ENDOCRINE SURGERY - PART 4 potx

15 Endoscopic Thyroid Surgery Laurent Biertho Les Cliniques Saint Joseph, Liege, Belgiu m Michel Gagner Mount Sinai School of Medicine, New York University, New York, New York, U.S.A. 1 INTRODUCTION Thyroid resection is one of the most common operations performed throughout the world. This procedure is classically realized through a transverse cervical incision and is a ssociated with a very low morbi dity and mortality rate. However, the visible scar on the anterior surface of the neck is disliked by many patients, especially by young women in which this operation is commonly performed. With the general tendency to perform a less invasive surgery, an endoscopic approach has been applied to neck surgery. The first endoscopic neck exploration was performed in 1995 for parathyroidectomy (1). Since then, endoscopic parathyroid resections have been performed worldwide, and large series have been reported (2,3). After experimentation on animal models (4) showing the feasibility of the technique, Hu ¨ scher performed the first endoscopic thyroid resection in 1997 (5). Nonethe- less, endoscopic thyroid surgery is more technically challenging, compared to parathyroidectomy, due to the size of the thyroid gland, the extent of the dissection required, and the higher rate of malignancy. The current indications, techniques, and results of endoscopic thyroid surgery are described in this chapter. 2 PREOPERATIVE WORKUP In addition to a detailed history, physical examination, and thyroid funct ion tests, the following exams are usually realized. Ultrasonography is performed to define the dimen- sion, nature and localization of the thyroid pathology and to evaluate the contralateral lobe. A Doppler study is also used to assess the vascularization of the gland in case of thyroiditis. Fine needle aspiration is used to define the histology of ‘‘cold’’ nodules and, before endoscopic thyroid surgery, to rule out a carcinoma. Atypical or suspicious cytology are currently considered as a contraindication for an endoscopic resection. One concern about fine needle aspiration is that subclinical hemorrhage can create substantial adhesions, making endoscopic dissection difficult (6). Other preoperative imaging studies (scintigraphy, computed tomography (CT) scanner, magnetic reso- 201 nance) are performed accordi ng to the suspected lesion and are similar to the classical workup used for thyroid pathologies. 3 INDICATIONS The ideal indication for endoscopic thyroid surgery is a solitary, nonfunctioning thyroid nodule of less than 30 mm in diameter. Other current indications include solitary toxic nodule, recurrent thyroid cyst, and small multinodular goiters. Moreover, a thin patient, with a long narrow neck is more suited for an endoscopic approach. 4 CONTRAINDICATIONS Contraindications to an endoscopic approach include nodules larger than 3 cm in diameter, a large multinodular goiter, history of prior neck surgery, thyroiditis, and patients with recent infection, inflammation, irradiation, or burn to the neck (6,7). Graves’ disease, with enlarged and highly vascular thyroid gland, is also considered a contraindication by most surgeons, due to the higher risk of bleeding. Obesity associated with a short, wide neck is also a relative contraindication, as space and exposure can be reduced. Patients with atypical, highly suspicious, or malignant cytology should be excluded, as endoscopic surgery may not allow a correct grading of the tumor. Finally, elderly patients or those with severe associated pathologies may not tolerate CO2 insufflation and should be excluded. 5 PROCEDURE After induction of a gen eral anesthesia, the patient is positioned with the neck slightly extended, or even slightly folded (8), with the table in a reversed Trende- lenburg position (Fig. 1). The sternal notch, anterior border of the sternocleidomastoid muscle (SCM), and external jugular v eins are marked with a pen. The procedure requires a 5 mm endosco pe, instruments, and trocars (Karl Storz Endoscopy, Tuttlingen, Ger- many) (Figs. 2, 3). Three main endoscopic approaches have been described: the cervical, the axillary, and the breast approach. 