Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2002-05-29
2004-08-31
Casler, Brian L. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S265000
Reexamination Certificate
active
06783513
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a body cavity access assembly and a procedure for dispensing a liquid, which may contain a biologically active compound, into a patient.
Minimally invasive surgical techniques, such as laparoscopic surgery, typically include the use of a trocar assembly. A trocar assembly includes an obturator (also known as a trocar) positioned within the channel of a cannula. The obturator and cannula are advanced through a body cavity wall so as to create a small opening or a port site wound therein. The obturator is then completely removed from the lumen of the cannula such that the cannula's channel provides an entrance for laparoscopic instruments into the interior of the body cavity. The body cavity is then insufflated with an inert gas, such as CO2, to provide easier access and visualization of the organs contained therein. An alternative to insufflation, which also aids in intra-abdominal visualization and provides access to the organs, is a mechanical lifting device. Once the surgery is complete the cannula is completely removed from the port site wound to rapidly desufflate the body cavity.
Surgery performed in this manner is associated with a lower post-operative pain, quicker recovery and improved immune function. (1, 2, 3, 4, 5, 6). Because of these advantages, laparoscopic surgery has experienced exponential growth. Benign laparoscopic surgery is now well accepted, and surgeons have progressed into the next field of laparoscopic surgery, i.e. laparoscopic cancer surgery. In particular, laparoscopic colon cancer surgery is now being evaluated in a National Institute of Health study. An initial result from this study confirms the laparoscopic method does have advantages over the conventional open surgery. (5, 6, 14).
However, the development of laparoscopic surgery for cancer has been hindered because of the major concern regarding the implantation of tumor cells in the port site wound. (2, 3, 6, 7). In fact, numerous port site recurrences have been documented in the medical literature heretofore, and these recurrences are associated with a decreased survival rate for patients who may have had a curative cancer (2, 3, 6, 7).
Specifically, the medical literature reports that the incidence of tumor cell implantation ranges from as high as 20% to a low of 0% (8). The follow-up evaluation of this wide incidence of port site implantation places a large emphasis on the surgeons learning curve. In particular, the beginning surgeon (less than 25-50 cases) will have a much higher incidence of port site implantation than the advanced surgeon (greater than 50 cases). In spite of using some of the most advanced surgeons in the world, the NIH study confirms an incidence of 1.3% port site implantation for laparoscopic methods (10) as compared to a 0.6% incidence for the open techniques (9).
Several mechanisms may be responsible for the above discussed implantation of tumor cells in the port site wound. For example, minimally invasive surgical techniques for treating cancer require the insertion and removal of laparoscopic instruments or cameras through the lumen of the cannula. In addition, these surgical techniques require that the cannula itself be moved relative to the port site wound such that the cannula is advanced further into, or withdrawn from, the body cavity (11). Moving the cannula in the above-described manner facilitates a surgeon's ability to optimally locate instruments within the body cavity thereby helping to ensure the successful completion of the medical procedure. However, the aforementioned manipulations of the laparoscopic instruments and cannula may result in the exposure of the port site wound to exfoliated cancer cells which creates a risk of implanting tumor cells in the walls of the port site wound (11, 12). In particular, exfoliated cancer cells may adhere to and thus contaminate a portion of the exterior surface of the cannula (11, 12). The contaminated portion of the exterior surface of the cannula may then be advanced into contact with the port site wound during insertion and removal from the port site wound (11, 12). This contact may dislodge the exfoliated cancer cells from the exterior surface of the cannula and thus cause the exfoliated cancer cells to be implanted in the port site wound (11, 12).
As briefly mentioned above, studies have shown that a physician will undergo a significant learning curve before becoming proficient in the performance of advanced laparoscopic surgery, such as cancer surgery (3, 13, 16). As a result, a relatively inexperienced surgeon may have a tendency to manipulate or handle a tumor to a greater degree during a surgical procedure than an experienced surgeon. For example, studies have shown a 14.6% incidence of viable tumor cells in proximity of the specimen where the surgeon is working with his or her instruments (15). In addition, an inexperienced surgeon may have a tendency to insert and withdraw an instrument through the lumen of the cannula a greater number of times than an experienced surgeon. The above-described increased manipulation of the instrument or the tumor can result in a greater incidence of tumor cell implantation in the port site wound.
Regardless of how these cells contaminate the wound, once implanted therein, viable tumor cells can cause a subcutaneous metastases or “port site recurrence” after the resection of malignant tissue. These “port site recurrences” have delayed the advancement of laparoscopic cancer surgery (2, 6, 7, 8, 9, 10, 11, 12) into all fields of cancer surgery, and is one reason why the benefits of laparoscopic surgery have not been available to cancer patients.
Furthermore, laparoscopic surgery performed for general surgery, gynecological surgery, urological surgery, or any other intraabdominal/intra-thoracic infection is associated with a small but real incidence of port site wound infection (1). The infecting bacteria causing these illnesses can contaminate the port site wound in the same manner as discussed above with regard to tumor cell contamination, and these infections can increase a patient's morbidity and consequently the length of a patient's hospital stay, thereby increasing their hospital bill.
What is needed therefore is an assembly and procedure which addresses on or more of the above described drawbacks and may be used for other situations in which dispensing a liquid during a laparoscopic or similar procedure would be desirable.
TABLE OF REFERENCES CITED IN THE BACKGROUND
1. Lord et al.,
Dis. Col. Rect
. 39(2):148 (1996)
2. Berman,
Important Advances in Oncology
1996
, Laparoscopic Resection for Colon Cancer: Cause for Pause
, Vincent DeVita Ed., p. 231
3. Falk et al.,
Dis. Col. Rect
. 36:28 (1993)
4. Liberman et al.,
Surg. Endo
. 10:15 (1996)
5. Whelan et al.,
Dis. Col. Rect
. 41(5):564 (1998)
6. Wexner et al.,
Am. Surg
. 64(1):12-18 (1998)
7. Greene,
Semin. Lap. Surg
. 2(3):153 (1995)
8. Kazemier,
Surg. Endo
. 9:216 (1995)
9. Reilly et al.,
Dis. Col. Rect
. 39(2):200 (1996)
10. Jacquet et al.,
Dis. Col. Rect
. 38(10):140 (1995)
11. Reymond et al.,
Surg. Endo
. 11:902 (1997)
12. Allardyce et al.,
Dis. Col. Rect
. 40(8):939 (1997)
13. Caushaj et al.,
Dis. Col. Rect
. 37(4):21 (Podium Abstract 1994)
14. Lee et al., (
oral presentation
, 6
th
World Congress of Endoscopic Surgery
, June 1998)
Surgical Endoscopy
12 (5):14 (1998)
15. Russell et al.,
Dis. Col. Rect
. 40(11):1294 (1997)
16. Neuhaus S J, (
oral presentation,
6
th
World Congress of Endoscopic Surgery
, June 1998)
Surgical Endoscopy
12 (5): 515 (1998)
17. Schneider C, (
oral presentation
, 6
th
World Congress of Endoscopic Surgery
, June 1998)
Surgical Endoscopy
12 (5): 517 (1998)
SUMMARY OF THE INVENTION
The invention generally relates to a body cavity access assembly including a conduit having a lumen through which a medical instrument may be advanced, an exterior surface, a liquid input adapted to be coupled to a source of liquid, and communicating with a plurality of exit ports defined along a portion of th
Casler Brian L.
Han Mark K
Wood Herron & Evans L.L.P.
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