Stump Appendicitis: Clinical and CT Findings.

OBJECTIVE. Recurrent inflammation of the appendiceal stump after appendectomy is rare; published case series have included no more than six patients. The purpose of this study was to report the clinical and CT findings in a larger original series. MATERIALS AND METHODS. A combined PACS and electronic medical record search identified the cases of 14 patients (nine men, five women; mean age, 42.8 years) with a confident diagnosis of stump appendicitis evaluated at CT. In seven cases, CT images obtained at the initial presentation of appendicitis were available for review. Relevant clinical and CT findings were reviewed by three abdominal radiologists in consensus. RESULTS. The mean time interval between initial appendectomy and stump appendicitis was 5.1 years (range, 5 weeks-17.5 years); seven cases occurred within 1 year of appendectomy. Ten (71%) of initial appendectomies were performed by a laparoscopic approach. CT showed the mean appendiceal stump length was 3.2 cm (range, 1.3-7.0 cm); residual stump length measured 2 cm or longer in all but one case. Appendicoliths were identified at the stump in seven (50%) cases; the mean diameter was 0.9 cm and mean maximal attenuation, 247 HU. Extensive inflammatory changes surrounded the appendiceal stump at CT in all cases, including peristump abscess in four (29%) cases. Seven of the 14 patients (50%) went on to open surgical management with either remnant appendectomy or partial ileocecectomy. CONCLUSION. Stump appendicitis has a characteristic CT appearance and may occur within the first year after appendectomy or many years later. A long (≥ 2 cm) appendiceal stump from laparoscopic appendectomy and retained appendicolith may predispose adult patients to recurrent obstruction and inflammation.