TISSUE SEALING METHOD
An improved method and equipment for tissue/vessel sealing is disclosed for the sealing, coagulation and transection of tissue during surgical procedures. The improvement is accomplished through better management of heat and moisture present during tissue treatment by having tissue grasping surfaces comprised of an outer non-conducting region and an inner conductive region, and including channels in the jaw assembly to direct steam and moisture away from surrounding tissue. The outer region follows the perimeter each jaw, isolating the treatment zone and preventing steam and excess heat from leaving the tissue treatment zone, reducing thermal margins and unintended patient burns. The outer region also prevents surrounding moisture from affecting the treatment zone and allowing more consistent results.
This application claims priority to U.S. Provisional Application Ser. No. 61/068,246, filed Mar. 6, 2008, the content of which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTIONThe present invention is in the technical field of electro-surgical medical devices.
More particularly, the present invention relates to devices used for the coagulation and sealing of vessels and tissue utilizing radio-frequency (RF) energy during open or laparoscopic surgical procedures.
BACKGROUND OF THE INVENTIONDevices used for the coagulation and sealing of vessels often utilizes heat generated by bipolar RF energy combined with clamping pressure to electrosurgically seal blood vessels and tissue as required during both open and laparoscopic surgical procedures. This process has become well accepted and replaces the use of sutures, clips and staples in many instances, reducing procedure time and cost.
However, consistent performance is a common issue with these types of devices, resulting in failed seals, blood loss and safety concerns. In addition, many instances of excessive energy delivery at the seal site results in over desiccated, charred tissue, sticking and unintended thermal damage to surrounding tissue structures. A major cause of unintended tissue damage is the generation of boiling fluid and steam during the sealing process. This hot vapor and fluid is released under pressure along the outer periphery of the jaws and can damage tissue more than 10 mm away from the target site. Because of this, improvements in reliability, performance and safety are very desirable to the surgeon.
BRIEF SUMMARY OF THE INVENTIONThe present invention relates to improved RF tissue coagulation and sealing by having better control of the target tissue area. This is accomplished by incorporating seal features outside of the clamp region to prevent heat, in the form of steam or hot fluid, from escaping outside of the clamped region and directing it back through the jaws of the device, into the treatment area instead of away from the site. Heat that was previously wasted or caused undesired damage by escaping is more efficiently used in the target region.
Because the heating of tissue and the generation of steam results in a large pressure increase at the target site, one or more inner channels can be located within the jaw assembly to provide pressure relief and direct exhaust out the back of the jaws and away from nearby tissue. The results of utilizing this wet heat are faster, more consistent results, reduced char and sticking, and better precision. Also, by channeling steam and the resulting excess heat away from the site and through the instrument, inadvertent burns to the patient and physician will be reduced.
Additionally, the disclosed invention prevents excess moisture outside of the target area to adversely effect energy delivery, a common problem of current sealing systems. During laparoscopic procedures visibility can be improved by the reduction of mist and particles in the operative cavity as well as a reduction in camera lens fogging. Further, exhaust can be filtered, reducing concerns over surgical plume. The disclosed invention also allows for the temperature monitoring of exhaust to aid in the control of energy delivery from the RF generator.
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In addition, the outer barriers 26 and 28 retain moisture in the tissue seal zone, preventing over desiccation and sticking of tissue 18 to the jaws 20 and 22. Blocking of escaping heat also prevents damage to tissue outside the seal zone, allowing the physician to operate in closer proximity to critical tissue structures. Additionally, it is understood that the seal regions of the jaws may be in the form of a conductive material mounted to the jaw or the jaws themselves may form this conductive surface. It is also understood that exhaust may be directed out the top outer surface of the jaws rather than the back, but this is not preferred.
The above described sealing features have the additional benefit of keeping excess moisture in the form of blood and/or irrigation fluid from interfering with delivery of the energy needed to properly seal tissue. Excess fluid can steal a tremendous amount of the RF energy being delivered, greatly increasing time to complete the seal. In addition many RF electro-surgical systems that utilize impedance (resistance) sensing features to control energy delivery and even indicate successful completion of tissue sealing. Excess fluid hampers such systems and can even give false indication of a good seal, resulting potential bloodloss.
Referring to more detail of the invention,
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The advantages of the present invention include in certain embodiments, without limitation, a reduction in the thermal margin and unintended tissue damage created by existing modalities when coagulating or sealing tissue. The management of heat and moisture also improves seal consistency while reducing energy requirements, reduces sticking and charring of tissue, and improves the surgical field of vision. Furthermore, when used with devices incorporating tissue cutting, the invention will aid in the transection/cutting of tissue by providing tension to the target tissue.
It is well within the skill of a person in the technical field, upon becoming conversant with, or otherwise having knowledge of, the present invention, to select suitable combinations of jaw and electrode components, elastomer configurations, and the like, in view of the type of tissue treatment device being designed and/or constructed.
