Application Of Modified Video-assisted Lateral Neck Dissection In Papillary Thyroid Carcinoma

PurposeTo explore the feasibility,safety and oncological completeness of the treatment of papillary thyroid carcinoma(PTC)by modified video-assisted lateral neck dissection(VALND),and then a prospective randomized controlled study was designed to compare with the traditional open lateral neck dissection(LND)to demonstrate the safety and oncological completeness of the modified VALND,and also demonstrated whether the procedure can improve the quality of life after surgery.MethodPart 1Previous literatures have reported VALND in the treatment of PTC with lateral cervical lymph node metastasis and achieved good surgical safety and oncological completeness,but failed to solve the difficult problems such as small and unstable surgical working space.In this study,the surgical operation space,surgical instruments and surgical methods of operation of three aspects of systematic improvement and innovation,so that the modified VALND is more suitable for cervical lymph node dissection now,we have completed a total of 119 cases of PTC with modified video-assisted lateral neck lymph node dissection.The levels of thyroid function,serum thyroglobulin antibody and serum thyroglobulin were detected every 6 months after surgery.The thyroid gland area and the lateral cervical area were examined by ultrasonography every 6 months after surgery.Part 2A prospective randomized controlled study was conducted to compare the modified VALND with conventional open LND.Patients were randomly assigned to the VA group(n=35)or open group(n=35)and were treated either by modified VALND or conventional open LND,respectively.We compared safety and oncologic completeness as well as functional outcomes such as postoperative subjective voice and swallowing difficulties.We also evaluated neck pain,skin sensory changes,and cosmetic outcomes after surgery using various quality of life(QoL)symptom scales.Neck and shoulder disability was assessed using arm abduction tests(AAT)and questions from the neck dissection impairment index(NDII).Operation time,complications,number of lymph nodes removed,postoperative pain(24 hours and 48 hours after surgery),postoperative follow-up detection of serum thyroglobulin antibody and serum thyroglobulin levels were recorded.ResultsPart 1:1 The surgical operation space suitable for the modified VALND has been explored.The surgical working space was maintained by three long deep retractors,which decomposed the surgical working space into horizontal working space and vertical working space.Horizontal working space by the assistant pull,intraoperative free and flexible adjustment,vertical working space maintained by the mechanical lifting device,intraoperative high stability.2 Developed a complete set of surgical instruments suitable for modified VALND,including a complete set of retractors,separation tongs and grasping tongs with or without suction devices.3 Optimize the modified VALND and make it a process of operation.4 Of the 119 patients,1 case was converted to open procedure.118 cases were successfully performed under the endoscope.The mean operation time of VALND was(72 ± 15)min,and mean postoperative hospital stay was(4.9 ±2.0)days.The mean maximum diameter of the primary tumor of the thyroid(1.3 ± 0.7)cm and the mean number of lymph nodes removed was(42.2 ± 13.0)in lateral compartment.There were 18 cases of transient hypocalcemia,no permanent hypocalcemia,4 cases of transient recurrent laryngeal nerve(RLN)injury,and 2 cases of permanent RLN injury(due to tumor invasion).The complications of lymph node dissection in the lateral cervical areas included 3 cases of temporary accessory nerve injury,2 case of temporary facial nerve mandibular branch injury,1 case of postoperative bleeding and 5 cases of minor chyle leak.Postoperative mean follow-up time(38±13)months,serum thyroglobulin(sTg)levels were(0.11 ± 0.37)ng/L on average,1 patient had tumor remnants,and all other cases had no tumor remnants or recurrence.Part 2:1 Modified VALND and conventional open LND obtained a similar surgical complications.2 Modified VALND and conventional open LND obtained a similar oncological completeness,including the number of resected lymph nodes,iodine uptake at 24 hours after I131 treatment,and serum thyroglobulin antibody levels,sTg levels and postoperative cervical imaging during follow-up.3 Total operating time was(176±16)minutes in the VALND group and(161 ±16)minutes in the open LND group(P =.0003).Subjective voice outcomes,postoperative swallowing difficulties and postoperative AAT and NDII were similar between the two groups.However,skin sensory changes(p = 0.0003)were significantly more frequent in the open LND group than in the VALND group,postoperative pain was observed less frequently after surgery in the VALND group(P<.0001).Cosmetic results evaluated by a verbal response scale and a numeric rating scale were in favor of the VALND group(p = 0.0003 and P = 0.0004,respectively).ConclusionsPart 1:The modified VALND is a safe and feasible approach in selected PTC patients with lateral neck lymph node metastasis.Learning curve of the modified VALND is short,and surgical incision is small and good postoperative beauty was achieved,and the VALND is worthy of clinical use.Part 2:1 In the treatment of PTC patients with lateral neck lymph node metastasis,modified VALND was similar to that of open LND in the term of surgical safety and oncological completeness.2 Although the mean operating time was longer about 15 minutes in the modified VALND group than in the open group,the modified VALND can improve postoperative QoL,including better cosmetic,less postoperative pain and lesser neck numbness.