To minimize the effect on the general situation of elderly patients, PKP under local anesthesia is an effective method for treating OVFs[10–12]. Liu et al. reported that local anesthesia for single vertebra PKP surgery can effectively relieve pain. Local anesthesia can provide the same clinical efficacy and spinal deformity correction as that of general anesthesia. Moreover, PKP surgery under local anesthesia can effectively reduce anesthesia-related complications such as cardiopulmonary system, allowing patients to get out of bed early and reduce hospitalization time and medical expenses. Fang et al. indicated that the type of anesthesia administered does not affect the clinical efficacy of PKP. However, previous literature mainly focused on PKP for OVF of a single vertebral body. With the increasing aging of the population, patients with m-OVFs are often encountered in the clinical setting. These patients who are about to undergo PKP for multiple vertebral fractures often need to be in a prone position for an extended time. Patients often have to increase the number of fluoroscopy procedures, prolong the operative time, or even terminate the operation because of body position-related discomfort, overdose on a local anesthetic drug, bone cement toxicity, and violent fluctuation of vital signs. However, no reports exist on the choice of anesthesia in PKP for patients with m-OVFs. In this study, we compared the effects of general anesthesia and local anesthesia on PKP for m-OVFs with respect to intraoperative conditions, clinical efficacy, spinal deformity correction, and medical expenditure.
During surgery under general anesthesia, vital signs such as mean arterial pressure and heart rate can be maintained within a relatively stable range because of the continuous application of narcotic analgesics, narcotic sedatives, and muscle relaxants, combined with efficient respiratory ventilation management. Patients lose the perception of pain stimulation, and no significant fluctuation of blood pressure and heart rate due to insufficient local anesthesia occurs during the operation. Abrupt fluctuations of blood pressure and heart rate need to be avoided to reduce cardiovascular complications and acute cerebral infarction[17–19]. Relative to those under local anesthesia, the operative time and fluoroscopy exposure times are reduced under general anesthesia for multiple vertebral PKP mainly because the patient shows no frequent change in position due to body position-related discomfort nor stimulation of intraoperative pain. With a general muscle relaxant, the surgeon can more effectively and accurately operate on the patient. For multiple vertebral PKP under general or local anesthesia, postoperative pain can be significantly alleviated, and a satisfactory clinical effect can be achieved. However, this study found that the improvement rate of postoperative pain in the local anesthesia group was lower than that in the general anesthesia group, and this difference could be attributed to the following: (1) Local anesthesia for multiple vertebral PKP is often inadequate, causing patients to experience severe pain during the operation, which significantly reduces the patient subjective satisfaction; (2) Patients with m-OVFs often have a rib fracture, humerus fracture, or intertrochanteric fracture simultaneously. Being in a prone position for an extended duration leads to perceptible body position-related discomfort, leading to patient dissatisfaction with preoperative pain management; (3) During PKP under local anesthesia, patients experience high local muscle tension. If the puncture cannot be achieved at one time, the puncture point and puncture angle will be difficult to adjust. Repeatedly adjusting the puncture angle increases the damage to surrounding soft tissue and nerve injury. (4) Often, patients under local anesthesia for PKP do not need time to recover from anesthesia after the operation, and patients can prematurely leave the bed, which shortens the time of wound repair. This study found that the vertebral height and kyphosis in the two groups significantly improved after the operation; however, the improvement rates in the vertebral height and local kyphosis Cobb angle were significantly higher in the general anesthesia group than in the local anesthesia group. The reasons could be as follows: (1) Under general anesthesia, the muscles around the spine become relaxed, and muscle relaxants can significantly reduce muscle tension, which facilitates the recovery of fracture vertebral height and correction of kyphosis; (2) Under general anesthesia, the operation is not affected by frequent changes in body position, unpredictable severe pain, and abrupt fluctuation of vital signs. Focus on precise positioning, targeted puncture, balloon dilatation, and bone cement injection is enhanced, which is conducive to the recovery of the vertebral height and kyphosis correction; (3) When taking general anesthesia, patients will not suffer from unbearable pain due to the sudden increase of pressure in the vertebral body during balloon dilatation, which is conducive to injecting larger volume of bone cement into each vertebral body and promoting the recovery of vertebral height.
In this study, the incidence of bone cement leakage, nerve complications, vertebral infection, cognitive dysfunction, and cardiopulmonary system complications is similar to those reported in the previous literature[20–22]. The incidence of bone cement leakage and nerve complications was higher in the general anesthesia group than in the local anesthesia group, but no significant difference between the two groups was indicated. In the previous literature, one of the advantages of PKP under local anesthesia is that it can interact with patients during the operation, which can effectively prevent neurological complications. However, the intraoperative interaction can only predict but not prevent the occurrence of spinal cord nerve injury. The surgeon should improve their surgical skills, optimize bone cement injection technology, and improve the accuracy of intraoperative C-arm fluoroscopy as the preferred choice to prevent bone cement leakage and spinal cord nerve injury. In this study, we used PKP under general anesthesia for m-OVFs. During the operation, the mean arterial pressure and heart rate were effectively maintained, and an effective lung ventilation control strategy was adopted. However, 7 patients still suffered from cognitive dysfunction even after the operation, which could be related to primary cardiovascular and cerebrovascular diseases in the elderly, organ dysfunction resulting in the slow metabolism of narcotic drugs, cerebral perfusion pressure, and intraoperative or postoperative hypoxemia. Although no significant difference was indicated between the two groups, cognitive dysfunction was still an important complication in elderly patients receiving surgery under general anesthesia. In addition, the incidence of postoperative cardiopulmonary complications in the general anesthesia group was lower than that in the local anesthesia group, which could be mainly caused by the short duration of general anesthesia and low dosage of narcotic drugs, allowing the patients to return to normal function early after the operation and recover their cardiopulmonary function. In this study, 2 patients suffered from postoperative vertebral infection, which was treated with bone cement removal, debridement, bone graft fusion, and internal fixation; 1 of the 2 patients died of infection secondary to operation. All patients included in this study were injected with bone cement via unilateral puncture balloon dilatation during the operation. Precise puncture positioning was performed before the operation, and the pressure for balloon expansion pressure was gradually increased. Each patient only needed a set of operation-related equipment, which substantially reduced the medical expenses of the patients. However, the medical costs incurred by the general anesthesia group was still $500 more than that incurred by the local anesthesia group, on the average. The difference in medical expenses was also one of the important indexes for the selection of the type of anesthesia.
This study has several limitations. First, this research is a single-center, small-sample retrospective study. Multiple-center prospective studies should be conducted to verify the conclusions drawn in this study. Second, methods for appraising clinical outcomes, such as cost-utility analysis, were not applied in this study.