Objective To explore the effect of a more aesthetic surgical incision in thyroid cancer neck clearance surgery. Methods From May 1999 to December 20006, 82 patients with differentiated thyroid cancer underwent modified neck clearance surgery using a collar-type skin-grain extension incision by extending the skin-grain along the side of the neck clearance to the position of the anterior border of the oblique muscle on the basis of the conventional thyroid collar incision, avoiding the vertical segment of the field hockey stick incision. There were 60 female and 22 male patients. Age ranged from 10 to 80 years, with a median age of 40.5 years. 96 sides of cervical clearance surgery were performed in 82 patients. The cervical clearance surgical procedures were: radical cervical clearance on one side, modified cervical clearance type I on one side, modified cervical clearance type II on eight sides, and modified cervical clearance type III on 86 sides. The average surgical anesthesia time among patients with collar skin lengthening incision was 197 min. 37.5 lymph nodes per side and 8.8 metastatic lymph nodes per side were detected on average in the total number of neck clearance specimens. The complication rate related to neck dissection was 9.8% (8/82). Follow-up ranged from 1 to 94 months, with a mean of 23 months. The lymph node recurrence rate was 1.2%, and no patient had tumor death. Conclusion The new collar skin lengthening incision with modified neck debulking surgery for differentiated thyroid cancer with cervical lymph node metastasis is technically feasible, and the preliminary results show satisfactory tumor treatment results. The patient’s neck incision scar was small and the appearance was maximally preserved. Zhang Bin, Department of Head and Neck Surgery, Cancer Hospital, Chinese Academy of Medical Sciences Papillary thyroid cancer with high cervical lymph node metastasis, 40% to 70% [1], is generally treated by modified neck clearing surgery, and the two main surgical incisions used in China are the field hockey stick incision [2] or the single-arm arc incision [3], although the above two incisions have adequate exposure of the surgical field, the postoperative scar of the vertical part of the lateral neck incision is thicker, especially for female Patients, obviously affect the appearance, we were inspired by the elective cervical clearing dermatome incision [4], and began to try the collar dermatome extension incision in the clinic, and the preliminary results are summarized below. Data and methods I. Clinical data From May 1999 to December 2006, a total of 82 patients underwent cervical lymph node dissection for thyroid cancer with a collar lengthening incision; 22 of them were male and 60 were female. Of the 82 patients, 58.2% (48) had undergone surgery of different types of thyroid primary foci at outside institutions, and the remaining 34 were primary patients. The pathological grading of cervical lymph nodes was N0:3 cases, N1a:46 cases, and N1b:33 cases. Remote metastasis M1: 4 cases; M078 cases. Eighty-two patients underwent cervical clearance surgery on 96 sides, of which 14 patients underwent double cervical clearance surgery at the same time. The cervical clearance surgical procedures were: radical cervical clearance on one side, modified cervical clearance type I (preserving only the paravertebral nerve) on one side, modified cervical clearance type II (preserving the paravertebral nerve, internal jugular vein or sternocleidomastoid muscle) in 8 cases, modified cervical clearance type III (preserving both the paravertebral nerve, internal jugular vein and sternocleidomastoid muscle) in 86 cases, and type III in which 12 cases preserved both the external jugular vein and the cervical plexus (commonly known as five-preservation cervical dissection). The pathology was all lymph node metastatic papillary thyroid cancer. The primary surgical procedures (including the second supplementary surgery in our hospital after residual surgery) were: total thyroidectomy in 32 cases, lobectomy with isthmus in 29 cases, and subtotal thyroidectomy in 21 cases. The skin and the broad cervical muscle were cut and the flap was turned up. The surgical area was exposed including the ipsilateral strap muscle, the inferior border of the submandibular gland, the anterior border of the sternocleidomastoid muscle, the caudal part of the parotid gland and the anterior border of the posterior cervical oblique muscle. Unlike the conventional incision, the posterior superior sternocleidomastoid muscle cannot be fully exposed. 2. Cervical clearance procedure: similar to the conventional modified cervical clearance procedure [5], with the following differences: (i) the lymph nodes in the submandibular and subchin regions (zone I) rarely metastasize, so there is no need to expose and clear zone I [5]; (ii) zone IIb clearance is completed from the anteromedial aspect of the sternocleidomastoid muscle, and the superior segment of the paraspinal nerve is first located and dissected to expose the superior end of the internal jugular vein. Two pulling hooks were used to pull apart the superior sternocleidomastoid muscle and the diastasis muscle respectively, and the fatty lymphoid tissue above the posterior aspect of the paraspinal nerve was excised. After separating the fatty lymphoid tissue from the surface of the cephalic and scapular raphe muscles, this mass of specimens was pulled forward under the paraspinal nerve and excised together with the lateral cervical specimens. All but two of the cleared specimens were pathologically negative, and all were found to have metastatic lymph nodes. The total number of lymph nodes per side of the cleared specimen ranged from 10 to 81, with a mean of 37.5; among them, 0-45 positive lymph nodes per side had a mean of 8.8; the duration of surgical anesthesia ranged from 75 to 390 min, with a mean of 197 min; 25 surgical complications occurred in 