- Email: [email protected]
Minimally invasive nonendoscopic thyroidectomy
Otolaryngology–Head and Neck Surgery (2006) 135, 744-747
ORIGINAL RESEARCH
Minimally invasive nonendoscopic thyroidectomy Ottavio Cavicchi, MD, Ottavio Piccin, MD, Alberto Rinaldi Ceroni, MD, and Umberto Caliceti, MD, Bologna, Italy OBJECTIVES: Minimal-access thyroid surgery, using various techniques, is increasingly being reported. The present study reviews our experience with thyroid surgery using a minimally invasive approach (MIT). STUDY DESIGN: Between October 2002 and December 2004, a prospective nonrandomized study of patients undergoing thyroid surgery was performed to evaluate the variables that might condition the indications to minimally invasive nonendoscopic approach. RESULTS: 296 patients underwent thyroid surgery; 46 of these were eligible for MIT through a 2.5- to 3-cm incision. There was one case of transient inferior laryngeal nerve palsy and no postoperative definitive hypoparathyroidism. MIT was converted to conventional thyroidectomy only in two cases. Cosmetic results were considered excellent by all patients. CONCLUSIONS: Minimal-access thyroid surgery is a safe and feasible alternative to conventional thyroid surgery in selected cases. The advantage that this technique offers, in addition to low morbidity, is an improved cosmetic result. © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
T
he concept of minimally invasive surgery has recently found many supporters in the management of thyroid disorders. The thyroid gland is frequently affected by benign or low-grade malignant diseases, and the majority of patients are young women who consider the aesthetic appearance to be very important. For this reason many surgeons have been prompted to try a minimally invasive approach to thyroid surgery. There are several ways to accomplish a minimally invasive access to the thyroid compartment. These include endoscopic thyroidectomy with or without CO2 insufflation,1-2 video-assisted thyroidectomy3 (with several surgical approaches to the thyroid gland that include, in addition to the From the ENT Department, S.Orsola Hospital, University of Bologna. Reprint requests: Dr Ottavio Cavicchi, ENT Department, S.Orsola Malpighi Hospital, via Massarenti 9, 40138 Bologna, Italy.
classical anterior cervical approach, the breast approach, the trans-axillary approach,4 and the approach through a small wound in the submandibular area5), and minimally invasive nonendoscopic thyroidectomy performed through a minimal incision with conventional retraction.6 The cosmetic result is not the only factor that has prompted the use of the minimally invasive approach to the thyroid gland. In fact, the concept of minimally invasive surgery is also strictly connected to the attempt to reduce surgical morbidity and consequently the social costs of hospital admission by reducing postoperative hospital stay. A note of caution regarding the use of the minimally invasive approach in patients with thyroid cancer has been expressed by some authors concerned about its oncological completeness. Only a few authors have reported postoperative data, such as scintigraphic evaluation of thyroid residuals or hematic levels of thyroglobulin (Tg).7-8 Moreover, very few authors have reported the possibility to perform safely the removal of paratracheal lymph nodes.9 In this study we report our experience with the minimally invasive nonendoscopic thyroidectomy technique (MIT) through a 2.5- to 3-cm skin incision and try to answer the questions that we asked ourselves in the initial stages of our surgical experience in this field: What are the clinical indications to perform MIT? Is MIT feasible and safe? What is the learning curve of MIT? Is MIT complete and safe in malignant disorders of the thyroid gland?
PATIENTS AND METHODS From October 2002 to December 2004, 296 patients underwent thyroid surgery for various disorders. Of these patients, 46 underwent MIT; 37 were women (80%) and nine E-mail address: [email protected].
