Comprehensive surgical management of the paralyzed diaphragm

Comprehensive Surgical Comprehensive Surgical Management of the Paralyzed Management of the Paralyzed

DiaphragmDiaphragm

Matthew R. Kaufman, MD, FACSPlastic & Reconstructive Surgery

The Center for Treatment of Paralysis and Reconstructive

Nerve Surgery

Center for Treatment of Paralysis and Reconstructive Nerve Surgery

Surgical Management of the Paralyzed Diaphragm

• No financial disclosures


Phrenic NerveAnatomy

• Originates from C3-C5– Primarily C4

• Motor innervation to diaphragm

• Sensory fibers– Pleura – Pericardium– Abdominal

components


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Phrenic Nerve AnatomyAccessory Phrenic Nerve

• Occurs in 15-25% of people• A branch of C5 which would otherwise

pass to subclavius• Begins lateral to the phrenic nerve in the

neck • Obliquely traverses scalenus anterior• Joins the phrenic nerve at the root of the

neck• Also supplies diaphragm with efferent

fibers


Phrenic Nerve AnatomyAccessory Phrenic Nerve

Accessory Phrenic Nerve


Respiratory Physiology•Volitional (day time)

breathing controlled by respiratory control center

•Night breathing regulated by CO2 levels measured in brain

•Signals go down nerves in the neck, chest to diaphragm

•Phrenic nerve branches out into the diaphragm muscles

•The diaphragm muscles contract drawing in air


Diaphragm ParalysisEtiology

• Peripheral (Phrenic Nerve Injury)

– Iatrogenic• Surgery• Anesthetic Blocks• Chiropractic

– Trauma• Blunt• Penetrating

– Neuropathy / Neuritis

– Viral

• Central – Spinal Cord Injury– Cord Compression– Central

Hypoventilation Syndrome

• Ondine’s Curse

– Tumors


Diaphragm ParalysisPhrenic Nerve Injury

• Demographics– Usually unilateral– Rarely ventilator or oxygen dependent– Severe limitations in physical functioning– Association with sleep-disordered breathing– PFTs often normal or near-normal– Abnormal Sniff Test– Told by MD: “…just learn to live with it…”– Some are offered diaphragm plication


Phrenic Nerve InjuryEtiology

• Iatrogenic– Neck

• Interscalene Block• Cervical Epidural• Neck Dissection• Carotid Bypass• Chiropractic

Manipulation


Phrenic Nerve InjuryEtiology

• Iatrogenic – Mediastinal / Chest

• Carotid-Subclavian Bypass• Aortic Surgery• Thymectomy• Coronary Bypass• Thoracic Outlet Release


Phrenic Nerve InjuryMediastinal Surgery

• Thymectomy


Ventilator DependencyDiaphragm Paralysis

• Spinal Cord Injury– Usually C3 or higher (rarely C4-C5)– Ventilator Dependent– Tracheostomy Dependent

• Central Hypoventilation Syndrome– Ondine’s curse– Oxygen dependent– Ventilator/ Bi-Pap at night



• Spinal Cord Injury (SCI)– 11,000 new cases/year– >50% cervical level– Interruption of descending bulbospinal respiratory

pathways• Respiratory paresis or paralysis

– Primary cause of death after SCI, regardless of level – Respiratory *

*National Spinal Cord Injury Statistical Center, 2006


Ventilator DependencySpinal Cord Injury

• Effect of SCI on Respiration– Paralysis of respiratory muscles

• Diaphragm– Major inspiratory muscle– Innervated by phrenic

motoneurons C3-5

• Accessory respiratory muscles– Intercostals– Thoracic/Abdominal muscles

– Reduction in tidal volume– Blunted response to hypercapnia



SCI is among the most expensive condition among all causes for hospitalization.

