Residual neurological function after sacral root resection during en-bloc sacrectomy: a systematic review

Clinical Anatomy of the Sacral Nerve Roots and Its Relevance to Their Reconstruction After Sacrectomy

BACKGROUND AND OBJECTIVES

En bloc sacrectomy is associated with sacral root transection causing loss of urinary bladder, rectum, and sexual function. The aim of the study was to determine the position of the pudendal branches (sensorimotor) and pelvic splanchnic nerves (parasympathetic) on the sacral roots relative to the sacrum, and the minimal and maximal defects in the sacral roots that can be reconstructed by grafting after various types of sacrectomy.

METHODS

Five cadaveric pelves were dissected bilaterally. The lengths and widths of the S1-S4 roots and their branches were measured. Then, the minimal and maximal defects between the proximal and distal stumps of the sacrificed roots were measured following 3 models of sacrectomy (below S2, below S1, and total sacrectomy).

RESULTS

The mean distance of the splanchnic nerves from the S2 and S3 anterior sacral foramina was 17.7 ± 7.3 and 23.6 ± 11.1 mm, respectively, and the mean distance of the pudendal S2 and S3 branches was 36.8 ± 13.7 and 30.2 ± 10.8 mm, respectively. The mean widths of the S2 and S3 roots were 9.3 ± 1.9 and 5.4 ± 1.2 mm, respectively. The mean maximal defects in S2 and S3 roots after various types of sacrectomies were between 61.8 ± 16.3 and 100.7 ± 14.3 mm and between 62.7 ± 20.2 and 84.7 ± 25.1 mm, respectively. There were no statistically significant differences between sides or sexes for all obtained measurements.

CONCLUSION

The reconstruction of the S2-S3 roots is anatomically feasible after partial or total sacrectomies in which the resection of the soft tissue does not extend further than approximately 1.5 to 2 cm ventrally from the sacrum.

The diagnostic accuracy of neuromonitoring for detecting postoperative bowel and bladder dysfunction in spinal oncology surgery: a case series

PURPOSE

Postoperative bowel and bladder dysfunction (BBD) poses a significant risk following surgery of the sacral spinal segments and sacral nerve roots, particularly in neuro-oncology cases. The need for more reliable neuromonitoring techniques to enhance the safety of spine surgery is evident.

METHODS

We conducted a case series comprising 60 procedures involving 56 patients, spanning from September 2022 to January 2024. We assessed the diagnostic accuracy of sacral reflexes (bulbocavernosus and external urethral sphincter reflexes) and compared them with transcranial motor evoked potentials (TCMEP) incorporating anal sphincter (AS) and external urethral sphincter (EUS) recordings, as well as spontaneous electromyography (s-EMG) with AS and EUS recordings.

RESULTS

Sacral reflexes demonstrated a specificity of 100% in predicting postoperative BBD, with a sensitivity of 73.33%. While sensitivity slightly decreased to 64.71% at the 1-month follow-up, it remained consistently high overall. TCMEP with AS/EUS recordings did not identify any instances of postoperative BBD, whereas s-EMG with AS/EUS recordings showed a sensitivity of 14.29% and a specificity of 97.14%.

CONCLUSION

Sacral reflex monitoring emerges as a robust adjunct to routine neuromonitoring, offering surgeons valuable predictive insights to potentially mitigate the occurrence of postoperative BBD.

Sacrectomy with Posterior-Only Approach in Sacral Tumors: An Analysis of 26 Cases and Review of Literature

BACKGROUND

Sacral masses can be removed using anterior, posterior, or combined approaches. Achieving total sacrectomy through a posterior-only approach results in a shorter procedure time, minimal tissue damage, and a reduced risk of complications. In this study, we aimed to share our experience with performing total sacrectomy using a posterior-only approach in 26 patients and to assess their clinical outcomes at our center.

MATERIALS AND METHODS

This retrospective study examines the clinical progression, surgical response, and outcomes of 26 patients with various sacral mass pathologies. We accessed patient information from our hospital records.

RESULTS

The study included 14 men (54%) and 12 women (46%), with an average age of 49.8 years. Most cases had a normal body mass index, while 6 were overweight. Sacrectomy was performed at a high level in 12 patients and at a middle level in 14 patients. In addition to pain, motor deficits were observed in 9 patients, and sphincter dysfunction was found in 5. Preoperative embolization was conducted for 11 patients. The most prevalent lesions were chordoma (8 patients), malignant peripheral nerve sheath tumor (4 patients), giant cell tumor (3 patients), and solitary plasmacytoma (3 patients). Only 1 patient experienced a temporary partial motor deficit after surgery. There were no instances of cerebrospinal fluid leakage. Five patients experienced local recurrence, and 1 had distant metastasis.

CONCLUSIONS

Performing sacrectomy for large or giant sacral tumors through a posterior approach is both feasible and safe, resulting in reduced morbidity and no significant change in overall survival.

Complication Pattern of Sacral Primary Tumor Resection: A Study on the Risk Factors of Surgical Site Infection and Bowel or Bladder Dysfunction and Their Associations with Length of Hospital Stay

STUDY DESIGN

Retrospective open cohort study.

PURPOSE

The current study aimed to explore the pattern of complications after primary sacral tumor resection, to investigate the possible effect of several perioperative parameters on the development of complications, and to identify which complications are associated with the length of hospital stay (LOS).

OVERVIEW OF LITERATURE

Primary sacral tumor (pST) resection is associated with a high complication rate. However, the number of studies on these complications and their effect on LOS is limited.

METHODS

The clinical data of 140 patients with pST surgeries and 106 subsequent patients with local recurrence surgeries in four subgroups (index surgery, local recurrence surgery, malignant, and benign tumor) were prospectively collected and analyzed. The prognostic value of several perioperative factors on the development of surgical site infection (SSI), bowel and bladder dysfunction (BBD), and LOS was investigated using the logistic and linear regression models.

RESULTS

The overall complication rates were 61.2% after index surgeries and 50.9% after local recurrence surgeries. The most frequent complications were SSI, vegetative dysfunction, urinary tract infections, and neurological deterioration. Age >55 years, malignant tumors, and red blood cell transfusion had a predictive effect on the development of SSI in the logistic model (p<0.01, R2=0.43). Bilateral S2 or S3 resection commonly caused postoperative BBD (chi-square test=62.5, degrees of freedom=4, p<0.001). In the multiple linear regression model, wound dehiscence, BBD, systemic and urinary tract infection, cerebrospinal fluid leak, and neurologic deterioration were associated with a significantly long LOS (p<0.01, R2=0.62).

CONCLUSIONS

Surgical resection of pSTs has a high complication rate. Its common complications are SSI and BBD, both of which can have a significant influence on global therapeutic outcome. Malignant tumor diagnosis, old age, and red blood cell transfusion can remarkably increase the risk of SSI. Further, the development of BBD is significantly associated with the number of resected sacral nerve roots. By decreasing perioperative complications, LOS can decrease significantly.

Complications and Functional Outcome Differences in Carbon Ion Radiotherapy and Surgery for Malignant Bone Tumors of the Pelvis: A Multicenter, Cohort Study

BACKGROUND

Carbon ion radiotherapy (CIRT) is an evolving treatment option for malignant pelvic tumors in patients with poor surgical indications. However, the difference in complications and functional outcomes between CIRT and surgery is poorly understood. This study compares the complications and functional outcomes of CIRT and surgery to facilitate treatment selection.

METHODS

A total of 28 patients who underwent CIRT for pelvic bone tumors while theoretically meeting the surgical resection criteria were included. Sixty-nine patients who underwent surgery for pelvic bone tumors were included as controls. Major complication rates and functional outcomes (ambulatory, pain, urination, constipation) were evaluated and compared at several time points (pretreatment, discharge, and final follow-up) between the groups.

RESULTS

Early (within 90 days) major complications were not observed in the CIRT group but occurred in 30% of the surgery group, which was statistically significant (P < 0.001). In contrast, late (after 90 days) major complications occurred more often in the CIRT group than in the surgery group (18% and 4%, respectively; P = 0.042). From pretreatment until discharge, all functional outcomes in the surgery group deteriorated (P < 0.001 for all) but did not change in the CIRT group (P = 0.77-1.00). At the final follow-up, all functional outcomes showed no significant intergroup difference (P = 0.28-0.92) due to the recovery trend in the surgery group and the deterioration trend in the CIRT group.

CONCLUSIONS

Compared with surgery, CIRT may have favorable safety and stable functional outcomes in the short-term but more late complications. Mid-term functional outcomes were similar between the groups.

