Quelle est l’épaisseur de l’appendice normal au scanner multibarrette ?

How to evaluate appendices with borderline diameters on CT: proposal of a quick solution to overcome the limitations of the established CT criteria

RATIONALE AND OBJECTIVES

To propose a useful computed tomography (CT) criterion, the diameter with compression (DWC), especially in appendices with borderline diameters.

MATERIALS AND METHODS

We retrospectively collected 216 patients with visible appendices on CT after clinicopathologic confirmation of appendicitis. Each CT criterion of appendicitis was evaluated by an experienced abdominal radiologist: maximal outer diameter (MOD), DWC, mural thickness and enhancement, periappendiceal infiltration, and appendicolith. DWC is the expected diameter after deduction of the intraluminal compressible contents such as air and feces. All the CT criteria were compared in the appendicitis and nonappendicitis group.

RESULTS

The areas under the receiver operating characteristic curve (AUC) of the MOD and the DWC were 0.967 and 0.973, respectively. The optimal cutoff value was 8.2 mm for the MOD and 6.6 mm for the DWC. Twenty-five of the 80 appendicitis patients (31.2%) and 62 of the 136 nonappendicitis patients (45.6%) had MODs between 5.7 mm and 9.8 mm in the overlap between the two groups. In this overlap, the AUC of the MODs declined sharply to 0.767, whereas the AUC of the DWCs remained 0.923. Use of the criterion of DWC >6.6 mm yielded a sensitivity of 84.0%, a specificity of 88.7%, and an accuracy of 87.4%. There were no other criteria with both sensitivity and specificity >80% in the range of overlap.

CONCLUSIONS

The proposed CT criterion of the DWC is not affected by normal distension or periappendiceal inflammation but only by true appendicitis. Therefore, DWC can improve the diagnostic performance of appendicitis regardless of the MOD.

Pitfalls and mimickers at 64-section helical CT that cause negative appendectomy: an analysis from 1057 appendectomies

PURPOSE

To determine the rate of negative appendectomy and clarify the causes of negative appendectomy in patients with clinically suspected acute appendicitis who had surgery after 64-section helical computed tomography (CT).

MATERIAL AND METHODS

A retrospective analysis of 1057 patients who had appendectomy after 64-section helical CT was performed to determine the rate of negative appendectomy. The 64-section helical CT examinations obtained with submillimeter and isotropic voxels in the patients with negative appendectomy were analyzed by two readers and compared to clinical, operative and histopathological reports, discharge summaries and original radiology reports.

RESULTS

The negative appendectomy rate was 1.7% (18/1057). Appendix enlargement (>6 mm) and fat stranding were present in 17 (17/18; 94%) and 6 patients (6/18; 33%), respectively. In 13 patients (13/18; 72%) 64-section helical CT findings were consistent with acute appendicitis. Interpretive errors in original imaging reports were identified in five patients (5/18; 28%).

CONCLUSION

The preoperative use of 64-section helical CT results in a very low rate of negative appendectomy. Patients with negative appendectomy have 64-section helical CT findings consistent with a diagnosis of acute appendicitis in the majority of cases. Interpretive errors are less frequent.

[Why should an abdominal CT scan be performed for suspected appendicitis in the adult patient? Lessons from ten clinical cases]

Ten years after its introduction, the contribution and indications for computed tomography (CT) in the diagnosis of appendicitis remain the subject of controversy among surgeons. Many argue that CT is frequently superfluous and costly, results in excessive radiation exposure, and delays surgical treatment. On our service, we perform 150 to 180 adult appendectomies annually. We feel that CT helps us to avoid unnecessary appendectomy, to clear up diagnostic uncertainty, and, most importantly, to guide the choice of surgical approach. We illustrate our experience through ten clinical cases in which the use of preoperative imaging has resulted in improved care.

Laparoscopic appendectomy without clip or ligature. An experimental study

BACKGROUND

We aimed to test the efficacy and safety of closure of the appendeceal stump with only laparoscopic bipolar electrocautery in rats.

METHODS

In this study, 40 female Wistar-Albino rats were used. In group I (n = 10), appendix vermiformis, approximately 1 cm in width, was completely ligated with 3/0 silk suture close to cecum, and removed. In group II (n = 20) and group III (n = 10), the appendeceal stump was coagulated by bipolar cautery. The coagulation of 70 mA took 10 s, and was repeated one more time. The stump was divided, and checked to ensure complete occlusion. Groups I and II underwent relaparotomy at 15 days, cecum was taken out, and the burst pressure of the stump was measured. Group III did not undergo relaparotomy; the burst pressure was measured during the first laparotomy.

RESULTS

All rats survived. At relaparotomy, no intra-abdominal complications were detected, including intestinal obstruction, abscess, and leakage. Omentum and fatty tissue of uterus was adhered to the appendix stump in group I, but only fatty tissue of uterus was adhered on the stump in group II. Although the intracecal pressure reached 30 cmH(2)O, at which pressure the cecum was highly stretched, ligated (group I) or coagulated (group II) stumps did not burst or opened. In group III, the burst or opening pressure of the stump (11.2 +/- 2.7 cmH(2)O) was significantly lower than in groups I and II (p < 0.001). Of group II rats, 80% had complete epithelial regeneration at the coagulated stump sites in contrast to ligated rats (p < 0.001) with severe inflammatory changes, abscess, and necrosis.

CONCLUSIONS

At late course, coagulated stumps did not allow the leakage or burst, unlike ligated stumps. However, coagulation of the stump seemed to contribute more to epithelial healing. This experimental model suggests that the closure of the stump with only bipolar coagulation was a safe and feasible method.