SURGICAL INSTRUMENT
The present invention relates to an instrument, especially but not exclusively for removing tissue, com- prising an elongate tubular member whose one end is di¬ rectly or indirectly connected to a suction pump for generating a subpressure in the tubular member, said tubular member being provided with at least one inlet through which the tissue is sucked in under the action of the subpressure in the tubular member, so as to be conveyed to a collecting vessel.
A tubular instrument connected to a suction pump is known in plastic surgery and is generally used to suck out fatty deposits. One advantage of this instrument is that long and disfiguring scar formations can be avoided al¬ though the operation area may be large. The tubular member which typically is of a length of 150-200 mm and a dia¬ meter of 3-10 mm, is inserted through centimetre long in¬ cisions in the skin and is hermetically connected to a suction pump with a collecting vessel. The inlet through which the fatty tissue is sucked in is either blunt or cutting. By moving the instrument back and forth under the skin, the tissue introduced into the inlet is torn or cut loose in lumps which are several millimetres in diameter, and is sucked out into the collecting vessel. Large blood vessels slide away from the inlet and therefore are preserved at least to some extent.
This technique suffers from several drawbacks. No accuracy is possible since the removal of tissue occurs unevenly, and sometimes no tissue at all is removed. This is due to the fact that the subpressure in the inlet of the tubular member, through which the tissue is to be sucked in, ceases when tissue that has already been torn or cut loose, clogs the tube. The operation area must therefore be sucked several times, which significantly prolongs the operation time and causes increasing irritation of the tissue. There will also be bleeding of clinical consequence, especially when the edges of the inlet of the tubular member are designed to be cutting. I a large number of patients, cosmetically unsatisfactory dimples in the skin remain in the operation area, which a least in part can be explained by the unsatisfactory function. The field of application for the prior art instrument is besides restricted to fatty tissue.
One object of the invention is to provide an instru ment of the type mentioned by way of introduction, by means of which the above drawbacks in removing tissue ar eliminated.
A further object is to provide an instrument which more versatile and can be used to remove e.g. tumour tissue. A still further object of the instrument according the invention is to facilitate removal of such tissues from the inside of the artery walls as can cause constri tion of the artery and result in impaired or, sometimes, stopped blood supply to the tissue. The characterising clause of claim 1 states the dis tinctive features of the invention.
Since the pressurised liquid supplied to the tubula member is caused to pass the area of the inlet of the tubular member, the tissue which, as the instrument is moved, is gradually introduced into the inlet of the tu¬ bular member, will be exposed to this pressurised liquid and broken up into extremely small tissue fragments, ty¬ pically including about 4-300 cells (this applies to fat tissue). The pressurised jet of liquid passes the inlet substantially in parallel with the plane of the inlet an "cuts" the tissue to pieces as it is sucked into the in¬ let. At the same time this fragmented tissue is subjecte to the sucking action of the suction pump, and the mixtu of liquid and fragments is sucked into the collecting vessel. The pressurised liquid hits the tissue in the fo of a jet whose diameter, distribution and direction are determined by the shape and orientation of the nozzle. T jet loses a minor portion of its kinetic energy when it hits the tissue, and assists most effectively in conveyin the liquid and the fragmented tissue in the direction of the sucking action. The subpressure in the tubular member prevents liquid from passing into the surrounding tissue. The advantage of the instrument resides in even and, con¬ sequently, rapid removal of tissue. The draining function is secured in that the tissue fragments are so small that the tubular member cannot be clogged, at the same time as the conveyance to the collecting vessel is rendered more effective by the thrust of the jet of water. The power of the jet can be adjusted so that tissue of different den¬ sity can be excised, and optimised to save blood vessels. The size of the inlet can also be varied. Preferred embodiments of the inventive instrument an distinctive features thereof are stated in the subclaims.
The invention will now be described in more detail below in the form of a number of embodiments and with re¬ ference to the accompanying drawings in which: Fig. 1 is a perspective view of a first embodiment o the instrument according to the invention;
Fig. 2 is a longitudinal section of the excising por tion of the tubular member included in the instrument and shown in Fig. 1; Fig. 3 is a longitudinal section of the excising por tion in a second embodiment; and
Figs 4, 5 and 6 illustrate a third, a fourth and a fifth embodiment of the instrument according to the in¬ vention. Figs 1 and 2 illustrate a tube 10 of circular cross- section which can be rigid and made of, for example, a tissue-compatible metal. The tube 10 can also be flexible and then be made of a tissue-compatible plastic material. If the instrument according to the invention is to be used to remove e.g. abdominal fat, its length can typically be 150-200 mm and its inner diameter 4-8 mm. Smaller sizes can be convenient in face surgery and bigger ones in ex- tensive operations.
In this embodiment, one end of the tube 10 is closed and softly rounded, as indicated at 11. In the vicinity of the closed end there is an oval inlet 12 preferably having non-cutting edges. Normally the inlet 12 is positioned about 5-30 mm from the rounded end 11.
