Ischiorectal abscess with retro and intraperitoneal dissemination: a case report

¹Department of Visceral Surgery, Faculty of Medicine and Pharmacy of Agadir, Ibn Zohr University, Agadir, Morocco

^&Corresponding author
Lahoucine Alzaz, Departments of Visceral Surgery, Faculty of Medicine and Pharmacy of Agadir, Ibn Zohr University, Agadir, Morocco

Introduction    

Anorectal abscess is an infection of soft tissues caused by the obstruction and then infection of the crypts and anal glands due to chronic constipation, inflammatory bowel diseases (Crohn's), malignant tumors, foreign bodies, and sexually transmitted diseases [1]. Parks et al. [2] are classified anorectal abscesses into perianal, ischiorectal, intersphincteric, and supralevator abscesses. Supralevator abscesses are the least frequent, with the maximum incidence of anorectal abscesses occurring in the third and fourth decade of life [3]. Men are more frequently affected than women [4]. CT scans are generally not deemed necessary, but they are discreetly useful in the case of a supralevator abscess. We present a rare case of an ischiorectal abscess in a patient who exhibited diffuse abdominal pain due to the significant extension of the abscess through the abdominal fascia and retroperitoneal region.

Patient and observation     

Patient information: a 65-year-old male patient presenting a medical history of uncontrolled diabetes has been admitted due to acute abdominal and perineal pain, accompanied by symptoms of constipation and abdominal distension.

Clinical findings: the clinical examination revealed a temperature of 39°, a distended abdomen with generalized abdominal defense, a perineal and digital rectal examination revealed a left peri-anal abscess that was indurated and not fistulized to the skin, with an internal opening located at 2 o'clock.

Diagnostic assessment: biological tests were requested, revealing a normal white blood cell count of 8720/mm³ and an increased C-Reactive Protein (CRP) of 249.9mg/l. Abdominal-pelvic CT scan revealed multiple retroperitoneal fluid collections, pneumo-retroperitoneum and an encapsulated intraperitoneal effusion in the peri-hepatic region accompanied by pneumoperitoneum (Figure 1).

Therapeutic interventions: given this clinical-scanographic picture, a perforative peritonitis was strongly suspected, and an emergency laparotomy was performed, revealing purulent effusion of the supra-mesocolic floor without any evident digestive perforation. Subsequently, a perineal incision and drainage of the anal abscess was performed with corrugated rubber drain.

Follow-up and outcome of interventions: in the postoperative period, the patient was admitted to the intensive care unit for 24 hours where he died from refractory septic shock.

Inform consent: an informed written consent was obtained from the patient to publish this work.

Discussion     

An ischiorectal abscess typically manifests as an acute condition and calls for prompt intervention in the form of incision and drainage, along with appropriate resuscitative measures and administration of effective antibiotics. A literature review indicates that while there have been a few reported cases of ischiorectal abscesses presenting with retro-pneumoperitoneum [5,6] but to the best of our knowledge, a single documented case in 2017 has been reported, indicating the occurrence of intraperitoneal dissemination of an ischiorectal abscess [6]. In our case, due to the presence of free air in the peritoneal cavity, we expected to find a perforative peritonitis, but surgical inspection revealed no obvious etiology, leaving the hypothesis of dissemination from the affected retroperitoneum.

The supra-levatorian space is a pelvic compartment located above the levator ani muscle that communicates anteriorly with the retzius space, laterally with the retro-inguinal spaces, and posteriorly with the retroperitoneum [7]. The pubo-rectal muscle acts as a barrier against abscess expansion. However, abscesses can rarely spread above or within the muscle, usually with a fistula, allowing the spread of inflammation into extraperitoneal anterior and posterior abdominal compartments [8]. The intra-peritoneal dissemination can be explained by the Interfascial Diffusion Theory [9]. In the case of rapid development of large fluid volumes, the storage capacities of retro-peritoneal spaces can be exceeded, causing the fluids to seek decompression routes within these sliding spaces.

The classic distinction between intraperitoneal and extraperitoneal compartments remains a daily clinical application. However, it is important to understand that the abdomen, pelvis, and retroperitoneum constitute an anatomical continuum through subserosal fat tissue and its expansions in mesenteric ligaments and folds [10]. The perirenal space communicates with the retro hepatic space at the area nuda. Communication between these two spaces occurs through the kneeland canal [7]. It is crucial to be aware of the different manifestations of ischiorectal abscesses and the risk of their dissemination, particularly in the presence of atypical symptoms. Prompt resuscitation and appropriate imaging should be conducted prior to any intervention as the progression of inflammation can be unpredictable and can extend in various anatomical planes, both within the peritoneal cavity and beyond it into the retroperitoneal space.

Conclusion     

The diagnosis of ischiorectal abscess presenting with abdominal symptoms, particularly in immunocompromised and elderly patients, strongly suggests extensive fasciitis which can rapidly compromise vital prognosis. Aggressive treatment is often necessary to ensure a good outcome for this potentially fatal condition, even with specialized care.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

All authors contributed to this work and read and agreed to the final manuscript.

Figure     

Figure 1: axial view of computed tomography (CT): scan showing: A) perirectal pneumo-retroperitoneum (red arrow); B) pneumo-retroperitoneum in pararenal space, retro duodenal, and peri vena cava, (VCI); C) pneumo-retroperitoneum in retro pancreas (red arrow); D) pneumoperitoneum (red arrow) and peri hepatic effusion (blue arrow)

References