Pelvic ring reconstruction with tibial allograft, screws and rods following enneking type I and IV resection of primary bone tumors

INTRODUCTION

Surgery of primary malignant tumors involving the sacroiliac joint requires wide resection, which often interrupts the pelvic ring. Nowadays, restoration of the pelvic ring to provide stability and which technique is most fitting remain subject to debate. The aim of this study is to evaluate the results of pelvic reconstruction with pedicle screw instrumentation and tibial allograft following Enneking Type I-IV resections.

PATIENTS AND METHODS

All patients who underwent reconstruction with tibial allograft, screws and rods after resection of areas I and IV for primary bone tumors between 2017 and 2022 were reviewed. Clinical and radiological characteristics, fusion rate and functional results were analyzed. The MSTS score and the TESS were used to evaluate functional results.

RESULTS

Seven patients were included in the study. Chondrosarcoma was the most common histology. Only four patients reported pain. No fractures were observed at tumor diagnosis. Computer-assisted navigation was used in six cases. Reconstruction was performed in four cases with a screw inserted in the homolateral L5 pedicle and in the ischium, in two cases with a screw in the homolateral L4 pedicle and another in the homolateral L5 pedicle, in the last case with two screws inserted in L4 and L5, one screw in the ischium and another one in the residual iliac wing. In this case a contralateral stabilization was also carried out. The spine screws and the iliac screws were connected with a rod. The mean follow-up for all 7 patients was 37 months. One patient (16.6%) died due to general complications not directly related to the surgery; while the others are alive and apparently free of disease. Complete fusion was obtained in four out of seven patients and the average time for fusion was 9 months. The average MSTS score and TESS were 58.7% and 57.8%, respectively.

DISCUSSION

The need for reconstruction is thoroughly debated in literature. The advantages of restoring posterior pelvis stability are the prevention of long-term pain associated with limb shortening and secondary scoliosis. Re-establishment of the pelvic ring can be achieved through synthetic, biologic or hybrid reconstructions.

CONCLUSIONS

More studies that assess the surgical consequences at long-term follow-up and help clarify the indications for reconstruction and the specific technique are necessary to confirm our preliminary results.

One-year follow-up after partial sacrectomy without stabilization in sacral chordoma: A case report and literature review

INTRODUCTION AND IMPORTANCE

Chordoma is a rare sarcoma of the bone with a slow-growing nature but an aggressive nature locally. The subtle onset and minor symptoms cause a delayed diagnosis. Unfortunately, Chordoma is discovered when the prognosis is poor, which make the management procedure more difficult.

CASE PRESENTATION

A 56 years old woman presented with back pain, bowel and bladder dysfunction, and numbness around the anus for the last six months. Sensory examination revealed hypoesthesia on the S2-S4 dermatomes and the rectal toucher revealed a mass. Pelvic x-ray revealed an osteolytic lesion on the sacrum and a MRI revealed a sacrum mass on S2. Confirmed by a CT Scan lumbosacral contrast that revealed a solid mass with osteolytic and osteosclerotic changes on the sacrum bone from S2 to the coccyx. We performed a partial en bloc sacrectomy by posterior approach with an inverted goblet incision without lumbopelvic stabilization.

CLINICAL DISCUSSION

A few months after surgery, the patient still had some similar complaints and went to physiotherapy and radiotherapy on a regular basis. 1 year follow-up, there was no recurrence process proven by adjunct examination and the improvement was demonstrated by the relief of back pain, and ability to do daily activities.

CONCLUSION

Chordoma can be improved by partial sacrectomy without lumbopelvic stabilization that revealed good results from function and complication. A multi-professional approach to the patient is essential.

Management of Chordoma of the Sacrum and Mobile Spine

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Chordomas account for 1% to 4% of primary tumors of the spine and sacrum.

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En bloc resection is the preferred surgical treatment for the management of chordomas.

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Proton beam radiation is increasingly being used as a postoperative radiation modality for the treatment of chordomas.

Surgery of resectable local recurrence following colorectal cancer: Compartmental surgery improves local control

BACKGROUND

This study aims to identify prognostic factors and define the best extent of surgery for optimizing treatment of local recurrence (LR) following colorectal cancer (CRC).

METHODS

An institutional database of consecutive patients who underwent radical resection (R0/R1) of LR following CRC was analyzed prospectively from 2010 to 2021 at one tertiary cancer center.

