The document discusses the development, anatomy, openings, effect on respiration, and disorders of the diaphragm. It begins by describing the diaphragm's embryological development from four sources and its adult anatomy. It then discusses openings in the diaphragm, how its curved shape facilitates respiration, and disorders such as diaphragm fatigue, paralysis, hernias, and tumors. Radiographic appearance and management of various conditions are also outlined.

1. Development of Diaphragm and it’s
Anomalies
Dr Jay Bhanushali
MD Pulmonary Medicine (PGY1)
Sources:
- Crofton Respiratory Diseases
- Fishman textbook
- Oxford Respiratory Handbook
- Internet for Pictures

2. Diaphragm
• It is the main muscle of inspiration and during quite breathing accounts for 70-
80% of work of breathing.
Embryology
• The arched musculotendinous division between the thorax and the abdomen has its origin in
vertebral, costal and spinal attachments from which muscular fibres curve upwards and inwards
from the periphery to be inserted into the fibrous sheet called the central tendon. The diaphragm
derives developmentally from four sources

3. • 1 The septum transversum is first seen at the third week of development as a mass of
mesoderm situated cranial to the pericardial cavity. This structure contributes to the more ventral
portions, i.e. the sternal and costal parts.
• 2 The second source is derived from paired dorsolateral portions, the pleuroperitoneal
membranes, which fuse with the dorsal mesentery of the oesophagus and the dorsal portion of
the septum transversum to complete the partition between the thoracic and abdominal cavities
and form the primitive diaphragm at about the seventh week of development.
• 3 The median portion of the diaphragm is derived from an irregular medial dorsal
portion of primary oesophageal mesentery that fuses with the septum transversum and
pleuroperitoneal membranes. The curves of the diaphragm develop from the growth of
muscle fibres into the dorsal mesentery of the oesophagus.
• 4 During weeks 9–12 the fourth source is contributed by marginal ingrowths of the
body wall. These contributions from the thoracic myotomes also contain nerve fibres of
the lower six or seven intercostal nerves that distribute sensory fibres to the peripheral
parts of the diaphragm.

4. ANATOMY
- Composed of 2 distinct muscle components, Costal portion and Crural Portion both of which are
inserted into central tendon.
- Costal portion arises anteriorly from Xiphoid process and from upper margin of 6 lower ribs
- Thick Crural portion arises from arcuate ligaments and are inserted into upper three lumbar
bodies on right and upper two lumbar bodies on left side.

5. Costal Portion Crural Portion

7. Openings of Diaphragm
The diaphragm has 3 major openings and 5 minor openings.
• Major
- Vena caval trunk –level T8 vertebra in the central tendon. It allows passage of Inferior vena cava
and some branches of the right phrenic nerve.
- Esophageal hiatus - level T10 vertebra in a sling of muscle fibers derived from the right crus at the
left of the median plane. It allows passage of esophagus, the right and left vagus trunks, the
esophageal branches of the left gastric vessels, and the lymph vessels.
- Aortic hiatus - level T12 vertebra between the crura. It allows passage of aorta, thoracic duct, and
azygos vein.

8. • Minor
- The lesser aperture of right crus (permits lesser and greater splanchnic nerves)
- The lesser aperture of left crus (permits hemiazygous vein; and lesser and greater splanchnic
nerves)
- Foramen of Morgagni is found in the areolar tissue between the sternal and costal part of
diaphragm contains the superior epigastric branch of the internal thoracic artery and the lymphatics
of the abdominal wall.

9. Effect of Anatomy of Diaphragm on Respiration
• Diaphragm acts as a Piston , moves down with inspiration generating a more negative pleural
pressure incoordination with rib cage which moves upwards and outwards in a Bucket handle
manner. This increase in size of the thoracic cage and draws the air into the lungs.
• The diaphragmatic curvature is like that of a hemisphere, the curvature is directly proportional to
pressure that it can exert on the lungs. This is commonly seen in patients with COPD where
flattening of diaphragm due to emphysema or air trapping occurs which decreases the efficiency
of diaphragm to generate pressure.

10. Zone of Apposition
• Dome shape increases diaphragmatic fxn through zone of apposition, which is that part of
diaphragm that lies next to the inner aspect of ribcage so when diaphragm contracts and
descents, it increases intra abdominal pressure which is transmitted laterally to the rib cage
facilitating the expansion of lower rib cage
• During severe hyperinflation, as seen in chronic bronchitis and emphysema, contraction of the
diaphragm produces paradoxical inward movement of the lower rib cage or Hoover’s sign.

