ABSTRACT
Introduction: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS TBNA) is an important means of obtaining a tissue for advanced lung cancer. Optimizing the EBUS TBNA needling technique is important to maintain procedural simplicity and maximize sample quality for emerging molecular diagnostics. Methods: We prospectively explored three versus 10 agitations of the needle in sequential passes into the lymph node using separate needles. Resulting Diff-Quik cytology smears were quantitatively assessed using microscopic (tumor cell cellularity, abundance scores, erythrocyte contamination) and DNA yields. Microscopy was reported by two cytopathologists, and an inter-rater assessment was made by four additional cytopathologists. Results: In 86 patients confirmed as having malignant disease by EBUS TBNA (45 males, 41 females), a mean of 5.3 smears were made per patient with a total of 459 smears scored by pathologists and 168 paired smears extracted for DNA. There was no significant difference between three versus 10 agitations for smear cellularity (p = 0.44), DNA yield (p = 0.84), or DNA integrity (p = 0.20), but there was significantly less contamination by erythrocytes from three agitations (chi-square p = 0.008). There was significantly more DNA in the first pass into the node using three agitations than with other passes and with 10 agitations (pass × agitations interaction, p = 0.031). Reviewing pathologists correctly classified smears as more than or equal to 25% cellularity 86.3% of the time (κ = 0.63 [95% confidence interval: 0.55-0.71]). Conclusions: Three agitations are noninferior to 10 agitations for overall abundance of malignant cells and DNA content on smears. A smear with adequate DNA for panel sequencing could almost always be made with the first needle pass using three agitations.
ABSTRACT
BACKGROUND: Gastroesophageal reflux disease (GORD) and microaspiration may be associated with acute graft dysfunction and development of obliterative bronchiolitis (OB) after lung transplantation. The "gold standard" for diagnosis of GORD is the 24-hour esophageal pH-monitoring study, although no simple, non-invasive screening test is routinely employed. Oil red O staining of alveolar macrophages in bronchoalveolar lavage (BAL) fluid identifies exogenous lipid and may be a surrogate marker for microaspiration. In this study we aimed to assess the utility of the lipid index in identifying patients with significant GORD. METHODS: Our investigation was a prospective analysis of 34 lung transplant patients who were transplanted between April 1999 and July 2006 at a single institution. All patients with recurrent respiratory infections, recurrent acute rejection, unexplained graft dysfunction or newly diagnosed OB had Oil red O staining of alveolar macrophages on BAL specimens at bronchoscopy and 24-hour esophageal pH monitoring. A quantitative assessment called the lipid index was performed resulting in a score from 0 to 400. Abnormal 24-hour pH studies were defined as acid exposure >3.4% in the distal and/or >1% in the proximal esophageal site. RESULTS: Thirty-four patients with a mean age 36.1 years and mean post-operative day of 571 +/- 648 had lipid indices of 143 +/- 94 (range 3 to 341). Twenty-four-hour pH studies revealed a distal mean of 16.1 +/- 6.2% and proximal mean of 6.4 +/- 3.7%. A lipid index >150 was 82.3% sensitive and 76.4% specific for an abnormal 24-hour pH result. Foreign material present on cytology of bronchial fluid seen in 28% of patients showed poor correlation with Oil red O stains and pH studies. CONCLUSIONS: The lipid index is an effective, non-invasive screening test that provides direct evidence of esophageal aspiration. Patients with high positive results should proceed to surgical assessment for Nissen fundoplication.
