WO1998029037A1

WO1998029037A1 - Biopsy needle

Info

Publication number: WO1998029037A1
Application number: PCT/GB1997/003494
Authority: WO
Inventors: Farook Al-Azzawi
Original assignee: University Of Leicester
Priority date: 1997-01-04
Filing date: 1997-12-18
Publication date: 1998-07-09
Also published as: GB9700092D0; AU5329798A; GB9802258D0; GB2323789A

Abstract

The present invention concerns biopsy needles comprising along its length and angled tip and a first shank mounted on a relatively thin rod-like extensor, in turn mounted on a second shank section, together with uses of same and methods of performing biopsies.

Description

Biopsy Needle

The histological diagnosis of tissue samples, in particular endometrial tissue, is very important in healthcare. Various techniques have been employed to obtain tissue samples - biopsy material provided by curettage is viewed by pathologists as being ideal (Dallenbach-Hellweg, G., 1987, Histopathology of the endometrium, Springer- Verlag, Berlin Heidelberg New York London Paris Tokyo, Fourth Edition), but requires a general anaesthetic. To avoid this need for a general anaesthetic, office biopsy techniques were introduced (i.e. techniques which do not require an operating theatre or general anaesthetic) (Novak, E., 1935, A suction curet apparatus for endometrial biopsy, JAMA, 104: 1497; Randall, L.M., 1935, Proc. Mayo Clin., 10: 143) and more recent modifications, such as vabra curette and pipelle samples have taken advantage of technological advances by using thinner disposable cannulae.

However, these office techniques have three major inherent deficiencies with regard to the adequate and accurate histological assessment of the endometrium:

1. They are blind biopsies - as such, they cannot be directed to a chosen area, i.e. one known to be fundamentally important. The operator cannot know with any degree of certainty whether a localised lesion has been biopsied or what percentage of the endometrial surface has been sampled.

2. The tissues obtained primarily represent the superficial functionalis of the endometrium, and not the stratum compacta or the basalis - this is particularly the case with suction curette. Deeper samples may be obtained by the use of a sharp curette under general anaesthetic, but only at the increased risk of uterine perforation.

3. Biopsies obtained cannot be oriented and examined vertically to include the whole thickness.

In addition, there is nowadays a growing interest in the my ometrial junction zone (MJZ). This zone cannot be sampled using currently available biopsy techniques, hindering histological and pathological analysis of the tissue.

Furthermore, current biopsy techniques and instruments cause significant patient discomfort subsequent to uterine contractions in response to stimulation by the biopsy instrument, causing endometrial damage, with the consequent release of prostaglandins

Furthermore, numerous investigations testing the reliability of these methods and apparatus in histological diagnosis, particularly that of carcinoma, show significant inaccuracies. Compared with specimens obtained at full curettage or after hysterectomy, the diagnosis disagreed in approximately 20% of cases (Denis, R. et al., 1973, Obstet. Gynecol., 122: 106; Hathcock, E.W. et al.,\91A, Am. J. Obstet. Gynaecol., 120: 205; Liu, D.T.Y. et al, 1975, Am. J. Obstet. Gynaecol., 122:106; Walters, D. et al., 1975, Obstet. Gynecol., 46: 160; Webb, M.J. and Gaffey, T.A., 1976, Obstet. Gynecol., 47: 239), and Grimes, D.A. (1982, Am. J. Obstet. Gynaecol, 142: 1-6) concluded that vabra device missed 2 -endometrial cancers out of 44 cancer cases. In a recent publication, the proportion of patients in whom histological diagnoses could not be obtained at dilatation and curettage was more than 42%. Recently Rodrigues, G.C. et al (1993, Am. J. Obstet. Gynaecol., 168: 55-59) have investigated the use of pipelle endometrial samplers and the vabra aspirator. They found that the former sampled only 4.2% ± 0.92% of the total endometrial surface, compared to vabra that was successful in sampling 41.6% ± 5.7% of the endometrium.