11. Radiological Appearance
• The right hemidiaphragm is usually higher than the left, the average level of the right dome being
at the anterior end of the sixth rib . The left hemidiaphragm lies half an interspace lower than the
right but appreciable unilateral elevation is not uncommon.
• The normally higher position of the right hemidiaphragm is usually attributed to the bulk of the
underlying liver, but the truth is that the left hemidiaphragm is depressed by the heart.
• Inversion of the diaphragm may occur on both the right and left sides most commonly as the
result of a massive pleural effusion or a tension pneumothorax. Difficult to demonstrate on a
plain chest radiograph,it is readily detected by ultrasound examination

12. Disorders of Diaphragm
• Diaphragm Fatigue
- Diaphragm and Myocardium are two muscles which never get rest throughout the life, the muscle
fibers comprising the diaphragm show a predominance of fiber types relatively resistant to
fatigue.
- 50% are type I or slow-twitch fibres, with a high oxidative and low glycolytic capacity
- 20% are type IIA or fast-twitch fibres, with both high oxidative andglycolytic capacities.
- The remaining 30% are type IIB or fast-twitch fibres, with low oxidative capacity and high
glycolytic activity, and are relatively susceptible to fatigue.

13. - During tidal breathing it operates at only about 10% of maximal. The more the respiratory force
exceeds 40%, the sooner the onset of fatigue.
- Diaphragmatic Electromyogram (EMG) using oesophageal or surface electrodes can be used to
detect Diaphragm Fatigue. A decrease in the ratio of high frequency to low-frequency power in
the EMG indicates fatigue.
- The technique has been used to detect fatigue early in patients being weaned from a ventilator
before the onset of clinical signs or carbon dioxide retention
- In adults with chronic obstructive pulmonary disease, the force reserve of the diaphragm has
been shown to be greatly reduced so that slight modifications of the pattern of breathing can
bring the diaphragm above the fatigue threshold.

14. - Clinical Features: Prominent rib cage movement in the supine position
indicates recruitment of other respiratory muscles and is a feature of
any disease or condition that leads to increase in the work of breathing.
More importantly, indrawing of the anterior abdominal wall during
inspiration is a significant indication of diaphragmatic fatigue or
paralysis.
Diaphragm Fatigue Tachypnea Respiratory Alterans Abdominal Paradox
• Finally, minute ventilation and respiratory rate fall with a resultant increase in Paco2 causing
Respiratory Acidosis
• Management: PPV to aid recovery of fatigued muscle, Aminophylline and has been shown to
increase the contractility of the diaphragm and to increase the pressure the diaphragm develops at a
constant frequency of phrenic nerve stimulation after fatigue

15. Diaphragm Paralysis
• Unilateral paralysis
- The most common cause of unilateral diaphragmatic paralysis is involvement of the phrenic nerve
by bronchogenic carcinoma.

16. • The ‘paralysis’ seen in association with supraphrenic or subphrenic infection may
be more apparent than real. In such subjects the diaphragm is often elevated and
immobile but recovery occurs as the infection clears. The same is true of the
elevation of the diaphragm associated with pulmonary embolism.
• Paralysis can also been seen on screening ,Such patients often gave a history of a
transient febrile illness, often associated with chest or shoulder pain; no other
cause was found and led to the problem being attributed to a ‘viral infection’.

17. • Clinical features
Paralysis of a hemidiaphragm alone does not usually give rise to symptoms, and where symptoms are present
they usually reflect the causative disease.
• Radiology
The affected diaphragm may or may not be elevated and shows paradoxical movement on respiration. This is
confirmed by fluoroscopy and may be accentuated by asking the patient to sniff, when the affected
hemidiaphragm rises while the unaffected hemidiaphragm moves downwards.
As discussed above, the diagnosis may not always be clear-cut even on screening, and ultrasonography has
proved a useful means of confirming the radiological suspicions
• Functional effects
Unilateral paralysis of the diaphragm reduces vital capacity by 20–25% in the upright posture, with a further 10–
20% reduction in the supine position. A 20% reduction in ventilation and perfusion to the lung on the affected
side has also been shown
• Management
In the large majority of cases, no treatment is necessary as the condition is symptomless. Occasionally, however,
the development of unilateral paralysis in someone with severe pulmonary impairment precipitates ventilator
failure. This has been described particularly after lung or cardiac surgery. In such circumstances recovery may
take place with time, such as when the paralysis occurred as a consequence of phrenic stretching or
hypothermia, and ventilatory support may be all that is necessary. If recovery does not occur, diaphragmatic
plication has proved to be an effective method of improving lung mechanics and the patient’s condition.