0194-5998/$32.00 © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2006.06.1246
Cavicchi et al
Minimally invasive nonendoscopic thyroidectomy
Figure 1 Cytologic preoperative finding. ptc, papillary thyroid carcinoma; fl, follicular lesion; tg, toxic goiter; mng, multinodular goiter; ta, toxic adenoma.
were men (20%), with a mean age of 34 years (range 18-51). Complete preoperative evaluation (biochemical assessment, ultrasonography, and fine needle aspiration biopsy) was obtained in all cases. The cytologic preoperative diagnosis is reported in Figure 1. In five cases clinical and functional data of chronic thyroiditis were revealed. Total thyroidectomy was performed in 38 cases (82%) and lobectomy in eight cases (18%). In patients with postoperative diagnosis of thyroid carcinoma, a 24-hour uptake with 1.85 Bq of I-131 and a neck scan were performed one month after operation, while levothyroxine therapy had been interrupted. Before the administration of I-131, blood was drawn to measure serum Tg. Tg was measured with a commercial immunometric assay (DPC, Los Angeles, CA) with a lower detection limit of 0.2 ng/mL and a functional sensitivity of 0.9 ng/mL. To verify vocal cord mobility all the patients underwent laryngostroboscopy before and one month after the operation. Serum calcium levels were evaluated every day of the hospital stay and three months later to rule out the presence of hypoparathyroidism. Our institutional review board approved this study.
745
be ligated or coagulated was the middle vein. Subsequently, the upper pole was dissected in a medio-lateral direction with the assistance of a retractor and Babcock clamp. The vessels of the upper pole were selectively ligated, either by conventional hand ligature or by harmonic scalpel in the last 10 cases. Then, the inferior pole was dissected and the venous vessels were ligated or coagulated, exposing at the end of this dissection the anterior tracheal wall. With the assistance of a retractor the recurrent area was clearly exposed and the recurrent nerve usually appeared in the thyrotracheal groove posterior to the Zuckerkandl tuberculum. To check the function of the inferior laryngeal nerve, an electrical stimulator was used (Xomed Stimuplex HNS11; maximum stimulation current 5mA, stimulation voltage 65V, stimulation frequency 1 Hz/2 Hz), while the postcricoid area was palpated to feel posterior cricoaritenoid muscle contractions in response to ipsilateral nerve stimulation. The strictly pericapsular dissection allowed visualization and easy access to the parathyroid glands, whose vascular supply was preserved by selective ligature of the branch of the inferior thyroid artery. After retracting the thyroid lobe medially and carefully lifting it up, the Berry and Gruber ligaments were dissected and the thyroid was removed (Fig 3). In case of lobectomy drainage was not mandatory, whereas one drainage tube was placed in total thyroidectomy.
RESULTS MIT was converted to “conventional” thyroidectomy in only two cases, due to unexpected bulky nodules larger than 3 cm. In these cases we referred to an ultrasound evaluation performed several months earlier. In the two cases of toxic goiter, surgery was very difficult because of increased blood loss. Also in the five cases of chronic thyroiditis, the adhesion of the thyroid gland to the surrounding tissues led to
Selection Criteria Selection criteria were: no previous neck surgery or irradiation, no pathological lymph nodes, nodule size less than 3 cm, and thyroid volume less than 20 mL. Low-grade well-differentiated malignancies, except for medullary carcinoma, were not an exclusion criterion to perform MIT.
Operative Technique Surgery was performed without supplementary light or endoscope. The patient was placed in the supine position; the neck was not hyperextended. A 2.5- to 3-cm incision was made 2.5 cm above the sternal notch, higher than the usual incision for conventional thyroidectomy (Fig 2). Subcutaneous fat and platysma were dissected and then the cervical linea alba was divided longitudinally for at least 3 cm. The muscle straps of the affected side were then retracted with a conventional retractor by a third surgeon. The first vessel to
Figure 2
Length of skin incision.