5.1 Cervical Approach 5.1.1 Incision and Creation of the Working Space A 10-mm incision is made at the sternal notch or just above it, and the cervical fascia is opened. A subplatysmal space is created by blunt dissection and introduction of a swab in the opening. A 5 mm trocar is inserted and secured in place with a Prolene purse string suture. CO 2 insufflation is started to a pressure of 8–12 mmHg. Initial dissection is made with the tip of a 0j, 5 mm endoscope (Karl Storz Endoscopy, Tuttlingen, Germany), along the anterior border of the SCM. Once a sufficient space is obtained, three additional trocars are inserted under visual control, and a 30j or occasionally 45j endoscope is used to perform the rest of the procedure (Fig. 4). 5.1.2 Dissection of the Thyroid Lobe The strap muscles are mobilized from the anterior surface of the thyroid gland. The use of electrocautery is usually avoided when laryngeal nerve is not yet exposed. Vascular clips, 5 mm (US Surgical, Norwalk, CT), or 5- mm ultrasonic scalpel (US Surgical, Norwalk, CT) are used for hemostasis. The middle thyroid vein is first dissected and divided between clips or with ultrasonic shear. 5.1.3 Dissection of the Recurrent Laryngeal Nerve and Parathyroid Gland The inferior thyroid artery, inferior parathyroid, and recurrent laryngeal nerve (RLN) are identified (Figs. 5, 6). With the nerve under visual control, the inferior thyroid artery is divided between clips. If the laryngeal nerve cannot be localized, the procedure s hould be converted to a classical, open approach. The laryngeal nerve is then separated from the posterior aspect of the thyroid gland using blunt dissection. The inferior and superior parathyroids glands are also mobilized and preserved. The superior thyroid vessels are dissected and transected between clips after identification of the superior laryngeal nerve (Fig. 7). The thyroid gland is retracted in the anteromedial direction, and the ligament of Berry and isthmus are divided using ultrasonic Figure 1 Position of the patient for a right thyroidectomy. Biertho and Gagner202 scalpel. The specimen is then placed in a retrieval bag and extracted through the supero-lateral trocar site (Fig. 8). 5.2 Transaxillary Approach In order to avoid any visible scars in the neck, Ikeda et al. (9,10) performed endoscopic thyroid resections using an axillary approach. A 30 mm incision is made in the axillar, and the lower layer of the platysma muscle is dissected through the upper layer of the pectoralis major. A 12 mm trocar is inserted, and CO 2 is insufflated with a pressure of 4 mmHg. Two other trocars are then inserted below the first one. Access to the thyroid is then gained through the subplatysmal space. The thyroid gland is exposed by dividing the sternothyroi d muscle. The recurrent laryngeal nerve is then identified, as are the parathyroid glands. The inferior and superior ped- icles are then controlled as described above. A closed suction drain is usually left in place at the end of the procedure. The advantages of this technique include Figure 6 Inferior thyroid artery, inferior parathyroid gland, and recurrent laryngeal nerve. Figure 4 Trocars position for a right thyroidectomy using a cervical approach. Endoscopic Thyroid Surgery 203 avoidance of any scars in the neck, the lateral approach to the thyroidal bed (similar to a classical approach), an easier dissection of the superior and inferior poles, and an easier access to the perithyroid fascia, which can be opened without injury to the glands or to the recurrent laryngeal nerve. The main disadvantages of this technique are probably the technical difficulties, the extent of the dissection, and the duration of the procedure (about 3 hr). 5.3 Breast Approach In 1998, Ishii et al. (11) described a technique of thyroid resection using a breast approach. The aim of this technique is also to avoid the presence of any scars in the neck. A 15 mm incision is made in the right or left parasternal border at the level of the nipples. A subcutaneous tunnel is created using blunt dissection, and a subplatysmal space is created. A 12 mm trocar is first inserted, and CO 2 insufflation is started, with a pressure of 5 mmHg. A subplatysmal space is developed from the superior margin of the thyroid cartilage to the lateral borders of the SCM. Two additional 5 mm trocars are then inserted at the upper margin of both mammary areolas. Dissection is started at the lower pole and proceeds to the posterior and lateral aspects of the gland. The recurrent laryngeal nerve and parathyroid glands are usually identified. Main disadvantages of this technique are the risk of keloid scars associated with incision in the chest, the technical difficulty of the procedure, the risk of hematoma due to the extent of the dissection, and the impossibility to use any of the incisions if a conversion is required. 