WO1998027870A1 - Connector of rod parts in surgical stapler apparatus - Google Patents

Abstract

Connector of rod parts in surgical stapler apparatus comprising a male member (9) and a female member (11) comprising an inlet portion (12), longitudinally located resilient members (13) separated by slits (14), and a base (15) wherein the outer surface of the male member (9) and inner surface of at least one of the resilient members (13) having engaging members (10 and 18) that engage the male (9) and female (11) members upon their connection.

Description

CONNECTOR OF ROD PARTS IN SURGICAL STAPLER APPARATUS

FIELD OF THE INVENTION

The invention relates to medical equipment, in particular, to staplers. May find application primarily in surgical devices for hollow organ stapling.

BACKGROUND OF THE INVENTION

Nowadays, detachable rods of surgical staplers for hollow organ anastomosis are being widely spread. Detachment presence permits to mount anvil and assembly stapler head inside the stapled hollow organs independently of each other, with their subsequent connection by means of detachment mechanism, which upgrades work convenience and improves its results.

The detachment for surgical stapler rod is known from the USA patent No. 5312024, comprising rod proximal portion made as male member with one annular recess and conical free end, and rod distal portion made as female member wherein entry portion is cut by longitudinal slots into several (4) portions.

The detachment drawbacks are as follows:

1) Relatively low connection rigidity directed perpendicular to rod axis and caused by longitudinal slots in entry portion of female member. It results into detachment accidental opening upon anvil exposure to lateral forces;

2) Degrading of protrusion strength parameters in the area of their transition to the bottom, as the protrusions are made on the very edge of springy members; 3) Relatively low detachment strength when connected, in particular, cutting and crushing strengths of recess and protrusions, with regard for utilization of only one annular recess and one circular row of protrusions.

The majority of indicated drawbacks restrict the possibility of using low-cost construction materials, particularly plastics, in the assembly, increase device cost, manifest themselves under rigid limitations of rod diameter, for instance, in devices for small-diameter hollow organ anastomoses .

Said USA patent No. 5312024 is the prototype of this invention.

The detachment for surgical stapler rod is also known from the USA patent No. 5205459, comprising rod proximal portion made as male member with annular recess and conically sharpened free edge, as well as rod distal portion made as female member with two longitudinally located opposing windows wherein V-shaped springy member, having protrusions on inner surface of both its ends is inserted.

The detachment shortcomings are as follows: diminished female member strength caused by windows for springy member arrangement, decreased engagement strength of springy member protrusions and annular recesses caused by small working area of protrusions, which results in crushing of working surfaces; high requirements are imposed on fixing tubular member hardness. The detachment is too sophisticated, expensive and production-unfavourable. Said shortcomings restrict potential application of low-cost construction materials and high tech production technologies, increase the assembly cost. SUMMARY OF THE INVENTION

An object of the present invention is provision for potential application of low-cost construction materials, specifically, plastics, for the manufacturing of rod detachment and surgical stapler as a whole.

Another object of the invention is simplification of design and manufacturing technology for rod detachment.

Another object of the invention is decrease in surgical stapler costs.

Another object of the invention is strength increase in surgical stapler rod detachment, when is is made of plastic.

Another object of the invention is reliability increase for rod detachment.

Another object of the invention is upgraded user operation of rod detachment.

The goals sought are achieved by surgical stapler rod detachment comprising:

Surgical stapler apparatus with detachable anvil containing means for hollow organ circular anastomosis of hollow comprising:

- housing;

- cartridge with staples located on distal side of said housing;

- anvil;

- at least one actuator;

- rod consisting of two parts: anvil rod with said anvil on distal end and control rod with said actuator;

- connector joining said anvil rod and control rod according to male-female concept and containing male and female members, one of them being located on distal end of said control rod, while the other, on proximal end of said anvil rod so that said female member comprises consecutively situated portions as follows: inlet portion with unchanging transversal dimensions, longitudionally located resilient members separated from each other by slits; and a base; so that each of said resilient members has distal and proximal ends rigidly bound to said inlet portion and base;

- outer surface of said male member and inner surface of at least one of said resilient members have engaging members that engage said male and female members upon their connection.

