Surgical treatment
A ventral slot refers to the surgical approach used to remove disc material from IVD herniation in the cervical spine , resulting in decompression of the spinal cord .
The vertebra is approached via an incision on the ventral aspect of the neck . An area of vertebra is burred away , allowing visualisation of the spinal cord , and the disc material is removed . The ‘ window ‘ is then left open to reduce compression of the spinal cord [ 5 ] .
This surgical approach facilitates the best access to and visualisation of the spinal cord ; however , it also requires the retraction and dissection of many soft tissue structures surrounding the area .
Nursing care
Initial anaesthetic recovery
During recovery from anaesthesia and in the following period , recumbent post-ventral-slot patients require monitoring regularly , sometimes continuously , due to a variety of potential postoperative complications .
Monitoring of these cases should include a number of parameters ( Table 1 ).
Table 1 . Parameters to monitor post anaesthesia .
Parameters Electrocardiogram ( ECG ) trace Neurological status Respiratory rate Respiratory pattern Respiratory effort Blood gas analysis Heart rate Blood pressure Mucous membrane colour
Haemorrhage and blood losses during surgery can lead to postoperative anaemia . A haemorrhage can occur when soft tissue dissection and retraction causes damage to the surrounding tissues . Laceration of the internal vertebral plexus , which runs from the foramen magnum to the sacral hiatus , can also occur . Haemorrhage around , and haematomas of , the spinal cord can occur , due to trauma and luxation , leading to secondary spinal cord compression [ 5 ] .
Soft tissue dissection and retraction can result in damage to the laryngeal nerve , carotid artery , vagus nerve , vertebral arteries and trachea , resulting in a variety of postoperative complications . Damage to the laryngeal nerve , which controls the intrinsic muscles of the larynx , can cause laryngeal paralysis . Further to this , tracheal trauma can result in tracheal collapse ; this is more prevalent in dogs with pre-existing clinical or subclinical tracheal disease , so extra vigilance should be used with these patients [ 5 ] .
Damage to the vagus nerve , which forms part of the sympathetic nervous system , can result in severe bradycardia , hypotension and cardiac arrhythmias . Indications of sympathetic nervous system damage include abnormal pupillary responses , gastrointestinal compromise , abnormal ECG traces , abnormal blood pressure readings and impaired bladder function [ 3 , 5 ] . In these cases , if the patient is able to remain stable , central nervous system adaptation can occur as axons ‘ sprout ’, allowing an increase in the density of functioning synapses and the surviving neurons to function in a new way [ 5 ] .
Handling
Instability of the vertebrae can occur post-surgery , causing collapse of the IVD space , vertebral column instability and fracture of the spinous processes [ 5 ] . Care should be taken during the handling , transport and re-anaesthetisation of these patients .
Neck support should be provided to account for potential instability , especially during intubation . Oral tablet medication should be avoided for these patients ; instead , patients should remain on intravenous medication until they are eating consistently and accepting oral medications in food , where appropriate .
These patients should never be placed on a slip leash or collar and lead – a harness that provides chest support should be used instead .
Monitoring
The outcome for these patients is dependent on their nervous system and overall health , into which VNs can provide significant input . VNs are also well placed to note changes in the patient ' s status , to act accordingly and to advocate for the patient . Monitoring of these patients should continue throughout their hospitalisation , as post-surgical complications can occur outside the acute surgical recovery phase .
In cases where surgical stabilisation is required , further potential complications could include the fracturing of vertebrae , implant failure and the migration of pins into the spinal cord , nerves or brainstem .
24 Veterinary Nursing Journal