Читать книгу Pearls and Pitfalls in Head and Neck Surgery - Группа авторов - Страница 14
ОглавлениеThyroid and Parathyroid Glands
Cernea CR, Dias FL, Fliss D, Lima RA, Myers EN, Wei WI (eds): Pearls and Pitfalls in Head and Neck Surgery. Basel, Karger, 2012, pp 16–17
DOI: 10.1159/000338385
1.8 Minimally Invasive Video-Assisted Thyroidectomy
Erivelto M. Volpia Gabrielle Materazzic Paolo Micollic Fernando L. Diasb
aDepartment of Head and Neck Surgery, School of Medicine, University of São Paulo, São Paulo, and bDepartment of Head and Neck Surgery, National Institut of Cancer, Rio de Janeiro, Brazil; cDepartment of Surgery, University of Pisa, Pisa, Italy
P E A R L S
• A careful preoperative selection of the patients is the only guarantee for a low complication rate: remember that only around 15% of patients can benefit from minimally invasive video-assisted thyroidectomy (MIVAT).
• MIVAT allows an excellent endoscopic visualization of nerves and parathyroid glands, and good control of major vessels. Moreover, the single central access allows bilateral resection without additional scars and optimal visualization of nerves and parathyroid glands even when the lobe has been extracted and the operation is conducted under direct vision.
• When using a Harmonic® scalpel, avoid putting the tip (no matter whether the blade is active or inactive) close to the nerve (less than 5 mm) and, if necessary, do not hesitate to use a clip.
• Do not prolong the endoscopic dissection too much. Once the nerve and parathyroid glands are identified and dissected, extract the lobe and continue resection under direct vision.
• Better postoperative course and cosmetic outcome are major benefits of MIVAT.
P I T F A L L S
• Only a limited number of patients undergoing thyroidectomy can be submitted to MIVAT.
• A preoperatively understaged tumor, the presence of metastatic lymph nodes in the central compartment, and excessive size of the nodule/gland are the most frequent reasons for conversion.
• Improper use of the Harmonic scalpel can jeopardize tracheal surface.
Introduction
MIVAT is characterized by a single central incision of 1.5 cm, 2 cm above the sternal notch. The operative space is maintained through an external retraction: no gas insufflation is utilized. Subcutaneous fat and platysma are carefully dissected to avoid any minimum bleeding. The midline is divided longitudinally as much as possible (3-4 cm). A 30° 5-mm endoscope is inserted through the skin incision. Under endoscopic vision, the dissection of the thyrotracheal groove is completed by using small instruments: atraumatic spatulas in different shapes, spatula-shaped suction tip, ear-nose-throat forceps, and scissors. Hemostasis is achieved by ultrasonic shears (Harmonic) and small (3 mm) vascular clips, either conventional or absorbable.
A careful selection of the patients is essential for a low incidence of complications and a good outcome. An important limit is the volume both of the nodule and of the gland. Similarly, the presence of adhesions, like in reoperations, can make the dissection extremely difficult. Thyroiditis can no longer be considered a contraindication [1]. General indications might be summarized in: (1) thyroid nodules less than 30 mm on their largest diameter, (2) thyroid gland volume less than 25 ml, and (3) no previous neck surgery or irradiation. MIVAT is indicated for benign nodules and low- and intermediate-risk well-differentiated thyroid cancers [1, 2].
Potential complications of MIVAT are roughly the same as in open surgery [1–4].
Practical Tips
MIVAT steps reproduce the conventional operation. Operative space is maintained by small retractors put on the strap muscles. The gland is approached from a central and anterior cervical wound. During MIVAT, the magnification of the endoscope allows a better visualization of the structures and utilization of spatulas and other atraumatic tools enable a less traumatic dissection.
The external branch of the superior laryngeal nerve can be easily identified during most of the procedures after the superior thyroid pedicle has been dissected.
The inferior laryngeal nerve also can be easily identified during MIVAT, due to the magnification of the endoscope. It is important to emphasize that during this phase of the operation, the endoscope must be held in an orthogonal position with the thyroid lobe and neurovascular trunk, with the 30° objective directed downward.
The incorrect use of the Harmonic scalpel can jeopardize the nerve. During the artery section, the surgeon should always remember to keep the inactive blade of the instrument oriented to avoid injuring the nerve, which always lies posterior to it and is very sensitive to heat transmission. There are some concerns about stretching the parenchyma and the inferior laryngeal nerve during the extraction phase. The complete dissection of the nerve during the endoscopic phase and lower traction on the lobe during the extraction prevents neuropraxia.
The parathyroid glands are easily visualized by the endoscope magnification and their manipulation by spatulas is easier than in open surgery.
Major bleeding can occur by injury of the upper pedicle and of small branches of the inferior thyroid artery. During MIVAT, the section of the upper pedicle is performed endoscopically as the first step of the procedure, completely under visual control. During this phase, the endoscope must be held almost parallel to the neurovascular trunk, with the 30° objective rotated upward, looking at the roof of the operative space.
Conclusion
In this chapter, indications and potential complications of MIVAT are discussed, and practical tips to avoid or at least limit the complication rate are highlighted. As long as the inclusion criteria are carefully respected, the MIVAT complication rate is similar to the conventional technique. Magnification during the endoscopic phase of the operation allows careful dissection of superior and inferior laryngeal nerves, easy identification and preservation of parathyroid glands, and safe section of the major and minor vessels under direct vision. Usually, better postoperative course and superior better cosmetic outcome are achieved, but only about 15% of patients fit the inclusion criteria, particularly in endemic goiter areas. This fact probably limits the diffusion of this technique, except in referral centers [2–4].
References
1 Minuto MN, Berti P, Miccoli M, Ugolini C, Metteucci V, Moretti M, Basolo F, Miccoli P: Minimally invasive video-assisted thyroidectomy: an analysis of results and a revision of indications. Surg Endosc 2012;26:818–822.
2 Del Rio P, Sommaruga L, Pisani P, Palladino S, Arcuri MF, Franceschin M, Sianesi M: Minimally invasive video-assisted thyroidectomy in differentiated thyroid cancer: a 1-year follow-up. Surg Laparosc Endosc Percutan Tech 2009;19:290–292.
3 Kim AJ, Liu JC, Ganly I, Kraus DH: Minimally invasive video-assisted thyroidectomy 2.0: expanded indications in a tertiary care cancer center. Head Neck 2011;33:1557–1560.
4 Miccoli P, Berti P, Frustaci GL, Ambrosini CE Materazzi G: Video-assisted thyroidectomy: indications and results. Langenbecks Arch Surg 2006;391:68–71.
Dr. Erivelto M.Volpi, MD
R. das Figueiras, 551 ap. 31
Santo Andre, SP 09080-370 (Brazil)
E-Mail eriveltovolpi@hotmail.com
