Inspire Implant

Question 1

Indications for Inspire Implant Placement

Answer 1

1) AHI between 15-65 with less than 25% central apneas
2) BMI:
- Insurance: BMI < 32
- Medicare: BMI < 35
3) Unable to use CPAP
4) Free of complete concentric collapse at the palate on DISE
5) Older than age 18

Question 2

Inspire Implant Placement Complications

Answer 2

• Stimulation lead and generator traction/tethering
• Neurapraxia of the Hypoglossal nerve
• Inappropriate stimulation and/or sensing lead connection with generator
• Pneumothorax
• Marginal mandibular nerve weakness
• Failure to place stimulation lead cuff around the hypoglossal nerve
• Blood vessel damage during tunneling
• Hematoma
• Device-related infection

Note: Each of the above complications is < 1% with current implant techniques & products

Question 3

Inspire Implant - Pre-Operative considerations

Answer 3

• Physical assessment of patient and implant site
• Medical history
• Cosmesis
• Hobbies
• MRI

Question 4

Inspire Implant and MRI scans

Answer 4

• Patients implanted with the Inspire 3028 generator may undergo an MRI scan of the head, neck, arms, and legs if a transmit-receive RF coil is used
• An MRI of the patient’s neck can be performed with the use of a transmit-receive head coil lowered onto the patient’s shoulders
• Required MRI equipment: a transmit-receive RF coil is required for all MRI scans. An MRI system that displays B1 + RMS is required for head and neck scans
• Patient’s with Inspire leads not connected to a generator cannot be scanned with an MRI.

Question 5

What areas of the body can be scanned with MRI with an Inspire Implant in place?

Answer 5

1) MRI Inclusion:
- Brain
- Lower extremities
- Neck
- Upper extremities

2) MRI Exclusion:
- Abdomen
- Breast
- Chest
- Hip
- Pelvis
- Shoulder

Question 6

Can a patient be an Inspire candidate if their Apnea-Hypopnea Index is above the range indicated for Inspire Implant placement?

Answer 6

Treatment options for patient’s whose AHI is above the accepted range for implant placement (AHI 15-65):

1) The patient could have another sleep study/home sleep study done to see if this would give a different answer
2) The patient would most likely benefit, but may still require CPAP - but with lower pressures
3) The patient could consider some of the more traditional sleep surgeries in an attempt to lower their AHI into the treatment range for the Inspire implant.

Question 7

Inspire implant infection prevention

Answer 7

• Give preoperative antibiotics within 60 minutes of incision critical
• Remove hair at or near incision sites
• Maintain sterility using proper aseptic technique: use Ioban on the wound
• Proper post-operative wound care

Question 8

Anesthesia concerns with Inspire implant

Answer 8

1) Intubation
- Oral: on opposite side of the implant
- Nasal intubation
2) Give prophylactic antibiotics within 60 minutes of incision is critical
3) Do not give paralytics after intubation

Question 9

Inspire Implant - Neck Incision

Answer 9

1) Neck incision:
- Midway between hyoid and mandible
- One cm lateral to the midline
- Length: 5 cm
2) Key landmarks:
- Midline
- Length of the mandible
- Hyoid
- EJ vein
Note: Best Practice - Mark the midline with head in neutral position

Question 10

Inspire Implant: patient position/possible room configuration

Answer 10

1) Rotate the table 180 degrees
2) Arm Position: Both arms loosely tucked
3) Chest (Working Side): Fee of EKG electrodes
4) Neck Extension: Shoulder roll with donut for extension

Question 11

Incision Planning: Chest Incision

Answer 11

1) Key Landmarks:
- Inferior border of clavicle
- Lateral border of sternum
- 1st, 2nd, and 3rd rib
2) Incision:
- Identify intercostal space between 2nd and 3rd rib
- Length: 5cm placed 3cm lateral to sternal margin, oriented roughly parallel to the intercostal space
3) Considerations:
- Cosmesis
- Interests/hobbies/occupation (purses, backpack, hunters)’
- Breast implants

Question 12

Essential Nerve Integrity Monitoring Supplies: Use the Medtronic NIM

Answer 12

1) Medtronic 18mm Prass Paired EMG Electrodes
- 5mm electrode spacing/5mm to insulation: #8227304
2) Medtronic Side-by-Side Bipolar Stimulator Probe
- 1.3mm probe spacing: #8225401

Question 13

Placement of NIM Electrodes in the Tongue

Answer 13

1) Red Channel: Hyoglossus - Insert ventrolateral along a parallel, shallow course
- Submucosal
- 3-4 cm from tip of tongue
- Inferior to the papilla/taste buds of the tongue

2) Blue Channel: Genioglossus - Insert lateral to the frenulum & anterior to the duct
- Electrode plunges deep into GG toward neck incision
- Avoid the tendon near mandible

3) Note: A NIM electrode may be placed to monitor the marginal mandibular nerve

Question 14

Skin Preparation for Inspire Implant

Answer 14

1) Scrub and pain with Chlorhexidine or Betadine
2) Block out surgical sites with Towels
3) Steri-Drape 1012 Clear Adhesive Drape: Adhere to mandible covering the face
4) 3M Ioban Drape: Overlap clear drape at mandible, downward
5) Large/U/Split Drape: From below chest incision
6) Medium/Half Drape: Over the head

Question 15

Nerves in the Submandibular Triangle

Answer 15

1) Hypoglossal Nerve: + tongue motion and NIM signal with stimulation
2) Mylohyoid Nerve: Located superficial to the mylohyoid muscle and has no tongue motion or red NIM signal with stimulation
3) Lingual Nerve: Located superior to the hypoglossal nerve and has no tongue motion and no NIM signal with stimulation

Question 16

Vena Comitans of the Hypoglossal Nerve

Answer 16

1) Predictably located, typically along the inferior border of the hypoglossal nerve
2) Ligate or retain based on anatomic presentation
3) Avoid suture clips

Question 17

Recommended Sequence for Hypoglossal Nerve Dissection

Answer 17

1) Identify breakpoint using visual cues and early NIM findings
2) Place small vessel loop around inclusion branches, minimizing nerve dissection
3) Confirm breakpoint by remapping with NIM
4) Enlarge window for cuff placement

Objective: Recruit protrusors and stiffeners, treating nerve gently

Question 18

Functional Breakpoint of the Hypoglossal Nerve

Answer 18

1) Definition: Point along superior, distal hypoglossal nerve that transitions from inclusion to exclusion branches
2) Goal: Unhindered protrusion of a stiffened tongue

Question 19

Identifying the Functional Breakpoint of the Hypoglossal Nerve

Answer 19

1) Neuroanatomy
- Nerve branching pattern and visual recognition
- Vasa Nervorum

2) Nerve Integrity Monitoring
- Genioglossus and T/V vs. Hyoglossus Waveforms

3) Muscle Contraction
- Hyoglossus
- Genioglossus
- Geniohyoid