Another preferable embodiment of the apparatus, wherein there is a fixing tubular member located in the housing and surrounding said female member in the area of its said resilient members from at least the moment of sutured tissue compression in the apparatus up to the bending termination of said staples.

Another preferable embodiment of the apparatus wherein said protrusions are made as at least one annular ridge, while said recesses are made as at least one annular recess for siting said ridge inside it so that said engaged member located on said female member has breaks generated by said longitudinal through slits.

Another preferable embodiment, wherein the detachment has a fixing tubular member located in the housing and surrounding said female member in the area of its said resilient members from at least the moment of suturing clearance achievement up to the moment of suturing termination for organs to be stapled.

Another preferable embodiment of the apparatus wherein said engaged members are made as at least one protrusion and one recess.

Another preferable embodiment of the apparatus wherein the height of said ridge and the depth of said recess are considerably larger than possible clearance between said fixing tubular member and said female member in the area of its said resilient members.

Rigid fixing of both ends in each resilient member in female member portions provides for larger connection rigidity in two rod parts and precludes the necessity of considerable rod elongation for making the detachment rigid. The detachment material consumption reduces with rod length, and the conveniency of rod part connection increases.

Said connection of resilient members does not require high springy properties from these members for female member unobstructed entry to fixing tubular member. No considerable springy efforts are also needed for keeping engaged engaging members made on inner surface of such resilient members. As the result, demands to springy properties of resilient members decrease so that they can be made of non-frangible plastic. It, as a consequence, leads to reduction of hardness demands for fixing tubular member.

Arrangement of engaged members not at the resilient member end (as in the prototype) but on their inner surface which has no free ends, enhances the bottom of engaged members and, in general, upgrades their strength in the area of their transition to the bottom.

Thus, the design proposed enhances rod detachment strength, reduces material requirements, decreases material consumption, increases its reliability and user-friendliness.

Another preferable embodiment of the apparatus is wherein there are two successively placed said ridges and two corresponding said recesses.

Another preferable embodiment of the apparatus, wherein said ridge, recess and adjacent portion of said male member placed in the proximity of said inlet portion of said female member connected to said male member have larger diameter than said ridge, recess and adjacent portion of said male member located farther of said inlet portion of female member.

The presence of several pairs of engaged members permits to make them of lesser height without diminishing the male and female member engagement force but enhancing their strength. The smaller are recesses in male and female members, the large is the area of their minimal transversal section, and, consequently, their rupture strength in this section.

Another preferable embodiment of the apparatus, wherein said female member is made of non-frangible plastic, for instance, of nylon.

Another preferable embodiment of the apparatus, wherein said male member is made of plastic.

Another preferable embodiment of the apparatus, wherein the entire said control rod, including the member of said connector associated with it is made as one integral detail, for instance, of plastic. Manufacturing of said detachment and rod members of plastic simplifies and reduces production costs.

BRIEF DESCRIPTION OF THE DRAWINGS

For complete understanding of the invention essence, objectives and advantages, detailed description of the drawings is offered wherein:

FIG. 1 shows the fragment of surgical stapler wherein the connector has one pair of trapezoid engaging members.

FIG. 2 contains the fragment of surgical stapler wherein the connector has two pairs of engaging members with round diversified-diameter profiles.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The description is made on the example of surgical stapler wherein the rod performs the functions of common control rod devised both for suturing gap determination and for staple bending. In the devices of this kind said actions are performed successively by proximal progress of said common control rod.

