Small Animal Surgical Emergencies. Группа авторов
and Urethrotomy in Dogs: Patient Positioning
The patient will be positioned in dorsal recumbency for a prescrotal or scrotal urethrostomy or urethrotomy and in sternal recumbency, with the patient's hind legs hanging over the end of the table and the tail retracted cranially for a perineal urethrostomy or urethrotomy. Depending on the size of the animal, magnification may be warranted. Recommended instruments are listed in Box 2.8.
Contrast Studies
For some patients, the use of an iodinated contrast material (Omnipaque™) in conjunction with radiography or fluoroscopy can provide preoperative or intraoperative information about the location of an obstruction, as well as the presence of extravasation of contrast material in cases of urinary tract trauma or surgical complications (Figures 2.15 and 2.16). The instruments necessary to perform a contrast study are listed in Box 2.9.
Figure 2.6 Instrumentation available to perform a ureterotomy in a cat. (a) Balfour retractor, 8‐0 nylon suture, microsurgical forceps, microsurgical needle holders, microsurgical scissors. (b) Vessel loops in thoracic surgery are often used to retract a vessel or structure during dissection or mobilization.
Figure 2.7 Weck‐Cel® cellulose eye spears are used to absorb and wick fluid away from a surgical site without damaging delicate tissues and are ideal for use in ureteral surgery.
Figure 2.8 Silicone vessel loops retracting a ureter containing a ureterolith.
Figure 2.9 Silicone vessel loops retracting a ureter.
Figure 2.10 Operating microscope set‐up prior to patient placement between two sandbag positioners.
Respiratory System
Temporary Tracheostomy
In an emergency, when the potential exists that airway access will be necessary, it is helpful to have a tracheostomy set readily available. This set should include the necessary instruments to approach the trachea quickly, and to place stay sutures in the tracheal rings cranial and caudal to the tracheostomy incision (Box 2.10, Figure 2.17a). Reusable metal tracheostomy tubes and commercial plastic disposable tracheostomy tubes come in a variety of sizes, depending on the size of the patient. To prevent dislodgement of the tube, a tracheostomy tube holder consisting of either Velcro straps or umbilical tape can be used to secure the tube once placed (Figure 2.17b). Having preprinted “cranial” and “caudal” labels to attach to the tracheal ring stay sutures will help to identify the direction in which to retract, should the tracheotomy site need to be reopened quickly.
Brachycephalic Upper Airway Surgery: Patient Positioning
The patient will be positioned in dorsal recumbency. Brachycephalic upper airway surgery can include staphylectomy, laryngeal sacculectomy and/or stenotic nares resection. A hanging airway set‐up allows for good visualization of airway structures (Figure 2.18). This can be done by placing tape behind the patient's upper canine teeth and connecting the tape to the top of two intravenous (IV) poles. Elevation of the IV poles will allow the mouth to hang open for visualization.
Arytenoid Lateralization (Laryngeal Tie‐Back Procedure): Patient Positioning
The patient can be positioned in left or right lateral recumbency. The surgical approach to correct laryngeal paralysis will be a done with a lateral neck incision. A right‐handed surgeon will often place the patient in right lateral recumbency to approach the larynx from the left side and a left‐handed surgeon will often place the patient in left lateral recumbency to approach the larynx from the right side. The forelimbs should be retracted caudally and a towel, sandbag, or bubble wrap placed under the neck to elevate the larynx. The instruments needed for arytenoid lateralization are listed in Box 2.11.
Lateral Thoracotomy for the Treatment of Pleural Space Disease
A lateral thoracotomy is indicated for patients that have unilateral disease, based on preoperative diagnostic evaluation. The approach is often performed in cases of lung lobe torsion and neoplasia and may be indicated in select cases of pyothorax, hemothorax, pneumothorax, and trauma. Recommended instruments are listed in Box 2.12.
Sternotomy for the Treatment of Pleural Space Disease
A sternotomy approach is performed when exploration of the left and right pleural space is warranted. It is the most common approach for a patient presenting with a pneumothorax. Additional instruments to those listed in Box 2.12, which are necessary for a sternotomy approach and closure, are listed in Box 2.13. Different types of sternal wire exist in a variety of sizes. One example is stainless steel wires with swaged on needles (Myo Wire II, A&E Medical).
Figure 2.11 (a) Perineal urethrostomy set‐up prior to positioning of patient. Note that the table is angled at approximately 20–30 degrees. (b) Lateral and (c) caudal view of cat being positioned for a perineal urethrostomy.
Cardiovascular System
Pacemaker Placement
Pacemakers may be placed through a lateral thoracotomy or a ventral midline celiotomy. In larger, deep‐chested dogs, for a ventral midline approach, sandbags are placed on either side of the thoracic cavity to aide in proper positioning.