Chapter 45 - Pharynx part II SURGERY Flashcards
1
Q
What is the primary surgical option for treating DDSP according to recent evidence?
A
Laryngeal tie-forward combined with partial bilateral resection of the thyrohyoideus muscle.
2
Q
What surgical procedure is deemed ineffective for DDSP treatment?
A
Tension and thermal palatoplasty.
3
Q
Which structural abnormalities should be addressed surgically in the nasopharynx?
A
Abnormalities such as epiglottitis, cysts, and granulomas.
4
Q
What is the maximum length of soft palate that can be resected during staphylectomy without compromising the oropharynx-nasopharynx seal?
A
0.75 cm
5
Q
How long does the laryngotomy site take to heal postoperatively?
A
Approximately 3 weeks.
6
Q
What is the position of the horse during staphylectomy?
A
Dorsal recumbency with head and neck extended.
7
Q
What incision length is typical for a laryngotomy during staphylectomy?
A
10 to 12 cm
8
Q
What type of suture material is used to reappose the cricothyroid membrane?
A
No. 0 polyglactin 910
9
Q
What is the purpose of a laryngeal tie-forward surgery?
A
To eliminate the gap between the epiglottis and the soft palate.
10
Q
Staphylectomy should be reserved to resect what?
A
a granuloma or cyst from the caudal free edge of the soft palate or for treatment of permanent DDSP as an additional step following a laryngeal tie-forward procedure.
11
Q
Describe the staphylectomy
A
A 10- to 12-cm (4- to 5-in) skin incision is made along the midline, centered over the cricothyroid space. The sternohyoideus muscles are divided bluntly using curved Mayo or Metzenbaum scissors. A self-retaining retractor, such as a Weitlaner or a Hobday, is placed between the separated sternohyoideus muscles, exposing the cricothyroid membrane. The cricothyroid membrane is sharply incised (along with the underlying laryngeal mucosa) with a scalpel along the midline, from the cricoid cartilage to the junction of the thyroid cartilages (Figure 45-22). A small blood vessel is usually also transected at the level of the caudal two thirds of the membrane. The vessel is ligated or cauterized. The self-retaining retractor is subsequently placed within the cricothyroid space. The caudal free margin of the soft palate rostral to the incision is identified. If the horse was intubated nasotracheally, the soft palate may not be displaced, and the caudal edge of the soft palate may have to be freed from beneath the epiglottis using a pair of sponge forceps. If the horse was intubated orally, the palate will be displaced and the endotracheal tube should be retracted at this time.
Id cyst and transect with satinsky thoracic scissors
Can be left to heal by 2nd intention or suture
12
Q
A
Figure 45-22. Schematic showing view of the ventral cervical area of a horse in dorsal recumbency and illustrating the landmarks for a laryngotomy. The sternohyoideus muscles have been bluntly separated on the ventral midline, and the cricothyroid membrane and underlying laryngeal mucosa is sharply incised from the cricoid rostrally to the thyroid cartilage. CT, Cricothyroid muscle overlying the ventral aspect of the cricoid cartilage; T, tracheal ring.
13
Q
In the treatment of permanent DDSP , the gap between the dorsal aspect of the epiglottis and the overlying soft palate is eliminated by the
A
tie-forward surgery (Figure 45-23, A and B). When needed, a laser-assisted staphylectomy follows the tie-forward procedure to permit the epiglottis to be repositioned dorsal to the soft palate after a swallow
14
Q
A
Figure 45-23. Lateral radiographic projection of a 4-year-old Thoroughbred gelding with a permanent displacement of the soft palate prior to surgery (A) and after laryngeal tie-forward (B). Note the air in the mouth and the ventral position of epiglottis prior to surgery. After surgery (B) the epiglottis is bulging (arrow) against the soft palate. Linear white densities are 5-cm (2-in) pins used to measure magnification of radiographs
15
Q
A
Figure 45-24. Intraoperative laser staphylectomy in a 4-year-old Thoroughbred colt with permanent DDSP after first having performed a laryngeal tie-forward. (A) The intended line of resection has been marked using a diode laser. (B) The left edge of the soft palate is grasped with a laryngeal forceps and the marked line of resection is cut.
