Neuromonitoring

Il Linfonodo Sentinella in Chirurgia: Attualità e Prospettive Direttore: Prof. A. Liboni 20 gennaio 2012 Ferrara, ITALY

Il monitoraggio nervoso intraoperatorio

Gianlorenzo Dionigi, MD, FACS Department of Surgical Sciences UNIVERSITY OF INSUBRIA (COMO – VARESE) - ITALY

This report does not endorse any specific Company or set of monitoring equipment

Exposure of RLN reduce the rate of RLN injury No identification Localized RLN RLN

Lahey FH, Ann Surg 1938

1.6

0.3

Riddell VH, Lancet 1956

3.5

2.1

Jazko, Surgery 1994

7.9%

1.2%

Wagner, Br J Surg 1994

21%

6.9%

Hermann, Ann Surg, 2002

2.1%

0.9%

Dralle H, Surgery 2004

1.16%

0.63%

Chiang, Surgery 2005

5.1%

0.9%

Partially exposed RLN

0.3% -

Completely dissected RLN

0.1% -

Gold standards for RLN management 1.

Extensive knowledge of RLN anatomy

2.

Visual identification of RLN

3.

Exposure of RLN

4.

Experience & training

5.

Pre- & post-op. laryngoscopy

Why neuromonitoring? RLN and laryngeal anatomy are the basis of modern thyroid surgery

Why do we need more

than anatomical nerve identification?

Neuromonitoring: history

•Laryngeal palpation with stimulation of RLN: feel for laryngeal twitch •Riddell published in 1970, studies over 1946-1960

•Palpation of posterior crico-arytenoid muscle, with stimulation of 0.5-2.0mA •Galivan 1986

Evolution of RLN Monitoring • Intra-operative invasive techniques

• Non-invasive surface electrodes

Lamadé W Transtracheal monitoring of the recurrent laryngeal nerve. Prototype of a new tube Intraoperative monitoring of the recurrent laryngeal nerve. A new method Chirurg. 1996 & 1997

ETT

ETT electrodes Stimulator probe

NIM monitor

RLN identified both visually and electrically

Intraoperative evidence of RLN injury Evidence RLN injury

Author

Reference

N

%

Bergenfelz A

Langenbecks Arch Surg 2008

1/10

11.3%

Chiang FY

Surgery 2005

3/40

7.5%

Lo CY

Arch Surg 2000

5/33

15%

Patlow CA

Ann Surg 1986

1/10

10%

Caldarelli D

Otolaryngol Clin North Am 1980

1/10

10%

Scandinavian Quality Register Thyroid Surgery

Intraoperative RLN injury causes • • • •

Section (mistake in surgical technique) Ligature (without transection) Mistake in hemostasis and dissection maneuvers Stretch/traction – Excessive traction during the medial traction of the thyroid lobe – Excessive aspiration near to the nerve (suction)

• Compression/contusion/pressure • Thermal/electrical injury – Diffusion by haemostatic devices

• Ischemia – Ligation of the inferior pole vessels before identifying RLN – Excessive dissection of the nerve with ischemia

Types of nerve injury – neuropraxia: simple contusion of a nerve • treated by simple observation • return to normal function over weeks to months

– axonotmesis: more significant disruption followed by degeneration • healing takes a prolonged time

– neurotmesis: complete division of a nerve • requires surgical repair

anatomical nerve lesions are only exceptional reasons for postop VC palsy Dralle H. WJS 2008 Bergenfelz A . Langenbecks Arch Surg 2008 Chiang FY . Surgery 2005 Lo CY . Arch Surg 2000 Patlow CA . Ann Surg 1986 Caldarelli D. Otolaryngol Clin North Am 1980

AUDIT True incidence of RLN injury

• No routine post-operative laryngoscopy 0.3% RLNP

• Routine postoperative laryngeal exams 7% RLNP

1. Evidence from the Literature (?)

Transient RLN palsy Parameter

Odds ratio

P value

Permanent RLN palsy Odds ratio

P value

Graves’ disease

1.40