International Journal of Pediatric Otorhinolaryngology 79 (2015) 755–757
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Case report
Using a new otologic operating microscope: Unexpected complications Marine Parodi *, Briac Thierry, Marion Blanchard, Vincent Couloigner, Erea–Noe¨l Garabe´dian Pediatric ENT Department, Necker–Sick Children Hospital, 149 rue de Se`vres, 75015 Paris, France
A R T I C L E I N F O
A B S T R A C T
Article history: Received 18 December 2014 Received in revised form 21 February 2015 Accepted 25 February 2015 Available online 6 March 2015
The present work report cases of auricular burns after routine otologic surgery possibly induced by the operating microscope. Single-center retrospective study. April 2013 to January 2014, eight children presented with auricular burns after otologic surgery. Median age was 10.1 years. Cheloid scar occurred in six cases. A small scar was present for the other two patients without any other sequelae. No patient had chondritis nor cartilage loss. There was no possibility of physical or electrical trauma in the pretragal or retroauricular cutaneous area during the operations. Therefore, the only remaining hypothesis to explain these burns was thermal damage induced by the operative microscope. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Operating microscope Otologic surgery Skin burn Complication
1. Introduction The use of operating microscopes is one of the most important technological advances of the last century in the field of otologic surgery. The quality of magnification has increased over the past years, as well as the possibility of greater light intensity thanks to improvements in light delivery strategies and in optical lens. However, high light intensity is believed to be involved in very rare cases of soft tissue burns in some specific surgical conditions. This complication has been sparsely reported. To our knowledge, only one team reported 4 cases of auricular burns after otologic surgery [1]. The present work report eight new cases cases of auricular burns after routine otologic surgery possibly induced by the operating microscope. We analyze different variables that might have influenced the occurrence of these soft tissue burns, and discuss measures to prevent this complication.
2. Materials and methods In this single-center retrospective case series, the medical charts of eight patients, in whom an auricular burn occurred after
* Corresponding author. Tel.: +33 1 71 39 67 84; fax: +33 1 44 49 25 73. E-mail address: [email protected] (M. Parodi). http://dx.doi.org/10.1016/j.ijporl.2015.02.028 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
otologic surgical procedures performed under stereomicroscope, were reviewed. We recorded patients’ demographics, surgical indications, operating reports, the type of microscope that was used, surgical length and burn characteristics. 3. Results From April 2013 to January 2014, eight children presented with auricular burns after otologic surgery. Median age was 10.1 years (min = 1 year, max = 14.5 years, mean: 9.9 years). Main clinical and surgical characteristics are reported in Table 1. No patient had associated medical conditions such as skin disease, diabetes or peripheral microvascular disease. Six patients were followed for chronic otitis (4 retraction pockets and 2 cholesteatomas). All six patients had injection of lidocaine with 1% epinephrine in the posterior and superior ear canal wall followed by an endaural approach. One patient had conductive deafness linked to ossicular malformation and underwent tympanoplasty for middle ear exploration and ossiculoplasty. Another patient underwent cochlear implantation for congenital bilateral profound hearing loss. In this latter case, the surgical approach was retroauricular. All ears were prepped with povidoneiodine 10%. A circular drape with adhesive (Mo¨nlycke, Barrier, ENT7, type 65020,) was placed around the ear. A OPMI1Pentero1 microscope (Carl Zeiss, Germany) with a xenon light source
M. Parodi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 755–757
756
Table 1 Demographic and surgical characteristics. Patient no.