RESULTS

In this study, 75 patients were included with LR following CRC and analyzed. Patients were categorized as compartmental resections (CompRe) (n = 47) if all adjacent organs were systematically removed, with or without tumor involvement, or noncompartmental resections (NoCompRe) (n = 28) if only contiguously involved organs were resected. NoCompRe were mainly related to contact between major vessels or bone and the tumor, with only 8/19 (42.1%) resections. Five-year overall survival and locoregional-free survival were 37.5% and 38.8% respectively. Local control was better in the CompRe than the NocompRe group (61.4% vs. 11%; p < 0.01). CompRe (hazard ratio: 2.34 [1.16-4.68]; p = 0.017) and absence of peritoneal metastasis (3.05 [1.03-9.02]; p = 0.044) were the two factors associated with decreased abdominal recurrences in multivariate analysis.

CONCLUSION

Complete compartmental surgery is safe and improves local control. Optimal LR resection needs to remove all contiguous organs, with or without tumor involvement.

A Novel Three-Dimensional Computational Method to Assess Rod Contour Deformation and to Map Bony Fusion in a Lumbopelvic Reconstruction After En-Bloc Sacrectomy

Introduction: En-bloc resection of a primary malignant sacral tumor with wide oncological margins impacts the biomechanics of the spinopelvic complex, deteriorating postoperative function. The closed-loop technique (CLT) for spinopelvic fixation (SPF) uses a single U-shaped rod to restore the spinopelvic biomechanical integrity. The CLT method was designed to provide a non-rigid fixation, however this hypothesis has not been previously tested. Here, we establish a computational method to measure the deformation of the implant and characterize the bony fusion process based on the 6-year follow-up (FU) data.

Materials and Methods: Post-operative CT scans were collected of a male patient who underwent total sacrectomy at the age of 42 due to a chordoma. CLT was used to reconstruct the spinopelvic junction. We defined the 3D geometry of the implant construct. Using rigid registration algorithms, a common coordinate system was created for the CLT to measure and visualize the deformation of the construct during the FU. In order to demonstrate the cyclical loading of the construct, the patient underwent gait analysis at the 6th year FU. First, a region of interest (ROI) was selected at the proximal level of the construct, then the deformation was determined during the follow-up period. In order to investigate the fusion process, a single axial slice-based voxel finite element (FE) mesh was created. The Hounsfield values (HU) were determined, then using an empirical linear equation, bone mineral density (BMD) values were assigned for every mesh element, out of 10 color-coded categories (1st category = 0 g/cm³, 10th category 1.12 g/cm³).

Results: Significant correlation was found between the number of days postoperatively and deformation in the sagittal plane, resulting in a forward bending tendency of the construct. Volume distributions were determined and visualized over time for the different BMD categories and it was found that the total volume of the elements in the highest BMD category in the first postoperative CT was 0.04 cm³, at the 2nd year, FU was 0.98 cm³, and after 6 years, it was 2.30 cm³.

Conclusion: The CLT provides a non-rigid fixation. The quantification of implant deformation and bony fusion may help understate the complex lumbopelvic biomechanics after sacrectomy.

Partial sacrectomy with patient-specific osteotomy guides

Background

Chordomas are rare, locally aggressive, malignant tumors. Surgical resection with sufficient margins defines the outcome. However, the necessity for wide margins often leads to sacrifice of important neurological structures. 3D-printed osteotomy guides are a promising solution for precise execution of surgical resection. We present probably the first sacrococcygeal chordoma resection with 3D-printed guides.

Methods

The case of a 49-year-old woman with a sacrococcygeal chordoma, resected with help of 3-D pre-operative planning and patient-specific 3D-printed osteotomy guides, is reported in detail.

Results

A sufficient tumor excision could be performed successfully while sparing nerve root S4. The planed margin has been exactly maintained, as confirmed by histology. The patient demonstrated an excellent clinical outcome with no evidence of local recurrence.

Conclusions

3-D pre-operative planning and patient-specific osteotomy guides can be used for planning and performing en-bloc surgical resection of sacral chordomas.

Nerve Root Sparing En Bloc Resection of Sacral Chondrosarcoma: Technical Note and Review of the Literature

BACKGROUND

Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life.

OBJECTIVE

To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature.

METHODS

A 38-yr-old woman with a 7.7 × 5.4 × 4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation.

RESULTS

Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though.

CONCLUSION

Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.

