(332) A Head-to-head Ergonomic Risk Assessment of the 4K-3D Exoscope vs. Standard Operating Microscope for Male Fertility Microsurgery
Authors: Deebel N , Reddy R , Weber A , Chu K , Ory J , Terlecki R , Ramasamy R 
Published: May 2023

Abstract

Introduction
Surgery for male fertility is ergonomically demanding secondary to the tedious and lengthy nature of surgeries performed. The standard operating microscope places surgeons in uncomfortable positions including a “heads down” posture which has been demonstrated to predispose microsurgeons to cervical strain and chronic pain. The 4K-3D exoscope eliminates the need for eyepieces allowing for a “heads up” posture. Additionally, given the standing position of surgeons using the 4K-3D exoscope, it is thought that surgeons may be able to maintain a more “neutral” upper arm position therefore reducing upper body stress.

Objective
This study aims to stratify ergonomic risk amongst infertility surgeons using the 4K-3D exoscope versus the operating microscope with wearable technology. Secondary objectives included surveying for optical differences and teaching utility between surgical modalities during infertility microsurgery.

Methods
The participating right-handed surgeon was fitted and calibrated with three wearable sensor inertial measurement units (IMUs) on the head and upper arms in the neutral position. Each IMU is comprised of an accelerometer, magnetometer, and gyroscope. This allows for measurement of the surgeon’s joint angle change throughout 4K-3D and operating microscope use. Microscopic surgical procedures which were considered for inclusion were: vasovasostomy, vasoepididymostomy, varicocelectomy, testicular sperm extraction (mTESE), and microsurgical epididymal sperm aspiration (MESA). The previously validated rapid upper limb assessment (RULA) was used to determine the proportion of time spent in ranges of risk. Categories 1-4 were assigned for the head and upper extremities (4= highest ergonomic risk). Finally, a 5-point Likert scale questionnaire related to ergonomic, optical, and teaching metrics was administered to six microsurgeons. Chi-squared analysis was used to test for differences in proportions.

Results
A total of 500 and 479 microsurgical minutes from 4K-3D exoscope and operating microscope guided surgeries respectively were analyzed. Examination of the bilateral upper extremities showed that the 4K-3D exoscope significantly favored score 1 positioning compared to the operating microscope indicating a lower level of ergonomic stress with 4K-3D exoscope usage (75.3% vs. 51.5%; p &lt; 0.0001). Finally, the operating microscope exposed the surgeon to a higher level 3 flexion (5.5% vs. 1.9%; p &lt;0.0001). When examining the head and neck, significantly more time was spent in the “extension” position (any degree of neck extension past neutral) using the 4K-3D exoscope compared to the operating microscope (51.8% vs. 19.5%; p &lt; 0.0001). During 4K-3D exoscope use, 67% of neck extension time was between 0-10 degrees. Additionally, 0-10 degrees of flexion (score 1) were maintained 33.6% vs. 7.7% of the time in operating microscope vs. 4K-3D exoscope respectively (p &lt; 0.0001). Assessment of the 5-point Likert scale survey demonstrated that most surgeons favored the 4K-3D exoscope in questionnaire topics of ergonomics, optics/clarity, lighting, and teaching.

Conclusions
The 4K-3D exoscope offers the surgeon favorable ergonomic positioning for the upper extremities which may reduce upper body work stress related injury. Similarly, a greater proportion of operative time was spent with the neck in mild extension with 4K-3D exoscope utilization which may place the patient in a “low risk” position (less than 20 degrees of extension) according to contemporary studies.

Disclosure
Yes, this is sponsored by industry/sponsor: Investigator Initiated Grant from Olympus.

Clarification
Industry funding only - investigator initiated and executed study
Any of the authors act as a consultant, employee or shareholder of an industry for: Boston Scientific.