Diaphragm😊

Diaphragm

General

• Muscle of respiration
• The phrenic nerve affected → paradoxical respiration

• Separates thoracic and abdominal cavities

Development of Diaphragm

Innervation

• Phrenic nerve (C3, C4, C5): Mixed nerve
• Motor: Ipsilateral hemidiaphragm
• Sensory:
• Central diaphragm
• Peritoneum
• Central peritoneum
• Peritoneum on under surface
• Parietal Pericardium
• Pleura
• Mediastinal pleura
• Diaphragmatic pleura
• Referred pain:
• Shoulder tip via C5 (supraclavicular nerve)
• Right crus of diaphragm
• Only part supplied by both phrenic nerve

• Subcostal nerve:
• Peritoneum below diaphragm

• T6–T12 intercostal nerves
• Peripheral part

Blood Supply

• Main: Inferior phrenic arteries (from abdominal aorta)

• Additional: Pericardiophrenic artery

Functions

• Major inspiratory muscle

• Contraction: Expands thoracic cavity → Inspiration (active)

• Relaxation: Thoracic cavity reduces → Expiration (passive)

• Keeps thoracic duct, IVC open during inhalation

Openings of Diaphragm

Major Openings

Note: Aortic opening lies behind posterior margin, not a true opening

• Clinical: Aortic aneurysm at aortic hiatus can compress:
• Azygos vein
• Thoracic duct

Minor Openings

• Space of Larry (Costo-Xiphoid gap):
• (Between sternum § costal origin of diaphragm)
• Superior epigastric artery (branch of ITA)
• Mnemonic: LarEEEE → Epigastric

• Medial arcuate ligament:
• Thickening of upper margin of psoas fascia
• Sympathetic chain

• Lateral arcuate ligament:
• Thickening of upper margin of fascia over quadratus lumborum.
• T12 subcostal vessels & nerve

• Structures piercing crus
• Splanchnic nerve
• Hemiazygous vein usually enters thorax by piercing (L) crux

• The azygous vein may sometimes pass through the
• right crus

• (L) phrenic nerve
• pierces muscle anterior to central tendon

• Splanchnic nerves pass through the
• R and L crus of the diaphragm

Clinical Significance

• Phrenic nerve injury:
• Causes diaphragmatic paralysis
• Loss of pericardial and mediastinal pleura sensation
• Inspiratory difficulty
• Bilateral lesion → Need for mechanical ventilation
• Paradoxical respiration:
• Chest moves inward during inspiration

Congenital Diaphragmatic Hernia

• Absence of the pleuroperitoneal membrane.

• Leads to persistence of the pleuroperitoneal canal (Bochdalek foramen)

• M/c → Left > right

• Clinical Features:
• Scaphoid abdomen with respiratory distress.

Type	Morgagni Hernia	Bochodalek Hernia
Location	Right anteromedial/Retrosternal	Most common Left posterolateral
Defect Development	Central tendon of diaphragm D/t enlarged Space of Larry (Contain Superior Epigastric Artery) (space between sternum § costal origins of diaphragm.	Pleuroperitoneal canal/membrane
Herniating Structures	Transverse colon	Stomach, spleen, transverse colon
Mnemonic	ㅤ	Boche → CPM → Left

Diagnosis:

• Prenatal detection can be done.
• scaphoid abdomen

• Bowel gas shadows are present in the thorax

• Diaphragmatic outline is not clearly visible

• Heart shadow is not visualized due to mediastinal shift

Complications

• 1st most common cause of death:
• Pulmonary hypoplasia
  (due to reduced space for lung development)
• scaphoid abdomen
• respiratory distress and
• features of mediastinal shift

• 2nd most common cause of death:
• Pulmonary hypertension (PPHN).
• Managed with inhaled nitrates.

Management (Mx)

• Best ventilation: IPPV (Intermittent Positive Pressure Ventilation).

• ExUtero Intrapartum Treatment Procedure (EXIT)
• Airway is ensured before the infant is separated from Placenta
• Also done in Laryngeal atresia, Stenosis, Teratoma, Hygroma, Oral tumors

• Resuscitation: 
• with Bag and mask ventilation C/I

• If there is severe respiratory distress
• Intubation and bag and tube ventilation needs to be done

• Surgical Management (Sx):
• Circular incision around the diaphragm.
• Bowel reduced back into abdominal cavity.
• Mesh placed to reinforce the repair.

Eventration of diaphragm

• Similar to CDH but not a true hernia.

• Thinning of pleuroperitoneal membrane



 

Diaphragmatic Injuries

• Most Common: Left side >> Right (protected by liver)

• Clinical Features:
• Breathlessness
• Bowel sounds present in thoracic cavity
• Coiling of Ryle’s tube in thoracic cavity

• BERGVIST TRIAD
• Diaphragm injury
• Rib #
• Spine/Pelvic #

• IOC: Diagnostic Lap > CECT

• Management:
• ICD is contraindicated → Risk of bowel injury
• Laparotomy:
• Reduce bowel contents,
• Repair diaphragm (Prolene sutures)