Multidisciplinary Management of Primary Sacral Tumors: A Tertiary Care Center's Experience and Literature Review

Sacral tumors are rare and can be benign or malignant. Their management is multifactorial and is based on the pathology, extent, and local and distant spread. Managing sacral tumors is challenging due to their proximity to visceral and neural structures. Surgical wide excision has been the standard of care for aggressive benign and malignant tumors. Our purpose was to evaluate the outcomes of a multimodal approach to managing primary sacral tumors in Sakra World Hospital, a tertiary spine care center in Bengaluru, India and perform a literature review to determine a workflow pathway. Our study was a retrospective review of patient records and included 15 patients with primary sacral tumors. Eleven surgically treated patients were evaluated clinically and radiologically and underwent biopsy before surgical excision by an all-posterior approach. A multidisciplinary approach that included intraoperative neural monitoring, plastic reconstruction, adjuvant chemotherapy, and radiotherapy was implemented whenever necessary. Sacral root preservation was attempted whenever feasible. Functional outcomes (based on the Visual Analog Scale [VAS] and Biagini scoring system) were analyzed along with disease control, with a minimum of 2 years of follow-up. The mean follow-up was 29±9.8 months. The mean VAS score significantly improved from 7.8±2.6 to 3.7±3.8 (p=0.026). Bowel function showed statistically significant improvement, from a mean score of 0.81±0.47 to 0.63±0.52 (p=0.026) at 2 years of follow-up. The mean pretreatment motor and bladder function scores were 0.53±0.31 and 0.74±0.44, respectively, improving to 0.48±0.33 and 0.68±0.56 at follow-up but without statistical significance. There was no significant loss of function, which is expected in radical sacral resections. In conclusion, primary sacral tumors require a multidisciplinary approach and management for optimal outcomes. A stand-alone posterior approach can be employed to treat most sacral lesions. En-bloc wide resection is the optimal treatment for primary malignant and aggressive benign tumors. Preservation of at least one functional S2 nerve root is imperative to preserve bowel and bladder function.

Nerve preservation during partial sacrectomy by two-stage anterior and posterior approach: illustrative case

BACKGROUND

Preserving the neurological function of sacral nerves during total or partial sacrectomy is challenging.

OBSERVATIONS

The authors describe a case of an osseous desmoplastic fibroma of the sacrum in a 51-year-old woman. The patient attended the authors’ institution with loss of muscle strength and sensitivity impairment in both legs, gait instability, bowel constipation, urinary incontinence, and weight loss. Preoperative magnetic resonance imaging and positron emission tomography/computed tomography showed intrapelvic and posterior extension of the tumor but sparing of S1 and the sacroiliac and lumbosacral joints. After a multidisciplinary discussion of the case, a staged anterior–posterior approach to the sacrum was chosen. The abdominal approach allowed full mobilization of the uterus, ovaries, bladder, and colon and protection of iliac vessels. After tumor resection, a synthetic surgical mesh was placed over the sacrum to minimize soft tissue defects. Then, the posterior stage allowed the authors to perform a bicortical osteotomy, achieving wide tumor excision with minimal nerve root injury. Spinopelvic fixation was not necessary, because both sacroiliac and lumbosacral joints remained intact. A few days after the surgery, the patient restarted ambulation and recovered sphincter control.

LESSONS

Multidisciplinary planning and a staged abdominal and posterior approach for partial sacrectomy were fundamental to preserve neurological function in this case.

Chordoma of the sacrum and mobile spine: a narrative review

Chordoma is a notochord-derived primary tumor of the skull base and vertebral column known to affect 0.08 to 0.5 per 100,000 persons worldwide. Patients commonly present with mechanical, midline pain with or without radicular features secondary to nerve root compression. Management of these lesions has classically revolved around oncologic resection, defined by en bloc resection of the lesion with negative margins as this was found to significantly improve both local control and overall survival. With advancement in radiation modalities, namely the increased availability of focused photon therapy and proton beam radiation, high-dose (>50 Gy) neoadjuvant or adjuvant radiotherapy is also becoming a standard of care. At present chemotherapy does not appear to have a role, but ongoing investigations into the ontogeny and molecular pathophysiology of chordoma promise to identify therapeutic targets that may further alter this paradigm. In this narrative review we describe the epidemiology, histopathology, diagnosis, and treatment of chordoma.

Surgical Strategy for Sacral Tumor Resection

PURPOSE

This study aimed to present our experiences with a precise surgical strategy for sacrectomy.

