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Biomedical subjects

A H Diacon

Publications and source records attributed to A H Diacon.

8 recordsLinked to original sources
PubMed2006

Ultrasound-assisted transthoracic biopsy: fine-needle aspiration or cutting-needle biopsy?

The present study compared the diagnostic yield of ultrasound-assisted cutting-needle biopsy (CNB) and fine-needle aspiration biopsy (FNAB) in chest lesions. A physician performed ultrasound and FNAB with a 22-G spinal needle in all patients, directly followed by a 14-G CNB in patients without contraindication. A total of 155 consecutive lesions arising from the lung (74%), pleura (12%), mediastinum (11%) or chest wall (3%) in patients with a final diagnosis of lung carcinoma (74%), other malignant tumours (12%), non-neoplastic disease (9%) or unknown (5%) were prospectively included. The overall diagnostic yield was 87%. Combined specimens were obtained in 123 lesions (79%). In these, yields of FNAB, CNB and both methods combined were 82, 76 and 89%, respectively. FNAB was significantly better than CNB in lung carcinoma (95 versus 81%) but CNB was superior in noncarcinomatous tumours and in benign lesions. On-site cytology was 90% sensitive and 100% specific for predicting a positive FNAB. One patient required drainage for pneumothorax (0.6%). Ultrasound-assisted fine-needle aspiration biopsy performed by chest physicians is an accurate and safe initial diagnostic procedure in patients with a high clinical probability of lung carcinoma. All other patients should undergo concurrent fine-needle aspiration biopsy and cutting-needle biopsy.

Adult↗
PubMed2006

Transbronchial needle aspirates: how many passes per target site?

Transbronchial needle aspiration is a bronchoscopic sampling method for a variety of bronchial and pulmonary lesions. The present study investigated whether and how serial needle passes contribute to the yield of transbronchial needle aspiration at specific target sites. A total of 1,562 needle passes, performed at 374 target sites in 245 patients with neoplastic disease (82%), non-neoplastic disease (15%) or undiagnosed lesions (3%), were prospectively recorded and rated for anatomical location, size, bronchoscopic appearance and underlying disease. Positive aspirates were obtained in 75% of patients and at 68% of target sites. A diagnosis was established with the first, second, third and fourth needle pass at 64, 87, 95 and 98% of targets, respectively. The absolute yield varied strongly with target site features, but the stepwise increment to the maximum yield provided by serial passes was similar across target sites. In conclusion, three transbronchial needle passes per site are appropriate when only a tissue diagnosis is sought and when alternative sites or sampling modalities are available. At least four or five passes should be carried out at lymph node stations critical for the staging of lung cancer.

Adolescent↗
PubMed2003

Diagnostic tools in tuberculous pleurisy: a direct comparative study.

Thoracoscopy is the most accurate yet most expensive tool for establishing the diagnosis of tuberculous (TB) pleurisy. However, most high TB-incidence regions have limited financial resources, lack the infrastructure needed for routine thoracoscopy and require an alternative, cost-effective diagnostic approach for pleural effusions. Altogether, 51 patients with undiagnosed exudative pleural effusions were recruited for a prospective, direct comparison between bronchial wash, pleural fluid microbiology and biochemistry (adenosine deaminase (ADA) and cell count), closed needle biopsy, and medical thoracoscopy. The final diagnosis was TB in 42 patients (82%), malignancy in five (10%) and idiopathic in four patients (8%). Sensitivity of histology, culture and combined histology/culture was 66, 48 and 79%, respectively for closed needle biopsy and 100, 76 and 100%, respectively for thoracoscopy. Both were 100% specific. Pleural fluid ADA of > or = 50 U x L(-1) was 95% sensitive and 89% specific. Combined ADA, lymphocyte/neutrophil ratio > or = 0.75 plus closed needle biopsy reached 93% sensitivity and 100% specificity. A combination of pleural fluid adenosine deaminase, differential cell count and closed needle biopsy has a high diagnostic accuracy in undiagnosed exudative pleural effusions in areas with high incidences of tuberculosis and might substitute medical thoracoscopy at considerably lower expense in resource-poor countries.

