Surgical anatomy of the feline tract
Keywords: surgery, ovariectomy, comparative, feline, ligaments, anatomy
A feline reproductive tract dissected in situ, suspended under water. Water has swelled some of the connective tissue obscuring fine blood vessels. The color contrast and saturation of the tract has been increased to delineate structures.
Image size: 1691 x 1196px
First, note that the uterus is bicornual with a very short uterine body, similar to that in bitches. The bladder has been reflected ventro-caudally to show the uterine body. The ureters can be seen at the base of the bladder.
In both queens and bitches, there is no major (middle) uterine artery such as the arteries seen in the ruminants and horses. Mesometrial vascular supply is only surgically significant, in pregnant queens and bitches, in older animals, and those with uterine pathology, Therefore, transection of the mesometrium in a cranial-to-caudal direction in nulliparous queens and bitches will usually not result in serious hemorrhage.
Close inspection of the image shows that the left kidney is situated slightly more caudal than the right kidney. The left ovary in turn, is also more caudal than the right. Therefore it is sometimes suggested that the left ovary is easier to remove and should be be removed first, while the abdominal incision is still stretching. However this difference in location is only slight and may not be important during surgery.
Fortunately there is far less adipose tissue around the uterus and ovaries in queens and the depth of the abdomen is generally less than in dogs, so ovariectomy is generally more straightforward in queens than bitches.
Ligamentous strictures surrounding the ovaries are of surgical importance. In queens, the utero-ovarian ligament (also known as the proper ligament of the ovary) is fragile in comparison to that of bitch Therefore caution should be exercised when grasping it to elevate the ovary in preparation for ovariectomy. As noted by Hill and Smeak (2010) rupture of this structure may not only cause hemorrhage but can also fracture the ovary, result in an ovarian remnant syndrome (see below). It is also important to realize that one usually cannot apply enough tension to the utero-ovarian ligament of queens to allow safe rupture of the suspensory ligament as has been described for bitches. That technique for bitches is well described by Hill and Smeak as well. Therefore, only light tension should be applied to the utero-ovarian ligament in queens, while the suspensory ligament is transected with scissors. This allows the ovary and its vascular pedicle to be elevated for safe removal. This approach also prevents painful sub-peritoneal hemorrhage due to tearing of the peritoneal blood supply at the base of the ovarian suspensory ligament.
Unlike bitches, queens do not have ovarian bursae that surrounds the ovaries completely.In the image above, one can see the surface of the ovaries This is not possible in bitches As alluded to already, rough handling the the utero-ovarian ligament in queens may fragment their ovaries. However, it is also possible to fragment a feline ovary merely by handling it. In such cases, the absence of a complete ovarian bursa allows ovarian fragments may be carried on instruments and the surgeon's gloves to other areas of the abdomen. The omentum and peritoneal surface are well vascularized, allowing ovarian fragments to seed and grow into accessory ovarian tissue. This is the essence of the feline ovarian remnant syndrome.
Reference.
Hill, L.N. and Smeak D.D 2010. Suspensory ligament rupture technique during ovariohysterectomy in small animals. Vetlearn. Compendium for continuing education for Veterinarians. June 2010. E1-8