The other end of the tube 10 is designed as or pro¬ vided with a sleeve-shaped grip or guide portion 13 which is, in turn, connected via a conduit 14 to a suction pump 15, whereby a suction effect in the direction of the arrow B arises.
One wall of the tube 10 is designed as or provided with a duct 16 (Fig. 2) having a diameter of e.g. 2 mm. One end of the duct 16 opens into a nozzle 17 disposed inside or outside the tube 10, between the inlet 12 there¬ of and the rounded end 11. The aperture of the nozzle 17 is disposed centrally in the tube 10 and directed to the opposite end of the tube 10, as shown by the arrow B which also symbolises the sucking direction provided by the suc- tion pump 15.
The other end of the duct 16 is connected to a thick- walled conduit 18 which is, in turn, connected to a liquid container 19. The liquid in the container 19 is adapted to be pressurised by means of a pressure-generating unit 20 of some prior art type. The liquid in the container 19 is a tissue-compatible solution to which an antibiotic and/or a vasoconstrictive substance is optionally added.
On application of the inventive instrument to tissue, the liquid from the container 19 is caused to flow under a pressure of typically 100-400 bars through the duct 16 in the direction of the arrow A, which results in the nozzle 17 forming a jet 21 whose direction of motion substanti¬ ally conforms with the sucking direction (arrow B). When the instrument, i.e. the tube 10, is inserted in the tissue or held against a tissue surface, the inlet 12 is clogged, whereby a subpressure is generated inside the tube 10. The tissue (not shown) thus is sucked through the inlet 12. Under the action of the jet of liquid 21, the sucked-in tissue is broken up into small fragments, and this mixture of liquid and small fragments is fed in the direction of the arrow B at a rate of about 0.5-1 m/s. N tissue is gradually sucked in through the inlet 12 of th tube 10, and by means of the jet of liquid 21 the tissue is excised evenly and rapidly. Owing to the fragmentation of the tissue, the risk that the interior of the tube 10; is clogged, is eliminated. The removed tissue is collecte in a vessel (not shown).
Figs 3-6 to which reference is now made, illustrate other feasible embodiments of the instrument according to the invention. The same reference numerals as in Figs 1-2 are used. In Fig. 3, the duct 16 for the pressurised liquid opens into a nozzle 17 which is disposed eccentrically in side the tube 10 and positioned between the laterally arranged inlet 12 and the closed end of the tube 10 and closest to the tube wall which has the inlet 12. Suck po- sitioning of the nozzle 17 implies that the jet of liquid 21 attacks sucked-in tissue at a somewhat earlier stage a compared with the embodiment according to Figs 1 and 2.
In Fig. 4, the inlet 12 of the tube 10 is formed ±n the end thereof. The nozzle 17 is disposed eccentrically inside the tube 10, and the aperture of the nozzle is angularly set so that the pressurised jet of liquid is di rected transversely of the longitudinal direction of the tube 10. Thus, the mixture of liquid and fragmented tissu is fed towards the opposite tube wall where the mixture it subjected to the sucking action indicated by the arrow B. Fig. 5 illustrate that the duct 16 for the pressur ised liquid is arranged in one wall of the tube, but it i obvious that the duct 16 can also be arranged inside or outside the cavity of the tubular member, and in the latter case the duct is caused to communicate via a leads- in with the interior of the tube 10 (Fig. 5). The tube IQ through which the tissue fragments are conveyed, can also be a direct extension of the tube 16 supplying the pressu rised liquid (Fig. 6). In this embodiment, the tube 10 usually is flexible. In a tubular instrument according to this embodiment, one end is consequently connected to a liquid reservoir, alternatively having a source of pres¬ sure, and the opposite end is connected to a suction pump The preferably rigid, tubular portion 16 for the pressur¬ ised liquid passes after the inlet 12 into a portion whic usually, but not necessarily, is flexible and whose inter ior is subjected to the sucking action (indicated by the arrow B) of the suction pump which is not shown in this Figure.
The instrument according to the invention can also b used outside plastic surgery. Thus, the instrument can also be used to remove vasoconstrictions and tumours.
In each of the embodiments stated above, the tubular member 12 can be provided with prior art fibre optics and, alternatively, electronic sensing means, for locati and monitoring the result of the excisive operation. Moreover it will be appreciated that the inlet 12 o the tubular member can be provided with a coarse- or fin meshed grating for preventing big blood vessels from bei pulled into the tube 10. The inlet 12 can also be provid with a loop or like member which has non-cutting edges a extends a short distance beyond the circumference of the inlet, thereby facilitating the introduction of tissue.
It is also possible to arrange a nozzle 17 the dire tion of which can be adjusted within limits by the opera¬ tor. To a person skilled in the art it is further obviou that the tube 16 for the pressurised liquid can also be flexible, which is illustrated by e.g. the embodiment shown in Fig. 5.