What is pyosalpinx?

Pyosalpinx: Definition, Diagnosis, and Management

Pyosalpinx is an acute inflammation of the fallopian tube that fills up and swells with pus, commonly resulting from inadequate or delayed treatment of pelvic inflammatory disease (PID). 1, 2

Pathophysiology and Etiology

• Pyosalpinx typically develops as a complication of untreated or inadequately treated pelvic inflammatory disease (PID) 1, 2
• It represents a severe sequel of chronic PID where the fallopian tubes become distended with purulent material 3
• Most commonly affects sexually active women, though rare cases have been reported in sexually inactive adolescents 3
• Common causative organisms include Chlamydia trachomatis, Neisseria gonorrhoeae, and various anaerobic and aerobic bacteria 1

Clinical Presentation

• Patients may present with lower abdominal pain that can be constant and worsening over days 2
• Symptoms may mimic other conditions such as ovarian torsion or appendicitis, creating diagnostic challenges 2
• Some patients may present with fever, particularly in cases with extensive infection 4
• Vaginal discharge may be present, especially muco-purulent discharge 5
• Bilateral adnexal tenderness on bimanual examination is a common finding 5
• In severe cases, pyosalpinx can exert mass effect on surrounding structures, potentially causing complications like obstructive uropathy 4

Diagnostic Imaging

Ultrasound Findings

• Transvaginal ultrasound (TVUS) is the first-line imaging modality for suspected pyosalpinx 1
• Characteristic findings include:
  • Complex adnexal masses adjacent to the ovaries (typically 2-3 cm in diameter) 1
  • Thick-walled, tubular structures with well-vascularized walls on color Doppler 1
  • Wall thickness >5 mm, cogwheel sign, and incomplete septa are specific findings that differentiate PID/pyosalpinx from hydrosalpinx 1
  • Presence of cul-de-sac fluid 1

Advanced Imaging

• CT may demonstrate pelvic fluid, peritoneal thickening, pyosalpinx, and even tubo-ovarian abscess in chronic PID 1
• MRI with T2-weighted imaging may show edema, fluid collections, and distension of fallopian tubes 1
• When infection is long-standing, distinguishing between inflammatory and neoplastic masses can be challenging; post-contrast T1-weighted imaging and diffusion-weighted imaging are particularly important 1

Diagnostic Criteria and Pitfalls

• The "cogwheel" sign (incomplete septa within the tubal wall) is present in 86% of acute cases and is a sensitive marker of acute disease 1
• A thick wall is present in 100% of acute cases 1
• In contrast, a thin wall and "beads-on-a-string" sign are indicators of chronic disease, present in 97% and 57% of chronic cases, respectively 1
• Pyosalpinx can mimic other conditions such as ovarian torsion or tumors, particularly in women of reproductive age 2

Complications

• Tubo-ovarian abscess (TOA) is a serious complication of PID/pyosalpinx 1
• TOA demonstrates loss of normal boundaries of structures, with pus-filled tissue showing complex adnexal mass with varying echogenicity, debris, septations, and irregular margins 1
• Pelvic ultrasound has a reported sensitivity of 93% and specificity of 98% for identification of TOA 1
• Long-term sequelae include infertility, chronic pelvic pain, ectopic pregnancy risk, and pelvic adhesions 1

Management

• Antibiotic therapy is the first-line treatment for pyosalpinx 5, 6
• Surgical intervention may be necessary in cases of severe infection or when medical management fails 5
• Laparoscopic approaches are preferred when available:
  • Laparoscopic drainage/aspiration of pyosalpinx preserves reproductive potential and ovarian function 6
  • Salpingostomy or salpingectomy may be performed depending on the severity and patient's fertility desires 2, 5
• In cases with complications such as obstructive uropathy, drainage of the excretory cavities (e.g., by JJ stent) may be necessary 4

Prevention

• Antimicrobial prophylaxis should be considered for patients prior to procedures like hysterosalpingography (HSG), especially those with a history of chlamydia or evidence of hydrosalpinges 5
• Early and appropriate treatment of PID is crucial to prevent progression to pyosalpinx 1
• Regular STI screening and treatment for sexually active individuals, particularly adolescents, can help prevent PID and its complications 1