Diaphragmatic hernia

The material has been collected from the standard text books and published papers

1. Diaphragmatic hernia

2. Hernia Hernia is defined as the protrusion of the content of a body cavity through a normal and abnormal opening in the wall of that cavity either to lie beneath the intact skin or to occupy another adjacent body cavity.

3. Constituents of hernia A hernia consists of- Ring Sac C ontent

4. Ring may be formed due to R upture in the abdominal wall(ventral hernia) Rupture of limiting wall(diaphragmatic hernia) Due to persistent prenatal opening(umbilical hernia) Sac The hernial sac made of tissue that e nclose the hernial content Wall of sac usually contains skin, muscular fibre, fibrous tissue and parietal peritoneum Absent in diaphragmatic hernia The content of hernia include Organs (a loop of bowel) Tissue ( omentum )

5. On the basis of location External hernia- It consist of hernial ring, sac and contents Internal hernias-which lacks the hernial sac e.g. diaphragmatic hernia

6. Diaphragmatic Hernia Passage of abdominal viscera into thoracic cavity through a congenital or acquired opening in the diaphragm Most commonly reticulum herniates but other organs like omasum , abomasum, loops of intestine, liver, spleen may get involved .

7. incidences Most frequently seen in she buffalo- right side with one or multiple rings In buffaloes – DH occurs in right hemidiaphragm (90%) and rarely in the left (7%)or in the center (3%) In dogs and cats – equal on both sides

8. Etiology Weakening of diaphragm TRP/ FB Increased intraabdominal pressure – Advanced pregnancy Tympany Straining during parturition Violent fall Musculotendineous junction (less tone and thickness) In dogs and cats DH is caused by trauma, particularly automobile accidents DH may also occur in animal with connective tissue disorder

9. Types of Hernia Congenital hernia Pleuroperitoneal hernia Serous lining of pleura and peritoneum---separated by transverse septum—when weaken/ trauma in fetuses—cause rupture of these and thus hernia Peritoniopericardial hernia (congenital hole in diaphragm and pericardium, also pericardium is fused with dia.---entry of abdominal parts in that hole) Acquired-secondary to trauma. Trauma is the most common cause of DH in dogs and cats 77-85% cases from traumatic origin 5-10% cases from congenital origin Rest from unknown causes

10. Weakest Spots of Rupture Common site for rupture – 12-15 cm ventral to hiatus oesophagi 12 cm ventral to foramen vena cavae close to central musculotendinous junction Other sites Completely in the tendinous part or in the ventral musculature

11. Clinical sign’s Recurrent tympany Reduced reticular motility Reduced milk yield Scant defecation or diarrhoea with foul smell Slight degree of melena In advanced cases regurgitation leads to aspiration pneumonia Brisket oedema Jugular pulsation may or may not be present (The herniated reticulum may lie between the heart and diaphragm) Pasty faeces

12. A-arching of back, B-abducted forelimbs, C-dullness, D-brisket oedema

13. Abduction of limbs may be observed In rare cases chronic cough In untreated cases inanition , progressive emaciation, weakness and dehydration and ultimately death dogs and cats- Severe dyspnoea Depend on the structures herniated and size of tear Signs of obstruction, gastric dilatation, liver problems (vomiting, anorexia, jaundice, exercise intolerance) Signs of pneumothorax and lung contusion

14. Pathology The herniated reticulum lies in the caudal mediastinum 5-10 cm caudal to xiphisternum between the heart and diaphragm Fibrous bands frequently observed Diaphragmatic abscess may be present Dogs and cats – Pleuroperitoneal hernia- Incomplete development of pleuroperitoneal canal during diaphragmatic development

15. Congenital pleuroperitoneal hernias seldom diagnosed in small animals because many affected animal die at birth or shortly thereafter. Located in dorsolatral part of diaphragm Intermediate part of left lumbar muscle of the crus may be absent 1-2 cm in diameter Animal die because of respiratory insufficiency Peritoniopericardial hernia – faulty development or prenatal injury of the septum transversum - teratogen, genetic defect, or prenatal injury In this type of hernia organ herniated into pericardial sac

16. Organs like liver, falciform ligament, omentum , spleen, Small intestine and very rarely stomach This leads to strangulation of viscera which leads to less venous drainage from liver Effusions Herniated stomach produce cardiac temponade Traumatic diaphragmatic hernia – costal muscle are more often ruptured then the central tendons Parietal surface of liver covers most of diaphragm so liver is the organ most herniated

17. Incarceration, strangulation and obstruction are the chief effect on the abdominal viscera Flow obstruction of stomach leads to tympany In liver hepatic venous stasis may develop Hydrothorax and ascites may develops Pleural effusion may be seen

18. Diagnosis History- history of recent parturition Clinical signs Auscultation – I ntestinal sound on thoracic cage is heard Muffled heart sound Reticular sound cranial to 6 th rib

19. Radiography Position- Right Lateral and supine and lateral projections are taken Plain and contrast radiography can be performed Plain radiograph – An empty reticulum appears as a air filled viscus in the thoracic cavity Contrast radiograph- for confirm diagnosis Barium meal is used as contrast material

20. ULTRASONOGRAPHY

21. Exploratory laparotomy can also be performed where x-ray facility of large animal is not available

22. TREATMENT Laparorumenotomy Evacuate rumen 3/4 th or full Replace the healthy liquor Off feed the animal for 48 hours after evacuation and fluid therapy should be maintained GA- Induced with thiopental sodium 5% solution @ 5 mg/kg b.wt Maintained with isoflurane IPPV after intubation

23. Sedation ( xylazine @0.1 mg/kg ) i/v L ocal anaesthesia (lignocaine HCl 2%) was given at surgical site Approaches Transabdominal Transthoracic

