Peri-rectal Abscess

Snehalata Topgi, M4

January 2014

• 19 yr old female w/ pmh Type1DM (dx 2006) presents to ED with L gluteal pain

• Pt noticed small, tender lump on L buttock 2.5 wks prior, which became enlarged and tender

• Saw PCP 5 days prior, dx with perirectal abscess and given PO Keflex course; I&D not performed

• 3 days prior had brown, malodorous drainage and returned to clinic; Bactrim added

• 1 day prior, having 101.9 fever, chills, worsening pain; decided to come to ED

Brief Clinical Hx

• Hypotensive SBP 80-90s, tachycardic 128, RR 18-20s, initially afebrile then spiked to 100.6, breathing well on room air.

• Blood glucose 400s, POC ketones negative. Lactate 2.6. Blood and urine cultures obtained.

• CT A/P ordered. • Patient started on IVF, Ertrapenem. General surgery was

consulted to evaluate abscess; performed I&D with drain placed at bedside.

• Patient was then transferred to MICU

• CONSTITUTIONAL: Awake, alert, cooperative• LUNGS: No increased work of breathing, good air

exchange, cta bilaterally, no crackles or wheezing • CV: regular rate and rhythm, normal S1 and S2, no murmur

noted and no edema • ABDOMEN: normal bowel sounds, soft, non-distended,

non-tender and no masses palpated • MSK: there is no redness, warmth, or swelling of the joints • NEUROLOGIC: AOx3, no focal deficits • SKIN: L medial gluteal: large area of erythema that is warm,

tender to palpation, firm; drain in place with no active draining at time of exam

Significant Physical Exam

• Septic shock

• Perirectal abscess• Fistula• Perforation• Nectrotizing fasciitis

Differential Diagnosis

• Transperineal Ultrasound– Detection of fistulous tracts and fluid collections in

preoperative planning, with high sensitivities of 85%.

• Xray, KUB• CT with contrast– In one retrospective study, CT scanning for perirectal

abscesses confirmed by surgical drainage yielded a sensitivity of 77%, with the false-negative patients being significantly more likely to be immunocompromised. (Caliste X, Nazir S, Goode T, et al. Sensitivity of computed tomography in

detection of perirectal abscess. Am Surg. Feb 2011;77(2):166-8.) • MRI

Options for Diagnostic Imaging

• Perirectal abscess extending to retroperitoneum

Diagnosis from CT

Normal Abdomen, Sagittal Anatomy

www.imaios.com

Hypodense fluid collection with multiple gas foci in the left perianal region .Abscess extends into the retroperitoneum, adjacent to the left perirectal Region.

Case Patient

Air is visualized tracking from this the abscess into the retroperitoneum, encasing the IVC and the left renal hila, to the level of the diaphragmatic hiatus.

Acc: 5489300

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Lower Abdomen, Coronal Anatomy

Concern for a fistulous connection with the rectum and thesigmoid colon. Cannot be confirmed because oral contrast has not advanced to the level of the rectum.

Normal >>>

<<< Case Patient

Other Example Cases

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^^^Posterior perirectal abscess ^^^Posterior perirectal abscess with extension intoIscheiorectal region

• Repeat CT obtained 3 days later– New bilateral pleural effusion– Reduction in azygoesophageal, retroperitoneal, and peroneal gas– Left gluteal abscess drain in place

• Plans for better DM control• Repeat CT in 2 weeks

Patient Follow-up

That’s it.Questions?