Implanting Devices –

A Practical Guide Dr Stuart Harris

Consultant Cardiologist & Electrophysiologist

Overview

• Patient preparation

• Equipment

• Incision

• Pocket formation

• Central venous access techniques

• Lead selection

• Pacing/Defibrillator parameters

• Post procedure care

Patient preparation

• Generally use left side

– More natural for operating (for right

handed operators)

– Easier to position leads (especially

atrial lead)

– 90% of patients are right handed

• Sedation (operator preference)

• Procedure field

Implantable Defibrillators

•“Oh come on, it’s just a big pacemaker”

Before you start...

• Operator

• Needs to be experienced Bradycardia Implanter

• Needs to know how the ICD works

• Needs to know about DFT testing, specifically what can go wrong and how to fix it, quickly

Implant basics

• Monitoring

• ECG, pulse oximetry

• BP- non invasive will do

• External defibrillator and pads (ICD’s)

• Spare defibrillator nearby (ICD’s)

• Aseptic technique and antibiotics

• General Anaesthetic or Sedation

GA or Local with Sedation?

• GA

• Total control

• Easier for patient

• Small risk of adverse

event due to the GA itself

• May not be readily

available

GA or Local with Sedation?

• Local with Sedation

• Less control (can still be safe)

• Potential for airway problems

• Some patients find it uncomfortable

or distressing

• No anaesthetist or anaesthetic

needed

• Readily available

Equipment

Draping

Incision

Deltopectoral incision

Oblique incision

Horizontal incision

Incision

• Operator preference

– access to both cephalic and subclavian/axillary veins

– cosmetic result

• Landmarks

– Lateral third of clavicle

– Delto-pectoral groove (indentation between clavicular

head of pectoralis major medially and deltoid laterally)

• Length of incision

– big enough for device

– longer if more subcutaneous tissue

• Local anaesthetic

Pocket formation

• Start or end of procedure?

• Subcutaneous or subpectoral?

Subpectoral implants

• The normal site for most patients is prepectoral

• Easier surgery and box change, less painful

• Fine for most patients

• You need to be able to perform a subpectoral implant if

needed

• Young patients

• Thin patients

• Mastectomy or surgery

Making the pocket

• Different manufacturers make different

shapes of ICD

• You need to make the pocket accordingly

• “Three fingers” rule usually applies

Pocket formation

Central venous access techniques

• Cephalic vein cut down

• Subclavian vein puncture

– intrathoracic – used to it

– extrathoracic – safer

• Axillary vein puncture

• Internal jugular puncture

Cephalic vein cut down

• Advantages

– exposed during dissection and directly punctured

so no risk of pneumothorax

– may be essential (e.g. pneumonectomy/severe

COPD)

• Disadvantages

– not always present

– may not be big enough for > 1 lead

– fiddly and may increase procedure time

– technique more skilled and requires practice

Cephalic Access

Cephalic vein

Pectoral muscle

Subclavian vein puncture

• Advantages

– almost always present

– always big enough for as many leads as you need

– usually quick

– technique widely practised

• Disadvantages

– pneumothorax/haemothorax (~2% of punctures)

– risk of arterial puncture

Subclavian vein puncture

Extrathoracic

Traditional

Anaesthetise under clavicle

Subclavian puncture

Lead through sheath

Tined lead

Active (screw-in) lead

Single Coil

• 1 high voltage coil per lead:

- RV (Right Ventricle)

- Other extra HV Coils/Patches

• 1 or 2 Connector Pins - (HV only or P/S + HV)

Dual Coil

• 2 High Voltage coils per lead: - RV + SVC

• 3 Connector Pins (P/S + 2 HV)

Active or passive leads?

• More flexibility over position with active leads

• Better stability but increased risk of perforation

• Easier to extract

• Remember in young patients life expectancy of

patient often much longer than that of lead

Dual coil or single coil

• Single coil leads have slightly higher DFT than

dual coil leads

• With dual coil leads in large hearts the SVC coil

can end up in the right atrium

― Increases DFT

• Single coil leads are much easier to extract

― SVC coil can tear the SVC as it is extracted

Dual coil or single coil

• Dual coil leads

• For older patients with not too dilated hearts

• Not expected to outlive their lead

• Single coil leads

• Younger patients

• Older patients with large hearts

• Can add a standalone SVC coil if DFT is high

Shock leads compared to brady pacing leads

• Stiffer

• Easy to perforate venous

structures and right heart

• Easier to damage during

implant

• Especially during extreme

manoeuvres

• You need to be good at

brady pacing first

RV apex vs septum

• RV Apex

• Usually good stability and R wave

• Lowest DFTs

• Pacing from here worsens heart failure

• RV Septum

• R wave smaller, poorer stability

• Higher DFTs

• Pacing from here neutral for heart failure

• Better in combination with LV lead

Shock lead electrical parameters

• In brady pacing, the threshold is usually the most

important factor

• For ICDs, the R wave is the most important factor

• Small R waves may lead to undersensing of VF and

failure to deliver therapy

• High sensitivities to allow for small R waves lead to

oversensing of noise and inappropriate shocks

Check leads with testing cables

Suturing the leads to the muscle

• Failure to do this properly is the commonest cause

of lead displacement

• Can be difficult

― Subpectorally

― CRT-D systems

• At least two sutures per lead

― Tug each one after you have sutured to make

sure

Connecting leads and device

• Pace/ sense part of the lead has an IS-1 connector

• Same as a brady pacing lead

• Defib part of the lead has a DF-1 connector

• Shorter

• Use the diagram on the defib to tell you where to place

each lead

• If you have a single coil shock lead you need to plug

the SVC port of the device

Connecting leads and device

• Common Cock ups

• Mixing up RV, RA, LV IS-1 leads

• DF1 in IS-1 or vice versa

• RV coil connected to SVC port or vice versa

• Multiple set screws in device- not all tightened up

• SVC port not plugged

• Beware confusing labelling on some leads/ devices

• RV coil labelled as “-”, SVC coil as “+”

• Remember Proximal coil is Positive

Wound closure

Chest x-rays

• Subclavian puncture needs PA on day of

procedure

• If exclusively cephalic then does not

need x-ray

• Careful inspection for pneumothorax

• No need for lateral x-ray routinely

Chest x-rays

Chest x-rays

Questions?