5.4 Gasless Endoscopy Intracranial pressure is increased when CO 2 insufflation of 15 mmHg is used to perform neck surgery in animal models (12). On the opposite, pressures of 10 mmHg do not seem to increase the intracranial pressure. However, other complications due to CO 2 insufflation in the neck can occur (e.g, hypercapnia, resp iratory acidosis, or subcutaneous emphysema). In order to reduce those complications, Hu ¨ scher et al. (5) described the use of a lifting device to perform an endoscopic thyroid surgery, with reduced CO 2 pressure (6 mmHg). Shimizu et al. Figure 7 Control of the superior thyroid pedicle. Biertho and Gagner204 (13,14) have also performed totally gasless endoscopic thyroid resections using Kirschner wires inserted hori- zontally in the subcutaneous layer of the anterior part of the neck. Those wires are lifted up and fixed to a L- shaped pole to create a tent-like working space. They have performed more than 40 cases using this technique and conclude that this procedure is safe and can be used in selected cases. Miccoli et al. (15,16) have also described a video- assisted thyroidectomy (VAT). Dissection of the thyroid lobe is performed through a 15 mm medial incision using a5mm30j endoscope with classical instruments. Work- ing space is maintained using an external retractor. 6 RESULTS The current reports of endoscopic thyroid resections involve mainly small series of cases. There was only one prospective randomized trial (16), and the largest series included 67 patients (15). The results, conversion rate, and morbidity in these series of endosc opic thyroi d resections have been reviewed (Tables 1 and 2). More than 130 endoscopic thyroid resections have been reported. Among these, 31 were total or subtotal thyroidectomies, 87 lobectomies, and 13 partial lobectomies. Most of the operations were performed for benign tumors (86.3%), including 12 cases of Graves’ diseases. Malignant tumors are considered, for most authors, a contraindication to an endoscopic resection. However, Miccoli et al. (15,16) consider small, low-risk (T1) papillary carcinomas an indication for a video- assisted resection. Operative time was globally increased compared to an open procedure, with a mean 136.4 minutes. How- ever, it should decrease as experience is gained. The global conversion rate was 7.6% (10 cases). The causes of conversion were: Carcinoma diagnosed on the frozen section that required an open completion in three cases. Insufficient working space in three cases. The two causes of conversion in Gagner et al.’s study (7) were a 7 cm cyst and a 4 cm nodule, leading to the conc lusion that endoscopic thyroid resections should not be attempted for tumors larger than 3 cm in diameter. Hemorrhage in two cases. Both conversions were due to bleeding from the superior pole, illustrating the difficulty in controlling bleeding in such a small working space, especially when the superior pedicle is involved. Table 1 Endoscopic Thyroid Resections: Histological Results Authors (Ref.) N Procedure N Histology N Mean size/mean weight Yeung (6) 8 Lobectomies 8 Benign tumors 8 1.98 cm (0.4–3.8) Gagner and Inabnet (7) 18 Lobectomies 10 Adenoma 13 2.7 cm (0.6–7) Subtotal thyroidectomy 4 Cyst 2 Isthmusectomy 4 Multinodular goiter 1 Papillary thyroid carcinoma 2 Ishii et al. (11) 5 Lobectomies 4 Follicular adenoma 5 4 Â 5 cm (3–7) Partial thyroidectomy 1 Shimizu et al. (13) 5 Lobectomies 2 Follicular adenoma 4 3.2 cm (2–4.5) Extirpation 3 Follicular carcinoma 1 Miccoli et al. (15) 67 Lobectomies 52 Follicular adenomas 43 2.1 cm (0.9–3) Total thyroidectomies 15 Toxic adenoma 6 Toxic multinodular goiter 3 Papillary carcinoma 15 Yamamoto et al. (18) 12 Subtotal thyroidectomy 12 Graves’ disease 12 44 g (18–92) Yeh et al. (19) 16 Lobectomy 13 Nodular hyperplasia 8 5.8 cm (3.5–8.0) Tumorectomy 3 Follicular adenoma 6 Hurthle tumor 1 Cyst 