Age at surgery (years)
Surgical procedure
Length of surgical procedure (min)
Location of burn
1 2 3 4 5 6
14.5 14 10 9 10 1
Tympanoplasty/retraction pocket/endaural approach Tympanoplasty/retraction pocket/endaural approach Tympanoplasty/cholesteatoma/endaural approach Tympanoplasty/retraction pocket/endaural approach Tympanoplasty/retraction pocket/endaural approach Cochlear implant/retroauricular approach
150 60 180 130 95 140
7
13.5
150
8
7
Middle ear exploration for ossicular malformation/endaural approach Tympanoplasty/retraction pocket/endaural approach
Pre-tragal Pre-tragal Pre-tragal Pre-tragal Pre-tragal Posterior part of helical rim Pre-tragal
(Superlux1) was used for all patients. Cumulative duration of use was between 60 min and 180 min (median: 135 min; mean: 123 min). Working distance was between 210 and 300 mm. Light intensity was between 65% and 100%. All cutaneous lesions were located 1 cm in front of the tragus in cases of endaural approach and were located at the back of the helical rim in the case of retroauricular approach. All lesions were oblong. Skin was erythematous and painful for a few hours after surgery; suggesting a physical, electrical or thermal trauma. All patients received application of Vaseline ointment. Despite skin care, a hypertrophic, cheloid scar occurred in six cases (Fig. 1). A small scar was present for the other two patients without any other sequelae (Fig. 2). No patient had chondritis nor cartilage loss.
80
Pre-tragal
More than 350 tympanoplasties and about 120 cochlear implantations are performed every year in our pediatric ENT department. Between April 2013 and January 2014, we noticed that few patients had pretragal burns after tympanoplasty. This
situation had never been seen before April 2013. The surgical technique has been the same for many years and had not changed recently. No new surgeon joined the team at that time. Burns occurred with different surgeons who have been performing this surgery for at least five years for the youngest and for more than 20 years for the oldest surgeons. Surgical instruments did not change. Surgical sterile drapes did not change; so that we did not consider the glue present on surgical drapes as a possible cause of burns. The only thing that was different since April 2013 was the fact that our team acquired a new operating microscope OPMI1 Pentero1 (Carl Zeiss1, Germany). Furthermore, there was no possibility of physical or electrical trauma in the pretragal or retroauricular cutaneous area during the operations. Therefore, the only remaining hypothesis to explain these burns was thermal damage induced by the operative microscope. Previously, we used a Leica M520F40 microscope (Leica Microsystems1, Germany) and had not experienced any burn with it. These two microscopes have the same kind of light source (Xenon illumination system 300 W). The OPMI1 Pentero1 is
Fig. 1. Cheloid scar.
Fig. 2. Pre-tragal skin burn.
4. Discussion
M. Parodi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 755–757
optimized to give the surgeon more light to work with. For this purpose, two technical improvements were implemented by the manufacturer: (1) the spot illumination that precisely adjusts the light cone and (2) the two-channel illumination system that delivers light wherever its needed. Consequently, the delivered light intensity is much higher. The user instruction guides of both microscopes contain warnings concerning burns due to high light intensity. The OPMI1 Pentero1 guide contains three pages of warnings and advices about burns due to the light. What was surprising was the exact same location of the burns in all patients. Even for the patient who received a cochlear implant. The ear was retracted forward due to a retroauricular approach and the burn was therefore at the back of the helix; but it was in fact in the same area of the surgical field. Physiological factors that could promote burning of the external ear are the thinness of the skin, a very scarce layer of underlying adipose tissue and a weak blood supply as a peripheral appendage. This is likely less valid for pretragal skin. A factor that can decrease auricular and preauricular skin perfusion and therefore promote burn is the prolonged used of retractors. One could also infer that lidocaine and epinephrine injections used at the beginning of the surgical procedure could weaken blood supply. However we never injected the tragus before harvesting the tragal cartilage graft during tympanoplasties. Nor did we perform an injection in the area of the helix during the cochlear implantation. Patients-related risk factors might be the thinness of skin in children compared to adult populations. Considering the small number of patients it is difficult to determine a skin phenotype that would be more susceptible to burn even if, intuitively, we would expect fair skins to be more fragile. Two of our patients had a Mediterranean skin tone (type IV Fitzpatrick scale) [2]. Since we understood that burns were likely related to the microscope, we took several measures to prevent burns. We limited light intensity to no more than 50%. We also tried to limit the light aperture to only include the field of view and therefore minimize the amount of skin exposed to heat. We also placed a
