Fundamentals of Microsurgery David A. Wilkie, DVM, MS, Diplomate ACVO Professor Department Chair The Ohio State University [email protected] Microsurgery Ophthalmic Vascular Urogenital Neurologic Microsurgery Definition Surgery utilizing magnification and small, handheld instruments and suture to correct defects in small &/or delicate tissues 16th CENTURY Ouch! To do a job….you need the right tools Microsurgery Differs from traditional surgery in: Surgeon position Magnification Specialized instrumentation Suture and needle size Dr. Dyce Surgeon Position Surgical Position Seated Specialized chairs with armrests Arms resting on armrest Essential for fine motor control Microsurgery Surgical Position Seated Specialized chairs with armrests Arms resting on table or armrest Essential for fine motor control Able to adjust height Height is adjustable Elbows and wrists are locked Magnification - There are choices… Fundamentals of Microsurgery Magnification – purpose: provide an improved view of the tissues of concern Will vary by tissue of interest allow a comfortable working distance for the surgeon Back straight, arms at 90 degrees facilitate adjustment of the interpupillary distance to suit the surgeon permit a wide field of view Microsurgery Differs from traditional surgery in: Specialized instrumentation Surgeon position Magnification Type & size of suture Human Hair 9-0 MonofilamentVicryl Fundamentals of Microsurgery Rules of microsurgery are meant as a foundation to guide the beginning ophthalmic surgeon Once understood, rules can occasionally be molded and adapted to suit the surgeon and the individual patient The surgeon must however always re-visit the basic microsurgical rules and principles when a new or unfamiliar technique or procedure is to be performed Fundamentals of Microsurgery Surgeons must have a goal and a plan to achieve the goal, but must also be adaptable and familiar with more than one technique so that obstacles encountered during the surgical procedure may be overcome. Fundamentals of Microsurgery Not all surgeries proceed according to the plan. All eyes are different and the surgeon who says “I always do it this way” is destined to encounter situations where their technique does not meet the patients needs. Fundamentals of Microsurgery Think of surgery like your commute to work We may all travel a different a route and method We get there in various ways, BUT…..we all get to the same destination Fundamentals of Microsurgery Think of surgery like your drive to work You have a route that you usually take Do you know other routes? What if there is an accident or detour, how would you respond? Fundamentals of Microsurgery Regardless of our individual variations, we must all follow the basic rules: to use appropriate magnification and instrumentation to be efficient and precise to ensure minimal tissue trauma to minimize surgical time to maintain the anterior chamber using small incisions and viscoelastic materials to obtain excellent tissue wound apposition with the smallest and most appropriate suture materials to achieve a successful, comfortable, cosmetic and whenever possible, visual outcome Fundamentals of Microsurgery The surgeon must at all times keep several ophthalmic microsurgical principles and rules in mind: time is trauma tissues should be handled as little and as efficiently as possible ophthalmic microsurgery procedures are comprised of a series of steps in sequence, each one designed to move the surgery forward towards the goal. The surgeon must be familiar with these steps, perform them economically, efficiently and atraumatically, making no wasted movements and moving steadily forward towards the surgical goal. Fundamentals of Microsurgery Magnification Began in 1876 using simple head loupes First microscope for human ophthalmic surgery described in 1950 and in veterinary ophthalmology in the 1970’s Fundamentals of Microsurgery Magnification – purpose: provide an improved view of the tissues of concern Will vary by tissue of interest allow a comfortable working distance for the surgeon Back straight, arms at 90 degrees facilitate adjustment of the interpupillary distance to suit the surgeon permit a wide field of view Fundamentals of Microsurgery Magnification Beginning surgeons should start with magnification early as part of their basic training Will improve their tissue handling and appreciation for tissue trauma and wound apposition Microsurgery Magnification Eyelids, conjunctiva 2-5X Cornea, urogenital 5-10X Intraocular, vascular, neurologic 8-15X 2.5X 10X 5X 15X Fundamentals of Microsurgery Magnification Essential to select the appropriate magnification. If we