Axial pedicle screw fixation technique, as a classic posterior fixation technique, is the first choice and gold standard of posterior axial screw fixation. Since it can pass through the whole vertebrae and play the role of three-column fixation, it has excellent biomechanical properties and is widely used in cervical spine surgery. However, with the deepening of clinical research, some scholars found that the application of axial pedicle screws was limited in patients with pedicle hypoplasia, high-riding vertebral artery and irreducible atlantoaxial dislocation. At the same time, in order to expose bone markers during screw placement, the muscle dissection of pedicle screws is wider compared with that of isthmus screws. Isthmus screw fixation, as a complementary technique for pedicle screw technique, has gradually attracted the attention of scholars in recent years and has been applied in the surgical treatment of various types of cervical spine diseases. The entry point of axial isthmus screw is closer to the midline of the spine and the inferior facet joint than pedicle screw, to avoid extensive muscle dissection during the operation, so that the paravertebral muscles can be protected, which make the surgery more minimally invasive and the invasion of the operation further reduced. At the same time, compared with the lateral mass or pedicle screw of the atlas combined with axial pedicle screw fixation, the lateral mass or pedicle screw of the atlas combined with axial isthmus screw fixation can increase the anteroposterior and vertical distance between the heads of C 1 and C 2 screws due to the change of screw entry points, which can provide a wider operative space for the three dimensional reduction of atlantoaxial dislocation. However, since the axis is a transitional vertebra between the upper and lower cervical spine which has complexity and variability in anatomical structure, many scholars have limited understanding of this new technique. There are no unified standards for screw placement and surgical details, which are mostly based on the personal experience of clinicians. Meanwhile, the biomechanical properties, surgical complications and long-term efficacy of this technique have received little attention and concern, resulting in the limitation of clinical application and promotion for this technique. This review evaluates the relative advantages of axial isthmus screws according to existing literature reports, and analyzes the anatomy, biomechanics, clinical applications and surgical complications of axial isthmus screw fixation technique, aiming to provide a reference for the safety and feasibility of axial isthmus screw placement.

OBJECTIVETo investigate the clinicopathological features and postoperative short-term complications in the elderly gastric cancer patients.

METHODSClinical data of 270 elderly patients with gastric cancer who underwent gastrectomy in Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine between July 2012 and June 2014 were analyzed retrospectively. Among 270 patients, 220 were 70 to 79 years old( old group) and 50 were ≥80 years old(oldest group). The clinicopathological features were compared between the two groups. Perioperative factors were analyzed to determine if they are associated with postoperative complications. Multivariate logistic regression model was performed.

RESULTSBefore operation, most elderly patients (n=161, 59.6%) had 2 or more than 2 comorbidities, including hypertension (n=154, 57.0%), anaemia (n=126, 46.7%), diabetes (n=53, 19.6%), arhythmia (n=52, 19.3%), cardiovascular disease(n=33, 12.2%), and chronic pulmonary disease(n=28, 10.4%). Elderly gastric cancers were more likely to locate at the lower third of the stomach (n=116, 43.0%). The pathological type was mainly the poorly differentiated carcinoma (n=152, 56.3%), and stage III was more common in TNM staging(n=138, 51.1%). As compared to the old group, the oldest group had more preoperative comorbid diseases(P=0.048), more previous surgery(P=0.029), more preoperative transfusion (P=0.019), more combined cholecystectomy (P=0.007) and feeding jejunostomy (P=0.037), but less tumor invasion of nerves(P=0.045). No significant differences in other clinicopathological parameters were found between the two groups (all P>0.05). A total of 121 (44.8%) patients presented postoperative complications, including severe complication in 30 cases(11.1%) and death in 4 cases(1.5%). Forty-seven patients(17.4%) presented operation-associated complications, including infection in 28 cases(10.4%) and leakage in 21 cases(7.8%). One hundred and seven(39.6%) patients presented non-operation-associated complications, including pneumonia in 48 cases(17.8%), hypertension in 23 cases(8.5%), and arhythmia in 17 cases(6.3%). Postoperative morbidities of Clavien-Dindo class II complication and non-operation-associated complication were higher in the oldest group compared with old group(P<0.05), while other postoperative complications were compared between the two groups, only urinary tract infection was significantly different(P<0.05). Univariate analysis showed that postoperative complications were significantly associated with age(χ(2)=7.308, P=0.007), number of comorbid diseases (χ(2)=10.872, P=0.001), cardiovascular disease (χ(2)=9.412, P=0.002), hypertension (χ(2)=4.934, P=0.026) and preoperative transfusion (χ(2)=3.911, P=0.048). Multivariate analysis showed that only the number of comorbid diseases was an independent risk factor for postoperative complications(OR=2.810, 95% CI: 1.710 to 4.616, P=0.000).

CONCLUSIONNon-operation-associated postoperative complications are more likely to occur in the elderly patients due to more comorbid diseases. Perioperative intensive care should be carried out for the elderly gastric cancer patients with comorbid diseases in order to improve surgical safety and efficacy.

Aged ; Aged, 80 and over ; China ; Comorbidity ; Gastrectomy ; adverse effects ; Humans ; Hypertension ; complications ; Logistic Models ; Multivariate Analysis ; Neoplasm Staging ; Postoperative Complications ; Retrospective Studies ; Risk Factors ; Stomach Neoplasms ; complications ; surgery

Objective: To monitor the WT1 mRNA level and its dynamic changes in patients with myelodysplastic syndromes (MDS) after hypomethylating agents (HMA) , as well as to assess the significance of WT1 mRNA levels and its dynamic changes in evaluating the efficacy of HMA and distinguishing the disease status of heterogeneous patients with stable disease (SD) . Methods: Bone marrow or peripheral blood samples of 56 patients with MDS who underwent hypomethylating agents (≥4 cycles) from November 2009 to March 2018 were tested by real-time quantitative polymerase chain reaction (PCR) to detect the expression of WT1 mRNA, and to observe the correlation between the dynamic changes of WT1 mRNA expression and clinical efficacy and prognosis of patients. Results: WT1 mRNA expression levels of MDS patients decreased significantly after 3 cycles of hypomethylating agent treatment. Besides, the WT1 mRNA expression levels of patients increased significantly after diseases progression. According to the dynamic changes of WT1 mRNA expression levels during SD, 45 cases could be further divided into increased group and non-increased group. In those SD patients with increased WT1 mRNA expression level, the ratio of suffering disease progression or transformation to AML was 95.65% (22/23) , whereas the ratio turned to be 9.09% (2/22) for the non-increased group (χ²=33.852, P<0.001) . Compared with those SD patients reporting no increase in WT1 mRNA expression level, the overall survival[17 (95%CI 11-23) months vs not reached, P<0.001] and progression-free survival [13 (95%CI 8-18) months vs not reached, P<0.001] of those SD patients reporting increase in WT1 mRNA expression level were significantly shorter. Conclusion WT1 mRNA expression level is a useful indicator to assess the efficacy of hypomethylating agents in MDS patients. Especially in patients with SD, detection of the changes in WT1 mRNA expression level is able to predict disease progression and help to make clinical decision.