FIG. 1 shows the fragment of surgical stapler comprising housing 1; cartridge 2 with staples 3; anvil 4; rod 5 with anvil rod 6 and anvil 4 on its distal end, and control rod 7 connected to actuator (not shown); connector 8 interjoining anvil rod 6 and connector rod 7. Connector 8 features male member 9 situated on anvil rod 6 proximal end and having engaging member in the form of circular recess 10, and female member 11 situated on control rod 7 distal end. Female member 7 comprises: entry section 12 looking like non-sectioned ring of unchanging transversal dimensions (i.e. with constant diameter) ; longitudinally situated resilient members 13 separated from each other by transversal through slits 14; base 15. The resilient member 16 proximal ends are rigidly connected to base 15, whereas the resilient member 17 distal ends are rigidly connected to entry section 12. An engaging member made as circular ridge 18 with radial ruptures generated by longitudinal through slits 14 separating resilient members 13 from each other, is located on inner surface of resilient members 13. Engaging members 10 and 13 bring male member 9 and female member 11 into interconnection. In an alternative embodiment shown in Fig. 1, there is a pair of engaging members 10 and 18 with trapezoid shape in longitudinal (axial) section of connector 8. The entire female member 11 is made integral with control rod 7 so that resilient members 13 are formed by longitudinal through slits 14, which do not advance into entry section 12.

In an alternative embodiment female member 11 is made of nylon.

In an alternative embodiment male member 9 is made of plastic .

In transversal section of female member 11 (transversal section is not shown), the area of longitudinal through slits 14 is considerably less than the area of resilient members 13, which upgrades the strength of resilient members 13 and connector 8 as a whole by axial effort transmission.

The apparatus has fixing tubular member 19 made as an orifice in housing 1 and encompasses female member 11 in the area of its resilient members 13 at least from the moment of stapled tissue compression, when major axial efforts begin to be transmitted through rod 5, up to the moment of staple 3 bending end. Thus, tubular member locking prevents transversal resilient member divergency and connector 8 disconnection. The connector locking in disseparated position in this period is also ensured by collar 18 height and recess 10 depth being considerably larger than potential spacing between fixing tubular member 19 and female member 11 in the area of its resilient members 13.

The apparatus is equipped with means for mutual angular orientation of anvil 4 and cartridge 2, comprising rod projecting members made as slot protrusions 20 located on anvil rod 6, and housing projecting members made as slot recesses 21 in housing 1.

The connector proposed operates as follows.

Before the anastomosis start the surgeon distally advances rod 5 with anvil 4 by actuator (not shown). In this process resilient members 13 leave tubular fixing member 19, that allowing the surgeon to separate anvil rod 6 with anvil 4 from control rod 7. Upon said separation resilient members 13 diverge transversally that permitting to disconnect engaging members 10 and 18, and to remove male member 9 out of female member 11. Then the surgeon in separate manner introduces anvil 4 and distal part of housing 1 with cartridge 2 into hollow organ sutured parts, ties preliminarily made purse string sutures and again connects anvil rod 6 and control rod

7, using connector 8. By this connection male member 9 through entry section 12 of female member 11 enters the zone of resilient members 13, forcing them transversally apart and bringing engaged members 10 and 18 into engagement. Following engagement of members 10 and 18, anvil rod 6 and control rod 7 are interconnectted by connector 8 so that owing to non-sectioned rigid entry section 12 this connection, from the start, sufficiently stringently locks anvil 4 against transversal displacement caused by lateral forces and prevents connector 8 disconnection under the effect of said lateral forces .

Then, using actuator (not shown), the surgeon forces anvil 4 and cartridge 2 close together through rod 5. During this pulling together there comes a point when the sutured organ tissue is compressed between anvil 4 and cartridge 2. By that moment resilient members 13 enter the fixing tubular member 19, which prevents transversal divergence of members 13, thus allowing transmission of greater axial efforts through connector 8. By that time slot protrusions 20 enter slot recesses 21, thus ensuring necessary angular orientation of anvil 4 and cartridge 2. On further proximal advancement of rod 5 major axial efforts necessary for staple 3 bending are transmitted through connector 8. These efforts are transmitted through all resilient members 13. In this process, their requisite strength is ensured by a relatively large transversal section area of resilient members 13, thanks to their arrangement along the entire circumference of female member 11, whereas the area of slits 14 between them is very small .

