondary). Management guidelines for spontaneous pneumothorax have been published by major professional organizations, but awareness and application among clinicians seems poor. First episodes of primary spontaneous pneumothorax can be managed with observation if the pneumothorax is small. If the pneumothorax is large or if the patient is symptomatic, manual aspiration via a small catheter or insertion of a small-bore catheter coupled to a Heimlich valve or water-seal device, should be performed. In general, definitive measures to prevent recurrence are recommended after the first recurrence of the pneumothorax, and can be achieved by medical (e.g. talc) or surgical (video-assisted thoracic surgery) pleurodesis. Secondary pneumothoraces should be treated with chest tube drainage followed by pleurodesis after the first episode to minimize any risk of recurrence. Traumatic pneumothoraces may be occult (not seen on an initial CXR) or non-occult. The majority are treated by placement of a chest tube. Selected patients may be treated conservatively, with approximately 10% of these patients eventually requiring chest tube placement. Iatrogenic pneumothoraces have a myriad of causes with transthoracic lung needle biopsy being most common. Transthoracic needle biopsy-related pneumothoraces have CT findings that can predict their occurrence and the need for chest tube placement. Iatrogenic pneumothoraces, regardless of cause, may be managed by observation or small bore chest tube placement, depending upon patient stability and the size of the pneumothorax.
Interventional bronchoscopy for treatment of tracheal obstruction secondary to benign or malignant thyroid disease.
STUDY OBJECTIVES: Surgery is the treatment of choice for symptomatic tracheal obstruction due to benign or malignant thyroid disease. In case of inoperability, or when surgery is refused, few therapeutic alternatives are available. Interventional bronchoscopic procedures have only been reported anecdotally. The objective of this study is to evaluate the results of interventional bronchoscopic procedures in the treatment of severe tracheal obstruction due to thyroid disease. STUDY DESIGN: Retrospective cohort analysis. SETTING: University hospital, tertiary referral center. PATIENTS: Thirty consecutive patients referred for bronchoscopic treatment of benign (n = 17) or malignant (n = 13) thyroid-related upper airway obstruction due to tracheomalacia, extrinsic compression, and/or tracheal ingrowth. Indications for bronchoscopic treatment were medical or surgical inoperability, prevention or treatment of tracheomalacia, and refusal of surgery. There were no procedure-related complications. INTERVENTIONS: Rigid bronchoscopy with dilatation, stenting and/or Nd-YAG laser treatment, and clinical follow-up. MEASUREMENTS AND RESULTS: Subjective improvement, pulmonary function tests, early and late complications, and survival. In the benign group, immediate (100% relief of dyspnea) and long-term (88% relief of dyspnea) results were excellent after airway stenting (21 stents used in 17 patients). There was one unrelated death 1 week after stenting in a 98-year-old patient. There were 6% and 30% short-term and long-term complications, respectively, that could be managed endoscopically. In the malignant group, Nd-YAG laser treatment (n = 3) and stenting (n = 13) yielded immediate and long-term success in 92% of patients. There were 15% short-term and 8% long-term complications. Median survival time was 540 days. CONCLUSIONS: Interventional bronchoscopic procedures including Nd-YAG laser treatment and stenting are valuable alternatives to surgery in inoperable thyroid-induced tracheal obstruction, or when surgery is refused.
Management of primary spontaneous pneumothorax.
The optimal management of primary spontaneous pneumothorax remains the subject of considerable controversy. During the last few years, however, interesting new data on pathogenesis and various treatment techniques have been published, which have led to the publication of some interesting and thought-provoking opinion articles. The author reviews the latest developments in pneumothorax pathophysiology and management.
Manual aspiration versus chest tube drainage in first episodes of primary spontaneous pneumothorax: a multicenter, prospective, randomized pilot study.
Although there is no agreement on the optimal treatment of patients presenting with a first episode of primary spontaneous pneumothorax, the majority of physicians prefer chest tube drainage for air evacuation. Manual aspiration of air has been proposed by some, but lack of sound comparative data and safety data has limited its use. In this first randomized, prospective, multicenter pilot study, 60 patients with a first episode of primary spontaneous pneumothorax were randomly allocated to manual aspiration (n = 27) or chest tube drainage (n = 33). Immediate success was obtained in 16 out of 27 (59.3%) in the manual aspiration group, and in 21 out of 33 (63.6%) in the chest tube drainage group (p = 0.9). One-week success rates were 25 out of 27 (93%) in the intention-to-treat manual aspiration group and 28 out of 33 (85%) in the chest tube drainage group (p = 0.4). Fourteen of 27 manual aspiration patients (52%) were hospitalized, versus 100% of the chest tube drainage patients (p < 0.0001). Recurrence rates with at least 1-year follow-up were 7 out of 26 (26%) in the manual aspiration group, and 9 out of 33 (27.3%) in the chest tube drainage group (p = 0.9). There were no complications associated with manual aspiration. Although statistical power is insufficient to formally confirm therapeutic equality, this pilot study suggests that in first episodes of primary spontaneous pneumothorax, manual aspiration seems equally effective as chest tube drainage and is safe, well tolerated, and feasible as an outpatient procedure in the majority of patients.
