Seeing Through The Problem: The Use Of 3-D CT Reconstruction In The Removal Of Multiple Foreign Bodies

Emma Stormer1, Andrew Watt2, Carl Davis1

1Dept of Paediatric Surgery and 2Dept of Paediatric Radiology, Royal Hospital for Sick Children, Yorkhill, Glasgow

SMJ 2007 52(2): 56

 

Abstract 

We report an unusual but invaluable use of three dimensional computed tomography (CT) reconstruction for the removal of multiple foreign bodies in a 7 year old boy following trauma. In a road traffic accident (RTA) a 7 year old boy sustained multiple facial lacerations from shattered glass. Facial CT scans were performed to exclude a mandible fracture requiring intervention, following which it was possible provide three dimensional reconstructions of the boy’s face revealing thirteen pieces of glass. Using this reconstruction as a guide in theatre twelve of the thirteen pieces of glass were retrieved with a satisfactory cosmetic result.

 

Case report

We report a 7-year-old boy who presented following an RTA in which he was a restrained rear seat passenger. He was noted to be agitated at the scene and required to be sedated prior to transfer to the accident and emergency department. On arrival his airway, breathing and circulation were stable. His GCS was 10 with eyes opening to pain, vocalising inappropriately and localising to pain. He was noted to have multiple lacerations on the left side of his face, with fragments of glass visible in the lacerations, along with significant swelling of the left cheek and mandibular area. He was intubated and ventilated for a CT head scan. This scan excluded an intracranial bleed and he was transferred to the Children's Hospital ventilated with spinal immobilisation in situ.

 

As he was ventilated it was not possible to clear his cervical spine and likewise it was not possible to achieve the standard plain radiographs to visualise his mandible. He underwent a facial CT scan which revealed bilateral mandibular condyle fractures, which did not require intervention. (Figure 1)

 

The CT scan also revealed several pieces of glass visible at variable depths within the soft tissues of the left cheek. Using these scans it was possible to perform three dimensional (3D) CT reconstructions. On these images it was apparent that thirteen pieces of glass were buried within the soft tissues. (Figure 2)

 

Using these images at time of theatre it was possible to remove twelve of these thirteen pieces. The last piece was thought to have been caught under the cervical collar which had been in place during the CT scan. Despite having this guide to the location of the foreign bodies the procedure performed by a consultant and surgical trainee, working in tandem, lasted approximately two hours. Following removal of these foreign bodies the lacerations were closed with 5’0 prolene. The sutures were removed on day 5 with satisfactory cosmetic results at day 10. He returned for one further procedure to remove an inclusion cyst which did not contain glass. (Figure 3)

 

Discussion 

Lacerations inflicted by glass fragments are a common problem presenting to Accident and Emergency departments. The mechanism with the highest associated retained glass fragments are motor vehicle accidents with the most frequent site being the head.1,2 The identification and retrieval of glass fragments can be challenging. Avner and Baker demonstrated that thorough exploration of the wound to the base was only 93% accurate at excluding foreign bodies.3 Several studies have shown that clinical examination alone is not sufficient.1, 2, 4, 5

 

Plain X-rays are unreliable in locating foreign bodies for two reasons. Foreign bodies with similar densities to soft tissues cannot be identified and the location of objects that are visible cannot accurately be ascertained due to the two dimensional projection.6

 

The consequences of retained foreign bodies can be deep and superficial infections, pain, delayed wound healing, inclusion cyst and the need for multiple surgical procedures.5, 4, 2, 3, 6 Avoiding these complications is obviously particularly advantageous when regarding facial wounds.

 

CT has been used to locate intra–ocular foreign bodies and intra cranial foreign bodies, and foreign bodies within soft tissues. Three dimensional CT reconstruction has been advocated for the removal of foreign bodies from various inaccessible sites including the paranasal sinuses, paraoesophageal space and deep within the brain. This may allow minimally invasive techniques of removal.7, 8, 9 Three dimensional CT has also been used to augment the anatomical view of the surgeon for maxillofacial operations.10 This is to our knowledge the first reported use of three dimensional CT reconstruction to locate multiple facial foreign bodies. CT is a superior modality compared to x-ray at locating foreign bodies because it is more sensitive at distinguishing density contrast, it also gives a three dimensional view of anatomy leading to accurate localisation.6

 

Without these images we believe it would have been impossible to locate all these fragments of glass and the procedure, whilst being incomplete, would also have been of substantially longer duration necessitating a longer general anaesthetic. This use of 3D CT reconstruction was invaluable for the aim of achieving the optimum cosmetic result following facial lacerations associated with multiple concealed foreign bodies in a child.

 

References 

  1. Steele MT, Tran LV, Watson WA, et al. Retained glass foreign bodies in wounds: predictive value of wound characteristics, patient perception, and wound exploration. Am J Emerg Med 1998;16(7):627-630 (Full text) 

  2. Montano JB, Steele MT, Watson WA. Foreign body retention in glass-caused wounds. Ann Emerg Med 1992;21(11):1360-1363 

  3. Avner JR, Baker MD. Lacerations involving glass. The role of routine roentgenograms. Am J Dis Child. 1992;146(5):600-602 

  4. Anderson MA, Newmeyer WL, Kilgore ES. Diagnosis and treatment of retained foreign bodies in the hand Am J Surg. 1982;144(1):63-67 

  5. Gron P, Anderson K, Vraa A. Detection of glass foreign bodies by radiography. Injury. 1986;17(6):404-406 

  6.  Firooznia H, Bjorkengren A, Hofstetter S, Rafii M, Golimbu C. Computed tomography in localization of foreign bodies lodged in extremities. Computerized Radiol. Vol 8, No 4, pp 237-239, 1984 

  7. Klapn I, Simicic L, Besenski N, Bumber Z, Janjanin S, Sruk V, Mihajlovic Z, Risavi R, Mladina R.  Application of 3D Computer-Assisted Techniques to Sinonasal Pathology – Case Report: War Wounds of Paranasal Sinuses Caused by Metallic Foreign Bodies, Am Journal of Otolaryngology, Vol 23, No 1 (Jan-Feb), 2002: pp 27-34 

  8. 3D-CT Highly Useful in Diagnosing Foreign Bodies in the Paraoesophageal Orifice, Nippon Jibiinkoka Gakkai Kaiho (Tokyo) 107: 800-803, 2004 (Abstract only -Article in Japanese) 

  9. Muhammad A, Maruno M, Maeda N, Kato A, Yshimine T. Syringe Needle located Deep in the Brain: Image-guided Removal, Surg Neurol 2000; 54:458-64 

  10. Enislidis G, Wagner A, Ploder O, Ewers R. Computed intraoperative navigation guidance – a preliminary report on a new technique, British Journal of Oral and Maxillofacial Surgery (1997) 35, 271-274

 

 

 

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