Is CT effective in cases of oesophageal fish bone ingestion?
Date First Published:
September 5, 2006
Last Updated:
September 7, 2006
Report by:
Debasis Das, SpR Radiology (Guy's & St. Thomas' Hospitals, London)
Three-Part Question:
In [patients who are suspected to have fish or chicken bones impacted in the oesophagus] is [computerised tomography more effective] than [plain radiography at diagnosis]?
Clinical Scenario:
A 60 year old man attends the ED complaining that a fish bone has got stuck in his throat. Clinical examination rules out impaction within the pharynx so you are concerned that the bone has become impacted within the oesophagus. Prior experience tells you that oesophageal abrasions secondary to ingested bones can often mimic impaction, that rigid oesophgoscopy (the definitive investigation) carries a significant mortality and morbidity rate, and that the most readily available non-invasive investigations, lateral neck and chest x-rays, are often unreliable. You wonder whether a CT scan of the neck would be a more accurate non-invasive tool?
Search Strategy:
Medline 1966 – week 3, February 2006. Limit to human and English.
Search Details:
({exp. Tomography, Spiral Computed/or exp. Tomography, X-ray computed/or CT. mp.} AND [{fish bone. mp.} OR {foreign body. mp. OR exp. Foreign bodies}] AND {exp. Esophagus/or oesophageal. mp.})
Outcome:
66 papers found of which 62 were irrelevant or of insufficient quality. The remaining four papers have been systematically reviewed.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| The management of possible fishbone ingestion. Akazawa Y, Watanabe S, Nobukiyo S, Iwatake H, Seki Y, et al. 2004 Japan | 76 patients with suspected fish bone ingestion. All patients underwent lateral neck x-ray and CXR, followed by CT. | Prospective, non-randomised study. | Sensitivity | CT: 100%, XR: 64.5% | XR sensitivity miscalculated by authors as 54.8%. |
| Specificity | CT: 100%, XR: 95.6% | ||||
| Positive predicitive value | CT: 100%, XR: 90.9% | ||||
| Computed tomography diagnosis of esophageal bone impaction: a prospective study. Eliashar R, Dano I, Dangoor E, Braverman I, Sichel J-Y. 1999 Israel | 45 patients with suspected fish and chicken bone ingestion. All patients underwent lateral neck x-ray and CXR, followed by CT. | Prospective, non-randomised study. | Sensitivity | CT: 100%, XR: 55.2% | |
| PRIMARY OUTCOME: Resting LVEF at 6 wks | 51% EF in immediate group v/s 50.1%EF in deferred;p 0.22 no significant difference | ||||
| Specificity | CT: 93.7%, XR: 100% | ||||
| PRIMARY OUTCOME: Exercise LVEF on hospital discharge | 50.7% EF in immediate group v/s 50.3%EF in deferred;p 0.60 no significant difference | ||||
| Positive Predicitive Value | CT: 96.7%, XR: 100% | ||||
| PRIMARY OUTCOME: Exercise LVEF LVEF at 6 wks | 54.3% EF in immediate group v/s 54.1%EF in deferred;p 0.86 no significant difference | ||||
| SECONDARY OUTCOME:Death within 6 days,at 6wks and 1 yr | 2.4%, 3.6% and 4.8% in immediate group v/s 2.4%, 3.5% and 5% in deferred;p 0.98, P 0.91 and p=0.87 - no significant difference | ||||
| The usefulness of computed tomography in the diagnosis of impacted fish bones in the oesophagus. Watanabe K, Kikuchi T, Katori Y, Fujiwara H, Sugita R, et al. 1998 Japan | 32 patients with suspected fish bone ingestion. All patients underwent lateral neck x-ray and CXR, but only 11 underwent CT. | Prospective, non-randomised study. | Sensitivity | CT: 100%, XR: 44% | Selection bias – why only 11 patients for CT? Low study numbers for CT. Statistics were not reported by authors (they have been calculated by ourselves). |
| Early detection of bacteraemia | No numerical data in results. "Elevated levels of CRP in serum did not differ significantly among patients with bacteremia, patients infected but without bacteremia, and patients who were apparently ill enough for infection to be considered and blood cultures taken, but in whom no infection could be found. Furthermore, some Furthermore, some patients with bacteremia had levels of CRP in the normal range and therefore therefore little reliance can be placed on a normal level of CRP as an indication that bacteremia is absent in an ill patient." | ||||
| Specificity | CT: N/A, XR: 100% | ||||
| Positive Predicitive Value | CT: 100%, XR: 100% | ||||
| The role of CT imaging in the evaluation of cervical esophageal foreign bodies. Braverman I, Gomori JM, Polv O, Saah D. 1993 Israel | 13 patients with suspected fish and chicken bone ingestion. All patients underwent lateral neck x-ray and CXR, followed by CT. | Prospective, non-randomised study. | Severity of infection | At < or =24h, the AUC(ROC)s of PLA2-II and PCT were superior to those of CRP. | Low study numbers. One patient underwent CT after oesophagoscopy, & one did not have an XR – both have been excluded form the results. Statistics were not reported (calculated by ourselves again). |
| Sensitivity | CT: 100%, XR: 80% | ||||
| Specificity | CT: 100%, XR: 50% | ||||
| Positive Predictive Value | CT: 100%, XR: 88.9% |
Author Commentary:
The studies reviewed above clearly show that CT of the neck is an extremely accurate, non-invasive diagnostic tool with a high PPV. However, of the 58 patients in the four series with positive X-Ray findings, there were only 3 false-positives. Thus, disregarding study 4 (which is appears to be a small-scale pilot study for Study 2 with skewed results), it is unsurprising that Studies 1-3 all still recommend plain X-ray as the initial radiographic screening tool. Positive results, which include soft tissue changes, warrant oesophagoscopy, while negative results should lead to a CT scan of the neck. Bearing in mind that there was 100% sensitivity amongst the 144 patients undergoing CT, and that there was just one false positive amongst the 80 patients with positive results, only visualisation of an actual fish or chicken bone should result in an oesophagoscopy at this point. Similarly, a negative CT scan should confidently exclude fish and chicken bones.
Bottom Line:
CT is more effective than plain radiography at identifying and excluding impacted oesophageal fish and chicken bones. However, plain radiography is also specific enough for positive results to warrant oesophagoscopy without any further imaging, and should thus continue being utilised as the first line radiological investigation.
References:
- Akazawa Y, Watanabe S, Nobukiyo S, Iwatake H, Seki Y, et al.. The management of possible fishbone ingestion.
- Eliashar R, Dano I, Dangoor E, Braverman I, Sichel J-Y.. Computed tomography diagnosis of esophageal bone impaction: a prospective study.
- Watanabe K, Kikuchi T, Katori Y, Fujiwara H, Sugita R, et al.. The usefulness of computed tomography in the diagnosis of impacted fish bones in the oesophagus.
- Braverman I, Gomori JM, Polv O, Saah D.. The role of CT imaging in the evaluation of cervical esophageal foreign bodies.