16
Q
Complications of staphylectomy
A
dysphagic, leading to signs of aspiration that include coughing, expulsion of feed material through the nose, and
pneumonia.
17
Q
What postoperative care is recommended for horses following staphylectomy?
A
Muzzle for several hours and antibiotics for 7 days.
18
Q
Standard myectomy what is it?
A
partial removal of sternohyoideus and sternothyroideus, with or without omohyoideus resection) is performed to reduce caudad retraction of the larynx
19
Q
Is it performed GA or Standing the standard myectomy ?
A
sternothyroideus and sternohyoideus muscles are removed with the horse standing as the procedure was first described. If the plan is to ALSO REMOVE a section of omohyoideus muscle, the procedure should be performed under GA with the horse positioned in dorsal recumbency and the head and neck extended
20
Q
A
A
10-cm ventral midline incision is made through the skin, continuing through the cutaneus colli muscles. The paired sternohyoideus muscles are identified. Using curved forceps, the sternohyoideus and sternothyroideus muscles are undermined. The sternothyroideus muscle is positioned caudolateral to the sternohyoideus muscle at this level of the neck. The muscles are elevated through the incision and clamped with a Rochester-Carmalt forceps at the proximal and distal extent of the incision. The muscle bellies are sharply transected between the forceps, removing a 6- to 8-cm-long section of muscle. The muscle tissue that was removed should be inspected to ensure that sections of both sternohyoid muscles and the smaller sternothyroid muscles were indeed removed. Previously, the omohyoideus muscle was sometimes removed; however, significant dead space was created, leading to a higher rate of incisional complications, and therefore resection of the omohyoideus is no longer recommended
21
Q
What should be monitored postoperatively to assess success of the laryngeal tie-forward?
A
Endoscopic positioning of the epiglottis relative to the soft palate.
22
Q
What is the common approach to minimize complications when performing a myectomy?
A
Avoiding resection of the omohyoideus muscle.
23
Q
How long post-surgery can training typically resume after a standard myectomy?
A
2 weeks after surgery.
24
Q
What are the common complications associated with standard myectomy?
A
Incisional seromas and infections.
25
In the end of standard myectomy what should you do?
The subcutaneous and skin layers are closed routinely. If a Penrose drain is used, it is placed alongside the ventral aspect of the trachea and tunneled through a stab incision distal to the surgical incision. A firm bandage is applied around the neck and may be removed along with the drain 24 hours later.
26
What is the postop for standard myectomy and minimally invasive myectomy?
NSAI Ds can be continued for 3 days, and antibiotics should be continued for 5 to 7 days. The horse is kept in a stall with daily hand walking for 2 weeks. Training can be resumed 2 weeks after surgery, when the sutures are removed. Complications are usually related to the incision and include incisional seromas and infections.
27
What is the reported success rate for standard myectomy in treating DDSP?
58% to 71%.
28
What is the common approach to minimize complications when performing a myectomy?
Avoiding resection of the omohyoideus muscle.
29
How long post-surgery can training typically resume after a standard myectomy?
2 weeks after surgery.
30
What are the common complications associated with standard myectomy?
Incisional seromas and infections.
31
What does minimally invasive myectomy involve?
Partial sternothyroidectomy or the Llewellyn procedure.
32
What is the length of incision typically made for minimally invasive myectomy?
5 to 7 cm.
33
What anatomical structure must be avoided during the transection of the sternothyroideus tendon?
The caudal laryngeal artery.
34
Describe surgical procedure of minimally invasive myectomy
Partial sternothyroideus myectomy and tenectomy is performed with the horse under general anesthesia.70 A 5- to 7-cm ventral midline skin incision is made centered on the cricoid cartilage. The subcutaneous tissue is incised, and the sternohyoideus muscles are divided bluntly using curved Mayo or Metzenbaum scissors. The blunt dissection is continued dorsal to the sternohyoideus muscle, exposing the caudolateral border of the thyroid cartilage. The tendon of insertion of the sternothyroideus muscle at the thyroid cartilage is identified, undermined, and elevated. The tendon is transected 1 cm caudal to its attachment to avoid
the caudal laryngeal artery, taking care to avoid damaging the cricothyroid muscle.Using one index finger, the sternothyroideus muscle is freed from the surrounding fascia and transected more proximally, thus removing a 3-cm section of muscle and do in the contralateral
35
During the minimally invasive myectomy damage to the cricothyroid muscles may result in what?
vocal cord collapse
36
What are the postoperative NSAID administration guidelines for minimally invasive myectomy?
