Ovariectomy of granulosa cell tumors in mares by use of the diagonal paramedian approach: 12 cases (1989-1995).

OBJECTIVE To describe the short- and long-term survival rates in horses undergoing ovariectomy for granulosa cell tumors by use of the diagonal paramedian approach. DESIGN Retrospective case study. ANIMALS 12 horses with granulosa cell tumors. PROCEDURE A diagonal paramedian approach for unilateral ovariectomy was used for removal of each mare's granulosa cell tumor. Information about complications and outcomes was analyzed. RESULTS Only minimal complications were detected postoperatively when the diagonal paramedian approach was used, regardless of the preferred technique for ovarian pedicle ligation or incisional closure and the use of pre- and postoperative medications. Clinical signs of moderate or severe postoperative abdominal pain were not evident in any of the 12 horses. Short- and long-term survival rates were 100%. CLINICAL IMPLICATIONS The diagonal paramedian approach was advantageous for ovarian tumor removal, because the ovary was immediately adjacent to the body wall at a portion of the incision site. Size of the ovary was not a limitation, because muscle tissues at the edges of the incision were flexible and easily retractable. All of these factors improved exposure, decreased traction on the ovary, increased our ability to observe the vasculature, and decreased postoperative morbidity, aiding in the removal of granulosa cell tumors in mares.