Severity of Injury

Avg Yearly Expenses 1st Yr

Avg. Yearly ExpensesSubsequent

Estimated Lifetime Costs 25 yrs old

Estimated Lifetime Cost 50 yrs old

High (C1-C4) Tetraplegia $775,567 $138,923 $3,059,184 $1,800,958

Low (C5-C8) Tetraplegia $500,829 $56,905 $1,729,754 $1,095,411

Yet a 20 year old tetraplegic on MV has their life expectancy drop by ~18 yrs vs. non-depenadent1

National Spinal Cord Injury Statistical Center, Birmingham, Alabama January 2008Treatment of Pulmonary Disease Following Cervical Spinal Cord Injury, Evidence

Report/Technology Assessment, Number 27


Ventilator DependencyImpact On the Diaphragm

• Compared 14 brain dead donors on PPV to 8 controls

• 18 hours of PPV causes marked atrophy

• 57% decrease Type 1 slow twitch

• Active muscles atrophy faster

• Inactivity leads to oxidative stress

• Increased proteolysis



• A CNS problem with no clinical CNS solution

• Peripheral nerve solution(s)– Electrical stimulation– Nerve transfer– Electrical stimulation +

Nerve transfer



• Above level of injury– Functioning nerves

• At level of injury– Inability to propagate a nerve stimulus– Cannot respond to externally applied

electrical stimulus• Below level of injury

– Inability to propagate a nerve stimulus– May respond to externally applied

electrical stimulus


Ventilator DependencyCongenital Central Hypoventilation

Syndrome(Ondine’s Curse)• Demographics

• Rare disorder (1 in 200,000/U.S.)• No known cure

• Pathophysiology• Problem integrating chemoreceptor

input to central ventilatory controllers• Genetic mutation identified• Association with Hirschprung’s disease

• Characteristics• Breathe reasonably well while awake• Apneic during sleep - require ventilatory

support • A third require ventilatory support

24h/day


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Ventilator DependencyDiaphragm Pacing

• Purpose– Electrically pulse phrenic nerves (or nerve/muscle

interface), causing diaphragmatic excursion• Goal

– Reduce or eliminate ventilator dependency • Experience

– Avery• 25 years • 82% rate of permanent diaphragmatically-paced

breathing– Synapse

• Recently FDA approved• SCI trial (100% paced with intact nerves)



• Criteria – Chronic respiratory failure– Central neurological disorder or High

Spinal injury – Preserved phrenic nerve integrity– Acceptable pulmonary function– Normal level of consciousness– Appropriate care and support



• Procedure (Avery)– Small incisions– Intraoperative

neurophysiological testing– Implantation of electrodes

and receiver• Diaphragm conditioning• Long-term pacing

Case Western University


Diaphragm Pacemaker


Diaphragm Pacemaker

Avery Biolabs


NeuRx Diaphragm Pacing System™

• External Pulse Generator “Paces” Diaphragm

• Home based conditioning replaces Mechanical Ventilation


Diaphragm Pacemaker

• NeuRx Diaphragm Pacing Device (Synapse) – Laparoscopic placement– Electrodes (4) applied to nerve/muscle junction– Avoid nerve manipulation– Application for neurodegnerative conditions (ALS)



• Benefits– Lower rate of pulmonary complications– Improved venous return– Normal breathing and speech– Ease of eating and drinking– Increased patient mobility– Cost-effective

• Risks– Phrenic nerve injury– Wire displacement



• Limitations– Lack of voluntary control of breathing– Only inspiration is triggered, thus cough may be weak– Inability to time spontaneous inspiratory efforts– No benefit for unilateral injuries*– C3-5 injuries may not be candidates due to Wallerian

degeneration*


Diaphragm ParalysisNeurotization

• Nerve transfers (Neurotization)– Definition

• Transferring intact, functioning nerves to phrenic nerves in order to restore function to the diaphragm

