Paraproctitis

Etiology and routes of infection spread

The purulent-inflammatory process in the pelvic and retroperitoneal tissue is most often secondary in nature. The main primary sources of infection include:

• Acute appendicitis.
• Osteomyelitis of the pelvic bones and spine.
• Inflammatory kidney diseases (pyonephrosis, renal carbuncle).
• Perforation of the colon (due to trauma or tumor process).

Most frequently, the infection spreads via contact or lymphogenic pathways (in which case the process manifests as ademoflegmon). Hematogenous infection is extremely rare.

The spread of the purulent process is strictly determined by anatomical structure. The exudate moves along natural fascial clefts or destroys them. For example, a typical pathway of pus spread runs along the anterior surface of the iliopsoas muscle (m. iliopsoas) into the iliac fossa, and then through the muscular lacuna onto the thigh. In advanced cases, perforation of the abscess into the rectum, free peritoneal cavity, or even pleural cavity is possible.

Classification and clinical presentation

Depending on the affected tissue compartment, four main forms of paraproctitis are distinguished. Each has its own specific clinical course and topography.

1. Subcutaneous paraproctitis

The focus is located subcutaneously around the anus. Patients complain of sharp pain in the anal canal, which significantly increases during defecation. Body temperature elevation is observed. Objectively, a distinct painful swelling and skin hyperemia are determined. When abscess formation occurs, a positive fluctuation sign is detected.

1. Ischiorectal paraproctitis

The process involves the deep layers of tissue of the ischiorectal fossae. It is characterized by a severe clinical course with pronounced intoxication, high fever, and chills. The pain is throbbing in nature. The infection can spread behind the rectum to the opposite side (horseshoe paraproctitis), reach the prostate gland, and spread upward. In the advanced stage, the diagnosis is facilitated by edema and skin hyperemia.

1. Submucosal paraproctitis

The abscess forms in the submucosal layer of the rectum, above the anal columns (Morgagni's columns). Pain here is less intense compared to the subcutaneous form. Digital rectal examination reveals edema and tenderness.

1. Pelvirectal paraproctitis

The rarest and most severe form. The abscess is localized high above the pelvic floor (above m. levator ani). The main danger of the initial stage is the complete absence of external signs of inflammation, which greatly complicates diagnosis. Subsequently, the process perforates the levator ani muscle and descends lower.

General symptoms and diagnosis

The initial period of the disease often proceeds atypically. Primary symptoms are general in nature: chills, fever, headache, weakness. Because of this, paraproctitis and other pelvic phlegmons can be masked in the first days as influenza, typhoid, or paratyphoid fever. Local symptoms (pain, swelling) appear later.

The nature of the pain depends on the localization of the process (paracolitis, paranephritis, iliac fossa abscess). The pain is often diffuse and worsens when trying to stand, sit, turn to the side, or rotate the thigh. When walking, patients assume a forced posture: bending forward and toward the affected side. If m. iliopsoas is involved, the psoas sign occurs — flexion contracture of the hip.

For the diagnosis of deep forms (e.g., the initial stage of ischiorectal paraproctitis) when there are no external signs, bimanual examination is mandatory. The physician inserts one finger into the rectum and palpates the area externally with the other, revealing a painful infiltrate.

Management tactics

Conservative treatment Indicated exclusively at the earliest stage (infiltration stage), when there is only a small infiltrate in the perianal region without purulent melting. Warm sitz baths with potassium permanganate solution, lumbar novocaine blockade, and thermal procedures (heating pads, UHF therapy) are used. Important: any thermal procedures must be combined with antibiotic therapy.

Surgical treatment When an abscess forms, the principle is singular — early emergency intervention. The surgery includes:

1. Opening of the abscess.
2. Removal of pus and necrotic tissues.
3. Mandatory digital revision of the cavity.
4. Division of tissue septa.
5. Drainage.

Semilunar and radial incisions are considered preferable because they are the least traumatic and provide good wound gaping for exudate outflow (e.g., radial for perianal abscess, arcuate for ischiorectal and retrorectal).

Class and exam questions

What else to study on this topic

• Features of pus spread along the iliopsoas muscle
• Similarities and differences in the clinical presentation of paranephritis and paracolitis
• Surgical tactics in horseshoe paraproctitis
• Differential diagnosis of the initial stage of paraproctitis with typhoid and paratyphoid fever
• Technique of lumbar novocaine blockade

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.