Implications of Computerized Tomography Colonography in Fully Intended but Aborted Optical Colonoscopy – a Retrospective Case-Control Study

Abstract

Introduction

If a complete optical colonoscopy (OC) cannot be performed, an alternative diagnostic method should be considered.

Objectives

The aim of this retrospective chart review study was to investigate the surgical and interventional endoscopic implications of CT colonography (CTC) after fully intended but aborted OC.

Methods

302 patients with CTC after an incomplete OC were compared to sex-matched controls who underwent a complete OC by the same examiner in the same year. The most common indications were preventive colonoscopy (29.1%) and pathological iFOBT (9.6%).

Results

The most common reasons for OC discontinuation were suspected adhesions (n=64) and a long sigmoid colon ± non-inflammatory diverticula (n=59). OC discontinuation was most prevalent in the sigmoid colon (n=149, 49.3%). Adenoma detection rates in patients undergoing preventive colonoscopy were 9.6 and 26.9 per cent in the CTC and the control groups, respectively (p<0.01). A total of 384 extracolonic CT findings were identified in 197 patients (65.2%) including 373 benign (97.1%) and 11 potentially malignant findings (2.9%). However, only two of these could be confirmed histologically.

Conclusion

In our cohort, CTC revealed only a small number of (pre-)malignant (extra-)intestinal findings. Therefore, we recommend a limited use of CTC, depending on the indication and the local findings that led to the discontinuation of OC.

Zusammenfassung

Einleitung

Wenn keine vollständige optische Koloskopie (OC) durchgeführt werden kann, sollte eine andere Untersuchungstechnik des Dickdarms gewählt werden.

Ziele

Ziel dieser retrospektiven Datenanalyse war es, die chirurgischen und interventionell-endoskopischen Implikationen der CT-Kolonografie (CTC) nach komplett intendierter aber aus technischen Gründen abgebrochener OC zu untersuchen.

Methodik

302 Patienten mit CTC nach inkompletter OC wurden mit Kontrollpersonen gleichen Geschlechts verglichen, bei denen im selben Jahr vom gleichen Untersucher eine vollständige OC durchgeführt wurde. Die häufigsten Indikationen waren die präventive Koloskopie (29,1%) und der pathologische iFOBT (9,6%).

Ergebnis

Häufigste OC-Abbruchgründe waren vermutete Adhäsionen (n=64) und ein langes Sigma ± Divertikel (n=59). Im Sigma wurde am häufigsten die OC abgebrochen (n=149, 49,3%). Die Adenom-Nachweisraten bei Patienten mit präventiver Koloskopie lagen bei 9,6% in der CTC- und 26.9% in der Kontrollgruppe (p<0,01). 384 extrakolonische CT-Befunde bei 197 Patienten (65,2%) umfassten 382 benigne (97,1%) und 13 potenziell maligne Befunde (2,9%), von denen nur zwei histologisch bestätigt werden konnten.

Schlussfolgerung

Die CTC erbrachte in unserer Kohorte nur eine geringe Zahl (prä-) maligner (extra-)intestinaler Befunde. Wir empfehlen daher in Abhängigkeit der Indikation und des zum Abbruch führenden Lokalbefundes der OC eine sehr enge Indikationsstellung zur CTC.

Keywords

Intestine - Endoscopy - Computerized Tomography Colonography - Colonoscopy

Schlüsselwörter

Darm - Endoskopie - Comptutertomographie Kolonographie - Koloskopie

Publication History

Received: 01 June 2025

Accepted after revision: 10 October 2025

Article published online:
09 December 2025

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