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Flashcards in 90. Esophagus Deck (55):
1

nerve supply that travels with thoracic esophagus into abdomen

dorsal and ventral vagal trunkscranially: pharyngoesophageal n, recurrent laryngeal nerves, paralaryngeal n, vagal n.

2

T/Fthe esophagus has a serosal outer layer

FALSEadventitia

3

diffierence in muscular composition of the esophagus in dogs vs cats

dogs---entirely skeletal musclecats---skeletal muscle and terminates as smooth muscle, terminal portion folds transversely (herringbone)

4

sphincters of the esophagus

had to ddx anatomicallycranial: cranial esophageal sphincter (made of cricopharyngeal/thyropharyngeal muscles)caudal: lower esophageal sphincter (gastroesophageal junction--hi P)

5

main blood supply to the esophagus

1. cervical esophagus: cranial and caudal thyroid arteries2. thoracic esophagus cranial 2/3: bronchoesophageal artery3. thoracic esophagus caudal 1/3: esophageal branches of aorta and dorsal intercostal arteries4. terminal abdominal esophagus: left gastric artery

6

3 phases of swallowing

1. oropharyngeal (oral (voluntary), pharyngeal (involuntary), pharyngoesophageal/cricopharyngeal): prehend, masticate, make bolus, push through cricopharyngeal sphincter (protect nasopharynx with contraction of palatal/pharyngeal constriction to close, caudal epiglottis reflection and vocal fold adduction to protect airway); final stage is relaxation of muscles while delivering bolus to cranial esophagus2. esophageal: primary peristaltic wave stimulated by dissension from bolus, pushes aborally; second wave will occur if dissension remains in esophagus3. gastroesophageal: muscularis relaxes ahead of the bolus and the bolus is propelled through gastroesophageal sphincter

7

nerves responsible for oropharyngeal stage of swallowing

5 trigeminal 7 facial9 glossopharyngeal10 vagus12 hypoglossal

8

in healthy dogs, esophageal transmit time with liquid vs kibble

DEPENDS ON POSITIONING!sternal: 3 (liquid) -4 (kibble) minR lateral recumbency: 7(liquid) --9 (kibble) minfaster in STERNAL

9

general causes of dysfunction of the esophagus

1. mechanical (or anatomic) lesions: FB, tumors, strictures, vascular ring anomalies, intussusceptions, hiatal hernias2. functional (or NM) lesions: hypoperistalsis/aperistalsis3. inflammatory lesions: acute vs chronic

10

reasons why esophagus has higher prevalence of incisional dehiscence

1. lack serosa (heals create fibrin seal and source of stem cells)2. segmental blood supply3. lack omentum4. constant motion5. tension at surgical site

11

T/Fcan ligate branches supplying thoracic esophagus and it will live

TRUE as long as cervical and abdominal portions are intact due to strong intramural blood plexuses in the submucosaCANNOT ligate cervical and thoracic segments at the same time (necrosis)

12

surgical approaches to the esophagus

1. ventral midline2. cranial median sternotomy3. right and left lateral thoracotomies depending on lesion

13

suture holding layer of esophagus

submucosa

14

resection of how much of the esophagus has been associated with an increased rate of dehiscence

resection of > 3-5 cm of esophagus has been associated with increased dehiscence

15

considerations for a two layer closure in the esophagus

1. intraluminal knots simple interrupted of submucosa, mucosa2. extraluminal knots inverting pattern or appositional simple interrupted(can consider simple interrupted or continuous single layer but interrupted is preferred)

16

what is the maximum cervical and thoracic esophagus that can be resected in experimental dogs

20% cervical 50% thoracicCAUTION: TENSION

17

method to relieve tension on esophageal R&A

circumferential PARTIAL myotomy of outer muscle layer (to heal by 2nd intention) caution with excessive mobilization due to disruption of the segmental blood supply

18

methods of esophageal R&A

--simple interrupted closure--end to end stapling devices--biodegradable anastomic ring--esophageal substitution