757
moist compress in front of the tragus during tympanoplasties with endaural approaches, or in any other over-exposed skin surface. In the last six months, with these precautions and also the fact that every surgeon in the department is now aware of this possible danger of complication we did not notice any new burn. In our hospital, neuro-surgeons also use an OPMI1 Pentero1 microscope. They did not report complication of this type. However, the skin of the scalp or of the back has a much more robust blood supply and is thicker than the skin of the external ear and is therefore less susceptible to burns. The orthopedic surgical team of our hospital did not neither experience burns possibly related to the use of an operating microscope among their patients. They used the same Leica M520F40 (Leica Microsystems1) microscope than ours for hand surgery and arterioveinous fistulas. In the literature, cases of cutaneous burns associated with operating microscope were described after otological surgery [1] and brachial plexus surgery [3,4]. According to Latuska et al., 82 unique cases of soft tissue burns associated with the use of an operating microscope had been voluntarily reported to the FDA since 2004. About 30% of cases occurred in the auricular region during tympanoplasties at focal length distances of 300 mm or less with xenon light source microscopes. It seemed important to us to report this possible complication of operating microscopes used at high light intensity levels and to present the safety measures.
References [1] R.F. Latuska, M.L. Carlson, B.A. Neff, et al., Auricular burns associated with operating microscope use during otologic surgery, Otol. Neurotol. 35 (2) (2014) 227–233. [2] T.B. Fitzpatrick, The validity and practicality of sun-reactive skin types I through VI, Arch. Dermatol. 124 (6) (1988) 869–871. [3] I.K. Choudhry, J. Kyriakedes, M.B. Foad, Iatrogenic burn caused by an operating microscope: case report, J. Hand Surg. Am. 38 (3) (2013) 545–547. [4] M.M. Al-Qattan, H.M. Clarke, A burn caused by the operating microscope light during brachial plexus reconstruction, J. Hand Surg. Br. 19 (Oct (5)) (1994) 550–551.
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Case report
Using a new otologic operating microscope: Unexpected complications Marine Parodi *, Briac Thierry, Marion Blanchard, Vincent Couloigner, Erea–Noe¨l Garabe´dian Pediatric ENT Department, Necker–Sick Children Hospital, 149 rue de Se`vres, 75015 Paris, France
A R T I C L E I N F O
A B S T R A C T
Article history: Received 18 December 2014 Received in revised form 21 February 2015 Accepted 25 February 2015 Available online 6 March 2015
The present work report cases of auricular burns after routine otologic surgery possibly induced by the operating microscope. Single-center retrospective study. April 2013 to January 2014, eight children presented with auricular burns after otologic surgery. Median age was 10.1 years. Cheloid scar occurred in six cases. A small scar was present for the other two patients without any other sequelae. No patient had chondritis nor cartilage loss. There was no possibility of physical or electrical trauma in the pretragal or retroauricular cutaneous area during the operations. Therefore, the only remaining hypothesis to explain these burns was thermal damage induced by the operative microscope. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Operating microscope Otologic surgery Skin burn Complication
1. Introduction The use of operating microscopes is one of the most important technological advances of the last century in the field of otologic surgery. The quality of magnification has increased over the past years, as well as the possibility of greater light intensity thanks to improvements in light delivery strategies and in optical lens. However, high light intensity is believed to be involved in very rare cases of soft tissue burns in some specific surgical conditions. This complication has been sparsely reported. To our knowledge, only one team reported 4 cases of auricular burns after otologic surgery [1]. The present work report eight new cases cases of auricular burns after routine otologic surgery possibly induced by the operating microscope. We analyze different variables that might have influenced the occurrence of these soft tissue burns, and discuss measures to prevent this complication.