For 3 to 7 days.
37
Figure 45-25. Schematic drawing showing the principle of the laryngeal tie-forward procedure. (A) Lateral view: note that the sutures are placed from the basihyoid into the lateral and caudal aspects of the lamina of the thyroid cartilage. The suture is passed four times through the thyroid cartilage and the most dorsal bite is immediately ventral to the tendon of the sternothyroid muscle. (B) Ventral view: the sutures course on the dorsal surface of the basihyoid bone and are tied with a slip knot on the ventral aspect of the junction of basihyoid bone and lingual process.
38
What anatomical structure does the laryngeal tie-forward aim to reposition?
The thyroid cartilage relative to the basihyoid bone.
39
How far rostral should the thyroid cartilage be positioned post-tie-forward surgery?
0.1 to 1.5 cm rostral to the caudal border of the basihyoid bone.
40
How long should the horse be kept in a stall postoperatively after a laryngeal tie-forward?
2 weeks.
41
What percentage increase in success rate is expected from laryngeal tie-forward compared to standard myectomy?
20% greater.
42
What is the length of the standard incision for a standard myectomy?
10 cm.
43
What is the significance of marking the resection site before laser-assisted staphylectomy
To prevent excessive resection due to the palate's elasticity
44
What suture pattern is used to close the laryngotomy site?
Simple-continuous pattern.
45
What anatomical muscle is commonly resected during a standard myectomy?
Sternohyoideus.
46
What is the expected recovery time before resuming training after a minimally invasive myectomy for Standardbreds?
2 to 3 days.
47
How is the sternohyoideus muscle managed during a laryngeal tie-forward?
It is separated and dissected free.
48
What type of retractor is often used during laryngotomy?
Weitlaner or Hobday retractor.
49
What is the consequence of excessive soft palate resection in horses?
Dysphagia and potential aspiration pneumonia.
50
What are the anatomical landmarks for making a laryngotomy incision?
Centered over the cricothyroid space.
51
What are common postoperative assessments for laryngeal tie-forward surgery?
Endoscopic evaluation and radiographs with head in an extended position.
52
What is the principle of tie forward?
The principle of the procedure is to replace the action of the thyrohoideus muscles bilaterally by sutures placed between the thyroid cartilage and the basihyoid bone (fig 45-25)
53
Describe surgical approach of TIE FORWARD
The ventral cervical and intermandibular areas extending 10 cm rostral to the basihyoid bone are prepared aseptically. A ventral skin incision is made starting 1 cm caudal to the cricoid cartilage and extending 2 cm rostral to the caudal aspect of the basihyoid bone. The sternohyoideus muscle is separated on the midline and bluntly dissected free of the dorsolateral aspect of the larynx lateral to the thyrohyoideus muscles. The sutures are first passed through the thyroid cartilage. A No. 5 USP polyblend suture (Fiberwire) is passed four times through the right lamina of the thyroid cartilage ventral to the insertion of the sternothyroid tendon (see Figure 45-25, and Figure 45-26). Alternatively, a metal buttress is placed on the medial side of the thyroid cartilage to minimize cutting of the thyroid cartilage with sutures (F. Rossignol, personal communication, 2010). The junction of the basihyoid and lingual process is identified with a Crile forceps after limited blunt dissection, and a wire passer is inserted dorsal to the basihyoid bone immediately lateral to the lingual process. The wire passer courses over the dorsal aspect of the basihyoid bone and exits on the midline at the caudal aspect of the basihyoid bone (Figure 45-27). After the needle has been cut from the sutures, the dorsal (leader) and the ventral (trailer) ends of suture of the contralateral side are passed into the wire passer and retrieved. The procedure is repeated on the other side (Figure 45-28) such that the dorsal (leader) and ventral (trailer) ends of the sutures of each side can be tied over the ventral aspect of the basihyoid. A bilateral partial sternothyroidectomy is performed at this time
54
The sutures on each side are then tied so the rostral aspect of the thyroid cartilage is located immediately dorsal and ____ to ___ cm rostral to the caudal border of the basihyoid bone
The sutures on each side are then tied so the rostral aspect of the thyroid cartilage is located immediately dorsal and 0.1 to 1.5 cm rostral to the caudal border of the basihyoid bone
55
In the postop management of tie forward it is important that the horses is placed in which position?
