Comparison of wedge to forceps videothoracoscopic lung biopsy. Gross and histologic findings

The decreased morbidity and rapid recovery after thoracoscopic lung biopsy compared with open lung biopsy by thoracotomy is increasingly recognized, as is the ability to obtain satisfactory diagnostic material thoracoscopically. To our knowledge, however, there has been no systematic comparison of specimen quality using different thoracoscopic biopsy techniques. The purpose of this study was to compare histologic features of lung parenchyma obtained by videothoracoscopic forceps and wedge biopsy techniques.

Five adult swine were anesthetized, intubated, and ventilated. Sequential left and right videothoracoscopies were performed to obtain biopsy specimens of lung parenchyma using 5-mm endoscopic cupped forceps. Specimens were obtained from fully inflated lung and from partially atelectatic (deflated) lung. Electrosurgery was applied during forceps biopsy for airleak closure. Limited wedge biopsy specimens were obtained using an endoscopic stapler. One hundred thirteen forceps biopsy specimens (55 inflated, 58 deflated) and 24 sections from 8 wedge biopsy specimens were examined. Specimens were assessed for overall histologic quality and ease of microscopic interpretation. Specific histologic features were then evaluated including presence of artifact, congestion and hemorrhage, degree of alveolar inflation, and number of bronchioles and vessels per cross-sectional area. Whole lungs from two animals were examined for extent and depth of lung injury at the areas of biopsy.

No major differences in overall microscopic specimen quality were detected among the different techniques nor were significant differences noted between lung inflated and lung deflated forceps biopsy technique. Wedge sections contained more vessels per unit area (p < 0.001), perhaps reflecting the more peripheral nature of forceps biopsy. Small amounts of thermal or crush artifact were noted on the surface of forceps biopsy specimens, but did not affect overall specimen quality.

Multiple 5-mm forceps biopsy specimens were of comparable quality to single wedge biopsy specimens obtained by endoscopic stapling. Although greater numbers of vessels were present in endoscopic stapled wedge biopsy specimens, multiple forceps biopsy specimens in fact, contain amply sufficient vessels for histologic analysis.