21 patients with an incidence of 25.6% (Table 1), among which complications related to cervical dissection (lymphatic leakage, wound effusion, and Horner’s sign) The incidence was only 9.8% (8/82). Patients with lymphatic leaks and wound effusions were treated accordingly during hospitalization. As of July 2007, 82 patients were followed up for 1 to 94 months, with a median time of 23 months; only one case was found to have a recurrence of a lymph node in the 2R region of the ipsilateral superior mediastinum 18 months after surgery (1.2%), which was reoperatively removed. No distant metastasis or death occurred. It was confirmed by outpatient review that most patients had a small neck scar and the incisional appearance was less affected Discussion Differentiated thyroid cancer (including papillary thyroid cancer and follicular carcinoma) has the following characteristics: (i) good prognosis, with a 10-year survival rate of 95-98% in the low-risk group [1]. (ii) Lymph node metastasis is not a significant factor affecting prognosis. (iii) The incidence rate of women is 2-4 times higher than that of men. Because of the large proportion of young women, treatment should also emphasize the function and appearance of the patient after surgery, in which the aesthetic appearance of the neck clearance incision is very important. Generally, if the incision is made in the same direction as the skin line, the postoperative incision will have less tension and less scar formation; conversely, the longitudinal incision will have a thicker postoperative scar [6]. The main surgical incisions currently applied for thyroid cancer neck clearance are the field hockey stick incision used by Lahey in 1940, which is a posterior vertical cervical incision coupled with a collar incision in the lower neck. If bilateral neck clearance surgery is performed, it becomes an apron incision [2]. This incision has a significant postoperative scar on the posterior vertical part of the neck. Some hospitals in China use a single-arm curved incision introduced by Li Shuling [3], which is a longitudinal curved incision from the mastoid process to the outer 1/3 of the clavicle. Characteristically, there is no incision in the anterior part of the neck, but the posterior longitudinal incision scar is thicker. The disadvantage of the above two commonly used incisions is the longitudinal incision at the back of the neck, which still has a significant impact on the appearance of modern women’s summer dressing. We started clinical trial of the collar skinfold extension incision in 1999, and later found a few similar reports in recent years in China and abroad by reviewing the literature [7-9], Uchino [7] referred to this incision as “an extended collar incision along the natural skinfold, while Shan [8] referred to a “single transverse incision” with the posterior border of the oblique muscle as the anterior border of the incision; in China, Xi [9] referred to this incision as ” The long low collar incision”, but did not describe the specific clearing area. The articles all mention that the advantage of this incision is that the postoperative scar is not obvious, and it is beneficial to preserve the appearance of female patients. It is possible that most physicians are skeptical that this incision can achieve complete lymph node clearance, believing that the lymph nodes of the deep superior jugular chain (zone II) are not easily exposed and cleared. However, according to our experience, this incision is not very difficult for surgeons experienced in cervical clearance, especially modified cervical clearance procedures. Although, both Uchino [7] and Shan [8] suggested that a slightly higher position of the collar incision, such as 3 cm above the sternotomy or at the level of the cricoid cartilage, is favorable for having a neck clearance operation, in fact, many patients have had previous thyroid surgery and the neck clearance incision can only be extended from the original collar incision. For patients with long necks where exposure is more difficult, this can be solved by extending the incision to reach inside the hairline. Our data showed that only one side (1.2%) had recurrence of neck lymph nodes after 18 months postoperatively, and the site of recurrence was not the difficult zone II, but the recurrence of lymph nodes at the entrance of the sternum, which is related to the tendency of differentiated thyroid cancer to metastasize in the upper mediastinum [10]. The rate of lymph node recurrence in the neck reported by S. H. Xi [9] was 2.8% (3/106), with 100% survival at 5 and 10 years. In addition, the average number of lymph nodes cleared in this group of neck clearance specimens was 37.5, which is comparable to the average number of lymph nodes cleared in neck clearance specimens with conventional incisions performed in our department during the same period (37) [11]. Indirectly, this suggests that the collar skin lengthening incision for cervical clearance does not affect the thoroughness of the procedure. The high incidence of surgical complications in this group (25.6%) was mainly related to temporary hypocalcemia after total thyroidectomy (14.6%). The incidence of complications truly related to neck clearance was only 9.8%, which generally healed with conservative management. The duration of surgical anesthesia in this group ranged from 75 to 390 min, with a mean of 197 min; the prolonged operative time may be related to bilateral clearing (15 cases) and 5 preserving surgery (12 cases), and may not be related to the incision. It is technically feasible to treat lymph node metastasis of differentiated thyroid cancer by using a collar-type dermatome incision, and the preliminary results showed satisfactory tumor treatment results; because the neck incision was along the dermatome, the postoperative incision scar was small, which satisfied the demand of some patients to preserve the aesthetic appearance of the neck.