salim hayek, md, phd division of pain medicine department of anesthesiology case western reserve...

Salim Hayek, MD, PhDDivision of Pain Medicine

Department of AnesthesiologyCase Western Reserve

University

SCS Complications

Learning Objectives

Be aware of common SCS Complications

Understand the reasons for complications

Strategies to minimize complications

Turner JA et al., Pain. 2004 Mar;108(1-2):137-47

Complications AN UNAVOIDABLE PROBLEM

34% of patients who received a stimulator had an adverse occurrence

PROPORTIONATE TO NUMBERS MUST BE ADDRESSED EARLY AN IMPLANT COORDINATOR IS

ESSENTIAL CAN BE REDUCED

Minimizing Complications

Preoperative Patient selection

Intraoperative Technique

Postoperative VigilancePain relief

3 tracks “NANS, as a specialty society, neither accredits

training programs nor certifies individuals to perform SCS”

Understanding and being able to manage complications: Crucial

Complications of SCS

Technical Biologic Other

Kumar K etal., J Neurosurg Spine 5:191–203, 2006

Total = 31.9%; in 42/160 patients

162 paddle leads; 28 percutaneous leads

Kumar K. et al., Pain 132 (2007) 179–188

PROCESS Study

Kumar K etal., J Neurosurg Spine 5:191–203, 2006

Lead Migration 18 cases

13 in axial plane5 in transverse plane

Cervical leads2x > thoracolumbar

Multipolar/multichannel leads

Gluteal placement Flexion-Extension: Up

to 9 cm displacement

Henderson JM et al., Neuromodulation, Volume 9, Number 3, 2006 183–191

Kumar K etal., J Neurosurg Spine 5:191–203, 2006

IPG in Anterior Abdominal Wall

Minimal excursionWalking: 0.2cmTwisting: 1.7 cm

Scoliosis: lateral displacementPaddle leads

Rosenow J et al., J Neurosurg Spine 5:183–190, 2006

Kumar K etal., J Neurosurg Spine 5:191–203, 2006

Percutaneous Lead Breakage

just cephalad to anchoring point

risk when >1cm between anchor tip and lead entry point into fascia

Kumar K etal., J Neurosurg Spine 5:191–203, 2006

2.1 cm displacement between epidural space and the TL fasciaStrain relief

loop

Paddle Lead Breakage

Henderson JM et al., Neuromodulation, Volume 9, Number 3, 2006 183–191

Strain: Fascia--Epidural

Rosenow J et al., J Neurosurg Spine 5:183–190, 2006

Twist-Lock Anchor

Pressure Forces of flexion-

extension

Henderson JM et al., Neuromodulation, Volume 9, Number 3, 2006 183–191

Simulated/sheep model

Use of a soft silastic anchor pushed through the fascia to provide a larger bend radius for the lead was associated with a time to failure 65 times longer than an anchored but unsupported lead

Failures of surgical paddle leads occurred when used with an anchor, whereas without an anchor, no failures occurred to 1 million cycles

Henderson JM et al., Neuromodulation, Volume 9, Number 3, 2006 183–191

The panel recommendeda paramedian approachKeeping the lead midline—prevent

lateral maximizing bend radius by pushing the

anchor through the fasciaanchoring of the extension connector

near the lead anchorStrain relief loop

Henderson JM et al., Neuromodulation, Volume 9, Number 3, 2006 183–191

Generator Placement

The anchor should be placed as near as possible to the spinous process to avoid lead movement generated by muscle contractions

Placement of the IPG in the buttock region may produce up to a fivefold increase in tensile loading compared with placement in the abdomen or midaxillary line. The panel therefore recommended that buttock IPG placement be reserved for special clinical situations and should not be routinely performed

Kumar K et al., Neuromodulation 10 (1):24–33, 2007

0 black braided nylon

Strain relief loopStrain relief loop

Avoid Anchoring Paddle Lead

Alo KM et al., Neuromodulation 1:30–45, 1998

The Good News

Improved education/techniques Newer extensionless systems have

resulted in a marked decrease in revision rates (e.g. 3.8%)

Advancements in anchoring technology

Anchor Options

Enhanced Silicon suture sleeves

Mechanical Anchors

Silicone suture sleeves

Types of Mechanical Anchors

Swift-LockTM ClikTM TwistLockTM

Audible and tactile “Clik” confirms lock using hex wrenchRadio-opaqueBi-directional

Anchor Design

Infections

Cameron T. Safety and Efficacy of Spinal Cord Stimulation for the Treatment of Chronic Pain: a 20-year Review. J Neurosurg 2004; 100: 254-267.

