Diverticular disease of the colon is a significant cause of morbidity and mortality in the western world and its frequency increased throughout the whole of the 20th
]. Since it is a disease of the elderly, and with an ageing population, it can be expected to occupy an increasing portion of the surgical and gastroenterological workload [3
GCDs are defined as those that are larger than 4 cm in diameter [4
] and with the increasing incidence of diverticular disease [3
], it is likely that the incidence of these giant lesions will increase further. Awareness of the presenting symptoms, investigations, differential diagnosis and management is therefore important.
As in our patient, it is not unusual for these patients to undergo multiple investigations before making the correct diagnosis. Plain supine abdominal X-ray is the simplest and most readily available investigation and should be used as the first line in suspected cases. If a large air filled structure with or without fluid levels is visualised then an abdominal CT scan would be indicated. Barium enema failed to demonstrate a communication between the giant diverticulum and the colon in approximately one-third of reported cases [1
]. It is therefore not surprising that no communication was identified in our patient. Barium enema can be useful at providing valuable information regarding the extent of further diverticula.
The use of abdominal ultrasound has been reported to be helpful in only 25% of cases [4
]. Early colonoscopy is advised in the setting of persistent or frequent acute diverticulitis to rule out concurrent pathology [9
]. Our patient was admitted acutely on two occasions a few months apart, however, the symptoms and signs were not suggestive of acute diverticulitis but were felt to be in keeping with enlarging GCD therefore colonoscopy was not performed.
The role of colonoscopy in diagnosing GCD is limited. The ostium between the diverticulum and the colon is frequently too small to be detected [1
] and even in cases with wide necked GCD, the ostium is not detected on sigmoidoscopy [1
]. The combination of a large soft, mobile mass in an elderly patient and a lucent cystic structure related to the sigmoid colon on AXR should suggest the diagnosis of a GCD [6
Other causes for intra-abdominal gas-filled cysts, radiologically mimicking GCD [2
], along with their principal distinguishing features, are summarised in . Steenvoorde et al.
suggested a histological classification of GCD based on three subtypes (). The distinction between type I and II has not always been made with both categories being discussed as one entity in many papers [5
]. Theories behind the formation of GCD type I and II are speculative and not mutually exclusive. The suggested aetiology of type I is based on the premise that the communication between the GCD and the colon is small enough to preclude the escape of air from the diverticulum [1
]. The two most widely accepted theories are, a unidirectional ball-valve mechanism causing gas entrapment and infection with gas producing organisms leading to progressive diverticula enlargement [5
]. However, such theories do not convincingly explain the existence of type I GCD with wide necks.
Differential diagnosis of intra-abdominal gas-filled cysts
Type II is postulated to form following a subserosal perforation resulting in a walled off abscess cavity that gradually enlarges to giant size [7
]. Type III contains all layers of bowel wall and structurally resembles a duplication cyst [7
] but is in continuity with the gut lumen and occurs in adults. Approximately 20% of GCD show no evidence of a communicating ostium between the colon and the diverticulum and it is thought that this tract may be lost due to inflammatory changes [5
Surgical management of a GCD involves either removing the diverticulum in isolation or colectomy. Diverticulectomy is not recommended as the mouth of the diverticulum may be wide and the surrounding inflammation could increase the potential for breakdown of the colonic closure [2
]. Giant diverticula appear mostly (81%) in the sigmoid colon [5
] with 50% of patients having concurrent sigmoid diverticula [4
], thus sigmoid colectomy with primary end-end anastomosis [7
] is the preferred operation. Resection is frequently difficult due to the inflammatory diverticulum and it is often densely adherent to surrounding structures [2
]. In complicated or emergency cases, the safest surgical solution may be a Hartmann’s procedure [7
The advent of laparoscopic colorectal surgery has had a significant impact on the postoperative recovery period for patients undergoing surgical resections for both benign and malignant colorectal disease. The most important advantages to the patient of laparoscopic surgery are reduction in pain, more rapid recovery of bowel function, better cosmetic results and a shorter hospital stay [5
]. Our patient was fit for discharge on day four and this undoubtedly was due to the minimally invasive surgery performed. Based on our experience in this patient along with the recommendations of the Cochrane review group [10
], surgical removal a GCD should be minimally invasive using laparoscopic techniques.