ostoperatively the horses are fed and watered at shoulder height to reduce stress on the sutures. They are administered NSAI Ds for 3 to 5 days. Horses are maintained in a box stall for 2 weeks with daily hand walking. Training often is resumed 2 to 3 days after this rest period.
56
Figure 45-26. Intraoperative view of the laryngeal tie-forward procedure. Surgical view showing one suture passed twice (approximately 1-cm bites) through the lamina of the thyroid cartilage with the most dorsal suture entering ventral to the tendon of the sternothyroid tendon. This gives a dorsal (leader) and ventral (trailer) end of the sutures that will be passed around the basihyoid bone. Orientation: caudal (left), rostral
(right).
57
Figure 45-27. Intraoperative view of the laryngeal tie-forward procedure. Surgical view showing a wire passer in place where it enters immediately lateral to the lingual process in the corner (white arrows) of the junction of the basihyoid and lingual process. The wire passer courses over the dorsal aspect of the basihyoid bone and exits on the midline at the caudal aspect of the basihyoid bone (black arrow). Orientation: caudal (bottom), rostral (top).
58
Figure 45-28. Intraoperative view of the laryngeal tie-forward procedure, after the sutures have been placed so that the dorsal suture (leader) has been passed ipsilateral to the lingual process and the ventral (trailer) end is passed on the contralateral side. Orientation: caudal (left), rostral (right).
59
Figure 45-29. Postoperative view of the larynx in a 3-year-old Standardbred filly. Note that the epiglottis is elevated and not contacting the soft palate.
60
Figure 45-30. Lateral radiograph of a 3-year-old Thoroughbred filly with intermittent displacement of the soft palate prior to surgery (A) and after laryngeal tie-forward (B). Note the tip of the epiglottis is more rostral and dorsal after surgery. Also, the ossification at the base of the thyroid cartilage (white arrow) is more rostral and dorsal after surgery. Linear white densities are 5-cm pins used to measure magnification of radiographs.
61
What embryonic event leads to choanal atresia in foals?
The failure to resorb the bucconasal membrane during embryonic development.
62
What is the primary risk associated with bilateral choanal atresia in foals?
It usually results in the foal’s death unless an emergency tracheostomy is performed at birth.
63
What symptoms might a foal with unilateral choanal atresia exhibit?
Loud respiratory noise, exercise intolerance, and asymmetry of airflow from the nostrils.
64
Which diagnostic techniques are utilized for choanal atresia?
Endoscopic examination, skull radiography, contrast radiography, and computed tomography
65
At what age is it recommended to treat unilateral choanal atresia, and why?
At 1 year of age, to facilitate surgical exposure and reduce the risk of postoperative complications.
66
What combination of medications is used for sedation during the first treatment approach for choanal atresia?
Detomidine and butorphanol.
67
What is the purpose of creating cross incisions in the choanal membrane during surgery?
To minimize bleeding from the vascular membrane and facilitate resection.
68
Describe the approach taken when the choanal membrane is osseous.
A nasal flap is created to access and resect the choanal membrane and part of the nasal septum.
69
What surgical method is used for resecting the membrane in very young foals?
Resection through a laryngotomy under endoscopic control.
70
What are the potential complications following surgery for choanal atresia?
Persistence of airway obstruction and the need for a stent to prevent stricture.
