Surgical instrument with curvilinear tissue-contacting surfaces

1. A surgical stapling instrument, comprising:

a handle assembly;

an elongated body portion extending distally from the handle assembly and defining a longitudinal axis;

a shell assembly disposed adjacent a distal end of the elongated body portion, the shell assembly including a curvilinear tissue-contacting surface oriented obliquely with respect to the longitudinal axis;

an anvil assembly located in a plane that is oriented obliquely with respect to the longitudinal axis and having a non-planar tissue contacting surface, the non-planar tissue contacting surface divided into exactly two curvilinear segments, each curvilinear segment being symmetrical with the other curvilinear segment and each curvilinear segment including exactly one concave portion and exactly one convex portion,

wherein the tissue-contacting surface of the anvil assembly is configured to align with the tissue-contacting surface of the shell assembly when the anvil assembly and shell assembly are in an approximated position.

2. The surgical stapling instrument of claim 1 , wherein the tissue-contacting surface of the shell assembly and the tissue-contacting surface of the anvil assembly are each curvilinear along at least a portion of their lengths.

3. The surgical stapling instrument of claim 1 , wherein the tissue-contacting surface of the shell assembly includes at least one convexly curved section and at least one concavely curved section.

4. The surgical stapling instrument of claim 1 , wherein the tissue-contacting surface of the anvil assembly includes at least one convexly curved section and at least one concavely curved section.

5. The surgical stapling instrument of claim 3 , wherein the tissue-contacting surface of the anvil assembly includes at least one convexly curved section and at least one concavely curved section.

6. The surgical stapling instrument of claim 1 , wherein the tissue-contacting surface of the shell assembly includes two curvilinear segments, the curvilinear segments being separated by a concave point and a convex point.

7. The surgical stapling instrument of claim 1 , wherein the shell assembly and the anvil assembly create a staple line disposed obliquely with respect to the longitudinal axis.

8. The surgical stapling instrument of claim 1 , wherein the shell assembly and the anvil assembly create a substantially elliptical staple line.

9. The surgical stapling instrument of claim 1 , wherein the elongated body portion includes a longitudinally curved portion.

10. The surgical stapling instrument of claim 1 , wherein the tissue-contacting surface of the shell assembly and the tissue-contacting surface of the anvil assembly are each curvilinear along at least a majority of their lengths.

11. The surgical stapling instrument of claim 1 , wherein the anvil assembly has first and second arrays of pockets to receive fasteners fired from the shell assembly, the first array lying in multiple non-parallel planes.

12. The surgical stapling instrument of claim 1 , wherein the shell assembly has first and second arrays of fasteners, each array lying in multiple non-parallel planes.

13. The surgical stapling instrument of claim 11 , wherein the second array of pockets lies in multiple non-parallel planes.

14. The surgical stapling instrument of claim 1 , wherein the anvil assembly includes an anvil rod detachably mountable to the surgical instrument.

15. The surgical stapling instrument of claim 1 , wherein the tissue-contacting surface of the shell assembly includes two curvilinear segments, each curvilinear segment being a substantially mirror image of the other.

16. The surgical stapling instrument of claim 1 , wherein the tissue-contacting surface of the anvil assembly includes two curvilinear segments, each curvilinear segment being a substantially mirror image of the other.