MATERIALS AND METHODS

This study comprised a retrospective review of 16 patients (6 males and 10 females) who underwent sacrectomy from 2011 to 2019. The average age was 42.4 years old, and the mean follow-up period was 40.8 months. Clinical data, including age, sex, history, pathology, radiographs, surgical approaches, onset of recurrence, and prognosis, were analyzed.

RESULTS

The main preoperative symptom was non-specific local pain. Nine patients (56%) complained of bladder and bowel symptoms. All patients required spinopelvic reconstruction after sacrectomy. Three patients, one high, one middle, and one hemi-sacrectomy, underwent spinopelvic reconstruction. The pathology findings of tumors varied (chordoma, n=7; nerve sheath tumor, n=4; giant cell tumor, n=3, etc.). Adjuvant radiotherapy was performed for 5 patients, chemotherapy for three, and combined chemoradiotherapy for another three. Six patients (38%) reported postoperative motor weakness, and newly postoperative bladder and bowel symptoms occurred in 5 patients. Three patients (12%) experienced recurrence and expired.

CONCLUSION

In surgical resection of sacral tumors, the surgical approach depends on the size, location, extension, and pathology of the tumors. The recommended treatment option for sacral tumors is to remove as much of the tumor as possible. The level of root sacrifice is a predicting factor for postoperative neurologic functional impairment and the potential for morbidity. Pre-operative angiography and embolization are recommended to prevent excessive bleeding during surgery. Spinopelvic reconstruction must be considered following a total or high sacrectomy or sacroiliac joint removal.

Image-guided percutaneous cryoablation of unresectable sacrococcygeal chordoma: Feasibility and outcome in a selected group of patients with long term follow-up

BACKGROUND

Chordoma is a rare malignant tumor of the axial skeleton. Percutaneous cryoablation (PCA) is a minimally invasive technique that allows freezing of tumors under imaging control. The purpose of our retrospective study was to investigate the outcome of PCA in a selected cohort of patients with sacrococcygeal chordoma, with a minimum of 5 years follow-up.

MATERIALS AND METHODS

Four patients were treated in 10 sessions. The mean follow-up was 57.3 months. We evaluated the feasibility, the procedure-related complications, the impact on pain control and oncological outcomes.

RESULTS

Freezing of 100% of the tumor volume was possible in 60%. Pain control was not reliably evaluable. Local recurrence occurred in 90% of the treated lesions; the mean time to progression was 8.1 months (range 1.5-16). At last follow-up, one patient had died of the disease, one of another cause and one was receiving the best supportive care. The only patient alive without the disease had received additional carbon-ion radiotherapy. The 5-year survival rate after index PCA was 50%.

CONCLUSION

Complete freezing of the tumor was technically challenging, mainly due to the complex local anatomy. Recurrence occurred in 90% of the lesions treated. PCA should be considered with caution in the curative management of sacrococcygeal chordoma.

Hip Arthroplasty Following Subtotal Sacrectomy for Chordoma

BACKGROUND/AIM

Chordomas often affect the sacrum with a high predilection for local-regional recurrence. Patients typically retain their ability to ambulate, and the development of metastatic disease in the periacetabular region can have significant morbidity and pain with ambulation. The purpose of the study was to describe the outcome of patients undergoing a hip arthroplasty following resection of a sacral chordoma.

PATIENTS AND METHODS

From 1990 to 2015, 84 patients underwent sacrectomy for chordoma, while four of these (5%) patients underwent hip arthroplasty. The most common level of nerve root sacrifice was S2-5 (n=2). The mean time between sacrectomy and hip arthroplasty was 7 years. Indications for arthroplasty included metastatic disease (n=3) and coxarthrosis (n=1).

RESULTS

Postoperatively two patients ambulated with a gait aid, and no patient had a Trendelenburg gait. The mean Harris Hip Score significantly improved from 49 to 80 postoperatively (p=0.02).

CONCLUSION

The results of this study indicate that hip arthroplasty is a durable treatment option for patients with metastatic disease or coxarthrosis following subtotal sacrectomy for chordoma.

The sacral chordoma margin

OBJECTIVE

Aim of the manuscript is to discuss how to improve margins in sacral chordoma.

BACKGROUND

Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery.

METHODS

A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed.

RESULTS

En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment.

CONCLUSION

Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.

Recurrence or neurological loss? Resection mode selection for patients with large sacral chordoma: an analysis of prognostic factors and quality of life

BACKGROUND

Surgical resection represents the main therapeutic method for sacral chordoma, but plans for resection mode must weigh neurological loss against complete tumor excision, a difficult balance to strike. The purpose of this study was to provide useful information contributing to surgical decision making in sacral chordoma.