– Advantages• Tremendous experience with this technique for brachial

plexus, extremities, facial nerve

• A reconstructive option for patients not candidates for pacing

• Or, perhaps to enhance results of pacing



• Krieger & Krieger (2000)– 6 patients– C3-5 injuries– Intercostal to phrenic + pacemaker


Diaphragm ParalysisSpinal Accessory Neurotization

• Potential Advantages– Tremendous experience in brachial plexus reconstruction– Higher axonal density in the donor nerve

• Intercostal: 1093• Spinal Accessory : 2145• [Phrenic: 800]

– Functionally linked to phrenic – Performed through neck incisions – Lower morbidity (no thoracotomy)

• Disadvantage• Longer distance for axonal regrowth


Diaphragm ParalysisSpinal Accessory Nerve

Brainstem

Spinal Cord

Dual Origins


Diaphragm Re-innervation Spinal Accessory Neurotization

• Goal– To provide ventilator-dependent patients the ability for

voluntary respiratory control +/- a diaphragm pacemaker

• Techniques– Transfer a branch of functioning Cr XI to

nonfunctioning phrenic bilaterally

• Status– Ongoing protocol – IRB Approval


Diaphragm Paralysis

Spinal Accessory Neurotization

• Phrenic Nerve

• Spinal Accessory Nerve


Diaphragm Paralysis

Spinal Accessory Neurotization

• Anticipated outcomes– Spontaneous diaphragm function– Improve pacemaker results– Low morbidity– Another treatment for diaphragm paralysis– REDUCED COST

• Medicare/Medicaid reimbursed?


Ventilator DependencySummary of Potential Treatment

Options• Diaphragm Pacemaker

– C-spine (C3 or higher) or Central abnormality

• Neurotization– C3 or higher, OR Central– Functioning donors– Poor pacemaker candidate

• Neurotization +/- Pacemaker– C3-5– Extensive direct injury to nerve


Unilateral Diaphragm Paralysis

Phrenic Nerve Injury


Phrenic Nerve Grafting

Nerve Interposition Graftor Nerve “Bypass”

Neck

Chest


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Phrenic Nerve Grafting


Diaphragm Re-Innervation

“Re-Innervation of the Paralyzed Diaphragm: Application of Nerve Surgery Techniques following Unilateral Phrenic Nerve Injury”. Kaufman et al.*

– N=12– Unilateral, symptomatic diaphragm paralysis– Minimum 6 months– No spontaneous improvement

*Submitted for publication to CHEST journal 10/10



• Evaluations– Sniff Test– Phrenic Nerve Conduction Study– Diaphragm EMG– PFTs– Standardized Quality of Life Survey

• Assess Physical Functioning



• Results– 8 males, 4 females– Mean age 54 (range 40-68)– Etiology

• Anesthetic Blocks (2)

• Surgery (6)

• Chiropractic Manipulation (2)

• Traumatic Event (2)

– Right (3), Left (9)



• Results– Treatment offered

• Neurolysis (12)

• Interposition nerve graft (7)

• Neurotization (2)

– Operative time • Mean= 165 minutes (range 50-250)

– Hospital stay• Mean= 2 days (range 1 to 4)



Quality of Life Improvements

Normal function = 100


Improvements in PFTs

Diaphragm Re-InnervationPhrenic Nerve Grafting

Return of Diaphragmatic Function 10 months following grafting



• Sniff test– 8/9 improved

• Incomplete assessments in 4/12– (2) too early to be tested– (1) expired from unrelated cardiac event 8 months later– (1) no improvement at 8 months*

• Complications– (1) infection at sural nerve harvest site


Diaphragm Re-InnervationConclusions

• Documentation of diaphragm re-innervation following nerve grafting– 67% objective improvements in diaphragm function

• A problem with almost no other treatment options– Diaphragm plication

• Restoring physiologic function always superior to “piggybacking” dead muscle

• Additional investigation – Standard of care for diaphragm paralysis?


Thank You!


Comprehensive surgical management of the paralyzed diaphragm

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