| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Original Research |
1 Joyce Eisenberg Keefer Breast Center, John Wayne Cancer Institute at St.
John's Health Center, Santa Monica, CA.
2 Department of Radiology, University of California, San Francisco–Mount
Zion Medical Center, 1600 Divisadero St., H2804, San Francisco, CA
94115-1667.
Received May 14, 2007;
accepted after revision September 15, 2007.
Address correspondence to R. J. Brenner
(james.brenner{at}radiology.ucsf.edu).
Abstract
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
MATERIALS AND METHODS. From January 2003 through December 2004, patients presenting for preoperative mammographic localization and operative excision of biopsy site marking clips were identified. Age, method of image-guided biopsy, number of excised specimens, and tissue diagnosis were determined. Specimen radiographs were used to identify cases of suspected intraoperative clip loss. Clips absent on specimen radiographs and postoperative mammograms were defined as lost intraoperatively. Biopsy site marking clips, surgical clips, and suction device apertures were measured.
RESULTS. In 78 surgical procedures performed during the study period, three (3.8%) of the patients experienced clip loss. Specimen radiographs confirmed the absence of clips in all submitted tissues. A median of four (range, three to five) separate biopsy specimens were excised among these three cases. A healing biopsy site from the stereotactic biopsy preceding the clip placement procedure was confirmed in all cases. Absence of the metallic clip was confirmed on postoperative mammograms. The apertures of two types of suction device were four and two times those of the biopsy clips.
CONCLUSION. Intraoperative loss of metallic clips placed at the conclusion of image-guided breast biopsy is unusual but can occur during subsequent surgical excision. Repeated inability to locate the clip on specimen radiographs after accurate preoperative localization should raise the suspicion that the target clip has been lost, not missed, during surgery, likely because of inadvertent removal of the clip with the suction device.
Keywords: biopsy clip • breast surgery • mammography • preoperative localization
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The growing use of image-guided biopsy has introduced clinical issues distinguishable from those encountered with traditional mammographically guided needle localization pro cedures. In a large number of instances, after core needle biopsy of a lesion, a small titanium or stainless steel clip is deployed into or near the biopsy cavity in an attempt to mark the sampled area and provide the surgeon with a target should subsequent operative intervention be needed [6]. Accurate placement of these clips is critical in the event that the mammographic lesion is sampled in its entirety during core biopsy, leaving no radiographic evidence of the mammographic or sonographic abnormality [7].
Accurate deployment of clip markers can be challenging. Studies [6–10] have shown variable rates of accuracy of placement, 2–20% of clips being placed more than 10 mm from the intended target. To explain this phenomenon, a number of investigators [8, 9] have reported on the existence of an accordion effect, a phenomenon whereby the clip is displaced away from the biopsy site along the z-axis as soon as compression is released. Routine use of collagen plugs or equivalent materials to assist with clip placement and coagulation after biopsy and clip deployment directly into, instead of near, the biopsy cavity have been reported to improve accuracy [8].
Even if a clip is accurately placed after image-guided biopsy, there is no assurance that the marker will remain in the correct position for the long term. Several case reports [11–14] have described the phenomenon of clip migration, which can result in movement of the marker. Most cases of discrepancy between clip position and biopsy site are likely due to clip misplacement complicated by the accordion effect during removal of compression used for the procedure [8, 9]. Attempts at technical improvements to prevent clip migration and displacement, including the use of microcoils and collagen plug systems, have been advocated to prevent movement away from the surgical target [8]. Despite these advances, the risk of clip migration remains after core biopsy [7–9].