746
Otolaryngology–Head and Neck Surgery, Vol 135, No 5, November 2006
Figure 3
Thyroid gland removed.
difficult dissection and increased operation time. We never performed frozen histopathological examination. In one case with preoperative diagnosis of follicular lesion treated with a lobectomy, a completion thyroidectomy was performed in a second stage because of the diagnosis of papillary carcinoma at final histology. This procedure was carried out through the same incision. In the remaining cases preoperative diagnosis was confirmed by final pathology. Transient inferior laryngeal nerve palsy was observed in one case (2.1%). Symptomatic and transient hypoparathyroidism was observed in five cases (13.1%) of total thyroidectomy. No definitive hypoparathyroidism was observed. Mean operative time was 152 minutes for total thyroidectomy and 95 minutes for lobectomy. Postoperative stay ranged from 48 to 72 hours. Postoperative analgesic therapy was never needed. We observed no postoperative bleeding or wound infections. Cosmetic results were considered excellent by all the patients (Fig 4). In malignancies the postoperative mean serum Tg level was 2.5 ng/mL (min ⬍0.5 ng/mL, max 3 ng/mL; 58.3% of the patients with values lower than 0.5 ng/mL). Postoperative whole-body radioiodine scintigraphy showed values of 131-I Na uptake in the thyroid bed at 72 hours ranging from 0 percent to 2.13 percent.
a standard neck incision. It is clear that the indication for MIT becomes larger according to the length of incision.4-10 We believe MIT is a technique that should be performed through a 2.5- to 3-cm incision. In our opinion few patients are suitable for MIT. In fact, we performed MIT in only 15.6 percent of thyroid surgery operations (46/296) as reported in high-volume referral centers.8 The pathologies indicated for MIT are mainly benign nodules no larger than 3 cm, and low-grade and early-stage well-differentiated papillary or follicular carcinoma.4,9,10 Absolute contraindications to MIT are bulky disease, previous surgery and radiotherapy on the neck, high-grade carcinoma, and the detection of preoperative lymph node metastasis. In our opinion the presence of toxic goiter and chronic thyroiditis are relative contraindications because of increased vascularization and adhesion of the thyroid gland to the surrounding tissues.
Is MIT Feasible and Safe? The answer to this question is unanimous in the literature4,9,10 and confirmed by our experience. In our series the rate of complications with this technique was very low and comparable to that reported in the literature for patients undergoing conventional thyroidectomy. These data confirm that during MIT it is possible to identify the inferior laryngeal nerve and the parathyroid glands and to preserve them easily even if the surgeon is working in a very small field. Moreover, MIT has none of the additional complications that can occur with the endoscopic technique with insufflation of CO2, such as hypercarbia, emphysema, and pneumomediastinum, and can be converted into conventional thyroidectomy when necessary.8 Concerning safety, we can offer the following technical advice when performing MIT: 1) Making the incision higher up than a traditional Kocher incision is a safer way to address superior pole vasculature. Although this type of incision is less aesthetically pleasing, as it is more noticeable, none of our patients complained about the cosmetic results. 2) A third assistant is useful for holding a hand-held retractor, which has to be repositioned as frequently as needed depending on where
DISCUSSION Our experience with MIT, despite the small series, has enabled us to answer the preliminary questions of this study with some scientific reliability.
What Are the Clinical Indications to Perform MIT? In the literature clinical indications for MIT are not in agreement. This fact depends on the lack of standardization of the length of the skin incision, which for some authors10 can be as long as 6 cm, which corresponds to the length of
Figure 4
Aesthetic result.
Cavicchi et al
Minimally invasive nonendoscopic thyroidectomy
the dissection is being made. However, this can be a problem in some institutions where residents are not present. 3) We endorse the use of the harmonic scalpel since this instrument facilitates the ligature of the superior pole vessels and decreases operative time. Vascular clips, can also certainly be an easier and safer technique than hand ligature. 4) We used a manual technique to evaluate the function of the inferior laryngeal nerve without difficulty. Although a laryngeal nerve monitoring endotracheal tube can certainly facilitate this maneuver, particularly in a small working space like this, it is very expensive.
What Is the Learning Curve? Since MIT reproduces the conventional methods of thyroidectomy, we believe that to perform MIT safely a long learning curve is not necessary for well-trained surgeons. Moreover, in our opinion, this technique is not easily teachable to residents who have not sufficient experience in conventional thyroidectomy. In fact, the small working space could hamper the control of the resident’s maneuvers from the trainer surgeon. With regard to this, we are in agreement with Brunaud,11 who asserts that the resident must undergo resident laboratory and clinical training before performing minimally invasive surgical procedures.
