Thoracotomy Thoracotomy

ThoracotomyThoracotomy

Opening of chest cavityOpening of chest cavityApproaches depends uponApproaches depends upon

1.1. Lesion typeLesion type – DH, lobectomy, pericardiotomy, thoracocentesis – DH, lobectomy, pericardiotomy, thoracocentesis

Approaches depends Approaches depends upon following factors upon following factors

FactorsFactors

Lesion type: DH, lobectomy, Lesion type: DH, lobectomy, pericardiotomy, thoracocentesispericardiotomy, thoracocentesis

Condition of the animal- whether an Condition of the animal- whether an early early diagnoseddiagnosed

- withstand extensive - withstand extensive sternotomy(splitting of sternum)/ sternotomy(splitting of sternum)/ Intercostal incision should be taken Intercostal incision should be taken upup

factorsfactors

Shape and size of thoraxShape and size of thorax

Less capacious- more manipulation- Less capacious- more manipulation- sternotomysternotomy

More capacious – more manipulation- More capacious – more manipulation- intercostal is sufficient/ rib split/ rib intercostal is sufficient/ rib split/ rib resection resection

Techniques of thoracotomyTechniques of thoracotomy Intercostal Intercostal

incision:incision: • Cranial to the rib – Cranial to the rib –

intercostal vessels intercostal vessels are located caudallyare located caudally

• Extend the incision Extend the incision to desired lengthto desired length

• A self retaining rib A self retaining rib retractor is used for retractor is used for adequate exposure adequate exposure of the intrathoracic of the intrathoracic organs.organs.

TechniquesTechniques

• Serratus ventralis Serratus ventralis dorsally and dorsally and external abdominal external abdominal obliqus ventrally – obliqus ventrally – after incising the after incising the facia. Separate the facia. Separate the fibres to expose fibres to expose external intercostal external intercostal muscle.muscle.

Thoracotomy Thoracotomy

• During During expiratory expiratory pause the pause the intercostal m intercostal m and pleura – and pleura – incised- midway incised- midway between the between the ribsribs

Closure Closure Chromic Chromic

catgut/nylon – catgut/nylon – cranial and caudal cranial and caudal to incision- ribs to incision- ribs opposed with opposed with towel clamps towel clamps

Adv: simple&quickAdv: simple&quickDis: insufficient- Dis: insufficient-

heart & great heart & great vesselsvessels

- Rib fracture when - Rib fracture when held with rib held with rib retractorretractor

Rib resectionRib resection

Technique Technique St. incision- over St. incision- over

rib- reflect rib- reflect periosteum- lat. periosteum- lat. and medialand medial

Rib resectionRib resection

Periosteal Periosteal elevator- used elevator- used to separate the to separate the periosteum periosteum medially and medially and laterallylaterally

ClosureClosure Series of Series of

interrupted sutures interrupted sutures placed about 1 cm placed about 1 cm apart- lateral and apart- lateral and medial periosteal medial periosteal surfaces- cranial surfaces- cranial and caudal edge and caudal edge of incisionof incision

Adv: -good Adv: -good healinghealing

No gapNo gap

Disadv: lot of Disadv: lot of skillskill

Time consumingTime consuming Weak point- Weak point-

absence of ribabsence of rib

Split rib technique Split rib technique

Expose the ribExpose the rib St. longitudinal St. longitudinal

incision- center- incision- center- oscillating bone oscillating bone saw.saw.

Rib is sectioned- Rib is sectioned- transversely at transversely at either ends- of either ends- of primary incisionprimary incision

Split rib technique Split rib technique

Adv: maximum Adv: maximum exposure- without exposure- without involvement of involvement of rib retractorrib retractor

Closure is simple Closure is simple and quick- and quick- interrupted interrupted stainless steel stainless steel wire wire

Disadv:Disadv:Dent formation along marginsDent formation along margins

Sternum splitting incision (Median Sternum splitting incision (Median sternotomy)sternotomy)

Required for extensive manipulation-Required for extensive manipulation-cardiac defects and associated structurescardiac defects and associated structures

Animal on dorsal recumbencyAnimal on dorsal recumbency Skin incision- manubrium to xiphoidSkin incision- manubrium to xiphoid Sternum split- chisel/splitter/ electrical Sternum split- chisel/splitter/ electrical

sawsaw Don’t sever vessels – either side of Don’t sever vessels – either side of

midline midline

Closure Closure

Drill hole in sternabrae- suture with Drill hole in sternabrae- suture with monofilament nylonmonofilament nylon

Disadv:Disadv:

-Postoperative pain- discomfort- depth -Postoperative pain- discomfort- depth of respiration is affectedof respiration is affected

-Inaccurate apposition-Inaccurate apposition

-cardiac output is reduced due to -cardiac output is reduced due to increased CVPincreased CVP

Transabdominal Transabdominal

Other approaches like Other approaches like transabdominal to repair DH- transabdominal to repair DH- paracostal incisionparacostal incision

Heart worm disease:Heart worm disease:

-dirofilaria immitis-dirofilaria immitis

-Mosquitoes- vectors-Mosquitoes- vectors

-Dog- Primary reservoir-Dog- Primary reservoir

Heart worm disease:Heart worm disease:

--33rdrd stage larva- stage larva- infective- 2-3 infective- 2-3 weeks- mosquito weeks- mosquito mouth partsmouth parts

