Once the twist occurs, blood cannot drain out of the ovary through its veins.
We operated the following week to find out what was going on. I made a vertical incision in her abdomen, which would allow access to other organs if necessary. What I found was a dead ovary, its vascular stalk twisted like an old rope. Instead of having the white color and hard texture of a normal ovary, Mrs. Harris’s ovary was a spongy, blue-black mass, filled with old clot and already attached by scar tissue to the pelvic wall. There was no sign of cancer. We removed the mass, then stitched up the five-inch incision. Mrs. Harris was home in two days and back to work in a month. The pathology report showed no evidence of cancer.
How and why ovarian torsion develops is unclear. It is unusual but not rare, accounting for roughly 3 percent of gynecologic emergencies. In humans the male and female gonads originate early in prenatal development from cells near the kidneys, but they migrate—in males to the scrotum, in females to the pelvis. The ovaries are loosely tethered to the spine by their elongated blood supply, and ligaments connect them to the uterus. Interruption of those ligaments, through either hysterectomy or tubal ligation, as in Mrs. Harris’s case, appears to make a woman more vulnerable to ovarian torsion. Changes within the ovary can also play a role. Ovaries with torsion are often found to have cysts in them, and a large cyst may unbalance an ovary, causing it to twist around its stalk.
Once the twist occurs, blood cannot drain out of the ovary through its veins, yet arterial blood, which flows at a higher pressure, continues to pour in. If a woman has surgery at this point, the ovary can be untwisted and saved; this can be done laparoscopically, and the ovary can be held in place by stitches to prevent torsion from happening again. Unless the twist is undone soon after it occurs, however, the ovary becomes so swollen with blood that it cannot accept any more. The ovary dies. One result is intense pain, from the ovary itself and from the surrounding pelvic lining, which grows inflamed from the decay of the dying organ. That peritoneal inflammation can cause buildup of fluids in the abdomen and release of CA-125, even in the absence of cancer. Eventually the nerves of the ovary die, the inflammation subsides, and the pain wanes. In Mrs. Harris’s case, the ultrasound images had shown blood flow, so the doctors had drawn the conclusion that the ovary was alive. More likely what they were seeing was blood still flowing shortly after the torsion occurred.
At her postoperative visit, Mrs. Harris was free of pain, but her sense of humor persisted: As she went through the door leaning on the arm of her still-sheepish husband, she reminded him that torsion also occurs in testicles.
Stewart Massad is a professor of gynecologic medicine at Washington University in St. Louis. The cases described in Vital Signs are real, but names and other details have been changed.