Is MIT Complete and Safe in Malignant Neoplasms of the Thyroid Gland? In the literature there are few studies about the oncological completeness of MIT in thyroid carcinoma.4-10 These studies, confirmed by our results, show that oncological completeness in resection of the thyroid gland is possible, and paratracheal lymph nodes and the pyramidal lobe can be safely removed. In our opinion this technique should be restricted to small well-differentiated follicular or papillary carcinomas (T1). Because of the high incidence of cervical metastasis, medullary carcinoma should be a contraindication for MIT. The high accuracy of cytological examination and preoperative imaging (ultrasound, CT, positron emission tomography) may help the safe planning of a minimally invasive approach. Nevertheless, the surgeon should not hesitate to plan or convert MIT into conventional thyroidectomy whenever there are preoperative or intraoperative doubts about grading and extension of the tumor.
CONCLUSIONS MIT is a safe and feasible alternative to conventional thyroid surgery in selected cases. The limiting factors to
747
this minimally invasive procedure are the size of the nodule and histological type; this technique may not be possible in cases of voluminous goiter and poorly differentiated carcinomas. The advantage that this technique offers, in addition to an improved aesthetic result, is a low morbidity. It is possible that the reduced dissection and a smaller skin incision lead to reduced postoperative pain, shorter hospital stay, and a quicker recovery, but equally the effects could be due to the patient’s perception rather than being a real effect. If this aspect is considered, maybe there is an advantage for MIT. MIT also has the advantage of allowing the surgeon to perform a completion thyroidectomy when necessary through the same incision. We believe that MIT is feasible in the hands of well-trained surgeons.
REFERENCES 1. Gagner M, Inabnet BW 3rd, Biertho L. Endoscopic thyroidectomy for solitary nodules. Ann Chir 2003;128(10):696 –701. (Grade B). 2. Kitano H, Fujimura M, Kinoshita T, et al. Endoscopic thyroid resection using cutaneous elevation in lieu of insufflation. Surg Endosc 2002;16(1):88 –91. (Grade C). 3. Miccoli P, Berti P, Raffaelli M, et al. Minimally invasive videoassisted thyroidectomy. Am J Surg 2001;181(6):567–70. (Grade C). 4. Shimazu K, Shiba E, Tamaki Y, et al. Endoscopic thyroid surgery through the axillo-bilateral-breast approach. Surg Laparosc Endosc Percutan Tech 2003;13(3):196 –201. (Grade C). 5. Yamashita H, Watanabe S, Koike E, et al. Video-assisted thyroid lobectomy through a small wound in the submandibular area. Am J Surg 2002;183(3):286 –9. (Grade C). 6. Park CS, Chung WY, Chang HS. Minimally invasive open thyroidectomy. Surg Today 2001;31(8):665–9. (Grade C). 7. Miccoli P, Elisei R, Materazzi G, et al. Minimally invasive videoassisted thyroidectomy for papillary carcinoma: a prospective study of its completeness. Surgery 2002;132(6):1070 –3; discussion 1073– 4. (Grade C). 8. Miccoli P, Minuto MN, Barellini L, et al. Minimally invasive video-assisted thyroidectomy—techniques and results over 4 years of experience (1999 –2002). Ann Ital Chir 2004;75(1):47–51. (Grade C). 9. Ferzli GS, Sayad P, Abdo Z, et al. Minimally invasive, nonendoscopic thyroid surgery. J Am Coll Surg 2001;192(5):665– 8. (Grade C). 10. Terris DJ, Bonnett A, Gourin CG, et al. Minimally invasive thyroidectomy using the Sofferman technique. Laryngoscope 2005;115(6): 1104 – 8. (Grade C). 11. Brunaud L, Zarnegar R, Wada N, et al. Incision length for standard thyroidectomy and parathyroidectomy: when is it minimally invasive? Arch Surg 2003;138(10):1140 –3. (Grade C).