71
Choanal atresia results in foals death unless emergency___________
Because horses are obligate nasal breathers, bilateral choanal atresia usually results in the foal’s death unless an emergency tracheostomy is performed at birth
72
Describe surgical intervention for choanal atresia
sedated, detomidine and butorphanol, and topical anesthesia with phenylephrine (2% lidocaine or mepivacaine hydrochloride and 10 mL of 0.15% phenylephrine) is applied to the membrane and nasal cavity. The endoscope is placed in the affected nostril and the outline of the choanal membrane is identified using equine laryngeal forceps. Using a 600-μm laser fiber placed in the biopsy channel of the videoendoscope and a diode laser set at 15 watts, selected vessels are cauterized by placing the laser tip adjacent to but not on the vessel itself. Blanching of the visible vessels on the membrane indicates that the vessels were obliterated and in doing so minimizes intraoperative bleeding. The membrane is incised, creating two lines of incision perpendicular to each other that cross at the center of the choanal membrane. This cross incision is made because the membrane (even though it appears thin) is vascular, and local pressure to stop the bleeding may be needed at times. If excessive bleeding occurs, a nasotracheal tube is passed through the membrane into the nasopharynx, where the cuff is inflated to apply pressure that promotes hemostasis at the surgical site. After a few minutes, the tube is removed and each flap is resected; the aforementioned forceps may be used to apply tension on the flaps as needed
73
What is the postop of choanal atresia?
Postoperatively, the patient receives a 5-day course of phenylbutazone (2.2 mg/kg PO BID) or a similar NSAID
74
If the foal has a bilaeral choanal what should you do as additional srugical intevention beside choanal membrane(bone) resection?
The choanal membrane (bone) is resected, as well as part of the nasal septum, using a nasal bone flap. The foal is anesthetized and placed in lateral recumbency, and an endotracheal tube is placed through a tracheostomy. A C-shaped incision (for unilateral lesions) or an S-shaped incision (for bilateral lesions) is made over the nasal bones starting at the level of the medial canthus of the eye and extending rostrad to approximately the middle of the nasal cavity, which is near the level of the infraorbital foramen. The periosteum is incised on the midline, extending laterally to an area near the nasomaxillary suture, taking care to stay at least 1 cm medial to the infraorbital canal. A nasal bone flap is created along the line of the periosteal incision by placing an osteotome at a 45-degree angle to create a ridge for the bone flap to rest on at the end of surgery. The nasal bone flap is made in the shape of the periosteal incision (note: the procedure must be performed bilaterally shortly after birth, unless a permanent tracheostomy is placed, if the atresia is bilateral). The nasal mucosa is excised, and the choanal membrane is identified and resected, along with the caudal nasal septum if necessary. The area is packed with sterile rolled gauze, which exits the nostril and is sutured to the false nostril.
75
What is the third approach for choanal atresia in foal?
The membrane is resected through a laryngotomy after placing the endoscope through the nares to illuminate the persistent membrane. The authors’ preference is to incise the membrane using endoscopic control and to place a stent in
the nostril to prevent stricture. Laser dissection of the membrane has been unrewarding because profuse hemorrhage associated with recumbency and general anesthesia rapidly obscures the endoscopic view, preventing the application of local pressure in a small foal. The membrane is incised best using laparoscopic scissors with unipolar/bipolar cautery or using the ligasure system (Medtronic) under endoscopic control while the foal is under general anesthesia. A nasotracheal tube is placed through the surgically created fenestration and sutured to the false nostrils. The stents are removed 14 days postoperatively. Appropriate antibiotic therapy is used
76
What is the prognosis and heritabiltiy of the choanal atresia?
Unknown
77
Nasopharyngeal dysfunction is characterized by
respiratory distress, respiratory stridor, and dysphagia, can occur in foals during the first month of life.
78
The diagnosis of nasopharyngeal dysfunction is made how?
Endoscopic examination may reveal severe nasopharyngeal edema, laryngeal edema, milk pooling in the nasopharynx, and persistent DDSP .
79
etiology of this obstructive syndrom
is unknown.
80
Most often, these foals recover from nasopharyngeal dysfunction in
10 to 30 days
81
What is the first medical approach to a foal with nasopharyngeal dysfunction?
physical examination, an endoscopic examination, and radiography of the thorax and pharyngeal region should be performed when evaluating a foal with nasopharyngeal dysfunction. While examining the foal, precautions should be taken to provide it with a patent airway if the examination induces respiratory distress. Appropriate blood work, including serum chemistry, complete blood count, serum immunoglobulin G (IgG) levels, and an arterial blood gas analysis, should be performed.
