Gallbladder polypoid lesions (GPLs) refer to any elevated lesion of the mucosal surface of the gallbladder wall, and the prevalence is estimated to be between 0.9% and 12.1%. GPLs include benign polyps and malignant polyps. Benign polyps are further classified as non-neoplastic polyps and neoplastic polyps. Cholesterol polyps are the most common benign polyps and adenocarcinoma is the main type of malignant polyp. Hepatitis B virus infection, liver function abnormalities, dyslipidemia, and obesity are the main risk factors for GPLs. Studies of biological mechanisms have focused on malignant gallbladder polyps, the development of which is regulated by hormone levels in vivo, gut microbiota, inflammation, oxidative stress, Salmonella typhimurium, and related molecules. Diagnostic modalities include chemical examination and imaging examination, with imaging examination currently being the mainstay. Treatment of patients with GPLs is based on the presence or absence of symptoms, age, size of the polyps, tendency of the polyp to increase, and risk factors for symptomatic malignancy to determine whether surgery should be performed.

Objective To evaluate the stability,safety and immune enhancement and anti-tumor effects of Wilms'tumor gene 1(WT1)peptide combined with AddaVaxTM emulsion vaccine for acute myeloid leukemia.Methods The stability of WT1 peptide in the adjuvant vaccine was evaluated using MALDI-TOF-MS time-of-flight mass spectrometry.Female C57BL/6 mice were randomly divided into PBS group,WT1 peptide group,and WT1 peptide+AddaVaxTMemulsion adjuvant vaccine group.The immunization was performed at a dose of 50 μg/mouse for antigen and 50 μg/mouse for adjuvant,with intramuscular injection on days 0,14,and 28.HE staining was used to assess the toxicity of intramuscular vaccination on mouse organ tissues.Cytokine levels were detected by ELISA,and the number of IFN-γ-secreting splenocytes was measured by ELISpot.Flow cytometry was employed to detect the maturation of bone marrow-derived dendritic cells(BMDCs)promoted by the vaccine in vitro and the promotion for lymphocyte activation,and H-2Db WT1 tetramer was utilized to detect the proportion of specific CD8+T cells.After establishing a mouse leukemia tumor model using the C1498-mWT1 stable cell line,the anti-tumor effects of the vaccine for prevention and treatment were evaluated.Results The WT1 peptide stably existed in the vaccine without causing significant organ tissue changes in mice after intramuscular injection.Compared to the mice immunized with WT1 aqueous solution,the mice after intramuscular injection of the WT1 peptide emulsion adjuvant vaccine showed stronger immune responses of Th1 cells,including IFN-γ and TNF-α,as well as Th17 cells of IL-17A(P＜0.05),and the mice had not only promoted number of IFN-γ secreting splenocytes(P＜0.01)but also enhanced maturation of BMDCs,as indicated by an increase in the proportions of CD40+/CD11c+and CD86+CD80+/CD11c+ cells(P＜0.05).Additionally,there were increases in both the proportion of CD4+/CD3+T and CD69+/CD8+T cells(P＜0.05)and the proportion of specific CD8+T cells(P＜0.05).In the anti-tumor effect study using the C1498-mWT1 mouse model,the median survival time of the WT1+AddaVaxTM group was extended by 6 d compared to the WT1 aqueous solution group.At day 50,the survival rate of mice in the WT1+AddaVaxTM group was still 28.5％,while all mice in the other groups had died(P＜0.05).Conclusion The vaccine with the WT1 peptide and AddaVaxTM emulsion adjuvant exhibits good immunological and anti-tumor effects.

