EP474 - 脱垂痔术后肛周坏死性筋膜炎伴上纵隔感染：一例罕见病例报告

Purpose/Background: Perianal Necrotizing Fasciitis (PNF) carries higher risk, with mortality of 36%–50%. Procedure for Prolapse and Hemorrhoids (PPH) is a minimally invasive surgery for Grade Ⅲ–Ⅳ mixed hemorrhoids, with common complications (bleeding, anastomotic stenosis) in 5%–10%. Post-PPH PNF progressing to ascending mediastinal infection is extremely rare, especially trans-regional (perianal to mediastinal) cases. This report provides reference for clinical practice.

Methods/Interventions: A 37-year-old male with no underlying diseases underwent Procedure for Prolapse and Hemorrhoids (PPH) + external hemorrhoid excision/ligation + Xiaozhiling Injection for mixed hemorrhoids. A stapler was used to resect ~3cm of rectal mucosa, with anastomosis 2.5cm above the dentate line.
On post-op Day 1, he developed severe perianal pain, high fever, and oliguria. The local hospital treated him with increased cefuroxime + metronidazole, but in vain; he was transferred to our hospital on post-op Day 3 due to suspected infection spread.
Admission exam: Extensive crepitus in neck/chest skin; moist perianal area with yellowish foul pus. Digital rectal exam showed a 0.5cm anastomotic depression (bowel perforation). Labs: WBC 14.59×10⁹/L, C-reactive protein 102.1mg/L, procalcitonin 2146pg/mL, creatinine 135μmol/L, and electrolyte disturbances. Emergency CT confirmed extensive emphysema (cervicothoracic subcutaneous, mediastinum, abdominopelvis), a 0.3×0.5cm anastomotic defect, and mild 5mm right mediastinal shift.
On post-op Day 4, emergency laparoscopic transverse colostomy, debridement of 10×8cm necrotic perianal fascia, removal of 2 exposed staples, and double-lumen drainage were done. Anti-infective therapy: Empirical imipenem-cilastatin + metronidazole → de-escalated to cefmenoxime (pus culture: Streptococcus pyogenes) → oral cefpodoxime. He was transferred to ICU for supportive care. On post-op Day 19, perianal full-thickness skin graft was performed; rectal fistula repair in Nov 2024 and perianal scar V-flap transfer in Feb 2025.

Results/Outcomes: The patient was discharged on September 29, 2024 (the 23rd postoperative day) with viable perianal skin graft and normalized inflammatory markers; during follow-up in April 2025, he had resumed light physical work without infection recurrence and with normal anal function, and imaging showed complete absorption of mediastinal emphysema, cervicothoracic subcutaneous emphysema and perianal inflammatory lesions, leaving only a 0.8cm×0.5cm non-viable granuloma.
When evaluated for stoma reversal in March 2025, he was found to have concurrent hemorrhagic enteritis (effectively controlled with mesalazine and probiotics); no severe complications like respiratory or circulatory failure occurred during the entire treatment and follow-up, and his quality of life gradually returned to the pre-illness level

Conclusion/Discussion: This rare case provides a comprehensive clinical pathway for the diagnosis and treatment of severe rare complications following PPH, confirming that early intervention and standardized management can significantly improve patient prognosis and reduce mortality.