Electrosurgical systems and methods for removing and modifying tissue

Abstract

The present invention provides systems, apparatus and methods for selectively applying electrical energy to body tissue in order to ablate, contract, coagulate, or otherwise modify a tissue or organ of a patients. An electrosurgical apparatus includes an electrode support bearing an active electrode in the form of a plasma blade or hook having an active edge and first and second blade sides. The active edge is adapted for severing a target tissue via localized molecular dissociation of tissue components. The first and second blade sides are adapted for engaging against, and coagulating, the severed tissue. A method of the present invention comprises positioning an electrosurgical probe adjacent to the target tissue so that a blade- or hook-like active electrode is brought into at least close proximity to the target tissue in the presence of an electrically conductive fluid. A high frequency voltage is applied between the active electrode and a return electrode to effect cool ablation or other modification of the target tissue. During application of the high frequency voltage, the electrosurgical apparatus may be translated, reciprocated, or otherwise manipulated such that the active edge is moved with respect to the tissue. The present invention volumetrically ablates or otherwise modifies the target tissue with minimal or no damage to surrounding, non-target tissue.

1 . An electrosurgical probe, comprising:
 a shaft having a shaft distal end portion and a shaft proximal end portion;   an aspiration lumen in fluid communication with a distal aspiration port;   at least one electrode support affixed to the shaft distal end portion;   a blade electrode affixed to the at least one electrode support, wherein the blade electrode comprises a first electrode arm, a second electrode arm, and a crosspiece extending between the first and second electrode arms; and   wherein the crosspiece comprises at least one active edge of the blade electrode operable for dissecting tissue via molecular dissociation of tissue components.   
     
     
         2 . The electrosurgical probe of  claim 1 , wherein the blade electrode further comprises a first blade side and a second blade side operable for engaging and coagulating severed tissue. 
     
     
         3 . The electrosurgical probe of  claim 1 , wherein the at least one electrode support comprises a first electrode support and a second electrode support, and wherein the first electrode arm and the second electrode arm are affixed to the first electrode support and the second electrode support, respectively. 
     
     
         4 . The probe of  claim 1 , wherein the crosspiece is substantially orthogonal to the first electrode arm and to the second electrode arm. 
     
     
         5 . The probe of  claim 1 , wherein the at least one active edge comprises a distal active edge operable for resection, transection, or dissection of tissue. 
     
     
         6 . The probe of  claim 1 , wherein the distal aspiration port is located proximal to the crosspiece, and the crosspiece spans the distal aspiration port. 
     
     
         7 . The probe of  claim 1 , wherein the blade electrode extends distally from the electrode support by a distance in the range of from about 0.1 mm to about 10 mm. 
     
     
         8 . The probe of  claim 1 , wherein the shaft distal end portion is curved. 
     
     
         9 . The probe of  claim 1 , wherein the shaft distal end portion terminates in a beveled edge and the at least one electrode support is disposed on the beveled edge. 
     
     
         10 . The probe of  claim 1 , wherein the blade electrode comprises a single metal blade having a shape selected from the group consisting of: substantially semicircular, substantially rectangular, hooked, and arcuate. 
     
     
         11 . The probe of  claim 1 , further comprising a fluid delivery unit associated with the shaft. 
     
     
         12 . The probe of  claim 11 , wherein the fluid delivery unit includes an outer sheath situated external to the shaft and forming an annular fluid delivery lumen between the outer sheath and the shaft, the annular fluid delivery lumen terminating in a fluid delivery port. 
     
     
         13 . The probe of  claim 12 , wherein the fluid delivery port is located at the shaft distal end portion proximal to a return electrode. 
     
     
         14 . An electrosurgical apparatus, comprising:
 a shaft having a shaft distal end portion and a shaft proximal end portion;   an electrode support arranged terminally on the shaft distal end portion;   a blade electrode disposed on the distal terminus of the electrode support, the blade electrode comprises a first electrode arm, a second electrode arm, and a crosspiece extending between the first and second electrode arms, the crosspiece including a distal active edge operable for localized ablation of tissue via molecular dissociation of tissue components; and   wherein the blade electrode has a contact surface operable for severing and coagulating tissue.   
     
     
         15 . The apparatus of  claim 14 , further comprising an aspiration lumen in fluid communication with a distal aspiration port, wherein the distal aspiration port is located proximal to the crosspiece, and the crosspiece spans the distal aspiration port. 
     
     
         16 . The apparatus of  claim 14 , wherein the blade electrode comprises a single metal blade having a shape selected from the group consisting of: substantially semicircular, substantially rectangular, hooked, and arcuate. 
     
     
         17 . An electrosurgical system, comprising:
 a plasma blade electrosurgical probe, the probe comprising:   a shaft having a shaft distal end portion and a shaft proximal end portion;   a shaft having a shaft distal end portion and a shaft proximal end portion;   an aspiration lumen in fluid communication with a distal aspiration port;   at least one electrode support affixed to the shaft distal end portion;   a blade electrode affixed to the at least one electrode support, wherein the blade electrode comprises a first electrode arm, a second electrode arm, and a crosspiece extending between the first and second electrode arms;   wherein the crosspiece comprises at least one active edge of the blade electrode operable for severing tissue via molecular dissociation of tissue components; and   a generator comprising a high frequency power supply, the high frequency power supply electrically coupled to the blade electrode.   
     
     
         18 . The system of  claim 17 , wherein the high frequency power supply is operable to apply pulses of high frequency voltage to the blade electrode. 
     
     
         19 . The system of  claim 17 , wherein the blade electrode has a shape selected from the group consisting of: substantially rectangular, substantially semicircular, hooked, and arcuate. 
     
     
         20 . The system of  claim 17 , wherein the blade electrode comprises a material selected from the group consisting of platinum, tungsten, palladium, iridium, and titanium.