Diseases of Diaphragm

Question 1

Embroyolgic development of diaphragm

Answer 1

• 7-10th week of gestation
• Components:
  
  • Septum transversum
  • L/R pleuroperitoneal membranes
  • Dorsal mesentary of esophagus

Question 2

Congenital diaphragmatic hernia (CHD) frequency

Answer 2

Rare, 1 in every 2000-3000 live births

Question 3

Decreased survival with CHD due to:

Answer 3

• Assocaited congenital abnormalities
• Prematurity
• Low birth weight

Question 4

MC timing of detection of CHD

Answer 4

In utero (by prenatal ultrasound)

Question 5

Bochdalek hernia

Answer 5

posterolateral CHD

• MC CHD (90%)
• Males (3:2)
• Left-sided (80-90%)
• Associated defects:
  
  • Cardiac
  • Renal
  • Neural
  • GI

Question 6

MC CHD

Answer 6

Bochdalek hernia (90% of all CHD)

• Left sided
• Males (3:2)
• Associated defects:
  
  • Cardiac
  • Renal
  • Neural
  • GI

Question 7

Major co-morbid state assocaited with CHD

Answer 7

Pulmonary hypoplasia and pulmonary HTN

• Due to early herniation and entrapment of abdominal orangs in chest with lung compression (directly on ipsilateral side, indirectly due to compression on contralateral side)
• Respiratory impairment
  
  • May require ECMO
• Feeding problems
• Growth retardation

Question 8

CXR finding with CHD

Answer 8

Intestinal loops or tip of orogastric tube in chest

Question 9

Moratality rate associated with Bochdalek hernia

Answer 9

~ 50%

Question 10

Surgical repair technique for Bochdalek hernia

Answer 10

• Approach from abdomen
• Reduction of hernia contents
• Resection of hernia sac (present in 20% of cases)
• Closure or reconstruction (non-absorbable mesh) of defect
• Resection of extralobar sequestration if present at time of hernia repair if patient stable

Question 11

Morgagni hernia

Answer 11

Anterior defect

• Between xiphoid and costochondral attachments of diaphragm
• < 2% of all CHD
• Asymptomatic (incidental diagnosis)
• Surgical correction advised
  
  • Risk of incarceration or strangulation of abdominal organs
  • Outcomes excellent
  • Abominal approach with primary or mesh closure

Question 12

MCC of acquired diaphragmatic hernias

Answer 12

Trauma

• Diphragm rupture occurs in ~ 3-5% of patients admitted for trauma
• Associated with severe injuries, thus has high mortality
• Mostly due to blunt trauma

Question 13

TOC for traumatic acquired diphragmatic hernia

Answer 13

Early surgical repair

(avoid compications of strangulation and obsruction)

• Prognosis highly influenced by severity of associated abdominal and overall injury scores

Question 14

Etilogy of diaphragmatic eventration

Answer 14

Failure of myoblast migration to muscular portion of diaphragm, impairing ability to contract

Question 15

Associated congenital defects with diaphragmatic eventration

Answer 15

• Spine and skelatal defects
• Hypoplastic lungs
• Pulmonary sequestration
• Transposition of viscera

Question 16

Etiology of diaphragmatic paresis/paralysis

Answer 16

Acquired condition due to interruption of phrenic nerve conduction to diaphragm.

Question 17

MCC of diaphragmatic paresis or paralysis

Answer 17

Phrenic nerve injury during surgery (chest or neck)

Phrenic nerve invasion by neoplasm

Question 18

Less common causes of diaphragmatic paralysis

Answer 18

• Idiopathic:
  
  • central line placement
  • spinal cord injury
  • bracheal plexus neuropathy (Parsonage-Turner syndrome)
• Neurologic disease:
  
  • myelitis
  • encephalitis
  • poliomyelitis
  • herpes zoster

Question 19

MC symptoms of diaphragmatic eventration and paralysis

Answer 19

Dyspnea (most patients asymptomatic)

• Due to ventiation impairment and V/Q mismatch in basal portions of lungs
• Orthopnea more typical of paralyssi due to shifting of abdominal organs towards the chest and reduced lung volumes

Question 20

Diagnostic study to evaluate diaphragmatic paralysis

Answer 20

Sniff test

• Paradoxial upward motion of the paralyzed diaphragm > 2 cm during sniffing under fluoroscopy
• US and MRI alternative modalities

Question 21

Definitive diagnostic study to evaluate diaphragm paralysis

Answer 21

EMG (w/ phrenic nerve stimuation)

Question 22

Surgical TOC for diaphragmatic eventration and paralysis

Answer 22

Diaphragm plication

• Goal: reduce paradoxical excursion of diaphragm during inspiration (increasing end-inspiratory and end-expiratory lung volumes)
• Laparotomy or Thoracotomy
• Technique: imbricating stitches in the central tendon of the diaphragm

Question 23

Acceptable period of observation for suspected diaphrgam paresis

Answer 23

1-2 years (unless symptomatic)

Question 24

Indications for diaphragmatic pacing

Answer 24

• Rarely used technique
• Indicaitons:
  
  • Central alveolar hypoventilation (Ondine’s curse)
  • High cervical cord injury (above C3)
  • ALS (to delay need for mechanical ventilation)

Question 25

Diaphragm pacing technique

Answer 25

Stimulation of phrenic nerve (in neck or chest) by contact with electrode

Question 26

Tumors of the diaphragm

Answer 26

* Primary tumors very rare * MC tumors: **_congenital cysts_** * Bronchogenic * Mesothelial * Teratoid * Benign tumors: * fibromas * angiomas * chondroma * hemangioma * leiomyoma * hemartoma * desmoid * Malignant tumors: very rare * rhabdomyosarcoma * leiomyosarcoma

Question 27

Neurogenic diaphragm tumors may be associated with \_

Answer 27

Hypertrophic pulmonary osteoarthropathy

Question 28

TOC for diaphragm tumors

Answer 28

Surgical resection with diaphragm repair/reconstruction (prosthetic mesh)

Question 29

Variety of clinical conditions characteried by passage of fluids, gases, tissues, secretons or intestinal content through diaphragmatic pores from abdomen to chest

Answer 29

Porous diaphragmatic syndrome

Question 30

Spontaneous pneumothorax occuring in women in relation to menses

Answer 30

Catamenial pneumothorax * Considered part of porous diaphragmatic syndromes * diaphragmatic defects associatedin 60% of cases * pores allow passage of air from abdoment to chest causing pneumothorax * Visceral pleura _endometrial implants_ and pelvic endometriosis: 20-70% of cases

Question 31

Surgical treatment for catamenial pneumothorax

Answer 31

* Repair of diaphragmatic defect (if present) * Can use mesh to cover the diaphragm * Resection of endometrial implant * Pleurodesis and/or pleurectomy * Hormonal therapy

Question 32

Agenesis of diaphragm

Answer 32

* Extremely rare * Usually diagnosed early after birth * High mortality rate * Familial inheritance with multifactorial genetic etiology

Question 33

Cantrell's Pentology

Answer 33

* Anterior diaphragmatic defect * Supraumbilical abdominal wall defect (omphalocele) * Diaphragmatic pericardial defect * Congenital intracardiac defect * VSD or LV diverticulum * Lower sternal defect * Defects cause _omphalocele_ and _ectopic cordis_

Question 34

Etiology of Cantrell's Pentology

Answer 34

Failure of lateral mesoderm during 3rd week of gestation

Question 35

Treatment for Cantrell's Pentology

Answer 35

Correction of: * Hernia defects (ventral and diaphragmatic) * Sternal defects * Intracardiac defects (VSD or LV diverticulum)