1 Total 131 Total or subtotal thyroidectomies 31 Benign tumors Carcinoma 113 18 Lobectomies 87 Less than one lobe 13 Endoscopic Thyroid Surgery 205 The two last conversions were due to (1) the difficulties in recognizing the normal anatomy, which is considerably different from the classical approach, and (2) adhesions. There were no preoperative or postoperative deaths. Global morbidity was 3.8% (5 cases). Four cases involved minor complications (two transient hypocal- cemias, one transient RLN palsy, and one incidental parathyroidectomy). There was one case of RLN palsy with hypocalcemia after a subtotal thyroidectomy for Graves’ disease. However, the techni que used was to dissect the thyroid in contact with the thyroid capsule, without any attempt to localize the RLN or the parathyroid glands. 7 DISCUSSION The results reported in Table 2 suggest that endoscopic thyroid surger y is feasible and safe. In a series of 6702 classical thyroidectomies, the overall complication rate was 3.8%, with an incidence of permanent laryngeal nerve palsy of 0.7% (17). These rates seem to be similar to those repo rted after endoscopic resections (a 3.8% morbidity rate with a 0.75% rate of laryngeal nerve palsy). This approach could offer different potential advantages: A better cosmetic result. Most people dislike having a scar on the anterior surface of the neck, especially as thyroid pathologies are frequently found in young women. The shorter skin incision and absence of musculo-cutaneous flap offer a better cosmetic result after endoscopic resection (Fig. 9). In a prospective randomized trial comparing a group of 25 patients undergoing a video-assisted thyroidectomy to another group of 24 patients undergoing a classical thyroidectomy, Miccoli et al. (16) foun d a better cosmetic result in the endoscopic group ( p < 0.01). Gagner and Inabnet (7) found the same results in a study comparing endoscopic versus conventional thyroid resections ( p < 0.005). Reduction in postoperative pain. This point is difficult to assess due to the low analgesic require- ment after both classical and endoscopic thyroid surgery. Post-operative convalescence could be reduced after an endoscopic thyroidectomy, as trauma to the tissues is decreased. However, the difference was not statistically significant in the study by Gagner and Inabnet (7). Potential reduction of RLN or parathyroid glands lesions: The endoscopic magnification may en- hance the identification and reduce the risk of lesion to the important neurovascul ar structures, laryngeal nerves, and parathyroid glands with their blood supply. However, this point has to be evaluated by large, prospective, randomized trials. Concerns a ssociated wi th endoscopic thyroidectomies have also been expressed: These procedures are technically complex and associated with an increased operative time. However, Table 2 Endoscopic Thyroid Resections: Operative Results Authors (Ref.) Operative time (min) Conversion Morbidity Yeung et al. (6) 241 (180–330) 37.5% (1 failure to define anatomy, 1 adhesion, 1 insufficient space) 0 Gagner et al. (7) 220 (120–330) 11.1% (2 insufficient working space) 5.6% (1 incidental parathyroidectomy) Ishii et al. (11) 226 (177–281) 0 0 Shimizu et al. (13) 126 (90–150) 0 0 Miccoli et al. (15) Lobectomy: 73.6 3% 4.48% Thyroidectomy: 110 (1 hemorrhage, 1 conversion for carcinoma) (2 transient postop hypocalcemia, 1 transient RLN palsy) Yamamoto et al. (18) 259.8 (175–420) 8.33% (1 bleeding from sup. pole) 8.33% (1 RLN palsy with hypoparathyoidism) Yeh et al. (19) 102 (28–300) 11.1% (2 conversions for carcinoma) 0 Total 136.4 (28–420) 10 (7.6%) 5 (3.8%) Biertho and Gagner206 operative time should decrease as experience is gained and with the development of new instruments and techniques. This approach also requires a very careful selection of patients in that the safety and feasibility of the operation is dependent on that selection. An increasing number of classical thyroidectomies are performed under local or loco-regional anesthesia in an outpatient hospitalization. Endo- scopic resections still require general anesthesia, which is not minimally invasive and usually requires an overnight stay. Even if video-assisted parathyroidectomies have been performed under local anesthesia (20), when CO 2 insufflation is used