24. Transabdominal Right cranial quadrent /right hypochondric area is prepared for the surgery 25-30 cm incision : 5 cm caudal to xiphoid cartilage :parallel to costal arch Severe the adhesions of diaphragm and reticulum Abdominal and thoracic organs

25. Close the ring with continuous suture or lock stitch or vest over Pants by using non absorbable suture materials(no 2) Close the abdominal incision using absorbable suture material w ith simple continuous suture in muscle and peritoneum Close the skin incision

26. Transthorecic Right or left lateral thoracotomy Midway on 7 th rib to downward toward costochondral junction Overlaying thoracic muscles incised

27. Rib resesection – Periosteum incised by scalpel Periosteum retracted cranially and caudally with periosteal elevator

28. Gigli wire is used Transect Rib wide and thin Disarticulate rib at costochondral Jn.

29. Incise pleura-herniated reticulum seen Separate the adhesions with lungs and pleura Push in abdominal cavity

30. Close the diaphragmatic rent Resect indurated diaphragmatic tissue along with reticulum if adhesions are extensive If small gap then close by few suture If large gap then use grafts Similarly, adhesions with pulmonary lobe requires partial/complete lobectomy It may recur, if animal is pregnant at the time of surgery after parturition so postpone surgery till parturition

31. Dogs and Cat Medicinal treatment If the animal is dyspnoeic, oxygen should be provided by face mask, nasal insufflation, or an oxygen cage. Positioning the animal in sternal recumbency with the forelimb elevated may help in ventilation. If moderate to severe pleural effusion is present, thoraco-centesis Should be performed. Fluid therapy and antibiotics should be given if animal in the shock.

32. Timing of surgical repair Depends upon- The extent of initial cardiopulmonary dysfunction. The presence and absence of organ entrapment The degree of compromised pulmonary function Whether or not animals condition is improving , stable, or detoriarating . Diaphragmatic herniorrhaphy may require immediate surgery if aggressive supportive care can not stabilize respiratory function

33. Acute dilatation of a herniated stomach or strangulated bowel are examples of situations where emergency surgery may be indicated.

34. Preoperative Management Prophylactic antibiotics in animals with hepatic herniation. Massive release of toxins into the circulation may occur with hepatic strangulation or vascular compromise. premedication such patients with steroids may be beneficial. An ECG should be performed on all trauma patients before surgery.

35. Anesthesia Supplementing oxygen before induction improves myocardial oxygenation Drugs with minimal respiratory depressant effect. Injectable anaesthetics allowing rapid intubation are preferred. Inhalation anaesthetics should be used for maintenance of anaesthesia

36. Intermittent positive pressure ventilation should be performed and high inspiratory pressure should be avoided to help to prevent re expansion pulmonary oedema. Methyleprednisolone may be beneficial to prevent reeexpansion pulmonary oedema

37. Surgical A pproches M idline abdominal celiotomy is the easiest and most versatile approach Position the animal head towards the top of the table and tilting the table at a 30-40 ̊ angle will facilitate gravitation of abdominal viscera out of the thorax. Rarely is it necessary to extend the incision into the thorax via a median sternotomy .

38. Surgical Procedure Incision is made from xiphoid to point caudal to umbilicus. Open the peritoneal cavity, diaphragm is exposed now. Herniated content are replaced in their proper position and inspected for damage. If adhesions exist, they should be broken down using blunt dissection Using large sponges or laparotomy pads moistened with warm saline, the liver and bowel are retracted caudally.

39. All thoracic fluids should be aspirated The lung should be expanded to remove atelectasis and to inspect and persistent tear of collapse Edges of the tear should be debrided Recommended to suture the hernia from dorsal to ventral Hernia is closed with single layer, simple continuous pattern using synthetic absorbable suture material ( dexon is preferred, vicryl ) (3-0 to 1 )or non absorbable suture material .

40. If the diaphragm is avulsed from the ribs, incorporate a rib in the continuous suture for added strength

41. Median sternotomy - S ternotomy of caudal 2-3 sternebrae Rarely performed alone May be necessary in irreducible hernia Lateral thoracotomy- 9 th intercostal approach It allows inspection of convex part of diaphragm Transsternal thoracotomy- 7 th -8 th rib provide good exposure

42. Postoperative Management Antibiotics should be given for 5-7 days Fluid therapy should be given Analgesics should be given

43. Horses and Camels Causes of diaphragmatic hernia in horses Congenital T his may occur as a secondary condition to pulmonary hypoplasia. In incomplete hernias, such as diaphragmatic diverticulum, the abdominal contents enter the thorax, however, are covered by a thin membrane Acquired diaphragmatic hernia (ADH ) trauma Internal pressure like in advanced pregnancy

44. Clinical signs The most common symptom seen is signs of severe abdominal pain. Respiratory distress such as difficulty with breathing Rapid breathing Blue mucous membranes Signs due to complications such as pneumothorax (fluid in the thoracic cavity) Muffled heart and lung sounds

45. Diagnosis History Clinical signs Ultrasonography Radiography

46. Treatment This will be done under general anesthesia Xylazine – 1.1 mg/kg b. wt. i/v Diazepam – 0.05 mg /kg b.wt i/v Ketamine -2.2 mg / kg Anesthesia maintained with either isoflurane or sevoflurane via an endotracheal tube

47. Ventral abdominal midline approach C arefully reduce the incarcerated intestine into the abdominal cavity. Repair the herniated rent with the non absorbable suture (no 2) If rent is large then polypropylene mash is used to close it Close the incision

48. Rib resection approach

49. https://www.youtube.com/watch?v=zRfc6mTZJko Thank you