19

esophageal patching

omentum, pericardium, SIS, muscle (sternothyroid, longus colli), buccal mucosal graftscan be used to reinforce closure (on-lay)can be used following esophagoplasty after longitudinal division of esophageal stricture (in-lay)

20

esophageal substitution

if massive resectioncan replace cervical esophagus with inverse tubed skin graft; can also use muscle grafts, gastric advancement for other areas of esophagus to be replacedmultistage procedureMINIMAL clinical experience

21

in embryos, what are the great vessels derived from

paired dorsal and ventral aortas and the 6 interconnecting pairs of aortic arches (6 brachial arches)arches 1,2 involute3rd arches becomes carotid arteriesleft 4th AA --> adult aortic archright 4th--> right subclavianleft 6th AA-->pulmonary trunk, ductus arteriosus (ligamentum arteriosus)right 6th-->pulmonary artery

22

7 types of vascular ring anomalies

1. PRAA with left LA (most common 95%)2. PRAA with right LA (NO ring, no obstruction)3. PRAA with aberrant LEFT subclavian artery and right LA (artery passes dorsal from the right sided Ao--single ring incomplete stricture)4. PRAA with aberrant left subclavian and Left LA (double ring strictures)5. Double AA (significant tracheal stenosis)6. normal AA (left) with persistent right LA (mirror image of PRAA and left LA--NEEDS A RIGHT LATERAL THORACOTOMY)7. aberrant right subclavian (arising from Ao instead of brachiocephalic trunk and travels dorsal across esophagus--partial ring, may not see clinical signs, but is common)

23

in PRAA patients with LA, how often is the ligamentum patent (ductus)? And what other abnormality may be present

left cranial vena cava 45%patent ductus 10%other congenital abnormalities 20%

24

signalment for PRAA

GSD, Irish Setter> 15 kg20% diagnosed by 2 months80% diagnosed by 6 months

25

diagnostic imaging for diagnosis of PRAA

--survey films (cranial focal dilation, check aspiration, VD right Ao and left deviation trachea)--positive contrast radiography (barium)--fluoroscopy--angiography--echocardiography--CT/MRI--Esophagoscopy (rule out other causes of esophageal obstruction, look what side aortic pulse is)

26

only vascular ring anomaly that cannot be addressed through a left lateral thoracotomy

normal AA (left) with a RIGHT LAnormal PRAA with left LA approach: left 4th in dogs, left 5th in cats

27

what structure wraps around the ligamentum arteriosus

left recurrent laryngeal nerve

28

why can you ligate and divide the subclavian arteries

collateral flow through vertebral artery

29

diagnosis and approach to double AA

both aortic arches contributeangiography would tell which side is contributing moreapproach, ligate, divide and oversew smaller side

30

prognosis and post op complications

continued regurgitation (NM functional loss, muscle atony)aspiration pneumoniadeath

31

prognosis of PRAA surgery in 1980s Shires and Liu

3 week survival 80%intermittent regurgitation present in 67% (2/3)poor outcome in 25%

32

Muldoon et al 2003 prognosis of PRAA

2 week survival 95%92% had complete resolution of all clinical signs8% had a “good” outcome50% dogs had follow up radiographs and all had radiographic evidence of megaesophagus

33

prognosis and reported surgery for congenital megaesophagus

hi mortality 75% die within a yresophagodiaphragmatic cardioplasty using the Torres technique (cut L diaphragm, trim, and resuture)--small case series

34

most common esophageal FB in dogs vs cats

dogs: ingested bones**cats: fish hooks, needles, string

35

common locations for esophageal FB

thoracic inletheart base (10-30%)caudal esophagus (70-80%)

36

success of FB retrieval with endoscopy

60% retrieved30% pushed into stomach10% required surgery

37

T/Facute esophageal penetrating injuries have a poorer prognosis that oropharyngeal injuries

