Perirectal Abscess with Anterior Extension to the Extraperitoneum and Space of Retzius: A Case Report

Introduction—This report illuminates the distinctive features of a successfully managed Retzius space infection arising from a complex perirectal abscess. It adds novel insights to the scientific literature by addressing the rarity of such occurrences, highlighting the diagnostic complexities associated with extraperitoneal spread, and underscoring the crucial role of a nuanced understanding of anatomy in navigating clinical scenarios involving anorectal abscesses. Patient’s Main Concerns and Important Clinical Findings—A 68-year-old male presented with dizziness and diffuse lower abdominal pain, accompanied by intermittent perianal pain for one month. Regardless of an initial misdiagnosis as hemorrhoids, the patient presented sepsis status with fever, hypotension, and tachycardia upon admission. Clinical examinations, including a digital rectal examination, laboratory findings, and imaging studies, revealed a substantial perianal abscess extending into the space of Retzius. Primary Diagnoses, Interventions, and Outcomes—The primary diagnosis involved a heterogeneous fluid-filled perianal abscess extending into the Retzius space, confirmed by abdominal contrast-enhanced computed tomography (CT). Immediate initiation of broad-spectrum antibiotics and subsequent incision and drainage in the 8 o’clock region was performed. Post-operatively, the patient experienced rectal bleeding, necessitating suturing ligation. A follow-up CT scan revealed an extraperitoneal abscess around the bladder, leading to CT-guided drainage and identification of microbial pathogens. Antibiotic treatment with piperacillin-tazobactam was administered. With two weeks of antibiotics and post-operative care, the patient’s symptoms improved, and he was discharged with no signs of recurrence or complications. Conclusions—This case report emphasizes the importance of early consideration and identification of extraperitoneal abscesses for timely intervention. The complexity of anatomical planes in extraperitoneal spaces poses diagnostic challenges, necessitating a strategic treatment. The successful management of this case underscores the significance of a multidisciplinary approach, including prompt diagnosis, appropriate antibiotic therapy, and timely surgical interventions, ultimately contributing to improved outcomes in cases involving complex anorectal abscesses.