Objective:To evaluate the efficacy and safety of peroral endoscopic myotomy (POEM) in achalasia of cardia (AC) patients with the long course.Methods:A total of 159 AC patients who received POEM from January 2015 to March 2022 in the First Affiliated Hospital of Soochow University were divided into the long course group (≥10 years) and the non-long course group (<10 years). The baseline information, POEM procedure and postoperative recurrence were compared and the differences between the recurrent patients and non-recurrent patients in the long course group were explored.Results:The age (57.09±14.30 years VS 42.08±15.68 years, t=5.569, P<0.001), the rate of treatment history [28.9% (13/45) VS 9.6% (11/114), χ2=9.319, P=0.020], the proportion of Henderson grade Ⅲ esophagus [17.8% (8/45) VS 6.1% (7/114), χ2=7.020, P=0.030] in the long course group were significantly higher than those in the non-long course group. The recurrence rate in the long course group was significantly higher than that in the non-long course group [33.3% (15/45) VS 14.9% (17/114), χ2=6.811, P=0.009]. In the long course group, the age (62.50 ± 16.94 years VS 53.77 ± 12.95 years, t=-2.121, P=0.040), and the rate of treatment history [53.3% (8/15) VS 16.7% (5/30), χ2=6.544, P=0.016] in the recurrent patients were higher than those in the non-recurrent patients. Conclusion:POEM is safe and effective for long-course AC patients. In patients with the long course, the aged patients with previous treatment are more likely to relapse.

Objective:To compare the short-term efficacy of Billroth Ⅱ+Braun anasto-mosis versus Roux-en-Y anastomosis in totally three-dimensional (3D) laparoscopic distal gastrectomy.Methods:The retrospective cohort study was conducted. The clinicopathological data of 140 patients with gastric cancer who were admitted to the First Medical Center of Chinese PLA General Hospital from January 2016 to January 2020 were collected. There were 105 males and 35 females, aged from 23 to 84 years, with a median age of 55 years. Of the 140 patients, 54 patients undergoing totally 3D laparoscopic distal gastrectomy with Billroth Ⅱ+Braun anastomosis were allocated into Billroth Ⅱ+Braun group, and 86 patients undergoing totally 3D laparoscopic distal gastrectomy with Roux-en-Y anastomosis were allocated into Roux-en-Y group, respectively. Observation indicators: (1) surgical situations; (2) postoperative situations; (3) follow-up. Follow-up using outpatient examination and telephone interview was conducted to detect remnant gastritis and its severity, bile reflux, reflux esophagitis in the postoperative 3 months up to April 2020. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Count data were described as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Comparison of ordinal data was analyzed using the Mann-Whitney U test. Results:(1) Surgical situations: 140 patients underwent totally 3D laparoscopic distal gastrectomy. The operation time, cases with volume of intraoperative blood loss <50 mL, 50 to 200 mL or >200 mL, the number of lymph node dissected were (233±39)minutes,15, 35, 4, 30±13 for the Billroth Ⅱ +Braun group , respectively, versus (240±52)minutes,25, 51, 10, 27±10 for the Roux-en-Y group, showing no significant difference between the two groups ( t=0.856， χ2=0.774， t=1.518， P>0.05). (2) Postoperative situations: cases with drainage tube, time to postoperative first flatus, cases with postoperative grade Ⅱ, Ⅲ, Ⅳ, Ⅴ complications, cases with postoperative complications, cases with postoperative severe complications, duration of postoperative hospital stay, surgery cost and total hospitalization cost of the Billroth Ⅱ+Braun group were 38, (3.5±0.8)days,4, 1, 0, 0, 5, 1, (9.0±5.0)days, (3.8±1.2)×10 4 yuan and (9.7±2.1)×10 4 yuan, respectively. The above indicators of the Roux-en-Y group were 59, (3.7±1.0)days, 9, 1, 0, 1, 11, 2, (9.0±4.0)days, (4.3±1.0)×10 4 yuan and (9.2±2.1)×10 4 yuan, respectively. There was a significant difference in the surgery cost between the two groups ( t=2.453, P<0.05), while there was no significant difference in cases with drainage tube, time to postoperative first flatus, cases with postoperative grade Ⅱ, Ⅲ, Ⅳ, Ⅴ complications, cases with postoperative complications, duration of postoperative hospital stay or total hospitalization cost between the two groups ( χ2=0.049, t=?1.339, Z=0.000, χ2=0.409, t=0.197, 1.383, P>0.05). There was also no significant difference in cases with postoperative severe complications between the two groups ( P>0.05).(3) Follow-up: 134 of 140 patients received the follow-up, including 52 cases in the Billroth Ⅱ+Braun group and 82 cases in the Roux-en-Y group. Results of follow-up within postoperative 3 months showed that the incidence rates of remnant gastritis, bile reflux, reflux esophagitis were 61.5%(32/52), 38.5%(20/52), 26.9%(14/52) for the Billroth Ⅱ+Braun group, respectively, versus 41.5%(34/82), 22.0%(18/82), 12.2%(10/82) for the Roux-en-Y group, showing significant differences between the two groups ( χ2=5.131, 4.270, 4.695, P<0.05). Cases with grade 0,Ⅰ,Ⅱ, Ⅲ, Ⅳ residual food were 42, 3, 5, 2,0 for the Billroth Ⅱ+Braun group, versus 67, 9, 1, 5,0 for the Roux-en-Y group, showing no significant difference between the two groups ( Z=?0.156, P>0.05). Cases with minimal lesion, grade A, grade B gastritis (severity of gastritis) were 6, 5, 3 for the Billroth Ⅱ+Braun group, versus 8, 2, 0 for the Roux-en-Y group, showing no significant difference between the two groups ( Z=?1.468, P>0.05). Conclusions:It is safe and feasible to operate Billroth Ⅱ+Braun or Roux-en-Y anastomosis in totally 3D laparoscopic distal gastrectomy. Billroth Ⅱ+Braun anastomosis can reduce the surgical cost. Roux-en-Y anastomosis has advantages in reducing the incidence of reflux esophagitis, bile reflux and reflux gastritis.