ORIGINAL RESEARCH
Minimally invasive nonendoscopic thyroidectomy Ottavio Cavicchi, MD, Ottavio Piccin, MD, Alberto Rinaldi Ceroni, MD, and Umberto Caliceti, MD, Bologna, Italy OBJECTIVES: Minimal-access thyroid surgery, using various techniques, is increasingly being reported. The present study reviews our experience with thyroid surgery using a minimally invasive approach (MIT). STUDY DESIGN: Between October 2002 and December 2004, a prospective nonrandomized study of patients undergoing thyroid surgery was performed to evaluate the variables that might condition the indications to minimally invasive nonendoscopic approach. RESULTS: 296 patients underwent thyroid surgery; 46 of these were eligible for MIT through a 2.5- to 3-cm incision. There was one case of transient inferior laryngeal nerve palsy and no postoperative definitive hypoparathyroidism. MIT was converted to conventional thyroidectomy only in two cases. Cosmetic results were considered excellent by all patients. CONCLUSIONS: Minimal-access thyroid surgery is a safe and feasible alternative to conventional thyroid surgery in selected cases. The advantage that this technique offers, in addition to low morbidity, is an improved cosmetic result. © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
T
he concept of minimally invasive surgery has recently found many supporters in the management of thyroid disorders. The thyroid gland is frequently affected by benign or low-grade malignant diseases, and the majority of patients are young women who consider the aesthetic appearance to be very important. For this reason many surgeons have been prompted to try a minimally invasive approach to thyroid surgery. There are several ways to accomplish a minimally invasive access to the thyroid compartment. These include endoscopic thyroidectomy with or without CO2 insufflation,1-2 video-assisted thyroidectomy3 (with several surgical approaches to the thyroid gland that include, in addition to the From the ENT Department, S.Orsola Hospital, University of Bologna. Reprint requests: Dr Ottavio Cavicchi, ENT Department, S.Orsola Malpighi Hospital, via Massarenti 9, 40138 Bologna, Italy.
classical anterior cervical approach, the breast approach, the trans-axillary approach,4 and the approach through a small wound in the submandibular area5), and minimally invasive nonendoscopic thyroidectomy performed through a minimal incision with conventional retraction.6 The cosmetic result is not the only factor that has prompted the use of the minimally invasive approach to the thyroid gland. In fact, the concept of minimally invasive surgery is also strictly connected to the attempt to reduce surgical morbidity and consequently the social costs of hospital admission by reducing postoperative hospital stay. A note of caution regarding the use of the minimally invasive approach in patients with thyroid cancer has been expressed by some authors concerned about its oncological completeness. Only a few authors have reported postoperative data, such as scintigraphic evaluation of thyroid residuals or hematic levels of thyroglobulin (Tg).7-8 Moreover, very few authors have reported the possibility to perform safely the removal of paratracheal lymph nodes.9 In this study we report our experience with the minimally invasive nonendoscopic thyroidectomy technique (MIT) through a 2.5- to 3-cm skin incision and try to answer the questions that we asked ourselves in the initial stages of our surgical experience in this field: What are the clinical indications to perform MIT? Is MIT feasible and safe? What is the learning curve of MIT? Is MIT complete and safe in malignant disorders of the thyroid gland?
PATIENTS AND METHODS From October 2002 to December 2004, 296 patients underwent thyroid surgery for various disorders. Of these patients, 46 underwent MIT; 37 were women (80%) and nine E-mail address: [email protected].