-Penetrate skin- -Penetrate skin- susceptible animal- susceptible animal- 3m- immature 3m- immature worms – reach worms – reach right side of heart- right side of heart- obtain full size- 15-obtain full size- 15-35 cm – 5-6months- 35 cm – 5-6months- live for live for >5years- >5years- non- infective non- infective microfilariaemicrofilariae

Heart worm disease:Heart worm disease:

-adult worm – pulmonary trunk-less no. -adult worm – pulmonary trunk-less no. in rt. Ventricle- but found in rt. Atrium in rt. Ventricle- but found in rt. Atrium and caudal vena cava in heavily and caudal vena cava in heavily infested animal infested animal

• -severity based on-severity based on

1.1.No. of worms and location No. of worms and location

2.2.Host immune responseHost immune response

3.3.Duration of infectionDuration of infection

Heart worm diseaseHeart worm diseasePathogenesis:Pathogenesis:Adult worm causes mechanical irritation Adult worm causes mechanical irritation

of intima and pulmonary arterial walls- of intima and pulmonary arterial walls- CHFCHF

Glomerulonephritis- immune complexesGlomerulonephritis- immune complexesPulmonary inflammation and edema Pulmonary inflammation and edema

Symptoms: coughing, exercise Symptoms: coughing, exercise intolerance, dyspnoea, cyanosis,wt.loss intolerance, dyspnoea, cyanosis,wt.loss despite good appetite hemoptysis, despite good appetite hemoptysis, syncope, epistaxis and ascites syncope, epistaxis and ascites

Diagnosis: Diagnosis: Antigen detection testAntigen detection testRight ventricular hypertrophy Right ventricular hypertrophy

patterns are seenpatterns are seenDetection of microfilariae in routine Detection of microfilariae in routine

blood examination- failure to detect- blood examination- failure to detect- doesnot rule out- presence of doesnot rule out- presence of microfilariae in heart- go for microfilariae in heart- go for concentration technique-count / ml concentration technique-count / ml of blood – 1000 MF=1 adult wormof blood – 1000 MF=1 adult worm

5-10% dogs – adult worm- no 5-10% dogs – adult worm- no detectable circulating MF- detectable circulating MF- eosinophillia is suggestiveeosinophillia is suggestive

Mild cases- RG appearance- normalMild cases- RG appearance- normalAngiocardiograms- linear filling Angiocardiograms- linear filling

defects – branches of pulmonary defects – branches of pulmonary arteryartery

Moderate and severe infections- RG- Moderate and severe infections- RG- dilatation of rt. Heart enlargement dilatation of rt. Heart enlargement and dilatation of pulmonary trunk and dilatation of pulmonary trunk and its arteriesand its arteries

Splitting of second heart sound- Splitting of second heart sound- suggestive of pulmonary suggestive of pulmonary hypertension- confirmed by direct hypertension- confirmed by direct cardiac catheterization –cardiac catheterization –measurement of rt.ventricular/ measurement of rt.ventricular/ pulmonary artery pressurepulmonary artery pressure

Treatment : Treatment :

1.Melarsomine dihydrochloride @ 2.5 1.Melarsomine dihydrochloride @ 2.5 mg/kg deep i.m.mg/kg deep i.m.

2.Ivermectin2.Ivermectin

33. Diethyl carbamazine @ 2.5 mg/ . Diethyl carbamazine @ 2.5 mg/ lb b.w.daily -10 days-1monthlb b.w.daily -10 days-1month

4. 6 weeks after-disappearance of 4. 6 weeks after-disappearance of clinical signs- dithiazanine iodide clinical signs- dithiazanine iodide (dizan)2-3mg/lb orally- kill the (dizan)2-3mg/lb orally- kill the microfilariae-7 daysmicrofilariae-7 days

5. Digoxin and diuretics are given 5. Digoxin and diuretics are given in CHFin CHF

3. 3. Restrict exercise- to reduce thrombosis Restrict exercise- to reduce thrombosis and endothelial damage and endothelial damage

4. Class IV dirofilariasis – Caval syndrome- 4. Class IV dirofilariasis – Caval syndrome- vena cavae syndrome -extreme vena cavae syndrome -extreme infestation- sudden onset- collapse with infestation- sudden onset- collapse with haemoglobinaria and respiratory distresshaemoglobinaria and respiratory distress

5. Surgical removal –questionable- 5. Surgical removal –questionable- suggested that – dogs- with less than 50 suggested that – dogs- with less than 50 worms- can tolerate chemotherapyworms- can tolerate chemotherapy

Puncture ventriculotomy:Puncture ventriculotomy:

Puncture ventriculotomy:Puncture ventriculotomy:

Apply a purse string Apply a purse string suture- pass an suture- pass an alligator foreceps – alligator foreceps – in rt. Ventricle- in rt. Ventricle- repeatedly repeatedly introduced and introduced and taken out while taken out while hemorrhage is hemorrhage is controlled by purse- controlled by purse- string suture string suture

Through median sternotomy-from Through median sternotomy-from right atrium and orifice of right atrium and orifice of tricuspid valve and caudal vena tricuspid valve and caudal vena cava to save the life of the dog.cava to save the life of the dog.

Rigid / flexible alligator Rigid / flexible alligator forceps/ intravascular retrieval forceps/ intravascular retrieval snare- via rt. Jugular vein with snare- via rt. Jugular vein with fluoroscopic guidance- pass fluoroscopic guidance- pass the instrument untill worms the instrument untill worms are no longer retrievedare no longer retrieved

Fluid therapy Fluid therapy