Complications in Equine Surgery. Группа авторов

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Complications in Equine Surgery - Группа авторов


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Paramount for these procedures is endoscopic surgical skill, the lack of which can cause catastrophic patient complications.

      Inadvertent incision or “escaped” laser energy have produced seriously unfortunate patient complications. Non‐contact delivery of this wavelength has the real potential for penetration beyond the pale pink mucous membrane to injure underlying pharyngeal nerves or arytenoid cartilage. Dysphagia or arytenoid chondritis (respectively) are serious complications. Contact incision/excision of tissue (such as vocal fold and laryngeal saccule) is far safer, yet the fiber should still be blackened and directed tangentially to underlying tissues. Additionally, failure to strip the plastic from the quartz fiber can result in flame outs when the plastic burns.

      Endoscopic laser surgery has also been used to address uterine cysts and uroliths. Perforation of the hollow organ is always a potential; however, the equine bladder is rather thick and the uterus is a quite thick muscular structure. Aside from the decision as to whether the cysts should be treated, the Nd:YAG/diode lasers can be used endoscopically to ablate or excise the fluid‐filled cysts. Some have “boiled” the interior fluid to “burst” the cyst. The author is unaware of complications except occasional hemorrhage, which should be controlled if it occurs. Insufflation is required to visualize the endometrium and cysts. Over‐insufflation can compress the cysts and make them difficult to locate or manipulate. The author has seen no report of air embolism or peritoneal insufflation from this procedure but the potential should not be discounted and air should always be evacuated after a procedure.

Photo depicts operating facility for standing endoscopic surgery. The video endoscopic monitor faces the surgeon making all the movements in the patient mimic those on the screen. The floor around the surgeon and assistants is free of cables or other debris.

      Source: Kenneth E. Sullins.

Photo depicts incomplete ventricular mucosal ablation left buried viable mucus-producing cells, resulting in a mucocoele that had to be surgically addressed.

      Source: Kenneth E. Sullins.

       Prevention

      Care should be taken to minimize inadvertent application of the laser fiber to normal tissues. Care should also be taken to minimize the hot laser fiber to touch normal tissues. In a confined cavity, insufflation should be kept to a minimum to limit compression of cysts and to reduce the likelihood of penetrating the thin wall of the insufflated organ.

       Pathogenesis

       Tarsal arthrodesis complications

      The Nd:YAG/diode laser has been applied to “arthrodese” the distal tarsal joints of horses with refractory distal tarsal osteoarthritis [34]. The laser fiber inserted into the joints through a needle generates sufficient heat to boil the joint fluid, thereby incapacitating the sensory nerves in the fibrous joint capsule. The needle becomes extremely hot and will burn the skin, possibly causing a significant slough, which opens the joint.

       Prevention

      The skin and needle should be constantly covered with gauze sponges soaked in frozen “slushy” sterile saline to avoid this complication. Furthermore, inserting the needle/laser from the down side of a limb of a horse in lateral recumbency makes it very difficult to maintain this freezing procedure on the limb.

      Definition

      Complications associated with the laser equipment

      Risk factors

       Aged endoscope

       Reuse of fibers

       Acute flexing of the endoscope

      Pathogenesis

      Successful endoscopic laser surgery requires practice and attention to detail for patient and equipment safety. The videoendoscope itself is at risk of serious damage.

      Quartz fibers (Nd:YAG‐Diode lasers) and waveguides (CO2 laser) can be relatively fragile and random laser energy escapes when they break. Carbon dioxide laser waveguides are highly polished semi‐flexible tubes and generally not flexible enough to pass safely through an endoscopic biopsy channel. Inserted in other ways can also overstress the waveguide, so the author rarely uses the CO2 laser in deep areas. The Nd:YAG and diode and some other lasers are commonly delivered endoscopically through much more flexible quartz fibers.

      Prevention

      Adequate patient sedation is absolutely required. The horse’s willingness to rest the extended head on a support device is a good measure of adequate sedation that should prevent sudden movements that would risk equipment and personnel. Most sedated horses tolerate the procedures very well.