0194-5998/$32.00 © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2006.06.1246
Cavicchi et al
Minimally invasive nonendoscopic thyroidectomy
Figure 1 Cytologic preoperative finding. ptc, papillary thyroid carcinoma; fl, follicular lesion; tg, toxic goiter; mng, multinodular goiter; ta, toxic adenoma.
were men (20%), with a mean age of 34 years (range 18-51). Complete preoperative evaluation (biochemical assessment, ultrasonography, and fine needle aspiration biopsy) was obtained in all cases. The cytologic preoperative diagnosis is reported in Figure 1. In five cases clinical and functional data of chronic thyroiditis were revealed. Total thyroidectomy was performed in 38 cases (82%) and lobectomy in eight cases (18%). In patients with postoperative diagnosis of thyroid carcinoma, a 24-hour uptake with 1.85 Bq of I-131 and a neck scan were performed one month after operation, while levothyroxine therapy had been interrupted. Before the administration of I-131, blood was drawn to measure serum Tg. Tg was measured with a commercial immunometric assay (DPC, Los Angeles, CA) with a lower detection limit of 0.2 ng/mL and a functional sensitivity of 0.9 ng/mL. To verify vocal cord mobility all the patients underwent laryngostroboscopy before and one month after the operation. Serum calcium levels were evaluated every day of the hospital stay and three months later to rule out the presence of hypoparathyroidism. Our institutional review board approved this study.
745
be ligated or coagulated was the middle vein. Subsequently, the upper pole was dissected in a medio-lateral direction with the assistance of a retractor and Babcock clamp. The vessels of the upper pole were selectively ligated, either by conventional hand ligature or by harmonic scalpel in the last 10 cases. Then, the inferior pole was dissected and the venous vessels were ligated or coagulated, exposing at the end of this dissection the anterior tracheal wall. With the assistance of a retractor the recurrent area was clearly exposed and the recurrent nerve usually appeared in the thyrotracheal groove posterior to the Zuckerkandl tuberculum. To check the function of the inferior laryngeal nerve, an electrical stimulator was used (Xomed Stimuplex HNS11; maximum stimulation current 5mA, stimulation voltage 65V, stimulation frequency 1 Hz/2 Hz), while the postcricoid area was palpated to feel posterior cricoaritenoid muscle contractions in response to ipsilateral nerve stimulation. The strictly pericapsular dissection allowed visualization and easy access to the parathyroid glands, whose vascular supply was preserved by selective ligature of the branch of the inferior thyroid artery. After retracting the thyroid lobe medially and carefully lifting it up, the Berry and Gruber ligaments were dissected and the thyroid was removed (Fig 3). In case of lobectomy drainage was not mandatory, whereas one drainage tube was placed in total thyroidectomy.
RESULTS MIT was converted to “conventional” thyroidectomy in only two cases, due to unexpected bulky nodules larger than 3 cm. In these cases we referred to an ultrasound evaluation performed several months earlier. In the two cases of toxic goiter, surgery was very difficult because of increased blood loss. Also in the five cases of chronic thyroiditis, the adhesion of the thyroid gland to the surrounding tissues led to
Selection Criteria Selection criteria were: no previous neck surgery or irradiation, no pathological lymph nodes, nodule size less than 3 cm, and thyroid volume less than 20 mL. Low-grade well-differentiated malignancies, except for medullary carcinoma, were not an exclusion criterion to perform MIT.
Operative Technique Surgery was performed without supplementary light or endoscope. The patient was placed in the supine position; the neck was not hyperextended. A 2.5- to 3-cm incision was made 2.5 cm above the sternal notch, higher than the usual incision for conventional thyroidectomy (Fig 2). Subcutaneous fat and platysma were dissected and then the cervical linea alba was divided longitudinally for at least 3 cm. The muscle straps of the affected side were then retracted with a conventional retractor by a third surgeon. The first vessel to
Figure 2
Length of skin incision.
