Doctoral Degrees (General Internal Medicine)

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Browsing Doctoral Degrees (General Internal Medicine) by browse.metadata.advisor "Bolliger, Chris T."

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    Refinements and innovations in biopsy and analysis techniques for pleural and lung disease
    (Stellenbosch : University of Stellenbosch, 2007-12) Diacon, Andreas Henri; Bolliger, Chris T.; Wright, Colleen A.; Walzl, Gerhard; University of Stellenbosch. Faculty of Health Sciences. Dept. of Medicine. Internal Medicine.
    1.1. Background Tumors arising from the lung, pleura, or chest wall are a frequent problem in clinical pulmonary medicine. Most lesions are either infectious, neoplastic or granulomatous in nature, but a variety of other differential diagnoses must be considered. An accurate diagnosis is important because the available treatments differ substantially, and because any delay will impair the prognosis in potentially curable patients with lung carcinoma. The investigations involve the disciplines of radiology, pulmonology, surgery, microbiology, and anatomical pathology and consume a respectable amount of resources. The aim of the work covered in this thesis was to optimize the available diagnostic methods for the routine use in a health care setting with limited resources. 1.2. Methods The general idea of this work was to identify conventional sampling methods that could be developed further to become more useful for the diagnosis of chest tumors in a low resource health care setting. The key method was research performed: a) to revise and expand the indication for a sampling method, b) to technically improve the sampling process, and c) to optimize sample transport, preparation and analysis in collaboration with the analytical laboratory. 1.3. Results A list of invasive diagnostic procedures, imaging methods and analytical processes were developed, evaluated and integrated into clinical practice. A) transbronchial needle aspiration, B) transthoracic cutting needle biopsy, C) transthoracic fine needle aspiration, D) transthoracic ultrasound, and E) rapid on-site evaluation of needle aspirates by a cytopathologist. Five studies pertaining to this thesis were published in international peerreviewed journals: â ¢ Safety and yield of ultrasound-assisted transthoracic biopsy performed by pulmonologists (Respiration 2004;71:519-22) This paper established that ultrasound-assisted transthoracic biopsy performed by pulmonologists is feasible, safe, practical, low-cost and has a high yield. â ¢ Utility of rapid on-site evaluation of transbronchial needle aspirates (Respiration 2005;72:182-8) This paper demonstrated the economical advantages of on-site evaluation of transbronchial specimens in a low-resource setting. â ¢ Transbronchial needle aspirates: comparison of two preparation methods (Chest 2005;127:2015-8) This paper demonstrated that preparing smears on-site has a far better yield than pooling samples into a vial. This means that the yield is improved over the current standard at no additional cost. â ¢ Transbronchial needle aspirates: how many passes per target site? (European Respiratory Journal 2007;29:112-6) This paper investigated the most economical and effective approach to serial sampling with transbronchial needle aspiration during flexible bronchoscopy. â ¢ Ultrasound assisted transthoracic biopsy: fine needle aspiration or cutting needle biopsy? (European Respiratory Journal 2007;29:357-62) This paper compared two common methods of sampling and demonstrates that the less expensive method is sufficient in the majority of cases. 1.4. Conclusion This work has impacted on current practice in multiple ways. Conventional methods have been optimized by improving technical factors and with the integration of interdisciplinary collaboration. The initiated research is ongoing with the aim to achieve continued technical and economical improvements in the diagnosis of chest tumors.
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    Ultrasound-assisted transthoracic diagnostic techniques
    (Stellenbosch : University of Stellenbosch, 2011-12) Koegelenberg, Coenraad Frederik Nicolaas; Bolliger, Chris T.; Diacon, Andreas H.; Wright, Colleen A.; University of Stellenbosch. Faculty of Health Sciences. Dept. of Medicine. Internal Medicine.
    ENGLISH ABSTRACT: Although transthoracic ultrasonography is a well established modality, it is still underutilised by chest physicians. The aim of this research project was to investigate the feasibility, diagnostic yield and safety of ultrasound(US)-assisted transthoracic biopsies performed by clinicians in various settings relevant to daily practice of respiratory medicine. We conducted four clinical trials which are summarised below: 1. In a prospective study on the feasibility of US-assisted transthoracic fine needle aspiration (TTFNA) of drowned lung secondary to a proximal mass lesion, a novel indication for US-assisted TTFNA was described. TTFNA passes >20mm from the visceral pleura had a sensitivity of 74.2% and were also more likely to contain malignant cells than more superficial passes. The surprisingly high yield and the fact that no serious complications were observed validated this approach, which may be an alternative to bronchoscopy. 2. In the largest single-centre study on US-assisted TTFNA with rapid on-site evaluation (ROSE) and cutting needle biopsy (CNB) in the setting of superior vena cava (SVC) syndrome ever reported, we were able to accurately diagnose 96% of all patients who presented with an associated mass lesion that abutted or infiltrated the chest wall. No pneumothoraces or major haemorrhage was caused. We also validated the single-session approach, and were able to conclude that US-assisted TTFNA (with ROSE) is the initial investigation of choice in suspected bronchogenic carcinoma, whereas both TTFNA and CNB need to be performed in all other cases. 3. We continued to validate the novel single-session sequential approach in a study on anterosuperior mediastinal masses. US-assisted TTFNA with ROSE was performed on 45 consecutive patients, immediately followed by CNB where a provisional diagnosis of epithelial carcinoma or probable tuberculosis (TB) could not be established. An accurate cytological diagnosis was made in 73.3%, and was more likely to be diagnostic in epithelial carcinoma and TB than all other pathology (p<0.001). CNB yielded a diagnosis in 88.2%. Overall 93.3% of patients were diagnosed by the single-session approach. No pneumothorax or major haemorrhage was observed. 4. In a prospective study, we compared US-assisted Abrams and Tru-Cut needle biopsies with regard to their yield for pleural TB. Pleural biopsy specimens obtained with Abrams needles contained pleural tissue in 91.0% of cases and were diagnostic in 81.8%, whereas Tru-Cut needle biopsy specimens only contained pleural tissue in 78.7% (p=0.015) and were diagnostic in 65.2% (p=0.022). In conclusion, we investigated the feasibility of US-assisted biopsies performed by respiratory physicians in various settings, and consistently found acceptable to very high diagnostic yields with minimal complications. Furthermore, we were able to validate a novel indication for US-assisted TTFNA (US-assisted TTFNA of drowned lung), validate the use of a single-session sequential approach (USassisted TTFNA with ROSE followed by CNB where indicated) in at least two clinical settings (SVC syndrome and anterosuperior mediastinal masses) and we were able to show that US-assisted Abrams needle biopsy is superior to Tru-Cut needles biopsy when histological confirmation of TB pleuritis is required.