19. • Bilateral paralysis
-Paralysis or weakness of both hemidiaphragms
is uncommon and may be idiopathic in origin
following viral infections or blunt trauma to the
chest, or occur in association with rare
neuromuscular diseases as well as the
more common quadriplegia following trauma
- ORTHOPNEA IS NOT ALWAYS CARDIAC !!
- REM sleep and Diaphragm paralysis

20. • Clinical features
- Dyspnoea is a usual feature of bilateral diaphragmatic paralysis as is paradoxical inward movement of the abdominal
wall during inspiration, both particularly marked when the subject is in the supine position.
- Respiratory rate is usually increased with a reduction in tidal volume. Alveolar hypoventilation may occur during
sleep with resultant carbon dioxide retention leading to disturbed sleep, morning headaches and daytime fatigue with
hypersomnolence. There may be associated sleep apnoea.
• Radiology
- Both diaphragms may be elevated on the chest film, move sluggishly or paradoxically with inspiration, and
paradoxical movement should be (but is not always) seen during sniffing. That fluoroscopy can be misleading is due to
contraction of abdominal muscles during expiration, which pushes the diaphragm up passively and allows it to
descend passively and apparently normally during inspiration.
• Functional changes
- In complete bilateral diaphragmatic paralysis, Vital capacity is reduced in the upright position and further decreased
in the supine position. Similarly, Pao2 is reduced and falls further on lying down. Studies have shown that the
ventilation–perfusion ratio is the same in both lungs in a normal subject occupying the lateral decubitus position,
whereas it is substantially reduced in the dependent lung of patients with bilateral diaphragmatic paralysis, a
phenomenon that must contribute to the postural hypoxia via shunting of blood.
- The reduced compliance, tentatively ascribed to microatelectasis, may explain the rapid respiratory rate in these
patients.
• Management
- Although spontaneous improvement in diaphragm function has been seen, permanent paralysis is the rule.
- Some patients have benefited from the use of respirator at night to manage the associated respiratory failure, and it
would seem reasonable to apply nasal continuous positive airway pressure. Diaphragmatic Plication can be done.

22. • Hiccup
Sudden inspiratory spasm of the diaphragm with associated
closure of the glottis is a familiar and harmless symptom
in the normal subject, usually caused by gastric distension.
The usual cause is a reflex transmitted by vagal efferents,
via vagal and respiratory nuclei in the medulla,
and phrenic nerves to the diaphragm and by somatic nerves
to other respiratory muscles. Some times there may be underlying
gastrointestinal or neurological disease.

23. Treatment
• Treatment depends on the cause and severity. Everyone is familiar with the various empirical
homely remedies recommended for transient hiccup that act via vagal stimulation. More
persistent episodes may respond to stimulation of the pharynx with a catheter introduced
through the nose. This intervention is believed to initiate afferent vagal impulses that inhibit the
hiccup reflex. Prolonged or distressing hiccup requires investigation and removal of the cause.
• If this is not possible, it may respond to intravenous injection of 50mg chlorpromazine. Other
drugs used have included haloperidol, metoclopramide,baclofen, antiepileptics and
antidepressants. In exceptional cases, phrenic nerve block by local anaesthetic.

24. Subphrenic abscess
Clinical features
• Subphrenic abscess may occur spontaneously due to perforation of a viscus, amoebic liver abscess or
pancreatitis, or may follow abdominal surgery .Such abscesses may occur on either or both sides. Features
include local costal or subcostal pain and tenderness, unexplained fever, tachycardia and leucocytosis. If
antibiotics have been taken, the course may be more chronic with vague pains, chronic ill-health, unexplained
fever and anaemia. Its importance for the chest physician lies in the associated changes that may be seen on a
chest film or on fluoroscopy.
Radiology
• The most common finding is an elevated hemidiaphragm on the affected side with diminished movement of the
diaphragm, although it should be noted that a reduction in diaphragmatic activity is a normal finding after
upper abdominal surgery. Other frequent findings include blunting of the costophrenic angle, pleural effusion
and pulmonary infiltrates or atelectasis. Air fluid levels may be seen in the abscess cavity. Fixation of the
diaphragm and displacement of intra-abdominal viscera may be seen. Radiologically, it may be difficult to
differentiate between a subphrenic abscess and a subpulmonary collection of fluid. Multiplanar
ultrasonography, especially on the right side, and CT are useful means of making the diagnosis.
Treatment
• The management of subphrenic abscess is by surgical drainage and appropriate antibiotic therapy.
Percutaneous drainage under ultrasonic or fluoroscopic guidance