2. Materials and methods In this single-center retrospective case series, the medical charts of eight patients, in whom an auricular burn occurred after
* Corresponding author. Tel.: +33 1 71 39 67 84; fax: +33 1 44 49 25 73. E-mail address: [email protected] (M. Parodi). http://dx.doi.org/10.1016/j.ijporl.2015.02.028 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
otologic surgical procedures performed under stereomicroscope, were reviewed. We recorded patients’ demographics, surgical indications, operating reports, the type of microscope that was used, surgical length and burn characteristics. 3. Results From April 2013 to January 2014, eight children presented with auricular burns after otologic surgery. Median age was 10.1 years (min = 1 year, max = 14.5 years, mean: 9.9 years). Main clinical and surgical characteristics are reported in Table 1. No patient had associated medical conditions such as skin disease, diabetes or peripheral microvascular disease. Six patients were followed for chronic otitis (4 retraction pockets and 2 cholesteatomas). All six patients had injection of lidocaine with 1% epinephrine in the posterior and superior ear canal wall followed by an endaural approach. One patient had conductive deafness linked to ossicular malformation and underwent tympanoplasty for middle ear exploration and ossiculoplasty. Another patient underwent cochlear implantation for congenital bilateral profound hearing loss. In this latter case, the surgical approach was retroauricular. All ears were prepped with povidoneiodine 10%. A circular drape with adhesive (Mo¨nlycke, Barrier, ENT7, type 65020,) was placed around the ear. A OPMI1Pentero1 microscope (Carl Zeiss, Germany) with a xenon light source
M. Parodi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 755–757
756
Table 1 Demographic and surgical characteristics. Patient no.
Age at surgery (years)
Surgical procedure
Length of surgical procedure (min)
Location of burn
1 2 3 4 5 6
14.5 14 10 9 10 1
Tympanoplasty/retraction pocket/endaural approach Tympanoplasty/retraction pocket/endaural approach Tympanoplasty/cholesteatoma/endaural approach Tympanoplasty/retraction pocket/endaural approach Tympanoplasty/retraction pocket/endaural approach Cochlear implant/retroauricular approach
150 60 180 130 95 140
7
13.5
150
8
7
Middle ear exploration for ossicular malformation/endaural approach Tympanoplasty/retraction pocket/endaural approach
Pre-tragal Pre-tragal Pre-tragal Pre-tragal Pre-tragal Posterior part of helical rim Pre-tragal
(Superlux1) was used for all patients. Cumulative duration of use was between 60 min and 180 min (median: 135 min; mean: 123 min). Working distance was between 210 and 300 mm. Light intensity was between 65% and 100%. All cutaneous lesions were located 1 cm in front of the tragus in cases of endaural approach and were located at the back of the helical rim in the case of retroauricular approach. All lesions were oblong. Skin was erythematous and painful for a few hours after surgery; suggesting a physical, electrical or thermal trauma. All patients received application of Vaseline ointment. Despite skin care, a hypertrophic, cheloid scar occurred in six cases (Fig. 1). A small scar was present for the other two patients without any other sequelae (Fig. 2). No patient had chondritis nor cartilage loss.
80
Pre-tragal
More than 350 tympanoplasties and about 120 cochlear implantations are performed every year in our pediatric ENT department. Between April 2013 and January 2014, we noticed that few patients had pretragal burns after tympanoplasty. This
situation had never been seen before April 2013. The surgical technique has been the same for many years and had not changed recently. No new surgeon joined the team at that time. Burns occurred with different surgeons who have been performing this surgery for at least five years for the youngest and for more than 20 years for the oldest surgeons. Surgical instruments did not change. Surgical sterile drapes did not change; so that we did not consider the glue present on surgical drapes as a possible cause of burns. The only thing that was different since April 2013 was the fact that our team acquired a new operating microscope OPMI1 Pentero1 (Carl Zeiss1, Germany). Furthermore, there was no possibility of physical or electrical trauma in the pretragal or retroauricular cutaneous area during the operations. Therefore, the only remaining hypothesis to explain these burns was thermal damage induced by the operative microscope. Previously, we used a Leica M520F40 microscope (Leica Microsystems1, Germany) and had not experienced any burn with it. These two microscopes have the same kind of light source (Xenon illumination system 300 W). The OPMI1 Pentero1 is
Fig. 1. Cheloid scar.
