Thesis (PhD)--University of Stellenbosch, 2011. / 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. / AFRIKAANSE OPSOMMING: Alhoewel transtorakale ultrasonografie ‘n gevestigde modaliteit is, word dit onderbenut deur pulmonoloë. Die doel van hierdie navorsingsprojek was om die praktiese uitvoerbaarheid, diagnostiese opbrengs en veiligheid van sonargerigte transtorakale biopsies uitgevoer deur klinici in verskeie situasies relevant tot die alledaagse praktyk te ontleed. Ons het vier kliniese proewe uitgevoer wat hieronder opgesom word: 1. In ‘n prospektiewe studie oor die praktiese uitvoerbaarheid van sonargerigte transtorakale fyn naald aspirasie (TTFNA) van areas van obstruktiewe pneumonitis sekondêr tot proksimale massa letsels, is ‘n nuwe indikasie vir sonargerigte TTFNA beskryf. TTFNA aspirasies wat >20mm van die visserale pleura geneem is, het ‘n sensitiwiteit van 74.2% gehad en was meer geneig om maligne selle op te lewer as meer oppervlakkige aspirasies. Die verbasende hoë diagnostiese sensitiwiteit en afwesigheid van ernstige komplikasies het die praktiese waarde van hierdie benadering bevestig. 2. In die grootste studie nog oor sonargerigte TTFNA met spoedige in-teater evalusies (SITE) en sny-naald biopsie (SNB) in die teenwoordigheid van superior vena cava (SVC) sindroom, kon ons 96% van pasiënte wat presenteer het met ‘n geassosieerde massa letsel wat die borskaswand betrek, akkuraat diagnoseer. Geen pneumotoraks of major bloeding is waargeneem nie. Ons kon ook die praktiese uitvoerbaarheid van ‘n enkelsessie benadering bevestig en kon tot die gevolgtrekking kom dat sonargerigte TTFNA (met SITE) die aanvanklike ondersoek van keuse is waar bronguskarsinoom vermoed word, maar dat beide TTFNA en SNB noodsaaklik is in ander gevalle. 3. Ons het voortgegaan om die waarde van die nuwe enkel-sessie benadering te bevestig in ‘n studie oor antero-superior mediastinale massas. Sonargerigte TTFNA met SITE is uitgevoer op 45 pasiënte en in gevalle waar ‘n voorlopige diagnose van epiteliale karsinoom of waarskynlike tuberkulose (TB) nie bevestig kon word nie, is dit onmiddelik gevolg deur SNB. ‘n Akkurate sitologiese diagnose is gemaak in 73.3% van gevalle en meer algemeen in epiteliale karsinoom en TB as ander patologie (p<001). SNB was diagnosties in 88.2%. In 93.3% kon ‘n diagnose verkry word met die enkel-sessie benadering. Geen pneumotoraks of major bloeding is waargeneem nie. 4. In ‘n prospektiewe studie is sonargerigte Abrams naald en Tru-Cut naald biopsies se opbrengs vir pleurale TB met mekaar vergelyk. Pleurale biopsie monsters wat met ‘n Abrams naalde geneem is, het pleurale weefsel in 91.0% gevalle getoon en was diagnosties in 81.8%, vergeleke met Tru-Cut naalde wat slegs in 87.7% pleurale weefsel opgelewer het (p=0.015) en wat net in in 65.2% diagnosties was (p=0.022). Opsommend het ons die praktiese uitvoerbaarheid van sonargerigte biopsies uitgevoer deur pulmonoloë in veskeie kliniese situasies nagevors, en het deurlopend aanvaarbare tot hoë diagnostiese opbrengste gevind met minimale komplikasies. Verder kon ons ‘n nuwe indikasie vir sonargerigte TTFNA beskryf en evalueer (sonargerigte TTFNA van obstruktiewe pneumonitis); ‘n enkel-sessie sekwensiële benadering se waarde bevestig (sonargerigte TTFNA met SITE, gevolg deur SNB waar aangedui) in ten minste twee kliniese situasies (SVC sindroom en anterosuperior mediastinale massas); en was dit moontlik om te bewys dat UK-geleide Abrams naald biopsies superior tot Tru-cut naald biopsies is in die histologiese bevestiging van TB pleuritis.