Advanced Breast Biopsy Instrument

Abstract & Commentary

Synopsis: The percutaneous biopsy instrument known as the advanced breast biopsy instrument removes one large core of breast tissue, resulting in 90% of tissue sampling unrelated to the lesion in question and failed to provide margin-free malignant lesion recovery in 85% of cases.

Source: Smathers RL. AJR Am J Roenthenol 2000;175:801.

Percutaneous tissue sampling of nonpalpable breast lesions (and even palpable ones) detected by screening mammography has enjoyed increased acceptance in the United States during the past 10 years following the introduction of large bore needle techniques. This approach provides sufficient tissue for histologic analysis, distinguishing it from cytologic analysis, which has been performed for 20 years in Europe. Both techniques are predicated upon precise placement of the sampling needle into the breast lesion, directed by computer-assisted stereotactic imaging.

Initial enthusiasm followed clinical validation using 14G needles with spring loaded biopsy devices, which were much more penetrating than earlier models. Improved sampling was noted for directional vacuum assisted needles, sometimes assisted by the use of 11G needles that were commercially available in the last few years. Understaging of disease (e.g., intraductal carcinoma being identified by core needle biopsy [CNB] as only atypical ductal hyperplasia, invasive carcinoma being identified by CNB as only intraductal carcinoma) as well as missed lesions are the main limitations of the procedure, recognizing that the latter problem applies equally to the alternative means of histologic analysis—namely, surgical excision. The advantages of percutaneous diagnosis relate primarily to decreased cost and morbidity, assuming that lesions that truly require tissue analysis are subject to the procedure. All such techniques involve the retrieval of multiple small core biopsy samples ranging from a maximum estimated 15mg (14 g) to 95mg (11 g) in weight.

The advanced breast biopsy instrument (ABBI) unit also uses stereotactic techniques to place a large cannula in front of a lesion, with a bore diameter of 10, 15, or 20 mm, and then advancing it in an attempt to remove one entire large biopsy sample. More closely designed to follow traditional excisional biopsy technique, the cannula takes tissue from the skin to beyond the lesion, the core separated from the breast with a wire "noose" that, with cautery, is retracted, allowing the operator to remove the entire unit and biopsy sample. In this way, only one sample is provided—with a large amount of tissue—and if the lesion is not recovered, then direct surgical excision follows.

The study of 101 ABBI-facilitated biopsies by six surgeons with localization assistance by a radiologist found 27 malignancies and 74 benign lesions, a profile consistent with most reported series. More than 90% of the tissue removed was unrelated to the lesion in question, with an average dimension of the removed specimen being 5.51 ± -2.18 cm × 1.65 ± 0.46 cm. Two lesions were missed by the technique.

Only four malignancies had "clean margins"—eight showing ductal carcinoma in situ (DCIS, intraductal carcinoma) at the margins and 23 showing invasive cancer at the margins. Tissue samples were often partially fragmented because of incomplete transection by the metal noose.

As a technique initially proposed for complete excision by percutaneous technique, the procedure fulfills its goal in a small number of cases.

Comment by R. James Brenner, MD, JD

If it looks like an excisional biopsy, maybe it can be billed as an excisional biopsy. Not according to the Health Care Financing Administration.

The introduction of image-directed histologic tissue sampling for screening detected lesions have been validated for properly selected cases by its clinically efficacy and cost-effectiveness. CNB techniques are tantamount to incisional biopsy and, with recognition of anticipated tissue sampling errors requiring subsequent excision, have obviated the need for surgical biopsy in a large percentage of cases. Translation: fewer surgical cases and potential turf battles.

Originally reimbursed for a professional fee approximating $70, CNB attracted little attention from the surgical community until an increasing number of cases were being diagnosed by radiologists instead of surgeons. With improved techniques, reimbursement increased, and cases continued to fall into the hands of radiologists.

US Surgical defined a technique in the ABBI that more closely approximated surgical excision and was primarily marketed to surgeons as the equivalent of excisional biopsy; thus, percutaneous cases could be accomplished with customarily higher professional reimbursement fees. Moreover, the difficult part of the procedure—the image-directed localization—could be performed for a relatively lower reimbursement fee by the radiologist. It was a promising pro-forma, especially because the surgical community often carried more influence with hospital administrators in being a source of patients. Besides, the concept of complete percutaneous removal of benign lesions as well as malignant lesions with free margins was medically appealing.

A number of papers have been published, including this one from one of the demonstration sites chosen by US Surgical to bring prospective customers, demonstrating that such goals have not been achieved. Mechanical problems, inability to retrieve entire lesions (for design reasons that are beyond the scope of this discussion), and inability to provide margin-free size estimates of malignant lesions, have failed to provide a basis for the increased morbidity associated with this percutaneous approach. In fact, the large amount of extraneous tissue obtained with this procedure has been modified by a different biopsy device using a similar design, but which suffers from the same considerations.

Coupled with the denial of reimbursement for excisional biopsy (likely a major disincentive), the problems with this technique have quieted enthusiasm, even among institutions that purchased prone biopsy tables suited for these disposable devices that cost more than $500 each (cost of CNB needles range from $10 to $220). Many of these users have changed to more traditional CNB techniques, with CNB instruments now available from the same vendor, as well as other vendors.

It may well be that future applications of complete lesion removal and adjuvant treatment by percutaneous means (e.g., radio-ablation) will have a distinct place for a select group of cases where imaging parameters are sufficiently specific to determine accurate size and devices adequate to ensure removal. But one cannot help but wonder if market-driven forces defined a need for a tool with questionable clinical application.