25. Malignant tumours
• Most malignant tumours are of mesenchymal origin and fibrosarcoma is the most common.
Clinical presentation
• Malignant diaphragmatic tumours may present with severe lower chest or hypochondrial pain that
radiates along intercostal nerves or to the shoulder . The pain is usually exacerbated by respiration
and may be associated with cough, dyspnoea or upper gastrointestinal symptoms. A haemorrhagic
pleural effusion may be present. A bulging of the hypochondrium that moves with respiration may
occur. A palpable mass is found in 10%.
• Hypertrophic pulmonary osteoarthropathy has been described in 10% of cases . The tumour may
metastasize or invade lung locally.
Diagnosis
• On radiography a mass is seen in the lower thorax that is difficult to separate from surrounding
structures. On fluoroscopy the mass is seen to move with the diaphragm.
• Pneumoperitoneum and pneumothorax may be needed to confirm that the mass arises from the
diaphragm. CT may be helpful in diagnosis and in particular may identify lipomas by their decreased
radiodensity.
Management
• If possible, surgical excision is indicated, with local repair using fascia lata or prosthetic material

26. Eventration of Diaphragm
• Eventration of the diaphragm is a condition in which all or part of the diaphragm
is largely composed of fibrous tissue with only a few or no interspersed muscle
fibres. It is usually congenital but may be acquired.
- Complete Eventration occurs on Left Side, Clinical features similar to Unilateral
Diaphragm paralysis
- Partial Eventration occurs on Right side, It is detected as an anteromedial bulge of
the diaphragm that moves paradoxically on respiration

28. Diaphragmatic Hernias

29. • Hiatus hernia
Herniation through the oesophageal hiatus is the most common type of diaphragmatic hernia. it
may present on a chest film as a retrocardiac opacity containing a fluid level. The uninitiated may
mistakenly diagnose a lung abscess or cyst.

30. Bochdalek hernia
• Bochdalek first described the embryology and the congenital absence of the
posterolateral part of the diaphragm in 1848. This is the most common site for congenital
diaphragmatic hernia and an incidence of 0.8 per 1000 live births has been reported. The
foramen of Bochdalek is normally closed by the eighth week of fetal life. Failure of the
pleuroperitoneal membrane to fuse with the septum transversum allows herniation of
the abdominal contents into the hemithorax; 75% occur on the left and there may be
other associated malformations, most commonly of the central nervous system . A 13th
pair of ribs is a reported association. The lung on the side of hernia is usually hypoplastic
with a reduction in the number of airway generations, although normal numbers of
alveoli are found in the segments that are present. The contralateral lung may also be
hypoplastic and this heralds a poor prognosis. In an extreme form, Bochdalek hernia
merges with congenital diaphragmatic agenesis, a condition more readily diagnosed by
antenatal ultrasound but which causes even more severe postnatal respiratory problems.

32. Clinical presentation
• The majority present soon after birth with respiratory distress. A scaphoid abdomen is usually noted.
Radiographically the diaphragm is not seen on the affected side and loops of intestine are found in
the thorax, with displacement of the mediastinum. There is a relative absence of gas in the abdomen.
Herniation on the right is less likely to be life-threatening, perhaps because the liver blocks the
defect. While a right-sided hernia may occasionally present with respiratory distress, asymptomatic
presentation with an intrathoracic mass of liver or bowel is more common.
Management and prognosis
• Management of patients in respiratory distress is with ventilatory support and correction of acidosis,
followed immediately by surgical repair, either by direct suture or with insertion of synthetic patches.
Contralateral pneumothorax may occur postoperatively due to the high inflation pressures required,
and prophylactic pleural intubation has been employed by some.
• Overall survival rates of 70–80% have been reported in neonates, with lower rates in those requiring
operation within the first 24 h of life. The majority of deaths are due to the presence of severely
hypoplastic lungs that are incapable of sustaining life. In those with unilateral hypoplasia,
compensatory emphysema may develop in the other lung.
Morgagni Hernia - more common in adult hood

33. Traumatic Hernia

34. QUIZ