A tubo-ovarian abscess (TOA) is a serious infection within the female reproductive system, forming a pus-filled mass that requires prompt medical attention. While it can lead to complications if left untreated, TOA is generally treatable.
Understanding Tubo-Ovarian Abscess
A tubo-ovarian abscess (TOA) is a confined collection of pus that develops within or around a fallopian tube and ovary. These structures are part of the adnexa, which includes the uterus, ovaries, and fallopian tubes, located within the female pelvis. The abscess forms from an infection causing inflammation and pus accumulation.
The infection typically spreads from the lower genital tract, ascending through the uterus and into the fallopian tubes. This upward movement of bacteria can lead to inflammation of the fallopian tube (salpingitis) and ovary (oophoritis), eventually resulting in a walled-off abscess. A TOA often involves both structures, forming a complex inflammatory mass.
Causes and Risk Factors
A tubo-ovarian abscess most commonly develops as a complication of pelvic inflammatory disease (PID). PID itself is often caused by sexually transmitted infections (STIs), such as Chlamydia trachomatis and Neisseria gonorrhoeae. These bacteria can ascend from the cervix or vagina, leading to infection in the upper reproductive organs.
Other factors can contribute to TOA formation, including infections spreading from nearby organs like the appendix, or following gynecological procedures such as a hysterectomy. Risk factors include a history of PID or STIs, multiple sexual partners, and being of reproductive age, particularly younger than 25 years. While an intrauterine device (IUD) is not generally considered a risk factor for TOA, long-term IUD use may increase risk for immunocompromised individuals. Endometriosis and uterine instrumentation are also associated with an increased risk.
Recognizing Symptoms and Diagnosis
Common symptoms often include lower abdominal or pelvic pain, which can range from mild to severe. This pain may be accompanied by fever, chills, and an unusual vaginal discharge that might be foul-smelling. Nausea and vomiting can also occur, along with pain during sexual intercourse. Some individuals may not experience all these typical symptoms, and fever or an elevated white blood cell count might sometimes be absent.
Diagnosis of a TOA typically begins with a physical examination. A healthcare provider may find tenderness in the lower abdomen, adnexa (ovary and fallopian tube area), and cervical motion. Blood tests are often performed to check for infection signs, such as an elevated white blood cell count, erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP) levels.
Imaging studies are important for confirming the presence and location of an abscess. Transvaginal ultrasound is frequently the initial imaging choice, providing detailed views of the pelvic organs. If ultrasound is inconclusive or to better assess infection extent, a computed tomography (CT) scan or magnetic resonance imaging (MRI) may be used.
Treatment Approaches
Treatment for a tubo-ovarian abscess typically begins with intravenous (IV) antibiotics. Broad-spectrum antibiotics are used to target bacteria that often cause these infections. Common antibiotic regimens include combinations like ampicillin/sulbactam with doxycycline, or clindamycin with gentamicin, sometimes alongside ceftriaxone and metronidazole. Clinical improvement, such as reduced pain and fever, is expected within 24 to 48 hours. Following the initial IV course, treatment usually transitions to oral antibiotics for a prescribed duration.
If the abscess is large (often greater than 4 cm) or does not respond to antibiotics within 48 to 72 hours, interventional procedures may be necessary. Image-guided drainage, performed percutaneously (through the skin) or transvaginally, removes pus from the abscess. This minimally invasive approach has high success rates, often helping avoid more extensive surgery and preserving fertility. Drainage is guided by ultrasound or CT imaging for accuracy.
Surgical options are considered when conservative and drainage treatments are unsuccessful, or in cases of abscess rupture or severe infection. Procedures can include laparoscopy, a minimally invasive technique, or laparotomy, which involves a larger abdominal incision. The abscess may be drained, or in more severe instances, the affected fallopian tube and ovary (salpingo-oophorectomy) might need to be removed. Following treatment, continued antibiotic use, rest, and pain management are important, along with follow-up appointments to ensure the infection has cleared and to monitor for complications.