Anatomical and Radiological Considerations When Colonic Perforation Leads to Subcutaneous Emphysema, Pneumothoraces, Pneumomediastinum, and Mediastinal Shift

Abstract

While colonoscopy is generally regarded as a safe procedure, colonic perforation can occur and the risk of this is higher when interventional procedures are undertaken. The presentation may be acute or delayed depending on the extent of the perforation. Extracolonic gas following colonic perforation can migrate to several body compartments that are embryologically related and it has previously been reported in the thorax, mediastinum, neck, scrotum, and lower limbs. This review discusses in detail the anatomical pathways that led to a rare case of widespread subcutaneous emphysema, bilateral pneumothoraces, pneumomediastinum, and mediastinal shift from colonic perforation during a diagnostic colonoscopy. This is further supported by a description of the radiological images.

Keywords: anatomical; colonoscopy; perforation; pneumomediastinum; pneumothorax; radiology.

Fig. 1

( A ) Sagittal section of the peritoneum and its reflections which form mesenteries and omental. The symphysis pubis, urinary bladder, and rectum are shown. ( B ) Peritoneum and its reflections in the axial section. (Adapted from Lumley et al 1987 14 ).

Fig. 2

Sagittal computed tomography image demonstrating pneumoperitoneum (green arrow), air in retroperitoneum (blue arrow) and alongside aorta (red arrows) and subcutaneous emphysema in the anterior chest wall (purple arrow).

Fig. 3

Coronal computed tomography image demonstrating free air in the peritoneum (blue arrow), retroperitoneum (red arrow), and subcutaneous emphysema in the abdominal wall around the flanks (purple arrows).

Fig. 4

Axial computed tomography image demonstrating free gas in the peritoneal cavity (blue arrow) and subcutaneous emphysema in the left chest/abdominal wall (purple arrow).

Fig. 5

Coronal computed tomography image demonstrating free air in the peritoneal cavity (blue arrow) and subcutaneous emphysema in the thoracic and abdominal walls (purple arrow).

Fig. 6

Structures seen on a transverse section through the mediastinum at the level of the 3rd thoracic vertebra (posterior) with the manubrium demonstrated anteriorly. (Adapted from Lumley et al 1987 14 ).

Fig. 7

A view from the peritoneal (caudal) surface of the diaphragm demonstrating the various transphrenic pathways. The aortic, esophageal, and caval hiatuses are circled. The esophageal and aortic hiatuses are between the right (RC) and left (LC) crura. The Morgagni hiatuses are on either side of the xiphoid (XL) process and costal (CL) attachments of the diaphragm. The lumbocostal triangle is posterolateral and is related to the lateral arcuate ligament (LAL). The septum transversum lacunar aplasia and diaphragmatic defects, porous diaphragm syndrome, are circled. Other communications can occur in different sites of central tendon (CT). MAL, medial arcuate ligament; P, psoas muscle; QL, quadratus lumborum muscle on right. (Reprinted with permission from Lidid et al 1999 11 ).

Fig. 8

Axial computed tomography image of extensive subcutaneous emphysema in the thoracic wall (red arrow) and left pneumothorax (blue arrow).

Fig. 9

Coronal computed tomography image of extensive subcutaneous emphysema in the neck and thoracic wall (red arrow), left pneumothorax (blue arrow), and pneumoperitoneum (purple arrow). Part of the right chest drain is visible (green arrow).

Fig. 10

Axial computed tomography image of subcutaneous emphysema in the neck (red arrow).