Upon transmission of said large axial efforts, the interaction between engaging members 10 and 18 generates considerable transversally acting efforts. These efforts cause friction forces between resilient members- 13 and fixing tubular member 19. But owing to circular disposition of resilient members and their large exterior area, specific pressure in said friction couple decreases. It is also promoted by location of engaging member 18 in median section of resilient members, which results into transversal force distribution along the considerable part of resilient member lengths. As the result, the friction and potential scorring emergence in this friction couple reduces. The design proposed also significantly enhances protrusion 18 shearing and lumping strengths owing to its circular disposition which increases its strength area, and owing to large available support base surface of resilient members 13 which extends from protrusion

18 proximally and distally and improves loading conditions for protrusion 18.

Thanks to above mentioned strength benefits of connector

8, the requirements to material strength properties decrease and promote its fabrication of plastics, which, in its turn, results in its low cost and high production technology.

In the alternative embodiment of Fig. 2 the stapler has the features as follows. There are two pairs of engaging members made as circular protrusions 22 and 23, and curcular recesses 24 and 25. The increase in the amount of engaging pairs additionally enhances shearing and lumping strengths of engaging protrusions, permits them to be of lesser height, which, in its turn, increases breaking strength of resilient members 13. Basically, such number of engaging pairs can be chosen which will ensure necessary strength under given application conditions. In the embodiment of Fig. 2 protrusion 22, recess 24 and adjacent portion 26 of male member 9 and female member 11 have larger diameter than protrusion 23, recess 25 and adjacent portion 27 of male member 9 and female member 11. Taking into consideration certain elongation of connector 8 members, caused by large axial efforts, it will reduce tensions in the narrowest places of male 9 and female 11 member cross sections at the expense of effort redistribution between the narrowest and the widest cross sections. As the result, the connector resistance to axial loads additionally increases. Longitudinal section of protrusions 22, 23 and recesses 24, 25 is round shaped which improves its smoothness and reduces efforts upon connector 8 connection and disconnection. In this, certain deterioratrion in protrusions 22, 23 lumping strength is compensated by their enlarged amount. Unlike Fig. 1, protrusions 22, 23 are made on male member 9, whereas recesses 24, 25 - on female member 11. The selection of member whereon protrusions or recesses are to be situated, depends, besides technological factors, on the strength ratio between male 9 and female 11 member materials. The recesses which weaken the member cross section are advisable to be located on the member made of more durable substance.

The rest of stapler design and operation does not differ from those described with regard to Fig. 1.

Though the description is made on the embodiment of staplers with common control rod, the connector proposed with the same advantages may also be used in alternative types of staplers .

Claims

CLAIMS :

1. Connector of rod parts in surgical stapler apparatus, comprising means for hollow organ circular anastomosis and containing: two members, male and female, interacting between them so that

- said female member comprises consecutively situated portions as follows: inlet portion with unchanging transversal dimensions; longitudionally located resilient members separated from each other by slits; and a base; so that each of said resilient members has distal and proximal ends rigidly bound to said inlet portion and base;

- outer surface of said male member and inner surface of at least one of said resilient members have engaging members that engage said male and female members upon their connection.

2. The connector according to claim 1, wherein all said portions of said female member are made as a unified piece members, whereas said resilient members are formed by making longitudinal through slits, which do not extend into said inlet portion.

3. The connector according to claim 1, wherein said engaged members are made as at least one protrusion and one recess .

4. The connector according to claim 3, wherein said protrusions are made as at least one annular ridge, while said recesses are made as at least one annular recess for siting of said ridge inside it, so that said engaged member located on said female member has breaks generated by said longitudinal through slits.

