Many surgical procedures involve inserting various instruments through the working channel of a surgical access device. The instruments are used to view, engage, and/or treat tissue within a body cavity or other surgical site to achieve a diagnostic or therapeutic effect. In laparoscopic abdominal procedures for example, the abdominal cavity is generally insufflated with CO2 gas to a pressure of around 15 mm Hg. The abdominal wall is pierced and a plurality of tubular cannulas, each defining a working channel, are inserted at various points into the abdominal cavity. A laparoscopic telescope connected to an operating room monitor can be used to visualize the operative field and can be placed through one of the cannulas. Other laparoscopic instruments such as graspers, dissectors, scissors, retractors, etc. can be placed through the other cannula(s) to facilitate various manipulations by the surgeon. In this type of procedure, because of the positioning of the cannulas, it can be relatively easy to bring the tips of two separate surgical instruments together in a working relationship within the abdominal cavity. For example, a first instrument could be passed through a cannula in the left side of the patient's abdomen and operated with the surgeon's left hand while a second instrument could be passed through another cannula in the right side of the patient's abdomen and operated with the surgeon's right hand. The surgeon can then easily bring the tips of the two instruments together at an internal point, e.g., in the center of the patient's abdomen. A laparoscope viewing instrument can also be passed through a third cannula, positioned for example in the center of the patient's abdomen, such that the tips of the two instruments can be easily visualized from above.
In other surgical procedures, however, visualization and triangulation is not as straightforward. For example, in Single Incision Laparoscopic Surgery (SILS) or Single Site Laparoscopic Surgery (SSLS), a single laparoscopic entry point is formed, e.g., through the navel. An access device having one or more working channels, and typically a plurality of working channels, is then installed in the entry point and all instruments required for performing the surgery are inserted through this same access device. In such procedures, the elongate shafts of the various instruments end up being generally parallel to one another while inserted through the access device. This can make it very difficult to bring the tips of two instruments together within the abdominal cavity, especially if the instruments do not have distal articulation capabilities. In addition, since the viewing scope is inserted generally along the same axis as the various other instruments, it can be difficult or impossible to see the tips of the instruments. These problems can unduly lengthen the duration of the surgery, potentially increasing the risk of patient complications. Also, in cases where it is impossible to achieve adequate positioning of the instruments' tips and/or visualization, a second or even third entry point must be formed, increasing trauma to the patient and creating additional scars.
Furthermore, when a surgical instrument inserted in any way into the body, it can be difficult to optimally position the instrument's tip relative to target tissue at the surgical site. Particularly when an instrument is inserted from above a surgical site, e.g., through the abdominal wall, there are limited angles of approach to target tissue at the surgical site, which can make effective and quick use of the instrument difficult. Attempting to position an instrument's distal tip at an optimal position relative to a target tissue can require the surgeon's hand to be awkwardly positioned to hold the instrument at a desired angle to optimally position the instrument's distal tip. It can also be difficult for a surgeon to operate the instrument's tip, e.g., grab tissue using graspers, cut tissue using scissors, etc., when the surgeon's hand is bent at an awkward angle.
Moreover, if an instrument has distal articulation abilities, it can be difficult to effectively operate the instrument's tip when the instrument is distally articulated. Providing an adequate force around a bend in the distal articulated area to operate the tip can be difficult, e.g., because of size limitations of the instrument and remote operation of the tip from the instrument's handle.
Accordingly, there is a need for methods and devices which allow laparoscopic procedures to be performed with an enhanced ability to position and visualize surgical instruments.