title: Robotic total thyroidectomy with modified radical neck dissection via unilateral retroauricular approach.
abstract: BACKGROUND
  Traditionally, total thyroidectomy was performed through an open transcervical incision; in cases where there was evident nodal metastasis, the conventional surgical approach was to extend the incision into a large single transverse incision to complete the required neck dissection. However, recent innovation in the surgical technique of thyroidectomy has offered the opportunity to reduce the patient's burden from these prominent surgical scars in the neck. Minimally invasive surgical techniques have been developed and applied by many institutions worldwide, and more recently, various techniques of remote access surgery have been suggested and actively applied.1-6 Since the advent of robotic surgical systems, some have adopted the concept of remote access surgery into developing various robotic thyroidectomy techniques. The more former and widely acknowledged robotic thyroidectomy technique uses a transaxillary (TA) approach, which has been developed by Chung et al. in Korea.7,8 This particular technique has some limitations in the sense that accessing the lymph nodes of the central compartment is troublesome. Terris et al. realized some shortcomings of robotic TA thyroidectomy, especially in their patients in the United States, and developed and reported the feasibility of robotic facelift thyroidectomy.9-13 In cases of thyroid carcinomas with lateral neck node metastases, most abandoned the concept of minimally invasive or remote access surgery and safely adopted conventional open surgical methods to remove the tumor burden. However, Chung et al. have attempted to perform concomitant modified radical neck dissection (MRND) after robotic thyroidectomy through the same TA port.14 This type of robot-assisted neck dissection (RAND) had some inherent limitations, due to fact that lymph nodes of the upper neck were difficult to remove. Over the past few years, we have developed a RAND via modified facelift (MFL) or retroauricular (RA) approach and reported the feasibility and safety of this technique.15, 16 Since then, we have actively applied such RAND techniques in various head and neck cancers. In our country, almost all cases of robotic total thyroidectomy utilize the TA approach. According to the reports made by Terris et al., robotic facelift thyroidectomy technique has been solely applied for ipsilateral hemithyroidectomy. For total thyroidectomy, Terris et al. performed the robotic surgery with bilateral RA incisions. Here, we intend to introduce our novel surgical method after successfully attempting simultaneous robotic total thyroidectomy and RAND via a single RA approach without an axillary incision. To our knowledge, this is the first to report in the medical literature.
  
  
  METHODS
  We present four cases of our surgical experience since the beginning of 2013. All patients received robotic total thyroidectomy with MRND via single RA port without axillary incision after approval from the institutional review board at Severance Hospital, Yonsei University College of Medicine. The inclusion criteria for this operation were as follows: (1) patients with malignant carcinomas of the thyroid gland with evident cervical lymph node metastasis on preoperative imaging studies which are indicated for surgery; (2) patients with no previous history of treatment for thyroid carcinoma. The exclusion criteria were as follows: (1) patients with recurred thyroid tumors; (2) patients with thyroid carcinomas that showed gross invasion to local structures or extensive extrathyroidal capsular spread; (3) patients with clinically evident neck nodal metastasis with extracapsular spread; (4) patients with past history of neck surgery of any kind. In order to assess the extent of disease, neck ultrasonography with fine needle aspiration, neck CT or MRI and PET-CT were performed as preoperative evaluation. All patients were given full information of the possible treatment options for their thyroid cancer comprising of open transcervical approach and robotic surgery via RA approach, including the advantages and disadvantages of each treatment choice and provided written, informed consents before the surgery. General clinical information of the patients is outlined in Table 1. The skin incision for the operation was designed just like the approach for robotic facelift thyroidectomy by Terris et al. and RAND, which has been first reported by our institution.11 (,) 16 The operation was performed by the following sequence. Initially, the skin-subplatysmal flap was elevated after making the skin incision to create sufficient working space. During this process, the elevated skin flap was retracted and maintained by retractors held by the assistant. After application of the self-retaining retractor (Sangdosa Inc., Seoul), neck dissection of the upper neck levels was performed under gross vision. Next, RAND through the RA incision was conducted followed by ipsilateral thyroidectomy with central compartment neck dissection (CCND) via the same approach. Finally, contralateral thyroidectomy with CCND was performed via the single RA port. During these steps, the operator is aided by the bedside assistant with long-suction tips to