Structural and functional integrity of ovarian tumor tissue obtained by ultrasonic aspiration

For patients with ovarian epithelial cancer, survival increases when residual disease approaches zero after surgical removal of the tumor. A previous study using the Cavitron Ultrasonic Surgical Aspirator (CUSA) (Cavitron Lasersonic Corp., Stamford, CT) showed the successful removal of ovarian tumors from areas often considered unresectable: the diaphragm, spleen, stomach, and small bowel. However, the CUSA has not yet been approved by the Food and Drug Administration for gynecologic surgery except on an experimental basis. This study was designed to test whether ultrasonic irradiation produced by the CUSA caused alterations in cell structure or physiology of gynecologic tissue in adjacent areas. Paired tumor samples, unirradiated and irradiated, were obtained from ten patients, and portions were sent for pathologic structural evaluation and physiologic tissue culture evaluation. Histologic sections, stained with hematoxylin and eosin, showed that CUSA irradiation produced only minor tissue distortion as observed under the light microscope. A correct diagnosis would have been made in all cases had only tissue fragments obtained from the CUSA specimen trap been stained. For nine of ten patients, initial tumor cell viability was similar in the two specimen types. Flow cytometric DNA analysis confirmed that surgical methods produced matched samples. Cells that survived high-frequency ultrasound appeared functionally intact. For five of eight patients, the cells from the CUSA specimen traps survived and/or divided to a greater extent than those from the knife-dissected tumors. Cells from both surgical routes attained a similar number of passages in culture. It seems reasonable to extrapolate these in vitro observations with pelvic tumor tissues to normal surrounding tissue left in situ. Thus pelvic tissue is believed to be uninjured by CUSA ultrasonic irradiation.