Periodontal and Peri-implant Plastic Microsurgery

Minimally Invasive Techniques with Maximum Precision

Glécio Vaz de Campos, Cláudio Julio Lopes

• Editorial: Quintessence Publishing Co, Inc
• Año: 2021
• ISBN:
  9781647240912
• Categoría: Medicina
• Categoría: Odontología

The minimally invasive philosophy underpinning periodontal and peri-implant microsurgery respects biologic principles, preserves healthy tissues, enhances patient well-being, and maximizes soft tissue esthetics. Distributed into nine carefully sequenced chapters, this book first presents the minimally invasive philosophy before demonstrating the protocols necessary for the development of new skills for the surgeon, walking the reader through each phase of learning and practice required to advance to the next. Once this training is complete, the book reviews the basics of ergonomics, magnification, and subepithelial connective tissue grafting before moving on to the hallmark chapter on microsurgical techniques. This chapter comprises half the book and systemically presents each microsurgical technique, illustrating it step by step and then showcasing its use in multiple clinical case examples. Digital planning and suturing are emphasized, as well as esthetic microsurgery and the correlation of these techniques with implantology. The authors' end goal is to equip clinicians to perform increasingly conservative, biologic, and predictable procedures with the greatest precision possible.

1

Minimally Invasive Surgery

Clinical outcomes are enhanced when the most accurate surgical approaches are performed using magnification systems, precise instruments, and microsurgical materials.

Reconstructive Vascular Microsurgery

Microsurgical techniques have a long history, but the broad application of vascular microsurgery in different medical specialties is a relatively recent phenomenon. The history of microsurgery is directly related to the development of optical magnification of the operatory field and the refinement of microinstruments.1

The first techniques to use the microscope were developed for research purposes. Carrel’s work on vascularized organ transplantation in 1902 seems to be the first record of the application of microsurgical techniques.2 Otorhinolaryngology was the first specialty to consider the benefits of microsurgery, and eye and ear microsurgery led to the development of more sophisticated operative microscopes, equipment, and techniques.

Otorhinolaryngology was the first specialty to consider the benefits of microsurgery

Jacobson et al were the first to publish on the use of microsurgery for small blood vessel anastomosis,3 and since then the use of magnifying glasses and microscopes has grown and developed widely. Today, more complicated procedures are possible both in animal models and clinically in patients. The most advanced techniques are initially developed and trained in animal models and then transferred to clinical use. Magnifying loupes are used for lower magnification levels (2× to 8×), while operative microscopes work at 9× to 40× magnification.

Microsurgery did not develop as a subspecialty of medicine. On the contrary, microsurgical techniques have been incorporated by a wide variety of specialties, such as pediatric surgery, neurosurgery, plastic surgery, and vascular surgery, being an essential element in the outcome of many surgeries and treatments.4

Learning microvascular techniques in the microsurgery laboratory is the first step for surgeons who wish to adhere to this treatment philosophy. Successful training in microvascular techniques requires excellent concentration and persistence, which may lead to frustration at first. The training environment should be calm and preferably without distractions of any kind. In order to maximize training and lessen the physiologic tremor that almost everyone experiences to some degree, appendicular muscle impact exercises, caffeine, and nicotine should be avoided 24 hours before any training. Also, the activity should be interrupted for 5 minutes every hour of training in order to reduce fatigue.

The instruments used for microvascular anastomosis include jeweler’s micro pliers, microscissors, microclips, a 10-mL syringe with 90-degree angled blunt insulin needle, clip holder, no. 11 scalpel, retractors, and monofilament sutures. The suture size should be 11-0 for vessels with 0.5-mm diameter, 10-0 for vessels with 1-mm diameter, and 9-0 for vessels with 2-mm diameter.

Surgeons must know how to work the operative microscope lens system and should opt for the appropriate magnification for the work to be performed. Binocular vision and work in the center of the field are also crucial for proper technique.

Once microsurgery trainees know the technical environment, they can begin to acquire and develop the skills for the microsuture technique. Initially, the training for this technique is practiced on nonanimal models prepared especially for this procedure. Suturing a rubber model is a training step that precedes suturing living and delicate structures and uses a wooden board with a hollow center covered with a rubber or latex strip. Several cuts in different shapes and sizes should be made in the rubber strip to simulate the edges of the structures that will be sutured, offering varying degrees of difficulty.5^,6

Microsutures are made by following some basic concepts. The point of entry of the needle must be perpendicular to the entry plane; otherwise, the edge will be inverted. The distance from its entry to the edge should be three times the diameter of the needle. If this distance is not respected, the edges will overlap. The needle exit on the other side should also be perpendicular to the cut in the rubber. As the surgeon’s confidence and skill improve, the diameter of the suture should decrease, and the microscope should be zoomed in progressively.5^,6

Following initial training on rubber models, practice should begin on animal models. Wistar rats are the ideal animals to practice vascular microsurgical techniques in the laboratory. The rats have a suitable vascular network with many easily accessible vessels and nerves of appropriate gauge for different types of sutures. As a basis for comparison, a 300-g rat, considered the ideal size, has a 1-mm-diameter femoral artery, a 2-mm aorta, and a 1.5-mm carotid artery. The anesthetic techniques must provide an adequate chemical containment, hypnosis, and analgesia for pain to allow for a fast and smooth recovery from the anesthesia.

The most favorable areas for training in a rat model are the inguinal region (femoral artery and vein) and the cervical region (carotid artery and jugular vein). The most commonly used techniques are end-to-end and end-to-side anastomosis. After preparation and proper anesthesia of the animal, delicate subcutaneous dissection is performed, and retractors are placed on the incision margins. The vessels used in training are identified and dissected with the microscissors, individualizing them. The difference between arteries and veins is observed by three main characteristics: arteries cross over veins, have a smaller gauge, and have a thicker vascular wall. Despite the smaller size, the arteries offer easier manipulation and have more resistant walls. For this reason, they are the vessel of choice for initiating microvascular anastomosis training. Handling should be minimal to avoid spasm and injury to the vascular wall, and the vessel’s outermost coat (ie, tunica adventitia) should be used to mobilize it (Fig 1-1a).

Fig 1-1 (a) Wistar rat prepared for laboratory training of microvascular anastomosis. (b) Microclip with the two stumps of the vessel stabilized for the first microsutures at positions 6 and 12 o’clock. (c) Exercise of microvascular anastomosis in the femoral artery finalized before removal of microclip. (d) The finalized femoral artery and vein microvascular anastomoses after microclip removal. Observe hemostasis achieved after microsutures.

To begin the microvascular anastomosis technique, the distal and proximal microclips are placed, followed by a complete transverse incision of the vessel using microscissors. Heparinized saline solution is used to irrigate the interior of the vessel in both stumps. The anastomosis is performed with the first two sutures placed on the upper and lower poles at 12 o’clock and 6 o’clock, respectively (Fig 1-1b). A long suture termination is left for later traction in order to visualize the position of the vessel edges and obtain a symmetric suture. The next suture sites to be performed with single stitches are those corresponding to 9 o’clock, 7:30, and 10:30 (eg, the posterior wall of the vessel). In order to achieve this, the clips are rotated 10 degrees to expose this wall. The next step is to undo the rotation of the vessel and suture its anterior wall with simple stitches at 3 o’clock, 1:30, and 4:30 (Fig 1-1c). Finally, the microclips are removed, and the region of the vessel with blood inside is drained toward the anastomosis. At this point, the patency of the vessel and the possible leakage of ...