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Positioning Accuracy in Otosurgery Measured with Optical Tracking.

Óvári A, Neményi D, Just T, Schuldt T, Buhr A, Mlynski R, Csókay A, Pau HW, Valálik I - PLoS ONE (2016)

Bottom Line: Instrument marker trajectories were compared within groups of experienced and less experienced surgeons performing uncompensated or compensated exercises.Experienced surgeons have significantly better positioning accuracy than novice ear surgeons in terms of mean displacement values of marker trajectories.The instrument support and the two-handed instrument holding techniques significantly reduce surgeons' tremor.

View Article: PubMed Central - PubMed

Affiliation: Department of Oto-Rhino-Laryngology, Head & Neck Surgery, "Otto Koerner", University Medical Center, Rostock, Germany.

ABSTRACT

Objectives: To assess positioning accuracy in otosurgery and to test the impact of the two-handed instrument holding technique and the instrument support technique on surgical precision. To test an otologic training model with optical tracking.

Study design: In total, 14 ENT surgeons in the same department with different levels of surgical experience performed static and dynamic tasks with otologic microinstruments under simulated otosurgical conditions.

Methods: Tip motion of the microinstrument was registered in three dimensions by optical tracking during 10 different tasks simulating surgical steps such as prosthesis crimping and dissection of the middle ear using formalin-fixed temporal bone. Instrument marker trajectories were compared within groups of experienced and less experienced surgeons performing uncompensated or compensated exercises.

Results: Experienced surgeons have significantly better positioning accuracy than novice ear surgeons in terms of mean displacement values of marker trajectories. The instrument support and the two-handed instrument holding techniques significantly reduce surgeons' tremor. The laboratory set-up presented in this study provides precise feedback for otosurgeons about their surgical skills and proved to be a useful device for otosurgical training.

Conclusions: Simple tremor compensation techniques may offer trainees the potential to improve their positioning accuracy to the level of more experienced surgeons. Training in an experimental otologic environment with optical tracking may aid acquisition of technical skills in middle ear surgery and potentially shorten the learning curve. Thus, simulated exercises of surgical steps should be integrated into the training of otosurgeons.

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Related in: MedlinePlus

Measurement set-up.Measurement set-up with stabilizer ring attached to deissected temporal bone (microscope not shown). Note surgeon’s hand resting with fingers V and IV on an armrest during manipulation with the forceps.
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pone.0152623.g003: Measurement set-up.Measurement set-up with stabilizer ring attached to deissected temporal bone (microscope not shown). Note surgeon’s hand resting with fingers V and IV on an armrest during manipulation with the forceps.

Mentions: An otosurgical microscope and otologic microinstruments were utilized: forceps and a pick(Karl Storz GmbH& Co. KG, Tuttlingen, Germany; catalog number: 221100 and225204) (Fig 1). The instruments were tested in different measurement protocols designed to simulate intraoperative conditions. Participants in the study performed basic surgical steps alternately using the pick and forceps. Overall, 10 different exercises were performed under visual control with the microscope (Table 1). Each session of measurements lasted for 10 s. There were several training trials to allow the subjects to become comfortable with the task but these were not included in the analysis. Some exercises traced freehand tremor while the test person was asked to hold an instrument above a fixed point on the promontory, without touching it (measurements No. 1, 2 and 7). Dynamic tasks consisted of either touching a point on the promontory with the pick (measurements No. 9 and 10), or grasping the long process of the incus with the forceps (No. 4, 5 and 6), 3–4 times each during the recording. These tasks approximated dissection exercises in middle ear surgery and the crimping process in stapes surgery, respectively. Tests were also performed with the instrument supported on a stabilizer tool (Figs 2–3) (No. 3, 6, 8 and 10). In the test battery, two-handed exercises were also included (No. 2 and 5). The surgeon’s hand (wrist) was always supported by an armrest during tasks (Fig 3). The effect of food abstinence, sleep deprivation or coffee consumption on tremor characteristics was not the subject of this study. However, physical exercise/sport up to 24 h before testing was an exclusion criterion. For the repeated measurements, we used an incomplete counterbalanced measures design using a “Latin Square” (Table 2). Counterbalancing was needed to ensure the validity of the experiment by eliminating factors changing the behavior of the test persons (for example, fatigue and stress). Every single task followed every other test once, allowing any carryover effects to be avoided during the statistical analysis.