82
What is the surgical approach to a foal with nasopharyngeal dysfunction?
Respiratory distress may be sufficiently severe that an emergency tracheotomy has to be performed immediately. If the foal has persistent DDSP , a laryngotomy followed by placement of a tracheostomy tube usually corrects this problem. Rarely, a staphylectomy may be needed. However, surgical intervention is not necessary in many foals. It is best to support the foal medically for 1 month to see if the problem resolves
83
What is the primary cause of cleft palate in foals?
84
What clinical signs indicate a potential cleft palate in foals?
Milk draining from the nose after nursing, coughing, and aspiration signs.
85
What is the initial step in the management of a diagnosed cleft palate?
Examination for other congenital defects and assessment of aspiration severity.
86
When might surgical intervention for cleft palate be delayed?
If the cleft is small and tracheal aspiration is minimal, monitoring is preferred.
87
What are the two primary surgical options for large cleft palates?
Surgical repair or euthanasia, depending on the severity and aspiration risk.
88
What is a common complication following cleft palate repair?
Complete or partial dehiscence of the repair, requiring potential reoperation.
89
Which surgical approach provides the best exposure to the hard and soft palate?
90
How are the mandibles stabilized after cleft repair?
Using a Steinmann pin and hemicerclage, with central incisors wired together.
90
What is done to minimize postoperative discomfort and dehiscence during the mandibular symphysiotomy?
A transverse incision at the lip base allows movement without lip incision.
91
What structures are transected to expose the buccal mucosa during surgery?
The attachments of the mylohyoid, geniohyoid, and genioglossus muscles.
91
Describe the positioning of the foal during a mandibular symphysiotomy.
The foal is placed under anesthesia and positioned in dorsal recumbency.
92
What is essential for visibility during soft palate repairs?
The use of a videoendoscope through a laryngotomy or transoral approach.
92
What is the order of suturing during soft palate repair?
Close the nasal mucosa first, followed by the oral mucosa and muscular layers.
92
What is the benefit of a two-step repair approach in cleft palate surgery?
It allows for healing of the initial repair before completing the procedure.
93
Why is it important to relieve tension on the repair site?
xcess tension can lead to dehiscence of the surgical closure.
94
What are two techniques to relieve tension during soft palate repair?
95
Why is splitting the thyroid cartilage sometimes necessary in cleft palate surgery?
To enhance access to the caudal aspect of the soft palate for better reconstruction.
96
What is left to heal by second intention post-surgery?
The subcutaneous tissues and skin after closure of the internal structures.
96
What closure technique is used for the cricothyroid membrane after thyroid cartilage suturing?
A simple-continuous pattern with 2-0 polyglactin 910 suture material.
97
what is palatoschisis?
cleft palate
98
Which day of gestation the cleft palate occurs?
traumatic mechanical factors that could affect palatal fold closure during the 47th day of gestation are possible causes
99
Cleft palate defects that occur on the midline with minimal tissue missing have a successful prognosis of
50%
If the hard palate is involved, the chance of success, defined as an animal that can eat and grow normally, drops significantly.
100
Name the surgical approaches for cleft palate (4)
S
urgical approaches to the palate include a transoral approach, laryngotomy, pharyngotomy, and mandibular symphysiotomy
101
Pharyngotomy in cleft palate resolution consists in
Pharyngotomy with splitting of the basihyoid bone is used to repair a cleft involving the caudal third of the soft palate
102
Mention the preparation for sx of mandibular symphysiotomy
Mandibular symphysiotomy provides the best exposure to the hard and soft palate (Figure 45-31).
To incise the edge and suture the soft palate, a mandibular symphysiotomy approach is commonly used:
GA - DR - tracheotomy is + tube is placed in the trachea. Hair is clipped from the lower lip to the proximal trachea, and the skin is prepared for aseptic surgery.
