Acute paraproctitis

Etiology and pathways of infection entry

The development of purulent inflammation in the perirectal tissue is usually caused by mixed microflora. The main pathogens are Escherichia coli (E. coli), Staphylococcus aureus and epidermidis, as well as various anaerobic bacteria.

The introduction of microorganisms into the perirectal tissue occurs through various defects and foci of inflammation. The main entry gates for infection:

• Anal fissures and skin excoriations.
• Inflamed hemorrhoids.
• Damage to the mucous membrane of the rectum and anal canal.
• Inflammation of the crypts (cryptitis).
• Perineal hematomas.

In addition, there are complicated forms of inflammation of the perirectal tissue. Phlegmons in this area can develop against the background of decaying tumors or as a consequence of gunshot wounds.

Features of the inflammatory process and spread pathways

Acute paraproctitis is characterized by pronounced tissue edema followed by purulent infiltration. Infection can spread in two ways: directly through the perirectal tissue or via the lymphatic route to the pelvic tissue.

Putrid-necrotic paraproctitis is of particular danger. This form differs in that it causes massive tissue breakdown (necrosis) without the formation of clearly demarcated abscesses.

The purulent process tends to migrate. For example, pus can descend downwards, passing between the tendinous arch and the obturator fascia, and enter the tissue of the ischioanal fossa. As a result, an abscess forms with a striking clinical picture of an ischioanal abscess.

Classification of abscesses by localization

Depending on where exactly the localized abscess forms, acute paraproctitis is divided into five main forms:

1. Subcutaneous
2. Submucosal
3. Ischioanal
4. Pelvirectal
5. Retrorectal

Each form has its own diagnostic features. Thus, with a low location of pelvirectal abscesses (above the levator ani muscle — m. levator ani), the pathology can be suspected relatively early. A routine digital rectal examination allows the doctor to determine the characteristic bulging of the bowel wall.

Retrorectal paraproctitis stands apart. Its etiology is associated with the introduction of infection into the lymph nodes (lymphogenous pathway). Initially, the abscess forms in the tissue behind the rectum. Subsequently, it is able to descend into the ischioanal tissue, causing phlegmonous inflammation there.

Surgical treatment and postoperative period

In putrid-necrotic paraproctitis, radical surgical tactics are applied. The scope of surgery consists of the complete excision of necrotic tissue strictly within healthy tissues. For adequate wound drainage, 2–3 additional incisions of the skin and subcutaneous tissue are performed. The choice of surgical approach depends on the localization (for example, specific approaches are used for ischioanal or pelvirectal abscesses).

Postoperative management:

• Regimen: The patient is prescribed strict bed rest.
• Complications: Reflex urinary retention frequently occurs.
• Treatment of urinary retention: To relieve this condition, a heating pad is applied to the bladder area or 5–10 ml of a 40% urotropin (methenamine) solution is administered intravenously.

Class and exam questions

What else to study on this topic

• Technique of opening retroperitoneal phlegmons (Pirogov and Shevkunenko incisions)
• Diagrams of approaches for ischioanal and pelvirectal abscesses
• Features of opening an abscess in paracolitis and iliopsoas abscess
• Anatomy of pelvic fascial spaces and pathways of pus spread

Other topics from the section "CHAPTER 11. SURGICAL INFECTION (PURULENT-INFLAMMATORY DISEASES)"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.