Fig. 2. Pre-tragal skin burn.
4. Discussion
M. Parodi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 755–757
optimized to give the surgeon more light to work with. For this purpose, two technical improvements were implemented by the manufacturer: (1) the spot illumination that precisely adjusts the light cone and (2) the two-channel illumination system that delivers light wherever its needed. Consequently, the delivered light intensity is much higher. The user instruction guides of both microscopes contain warnings concerning burns due to high light intensity. The OPMI1 Pentero1 guide contains three pages of warnings and advices about burns due to the light. What was surprising was the exact same location of the burns in all patients. Even for the patient who received a cochlear implant. The ear was retracted forward due to a retroauricular approach and the burn was therefore at the back of the helix; but it was in fact in the same area of the surgical field. Physiological factors that could promote burning of the external ear are the thinness of the skin, a very scarce layer of underlying adipose tissue and a weak blood supply as a peripheral appendage. This is likely less valid for pretragal skin. A factor that can decrease auricular and preauricular skin perfusion and therefore promote burn is the prolonged used of retractors. One could also infer that lidocaine and epinephrine injections used at the beginning of the surgical procedure could weaken blood supply. However we never injected the tragus before harvesting the tragal cartilage graft during tympanoplasties. Nor did we perform an injection in the area of the helix during the cochlear implantation. Patients-related risk factors might be the thinness of skin in children compared to adult populations. Considering the small number of patients it is difficult to determine a skin phenotype that would be more susceptible to burn even if, intuitively, we would expect fair skins to be more fragile. Two of our patients had a Mediterranean skin tone (type IV Fitzpatrick scale) [2]. Since we understood that burns were likely related to the microscope, we took several measures to prevent burns. We limited light intensity to no more than 50%. We also tried to limit the light aperture to only include the field of view and therefore minimize the amount of skin exposed to heat. We also placed a
757
moist compress in front of the tragus during tympanoplasties with endaural approaches, or in any other over-exposed skin surface. In the last six months, with these precautions and also the fact that every surgeon in the department is now aware of this possible danger of complication we did not notice any new burn. In our hospital, neuro-surgeons also use an OPMI1 Pentero1 microscope. They did not report complication of this type. However, the skin of the scalp or of the back has a much more robust blood supply and is thicker than the skin of the external ear and is therefore less susceptible to burns. The orthopedic surgical team of our hospital did not neither experience burns possibly related to the use of an operating microscope among their patients. They used the same Leica M520F40 (Leica Microsystems1) microscope than ours for hand surgery and arterioveinous fistulas. In the literature, cases of cutaneous burns associated with operating microscope were described after otological surgery [1] and brachial plexus surgery [3,4]. According to Latuska et al., 82 unique cases of soft tissue burns associated with the use of an operating microscope had been voluntarily reported to the FDA since 2004. About 30% of cases occurred in the auricular region during tympanoplasties at focal length distances of 300 mm or less with xenon light source microscopes. It seemed important to us to report this possible complication of operating microscopes used at high light intensity levels and to present the safety measures.
References [1] R.F. Latuska, M.L. Carlson, B.A. Neff, et al., Auricular burns associated with operating microscope use during otologic surgery, Otol. Neurotol. 35 (2) (2014) 227–233. [2] T.B. Fitzpatrick, The validity and practicality of sun-reactive skin types I through VI, Arch. Dermatol. 124 (6) (1988) 869–871. [3] I.K. Choudhry, J. Kyriakedes, M.B. Foad, Iatrogenic burn caused by an operating microscope: case report, J. Hand Surg. Am. 38 (3) (2013) 545–547. [4] M.M. Al-Qattan, H.M. Clarke, A burn caused by the operating microscope light during brachial plexus reconstruction, J. Hand Surg. Br. 19 (Oct (5)) (1994) 550–551.
