Noah's diaphragmatic defect

Written by Claudio Motta DVM MRCVS Resident in Small Animal Surgery

Noah was seen in September following an unknown traumatic event which occurred the previous night. Investigations at the referring vet practice involved radiographs and abdominal ultrasound which were suggestive of a diaphragmatic rupture, multiple pelvic fractures and mandibular symphyseal separation.

On presentation, Noah was quiet, but alert and he was moderately dyspnoeic. Neurological assessment revealed reduced hind limb withdrawal and perineal reflexes and delayed hind limb proprioceptive response. The general clinical examination was otherwise within normal limits.

After a discussion with the owners, Noah was admitted to the hospital for further investigation. Haematology and serum biochemistry changes were suggestive of mild dehydration/hypovolemia.

Under anaesthesia, whole body computed tomography confirmed mandibular symphyseal separation, calvarial non-displaced fracture, right frontoparietal bone depression fracture and extensive diaphragmatic rupture and multiple pelvic fractures. The fractures at the level of the pelvis were causing severe narrowing of the pelvic canal. Pelvic diameter reduction caused by unreduced fractures is of particular concern, particularly if pelvic canal is narrowed by 50% or more and may result in obstipation.

Computed tomography  sagittal view of a normal thorax (image above) and Noah’s thorax (Image below): In the image below shows a very large midline diaphragmatic defect (arrowheads). A large volume of fat attenuating tissue consistent with falciform and mesenteric fat was identified entering into the thorax through the diaphragmatic defect (arrows). The fat was occupying almost the entire left hemithorax  causing a mass effect displacing the heart to the right (mediastinal shift) and causing severe compression of the lung lobes. The cranial and right middle lung lobes were almost completely collapsed.

Computed tomography transverse view of the sacrum and pelvis (image above): Oblique, complete articular fracture of the left sacral wing. The fracture line extended into the sacroiliac joint and did not communicate with the sacral foramina. It contained almost the entire articular margins of the left sacroiliac joint. This large fragment, and therefore the left sacroiliac joint were minimally displaced ventrally and cranially.

Under the same anaesthetic Noah was moved to theatre and his diaphragm was repaired following removal of the herniated abdominal fat and omentum from the thoracic cavity. A transilial Kirschner  wire was placed restoring the pelvic canal diameter. The mandibular symphysis separation was repaired with orthopaedic wire.

Post-operative ventro-dorsal  and lateral radiographic projections of the pelvis revealing satisfactory pelvic diameter.

Post-operative ventro-dorsal and lateral radiographic projection of the mandibular revealing satisfactory symphyseal separation repair.

Noah was bright and comfortable when discharged a few days following surgery. We contacted the client recently who reported Noah continues to improve on a daily basis and is eating comfortably.