consider ourselves ophthalmic microsurgeons then we must use the appropriate magnification at all times. Fundamentals of Microsurgery Magnification Head Loupes used for microsurgery when operating microscopes are not available such as in the field or a large animal barn setting and for orbital and eyelid surgeries Operating Microscope Better choice, especially for ≥ 5X Fundamentals of Microsurgery Magnification Head Loupes Simple loupes Galilean-type loupes Prismatic loupes (Keplerian) Fundamentals of Microsurgery Magnification Simple Loupes one pair of positive meniscus lenses limited by spherical aberration and color fringing plastic construction fixed interpupillary distance very short working distance poor surgeon body and arm position strain on the surgeon’s neck and back. POOR CHOICE Fundamentals of Microsurgery Magnification Galilean Loupes up to 2.5x magnification multiple lenses to offer magnification and are generally lightweight and less expensive adjustable interpupillary distance working distance varies Fundamentals of Microsurgery Magnification Prismatic Loupes up to 8.0x magnification ≥5.0x a microscope is preferred highest optical quality series of lenses and prisms to magnify the subject similar in principle to low-power telescopes greater magnification sharp resolution greater depth of field heavier and more expensive Fundamentals of Microsurgery Magnification Prismatic Loupes As magnification increases they become long and heavy Shallow depth of field Head movements make use difficult (>5X) Fundamentals of Microsurgery Magnification Loupes Surgeons should have their own loupes Surgeons should have both a Galilean and a Prismatic set with lower and higher magnification Can add light source if desired Fundamentals of Microsurgery Magnification Loupes - styles Fundamentals of Microsurgery Magnification Loupes - light Fundamentals of Microsurgery Magnification Operating Microscope magnification from 5-40x For ophthalmic microsurgery, magnification of 5-20x is generally sufficient. Increased cost and maintenance longer surgical setup time less intraoperative positioning flexibility less portability Fundamentals of Microsurgery Magnification Operating Microscope Coaxial illumination Projected through viewing objective variable magnification motorized continuous zoom motorized focus motorized X-Y axis Foot controls adjust light, magnification, zoom, focus and X-Y axis Allow multiple surgeons Floor, table or ceiling mount Additional attachments Fundamentals of Microsurgery Magnification Operating Microscope Floor mounted Ceiling Mounted Table Mounted Portable 2.0-9.0X Fundamentals of Microsurgery Magnification Operating Microscope Attachments Video/camera laser – need a filter Fundamentals of Microsurgery Magnification Operating Microscope While portable - movement over distance is discouraged Articulating arms with tension adjustment Gross focus done manually prior to start of surgery Fundamentals of Microsurgery Magnification Operating Microscope Optical head has Primary surgeon Beam splitter Assistant surgeon Video attachment Fundamentals of Microsurgery Magnification Operating Microscope Objective lens 150-400mm 175 mm most common in ophthalmology Magnification: Magnification = Focal length of binocular tubes x magnifying power of Focal length of the objective the eye pieces x magnifying power of magnification changer Fundamentals of Microsurgery Magnification Prior to surgery Center the X-Y axis Lowest magnification Zero the fine focus Adjust the gross focus manually Fundamentals of Microsurgery Magnification Prior to surgery Adjust the interpupillary distance Fundamentals of Microsurgery Magnification Prior to surgery Adjust the chair and table height Fundamentals of Microsurgery Magnification Prior to surgery Ensure the surgeons view and the video view are both in focus Verify at the highest magnification to be used Fundamentals of Microsurgery Magnification Prior to surgery Position all foot pedals where they can be reached With multiple foot pedals the microscope pedal goes to the non- dominant foot Fundamentals of Microsurgery Magnification Prior to surgery KNOW WHERE ALL THE FOOT PEDAL CONTROLS ARE BEFORE STARTING SURGERY Fundamentals of Microsurgery Magnification Use your magnification Adjust during surgery – cornea vs lens Fundamentals of Microsurgery Magnification As magnification increases The field of view and depth of field decrease At 3.5X - field of view is 50mm and depth of field is 2.6mm At 20X - field of view is 10mm and depth of field is 0.4mm Fundamentals of Microsurgery Magnification As magnification increases The field of view and depth of field decrease At 3.5X - field of