Titanium mesh cage is one of the fusion devices used in anterior cervical corpectomy and fusion (ACCF). It can not only immediately rebuild the stability of cervical spine during the operation, maintain the height and physiological curvature of intervertebral vertebrae, but also avoid the complications of bone donor area caused by autologous bone extraction. Therefore, titanium mesh cage has become the most commonly used internal plant in ACCF. However, there exist many problems in traditional titanium cage, such as stress shielding and titanium cage sinking, which will affect the surgical effect to a certain extent, and even lead to serious postoperative complications requiring revision surgery. At present, a variety of new titanium cages have been invented, which can solve the problems caused by traditional titanium cage to a certain extent. Biomechanical evaluation and its testing methods are an indispensable process for judging whether a new type of spinal fusion cage can be used in clinical practice. This article reviews the biomechanical studies related to cervical spine anatomy, the biomechanical properties of traditional titanium cages and new titanium cages, so as to provide new ideas for the improvement of traditional titanium cages and the development of new titanium cages.

Objective:To compare short-term efficacy of robotic versus 3D laparoscopic-assisted D2 radical distal gastrectomy in gastric cancerpatients and those with different body mass index (BMI).Method:A retrospective cohort study was performed. Inclusion criteria:(1) gastric cancer proved by preoperative pathological results and tumor location was suitable for D2 radical distal gastrectomy; (2) no distal metastases such as in liver, kidney or abdominal cavity, and no direct invasion to the pancreas or colon on preoperative imaging; (3) postoperative pTNM stage ranged from I to III; (4) no conversion to open surgery or change of surgical procedure during operation; (5) complete clinicopathological data. Patients with severe chronic diseases, other malignant tumors, tumor invasion of other organs or distant metastases, benign gastric tumors, gastrointestinal stromal tumors and recurrent gastric cancer were excluded. According to the above criteria, 531 patients who underwent robotic or 3D laparoscopic-assisted distal gastrectomy at the General Surgery Department of Chinese PLA General Hospital from January 2016 to December 2019 were enrolled. Among them, 344 patients underwent 3D laparoscopic-assisted distal gastrectomy (3D-LADG group), including 250 males, 94 females, 66 cases (19.2%) with a BMI ≥ 25 kg/m 2, and 278 cases (80.8%) with a BMI < 25 kg/m 2, and 187 patients underwent robotic-assisted distal gastrectomy (RADG group), including 122 males, 65 females, 69 cases (36.9%) with a BMI≥25 kg/m 2 and 118 cases (63.1%) with a BMI < 25kg/m 2. There were no significant differences in baseline characteristics between the two groups (all P > 0.05). Operative indicators, postoperative recovery, pathological characteristics and complication rate were compared between the two groups. Subgroup analysis stratified BMI was also performed. Results:Compared with RADG group, 3D-LADG group presented more harvested lymph nodes (29.1±12.4 vs. 25.2±9.0, t=4.238, P<0.001), shorter postoperative hospital stay [8.0 (7.0 to 10.0) days vs. 10.0 (9.0 to 11.0) days, Z=-6.205, P<0.001], less operative cost [(3.6×10 4±1.1×10 