Metastatic Spine Tumour Surgery: Minimally Invasive versus Open Approach
Authors: Kumar Naresh 
Published: May 2015

Background Minimally invasive surgery (MIS) approaches have shown encouraging results for early wound healing, reduced intraoperative blood loss, and shortened hospital stay in management of degenerative spine diseases. Such surgical strategies in metastatic spine disease (MSD) are highly desirable in reducing surgical morbidity and enabling earlier initiation of oncological treatment. However, previous studies conducted were case series; none comparing the outcomes between MIS and open approaches. We aimed to investigate and compare the outcomes of open and MIS approach in patients with symptomatic MSD who underwent posterior spinal stabilization and/or decompression. Materials and Methods We prospectively analyzed data of patients undergoing surgery for MSD at our institution. We included 22 patients who underwent posterior surgery using MIS and other 22 patients using open approach. Preoperative, intraoperative, and postoperative data were collected for direct comparison of the two approaches. Generalized linear model was exploited to estimate the effect of MIS on outcomes, adjusting potential confounders. All patients were followed-up for a minimum period of 3 months from the time of surgery until the end of study period or till their demise. Results All patients showed improvement in pain and neurological status. Within 2 weeks of the operative procedure, significant pain relief (VAS score ≤ 2) was seen in 17 patients in MIS group and 12 patients in open group. t-test revealed a significant difference between preoperative and postoperative mean VAS score in the MIS as well as the open group. All patients in the two groups showed neurological improvement in postoperative period. Full normal function (Frankel score E) was achieved in 82% of the patients in the MIS group compared with 54% in the open group postoperation. Kruskal–Wallis analysis showed a significant difference in Frankel score between preoperation and postoperation in the MIS group ( p < 0.01). Independent ambulation was observed within 3 months of surgery in 88% of the patients in the MIS group as compared with 64% in the open group. This difference, however, was not significant. A significant increase in the amount of blood loss was associated with more levels of decompression and larger number of screws inserted. In multivariate analysis, the amount of blood loss was significantly lower (537 mL less) in the MIS group than the open group. A significant difference in time to start radiotherapy from index surgery was observed between the MIS and open groups. Both univariate and multivariate analyses showed that patients in the MIS group could start radiotherapy 7 days earlier than those in the open group. Operative time, duration of hospital stay, and time to initiate chemotherapy were also favorable in the MIS group, though the difference was not statistically significant. Conclusion MIS in MSD has shown promising results for patients suffering from clinically significant instability, back pain, or motor deficits. The introduction of MIS can be a game-changer in the treatment of MSD because of less perioperative morbidity and allowing earlier radiotherapy and/or chemotherapy.