manipulate and direct the dissected specimen to maintain optimal surgical view or to suck out the fume created by the thermocoagulation from the Harmonic shears. The da Vinci robotic surgical system (Intuitive Surgical, Sunnyvale, CA) was introduced via the RA port with a facedown 30° dual-channel endoscopic arm placed in the center, and two instrument arms equipped at either side with 5-mm Maryland forceps and Harmonic curved shears. During the step of robotic contralateral thyroidectomy, a ProGrasp forceps was utilized at times, instead of 5-mm Maryland forceps. The rest of the surgery was completed with the robotic system (see Video for demonstration of operation for patient 2). Table 1 Clinical characteristics of the patients Patient Sex/age (yr) BMI Side(a) Approach Pathology(b) Tumor size(c) (cm) CCND(d) MRND(d) Drain removal day Drainage amount (ml) Hospital stay (days) 1 F/38 23.8 L RA PC 0.7 2/5 8/23 8 788 11 2 F/18 18.3 L RA PC 0.8 2/8 7/35 6 398 9 3 F/44 23.1 L RA PC 0.9 5/12 5/27 6 607 9 4 F/26 32.9 L RA PC 1.4 3/14 9/48 7 476 15 BMI body mass index, RA retroauricular approach, PC papillary carcinoma, CCND central compartment neck dissection, MRND modified radical neck dissection (a)Side refers to the site of main lesion (b)Pathology refers to the primary tumor within the thyroid gland (c)Tumor size refers to the diameter of the largest tumor in the thyroid gland (d)For each type of lymph node dissection, the number of positive nodes/total number of retrieved nodes is stated
  
  
  RESULTS
  For all of the patients, robotic total thyroidectomy with MRND (levels II, III, IV, V) via unilateral RA approach was successfully completed without any significant intraoperative complications or conversion to open or other approach methods. The total operation time was defined as the time from initial skin incision to removal of the final specimen, which was an average 306.1 ± 11.1 min (Table 2). This included the time for skin flap elevation and neck dissection under gross vision (87 ± 2.8 min), setting up the robotic system for RAND (6.8 ± 2.4 min), console time using the robotic system for RAND (59.3 ± 2.2 min), flap elevation for thyroidectomy (11.3 ± 2.5 min), robotic arms docking for ipsilateral thyroidectomy (6.3 ± 2.5 min), console time for ipsilateral thyroidectomy (61.3 ± 2.1 min), robotic arms docking for contralateral thyroidectomy (6.3 ± 2.5 min), and console time for contralateral thyroidectomy (61.8 ± 2.1 min). The working space created from RA incision was sufficient, and manipulations of the robotic instruments through this approach were technically feasible and safe without any mutual collisions throughout the entire operation. It also allowed for an excellent magnified surgical view enabling visualization of important local anatomical structures. There was no postoperative vocal cord palsy due to recurrent laryngeal nerve injury. However, two patients developed transient hypoparathyroidism, which resolved in the end without the need for calcium or vitamin D supplementation after certain period of medical management (Table 3). Also, there was no incidence of postoperative hemorrhage or hematoma formation, although a single patient developed a postoperative seroma on postoperative day 9, which was managed conservatively without the need for further surgical intervention. On average, the wound catheter was removed 6.8 ± 1 days after surgery and the patient was discharged from the hospital at an average 11 ± 2.8 days from admission (Table 1). Final surgical pathology confirmed the diagnosis of papillary carcinoma for every patient. The total number of cervical nodes retrieved from CCND and MRND was 9.8 ± 4 and 33.1 ± 11 respectively, and the number of positive metastatic nodes was 3 ± 1.4 and 7.3 ± 1.7 respectively (Table 1). In three patients (patients 2, 3, and 4), the presence of one parathyroid gland was each verified in the pathology specimen. All four patients have received high-dose (150 mCi) radioiodine ablation (RAI) therapy after the operation and are being followed up (average 11.3 months, range 9-13 months) on a regular basis with no evidence of recurrence (post-RAI, most recent, nonsuppressed thyroglobulin range 0.1-0.4 ng/ml, antithyroglobulin antibody range 13.7-147.5 IU/ml). (ABSTRACT TRUNCATED)
authors.affiliation: Department of Otorhinolaryngology, Severance Hospital, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
authors.forename: Hyung Kwon
authors.initials: HK
authors.lastname: Byeon
authors.forename: F Christopher
authors.initials: FC
authors.lastname: Holsinger
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Tufano
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Chung
authors.forename: Won Shik
authors.initials: WS
authors.lastname: Kim
authors.forename: Yoon Woo
authors.initials: YW
authors.lastname: Koh
authors.forename: Eun Chang
authors.initials: EC
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D001365:Axilla; D002291:Carcinoma, Papillary / Q000556:secondary / Q000601:surgery*; D004724:Endoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D037981:Neck Dissection / Q000379:methods*; D009367:Neoplasm Staging; D011379:Prognosis; D012371:Robotics / Q000379:methods*; D013524:Surgical Flaps; D013964:Thyroid Neoplasms / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods*