Two Patients: 6-year-old German Shepherd & 9 month-old Australian Cattle dog

These two cases were presented in our virtual rounds sessions and we thought they were so interesting we’d share them here for those who may have missed them.

6 year-old Canine, German Shepherd

History: Presented for gagging.

Images:

Findings:

  • There is a relatively straight, thick tubular, heterogenous soft tissue and gas opacity structure outlined by a small amount of gas superimposed with the caudal oral cavity that extends caudally to the level of the thoracic inlet consistent with a large stick foreign body. This foreign body measures on the order of 25-30 cm in length and extends along the left side of the neck, causing rightward deviation of the larynx and trachea cranially.
  • Laryngeal structures appear mildly swollen with gas in the laryngeal saccules, likely due to dyspnea.
  • Rostrally there is a small amount of emphysema or radiolucent foreign material that extends dorsal to the pharynx.
  • Caudally there is gas extending into the subcutaneous tissues of the left clavicular /prescapular region.
  • There is a small amount of gas seen within the cranial aspect of the cranial mediastinum associated with a foreign body. The rest of the intrathoracic structures appear within normal limits. There is no evidence of pneumothorax. The thoracic portion of the trachea is normal. No abnormalities of the cardiopulmonary structures are seen.

Conclusions:

  • Large stick foreign body of the caudal oral cavity and left cervical region causing rightward displacement and probable swelling/inflammation of the larynx. Mild pneumomediastinum and subcutaneous emphysema are associated with this foreign body, however, no other thoracic abnormalities are seen.
  • Concern that there is esophageal perforation (versus other trauma contributing to the SC emphysema).

Recommendations: CT and surgical consultation are recommended for foreign body removal and management.

9 month-old Canine, Australian Cattle dog

History: Presented for chronic cough, sliding hiatal hernia on recent previous radiographs.

Images:

Findings:

  • Patchy interstitial coalescing to alveolar pulmonary pattern especially present in the right caudal lung lobe with few faint air bronchograms.
  • A hiatal hernia is suspected, but a coexisting soft tissue opaque mass at the lower esophageal sphincter region (mural or extramural abscess or granuloma; or luminal foreign object) could not be ruled out.
  • Moderate diffuse bronchial pulmonary pattern is also present.
  • Ill-defined, linear to serpentine, few cm gas-filled structure with mildly undulating margins superimposed over the caudo dorsal lung field (ventral to T9-11),  cranial to the stomach and dorsal to the caudal vena cava. (left lat)
  • Small volume of gas in the mid-thoracic esophagus just dorsal to the carina (right lateral).
  • The right fourth and fifth ribs are thickened at the mid-body.

Conclusion:

  • Small volume of gas in the mid thoracic esophagus just dorsal to the carina (right lateral).  A wide soft tissue convex bulge of the esophagus at the lower esophageal sphincter region is noted.
  • Mixed focal alveolar and diffuse bronchial pulmonary patterns with diffs to include aspiration pneumonia or chronic bronchopneumonia (disease in transition evolving/resolving bouts of aspiration).
  • Ill-defined gas-filled structure caudally was most likely the stomach, consistent with the previous diagnosis of a sliding hiatal hernia. Other possible differentials included an intrathoracic abscess, bulla, or hemo-pneumatocele. The thickening of the ribs may have been due to a previous traumatic injury (associated to the inciting cause or not).

Recommendations: Thoracic CT.

Follow up: A Thoracic CT was performed.

Key Images:

Findings:

  • Long, curvilinear, cylindrical, soft tissue dense structure with hollow, gas- and fluid-filled center is in the esophagus and stomach, extending from the left 4th rib caudally to ~L1 in the stomach. A portion of the stomach was herniated through the esophageal hiatus, and the gastric fundus extends caudally due to the intraluminal foreign body.
  • Right cranial, right middle, and right caudal lung lobe alveolar pulmonary, most severe surrounding the cranial aspect of foreign body. The proximal portions of the right 4th, 5th, and 6th ribs are thickened, with thickened cortices corresponding with the craniodorsal border of the described foreign body. Post contrast, a sharply marginated, soft tissue dense structure with a contrast enhancing rim and fluid dense center was seen surrounding the cranial aspect of the foreign body.

Conclusion:

  • An esophagogastric wood foreign body with questionably bronchopneumonia in right cranial and caudal lung lobes (early pulmonary abscess, granuloma or chronic pulmonary scarring or fibrosis not excluded), and hiatal hernia are suspected. Presumptively the foreign body was ingested. Much lesser consideration was given to penetrating wound/ impalement.
  • Outcome: A 16cm long wooden stick was removed via gastrotomy. Rigid laparoscopy confirmed lack of mural defects. Hiatal hernia and LES region reduction was performed surgically via closure of the enlargement of the esophageal hiatus with simple interrupted sutures. Left incisional gastropexy was performed. Mucopurulent material from the endotracheal tube resulted in Streptococcus sp. and Escherichia coli growth. Recovery was uneventful; and a 7 days phone follow revealed the dog had a mild intermittent cough, but was more active and improving rapidly. Presumptively, the stick was ingested and became chronically lodged. Impalement with subsequent para- to intraesophageal migration seemed much less likely.