METHODS

A retrospective review was performed on 47 patients with large sacral chordoma. Prognostic factors affecting recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox proportional hazards model. Quality of life was assessed by the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire and compared using Student's t test.

RESULTS

Resection mode was the independent prognostic factor affecting RFS, while independent prognostic factors affecting OS were resection mode and postoperative recurrence. As for quality of life, the en bloc resection group showed a higher score in emotional well-being, while the piecemeal resection group scored better in function well-being. No significant difference was identified in total the FACT-G score between two groups.

CONCLUSIONS

On the one hand, en bloc resection showed huge advantages in disease control for sacral chordoma. On the other hand, despite the unsatisfaction in functional well-being, en bloc resection did not sacrifice quality of life significantly in terms of the total FACT-G score.

Surgical management of giant presacral schwannoma: systematic review of published cases and meta-analysis

OBJECTIVE

Giant presacral schwannomas are rare sacral tumors found in less than 1 of every 40,000 hospitalizations. Current management of these tumors is based solely upon case reports and small case series. In this paper the authors report the results of a systematic review of the available English literature on presacral schwannoma, focused on identifying the influence of tumor size, tumor morphology, surgical approach, and extent of resection (EOR) on recurrence-free survival and postoperative complications.

METHODS

The medical literature (PubMed and EMBASE) was queried for reports of surgically managed sacral schwannoma, either involving 2 or more contiguous vertebral levels or with a diameter ≥ 5 cm. Tumor size and morphology, surgical approach, EOR, intraoperative and postoperative complications, and survival data were recorded.

RESULTS

Seventy-six articles were included, covering 123 unique patients (mean age 44.1 ± 1.4 years, 50.4% male). The most common presenting symptoms were leg pain (28.7%), lower back pain (21.3%), and constipation (15.7%). Most surgeries used an open anterior-only (40.0%) or posterior-only (30%) approach. Postoperative complications occurred in 25.6% of patients and local recurrence was noted in 5.4%. En bloc resection significantly improved progression-free survival relative to subtotal resection (p = 0.03). No difference existed between en bloc and gross-total resection (GTR; p = 0.25) or among the surgical approaches (p = 0.66). Postoperative complications were more common following anterior versus posterior approaches (p = 0.04). Surgical blood loss was significantly correlated with operative duration and tumor volume on multiple linear regression (both p < 0.001).

CONCLUSIONS

Presacral schwannoma can reasonably be treated with either en bloc or piecemeal GTR. The approach should be dictated by lesion morphology, and recurrence is infrequent. Anterior approaches may increase the risk of postoperative complications.

Robotic Surgery Assisted Staged En-Bloc Sacrectomy for Sacral Chordoma: A Case Report

CASE

Two male patients aged 37 years and 39 years, diagnosed with sacral chordoma, underwent robotic-assisted preparatory adhesiolysis from the anterior aspect of the tumor, followed by posterior en-bloc partial sacrectomy. The average total operative time was 360 minutes (anterior docking + anterior console + posterior excision), and mean blood loss was 930 mL. Both patients were mobilized early, had no postoperative complications, and were free of local recurrence at 18 month of follow-up.

CONCLUSIONS

Robotic-assisted surgery is a novel, valid, safe, and minimally invasive technique which drastically reduces the associated surgical complications of single-staged posterior sacrectomy, resulting in excellent functional and oncological outcome.

Patient-Specific Three-Dimensional Model for a Safe Surgical Pathway in Sacral Chondrosarcoma