Definition of gross tumor volume in lung cancer: inter-observer variability.
BACKGROUND AND PURPOSE: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance. MATERIALS AND METHODS: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were compared on the base of geometric volume, dimensions and extensions. Judgement of invasion of lymph node (LN) regions was evaluated using the ATS/LCSG classification of LN. Clinical relevance of the variation was studied through 3D-dosimetry of standard conformal plans: volume of critical organs (heart, lungs, esophagus, spinal cord) irradiated at toxic doses, 95% isodose volumes of GTVs, normal tissue complication probabilities (NTCP) and tumor control probabilities (TCP) were compared for evaluation of observer variability. RESULTS: Before evaluation of observer variability, critical review of planning CT scan led to up- (two cases) and downstaging (one case) of patients as compared to the respective diagnostic scans. The defined GTVs showed an inter-observer variation with a ratio up to more than 7 between maximum and minimum geometric content. The dimensions of the primary tumor had inter-observer ranges of 4.2 (transversal), 7.9 (cranio-caudal) and 5.4 (antero-posterior) cm. Extreme extensions of the GTVs (left, right, cranial, caudal, anterior and posterior) varied with ranges of 2.8-7.3 cm due to inter-observer variation. After common review, only 63% of involved lymph node regions were delineated by the clinicians (i.e. 37% are false negative). Twenty-two percent of drawn in lymph node regions were accepted to be false positive after review. In the conformal plans, inter-observer ranges of irradiated normal tissue volume were on average 12%, with a maximum of 66%. The probability (in the population of all conformal plans) of irradiating at least 95% of the GTV with at least 95% of the nominal treatment dose decreased from 96 to 88% when swapping the matched GTV with an unmatched one. The average (over all patients) inter-observer range in NTCP varied from 5% (spinal cord) to 20% (ipsilateral lung), whereas the maximal ranges amounted 16% (spinal cord) to 45% (heart). The average TCP amounted 51% with an average range of 2% (maximally 5%) in case of matched GTVs. These values shifted to 42% (average TCP) with an average range of 14% (maximally 31%) when defining unmatched GTVs. Four groups of causes are suggested for the large inter-observer variation: (1) problems of methodology; (2) impossible differentiation between pathologic structures and tumor; or (3) between normal structures and tumor, and (4); lack of knowledge. Only the minority of these can be resolved objectively. For most of the causal factors agreements have to be made between clinicians, intra- and inter-departmentally. Some of the factors will never be unequivocally solved. CONCLUSIONS: GTV definition in lung cancer is one of the cornerstones in quality assurance of radiotherapy. The large inter-observer variation in GTV definition jeopardizes comparison between clinicians, institutes and treatments.
Magnesium treatment for asthma: where do we stand?
Explore the source record for details and available documents.
Chest ultrasound is OK for mountaineers and astronauts... And for pulmonologists?
Explore the source record for details and available documents.
The wrong stent at the wrong time: a cautionary tale.
Self-expandable metallic stents have been promoted for a multitude of indications because of their easy insertion and convenience. This may lead to inappropriate use. We report two patients in whom self-expandable metallic stents led to severe early or late complications. The correct choice of the type of a stent demands expertise with consideration and anticipation of late side effects especially in benign stenosis.
Pathogenesis and treatment of primary spontaneous pneumothorax: an overview.
The exact pathogenesis of primary spontaneous pneumothorax (PSP) remains unknown. Furthermore, various specialists including pulmonologists, surgeons, emergency care physicians, radiologists and others are known to treat this disorder in clinical practice. As a consequence, guidelines on the management of PSP are scarce, and differences in treatment approaches persist. In this paper, evidence on the pathogenesis and on various treatment techniques and strategies is reviewed. An algorithmic treatment approach is proposed.
A vanishing carina: a rare cause of cough.
Explore the source record for details and available documents.