Skin incision is made from the hyoid to the lower lip Fig 45-31
103
The skin and gingiva over the mandibular symphysis are completely incised, and the mandibular symphysis is severed using a scalpel blade (in a neonate), an osteotome, or an oscillating bone saw. It is preferable to avoid incising the lip to minimize postoperative dehiscence and discomfort. This is achieved by making a transverse incision at the base of the lip so the lip can first be moved caudad to give access to the symphysis. After splitting the symphysis, the lip is moved orally. The mandible spread achieved is slightly less after splitting the mandibular symphysis compared with splitting the lower lip, but it reduces morbidity. Surgical dissection subsequently proceeds along the right ramus of the mandible, and the attachments of the mylohyoid, geniohyoid, and genioglossus muscles are transected, exposing the buccal mucosa. The buccal mucosa is sharply incised, allowing the rami of themandibles to be retracted (see Figure 45-31, C and D). A thin malleable retractor may be inserted through the laryngotomy over the base of the tongue to push the tongue out of the surgical field. Moist towels should be used to retract the mandibles.
After the cleft is repaired, the mandibles are apposed and stabilized best with a Steinmann pin supplemented by a hemicerclage, and the central incisors are wired together. The buccal mucosa is closed, and the geniohyoid and mylohyoid muscle layers are apposed and reattached. The lip is replaced in its correct anatomical position by closing the gingiva, muscle layer, and skin (see Figure 45-31, I). The laryngotomy is left open, and the skin incision from the mandibular symphysis to the laryngotomy is closed with sutures interrupted by 2-cm gaps for drainage
104
which muscles are incised during the mandibular symphisiotomy
he attachments of the mylohyoid, geniohyoid, and genioglossus muscles are transecte
105
Figure 45-31. Cleft palate repair via mandibular symphysiotomy. (A, B’ and B) A ventral midline incision is made from the angle of the mandible to the lip. Before splitting the symphysis, a hole is prepared to facilitate realignment of the bones during closure. The lip has been moved orally to avoid morbidity associated with incising it. (B) a, Mylohyoideus; b, mandibular lymph nodes; c, sternohyoideus and omohyoideus muscles
106
(C) The mandibles are spread, and the rostral oral mucosa is incised. The mylohyoid and geniohyoideus muscles are incised near their tendinous origin. They should be cut with enough tissue left to suture them together for closure. (D) The exposed ventral surface of the oral mucosa is tensed by further spreading of the mandibles. It is incised as far caudad as possible. Care is taken to avoid the sublingual salivary gland near the mandible and the lingual nerve near the tongue. (E) The edges of the incision are covered with moistened sponges or towels and spread as far as possible. The nasotracheal tube is visible through the cleft. Two stay sutures are placed at the caudal corners of the cleft.
107
Soft palate repair -What is the first step in soft palate repair once the cleft is identified?
A surgical light is directed into the incision to evaluate the cleft.
107
(F) Tensing the edges of the cleft with the stay suture, a No. 12 Bard-Parker blade is used to split the thickness of the tissue. The stay sutures can be held by an instrument inserted through a laryngotomy. (G) A simple-continuous (or a Lembert) pattern is placed in the nasal side of the split edge in a rostral-to-caudal direction. (H) A continuous horizontal mattress pattern is placed in the oral side of the split edge. Two to four widely spaced interrupted vertical mattress sutures are placed to reduce tension on the primary suture line. (I) Soft tissues are apposed and a lag screw or pin with figure-of-eight wire is placed using the previously drilled hole. A cerclage wire around the rostral mandible just caudal to the erupted incisors augments stability.
Figure
108
Figure 45-32. Laryngotomy approach for repair of the caudal aspect of a cleft palate. The two parts of the cleft palate are retracted with Allis forceps. Good visibility of the cleft palate was achieved by splitting the thyroid cartilage longitudinally.
109
What is the purpose of using a videoendoscope in soft palate surgery?
To improve visibility during the repair, especially if a pharyngotomy is performed.
110
What are stay sutures, and where are they placed during the repair?
Stay sutures are passed through the soft palate at the cleft's caudal extent and secured at the laryngotomy site.
111
What incision technique is used to extend the cleft during repair?