Discussion Topics:

Wood, Migrated or Aerodigestive Foreign Bodies:

  • Survey radiographs are the initial diagnostic imaging modality of choice when a migrated or ingested/inhaled (wooden/plant based foreign body is suspected, but these are rarely identified by radiographs (reported sensitivity of 15%).
  • In general, cross-sectional imaging is superior to radiography for foreign body and adjacent soft tissue differentiation.2,6 114 CT Hounsfield unit (HU) evaluation can investigate potential foreign body density. Adjacent emphysema can improve conspicuity, especially in the lung window (-1250–250 HU), and evaluation of multiple image planes aids in mitigating anatomic noise from superimposed structures.
  • Virtual CT bronchoscopy may preclude unnecessary bronchoscopy or aid in retrieval planning for inhaled wood or plant based foreign bodies.
  • CT is a more accurate modality for the detection of wooden foreign bodies and enables efficient, cross-sectional examination of any part of the body with high spatial resolution and wooden foreign body detection sensitivity and specificity of 79% and 93%, respectively.
  • Wood foreign bodies have a wide range of CT attenuation values reflecting differences in the native density of wood inherent to plant species, maturity, moisture content, and overall composition. In standard window settings, centrally gas lucent wood shards can easily be mistaken for gas tracts.
  •  Wood foreign bodies can be distinguished from gas tracts by viewing with a wider window width and level setting (up to 1,000 and -500 H, respectively) for optimization of detection.
  •  After ~1 week of wood foreign body implantation, it absorbs surrounding blood by-products, exudate, and lymphatic fluid which increases the moisture content and the attenuation value, causing the external surface of the foreign body to be hyperdense compared to the internal surface, (see provided CT image). 
  • Other modalities used to detect wood foreign bodies include ultrasound (sensitivity of 90.0%, specificity of 96.7%) when the object is superficial and there is no overlying bone or gas.
  • Deeply implanted wood foreign bodies or foreign bodies within the respiratory tract are more difficult to detect with u/s. but may aid in detection of foreign bodies that are partially within or juxedaposed to the airway; or within inflamed or abscessed soft tissue, by exhibiting a hyperechoic border with distal acoustic shadowing.
  • MRI is also useful for the detection of wood foreign bodies; but may not be necessary or practical. When MRI is pursued, plastic, porcelain, glass, and dry wood foreign bodies may be obvious given superior contrast resolution. These materials are generally hypointense to muscle, but the appearance of plant material or wood can vary due to water content. Additionally, certain pulse sequences such as short tau inversion recovery and 3-D fast spin gradient recall, can exploit surrounding inflammation and gas, respectively.
  • Of noted, occult inhaled aero-digestive foreign bodies can be challenging to diagnose and practitioners should be aware of the availability, usefulness and limitations of each of the potentially applicable diagnostic modalities.
  • Fluoroscopic digital subtraction can aid in detecting radiolucent foreign bodies. Additionally, radiographic, fluoroscopic or CT fistulography with a non-ionic iodinated contrast agent can enhance occult foreign material detection in gas tracts or soft tissue swellings.

Resources:

What is Your Diagnosis? Tollefson CR, Hiebert EC,   Lee AM, Gambino JM DVM. WYD Pharyngeal plant based foreign body in a cat JAVMA December 1, 2018, Vol. 253, No. 11, Pages 1405-1407 https://doi.org/10.2460/javma.253.11.1405

Peterson, Jeffrey J., Laura W. Bancroft, and Mark J. Kransdorf. Wooden foreign bodies: imaging appearance. Am J Roentgenol 2002; 178.3: 557-562.

Kantarci, Mecit, Hayri Ogul, and R. Murat Karasen. Detection of a giant wooden foreign body with multidetector computed tomography and multiplanar reconstruction imaging. Am J Emerg Med 2007; 25.2: 211-213.

Lamb, Christopher R., Elizabeth H. W. Pope, and Karla C. L. Lee. Results of computed tomography in dogs with suspected wooden foreign bodies. Vet Radiol Ultrasound 2017; 58.2: 144-150

Ober, Christopher P., Jeryl C. Jones, Martha Moon Larson, et al. Comparison of ultrasound, computed tomography, and magnetic resonance imaging in detection of acute wooden foreign bodies in the canine manus. Vet Radiol Ultrasound 2008; 49.5: 411-418

Jones JC, Ober CP. Computed Tomographic Diagnosis of Nongastrointestinal Foreign 137 Bodies in Dogs. J Am Anim Hosp Assoc 2007;43:99-111.

Passàli D, Lauriello M, Bellussi L et-al. Foreign body inhalation in children: an update. Acta Otorhinolaryngol Ital 2010;30(1): 27-32.

Aras MH, Miloglu O, Barutcugil C, et al. Comparison of the sensitivity for detecting foreign bodies among conventional plain radiography, computed tomography, and ultrasound. Dentomaxillofac Rad 2010;39,72-78.

Pattamapaspong N, Srisuwan T, Sivasomboon C, et al. Accuracy of radiography, computed tomography and magnetic resonance imaging in diagnosing foreign bodies in the foot. La Radiologicamedica 2013;118:303-310.

Karnwal A, Ho EC, Hall A, et al. Lateral soft tissue neck X-rays: are they useful in management of upper aero-digestive tract foreign bodies? J Laryngol Otol 2008; 122(8):845-

Header photo credit: Marcus Cramer on Unsplash

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