Minimally Invasive Surgery (VMIS) for Bone Regeneration

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© Springer Nature Switzerland AG 2020

S. Nares (ed.)Advances in Periodontal Surgerydoi.org/10.1007/978-3-030-12310-9_6

6. Videoscope-Assisted Minimally Invasive Surgery (VMIS) for Bone Regeneration

Stephen Harrel1  
(1)

Department of Periodontology, Texas A&M College of Dentistry, Dallas, TX, USA
 
 
Stephen Harrel
Keywords

Minimally invasiveVideoscopePeriodontal surgeryBone regenerationBone graftsBiologics

Minimally invasive surgery was first defined in a 1990 editorial in the British Journal of Surgery as the ability to perform a standard surgical procedure through a much smaller opening than had been used previously [1]. The need for this definition was based on the growing popularity of medical surgical procedures that were being introduced at the time that used various forms of improved lighting and magnification. These visualization improvements included surgical loops with headlights, surgical microscopes, and hard (non-flexible) endoscopes. Prior to the introduction of the term “minimally invasive surgery,” the instrument used for magnification often defined many of these procedures. Examples would be microsurgery when a surgical microscope was used or endoscope surgery when an endoscope was used. In the process of introducing the concept of minimally invasive surgery to medicine in 1993, Hunter and Sackier made the point that the procedure had to accomplish the same beneficial end point that was obtained with larger surgical openings [2]. This was to counter the fact that in some cases surgeons were performing a surgical procedure using smaller incisions and using new technology but were not obtaining the positive results that were obtained with traditional larger incisions. Periodontal procedures have faced a somewhat similar dilemma with the words “minimally invasive” being applied to many procedures that are not significantly smaller or as effective as more traditional procedures using a larger access approach.

In the periodontal literature, the first description of a minimally invasive procedure was in 1995 by Harrel and Rees [3]. Following the original description, a detailed minimally invasive procedure for periodontal bone regeneration (MIS) was described by Harrel in 1999–2001 [46]. This procedure used much smaller incisions than are traditionally used for bone grafting. At that time either surgical magnification loops or a surgical microscope was utilized for visualization. Several case series using this technique were published showing results that were similar or improved when compared to traditional bone regeneration procedures.

In 2005, Harrel and Wilson published a case series that described the use of enamel matrix derivative (EMD) used in conjunction with the then current minimally invasive bone grafting procedure. Improved results from MIS were reported at 1 year postoperatively [7]. In 2009, a 6-year long-term report of this same group of patients showed that the favorable results originally reported were stable or improved over time [8]. This was felt to establish the fact that a minimally invasive surgical approach yielded long-term results that were equal to or improved when compared to more traditional large incision surgery. Harrel and Wilson used high magnification surgical loops for their technique. In 2007, Cortellini and Tonetti modified the original Harrel MIS procedure to include the papilla preservation incision and suturing techniques. They termed their procedure the minimally invasive surgery technique (MIST). They published several studies that showed various modifications of the MIST approach yielded results similar to those reported by Harrel and Wilson [9]. Cortellini and Tonetti utilized a surgical microscope for their technique.

Within this historical context, it became obvious that a new means of visualization was necessary to allow a move to smaller incisions than those being used at that time. The surgical access incisions reported by Harrel and Wilson as well as those used by Cortellini and Tonetti while much smaller than traditional incisions remained larger than ideal. The size and types of incisions were dictated by the use of the visualization method used, either magnification loops or a surgical microscope. Additionally, these forms of magnification were more applicable to the use of a buccal approach, which influenced the placement of entry flaps for all types of minimally invasive periodontal surgery. A surgical microscope or surgical loops can be used with a mirror for lingual access flaps, but this tends to limit the field of vision, and it is difficult to obtain visual angles that allow complete visualization of the bony defect. Because a buccal approach necessitates a flap in an esthetically sensitive area, a visualization method that allows for the effective use of a lingual approach is preferable.

