Refinement on surgical technique: role of magnification.

Numerous technological advances have resulted in a revolutionary development in surgical technique. Such progress includes magnification devices, suture and implant materials, developments in endoscopy, intraoperative imaging, stereotactic surgery, and miniaturization of instruments, among others. We focus on the role of magnification in this editorial, and will consider others in subsequent ones.

The application of magnification has indeed revolutionized microvascular and reconstructive surgery.[1] Complex and specialized procedures have become possible in the areas of neurosurgery, vascular surgery, hand and plastic surgery, otorhinolaryngology, transplantation surgery, oncology, urology, pediatric surgery, and other surgical disciplines.

Magnification is achieved using binocular loupes, endoscopes or microscopes. Loupes in general use typically have a magnification of 2.5x to 5x, while microscopes provide a magnification of 6x to 40x. Loupes should preferably be custom made, to take into account corrected vision and interpupillary distance. Other considerations are the field of view, depth of a field, and the working distance. Smaller magnifications reveal a wider field at the expense of tissue details. A comfortable working distance prevents excessive body angulations and strain.

With magnification, tissue visualization is enhanced, precise anatomic details are appreciated, suture placement is precise and easier, microsurgical instruments can be better positioned, and smaller neurovasculature appreciated. Magnification may lead to a substantial decrease in positive margins[2] and nerve injuries[3] during oncological surgeries. Some have found loupes crucial for wound care and skin closure in the Emergency Room.[4] Magnification obtained during endoscopic surgical procedures has helped in the understanding of anatomic details of various organs and regions. Magnification has made it possible to correct numerous congenital anomalies in neonates and to create arteriovenous fistula for dialysis in children.

Despite these apparent advantages many surgeons do not embrace the use of magnification. In a survey in Scotland by Jarret,[5] general surgeons, urologists, orthopedic surgeons, and gynecologists are infrequent or non-users of magnification.

Magnification is cumbersome, may increase surgical time, and cause neck strain and fatigue. Stereoacuity and depth of perception are reduced with increasing magnification, which cannot be improved with the familiarity of the magnifying instrument.[6] Magnifying lenses may also be fogged during surgery. A microscope limits the operation field and leads to a longer operating time.[7]

Unlike microscopes, loupes are cheaper and more affordable for third world surgeons.[8] In many situations they can obviate the need for a microscope. Microsurgical procedures involving vessels greater than 1.5 mm can safely be performed with loupes of 3.5x to 4x magnification.[9] In some head and neck, free, microvascular tissue transfers, the usefulness of loupe magnification is validated.[10] Loupes offer comfort and easy access to an uncomplicated visualization of the operating field.

In conclusion, the use of magnification is encouraged to increase surgical refinement. Both microscopes and loupes have their own significance. Loupes are generally useful across several surgical disciplines. We encourage surgeons in developing nations, where there is no funding for microscopes, to explore the potentials of loupe-magnification.