Infections

12%

Gaynes RP et al., Clin Infect Dis 2001;33(S2):S69-77 Haridas M, Malangoni MA. Surgery 2008;144:496-503

Surgical Site Infection--SSI

Increased risk of SSIASA classificationprolonged operative time – defined as 75th

% hypoalbuminemia ( 3.4 mg/dL)anemia (Hgb 10 g/dL)excessive alcohol use (not defined)history of COPDhistory of CHFinfection at remote sitecurrent operation through a previous

incisionperioperative hyperglycemia

Nery PB et al., J Cardiovasc Electrophysiol 2010 Jan 22 Cesar de Oliveira J et al., Circ Arrhythmia Electrophysiol 2009;2:29-34

Lessons from the Heart

Historic infection rates for implanted cardiac devices (ICDs - pacemakers and defibrillators) 0.5-6%

More recently as low as 1% A PRDBPCT evaluated infection risk:

prophylactic cefazolin vs. placeboTrial was interrupted early by the safety

committee because of the dramatically higher rate of infection in those that did not receive antibiotics vs. those that did (3.28% vs. 0.63%)

Infection Prevention: Antibiotic Prophylaxis

RECOMMENDATIONCategory IA

cefazolin 1-2 g iv 30 minutes prior to incision

clindamycin 600 mg iv 30 minutes prior to incision [ß-lactam allergy]

vancomycin 1 g iv over 60 minutes prior to incision

[MRSA carriers]

Gyssens. Drugs 57:175-85; 1999

SCS Infection Prevention

Chlorhexidine more effective than Povidone Iodine skin prep

Minimize OR traffic Preoperative antibiotics Meticulous hemostasis Gentle tissue handling

Maki DG et al.,: Prospective randomised trial of povidone-iodine, alcohol, and chlorhexidine for prevention of infection associated with central venous and arterial catheters. Lancet 338:339-343, 1991

Kinirons B et al: Chlorhexidine versus povidone iodine in preventing colonization of continuous epidural catheters in children: a randomized, controlled trial. Anesthesiology 94:239-244, 2001

Infection Recommendations?

How to manage an Infected SCS?

The gold standard in treating deep SCS infections is a 2-stage procedure: the initial stage involves removal of

implanted material, wound debridement, and antibiotic treatment ID consult

After wound healing has occurred and no infection imminent, re-implantation can be performed

Can an Infected SCS be Salvaged?

SCS Leads epidural space IPG is by far the most expensive SCS

component No case reports of keeping generator in an

open incision after I&D Distinguish superficial vs. deep SSI Attempts at salvaging SCS in the setting of

SSI should be made only in the setting of:Complete patient understanding of potential risksClose follow up by implanter and ID specialist Careful serial monitoring of patient

Clinically Laboratory values such as CRP

Rare Surgical Complications CSF fluid leak/headache Post-op bleeding/hematoma Pocket Seroma Wound dehiscence Epidural abscess/meningitis Headache CSF Leak Pain in the incision site Allergic response to the system Programmer or telemetry problems Residual pain phenomenon Postural Changes

Technical Complications

Too deep an insertion Too superficial an insertion IPG flip Rib/iliac crest friction Anchor/lead erosion Anchor protrusion Uncomfortable position

sittingStanding: protrusionlaying down

CONCLUSION Overall SCS represents a low risk

effective therapy to control chronic pain

Complications do occur and range in severity from minor to fatal

Recognizing a complication early and understanding how to intervene appropriately is your responsibility

Surgical backup and extreme vigilance are highly desirable

Thank You!!

Do It Yourself

The EGL Scan(Electronically Generated Lead

scan)