Based on the desire to utilize both smaller surgical openings and the need to perform surgical procedures from the lingual, research was initiated to develop a videoscope that would allow for these improvements. A videoscope is a very small camera that can be placed in the surgical site. This is different from an endoscope that places an optical lens in the surgical site and has an external camera. A videoscope is capable of much improved true color optics and also can be made smaller than most traditional endoscopes. A videoscope for use in periodontal minimally invasive surgery has to be small enough to allow visualization of the defect and allow for easy access to the defect using a lingual approach and needs to incorporate technology that prevents the fouling of the lens with moisture, blood, or surgical debris. Past attempts to use a videoscope for periodontal surgery had failed to achieve these results due to both size constraints and the fact that the lens could not be kept clean and would rapidly be obscured by blood. With grants from the National Institutes of Health (Bethesda, MD, USA), a videoscope prototype was developed that overcame these problems and was first described in 2013 [10]. The currently used videoscope is shown in Fig. 6.1. This videoscope is small enough to fit into minimally invasive incisions and uses a constant stream of air to keep the optics clear.

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Fig. 6.1

(a) The MicroSight™ videoscope used for VMIS (b). The handpiece of the videoscope. The rotatable tip of the handpiece has an integral tissue retractor (arrow) to allow gentle displacement of the tissue for visualization

6.1 Videoscope-Assisted Minimally Invasive Surgery (VMIS) for Periodontal Defects

A surgical procedure that utilized the advantages of the newly developed videoscope was designed and tested, again with the assistance of National Institutes of Health funding. The procedure has been described as videoscope-assisted minimally invasive surgery or VMIS. The essential elements of VMIS are (1) the use of only a single small, usually lingual, flap, (2) the use of split thickness incisions to preserve as much of the blood supply as possible, (3) avoiding the use of a periosteal elevator so that most of the blood supply from the periosteum to the bone and soft tissue remains intact, (4) leaving the buccal papilla and esthetic facial gingiva intact and unreflected whenever possible, and (5) the use of simple suturing techniques that do not pass sutures through the thin marginal tissue of the incision. Each of these steps is outlined in detail in the following paragraphs.

The guiding principle for the design of the soft tissue access flaps used in VMIS is aimed at preserving as much of the blood supply to the surgical area as possible. This is based on the experience in medicine that the less damage to the blood supply, the more rapid the healing of the tissue and the more rapid the healing, the less discomfort and morbidity the patient will experience. It is also theorized that better preservation of the blood supply will be beneficial in the regeneration of bone and periodontal attachment. Another factor in the design of VMIS flaps is, if at all possible, avoidance of any flaps or incisions on the facial aspect in order to preserve esthetic soft tissue contours.

The VMIS procedure may be used in multiple situations but is most frequently used to treat the isolated interproximal deep lesions with bone loss that have not fully responded to nonsurgical periodontal treatment. The flap design described here assumes an area of bone loss confined to the interproximal area with minimal extension to the facial and lingual of the teeth. In most cases, the flap can be limited to the lingual of the lesion. The videoscope allows for visualization of the interproximal bone structure from the lingual without the elevation of the papilla. Unlike the surgical microscope, visualization of the lesion utilizing a lingual access incision is straightforward and relatively simple. The obvious exception to the use of a lingual flap is when the bony defect is isolated to only the buccal aspect.

The incisions are shown in Fig. 6.2. A sulcular incision is made in the interproximal aspect of the teeth in the area of bone loss. Care is taken in making this sulcular incision to not remove any of the gingival tissue. In other words, unlike many traditional types of periodontal surgical procedures, removing the sulcular lining or removing a small “collar” of soft tissue is avoided. The purpose of the sulcular incision is merely to sever any attachment to granulation tissue that has formed in the bony defect. The sulcular incision is not for the purpose of introducing a periosteal elevator to elevate a “flap.” A periosteal elevator is designed to remove the periosteum from the underlying bone. The periosteum is the major blood supply to the gingival tissue, and with VMIS, every effort is made to retain the periosteum undisturbed. Any further tissue reflection uses a split thickness incision made by sharp dissection on the lingual at the base of the interproximal papilla. An Orban Knife that has been reduced in size is usually used for this procedure. The incision should be made to the crest of the remaining bone. This procedure is shown in Fig. 6.3. If at all possible, this split thickness incision is not extended beyond the margin of the remaining bone and in no instance is a periosteal elevator used to make the flap larger. The purpose of this incision and flap is to gain enough access for the placement of the soft tissue retractor that is integral to the videoscope. The videoscope in place and the integral adjustable retractor used for tissue control is shown in Fig. 6.4. Depending on the anatomy of the teeth and the bony lesion, the mesiodistal length of this incision is usually no more than 5–6 mm, and the depth of the incision is dictated by the remaining height of the bone on the lingual aspect of the defect.

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Aug 28, 2021 | Posted by in Periodontics | Comments Off on Minimally Invasive Surgery (VMIS) for Bone Regeneration
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