In a large multi-centre study of hormone replacement therapy, the endometrium was not assessable in 112 cases out of 413 (27.1%) using the pipelle sampler. These figures cast doubt on the reliability of the methods currently widely employed for endometrial assessment (Habiba, M. et al., 1995, Br. J. Obstet. Gynaecol., 102(3): 262). Worthy of mention is the difficulty encountered in postmenopausal women, where the presently available methods cannot recover assessable tissue in cases with atrophic endometrium, hence diagnosis is often reached by exclusion.

According to the present invention, there is provided a safe, easy-to-use, reliable and accurate biopsy needle which overcomes the aforementioned deficiencies of the prior art, comprising along its length an angled tip and a first shank mounted on a relatively thin rod-like extensor, in turn mounted on a second shank section. The needle may have a total length of at least 40 cm. It may, for example, have a total length of about 48 cm. The angled tip and first shank section may have a combined length of about 5 cm. The rod-like extensor may have a length of about 18 cm. The second shank section may have a length of at least 15 cm. It may, for example, have a length of about 25 cm. The rod-like extensor may have an arc of less than 180° about the centre axis of the needle. It may have an arc of less than 90°. It may have an arc of about 60°.

The biopsy needle may have a diameter of about 16G (1.6mm).

The biopsy needle may be used in endometrial biopsies. It may allow the collection of an endometrial sample having all layers of the endometrium and the inner myometrium. It may allow the collection of an endometrial sample including the MJZ.

It may allow the collection of a longitudinally oriented sample.

Also provided according to the present invention is the use of a biopsy needle according to the present invention in endometrial biopsy.

Also provided according to the present invention is a method of biopsy, for example endometrial biopsy, comprising the useof a biopsy needle according to the present invention. The method may comprise the steps of performing a biopsy as described below.

The present invention will be further apparent from the following description and drawings which show, by way of example only, forms of biopsy needle. Of the figures:

Figure 1 A shows a side view of a biopsy needle according to the present invention; and Figure IB shows a side view of a conventional biopsy needle.

Figure 1 illustrates a biopsy needle 11 comprising along its length an angled tip 12 and a first shank 13 mounted on a relatively thin rod-like extensor 14, in turn mounted on a second shank section 15.

The needle 11 has a total length of about 48cm. The angled tip 12 and first shank section 13 have a combined length of about 5cm. The rod-like extensor 14 has a length of about 18cm and an arc of about 60°. The second shank section 15 has a length of about 25cm.

The biopsy needle 11 of the present invention (Figure 1), having a diameter of 16G (1.6mm) and a length of about 48cm, driven by a high speed Core Cut (not shown) (Biomed-Instrumente Produkte GmbH, Am Brand 1, D-8087, Tϋrkenfeld, Germany) was used according to standard biopsy procedure and the Core Cut manufacturers instructions. The use of the high speed Core Cut minimises tissue displacement and trauma. The Core Cut was adjusted to penetrate to a depth of 16 mm.

The core cut is a two-stage biopsy gun. The first spring action thrusts the inner trocar (i.e. the biopsy needle 11) forwards, followed almost instantaneously by a similar thrust of the outer cutting cannula.

Figure 2 illustrates the contrasting conventional biopsy needle 21 having an angled tip 22 attached to a shank, section 23. It has a total length of approximately 34cm and is of a similar, diameter to that of the biopsy needle 11. The biopsy needle 11 was used in outpatient procedure under local anaesthetic (Downes, E. and Al-Azzawi, F., 1993, Eur. J. Obstet. Gynecol. Reprod. Biol., 48: 37-41), using CO₂ distension medium and the Wolf luminal 2.7 mm (8Fr), 25 ° hysteroscope with the 15 Fr rigid sheath. This instrument allows an operative channel of 2.3 mm (7 Fr). Patients undergoing outpatients hysteroscopy were randomized to either endometrial pipelle biopsy or to Hysteroscopic needle biopsy (HNB) together with an endometrial pipelle biopsy. The pain and tolerability scores were assessed on a visual analogue scale as detailed elsewhere (Downes & Al Azzawi, 1993, supra). The results were compared using the χ² (Chi-squared) test.