for endoscopic resection, general anesthesia is required. The length of hospital stay for endoscopic thyroid surgery ranges from 1 to 7 days and is usually increased compared to a classical approach. A thyroid carcinoma cannot be totally ruled out by the preoperative work-up, and we still ignore the outcomes when resection is performed by endoscopy. Canalar carcinoma diagno sed on a frozen section should be converted to radicalize the thyroidectomy. For follicular carcinoma, a final his- topathological exam should be required, and the patient should be reoperated using a classical approach if the diagnosis is confirmed. However, for some authors (15), a low-risk (T1) small papillary carcinoma can be resected by endoscopy,as lymph- adenomectomy is not required and resection is judged adequate. 8 CONCLUSION Endoscopic thyroid resections are feasible and safe given very careful selection of patients. Potential advantages include better cosmetic results and reduced postoperative pain and morbidity rate. It is, however, technically complex and requires increased operative time, a general anesthesia, and a longer hospital stay. Large prospective randomized studies are still needed to refine the indications for endoscopic thyroid surgery and to confirm its safety and efficacy. REFERENCES 1. Gagner M. Endoscopic subtotal parathyroidectomy in patients with primary hyperparathyroidism. Br J Surg 1996; 83:875. 2. Miccoli P, Berti P, Conte M, Raffaelli M, Materazzi G. Minimally invasive videoassisted parathyroidectomy: lesson learned from 137 cases. J Am Coll Surg 2000; 191:613–618. 3. Howe JR. Minimally invasive surgery: minimally invasive parathyroid surgery. Surg Clin North Am 2000; 80:1346–1399. 4. Jones DB, Quasebarth MA, Brunt LM. Videoen- doscopic thyroidectomy: experimental development of a new Technique. Surg Laparosc Endosc 1999; 9: 167. 5. Hu ¨ scher CSG, Chiodini S, Napolitano C, Rcher A. En- doscopic right thyroid lobectomy. Surg Endosc 1997; 11: 877. 6. Yeung GH. Endoscopic surgery of the neck: a new frontier. Surg Laparosc Endosc 1998; 8:227–232. 7. Gagner M, Inabnet WB III. Endoscopic thyroidectomy for solitary thyroid nodules. Thyroid 2001; 11:161– 163. 8. Yeung HC, Ng WT, Kong CK. Endoscopic thyroid and parathyroid surgery. Surg Endosc 1997; 11: 1135. 9. Ikeda Y, Takami H, Sasaki Y, Kan S, Niimi M. Endo- scopic resection of thyroid tumors by the axillary approach. J Cardiovasc Surg 2000; 41:791–792. 10. Ikeda Y, Takami H, Sasaki Y, Kan S, Niimi M. Endo- scopic neck surgery by the axillary approach. J Am Coll Surg 2000; 191:336–340. 11. Ishii S, Oghami M, Arisawa Y, Ohmori T, Noga K, Kitajima M. Endoscopic thyroidectomy with anterior chest wall approach. Surg Endosc 1998; 12:611. 12. Rubino F, Pamoukian VN, Zhu JF, Deutsch H, Inabnet WB, Gagner M. Endoscopic endocrine neck surgery with carbon dioxide insufflation: the effect on intracranial pressure in a large animal model. Surgery 2000; 128:1035–1042. 13. Shimizu K, Akira S, Jasmi AY, Kitamura Y, Kitagawa W, Akasu H, Tanaka S. Videoassisted neck surgery: endoscopic resection of thyroid tumors with a very minimal neck wound. J Am Coll Surg 1999; 188:697– 703. 14. Shimizu K, Kitagawa W, Akasu H, Tanaka S. Endo- scopic hemithyroidectomy and prophylactic lymph node dissection for micropapillary carcinoma of the thyroid by using a totally gasless anterior neck skin lifting method. J Surg Oncol 2001; 77:217–220. 15. Miccoli P, Berti P, Raffaelli M, Conte M, Materazzi G, Galleri D. Minimally invasive video-assisted thyroidectomy. Am J Surg 2001; 181:567–570. 16. Miccoli P, Berti P, Raffaelli M, Materazzi G, Baldacci S, Rossi G. Comparison between minimally invasive video-assisted thyroidectomy and conventional thyroidectomy: a prospective randomized study. Surgery 2001; 130:1039–1043. 17. Bliss RD, Gauger P, Delbridge LW. Surgeon’s approach to the thyroid gland: surgical anatomy and the Endoscopic Thyroid Surgery 207 importance of technique. World J Surg 2000; 24:891– 897. 18. Yamamoto M, Sasaki A, Asahi H, Shimada Y, Sato N, Nakajima J, Mashima R, Saito K. Endoscopic subtotal thyroidectomy for patients with Graves’ disease. Surg Today 2001; 31:1–4. 19. Yeh TS, Jan YY, Hsu BRS, Chen KW, Chen MF. Video-assisted endoscopic thyroidectomy. Am J Surg 2000; 180:82–85. 