4) yuan vs. (6.2×10 4±3.5×10 4) yuan, t=-9.727, P<0.001], less cost of hospitalization [8.6×10 4(7.5×10 4 to 10.0×10 4) yuan vs. 12.8×10 4(11.7×10 4 to 14.1×10 4) yuan, Z=-15.997, P<0.001] and longer first flatus time [(3.9±1.0) days vs. (3.4±1.2) days, t=4.271, P<0.001], whose differences were all statistically significant (all P<0.05). While there were no statistically significant differences in operation time, intraoperative blood loss, overall complication rate [10.8%(37/344) vs. 12.8%(24/187), χ 2=0.515, P=0.473] and severe complications rate [2.0%(7/344) vs. 3.2%(6/187), χ 2=0.294, P=0.588] between 3D-LADG group and RADG group (all P>0.05). In BMI<25 kg/m 2 group, propensity score matching (PSM) was used to reduce bias of baseline characteristics. After PSM, 3D-LADG group presented higher proportion of intraoperative blood loss <50 ml [26.7% (31/116) vs. 8.6% (10/116), χ 2=13.065, P<0.001], more harvested lymph nodes [30.3±12.2 vs. 25.3±9.5, t=-3.192, P=0.002] and shorter postoperative hospital stay [9.0 (7.0 to 10.0) days vs. 10.0 (9.0 to 11.0) days, Z=-4.275, P<0.001] compared with RADG group, while other perioperative indicators showed no statistically significant differences between the two groups (all P>0.05). In BMI≥25 kg/m 2 group, 3D-LADG group presented higher proportion of intraoperative blood loss >200 ml [18.2% (12/66) vs. 1.4% (1/69), χ 2=10.853, P=0.001] and shorter postoperative hospital stay [8.0 (6.0 to 10.0) days vs. 9.0 (8.0 to 10.5) days, Z=-3.039, P=0.002] compared with RADG group, while other perioperative indicators also showed no statistically significant differences between the two groups (all P>0.05). Conclusion:It is safe and feasible to perform 3D-LADG and RADG for patients with gastric cancer. The short-term efficacy of both is similar.

Objective:To compare short-term efficacy of robotic versus 3D laparoscopic-assisted D2 radical distal gastrectomy in gastric cancerpatients and those with different body mass index (BMI).Method:A retrospective cohort study was performed. Inclusion criteria:(1) gastric cancer proved by preoperative pathological results and tumor location was suitable for D2 radical distal gastrectomy; (2) no distal metastases such as in liver, kidney or abdominal cavity, and no direct invasion to the pancreas or colon on preoperative imaging; (3) postoperative pTNM stage ranged from I to III; (4) no conversion to open surgery or change of surgical procedure during operation; (5) complete clinicopathological data. Patients with severe chronic diseases, other malignant tumors, tumor invasion of other organs or distant metastases, benign gastric tumors, gastrointestinal stromal tumors and recurrent gastric cancer were excluded. According to the above criteria, 531 patients who underwent robotic or 3D laparoscopic-assisted distal gastrectomy at the General Surgery Department of Chinese PLA General Hospital from January 2016 to December 2019 were enrolled. Among them, 344 patients underwent 3D laparoscopic-assisted distal gastrectomy (3D-LADG group), including 250 males, 94 females, 66 cases (19.2%) with a BMI ≥ 25 kg/m 2, and 278 cases (80.8%) with a BMI < 25 kg/m 2, and 187 patients underwent robotic-assisted distal gastrectomy (RADG group), including 122 males, 65 females, 69 cases (36.9%) with a BMI≥25 kg/m 2 and 118 cases (63.1%) with a BMI < 25kg/m 2. There were no significant differences in baseline characteristics between