Positioning Accuracy in Otosurgery Measured with Optical Tracking.

Óvári A, Neményi D, Just T, Schuldt T, Buhr A, Mlynski R, Csókay A, Pau HW, Valálik I - PLoS ONE (2016)

Measurement set-up.Measurement set-up with stabilizer ring attached to deissected temporal bone (microscope not shown). Note surgeon’s hand resting with fingers V and IV on an armrest during manipulation with the forceps.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814076&req=5

pone.0152623.g003: Measurement set-up.Measurement set-up with stabilizer ring attached to deissected temporal bone (microscope not shown). Note surgeon’s hand resting with fingers V and IV on an armrest during manipulation with the forceps.
Mentions: An otosurgical microscope and otologic microinstruments were utilized: forceps and a pick(Karl Storz GmbH& Co. KG, Tuttlingen, Germany; catalog number: 221100 and225204) (Fig 1). The instruments were tested in different measurement protocols designed to simulate intraoperative conditions. Participants in the study performed basic surgical steps alternately using the pick and forceps. Overall, 10 different exercises were performed under visual control with the microscope (Table 1). Each session of measurements lasted for 10 s. There were several training trials to allow the subjects to become comfortable with the task but these were not included in the analysis. Some exercises traced freehand tremor while the test person was asked to hold an instrument above a fixed point on the promontory, without touching it (measurements No. 1, 2 and 7). Dynamic tasks consisted of either touching a point on the promontory with the pick (measurements No. 9 and 10), or grasping the long process of the incus with the forceps (No. 4, 5 and 6), 3–4 times each during the recording. These tasks approximated dissection exercises in middle ear surgery and the crimping process in stapes surgery, respectively. Tests were also performed with the instrument supported on a stabilizer tool (Figs 2–3) (No. 3, 6, 8 and 10). In the test battery, two-handed exercises were also included (No. 2 and 5). The surgeon’s hand (wrist) was always supported by an armrest during tasks (Fig 3). The effect of food abstinence, sleep deprivation or coffee consumption on tremor characteristics was not the subject of this study. However, physical exercise/sport up to 24 h before testing was an exclusion criterion. For the repeated measurements, we used an incomplete counterbalanced measures design using a “Latin Square” (Table 2). Counterbalancing was needed to ensure the validity of the experiment by eliminating factors changing the behavior of the test persons (for example, fatigue and stress). Every single task followed every other test once, allowing any carryover effects to be avoided during the statistical analysis.

Bottom Line: Instrument marker trajectories were compared within groups of experienced and less experienced surgeons performing uncompensated or compensated exercises.Experienced surgeons have significantly better positioning accuracy than novice ear surgeons in terms of mean displacement values of marker trajectories.The instrument support and the two-handed instrument holding techniques significantly reduce surgeons' tremor.

View Article: PubMed Central - PubMed

Affiliation: Department of Oto-Rhino-Laryngology, Head & Neck Surgery, "Otto Koerner", University Medical Center, Rostock, Germany.

ABSTRACT

Objectives: To assess positioning accuracy in otosurgery and to test the impact of the two-handed instrument holding technique and the instrument support technique on surgical precision. To test an otologic training model with optical tracking.

Study design: In total, 14 ENT surgeons in the same department with different levels of surgical experience performed static and dynamic tasks with otologic microinstruments under simulated otosurgical conditions.

Methods: Tip motion of the microinstrument was registered in three dimensions by optical tracking during 10 different tasks simulating surgical steps such as prosthesis crimping and dissection of the middle ear using formalin-fixed temporal bone. Instrument marker trajectories were compared within groups of experienced and less experienced surgeons performing uncompensated or compensated exercises.

Results: Experienced surgeons have significantly better positioning accuracy than novice ear surgeons in terms of mean displacement values of marker trajectories. The instrument support and the two-handed instrument holding techniques significantly reduce surgeons' tremor. The laboratory set-up presented in this study provides precise feedback for otosurgeons about their surgical skills and proved to be a useful device for otosurgical training.

Conclusions: Simple tremor compensation techniques may offer trainees the potential to improve their positioning accuracy to the level of more experienced surgeons. Training in an experimental otologic environment with optical tracking may aid acquisition of technical skills in middle ear surgery and potentially shorten the learning curve. Thus, simulated exercises of surgical steps should be integrated into the training of otosurgeons.

Show MeSH
Related in: MedlinePlus