Novel method of assessing surgical margin status in laparoscopic specimens

To develop a novel method of inking laparoscopic specimens before piecemeal extraction to evaluate the surgical margins.

Methylene blue, indigo carmine, and India ink were tested in vitro on cadaveric bovine kidneys before manual morcellation in laparoscopic retrieval bags, and subsequently in pigs in vivo undergoing laparoscopic nephrectomy. Tissue fragments were examined both grossly and microscopically after routine histologic processing. On the basis of the findings in these experiments, we used India ink clinically in 4 cases of laparoscopic nephrectomy and adrenalectomy for suspected tumor and assessed the ability to indicate specimen margins grossly and microscopically.

Methylene blue and India ink were the substances that best covered the surface of the surgical specimen completely, were best retained on the tissue, and were most easily washed from the retrieval bag. Gross inspection of the morcellated specimens easily distinguished the inked pieces, signifying tissue present at the surgical margin, from the uninked pieces. During morcellation, neither contamination of central tissue with ink nor leakage of ink from the bag occurred. India ink consistently endured fixation, embedding, and sectioning, with the black, inked margins of the specimen visible microscopically.

Application of India ink before laparoscopic organ morcellation specifically marks the margins of the specimen. This technique allows pathologic determination of the surgical margin status, as well as fractionation of the tissue fragments, and addresses a criticism of organ morcellation. These improvements in the pathologic analysis of laparoscopically excised specimens may obviate the need for intact organ removal.