the two groups (all P > 0.05). Operative indicators, postoperative recovery, pathological characteristics and complication rate were compared between the two groups. Subgroup analysis stratified BMI was also performed. Results:Compared with RADG group, 3D-LADG group presented more harvested lymph nodes (29.1±12.4 vs. 25.2±9.0, t=4.238, P<0.001), shorter postoperative hospital stay [8.0 (7.0 to 10.0) days vs. 10.0 (9.0 to 11.0) days, Z=-6.205, P<0.001], less operative cost [(3.6×10 4±1.1×10 4) yuan vs. (6.2×10 4±3.5×10 4) yuan, t=-9.727, P<0.001], less cost of hospitalization [8.6×10 4(7.5×10 4 to 10.0×10 4) yuan vs. 12.8×10 4(11.7×10 4 to 14.1×10 4) yuan, Z=-15.997, P<0.001] and longer first flatus time [(3.9±1.0) days vs. (3.4±1.2) days, t=4.271, P<0.001], whose differences were all statistically significant (all P<0.05). While there were no statistically significant differences in operation time, intraoperative blood loss, overall complication rate [10.8%(37/344) vs. 12.8%(24/187), χ 2=0.515, P=0.473] and severe complications rate [2.0%(7/344) vs. 3.2%(6/187), χ 2=0.294, P=0.588] between 3D-LADG group and RADG group (all P>0.05). In BMI<25 kg/m 2 group, propensity score matching (PSM) was used to reduce bias of baseline characteristics. After PSM, 3D-LADG group presented higher proportion of intraoperative blood loss <50 ml [26.7% (31/116) vs. 8.6% (10/116), χ 2=13.065, P<0.001], more harvested lymph nodes [30.3±12.2 vs. 25.3±9.5, t=-3.192, P=0.002] and shorter postoperative hospital stay [9.0 (7.0 to 10.0) days vs. 10.0 (9.0 to 11.0) days, Z=-4.275, P<0.001] compared with RADG group, while other perioperative indicators showed no statistically significant differences between the two groups (all P>0.05). In BMI≥25 kg/m 2 group, 3D-LADG group presented higher proportion of intraoperative blood loss >200 ml [18.2% (12/66) vs. 1.4% (1/69), χ 2=10.853, P=0.001] and shorter postoperative hospital stay [8.0 (6.0 to 10.0) days vs. 9.0 (8.0 to 10.5) days, Z=-3.039, P=0.002] compared with RADG group, while other perioperative indicators also showed no statistically significant differences between the two groups (all P>0.05). Conclusion:It is safe and feasible to perform 3D-LADG and RADG for patients with gastric cancer. The short-term efficacy of both is similar.

Objective To determine the risk factors associated with early allograft dysfunction (EAD) after liver transplantation. Methods We retrospectively analyzed the records of 138 patients who underwent liver transplantation from January 2006 to October 2016 in our department. Transplant recipients were divided into two groups:those who met the diagnostic criteria of EAD (EAD group) and those who did not (non-EAD group). We compared blood flow into the transplanted livers and other clinical features between the two groups using univariate and multivariate analysis. Results Intraoperative portal vein flow (PVF) maximum was significantly different between the two groups. Multivariate analysis revealed that intraoperative PVF maximum ＜1 600 mL/min was the only independent risk factor for the occurrence of EAD after liver transplantation in this cohort. Conclusion Intraoperative PVF maximum ＜1 600 mL/min is an independent risk factor for the occurrence of EAD after liver transplantation. Measuring intraoperative blood flow into the transplanted liver in liver transplant recipients may help identify patients at risk for developing EAD.

