The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
One aspect of the invention provides devices and techniques for accessing the peritoneal cavity for, e.g., performing laparascopic, percutaneous and/or transgastric procedures in the peritoneal cavity. An example of such procedures is the diagnostic and therapeutic stimulation of abdominal and pelvic structures accessed through natural orifices, such as the mouth. This exemplary technique uses a standard endoscope and instruments to make a gastrostomy. The endoscope may then be passed into the peritoneal space within the peritoneal cavity and manipulated (by, e.g., bending or retroflexing) to view desired structures. A mapping instrument may be passed through one of the endoscope working channels to diagnose or identify structures. Upon completion of mapping, stimulating electrodes may be placed into target tissue using a percutaneous needle under endoscopic visualization and assistance. Alternatively, electrodes may be passed through a lumen of the endoscope. The electrode leads then may be attached to a stimulator disposed within the patient (e.g., in a subcutaneous pocket formed in the patient) and or percutaneously to an external stimulator.
The devices and techniques according to this aspect of the invention may be applied to a wide variety of disorders of the abdomen and pelvis. In many of these procedures, the target location or site is mapped prior to placement of either a trial percutaneous lead or a permanent implantable pulse generator.
After an opening is made in the stomach wall using a standard technique (e.g., gastrostomy), the opening is expanded to accommodate the endoscope (14), and the distal end of the endoscope is passed through the opening into the peritoneal cavity (16). After using the endoscope's viewing capabilities to locate target tissue site, a diagnostic mapping device is passed through a lumen of the endoscope so that its distal end is in the peritoneal cavity (18). Diagnostic electrical mapping may be then be performed on the target tissue (20). The mapping procedure may be used to diagnose the patient and to determine which therapeutic procedure should be performed, such as the implantation of stimulation or sensing electrodes, implantation of a stimulating device and/or tissue ablation (22, 24).
After completion of the procedure, the opening in the stomach is closed, and the endoscope is removed from the patient (26). Gastrostomy closing may be performed by placement of a percutaneous endoscopic gastrostomy (PEG) tube or by use of a ligating system, clip or T-bar device cinched to close the opening without placement of a PEG.
After movement of the endoscope (e.g., bending, retroflexing) for visualization of target structures, a mapping instrument may be passed through a lumen of the endoscope to stimulate and map target tissue within the peritoneal cavity (70, 72). Mapping stimulation responses may be monitored with instrumentation (e.g., EMG, ENG, pressure catheters, etc.) or queried from the patient (as in the case of awake endoscopy for identifying sources of chronic pain). The mapping stimulation may be a single pulse to evoke a twitch or action potential or a train of pulses to elicit a contraction or propagation of nervous system impulses. If the desired response is not elicited in the target tissue, the mapping stimulation may be repeated (74). Otherwise, if mapping is successful, the target site may be marked for electrode placement or other intervention (76).
A stimulation electrode may then introduced into the peritoneum and placed in the target tissue, such as by a percutaneous needle under visualization from the endoscope (78, 80, 82). For example, an electrode such as a barbed style electrode (e.g., a Synapse Peterson, Memberg or single helix electrode) may be loaded into a non-coring needle and penetrated through the skin. Using endoscopic visualization and (if desirable or necessary) with an endoscopic grasping tool, the electrode may be placed in the target tissue. The needle may then be removed, leaving the electrode leads extending percutaneously for connection to an external stimulation device (84). Alternatively, barbed electrodes may be placed endoscopically by introducing a small gauge needle through a lumen of the endoscope for direct placement in the target tissue. The electrode leads may be connected to a subcutaneously-placed stimulator or to a microstimulator (such as a BIONĀ® microstimulator) passed through the endoscope lumen and placed with the electrode. As yet another alternative, the electrode may be placed laparascopically using a single laparascopic port and visualization from the endoscope. This alternative may permit the manipulation and placement of larger electrodes in the peritoneal cavity.
The devices and methods described above may be used as part of many procedures, such as:
Diaphragm conditioning. The device and method may be used to identify phrenic nerve motor points and to implant electrodes in the diaphragm to condition or pace the diaphragm.
Gastro-esophageal reflux disease (GERD) treatment. Mapping of structures within the peritoneal cavity may be used to identify a stimulus location to elicit the best contraction of the lower esophageal sphincter (LES). A trial electrode may then be placed in the LES, and a pH sensor placed in the esophagus. After two or three days of reduced reflux, the electrode may be connected to an implantable pulse generator (IPG).
Gastroparesis. Mapping may be used to identify a stimulus location that causes stomach wall contraction. A trial electrode placed in the stomach with the electrode lead passing percutaneously outside of the patient. Upon demonstration of improved gastric emptying and reduction in nausea, the electrode may be connected to an IPG.
Morbid obesity. Mapping may be used to elicit a sensation of satiety. Trial electrodes may be placed in the stomach with the electrode leads passing percutaneously outside of the patient. The electrodes may be removed after successful weight loss or connected to an IPG if on-going treatment is required.
Chronic pain from pancreatitis treated by neuromodulation at the celiac plexus. Mapping may be used to identify a location where neuromodulation of pain takes place, and trial electrode placed into the celiac plexus. Following a demonstration of pain reduction, the temporary lead or electrode may be connected to an IPG.
Chronic pain from unspecified abdominal or pelvic pain, treated by neuromodulation at the superior hypogastric plexus, the mesenteric plexus, or other nervous system structure through which the pain pathways are mediated. Mapping may be used to identify the location where neuromodulation of pain takes place. Following demonstrated trial pain reduction, the temporary lead or electrode may be connected in to an IPG.
Nerve sparing. The devices of this invention may be used diagnostically to identify specific tissue structures a surgeon may wish to spare during a surgical procedure. A mapping stimulus may be applied to nerve or muscle tissue to elicit a response, responsive tissue noted or marked, and marked tissue may be avoided during the subsequent surgical procedure.
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
This application is related to the following copending patent application, filed on even date herewith: Method And Apparatus For Transgastric Neurostimulation, Attorney Docket No. 33990-702.201, which is incorporated herein by reference in its entirety.