Abscess pelvic

BASIC INFORMATION ABOUT PELVIC ABSCESS

Pelvic abscess is an acute or chronic infection, most commonly involving the pelvic viscera, initially localized and thus creating its own unique environment, so that treatment and possible cure require specific therapy. There are four categories based on etiologic factors:
• Ascending infection, spreading from cervix through endometrial cavity to adnexa, forming a tuboovarian complex
• Infection occurring in the puerperium, which spreads to the adnexa from the endometrium or myometrium via hematogenous or lymphatic route
• Abscess complicating pelvic surgery
• Involvement of the pelvic viscera secondary to spread from contiguous organs, such as appendicitis or diverticulitis

SYNONYMS
Tuboovarian abscess (TOA)
Vaginal cuff abscess

EPIDEMIOLOGY & DEMOGRAPHICS
INCIDENCE:
• 34% of hospitalized patients with PID
• 1% to 2% of patients undergoing hysterectomy, most with vaginal approach
• Peak incidence third to fourth decade
• 25% to 50% are nulliparous

RISK FACTORS: Same risk factors as for PID, although in 30% to 50% of patients there is no prior history of sal-pingitis before abscess forms.

• Physical examination
• Sonogram or CT scan: commonly employed because, owing to associated pain and guarding, a suboptimal abdominal or pelvic examination is the rule rather than
the exception
• Most common cause of preventable death: physician delay in diagnosis

LABORATORY TESTS
• CBC including WBC with differential, Hgb, and Hct
• Aerobic as well as anaerobic cultures of cervix, blood, urine, sputum, peritoneal cavity (if entered), and abscess cavity before starting antibiotics
• Pregnancy test in patients of reproductive age if the possibility of pregnancy exists

IMAGING STUDIES
• Sonogram: noninvasive, inexpensive study to confirm diagnosis, estimate size of abscess, and monitor response to therapy; sensitivity >90%
• CT scan: used for both diagnosis and therapy (CT-guided drainage)
1. Primary focus where sonogram provided insufficient information, as with intraabdominal vs. pelvic abscesses
2. Success rate with CT-guided abscess drainage: unilocular, 90%; multilocular, 40%

TREATMENT
Major concerns:
1. Desire for future fertility
2. Likelihood of rupture of abscess, with resulting peritonitis, septic shock, and morbid sequelae
ACUTE GENERAL Rx
• Decision as to whether patient requires immediate surgery (uncertain diagnosis or suspicion of rupture) or management with IV antibiotics, reserving surgery for those with inadequate clinical response (e.g., 48 to 72 hr of therapy, with persistent fever or leukocytosis, increasing size of mass, or suspicion of rupture)
• Poor response to medical therapy in those with adnexal masses >8 cm, bilateral disease, or immunocompromise
• Antibiotic combinations:
1. Clindamycin 900 mg IV q8h or metronidazole 500 mg IV q6-8h plus gentamicin either 5 to 7 mg/kg q24h or 1.5 mg/kg q8h
2. Alternatives: ampicillin sulbactam 3 g IV q6h or cefoxitin 2 g IV q6h or cefotetan 2 g IV q12h plus doxycyline 100 mg IV q12h
• During medical management, high index of suspicion for acute rupture, such as acute worsening of abdominal pain or new-onset tachycardia and hypotension, mandating immediate surgical intervention after patient stabilization
• Surgical options:
1. Laparoscopy with drainage and irrigation
2. Transvaginal colpotomy (abscess must be midline, dissect rectovaginal septum, and be adherent to vaginal fornix)
3. Laparotomy, including total abdominal hysterectomy with bilateral salpingo-oophorectomy or unilateral salpingo-oophorectomy
4. Evidence of ruptured TOA = surgical emergency
DISPOSITION
• Of patients treated with medical therapy, response in 75%, with a 50% pregnancy rate
• No response in 30% to 40%; can be treated with either CT-guided drainage or surgical intervention, keeping in mind that unilateral adnexectomy may give equal chance of cure vs. hysterectomy, yet preserve reproductive potential.

PHYSICAL FINDINGS & CLINICAL PRESENTATION
• Abdominal or pelvic pain (90%)
• Fever or chills (50%)
• Abnormal bleeding (21%)
• Vaginal discharge (28%)
• Nausea (26%)
• Up to 60% to 80% present in the absence of fever or leukocytosis; lack of these findings should not rule out diagnosis

ETIOLOGY
• Mixed flora of anaerobes, aerobes, and facultative anaerobes, such as E. coli, B. fragilis, Prevotella species, aerobic streptococci, Peptococcus, and Peptostreptococcus
• N. gonorrhoeae and Chlamydia are the major etiologic factors in cervicitis and salpingitis but are rarely found in abscess cavity cultures.
• In elderly patients consider diverticular disease.

DIAGNOSIS
DIFFERENTIAL DIAGNOSIS
• Pelvic neoplasms, such as ovarian tumors and leiomyomas
• Inflammatory masses involving adjacent bowel or omentum, such as ruptured appendicitis or diverticulitis
• Pelvic hematomas, as may occur after C-section or hysterectomy