20. Miccoli P, Bendinelli C, Berti P, Vignali E, Pinchera A, Marcocci C. Video-assisted versus conventional parathyroidectomy in primary hyperparathyroidism: a prospective randomized study. Surgery 1999; 126:1117– 1121. Biertho and Gagner208 16 Video-Assisted Thyroid Surgery Paolo Miccoli, Piero Berti, and Gabriele Materazzi University of Pisa, Pisa, Italy 1 INTRODUCTION The first minimally invasive procedure ever performed in the neck district was an endoscopic parathyroidectomy carried out by Gagner in 1995 (1). Parathyroid pathology seemed in fact very viable to be treated endo- scopically: indeed parathyroid adenomas are almost always benign, their volume rarely exceeds 3 cm, and they do not present important vascular connections. The success obtained with this and other similar procedures (2,3) convinced several surgeons to remove small thyroid nodules as well as parathyroid adenomas; in spite of the concern expressed by some endocrine surgeons, both endoscopic and video-assisted thyroidectomy soon became quite popular. This trend is expressed in the papers that appeared or are about to appear on surgical reviews (4–7). 2 MINIMALLY INVASIVE VIDEO-ASSISTED THYROIDECTOMY This technique, in its present from, is characterized by the absence of any gas insufflation and by the external retraction. It was first described in 1999 (8), at which time a short insufflation was used to create the operative space. Later a blunt dissection proved to be sufficient to create a good space between the thyroid and the strap muscles so as to rely only on external retraction (4). Since that time more than 240 procedures have been performed by the authors and the operation has been adopted in several centers (9). 3 INDICATIONS A careful selection of patients is of paramount importance to assure a good outcome for this operation: the greatest limit is represented by the volume of the nodule and even more of the gland to be operated on. The lobe in fact has to be removed without disrupting its capsule bec ause of the necessity of an accurate histological evaluation in that these nodules are often suspect for carcinoma (either follicular or papillary). Othe r important limits are represented by the presence of adhesions that can make it difficult to recognize the most important structures, such as the recurrent nerve. Therefore, redo surgery is considered a contraindication for this procedure, but great caution should also be addressed to thyroiditis. For this reason an accurate evaluation of thyroid antibodies, characteristically increased in this disease, must be obtained before operating on these patients. Also, operative ultrasonographic study should be the most accurate because it is important to correctly evaluate thyroid and nodule volume and because it can help to recognize echographic aspects of thyroiditis. General indications might be summarized as follows: 1. Thyroid nodules <30 mm at largest diameter 2. Thyroid gland volume <20 mL, as estimated by ultrasound 209 3. No history of thyroiditis 4. No previous neck surgery or irradiation 5. Presence of benign, follicular, or ‘‘low-risk’’ papillary carcinoma determined by cytological examination 4 TECHNIQUE The procedure can be divided into four separate steps. 4.1 Preparation of the Operative Space The patient, under general endotracheal anesthesia, is in supine position with the neck not extended: hyper- extension must be avoided because it would reduce the operative space. The skin is protected by means of a sterile film (TegadermR). A 1.5 cm horizontal skin incision is performed 2 cm above the sternal notch in the central cervical area (Fig. 1). Subcutaneous fat and platysma are carefully dissected so as to avoid any mini- mum bleeding. Two small retractors (army-navy type) (Fig. 2) are used to expose the midline, which has to be incised for 2–3 cm on an absolutely bloodless plane. The blunt dissection of the thyroid lobe from the strap muscles is completely carried out through the skin incision by gentle retraction and using tiny spatulas. The same small retractors maintain the operative space in which a 30j 5 or 7 mm endoscope is inserted through the skin incision: from this moment on the procedure is entirely endoscopic until the extraction of the affected lobe. Preparation of the thyro-tracheal groove is com- pleted under endoscopic vision by using small (2 mm in diameter) instruments (Fig. 3). 