746
Otolaryngology–Head and Neck Surgery, Vol 135, No 5, November 2006
Figure 3
Thyroid gland removed.
difficult dissection and increased operation time. We never performed frozen histopathological examination. In one case with preoperative diagnosis of follicular lesion treated with a lobectomy, a completion thyroidectomy was performed in a second stage because of the diagnosis of papillary carcinoma at final histology. This procedure was carried out through the same incision. In the remaining cases preoperative diagnosis was confirmed by final pathology. Transient inferior laryngeal nerve palsy was observed in one case (2.1%). Symptomatic and transient hypoparathyroidism was observed in five cases (13.1%) of total thyroidectomy. No definitive hypoparathyroidism was observed. Mean operative time was 152 minutes for total thyroidectomy and 95 minutes for lobectomy. Postoperative stay ranged from 48 to 72 hours. Postoperative analgesic therapy was never needed. We observed no postoperative bleeding or wound infections. Cosmetic results were considered excellent by all the patients (Fig 4). In malignancies the postoperative mean serum Tg level was 2.5 ng/mL (min ⬍0.5 ng/mL, max 3 ng/mL; 58.3% of the patients with values lower than 0.5 ng/mL). Postoperative whole-body radioiodine scintigraphy showed values of 131-I Na uptake in the thyroid bed at 72 hours ranging from 0 percent to 2.13 percent.
a standard neck incision. It is clear that the indication for MIT becomes larger according to the length of incision.4-10 We believe MIT is a technique that should be performed through a 2.5- to 3-cm incision. In our opinion few patients are suitable for MIT. In fact, we performed MIT in only 15.6 percent of thyroid surgery operations (46/296) as reported in high-volume referral centers.8 The pathologies indicated for MIT are mainly benign nodules no larger than 3 cm, and low-grade and early-stage well-differentiated papillary or follicular carcinoma.4,9,10 Absolute contraindications to MIT are bulky disease, previous surgery and radiotherapy on the neck, high-grade carcinoma, and the detection of preoperative lymph node metastasis. In our opinion the presence of toxic goiter and chronic thyroiditis are relative contraindications because of increased vascularization and adhesion of the thyroid gland to the surrounding tissues.
Is MIT Feasible and Safe? The answer to this question is unanimous in the literature4,9,10 and confirmed by our experience. In our series the rate of complications with this technique was very low and comparable to that reported in the literature for patients undergoing conventional thyroidectomy. These data confirm that during MIT it is possible to identify the inferior laryngeal nerve and the parathyroid glands and to preserve them easily even if the surgeon is working in a very small field. Moreover, MIT has none of the additional complications that can occur with the endoscopic technique with insufflation of CO2, such as hypercarbia, emphysema, and pneumomediastinum, and can be converted into conventional thyroidectomy when necessary.8 Concerning safety, we can offer the following technical advice when performing MIT: 1) Making the incision higher up than a traditional Kocher incision is a safer way to address superior pole vasculature. Although this type of incision is less aesthetically pleasing, as it is more noticeable, none of our patients complained about the cosmetic results. 2) A third assistant is useful for holding a hand-held retractor, which has to be repositioned as frequently as needed depending on where
DISCUSSION Our experience with MIT, despite the small series, has enabled us to answer the preliminary questions of this study with some scientific reliability.
What Are the Clinical Indications to Perform MIT? In the literature clinical indications for MIT are not in agreement. This fact depends on the lack of standardization of the length of the skin incision, which for some authors10 can be as long as 6 cm, which corresponds to the length of
Figure 4
Aesthetic result.
Cavicchi et al
Minimally invasive nonendoscopic thyroidectomy
the dissection is being made. However, this can be a problem in some institutions where residents are not present. 3) We endorse the use of the harmonic scalpel since this instrument facilitates the ligature of the superior pole vessels and decreases operative time. Vascular clips, can also certainly be an easier and safer technique than hand ligature. 4) We used a manual technique to evaluate the function of the inferior laryngeal nerve without difficulty. Although a laryngeal nerve monitoring endotracheal tube can certainly facilitate this maneuver, particularly in a small working space like this, it is very expensive.
What Is the Learning Curve? Since MIT reproduces the conventional methods of thyroidectomy, we believe that to perform MIT safely a long learning curve is not necessary for well-trained surgeons. Moreover, in our opinion, this technique is not easily teachable to residents who have not sufficient experience in conventional thyroidectomy. In fact, the small working space could hamper the control of the resident’s maneuvers from the trainer surgeon. With regard to this, we are in agreement with Brunaud,11 who asserts that the resident must undergo resident laboratory and clinical training before performing minimally invasive surgical procedures.