In addition to misplacement and migration, a third issue with the growing use of clip markers is the inability of the surgeon to recover the metallic clip at excisional biopsy. Although lack of recovery of clips in the operating room can be attributed to inaccurate localization or placement of the clip a distance from the suspicious lesion, we have observed this problem even after precise preoperative radiographic localization. The absence of a biopsy clip in a surgical specimen raises the possibility that excision of the suspicious area was incomplete, but this situation is not always due to the surgeon's inability to find and excise the metallic marker. Instead, it is possible that these clips may be lost intraoperatively: The lack of evidence of recovery on specimen radiographs and in tissues submitted for pathologic review is corroborated by the absence of the clips on subsequent postoperative mammograms. We hypothesized that intraoperative loss of metallic clips placed during image-guided biopsy does occur during a surgical procedure, report our experience with this clinical situation, and suggest a likely mechanism to explain the situation.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The study was confined to clips preoperatively localized with radiographic guidance. The term "clip" was applied to all similar metal markers in the recognition that some investigators differentiate the terms "clip" and "marker" for the metallic surrogate device placed at the biopsy site. Some of the clips were placed at institutions other than ours, and the patient was referred to our institution for surgery, so specific types of all clips were not confirmed. At visual inspection of the mammographic images, all clips placed at other institutions resembled and had the same measurements as clips placed at our institution. During the study period, only the MammoMark biopsy site marker (Artemis Medical) was used at our institution. Preoperative mammograms were used to determine the distance between the needle or localization wire tip and the target lesion. Review of specimen radiographs identified cases of suspected intraoperative failure to recover clips placed with image guidance. Postoperative mammograms were used to confirm the absence of these metallic clips in the native breast. Clips absent on specimen radiographs and postoperative mammograms and in the tissues submitted for pathologic review were defined as being lost intraoperatively, and patients with such clips formed the study population.
Clip size was determined and compared with the size of a standard medium surgical clip. Maximum diameters of these two clips were compared with the diameter of the apertures of the commonly used Yankauer and the less frequently used Andrews suction devices to determine the likelihood that either clip would be inadvertently removed by suctioning during the procedure. Approval was obtained from the designated institutional review board.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Specific patient characteristics are reported in Table 1. Final pathologic examination confirmed the presence of a healing site of percutaneous core needle biopsy in the three cases, confirming that the tissues sampled during image-guided biopsy had been surgically excised in all instances despite the lack of an identifiable marker. None of the three patients needed additional procedures to establish a diagnosis.
|
Postprocedure mammograms were performed within 1 month after the operation in each of the three cases. Two patients underwent follow-up imaging on postoperative day 1 and the third on postoperative day 18. The absence of a metallic clip was confirmed in all three patients, allowing the classification intraoperative loss (Fig. 1A, 1B, 1C, 1D, 1E).
|
|
|
|
|
|
|
|
|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
We describe the existence of another, relatively unreported [15] clinical phenomenon: intraoperative loss of metallic clips placed at image-guided breast biopsy. We confirmed intraoperative clip loss in three patients presenting to our institution for excisional biopsy after successful image-guided breast biopsy. In all cases, the metallic clip placed at stereotactic core biopsy was defined as lost only after it was documented to be absent in tissues submitted for pathologic examination and on both specimen and postoperative radiographs. Excision of the appropriate tissue site was confirmed at pathologic examination by documentation of the presence of the previous image-guided biopsy cavity site. In addition, the lesions in question were confirmed to have been excised mammographically by use of measurements and anatomic landmarks on preoperative images, as previously reported [16].
Although the frequency of intraoperative clip loss is low, we believe that awareness of the existence of this problem is important. Failure to recover a clip in the operating room can lead to alteration of surgical conduct. In each of the three patients described in our study, multiple specimens (median of four as opposed to a median of 1.5 when the clip is located) were removed in an unsuccessful attempt to find a target no longer contained within the breast. The pathologic findings confirmed that the previous biopsy site, which served as a surrogate for the metallic marker, was within the first or second submitted tissue specimen in all three cases. Although the cosmetic result for each patient was acceptable, risk of an undesired outcome should not be underestimated when clip loss leads to unnecessary blind excision of additional breast tissue and prolonged anesthesia.
Although it is impossible to state with certainty how the clips were lost intraoperatively, we believe that this phenomenon can be explained by comparing the size of the clip and the size of the suction device aperture. Biopsy clips and markers of a size similar to the 1-mm biopsy site marker (Fig. 2A) can be displaced into and become free floating within the surgical biopsy cavity filled with sterile irrigation fluid, blood, or both. Because biopsy clips are considerably smaller than the 6-mm surgical clips (Fig. 2B) used to mark the segmental mastectomy site, as fluid is suctioned, the biopsy site marker can enter the suction aperture, which is 4 mm in diameter (Fig. 3A). A surgical clip, however, must have a precise orientation in relation to the suction aperture to enter the device (Fig. 3B). Even a common alternative suction device, the Andrews suction tip aperture, is twice the size of a biopsy clip.
