Subcutaneous cervical emphysema and pneumomediastinum due to a lower gastrointestinal tract perforation

Abstract

This case report describes a 69-year-old man presen-ting with an extensive subcutaneous emphysema in his neck and generalized peritonitis caused by a lower gastrointestinal tract perforation. This case emphasizes that subcutaneous emphysema patients with negative thoracic findings should be scrutinized for signs of retroperitoneal hollow viscus perforation.

Key Words: Subcutaneous cervical emphysema; Pneumomediastinum; Gastrointestinal tract perforation; Malignancy; Diverticulitis

INTRODUCTION

Pneumomediastinum usually occurs following esopha-geal or chest trauma. It can also occur spontaneously in association with asthma, excessive coughing, or straining. Cervical emphysema occurs when air moves through tissue planes into subcutaneous areas of the face and neck. Subcutaneous neck emphysema, pneumomediastinum, and retropneumoperitoneum have been reported infrequently following colonoscopic perforation. Iatrogenic colonic perforation is a serious but rare complication of colonoscopy. A perforation risk rate of 0.12% has been reported[1].

Subcutaneous emphysema caused by non-traumatic perforations of the colon is extremely rare. However, it should be considered when no obvious case can be found for the origin of subcutaneous emphysema or a pneumomediastinum.

CASE REPORT

A 69-year-old man presented himself at the Accident and Emergency Department with a 6-h history of swelling in the neck, an altered voice and abdominal pain. He was treated for a painful fifth rib on the left which was caused by a metastasis of an unknown primary tumor. Analysis for the primary tumor was ongoing, but not yet concluded. Radiotherapy was started and prednisolone was prescribed.

Physical examination revealed signs of extensive subcutaneous emphysema in his neck and generalized peritonitis. Laboratory blood and urine tests were normal apart from an elevated white cell count of 23 × 10⁹ cells/L. A plain radiograph of the thorax showed free intraperitoneal air, pneumomediastinum and extensive subcutaneous emphysema, but no sign of pneumothorax (Figure 1).

Figure 1 Thorax X-ray examination of the patient showing free air in abdomen, pneumomediastinum and severe subcutaneous cervical emphysema.

An explorative laparotomy was performed, a perforation of the small bowel and the caecum was found, which were oversew. There were two perforations of the sigmoid but no palpable tumor. A sigmoid resection was performed with a permanent colostomy. The proximal end of the distal segment was oversew and left in place with a blind rectal pouch. The patient was admitted to the Intensive Care Unit after operation. Pathological examination showed diverticulitis with a perforation, and no tumor was found in the resected sigmoid.

After consultation with the patient and his family, the patient received no further surgical treatment. The patient died of respiratory arrest 12 d after surgery.

DISCUSSION

Non-traumatic subcutaneous emphysema is a rare presentation of lower gastrointestinal tract perforation due to colorectal cancer or diverticulitis[2–6].

As the rectosigmoid is located in the retroperito-neum, injury can be present in the absence of peritonitis. Mediastinal and cervical emphysema may develop due to dissection of air via contiguous tissue planes, which occurs along the perivascular adventitia to the anterior pararenal space, through the diaphragmatic hiatus along the adventitia of great vessels to the mediastinum and pericardium/or pretracheal fascia to the neck[78]. Subcutaneous emphysema patients with negative thoracic findings should be scrutinized for signs of retroperitoneal hollow viscus perforation to improve their outcome.