Objective To evaluate the long-term efficacy of cervical artificial disc replacement for patients with degenerative cervical canal stenosis.Methods All of 43 patienta underwent single level Bryan cervical artificial disc replacement for degenerative cervical canal stenosis were retrospectively analyzed with a minimum 10 years follow-up in our hospital between December 2003 and December 2007.There were 28 males and 15 females with an average age of 56.7 ± 8.0 years which ranged from 37 to 76 including 1 case of C3.4 level,11 xases of ~ level,26 cases of C~ level and 5 cases of C6,7 level.According to the symptoms and location of compression on radiograph,the patients were divided into 3 groups:15 patients in radiculopathy group,10 patients in myelopathy group and 18 patients in myeloradiculo p~hy group.Radidogical evaluation indexes include global range of motion (ROM),segmental ROM,segmental Cobb angle.Clinical evaluation indexes including Japanese Orthopaedic Association (JOA) score,neck disability index (NDI) and Odom's criteria.The variable data were analyzed by one-way ANOVA,the grading data were analyzed by Kruskal-Wallis H test.The preoperative and postoperative data were analyzed by paired t test.Results At the last follow-up,the Cobb angle of the operative segment was 1.29°±1.34°in myelopathy group(t=4.606,P=0.001),0.71°±2.20°in radiculopathy group (t=2.355,P=0.034),and 0.69°±2.12° in myeloradiculopathy group (t=3.312,P=0.004),which was significantly lower than that before operation.At the last follow-up,ROM of the operative segment in myelopathy group was 6.41 o ±4.87°,which was significantly lower than that before operation (11.46° ±5.19°,t=3.589,P＜ 0.05),and there was no significant difference in the other two groups.There was no significant difference in other imaging parameters among the three groups.JOA scores at the last follow-up were 16.33±0.75 in radiculopathy group (t=5.857,P＜ 0.001),16.00±1.05 in myelopathy group(t=8.337,P＜ 0.001) and 14.78±1.69 in radiculopathy group (t=4.045,P＜ 0.001);NDI were 13.07％±5.90％ in radiculopathy group (t=7.097,P＜ 0.001),12.60％±4.22％ in myelopathy group (t=7.319,P＜ 0.001) and 23.11％±14.18％ in radiculopathy group (t=4.229,P＜ 0.001),which were all significantly improved than those before operation.The excellent and good rate of Odom's criteria (H=2.719,2.411,P＜ 0.05),JOA (LAD-t=3.770,4.080,P＜0,05) and NDI(LAD-t=2.850,2.643,P＜ 0.05) at the last follow-up of the patients in radiculopathy group and myelopathy group were better than those of patients in myeloradiculopathy group (P＜ 0.05).Conclusion Cervical artificial disc replacement has a satisfied long-term clinical efficacy with degenerative cervical canal stenosis.The efficacy of myelopathy and radiculopathy were better than myeloradiculopathy.

Objective To explore and analyze the risk factors of axial symptoms after posterior cervical laminoplasty.Methods Retrospectively follow up the patients taking posterior cervical laminoplasty in Jishuitan Hospital during May 2005 to July 2011,due to multi-segmental cervical stenosis or (and) cervical ossification of posterior longitudinal ligament.All patients' gender,diagnosis,age,preoperative neck and shoulder pain,VAS score,course of disease,presence or absence of root symptoms,medical complications,operation time,operation method,blood loss,postoperative neck support time,presence or absence of C5 nerve root paralysis,preoperative JOA and postoperative best JOA,preoperative C2-C7 Cobb angle in neutral position,flexion position,post-extension and calculate the activity were collected.Record the process of axial symptoms in details and statistically analysis by SPSS.Results All of 146 patients were followed up for 58-134 months with an average of 89.5±18.4 months.There were 57 cases of axial symptoms,the overall incidence was 39.0％;except for 7 cases with symptom relief in 6 months,the other 50 cases (34.25％ of the total number of follow-up) of the axial symptoms continued by the time of follow-up.35 patients (23.97％) were characterized by stiffness and 22 patients (18.49％) showed pain,traction and tightness.36 patients (24.66％) showed axial symptoms on the shoulder and back,10 (6.85％) appeared around the wound and 11 (7.53％) appeared on both the shoulder and the wound.Univariate logistic regression analysis showed that intraoperative blood loss (P=0.019,odds ratio(OR) 1.857,95％ CI 1.107-3.116) and postoperative best JOA score (P=0.008,0R=0.780,95％ CI:0.650-0.936) significantly affected the occurrence of postoperative axial symptoms.Multifactor Logistic regression analysis was carried out by stepwise forward method.It was found that besides the intraoperative blood loss and postoperative best JOA score,the following factors also affected the incidence of axial symptoms after operation (P＜0.05):diagnosis,preoperative age,the extension of C2-C7 Cobb angle before operation,and the operation destruction of C7 spinous process muscle stops.The diagnosis of ossification of the posterior longitudinal ligament,preoperative age,and the extension of C2-C7 Cobb angle before operation were the protective factors for the axial symptoms,and the diagnosis of multiple segments of the cervical spinal stenosis and the operation destruction of C7 spinous process were the risk factors for the axial symptoms after the operation.Conclusion Younger,less preoperative C2-C7 Cobb extension,the operation destroys the C7 spinous process muscle stop point,more intraoperative blood loss,lower postoperative best JOA score and patients with multi-segment cervical stenosis more are more easily to have axial symptoms after posterior cervical double door laminoplasty.