Adenosine Deaminase↗
PubMed2001

Functional evaluation before and after interventional bronchoscopy in patients with malignant central airway obstruction.

Rigid or flexible interventional bronchoscopy is increasingly accepted for treating central tracheal or bronchial obstruction caused by incurable pulmonary malignancy. Immediate and sustained symptomatic relief and improvement of quality of life can be offered to patients suffering from dyspnoea and facing death by suffocation. Selection of patients based on functional aspects is of central importance for success in endoscopic treatment. A thorough workup is conducted with close cooperation between the various specialists involved in thoracic oncology (pulmonologist, oncologist, radio-oncologist, thoracic and upper airway surgeon). Careful history taking, clinical examination, pulmonary function testing (PFT) and radiologic imaging are needed to assess the general condition of the patient and give information of type and stage of the underlying malignancy. In eligible patients, timing and method of the intervention depend on the acuteness of the presentation and the endoscopic assessment of the lesion responsible for the obstruction. Regular postinterventional follow-up should be conducted by the patient's doctor and consist of clinical examination, PFT and chest radiography. Close cooperation with the specialist centre is necessary to refer patients for repeat bronchoscopy and management of suspected recurrences or complications.

Airway Obstruction↗
PubMed2000

Prospective randomized comparison of thoracoscopic talc poudrage under local anesthesia versus bleomycin instillation for pleurodesis in malignant pleural effusions.

Induction of pleurodesis offers benefit for patients with metastatic tumors and symptomatic malignant pleural effusions, but the best method for achieving this is still unknown. In this prospective, randomized comparison of two well-established pleurodesis procedures, 36 patients with malignant pleural effusions, expanded lungs after drainage, and expected survival of > 1 mo received either bleomycin instillation (60E) via a small-bore thoracostomy tube or thoracoscopic talc poudrage (5 g) under local anesthesia. Efficacy, safety, and cost could be evaluated for 32 treatments (17 bleomycin, 15 talc) in 31 patients. Recurrence rates of effusion with bleomycin and talc poudrage after 30 d were 41% and 13% (p = 0.12), respectively, those after 90 d were 59% and 13%, respectively (p = 0.01), and those after 180 d were 65% and 13% (p = 0.005), respectively. Neither procedure showed any major adverse effect, and both were equally well tolerated. Cost estimation favored thoracoscopic talc poudrage, both for the initial hospitalization and with regard to recurrences. In conclusion, thoracoscopic talc pleurodesis under local anesthesia is superior to bleomycin instillation for pleurodesis in cases of malignant pleural effusion.

Aged↗
PubMedDate not supplied

Safety and yield of ultrasound-assisted transthoracic biopsy performed by pulmonologists.

BACKGROUND: Transthoracic ultrasound (US) has gained popularity as a tool for visualizing pleural effusions and assisting thoracentesis or chest drain placement. In the absence of effusion, US just as well demonstrates solid masses involving or abutting the pleura, yet biopsy of such lesions is not widely performed by chest physicians. OBJECTIVE: To assess the feasibility and the safety of US-assisted cutting needle biopsy performed by chest physicians in routine practice. METHODS: Lesions involving or abutting the pleura > or =20 mm in diameter on US were sampled with a 14-gauge cutting needle under local anesthesia. Biopsy site, needle direction and depth of penetration were determined with US. The procedure was performed without direct US guidance in 'free-hand' technique. RESULTS: Ninety-one patients underwent 96 cutting-needle biopsies for suspected peripheral lung tumors (n = 44, 46%), pleural-based (n = 39, 41%), mediastinal (n = 10, 10%), or chest wall lesions (n = 3, 3%), which were single in 71%, multiple in 6% and diffuse in 23%. Sensitivity for malignant neoplasms (n = 65) was 85.5% and 100% for mesothelioma (n = 10). Pneumothorax occurred in 4%. CONCLUSIONS: US-assisted cutting-needle biopsy of lesions > or =20 mm in diameter is safe in the hands of pulmonologists. The yield for neoplastic disease including mesothelioma is high.

Adult↗