RESUMO
BACKGROUND: Biomarkers can be subtle tools to aid the diagnosis, prognosis and monitoring of therapy and disease progression. The validation of biomarkers is a cumbersome process involving many steps. Serum samples from lung cancer patients were collected in the framework of a larger study for evaluation of biomarkers for early detection of lung cancer. The analysis of biomarker levels measured revealed a noticeable difference in certain biomarker values that exhibited a dependence of the time point and setting of the sampling. Biomarker concentrations differed significantly if taken before or after the induction of anesthesia and if sampled via venipuncture or arterial catheter. METHODS: To investigate this observation, blood samples from 13 patients were drawn 1-2 days prior to surgery (T1), on the same day by venipuncture (T2) and after induction of anesthesia via arterial catheter (T3). The biomarkers Squamous Cell Carcinoma antigen (CanAG SCC EIA, Fujirebio Diagnostics, Malvern, USA), Carcinoembrionic Antigen (CEA), and CYFRA 21-1 (Roche Diagnostics GmbH, Mannheim, Germany) were analyzed. RESULTS: SCC showed a very strong effect in relation to the sampling time and procedure. While the first two points in time (T1; T2) were highly comparable (median fold-change: 0.84; p = 0.7354; correlation ρ = 0.883), patients showed a significant increase (median fold-change: 4.96; p = 0.0017; correlation ρ = -0.036) in concentration when comparing T1 with the sample time subsequent to anesthesia induction (T3). A much weaker increase was found for CYFRA 21-1 at T3 (median fold-change: 1.40; p = 0.0479). The concentration of CEA showed a very small, but systematic decrease (median fold-change: 0.72; p = 0.0039). CONCLUSIONS: In this study we show the unexpectedly marked influence of blood withdrawal timing (before vs. after anesthesia) and procedure (venous versus arterial vessel puncture) has on the concentration of the protein biomarker SCC and to a less extent upon CYFRA21-1. The potential causes for these effects remain to be elucidated in subsequent studies, however these findings highlight the importance of a standardized, controlled blood collection protocol for biomarker detection.
RESUMO
BACKGROUND: Bronchopleural fistulas (BPF) are a dreaded complication after lobectomy and pneumonectomy and are associated with high morbidity and mortality. BPF are treated by a range of surgical and endoscopic techniques. Amplatzer devices (ADs), normally used for the closure of cardiac defects, may enable the minimally invasive occlusion of these defects. METHODS: Three patients with BPF were treated with the bronchoscopic closure of BPF using AD. Under general anaesthesia, the fistula was located using bronchography and the self-expanding AD was placed under direct bronchoscopic and fluoroscopic guidance into the fistula. Bronchography was used to control the complete occlusion of the BPF. RESULTS: Three male patients with a mean age of 63 years (range, 53-73 years) were successfully treated by AD. Two BPF occurred after lobectomy of the right lower lobe for lung cancer and one after right pneumonectomy for lung cancer. In all patients the bronchoscopic procedure was successful and symptoms of empyema and BPF showed no recurrence over a median follow-up of 22 months. CONCLUSIONS: Endobronchial closure of BPF using AD represents a safe, effective and promising method for postoperative BPF.