Surgical workflow for fully navigated high sacral amputation in sacral chordoma

Three-dimensional virtual reality-assisted surgical planning for neuronavigated sacrectomy of a chordoma: a technical note

PURPOSE

Sacral chordomas are slow growing but locally aggressive tumours with a high rate of local recurrence if not completely removed. Surgical resection with negative margins represents the most important survival predictor but it can be challenging to accomplish. Thanks to improvements in intraoperative imaging and surgical techniques, en bloc resection through a partial sacral resection with wide surgical margins has become feasible but it comes with a significant morbidity rate. In this technical note we detail the virtual reality-assisted surgical planning used during resection.

METHODS

A 70-year-old patient underwent en bloc resection of the tumor by an antero-posterior two-stage surgery approach. Pre-operatively, based on MR- and CT-imaging, virtual objects were designed, representing the tumour, the surrounding bone and the neurovascular structures. This 3D-model was used to plan the well delimited partial sacral resection and the posterior surgical approach. Intraoperatively the instruments were registered, allowing for a real-time visualization of the tumor, of the neurovascular structures, and for an optimal margin control resection.

RESULTS

Postoperatively the patient was intact in the lower extremities, without any deficit up to S1 roots. An intentional middle-low sacral amputation of S2-S5 roots was necessary to have a wide resection with free margins. At follow-up, the patient did not present any lower extremities motor deficit with an improvement of sensory function on S1 dermatome.

CONCLUSION

Three-dimensional virtual reality-assisted surgical planning for neuronavigated sacrectomy in chordoma is useful, feasible and safe. This technology can increase surgeon's chances to perform a larger margin-free resection decreasing the risk of neurovascular damage.

Novel Applications of Spinal Navigation in Deformity and Oncology Surgery-Beyond Screw Placement

Computer-assisted navigation has made a major impact on spine surgery, providing surgeons with technological tools to safely place instrumentation anywhere in the spinal column. With advances in intraoperative image acquisition, registration, and processing, many surgeons are now using navigation in their practices. The incorporation of navigation into the workflow of surgeons continues to expand with the evolution of minimally invasive techniques and robotic surgery. While numerous investigators have demonstrated the benefit of navigation for improving the accuracy of instrumentation, few have reported applying this technology to other aspects of spine surgery. Surgeries to correct spinal deformities and resect spinal tumors are technically demanding, incorporating a wide range of techniques not only for instrumentation placement but also for osteotomy planning and executing the goals of surgery. Although these subspecialties vary in their objectives, they share similar challenges with potentially high complications, invasiveness, and consequences of failed execution. Herein, we highlight the utility of using spinal navigation for applications beyond screw placement: specifically, for planning and executing osteotomies and guiding the extent of tumor resection. A narrative review of the work that has been done is supplemented with illustrative cases demonstrating these applications.

Total sacrectomy with a combined antero-posterior surgical approach for malignant sacral tumours

Purpose

To investigate the indications, approaches, resection methods, and complications of total sacrectomy with a combined antero-posterior approach for malignant sacral tumours.

Methods

Fourteen cases of primary malignant sacral tumours treated with total sacrectomy between January 2012 and 2018 were retrospectively analysed. All patients presented with pre-operative lumbosacral pain or constipation. A combined antero-posterior approach was used for tumour resection, and the spinal pedicle screw rod system was used to achieve ilio-lumbar stability. The visual analogue scale (VAS) and Musculoskeletal Tumor Society (MSTS) scores were used to assess pain and lower limb function, respectively. The mean operative time and intra-operative blood loss were 6.54 hours and 2935 mL, respectively. The mean follow-up period was 62 months.

Results

None of the patients died peri-operatively. At the last follow-up, ten patients were continuously disease-free, three were alive with disease, and one died of disease from lung metastasis. Tumour recurrence occurred in three patients. The MSTS scores ranged from 6 to 28 (20.00–93.33%, 6/30–28/30) with an average of 20 (66.67%, 20/30). Seven patients could walk independently in public, five could only walk at home using a walking aid, and two could only lie down and stand for a short time. Thirteen patients developed post-operative complications such as skin necrosis, screw loosening, connecting rod fracture, neuropathic pain, sciatic nerve injury, dysuria, and urinary incontinence.

Conclusion

Total sacrectomy can effectively treat malignant sacral tumours with good resection boundaries and prognosis. However, the high incidence of post-operative complications may impact post-operative neurological function.

Surgical revision strategies for postoperative spinal implant infections (PSII)

Over the last years the number of spine surgeries with instrumentation has grown to an indispensable column in the treatment for different pathologies of the spine. A further increase in the incidence of instrumented spinal surgery is expected throughout the next years. Although the implementation and development of new techniques offer faster and more minimal invasive procedures, shortening surgery time, reducing soft tissue injury and revision due to hardware misplacement, the incidence of postoperative spinal implant infections (PSII) remains high. PSII related complications and revision procedures pose an enormous socioeconomic burden. Therefore, standardized strategies and protocols for treatment of PSII are urgently needed. While in former times hardware exchange or hardware removal was common practise in the field of spine surgery this approach has changed over the last years. Although the evidence from clinical studies in the field of PSII is of limited evidence, critical variables for revision strategies of PSII have been identified. Further, to quickly advance in the field of PSII it is certainly important to extrapolate and learn using data regarding the management from other fields of prosthetic joint infections. This should include clinical as well as experimental work in particular in the context of the biofilm, sonication as well as microbiological concepts. Over the last years, at our institution standardized procedures for diagnostic, surgical as well as antimicrobial treatment have been developed, based on the latest recommendations in peer-reviewed literature and our own data. Here we give an overview about surgical revision strategies for PSII and discuss the key points of our standardized protocol.