Tubo-Ovarian Abscess Following Perforated Appendicitis in an Adolescent

Introduction

Appendicitis is the most common cause of emergency abdominal surgery in children. ¹ Delay in diagnosis correlates strongly with the rate of perforation. ² Complications of perforated appendicitis include pleural effusion, wound infection, prolonged ileus, urinary tract infection, urinary retention, intra-abdominal abscess, gastrointestinal bleeding, wound dehiscence, pneumonia, and intestinal obstruction.^3,4 The proximity of the fallopian tubes to the appendix and the peristaltic nature of the tube make it reasonable to believe that there would be a risk of tubo-ovarian abscess (TOA) following perforation of the appendix. Only one such case has been reported in the literature. ⁵ This article presents the case of a 17-year-old female who developed bilateral TOA following perforated appendicitis.

Case

A 17-year-old female, who was not sexually active, presented to the emergency department in September 2008 with severe right lower quadrant pain associated with fever, nausea, and vomiting. An abdominal computed tomography (CT) scan revealed a markedly dilated appendix, 1.8-cm appendicolith, significant surrounding fat stranding, and free fluid. She was taken to the operating room for laparoscopic appendectomy. Intraoperative findings included an entirely gangrenous and necrotic perforated appendix. Her postoperative course was complicated by persistent abdominal pain with distention, fever, and an elevated C-reactive protein level, which peaked at 23.3. She was treated with ertapenem throughout her hospital course. Her abdominal pain failed to resolve within a week and a repeat abdominal CT was obtained, which revealed multiple intraloop abscesses. A pelvic ultrasound obtained 3 weeks postoperatively detected a small left ovarian cyst, and she was referred to a gynecologist. A follow-up ultrasound obtained in November 2008 showed an increase in the size of the left ovarian cyst, which was suggestive of a TOA versus a hemorrhagic cyst. The ultrasound study also revealed fluid in the right fallopian tube. The patient showed no signs or symptoms of infection (white blood cells [WBC] 6.5), and the dilated tube was thought to be from adhesions to the fimbria of the tube. Three (3) weeks later, however, she presented with sharp abdominal pain and a WBC count of 13.4. A pelvic ultrasound at that time revealed bilateral tubular structures suggestive of TOAs. She was admitted and started on doxycycline and cefoxitin. Testing for both gonorrhea and chlamydia were negative. On hospital day 2, her pain remained unchanged and her antibiotics were changed to ampicillin, gentamicin, and metronidazole. She improved and was discharged on hospital day 6 with continued antibiotic treatment. Because she improved with antibiotic therapy, there was no indication to attempt to drain the TOAs. A follow-up ultrasound at the time revealed resolution of the TOAs. Despite this treatment, she continued to have intermittent left-sided and periumbilical abdominal pain that was exacerbated by her menstrual cycles. She was placed on the Ortho Evra patch for ovarian suppression and an ultrasound was ordered to follow the resolution of the TOAs. The patient presented again with an exacerbation of the abdominal pain in February 2009. An abdominal and pelvic CT scan was performed. The CT revealed a complex left pelvic cyst and an increased amount of fluid in the right adnexa. In April 2009, she was taken to the operating room for a diagnostic laparoscopy, which revealed multiple pelvic inclusion cysts and multiple bands of thin adhesive disease, which are common findings after TOA.

Discussion

TOA occurs as a complication of pelvic inflammatory disease (PID) in almost all cases. However, less common causes include inflammatory bowel disease, bowel perforation, and as a complication of perforated appendicitis, as presented here. The patient presented here has never been sexually active and developed a TOA immediately following a prolonged hospital course for perforated appendicitis. We are confident that this reliable patient has no history of sexual activity, making it unlikely that this case of bilateral TOA was caused by PID. Although not very sensitive, negative screening tests for gonorrhea and chlamydia infection, her inability to tolerate pelvic examination, and the temporal course following perforated appendicitis provide further evidence arguing against a sexually transmitted cause of the bilateral TOA.