A thin strip of mucosa is excised, followed by a narrow incision using a No. 12 hooked blade.
111
Why is silk suture material preferred for closing the oral mucosa?
It has excellent handling characteristics and provides good knot security.
112
In what order should the mucosal layers be closed during soft palate repair?
The nasal mucosa is closed first, followed by the oral mucosa and muscular layers.
113
What complications can arise from tension on the repair site?
Dehiscence, which can be evident through nasal reflux of food and coughing.
114
What are tension-relieving incisions, and where are they made?
Incisions made parallel to the closure plane in the lateral mucosa to reduce tension.
115
What alternative method can be used to relieve tension in the palate during repair?
Placing widely spaced interrupted vertical mattress sutures in the palate.
115
What surgical options exist to address tension from the tensor veli palatini muscle?
Transection of its tendon or performing an osteotomy of the hamulus of the pterygoid.
116
What are the risks of performing certain tension-relieving procedures in athletic horses?
It can lead to instability of the soft palate, affecting respiratory soundness during exercise.
117
Why might a combined transoral and laryngotomy approach be used?
To facilitate good apposition and reconstruction of the caudal aspect of the soft palate.
118
What surgical technique is employed to improve access to the caudal soft palate?
Sagittal splitting of the thyroid cartilage.
119
How is the thyroid cartilage closed post-repair?
With three single interrupted sutures of No. 2 monofilament nylon.
120
What closure technique is used for the cricothyroid membrane?
A simple-continuous pattern with 2-0 polyglactin 910 suture material.
121
What type of flaps are used in hard palate defect repair?
Mucoperiosteal flaps.
122
What is the healing approach for subcutaneous tissues and skin after soft palate repair?
Healing by second intention.
123
How is hemorrhage controlled during hard palate repair?
v
123
What is the purpose of the mucoperiosteal incision in hard palate repair
By injecting 2% lidocaine with epinephrine along the incision lines.
124
What is the purpose of the mucoperiosteal incision in hard palate repair?
To elevate the mucoperiosteum to the edge of the defect for closure.
124
Where is the palatine artery located, and why is it significant?
It emerges from the palatine foramina; preserving it is crucial to avoid complications.
124
What technique is employed to ensure proper closure of the nasal mucosa during hard palate repair?
Closing in a simple-continuous pattern with absorbable suture material.
125
How are the mucoperiosteal flaps secured together post-repair?
Using horizontal mattress sutures.
126
What is the typical healing method for defects along the lateral aspect of mucoperiosteal flaps?
Healing by second intention.
127
What feeding method is recommended for foals after extensive palate repairs?
Enteral feeding through a nasogastric tube or parenteral nutrition for 7 to 10 days.
128
What is the recommended duration for broad-spectrum antibiotic treatment post-surgery?
Generally, 5 days unless pneumonia is present, in which case treatment continues until resolved.
129
How is the repair assessed in the early postoperative period?
Through careful oral examination, avoiding endoscopic examination initially.
130
What is the most likely and severe complication of palate repair?
Dehiscence, typically noticeable within the first 7 to 14 days.
131
What signs may indicate dehiscence of the palate repair?
Nasal reflux of food and coughing.
132
Nasal reflux of food and coughing.
Pneumonia, osteomyelitis of the mandible, salivary fistulas, and incisional infections.
133
Why is digital palpation not recommended for assessing the repair?
It can disturb the delicate surgical site and lead to complications
134
What are common indicators of pneumonia following palate surgery?
Symptoms such as coughing, nasal discharge, and difficulty breathing.
135
What measures can be taken to minimize the risk of complications post-surgery?
Careful monitoring, appropriate feeding strategies, and timely antibiotic administration.
136
What is the role of stay sutures in the surgical repair of the soft palate?
They help to tension the edges of the cleft for better apposition during closure.
136
Why might postoperative assessments be crucial within the first week?
Early detection of complications like dehiscence can improve outcomes.
137
What can be done to ensure optimal healing of the mucoperiosteal flaps?
Proper suturing technique and avoiding tension during closure.
138
What should be monitored closely in foals recovering from palate surgery?
Signs of aspiration pneumonia and the integrity of the surgical repair.