5. The connector according to claim 4, wherein there are at least two successfully placed said ridges and two corresponding said recesses.

6. The connector according to claim 5, wherein said ridge, recess and adjacent portion of said male member placed in the proximity of said inlet portion of said female member connected to said male member have larger diameter than said ridge, recess and adjacent portion of said male member located farther of said inlet portion of female member.

7. The connector according to claim 1 , wherein said female member is made of non-frangible plastic, for instance, of nylon.

8. The connector according to claim 1, wherein said male member is made of plastic.

9. The connector according to claim 4, wherein said ridge and recess in longitudinal section of said rod have shape generated by crooked line, for instance, a trapezoid-shaped profile.

10. The connector according to claim 4, wherein said ridge and recess in longitudinal section of said rod have shape generated by a smooth line, for instance, semi-circular profile.

11. The connector according to claim 1, wherein in transversal section in the zone of said resilient members, the area of said slits is considerable smaller than the area of said resilient members.

12. Surgical stapler apparatus with detachable anvil comprising means for hollow organ circular anastomosis, including:

- housing;

- cartridge with staples located on distal side of said housing;

- anvil;

- at least one actuator;

- rod consisting of two parts: anvil rod with said anvil on distal end and control rod with said actuator;

- connector joining said anvil rod and control rod according to male-female concept and containing male and female members, one of them being located on distal end of said control rod, while the other, on proximal end of said anvil rod so that said female member comprises consecutively situated portions as follows: inlet portion with unchanging transversal dimensions, longitudionally located resilient members separated from each other by slits; and a base; so that each of said resilient members has distal and proximal ends rigidly bound to said inlet portion and base;

- outer surface of said male member and inner surface of at least one of said resilient members have engaging members that engage said male and female members upon their connection.

13. The apparatus according to claim 12, wherein there is a fixing tubular member located on surgical stapler pieces and surrounding said female member in the area of its said resilient members from at least the moment of sutured tissue compression in the apparatus up to the bending termination of said staples.

14. The apparatus according to claim 13, wherein protrusions are made as at least one annular ridge, while said recesses are made as at least one annular recess for siting said ridge inside it so that said engaged member located on said female member has breaks generated by said longitudinal through slits.

15. The apparatus according to claim 14, wherein the detachment has a fixing tubular member located on surgical stapler pieces and surrounding said female member in the area of its said resilient members from at least the moment of suturing clearance achievement up to the moment of suturing termination for organs to be stapled.

16. The apparatus according to claim 15, wherein the height of said ridge and the depth of said recess are considerably larger than possible clearance between said fixing tubular member and said female member in the area of its said resilient members.

17. The apparatus according to claim 16, wherein there are two successively placed said ridges and two corresponding said recesses .

18. The apparatus according to claim 17, wherein ridge, recess and adjacent portion of said male member placed in the proximity of said inlet portion of said female member connected to said male member have larger diameter than said ridge, recess and adjacent portion of said male member located farther of said inlet portion of female member.

19. The apparatus according to claim 12, wherein female member is made of non-frangible plastic, for instance, of nylon.

20. The apparatus according to claim 12, wherein male member is made of plastic.

21. The apparatus according to claim 12, wherein entire said control rod, including the member of said connector associated with it is made as one integral detail, for instance, of plastic.

22. The apparatus according to claim 12, wherein there are means of angular orientation of said anvil relative to said cartridge including alignment members of the rod and alignment members of the housing interacting between them.

23. The apparatus according to claim 12, wherein said alignment members are made as slot protrusions and slot recesses so that said alignment members of the rod are located on said anvil rod and the entire said anvil rod with mounted on it member of said connector and said alignment members of the rod is made as one integral detail, for instance, of plastic.

24. Connector of rod parts in surgical stapler apparatus, and surgical stapler apparatus according to any of claims 1-23, substantially as shown and described in connection with any of Figs. 1-2.