Results:

40 procedures were performed without complications. There was no significant difference between the pain scores of women who underwent HNB (3.0 ± 2.7) and those who had a pipelle biopsy (3.7 ± 2.2), (p > 0.3). Pain was rated subjectively by the patients on a scale of 0-10, 0 indicating no pain and 10 extreme pain. The tolerability scores of both groups were 4.4 + 3.6, and 3 ± 2.6 respectively (p > 0.1). Tolerability was rated subjectively by the patients, 0 indicating total tolerability and 10 intolerability. It was possible to obtain a tissue sample at every attempt. The specimens were fixed in a formalin and oriented longitudinally in paraffin. The width of the sample was about 1 mm, providing a core from which up to 30 histological sections could be obtained. Microscopic examination revealed all layers of the endometrium and the inner myometrium in every case. Histological diagnosis was possible in all cases and corresponded to that obtained by pipelle in the same patient. Diagnosis of atrophic endometrium was obtained in 7 cases, 8 were proliferative, and 25 had secretory endometrium. Adenomyosis was diagnosed in two cases. Discussion:

The use of this new biopsy needle overcomes all deficiencies associated with previous methods and apparatus for endometrial biopsy. In addition, the use of the core cut reduced the number of passes required and simplified the procedure. The high speed of the core cut also ensured that the procedure was well tolerated, and this was comparable to the high tolerance to a similar device used for testicular biopsy (Morey, A.F. et al, 1994, Brit. J. Urol., 74: 366-369). HNB could be targeted to specific regions of interest under vision, and a full thickness including the basalis could be obtained in all cases. The biopsies could furthermore be orientated during processing to allow examination of the deeper layers. Biopsies were obtained from the myometrial junctional zone (MJZ) in all cases, and this work presents new prospects in the study of its structural and functional correlates. The finding of adenomyosis in two specimens is interesting. Laparoscopic myometrial biopsy has been reported to have a 8% to a 18.7% sensitivity for this diagnosis (Popp, L.W. et al.,\99?>, Am. J. Obstet. Gynecol., 169: 546- 549), but we are able to target the uterine fundus, through a transcavitary approach we expect a higher success rate.

Conclusion:

The present invention is an innovative, safe and well tolerated device for biopsies and in particular endometrial sampling, that is useful for both routine histological diagnosis and for endometrial research. It provides directed endometrial/junctional zone myometrial diagnosis. The area of interest can be biopsied under hysteroscopic guidance in an outpatient set up.

Claims

1. A biopsy needle comprising along its length an angled tip and a first shank mounted on a relatively thin rod-like extensor, in turn mounted on a second shank section.

2. A biopsy needle according to claim 1, having a total length of at least 40 cm.

3. A biopsy needle according to claim 2, having a total length of about 48 cm.

4. A biopsy needle according to any one of the preceding claims, the angled tip and first shank section having a combined length of about 5 cm.

5. A biopsy needle according to any one of the preceding claims, the rod-like extensor may have a length of about 18 cm.

6. A biopsy needle according to any one of the preceding claims, the second shank section having a length of at least 15 cm.

7. A biopsy needle according to claim 6, the second shank section having a length of about 25 cm.

8. A biopsy needle according to any one of the preceding claims, the rod-like extensor having an arc of less than 180┬░ about the centre axis of the needle.

9. A biopsy needle according to claim 8, the rod-like extensor having an arc of less than 90┬░.

10. A biopsy needle according to claim 9, the rod-like extensor having an arc of about 60┬░.

11. A biopsy needle according to any one of the preceding claims, having a diameter of about 16G (1.6mm).

12. A biopsy needle according to any one of the preceding claims, being an endometrial biopsy needle.

13. A biopsy needle according to claim 12, allowing the collection of an endometrial sample having all layers of the endometrium and the inner myometrium.

14. A biopsy needle according to claim 13, allowing the collection of an endometrial sample including the myometrial junction zone.

15. A biopsy needle according to any one of the preceding claims, allowing the collection of a longitudinally oriented sample.

16. The use of a biopsy needle according to any one of the preceding claims in endometrial biopsy.

17. A method of biopsy comprising the use of a biopsy needle according to any one of claims 1-15.