Measures that can be used to confirm removal of localized lesions, even when the clip is not present on the specimen radiograph, include radiographic visualization of residual calcifications not retrieved at stereotactic biopsy, visual identification of the methylene blue dye often injected during the localization procedure, retrieval of a distal portion of a localization wire appropriately placed adjacent to the suspect lesion, and even histologic examination for evidence of previous stereotactic biopsy artifact and similar histopathologic changes [16]. When the entire mammographic lesion has been removed, however, with only the clip as an indicator of the biopsy site, intraoperative assessment is complete only with identification of the clip on the specimen radiograph.
Although the rate of failure of needle localization biopsy in a dedicated breast imaging environment has been reported to be 2.5% [17], intraoperative clip loss does not easily fit the traditional definitions of a failed procedure. A failed biopsy classically is one in which the target lesion is missed, making subsequent tissue diagnosis impossible and necessitating an additional invasive procedure. In a trial reported by Jackman and Marzoni [17], a biopsy was classified a failure if the target lesion was missed at the initial procedure. Unlike the cases in the earlier trial, in all three cases in our series, the pathologist not only confirmed that the pathologic finding from the initial percutaneous biopsy was present in the excised specimen but also was able to render a tissue diagnosis on the basis of submitted tissues. No patient needed a second surgical procedure, including the patient with ductal carcinoma in situ. This finding indicated that adequate biopsy had been performed in all instances despite the absence of the metallic marker.
Adherence to certain radiologic and operative principles can help prevent intraoperative clip loss and the unnecessary tissue excision performed as a consequence. First, the radiologist should perform the most accurate localization procedure possible to minimize the risk that the surgeon will dislodge the clip with excessive tissue manipulation. If the clip has been documented to be a distance from the original target site, bracketing of the area with multiple localization wires can be useful. Second, the surgeon should complete the excision whenever possible without entering the previous biopsy cavity site, eliminating the risk that the clip will be dislodged and lost. If it is acknowledged that the previous biopsy site has been violated, we recommend that excessive manipulation of the tissues and suctioning of the area be kept to a minimum. Finally, the radiologist evaluating the specimen radiograph in tandem with the preoperative localization needs to be aware that the lost clip phenomenon can occur and that when multiple specimen radiographs do not show the clip after proper localization, intraoperative communication to the surgeon regarding this possibility should be undertaken.
Our study had recognized limitations. We did not subject all drapes, towels, and sponges to radiography, and visual inspection of such materials for a 1-mm clip was unlikely to be successful. Second, although most clips were presumably placed after stereotactic biopsy, we did not confirm this approach before surgery. However, the aim of this study was related to loss of a clip during surgery after mammographic localization with precise tolerance levels. Although removal of a clip and immediate associated tissue, if unsuccessful during surgery, can be accomplished by percutaneous means [16, 17], the issue of intraoperative clip loss was the focus of this study. It may be possible to make operative adaptations for radiographic evaluation of the fluid suctioned during the procedure or to drain the fluid to avoid this problem. However, because the frequency of suctioning of clips is low, we have not found the operating team amenable to this potential solution. Finally, because the Yankauer suction device is the device most commonly used at our institution, we cannot specifically comment on whether use of the smaller Andrews suction tip would result in fewer episodes of clip loss.
Although the accuracy of clip deployment has been addressed in the literature [8, 9, 18, 19], we offer one of the first reports of another important clinical entity: intraoperative loss of metallic clips placed at the conclusion of image-guided breast biopsy. Although clip loss occurs in only a small percentage of all patients presenting for needle localization breast biopsy, awareness of its existence is important. Intraoperative clip loss can lead to an increase in the amount of tissue excised, prolongation of surgical procedures, and unnecessary anxiety on the part of the patient and the treating clinicians. When the targeted area has been removed but a metallic clip is not found on specimen radiographs, suspicion that this target has been lost should be communicated intraoperatively to the surgeon, who should consider ending the procedure.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