TRUE36% mortality

38

acquired vs congenital esophageal strictures

congenital (rare)acquired--damage extending to muscular layer, heals by fibrosis and wound contracturemost common injury causing stricture---REFLUX 50% in dogs

39

esophageal strictures in cats has been associated with what oral drug (s)

doxycyclineclindamycinretention of tablets causes focal esophagitis and subsequent stricture formationgive with water

40

diagnosis of esophageal stricture

--positive contrast esophagogram --esophagoscopy (allows biopsy and treatment in same episode)--fluoroscopy60-75% single (caudal thoracic esophagus) 40% multiple

41

treatment for acquired esophageal strictures

--bougienage (longitudinal shear force)--balloon dilatation (radial force to open)+/- esophageal stents+/- depository GCC, mitomycin cmay need multiple attempts for dilation--surgery reserved for failed therapy (esophagoplasty--patch or simple, R&A, esophageal substitution--free skin tube flap, free jejunal segment)

42

outcome following dilatation with bougienage or balloon dilatation for esophageal strictures

70-90%may need multiple episodes

43

traction vs pulsion diverticulum of the esophagus

pulsion --mucosa out pouch through defect in tunica muscularistraction--full thickness deviation of the esophageal wall

44

where is an epiphrenic diverticula located

btwn heart base and diaphragm

45

in relation to time after anesthesia, when do acquired esophageal strictures occur

~3 weeks after anesthesia

46

T/Fbronchoesophageal fistula are more common in dogs than tracheoesophageal fistula

TRUEbronchoesophageal fistula most frequently communicate with right caudal lung lobe bronchusexcise and repair rather than just ligatepx depends on how extensive the lung pathology is

47

cricopharyngeal dysphagia

swallowing disorder--congenital, dx < 12 mocharacterized by cricopharyngeal achalasia (failure of upper esophageal sphincter to open/relax) or asynchrony (incoordination)food remains in pharynxfailure of the cricopharyngeal phase of swallowing

48

diagnosis of cricopharyngeal dysphagia

oral examendoscopic examsurgery films (generally normal)definitive dx fluoroscopy with visualization of swallow--normal bolus formed, normal pharyngeal contraction, but failure of RELAXATION of cricopharyngeal muscles/sphincter

49

differential to cricopharyngeal dysphagia

--pharyngeal dysphagia (weak contraction)important to ddx bc cricopharyngeal myotomy improves cricopharyngeal dysphagia but worsens pharyngeal dysphagia

50

treatment for cricopharyngeal dysphagia

cricopharyngeal myotomy or myectomy +/- thyropharyngeal myotomy (use hemoclips to ID post op)placement of orogastric tubecricopharyngeal muscle (single unpaired)O: lateral side of one cricoid spreads dorsally over esophagusI: contralateral cricoid cartilageinnervated by glossopharyngeal (9), vagus--pharyngeal branch (10)blood supply: cranial thyroid artery

51

how is the cricopharyngeal muscle approached for treatment of cricopharyngeal dysphagia

ventral midline (have to rotate larynx 180 degrees with stay sutures)orlateral (preferred)remove 2-2.5 cm of cricopharyngeal muscle

52

prognosis of cricopharyngeal dysphagia

treated young---px good to excellentimmediate alleviation of clinical signs 13/14 dogscomplete resolution only 50%recurrence possible with fibrosis/contracture of surgery siteno diff myotomy vs myectomy or surgeon experiencepoorer outcome if concurrent esophageal dysfx or stricture, underlying NM disease etc

53

esophageal neoplasia

SCC (#1 in cats)leiomyosarcoma/leiomyoma (B)OSAFSA (sarcoma related---spirocerca lupi)plasmacytoma (B)usually advanced, met 50%generally poor prognosis unless benign

54

most common location of esophageal neoplasia in dogs vs cats

dogs--caudal thoracic esophaguscats--cranial thoracic esophagus

55

percentage of dogs with spirocerca lupi related esophageal sarcoma and hyper tropic osteopathy

40%

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