Sacral tumors are amongst the most challenging procedures to treat because of the complex anatomy. This study determined whether patient-specific models change preoperative planning decisions made in preparation for en bloc resection of complex sacral mass surgical procedures. Imaging showed a big encapsulated mass at the S2-3 level involving the neural foramina and obscuring the nerve roots. High-resolution images were acquired and utilized to generate a patient-specific 3D tumor model. The visual and tactile inspection of 3D models allowed the best anatomical understanding, with faster and clearer comprehension of the surgical anatomy. The 3D sacral model was for observation of previously unapparent anatomical details; with this new technology, surgeon can observe their planned surgical intervention, explore the patient-specific anatomy and extension of the tumor, and sharpen their procedure choices. Moreover, multiple planes showed how far the angles on the plane would extend for osteotomy of the sacrum. Another result was identifying correct guides and safe venture landmarks. The study helped to establish safe osteotomy line wherever the nerve roots were retained and enabled osteotomy by preserving bilaterally the S1 and S2 nerve roots for wide excision of wide excision of primary sacral tumor to get adequate bowel and bladder functions. Finally, it helped to determine whether or not the remaining bone in the sacrum is sufficient for spinopelvic stability and needed fixation. It was decided spinopelvic fixation was not necessary for this case. Surgical intervention of sacral tumors varies depending on the tumor, its size, extension, and location. Surgery can have profound risks including unnecessary nerve root resection spinopelvic instability and suboptimal oncological resection. 3D models help to transfer complex anatomical information to clinicians and provide guidance in the preoperative planning stage, for intraoperative navigation and for surgical training purposes.

Immunotherapy as a Potential Treatment for Chordoma: a Review

Chordoma is a locally aggressive primary malignancy of the axial skeleton. The gold standard for treatment is en bloc resection, with some centers now advocating for the use of radiation to help mitigate the risk of recurrence. Local recurrence is common, and salvaging local failures is quite difficult. Chemotherapy has been ineffective and small molecule targeted therapy has had only marginal benefits in small subsets of patients with rare tumor phenotypes or refractory disease. Recent successes utilizing immunotherapy in a variety of cancers has led to a resurgence of interest in modifying the host immune system to develop new ways to treat tumors. This review will discuss these studies and will highlight the early studies employing immune strategies for the treatment of chordoma.

Effects of primary and recurrent sacral chordoma on the motor and nociceptive function of hindlimbs in rats: an orthotopic spine model

OBJECTIVE Chordoma is a slow-growing, locally aggressive cancer that is minimally responsive to conventional chemotherapy and radiotherapy and has high local recurrence rates after resection. Currently, there are no rodent models of spinal chordoma. In the present study, the authors sought to develop and characterize an orthotopic model of human chordoma in an immunocompromised rat. METHODS Thirty-four immunocompromised rats were randomly allocated to 4 study groups; 22 of the 34 rats were engrafted in the lumbar spine with human chordoma. The groups were as follows: UCH1 tumor-engrafted (n = 11), JHC7 tumor-engrafted (n = 11), sham surgery (n = 6), and intact control (n = 6) rats. Neurological impairment of rats due to tumor growth was evaluated using open field and locomotion gait analysis; pain response was evaluated using mechanical or thermal paw stimulation. Cone beam CT (CBCT), MRI, and nanoScan PET/CT were performed to evaluate bony changes due to tumor growth. On Day 550, rats were killed and spines were processed for H & E-based histological examination and immunohistochemistry for brachyury, S100β, and cytokeratin. RESULTS The spine tumors displayed typical chordoma morphology, that is, physaliferous cells filled with vacuolated cytoplasm of mucoid matrix. Brachyury immunoreactivity was confirmed by immunostaining, in which samples from tumor-engrafted rats showed a strong nuclear signal. Sclerotic lesions in the vertebral body of rats in the UCH1 and JHC7 groups were observed on CBCT. Tumor growth was confirmed using contrast-enhanced MRI. In UCH1 rats, large tumors were observed growing from the vertebral body. JHC7 chordoma-engrafted rats showed smaller tumors confined to the bone periphery compared with UCH1 chordoma-engrafted rats. Locomotion analysis showed a disruption in the normal gait pattern, with an increase in the step length and duration of the gait in tumor-engrafted rats. The distance traveled and the speed of rats in the open field test was significantly reduced in the UCH1 and JHC7 tumor-engrafted rats compared with controls. Nociceptive response to a mechanical stimulus showed a significant (p < 0.001) increase in the paw withdrawal threshold (mechanical hypalgesia). In contrast, the paw withdrawal response to a thermal stimulus decreased significantly (p < 0.05) in tumor-engrafted rats. CONCLUSIONS The authors developed an orthotopic human chordoma model in rats. Rats were followed for 550 days using imaging techniques, including MRI, CBCT, and nanoScan PET/CT, to evaluate lesion progression and bony integrity. Nociceptive evaluations and locomotion analysis were performed during follow-up. This model reproduces cardinal signs, such as locomotor and sensory deficits, similar to those observed clinically in human patients. To the authors' knowledge, this is the first spine rodent model of human chordoma. Its use and further study will be essential for pathophysiology research and the development of new therapeutic strategies.