The above described embodiments are exemplitive, and the terminology is employed for illustration purposes and not limitation purposes. The present invention is not limited to the combinations and sub-combinations illustrated herein.
Claims
1. An electrosurgical instrument for treatment of tissue with distal end effectors comprising of:
- i. a jaw assembly of paired first and second opposing jaw members which are moveable between an open and closed position for grasping and delivering energy to target tissue, and
- ii. at least one jaw member having an inner area of its grasping surface that is conductive for the sealing of tissue, and
- iii. contains an outer region on the entire perimeter of the jaw's grasping surface that is non-conductive and configured to prevent escape of heat from the tissue treatment site during application of electrical energy, and
- iv. said jaw assembly containing at least one feature to provide pressure relief by directing escaping heat and moisture back within the jaw, and
- v. exhausting said heat and moisture away from the tissue treatment site and nearby tissue.
2. The jaw assembly of claim 1 where the pressure directing feature comprises at least one channel in at least one of jaw.
3. The jaw assembly 2, wherein the pressure directing feature is located at the interface of the conductive and non-conductive portions of the grasping surface of at least one jaw, following the perimeter shape of the jaw.
4. The jaw assembly 2, wherein the pressure directing feature is located in the conductive grasping region of at least one jaw.
5. The jaw assembly 2, wherein the pressure directing feature comprises a pattern in the form of channels or openings traveling from the non-conducting grasping surface of the jaws inward, through the conductive portion of the jaws.
6. The jaw assembly of claim 1 configured so that excess heat and pressure are directed to exhaust out the back region of the jaw assembly.
7. The jaw assembly of claim 1 configured so that excess heat and pressure are directed to exhaust through the shaft or body of the instrument.
8. The jaw assembly of claim 1 configured so that excess heat and pressure are directed to exhaust out the outer middle surface of at least one jaw.
9. The jaw assembly of claim 1 where the outer, non-conductive grasping surface is configured to come into tissue contact prior to the inner, conductive region of the grasping surface and provide sufficient pressure to prevent steam and other hot moisture from escaping the outer perimeter of jaws.
10. The jaw assembly of claim 1 where the outer, non-conductive grasping surface is configured to come into tissue contact at the same time as the inner, conductive region of the grasping surface and provide sufficient pressure to prevent steam and other hot moisture from escaping the outer perimeter of jaws.
11. The jaw assembly of claim 1 where the outer, non-conductive grasping surface is configured to come into tissue contact after the inner, conductive region of the grasping surface and provide sufficient pressure to prevent steam and other hot moisture from escaping the outer perimeter of jaws.
12. The jaw assembly of claim 1 where the outer, non-conductive region of the grasping surface is configured to provide an inside to out tensioning of tissue being grasped.
13. The jaw assembly of claim 1 where the outer, non-conductive region of the grasping surface is moveable in relation to the inner, conductive region.
14. The jaw assembly of claim 1 where the outer, non-conductive region of the grasping surface is in the form of an elastomeric material.
15. The jaw assembly of claim 1 where the outer, non-conductive region of the grasping surface provides a physical and electrical barrier to conductive fluids outside of the tissue grasp region.
16. The jaw assembly of claim 1 where the outer, non-conductive regions of the grasping surfaces contain surface features to aid in tissue retraction.
17. The jaw assembly of claim 1 where the outer, non-conductive region of the grasping surface is configured to aid in the release of treated tissue.
18. A method for controlled application energy to tissue consisting of:
- i. engaging target tissue between an assembly of two jaws, each containing a non-conductive outer grasping region and a conductive inner grasping region, and
- ii. delivering energy to heat the grasped tissue and where the outer grasping region prevents the escape of heat and moisture from the outer perimeter of the grasping surface, and
- iii. excess heat and moisture is directed back through jaw assembly, and
- iv. is exhausted away from tissue treatment region and surrounding tissue.
19. A method for controlled application energy to tissue consisting of:
- i. engaging target tissue between an assembly of two jaws, each containing a non-conductive outer grasping region and a conductive inner grasping region, and
- ii. where the outer grasping region provides outward tensioning of grasped tissue, and
- iii. delivering energy to heat the grasped tissue, and
- iv. where the outer grasping region prevents the escape of heat and moisture from the outer perimeter of the grasping surface, and
- v. excess heat and moisture is directed back through jaw assembly, and
- vi. is exhausted away from tissue treatment region and adjacent tissue, and
- vii. the treated tissue is then transected.
Type: Application
Filed: Jan 24, 2014
Publication Date: Aug 7, 2014
Inventor: Scott T. Latterell (Hermosa Beach, CA)
Application Number: 14/163,766
International Classification: A61B 18/00 (20060101);