The fallopian tubes are tubular structures whose physiologic role is to collect ovulated eggs that are released from the ovary and bring them into the uterus. The fimbriated ends of each fallopian tube have many frond-like projections that provide a wide surface area for pickup of ovulated eggs that are released into the peritoneal cavity. ⁶ Because the tube is designed to collect the ovum from the peritoneal cavity and bring it into the tube, it is reasonable to believe that the fimbria would also enable the tube to bring bacteria from the peritoneal cavity into the lumen, leading to the formation of TOA.

Techniques to reduce the occurrence of intra-abdominal abscess following perforated appendicitis may be effective at reducing the risk of TOA following perforated appendicitis. The use of intraoperative irrigation to decrease the incidence of postoperative abscess and infectious complications remains controversial. In addition to intraoperative irrigation, others have promoted the use of a scoring system to identify patients at high risk of developing intra-abdominal abscess following perforated appendicitis and then treating these patients with broad-spectrum antibiotics postoperatively (imipenem plus cilastatin until 48 hours of apyrexia, followed by 7 days of amoxicillin plus clavulanate). Factors included in the scoring system include the following: clinical findings of peritonitis, leukocytes >15,000, axillary–rectal temperature difference >1°C, intraoperative findings of gangrenous or perforated appendicitis, and iatrogenic perforation secondary to inflammation of the appendix. ⁷

PID is usually caused by an initial cervical infection by Chlamydia trachomatis or Neisseria gonorrhoeae, which pave the way for polymicrobial aerobic and anaerobic infection. The infection is spread to the uterus and tubes through lymphatic spread or through the endometrium and salpinges to the tubo-ovarian complex. ⁸ TOAs tend to be polymicrobial, including anaerobic, aerobic, and facultative organisms such as Escherichia coli, Prevotella, Bacterioides, and Pepotostreptococcus species. N. gonorrhoeae is often isolated from the endocervix. In this case, because the patient was not sexually active, the inciting bacteria would presumably come from the ruptured appendix, leading to a polymicrobial infection. The classic presentation of TOA includes abdominal pain, fever, pelvic mass on examination, and leukocytosis, although women can be afebrile with a normal WBC count. ⁹

Patients with TOA should be hospitalized and treated with antibiotic therapy until pain and tenderness have resolved, the patient has defervesced, leukocytosis has normalized, and the mass has either decreased or stabilized in size. ⁹ TOA can usually be managed with antimicrobial therapy; however, a life-threatening infection or ruptured TOA is a surgical emergency. ⁹ Selection of an appropriate antibiotic is dependent upon choosing an agent with anaerobic, Gram-positive and Gram-negative aerobic coverage. Metronidazole or clindamycin are used as they have broad anaerobic spectra and are able to penetrate the abscess wall in conjunction with an aminoglycoside. ⁹

TOA can be diagnosed by a number of screening modalities including CT, ultrasound, scintigraphy, and radionuclide scanning. CT and ultrasound are the most accepted and readily available modalities. ⁹ CT has a higher sensitivity (78%–100%) than ultrasound (75%–82%). ⁹ CT findings that may be suggestive of TOA include a peripherally enhancing low-density pelvic mass, anterior displacement of the round ligament, and the presence of satellite lesions adjacent to main masses. ¹⁰ Other findings include a thick, uniform, enhancing abscess wall, multiloculated, with an increased fluid density. ⁹ Ultrasound findings reveal a complex adnexal mass or a cystic-type mass with multiple internal echoes. ⁹

Ultrasound or CT can be used to guide minimally invasive drainage of pelvic abscesses. A review of 302 cases of TOA that underwent transvaginal ultrasound-guided drainage showed that the treatment was successful in 93.4% of women. However, no large-scale randomized trials addressing the role of image-guided drainage have been conducted. The rate of fertility and ectopic pregnancy after this treatment are unknown.^9,11

Conclusions

Although TOA is a rare complication of perforated appendicitis, surgeons should be aware of this as a possible postoperative complication. Care should be taken perioperatively to decrease the risk of postoperative abscess formation. In female patients with persistent postoperative abdominal pain, fever, and leukocytosis, the possibility of TOA should be considered.