Is MIT Complete and Safe in Malignant Neoplasms of the Thyroid Gland? In the literature there are few studies about the oncological completeness of MIT in thyroid carcinoma.4-10 These studies, confirmed by our results, show that oncological completeness in resection of the thyroid gland is possible, and paratracheal lymph nodes and the pyramidal lobe can be safely removed. In our opinion this technique should be restricted to small well-differentiated follicular or papillary carcinomas (T1). Because of the high incidence of cervical metastasis, medullary carcinoma should be a contraindication for MIT. The high accuracy of cytological examination and preoperative imaging (ultrasound, CT, positron emission tomography) may help the safe planning of a minimally invasive approach. Nevertheless, the surgeon should not hesitate to plan or convert MIT into conventional thyroidectomy whenever there are preoperative or intraoperative doubts about grading and extension of the tumor.
CONCLUSIONS MIT is a safe and feasible alternative to conventional thyroid surgery in selected cases. The limiting factors to
747
this minimally invasive procedure are the size of the nodule and histological type; this technique may not be possible in cases of voluminous goiter and poorly differentiated carcinomas. The advantage that this technique offers, in addition to an improved aesthetic result, is a low morbidity. It is possible that the reduced dissection and a smaller skin incision lead to reduced postoperative pain, shorter hospital stay, and a quicker recovery, but equally the effects could be due to the patient’s perception rather than being a real effect. If this aspect is considered, maybe there is an advantage for MIT. MIT also has the advantage of allowing the surgeon to perform a completion thyroidectomy when necessary through the same incision. We believe that MIT is feasible in the hands of well-trained surgeons.
REFERENCES 1. Gagner M, Inabnet BW 3rd, Biertho L. Endoscopic thyroidectomy for solitary nodules. Ann Chir 2003;128(10):696 –701. (Grade B). 2. Kitano H, Fujimura M, Kinoshita T, et al. Endoscopic thyroid resection using cutaneous elevation in lieu of insufflation. Surg Endosc 2002;16(1):88 –91. (Grade C). 3. Miccoli P, Berti P, Raffaelli M, et al. Minimally invasive videoassisted thyroidectomy. Am J Surg 2001;181(6):567–70. (Grade C). 4. Shimazu K, Shiba E, Tamaki Y, et al. Endoscopic thyroid surgery through the axillo-bilateral-breast approach. Surg Laparosc Endosc Percutan Tech 2003;13(3):196 –201. (Grade C). 5. Yamashita H, Watanabe S, Koike E, et al. Video-assisted thyroid lobectomy through a small wound in the submandibular area. Am J Surg 2002;183(3):286 –9. (Grade C). 6. Park CS, Chung WY, Chang HS. Minimally invasive open thyroidectomy. Surg Today 2001;31(8):665–9. (Grade C). 7. Miccoli P, Elisei R, Materazzi G, et al. Minimally invasive videoassisted thyroidectomy for papillary carcinoma: a prospective study of its completeness. Surgery 2002;132(6):1070 –3; discussion 1073– 4. (Grade C). 8. Miccoli P, Minuto MN, Barellini L, et al. Minimally invasive video-assisted thyroidectomy—techniques and results over 4 years of experience (1999 –2002). Ann Ital Chir 2004;75(1):47–51. (Grade C). 9. Ferzli GS, Sayad P, Abdo Z, et al. Minimally invasive, nonendoscopic thyroid surgery. J Am Coll Surg 2001;192(5):665– 8. (Grade C). 10. Terris DJ, Bonnett A, Gourin CG, et al. Minimally invasive thyroidectomy using the Sofferman technique. Laryngoscope 2005;115(6): 1104 – 8. (Grade C). 11. Brunaud L, Zarnegar R, Wada N, et al. Incision length for standard thyroidectomy and parathyroidectomy: when is it minimally invasive? Arch Surg 2003;138(10):1140 –3. (Grade C).