4.2 Ligature of the Main Thyroid Vessels Neither clips nor ligatures are currently used to achieve hemostasis. A Harmonic Scalpel device (UltracisionR) is utilized for all the vessels. The first one to be separated is the middle vein, if present, or the small veins between jugular vein and thyroid capsule. Their section allows a beter exposure of the thyroid space. The upper pedicle is then prepared by retracting the thyroid lobe downward and medially (Fig. 4). The spatula is used to retract the vessels laterally. This also allows the external branch of the superior laryngeal nerve (Fig. 5) to be easily identified during most procedures. Injury can be avoided by keeping the inactive blade of the Ultracision device in the posterior position so as to not transmit heat to this delicate structure. 4.3 Visualization and Dissection of the Recurrent Nerve and Parathyroid When retracting medially and lifting up the thyroid lobe by means of retractors, the cervical fascia can be opened by gentle spatula retraction and the recurrent ne rve appears in the groove between trachea and thyroid. A good anatomical landmark for its visualization is the Zuckerkandl lobe of the thyroid. Superior parathyroid gland can be easily visualized thanks to endoscopic magni fication and dissected by Ultracision . Both of these structures must be carefully separated from the thyroid lobe before it is extracted (Fig. 6). 4.4 Extraction of the Lobe and Resection At this point in time the lobe is completely freed. The endoscope and retractors can be removed and the upper portion of the gland rotated and pulled out using conventional forceps. Gentle traction over the upper pole allows the thyroid lobe to be completely extracted (Fig. 7). The operation is now conducted as in open surgery under direct vision. The lobe is freed from the trachea by dissecting Berry’s ligament. It is very impor - tant to check the laryngeal nerve once again so as to avoid its injury before the final step. The isthmus is then dissected from the trachea and divided by means of Ultracision. Drainage is not necessary. The midline is then ap- proached by a single stitch; the platysma is closed by a subcuticular readsorbable suture, and a cyanoacrylate sealant is used for the skin (Fig. 8). Surgical follow-up should include direct laryngos- copy to check vocal cord mobility and neck ultrasonography in all cases. Serum calcium measurement is obtained in those patients submitted to total thyroidectomy in order to evaluate their parathyroid function. 5 RESULTS Our experience consists of 241 patients operated on since June 1998. Female-to-male ratio was 4:1. Lobec- tomy was carried out in 148 (61.4%) patients, total thyroidectomy in 93 (38.6%) patients. Mean operative time of lobectomy was 49.4 (range 20–120) minutes, while total thyroidectom y was accomplished in 61.8 (30–130) minutes. Preoperative diagnosis is shown in Table 1. Conversion to traditional cervicotomy was required in 4 cases (1,6%). Two cases occurred at the beginning of the experience. In the first one conversion was due to intraoperative bleeding from the upper vascular ped- Miccoli et al.210 [...]... 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[Tc-99m sestamibi/iodine-123 (or Tc-99m pertechnetate)] Subtraction Protocol Sestamibi, after intravenous injection, is taken up by both the enlarged parathyroid glands and the thyroid (6,7) Therefore, another radiopharmaceutical that is concentrated only by the thyroid [either iodine-123 (I123) sodium iodide given orally, or Tc-99m-pertechnetate given intravenously] is administered The I-123 (or Tc-99m . RESULTS Our experience consists of 241 patients operated on since June 1998. Female-to-male ratio was 4: 1. Lobec- tomy was carried out in 148 (61 .4% ) patients, total thyroidectomy in 93 (38.6%) patients that a large non-(1– 84) PTH fragment is detected by this assay (8). This large amino-terminal truncated fragment(s), missing the first 4 6 N-terminal amino acids, has 100% cross-reactivity with. Howe JR. Minimally invasive surgery: minimally invasive parathyroid surgery. Surg Clin North Am 2000; 80:1 346 –1399. 4. Jones DB, Quasebarth MA, Brunt LM. Videoen- doscopic thyroidectomy: experimental

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